STABLE LIQUID DETERGENTS CONTAINING ANIONIC SURFACTANT AND MONOSULFONATED BRIGHTENER

Abstract: Stable isotropic liquid laundry detergents containing anionic surfactant and monosulfonated brightener to reduce brightener staining of fabrics. Monosulfonated naphthot­ riazolyl stilbene brighteners are preferred.

Description: Technical Field The present invention relates to stable, preferably single-phase, isotropic liquid laundry detergents containing anionic synthetic surfactant and a monosulfonated brightener which reduces or eliminates brightener staining of fabrics while maintaining an acceptable level of whitening. Particularly preferred are monosulfonated naphthotriazolyl stilbene (NTS) brighteners. Preferred compositions also contain a minor amount of a second brightener to further improve fabric whitening. In such compositions, the monosulfonated brightener herein should represent at least 75% by weight of the total brightener in order to provide the desired reduction in fabric staining. Optical brighteners, also known as fluorescent whitening agents, are commonly used in laundry detergents. Brighteners deposit onto fabrics where they absorb ultraviolet radiant energy and reemit it as a blue light. This reduces or eliminates any yellowish cast to fabrics and gives them a brighter appearance. However, undesirable brightener staining can occur when liquid detergents come in direct contact with cotton-containing fabrics, such as during pretreatment. The present invention reduces or eliminates such staining while maintaining an acceptable level of fabric whitening. Background Art British Patent 2,028,365, Gray, published March 5, 1980, discloses built liquid detergents containing anionic surfactants and one or more brighteners, including NTS brighteners. US patent 3,573,211, issued March 30, 1971, discloses liquid detergent compositions comprising chlorine substituted mono-naphto-triazoles brighteners. U.S. Patent 3,812,041, Inamorato, issued May 21, 1974, discloses unbuilt liquid detergents containing nonionic surfactants and anionic surfactants in a weight ratio of nonionic to anionic of at least 1. Optional brighteners can include the NTS type. U.S. Patent 3,959,157, Inamorato, issued May 25, 1976, discloses liquid detergents containing nonionic surfactants, quaternary ammonium softening agents and optional brighteners, including NTS brighteners. U.S. Patent 4,430,236, Franks, issued February 7, 1984, discloses liquid detergents containing nonionic surfactants, optional anionic surfactants, hydrogen peroxide, brightener, and preferably quaternary ammonium softening compounds. NTS brighteners are specifically mentioned as being useful. Japanese Patent Application J74-017004, published April 26, 1974, discloses liquid detergents containing NTS brighteners said to be stable to light. German Patent Application 2,543,998, published April 7, 1977, discloses clear liquid detergents containing certain diphenyl distyryl brighteners. Examples 1 and 2 are of liquid detergents containing mixtures of monosulfonated and disulfonated brighteners. Summary of the Invention The present invention relates to stable isotropic liquid laundry detergent compositions comprising, by weight: (a) from 3% to 50% of an anionic synthetic surfactant; and (b) from 0.01% to 1% of a monosulfonated brightener which represents at least 75% of the total brightener in the composition, said monosulfonated brightener being free of chlorine substituents; said compositions containing less than 2% of quaternary ammonium cationic surfactants having 2 chains, each containing an average of from 16 to 22 carbon atoms. 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl)amino)-2-stilbenesulfonic acid, or a water-soluble salt thereof, is a preferred brightener herein. Detailed Description of the invention The compositions of the present invention comprise from 3% to 50%, preferably from 7% to 40%, and most preferably from 15% to 25%, by weight of an anionic synthetic surfactant. Suitable anionic surfactants are disclosed in U.S. Patent 4,285,841, Barrat et al, issued August 25, 1981, and in U.S. Patent 3,929,678, Laughlin et al, issued December 30, 1975. Useful anionic surfactants include the water-soluble salts, particularly the alkali metal, ammonium and alkylolammonium (e.g., monoethanolammonium or triethanolammonium) salts, of organic sulfuric reaction products having in their molecular structure an alkyl group containing from 10 to 20 carbon atoms and a sulfonic acid or sulfuric acid ester group. (Included in the term "alkyl" is the alkyl portion of aryl groups.) Examples of this group of synthetic surfactants are