Indian Patents
Title of Invention

PROCESS COMPOSITIONS AND PRODUCTION OF ACYL ALKYLISETHIONATE COMPOSITIONS
Abstract Abstract PROCESS COMPOSITIONS AND PRODUCTION OF ACYL ALKYLISETHIONATE COMPOSITIONS Methods and compositions are provided for forming ester based compositions. The ester based compositions may be used in consumer products. In one aspect, a method is provided for producing acyl alkylisethionate esters by the esterification of a sulfonate composition having two or more sulfonate isomers with fatty acid(s). In another aspect, a method is provided for forming an ester based composition including a blend of acyl alkylisethionate and acylisethionate esters.
Full Text



Due mainly to its low water solubility, SCI is not suitable for use in liquid cleansers. One method for improving SCI's limited water solubility is to combine SCI with other surfactants such as taurate, amphoacetates and betaines. This combination of surfactants, however, produces relatively hazy solution, which tend to separate during storage.
Therefore, it would be desirable to produce acyl isethionate esters that are highly water soluble, hydrolytically-stable and non-irritating for use in aqueous as well as non-aqueous consumer products such as personal care cleansers.
SUMMARY OF THE INVENTION
The present invention includes certain preferred combinations of the acyl alkylisethionate ester compositions, processes for forming the acyl alkylisethionate ester compositions, and additional processing thereof into useful articles. The present invention also includes alkyl-substituted hydroxyalkyi sulfonates and methods of preparing alkyl-substituted hydroxyalkyl sulfonates.
One embodiment of the invention is a process comprising: providing at least one alkylene oxide having between 2 and 8 carbon atoms; providing an aqueous solution comprising a bi¬sulfite anion. The alkylene oxide is contacted with the aqueous solution while maintaining a pH between about 5 and about 10. A mixture is then formed of (i) a first isomer having the structure:








An alternative embodiment of the invention is a persona] care cleanser comprising:
an acyl alkylisethionate ester composition having two or more esters according to the formula:

wherein at least a first ester comprises R having a hydrocarbon group having between about 4 and 25 carbon atoms, R1 and R2 each comprise a straight chain or branched C| to Ce alkyl group or a hydrogen atom with at least one of R1 or R2 comprising the alkyl group and at least one of R1 or R2 comprising the hydrogen atom, and at least a second ester comprises R having a hydrocarbon group having between about 4 and 25 carbon atoms, R| comprises a hydrogen atom, R2 comprises a hydrogen atom, and X for the first ester ion and the second ester ion are each selected from the group consisting of hydrogen, an alkali metal, an alkaline earth metal, zinc, aluminum, ammonium, ammonium ions substituted with one or more organic groups, and combinations thereof.
Weight percents disclosed herein are based on the total weight of the composition, unless otherwise specified or unless would otherwise be understand by one of ordinary skill in the art. Additionally, unless otherwise specified all pressures are absolute pressures based on the total weight of the composition, unless otherwise specified or unless would otherwise be understand by one of ordinary skill in the art. Moreover, all measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
BRIEF DESCRIPTION OF FIGURES
For a detailed understanding and better appreciation of the present invention, reference should be made to the following detailed description of the invention, taken in conjunction with the accompanying figures.

FIGURE lA depicts the foaming characteristics of SCMI; and
FIGURE IB depicts the foaming characteristics of sodium lauryl ether sulfate (SLES) and sodium lauryl sulfate (SLS).
DETAILED DESCRIPTION OF THE INVENTION
The following is a detailed description of certain preferred combinations of the acyl alkylisethionate ester compositions, processes for forming the acyl alkylisethionate ester compositions, and additional processing thereof into useful articles. Those skilled in the art will appreciate that numerous modifications to these preferred embodiments may be made without departing from the scope of the invention. For example, while certain specific acyl alkylisethionate ester compositions are exemplified, other compositions are also contemplated. Additionally, while some products are discussed as uses for the composition, other uses, are also contemplated.
The present invention provides processes for forming acyl alkylisethionate ester compositions. The acyl alkylisethionate ester compositions generally have improved solubility and hydrolytic stability as compared to acyl isethionate compositions while retaining beneficial properties including, high-tight foaming, and non-irritating to human tissue. The acyl alkylisethionate ester compositions would be useful as primary or secondary surfactants in aqueous and non-aqueous consumer products such as personal care cleansers. The acyl alkylisethionate ester compositions may include isomeric acyl alkylisethionate esters, a blend of an acyl alkylisethionate ester and an acyl isethionates ester, or mixtures thereof. Salt derivatives of the esters described herein may also be used for the respective esters in forming the acyl alkylisethionate ester compositions.
An acyl alkylisethionate ester herein refers to an acyl isethionate ester in which at least one hydrogen atom on the alkyl moiety of the isethionate portion of the molecule is substituted with an alkyl group. For example, an alkyl group is substituted onto at least one carbon atom of the alkane sulfonate portion of the acyl isethionate ester. An acyl isethionate ester herein refers to an isethionate ester without an alkyl substitution, such as sodium cocoyl isethionate

(SCI). In one embodiment of the invention, the acyl alkylisethionate ester has the following general formula (I):
wherein R is any hydrocarbon group having between 4 and 25 carbon atoms; R| and R2 are each independently selected from the group consisting of hydrogen and a branched or straight aliphatic C1 to C6 alkyl group; and X is any cationic species present for charge neutrality such as hydrogen, ammonium and ammonium ions which are substituted with one or more organic groups, an alkali metal including sodium, potassium, and lithium, an alkaline earth metal including calcium and magnesium, zinc, aluminum, and combinations thereof, in a preferred embodiment, only one of R| and R2 is a branched or straight aliphatic C| to C(, alkyl group while the remaining R| or R2 is hydrogen. The respective compounds having the aliphatic group on R|, or alternatively, R2 form the respective isomers of the compound of Formula (I). An example of a compound is sodium cocoyl methyl isethionate (SCMI).
In another example, ths. acyl alkylisethionate ester is an alkyl-substituted acylpropylsulfonate ester having the general formula (II):

R may comprise any hydrocarbon group having between 4 and 25 carbon atoms. R is preferably selected from the groujj consisting of straight-chain hydrocarbon groups, branched hydrocarbon groups, saturated hydrocarbon groups, unsaturated hydrocarbon groups, and combinations thereof. R\, R2, and R3 are each independently selected from the group consisting of hydrogen and a branched or straight aliphatic C1 to C6 alkyl group. In one prefeaed embodiment of the formula, one of R1 and R2 and R3 is a branched or straight aliphatic C1 to Ce alkyl group while the remaining functional groups, R1, R2, or R3, are hydrogen. Alternatively, two of R1 and R2 and R3 are a branched or straight aliphatic C1 to Ce alkyl group while the remaining functional group, K\, R2, or Rj, is hydrogen. In another embodiment, R| and R? and R3 are each a branched or straight aliphatic Ci to Ce alkyl group.

In another embodiment, R\ and R2 and R3 are each hydrogen. X may be any cationic species present for charge neutrality such as hydrogen, an alkali metal such as sodium, potassium and lithium, calcium, magnesium, zinc, aluminum, ammonium and ammonium ions which are substituted with one or more organic groups.
Isomeric acyl alkylisethionate esters of the present invention may be prepared by direct esterification of one or more alkyl-substituted isethionates, for example methyl-substituted isethionates. In an embodiment, isomeric acyl alkylisethionate esters of the present invention may be prepared by contacting two or more alkyl-substituted isethionates in the presence of a carboxylic acid. In another embodiment, isomeric acyl alkylisethionate esters of the present invention may be prepared by contacting one, two, or more alkyl-substituted isethionates and at least one sodium isethionate in the presence of a carboxylic acid. The isomeric alkyl-substituted isethionates may be prepared by reacting an alkylene oxide(s) with anions derived from a mineral acid, such as an aqueous solution of bisulfite anions. Preferred alkylene oxides have between 2 and 8 carbon atoms per molecule. The invention contemplates that alkylene oxides having 2 or more carbon atoms may be used. Examples of suitable alkylene oxides used in preparing the isethionates may include propylene oxide, ethylene oxide, butylene oxide, and combinations thereof
The aqueous solution of bisulfite may have a concentration from about 10% to about 70% by weight, such as between about 20% and about 50%, for exam.ple, between about 30% and about 45%. The aqueous solution of bisulfite may include any alkali metal aqueous solution • of bisulfite, such as sodium or potassium bisulfite. Additionally, the aqueous bisulfite solution may contain one or more cations such as sodium, potassium, lithium, magnesium, calcium, and ammonium ions are present in the aqueous bisulfite solution to maintain charge neutrality, and in fact any ion by which charge neutrality may be accomplished is suitably included in the aqueous solution, including mono-positive ions, di-positive ions, and triply positive ions. The cations may form salts with the anions formed during the reaction. For example, sodium alkylisethionates (SAI) may be produced from the presence of sodium ions in the aqueous solution. In an embodiment, the aqueous solution is comprised of sulfite ions and bi-sulfite ions. Preferably the aqueous solution comprises 25 wt. % to 99 wt. % sulfite ions and I wt. % to 75. wt % bi-sulfite ions. In another embodiment, the aqueous solution

comprises 40 wt. % to 99 wt. % sulfite ions and 1 wt. % to 60 wt. % bi-sulfite ions. In an embodiment, the aqueous solution, comprising bi-sulfite ions or a combination of hydroxide solution and sulftir dioxide.
In one embodiment, the alkyl-substituted isethionate is an alky-substituted hydroxyethane sulfonate produced by the following reactions:
(I)
O Ri R2 R3 ^
pR CH—CH2+ pHSOj- —--*► q HO-CHCH SO3 + r HO-CHCH SO3
and (II)
O R H H R
/ \ II. II.
pR—CH —CH2 + p HSO3- ^ q HO-CHCH—SO3 + r HO-CHCH^S03_
R is a C| to Cs alkyl group, R| and R? are each independently selected from the group of hydrogen and a C\ to C(, alkyl group. In a preferred embodiment of a compound from reaction (I), only one of R| and R2 is hydrogen while the other is a Ci to Cs alkyl group. R3 and R4 are each independently selected fi-om the group of hydrogen and a Ci to Ce alkyl group. In a preferred embodiment of a compound fi-om reaction (I), only one of R3 and R4 is hydrogen while the other is a Ci to Ce alkyl group. Q + r is equal to p for both reactions (I) and (II).
The respective presence of alkyl group (R) on the first and second carbon atoms, as shown in reaction (II), of the anions, may form substituted primary and secondary hydroxy! isomeric sulfonates. Preferably, the molar ratios of the substituted secondary hydroxy! carbon to substituted primary hydroxyl carbon at between about 19:1 to about 1:19, between about 19:1 and about 4:1, such as between about 17:3 and about 19:1, for example, about 15:1 to about 1:15. Preferably, propylene oxide, butylene oxide and oxides up to six carbon atoms are used to produce isomers containing primary hydroxyls and secondary hydroxyl sulfonates. The ratio may vary depending upon-the reaction conditions and production of by products such as

propylene glycol, butylene glycol, propoxylated/butoxylated sodium alkylisethionates, among others.
In one example of the reaction, propylene oxide is reacted with sodium bisulfite/sulfite to produce sodium 2-methy! 2-hydroxyethane sulfonate and/or sodium 1-methyl 2-hydroxyethane sulfonate or a mixture thereof. In another example butylene oxide is reacted with sodium bisulfite/sulfite to produce sodium 2-ethyl 2-hydroxyethane sulfonate and/or sodium 1 -ethyl 2-hydroxyethane sulfonate or a mixture thereof.
Additionally, a mixture of alkyl-substituted isethionate may be formed by using one or more oxides. In one example, a mixture of propylene oxide and butylene oxide is reacted with sodium bisulfite/sulfite to produce sodium 2-methyI 2-hydroxyethane sulfonate, sodium 2-ethyl 2-hydroxyethane sulfonate, sodium 1-methyl 2-hydroxyethane sulfonate, and/or sodium
]-ethyl-2-hydraxyethane sulfonate, or mixtures thereof In one example, a mixture of ethylene oxide, propylene oxide and/or butylene oxide may be used to generate a mixture of sodium alkylisethionate and sodium isethionate compounds.
The various oxides can be combined in any proportion by. varying molar ratios to obtain the desired amounts of each alkyl-substituted hydroxyalkyl sulfonate, in one example, a preferred mixture of alkylisethionates and isethionates can be produced by mixing propylene oxide, and/or butylene oxide with ethylene oxide in any proportion containing ethylene oxide, propylene oxide, and/or butylene oxide, or a combination thereof. The oxide mixture produces isethionates, and isomeric mixtures of methylisethionates, and/or ethylisethionates, in the above reactions.
The alkyl-substituted isethionate may be used in the esterification process as follows to form an acyl alkylisethionate that is, completely water soluble sodium cocoyl alkylisethionate esters (SCAI) by reaction of SAI with fatty acids and a catalyst(s), and unlike pure SCI, water soluble to generate clear formulations for personal care applications.
During production of the alkyl-substituted isethionates, also referred herein as alkylisethionates, the pH of the reaction solution comprising the alkylene oxide and bisulfite

