MXPA99004922A - Laundry detergent with carbonate addition containing a carboxylic polymer as an anti-incrupt agent - Google Patents

Abstract

A laundry detergent composition wherein the solids content comprises an active surfactant, at least about 60% gypsum based on the weight of the solids of a soluble alkali carbonate additive, and a minor amount of carboxylic polymer which is a copolymer of about 70 to 95% by weight of acrylic acid 1, from about 5 to 30% by weight of maleic acid based on the weight of the polymer, the copolymer having an average molecular weight of about 1500 to 2500. Preferably the composition also contains a minor amount of a prota enzyme

Description

LAUNDRY DETERGENT WITH CARBONATE ADDITION CONTAINING A CARBOXYLIC POLYMER AS AN ANTI-INCRUSTATION AGENT BACKGROUND OF THE INVENTION Field of the Invention This invention relates to laundry detergent compositions having an alkaline carbonate additive content highly soluble in water. Laundry detergent compositions comprising a water soluble alkali carbonate are well known in the art. For example, it is conventional to use that carbonate as an additive of detergent compositions that complement and improve the cleaning effect of an active surfactant present in the composition. These additives improve the cleaning power of the detergent composition, for example, by means of sequestration or precipitation of hardness caused by metal ions such as calcium, peptization of soil agglomerates, reduction of critical concentration of micelle, and neutralization of acidic soil, as by means of improving various properties of the active detergent, such as its stabilization of solid soil suspensions, solubilization of water-insoluble materials, emulsification of soil particles, and characteristics of foaming and foaming solutions. It is possible that other mechanisms are present by means of which the additives improve the cleaning power of the detergent compositions, but are less understood. The additives are important not only for their effect in improving the cleaning ability of the active surfactants in the detergent compositions, but also because they allow a reduction in the amount of the surfactant used in the composition, the surfactant being generally more expensive than the additive While laundry detergents containing a relatively large amount of carbonate additive are generally very satisfactory in their cleaning capacity, the use of these carbonate additives often causes the problem of calcium carbonate precipitation, which may result in elevation of fabric incrustation due to the deposition of calcium carbonate on the fiber surfaces of the fabrics that in turn causes the fabric to have a stiffening hand and gives the colored fabrics a dull appearance. Thus, any change in the available laundry detergent formulations based on carbonate which reduces its tendency to cause embedding in the fabrics is very convenient. The following references of the prior art can be considered relevant or a material for the invention claimed herein. U.S. Patent No. 3,858,854, issued January 7, 1975 to Win et al., Discloses detergent compositions comprising a surfactant which may be anionic, nonionic or amphoteric, or a combination of two or more surfactants, a salt of water soluble additive which may be carbonate or sodium bicarbonate, and beads comprising an enzyme which may be a protase. U.S. Patent No. 4,265,790, issued May 5, 1981 to Winston et al .; 4,464, 292, issued on August 7, 1984 to Lengyel; and 5,376,300, issued December 27, 1994 to Bolkan et seq., each disclosing the detergent compositions comprising a long chain ethoxylated alcohol and a sulfate of a long chain ethoxylated alcohol as a combination of nonionic and anionic surfactants, and more than 70% by weight of anhydrous sodium carbonate (soda ash) as a detergent improver. These patents also teach that enzymes may be present in their compositions, and the Bolkan et al. Patent mentions that a carbolylic polymer, for example a copolymer of acrylic and maleic acids, may be included in the composition. U.S. Patent No. 5,308,530, issued May 3, 1994 to Aronson et seq., Discloses detergent compositions comprising a carboxylic polymer additive and an anti-redeposition agent containing a C8 to Cis alkyl group, a calcium sensitive enzyme that can be a protase and a surfactant. BRIEF SUMMARY OF THE INVENTION In accordance with this invention, a laundry detergent composition is provided