GB2169916A - Built liquid detergent containing anionic, ethoxylated nonionic and amide surfactants - Google Patents

Abstract

Heavy-duty aqueous liquid laundry detergent compositions contain anionic synthetic surfactant, a mixture of ethoxylated nonionic surfactant and amide surfactant in a weight ratio of from about 4:1 to about 1:4, and a calcium selective builder, preferably a fatty acid or polycarboxylate builder.

Description

1

SPECIFICATION

Built liquid detergent containing anionic, ethoxy- 65 fated nonionic and arnide surfactants Technical Field

The present invention relates to heavy-duty liquid laundry detergent compositions containing anionic synthetic surfactant, ethoxylated nonionic surfactant, amide surfactant, and a calcium-selective detergent builder. This combination of ingredients provides superior cleaning on greasy and oily soils and overall outstanding detergency performance under a wide variety of laundering conditions, including washing in cool and cold water.

Background Art

U.S. Patent 4,153,570, Hennemann et al, issued May 8,1979, discloses a low-foaming liquid deter gents containing a specific mixture of anionic surfac tants, ethoxylated nonionic surfactants, amide sur factant, fatty acid soap, hydrotrope and solvent. The compositions have a low ratio of anionicto nonionic surfactant. They can contain up to 6% of the soap, and upto 2% of a heavy metal complexing agent.

U.S. Patent 3,707,503 Ken ny, issued Decem ber 26, 1972, discloses stable, controlled sudsing heavy-duty liquid detergents containing anionic surfactants, fatty 90 acid alkanolamide in a weight ratio of fatty acid to amide of 1:2 to 1: 11.

British Patent 1,573,908, Owen, published August 28,1980, discloses concentrated liquid detergents containing anionic, ethoxylated nonionic and amide 95 surfactants. There is no reference to detergent builders.

U.S. Patent 3,856,711, Mausner et al, issued De cember 24,1974, discloses concentrated, low-foam ing liquid detergents containing anionic, ethoxylated nonionic and amide surfactants. Detergent builders are not mentioned.

European Patent Application No. 0 095 205, Wertz et al, published November 30,1983, discloses deter gent compositions containing anionic surfactants, quaternary ammonium, amine or amine oxide surfac tants, and fatty acids, and formulated to provide a near-neutral wash pH. The compositions are preferably liquid detergents which additionally contain ethoxylated nonionic surfactants and polycarboxylate builders.

Summary of the Invention

The present invention encompasses a heavy-duty liquid laundry detergent composition comprising, by weight:

(a) from about 10% to about50%, on an acid basis, of an anionic synthetic surfactant; (b) from about5% to about20% of a mixture of:

(i) an ethoxylated alcohol oral kyl phenol nonionic surfactant having an HLB of from about 5to about17;and 00 anamidesurfactantofthefornula 0 R 2 R 1 - 1C1 - NI - R 3 wherein R' isanalkyi,hydroxyalkyl oralkenyl radical containing from about 8 to about 20 carbon atoms, and R 2 and R 3 are selected from the group consisting GB 2 169 916 A 1 of hydrogen, methyl, ethyl, propyl, isopropyl, 2hydroxyethyl, 2- hydroxypropyl, 3-hydroxypropyl, and said radicals additionally containing upto about 5 ethylene oxide units, provided that at least one of R 2 and R 3 contains a hydroxyi group; (c) from about 5% to about 30% of a calcium- selective detergent builder; and (d) from about 20% to about 75% of water; wherein the weight ration of (a) to (b) is from about 2:1 to about4A and the weight ratio of (i) to (H) isfrom about4A to about 1:4.

Detailed Description of the Invention

The liquid detergents of the present invention contain anionic synthetic surfactant, ethoxylated nonionic surfactant, amide surfactant, and a calcium selective builder. As used herein, theterm calcium- selective builder means any detergent builderthat preferentially controls calcium ion in the wash solution, ratherthan magnesium or other hardness ions. This includes all manner of detergent builders exceptfor polyphosphates, such as the tripolyphos- phates, pyrophosphates, orthophosphates and glassy polymeric metaphosphates. The calcium-selective builder should be used at a level sufficientto sequester of at least about 2.0, preferably at least about 2. 5, more preferably at least about 3.0, grains per gallon of calcium carbonate, while leaving at least about 0.5, preferably at least about 1. 0, more preferably at least about 1.5, and up to a maximum of about 4, grains per gallon of unsequestered hardness, preferably in the form of magnesium. The calciumselective builder generally represents from about 5% to about 30%, preferably from about 8% to about 25%, more preferablyfrom about 10% to about 20%, byweight of the composition.

