Title of Invention	" PROCESS FOR MAKING A SYNTHETIC LAUNDRY DETERGENT BAR COMPOSITION"
Abstract	The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized synthetic detergent active; adding a divalent metal compound to the neutralized active and optionally adding other optional components, and forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials. The bars have improved physical properties, such as appropriate bar hardness and reduced smearing

Title of Invention

" PROCESS FOR MAKING A SYNTHETIC LAUNDRY DETERGENT BAR COMPOSITION"

Abstract

The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized synthetic detergent active; adding a divalent metal compound to the neutralized active and optionally adding other optional components, and forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials. The bars have improved physical properties, such as appropriate bar hardness and reduced smearing

Full Text	FIELD This invention relates to a process for making a laundry detergent bar composition containing phosphate materials. BACKGROUND In societies where mechanical washing machines are not common, laundry detergent bars comprising synthetic organic surfactants and detergency builders are used in the laundering of clothes. Technical developments in the field of laundry detergent bars have concerned formulating bars which are effective in cleaning clothes; which have acceptable sudsing characteristics in warm and cool water and in hard and soft water; which have acceptable in-use wear rates, hardness, durability, and feel; which have low smear; which have the appropriate level of sudsing; which are mild to the skin; and which have a pleasing odor and appearance. Methods for making such laundry detergent bars are also well known in the art. It is known in the art to use or make a structuring system In the process for making a bar, so that the resultant bar has appropriate physical properties. A common material used for such structuring system includes siliceous materials, such as aluminosilicate, silica, silicates, and clays. There is a continuing need to find alternative methods for making laundry bar compositions with Improved physical properties, In addition, there is a continuing need to find such bar process methods which are less expensive, so that consumers can enjoy better value for their purchases. It has now been found that an improved process for making laundry bar compositions containing phosphate materials and divalent metals results in bars having better physical properties, better cleaning performance, as well as improved mildness properties. None of the existing art provides all of the advantages and benefits of the present invention. SUMMARY The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized synthetic detergent active; adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and optionally, adding other optional components, and forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials. These and other features, aspects, and advantages of the present invention will become evident to those skilled in the art from a reading of the present disclosure. DETAILED DESCRIPTION While this specification concludes with claims distinctly pointing out and particularly claiming that which is regarded as the invention, it is believed that the invention can be better understood through a careful reading of the following detailed description of the invention. In this specification, all percentages, ratios, and proportions are by weight, all temperatures are expressed in degrees Celsius, molecular weights are in weight average, and the decimal is represented by the point (.), unless otherwise indicated. As used herein, "comprising" means that other steps and other ingredients which do not affect the end result can be added. This term encompasses the terms "consisting of" and "consisting essentially of". All cited references are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention, The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized detergent active; adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and optionally, adding other optional components, and forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials. The laundry detergent bars produced by the process of the present invention have improved physical properties. Improved physical properties include but are not limited to the following: appropriate bar hardness, reduced smearing, reduced mushiness, and improved overall appearance of the bar when both wet and dry. In one particular instance, a bar when is exposed to the wash water forms a creamy layer on the outside of the bar, so that when the consumer uses the bar, it is smooth to the hands. Although the bar is substantially free of siliceous materials, the bars made by the process of the present invention have good physical properties. By using divalent metal compounds and phosphate materials and not siliceous materials in the process of the present invention, the bar formulation cost is decreased while still retaining good bar physical properties, Process The preferred process of the present invention is described below. The detergent bars can be processed in conventional soap or detergent bar making equipment with some of all of the following key equipment:blender/mixer, mill or refining plodder, two-stage vacuum plodder, logo printer/cutter, cooling tunnel and wrapper. In a preferred process, the raw materials are mixed in the blender. An acid surfactant, such as alkyl benzene sulfonic acid, is reacted with alkaline inorganic salts to complete neutralization, the amount of alkaline inorganic salt being at least sufficient to completely neutralize the acid. In an alternate process, neutralized surfactant is added in the blender. The divalent metal compound is added to a neutralized detergent active. The detergent active should be substantially neutralized so that any reaction between the divalent metal compound and detergent active can be minimized, or preferably, eliminated. Although not wanting to be limited by theory, it is believed that if the acid detergent active and divalent metal compound react, the resultant salt does not act as a surfactant, but instead acts to depress the cleaning and sudsing performance of the bar Composition. The phosphate material is also added to the mixer. If using an acid form of detergent active, substantially all of the phosphate material is preferably added before neutralization of the detergent active Is substantially completed, and the divalent metal is added after neutralization, it is also acceptable to add part of the phosphate material before and part after the neutralization of the detergent active. If starting with an already neutralized detergent active, the phosphate material can be added at the same time, or after the addition of the divalent metal compound. In another variation of the process the divalent metal compound can be premixed with the phosphate material and then added to the neutralized detergent active. Similarly, it is also possible to add the divalent metal compound in the form of a slurry or suspension, instead of adding it in a powder, or dry form. Although not wanting to be limited by theory, it is believed that the phosphate material and the divalent metal compound forms a complex which acts as a structurant in the bar matrix and therefore, Improves the physical properties of the resultant bar composition. Other optional components are then added to the mixture. Some of the optional components may be present in the mixture when the surfactant, divalent metal compound, and/or the phosphate material is added to the mixture. The composition is substantially free of siliceous materials. The mixing can take from one minute to one hour, with the usual mixing time being from about two to twenty minutes. The blender mix is charged to a surge tank. The product is conveyed from the surge tank to the mill or refining plodder via a multiworm conveyor. After milling or preliminary plodding, the product is then conveyed to a two-stage vacuum plodder, operating at high vacuum, e.g. 600 to 740 mm of mercury vacuum, so that entrapped air/gas is removed. The product is extruded and cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage, Another preferred laundry bar composition is made by the following method; The raw materials are first mixed In a blender. Sodium carbonate and pre-neutralized CFAS is mixed for about 1-2 minutes, in order to make a mixed anlonlc LAS/Alkyl Sulfate surfactant bar composition. This is followed by the addition of linear alkyl benzene sulfonic acid and sulfuric acid (if present in the formulation). The acids are then completely neutralized by the sodium carbonate in the seat of the blender. (The amount of sodium carbonate should be at least an amount sufficient to neutralize the acids,) Sodium trlpolyphosphate is added before the acids are completely neutralized. The materials are mixed for an additional 1-2 minutes after dosing. Once the neutralization reaction is completed, a chelant, If present is added, followed by calcium oxide or calcium hydroxide and other optional surfactants, and any other additional optional components, The mixing can take from one minute to one hour, with the usual mixing time being from about five to ten minutes. As one of the last ingredients, bleach and enzymes are added to the mixture and then mixed for an additional one to five minutes. The composition is substantially free of siliceous materials. The blender mix is charged to a surge tank. The product is conveyed from the surge tank to the mill or refining plodder via a multi-worm conveyor. After milling or preliminary plodding, the product is then conveyed to a two-stage vacuum plodder, operating at high vacuum, e.g. 600 to 740 mm of mercury vacuum, so that entrapped air is removed. The product is extruded and cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage. Composition From the aforementioned process, the present invention employs a number of ingredients to provide a suitable laundry detergent bar product. Detergent active The detergent bars of the present invention contain detergent actives, or surfactants. Typical detergent actives include anionic, nonionic, catlonic, zwitterionic, and amphoteric surfactants. Detergent actives can be included at levels of from about 5% to about 60%, preferably from about 15% to about 30%, and more preferably from about 20% to about 25%, by weight of the total bar composition. The detergent active can be. either an acid form, neutralized form, or mixtures thereof. Anionic synthetic detergent surfactants which are suitable for use herein include the water-soluble salts, preferably the alkali metal, ammonium and alkylotammonium salts of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C 8.18 carbon atoms) such as those produced by reducing the giycerides of tallow or coconut oil; and the sodium and potassium alkyibenzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099 and 2,477,383. Especially valuable are linear straight chain alkyibenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 10 to 18, abbreviated as CI0-18 LAS. The alkali metal salts, particularly the sodium salts of these surfactants are preferred, Alkyibenzene sulfonates and processes for making them are disclosed in U.S. Patent Nos. 2,220,099 and 2,477,383. Mixtures of the above types of anionic surfactants are preferred. Specifically, preferred anionic surfactants are C-1o-18 linear alkyl benzene sulfonates, C1o-18 alkyl sulfates, and mixtures thereof. One preferred composition comprises from about 10% to about 30% LAS, by weight of the total bar composition for a primarily LAS-surfactant based bar. Another preferred composition comprises a mixture of LAS:alkyl sulfate in a ratio of from about 10:90 to about 50:50, preferably from about 20:80 to about 40:60 Other anionic synthetic surfactants suitable for use herein are the sodium alky! glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates. Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat. 3,024,273, Whyte et al., issued March 6, 1962. In addition, suitable anionic synthetic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonlc acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 3 to 20 carbon atoms in the alkane moiety. Amine Oxides are excellent co-surfactants that may be used in alone or in addition to other detergent actives, Preferred types are C12-C18 amine oxides, preferably C14. If included, the level of amine oxide in the final bar composition is from about 1% to about 10%, preferably, from about 2% to about 5%. Other anionic synthetic surfactants suitable for use herein are sodium afkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates. Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat. 3,024,273, Whyte et al., issued March 6, 1962, In addition, optional anionic synthetic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about ,1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the aikane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane moiety. In addition, a hydrotrope, or mixture of hydrotropes, may be present in the laundry detergent bar, Preferred hydrotropes include the alkali metal, preferably sodium, salts of toluene sulfonate, xylene sulfonate, cumene sulfonate, sulfosuccinate, and mixtures thereof. Preferably, the hydrotrope is added to the linear alkyl benzene sulfonic acid prior to its neutralization. The hydrotrope, if present, will preferably be present at from about 0.5% to about 5% of the laundry detergent bar. Divalent metal compound The detergent bars of the present invention contain a divalent metal compound. Divalent metal compounds can be included at levels of from about 0.1% to about 50%, preferably 1% to about 20%, more preferably from about 1 % to about 10%, by weight of the total bar composition, Divalent metal compounds useful in the present invention include divalent metal oxides, chlorides, hydroxides, and mixtures thereof. Examples include calcium oxide, calcium chloride, calcium hydroxide, magnesium oxide, magnesium chloride, magnesium hydroxide, and mixtures thereof. Commercially available materials are useful for the process. Calcium oxide is a preferred divalent metal compound. Calcium oxide can be added as it is, or aa calcium hydroxide. Calcium hydroxide can be either anhydrous or a hydrate Similarly, other divalent metal oxides can be added in its hydroxide form, and can be either anhydrous or a hydrate. The divalent metal compounds are preferably in a fine powder form, with preferably 95% of the material passing through Tyler 300 mesh. The material preferably Is white to off-white in color, free flowing and devoid of any odor. Phosphate materials The detergent bars of the present invention contain a phosphate material. Phosphate materials can be included at levels of from about 5% to about 60%, preferably from about 5% to about 20%, by weight of the total bar composition. Phosphate materials useful in the present invention include phosphate, phosphonate, phosphoric acid, and mixtures thereof. Examples of phosphate include water-soluble alkali-metal salts of phosphates, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof. Preferred phosphates include water-soluble alkali-metal salt of tripolyphosphate alone, or a mixture of tripolyphosphate and pyrophosphate. Especially preferred examples of phosphate include sodium tripolyphosphates (STPP) and tetra sodium pyrophosphates (TSPP), and mixtures thereof. Phosphoric acid can be added as orthophosphoric acid, or meta phosphoric acid or in the form of derivatives such as esters of the phosphoric acid. Phosphoric anhydride can also be used as a phosphate material in the present invention. Phosphonates which may be useful in the present invention include phosphonate chelants. Such chelants include one selected from the group consisting of dlethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methyiene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetraiacetlc acid), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof. Optional Components The bars of the present invention are substantially free of siliceous materials, preferably containing less than about 1%, more preferably not containing any in the bar composition. Siliceous materials include silica in finely divided form, silicates, polymeric silicates and aluminosilicates, and clays. The composition can optionally contain in addition to the phosphate material, non-phosphate material, or non-phosphate detergent builder. Specific examples of non-phosphate, inorganic detergency builders include water-soluble inorganic carbonate and bicarbonate salts. The alkali metal (e.g., sodium and potassium) carbonates and bicarbonates are particularly useful herein. Other specifically preferred examples of builders include polycarboxylates. Sodium carbonate, another optional ingredient, is particularly preferred as a neutralizing inorganic salt for an acid precursor of an anionic surfactant used in such compositions, such as the alkyl ether sulfuric acid and alkylbenzene sulfonic acid. Co-polymers of acrylic acid and maleic acid are preferred in the subject compositions as auxiliary builders. Soil suspending agents can be used. Soil suspending agents can also include water-soluble salts of carboxymethylcellulose and carboxyhydroxymethylcellulose. A preferred soil suspending agent is an acrylic/maleic copolymer, commercially available as Sokolan*, from BASF Corp. Other soil suspending agents include polyethylene glycols having a molecular weight of about 4OO to 10,000, and ethoxylated mono- and polyamines, and quaternary salts thereof. If included, it can .be at levels up to about 5%, preferably about 0.1-1%. The bleach agent in the detergent composition, when included, is preferably at a level from about 0.10% to about 60% by weight; more preferably, from about 1 % to about 50%; most preferably, from about 1 % to about 20%, The bleach agents used herein can be any of the bleachagents useful for detergent compositions in textile cleaning, hard surface cleaning, or other cleaning purposes that are now known or become known. Mixtures of bleach agents can also be used. A useful bleach agent that can be used encompasses percarboxylic acid bleach agents and salts thereof. Suitable examples of this class of agents include magnesium monoperoxyphthalate hexahydrate, the magnesium salt of metachloro perbenzolc acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanediolc acid. Such bleach agents are disclosed in U.S. Patent 4,483,781, Hartman, issued November 20, 1984, U.S. Patent Application 740,446, Burns et al, filed June 3, 1985, European Patent Application 0,133,354, Banks et al, published February 20, 1985, and U.S. Patent 4,412,934, Chung et al, issued November 1, 1983. Highly preferred bleach agents also include 6-nonylamino-6~ oxoperoxycaproic acid as described in U.S. Patent 4,634,551, issued January 6, 1987 to Burns et al. Other peroxygen bleach agents can also be used. Suitable peroxygen bleach compounds include sodium carbonate peroxyhydrate and equivalent "percarbonate" bleaches, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Persulfate bleach (e.g., OXONE, manufactured commercially by DuPont) can also be used. Bleach agents other than oxygen bleach agents are also known in the art and can be utilized herein. One type of non-oxygen bleach agent of particular interest includes photoactivated bleach agents such as the sulfonated zinc and/or aluminum phthalocyanines. See U.S. Patent 4,033,718, issued July 5, 1977 to Holcombe et al. If used, detergent compositions will typically contain from about 0.025% to about 1.25%, by weight, of such bleaches, especially sulfonate zinc phthalocyanlne. An optional useful percarbonate bleach comprises dry particles having an average particle size in the range from about 500 micrometers to about 1,000 micrometers, not more than about 10% by weight of said particles being smaller than about 200 micrometers and not more than about 10% by weight of said particles being larger than about 1,250 micrometers. Optionally, the percarbonate can be coated with silicate, borate or water-soluble surfactants. Percarbonate is available from various commercial sources such as FMC, Solvay and Tokai Denka. When included, the preferred bleach agent for the present invention are those peroxygen bleaching compounds which are capable of yielding hydrogen peroxide in an aqueous solution. These compounds are well known in the art and include hydrogen peroxide and the alkali metal peroxides, organic peroxide bleaching compounds such as urea peroxide, and inorganic persalt bleaching compounds, such as the alkali metal perborates, percarbonates, perphosphates, and the like. Mixtures of two or more such bleaching compounds can also be used, if desired. Preferred peroxygen bleaching compounds to be used in the present invention include sodium perborate, commercially available in the form of mono- and tetra-hydrates, sodium carbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Particular preferred are sodium perborate tetrahydrate, and especially/ sodium perborate monohydrate. Sodium perborate monohydrate is especially preferred because it is very stable during storage and yet still dissolves very quickly in the bleaching solution. Another optional component of the present invention is a detergent chelant. Such chelants are able to sequester and chelate alkali cations (such as sodium, lithium and potassium), alkali metal earth cations (such as magnesium and calcium), and most importantly, heavy metal cations such as iron, manganese, zinc and aluminum. Preferred cations Include sodium, magnesium, zinc, and mixtures thereof. The detergent chelant is preferably a phosphonate chelant, particularly one selected from the group consisting of diethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methylene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetra(acetic acid), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof. Preferably such salts or complexes have a molar ratio of metai ion to chelant molecule of at least 1:1, preferably at least 2:1, The detergent chelant can be included in the laundry bar at a level up to about 5%, preferably from about 0.1% to about 3%, more preferably from about 0.2% to about 2%, most preferably from about 0.5% to about 1,0%. Another optional component of the laundry bar is fatty alcohol having an alkyl chain of 8 to 22 carbon atoms, more preferably from 12 to 18 carbon atoms. A preferred fatty alcohol has an alkyl chain predominantly containing from 16 to 18 carbon atoms, so-called "high-cut fatty alcohol," which can exhibit less base odor of fatty alcohol relative to broad cut fatty alcohols. Typically fatty alcohol, if any, is present in the laundry bar at up to a Ievel of 10%, more preferably from about 0.75% to about 6%, most preferably from about 2% to about 5%. The fatty alcohol is generally added to a laundry bar as free fatty alcohol. However, low levels of fatty alcohol can be introduced into the bars as impurities or as unreacted starting material. For example, laundry bars based on coconut fatty alkyl sulfate can contain, as unreacted starting material, from 0.1% to 3.5%, more typically from 2% to 3%, by weight of free coconut fatty alcohol on a coconut fatty alkyl sulfate basis. Another optional component in the laundry bar Is a dye transfer inhibiting (DTI) ingredient to prevent diminishing of color fidelity and intensity in fabrics. A preferred DTI ingredient can include polymeric DTI materials capable of binding fugitive dyes to prevent them from depositing on the fabrics, and decolorization DTI materials capable of decolorizing the fugitives dye by oxidation. An example of a decolorization DT! is hydrogen peroxide or a source of hydrogen peroxide, such as percarbonate or perborate. Non-limiting examples of polymeric DTI materials include polyvinylpyrridine N-oxide, polyvinylpyrrolidone (PVP), PVP-polyvinylimidazole copolymer, and mixtures thereof. Copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (referred to as "PVPI") are also preferred for use herein. The amount of DTI Included in the subject compositions, if any, is about 0.05-5%, preferably about 0.2-2%. Another optional component in the laundry bar is a fabric softener component. Such materials can be used, if any, at levels of about 0,1% to 5%, more preferably from 0.3% to 3%, and can include: amines of the formula R4R5R6N, wherein R4 is C5 to C22 hydrocarbyl, R5 and R6 are independently C1 to C1o hydrocarbyl. One preferred amine is ditallowmethyl amine; complexes of such amines with fatty acid of the formula R7COOH, wherein R7 is C9 to C22 hydrocarbyl, as disclosed in EP No. 0,133,804; complexes of such amines with phosphate esters of the formula R80-P(0)(OH)-OR9 and HO-P(0)(OH)-OR9 wherein R8 and R9 are independently C1 to C20 alkyl of alkyl ethoxylate of the formula -alkyl-(OCH2CH2); cyclic amines such as imidazolines of the general formula 1-(higher alkyl) amido (lower alkyl)-2-(hlgher alkyl)lmidazoline, where higher alkyl is from 12 to 22 carbons and lower alkyl is from 1 to 4 carbons, such as