the alkyl sulfates, especially those obtained by sulfating the higher alcohols (C₈-C₁₈ carbon atoms) such as those produced by reducing the glycerides of tallow or coconut oil; and the alkylbenzene sulfonates in which the alkyl group contains from 9 to 15 carbon atoms, in straight chain or branched chain configuration, e.g., those of the type described in U. S. Patents 2,220,099 and 2,477,383. Especially valuable are linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alkyl group is from 11 to 14. Other anionic surfactants herein are the water-soluble salts of: paraffin sulfonates containing from 8 to 24 (preferably 12 to 18) carbon atoms; alkyl glyceryl ether sulfonates, especially those ethers of C₈₋₁₈ alcohols (e.g., those derived from tallow and coconut oil); alkyl phenol ethylene oxide ether sulfates containing from 1 to 4 units of ethylene oxide per molecule and from 8 to 12 carbon atoms in the alkyl group; and alkyl ethylene oxide ether sulfates containing 1 to 4 units of ethylene oxide per molecule and from 10 to 20 carbon atoms in the alkyl group. Other useful anionic surfactants herein include the water-soluble salts of esters of alpha-sulfonated fatty acids containing from 6 to 20 carbon atoms in the fatty acid group and from 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-1-sulfonic acids containing from 2 to 9 carbon atoms in the acyl group and from 9 to 23 carbon atoms in the alkane moiety; water-soluble salts of olefin sulfonates containing from 12 to 24 carbon atoms; and beta-alkyloxy alkane sulfonates containing from 1 to 3 carbon atoms in the alkyl group and from 8 to 20 carbon atoms in the alkane moiety. Preferred anionic surfactants are the C₁₀-C₁₈ alkyl sulfates containing an average of from 0 to 4 ethylene oxide units per mole of alkyl sulfate, C₁₁-C₁₃ linear alkylbenzene sulfonates, and mixtures thereof. The compositions herein can also contain other synthetic surfactants known in the art, such as the nonionic, cationic, zwitterionic, and ampholytic surfactants described in the above-cited Barrat et al and Laughlin et al patents. Preferably, the total synthetic surfactant represents from 15% to 60%, preferably from 20% to 40%, by weight of the composition. In addition, the anionic synthetic surfactant preferably represents at least 25%, more preferably at least 30%, and most preferably at least 50%, by weight of the synthetic surfactant in the composition. It is believed that such anionic surfactant-containing systems provide a sufficiently high level of cleaning and antiredeposition performance that good fabric whitening can be maintained when using the monosulfonated brighteners herein instead of more effective (but higher staining) brighteners. A preferred cosurfactant, used at a level of from 2% to 30%, preferably from 3% to 25%, more preferably from 4% to 15%, by weight of the composition, is an ethoxylated nonionic surfactant of the formula R¹(OC₂H₄) n OH, wherein R¹ is a C₁₀-C₁₆ alkyl group or a C₈-C₁₂ alkyl phenyl group, n is from 3 to 9, and said nonionic surfactant has an HLB (hydrophile-lipophile balance) of from 10 to 13. These surfactants are more fully described in U.S. Patents 4,285,841, Barrat et al, issued August 25, 1981, and 4,284,532, Leikhim et al, issued August 18, 1981. Particularly preferred are condensation products of C₁₂-C₁₅ alcohols with from 3 to 8 moles of ethylene oxide per mole of alcohol, e.g., C₁₂-C₁₃ alcohol condensed with about 6.5 moles of ethylene oxide per mole of alcohol. While these nonionic surfactants are preferably included in the present compositions to enhance cleaning, it is believed they also tend to solubilize the NTS brighteners and prevent them from depositing on fabrics. This can lead to poorer whiteness maintenance in compositions in which the nonionic surfactant comprises a major amount of the synthetic surfactant. Other preferred cosurfactants, used at a level of from 0.5% to 3%, preferably from 0.7% to 2%, by weight, are certain quaternary ammonium, amine or amine oxide surfactants. The quaternary ammonium surfactants useful herein are of the formula: [R²(OR³) y ][R⁴(OR³) y ]₂R⁵N⁺X⁻ wherein R² is an alkyl or alkyl benzyl group having from 6 to 16 carbon atoms in the alkyl chain; each R³ is selected from the group consisting of -CH₂CH₂-, -CH₂CH(CH₃)-, -CH₂CH(CH₂OH)-, -CH₂CH₂CH₂-, and mixtures thereof; each R⁴ is selected from the group consisting of C₁-C₄ alkyl, C₁-C₄ hydroxyalkyl, benzyl, and hydrogen when y is not 0; R⁵ is the same as R⁴ or is an alkyl chain wherein the total number of carbon atoms of R² plus R⁵ is from 8 to 16; each y is from 0 to 10 and the sum of the y values is from 0 