It is believed thatthe calcium-selective builder adequately controls wash water hardness, preventing excessive interactions with anionic surfactants and with soils, while allowing sufficient free hardness to complex some of the anionic su rfactant to produce a hardness-surfactant (such as magnesium linear al kyl benzene su Ifonate) that is highly effective at removing greasy and oily soils. Such hardnesssurfactants pack atthe oillwater interface where they lower interfacial tension and enhance removal of greasyloily soils. The ethoxylated nonionic surfac- tants herein suspend hardness-surfactants in the wash watersolution. They are used at a level high enough to prevent excessive precipitation of hardness-surfactants atthe oillwater interface (which makes soil removal more difficult), but low enough to allowforthe desired adsorption and packing atthe interface.The amide surfactants further reduce oillwater interfacial tension, by hydrogen bonding with anionic surfactants,to improve greasyloily soil removal. Itwill be appreciated thatthe level and type of surfactants and builders herein can thus be selected to opitimize greasy/oily soil removal while providing overall outstanding detergency performance.

Anionic Synthetic Surfactant The detergent compositions herein contain from about 10% to about 50%, preferablyfrom about 15% to about40%, more preferablyfrom about 18% to about 30%, byweight, on an acid basis, of an anionic 2 GB 2 169 916 A 2 synthetic surfactant. Anionic synthetic surfactants aredisclosed in U.S. Patent 4,285,841, Barratetal, issued August 25,1981, and in U.S. Patent 3, 919,678, Laughlin eta[, issued December 30,1975, both 5 incorporated herein by reference.

Useful anionic surfactants includethe water-soluble salts, particularlythe alkali metal, ammonium and alkylolammonium (e.g., monoethanolammonium or triethanolammonium) salts, of organic sulfuric reac- tion products having in their molecular structure an alkyl group containing from about 8to about20 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 synthetiGsurfactants are the alkyl sulfates, especially those obtained bysulfating the higher alcohols (C8-C18 carbon atoms) such asthose produced by reducing the glycerides of tallow orcoconut oil; and the alkylbenzene sulfonates in which the alkyl group contains from about 9 to about 15 carbon atoms, in straightchain or branched chain configuration, e.g., those of thetype described in United States Patents 2,220,099 and 2,477,383.

Otheranionic surfactants herein arethe water soluble salts of: paraffin sulfonates containing from about8 to 24 (preferably about 12 to 18) carbon atoms; alkyl glyceryl ether sulfonates, especially those ethers of CB-18 alcohols (e.g.,those derived from tallow and coconut oil); alkyl phenol ethylene oxide ether sulfates containing from about 1 to about 4 units of ethylene oxide per molecule and from about 8to 12 carbon atoms in the alkyl group; and alkyl ethylene oxide ethersulfates containing about 1 to about4 units of ethylene oxide per molecule and from about 10 to about 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 about 6to 20 carbon atoms in the fatty acid group and from about 1 to 10 carbon atoms in the ester group; water-soluble salts of 2-acyloxy-alkane-l- suffonic acids containing from about2to 9 carbon atoms in the acyl group and from about9 to about 23 carbon atoms in the alkane moiety; water- soluble salts of olefin sulfonates containing from about 12to 24 carbon atoms; and beta-alkyloxy alkane sulfonates containing from about 1 to 3 carbon atoms in the alkyl group and from about8to 20 carbon atoms in the alkane moiety.

Preferred anionic surfactants herein arethe alkyl sulfates of the formula RO(C2H40)XS03M+ wherein R is an alkyl chain having from about 12 to about 18 carbon atoms, saturated or unsaturated, M is a cation which makesthe compound water-soluble, especially an alkali metal, ammonium or substituted ammonium cation, and x is from 0 to about 4. Preferably, R isa C12-Cl6alkyl orhydroxyalkyl group, especially a C12-Clr, alkyl, and m is from about 0 to about3.

Highly preferred anionic surfactants are the linear straight chain alkylbenzene sulfonates in which the average number of carbon atoms in the alky group is from about 12to about 13, and the C12-C15 alcohol sulfates containing from 0 to about 3 ethylene oxide units, as described above. Also preferred are mix- tures of these surfactants in a weight ratio of from about3:1 to about 1:3, preferablyfrom about2:1 to about 1:2. These anionics form hardness, preferably magnesium, surfactants that are particularly effective at lowering interfacial tension and removing greasy/ oily soils.