described in UK Patent Application GB 2,173,827; and quaternary ammonium compounds of the formula R10R11R12R13N+ X-, wherein RIO is alkyl having 8 to 20 carbons, R11 is alkyl having 1 to 10 carbons, R12 and R13 are alkyl having 1 to 4 carbons, preferably methyl, and X is an anion, preferably Cl- or Br, such as C12-13 alkyl trimethyl ammonium chloride. Sodium sulfate is a well-known filler that is compatible with the compositions of this invention. It can be a by-product of the surfactant sulfation and sulfonation processes, or it can be added separately. Calcium carbonate (also known as Calcarb) Is also a well known and often used filler component of laundry bars. Filler materials are typically used, if included, at levels up to 40%, preferably from about 5% to about 25%. Optical brighteners are also optional ingredients in laundry bars of the present invention. Preferred optical brighteners are diamino stilbene, distyrilbiphenyl-type optical brighteners. Preferred as examples of such brighteners are 4,4'-bis{[4-anilino-6-bis(2-hydoxyethyl} amino-1,3,5-trizin-2- yl]amino}stilbene-2f2'-disulfonic acid disodium salt, 4-4'-bis(2-sulfostyryl) biphenyl and 4,4'-bis[(4-anilino-6-morpholino-1 /3/5-triazin-2-yl) amino]siilbene-2,2'-disulfonic acid disodium salt. Such optical brighteners, or mixtures thereof, can be used at levels In the bar of from about 0.05% -1.0%. Dyes, pigments, germicides, and perfumes can also be added to the bar composition. If Included, they are typically at levels up to about 0.5%. Another optional component of the subject invention composition is a photobleach material/ particularly phthalocyanine photobleaches which are described in U.S. Patent 4,033,718 issued July 5, 1977, incorporated herein by reference. Preferred photobleaches are metal phthalocyanine compounds, the metal preferably having a valance of +2 or +3; zinc and aluminum are preferred metals. Such photobleaches are available, for example, under the tradename TINOLUS or as zinc phthalocyanine sulfonate. The photobleach components, if included, are typically in the subject compositions at levels up to about 0.02%, preferably from about 0.001% to about 0.015%, more preferably from about 0.002% to about 0.01%. Another useful optional component of the subject compositions are detergent enzymes. Particularly preferred are lipase, protease, cellulase, amylase, and mixtures thereof. Enzymes, if included, are typically at levels up to about 5%, preferably about 0.5-3%. Another useful optional component which can be used as processing aids include glycerine and coconut monoethano! amide. The detergent composition can optionally contain a polyamine soil release agent related to modified polyamines. See U.S. 5,565,145 issued October 15,1996 to Watson et al. Modified polyethylene!mine polymers may also be included herein. These modified polyethyleneimine polymers comprise backbones that can be either linear or cyclic. The polyamine backbones can also comprise polyamine branching chains to a greater or lesser degree. In general, the polyamine backbones described herein are modified in such a manner that each nitrogen of the polyamine chain is thereafter described in terms of a unit that is substituted, quaternized, oxidized, or combinations thereof. Preferred modified pofyethyleneimine polymers are generally polyalkyleneaminss (PAA's), polyalkyleneimines (PAI's), preferably polyethyleneamine (PEA's), polyethyleneimines (PEI's), or PEA's or PEI's connected by moieties having longer R units than the parent PAA's, PAI's, PEA's or PEI's. A common polyalkyleneamine (PAA) is tetrabutylenepentamine. PEA's are obtained by reactions involving ammonia and ethylene dichloride, followed by fractional distillation. The common PEA's obtained are triethylenetetramine (TETA) and teraethylenepentamine (TEPA). Above the pentamines, i.e., the hexamines. heptamines, octarnines and possibly nonamines, the cogenerically derived mixture does not appear to separate by distillation and can include other materials such as cyclic amines and particularly piperazines. There can also be present cyclic amines with side chains in which nitrogen atoms appear. See U.S. Patent 2,792,372, Dickinson, issued May 14, 1957, which describes the preparation of PEA's. Preferred amine polymer backbones comprise R units that are C2 alkylene (ethylene) units, also known as polyethyleneimines (PEI's), Preferred PEI's have at least moderate branching, that is the ratio of m to n is less than 4:1, however PEI's having a ratio of m to n of about 2:1 are most preferred. Preferred backbones, prior to modification have the general formula: wherein m and n are the same as defined herein above. Preferred PEI's, prior to modification, will have a molecular weight greater than about 200 Daltons. The polyamine soil release agents of the present invention if included in the detergent composition, is included from about 0.01% to about 5%; preferably about 0.3% to about 4%; more preferably about 0.5% to about 2.5%, by weight of the detergent composition. Moisture The final bar composition should have no more than about 15% moisture. The moisture level of the total bar composition can be determined by any methods known in the art by one skilled in the area of laundry bar compositions. One common method is the Bldwell Sterling Distillation method; Another known method is the Karl Fischer Moisture Titration Method. See AOCS official method Dd2a-59 issue 93 and AOCS official method Dd2b-59 issue 89. Bar Physical Properties The bars of the present invention have improved physical properties, including improved in-process and aged hardness of the bar as well as reduced solubility in water during washing. In addition, the bars of the present invention have improved cleaning benefits as well as mildness benefits. he bars of the present invention are sufficiently hard. A preferred test method measures bar hardness after three weeks of aging. Bars are aged for three weeks at 80°F/80 relative humidity (RH). To measure the bar hardness, a needle with a point angle of 43° attached to a force gauge (Control International, Lincolnwood, IL, USA) was forced onto the plane of the bar surface to a depth of 5.8 mm. A preferred bar hardness reading of laundry bar compositions using this test method is about 55-70 Ibs. Bars of the present invention fall within the range. Another method to measure bar hardness is to measure the penetration of a needle through the bar surface under a standard weight for 5 seconds using a cone penetrometer. One such penetrometer is made by Associated Instrument Manufacturers India Pvt. Ltd. (Model number AIM 512). The weight of the rod and the cone is 149 grams and an additional 50 gram weight is placed on the cone. The penetration reading of a fresh bar made as per the present invention will typically be about 20-30 (1/10 mm) and 15-20 (1/10 mm) after 40 minutes. Bars aged about 3 days at ambient conditions will typically have a bar penetration reading of about 5-12 (1/10 mm). Another physical property of interest is the bar solubility in water. One method of determining the bar solubility is to submerge a bar having the following dimensions 75mm x 55mm in 250 ml of water in a beaker for 2 hours, drying the bar at 60 deg. C for 2 hours and then weighing the bar. To have acceptable bar solubility, the difference in weight should be about 5-20 grams for a 125 gram bar (12-16% of the original weight of the bar), more preferably 5-15 grams (4-12% of the original weight of the bar). According to the present invention is provided a process for making a synthetic laundry detergent bar composition comprising the steps of characterized in that: a. providing a neutralized synthetic detergent active such as herin described; b. adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and optionally, adding other optional detergent adjunct components, and c. forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition comprises phosphate materials. The following examples further describe and demonstrate the preferred embodiments within the scope of the present invention. The examples are given solely for the purpose of illustrations, and are not to be construed as limitations of the present invention since many variations thereof are possible without departing from its spirit and scope. Example 1 In order to make 100 kg of finished product/ about 6 kg dry flakes of neutralized NaCFAS (sodium salt of coconut fatty alcohol sulfate), 4 kg of sodium carbonate, 18 kg of sodium tripolyphosphate and 50 kg of sodium sulfate are added to the mixer. The mixer used is a ploughshear kind of mixer (trade name: KM Mixer by Littleford Inc.). The KM Mixer main shaft rpm is adjusted to 130. Hot oil at 60°C is circulated around the jacket of the mixer to minimize any heat loss during the process. The powders added are at ambient temperature. The mixer is started and at the same time, about 11 kg of the neutralized NaCFAS paste is added to the mixer. The paste temperature is in the range of 55-60°C. The mixture is mixed for about 3 minutes. Then, about 7 kg of LAS (linear alkyl benzene suifonate acid and 2.5 kg of sulfuric acid are added to the batch. The mixture is further mixed for about 3 minutes. This is followed by the'addition of 1 kg of C12 coco fatty alcohol, 40 kg of calcium carbonate, and 3 kg of calcium hydroxide. The mixture is mixed for about a minute. This is followed by the addition of optional components such as brighteners, anti-redeposition agents, soil release polymers, etc. After the mixture is further mixed, enzymes are added to the batch and mixed for about 30 additional minutes. The final form of the batch is lumpy. The temperature of the batch at the end of the mixing cycle is about 65-70°C. The mixture is then dropped into a surge tank which continuously feeds to a refiner plodder. The output of the refiner plodder is a detergent mass in the form of noodles which are then fed to a duplex vacuum plodder. A vacuum of about -0.9bar(670mm of Hg) is maintained to remove any entrapped error in the detergent matrix. The bar coming out of the final stage of the duplex vacuum plodder is at 55-60°C, This bar is cooled to about 50°C and then packed into polyethylene wrappers. Various bar compositions (Examples 2 through 4) are prepared by the process of the invention. Examples 2 through 4 have improved physical properties, including acceptable bar hardness, and reduced smearing, (Tabl e Removed) The synthetic laundry detergent bar composition made by the process of the present invention is a synergistic composition wherein the ingredients are reacting synergistically to produce unexpected results. No chemical reaction is taking place. WE CLAIM: 1. A process for making a synthetic laundry detergent bar composition comprising the steps of characterized in that: a. providing a neutralized synthetic detergent active such as herein described; b. adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and optionally, adding other optional detergent adjunct components, and c. forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition comprises phosphate materials. 2. The process as claimed in claim 1, wherein all the phosphate material is added before providing the neutralized active. 3. The process as claimed in claim 1, wherein the synthetic detergent active is selected from the group consisting of anionic, nonionic, cationic, zwitterionic, amphoteric, and mixtures thereof. 4. The process as claimed in claim 1, wherein the divalent metal compound is selected from the group consisting of calcium oxide, calcium hydroxide, calcium chloride, magnesium oxide, magnesium hydroxide, magnesium chloride, and mixtures thereof. 5. The process as claimed in claim 1, wherein a premixture of the divalent metal compound and phosphate compound is formed before adding the premixture to the neutralized active. 6. The process as claimed in claim 1, wherein the phosphate material is selected from the group consisting of phosphate, phosphonate, phosphoric acid, and mixtures thereof. 7. The process as claimed in claim 6, wherein the phosphate material is selected from the group consisting of water-soluble alkali-metal salts of phosphates, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof. 8. A process as claimed in claim 1 wherein said neutralized synthetic detergent active comprises a phosphate material. 9. The process as claimed in claim 8, wherein a peroxygen bleach and an enzyme is further added. 10. A process for making a synthetic laundry detergent bar substantially as hereinbefore described in any of the Examples.