wherein the solids content comprises an active surfactant, at least 60% by weight based on the weight of the solids of a soluble alkaline carbonate additive. , and a minor amount of a carboxylic polymer which is a copolymer of almost 70 to 95% by weight of acrylic acid and almost 5 to 30% by weight of maleic acid based on the weight of the polymer, said copolymer having an average molecular weight in number from 1,500 to 2,500. It was found that the detergent composition has an unexpectedly low amount of fouling in the fabrics that usually results from the use of a high carbonate detergent composition. DETAILED DESCRIPTION OF THE INVENTION The active surfactant component of the detergent composition of this invention can be, for example, one or more of many suitable synthetic detergent active compounds that are commercially available and described in the literature, for example, in "Surface Active Agents and Detergents" (Surface Active Agents and Detergents), Volumes 1 and 2 by Schwartz, Perry and Berch. Various active detergents and surfactants are also described in, for example, U.S. Patent Nos. 3,957, 695; 3, 865,754; 3,932,316 and 4,009,114. In general, the composition can include an active compound of anionic, nonionic, amphoteric or amphoteric ion detergent, or the combination of two or more of those compounds. Preferably, the laundry detergent compositions of this invention contain at least one anionic or nonionic surfactant, and even more preferably it is a combination of the two types of surfactants. The water-soluble anionic surfactants contemplated are the metal alkali metal salts (such as sodium and potassium) of the highly linear alkyl benzene sulfonates and the metal alkali metal salts of ethoxylated and non-ethoxylated sulphated fatty alcohols and ethoxylated alkyl phenols. The individual salt will be conveniently selected depending on the particular formulation and the proportions therein. The sodium alkylbenzene sulfonate (LAS) surfactant, if used in the composition of the present invention, preferably has a straight chain alkyl radical of average length of about 11 to 13 carbon atoms. Specific sulfated surfactants that can be used * in the compositions of the present invention include sulfated ethoxylated and non-ethoxylated fatty alcohols, preferably primary and secondary linear monohydric alcohols with C? 0-C? 8, preferably C? 2-C? 6 , and more preferably, Cn-C? 5, alkyl groups and, if ethoxylated, on average about 1-15, preferably 2-12, and more preferably 2-7 moles of ethylene oxide (EO) per mole of alcohol, and ethoxylated alkylphenols sulfated with C8-C6, alkyl groups preferably C8-C9 groups, and on average 4-12 moles of EO per mole of alkylphenol. The preferred class of anionic surfactants are linear ethoxylated alcohols, such as C? 2-Ci Ci alco alcohols ethoxylated with on average about 1 to 12 moles of ethylene oxide per mole of alcohol. A most preferred nonionic detergent is a C12-C15 alcohol ethoxylated with 2.5-4.5 moles of ethylene oxide per mole of alcohol. To modify the detergent effect, the sudsing characteristics and other properties of the composition, combinations of the above types of synthetic detergents of surfactants, for example, of anionic and nonionic surfactants, or of different specific anionic or nonionic surfactants can be used. For example, a mixture of different fatty alcohols of 12 to 15 carbon atoms can be ethoxylated, sulfated directly, or sulfated after ethoxylation, a fatty alcohol can be partially ethoxylated and sulphated, or an ethoxylated fatty acid can be partially sulfated to produce a mixture of different anionic and nonionic surfactants or different specific anionic and nonionic surfactants. The total active surfactant in the composition may be on a scale of for example, about 5 to 15% by weight, preferably about 8 to 12% by weight based on the weight of the solids of the composition. If, as preferred, the active surfactant comprises a combination of anionic and nonionic surfactants, then the anionic surfactant is present on the scale, for example, from about 4 to 14% by weight, preferably about 5 to 10% by weight , and the non-ionic surfactant is present on the scale, for example, from about 2 to 8% by weight, preferably about 3 to 5% by weight, all based on the total weight of the solids. The water-soluble alkaline carbonate additive in the detergent composition of this invention can be, for example, a metallic alkali