NonionicSurfactant Compositions of the present invention also contain from about 5% to about 20%, preferablyfrom about 6% to about 15%, more preferably from about 7% to about 12%, by weight of a mixture of an ethoxylated nonionic surfactant and an amide surfactant in a weight ratio of from about 4:1 to 1:4, preferablyfrom about 3:1 to about 1:3, more preferably from about 2:1 to about 1:2. In addition, the weight ratio of anionic synthetic surfactant (on an acid basis) to the tota I non ionic su rfacta nt (both the ethoxylated nonionic and the amide) should be from about 2:1 to about4: 1, preferably from about 2.5:1 to about 3.5: 1, to ensure the formation and adsorption of sufficient hardness su rfactants atthe oil/water interface to provide good greasy/oily soil removal.

The ethoxylated nonionic surfactants herein have an HLB (hydrophiliclipophilic balance) of from about go 5 to about 17, preferably from about 6 to about 13. HLB is defined in detail in Nonionic Surfactants, by M. J. Schick, Marcel Dekker, Inc., 1966, pages 607-613, incorporated herein by reference. Suitable ethoxylated nonionic surfactants herein are asfollows:

(1) The polyethylene oxide condensates of alkyl phenols. These compounds include the condensation products of alkyl phenols having an alkyl group containing from about6to 12 carbon atoms in either a straight chain or branched chain configuration with 1 oo ethylene oxide, said ethylene oxide being present in an amount equal to 3 to 25 moles of ethylene oxide per mole of alkyl phenol.

Examples of compounds of thistype include nonyl phenol condensed with about9.5 moles of ethylene oxide per mole of nonyl phenol; clodecylphenol condensed with about 12 moles of ethylene oxide per mole of phenol; dinonyl phenol condensed with about 15 moles of ethylene oxide per mole of phenol; and diisooctyl phenol condesned with about 15 moles of ethylene oxide per mole of phenol. Commercially available nonionic surfactants of this type include Igepal CO-630, marketed bythe GAFCorporation, and Triton X-45, X-1 14, X-1 00, and X-1 02, all marketed bythe Rohm & Haas Company.

(2) The condensation products of aliphatic alcohols with from about 1 to about 25 moles of ethylene oxide. The alkyl chain of the aliphatic alcohol can either be straight or branched, primary or secondary, and generally contains from about 8 to about 22 carbon atoms. Examples of such ethoxylatedalcohols include the condensation productof myristyl alcohol condensed with about 10 moles of ethylene oxide per mole of alcohol; and the condensation product of about 9 moles of ethylene oxide with coconut alcohol (a mixture of fatty alcohols with alkyl chains varying in length from 10 to 14 carbon atoms). Examples of commercially available nonionicsurfactants in this type include Tergitol 15-S-9, marketed by union Carbide Corporation, Neodol 45-9, Neodol 23-6.5, Neodol 45-7, and Neodol 45-4, marketed by 3 GB 2 169 916 A 3 Shell Chemical Company, and Kyro EGB, marketed byThe Procter & Gamble Company.

(3) The condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of these compounds has a molecularweight of from about 1500to 1800 and exhibitswater insolubility. The addition of polyoxyethylene moietiesto this hydrophobic portion tends to increase the water solubility of the molecule as a whole, and the liquid character of the product is retained uptothe pointwherethe polyoxyethylene content is about50% of the total weight of the condensation product, which corresponds to condensationwith upto about40 moles of ethylene oxide. Examples of compounds of thistype include certain ofthe commercially available Pluronicsurfactants, marketed byWyandotte Chemical Corporation.

(4) The condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenedia mine. The hydrophobic moiety of these products consists of the reaction product of ethylenediamine and excess propylene oxide, said moiety having a molecular weight of from about 2500 to about 3000. This hydrophobic moiety is condensed with ethylene oxide to the extentthatthe condesnation product containsfrom about40% to about80% byweightof poluoxyehtylene and has a molecularweight of from about 5,000 to about 11,000. Examples of this type of nonionic surfactant include certain of the commercially available Tetrionic compounds, marketed by Wyandotte Chemical Corporation.

Preferred ethoxylated nonionic surfactants are of the formula W(OC2H4)n0H, wherein R' is a C10-C16 alkyl group or a C8-C12 alkyl phenyl group, n is from about 3 to about 9, and said nonionicsurfactants has an HLB (hydrophile-lipophile balance) of from about 9 to about 13, preferably from about 10 to about 13.