may range from about 4 to about 10. A preferred pH of the reaction solution may be between about 5 to about 10. It is believed such a pH range will minimize side reactions and side products such as diols. In another preferred pH level, the pH of the reaction solution may be maintained optimally at a pH of about 7. It is believed that such a pH level will maximize production of alkyl-substituted isethionates having a high content of secondary ester link carbons. To maintain the pH of the reaction solution at a desired pH range during the entire reaction, a weak acid or buffering acid and/or more bisulfite may be added to the reaction solution as needed.
Alternatively a mixture of alkylisethionates could be made by forming the alkyl-substituted isethionates from respective oxides, such as propylene oxide and butylene oxide, separately and then combined into one mixture before the esterification process. The respective amount of the individual alkyl-substituted isethionates formed from the respective oxides may be detemiined for the esterification process to produce isethionates with desired properties, such as a desired viscosity or solubility. The use of a mixture of alkyl-substituted isethionates from reaction with the respective oxides has been observed to have lowered the melt point and improved homogeneity of the mixture at lower temperature, and decreased reaction times, of the products formed in the subsequent esterification process.
In an alternative embodiment, the alkyl-substituted isethionates are prepared by making the bisulfite/sulfite in situ by reacting a hydroxide solution, such as sodium hydroxide, with sulfiir dioxide under pressure. Suitable hydroxide solution concentrations include 10, 25, and 50% by weight sodium hydroxide, alternatively the solution may comprises a sodium hydroxide concentration of from about 25% by weight to about 45% by weight. Suitable hydroxide solutions include potassium hydroxide, ammonium hydroxide, sodium hydroxide, or combinations thereof In a preferred embodiment of the hydroxide solution, the hydroxide solution may comprise a 50% by weight sodium hydroxide solution. The alkylene oxide can be added concurrently or after to produce the corresponding isethionates and alkyl-substituted isethionates.
Furthermore, the temperature and pressure of the reaction solution during production of the alkyl-substituted isethionates may range between about 20°C and about 200°C, such as

between about 30°C and about 95°C, for example between about 50°C and about 80°C; and from between about 0.00 psi to about 103 psi, such as between about 2.0 psi and about 7.0 psi , for example, between about 10.00 psi and about 50 psi respectively. The temperature and pressure of the reaction solution may be held constant during the entire reaction or one or both may be raised or lowered at any time for any time period to produce the desired alkyl-substituted isethionate.
Furthermore, the alkyl-substituted isethionates may be prepared as a liquid or in solid form. For example, the alkyl-substituted isethionates may first be prepared in liquid form then dried to form a powder. A preferred method of drying the alkyl-substituted isethionates is spray drying. For example, alkyl-substituted isethionates are prepared in liquid form by reacting propylene oxide and/or butylene oxide with sodium bisulfite. The liquid salts of the alkyl-substituted isethionate are then spray dried to the corresponding powder form. The alkyl-substituted isethionate powders have been found to be less hygroscopic and therefore easier to handle than non-alkyl-substituted isethionate powders making their transportation more efficient and less expensive. In addition, use of the alkyl-substituted isethionate powder allows for the elimination of a water removal step that is normally required when using a liquid alkyl-substituted isethionate during direct esterification.
The alkyl-substituted isethionates may then be used in producing the acyl alkylisethionate esters of the present invention by direct esterification of an alkyl-substituted isethionate mixture with a carboxylic acid. More than one alkyl-substituted isethionates mixture and/or more than one carboxylic acid may be used in the esterification reaction. Esterification occurs by mixing alkyl-substituted isethionate with carboxylic acids and optionally an esterification catalyst under esterification conditions. The alkyl-substituted isethionate can be present as the salt of the alkyl-substituted isethionate or in its acidic form. Alternatively, a composition of alkyl-substituted isethionate and isethionate may also be used in the esterification process.
Esterification for one embodiment may occur according to the reaction (III):

O t^t^O o R, R20
II I I II II I I II
R-COH + HOCHCHSOX "—^ R-CO-CHCHSOX +}ip.
O ^
R is any hydrocarbon group having between about 4 and about 25 carbon atoms. The hydrocarbon group may include straight-chain, branched, saturated, unsaturated hydrocarbon groups, and combinations thereof. R| and R2 may each independently be hydrogen or an alky! group having 1 to 6 carbons, Ci to Ce alkyl. In a preferred embodiment of the reaction, at least one of Ri and R2 is hydrogen and at least one of at least one of Ri and R2 is a Ci to Ce alkyl group. X is a cationic species present for charge neutrality. Suitable cationic species are selected from the group consisting of hydrogen, alkali metals, alkaline earth metals, zinc, aluminum, ammonium, and ammonium ions which are substituted with one or more organic groups, and combinations thereof. When X is hydrogen, the alkyl-substituted alkylisethionic acid is present, which we have surprisingly found to be catalytic during esteriftcation. X can be present as hydrogeri by addition of any strong acid, however, it is most preferable to add the alkyl-substituted alkylisethionic acid itself in its pure form when it is added as an esterification catalyst.
In one embodiment of an acyl alkyl isethionate ester composition, the composition includes a blend of isomeric acyl alkylisethionate esters with acyl isethionate esters. A composition including the blend of the isomeric acyl alkylisethionate esters and the acyl isethionate esters may be achieved by independently producing the respective esters and then mixing the esters in desired ratios to obtain a desired solubility. Alternatively, a composition including a blend of the isomeric acyl alkylisethionate esters with acyl isethionate esters may be achieved by blending alkyl-substituted isethionate and isethionate precursors, such as sodium alkylisethionate and sodium isethionate, respectively, prior to esterifi cation as described herein. In either composition formation process, the molar ratio of isomeric acyl alkylisethionate esters to acyl isethionate esters in the composition may be between about 0.5:9.5 and about 9.5:0.5, such as between about 3:7 and about 7:3. Alternatively, a mixture of isomeric acyl alkylisethionate esters, as described herein, may be substituted for the isomeric in the composition described abc"

The acyl isethionate esters have the formula (IV):
H H
I I
RCOO —CHCH SO3X ^
R is any hydrocarbon group having between 4 and 25 carbon atoms. R is preferably selected from the group consisting of straight-chain hydrocarbon groups, branched hydrocarbon groups, saturated hydrocarbon groups, unsaturated hydrocarbon groups, and combinations thereof. X may be £my cationic species present for charge neutrality such as hydrogen, ammonium and ammonium ions which are substituted with one or more organic groups, an alkali metal including sodium, potassium, and lithium, an alkaline earth metal including calcium and magnesium, zinc, aluminum, and combinations thereof. An example of a compound is sodium cocoyl isethionate ester (SCI).
In one embodiment of the esterification reaction, isethionates may be included with alkyl-substituted isethionates to co-produce acyl isethionate esters from the isethionates with the production of the acyl alkylisethionate esters from alkyl-substituted isethionates during the same reaction process. For example, sodium cocoyl isethionate esters and sodium cocoyl alkylisethionates may be produced from an esterification reaction using sodium isethionates and sodium alkylisethionates as reactants with the carboxylic acid. In a mixed isethionate and alkyl-substituted isethionate reaction, the ratio of isethionate to alkyl-substituted isethionate may be between about 0.5:9.5 and about 9.5:0.5, such as between about 3:7 and about 7:3. The ratios are illustrative, and the invention contemplates that the ratio of the respective components may be varied to produce compounds having desired physical properties, such as solubility. Suitable isethionate compounds include 10, 20, 30 wt% isethionate and the balance is alkyl-substituted isethionate. The ratio are illustrative, and the invention contemplates that the ratio of the respective components may be varied to produce compounds having desired physical properties, such as solubility.
It has been surprisingly found that a mixed isethionate and alkyl-substituted isethionate esterfication reaction can occur at a lower temnerature. at about 200°r! for a SI and SMT

reaction, than the individual isethionate components, about 220°C to about 250°C for SMI and SI esterification reactions.
The carboxylic acids employed in producing the esters of the present invention have the general formula (IV): R-COOH where R is any hydrocarbon group having between about 4 to about 25 carbon atoms. The R hydrocarbon group can be saturated or unsaturated, and straight-chain, branched, and combinations thereof. Generally, an excess of carboxylic acid is used in producing the esters of the present invention. Thus, the amount of carboxylic acid used may range from a mole ratio of carboxylic acid to isethionate of 1.5:1 to 1.1:1. However, a mole ratio range of carboxylic acid to isethionate as high as 2:1 to as low as 0.9:1 may be used if desired.

Examples of carboxylic acids suitable for use in the present invention include: coco acid; butyric acid; hexanoic acid; caproic acid; caprylic acid; capric acid; lauric acid; myristic acid; palmitic acid; palmitoleic acid; stearic acid; oleic acid; linoleic acid; arachidic acid; gadoleic acid; arachidonic acid; (EPA); behinic acid; eruic acid; (DHA); lignoceric acid; naturally occurring fatty acids such as coconut oil, tallow, palm kernel oil, butterfat, palm oil, olive oil, com oil, linseed oil, peanut oil, fish oil and rapeseed oil; synthetic fatty acids made as chains of a single length or a selected distribution of chain lengths; and mixtures of any of the foregoing.
Those skilled in the art will appreciate that fatty acids obtained from naturally occurring sources are mixtures of acids having various carbon chains of various lengths. Therefore, it is within the scope of this invention to use one or more naturally occurring fatty acids (including mixtures thereof), synthetic fatty acids (including mixtures thereof) and mixtures of both natural and synthetic fatty acids. Moreover, "coco acid" or "coco fatty acid" as used herein is a commercial fatty acid mixture containing a range of carboxylic acids having chain lengths of between about Cg to Cis, and some saturation which may be removed by hydrogenation. Thus, hydrogenated coco acid is a mixture of carboxylic acids having Cg to C|8 chain lengths, mostly lauric and myristic, together with some capric and caprylic acids, and contains very little, if any, unsaturation.
In producing an acyl alkylisethionate ester by the reaction of a carboxylic acid with an alkylisethionate, such as an alkyl-substituted hydroxyethane sulfonate, the carbon atom of the hydroxyethane sulfonate portion of the molecule connected to the oxygen atom of the ester linkage is herein referred to as the "ester link carbon atom." It has been surprisingly found that when the alkylisethionate contains a high degree of ester link carbons that are secondary carbon atoms, the hydrolytic stability of the final acyl alkylisethionate ester product is substantially increased. No similar increase in hydrolj/tic stability has been observed with regards to increasing the secondary carbon content of the other carbon atom bonded directly to the sulfur atom in the alkylisethionate. Therefore, it is highly desirable to produce an alkyl-substituted isethionate that permits an acyl alkylisethionate ester produced therefrom to possess as high a degree of ester link carbons which are secondary carbon atoms as possible.