carbonate, bicarbonate or sesquicarbonate, preferably sodium or potassium carbonate, bicarbonate or sesquicarbonate and more preferably sodium carbonate. A combination of more than one such compound can be used, for example, sodium carbonate and sodium bicarbonate. Water soluble alkaline carbonate may be present, for example, in an amount of at least about 60% by weight, preferably about 70 to 85% by weight. If a combination of alkali metal carbonate and bicarbonate is used as the water soluble carbonate, then the alkali metal carbonate, for example, sodium carbonate, is preferably used in an amount of about 70 to 84% by weight, and the alkali metal bicarbonate , for example, sodium bicarbonate, in an amount of approximately 80 to 15% by weight. All the above percentages are based on the total solids of the composition. The carboxylic polymer contemplated is a copolymer of about 70 to 95, preferably about 85 to 93% by weight, of acrylic acid with about 5 to 30, preferably about 7 to 15%, of maleic acid, based on the weight of the copolymer, the latter having an average molecular weight of about 1500 to 2500, preferably about 1700 to 2300. In particular, a copolymer of about 90% by weight of acrylic acid with about 10% by weight of maleic acid having an average molecular weight of about 200. To ensure substantial solubility in water, the polymer is completely or partially neutralized, for example, with metal alkali ions, preferably sodium ions. The carboxylic polymer can be completely or partially neutralized with base before being mixed with other components of the detergent composition or can be compounded as a non-neutralized polymer that is partially or completely neutralized in situ during washing by means of basic compounds, generally the additive of alkaline carbonate, for example, sodium carbonate, which has the effect of raising the pH of the composition.The carboxylic polymer, which acts as soil dispersion / antinucleation agent, may be present, for example, in an amount of about 0.025 to 1.9% by weight, preferably approximately 0.05 to 1.4% by weight, calculated as a solid non-neutralized polymer and based on the total weight of the solids of the composition.When neutralized completely or partially with sodium hydroxide, the salt of polymer is present in an amount a little greater than that corresponding to the non-neutralized polymer due to the weight may of the neutralized sodium ions on the substituted hydrogen of the non-neutralized polymer. To improve its removal function, the detergent composition of this invention also preferably contains a protase enzyme, also known in the art as a proteolytic enzyme. Enzymes falling within this class recognized by the art include, for example, the disclosed US Pat. Nos. 3,858,854 to Win et al. And 5,308,530 to Aronson et al., Which have already been mentioned, and 4,318,818 to Letton et seq.; Do not.1,800,508; German document filed No. 1,800,508; Published Dutch Patent Application No. 6,815,944; Practical Biotechnology Manual of Novo, Novo Industri A / S, 1986, pgs. 54-47. The specific protase enzymes that can be used are, for example, pepsin, trypsin, chymotrypsin, papain, bromelain, coleginase, keratinase, carboxylase, aminopeptidase, elastase, subtilisin and aspergillopepidase A and B. Preferred enzymes they are those of subtilisin manufactured and cultivated from special spore deformations that form bacteria, in particular Bacillus subtilis. Some convenient protase enzymes that can be obtained commercially are Alcalasa, Savinasa and Esparasa, all from Novo Industri A / S, Maxatase and Maxacal from Gist-Brocades and Kazusase from Showa Denko. The protase enzyme may be present in the composition in an amount of about 0.04 to 1.6% by weight, preferably about 0.3 to 1.1% by weight based on the weight of the solids in the composition. The detergent compositions of the invention are generally prepared so as not to contain phosphate, that is, to exclude the presence of additives with phosphates and sequestrants with phosphates such as sodium tripolyphosphate (STPP) because these Agents tend to cause eutrophication when they are present in washing wastewater. However, for certain purposes a small amount thereof, for example, up to about 0.5% may be present as phosphorus based on the weight of the solids of the composition. The detergent composition of this invention is preferably in the form of a dry-looking powder, in which case the percentages