Amide surfactants herein are of the formula 0 R 2 R 1 9 - 1 3 - C N - R wherein R' is an alkyl, hydroxyalkyl or alkenyl radical containing from about 8 to about 20 carbon atoms, and R'and R 3 are selectedfrom the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl, 2- hydroxyethy], 2-hydroxypropyl, 3-hydroxypropy], and said radicals additionally containing up to about 5 ethylene oxide units, provided at least one of R 2 and R 3 contains a hydroxyl group.

Preferred amides arethe C8-C20 fatty acid alkylol amides in which each alkylol group containsfrom 1 to 115 3 carbon atoms, and additionally can contain up to about 2 ethylene oxide units. Particularly preferred are the C12-C16fatty acid monoethanol and diethanol amides.

Calcium-Selective Builder The composition of the present invention comprise from about 5% to about 30%, preferably f rom about 8% to about 25%, more preferably from about 10% to about 20%, by weight of a calcium-selective builder.

Preferred builders herein are fatty acids containing from about 12 to about 22 carbon atoms. Preferred are saturated fatty acids containing f rom about 12 to about 18 carbon atoms.

Suitable saturated fatty acids can be obtained from natural sources such as plant or animal esters (e.g., palm kernel oil, palm oil and coconut oil) orsynthetically prepared (e.g., via the oxidation of petroleum or by hydrogenation of carbon monoxide via the FisherTropsch process). Examples of suitable saturated fatty acids for us in the composition of this invention include capric, lauric, myristic, coconut and palm kernel fatty acid. Preferred are saturated coconut fatty acids; from about 5:1 to 1: 1 (preferably about 3: 1) weight ratio mixtures of lauric and mystic acid; mixtures of the above with minor amounts (e.g., 1%-30% of total fatty acid) of oleic acid; and palm kernel fatty acid.

Other preferred builders herein are the watersoluble polycarboxylate builders described in U.S.

Patent 4,284,532, Leikhim et al, issued August 18, 1981, incorporated herein by reference.

The various aminopolycarboxylates, cycloalkane polycarboxylates, ether polycarboxylates, alkyl polycarboxylates, epoxy polycarboxylates, tetrahydrofur- an polycarboxylates, benzene polycarboxylates, and polyacetal polycarboxylates are suitable for use herein.

Examples of such polycarboxylate builders are sodium and potassium ethylenediaminetetraacetate; sodium and potassium nitrilotriacetate; thewatersoluble salts of phytic acid, e.g., sodium and potassium phytates, disclosed in U.S. Patent 1,739, 942, Eckey, issued March 27,1956, incorporated herein by reference; the polycarboxylate materials described in U.S. Patent 3,364,103, incorporated herein by reference; and the watersoluble salts of polycarboxylate polymers and copolymers described in U.S. Patent 3,308,067, Diehl, issued March 7,1967, incorporated herein by reference.

Useful detergent builders also include the watersoluble salts of polymeric aliphatic polycarboxylic acids having the following structural and physical characteristics: (a) a minimum molecularweight of about350 calculated as to the acid from; (b) an equ iva lent weight of about 50to aboul:80 calculated as to acid form; (c) at least45 mole percent of the monomeric species having at leasttwo carboxyl radicals separated from each other by not morethan two carbon atoms; (d) the site of attachment of the polymer chain of any carboxyl containing radical being separated by not more than three carbon atoms along the polymer chain from the site of attachment of the next carboxyl-containing radical. Specific examples of such builders arethe polymers and copolymers of itaconic acid, aconitic acid, maleic acid, mesaconic acidjumaric acid, methylene malonic acid, and citraconic acid.

Other suitable polycarboxylate builders include the water-soluble salts, especiallythe sodium and potas- sium salts, of mellitic acid, citric acid, pyromellitic acid, benzene pentacarboxylic acid, oxydiacetic acid, carboxymethyloxysuccinic acid, carboxymethyloxymalonic acid, cis-cyclohexanehexacarboxylic acid, cis- cyclopentanetetracarboxylic acid and oxydisucci- nic acid.

Other polycarboxylates for use herein arethe polyacetal carboxylates described in U.S. Patent 4 4,144,226, issued March 13,1979 to Crutchfield etal, and U.S. Patent 4,146,495, issued March 27,1979 to Crutchfield etal, both incorporated herein by refer ence.