Additionally, an esterification catalyst may be employed and combined with the alkyl-substituted isethionate and carboxylic acid. Esterification catalysts suitable for use include alkylisethionic acids, salts of hydroxyalkane sulfonates, methane sulfonic acid, p-toluene. sulfonic acid, inorganic acids such as sulfuric acid, phosphoric acid, phosphorous acid, boric acid or their anhydrides, heavy metal salts such as zinc sulfate, zirconium sulfate, zinc isethionate, zinc alkylisethionates, zinc cocoate, zinc citrate, zinc borate, aluminurn sulfate, titanium sulfate or tungsten phosphate, metal oxides such as zinc oxide, aluminum oxide, magnesium oxide, cerium oxide, zirconium oxide or lanthanum oxide, organic acids such as citric acid and glycolic acid, and also mixtures of two or more of these catalysts, and soaps formed from heavy metals and metal oxides. The esterification catalyst may be employed in an amount from 0.05 to 2% by weight, preferably from 0.05% to 1% by weight, based on total weight of the reactants.
In one embodiment, the acy] alkylisethionate sster is prepared using the acidic form of alkyl-substituted hydroxyethane sulfonate as the esterification catalyst. The alkyl-substituted hydroxyethane isethionic acid can be added in its pure form or a strong acid can be added to the reaction mixture containing carboxylic acid and salt of the alkyl-substituted hydroxyethane isethionate to convert the isethionate salt to the acidic form.
The dual use of the alkyl-substituted hydroxyethane sulfonate as both a reactant and a catalyst is preferred since there is no need to quench or to remove the catalyst, there is no catalyst residues so there is minimal change in the molecular weight distribution of the acyl alkylisethionate ester, manufacturing capital expenditures are reduced and processing time is decreased.
In general detail, the esterification reaction can be conducted by charging the carboxylic acid, alkyl-substituted isethionate and isethionate as necessary, and optionally the esterification catalyst under atmospheric pressure or vacuum to a reaction vessel. The reaction vessel is flushed thoroughly with dry inert gas, such as nitrogen. Direct esterification is carried out by heating the reaction mixture to the reaction temperature with stirring. The water that may be introduced into the reaction mixture with the starting components and the water that is formed as a result of the esterification reaction is discharged from the reaction vessel. In

addition, it may be also be required to distill off some of the excess carboxylic acid during the course of the esterification reaction. The reaction time to complete esterification will vary from 1 to 12 hours depending on the reaction temperature, and if present, the amount of esterification catalyst. The final ester product can then be delivered in liquid or solid form, such as a solution, powder, flakes or paste, for use as a raw material in the formulation of personal care cleansers.
The esterification reaction may be performed in a reaction vessel under atmospheric pressure. However, to aid in water removal, mild vacuum (500-550 mm Hg) may be applied during commencement of the charging of the reactants or anytime during the reaction. Applying mild vacuum also allows for water removal without distilling of the carboxylic acid. Preferably, the vacuum applied is not allowed to drop below 500 mm Hg so as to prevent carboxylic acid distillation when such is not desired.
Generally, the reaction vessel is heated to a single reaction temperature range. However, the process can employ more than one reaction temperature range. For example, the reaction vessel may be heated to a first reaction temperature range and held at that temperature range for a period of time to remove water, then subsequently heated further to a second temperature range higher than the first and held for a period of time. The reaction temperature ranges employed during the esterification reaction may range from about 180° C to about 240°C. However, it has been surprisingly found that if alkyl-substituted isethionic acid is used as the catalyst, the reaction temperature can be lowered to a temperature range of about 90°C to about ISO^C, preferably about 120°C to about 160°C.
In one embodiment, the acyl alkylisethionate ester is produced by combining one or more carboxylic acids and one or more sodium salts of the alkyl-substituted isethionate with an alkyl-substituted isethionic acid catalyst to a reaction vessel. Additionally, an isethionate ester may be formed in situ with the acyl alkylisethionate ester as described herein. The reaction vessel is purged using nitrogen and the reaction mixture is heated at a first temperature range of about 120°C to about 130°C for 30 minutes to remove water from the reaction components. The reaction mixture is then subsequently heated to a range of about 140°C to about 15G°C to start the esterification reaction. Mild vacuum (500-550 mm Hg) is

applied during the esterification reaction to assist in removal of water and the reaction mixture is continually heated until the distilling over of water ceases. The vacuum can be adjusted during the reaction to prevent carboxylic acid fi"om distilling over. After esterification is complete, the residual alkyl-substituted isethionic acid present as a catalyst may be neutralized with an alkali such as caustic, amine, ammonia or substituted ammonium compounds such as mono-, di-, and triamines, and alkanolamine such as ethanolamine. The excess fatty acid can be conveniently removed by vacuum distillation at temperatures and pressures varying from about 100° and about 250°C and between about 1 and about 200 mm Hg to make the product substantially fatty acid free.
The acyl alkylisethionate esters according to the present invention produced from alkyl-substituted isethionates are much more hydrolytically stable than acyl isethionate esters produced from non-alkyl-substituted isethionates, such as SI.
Thus, it has been surprisingly found that by substituting hydrogen with Ci to Cs alkyl groups on one or both of the carbon atoms of the ethane sulfonate portion of an acyl alkylisethionate ester, hydrol>'tic stability and water solubility of the acyl alkylisethionate ester is dramatically improved. That is by providing a C| to Ce on one or both of the carbon atoms of the isethionic acid (or isethionate salt) raw material used in producing the acylethylisethionate ester, the water solubility and hydrolytic stability of the modified ester is improved. This result is wholly unexpected in view of the common knowledge in the art that increasing the hydrocarbon character of a material generally results in a reduction of water solubility. As a result of this improved solubility and hydrolytic stability, the acyl alkylisethionates of the present invention are suitable for use in liquid personal care cleaners and not limited to soap bars.
In one embodiment of the reaction processes described herein, using the respective reactants herein, allow for the formation of acyl alkylisethionate ester compositions having both acyl isethionate esters and acyl alkylisethionate esters. For example, an acyl alkylisethionate ester composition may include of sodium cocoyl alkylisethionate isomeric esters (SCAl) and sodium cocoyl isethionates esters (SCI) from a blend of sodium isethionate (SI) and sodium alkylisethionate isomeric mixture (SAI). The blend of acyl isethionate esters and acyl

alkylisethionate esters in a composition have been observed to have lowered the melt temperatures of ester products and the ester products remain liquid at considerably lower temperatures than individual esters. In addition, it has also been observed that blend of acyl isethionate esters and acyl alkylisethionate esters provide improved homogeneity of the mixture at lower temperature with decreased reaction times during the esterification process.
Additionally, the blending of isethionates and alkyl-substituted isethionates prior to the esterification process has been observed to result in a composition having water soluble isethionate esters. For example, the blending of water insoluble sodium cocoyl isethionates with sodium cocyl alkylisethionates has been observed to result in a composition having water soluble sodium cocyl isethionates. Additionally, this blending enhanced not only the solubility but also the processability of the isethionate esters by lowering the melt temperatures of the reactants which allows for lowering the reaction temperatures. -A-dditionally, the reaction mass is more homogeneous at a lower temperature due to the lower melt temperatures of the reactants, the reaction is faster and the esterification is far more complete than single ester processes. Thus, the blending of the respective isethionates improves the economics of the esterification process and ester products compared to the process and products in manufacturing pure component esters blending for formulation purposes.
For example, a blend of sodium isethionate (SI) with sodium alkylisethionates, particularly, sodium methyl and ethyl isethionates separately or mixtures was reacted with fatty acids (carboxylic acids) using a catalyst such as zinc oxide at between about 200**C and about 225"C. The reaction was observed to have a much higher ester formation at lower temperatures between about 200°C and about .225'C compared to between about 240°C and about 250°C with the esters remaining liquids at lower temperatures without product degradation. It was also observed that the blends prevented the solids formation during the addition of isethionate solution to fatty acid at temperatures below 150°C and reduced the amount of fatty acid distilled over into water layer during the esterification process. Also, the reaction time was observed to be reduced by 25% and at most 50% compared to single sodium alkylisethionates reactions.

It is believed that varying the level of each of the isethionate and alkylisethionate component for the esterification, can produce ester products with a desired water solubility. For example, by increasing the level of sodium methyl isethionate or sodium ethyl isethionate in a composition having sodium isethionate, the solubility of the resulting ester was observed to improve from almost no solubility of the sodium isethionate ester to almost 30% solubility when sodium isethionate ester is mixed with either sodium methyl isethionate or sodium ethyl isethionate esters. More specifically, a composition of sodium cocoyl methyl isethionate (SCMI) and sodium cocoyl isethionate (SCI) resulted in water soluble isethionate esters when compared to water insoluble sodium cocoyl isethionate (SCI). The blending of sodium isethionate (SI) and sodium alkylisethionates (SAI) (especially, sodium methyl isethionate (P-salt), sodium ethyl isethionate, (B-salt) and reacting with fatty acids produced esters having improved water solubility compared to SCI from sodium isethionate. The ability to control the physical properties of the ester products, such as solubility, would allow for the manufacturing of tailor esters to suit customer needs.
Thus, the blend of esters as d-sscribed herein gave une}:pected or surprising results by improving solubility of isethionate esters, the alkylisethionate esters blends are milder than single component isethionates including SCI as shown in (Example 29 and Table 3 herein), the alkylisethionate esters blends have a lower melting point than single component esters, the blend of reactants to form the alkylisethionate esters blends have lower esterification reaction temperatures and shorter esterification reaction times with less product degradation.
Post-Esterification Processing:
Once formed, the acyl alkylisethionate ester compositions may be used as a surfactant or surface active agent in a variety of personal care cleansers. Personal care cleansers include, but are not limited to: liquid soaps, shampoos, shower gels, bubble baths, synthetic soap-combi-bars, acne washes, anti-dandruff shampoos, make-up removers, facial scrubs, baby wipes and children wipes. Thus, the compounds of the invention may be used in any personal care cleansing composition as may be known to those skilled in the art.

The acyl alkylisethionate ester compositions of the present invention may be used in personal care cleansers as a primary surfactant at levels ranging from 1% to 60% by weight. In addition, the acyl alkylisethionate ester compositions of the present invention may be blended with other surfactants and materials which are used in personal care cleansers at acyl alkylisethionate ester composition levels ranging up to about 60% by weight. To the extent that other surfactants may be used in combination with the acyl alkylisethionate ester compositions of the present invention in forming binary active systems, ternary active systems etc., the acyl alkylisethionate ester composition may comprise the majority of the surface active system (if more than one active is required) in which it is referred to as the primary surfactant, or it may comprise less than the majority of the surface active system in which it is referred to as the secondary surfactant.
Surfactants which may be used in combination with the acyl alkylisethionate ester compositions in forming the personal care cleanser may include amphoteric/zwitterionic surfactants, anionic surfactants, nonionic surfactants, cationic surfactants, and combinations thereof.
Amphoteric surfactants useful in the invention can broadly be described as a surface active agent containing at least one anionic and one cationic group and can act as either acids or bases depending on pH. Suitable amphoteric surfactants include aliphatic derivatives of heterocyclic secondary and tertiary amines in which the aliphatic radical may be straight or branched and wherein one of the aliphatic substituents contains from about 6 to about 20, preferably 8 to 18, carbon atoms and at least one contains an anionic water-solubilizing group, for example, a carboxyl group, a phosphonate group, a.phosphate group, a sulfonate group, a sulfate group or combinations thereof
Zwitterionic surfactants can be broadly described as surface active agents having a positive and negative charge in the same molecule which molecule is zwitterionic at all pHs. Examples of zwitterionic surfactants include betaines and sultaines. The zwitterionic compounds may contain a quaternary ammonium, quaternary phosphonium or a tertiary sulfonium moiety. The cationic atom in the quaternary compound can be part of a

heterocyclic ring. Preferred 2weitterionic compounds include at least one aliphatic group, straight chain or branched, containing from about 6 to 20, preferably 8 to 18, carbon atoms and at least one aliphatic substituent containing an anionic water-solubilizing group, for example, a carboxyl group, a phosphonate group, a phosphate group, a sulfonate group, a sulfate group or combinations thereof.
Examples of suitable amphoteric and zwitterionic surfactants include the alkali metal, alkaline earth metal, ammonium or substituted ammonium salts of alkyl amphocarbpxyglycinates and alkyl amphocarboxypropionates, alkyl amphodipropionates, alkyl monoacetate, alkyl diacetates, alkyl amphoglycinates, alkyl amphopropionates, and combinations thereof The alkyl includes an alkyl group having from 6 to about 20 carbon atoms. Other suitable surfactants include alkyliminomonoacetates, alkyliminidiacetates, alkyliminopropionates, alkyliminidipropionates, and alkylamphopropylsulfonates having between 12 and 18 carbon atoms, aikyl betaines and alkylamidoalkylene betaines and alkyl sultaines, alkylamidoaikylenehydroxy sulfonates, and combinations thereof.
Preferred anionic surfactants include compounds having a long chain hydrocarbon hydrophobic group and a hydrophilic group. The anionic surfactants may be in the fonn of salts such as carboxylate, sulfonate, sulfate or phosphate groups with sodium, potassium, calcium, magnesium, barium, iron, ammonium, amine salts, and combinations thereof, as the cationic portion of the salt.
Preferred anionic surfactants may also include the alkali metal, ammonium and alkanol ammonium salts of organic sulfuric reaction products having in their raolecular structure an alkyl, or alkaryl group containing from 8 to 22 carbon atoms and a sulfonic or sulfuric acid ester group.
Examples of anionic surfactants include water soluble salts of alkyl benzene sulfonates having between 8 and 22 carbon atoms in the alkyl group, alkyl ether sulfates having between 8 and 22 carbon atoms in the alkyl group and 2 to 9 moles ethylene oxide in the ether group, or combinations thereof Other suitable anionic surfactants include alkyl sulfosuccinates,
alkyi ether sulfosuccinates, olefin sulfonates, alkvl sarcosinatss, alkyl monoglyceride sulfates