by weight of the various components already mentioned have approximately the weight of the total composition as a basis. However, dry appearance powder usually has water in an amount, for example, of about 1 to 12% by weight, preferably about 2 to 10% by weight based on the total weight of the composition. The laundry detergent compositions of this invention may also contain various auxiliaries common to detergent formulations such as optical brighteners, carboxymethylcellulose, perfumes, dyes, pigments, solubility enhancers such as potassium chloride, other additives such as sodium sulfate, and peroxide-generating persalts as bleaching agents. The following examples further illustrate the invention: Examples 1-4 and Comparative Example A These examples illustrate the low level of encrustation caused by a detergent composition of this invention containing the contemplated polymer, as the comparison is made with an identical composition except that it contains a closely related polymer but does not contemplated. In Comparative Example A, a control composition was prepared with the components listed in Table I in the amounts indicated in grams. Table I Component Quantity (grams) Sodium Carbonate 73.79 Anionic Surfactant 5. .60 Non-ionic Surfactant 3. .09 Na Salt of Polymer Solids Carboxilic coo 0., 99 Optical Brightener (Solids) 0.20 Sodium Carboxymethylcellulose ( 100% active) or. .21 Sodium Bicarbonate 0., 95 Water 5., 23 Perfume 0., 09 Potassium Chloride 2., 85 Sodium Sulfate 2., 01 Of the components of Table I, the anionic surfactant was the sodium salt of a sulfated C? 2 to Ci 4 alcohol ethoxylated with about 3 moles of ethylene oxide per mole of alcohol, the non-ionic surfactant was a C alcohol alcohol. 2 a C? ethoxylated with about 3 moles of ethylene oxide per mole of alcohol, and the carboxylic polymer was the sodium salt of a copolymer of about 90 weight% of acrylic acid and about 10 weight% of maleic acid, with a molecular weight number average of approximately 3000 (Polymer 448 of Rohm and Haas). Anionic and non-ionic surfactants, and the sodium sulfate together constituted the reaction product of the partial sulfation of the nonionic surfactant with concentrated sulfuric acid, followed by the neutralization of the sulfated product with sodium carbonate, as described in the aforementioned U.S. Patent No. 4,464,292 of Lengyel. In Examples 1 to 4, the detergent contained the same components in the amounts listed in Table I except that the NA salt of carboxylic polymer was the sodium salt of a copolymer of approximately 90% by weight of acrylic acid and approximately 10% by weight. Weight% of maleic acid, with an average molecular weight number of approximately 2000 (Polymer C + D # 3 of Rohm and Haas) in quantities of Q.50, 0.99, 1.98 and 2.97 grams respectively. The five detergent compositions for the encrustation of fabrics were tested by repeating the washing of cotton fabrics at 35 ° C with washing water containing 250 ppm of Ca and Mg of hardness with a molar ratio of Ca / Mg of 2: 1, determining that hardness as CaC03 as described in ASTM D1126-86. To perform each test, four samples of 25.4 cm fabric are washed. x 25.4 cm., 100% cotton simple stitching for 12 minutes with 95g. of the detergent composition being tested so that the washing solution contained about 0.14% by weight of detergent. After the washing is finished, 2.00 to 4.00 g are removed. of calcium carbonate embedded in fabrics in 100 ml. 0.2 N hydrochloric acid for 30 minutes, and an aliquot of 2.0 to 4.0 ml is analyzed. to verify the hardness by means of the titration method. The scale is expressed as mg. of calcium carbonate per gram of fabric obtained after 3 and 5 cycles of machine use. The results are shown in Table II. Table II (Single seam cotton samples) Example Embedding 3 cycles 5 cycles A 90 160 1 32 135 2 10 60 3 8 38 4 5 21 The above incrustation determinations resulting from the five compositions were repeated, except that the washed fabrics were cotton samples of double stitched interlacing. The results are shown in Table III.

Table III (Double-sewn cotton samples) Example Embedding 3 cycles 5 cycles A 102 169 1 69 158 2 33 101 3 20 74 4 10 39 The above incrustation determinations resulting from the five compositions were repeated, except that the washed fabrics were samples of double stitching (interlaced) of polyester / cotton (50% polyester / 50% cotton). The results are shown in Table IV.