Full Text

FIELD
This invention relates to a process for making a laundry detergent bar composition containing phosphate materials.
BACKGROUND
In societies where mechanical washing machines are not common, laundry detergent bars comprising synthetic organic surfactants and detergency builders are used in the laundering of clothes. Technical developments in the field of laundry detergent bars have concerned formulating bars which are effective in cleaning clothes; which have acceptable sudsing characteristics in warm and cool water and in hard and soft water; which have acceptable in-use wear rates, hardness, durability, and feel; which have low smear; which have the appropriate level of sudsing; which are mild to the skin; and which have a pleasing odor and appearance.
Methods for making such laundry detergent bars are also well known in the art. It is known in the art to use or make a structuring system In the process for making a bar, so that the resultant bar has appropriate physical properties. A common material used for such structuring system includes siliceous materials, such as aluminosilicate, silica, silicates, and clays.
There is a continuing need to find alternative methods for making laundry bar compositions with Improved physical properties, In addition,
there is a continuing need to find such bar process methods which are less expensive, so that consumers can enjoy better value for their purchases. It has now been found that an improved process for making laundry bar compositions containing phosphate materials and divalent metals results in bars having better physical properties, better cleaning performance, as well as improved mildness properties. None of the existing art provides all of the advantages and benefits of the present invention.
SUMMARY
The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized synthetic detergent active; adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof;
and optionally, adding other optional components, and forming into bars;

wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials.
These and other features, aspects, and advantages of the present invention will become evident to those skilled in the art from a reading of the present disclosure.
DETAILED DESCRIPTION
While this specification concludes with claims distinctly pointing out and particularly claiming that which is regarded as the invention, it is believed that the invention can be better understood through a careful reading of the following detailed description of the invention. In this specification, all percentages, ratios, and proportions are by weight, all temperatures are expressed in degrees Celsius, molecular weights are in weight average, and the decimal is represented by the point (.), unless otherwise indicated.
As used herein, "comprising" means that other steps and other ingredients which do not affect the end result can be added. This term encompasses the terms "consisting of" and "consisting essentially of".
All cited references are incorporated herein by reference in their entireties. Citation of any reference is not an admission regarding any determination as to its availability as prior art to the claimed invention,
The present invention is directed to a process for making a synthetic laundry detergent bar composition having the steps of providing a neutralized detergent active; adding a divalent metal compound to the neutralized active, wherein the divalent metal compound is selected from the group consisting of divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and optionally, adding other optional components, and forming into bars; wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition further comprises phosphate materials.
The laundry detergent bars produced by the process of the present invention have improved physical properties. Improved physical properties include but are not limited to the following: appropriate bar hardness, reduced smearing, reduced mushiness, and improved overall appearance of the bar when both wet and dry. In one particular instance, a bar when is exposed to the wash water forms a creamy layer on the outside of the bar, so that when the consumer uses the bar, it is smooth to the hands. Although the bar is substantially free of siliceous materials, the bars made by the process of the present invention have good physical properties. By using divalent metal compounds and phosphate materials and not siliceous materials in the process of the present invention, the bar formulation cost is decreased while still retaining good bar physical properties,
Process
The preferred process of the present invention is described below. The detergent bars can be processed in conventional soap or detergent bar making equipment with some of all of the following key equipment:blender/mixer, mill or refining plodder, two-stage vacuum plodder, logo printer/cutter, cooling tunnel and wrapper.
In a preferred process, the raw materials are mixed in the blender. An acid surfactant, such as alkyl benzene sulfonic acid, is reacted with alkaline inorganic salts to complete neutralization, the amount of alkaline inorganic salt being at least sufficient to completely neutralize the acid. In an alternate process, neutralized surfactant is added in the blender. The divalent metal compound is added to a neutralized detergent active. The detergent active should be substantially neutralized so that any reaction between the divalent metal compound and detergent active can be minimized, or preferably, eliminated. Although not wanting to be limited by theory, it is believed that if the acid detergent active and divalent metal compound react, the resultant salt does not act as a surfactant, but instead acts to depress the cleaning and sudsing performance of the bar Composition.
The phosphate material is also added to the mixer. If using an acid form of detergent active, substantially all of the phosphate material is preferably added before neutralization of the detergent active Is substantially completed, and the divalent metal is added after neutralization, it is also acceptable to add part of the phosphate material before and part after the neutralization of the detergent active. If starting with an already neutralized detergent active, the phosphate material can be added at the same time, or after the addition of the divalent metal compound.
In another variation of the process the divalent metal compound can be premixed with the phosphate material and then added to the neutralized detergent active. Similarly, it is also possible to add the divalent metal compound in the form of a slurry or suspension, instead of adding it in a powder, or dry form.
Although not wanting to be limited by theory, it is believed that the phosphate material and the divalent metal compound forms a complex which acts as a structurant in the bar matrix and therefore, Improves the physical properties of the resultant bar composition.
Other optional components are then added to the mixture. Some of the optional components may be present in the mixture when the surfactant, divalent metal compound, and/or the phosphate material is added to the mixture. The composition is substantially free of siliceous materials. The mixing can take from one minute to one hour, with the usual mixing time being from about two to twenty minutes. The blender mix is charged to a surge tank. The product is conveyed from the surge tank to the mill or refining plodder via a multiworm conveyor.
After milling or preliminary plodding, the product is then conveyed to a two-stage vacuum plodder, operating at high vacuum, e.g. 600 to 740 mm of mercury vacuum, so that entrapped air/gas is removed. The product is extruded and cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage,
Another preferred laundry bar composition is made by the following method; The raw materials are first mixed In a blender. Sodium carbonate and pre-neutralized CFAS is mixed for about 1-2 minutes, in order to make a mixed anlonlc LAS/Alkyl Sulfate surfactant bar composition. This is followed by the addition of linear alkyl benzene sulfonic acid and sulfuric acid (if present in the formulation). The acids are then completely neutralized by the sodium carbonate in the seat of the blender. (The amount of sodium carbonate should be at least an amount sufficient to neutralize the acids,) Sodium trlpolyphosphate is added before the acids are completely neutralized. The materials are mixed for an additional 1-2 minutes after dosing. Once the neutralization reaction is completed, a chelant, If present
is added, followed by calcium oxide or calcium hydroxide and other optional surfactants, and any other additional optional components, The mixing can take from one minute to one hour, with the usual mixing time being from about five to ten minutes. As one of the last ingredients, bleach and enzymes are added to the mixture and then mixed for an additional one to five minutes. The composition is substantially free of siliceous materials. The blender mix is charged to a surge tank. The product is conveyed from the surge tank to the mill or refining plodder via a multi-worm conveyor.
After milling or preliminary plodding, the product is then conveyed to a two-stage vacuum plodder, operating at high vacuum, e.g. 600 to 740 mm of mercury vacuum, so that entrapped air is removed. The product is extruded and cut to the desired bar length, and printed with the product brand name. The printed bar can be cooled, for example in a cooling tunnel, before it is wrapped, cased, and sent to storage.
Composition
From the aforementioned process, the present invention employs a number of ingredients to provide a suitable laundry detergent bar product. Detergent active
The detergent bars of the present invention contain detergent actives, or surfactants. Typical detergent actives include anionic, nonionic, catlonic, zwitterionic, and amphoteric surfactants. Detergent actives can be included at levels of from about 5% to about 60%, preferably from about 15% to about 30%, and more preferably from about 20% to about 25%, by weight of the total bar composition. The detergent active can be. either an acid form, neutralized form, or mixtures thereof.
Anionic synthetic detergent surfactants which are suitable for use herein include the water-soluble salts, preferably the alkali metal, ammonium and alkylotammonium salts of organic sulfuric reaction products having in their molecular structure an alkyl group containing from about 10 to about
20 carbon atoms and a sulfonic acid or sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of acyl groups.) Examples of this group of synthetic surfactants are the sodium and potassium alkyl sulfates, especially those obtained by sulfating the higher alcohols (C 8.18 carbon atoms) such as those produced by reducing the giycerides of tallow or coconut oil; and the sodium and potassium alkyibenzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U.S. Patents 2,220,099 and 2,477,383. Especially valuable are linear straight chain alkyibenzene sulfonates in which the average number of carbon atoms in the alkyl group is from about 10 to 18, abbreviated as CI0-18 LAS. The alkali metal salts, particularly the sodium salts of these surfactants are preferred, Alkyibenzene sulfonates and processes for making them are disclosed in U.S. Patent Nos. 2,220,099 and 2,477,383.