and ether sulfates, alkyl ether carboxylates, paraffinic sulfonates, mono and di alkyl phosphate esters and ethoxylated derivatives, acyl methyl taurates, fatty acid soaps, collagen hydrosyiate derivatives, sulfoacetates, acyl lactates, arylpxide disulfonates, sulfosucinamides, naphthalene-formaldehyde condensates, or combinations thereof Aryl groups generally include one and two rings, alkyl generally includes from 8 to 22 carbon atoms and the ether groups generally range from 1 to 9 moles of ethylene oxide (EO) and/or propylene oxide (PO), preferably Ethylene oxide.
Further examples of suitable anionic surfactants include linear alkyl benzene sulfonates such as decylbenzene sulfonate, undecylbenzene sulfonate, dodecylbenzene sulfonate, tridecylbenzene sulfonate, nonylbenzene sulfate and the sodium, potassium, ammonium, triethanol ammonium and isopropyl ammonium salts thereof, or combinations thereof.
Nonionic surfactants may also be used in combination with the acyl alkylisethionate ester compositions of the present invention. The nonionic surfactant may be any of the known nonionic surfactants which are generally selected on the basis of compatibility, effectiveness and economy.
Examples of suitable nonionic surfactants include condensates of ethylene oxide with a hydrophobic moiety which has an average hydrophilic lipolytic balance (HLB) between about 8 to about 16, and preferably between about 10 and about 12.5. The surfactants include the ethoxylated primary or secondary aliphatic alcohols having from about 8 to about 24 carbon atoms, in either straight or branch chain configuration, with from about 2 to about 40, and preferably between about 2 and about 9 moles of ethylene oxide per mole of alcohol. Other suitable nonionic surfactants include the condensation products of from about 6 to about 12 carbon atoms alkyl phenols with about 3 to about 30, and preferably between about 5 to about 14 moles of ethylene oxide.
Preferred cationic surfactants include a cationic surfactant having at least one long chain alkyl group of about 10 to 24 carbon atoms is suitable for optional use in the present invention.

Alternatively, optional additives may be used in combination with acyl alkylisethionate ester compositions in formulating personal care cleansers. Optional additives include pH adjusting chemicals, phase regulants, detergent hydrotropes, defoamers, an inorganic or organic builder, or combinations thereof.
The pH adjusting chemicals, for example, lower alkanolamines such as monoethanolamine (MEA) and triethanolamine (TEA). Sodium hydroxide solutions may also be utilized as an alkaline pH adjusting agent. The pH adjusting chemicals function to neutralize acidic materials that may be present. Mixtures of more than one pH adjusting chemical can also be utilized.
Phase regulants (well known liquid detergent technology) may also be used as an optional additive. Phase regulants can be represented by lower aliphatic alcohols having from 2 to 6 carbon atoms and from 1 to 3 hydroxyl groups, ethers of diethylene glycol and lower aliphatic monoalcohols having from 1 to 4 carbon atoms and the like.
Examples of detergent hydrotropes include salts of alkylarylsulfonates having up to 3 carbon atoms in the alkyl group e.g., sodium, potassium, ammonium, and ethanolamine salts of xylene, toluene, ethylbenzene, cumene, and isopropylbenzene sulfonic acids.
Defoamers include high molecular weight aliphatic acids, especially saturated fatty acids and soaps derived from them, dyes and perfumes; fluorescent agents or optical brighteners; anti-redeposition agents, such as carboxymethyl cellulose and hydroxypropylmethyl cellulose; suspension stabilizing agents and soil release promoters such as copolymers of polyethylene terephthalate and polyoxyethylene terephthalate; antioxidants; softening agents and anti-static agents; photo activators and preservatives; polyacids, suds regulators, opacifiers, bacteriacide, and the like. Suds regulators may include, for example, alkylated polysiloxanes, opacifiers may include, for example, polystyrene, and bactericide may include, for example, butylated hydroxytoluene.
An inorganic or organic builder may optionally be added to the final composition. Examples
of inorganic builders include water-soluble alkali metal carbonates, bicarbonates, silicates

and crystalline and amorphous alumino silicates. Examples of organic builders include the alkali metal, alkaline metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates, polyacetyl, carboxylates and polyhydroxy sulfonates. One example of a commonly used builder is sodium citrate.
The optional ingredients and optional surfactants can be added to the acyl alkylisethionate ester composition before, during or after formulation of the personal care cleanser. In addition, bliends of the acyl alkylisethionate ester composition in combination with these optional ingredients and surfactants can be made directly for sale or for compounding to meet the needs of the user.
Thus, the acyl alkylisethionate esters of the present invention are useful in formulations which contain materials typically used by and known to those skilled in the art as being useful in formulating soap products, detergent products, and other cleansing-Iike products, particularly, but not limited, to personal care cleansers. For purposes of this invention, the words "material known to those skilled in the art as being useful in formulating soaps, detergents, and the like" means one or more of the materials selected from the group consisting of: fatty acids, alkyl sulfates, ethanolamines, amine oxides, alkali carbonates, water, ethanol, isopropanol, pine oil, sodium chloride, sodium silicate, polymers, alcohol alkoxylates, zeolites, perborate salts, alkali sulfates, enzymes, hydrotropes, dyes, fragrances, preservatives, brighteners, builders, polyacrylates, essential oils, alkali hydroxides, ether sulfates, alkylphenol ethoxylates, fatty acid amides, alpha olefin sulfonates, paraffin sulfonates, betaines, chelating agents, tallowamine ethoxylates, polyetheramine ethoxylates, ethylene oxide/propylene oxide block copolymers, alcohol ethylene oxide/propylene oxide low foam surfactants, methyl ester sulfonates, alkyl polysaccharides, N-methyl glucamides, alkylated sulfonated diphenyl oxide, and water soluble alkylbenzene sulfonates or alkyltoluene sulfonates, as the use of such in formulating soaps, detergents, and the cleansing-like products are known in the.art.
In one embodiment, the acyl alkylisethionate ester compositions of the present invention may be present in facial and body cleansing compositions. These cleansing compositions may
also comprise a fatty acid soap together with other non-soap surfactants, such as mild

synthetic surfactants. Body and facial cleaning compositions may also generally include a moisturizer or emollient and polymeric skin feel and mildness aids. The compositions may further optionally include thickeners (e.g., magnesium aluminum silicate, carbopol), conditioners, water soluble polymers (e.g., carboxymethylcellulose), dyes, hydrotropes brighteners, perfumes, germicides, or combinations thereof. For liquid soap products, the acyl alkylisethionate composition herein may comprise between about 60 wt.% and about 90 wt.% of the acyl alkylisethionate compound, such as SCMI, and between about 10 wt.% to 40 wt.% of the acyl isethionate compound, such as SCI. For solid soap formulations, the acyl alkylisethionate composition herein may comprise between about 10 wt.% and about 40 wt.% of the acyl alkylisethionate compound, such as SCMI, and between about 60 wt.% to 90 wt.% of the acyl isethionate compound, such as SCI.
In another embodiment, the acyl alkylisethionate ester compositions of the present invention
may be present in a shampoo. The shampoo composition may also comprise one or more other surfactants, a compound considered useful for treating dandruff, such as selenium sulfide, a suspending agent, an amide, nonionic polymer material for aiding in dispersing particles, nonvolatile silicone fluid, and a variety of other nonessential components suitable for rendering the composition more useful in various formulations, such as preservatives, viscosity modifiers, pH adjusting chemicals, perfumes, dyes, or combinations thereof.
In still another embodiment, the acyl alkylisethionate ester compositions of the present invention may be present in a light duty liquid detergent composition. The light duty liquid detergent composition may further include one or more other surfactants, opacifiers (e.g. ethylene glycol distearate), thickeners (e.g. guar gum), antimicrobial agents, anti-tamish agents, heavy metal chelators (e.g. EDTA), perfumes, dyes, or combinations thereof
In a further embodiment, the acyl alkylisethionate ester composition of the present invention may be present in a heavy duty liquid detergent composition. The heavy duty liquid detergent composition may also include one or more other surfactants, an electrolyte {i.e., water soluble salt), enzymes with or without stabilizers such as calcium ion, boric acid, propylene glycol and /or short chain carboxylic acids, conventional alkaline detergency builders, or combinations thereof.

In yet another embodiment, the acyl alkylisethionate ester composition may be present in a conditioner composition that comprises alkylamine compounds.
In a different embodiment, the acyl alkylisethionate ester compositions of the present invention may be present in a cosmetic composition. The cosmetic composition may further include at least one polymer thickening agent, one or more chemical preservatives or water activity depressants to prevent microbial spoilage, a sun-screening agent such as p-aminobenzoic acid, and a vehicle. The cosmetic composition medium can include any diluent, dispersant or carrier useful in ensuring an even distribution of the composition when applied to skin and may include water, an emollient such as an alcohol or oil, a propellant for example, trichloromethane, carbon dioxide or nitrous oxide, a humectant, a powder such as chalk, talc, and starch, or combinations thereof.
Advantages of the acyl alkylisethionate ester compositions described herein in the products described herein include improved solubility compared to acyl isethionate esters such as SCI, non-irritating properties of the acyl alkylisethionate ester compositions allow the composition to be used as a primary surfactant in place of traditional anionic surfactants such as sodium lauryl sulfate and sodium lauryl ether sulfate in personal care cleansers, and "sulfate-free" personal care cleansers can be made using tlie acyl alkylisethionate ester compositions without requiring the addition of taurates and sarcosinates needed for removing sulfates in current personal care cleansers.
The examples which now follow should be considered exemplary of the present invention, and are in no way limiting:
Experimental Data
The following viscosities were measured in a Brookfield Programmable DV-II + viscometer. The saponification value: mg of KOH per gram of material.

The respective acid value: mg of KOH per gram of material.
The correct sap value of the ester: saponification value - acid value.
EXAMPLE 1 Preparation of Sodium Methyl Isethionate
A 3-gallon stainless steel-316 autoclave reactor with 9.40 pounds of 35% aqueous sodium bisulfite solution having a pH 6.5-7.0 and then nitrogen purged to exclude air. The reactor was then heated to about 70°C and 1.0 pounds of propylene oxide was added to the reactor at a pressure of 60 psi. The reactants were allowed to react for about 30 minutes at a temperature of about 80°C after which time the pressure in the reactor dropped to about 1 psi. The reaction was allowed to continue for 60 minutes at 80°C, cooled to 50°C, and the product solution was removed fi-om the reactor and analyzed. Anali'sis showed the product solution having a pH of 13.50, A second 3-gallon stainless steel-316 autoclave reactor with 9.69 pounds of 35% aqueous sodium bisulfite solution having a pH 6.5-7.0 and then nitrogen purged to exclude air. The reactor was heated to about 70°C and 1.5 pounds of propylene oxide was added to the reaction at a pressure of 60 psi. The reactants were allowed to react at 80°C for 30 minutes after which time the pressure dropped to about 1 psi. The reaction was allowed to continue for 60 minutes at a temperature of 95°C then cooled to 50°C and the product solution was removed from the reactor and analyzed. Analysis showed the product solution having a pH of 14.00, about 3.0 % by weight propylene glycol, and both the 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl 2-hydroxy ethane 1-sulfonate isomers present.
In a 170-gallon stainless steel-316 reactor equipped with an agitator, nitrogen line, oxide line, temperature probe and a pH probe, with 300 pounds of DI water and 120 pounds of 50% caustic solution. The reactor was pressure purged with nitrogen three times (40-0 psig). SO2 was then passed through the reactor and solution with stirring to a pH of 7.0-7.50. The reactor was then heated to about 70°-75°C and propylene oxide was added to the reactor at a

