Title of Invention	"A PROCESS FOR MAKING A CARBOXYMETHYL CELLULOSE (CMC)"
Abstract	A process for making a carboxymethyl cellulose CMC comprising, a) reacting in a slurry process, a source of cellulose, and 40 to 80 wt % of the stoichiometric amount of NaOH for a sufficient time and at a sufficient temperature to form an alkali cellulose, and b) adding to the alkali cellulose an amount of NaOH to bring the total amount of NaOH to about the stoichiometric level, and c) immediately after step b, adding monochloroacetic acid to step b in a sufficient amount and reacting the slurry at a temperature and time sufficient to effect etherification in order to form the CMC product.

Title of Invention

"A PROCESS FOR MAKING A CARBOXYMETHYL CELLULOSE (CMC)"

Abstract

A process for making a carboxymethyl cellulose CMC comprising, a) reacting in a slurry process, a source of cellulose, and 40 to 80 wt % of the stoichiometric amount of NaOH for a sufficient time and at a sufficient temperature to form an alkali cellulose, and b) adding to the alkali cellulose an amount of NaOH to bring the total amount of NaOH to about the stoichiometric level, and c) immediately after step b, adding monochloroacetic acid to step b in a sufficient amount and reacting the slurry at a temperature and time sufficient to effect etherification in order to form the CMC product.