to 15; and X is any compatible anion. Preferred of the above are the alkyl quaternary ammonium surfactants, especially the mono-long chain alkyl surfactants described in the above formula when R⁵ is selected from the same groups as R⁴. The most preferred quaternary ammonium surfactants are the chloride, bromide and methylsulfate C₈₋₁₆ alkyl trimethylammonium salts, C₈₋₁₆ alkyl di(hydroxyethyl)methylammonium salts, the C₈₋₁₆ alkyl hydroxyethyldimethylammonium salts, C₈₋₁₆ alkyloxypropyl trimethylammonium salts, and the C₈₋₁₆ alkyloxypropyl dihydroxyethylmethylammonium salts. Of the above, the C₁₀-C₁₄ alkyl trimethylammonium salts are preferred, e.g., decyl trimethylammonium methylsulfate, lauryl trimethylammonium chloride, myristyl trimethylammonium bromide and coconut trimethylammonium chloride and methylsulfate. Under cold water washing conditions, i.e., less than about 65°F (18.3°C), the C₈₋₁₀ alkyl trimethylammonium surfactants are particularly preferred since they have lower Kraft boundaries and crystallization temperatures than the longer chain quaternary ammonium surfactants. Amine surfactants useful herein are of the formula: [R²(OR³) y ][R⁴(OR³) y ]R⁵N wherein the R², R³, R⁴, R⁵ and y substituents are as defined above for the quaternary ammonium surfactants. Particularly preferred are the C₁₂₋₁₆ alkyl dimethyl amines. Amine oxide surfactants useful herein are of the formula: [R²(OR³) y ][R⁴(OR³) y ]R⁵N → 0 wherein the R², R³, R⁴, R⁵ and y substituents are also as defined above for the quaternary ammonium surfactants. Particularly preferred are the C₁₂₋₁₆ alkyl dimethyl amine oxides. Amine and amine oxide surfactants are preferably used at higher levels than the quaternary ammonium surfactants since they typically are only partially protonated in the present compositions. For example, preferred compositions herein can contain from 0.5% to 1.5% of the quaternary ammonium surfactant, or from 1% to 3% of the amine or amine oxide surfactants. The compositions herein can also contain minor amounts, i.e. less than 2%, preferably less than 1%, by weight of quaternary ammonium cationic surfactants having 2 chains, each containing an average of from 16 to 22 carbon atoms. These surfactants are disclosed in British Patent 2,041,968, Murphy, published September 19, 1979. However, the compositions are preferably substantially free of such surfactants because they can cause an undesirable "quat" staining of fabrics, thereby reducing or eliminating the benefits obtained from using the low staining monosulfonated brighteners herein. The di-long chain cationic surfactants also tend to complex with the anionic brighteners and surfactants herein, reducing the effectiveness of both materials. Monosulfonated Brightener The compositions of the present invention contain from 0.01% to 1%, preferably from 0.05% to 0.5%, more preferably from 0.1% to 0.3%, by weight of a monosulfonated brightener which is free of chlorine substituents. While not intending to be limited by theory, it is believed that the monosulfonated brighteners herein cause less staining of fabrics because their lack of symmetry reduces crystal growth and build up of brightener on fabrics. For example, the preferred NTS brighteners herein have substantial substitution (i.e., naphthotriazolyl and sulfonate groups) on one side of a stilbene group and no substitution on the other side. Preferred monosulfonated brighteners are of the formulas wherein one R per molecule is SO₃M; M is a compatible cation, such as hydrogen, sodium (preferred), potassium, ammonium, or substituted ammonium (e.g., mono-, di-, or tri-ethanolammonium); and each other R is selected from the group consisting of hydrogen, hydroxy, alkyl, hydroxyalkyl, oxyalkyl, amino, substituted amino where each substituent is hydroxy, alkyl, hydroxyalkyl, or oxyalkyl, morpholino, anilino, halogen and cyano, said alkyl groups containing from 1 to 4 carbon atoms. Preferred brighteners are those of the above formulas where the SO₃M group is attached directly to the stilbene portion of the molecule. Preferably, each other R is selected from the group consisting of hydrogen, hydroxy, alkyl, hydroxyalkyl, amino, substituted amino where each substituent is hydroxy, alkyl or hydroxyalkyl, morpholino and anilino, said alkyl groups containing from 1 to 3 carbon atoms In a particularly preferred brightener of formula (I), each other R is hydrogen, i.e., sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbene-sulfonate, which is commercially available as Tinopal® RBS from Ciba-Geigy. Preferred brighteners of formula (2) are those wherein the other R attached to the stilbene portion of