rate of 0.50 lb/minute. The pH during the reaction controlled addition by the addition of small injections of SO2. Furthermore, the addition of PO was slowed towards the end of the reaction to maintain good pH control. The reactants were allowed to digest at 95°C for 4 hours. A total of 93 pounds of SO2 and 90 pounds of propylene oxide were used during the entire reaction. The reactor was then opened to fiime hood and stripped of any unreacted propylene oxide with a nitrogen purge for one hour. The reaction mixture was cooled to room temperature and discharged into drums. The clear and colorless product was analyzed and the results showed: 0.50% by weight propylene glycol and 50.20% by weight sodium methyl isethionate (with both 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl, 2-hydroxy ethane 1 -sulfonate isomers present in about 15:1 molar ratio).
EXAMPLE 2 Preparation of Sodium Ethyl Isethionate
A 3-gaIlon stainless steel-316 autoclave reactor with 9.69 pounds of 35% aqueous sodium bisulfite solution having a pH 6.5-7.0 and then nitrogen purged to exclude air. The reactor was then heated to about 70°C and 2.6 pounds butylsne oxide was added to the reactor at a pressure of 60 psi. The reactants were allowed to react for about 30 minutes at a temperature of about 80°C after which time the pressure in the reactor dropped to about 1 psi. The reaction was allowed to continue for 60 minutes at 95°C then cooled to SO'C and the product solution was removed from the reactor. Upon cooling, shiny crystalline plates separated out of the product solution requiring water be added to dissolve the solids back into solution. The product solution was then analyzed and analysis showed the product solution having a pH of 14.00, about 3.0 % by weight butylene glycol, and both the 2-ethyl, 2-hydroxy ethane 1 -sulfonate and 1 -ethyl 2-hydroxy ethane 1 -sulfonate isomers present.
A second 3-gallon stainless steel-316 autoclave reactor with 9.69 pounds of 35% aqueous sodium bisulfite solution having a pH 5.0-5,5 and then nitrogen purged to exclude air. The reactor was heated to about 70°C and 2.6 pounds of butylene oxide was added to the reaction at a pressure of 60 psi. The reactants were allowed to react at 80°C for 30 minutes after which lime the pressure dropped to about 1 psi. The reaction was allowed to continue for 60 minutes at a temperature of 95°C then cooled to 50°C and the product solution was removed

from the reactor. Upon cooling, shiny crystalline plates separated out of the product solution requiring water be added to dissolve the solids back into solution. The product solution was then analyzed and analysis showed the product solution having a pH of 14.00, about 13.0 % by weight butylene glycol, and both the 2-ethyI, 2-hydroxy ethane I-sulfonate and 1-ethyl 2-hydroxy ethane 1 -sulfonate isomers present in about 14.8:1 molar ratio.
EXAMPLE 3 Preparation of Sodium Cocoyl (Cg to Cig) Methyl Isethionate Ester
A laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple and gas sparging provision) was initially charged with 212 grams (0.98 moles) of a carboxylic acid (hydrogenated coco acid C-110, P&.G Chemicals, Cincinnati, Ohio). Also added to the i-eactor was a total of 165 grams (1.0 mole, solid) of sodium methyl isethionate containing a mixture of the sodium salts of 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl, 2-hydroxy ethane 1-sulfonate. 5.00 grams of the corresponding zinc methylisethionate, in the same isomer proportions as above, was added as a catalyst. The reactor was flushed thoroughly with dry nitrogen and heated to I20'-130°C for 30 minutes to remove any water from the sodium methyl isethionate. The temperature of the reactor contents was then raised to 200° C for 6 hours after which time excess fatty acid is removed by distillation under vacuum at 10 mm Hg to acceptable fatty acid levels ( In a second laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) was added 131.5 grams (0.625 moles) of a carboxylic acid (Coconut fatty acid C-110, P&G Chemicals, Cincinnati, Ohio), a total of 82.5 grams (0.5 moles solids) of sodium methyl isethionate containing a mixture of the sodium salts of 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl 2-hydroxy ethane 1 -sulfonate, and 2.2 grams of zinc citrate as a catalyst. The reactor is flushed thoroughly with dry nitrogen and the solution is heated at 220°C for 6 hours after which time excess fatty acid is removed by distillation under vacuum at 10 mm Hg to acceptable fatty acid levels (
liquid product is removed from the reactor and analyzed and the results showed a product containing 81.5% by weight of the corresponding esters suitable for blending into a personal care cleansing conriposition, 12.0% by weight unreacted carboxylic acid, and 3.9% by weight unreacted sodium methyl isethionate..
EXAMPLE 4 Preparation of Sodium Capryloyl/Caproyl (Cg to Cio) Methyl Isethionate Ester
In a laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 118 grams (0.75 moles) of a carboxylic acid (fatty acid C810, P&G Chemicals, Cincinnati, Ohio) and to the reactor was added a total of 82 grams (0.5 moles solids) of sodium methyl isethionate containing a mixture of the sodium salts of 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl 2-hydroxy ethane 1-sulfonate. 2.2 grams of zinc citrate was added to the mixture as a catalyst. The reactor was flushed thoroughly with dry nitrogen and the reactants heated at 220°C for 6 hours after which time the product was cooled to 160°C - I70°C. The liquid product was removed from the reactor and analyzed and the results showed the white solid had a saponification value of 1 86, actives by two phase titration 2.54 meq/g and containing 86.7% by weight of the corresponding esters suitable for blending into a personal care cleansing composition, 6.7% by weight unreacted carboxylic acid, and 6.5% by weight unreacted sodium methyl isethionate with isomer ratio of secondary vs. primary hydroxyl in 39:1, a clear indication of, as expected, preferential esterification of primary hydroxyl over secondary in the methyl isethionate mixture.
EXAMPLE 5 Preparation of Sodium Caproyl (Cio) Methyl Isethionate Ester
In a laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thennocouple, and gas sparging provision) 108 grams (0.625 moles) of a carboxylic acid (fatty acid C-1095, P&G Chemicals, Cincinnati, Ohio) and to the reactor was added a total of 82.5 grams (0.5 moles solids) of sodium methyl isethionate
containing a mixture of the sodium salts of 2-methyl, 2-hydroxy ethane 1 -sulfonate and 1 -

methyl 2-hydroxy ethane 1-sulfonate. 1.9 grams of zinc citrate was added to the mixture as a catalyst. The reactor was flushed thoroughly with dry nitrogen and the reactants heated to 220°C for 6 hours after which time the product was cooled to 160°C - 170°C. The liquid product was removed from the reactor and analyzed and the resulting white solid contained 82,5% by weight of the corresponding ester suitable for blending into a personal care cleansing composition, 7.7% by weight unreacted carboxylic acid, and 7.4% by weight unreacted sodium methyl isethionate.
EXAMPLE 6
Preparation of Sodium Lauroyl (C12) Methyl Isethionate Ester
In a laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 125 grams (0.625 moles) of a carboxylic acid (fatty acid CI 299, P&G Chemicals, Cincinnati, Ohio) and to the reactor was added a total of 83 grams (0.5 moles solids) of sodium methyl isethionate containing a mixture of the sodium salts of 2-methyl, 2-hydroxy ethane 1-sulfonate and 1-methyl 2-hydroxy ethane 1-sulfonate. 2.2 grams of zinc citrate was added to the mixture as a catalyst. The reactor was flushed thoroughly with dry nitrogen and the reactants heated to 220°C for 6 hours after which time the liquid product was cooled to 160°C - 170°C and poured into a one liter beaker. The resulting white solid was removed from the reactor and analyzed and the results showed a product containing 82.0% by weight of the corresponding ester suitable for blending into a personal care cleansing composition, 15.6% by weight unreacted carboxylic acid, and 3.9% by weight unreacted sodium methyl isethionate.
EXAMPLE 7 Preparation of Sodium Cocoyl (C12 - Cig) Methyl Isethionate Ester
In a laboratory reactor (500 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 137.5 grams (0.625 moles) of a carboxylic acid (fatty acid Emery 627, Cognis, Cincinnati, Ohio) and to the reactor was added a total of 85 grams (0.5 moles solids) of sodium methyl isethionate
(95% by weight) containing a mixture of the sodium salts of 2-methy!, 2-hydroxy ethane 1-

sulfonate and 1-methyl 2-hydroxy ethane 1-sulfonate. 1.2 grams of zinc citrate was added to the mixture as a catalyst. The reactor was flushed thoroughly with dry nitrogen and the reactants heated to 220°C for 6 hours after which time the product solution was cooled to 160°C - 170°C and poured into a one liter beaker. The white solid was removed from the beaker and analyzed and the results showed a product containing 82.2% by weight of the corresponding esters suitable for blending into a personal care cleansing composition, and 7.9% by weight unreacted carboxylic acid.
EXAMPLE 8 Preparation of Sodium Cocoyl (Cg — C\s) Methyl Isethionate Ester
In a laboratory reactor (2000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 780 grams (3.75 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 6.34 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175°C. Sodium methyl isethionate solution in water (sulfonic SMI, 1040 grams, 47%, 3.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225"C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped by dry nitrogen purge for 2-3 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 2-liter beaker under nitrogen and allowed it to cool to room temp. A total 995 grams of light yellow waxy solid ester was obtained. Acid value of this ester was 19.55, i.e., 7.25% and ester's correct sap value of 135.92, i.e., 85.27% and estimated unreacted surfonic SMI was 7.20%
EXAMPLE 9 Preparation of Sodium Cocoyl (Cg - Cig) Ethyl Isethionate Ester

In a laboratory reactor (2000 mi round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 800 grams (3.85 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 7.00 grams of zinc oxide (ZnO, 0.50 wt.%) and 528g of sodium ethyl isethionate solid (3.00 moles) to the reactor and heated slowly with stirring mechanically under nitrogen to a temperature of 200-225"C. over 60-70 minutes and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215'*C. The excess fatty acid was stripped by dry nitrogen purge for 2-3 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 2-liter beaker under nitrogen and allowed it to cool to room temp. A total 1 100 grams of colorless waxy solid ester was obtained. Acid value of this ester was 22.80, i.e., 8.62% and ester's correct sap value of 127.10, i.e., 83.83% and estimated unreacted surfonic SMI was 7.20%.
EXAMPLE 10 Preparation of Sodium Cocoyl (Cg - C|g) Methyl Isethionate Ester
In a laboratory reactor (2000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 780 grams (3.75 moles) of a carboxylic acid (fatty acid C-101, P&G, Cincinnati, Ohio) and 6.30 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175"C. Sodium methyl isethionate solution in water (surfonic SMI, 1040 grams, 47%, 3.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225'C and continued for 4 hours and then the excess fatty acid was stripped by dry nitrogen purge for 2-3 hours to lower fatty acid to a desired level, below 10%, preferably 6-8%. A sample was taken for acid value and was considered to be substantially complete if it was below 30. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into 2-liter beaker under nitrogen and allowed it to cool to room temp. A total 934 grams of waxy solid ester was obtained. Acid value of this ester was 26.06, i.e..

9.66% and ester's correct sap value of 128.65, i.e., 80.71% and estimated unreacted surfonic SMI was 9.50%.
EXAMPLE 11 Preparation of Sodium Cocoyl (Cg - Cis) Methyl Isethionate Ester
In a. laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams ' of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175"C. Sodium methyl isethionate solution in water (surfonic SMI, 352.20 grams, 46%, 1.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped under vacuum at 175-200 mmHg over 1-2 hours with nitrogen leak into the system to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 341 grams of light yellow waxy solid ester was obtained. Acid value of this ester was 21.45, i.e., 7.95% and ester's correct sap value of 115.82, i.e., 72.66% and estimated unreacted surfonic SMI was 12.99%.
EXAMPLE 12 Preparation of Sodium Cocoyl (Cg - Cig) Methyl Isethionate Ester (10 niole% excess fatty acid)
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 228.80 grams (1.10 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.00
grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred

mechanically to a temperature of !70-175"C. Sodium methyl isethionate solution in water (surfonic SMI, 352.20 grams, 46%, 1.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped by purging with nitrogen for 1-2 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 340 grams of light yellow waxy solid ester was obtained. Acid value of this ester was 23.52, i.e., 8.72% and ester's correct sap value of 119.72, i.e., 75.11% and estimated unreacted surfonic SMI was 12.86%.
EXAMPLE 13 Preparation of Sodium Cocoyl (Cg - Cig) Methyl Isethionate Ester (5 mole% excess fatty acid)
>
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an
addition funnel, a condenser, a thermocouple, and gas sparging provision) 218.40 grams (1.05 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.00 grams of zinc oxide (ZnO, 0-50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of ]70-175°C. Sodium methyl isethionate solution in water (surfonic SMI, 352.20 grams, 46%, 1.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225"C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped by purging with nitrogen for 1-2 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 356.20 grams of light yellow waxy solid ester was obtained. Acid value of this ester was 48.11, i.e.. 17.84% and

ester's correct sap value of 95.04, i.e., 59.62% and estimated unreacted surfonic SMI was 18.36%,
EXAMPLE 14 Preparation of Sodium Cocoyl (Cg — Ctg) Methyl Isethionate Ester (No excess fatty acid)
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 208.0 grams (1.00 moles) of a carboxylic acid (fatty acid Emery 626, Cognis,, Cincinnati, Ohio) and 1.90 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175"C. Sodium methyl isethionate solution in water (surfonic SMI, 352.20 grams, 46%, 1.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225^*0 and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped by purging with nitrogen for 1-2 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 346.40 grams of light yellow waxy solid ester was obtained. Acid value of this ester was 34376, i.e., 12.74% and ester's correct sap value of 114.28, i.e., 71.69% and estimated unreacted surfonic SMI was 13.24%.
EXAMPLE 15 Preparation of Sodium Oleyl Methyl Isethionate Ester
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 353 grams (1.25 moles) of oleic acid and 2.60 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of \10-\15°C. Sodium methyl isethionate solution in water (surfonic SMi, 352.20 grams, 46%, 1.0 moles) was added slowly

over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 230°C and continued for 6 hours. The reaction mixture becomes completely homogeneous around 215-220°C. The excess fatty acid was stripped with nitrogen sweep for 2-3 hours to lower the acid below 10%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1 -hter beaker under nitrogen and allowed it to cool to room temp. A total 412 grams of yellow waxy solid ester was obtained. Acid value of this ester was 21.0, i.e., 10.57% and ester's correct sap value of 113.00, i.e., 69.94% and estimated unreacted surfonic SMI was 11.82%.
EXAMPLE 16 Preparation of Sodium CocoyI (CI 2 - Cig) Methyl Isethionate Ester
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 275 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 627, Cognis, Cincinnati, Ohio) and 4.40 grams of zinc oxide (ZnO, 1.00 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175"C. Sodium methyl isethionate solution in water (surfonic SMI, 352.20 grams, 46%, 1.0 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as surfonic SMI addition continued. After the addition of surfonic SMI was completed, the reaction mixture was heated slowly over 30-45 minutes to 220°C and continued for 6 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped with nitrogen purge for 2-3 hours to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 361 grams of light yellow waxy soHd ester was obtained. Acid value of this ester was 21.0, i.e., 8.24% and ester's correct sap value of 132.80, i.e., 86.18% and estimated unreacted surfonic SMI was 6.20%