Full Text	FIELD OF INVENTION The present invention relates to water-soluble carboxymethylcelluloses (CMCs) that exhibit unique and highly desirable rheology and performance in end use systems and to a process for the preparation thereof. The CMCs of the present invention exhibit associative behavior both in neat solutions and in filled systems. The association is shear reversible, which enhances utility. BACKGROUND OF THE INVENTION Carboxymethylcellulose (CMC) is one of the most versatile and widely used cellulose ethers as a component for aqueous systems. It may act as a suspending agent, thickening agent, protective colloid, humectant, and for the control of crystallization of some other components. CMC is physiologically inert and is an anionic polyelectrolyte. The above noted characteristics makes CMC suitable for use in a wide spectrum of applications in the food, pharmaceutical, personal care; paper, building materials and construction, oilfield, and other industries. There are many types of commercial CMCs available varying with respect to average degree of polymerization and substitution. The chemical and physical properties of the CMCs depend not only on the average degree of polymerization and substitution, but also on the overall solubility of the CMC as well as the distribution of carbomethoxy substituents along the cellulose chains. Both smoothly and blocky substituted CMCs are well known in the art. Blocky CMCs can be produced by lowering DS and/or changing the manufacturing process. However, processes that target a blocky CMC produce CMCs with limited solubility. In many cases a substantial portion of the CMC forms a swollen gel in aqueous applications. Such gels are undesirable in many applications, such as toothpaste, where the gel structure imparts an undesirable gel appearance in the toothpaste. US Patent Re 32,976 discloses a smoothly substituted, enzyme and salt resistant CMC which is prepared using an etherification agent which comprises at least 50% isopropyl monochloroacetate. Smoothly substituted CMCs will not provide the associative properties of the current invention. The CMCs of the present invention are prepared from monochloroacetic acid or sodium chloroacetate, not isopropyl monochloroacetate. US Patent No. 4,579,943 discloses a CMC that has high liquid absorbing property that is derived from regenerated cellulose, having cellulose II form. The CMCs are of relatively low DS (0.1-0.64) and are substantially insoluble in water. The CMCs of the current invention are derived from cellulose I, not cellulose II or regenerated cellulose. Publication WO 99/20657 discloses a CMC that has a tan delta of less than 1.0 at a concentration of 0.5 % under specific testing conditions. The CMC of the current invention do not have a tan delta less than 1.0 at 0.5% concentration. The publication by G. Mann, J. Kunze, F. Loth and H-P fink of Fraunhofer Institutfur Angewandte Polymerforschung entitled "Cellulose ethers with a Blocklike Distribution of the Substituents by Structure-selective Derivatization of Cellulose", Polymer, vol. 39, No. 14, pp. 3155-3165, Published 1998, discloses the preparation and testing of block-like distribution of CMC. The CMC is prepared by a step-by-step etherification reaction where a systematic carboxymethylation in alcohol-water medium is conducted while maintaining a low NaOH concentration (NaOH/AGU molar ratio formed at elevated temperatures (50 - 70° C). It is reported that this process produces block-like cellulose ethers, including CMC, or cellulose etheresters with alternating hydrophilic and hydrophobic as well as various ionic chain segments. The CMCs are swollen particles in water and are not substantially soluble. The CMCs of the present invention are produced at higher NaOH/AGU ratios (about 1.1 to about 1.9) and low alkali cellulose temperatures (20 - 30° C), and are substantially soluble in water. There is still a need for an associative, thixotropic CMC that exhibits associative behavior both in neat solutions and in filled systems. The association would be shear reversible, which would enhance utility. Such rheology would provide high thickening efficiency, and stabilize emulsions and suspensions, yet allow processing advantages such as ease of pumping or spreading, due to the reversible shear thinning characteristics of the associative network. SUMMARY OF THE INVENTION The present invention is related to a composition comprising CMC having a relative urea/water ratio of less than about 0.9. The relative urea ratio is defined as: Relative Viscosity in 6M Urea = Dynamic Viscosity of 1 % CMC in 6M = Dynamic Viscosity of 1 % CMC in urea 6M urea 6M urea viscosity 1.4 cP Relative Viscosity in Water = Dynamic Viscosity of 1 % CMC in = Dynamic Viscosity of 1 % CMC in Water 6M urea Water viscosity 0.89 cP Relative Urea/Water Ratio = Relative Viscosity in 6M Urea Relative Viscosity in Water This invention is also directed to a process for making a CMC comprising a) reacting in an aqueous slurry of isopropyl alcohol, a source of cellulose, and about 50 - 80% of the stoichiometric level of alkali for a sufficient time and at a sufficient temperature to form an alkali cellulose b) adding sufficient alkali to bring the total alkali concentration to stoichiometric levels, followed by addition of the requisite amount of etherification agent, c) completing the etherification reaction and optionally, d) adjusting final molecular weight/viscosity by addition of oxidizing agents capable of degrading cellulosic chains. This invention also comprehends the use of the CMC of the present invention in an aqueous rheology modifier system as a vehicle component of a personal care, household care, plaint, building material, construction, pharmaceutical, oilfield, food, paper making or paper coating composition. BRIEF DESCRIPTION OF DRAWINGS Figure 1 shows a graph of toothpaste viscosity over time. Figure 2 shows a graph of toothpaste viscosity overtime that has been normalized. Figure 3 shows a graph of toothpaste structure over time. Figure 4 shows a graph of toothpaste structure overtime that has been normalized. Figure 5 shows a graph of crushing strengths of blends of polymers. Figure 6 shows a graph of percent drug dissolved over time. Figure 7 shows a graph of percent drug dissolved over time. DETAILED DESCRIPTION OF THE INVENTION A CMC has been surprisingly discovered that exhibits unique and highly desirable rheology and performance properties in end use systems. In accordance with the present invention, the viscosity builds up not only by means conventional to CMC, but also is boosted significantly by molecular association. The association leads to network formation and gel-like rheological properties. The fact that the association is shear reversible enhances utility. The CMCs of the present invention have been shown to lower the CMC use level needed and to provide rheology attributes unique from other CMCs available today. The unique rheology provides high thickening efficiency, and stabilizes emulsions and suspensions. The CMCs of the present invention provide significantly enhanced performance over known CMCs in aqueous systems including personal care formulations (e.g., toothpaste, skin care, and hair care), medical care (e.g., wound care and ostomy,), food applications (i.e., tortillas, cake mixes, bread mixes, bread, ice cream, sour cream, pasteurized processed cheese spreads, and cheese foods), beverages (i.e., instant cold/hot drinks, ready to drink beverages, and fruit flavored drinks), paint systems, building and construction materials (such as joint formulations), mineral processing, oil field formulations (e.g., drilling fluids), paper making and paper coating formulations, household formulations (e.g., laundry detergents, fabric softeners), and pharmaceutical formulations. In accordance with the present invention, when the composition is a personal care composition, it includes (a) from about 0.1 % to about 99.0 % by weight of the vehicle component and (b) at least one active personal care ingredient. Examples of the at least one active personal care ingredient are deodorant, skin coolants, emollients, antiperspirant actives, moisturizing agents, cleansing agents, sunscreen actives, hair treatment agents, oral care agents, tissue paper products, and beauty aids. In accordance with the present invention, the composition is a household care composition, it includes (a) from about 0.1 % to about 99.0 % by weight of the vehicle component and (b) at least one active household care ingredient. Examples of the at least one active household care ingredient are industrial grade bar, gel and liquid soap actives, all purpose cleaning agents, disinfecting ingredient, rug and upholstery cleaning actives, laundry softeners actives, laundry detergent ingredients, dishwashing detergents, toilet bowl cleaning agents and fabric sizing agents. In addition to the ingredients conventionally used in the personal care and household care, the composition according to the present invention can optionally also include ingredients such as a colorant, preservative, antioxidant, nutritional supplements, activity enhancer, emulsifiers, viscosifying agents (such as salts, i.e., NaCI, NHUCI & KCI, water-soluble polymers, i.e., hydroxyethylcellulose, and fatty alcohols, i.e., cetyl alcohol), alcohols having 1-6 carbons, and fats and oils. The CMCs may also be used in combination with other known rheology modifiers including, but not limited to, polysaccharides (e.g., carrageenan, guar, hyaluronicacid, glucosaminoglycan, hydroxyethyl cellulose, hydrophobically modified hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, methylcellulose, cationic guar, carbomer), biopolymers (e.g., xanthan), synthetic polymers (polyethylene glycol, polyvinylacetate, chlorohexidiene), and thickening silicas. The use of CMC in toothpaste formulations is well known in the toothpaste industry as a binder system for toothpaste that gives the toothpaste a desirable high structure. The binder system includes CMC types with other polysaccharides, inorganic salts, chelating agents and combinations thereof. Commercially available CMC types vary in the degree of structure they provide to the toothpaste. Highly thixotropic grades of CMC tend to render toothpaste of higher structure. These thixotropic CMC types also tend to contribute to greater post-thickening. Cellulose gum (CMC) alone has been a traditional binder for toothpaste. In toothpaste, CMC provides viscosity, stand-up or structure, and syneresis control. Toothpaste made with CMC is also known to have a slow rate in viscosity build up over the shelf life of the toothpaste thus not reaching a stable viscosity until after first 30 days or more. This is also called "post-thickening". Other binders commonly used in toothpaste are carrageenan or carrageenan and xanthan together. Carrageenan and xanthan provide good stand-up, viscosity and syneresis control; however, they tend to be more expensive alternatives as compared to CMC. Toothpaste made with carrageenan and xanthan tend to exhibit a stable viscosity rather quickly after processing and little post-thickening. In accordance with the present invention, the CMC of the present invention can be use either alone or in combination with other polysaccharides, synthetic polymers and or salts and provide high efficiencies and enhanced performance. See the toothpaste Examples hereinafter for the demonstration of the unexpected results of the present invention. Use of the CMCs of the present invention have allowed a use level reduction of about 40% while maintaining critical toothpaste properties such as stand-up, gloss and syneresis control. The lower use levels and/or shear thinning behavior of the CMCs may offer additional advantages to toothpaste properties such as improved flavor release, improved actives delivery, improved fluoride delivery, higher gloss, improved extrudability from the tube, and improved anti-microbial effectiveness. Potential improvements to the toothpaste manufacturing process include, but are not limited to, reduction of entrapped air during manufacturing process, improvements in mixing operations, and improvements in extrusion into tubes. Water-based protective coating compositions (commonly referred to as paints) in which cellulose ether derivatives are conventionally used include latex paints or dispersion paints, of which the principal ingredients are film-forming lattices such as styrenebutadiene copolymers, vinyl acetate polymers and copolymers, and acrylic polymers and copolymers. Typically, they also contain opacifying pigments, dispersing agents and water-soluble protective colloids, the proportions being, by weight of the total composition, about 10 parts to about 50 parts of a latex, about 10 parts to about 50 parts of an opacifying pigment, about 0.1 part to about 2 parts of a dispersing agent, and about 0.1 part to about 2 parts of a water-soluble protective colloid. Water soluble protective colloids conventionally used in the manufacture of latex paints (to stabilize the lattices and maintain the wet edge of a painted area longer in use) include casein, methyl cellulose, hydroxyethylcellulose (HEC), sodium carboxymethyl cellulose (CMC), polyvinyl alcohol, starch, and sodium polyacrylate. The disadvantages of the natural based cellulose ethers are that they may be susceptible to biological degradation and frequently impart poor flow and leveling properties, while the synthetic materials such as polyvinyl alcohol often lack enough thickening efficiency to maintain sag resistance. The thickening efficiency of the cellulose ethers is usually improved by increasing their molecular weight which normally is more expensive. In accordance with the present invention, the CMC of the present invention can be used in lower amounts in paints and provide unexpected high quality results. This is illustrated in the working Examples hereinafter. The CMCs of the present invention are prepared using conventional slurry process methods. For example, isopropyl alcohol, water, and about 50 -80% of the stoichiometric amount of NaOH are reacted with cellulose at a temperature of about 20°C for a sufficient time to produce alkali cellulose, about 1.5 hours. Sufficient NaOH is added to bring the total NaOH level to or slightly above stoichiometric levels and monochloroacetic acid is added shortly after the second NaOH addition. The reaction conditions are normally to raise the temperature to about 70°C for about one to two hours to effect etherification. The molecular weight and viscosity of the CMC can be adjusted (reduced) by addition of an oxidizing agent, such as hydrogen peroxide, subsequent to etherification. The reaction mass is then optionally cooled, excess base neutralized, if necessary, and the product is washed. This product can then be dried and ground. The critical feature of this invention is that the amount of alkali utilized to effect etherification is less than stoichiometric and that the remaining alkali is added just prior to the etherification agent. The degree of substitution of the CMC is about 0.6 to about 1.2. In accordance with the present invention, the CMC can be differentiated from prior art CMCs by their being substantially soluble in aqueous media environments and their behavior in environments that do not favor association. It is a known fact that urea breaks up association by breaking hydrogen bonds. The subject CMCs exhibit a viscosity decrease in the presence of urea, as determined by the relative urea ratio. The relative urea ratio is defined as: Relative Viscosity in 6M Urea = Dynamic Viscosity of 1 % CMC in 6M = Dynamic Viscosity of 1 % CMC in urea 6M urea 6M urea viscosity 1.4 cP Relative Viscosity in Water = Dynamic Viscosity of 1 % CMC in = Dynamic Viscosity of 1 % CMC in Water 6M urea Water viscosity 0.89 cP Relative Urea/Water Ratio = Relative Viscosity in 6M Urea Relative Viscosity in Water EXAMPLES The following examples are merely set forth for illustrative purposes, but it is to be understood that other modifications of the present invention within the skill of an artisan in the related industry can be made without departing from the spirit and scope of the invention. All percentages and parts are by weight unless specifically stated otherwise. Example 1 Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.945g) were charged into a jacketed resin kettle reactor equipped with an air driven stirrer, stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser, vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 6.4% moisture) was added to the reactor, the reactor was sealed, and the agitator was adjusted to obtain good mixing. The reactor was inerted and the mixture was cooled to 20°C. Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 1 hour at 20°C after the caustic addition was completed. Aqueous NaOH (50%, 16.02g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 5 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 42.91 g) was added to the reactor through an open reactor port, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1.5 hours. The reaction slurry was filtered and the resulting wet cake was washed three times with 565g of 80% aqueous methanol and one time with 1000g of pure methanol. The resulting wet cake was broken into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The product was ground in Retsch Grinding Mill using a 1mm screen. Degree of Substitution (DS) = 0.89 Example 2 Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.945g) were charged into a jacketed resin kettle reactor equipped with an air driven stirrer, stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser, vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.Og, 6.4% moisture) was added to the reactor, the reactor was sealed, and the agitator was adjusted to obtain good mixing. The reactor was inerted and the mixture was cooled to 20°C. Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 1 hour at 20°C after the caustic addition was completed. Aqueous NaOH (50%, 16.02g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 5 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 42.91g) was added to the reactor through an open reactor port, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1.5 hours. 1.6 ml of 6% H202 was added to the reactor and the slurry was heated at 70°C for 30 minutes. The reaction slurry was filtered and the resulting wet cake was washed three times with 565g of 80% aqueous methanol and one time with 1000g of pure methanol. The resulting wet cake was broken into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The product was ground in Retsch Grinding Mill using a 1 mm screen. Degree of Substitution (DS) = 0.87. Example 3 Isopropyl alcohol (IPA, 123.4 gallons), water (130.3 Ibs), methanol (6.36 gallons), and NaOH (flake, 35.4 Ibs.) were charged into the reactor. The reactor was inerted and the caustic/solvent mix was cooled to about 20°C, at which time a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation was adjusted to give good mixing in the slurry and the slurry was recooled to about 20°C. The reaction slurry was held for 1 hour at 20°C. Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the reaction mixture was held for 15 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 70.5 Ibs.). IPA (9.0 gallons), dichloroacetic acid (DCA, 926.8g) and acetic acid (79.9g) were added to the reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1 hour. 282g of 18% H2O2 was added to the reactor and the slurry was heated at 70°C for 60 minutes. The reaction slurry was centrifuged and the wet cake was washed with three times with 300 gallons of 80% methanol and two times with 300 gallons 100% methanol. The material was dried in an Abbe dryer under vacuum at 80 - 90°C to a moisture content of 4 - 6 %. The product was ground in a micropulverizer through a 0.0278 inch screen. Degree of Substitution (DS) = 0.79. Example 4 The conditions of Example 3 were repeated. DS = 0.78 Example 5 Isopropyl alcohol (IPA, 121.9 gallons), water (130.0 Ibs), methanol (6.29 gallons), and NaOH (flake 45.6 Ibs.) were charged into the reactor. The reactor was inerted and the caustic/solvent mix was cooled to about 20°C, at which time a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation was adjusted to give good mixing in the slurry and the slurry was recooled to about 20°C. The reaction slurry was held for 1 hour at 20°C. Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the reaction mixture was held for 15 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 81.0 Ibs.). IPA (9.0 gallons), dichloroacetic acid (DCA, 1065.9g) and acetic acid (91.9g) were added to the reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1 hour. 188g of 18% H202 was added to the reactor and the slurry was heated at 70°C for 60 minutes. The reaction slurry was centrifuged and the wet cake was washed with three times with 300 gallons of 80% methanol and two times with 300 gallons 100% methanol. The material was dried in an Abbe dryer under vacuum at 80 - 90°C to a moisture content of 4 - 6 %. The product was ground in a micropulverizer through a 0.0278 inch screen. Degree of Substitution (DS)= 0.86. Example 6 The conditions of Example 5 were repeated. DS = 0.86 Example 7 Isopropyl alcohol (IPA, 121.1 gallons), water (146.0 Ibs), methanol (6.24 gallons), and NaOH (flake, 35.4 Ibs.) were charged into the reactor. The reactor was inerted and the caustic/solvent mix was cooled to about 20°C, at which time a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation was adjusted to give good mixing in the slurry and the slurry was recooled to about 20°C. The reaction slurry was held for 1 hour at 20°C. Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the reaction mixture was held for 15 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 70.5 Ibs.). IPA (9.0 gallons), dichloroacetic acid (DCA, 926.8g) and acetic acid (79.9g) were added to the reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1 hour. 282g of 18% H202 was added to the reactor and the slurry was heated at 70°C for 60 minutes. The reaction slurry was centrifuged and the wet cake was washed with three times with 300 gallons of 80% methanol and two times with 300 gallons 100% methanol. The material was dried in an Abbe dryer under vacuum at 80 - 90°C to a moisture content of 4 - 6%. The product was ground in a micropulverizer through a 0.0278 inch screen. Degree of Substitution (DS) = 0.79. Example 8 Isopropyl alcohol (IPA, 14 kg), water (2184g), methanol (728.8g), were charged into the reactor. The reactor was inerted and the solvent mix was cooled to about 20°C, at which time a cellulose pulp (1800 g, 3.6% moisture) was added to the reactor. The agitation was adjusted to give good mixing in the slurry, the slurry was recooled to about 20°C, and NaOH (flake, 691.4g) was added to the reactor. The reaction slurry was held for 1 hour at 20°C. Aqueous NaOH (50%, 353.6g) was added to the reactor and the reaction mixture was held for 15 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 939.8g). IPA (977g), dichloroacetic acid (DCA, 27.3g) and acetic acid (2.4g) were added to the reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1 hour. The reaction slurry was filtered, and the resulting wet cake was washed three times with 12 gallons of 80% aqueous methanol, and one time with 12 gallons of 95% methanol. The material was dried in a vacuum tray dryer at 70°C to a final moisture content of 4 - 6%. The dried product was ground in a micropulverizer through a 0.0278 inch screen. Degree of Substitution = 0.73. Example 9 Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.95g) were charged into a jacketed resin kettle reactor equipped with an air driven stirrer, stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser, vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 6.8% moisture) was added to the reactor, the reactor was sealed, and the agitator was adjusted to obtain good mixing. The reactor was inerted and the mixture was cooled to 20°C. Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 1 hour at 20°C after the caustic addition was completed. Aqueous NaOH (50%, 36.37g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 5 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 42.91 g) was added to the reactor through an open reactor port, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1.5 hours. 1.6 ml of 6% hfeC^ was added to the reactor and the slurry was heated at 70°C for 30 minutes. The reaction slurry was filtered and the resulting wet cake was washed three times with 565g of 80% aqueous methanol and one time with 1000g of pure methanol. The resulting wet cake was broken into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The product was ground in Retsch Grinding Mill using a 1 mm screen. Degree of Substitution (DS) = 0.62. 1 % aqueous viscosity = 2200 cps. Example 10 Isopropyl alcohol (IPA, 713.86g) and deionized (Dl) water (73.79g) were charged into a jacketed resin kettle reactor equipped with an air driven stirrer, stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser, vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 3.7% moisture) was added to the reactor, the reactor was sealed, and the agitator was adjusted to obtain good mixing. The reactor was inerted and the mixture was cooled to 20°C. Aqueous NaOH (50%, 39.98g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 1 hour at 20°C after the caustic addition was completed. Aqueous NaOH (50%, 35.77g) was slowly added to the reactor through the addition funnel, maintaining the mixture slurry temperature at 20°C. The reaction mixture was held for 5 minutes at 20°C after the caustic addition was completed. Monochloroacetic acid (MCA, 42.25g) was added to the reactor through an open reactor port, maintaining a reactor slurry temperature of 20°C. After MCA addition was completed, the reaction slurry was heated to 70°C and held for 1.5 hours. The reaction slurry was filtered and the resulting wet cake was washed three times with 565g of 80% aqueous methanol and one time with 1000g of pure methanol. The resulting wet cake was broken into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The product was ground in Retsch Grinding Mill using a 1mm screen. Degree of Substitution (DS) = 0.84. 1% aqueous viscosity = 3760 cps. Example 11 This Example illustrates the behavior of the preparations of a 1.0% CMC samples of the present invention in a 6.0 M urea solution. The 1 % CMC solution was prepared in the following equipment: Caframo RZR1 overhead stirrer, 8-oz. glass jars, stainless steel stirring shaft with two 3-blade propellers (1.5 inch diameter), Parafilm®, deionized (Dl) water, Germaben II. A 0.50% Germaben solution was prepared by adding the Germaben II to Dl water. This solution was then weighed into an 8-oz. glass jar. The solution was then stirred with an overhead stirrer, while the CMC was quickly added to the solution. The CMC level is 1.0% of the final sample weight. CMC weight is corrected for moisture content. As the viscosity begins to increase, the speed of the stirrer was increased to the maximum rate that does not cause splashing out of the sample. The jar is covered with Parafilm while mixing to prevent evaporation of water and loss from splashing. The sample is stirred for one hour. After one hour of stirring at the highest rate, the stirring speed was decreased to a setting of 4 for one additional hour. The sample was centrifuged for approximately 5 minutes to remove trapped air. The behavior of the samples were studied in the following equipment: Caframo RZR1 overhead stirrer, 8-oz. glass jars, stainless steel stirring shaft with two 3-blade propeller (1" diameter), Parafilm®, 6.0M Urea (180.18g urea diluted to 500ml) Procedure: 6.0M urea solution was weighed into an 8-oz. glass jar. The solution was stirred with an overhead Caframo RZR1 stirrer, as the CMC was quickly added to the solution. The CMC level was 1.0% of the final sample weight. CMC weight was corrected for moisture content. As the viscosity begins to increase, the speed of the stirrer was increased to the maximum rate that does not cause splashing out of the sample. The jar was covered with Parafilm while mixing to prevent evaporation of water and loss from splashing. The sample was stirred for one hour. After one hour of stirring at the highest rate, the stirring speed was decreased to a setting of 4 for one additional hour. The sample was centrifuged for approximately 5 minutes to remove trapped air. Table 1 CMC Example 8 Example 1 Example 2 Example 7 Example 5 Example 3 Example 4 Example 6 Aqualon 7LF Aqualon 7LF Aqualon 7L Aqualon 7H3SF Aqualon 7H3SF Aqualon 7H3SF Aqualon 7H3XSF Aqualon 7H3SXF Aqualon 7HF Aqualon 7H4F Aqualon 7M8SF Aqualon 9M31F Aqualon 9M31F Aqualon 9M31F Aqualon 9M31XF Amtex Antisol FL 300000 Aqualon Aquapac Aqualon Aquapac DKS Cellogen HE-90 DKS Cellogen HP-5HS Fine Gum SA-H Monpac Regular Novlant Cekol SOOT Noviant Cekol 700 Noviant Cekol 2000 PAC-R TylopurdOOO P2 Walocel CRT 2000 DS 0.73 0.89 0.87 0.79 0.86 0.79 0.78 0.86 0.81 0.79 0.97 0.92 0.88 0.89 0.86 0.77 0.9 0.92 0.9 1% Dynamic Water viscosity 1113 574 238 762 265 286 346 163 11 11 9 7191 2286 7337 3262 3111 7023 4875 68 260 577 539 282 168 2852 7795 11446 100 4417 463 2755 47 53 139 7335 316 180 1% Dynamic 6M Urea viscosity 1364 632 288 539 338 355 398 228 16 17 14 12754 4179 13258 5909 4950 11648 8576 111 467 1065 823 470 282 8510 12583 19881 179 8154 1016 5980 68 96 246 11798 558 285 Relative U/W ratio 0.78 0.70 0.77 0.45 0.81 0.79 0.73 0.89 0.97 0.96 0.97 1.13 1.16 1.15 1.15 1.01 1.05 1.12 1.03 1.14 1.17 0.97 1.06 1.07 1.90 1.03 1.10 1.14 1.17 1.40 1.38 0.92 1.16 1.13 1.02 1.12 1.01 The flavor was mixed in the same way. After all formula components were together, the mixture was mixed under vacuum for 15 minutes at high speed. The batch was then packed into 2-oz. jars and 6-oz. toothpaste tubes. Toothpaste samples were stored for 30 days at room temperature. Samples were equilibrated in a 25°C water bath for 4 hours prior to any tests conducted. Viscosity was measured using a Brookfield DV-I fitted with a T-bar style spindle. A helipath stand was used to allow the spindle to sweep downward through the sample to prevent the effects of shear. Viscosity was taken every 30 seconds over 2 minutes and values were averaged. Toothpaste consistency was measured using a rack test. The rack designed with cross bars of increasing distance apart left to right. The toothpaste tube containing the sample to be measured is fitted with a stainless orifice fitting to eliminate differences in orifice size that may occur. The tube is squeezed in a uniform manner across the rack, extruding the paste onto the rack in a ribbon. After 15 seconds it is recorded at which opening the ribbon has fallen through the opening and broken. The opening number from left to right is the value recorded as a "Cuban" value. The toothpaste data are summarized in Table 2. Table 2 Polymer Example 2 Example 1 Example 3 Example 4 Example 5 Example 6 Example 7 Cekol SOOT Cekol 2000 9M31XFGL 9M31F 30 day Toothpaste Viscosity 137500 188125 146750 136250 120000 94500 125750 61875 25875 40125 32500 Cuban 5 10 6 6 5 3 5 2 0 0 0 Comments severe syneresis syneresis syneresis Example 14 The CMC's of the present invention in combination with other polymers exhibit decreased post thickening and structure build and enhanced initial structure in toothpaste formulations. Viscosity is one measure of post-thickening in toothpaste. Toothpaste samples were packed into vials and the viscosity was measured using a Brookfield DV-I fitted with a T-bar style spindle. A helipath stand was used to allow the spindle to sweep downward through the sample to prevent the effects of shear. Viscosity was taken every 30 seconds over 2 minutes and values were averaged It can be seen from the data in the graph (Figure 1) that most samples exhibited a change in viscosity