Other calcium-selective detergent builders useful herein include the aluminosilicate ion exchange material described in U.S. Patent 4,405,483, Kuzel et al, issued September 20,1983, incorporated herein by reference. Crystalline aluminosilicates are of the formula Na,[(A1 02)Z(SiO2),].xH20 wherein zandy are at leastabout6,the molarratio of ztoyisfrom about 1.Oto aboutO.5 and xisfrom about to about 264. Amorphous hydrated aluminosili cate material useful herein as the empirical formula M,(zAl 02YSi02) wherein M is sodium, potassium, ammonium, or substituted ammonium, z is from about 0.5 to about2, y is 1 and said material has a magnesium ion exchange capacity of at least about 50 milligram 85 equivalents of CaC03 hardness per gram of anhyd rousaluminosilicate.

Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations ZeoliteA, Zeolite B, and Zeolite X. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material hasthefor mula Nal2f(Al 02)12(SiO2)121-xH20 wherein x is from about 20 to about 30, especially 95 about27.

Water The compositions also contain from about 20% to about 75%, preferably from about 25% to about 65%, more preferably from about 30% to about 55%, of 100 water.

Optional Components Optional components for use in the liquid cleter gents herein include neutralizing agents, buffering agents, phase regulants, solvents, hydrotropes, en zymes, enzyme stabilizing agents, polyacids, suds regulants, opacif iers, antioxidants, bacteriacides, dyes, perfumes, and brighteners described in U.S.

Patent 4,285,841, Barrat et al, issuedAugust 25,1981, incorporated herein by reference.

The compositions herein are preferably form u lated to provide an initial pH of from about7.0 to about9.0, preferablyfrorn about 7.0 to about 8.5, more prefer ablyfrorn about7.2 to about 8.0, at a concentration of from about 0.1 % to about 1 % byweight in water at 200C. Such near-neutral wash pH's are preferred for best overall detergency performance, including on greasy and oily soils.

A preferred neutralization system contains from about 0 to about 0.04 moles, preferably from about 0.01 to about 0.035 moles, more preferably from aboutO.015to about 0.03 moles, per 100 grams of composition of an alkanolamine selected from the group consisting of monoethanolamine, diethanola mine, triethanolamine, and mixtures thereof. Low levels of the alkanolamines, particularly monoetha nolamine, are preferred to enhance product stability, detergency performance, and odor. Howeverthe amountof alkanolamine should be minimizedfor best chlorine bleach compatibility. While the present GB 2 169 916 A 4 compositions can contain mixtures of the alkanolamines, best color stability is obtained using single alkanolamines.

In addition, preferred compositions herein contain potassium and sodium ions in a potassium to sodium molar ratio of from aboutO.1 to about 1.3, preferably from aboutO.6to about 1,for best phase stability.

A preferred solventsystern is comprised of ethanol, a polyol and water. Ethanol is preferably presentata level of from about2% to about 10%, more preferably from about5% to about9%, byweight of the composition.

Any polyol containing 2 to 6 carbon atoms and from 2to 6 hydroxy groups can be used in the present compositions. Examples of such polyols are ethylene glycol, propylene glycol and glycerine. Propylene glycol is particularly preferred. The polyol preferably represents from bout 2% to about 15%, more preferably from about 3% to about 10%, byweightof the composition.

Preferred compositions herein further contain from aboutO.5% to about 5%, preferablyfrom about 1 % to about3%, byweight of a highly ethoxylated polyethylenearnine or polyethyleneimine soil remov- go al and antiredeposition agent, such as those describes in European Patent Application No. 112,593, Vander Meer, published July 4,1984, incorporated herein by reference. A particularly preferred material istetraethylene pentaimine ethoxylated with about 15-18 moles of ethylene oxide at each hydrogen site.

Thefollowing examples illustrate the compositions of the present invention.

All parts, percentages and ratios used herein are by weight unless otherwise specified.

EXAMPLE I

Heavy-duty liquid laundry detergent of the present invention are asfollows Components C 13 linear alkylbenzene sulfonic acid C 14-1. alkyl polyethoxylate (2.25) sulfuric acid C 12-13 alcohol polyethoxylate (6.5). Coconutalkyl diethanolamide Whole cut palm kernel fatty acid Citric acid Protease enzyme (2.0 AU/g) TFPA-E 15-18 Moncethanolamine Sodium hydroxide Potassium hydroxide Propylene glycol Ethanol Sodium f0rmate Minors and water PH in wash water at 20C at 0. 2% oncentration Wt-3 B 11.0 13.0 11.0 13.0 5.0 3.0 5.0 3.0 10.0 10.0 4.0 4.0 0.75 0.75 2.0 2.0 2.0 2.0 4.0 4.0 1.6 1.6 5.5 3.5 6.5 6.5 1.0 1.0 Balance to 100 7.2 7.2 15.0 10.0 3.0 5.0 15.0 0.75 2.0 2.0 4.0 1.6 5.5 6.5 1.0 Alcohol and monoethoxylated alcohol removed.

