CN110621769A

CN110621769A - Laundry detergent compositions

Info

Publication number: CN110621769A
Application number: CN201880027340.XA
Authority: CN
Inventors: S·N·巴切洛尔; J·M·伯德
Original assignee: Unilever Nederland BV
Current assignee: Unilever IP Holdings BV
Priority date: 2017-05-10
Filing date: 2018-04-03
Publication date: 2019-12-27
Also published as: BR112019023390A2; AR111780A1; WO2018206197A1; EP3622045A1; EP3622045B1; ZA201906405B

Abstract

An aqueous liquid laundry detergent composition comprising: (i)5-19 wt% of LAS, (ii)0.5-8 wt% of alkyl ether carboxylic acid of the structureSurfactant (b): r₂‑(OCH₂CH₂)_n‑OCH₂-COOH, wherein R₂Is C₁₆‑C₁₈A linear alkyl chain; n is 10 to 25 and the ratio of (ii) to (i) is 0.05 to 1; (iii) at least 60% by weight of water; (iv)0-2 wt% of an ethoxylated alcohol nonionic surfactant, wherein the ratio of (iv) to (i) is 0-0.2; and (v)0-1 wt% of a phosphorus-containing chemical; wherein the composition optionally comprises an additional anionic surfactant, wherein the ratio of additional surfactant to (i) is from 0 to 0.55. A method of treating a textile, comprising: a) treating a textile with 1g/L of an aqueous solution of the composition; and b) contacting the solution for 10 minutes to 2 days, followed by rinsing and drying.

Description

Laundry detergent compositions

Technical Field

The present invention provides laundry detergent compositions. In particular, the present invention relates to aqueous liquid laundry detergent compositions for use in domestic laundry.

Background

Aqueous household laundry detergent formulations comprising alkyl ether carboxylates in combination with other anionic surfactants as the primary surfactant are known. The alkyl ether carboxylates enhance the cleaning performance of the detergent and it is desirable to maximize this enhancement.

WO2016/180552(Unilever) discloses an enzymatic dispersant formulation for home laundry comprising an alkyl ether carboxylic acid, a protease, an anionic surfactant and optionally a nonionic surfactant. Exemplified are formulations comprising alkyl ether carboxylate and a surfactant system comprising linear alkylbenzene sulfonate, a nonionic surfactant and sodium lauryl ether sulfate in a weight ratio of 4:1: 5.

DE102013218614(Henkel) discloses liquid detergent formulations comprising a surfactant mixture comprising at least one ether carboxylate with improved cleaning performance, especially against greasy stains and/or at low temperatures. Exemplified are formulations comprising alkyl ether carboxylate and a surfactant system comprising linear alkylbenzene sulfonate, nonionic surfactant and lauryl ether sulfate in a weight ratio of 4:2: 5.

Disclosure of Invention

We have found that aqueous laundry detergent formulations with high ratios of linear alkylbenzene sulphonate to other non-alkyl ether carboxylate surfactants give much greater benefit from the addition of specific alkyl ether carboxylate surfactants.

In one aspect, the present invention provides an aqueous liquid laundry detergent composition comprising:

(i)5-19 wt% of a linear alkylbenzene sulphonate anionic surfactant,

(ii)0.5 to 8 wt% of an alkyl ether carboxylic acid anionic surfactant of the structure:

R₂-(OCH₂CH₂)_n-OCH₂-COOH，

wherein:

R₂is selected from C₁₆-C₁₈A linear alkyl chain; wherein n is selected from 10 to 25 and wherein the weight ratio of alkyl ether carboxylic acid to linear alkylbenzene sulfonate surfactant is from 0.05 to 1;

(iii) at least 60% by weight of water;

(iv)0-2 wt% of an ethoxylated alcohol nonionic surfactant, wherein the weight ratio of ethoxylated alcohol nonionic surfactant to linear alkylbenzene sulfonate surfactant is 0-0.2; and

(v)0-1 wt% of a phosphorus-containing chemical;

wherein the composition optionally comprises an additional anionic surfactant, wherein the weight ratio of additional surfactant to linear alkylbenzene sulphonate is from 0 to 0.55, preferably from 0 to 0.1.