Mixtures of the above types of anionic surfactants are preferred. Specifically, preferred anionic surfactants are C-1o-18 linear alkyl benzene sulfonates, C1o-18 alkyl sulfates, and mixtures thereof. One preferred composition comprises from about 10% to about 30% LAS, by weight of the total bar composition for a primarily LAS-surfactant based bar. Another preferred composition comprises a mixture of LAS:alkyl sulfate in a ratio of from about 10:90 to about 50:50, preferably from about 20:80 to about
40:60
Other anionic synthetic surfactants suitable for use herein are the sodium alky! glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates. Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat. 3,024,273, Whyte et al., issued March 6, 1962.
In addition, suitable anionic synthetic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonlc acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the alkane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about 3 to 20 carbon atoms in the alkane moiety.
Amine Oxides are excellent co-surfactants that may be used in alone or in addition to other detergent actives, Preferred types are C12-C18 amine oxides, preferably C14. If included, the level of amine oxide in the final bar composition is from about 1% to about 10%, preferably, from about 2% to about 5%.
Other anionic synthetic surfactants suitable for use herein are sodium afkyl glyceryl ether sulfonates, especially those ethers of higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulfonates and sulfates. Preparation of alkyl glyceryl ether sulfonates are described in detail in U.S. Pat. 3,024,273, Whyte et al., issued March 6, 1962,
In addition, optional anionic synthetic surfactants include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from about 6 to 20 carbon atoms in the fatty acid group and from about ,1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxyalkane-1-sulfonic acids containing from about 2 to 9 carbon atoms in the acyl group and from about 9 to about 23 carbon atoms in the aikane moiety; water-soluble salts of olefin and paraffin sulfonates containing from about 12 to 20 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3
carbon atoms in the alkyl group and from about 8 to 20 carbon atoms in the alkane moiety.
In addition, a hydrotrope, or mixture of hydrotropes, may be present in the laundry detergent bar, Preferred hydrotropes include the alkali metal, preferably sodium, salts of toluene sulfonate, xylene sulfonate, cumene sulfonate, sulfosuccinate, and mixtures thereof. Preferably, the hydrotrope is added to the linear alkyl benzene sulfonic acid prior to its neutralization. The hydrotrope, if present, will preferably be present at from about 0.5% to about 5% of the laundry detergent bar. Divalent metal compound
The detergent bars of the present invention contain a divalent metal compound. Divalent metal compounds can be included at levels of from about 0.1% to about 50%, preferably 1% to about 20%, more preferably from about 1 % to about 10%, by weight of the total bar composition,
Divalent metal compounds useful in the present invention include divalent metal oxides, chlorides, hydroxides, and mixtures thereof. Examples include calcium oxide, calcium chloride, calcium hydroxide, magnesium oxide, magnesium chloride, magnesium hydroxide, and mixtures thereof. Commercially available materials are useful for the process. Calcium oxide is a preferred divalent metal compound. Calcium oxide can be added as it is, or aa calcium hydroxide. Calcium hydroxide can be either anhydrous or a hydrate Similarly, other divalent metal oxides can be added in its hydroxide form, and can be either anhydrous or a hydrate.
The divalent metal compounds are preferably in a fine powder form, with preferably 95% of the material passing through Tyler 300 mesh. The material preferably Is white to off-white in color, free flowing and devoid of any odor. Phosphate materials
The detergent bars of the present invention contain a phosphate material. Phosphate materials can be included at levels of from about 5% to about 60%, preferably from about 5% to about 20%, by weight of the total bar composition.
Phosphate materials useful in the present invention include phosphate, phosphonate, phosphoric acid, and mixtures thereof. Examples of phosphate include water-soluble alkali-metal salts of phosphates, pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates, and mixtures thereof. Preferred phosphates include water-soluble alkali-metal salt of tripolyphosphate alone, or a mixture of tripolyphosphate and pyrophosphate. Especially preferred examples of phosphate include sodium tripolyphosphates (STPP) and tetra sodium pyrophosphates (TSPP), and mixtures thereof.
Phosphoric acid can be added as orthophosphoric acid, or meta phosphoric acid or in the form of derivatives such as esters of the phosphoric acid. Phosphoric anhydride can also be used as a phosphate material in the present invention.
Phosphonates which may be useful in the present invention include phosphonate chelants. Such chelants include one selected from the group consisting of dlethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methyiene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetraiacetlc acid), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof. Optional Components
The bars of the present invention are substantially free of siliceous materials, preferably containing less than about 1%, more preferably not containing any in the bar composition. Siliceous materials include silica in finely divided form, silicates, polymeric silicates and aluminosilicates, and clays.
The composition can optionally contain in addition to the phosphate material, non-phosphate material, or non-phosphate detergent builder. Specific examples of non-phosphate, inorganic detergency builders include water-soluble inorganic carbonate and bicarbonate salts. The alkali metal (e.g., sodium and potassium) carbonates and bicarbonates are particularly useful herein. Other specifically preferred examples of builders include polycarboxylates.
Sodium carbonate, another optional ingredient, is particularly preferred as a neutralizing inorganic salt for an acid precursor of an anionic surfactant used in such compositions, such as the alkyl ether sulfuric acid and alkylbenzene sulfonic acid. Co-polymers of acrylic acid and maleic acid are preferred in the subject compositions as auxiliary builders.
Soil suspending agents can be used. Soil suspending agents can also include water-soluble salts of carboxymethylcellulose and carboxyhydroxymethylcellulose. A preferred soil suspending agent is an acrylic/maleic copolymer, commercially available as Sokolan*, from BASF Corp. Other soil suspending agents include polyethylene glycols having a molecular weight of about 4OO to 10,000, and ethoxylated mono- and polyamines, and quaternary salts thereof. If included, it can .be at levels up to about 5%, preferably about 0.1-1%.
The bleach agent in the detergent composition, when included, is preferably at a level from about 0.10% to about 60% by weight; more preferably, from about 1 % to about 50%; most preferably, from about 1 % to about 20%, The bleach agents used herein can be any of the bleachagents useful for detergent compositions in textile cleaning, hard surface cleaning, or other cleaning purposes that are now known or become known. Mixtures of bleach agents can also be used.
A useful bleach agent that can be used encompasses percarboxylic acid bleach agents and salts thereof. Suitable examples of this class of agents include magnesium monoperoxyphthalate hexahydrate, the magnesium salt of metachloro perbenzolc acid, 4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanediolc acid. Such bleach agents are disclosed in U.S. Patent 4,483,781, Hartman, issued November 20,
1984, U.S. Patent Application 740,446, Burns et al, filed June 3, 1985,
European Patent Application 0,133,354, Banks et al, published February 20,
1985, and U.S. Patent 4,412,934, Chung et al, issued November 1, 1983.
Highly preferred bleach agents also include 6-nonylamino-6~
oxoperoxycaproic acid as described in U.S. Patent 4,634,551, issued
January 6, 1987 to Burns et al.
Other peroxygen bleach agents can also be used. Suitable peroxygen bleach compounds include sodium carbonate peroxyhydrate and equivalent "percarbonate" bleaches, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Persulfate bleach (e.g., OXONE, manufactured commercially by DuPont) can also be used.
Bleach agents other than oxygen bleach agents are also known in the art and can be utilized herein. One type of non-oxygen bleach agent of particular interest includes photoactivated bleach agents such as the sulfonated zinc and/or aluminum phthalocyanines. See U.S. Patent 4,033,718, issued July 5, 1977 to Holcombe et al. If used, detergent compositions will typically contain from about 0.025% to about 1.25%, by weight, of such bleaches, especially sulfonate zinc phthalocyanlne.
An optional useful percarbonate bleach comprises dry particles having an average particle size in the range from about 500 micrometers to about