from the first day after processing through 30 days. When the data are normalized to the initial viscosity as 100%, the change over time is more apparent (Figure 2). Toothpaste made with combinations of Example 7 CMC with other polysaccharides or inorganic salts exhibited lower post-thickening compared to toothpaste made with Example 7 alone. Toothpaste structure is also an important aspect. This property may be measured by force required for compression using a MTS Servo Hydraulic test system from MTS Systems Corporation, Minneapolis, MN. The instrument was fitted with a half-inch acrylic cylinder probe, toothpaste samples were packed into vials after processing and measured directly without disturbance. It can be seen below in Table 3 that the Example 7 CMC alone or with other polysaccharides or inorganic salt produced toothpaste of similar or greater initial structure compared to toothpaste made with carrageenan and xanthan and much greater initial structure than toothpaste made with commercial CMC 9M31F. Peak force of compression was monitored over 30 days. It was found that most samples changed in values (Figure 3). The comparison can be made more Example 12 Dynamic viscosities were measured using at 25°C using an RFS III strained controlled rheometer by Rheometrics using a 40 mm parallel tool geometry with the gap set at 2 mm. The samples were pre-sheared at 100s"1 for 60 second upon loading to erase the loading history. The pre-shearing was followed by the steady shear experiment between 0.01 and 100s"1. Each point data is the average of clockwise and counter-clockwise rotations each with the duration of 20 sec. All samples exhibited a low shear Newtonian plateau, the average of which was used in the data analysis and further comparisons. The dynamic viscosities of the aqueous and 6M 1% CMC solutions are summarized in Table 1. The relative urea/water ratios are also summarized in Table 1, above. Example 13 The CMC's of the present invention exhibit enhanced thickening capabilities and syneresis control in toothpaste formulations. Calcium Carbonate Based Toothpaste formulation: Ingredient: wt. % Calcium carbonate 45.00 Sorbo® sorbitol (70% solids) 27.00 Distilled water 23.97 CMC Polymer (Table 2) 0.60 Sodium lauryl sulfate, 100% active powder 1.00 Sodium monofluorophosphate 0.76 Sodium benzoate 0.50 Flavor 0.55 Tetra sodium pyrophosphate 0.42 Sodium saccharin 0.20 100.00 Standard laboratory toothpaste preparation was performed. Salts were first dissolved in part of the water and warmed for complete dissolution. The CMC was dispersed in the sorbitol, using an overhead mixer with a propeller attachment. After the CMC was well dispersed, the balance of the water was added with continued mixing until the CMC appeared dissolved. The warm salt solution was mixed into the CMC solution. This was then transferred to a 1-quart Ross double planetary mixer. The calcium carbonate was then stirred in the mixer, and after it was well dispersed, a vacuum was applied. After mixing under vacuum for 20 minutes, the sodium lauryl sulfate was mixed in without vacuum. easily if the data are normalized to the initial structure value as 100% as shown in Figure 4. From the normalized data of Figure 4, it can be seen that toothpaste samples made with combinations of CMC of Example 7 with other polysaccharides or inorganic salt have lower structure build over time. From the work outlined here, it can be concluded that toothpaste with high structure and low post-thickening can be made with CMCs of the present invention in combination with other polysaccharides, inorganic salts or combinations thereof. The toothpaste formulation used in this Example was as follows: Ingredient Sorbitol (Sorbo) Glycerine PEG 400 Sident 9 Sident 22S Sodium Saccharine Sodium Monofluorophosphate Sodium Benzoate Sodium Lauryl Sulfate Flavor Water Wt. % 29.2 6 3 14 16 0.20 0.23 0.20 1.20 0.50 q.s. The different polymers used in this Example in the formulation was as follows: Formulation 1 2 3 4 5 6 7 8 Polymer: wt% Carrageenan(THPI) 0.7 CMC Example 7 1 .0 CMC9M31F 1.0 CMC Example 7 0.5 CMC Example 7 0.6 CMC Example 7 0.7 CMC Example 7 1 .0 CMC Example 7 0.7 Polymer: Xanthan (Rhodicare) wt% 0.3 N/A N/A Natrosol + 330 Natrosol 250 M Carrageenan Sodium Silicate Xanthan 0.3 0.6 0.3 0.5 0.3 Table 3 Initial Toothpaste Structure Peak Force Compression from MTS Polymer Carageenan/Xanthan Example 7 Example 7 / HMHEC Example 7 / Na2SiO3 Example 7 / HEC Example 7 / Carrageenan Example 7 / Xanthan CMC 9M31 F Peak Force Compression, g 56.5 51.1 78.1 60.8 75.1 75.3 35.0 14.7 Toothpaste after 24 hours, ambient temperature. The identity and supplier of the ingredients of this Example are as follows: Sorbitol Glycerine PEG 400 Silica, thickening Silica, abrasive Sodium Lauryl Sulfate Flavor Sodium Silicate, crystalline Sodium Benzoate Saccharine Sodium Fluorophosphate Carrageenan Xanthan CMC9M31F HM HEC Natrosol Plus 330 CS HEC Natrosol 250 M Pharm Sorbo, 70%, USP/FCC, SPI Pharma, New Castle, DE. USA Glycerine, USP, Spectrum Chemical, Gardena, CA, Polyethylene Glycol NF, Dow Chemical, Midland, Ml USA , USA Sident 9, Degussa, Frankfurt, Germany Sident 22S, Degussa, Franfurt, Germany Stepan, Northfield, IL, USA Fresh Mint, Givaudan, UK JT Baker, reagent grade Fisher Scientific, reagent grade Sigma, reagent grade Alfa Aesar, Ward Hill, ME, USA THP1, CP Kelco, San Diego, CA, USA Rhodicare S, Rhodia, Cranbury NJ, USA Aqualon Aqualon Aqualon Example 15 The CMC's of the present invention exhibit enhanced thickening capabilities in beverage formulations. Beverage Example Orange Beverage - Reference Ingredients Wt% Orange Juice concentrate, 45 Brix 7.00 Sugar 40.00 Citric acid 0.05 Sodium benzoate 0.55 Water 52.14 Cellulose Gum, CMC-9M31F 0.60 Orange Beverage - Test Example Ingredients Wt% Orange Juice concentrate, 45 Brix 7.00 Sugar 40.00 Citric acid 0.05 Sodium benzoate 0.55 Water 52.14 Polymer Example/ 0.42 Mix cellulose gum or polymer into water, allow to mix for 20 minutes. Premix acid, preservative and sugar, add and mix 5 minutes. Add juice concentrate, mix 3 minutes. Beverage results: Reference Test Example Viscosity, 24 hours, cps 53.0 51.0 Brookfield LV, spindle 2, 30 rpm, 20s Example 16 The CMC's of the present invention exhibit enhanced thickening capabilities in food formulations. Cake Mix and Cake Example CAKE MIX - Reference Ingredients for Drv Mix % Flour wt Wt%ofdrvmix Bleached Cake Flour 100 40.4 Sugar 105.9 42.2 Shortening 27.2 11.0 Milk Solids Nonfat 3.7 1.5 Dextrose(1) 2.5 1.0 Salt 2.5 1.0 Sodium Bicarbonate(2) 2.2 0.9 Sodium aluminum phosphate(3) 1.2 0.9 Vanilla Powder^ 1.2 0.5 Butter Flavor(5) 0.3 0.1 Cellulose Gum, CMC-7HF 1.2 0.5 CAKE MIX - Test Example Ingredients for Drv Mix % Flour wt Wt % of dry mix Bleached Cake Flour Sugar Shortening Milk Solids Nonfat Dextrose0 > Salt Sodium Bicarbonate (2) Sodium aluminum phosphate (3) Vanilla Powder(4) Butter Flavor(5) Polymer Example 9 100 105.9 27.2 3.7 2.5 2.5 2.2 1.2 1.2 0.3 0.72 40.4 42.2 11.0 1.5 1.0 1.0 0.9 0.9 0.5 0.1 0.3 (1) Arm & Hammer Baking Soda, Church & Dwight (2) Cantab Dextrose, Penford Food Ingredient Company (3) Levair, FCC Grade Sodium Aluminum Phosphate, Rhodia Food Ingredients (4) Vanilla FL Pure Pwd K, Virginia Dare (5) Butter FL N&A Pwd 685 KD, Virginia Dare Formulation for the Finished Cake - One 8-inch Laver Dry mix, g 270 Water, g 140 Whole egg, g 53 Dry ingredients were blended on mixer with paddle attachment until evenly mixed. Water and egg were added to mix and mixed on medium speed for 3 minutes. The batter was poured into a greased cake pan and baked in a moderate oven (350°F/177°C) for 30 minutes. Cake results: Reference Batter Viscosity, cps Brookfield RV, spindle 3, 10 rpm, 30 s Batter density, g/100mls Cake height, cm Crumb cell structure Bake out Crumb moisture, 24 hours after bake, % 5660 111 3.8 even OK 39.0 Test Example 7650 113 3.8 even OK 39.0 Example 17 The CMCs of the present invention exhibit efficiency by the use of reduced amounts but yet obtain corporate results with prior art materials. The film forming and viscosity properties are enhanced in food preparations. Masa and Corn Tortilla Example MASA - Reference Ingredients for Drv Mix NCF(1) Sodium Benzoate Fumaric Acid Cellulose Gum, CMC-7H4F K MASA - Test Example Ingredients for Dry Mix NCF(1) Sodium Benzoate Fumaric Acid Polymer Example 10 % Flour wt 100 0.4 0.3 0.5 % Flour wt 100 0.4 0.3 0.3 Wt % of drv mix 98.83 0.39 0.29 0.49 Wt % of drv mix 98.63 0.39 0.29 0.29 (l)Nixtamalized corn flour, Quaker Oats Company Dry ingredients were blended on mixer with paddle attachment until evenly mixed. Water was added to mix and mixed on medium speed for 2 minutes. Dough was portioned into 50g balls and pressed on a tortilla press. The tortillas were baked on an ungreased skillet for 1 minutes on each side. Tortillas were cooled on a wire rack, wrapped in foil sheets and checked for pliability and reheat after 1 day. Tortilla results: Reference Test Example Appearance after bake even blisters even blisters Pliability good roll, no cracks good roll, no cracks Reheat good puff good puff Example 18 The CMC's of the present invention exhibit enhanced tablet crushing strength without effecting drug release kinetics. The following formulations were prepared: Material Example 7 Klucel HXF Phenylpropanolamine Avicel PH101 Magnesium Stearate Total batch size % 7.5 22.5 20.0 49.5 0.5 1500q 3750 Tablets Wt per Tab (Mq) 30 90 80 198 2 Material Example 7 Natrosol 250 HX Theophylline Avicel PH 101 Magnesium Stearate Total batch size % 7.5 22.5 20.0 49.5 0.5 1500g 3750 Tablets Wt per Tab (Mg) 30 90 80 198 2 Material CMC12M8PH Klucel HXF Phenylpropanolamine Avicel PH101 Magnesium Stearate Total batch size % 7.5 22.5 20 49.5 0.5 1500g 3750 Tablets Wt per Tab (Mg) 30 90 80 198 2 Material CMC12M8PH Natrosol 250 HX Theophylline Avicel PH101 Magnesium Stearate Total batch size % 7.5 22.5 20 49.5 0.5 1500g 3750 Tablets Wt per Tab (Mg) 30 90 80 198 2 Experimental Procedures: All ingredients were sieved through a 20 mesh screen. All ingredients except magnesium were then dry blended in a 4 quart low shear Hobart mixer for 2 minutes. Thereafter water was added at a rate of 100 g/min while using low speed stirring. A total of 500ml per 1500 g of powder was added to the formulations containing Klucel. This was increased to 700g for Natrosol containing formulations. The wet masses were tray dried at 60°C down to less than 2 % moisture content. Following the drying step, the granulations were milled using the Fitzpatrick Comminutor Fitzmill at 2300 rpm, knives forward. The reduced granulation was then lubricated by addition of 0,5% magnesium stearate. This final mix was blended for 3 minutes in a V-blender. Compactibility: As shown in Figure 5 for both model formulations, the inclusion of Example 7 CMC in place of CMC 12M8 pH in the tablet matrix results in a significant increase in tablet crushing strength. Drug Release Kinetics While compactibility is improved, inclusion of Example 7 CMC does not manifest in significant differences in the release kinetics when compared to 12M8 pH. This shown in figures 6 and 7 for both highly soluble drug (phenylpropanolamine) and a sparingly soluble drug (Theophylline). Additionally no differences were evident at pH 1.5 or 6.8 between the Example 7 CMC and CMC 12M8 containing formulations. Example 19 The CMC's of the present invention exhibit enhanced thickening efficiency, enchanced high shear viscosity (ICI), improved spatter resistance and improved water resistance in paint formulations. 27 Model of an interior latex flat paint based on Acronal 290 D. Position 1. 2. 3. 4. 5. 6. pre-mix 7. 8. 9. 10. mill base 11. 13. 14. 15. let down PVC (%) NVW (%) Ingredients Water Calgon N Pigmentverteiler A CA24 Agitan 280 thickener Kronos 2057 Omyalite 90 Ourcal 5 Talcom AT 200 Acronal 290 D butylglycol Texanol additional water 80% 61% Function Parts wetting agent dispersing agent preservative defoamer Theological modifier pigment extender extender extender latex binder coalescing agent by weight 230.0 1.5 3.0 3.0 5.0 variable 198.0 140.0 198.0 28.0 93.0 20.0 5.0 71.5 Suppliers: 2 Benckiser Knapsack GmbH 3 BASF AG 4 Biochema Schwaben - Dr. Lehmann & Co. 5 Munzing Chemie GmbH 6 Aqualon / HERCULES 7 Kronos Titan GmbH 8 Pluss Staufer SG 9 Pluss Staufer SG 10 a/s Norwegian Talc 11 BASF AG 12 Shell Nederland Chemie BV 13 Eastman Chemicals BLANOSE7M31C O.S7 7050 98 toe 125 600 2-3 BLANOSE7MJ1C 6780 97 103 120 600 2-3 BLANOSF7M31C 045 6500 97 104 100 550 Example 7 CMC 0.41 78SO 97 107 180 600 Rating 1) 2) 0-10,10 > BEST Wattr rttittane* tt*t ace. Grknthaw; 0 mm » belt ICI Viscosity Determination: Determined using ASTM D4287-83 Krebs Stormer Viscosity Measurement: Determined using ASTM D 562 Levelling Leneta : Determined using ASTM D 4062-81 Levelling test NYPC: Determined using ASTM D 2801-69 Sag Resistance: Determined using ASTM D4400-84 Spatter Resistance - Roller: The following equipment was used to evaluate the samples: paint roller with synthetic fibers e.g. verfroller 15 cm art.nr. 32913 ex Van Vliet Kwastenfabriek wall paper (woodchip quality) e.g. Erfurt Raufaser 52 Procedure: About 200 grams of paint is taken up by the roller. Paint is applied on a woodchip wallpaper with dimensions 100 x 50 cm placed in vertical position. Paint is applied by ten- up and down strokes with the roller. A piece of black carch paper is placed horizontally 50 cm below the bottom line of the wallpaper. The amount of spatter that is intercepted on the black paper is compared to a series of reference charts rating from 1 to 10. A rating of 1 means severe spatter and a rating of 10 stands for completely spatter free. Water Retention (According GRIMSHAW) Equipment used in this part of the experment is: Substrate: Whatman No. 1 circular Filter paper (diameter 12.5 cm) Clamp ring inner diameter 7.7 cm outer diameter 12.6 cm Pasteur pipette (poly ethylene disposable) Colorant: Quink parket permanent block ink Balance Procedure 1. Mix a blend of paint/colorant thoroughly in an aluminum cup. Depending on the viscosity the following ratio's can be chosen: Paint: colorant 50:50 60:40 75:25 Total amount 4-5 grams 2. Put the filter paper between two clamp rings and fix these with paper clips. 3. Weigh the clamped filter paper and apply with a Pasteur pipette 0.5 or 1.0 gram (depending the fluidity of the colored point blob) on the center of the filter paper. 4. Allow an overnight drying at room temperature. 5. Measure with a ruler the shaded stain round the paint center on 6 different spots. 6. The average expressed in mm is a measure for the water retention. A low value means a good water retention. 7. Report the used test conditions, ratio and amount of paint as well as the increase of the stain in mm. While this invention has been described with respect to specific embodiments, it should be understood that these embodiments are not intended to be limiting and that many variations and modifications are possible without departing from the scope and spirit of this invention. We claim: 1. A process for making a carboxymethyl cellulose (CMC) comprising, a) reacting in a slurry process, a source of cellulose, and 40 to 80 wt % of the stoichiometric amount of NaOH for a sufficient time and at a sufficient temperature to form an alkali cellulose, and b) adding to the alkali cellulose an amount of NaOH to bring the total amount of NaOH to about the stoichiometric level, and c) immediately after step b, adding monochloroacetic acid to step b in a sufficient amount and reacting the slurry at a temperature and time sufficient to effect etherification in order to form the CMC product. 2. The process as claimed in claim 1, wherein the sufficient time and temperature to effect etherification is about 70°C for 1 to 2 hours. 3. The process as claimed in claim 1, wherein the CMC product is then cooled, any excess base is neutralized, washed, dried, and ground. 4. A CMC product prepared by a process as claimed in any of the preceding claims.