Table IV (Polyester / cotton double seam samples) Example Embedding 3 cycles 5 cycles A 33 103 1 12 73 2 4 34 3 4 21 4 1 9 The results shown in Table II, III and IV indicate that with respect to the three types of samples tested, and after 3 and 5 wash cycles, the presence of the detergent composition of a contemplated polymer according to the invention (Examples 1 to 4) caused substantially less fouling than when the composition contained a closely related polymer but not contemplated (Comparative Example A), despite the fact that in Example 1 an amount of contemplated polymer was present in the composition that was only half that of the non-contemplated polymer present in the composition of Comparative Example A. In addition, successively and significantly in most cases the result was lower amounts of scale when the amount of polymer contemplated was twice (Example 2), 4 times (Example 3) and 6 times (Example 4), the amount present in the composition of Example 1. Example 5 and Comparative Example B These examples illustrate substantial improvement in the cleaning ability with respect to the removal of certain types of spots that is obtained when a protase enzyme is present in the detergent composition of this invention. In Comparative Example B, the detergent composition contained the components shown in Table V at the stated weight percentages.

Table V Component Quantity (grams) Sodium carbonate 76.68 Anionic Surfactant 5.89 Non-ionic Surfactant 3.25 Salt, Carboxylic Polymer Solids 0.58 Optical Brightener (Solids) 0.21 Sodium Carboxymethylcellulose (100% active) 0.22 STPP 1.45 Sodium Bicarbonate 1.00 Water 5.50 Perfume 0.11 Chloride of Potassium 3.00 Sodium Sulfate 2.12 Of the components listed in Table V, the anionic and nonionic surfactants are the same as the composition of Comparative Example A, listed in Table I; the carboxylic polymer was a conventional anti-redeposition agent for detergents, namely, the sodium salt of a polymer blend of 50% by weight of a polyacrylic acid with an average molecular weight of about 4500. and 50% by weight of a 50:50 acrylic and methacrylic acid copolymer with an average molecular weight of about 3500 (Polymer 912 of Rohm and Haas), an effective conventional anti-redeposition agent; and STPP is sodium tripolyphosphate. After the ASTM D-3050 procedure, using large-sized Whirlpool washers, cotton and polyester / cotton samples (a mixture of 50% cotton and 50% polyester) stained with several common substances were washed at 95 ° F. with 95 grams of the detergent composition of Comparative Example B, using a 12-minute wash cycle and washing water containing 100 ppm of calcium and magnesium hardness with a molar ratio of Ca / Mg of 2: 1, calculating that hardness as CaC0 as described in D-1126-86 of ASTM. Four identical samples were stained, two on each of the two machines. The reflectances of the four clean samples, the stained samples and the washed samples were measured using a regular spectrophotometer, and the percentage of stain removal was calculated from the measurements of the spectrophotometer. In Example 5, the same detergent composition as in Comparative Example B was tested, except that the sodium salt of the carboxylic polymer of the composition was the same polymer contemplated according to the invention as used in the compositions of Examples 1 to 4 , and was present in the composition of this example in an amount of approximately 0.42% by weight; the composition also contained approximately 0.82% by weight of the "Savinasa" protase enzyme sold by Novo Industri A / S; and the cleaning tests used 85 grams instead of 95 of detergent composition. The results in terms of the percent removal of the various spots of the different fabrics, washing with the detergent compositions of Comparative Example B and Example 5 are shown in Table VI, where "EMPA" 116 indicates the stain by means of a mixture of blood, milk and carbon black from natural gas on cotton, and w117 from EMPA "indicates the stain by means of a mixture of blood, milk and carbon black in polyester / cotton. The acronym 'EMPA' stands for ^ Eldgenossiche Materials Prufungs Anstalt, a Swiss government testing center. Each of the numerical values of Example 5 of Table VI was determined to present a significant increase over the corresponding values in Comparative Example B, having been determined in accordance with significant minimum differences (LSDs) as derived from a use of an analysis of variation (ANOVA for its acronym in English) of an address per statistical graph software package.