Tetraethylene pentaimine ethoxylated with 15-18 moles (avg.) of ethylene oxide at each hydrogen site.

Composition A is preferably prepared by adding the components, with continuous mixing, in the following order: paste premix of alkylbenzene sulfonic acid, sodium hydroxide, propylene glycol and ethanol; paste premix of alkyl polyethoxylate sulfuric acid, sodium hydroxide and ethanol; premix of water, brighteners, aikanolamine, and alcohol polyethoxylate; alcohol polyethoxylate; ethanol; sodium and potassium hydroxide; fatty acid; citric acid; premix of formate, amide and TEPA-E15-18; adjust pHto about 8.1; and balance of components.

Compositions B and C can be prepared in a similar manner.

Composition A provided better overall cleaning, particularly on greasyloiiy soild atwarm (95T) wash watertemperatures, than similar compositions con taining 8% of the alcohol polyethoxylate and none of the amide, and 8% of the amide and none of the 75 alcohol polyethoxylate.

Claims (10)

1. A heavy-duty liquid laundry detergent cornposition comprising, by weight:

(a) from about 10% to about50%, on an acid basis, of an anionic synthetic surfactant; (b) from about5% to about20% of a mixture of:

(i) an ethoxylated alcohol of alkylphenol nonionic surfactant having an HLB of from about 5to about 17; and (5) an amide surfactant of the formula 0 R 2 1 _ 0 1 3 R C _ N _ R wherein R' isan alkyl,hydroxyalkyl oran alkenyl radical containing from about 8 to about 20 carbon atoms, and R 2 and R'are selected from the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropy], and said radicals additionally containing up to about 5 ethylene oxide units, provided at least one of R2 and R' contains a hydroxyl group; (c) from about 5% to about 30% of a calciumselective detergent builder; and (d) from about 20% to about 75% of water; wherein the weight ratio of (a) to (b) is from about 2:1 to about4A and theweight ratio of (i) to (ii) isfrom about4A to about 1:4.

2. A composition according to Claim 1 wherein the anionic synthetic surfactant comprises a C12-13 linear alkylbenzene sulfonate, an alkyl sulfate of the formula RO(C21- 140)mSO3M, wherein R is a C1215 alkyl group, m isfrom about Oto about3, and M is a compatible cation; or mixtures thereof.

3. A composition according to Claim 1 wherein the ethoxylated nonionic surfactant is of the formula Rl(OC2H4),,OH, wherein R' is a C10-16 alkyl orC8-12 alkylphenyl group, n is from about 3 to about 9, and said surfactant has an HLB of from about 10to about 13.

4. A composition according to Claim 3 wherein the amide surfactant is a C12-C116fatty acid monoethanol or diethanol amide.

5. A composition according to Claim 4 comprising fromabout6% to about 15% ofthe mixture of (i) and (ii).

6. A composition according to Claim 5 comprising from about7% to about 12% of the mixture of (i) and (ii), wherein the weight ratio of (i) to (ii) is from about 2:1 to about 1:2.

7. A composition according to Claim 6 comprising from about 18% to about 30%, on an acid basis, of the anionic synthetic surfactant, which is a mixture of a C12-13 linear alkylbenzene sulfonate and an alkyl GB 2 169 916 A 5 sulfate of theformula R0(C2H40)mS03M, wherein R is a C12-C15 alkyl group, m isfrom about0to about3, and M is a compatible cation, the weight ratio of said alkylbenzene sulfonateto alkyl sulfate beingfrom about2:1 to about 1:2.

8. A composition according to Claim 7 wherein the calcium-selective detergent builder comprises a saturated fatty acid containing from about 12 to about 18 carbon atoms.

9. A composition according to Claim 7 wherein the calcium-selective detergent builder comprises a water soluble polycarboxylate builder. rr/0 1 D/C29)

10. A heavy-duty liquid laundry detergent composition substantially as described with reference to the Example.

Printed in the United Kingdom for Her Majesty's Stationery Office, 8818935, 7186 18996. Published at the Patent Office, 25 Southampton Buildings, London WC2A lAY, from which copies may be obtained.