Full Text

FIELD OF INVENTION
The present invention relates to water-soluble carboxymethylcelluloses
(CMCs) that exhibit unique and highly desirable rheology and performance in
end use systems and to a process for the preparation thereof. The CMCs of the
present invention exhibit associative behavior both in neat solutions and in filled
systems. The association is shear reversible, which enhances utility.
BACKGROUND OF THE INVENTION
Carboxymethylcellulose (CMC) is one of the most versatile and widely
used cellulose ethers as a component for aqueous systems. It may act as a
suspending agent, thickening agent, protective colloid, humectant, and for the
control of crystallization of some other components. CMC is physiologically inert
and is an anionic polyelectrolyte. The above noted characteristics makes CMC
suitable for use in a wide spectrum of applications in the food, pharmaceutical,
personal care; paper, building materials and construction, oilfield, and other
industries.
There are many types of commercial CMCs available varying with respect
to average degree of polymerization and substitution. The chemical and
physical properties of the CMCs depend not only on the average degree of
polymerization and substitution, but also on the overall solubility of the CMC as
well as the distribution of carbomethoxy substituents along the cellulose chains.
Both smoothly and blocky substituted CMCs are well known in the art. Blocky
CMCs can be produced by lowering DS and/or changing the manufacturing
process. However, processes that target a blocky CMC produce CMCs with
limited solubility. In many cases a substantial portion of the CMC forms a
swollen gel in aqueous applications. Such gels are undesirable in many
applications, such as toothpaste, where the gel structure imparts an undesirable
gel appearance in the toothpaste.
US Patent Re 32,976 discloses a smoothly substituted, enzyme and salt
resistant CMC which is prepared using an etherification agent which comprises
at least 50% isopropyl monochloroacetate. Smoothly substituted CMCs will not
provide the associative properties of the current invention. The CMCs of the
present invention are prepared from monochloroacetic acid or sodium
chloroacetate, not isopropyl monochloroacetate.
US Patent No. 4,579,943 discloses a CMC that has high liquid absorbing
property that is derived from regenerated cellulose, having cellulose II form. The
CMCs are of relatively low DS (0.1-0.64) and are substantially insoluble in water.
The CMCs of the current invention are derived from cellulose I, not cellulose II or
regenerated cellulose.
Publication WO 99/20657 discloses a CMC that has a tan delta of less
than 1.0 at a concentration of 0.5 % under specific testing conditions. The CMC
of the current invention do not have a tan delta less than 1.0 at 0.5%
concentration.
The publication by G. Mann, J. Kunze, F. Loth and H-P fink of Fraunhofer
Institutfur Angewandte Polymerforschung entitled "Cellulose ethers with a Blocklike
Distribution of the Substituents by Structure-selective Derivatization of
Cellulose", Polymer, vol. 39, No. 14, pp. 3155-3165, Published 1998, discloses
the preparation and testing of block-like distribution of CMC. The CMC is
prepared by a step-by-step etherification reaction where a systematic
carboxymethylation in alcohol-water medium is conducted while maintaining a
low NaOH concentration (NaOH/AGU molar ratio formed at elevated temperatures (50 - 70° C). It is reported that this process
produces block-like cellulose ethers, including CMC, or cellulose etheresters with
alternating hydrophilic and hydrophobic as well as various ionic chain segments.
The CMCs are swollen particles in water and are not substantially soluble. The
CMCs of the present invention are produced at higher NaOH/AGU ratios (about
1.1 to about 1.9) and low alkali cellulose temperatures (20 - 30° C), and are
substantially soluble in water.
There is still a need for an associative, thixotropic CMC that exhibits
associative behavior both in neat solutions and in filled systems. The
association would be shear reversible, which would enhance utility. Such
rheology would provide high thickening efficiency, and stabilize emulsions and
suspensions, yet allow processing advantages such as ease of pumping or
spreading, due to the reversible shear thinning characteristics of the associative
network.
SUMMARY OF THE INVENTION
The present invention is related to a composition comprising CMC having
a relative urea/water ratio of less than about 0.9. The relative urea ratio is
defined as:
Relative Viscosity in 6M Urea = Dynamic Viscosity of 1 % CMC in 6M = Dynamic Viscosity of 1 % CMC in
urea 6M urea
6M urea viscosity 1.4 cP
Relative Viscosity in Water = Dynamic Viscosity of 1 % CMC in = Dynamic Viscosity of 1 % CMC in
Water 6M urea
Water viscosity 0.89 cP
Relative Urea/Water Ratio = Relative Viscosity in 6M Urea
Relative Viscosity in Water
This invention is also directed to a process for making a CMC comprising
a) reacting in an aqueous slurry of isopropyl alcohol, a source of cellulose, and
about 50 - 80% of the stoichiometric level of alkali for a sufficient time and at a
sufficient temperature to form an alkali cellulose b) adding sufficient alkali to
bring the total alkali concentration to stoichiometric levels, followed by addition of
the requisite amount of etherification agent, c) completing the etherification
reaction and optionally, d) adjusting final molecular weight/viscosity by addition
of oxidizing agents capable of degrading cellulosic chains.
This invention also comprehends the use of the CMC of the present
invention in an aqueous rheology modifier system as a vehicle component of a
personal care, household care, plaint, building material, construction,
pharmaceutical, oilfield, food, paper making or paper coating composition.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 shows a graph of toothpaste viscosity over time.
Figure 2 shows a graph of toothpaste viscosity overtime that has been
normalized.
Figure 3 shows a graph of toothpaste structure over time.
Figure 4 shows a graph of toothpaste structure overtime that has been
normalized.
Figure 5 shows a graph of crushing strengths of blends of polymers.
Figure 6 shows a graph of percent drug dissolved over time.
Figure 7 shows a graph of percent drug dissolved over time.
DETAILED DESCRIPTION OF THE INVENTION
A CMC has been surprisingly discovered that exhibits unique and highly
desirable rheology and performance properties in end use systems.
In accordance with the present invention, the viscosity builds up not only
by means conventional to CMC, but also is boosted significantly by molecular
association. The association leads to network formation and gel-like rheological
properties. The fact that the association is shear reversible enhances utility.
The CMCs of the present invention have been shown to lower the CMC
use level needed and to provide rheology attributes unique from other CMCs
available today. The unique rheology provides high thickening efficiency, and
stabilizes emulsions and suspensions. The CMCs of the present invention
provide significantly enhanced performance over known CMCs in aqueous
systems including personal care formulations (e.g., toothpaste, skin care, and
hair care), medical care (e.g., wound care and ostomy,), food applications (i.e.,
tortillas, cake mixes, bread mixes, bread, ice cream, sour cream, pasteurized
processed cheese spreads, and cheese foods), beverages (i.e., instant cold/hot
drinks, ready to drink beverages, and fruit flavored drinks), paint systems,
building and construction materials (such as joint formulations), mineral
processing, oil field formulations (e.g., drilling fluids), paper making and paper
coating formulations, household formulations (e.g., laundry detergents, fabric
softeners), and pharmaceutical formulations.
In accordance with the present invention, when the composition is a
personal care composition, it includes (a) from about 0.1 % to about 99.0 % by
weight of the vehicle component and (b) at least one active personal care
ingredient. Examples of the at least one active personal care ingredient are
deodorant, skin coolants, emollients, antiperspirant actives, moisturizing agents,
cleansing agents, sunscreen actives, hair treatment agents, oral care agents,
tissue paper products, and beauty aids.
In accordance with the present invention, the composition is a household
care composition, it includes (a) from about 0.1 % to about 99.0 % by weight of
the vehicle component and (b) at least one active household care ingredient.
Examples of the at least one active household care ingredient are industrial
grade bar, gel and liquid soap actives, all purpose cleaning agents, disinfecting
ingredient, rug and upholstery cleaning actives, laundry softeners actives,
laundry detergent ingredients, dishwashing detergents, toilet bowl cleaning
agents and fabric sizing agents.
In addition to the ingredients conventionally used in the personal care and
household care, the composition according to the present invention can
optionally also include ingredients such as a colorant, preservative, antioxidant,
nutritional supplements, activity enhancer, emulsifiers, viscosifying agents (such
as salts, i.e., NaCI, NHUCI & KCI, water-soluble polymers, i.e.,
hydroxyethylcellulose, and fatty alcohols, i.e., cetyl alcohol), alcohols having 1-6
carbons, and fats and oils.
The CMCs may also be used in combination with other known rheology
modifiers including, but not limited to, polysaccharides (e.g., carrageenan, guar,
hyaluronicacid, glucosaminoglycan, hydroxyethyl cellulose, hydrophobically
modified hydroxyethyl cellulose, ethyl hydroxyethyl cellulose, hydroxypropyl
methylcellulose, hydroxyethyl methylcellulose, methylcellulose, cationic guar,
carbomer), biopolymers (e.g., xanthan), synthetic polymers (polyethylene glycol,
polyvinylacetate, chlorohexidiene), and thickening silicas.
The use of CMC in toothpaste formulations is well known in the
toothpaste industry as a binder system for toothpaste that gives the toothpaste a
desirable high structure. The binder system includes CMC types with other
polysaccharides, inorganic salts, chelating agents and combinations thereof.
Commercially available CMC types vary in the degree of structure they
provide to the toothpaste. Highly thixotropic grades of CMC tend to render
toothpaste of higher structure. These thixotropic CMC types also tend to
contribute to greater post-thickening.
Cellulose gum (CMC) alone has been a traditional binder for toothpaste.
In toothpaste, CMC provides viscosity, stand-up or structure, and syneresis
control. Toothpaste made with CMC is also known to have a slow rate in
viscosity build up over the shelf life of the toothpaste thus not reaching a stable
viscosity until after first 30 days or more. This is also called "post-thickening".
Other binders commonly used in toothpaste are carrageenan or
carrageenan and xanthan together. Carrageenan and xanthan provide good
stand-up, viscosity and syneresis control; however, they tend to be more
expensive alternatives as compared to CMC. Toothpaste made with
carrageenan and xanthan tend to exhibit a stable viscosity rather quickly after
processing and little post-thickening.
In accordance with the present invention, the CMC of the present
invention can be use either alone or in combination with other polysaccharides,
synthetic polymers and or salts and provide high efficiencies and enhanced
performance. See the toothpaste Examples hereinafter for the demonstration of
the unexpected results of the present invention.
Use of the CMCs of the present invention have allowed a use level
reduction of about 40% while maintaining critical toothpaste properties such as
stand-up, gloss and syneresis control. The lower use levels and/or shear
thinning behavior of the CMCs may offer additional advantages to toothpaste
properties such as improved flavor release, improved actives delivery, improved
fluoride delivery, higher gloss, improved extrudability from the tube, and
improved anti-microbial effectiveness. Potential improvements to the toothpaste
manufacturing process include, but are not limited to, reduction of entrapped air
during manufacturing process, improvements in mixing operations, and
improvements in extrusion into tubes.
Water-based protective coating compositions (commonly referred to as
paints) in which cellulose ether derivatives are conventionally used include latex
paints or dispersion paints, of which the principal ingredients are film-forming
lattices such as styrenebutadiene copolymers, vinyl acetate polymers and
copolymers, and acrylic polymers and copolymers. Typically, they also contain
opacifying pigments, dispersing agents and water-soluble protective colloids, the
proportions being, by weight of the total composition, about 10 parts to about 50
parts of a latex, about 10 parts to about 50 parts of an opacifying pigment, about
0.1 part to about 2 parts of a dispersing agent, and about 0.1 part to about 2
parts of a water-soluble protective colloid.
Water soluble protective colloids conventionally used in the manufacture
of latex paints (to stabilize the lattices and maintain the wet edge of a painted
area longer in use) include casein, methyl cellulose, hydroxyethylcellulose
(HEC), sodium carboxymethyl cellulose (CMC), polyvinyl alcohol, starch, and
sodium polyacrylate. The disadvantages of the natural based cellulose ethers
are that they may be susceptible to biological degradation and frequently impart
poor flow and leveling properties, while the synthetic materials such as polyvinyl
alcohol often lack enough thickening efficiency to maintain sag resistance. The
thickening efficiency of the cellulose ethers is usually improved by increasing
their molecular weight which normally is more expensive.
In accordance with the present invention, the CMC of the present
invention can be used in lower amounts in paints and provide unexpected high
quality results. This is illustrated in the working Examples hereinafter.
The CMCs of the present invention are prepared using conventional slurry
process methods. For example, isopropyl alcohol, water, and about 50 -80% of
the stoichiometric amount of NaOH are reacted with cellulose at a temperature
of about 20°C for a sufficient time to produce alkali cellulose, about 1.5 hours.
Sufficient NaOH is added to bring the total NaOH level to or slightly above
stoichiometric levels and monochloroacetic acid is added shortly after the
second NaOH addition. The reaction conditions are normally to raise the
temperature to about 70°C for about one to two hours to effect etherification.
The molecular weight and viscosity of the CMC can be adjusted (reduced) by
addition of an oxidizing agent, such as hydrogen peroxide, subsequent to
etherification. The reaction mass is then optionally cooled, excess base
neutralized, if necessary, and the product is washed. This product can then be
dried and ground. The critical feature of this invention is that the amount of alkali
utilized to effect etherification is less than stoichiometric and that the remaining
alkali is added just prior to the etherification agent. The degree of substitution of
the CMC is about 0.6 to about 1.2.
In accordance with the present invention, the CMC can be differentiated
from prior art CMCs by their being substantially soluble in aqueous media
environments and their behavior in environments that do not favor association. It
is a known fact that urea breaks up association by breaking hydrogen bonds.
The subject CMCs exhibit a viscosity decrease in the presence of urea, as
determined by the relative urea ratio. The relative urea ratio is defined as:
Relative Viscosity in 6M Urea = Dynamic Viscosity of 1 % CMC in 6M = Dynamic Viscosity of 1 % CMC in
urea 6M urea
6M urea viscosity 1.4 cP
Relative Viscosity in Water = Dynamic Viscosity of 1 % CMC in = Dynamic Viscosity of 1 % CMC in
Water 6M urea
Water viscosity 0.89 cP
Relative Urea/Water Ratio = Relative Viscosity in 6M Urea
Relative Viscosity in Water
EXAMPLES