In a second aspect, the present invention provides a domestic method of treating a textile, the method comprising the steps of:

a) treating the textile with at least 1g/L of an aqueous solution of a laundry detergent composition as defined in the first aspect; and the combination of (a) and (b),

b) the aqueous laundry detergent solution is left in contact with the textile for a period of time from 10 minutes to 2 days, and then the textile is rinsed and dried.

Detailed Description

Weight percentages (wt.%) summarized herein are weight percentages based on the total composition, unless otherwise specified.

The indefinite articles "a" and "an" as used herein mean at least one or more unless otherwise indicated.

Preferably, the laundry contains 0.3-3 wt.% of human sebum.

In the method aspect of the invention, the surfactant used is preferred as is preferred in the composition aspect of the invention.

The domestic method is preferably carried out in a domestic washing machine or by hand washing. The washing temperature is preferably 280-320K. The main wash time is preferably 10 to 60 minutes.

The textile product is preferably an item of clothing, bedding or tablecloth. Preferred articles of clothing are shirts, pants, undergarments and pullovers containing polyester cotton.

The pH of the composition is preferably 7 to 11, preferably 7 to 10. The pH may suitably be measured so that a dilution of 5g/L of the aqueous liquid laundry detergent in demineralised water has the pH indicated.

The compositions of the present invention may contain 0-1% by weight of a phosphorus-containing chemical. Thus, the formulations may (and preferably do) be free of phosphorous-containing chemicals, but when present, they may only be present at levels up to 1 wt% based on the total formulation.

The surfactants of the present invention can be neutralized with any suitable base. Typical amines used for neutralizing surfactants are monoethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, monoaminohexanol, 2- [ (2-methoxyethyl) methylamino ] ethanol, propanolamine, N-methylethanolamine, diethanolamine, monobutanolamine, isobutanol amine, monopentanolamine, 1-amino-3- (2-methoxyethoxy) -2-propanol, 2-methyl-4- (methylamino) -2-butanol, 6-amino-1-hexanol, heptanediol, isotataline (isoetarine), norepinephrine, sphingosine, phenylpropanolamine and mixtures thereof.

The surfactants of the present invention are preferably neutralized with aqueous sodium hydroxide.

Preferably, the aqueous liquid laundry detergent composition comprises less than or equal to 5 wt% (i.e. 0-5 wt%), more preferably less than or equal to 0.2 wt% (i.e. 0-0.2 wt%) of a hydrotrope (hydrotrope) selected from the group consisting of: ethylene glycol; 1, 3-propanediol; 1, 2-propanediol; 1, 4-butanediol; 1, 5-pentanediol; 1, 6-hexanediol; 2, 3-butanediol; 1, 3-butanediol; diethylene glycol; triethylene glycol; polyethylene glycol; glycerol formaldehyde dipropylene glycol; polypropylene glycol dipropylene glycol n-butyl ether; and mixtures thereof. Preferably, the low level of hydrotrope is selected from 1, 2-propanediol; dipropylene glycol; polypropylene glycol; 2, 3-butanediol; dipropylene glycol n-butyl ether; and mixtures thereof.

The detergent is preferably blue, green or violet in colour. The detergent is preferably transparent and has a maximum optical density (1cm) of 1.5 in the range of 400-700 nm.

The weight of the anionic surfactant is calculated as its protonated form.

Alkyl ether carboxylic acids

The liquid laundry compositions comprise from 0.5 to 8 wt%, preferably from 0.5 to 6 wt%, more preferably from 1 to 6 wt%, most preferably from 2 to 6 wt% of alkyl ether carboxylic acid anionic surfactant.

Weight of alkyl ether carboxylic acid in protonated form R₂-(OCH₂CH₂)_n-OCH₂COOH calculation. They may be used as salts, for example sodium or amine salts.

The alkyl chain may be linear or branched, preferably it is linear.

The alkyl chain may be aliphatic or contain one cis or trans double bond.

Alkyl chain (R)₂) Is selected from C₁₆-C₁₈A linear alkyl chain.