Table VI Ex. B Comp. Example 5 Stained Sample Grass in Cotton 47.1 62.7 116 of EMPA in Cotton 45.4 61.8 117 of EMPA in 22.1 74.4 Polyester / Cotton The results shown in Table V indicate that the detergent composition containing a contemplated polymer, under the invention, and a protase enzyme (Example 5) is effective to remove substantially larger proportions of certain test spots than a composition containing a polymer carboxylic which is a known anti-redeposition agent, but without an enzyme (Comparative Example B). This indicates the advantages of the composition of the invention to remove certain spots that are generally considered very difficult to remove. It should be noted that the compositions of these examples contain 1.45% by weight of STPP (0.36% by weight as phosphorus), although, as already mentioned, the absence of any phosphate in the composition is preferable or its quantity is limited to no more of about 0.5% weight as phosphorus of the solids of the composition. The reason for the inclusion of STPP in the compositions of these examples is that, as is known in the art, phosphate additives such as STPP contribute significantly to the detergent power or cleaning ability of the detergent compositions. Thus, the contribution of a protase enzyme to that cleaning capacity was perceived more clearly than the demonstration if it was additional to the presence of a phosphate in the composition than without the presence thereof. In large part, however, the absence of phosphate in the composition is preferred since it has been found that phosphates in wash waste water are mainly the cause of eutrophication of several layers of water.

Claims (17)

1. CLAIMS 1. A laundry detergent composition wherein the solids cnt comprises an active surfactant, at least 60% by weight based on the weight of the solids of a soluble alkaline carbonate additive, and a minor amount of a carboxylic polymer which is a copolymer of about 70 to 95% by weight of acrylic acid and about 5 to 30% by weight of maleic acid based on the weight of the polymer, said copolymer having an average molecular weight of about 1500 to 2500.
2. 2. The The composition of claim 1 wherein the carboxylic polymer is a copolymer of from about 85 to 93% by weight of acrylic acid with from about 7 to 15% by weight of maleic acid.
3. 3. The composition of claim 2 wherein the molecular weight is about 1700 to 2300.
4. 4. The composition of claim 1 wherein the carboxylic polymer is present in the proportion of about 0.025 to 1.9% by weight calculated as solid polymer. not neutralized and based on the weight of the solids in the composition.
5. The composition of claim 4 wherein the proportion of the carboxylic polymer is from about 0.05 to 1.4% by weight.
6. 6. The composition of claim 1 wherein the alkali carbonate is sodium carbonate.
7. The composition of claim 6 wherein the sodium carbonate is present in an amount of about 70 to 84% by weight.
8. 8. The composition of claim 7 which further comprises about 1 to 15 weight% of sodium bicarbonate.
9. 9. The composition of claim 1 wherein the active surfactant comprises an anionic surfactant and a non-anionic surfactant.
10. The composition of claim 9 wherein the anionic surfactant is an alkali metal salt of ethoxylated linear sulphonated C 12 -C 16 alcohols with an average of about 1 to 12 moles of ethylene oxide per mole of alcohol and is present in a amount of about 4 to 14% by weight, and the non-anionic surfactant comprises C12-C16 linear alcohols ethoxylated with an average of about 1 to 12 moles of ethylene oxide per mole of alcohol and is present in an amount of about 2 to 8% weight based on the total weight of the solids.
11. 11. The composition of claim 1 further comprising a minor amount of a protase enzyme.
12. 12. The composition of claim 11 wherein the enzyme is present in an amount on the scale of about 0.04 to 1.6% by weight based on the weight of the solids of the composition.
13. The composition of claim 12 wherein the scale is from about 0.3 to 1.1% by weight.
14. 14. The composition of claim 1 which does not substantially cin phosphate.
15. 15. The composition of claim 1 which cins a phosphate in an amount of not more than about 0.5% by weight as phosphorus, based on the weight of the solids in the composition.
16. 16. The composition of claim 15 wherein the phosphate is sodium tripolyphosphate (STPP) which is present in an amount not greater than about 2% by weight as STPP, based on the weight of the solids of the composition.
17. 17. A process comprising washing a fabric in an aqueous wash solution cining the composition of claim 1.