Blend Preparations:
EXAMPLE 17 Preparation of 9:1 blend of Sodium Cocoyl (Cg - C|g) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition ftinnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175°C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 317.00 grams, 46%, 0.90 moles) and sodium isethionate solution (surfonic SI, 38.00 grams, 57%, 0.10 moles) was added slowly ovei- 60-70 minutes at a temperature of 175-180°C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMl/Sl addition continued. After the addition of surfonic SMI/SI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225^C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215'C. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 362 grams of almost colorless soft solid ester was obtained. Acid value of this ester was 16.96, i.e., 6.29% and ester's correct sap value of 134.43, i.e.. 84.01% and estimated unreacted surfonic SMI+Sl was 7.16%
EXAMPLE 18 Preparation of 8:2 blend of Sodium Cocoyl (Cg — Cig) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
Iri a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25
moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams

of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-175"C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 282.00 grams, 46%, 0.80 moles) and sodium isethionate solution (surfonic SI, 52.00 grams, 57%, 0.20 moles) was added slowly over 60-70 minutes at a temperature of 120-130"C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMl/SI addition continued. After the addition of surfonic SMI/SI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225'C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215**C. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it. to cool to room temp. A total 362 grams of almost colorless soft solid ester was obtained. Acid value of this ester was 23.51, i.e.. 8.72% and ester's correct sap value of 131.71, i.e.. 81.99% and estimated unreacted surfonic SMI+SI was 8.06%
EX-AMPLE 19 Preparation of 7:3 blend of Sodium Cocoyl (Cg - C\%) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 150-155°C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 247.00 grams, 46%, 0.70 moles) and sodium isethionate solution (surfonic SI, 78.00 grams, 57%, 0.30 moles) was added slowly over 60-70 minutes at a temperature of 125-145'C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend-.of surfonic SMl/SI addition continued. After the addition of surfonic SMI/SI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 170-175°C. The excess fatty acid was stripped with

nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 355 grams of almost colorless soft solid ester was obtained. Acid value of this ester was 20.53, i.e., 7.61% and ester's correct sap value of 147.69, i.e., 91.56% and estimated unreacted surfonic SMI+SI was 3.85% .
EXAMPLE 20 Preparation of 6:4 blend of Sodium Cocoyl (Cg - Cig) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 140-145'*C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 211.30 grams, 46%, 0.60 moles) and sodium isethionate solution (surfonic SI, 103.80 grams, 57%, 0.40 moles) was added slowly over 40-50 minutes, at a temperature of 130-150°C at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/Sl addition continued. After the addition of surfonic SMl/Sl was completed. The reaction mixture becomes completely homogeneous around 160-165"C. The reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 360.30 grams of almost colorless solid ester was obtained. Acid value of this ester was 21.25, i.e., 7.881% and ester's correct sap value of 139.23, i.e.. 85.97% and estimated unreacted surfonic SMl+Sl was 6.31%.

EXAMPLE 21 Preparation of 5:5 biend of Sodium Cocoyl (Cg - C|g) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 140-145°C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 176.0 grams, 46%, 0.50 moles) and sodium isethionate solution (surfonic SI, 130.0 grams, 57%, 0.50 moles) was added slowly over 40-50 minutes at a temperature of 132-160°C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/Sl addition continued. After the addition of surfonic SMI/SI was completed. The reaction mixture becomes completely homogeneous around ISO-ISS^C. The reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 363.50 grams of almost colorless solid ester was obtained. Acid value of this ester was 22.78, i.e., 8.45% and ester's correct sap value of 133.39, i.e., 82.03% and estimated unreacted surfonic SMI+SI was 8.0%.
EXAMPLE 22 Preparation of 4:6 blend of Sodium Cocoyl (Cs - Cjj) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition ftmnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred
mechanically to a temperature of 140-145°C. A blend of Sodium methyl isethionate solution

in water (surfonic SMI, 140.87 grams, 46%, 0.40 moles) and sodium isethionate solution (surfonic SI, 155.70 grams, 57%, 0.60 moles) was added slowly over 40-45 at a temperature of 140-157°C and minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/SI addition continued. After the addition of surfonic SMI/SI was completed. The reaction mixture becomes completely homogeneous around ISO-ieS^C. The reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 364 grams of almost colorless solid ester was obtained. Acid value of this ester was 22.69, i.e., 8.41% and ester's correct sap value of 140.90, i.e., 86.30% and estimated unreacted surfonic SMl+SI was 6.05% .
EXAMPLE 23 Preparation of 3:7 blend of Sodium Cocoyl (Cg - Cig) Methyl Isethionate (SCMI) and sodium cocoy! isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2-10 grams of zinc oxide (ZhO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 145-155°C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 105.65 grams, 46%, 0.30 moles) and sodium isethionate solution (surfonic SI, 181.75 grams, 57%, 0.70 moles) was added slowly over 40-45 minutes at a temperature of 150-165°C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/SI addition continued. After the addition of surfonic SMI/Sl was completed. The reaction mixture becomes completely homogeneous around 160-165"C. The reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color

formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 370 grams of almost colorless solid ester was obtained. Acid value of this ester was 22.75, i.e.. 8.43% and ester's correct sap value of 136.37, i.e., 83.18% and estimated unreacted surfonic SMI+SI was 7.40%.
EXAMPLE 24 Preparation of 2:8 blend of Sodium Cccoyl (Cg - C|g) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 155-165"C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 70.40 grams, 46%, 0.20 moles) and sodium isethionate solution (surfonic SI, 207.72 grams, 57%, 0.80 moles) was added slowly over 40-45 minutes at a temperature of 130-177°C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/SI addition continued. After the addition of surfonic SMI/SJ. was completed. The reaction mixture becomes completely homogeneous around 170-175"C. The reaction mixture was heated slowly over 30-45 minutes to 225°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 369 grams of almost colorless solid ester was obtained. Acid value of this ester was 28.89, i.e., 10.71% and ester's correct sap value of 132.67, i.e., 80.60% and estimated.unreacted surfonic SMI+Sl was 8.52%.

EXAMPLE 25 Preparation of 1:9 blend of Sodium Cocoyl (Cg - C\z) Methyl Isethionate (SCMI) and sodium cocoyl isethionate (SCI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition fiinnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 2.10 grams of zinc oxide (ZnO, 0.50 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 155-165'C. A blend of Sodium methyl isethionate solution in water (surfonic SMI, 35.20 grams, 46%, 0.10 moles) and sodium isethionate solution (surfonic SI, 233.70 grams, 57%, 0.90 moles) was added slowly over 40-45 minutes at a temperature of 130-150°C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/SI addition continued. After the addition of surfonic SMI/Sl was completed. The reaction mixture becomes completely homogeneous around 170-175°C. The reaction mixture was heated slowly over 30-45 minutes to 225-240'C and continued for 4 hours. The temperature has gradually increased with time to make it less viscous because of SCI which was considerably higher melting. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level,'below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 348 grams of almost colorless solid ester was obtained. Acid value of this ester was 16.50, i.e.. 6.12% and ester's correct sap value of 138.14, i.e., 83.57% and estimated unreacted surfonic SMI+SI was 7.65% .
EXAMPLE 26 Preparation of 9:1 blend of Sodium Cocoyl (Cg - C\z) Methyl Isethionate (SCMI) and sodium cocoyl Ethyl Isethionate (SCEI) Esters
In a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 1.00 grams of zinc oxide (ZnO, 0.25 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of 170-1 75"C. A blend of Sodium methyl isethionate solution

in water (surfonic SMI, 317.00 grams, 46%, 0.90 moles) and sodium ethyl isethionate (surfonic SEl, 17.60 grams, solid, 0.10 moles) was added slowly over 60-70 minutes at a temperature of 125-136"C and at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SMI/SEl addition continued. After the addition of surfonic SMI/SEI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225'C and continued for 4 hours. The reaction mixture becomes completely homogeneous around 210-215°C. The excess fatty acid was stripped with nitrogen purge over 1-2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to room temp. A total 356.80 grams of almost colorless soft solid ester was obtained. Acid value of this ester was 36180, i.e., 13.64% and Active ester component value 73.37% and estimated unreacted surfonic SMI+SEI was 12.15%
EXAMPLE 27 Preparation of 9:1 blend of Sodium Cocoyl (Cg - Cig) Isethionate (SCMl) and sodium cocoyl Ethyl Isethionate (SCEI) Esters
in a laboratory reactor (1000 ml round bottom flask equipped with a mechanical stirrer, an addition funnel, a condenser, a thermocouple, and gas sparging provision) 260 grams (1.25 moles) of a carboxylic acid (fatty acid Emery 626, Cognis, Cincinnati, Ohio) and 1.00 grams of zinc oxide (ZnO, 0.25 wt.%) were charged into the reactor, heated, and stirred mechanically to a temperature of IVO-ITS^C. A blend of Sodium isethionate solution in water (surfonic SI, 233.68 grams, 57%, 0.90 moles) and sodium ethyl isethionate solution (surfonic SEI, 17.60 grams, solid, 0.10 moles) was added slowly over 60-70 minutes at a rate that keeps the mixture completely liquid. Water was distilled over from the reaction mixture as the blend of surfonic SI/SEl addition continued. After the addition of surfonic SI/SEI was completed, the reaction mixture was heated slowly over 30-45 minutes to 225-230°C and continued for 4 hours. The excess fatty acid was stripped with nitrogen purge over 1 -2 hours with to a desired fatty acid level, below 10%, preferably 6-8%. It was very important to keep air away from the hot reaction mixture to prevent color formation. The viscous and hot reaction product was poured into a 1-liter beaker under nitrogen and allowed it to cool to





Again, the results of this foam test show that foaming can be significantly increased when using a stripped coco fatty acid feed SCMl instead of whole coco fatty acid. The C\2 to C|8 SCMI flash foam height, as well as the stability at 10 minutes, were better than SLES alone and were similar to SLES/betaine performance. Furthermore, the C12 to Cig SCMl was again synergistic with CAPB as shown by the results for Samples 4 and 5 when 25% and 18% by weight of SCMI was replaced with CAPB. Thus, SCMl can be used with other surfactants and still maintain or improve excellent foaming properties.
Finally, as shown in Figures lA and IB, the foam appearance of SCMI was tighter and creamier than SLES or SLS based cleansers making the use of SCMI in personal care cleansers highly desirable. All samples shown in Figures lA and IB were at 0.5% active of surfactant.
EXAMPLE 29
Zein irritation Score
To evaluate the mildness of the products of the present invention, Zein scores were determined for a variety of sulfate and isethionate surfactants and their scores are reported in Table III;
TABLE III