The alkyl ether carboxylic acids have n selected from 10 to 25, preferably 10 to 20.

The weight ratio of alkyl ether carboxylic acid to linear alkylbenzene sulphonate surfactant is from 0.05 to 1, preferably from 0.1 to 0.6.

Alkyl ether carboxylic acids are available from KaoHuntsmanAnd ClariantMost preferred are the sodium salts of alkyl ether carboxylates.

Alkyl ether carboxylic acid synthesis is discussed in the International Surfactants Organic Chemistry, edited by H.W.Stache (Marcel Dekker, New York 1996).

They can be synthesized by reaction of the corresponding alcohol ethoxylates with chloroacetic acid or sodium monochloroacetate in the presence of NaOH:

R₂-(OCH₂CH₂)_n-OH+NaOH+ClCH₂COONa→R₂-(OCH₂CH₂)_n-OCH₂COOH+NaCl+H₂O

in this synthesis, residual R may be present₂-(OCH₂CH₂)_n-OH, preferably R in alkyl ether carboxylic acids₂-(OCH₂CH₂)_nThe content of-OH is from 0 to 10% by weight. Low levels of diethanoic acid and glycolic acid may be present as by-products.

NaCl from synthesis may be present in an aqueous liquid laundry detergent composition. Additional NaCl may be added to the composition.

Their alkyl ether carboxylic acids can also be synthesized by oxidation reactions:

R₂-(OCH₂CH₂)_n-O CH₂CH₂OH→R₂-(OCH₂CH₂)_n-OCH₂COOH

the oxidation is usually carried out under basic conditions, using oxygen as oxidant in the presence of a metal catalyst such as Pd/Pt, as described in DE3135946, DE2816127 and EP 0304763.

Straight chain alkyl benzene sulfonate

The linear alkylbenzene sulphonate is present in an amount of from 5 to 19 wt%, preferably from 6 to 19 wt%, more preferably from 7 to 19 wt%, even more preferably from 8 to 19 wt%, most preferably from 9 to 19 wt%.

The linear alkyl benzene sulfonate is a neutralized form of linear alkyl benzene sulfonic acid. Neutralization can be carried out with any suitable base. Most preferred is the sodium salt.

Linear alkyl benzene sulphonic acids have the following structure:

wherein x + y is 7, 8, 9 or 10.

Preferably, x + y ═ 8 is present at a weight content greater than 28% by weight of the total linear alkylbenzene anionic surfactant content.

Preferably, x + y ═ 9 is present at a weight content greater than 28% by weight of the total linear alkylbenzene anionic surfactant content. Weight is expressed as protonated form.

Surfactants can be produced by a number of different routes. Synthesis is discussed in International Surfactants Organic Chemistry, edited by H.W.Stache (Marcel Dekker, New York 1996).

The linear alkyl benzene sulphonic acid may be prepared by sulphonation of linear alkyl benzene. Sulfation can be carried out with concentrated sulfuric acid, oleum or sulfur trioxide. Preferably linear alkyl benzene sulphonic acid produced by reacting linear alkyl benzene with sulphur trioxide.

Linear alkylbenzenes can be produced by a variety of routes. Examples include:

benzene may be alkylated with n-olefins using an HF catalyst.

Benzene can be alkylated with n-olefins in a fixed bed reactor using a solid acidic catalyst (DETAL process), such as an aluminosilicate.

Benzene may be alkylated with n-olefins using an aluminum chloride catalyst. Benzene may be alkylated with n-chlorinated paraffins using an aluminum chloride catalyst.

The weight percentage of linear alkylbenzene sulphonate surfactant relative to the total non-alkyl ether surfactant is preferably from 50 to 100 wt%, preferably from 60 to 100 wt%, more preferably from 70 to 10 wt%, most preferably from 80 to 100 wt%.

Water (W)

The liquid detergent composition is aqueous. Which comprises at least 60% by weight of water.

Preferably it comprises at least 65 wt.%, more preferably at least 70 wt.%, most preferably at least 75 wt.% water. Exemplary preferred weight ranges for the water content include 60 to 94.5 weight percent, preferably 62.5 to 92.5 weight percent, more preferably 65 to 90 weight percent.