The following examples are merely set forth for illustrative purposes, but it
is to be understood that other modifications of the present invention within the
skill of an artisan in the related industry can be made without departing from the
spirit and scope of the invention. All percentages and parts are by weight unless
specifically stated otherwise.
Example 1
Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.945g) were
charged into a jacketed resin kettle reactor equipped with an air driven stirrer,
stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser,
vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 6.4%
moisture) was added to the reactor, the reactor was sealed, and the agitator was
adjusted to obtain good mixing. The reactor was inerted and the mixture was
cooled to 20°C.
Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 1 hour at 20°C after the caustic addition was
completed.
Aqueous NaOH (50%, 16.02g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 5 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 42.91 g) was added to the reactor
through an open reactor port, maintaining a reactor slurry temperature of 20°C.
After MCA addition was completed, the reaction slurry was heated to 70°C and
held for 1.5 hours. The reaction slurry was filtered and the resulting wet cake
was washed three times with 565g of 80% aqueous methanol and one time with
1000g of pure methanol. The resulting wet cake was broken into small particles
and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry
at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The
product was ground in Retsch Grinding Mill using a 1mm screen. Degree of
Substitution (DS) = 0.89
Example 2
Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.945g) were
charged into a jacketed resin kettle reactor equipped with an air driven stirrer,
stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser,
vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.Og, 6.4%
moisture) was added to the reactor, the reactor was sealed, and the agitator was
adjusted to obtain good mixing. The reactor was inerted and the mixture was
cooled to 20°C.
Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 1 hour at 20°C after the caustic addition was
completed.
Aqueous NaOH (50%, 16.02g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 5 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 42.91g) was added to the reactor
through an open reactor port, maintaining a reactor slurry temperature of 20°C.
After MCA addition was completed, the reaction slurry was heated to 70°C and
held for 1.5 hours. 1.6 ml of 6% H202 was added to the reactor and the slurry
was heated at 70°C for 30 minutes. The reaction slurry was filtered and the
resulting wet cake was washed three times with 565g of 80% aqueous methanol
and one time with 1000g of pure methanol. The resulting wet cake was broken
into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for
5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an
additional 20 minutes.) The product was ground in Retsch Grinding Mill using a
1 mm screen. Degree of Substitution (DS) = 0.87.
Example 3
Isopropyl alcohol (IPA, 123.4 gallons), water (130.3 Ibs), methanol (6.36
gallons), and NaOH (flake, 35.4 Ibs.) were charged into the reactor. The reactor
was inerted and the caustic/solvent mix was cooled to about 20°C, at which time
a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation
was adjusted to give good mixing in the slurry and the slurry was recooled to
about 20°C. The reaction slurry was held for 1 hour at 20°C.
Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the
reaction mixture was held for 15 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 70.5 Ibs.). IPA (9.0 gallons),
dichloroacetic acid (DCA, 926.8g) and acetic acid (79.9g) were added to the
reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition
was completed, the reaction slurry was heated to 70°C and held for 1 hour. 282g
of 18% H2O2 was added to the reactor and the slurry was heated at 70°C for 60
minutes.
The reaction slurry was centrifuged and the wet cake was washed with
three times with 300 gallons of 80% methanol and two times with 300 gallons
100% methanol. The material was dried in an Abbe dryer under vacuum at 80 -
90°C to a moisture content of 4 - 6 %. The product was ground in a
micropulverizer through a 0.0278 inch screen. Degree of Substitution (DS) =
0.79.
Example 4
The conditions of Example 3 were repeated. DS = 0.78
Example 5
Isopropyl alcohol (IPA, 121.9 gallons), water (130.0 Ibs), methanol (6.29
gallons), and NaOH (flake 45.6 Ibs.) were charged into the reactor. The reactor
was inerted and the caustic/solvent mix was cooled to about 20°C, at which time
a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation
was adjusted to give good mixing in the slurry and the slurry was recooled to
about 20°C. The reaction slurry was held for 1 hour at 20°C.
Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the
reaction mixture was held for 15 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 81.0 Ibs.). IPA (9.0 gallons),
dichloroacetic acid (DCA, 1065.9g) and acetic acid (91.9g) were added to the
reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition
was completed, the reaction slurry was heated to 70°C and held for 1 hour.
188g of 18% H202 was added to the reactor and the slurry was heated at 70°C
for 60 minutes.
The reaction slurry was centrifuged and the wet cake was washed with
three times with 300 gallons of 80% methanol and two times with 300 gallons
100% methanol. The material was dried in an Abbe dryer under vacuum at 80 -
90°C to a moisture content of 4 - 6 %. The product was ground in a
micropulverizer through a 0.0278 inch screen. Degree of Substitution
(DS)= 0.86.
Example 6
The conditions of Example 5 were repeated. DS = 0.86
Example 7
Isopropyl alcohol (IPA, 121.1 gallons), water (146.0 Ibs), methanol (6.24
gallons), and NaOH (flake, 35.4 Ibs.) were charged into the reactor. The reactor
was inerted and the caustic/solvent mix was cooled to about 20°C, at which time
a cellulose pulp (108lbs, 4% moisture) was added to the reactor. The agitation
was adjusted to give good mixing in the slurry and the slurry was recooled to
about 20°C. The reaction slurry was held for 1 hour at 20°C.
Aqueous NaOH (50%, 58.7 Ibs.) was added to the reactor and the
reaction mixture was held for 15 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 70.5 Ibs.). IPA (9.0 gallons),
dichloroacetic acid (DCA, 926.8g) and acetic acid (79.9g) were added to the
reactor, maintaining a reactor slurry temperature of 20°C. After MCA addition
was completed, the reaction slurry was heated to 70°C and held for 1 hour. 282g
of 18% H202 was added to the reactor and the slurry was heated at 70°C for 60
minutes.
The reaction slurry was centrifuged and the wet cake was washed with
three times with 300 gallons of 80% methanol and two times with 300 gallons
100% methanol. The material was dried in an Abbe dryer under vacuum at 80 -
90°C to a moisture content of 4 - 6%. The product was ground in a
micropulverizer through a 0.0278 inch screen. Degree of Substitution (DS) =
0.79.
Example 8
Isopropyl alcohol (IPA, 14 kg), water (2184g), methanol (728.8g), were
charged into the reactor. The reactor was inerted and the solvent mix was
cooled to about 20°C, at which time a cellulose pulp (1800 g, 3.6% moisture)
was added to the reactor. The agitation was adjusted to give good mixing in the
slurry, the slurry was recooled to about 20°C, and NaOH (flake, 691.4g) was
added to the reactor. The reaction slurry was held for 1 hour at 20°C.
Aqueous NaOH (50%, 353.6g) was added to the reactor and the reaction
mixture was held for 15 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 939.8g). IPA (977g), dichloroacetic
acid (DCA, 27.3g) and acetic acid (2.4g) were added to the reactor, maintaining
a reactor slurry temperature of 20°C. After MCA addition was completed, the
reaction slurry was heated to 70°C and held for 1 hour.
The reaction slurry was filtered, and the resulting wet cake was washed
three times with 12 gallons of 80% aqueous methanol, and one time with 12
gallons of 95% methanol. The material was dried in a vacuum tray dryer at 70°C
to a final moisture content of 4 - 6%. The dried product was ground in a
micropulverizer through a 0.0278 inch screen. Degree of Substitution = 0.73.
Example 9
Isopropyl alcohol (IPA, 696.67g) and deionized (Dl) water (76.95g) were
charged into a jacketed resin kettle reactor equipped with an air driven stirrer,
stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser,
vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 6.8%
moisture) was added to the reactor, the reactor was sealed, and the agitator was
adjusted to obtain good mixing. The reactor was inerted and the mixture was
cooled to 20°C.
Aqueous NaOH (50%, 60.92g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 1 hour at 20°C after the caustic addition was
completed.
Aqueous NaOH (50%, 36.37g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 5 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 42.91 g) was added to the reactor
through an open reactor port, maintaining a reactor slurry temperature of 20°C.
After MCA addition was completed, the reaction slurry was heated to 70°C and
held for 1.5 hours. 1.6 ml of 6% hfeC^ was added to the reactor and the slurry
was heated at 70°C for 30 minutes. The reaction slurry was filtered and the
resulting wet cake was washed three times with 565g of 80% aqueous methanol
and one time with 1000g of pure methanol. The resulting wet cake was broken
into small particles and dried in a fluidized bed dryer for 35 minutes. (Air-dry for
5 minutes, heat-dry at 50°C for 10 minutes, and heat-dry at 70°C for an
additional 20 minutes.) The product was ground in Retsch Grinding Mill using a
1 mm screen. Degree of Substitution (DS) = 0.62. 1 % aqueous viscosity = 2200
cps.
Example 10
Isopropyl alcohol (IPA, 713.86g) and deionized (Dl) water (73.79g) were
charged into a jacketed resin kettle reactor equipped with an air driven stirrer,
stainless steel agitator, a pressure equalizing addition funnel, a reflux condenser,
vacuum, nitrogen inlet and a thermocouple. A cellulose pulp (65.0g, 3.7%
moisture) was added to the reactor, the reactor was sealed, and the agitator was
adjusted to obtain good mixing. The reactor was inerted and the mixture was
cooled to 20°C.
Aqueous NaOH (50%, 39.98g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 1 hour at 20°C after the caustic addition was
completed.
Aqueous NaOH (50%, 35.77g) was slowly added to the reactor through
the addition funnel, maintaining the mixture slurry temperature at 20°C. The
reaction mixture was held for 5 minutes at 20°C after the caustic addition was
completed. Monochloroacetic acid (MCA, 42.25g) was added to the reactor
through an open reactor port, maintaining a reactor slurry temperature of 20°C.
After MCA addition was completed, the reaction slurry was heated to 70°C and
held for 1.5 hours. The reaction slurry was filtered and the resulting wet cake
was washed three times with 565g of 80% aqueous methanol and one time with
1000g of pure methanol. The resulting wet cake was broken into small particles
and dried in a fluidized bed dryer for 35 minutes. (Air-dry for 5 minutes, heat-dry
at 50°C for 10 minutes, and heat-dry at 70°C for an additional 20 minutes.) The
product was ground in Retsch Grinding Mill using a 1mm screen. Degree of
Substitution (DS) = 0.84. 1% aqueous viscosity = 3760 cps.
Example 11
This Example illustrates the behavior of the preparations of a 1.0% CMC
samples of the present invention in a 6.0 M urea solution.
The 1 % CMC solution was prepared in the following equipment:
Caframo RZR1 overhead stirrer, 8-oz. glass jars, stainless steel
stirring shaft with two 3-blade propellers (1.5 inch diameter),
Parafilm®, deionized (Dl) water, Germaben II.
A 0.50% Germaben solution was prepared by adding the Germaben II to
Dl water. This solution was then weighed into an 8-oz. glass jar. The solution
was then stirred with an overhead stirrer, while the CMC was quickly added to
the solution. The CMC level is 1.0% of the final sample weight. CMC weight is
corrected for moisture content. As the viscosity begins to increase, the speed of
the stirrer was increased to the maximum rate that does not cause splashing out
of the sample. The jar is covered with Parafilm while mixing to prevent
evaporation of water and loss from splashing. The sample is stirred for one
hour. After one hour of stirring at the highest rate, the stirring speed was
decreased to a setting of 4 for one additional hour. The sample was centrifuged
for approximately 5 minutes to remove trapped air.
The behavior of the samples were studied in the following equipment:
Caframo RZR1 overhead stirrer, 8-oz. glass jars, stainless steel
stirring shaft with two 3-blade propeller (1" diameter), Parafilm®,
6.0M Urea (180.18g urea diluted to 500ml)
Procedure:
6.0M urea solution was weighed into an 8-oz. glass jar. The solution was
stirred with an overhead Caframo RZR1 stirrer, as the CMC was quickly added
to the solution. The CMC level was 1.0% of the final sample weight. CMC
weight was corrected for moisture content. As the viscosity begins to increase,
the speed of the stirrer was increased to the maximum rate that does not cause
splashing out of the sample. The jar was covered with Parafilm while mixing to
prevent evaporation of water and loss from splashing. The sample was stirred
for one hour. After one hour of stirring at the highest rate, the stirring speed was
decreased to a setting of 4 for one additional hour. The sample was centrifuged
for approximately 5 minutes to remove trapped air.
Table 1
CMC
Example 8
Example 1
Example 2
Example 7
Example 5
Example 3
Example 4
Example 6
Aqualon 7LF
Aqualon 7LF
Aqualon 7L
Aqualon 7H3SF
Aqualon 7H3SF
Aqualon 7H3SF
Aqualon 7H3XSF
Aqualon 7H3SXF
Aqualon 7HF
Aqualon 7H4F
Aqualon 7M8SF
Aqualon 9M31F
Aqualon 9M31F
Aqualon 9M31F
Aqualon 9M31XF
Amtex
Antisol FL
300000
Aqualon
Aquapac
Aqualon
Aquapac
DKS Cellogen
HE-90
DKS Cellogen
HP-5HS
Fine Gum SA-H
Monpac Regular
Novlant Cekol
SOOT
Noviant Cekol
700
Noviant Cekol
2000
PAC-R
TylopurdOOO
P2
Walocel CRT
2000
DS
0.73
0.89
0.87
0.79
0.86
0.79
0.78
0.86
0.81
0.79
0.97
0.92
0.88
0.89
0.86
0.77
0.9
0.92
0.9
1%
Dynamic
Water
viscosity
1113
574
238
762
265
286
346
163
11
11
9
7191
2286
7337
3262
3111
7023
4875
68
260
577
539
282
168
2852
7795
11446
100
4417
463
2755
47
53
139
7335
316
180
1%
Dynamic
6M Urea
viscosity
1364
632
288
539
338
355
398
228
16
17
14
12754
4179
13258
5909
4950
11648
8576
111
467
1065
823
470
282
8510
12583
19881
179
8154
1016
5980
68
96
246
11798
558
285
Relative
U/W ratio
0.78
0.70
0.77
0.45
0.81
0.79
0.73
0.89
0.97
0.96
0.97
1.13
1.16
1.15
1.15
1.01
1.05
1.12
1.03
1.14
1.17
0.97
1.06
1.07
1.90
1.03
1.10
1.14
1.17
1.40
1.38
0.92
1.16
1.13
1.02
1.12
1.01
The flavor was mixed in the same way. After all formula components were
together, the mixture was mixed under vacuum for 15 minutes at high speed.
The batch was then packed into 2-oz. jars and 6-oz. toothpaste tubes.
Toothpaste samples were stored for 30 days at room temperature.
Samples were equilibrated in a 25°C water bath for 4 hours prior to any tests
conducted.
Viscosity was measured using a Brookfield DV-I fitted with a T-bar style
spindle. A helipath stand was used to allow the spindle to sweep downward
through the sample to prevent the effects of shear. Viscosity was taken every 30
seconds over 2 minutes and values were averaged.
Toothpaste consistency was measured using a rack test. The rack
designed with cross bars of increasing distance apart left to right. The
toothpaste tube containing the sample to be measured is fitted with a stainless
orifice fitting to eliminate differences in orifice size that may occur. The tube is
squeezed in a uniform manner across the rack, extruding the paste onto the rack
in a ribbon. After 15 seconds it is recorded at which opening the ribbon has
fallen through the opening and broken. The opening number from left to right is
the value recorded as a "Cuban" value.