Product Zein Score (mg N/100 ml solution)
Sodium Lauryl Sulfate 527
Sodium Cocoyl Isethionate 254
Sodium Cocoyl Methyl Isethionate 147
Sodium Cocoyl Ethyl Isethionate 104
Sodium Lauroyl Isethionate 160
Sodium Lauroyl Methyl Isethionate 134
Sodium Lauroyl Ethyl Isethionate 187
From these in vitro results, the methyl and ethyl isethionates of the present invention were expected to be less irritating and therefore milder than sodium cocoyl isethionate which has











limitations of any one or more of the independent claims, with the remaining dependent claims in their original text being read and applied to any independent claim so modified. This also includes combination of the features and/or limitations of one or more of the independent claims with the features and/or limitations of another independent claim to arrive at a modified independent claim, with the remaining dependent claims in their original text being read and applied to any independent claim so modified. Accordingly, the presently disclosed invention was intended to cover all such modifications and alterations, and was limited only by the scope of the claims which follow, in view of the foregoing and other contents of this specification. Throughout this specification, various percentages have been set forth and these percentages all refer to percent by weight, unless set-forth to the contrary.
Blend Solubility Experiments:
Surfonic SCMl has demonstrated its ability to enhance the solubility of SCI and AGS-1214 in formulations which couldn't have been possible otherwise. SCMl could be used as primary and/or secondary surfactant to enhance the performance and reduce the skin irritation levels. The formulations below demonstrate these but not limited to them only. The following are example formulations having SCMl, SCI, and AGS-1214P mixtures.
EXAMPLE 32
A reduced irritation formulation using SCMl and SLS was prepared as follows. The
following components were added:
Ingredient Amount (% by weight)
SCMl Solution (30% solids) 30.50
SLS Solids 2.00
CapB (35% solids) 2.50
KCl Solid 1.00
Water and Preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to SO-SS^C to dissolve all solids and cooled to about 30"C. Solid KCl was added and mixed well to desired viscosity and then added.desired preservative. The clear viscous liquid had a viscosity of 2760°Cps@ 30 rpm. Spindle # 3 and had a pH of 6.30

EXAMPLE 33 A reduced irritation formulation using SCMI and AGS-I2I4P was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 30.S0
AGS-1214P (57% solids) 9.00
CapB (35% solids) 2.50
Cocoamide MEA 2.00
KCl solid 1.00
Water and preservative QstolOO,
and then all of the components were weighed into a beaker and wanned up to 50-55°C to dissolve all solids and cooled to about 30"C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 17972cps@ 5 rpm. Spindle # 3 and had a pH of 6.30
EXAMPLE 34 A reduced irritation formulation using SCMI and SCI was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 30.00
SCI (solid) 5.00
CapB (35% solids) 2.00
Cocoamide MEA 2.00
KCl solid 0.50
Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and wanned up to SO-SS^C to dissolve all solids and cooled to about SCC. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 5273cps@ 5 rpm. Spindle # 3 and had a pH of 6.50

EXAMPLE 35
A reduced irritation formulation using SCMl, SLS and Gello Gelatin was prepared as
follows. The following components were added:
Ingredient Amount (% by weight)
SCMl solution (30% solids) 40.00
SLS (solids) 2.00
CapB (35% solids) 2.00
Cocoamide ME A 2.00
KCl solid LOO
1% gello gelatin Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55"C to dissolve all solids and cooled to about 30°C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 3363cps@ 30 rpm. Spindle # 3 and had a pH of 6.30
EXAMPLE 36
A. reduced irritation formulation using SCMl, AGS-1214P and Gello Gelatin was prepared as
follows. The following components were added:
Ingredient Amount (% by weight)
SCMl solution (30% solids) 30.00
AGS-1214P (57% solids) 5.00
CapB (35% solids) 2.00
Cocoamide MEA 2.00
KCl solid 0.25
2% gellogelatin Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 1408cps@ 30 rpm. Spindle # 3 and had a pH of 6.30

EXAMPLE 37 A reduced irritation formulation using SCMI and SCI was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 25.00
SCI (solids, 85% ester) 4.70
CapB (35% solids) 2.00
CocoamideMEA 2.00
KCl solid 1.00
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and wanned up to 50-55°C to dissolve all solids and cooled to about 30°C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 880°Cps@ 30 rpiB. Spindle # 3 and had a pH of 6.50
EXAMPLE 38
A reduced irritation formulation using SCMI, SLS and Cello Gelatin was prepared as
follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 25.00
AGS-1214P (57% solids) 10.00
CapB (35% solids) 2.00
CocoamideMEA 2.00
KCl solid 0.50
1 % gellogelatin Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-5 5°C to dissolve all solids and cooled to about 30'C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of leOO^Cps® 30 rpm. Spindle # 3 and had a pH of 7.00.

EXAMPLE 39 A reduced irritation formulation using SCMI, SCI, and AGS-1214P was prepared as follows. The following components were added;
Ingredient Amount (% by weight)
SCMI (30% solids) 25.00
SCI solid (85% ester) 3.00
AGS.1214P (57% solids) 5.00
CapB (35% solids) 2.00
Cocamide MEA 2.00
KCl (solid) 1.00
Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. Solid KCl was added and mixed well to desired viscosity and then added desired preservative. The clear viscous liquid had a viscosity of 10582cps@ 10 rpm. Spindle # 3 and had apH of 6.50
EXAMPLE 40 A reduced irritation formulation using SCMI, SLES and Kelzan ST was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 30.00
SLES (70% solids) 2.00
CapB (35% solids) 2.00
Cocoamide MEA 2.00
KCl solid 0.00
2% Kelzan ST in Water and preservative Qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired preservative. This not so clear viscous liquid had a viscosity of 1770°Cps@ 20 rpm. Spindle # 3 and had a pH of 7.10.

EXAMPLE 41 A reduced irritation formulation using SCMI and SLS was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI solution (30% solids) 25.00
SLS (70% solids) 4.00
CapB (35% solids) 2.00
Cocoamide MEA 2.00
KCl solid 1.00
Water and preservative QstolOO,
and then all of the components were weighed into a beaker and warmed up to 50-5S'C to dissolve all solids and cooled to about 30*'C. KCl was added, mixed well and measured viscosity and then added desired preservative. This clear viscous liquid had a viscosity of 1374cps@ 60 rpm. Spindle # 3 and had a pH of 6.50.
EXAMPLE 42 A reduced irritation formulation using SCMI and AGS-I2I4P was prepared as follows. The following components were added:
Ingredient Amoxxnt (% by weight)
SCMI solution (10% solids) 30.00
AGS-1214P (57% solids) 6.00
CapB (35% solids) 1.00
Cocoamide MEA 1.00
KCl solid 1.25
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55**C to dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired preservative. This clear viscous liquid had a viscosity of 2238cps@ 10 rpm. Spindle # 3 and had a pH of 6.50.
EXAMPLE 43 A reduced irritation formulation using SCMI and SOMI was prepared as follows. The following components were added;

Ingredient Amount (% by weight)
SCMl solution (10% solids) 71.00
SOMI (sodium oleyl methylisethionate, 25.00
10% solids)
CapB (35% solids) 2.00
Cocoamide MEA 2.00
KCl solid 0.25
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to
dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired
preservative. This clear viscous gel like material had a viscosity of 3539cps@ 20 rpm.
Spindle # 3 and had a pH of 6.50.
EXAMPLE 44 A reduced irritation formulation using SCMI/SC] blend and SCI was prepared as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (9:1) solid (84.0% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empicol SDDAJEF (35%) 3.00
Glycereth 26 3.00
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to
dissolve all solids and cooled to about 30"C. and measured viscosity and then added desired
preservative. This clear viscous material had a viscosity of 433cps@ 100 rpm. Spindle # 3
and had a pH of 7.47 and adjusted to 5.60 with 20% citric acid solution. It remained clear at
7C for three days.
EXAMPLE 45 A reduced irritation formulation using SCMI/SCI blend, SLES and Kelzan ST was prepared as follows. The following components were added:

Ingredient Amount (% by weight)
SCMl+SCI (8:2) solid (82.0% active) 5.10
Empigen BR (A&W, 35%)) 12.00
EmpigenCDR-60(A&W, 35%) 3.00
Empicol SDD/UEF (35%) 3.00
Glycereth 26 3.00
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to
dissolve all solids and cooled to about SCC. and measured viscosity and then added desired
preservative. This clear viscous material had a viscosity of 365°Cps@ 100 rpm. Spindle # 3
and had a pH of 6.64 and was lowered with 20% citric acid to 5.58. It remained clear at 7C
for three days.
EXAMPLE 46 A reduced irritation formulation using SCMI/SCl blend, SLES and Kelzan ST was prepared as follows. TTie following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (7:3) solid (89.0% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empicol SDD/UEF (35%) 3.00
Glycereth 26 3.00
Water and preservative qs to 100,
and then all of the components were weiglied into a beaker and warmed up to 50-55"C to
dissolve all solids and cooled to about 30'*C. and measured viscosity and then added desired
preservative. This clear viscous material had a viscosity of 202cps@ 100 rpm. Spindle # 3
and had a pH of 7.41 and was lowered with 20% citric acid to 5.60. Viscosity was increased
with 0.50g of KCl to 2819cps@20 rpm. It remained clear at 7C for three days.
EXAMPLE 47 A reduced irritation formulation using SCMl/SCI blend, SLES and Kelzan ST was prepared as follows. The following components were added:

Ingredient Amount (% by weight)
SCMI+SCI (6:4) solid (86.0% active) 5.00
Empigen BR (A&W, 3 5%)) 10.00
Empigen CDR-60 (A«&W, 35%) 5.00
Empicol SDD/UEF (35%) 3.00
Glycereth26 3.00
KClsoHd 0.60
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to
dissolve all solids and cooled to about 30°C- and measured viscosity and then added desired
preservative. This clear viscous material had a viscosity of 136cps@ 100 rpm. Spindle # 3
and had a pH of 7.40 and was lowered with 20% citric acid to 5.54. Viscosity was increased
with KCl to 1782cps@20 rpm. It remained clear at 7C for three days. No phase separation
even after four freeze and thaw cycles.
EXAMPLE 48
A reduced irritation formulation using SCMl/SCI blend, SLES and Kelzan ST was prepared
as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (5:5) solid (82.0% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empicol SDD/UEF (35%) 3.00
GIycereth26 3.00
ICCI solid 0.50
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired preservative. This clear viscous materia! had a viscosity of 305'Cps(g 100 rpm. Spindle #3 and had a pH of 7.32 and was lowered with 20% citric acid to 5.56. Viscosity was increased with KCl to 1674cps@20 rpm. It remained clear at 7C for three days. No phase separation even after four freeze and thaw cycles. Solids 15.30%

EXAMPLE 49
A reduced irritation formulation using SCMI/SCI blend, SUES and Kelzan ST was prepared
as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (4:6) solid (86.30% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empicol SDD/UEF (35%) 3.00
Glycereth26 3.00
KCl solid 0.50
Water and preservative qs to ] 00,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired preservative. This clear viscous material had a viscosity of 199cps@ 100 rpm. Spindle#3 and had a pH of 7.18 and was lowered with 20% citric acid to 5.46. Viscosity was increased with K.C1 to 3713cps@20 rpm. It remained clear at 7C for three days. No phase separation even after four freeze and thaw cycles. Solids 15.50%
EXAMPLE 50
A reduced irritation formulation using SCMI/SCI blend, SLES and Kelzan ST was prepared
as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (3:7) solid (83.20% active) 5.00
Empigen BR (A«&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empicol SDD/UEF (35%) 3.00
Glycereth26 3.00
KCl solid 0.50
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55"C to dissolve all solids and cooled to about 30"C. and measured viscosity and then added desired

preservative. This clear material was mixed with KCI and has a viscosity of 4751cps@ 20 rpm. Spindle # 3 and had a pH of 7.27 and was lowered with 20% citric acid to 5.65. It remained clear at 7C for three days. No phase separation even after four freeze and thaw cycles. Solids 16.30%
EXAMPLE 51
A reduced irritation formulation using SCMl/SCIblend, SLES and Kelzan ST was prepared
as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (2:8) solid (80.60% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
EmpicolSDD/UEF(35%) 3.00
Glycereth 26 3.00
KCI solid 0.50
Water and preservative qstolOO
and then all of the components were weighed into a beaker and wanned up to 50-55°C to dissolve all solids and cooled to about 30"C. and measured viscosity and then added desired preservative. This clear material was mixed KCI and has a viscosity of 8242cps@ 10 rpm. Spindle # 3 and had a pH of 7.16 and was lowered with 20% citric acid to 5.50. It remained clear at 7C for three days. No phase separation even after four freeze and thaw cycles and remained clear at room temperature. Solids 16.16%
EXAMPLE 52
A reduced irritation formulation using SCMI/SCl blend, SLES and Kelzan ST was prepared
as follows. The following components were added:
Ingredient Amount (% by weight)
SCMI+SCI (1:9) solid (83.60% active) 5.00
Empigen BR (A&W, 35%)) 10.00
Empigen CDR-60 (A&W, 35%) 5.00
Empico! SDD/UEF (35%) 3.00
Glycereth 26 3.00

KCl solid 0.50
Water and preservative qs to 100,
and then all of the components were weighed into a beaker and warmed up to 50-55°C to dissolve all solids and cooled to about 30°C. and measured viscosity and then added desired preservative. This clear material was mixed with KCl and has a viscosity of 980"Cps@ 100 rpm. Spindle#3 and had a pH of 7.56 and was lowered with 20% citric acid to 4.95. It remained clear at 7C for three days. No phase separation even after four freeze and thaw, cycles and remained clear at room temperature. Solids 15.60%
While the foregoing was directed to various embodiments of the invention, other and further embodiments of the invention maybe devised without departing from the basic scope thereof and the scope thereof is determined by the claims that follow.