Ethoxylated alcohol nonionic surfactant

Ethoxylated alcohol nonionic surfactants may be absent or present in the formulation. If present, it is present in an amount of up to 2% by weight.

The weight ratio of ethoxylated alcohol nonionic surfactant to linear alkylbenzene sulphonate surfactant is from 0 to 0.2. This means that the ethoxylated alcohol nonionic surfactant may not be present (so the weight ratio of ethoxylated alcohol nonionic surfactant to linear alkylbenzene sulphonate surfactant is 0); or if present, at most one fifth the weight content of the linear alkylbenzene sulphonate surfactant.

The nonionic surfactant is preferably a fatty alcohol ethoxylate nonionic surfactant.

The ethoxylated nonionic surfactant is preferably a primary alcohol ethoxylate, more preferably C ethoxylated with an average of 1 to 20 moles of ethylene oxide per mole of alcohol₈-C₂₀An aliphatic alcohol. Most preferably, the ethoxylated alcohol nonionic surfactant is selected from the group consisting of C having 7-9 moles of ethylene oxide per mole of alcohol₁₂-C₁₅An aliphatic primary alcohol; r₂-(OCH₂CH₂)_n-OH and R₂-(OCH₂CH₂)_n+1-OH。

Preferably, the alkyl chain is linear.

Additional surfactants

Aqueous liquid laundry detergents may contain additional surfactants, as described, for example, in "Surface Active Agents", Vol.1, Schwartz & Perry, Interscience 1949; volume 2, Schwartz, Perry & Berch, Interscience 1958; current versions of "McCutcheon's emulsifiers and Detergents", published by Manufacturing conditioners Company, or "Tenside-Taschenbuch", H.Stache, 2 nd edition, Carl Hauser Verlag, 1981, or International Surfactants, edited by Helmut W.Stache, Organic chemistry (Marcel Dekker 1996).

Preferably the weight ratio of additional surfactant (total) to linear alkylbenzene sulphonate is from 0 to 0.55. This means that no additional surfactant may be present (hence a weight ratio of additional surfactant to linear alkylbenzene sulphonate surfactant of 0); or if present, the additional surfactant, in an amount of up to 55% by weight of the linear alkylbenzene sulphonate surfactant.

Preferably the weight ratio of additional surfactant to linear alkylbenzene sulphonate is from 0 to 0.55, more preferably from 0 to 0.1. Exemplary preferred weight ratios of additional surfactant (when present) to linear alkylbenzene sulfonate include 0.01 to 0.55, more preferably 0.01 to 0.1.

The additional surfactant is preferably an anionic surfactant.

Therefore, it is preferred that the weight ratio of additional anionic surfactant to linear alkylbenzene sulphonate is from 0 to 0.55, more preferably from 0 to 0.1. Exemplary preferred weight ratios of additional anionic surfactant (when present) to linear alkylbenzene sulphonate comprise from 0.01 to 0.55, more preferably from 0.01 to 0.1.

Examples of suitable additional anionic detergent compounds are: alkyl ether sulfates, especially lauryl ether sulfate having 1-3 moles of ethoxylation; alkyl sulfates, especially by reacting straight or branched chain C₈-C₁₈Those obtained by alcohol sulphation; soap; alkyl (preferably methyl) ester sulfonates, and mixtures thereof. Alkyl ether sulfates and alkyl sulfates are particularly preferred.

Alkoxylated polyethyleneimines

The formulation may comprise an alkoxylated polyethyleneimine comprising a polyethyleneimine backbone, wherein the modification of the polyethyleneimine backbone is intended to render the polymer non-quaternized. Such materials may be represented as PEI (X) YAO, where X represents the molecular weight of unmodified PEI and Y represents the average moles of Alkoxylation (AO) per available NH in the unsubstituted polyethyleneimine backbone. Y is preferably from 7 to 40, more preferably from 16 to 26, most preferably from 18 to 22. X is selected to be about 300 to about 10000 weight average molecular weight, and is preferably about 600.