the molecule is hydrogen, one R attached to the triazine rings is anilino and the other R is diethanolamino, morpholino, methylhydroxyethylamino, 2-hydroxypropyl amino, or anilino. Particularly preferred is 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl)-amino)-2-stilbene-sulfonic acid, and the water-soluble salts thereof. Preferred brighteners of formula (3) and (4) are those wherein the other R's are all hydrogen. Preferred compositions herein also contain a minor amount of a second brightener to improve fabric whitening. In such compositions, the monosulfonated brightener herein represents from 75% to 99%, preferably from 75% to 95%, more preferably from 80% to 95%, most preferably from 85% to 90%, by weight of the total brightener in order to improve whitening while reducing staining to an acceptable degree. Suitable co-brighteners include any of those known for use in detergent compositions. Examples are disclosed in U.S. Patent 3,812,041, Inamorato, issued May 21, 1974, particularly from column 6, line 45 to column 8, line 42, incorporated herein by reference. Other Components The compositions of the present invention preferably contain from 25% to 65%, more preferably from 30% to 60%, most preferably from 40% to 55%, by weight of water. The compositions also preferably contain from 3% to 30%, more preferably from 5% to 20%, by weight of a fatty acid containing from 10 to 22 carbon atoms. The fatty acid can also contain from 1 to 10 ethylene oxide units in the hydrocarbon chain. Preferred are saturated fatty acids containing from 10 to 14 carbon atoms. In addition, the weight ratio of C₁₀-C₁₂ fatty acid to C₁₄ fatty acid should be at least 1, preferably at least 1.5. Suitable saturated fatty acids can be obtained from natural sources such as plant or animal esters (e.g., stripped palm kernel oil, stripped palm oil and coconut oil) or synthetically prepared (e.g., via the oxidation of petroleum or by hydrogenation of carbon monoxide via the Fisher-Tropsch process). Examples of suitable saturated fatty acids for use in the compositions of this invention include capric, lauric, myristic, coconut and palm kernel fatty acid. Preferred are saturated coconut fatty acids, from 5:1 to 1:1 (preferably about 3:1) weight ratio mixtures of lauric and myristic acid, mixtures of the above with minor amounts (e.g., 10%-30% of total fatty acid) of oleic acid; and stripped palm kernel fatty acid. The compositions herein also preferably contain up to 25%, preferably from 1% to 10%, by weight of a detergent builder material. Detergent builders are described in U.S. Patent 4,321,165, Smith et al, issued March 23, 1982. However, the compositions preferably contain less than 10%, more preferably less than 5%, of phosphate materials. Most preferably, the compositions are substantially free of phosphates. Preferred builders are the polycarboxylate materials described in U.S. Patent 4,284,532, Leikhim et al, issued August 18, 1981. Citric acid is particularly preferred. Other optional components for use in the liquid detergents herein include enzymes, enzyme stabilizing agents, polyacids, soil removal agents, antiredeposition agents, suds regulants, hydrotropes, opacifiers, anti-oxidants, bactericides, dyes, perfumes, and other brighteners known in the art. Such optional components generally represent less than 15%, preferably from 2% to 10%, by weight of the composition. The following examples illustrate the compositions of the present invention. All parts, percentages and ratios used herein are by weight unless otherwise specified. EXAMPLE I The fabric staining tendency of various brighteners was evaluated in the following composition. Brightener A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.2% C.I. Fluorescent Brightener 230 C = 0.2% of a hexasulfonated stilbene brightener D = 0.2% tetrasodium 4,4'-bis((4-[bis(2-hydroxyethyl)-amino]-6-(p-sulfoanilino)-1,3,5-triazin-2-yl)-amino)-2,2'-stilbene disulfonate E = 0.2% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) The above brighteners are preferably added to the composition as a premix containing, on a finished product basis, 2% monoethanolamine, 2% alcohol polyethoxylate and 2% water, to aid their solubilization. Samples containing the above brighteners were applied to 100% cotton swatches (unbrightened unless otherwise noted), both damp and dry, for 10 minutes, and to dry swatches for 1 hour. The swatches were then washed, dried and graded under ultraviolet light for brightener staining by a panel of expert graders, using the following scale. O = no visible stain T = trace of stain 1.0 = very light stain 1.5 = light stain 