The toothpaste data are summarized in Table 2.
Table 2
Polymer
Example 2
Example 1
Example 3
Example 4
Example 5
Example 6
Example 7
Cekol SOOT
Cekol 2000
9M31XFGL
9M31F
30 day
Toothpaste
Viscosity
137500
188125
146750
136250
120000
94500
125750
61875
25875
40125
32500
Cuban
5
10
6
6
5
3
5
2
0
0
0
Comments
severe
syneresis
syneresis
syneresis
Example 14
The CMC's of the present invention in combination with other polymers
exhibit decreased post thickening and structure build and enhanced initial
structure in toothpaste formulations.
Viscosity is one measure of post-thickening in toothpaste. Toothpaste
samples were packed into vials and the viscosity was measured using a
Brookfield DV-I fitted with a T-bar style spindle. A helipath stand was used to
allow the spindle to sweep downward through the sample to prevent the effects
of shear. Viscosity was taken every 30 seconds over 2 minutes and values were
averaged
It can be seen from the data in the graph (Figure 1) that most samples
exhibited a change in viscosity from the first day after processing through 30
days. When the data are normalized to the initial viscosity as 100%, the change
over time is more apparent (Figure 2). Toothpaste made with combinations of
Example 7 CMC with other polysaccharides or inorganic salts exhibited lower
post-thickening compared to toothpaste made with Example 7 alone.
Toothpaste structure is also an important aspect. This property may be
measured by force required for compression using a MTS Servo Hydraulic test
system from MTS Systems Corporation, Minneapolis, MN. The instrument was
fitted with a half-inch acrylic cylinder probe, toothpaste samples were packed
into vials after processing and measured directly without disturbance.
It can be seen below in Table 3 that the Example 7 CMC alone or with
other polysaccharides or inorganic salt produced toothpaste of similar or greater
initial structure compared to toothpaste made with carrageenan and xanthan and
much greater initial structure than toothpaste made with commercial CMC
9M31F.
Peak force of compression was monitored over 30 days. It was found that
most samples changed in values (Figure 3). The comparison can be made more
Example 12
Dynamic viscosities were measured using at 25°C using an RFS III
strained controlled rheometer by Rheometrics using a 40 mm parallel tool
geometry with the gap set at 2 mm. The samples were pre-sheared at 100s"1 for
60 second upon loading to erase the loading history. The pre-shearing was
followed by the steady shear experiment between 0.01 and 100s"1. Each point
data is the average of clockwise and counter-clockwise rotations each with the
duration of 20 sec. All samples exhibited a low shear Newtonian plateau, the
average of which was used in the data analysis and further comparisons. The
dynamic viscosities of the aqueous and 6M 1% CMC solutions are summarized
in Table 1. The relative urea/water ratios are also summarized in Table 1,
above.
Example 13
The CMC's of the present invention exhibit enhanced thickening
capabilities and syneresis control in toothpaste formulations. Calcium Carbonate
Based Toothpaste formulation:
Ingredient: wt. %
Calcium carbonate 45.00
Sorbo® sorbitol (70% solids) 27.00
Distilled water 23.97
CMC Polymer (Table 2) 0.60
Sodium lauryl sulfate, 100% active powder 1.00
Sodium monofluorophosphate 0.76
Sodium benzoate 0.50
Flavor 0.55
Tetra sodium pyrophosphate 0.42
Sodium saccharin 0.20
100.00
Standard laboratory toothpaste preparation was performed. Salts were
first dissolved in part of the water and warmed for complete dissolution. The
CMC was dispersed in the sorbitol, using an overhead mixer with a propeller
attachment. After the CMC was well dispersed, the balance of the water was
added with continued mixing until the CMC appeared dissolved. The warm salt
solution was mixed into the CMC solution. This was then transferred to a 1-quart
Ross double planetary mixer. The calcium carbonate was then stirred in the
mixer, and after it was well dispersed, a vacuum was applied. After mixing under
vacuum for 20 minutes, the sodium lauryl sulfate was mixed in without vacuum.
easily if the data are normalized to the initial structure value as 100% as
shown in Figure 4. From the normalized data of Figure 4, it can be seen that
toothpaste samples made with combinations of CMC of Example 7 with other
polysaccharides or inorganic salt have lower structure build over time.
From the work outlined here, it can be concluded that toothpaste with high
structure and low post-thickening can be made with CMCs of the present
invention in combination with other polysaccharides, inorganic salts or
combinations thereof.
The toothpaste formulation used in this Example was as follows:
Ingredient
Sorbitol (Sorbo)
Glycerine
PEG 400
Sident 9
Sident 22S
Sodium Saccharine
Sodium Monofluorophosphate
Sodium Benzoate
Sodium Lauryl Sulfate
Flavor
Water
Wt. %
29.2
6
3
14
16
0.20
0.23
0.20
1.20
0.50
q.s.
The different polymers used in this Example in the formulation was as
follows:
Formulation
1
2
3
4
5
6
7
8
Polymer: wt%
Carrageenan(THPI) 0.7
CMC Example 7 1 .0
CMC9M31F 1.0
CMC Example 7 0.5
CMC Example 7 0.6
CMC Example 7 0.7
CMC Example 7 1 .0
CMC Example 7 0.7
Polymer:
Xanthan (Rhodicare)
wt%
0.3
N/A
N/A
Natrosol + 330
Natrosol 250 M
Carrageenan
Sodium Silicate
Xanthan
0.3
0.6
0.3
0.5
0.3
Table 3
Initial Toothpaste Structure
Peak Force Compression from MTS
Polymer
Carageenan/Xanthan
Example 7
Example 7 / HMHEC
Example 7 / Na2SiO3
Example 7 / HEC
Example 7 / Carrageenan
Example 7 / Xanthan
CMC 9M31 F
Peak Force
Compression, g
56.5
51.1
78.1
60.8
75.1
75.3
35.0
14.7
Toothpaste after 24 hours, ambient temperature.
The identity and supplier of the ingredients of this Example are as follows:
Sorbitol
Glycerine
PEG 400
Silica, thickening
Silica, abrasive
Sodium Lauryl Sulfate
Flavor
Sodium Silicate, crystalline
Sodium Benzoate
Saccharine
Sodium Fluorophosphate
Carrageenan
Xanthan
CMC9M31F
HM HEC Natrosol Plus 330 CS
HEC Natrosol 250 M Pharm
Sorbo, 70%, USP/FCC, SPI Pharma, New Castle, DE. USA
Glycerine, USP, Spectrum Chemical, Gardena, CA,
Polyethylene Glycol NF, Dow Chemical, Midland, Ml
USA
, USA
Sident 9, Degussa, Frankfurt, Germany
Sident 22S, Degussa, Franfurt, Germany
Stepan, Northfield, IL, USA
Fresh Mint, Givaudan, UK
JT Baker, reagent grade
Fisher Scientific, reagent grade
Sigma, reagent grade
Alfa Aesar, Ward Hill, ME, USA
THP1, CP Kelco, San Diego, CA, USA
Rhodicare S, Rhodia, Cranbury NJ, USA
Aqualon
Aqualon
Aqualon
Example 15
The CMC's of the present invention exhibit enhanced thickening
capabilities in beverage formulations.
Beverage Example
Orange Beverage - Reference
Ingredients Wt%
Orange Juice concentrate, 45 Brix 7.00
Sugar 40.00
Citric acid 0.05
Sodium benzoate 0.55
Water 52.14
Cellulose Gum, CMC-9M31F 0.60
Orange Beverage - Test Example
Ingredients Wt%
Orange Juice concentrate, 45 Brix 7.00
Sugar 40.00
Citric acid 0.05
Sodium benzoate 0.55
Water 52.14
Polymer Example/ 0.42
Mix cellulose gum or polymer into water, allow to mix for 20 minutes.
Premix acid, preservative and sugar, add and mix 5 minutes. Add juice
concentrate, mix 3 minutes.
Beverage results: Reference Test Example
Viscosity, 24 hours, cps 53.0 51.0
Brookfield LV, spindle 2, 30 rpm, 20s
Example 16
The CMC's of the present invention exhibit enhanced thickening
capabilities in food formulations.
Cake Mix and Cake Example
CAKE MIX - Reference
Ingredients for Drv Mix % Flour wt Wt%ofdrvmix
Bleached Cake Flour 100 40.4
Sugar 105.9 42.2
Shortening 27.2 11.0
Milk Solids Nonfat 3.7 1.5
Dextrose(1) 2.5 1.0
Salt 2.5 1.0
Sodium Bicarbonate(2) 2.2 0.9
Sodium aluminum phosphate(3) 1.2 0.9
Vanilla Powder^ 1.2 0.5
Butter Flavor(5) 0.3 0.1
Cellulose Gum, CMC-7HF 1.2 0.5
CAKE MIX - Test Example
Ingredients for Drv Mix % Flour wt Wt % of dry mix
Bleached Cake Flour
Sugar
Shortening
Milk Solids Nonfat
Dextrose0 >
Salt
Sodium Bicarbonate (2)
Sodium aluminum phosphate (3)
Vanilla Powder(4)
Butter Flavor(5)
Polymer Example 9
100
105.9
27.2
3.7
2.5
2.5
2.2
1.2
1.2
0.3
0.72
40.4
42.2
11.0
1.5
1.0
1.0
0.9
0.9
0.5
0.1
0.3
(1) Arm & Hammer Baking Soda, Church & Dwight
(2) Cantab Dextrose, Penford Food Ingredient Company
(3) Levair, FCC Grade Sodium Aluminum Phosphate, Rhodia Food Ingredients
(4) Vanilla FL Pure Pwd K, Virginia Dare
(5) Butter FL N&A Pwd 685 KD, Virginia Dare
Formulation for the Finished Cake - One 8-inch Laver
Dry mix, g 270
Water, g 140
Whole egg, g 53
Dry ingredients were blended on mixer with paddle attachment until
evenly mixed. Water and egg were added to mix and mixed on medium speed
for 3 minutes. The batter was poured into a greased cake pan and baked in a
moderate oven (350°F/177°C) for 30 minutes.
Cake results: Reference
Batter Viscosity, cps
Brookfield RV, spindle 3, 10 rpm, 30 s
Batter density, g/100mls
Cake height, cm
Crumb cell structure
Bake out
Crumb moisture, 24 hours after bake, %
5660
111
3.8
even
OK
39.0
Test Example
7650
113
3.8
even
OK
39.0
Example 17
The CMCs of the present invention exhibit efficiency by the use of
reduced amounts but yet obtain corporate results with prior art materials. The
film forming and viscosity properties are enhanced in food preparations.
Masa and Corn Tortilla Example
MASA - Reference
Ingredients for Drv Mix
NCF(1)
Sodium Benzoate
Fumaric Acid
Cellulose Gum, CMC-7H4F K
MASA - Test Example
Ingredients for Dry Mix
NCF(1)
Sodium Benzoate
Fumaric Acid
Polymer Example 10
% Flour wt
100
0.4
0.3
0.5
% Flour wt
100
0.4
0.3
0.3
Wt % of drv mix
98.83
0.39
0.29
0.49
Wt % of drv mix
98.63
0.39
0.29
0.29
(l)Nixtamalized corn flour, Quaker Oats Company
Dry ingredients were blended on mixer with paddle attachment until
evenly mixed. Water was added to mix and mixed on medium speed for 2
minutes. Dough was portioned into 50g balls and pressed on a tortilla press.
The tortillas were baked on an ungreased skillet for 1 minutes on each side.
Tortillas were cooled on a wire rack, wrapped in foil sheets and checked for
pliability and reheat after 1 day.
Tortilla results: Reference Test Example
Appearance after bake even blisters even blisters
Pliability good roll, no cracks good roll, no cracks
Reheat good puff good puff
Example 18
The CMC's of the present invention exhibit enhanced tablet crushing
strength without effecting drug release kinetics.
The following formulations were prepared:
Material
Example 7
Klucel HXF
Phenylpropanolamine
Avicel PH101
Magnesium Stearate
Total batch size
%
7.5
22.5
20.0
49.5
0.5
1500q
3750 Tablets
Wt per Tab (Mq)
30
90
80
198
2
Material
Example 7
Natrosol 250 HX
Theophylline
Avicel PH 101
Magnesium Stearate
Total batch size
%
7.5
22.5
20.0
49.5
0.5
1500g
3750 Tablets
Wt per Tab (Mg)
30
90
80
198
2
Material
CMC12M8PH
Klucel HXF
Phenylpropanolamine
Avicel PH101
Magnesium Stearate
Total batch size
%
7.5
22.5
20
49.5
0.5
1500g
3750 Tablets
Wt per Tab (Mg)
30
90
80
198
2
Material
CMC12M8PH
Natrosol 250 HX
Theophylline
Avicel PH101
Magnesium Stearate
Total batch size
%
7.5
22.5
20
49.5
0.5
1500g
3750 Tablets
Wt per Tab (Mg)
30
90
80
198
2
Experimental Procedures:
All ingredients were sieved through a 20 mesh screen. All ingredients
except magnesium were then dry blended in a 4 quart low shear Hobart mixer
for 2 minutes. Thereafter water was added at a rate of 100 g/min while using
low speed stirring. A total of 500ml per 1500 g of powder was added to the
formulations containing Klucel. This was increased to 700g for Natrosol
containing formulations. The wet masses were tray dried at 60°C down to less
than 2 % moisture content. Following the drying step, the granulations were
milled using the Fitzpatrick Comminutor Fitzmill at 2300 rpm, knives forward.
The reduced granulation was then lubricated by addition of 0,5% magnesium
stearate. This final mix was blended for 3 minutes in a V-blender.
Compactibility:
As shown in Figure 5 for both model formulations, the inclusion of
Example 7 CMC in place of CMC 12M8 pH in the tablet matrix results in a
significant increase in tablet crushing strength.
Drug Release Kinetics
While compactibility is improved, inclusion of Example 7 CMC does not
manifest in significant differences in the release kinetics when compared to
12M8 pH. This shown in figures 6 and 7 for both highly soluble drug
(phenylpropanolamine) and a sparingly soluble drug (Theophylline). Additionally
no differences were evident at pH 1.5 or 6.8 between the Example 7 CMC and
CMC 12M8 containing formulations.
Example 19
The CMC's of the present invention exhibit enhanced thickening
efficiency, enchanced high shear viscosity (ICI), improved spatter resistance and
improved water resistance in paint formulations.
27
Model of an interior latex flat paint based on Acronal 290 D.
Position
1.
2.
3.
4.
5.
6.
pre-mix
7.
8.
9.
10.
mill base
11.
13.
14.
15.
let down
PVC (%)
NVW (%)
Ingredients
Water
Calgon N
Pigmentverteiler A
CA24
Agitan 280
thickener
Kronos 2057
Omyalite 90
Ourcal 5
Talcom AT 200
Acronal 290 D
butylglycol
Texanol
additional water
80%
61%
Function Parts
wetting agent
dispersing agent
preservative
defoamer
Theological modifier
pigment
extender
extender
extender
latex binder
coalescing agent
by weight
230.0
1.5
3.0
3.0
5.0
variable
198.0
140.0
198.0
28.0
93.0
20.0
5.0
71.5
Suppliers:
2 Benckiser Knapsack GmbH
3 BASF AG
4 Biochema Schwaben - Dr. Lehmann & Co.
5 Munzing Chemie GmbH
6 Aqualon / HERCULES
7 Kronos Titan GmbH
8 Pluss Staufer SG
9 Pluss Staufer SG
10 a/s Norwegian Talc
11 BASF AG
12 Shell Nederland Chemie BV
13 Eastman Chemicals
BLANOSE*7M31C O.S7 7050 98 toe 125 600 2-3
BLANOSE*7MJ1C 6780 97 103 120 600 2-3
BLANOSF7M31C 045 6500 97 104 100 550
Example 7 CMC 0.41 78SO 97 107 180 600
Rating
1)
2)
0-10,10 > BEST
Wattr rttittane* tt*t ace. Grknthaw; 0 mm » belt
ICI Viscosity Determination: Determined using ASTM D4287-83
Krebs Stormer Viscosity Measurement: Determined using ASTM D 562
Levelling Leneta : Determined using ASTM D 4062-81
Levelling test NYPC: Determined using ASTM D 2801-69
Sag Resistance: Determined using ASTM D4400-84
Spatter Resistance - Roller:
The following equipment was used to evaluate the samples:
paint roller with synthetic fibers e.g. verfroller 15 cm art.nr. 32913 ex Van
Vliet Kwastenfabriek
wall paper (woodchip quality) e.g. Erfurt Raufaser 52
Procedure:
About 200 grams of paint is taken up by the roller. Paint is applied on a
woodchip wallpaper with dimensions 100 x 50 cm placed in vertical position.
Paint is applied by ten- up and down strokes with the roller. A piece of black
carch paper is placed horizontally 50 cm below the bottom line of the wallpaper.
The amount of spatter that is intercepted on the black paper is compared to a
series of reference charts rating from 1 to 10. A rating of 1 means severe spatter
and a rating of 10 stands for completely spatter free.
Water Retention (According GRIMSHAW)
Equipment used in this part of the experment is:
Substrate: Whatman No. 1 circular
Filter paper (diameter 12.5 cm)
Clamp ring inner diameter 7.7 cm
outer diameter 12.6 cm
Pasteur pipette (poly ethylene disposable)
Colorant: Quink parket permanent block ink
Balance
Procedure
1. Mix a blend of paint/colorant thoroughly in an aluminum cup.
Depending on the viscosity the following ratio's can be chosen:
Paint: colorant 50:50
60:40
75:25
Total amount 4-5 grams
2. Put the filter paper between two clamp rings and fix these with paper clips.
3. Weigh the clamped filter paper and apply with a Pasteur pipette 0.5 or 1.0
gram (depending the fluidity of the colored point blob) on the center of the
filter paper.
4. Allow an overnight drying at room temperature.
5. Measure with a ruler the shaded stain round the paint center on 6 different
spots.
6. The average expressed in mm is a measure for the water retention. A low
value means a good water retention.
7. Report the used test conditions, ratio and amount of paint as well as the
increase of the stain in mm.
While this invention has been described with respect to specific
embodiments, it should be understood that these embodiments are not intended
to be limiting and that many variations and modifications are possible without
departing from the scope and spirit of this invention.