The alkoxylation is preferably selected from ethoxylation or propoxylation, or a combination of both, most preferably ethoxylation. The alkoxy chain may be terminated by a group selected from: h; CH (CH)₃；SO₃ ^-；CH₂COO^-；PO₃ ^2-；C₂H₅(ii) a N-propyl, isopropyl; n-butyl; a tertiary butyl group; and sulfosuccinates, most preferably H.

Most preferably, the alkoxylated PEI is PEI (600)20 EO.

The alkoxylated polyethyleneimine may be contained in an amount of 0.1 to 10 wt%.

In certain embodiments, it is preferred that the aqueous liquid laundry detergent composition does not comprise from 1 to 8 wt% of alkoxylated polyethyleneimine.

Polymer and method of making same

The composition may comprise one or more additional polymers.

Examples are carboxymethylcellulose, poly (ethylene glycol), poly (vinyl alcohol), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers, lauryl methacrylate/acrylic acid copolymers, and terephthalate polyester soil release polymers including polymers of aromatic dicarboxylic acids and alkylene glycols (including polymers containing polyalkylene glycols), as described in WO2009/153184, EP2692842 and WO 2014/019903. Copolymers as described in WO2014/082955(Unilever) may be present.

Polymers for preventing dye deposition may be present, for example poly (vinylpyrrolidone), poly (vinylpyridine-N-oxide) and poly (vinylimidazole).

Such polymers are most preferably present in an amount of less than 0.4 wt.%.

The composition is preferably free of silicone polymers and polymers with quaternized N groups.

When the polymer is considered to be a builder and/or a chelant, then the level of polymer is included in the total level of builder and chelant.

Builders and chelating agents

The detergent composition may also optionally comprise relatively low levels of organic detergent builder or chelant materials. Examples include alkali metals, citrates, succinates, malonates, carboxymethylsuccinates, carboxylates, polycarboxylates and polyacetylcarboxylates. Specific examples include sodium, potassium and lithium salts of oxydisuccinic acid, trimellitic acid, benzene polycarboxylic acids, ethylene diamine tetraacetic acid, diethylene triamine pentaacetic acid, alkyl or alkenyl succinic acids, nitrilotriacetic acid and citric acid.

Aqueous liquid laundry detergent formulations, if used, contain 0.1 wt% to 3.0 wt% of builder and chelant materials. Citrate salts are most preferred.

Phosphorus-containing chemicals

The phosphorus-containing chemical is an inorganic or organic chemical containing phosphorus.

Examples are sodium tripolyphosphate, DEQUEST^TMOrganic phosphonate type chelants sold by Monsanto, and alkane hydroxy phosphonates.

The aqueous liquid laundry detergent composition comprises 0-1 wt% of a phosphorus-containing chemical.

Shading dye

Dyes are described in Color Chemistry Synthesis, Properties and Applications of Organic Dyes and Pigments (H Zollinger, Wiley VCH, Z ü rich, 2003) and Industrial dye Chemistry, Properties Applications (K Hunger (ed), Wiley-VCH Weinheim 2003).

Hueing dyes for laundry detergents preferably have more than 5000L mol at the absorption maximum in the visible range (400-700nm)^-1cm^-1Preferably greater than10000L mol^-1cm^-1The extinction coefficient of (a). The color of the dye is blue or violet.

Preferred shading dye chromophores are azo, azine and anthraquinone.

Preferred examples of azo dyes are direct violet 9, direct violet 99, direct violet 35 and the dyes indicated below:

the azo dyes are preferably selected from sulfonated phenazine dyes. A preferred example is acid blue 98, acid Violet 50, CAS-No 72749-80-5 dye, acid blue 59.

The preferred anthraquinone dyes are disperse violet 28, and a reactive blue anthraquinone dye covalently attached to an alkoxylated polyethyleneimine. The alkoxylation is preferably selected from ethoxylation and propoxylation, most preferably propoxylation. Preferably, 80 to 95 mol% of the NH groups in the polyethyleneimine are replaced by isopropanol groups by propoxylation. Preferably, the molecular weight of the polyethyleneimine prior to reaction with the dye and propoxylation is 600-1800.