2.0 = medium light stain 2.5 = medium stain 3.0 = heavy stain The results, after averaging the grades, were as follows. Brightener E of the present invention caused much less staining of cotton fabrics than the other brighteners. EXAMPLE II Example I was repeated (10 minute application only) using the following brighteners. A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.2% C.I. Fluorescent Brightener 71 (a disulfonate) C = 0.2% C.I. Fluorescent Brightener 230 D = 0.2% of an anionic stilbene brightener E = 0.2% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) In the above testing, Brightener E of the present invention caused much less staining of cotton fabrics. EXAMPLE III Various brighteners were again evaluated as described in Example I, except using the following grading scale. O = no visible stain T = possible trace 1 = very slight stain 2 = light but definite stain 3 = very visible stain 4 = stained the most possible Brightener A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.15% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) + 0.05% of dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate C = 0.18% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) + 0.02% of dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate D = 0.2% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) Brighteners B (with 75% of total brightener being D), C (with 90% of total brightener being D), and D of the present invention again caused less staining of cotton fabrics. EXAMPLE IV The following brighteners were evaluated, as described in Example III. A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.1% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) C = 0.15% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) D = 0.2% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) The above results show that Brighteners B, C and D of the present invention caused little or no staining at levels between 0.1% and 0.2%. EXAMPLE V The following brighteners were evaluated as described in Example III under various pretreatment times and conditions. A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.2% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) C = 0.18% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) + 0.02% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate D = 0.15% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) + 0.05% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate Brighteners B, C (with 90% of total brightener being B), and D (with 75% of total brightener being B) of the present invention provided less staining of cotton fabrics. EXAMPLE VI Brightener staining was evaluated as described in Example III using the following compositions. Composition A = a commercially available detergent believed to contain the following components. Composition C = Composition B except replace indicated brightener with 0.2% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate. Composition D = Composition B except replace indicated brightener with 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate and 0.076% of dipotassium 4,4'-bis-(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate. Composition E = Composition of Example I with 0.13% of disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate and 0.076% of dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate. Composition F = Composition of Example I with 0.15% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbene-sulfonate and 0.05% of disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate. Composition G = Composition of Example I with 0.15% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbene-sulfonate and 0.02% of disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate. Composition H = Composition of Example I with 0.15% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbene-sulfonate The results were as follows. Compositions C, G and H of the present invention caused less staining of cotton fabrics than the other compositions. Composition F of the invention caused less staining than Composition E, and about the same level of staining as Composition A even though F contained more than twice the level of brightener in A. EXAMPLE VII Brightener staining was evaluated as described in Example VI on a wide variety of fabrics, using the following compositions. Composition A = Composition E from Example VI Composition B = Composition H from Example VI Composition C = Composition B from Example VI Composition D = Composition B from Example VI, except replace indicated brightener with the brightener mixture of Composition G of Example VI. Composition E = Composition G from Example VI. The results were as follows. On polycotton (35% C), wool, polyester and triacetate fabrics, all grades were "0" except for grades of "T" for overnight contact of Composition A on polycotton (35% C), D on wool, and B and E on triacetate, and for 10 minute contact of Composition E on triacetate. The above results show that Compositions B, D and E of the present invention cause less staining on a variety of fabrics. EXAMPLE VIII Brightener staining was evaluated as described in Example III, using the following brighteners. A = 0.13% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate +0.076% dipotassium 4,4'-bis(4-phenyl-1,2,3-triazol-2-yl)stilbene-2,2'-disulfonate B = 0.15% sodium 4-(2H-naphtho [1,2-d] triazol-2-yl)-2-stilbenesulfonate) C = B + 0.01% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate D = B + 0.015% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate E = B + 0.02% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate Brighteners B, C, D and E of the invention caused less staining than Brightener A. EXAMPLE IX Brightener staining was evaluated as described in Example VI using the following compositions. Composition A = Composition E of Example VI. Composition B = Composition G of Example VI. Composition C Composition D = Composition C, except replace indicated brighteners with 0.15% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate and 0.02% of disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate. Composition E = Composition C, except replace indicated brighteners with 0.15% of sodium 4-(2H-naphtho-[1,2-d] triazol-2-yl)-2-stilbenesulfonate. The results were as follows. Compositions B, D and E of the invention all caused less staining of the cotton fabrics. EXAMPLE X Brightener staining was evaluated as described in Example IX using the following compositions. Composition A = Composition C of Example IX Composition B = Composition E of Example IX Composition C = Composition D of Example IX Composition D = Composition C of Example IX, except replace indicated brighteners with 0.2% of sodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl)-amino)-2-stilbene sulfonate. Composition E = Composition C of Example IX, except replace indicated brighteners with 0.2% of 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl)amino)-stilbene. (Brightener not solubilized in composition.) Composition F = Composition C of Example IX, except replace indicated brighteners with 0.2% of disodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl)-amino)-2,2'-stilbene disulfonate. Composition G = Composition D, except with only 0.15% of the indicated brightener. Composition H = Composition F, except with only 0.15% of the indicated brightener. The results were as follows. Compositions B, C, D and G of the present invention caused less staining of the cotton fabrics. While the preferred monosulfonated brightener in Composition B causes less staining than the brightener in G, the brightener in G provides better whitening performance. EXAMPLE XI Brightener staining was evaluated as described in Example IX using the following compositions. Composition A = Composition C of Example IX Composition B = Composition E of Example IX Composition C = Composition D of Example IX Composition D = Composition C of Example IX, except replace indicated brighteners with 0.2% of disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate. Composition E = Composition C of Example IX, except replace indicated brighteners with 0.12% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate and 0.06% of disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate. Composition F = Composition C of Example IX, except replace indicated brighteners with 0.15% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate and 0.02% of disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate. Composition G = Composition C of Example IX, except replace indicated brighteners with 0.096% of sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate and 0.088% of disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate. The results were as follows. Compositions B, C, and F of the present invention caused less staining of the cotton fabrics. EXAMPLE XII Brightener staining was evaluated as described in Example III using the following compositions. The results were as follows. Only Composition D is within the scope of the present invention, although the monosulfonated brightener also provided reduced staining in A (which did not contain an anionic surfactant) and E (which was not a stable isotropic liquid). EXAMPLE XIII Brightener staining was evaluated as described in