1,000 micrometers, not more than about 10% by weight of said particles being smaller than about 200 micrometers and not more than about 10% by weight of said particles being larger than about 1,250 micrometers. Optionally, the percarbonate can be coated with silicate, borate or water-soluble surfactants. Percarbonate is available from various commercial sources such as FMC, Solvay and Tokai Denka.
When included, the preferred bleach agent for the present invention are those peroxygen bleaching compounds which are capable of yielding hydrogen peroxide in an aqueous solution. These compounds are well known in the art and include hydrogen peroxide and the alkali metal peroxides, organic peroxide bleaching compounds such as urea peroxide, and inorganic persalt bleaching compounds, such as the alkali metal perborates, percarbonates, perphosphates, and the like. Mixtures of two or more such bleaching compounds can also be used, if desired.
Preferred peroxygen bleaching compounds to be used in the present invention include sodium perborate, commercially available in the form of mono- and tetra-hydrates, sodium carbonate peroxyhydrate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Particular preferred are sodium perborate tetrahydrate, and especially/ sodium perborate monohydrate. Sodium perborate monohydrate is especially preferred because it is very stable during storage and yet still dissolves very quickly in the bleaching solution.
Another optional component of the present invention is a detergent chelant. Such chelants are able to sequester and chelate alkali cations (such as sodium, lithium and potassium), alkali metal earth cations (such as magnesium and calcium), and most importantly, heavy metal cations such as iron, manganese, zinc and aluminum. Preferred cations Include sodium, magnesium, zinc, and mixtures thereof.
The detergent chelant is preferably a phosphonate chelant, particularly one selected from the group consisting of diethylenetriamine penta(methylene phosphonic acid), ethylene diamine tetra(methylene phosphonic acid), and mixtures and salts and complexes thereof, and an acetate chelant, particularly one selected from the group consisting of diethylenetriamine penta(acetic acid), ethylene diamine tetra(acetic acid), and mixtures and salts and complexes thereof. Particularly preferred are sodium, zinc, magnesium, and aluminum salts and complexes of diethylenetriamine penta(methylene phosphonate) diethylenetriamine penta (acetate), and mixtures thereof.
Preferably such salts or complexes have a molar ratio of metai ion to chelant molecule of at least 1:1, preferably at least 2:1, The detergent chelant can be included in the laundry bar at a level up to about 5%, preferably from about 0.1% to about 3%, more preferably from about 0.2% to about 2%, most preferably from about 0.5% to about 1,0%.
Another optional component of the laundry bar is fatty alcohol having an alkyl chain of 8 to 22 carbon atoms, more preferably from 12 to 18 carbon atoms. A preferred fatty alcohol has an alkyl chain predominantly containing from 16 to 18 carbon atoms, so-called "high-cut fatty alcohol," which can exhibit less base odor of fatty alcohol relative to broad cut fatty alcohols. Typically fatty alcohol, if any, is present in the laundry bar at up to a Ievel of 10%, more preferably from about 0.75% to about 6%, most preferably from about 2% to about 5%. The fatty alcohol is generally added to a laundry bar as free fatty alcohol. However, low levels of fatty alcohol can be introduced into the bars as impurities or as unreacted starting material. For example, laundry bars based on coconut fatty alkyl sulfate can contain, as unreacted starting material, from 0.1% to 3.5%, more typically from 2% to 3%, by weight of free coconut fatty alcohol on a coconut fatty alkyl sulfate basis.
Another optional component in the laundry bar Is a dye transfer inhibiting (DTI) ingredient to prevent diminishing of color fidelity and intensity in fabrics. A preferred DTI ingredient can include polymeric DTI materials capable of binding fugitive dyes to prevent them from depositing on the fabrics, and decolorization DTI materials capable of decolorizing the fugitives dye by oxidation. An example of a decolorization DT! is hydrogen peroxide or a source of hydrogen peroxide, such as percarbonate or perborate. Non-limiting examples of polymeric DTI materials include polyvinylpyrridine N-oxide, polyvinylpyrrolidone (PVP), PVP-polyvinylimidazole copolymer, and mixtures thereof. Copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (referred to as "PVPI") are also preferred for use herein. The amount of DTI Included in the subject compositions, if any, is about 0.05-5%, preferably about 0.2-2%.
Another optional component in the laundry bar is a fabric softener component. Such materials can be used, if any, at levels of about 0,1% to 5%, more preferably from 0.3% to 3%, and can include: amines of the formula R4R5R6N, wherein R4 is C5 to C22 hydrocarbyl, R5 and R6 are independently C1 to C1o hydrocarbyl. One preferred amine is ditallowmethyl amine; complexes of such amines with fatty acid of the formula R7COOH, wherein R7 is C9 to C22 hydrocarbyl, as disclosed in EP No. 0,133,804; complexes of such amines with phosphate esters of the formula R80-P(0)(OH)-OR9 and HO-P(0)(OH)-OR9 wherein R8 and R9 are independently C1 to C20 alkyl of alkyl ethoxylate of the formula -alkyl-(OCH2CH2); cyclic amines such as imidazolines of the general formula 1-(higher alkyl) amido (lower alkyl)-2-(hlgher alkyl)lmidazoline, where higher alkyl is from 12 to 22 carbons and lower alkyl is from 1 to 4 carbons, such as described in UK Patent Application GB 2,173,827; and quaternary ammonium compounds of the formula R10R11R12R13N+ X-, wherein RIO is alkyl having 8 to 20 carbons, R11 is alkyl having 1 to 10 carbons, R12
and R13 are alkyl having 1 to 4 carbons, preferably methyl, and X is an anion, preferably Cl- or Br, such as C12-13 alkyl trimethyl ammonium chloride.
Sodium sulfate is a well-known filler that is compatible with the compositions of this invention. It can be a by-product of the surfactant sulfation and sulfonation processes, or it can be added separately. Calcium carbonate (also known as Calcarb) Is also a well known and often used filler component of laundry bars. Filler materials are typically used, if included, at levels up to 40%, preferably from about 5% to about 25%.
Optical brighteners are also optional ingredients in laundry bars of the
present invention. Preferred optical brighteners are diamino stilbene,
distyrilbiphenyl-type optical brighteners. Preferred as examples of such
brighteners are 4,4'-bis{[4-anilino-6-bis(2-hydoxyethyl} amino-1,3,5-trizin-2-
yl]amino}stilbene-2f2'-disulfonic acid disodium salt, 4-4'-bis(2-sulfostyryl)
biphenyl and 4,4'-bis[(4-anilino-6-morpholino-1 /3/5-triazin-2-yl)
amino]siilbene-2,2'-disulfonic acid disodium salt. Such optical brighteners, or mixtures thereof, can be used at levels In the bar of from about 0.05% -1.0%.
Dyes, pigments, germicides, and perfumes can also be added to the bar composition. If Included, they are typically at levels up to about 0.5%.
Another optional component of the subject invention composition is a photobleach material/ particularly phthalocyanine photobleaches which are described in U.S. Patent 4,033,718 issued July 5, 1977, incorporated herein by reference. Preferred photobleaches are metal phthalocyanine compounds, the metal preferably having a valance of +2 or +3; zinc and aluminum are preferred metals. Such photobleaches are available, for example, under the tradename TINOLUS or as zinc phthalocyanine sulfonate. The photobleach components, if included, are typically in the subject
compositions at levels up to about 0.02%, preferably from about 0.001% to about 0.015%, more preferably from about 0.002% to about 0.01%.
Another useful optional component of the subject compositions are detergent enzymes. Particularly preferred are lipase, protease, cellulase, amylase, and mixtures thereof. Enzymes, if included, are typically at levels up to about 5%, preferably about 0.5-3%.
Another useful optional component which can be used as processing aids include glycerine and coconut monoethano! amide.
The detergent composition can optionally contain a polyamine soil release agent related to modified polyamines. See U.S. 5,565,145 issued October 15,1996 to Watson et al.
Modified polyethylene!mine polymers may also be included herein. These modified polyethyleneimine polymers comprise backbones that can be either linear or cyclic. The polyamine backbones can also comprise polyamine branching chains to a greater or lesser degree. In general, the polyamine backbones described herein are modified in such a manner that each nitrogen of the polyamine chain is thereafter described in terms of a unit that is substituted, quaternized, oxidized, or combinations thereof.
Preferred modified pofyethyleneimine polymers are generally polyalkyleneaminss (PAA's), polyalkyleneimines (PAI's), preferably polyethyleneamine (PEA's), polyethyleneimines (PEI's), or PEA's or PEI's connected by moieties having longer R units than the parent PAA's, PAI's, PEA's or PEI's. A common polyalkyleneamine (PAA) is tetrabutylenepentamine. PEA's are obtained by reactions involving ammonia and ethylene dichloride, followed by fractional distillation. The common PEA's obtained are triethylenetetramine (TETA) and teraethylenepentamine (TEPA). Above the pentamines, i.e., the hexamines. heptamines, octarnines and possibly nonamines, the cogenerically derived mixture does not appear to separate by distillation and can include other materials such as cyclic amines and particularly piperazines. There can also be present cyclic amines with side chains in which nitrogen atoms appear. See U.S.
Patent 2,792,372, Dickinson, issued May 14, 1957, which describes the preparation of PEA's.
Preferred amine polymer backbones comprise R units that are C2 alkylene (ethylene) units, also known as polyethyleneimines (PEI's), Preferred PEI's have at least moderate branching, that is the ratio of m to n is less than 4:1, however PEI's having a ratio of m to n of about 2:1 are most preferred. Preferred backbones, prior to modification have the general formula:
wherein m and n are the same as defined herein above. Preferred PEI's, prior to modification, will have a molecular weight greater than about 200 Daltons.
The polyamine soil release agents of the present invention if included in the detergent composition, is included from about 0.01% to about 5%; preferably about 0.3% to about 4%; more preferably about 0.5% to about 2.5%, by weight of the detergent composition. Moisture
The final bar composition should have no more than about 15% moisture. The moisture level of the total bar composition can be determined by any methods known in the art by one skilled in the area of laundry bar compositions. One common method is the Bldwell Sterling Distillation method; Another known method is the Karl Fischer Moisture Titration Method. See AOCS official method Dd2a-59 issue 93 and AOCS official method Dd2b-59 issue 89. Bar Physical Properties
The bars of the present invention have improved physical properties, including improved in-process and aged hardness of the bar as well as reduced solubility in water during washing. In addition, the bars of the present invention have improved cleaning benefits as well as mildness benefits.
he bars of the present invention are sufficiently hard. A preferred test method measures bar hardness after three weeks of aging. Bars are aged for three weeks at 80°F/80 relative humidity (RH). To measure the bar hardness, a needle with a point angle of 43° attached to a force gauge (Control International, Lincolnwood, IL, USA) was forced onto the plane of the bar surface to a depth of 5.8 mm. A preferred bar hardness reading of laundry bar compositions using this test method is about 55-70 Ibs. Bars of the present invention fall within the range. Another method to measure bar hardness is to measure the penetration of a needle through the bar surface under a standard weight for 5 seconds using a cone penetrometer. One such penetrometer is made by Associated Instrument Manufacturers India Pvt. Ltd. (Model number AIM 512). The weight of the rod and the cone is 149 grams and an additional 50 gram weight is placed on the cone. The penetration reading of a fresh bar made as per the present invention will typically be about 20-30 (1/10 mm) and 15-20 (1/10 mm) after 40 minutes. Bars aged about 3 days at ambient conditions will typically have a bar penetration reading of about 5-12 (1/10 mm).
Another physical property of interest is the bar solubility in water. One method of determining the bar solubility is to submerge a bar having the following dimensions 75mm x 55mm in 250 ml of water in a beaker for 2 hours, drying the bar at 60 deg. C for 2 hours and then weighing the bar. To have acceptable bar solubility, the difference in weight should be about 5-20 grams for a 125 gram bar (12-16% of the original weight of the bar), more preferably 5-15 grams (4-12% of the original weight of the bar).
According to the present invention is provided a process for making a synthetic laundry detergent bar composition comprising the steps of characterized in that:
a. providing a neutralized synthetic detergent active such as herin
described;
b. adding a divalent metal compound to the neutralized active, wherein
the divalent metal compound is selected from the group consisting of
divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and
optionally, adding other optional detergent adjunct components, and
c. forming into bars;
wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition comprises phosphate materials.
The following examples further describe and demonstrate the preferred embodiments within the scope of the present invention. The examples are given solely for the purpose of illustrations, and are not to be construed as limitations of the present invention since many variations thereof are possible without departing from its spirit and scope.
Example 1
In order to make 100 kg of finished product/ about 6 kg dry flakes of neutralized NaCFAS (sodium salt of coconut fatty alcohol sulfate), 4 kg of sodium carbonate, 18 kg of sodium tripolyphosphate and 50 kg of sodium sulfate are added to the mixer. The mixer used is a ploughshear kind of mixer (trade name: KM Mixer by Littleford Inc.). The KM Mixer main shaft rpm is adjusted to 130. Hot oil at 60°C is circulated around the jacket of the mixer to minimize any heat loss during the process. The powders added are at ambient temperature. The mixer is started and at the same time, about 11 kg of the neutralized NaCFAS paste is added to the mixer. The paste temperature is in the range of 55-60°C. The mixture is mixed for about 3 minutes. Then, about 7 kg of LAS (linear alkyl benzene suifonate acid and 2.5 kg of sulfuric acid are added to the batch. The mixture is further mixed for about 3 minutes. This is followed by the'addition of 1 kg of C12 coco fatty alcohol, 40 kg of calcium carbonate, and 3 kg of calcium hydroxide. The mixture is mixed for about a minute. This is followed by the addition of optional components such as brighteners, anti-redeposition agents, soil release polymers, etc. After the mixture is further mixed, enzymes are added to the batch and mixed for about 30 additional minutes. The final form of the batch is lumpy. The temperature of the batch at the end of the mixing cycle is about 65-70°C. The mixture is then dropped into a surge tank which continuously feeds to a refiner plodder. The output of the refiner plodder is a detergent mass in the form of noodles which are then fed to a duplex vacuum plodder. A vacuum of about -0.9bar(670mm of Hg) is maintained to remove any entrapped error in the detergent matrix. The bar coming out of the final stage of the duplex vacuum plodder is at 55-60°C, This bar is cooled to about 50°C and then packed into polyethylene wrappers.
Various bar compositions (Examples 2 through 4) are prepared by the process of the invention. Examples 2 through 4 have improved physical properties, including acceptable bar hardness, and reduced smearing,
(Tabl e Removed)