We claim:
1. A process for making a carboxymethyl cellulose (CMC) comprising,
a) reacting in a slurry process, a source of cellulose, and 40 to 80 wt %
of the stoichiometric amount of NaOH for a sufficient time and at a
sufficient temperature to form an alkali cellulose, and
b) adding to the alkali cellulose an amount of NaOH to bring the total
amount of NaOH to about the stoichiometric level, and
c) immediately after step b, adding monochloroacetic acid to step b in a
sufficient amount and reacting the slurry at a temperature and time
sufficient to effect etherification in order to form the CMC product.

2. The process as claimed in claim 1, wherein the sufficient time and
temperature to effect etherification is about 70°C for 1 to 2 hours.
3. The process as claimed in claim 1, wherein the CMC product is then
cooled, any excess base is neutralized, washed, dried, and ground.
4. A CMC product prepared by a process as claimed in any of the preceding
claims.

Documents:

1883-delnp-2005-abstract-10-04-2008.pdf

1883-delnp-2005-abstract.pdf

1883-delnp-2005-claims-04-04-2008.pdf

1883-delnp-2005-claims-10-04-2008.pdf

1883-delnp-2005-claims.pdf

1883-delnp-2005-correspondence-others-04-04-2008.pdf

1883-delnp-2005-correspondence-others-09-04-2008.pdf

1883-delnp-2005-correspondence-others-10-04-2008.pdf

1883-delnp-2005-correspondence-others.pdf

1883-delnp-2005-description (complete)-10-04-2008.pdf

1883-delnp-2005-description (complete).pdf

1883-delnp-2005-drawings-04-04-2008.pdf

1883-delnp-2005-drawings.pdf

1883-delnp-2005-form-1-04-04-2008.pdf

1883-delnp-2005-form-1-10-04-2008.pdf

1883-delnp-2005-form-1.pdf

1883-delnp-2005-form-18.pdf

1883-delnp-2005-form-2-04-04-2008.pdf

1883-delnp-2005-form-2-10-04-2008.pdf

1883-delnp-2005-form-2.pdf

1883-delnp-2005-form-3-09-04-2008.pdf

1883-delnp-2005-form-3.pdf

1883-delnp-2005-form-5.pdf

1883-delnp-2005-gpa-10-04-2008.pdf

1883-delnp-2005-gpa.pdf

1883-delnp-2005-pct-105.pdf

1883-delnp-2005-pct-304.pdf

1883-delnp-2005-pct-408.pdf

1883-delnp-2005-pct-409.pdf

1883-delnp-2005-pct-416.pdf

1883-delnp-2005-pct-request form.pdf

1883-delnp-2005-pct-search report.pdf

1883-delnp-2005-petition-137-09-04-2008.pdf

1883-delnp-2005-petition-138-09-04-2008.pdf

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Patent Number

221598

Indian Patent Application Number

1883/DELNP/2005

PG Journal Number

32/2008

Publication Date

08-Aug-2008

Grant Date

26-Jun-2008

Date of Filing

05-May-2005

Name of Patentee

HERCULES INCORPORATED

Applicant Address

1313 NORTH MARKET STREET, HERCULES PLAZA, WILMINGTON, DELAWARE 19894-0001, U.S.A.

Inventors:

#	Inventor's Name	Inventor's Address
1	MARY JEAN CASH	2837 GRUBB ROAD, WILMINGTON, DE 19810, U.S.A.
2	PATRICK J. COWAN	13 BERNARD BOULEVARD, HOCKESSIN, DE 19707, U.S.A.
3	GIJSBERT KROON	BUITENDAMS 472, NL-3371 BW HARDINXVELD GIESSENDAM, NETHERLANDS.

PCT International Classification Number

C08B 11/12

PCT International Application Number

PCT/US2003/038100

PCT International Filing date

2003-11-26

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	60/429,291	2002-11-26	U.S.A.