Example XI in the following composition. Brightener A = 0.12% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate + 0.06% disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate B = 0.18% sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate C = 0.15% sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate + 0.02% disodium 4,4'-bis((4-anilino-6-methylhydroxyethylamino-1,3,5-triazin-2-yl)amino)-2,2'-stilbene disulfonate D = 0.15% sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate + 0.02% disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate E = 0.12% sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate + 0.06% disodium 2,2-(4,4'-biphenylene divinylene)-dibenzenesulfonate The results were as follows. Compositions B, C, D of the present invention caused less staining of the cotton fabrics. EXAMPLE XIV Brightener staining was evaluated in the following composition. Brightener A = 0.17% sodium 4-(2H-naphtho[1,2-d] triazol-2-yl)-2-stilbenesulfonate B = 0.17% sodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl) amino)-2-stilbenesulfonate C = 0.17% disodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl) amino)-2,2'-stilbenedisulfonate Samples of the above compositions were applied to unbrightened, unbleached raw cotton tracer fabrics. The fabrics were then washed in 30°C water with 120 g of composition, using the fine fabric cycle setting (low agitation, high water volume). The fabrics were dried and graded in normal daylight by a panel of expert graders. There was little to no staining visible with Brightener A, light to hardly visible staining with Brightener B, and very clearly visible staining with Brightener C. In a whiteness test of the above compositions, Brighteners B and C provided comparable whitening, whereas Brightener A was less effective at whitening. The above composition preferably also contains about 1.5% of tetraethylene pentaimine ethoxylated with 15-18 moles (avg.) of ethylene oxide at each hydrogen site. EXAMPLE XV A preferred liquid laundry detergent by virtue of the low odor properties of its grease removal solvent system, its stability in microemulsion form, and its enzymatic cleaning activity (by virtue of its pH) is as follows. The above composition is used in an aqueous laundry bath at a concentration of 100 ml/10 liters and provides an in-use pH of about 7.2 (varies with water hardness).

Claims: A stable isotropic liquid laundry detergent composition comprising, by weight: (a) from 3% to 50% of an anionic synthetic surfactant; and (b) from 0.01% to 1% of a monosulfonated brightener which represents at least 75% of the total brightener in the composition, said monosulfonated brightener being free of chlorine substituents; said composition containing less than 2% of quaternary ammonium cationic surfactants having 2 chains, each containing an average of from 16 to 22 carbon atoms. A composition according to Claim 1 wherein the monosulfonated brightener represents from 75% to 95% of the total brightener in the composition. A composition according to Claim 2 wherein the monosulfonated brightener represents from 85% to 90% of the total brightener in the composition. A composition according to Claim 1 comprising from 15% to 25% of the anionic synthetic surfactant, which comprises a C₁₀-C₁₈ alkyl sulfate containing an average of from 0 to 4 ethylene oxide units per mole of alkyl sulfate, a C₁₁-C₁₃ linear alkylbenzene sulfonate, or mixtures thereof. A composition according to Claim 4 comprising from 0.1% to 0.3% of the monosulfonated brightener. A composition according to Claim 5 further comprising from 4% to 15% of a nonionic surfactant which is a condensation product of a C₁₂-C₁₅ alcohol with from 3 to 8 moles of ethylene oxide per mole of alcohol. A composition according to Claim 6 further comprising from 5% to 20% of a C₁₀-C₂₂ fatty acid. A composition according to Claim 1 being substantially free of quaternary ammonion cationic surfactants having 2 chains, each containing an average of from 16 to 22 carbon atoms. A composition according to Claim 1 being substantially free of phosphate materials. A composition according to Claims 1, 2, 3, 4, 5, 6, 7, 8 or 9 wherein the monosulfonated brightener is sodium 4,4'-bis((4-anilino-6-morpholino-1,3,5-triazin-2-yl) amino)-2-stilbenesulfonate. A composition according to Claims 1, 2, 3, 4, 5, 6, 7, 8 or 9 wherein the monosulfonated brightener is sodium 4-(2H-naphtho[1,2-d]triazol-2-yl)-2-stilbenesulfonate.

Inventors: HALAS, LINDA A., PELTRE, PHILLIPPE P., WEVERS, JEAN
Applicants: THE PROCTER & GAMBLE COMPANY
Application year: 1985
Main classification: C11D3
IPC codes: C11D3, C11D17