The synthetic laundry detergent bar composition made by the process of the present invention is a synergistic composition wherein the ingredients are reacting synergistically to produce unexpected results. No chemical reaction is taking place.

WE CLAIM:
1. A process for making a synthetic laundry detergent bar composition comprising the steps of characterized in that:
a. providing a neutralized synthetic detergent active such as herein
described;
b. adding a divalent metal compound to the neutralized active, wherein
the divalent metal compound is selected from the group consisting of
divalent metal oxides, chlorides, hydroxides, and mixtures thereof; and
optionally, adding other optional detergent adjunct components, and
c. forming into bars;
wherein the bar composition is substantially free of siliceous materials, and wherein the bar composition comprises phosphate materials.
2. The process as claimed in claim 1, wherein all the phosphate material is added
before providing the neutralized active.
3. The process as claimed in claim 1, wherein the synthetic detergent active is
selected from the group consisting of anionic, nonionic, cationic, zwitterionic,
amphoteric, and mixtures thereof.
4. The process as claimed in claim 1, wherein the divalent metal compound is
selected from the group consisting of calcium oxide, calcium hydroxide,
calcium chloride, magnesium oxide, magnesium hydroxide, magnesium
chloride, and mixtures thereof.
5. The process as claimed in claim 1, wherein a premixture of the divalent metal
compound and phosphate compound is formed before adding the premixture to
the neutralized active.
6. The process as claimed in claim 1, wherein the phosphate material is selected
from the group consisting of phosphate, phosphonate, phosphoric acid, and
mixtures thereof.
7. The process as claimed in claim 6, wherein the phosphate material is selected
from the group consisting of water-soluble alkali-metal salts of phosphates,
pyrophosphates, orthophosphates, tripolyphosphates, higher polyphosphates,
and mixtures thereof.
8. A process as claimed in claim 1 wherein said neutralized synthetic detergent
active comprises a phosphate material.
9. The process as claimed in claim 8, wherein a peroxygen bleach and an enzyme
is further added.
10. A process for making a synthetic laundry detergent bar substantially as
hereinbefore described in any of the Examples.

Documents:

993-del-1999-abstract.pdf

993-del-1999-assignment.pdf

993-del-1999-claims.pdf

993-del-1999-correspondence-others.pdf

993-del-1999-correspondence-po.pdf

993-del-1999-description (complete).pdf

993-del-1999-form-1.pdf

993-del-1999-form-19.pdf

993-del-1999-form-2.pdf

993-del-1999-form-3.pdf

993-del-1999-form-5.pdf

993-del-1999-gpa.pdf

993-del-1999-petition-137.pdf

993-del-1999-petition-138.pdf

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Patent Number

215793

Indian Patent Application Number

993/DEL/1999

PG Journal Number

12/2008

Publication Date

21-Mar-2008

Grant Date

03-Mar-2008

Date of Filing

20-Jul-1999

Name of Patentee

THE PROCTER & GAMBLE COMPANY

Applicant Address

ONE PROCTER & GAMBLE PLAZA, CINCINNATI, STATE OF OHIO, U.S.A.

Inventors:

#	Inventor's Name	Inventor's Address
1	LASAP, RICHARD TUGAO	1472-B PAGKAKAISA ST.,KASILAWAN, MAKATI, METRO MANILA 1206, PHILIPPINES.
2	MURKUNDE, ROHAN GOVIND	1208,PRINCE TOWER, TORDESILLAS ST. SALCEDO, VILLAGE, MAKATI, METRO MANILA 1227, PHILIPPINES.
3	CHAVEZ, DARIUS GARCIA	1827 ROAD NINE, FABIE, ESTATE STA. ANA, MANILA 1009 PHILIPPINES.
4	VILLAOBOS, MARICEL LEGASPI	34 KAINGIN KAWIT, CAVITE 1404, PHILIPPINES.
5	SHENAI, VINAY MADHAV	UNIT 402, ORIENT MANSION CONDO, TORDESILLAS ST. SALECDO VILLAGE, MAKATI CITY 1227,PHILIPPINES.

PCT International Classification Number

C11D 9/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	US98/15348	1998-07-23	U.S.A.