What Is Claimed Is:




(ii) a second alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and combinations thereof, wherein the first alkylene oxide is different from the second alkylene oxide; and optionally
(iii) a third alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylenes oxide and combination thereof.
8. The process according to claim 7, wherein the first alkylene oxide comprises propylene oxide and the second alkylene oxide comprises butylene oxide, alternatively the first alkylene oxide comprises propylene oxide and the second alkylene oxide is ethylene oxide.
9. The process of claims 7-8, wherein a molar ratio of the first alkylene oxide to second alkylene oxide is about 1:1 or greater, and optionally a molar ratio of the first alkylene oxide to second alkylene oxide to third alkylene oxide is about 1:1:1 or greater.
10. The process according to claims 1-9, wherein Ri and R4 are individually selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, and combinations thereof.
11. The process according to claims 1 -10, wherein the pH is between about 6 and about 8.
12. A process comprising:
providing a hydroxide solution;
providing sulfur dioxide;
providing at least one alkylene oxide having between 2 and 8 carbon atoms per molecule;




17. The process according to claims 12-16, wherein the at least one alkylene oxide is
selected from the group consisting of propylene oxide, ethylene oxide, butylene oxide, and
combinations thereof.
18. The process according to claims 12-17, wherein the at least one alkylene oxide further
comprises:
(i) a first alkylene oxide selected from the group consisting of ethylene oxide,
propylene oxide, butylene oxide, and combinations thereof;
(ii) a second alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide, and combinations thereof; and optionally
(iii) a third alkylene oxide selected from the group consisting of ethylene oxide, propylene oxide, butylenes oxide and combination thereof, wherein the first alkylene oxide, the second alkylene oxide, and the third alkylene oxide are each different.
19. The process according to claim 18, wherein the first alkylene oxide comprises propylene oxide and the second alkylene oxide comprises butylene oxide, alternatively the first alkylene oxide comprises propylene oxide and the second alkylene oxide is ethylene oxide.
20. The process of claims 18-19, wherein a molar ratio of the first alkylene oxide to second alkylene oxide is about 1:1 or greater, and optionally a molar ratio of the first alkylene oxide to second alkylene oxide to third alkylene oxide is about 1:1:1 or greater.
21. TTie process according to claims 12-20, wherein R| and R4 are individually selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, and combinations thereof.
22. An composition of matter, comprising:
a mixture of
(i) a first isomer having the structure:
wherein R| is a straight chain or branched Ci to Ca alkyl group and R2 is a hydrogen



27. The process of claim 26, wherein the carboxylic acid is selected from the group consisting of coco acid, butyric acid, hexanoic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, gadoleic acid, arachidonic acid, (EPA), behinic acid, eruic acid, (DHA), lignoceric acid, coconut oil, tallow, palm kernel oil, butterfat, palm oil, olive oil, com oil, linseed oil, peanut oil, fish oil, rapeseed oil, and combinations thereof.
28. The process of claims 26-27, wherein the isomeric mixture comprises a methyl isethionate anion, an ethyl isethionate anion, or combinations thereof.
29. The process of claims 26-28, wherein the isometric mixture comprises between about 30 wt.% and about 70 wt.% of the first and second isomers.
30. The process of claims 26-29 further comprising:
contacting the first and isomeric mixture and the carboxylic acid, wherein the temperature is maintained at a range between about 90°C and about 260°C.
3!. The process according to claim 30, further comprising:
applying a vacuum of about 1 mm to about 300 mm Hg at a temperature of about SO'^C to about 25P°C to the acyl alkylisethionate ester composition; and
reducing the amount of carboxylic acid in the surfactant material to less than about 10% by weight.
32. A process for forming composition of matter, comprising:
providing a mixture of alkylisethionates and isethionates at a molar ratio of alkylisethionates to isethionates between about 19:1 and about 1:19;
reacting the mixture with a fatty acid having a carbon chain length between about 4 carbon atoms and about 25 carbon atoms, alternatively between about 6 carbon atoms and about 18 carbon atoms; and
producing a water soluble composition of isethionate esters with at least 30% solubility.

33. The process of claim 32, wherein the fatty acid is selected from the group of saturated
fatty acids, unsaturated fatty acids, pure individual fatty acids, and combinations thereof.
34. The process of claims 32-33, wherein the fatty acid is selected from the group of
consisting of coconut oil, tallow, palm kernel oil, butterfat, palm oil, olive oil, com oil,
linseed oil, peanut oil, fish oil, rapeseed oil, and combinations thereof.
35. The process of claims 32-34, wherein the alkylisethionates are selected from the
group consisting of sodium 2-methyl 2-hydroxyethane sulfonate, sodium 1-methyl 2-
hydroxyethane sulfonate, sodium 2-ethyl 2-hydroxyethane sulfonate, sodium 1-ethyl 2-
hydroxyethane sulfonate, and combinations thereof.


wherein R is a functional group having between about 4 and about 25 carbon atoms; Rj and R4 are independently a straight chain or branched Ci to Ce alkyl group or a hydrogen atom, wherein if R3 is the alkyl group then R4 is the hydrogen, and if R3 is the alkyl group then R4 is the hydrogen.
37. The composition of claim 36, wherein the first ester anion comprises an acyl alkylisethionate ester anion, the second ester anion is an acylisethionate ester anion, and, if present, the third ester anion comprises an acyl alkylisethionate ester anion.
38. The composition of claim 37, wherein the composition comprises from about 70 wt% to about 95 wt% acyl alkylisethionate ester anion(s) and from about 5 wt% to about 30 wt% acylisethionate ester anion, and wherein the composition is water soluble.
39. The composition of claim 38, wherein the acyl alkylisethionate ester anion(s) are a sodium cocoyl alkylisethionate ester anion(s) and the acylisethionate ester anion is a sodium cocoyi isethionate ester anion.
40. The composition of claims 36-39, wherein the melt temperature of the composition ranges from about 170°C to about 250°C.
41. The composition of claim 36-39, wherein the melt temperature of the composition ranges from about 180°C to about 200°C.
42. The composition of claims 37-41, wherein the first ester anion comprises a cocoyl alkylisethionate ester ion, the second ester anion is a cocoyl isethionate ester anion, and, if present, the third ester anion comprises a cocoyl alkylisethionate ester ion.
43. The composition of claims 36-42, wherein the first ester anion comprises a cocoyl methyl isethionate anion, the second ester ion comprises an cocoyl isethionate anion, and if present, the third ester anion comprises a cocoyl ethyl isethionate anion.

44. The composition of claims 36-43, wherein a mixture of the first and second ester anion comprises between about 10 wt.% and about 90 wt.% of the composition.
45. The composition of claims 36-44, wherein R is selected from the group consisting of straight-chain hydrocarbon groups, branched hydrocarbon groups, saturated hydrocarbon groups, unsaturated hydrocarbon groups, and combinations thereof, and R' is selected from the group consisting of straight-chain hydrocarbon groups, branched hydrocarbon groups, saturated hydrocarbon groups, unsaturated hydrocarbon groups, and combinations thereof.
46. The composition of claims 36-45, wherein R is a hydrocarbon having between about 4 and about 25 carbon atoms; R| comprises a methyl fianctional group or an ethyl functional group; R2 is hydrogen; R3 is hydrogen; and R4 comprises a methyl functional group or an ethyl functional group.
47. The composition of claims 36-46 further comprising:
at least one component selected from the group consisting of water, a surfactant, and combinations thereof.
48. The composition of claims 36-47 further comprising:
between about 99.50 molar % and about 0.25 molar % of the first and second ester anions; and
one or more additives selected from the group consisting of: fatty acids, alkyl sulfates, an ethanolamine, an amine oxide, alkali carbonates, water, ethanol, isopropanol, pine oil, sodium chloride, sodium silicate, polymers, alcohol alkoxylates, zeolites, perborate salts, alkali sulfates, enzymes, hydrotropes, dyes, fragrances, preservatives, brighteners, builders, polyacrylates, essential oils, alkali hydroxides, water-soluble branched alkylbenzene sulfonates, ether sulfates, alkylphenol alkoxylates, fatty acid amides, alpha olefin sulfonates, paraffin sulfonates, betaines, chelating agents, tallow amine ethoxyiates, polyether amine ethoxylates, ethylene oxide/propylene oxide • block copolymers, alcohol ethylene oxide/propylene oxide low foam surfactants, methyl ester sulfonates, alkyl polysaccharides, N-methyl glucamides, alkylated sulfonated biphenyl oxide, polyethylene glycol, and combinations thereof.

49. A personal care cleanser comprising:
an acyl alkylisethionate ester composition having two or more esters according to the formula:

wherein at least a first ester comprises R having a hydrocarbon group having between about 4 and 25 carbon atoms, Ri and R2 each comprise a straight chain or branched Ci to C(, alkyl group or a hydrogen atom with at least one of R| or R2 comprising the alkyl group and at least one of R| or R2 comprising the hydrogen atom, and at least a second ester comprises R having a hydrocarbon group having between about 4 and 25 carbon atoms, R| comprises a hydrogen atom, R2 comprises a hydrogen atom, and X for the first ester ion and the second ester ion are each selected fi-om the group consisting of hydrogen, an alkali metal, an alkaline earth metal, zinc, aluminum, ammonium, ammonium ions substituted with one or more organic groups, and combinations thereof.
50. The personal care cleanser of claim 49, ftirther comprising at least one component selected from the group consisting of amphoteric surfactant; zwitterionic surfactant; anionic surfactant; nonionic surfactant; cationic surfactant; water and combinations thereof.
51. The personal care cleanser of claims 49-50, wherein the first ester is an acyl alkylisethionate ester and the second ester is an acylisethionate ester.
52. The personal care cleanser of claims 49-51, wherein the first ester is a sodium cocoyi alkylisethionate ester and the second ester is a sodium cocoyi isethionate ester.
53. The persona! care cleanser of claims 49-52, wherein the first ester comprises sodium cocoyi methyl isethionate, sodium cocoyi ethyl isethionate, or combinations thereof, and the second ester comprises sodium cocoyi isethionate.

54. The composition of claims 49-53, wherein the composition comprises between about
5 wt.% and about 70 wt.% of the first and second ester anions.
55. The composition of matter of claims 49-54, wherein the acyl alkylisethionate ester
composition is present in an amount ranging between about 1% by weight to about 60% by
weight.
56. The composition of matter of claims 49-55, wherein the composition of matter is a
shampoo, baby shampoo, baby wipe, children wipe, make-up remover tissue, shower gel,
foam bath, liquid soap, soap bar, syndet bar, or acne wash.

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Patent Number 269488
Indian Patent Application Number 5932/CHENP/2008
PG Journal Number 44/2015
Publication Date 30-Oct-2015
Grant Date 26-Oct-2015
Date of Filing 31-Oct-2008
Name of Patentee HUNTSMAN PETROCHEMICAL LLC
Applicant Address 10003 WOODLOCH FOREST DRIVE, THE WOODLANDS, TEXAS 77380,
Inventors:
# Inventor's Name Inventor's Address
1 ANANTANENI, PRAKASA, RAO, 13019 PARTRIDGE BEND DRIVE, AUSTIN, TX 78729,
2 SMITH, GEORGE, A., 75 NORTH CONCORD VALLEY CIRCLE, THE WOODLANDS TX 77382,
3 RENNER, MARTIN, J., 31 WIND RIVER DRIVE, CONROE, TX 77384,
PCT International Classification Number C11D 1/06
PCT International Application Number PCT/US07/10519
PCT International Filing date 2007-05-01
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/797,055 2006-05-02 U.S.A.
2 10/586,027 2006-07-13 U.S.A.