Mixtures of hueing dyes may be used.

The hueing dye is preferably present in the composition in an amount of from 0.0001 to 0.5 wt%, more preferably from 0.001 to 0.1 wt%. Depending on the nature of the hueing dye, there is a preferred range depending on the efficacy of the hueing dye, which depends on the class and the specific efficacy within any particular class.

Enzyme

Preferably, each enzyme is present in the laundry compositions of the present invention at a level of from 0.0001 wt% to 0.1 wt% protein.

The protease is preferably present in an aqueous liquid laundry detergent composition. Proteases hydrolyze the peptides and bonds within the protein, which results in enhanced removal of protein or peptide containing stains in the context of laundry.

Most preferably, the protease is subtilisin (EC 3.4.21.62).

The lipase is preferably present in an aqueous liquid detergent composition. Preferred commercially available lipases include Lipolase^TMAnd Lipolase Ultra^TM，Lipex^TMAnd Lipoclean^TM(Novozymes A/S)。

Suitable amylases (alpha and/or beta) include those of bacterial or fungal origin. Chemically modified or protein engineered mutants are included. Amylases include, for example, alpha-amylases obtained from Bacillus, such as particular strains of Bacillus licheniformis described in more detail in GB1,296,839, or strains of Bacillus disclosed in WO95/026397 or WO 00/060060. The commercially available amylase is Duramyl^TM，Termamyl^TM，Termamyl Ultra^TM，Natalase^TM，Stainzyme^TM，Fungamyl^TMAnd BAN^TM(Novozymes A/S)，Rapidase^TMAnd Purastar^TM(from Genencor International Inc.).

Fluorescent agent

The composition preferably comprises a fluorescent agent (brightener). Fluorescent agents are well known, and many such fluorescent agents are commercially available. Typically, these fluorescent agents are provided and used in the form of their alkali metal salts, e.g., sodium salts.

Preferred classes of fluorescers are: distyrylbiphenyl compounds, such as Tinopal (trade mark) CBS-X, diaminostilbene disulfonic acid compounds, such as Tinopal DMS pure Xtra and Blankophor (trade mark) HRH, and pyrazoline compounds, such as Blankophor SN.

Preferred fluorescent agents are: sodium 2- (4-styryl-3-sulfophenyl) -2H-naphtho (napthol) [1,2-d ] triazole, disodium 4,4' -bis { [ (4-anilino-6- (N-methyl-N-2-hydroxyethyl) amino-1, 3, 5-triazin-2-yl) ] amino } stilbene-2-2 ' -disulfonate, disodium 4,4' -bis { [ (4-anilino-6-morpholinyl-1, 3, 5-triazin-2-yl) ] amino } stilbene-2-2 ' -disulfonate, and disodium 4,4' -bis (2-sulfostyryl) biphenyl.

The total amount of fluorescent agent or agents used in the composition is preferably 0.0001 to 0.5 wt%, more preferably 0.005 to 2 wt%, most preferably 0.05 to 0.25 wt%.

Perfume

The composition preferably comprises a perfume.

The perfume is preferably comprised in 0.01-2 wt%, more preferably 0.05-0.5 wt%, most preferably 0.1-1 wt%. Many suitable examples of fragrances are provided in CTFA (Cosmetic, Toiletry and Fragrance Association)1992International layers Guide, published by CFTA Publications, and OPD1993Chemicals layers Directory 80th annular Edition, published by Schnell Publishing Co.

The international daily-use perfumery association has issued a list of fragrance ingredients (fragrances) in 2011. (http:// www.ifraorg.org/en-us/ingredients #. U7Z4 hPldWzk).

The international daily fragrance institute provides a database of fragrances (fragrances) with safety information.

Some or all of the perfume may be encapsulated, typical perfume components which facilitate encapsulation include those having a relatively low boiling point, preferably a boiling point of less than 300 ℃, preferably 100 ℃ and 250 ℃. It is also advantageous to encapsulate perfume components having a low Clog P (i.e. those that will have a higher tendency to partition into water), preferably having a Clog P of less than 3.0.

Preferably, the laundry treatment composition does not comprise a peroxygen bleach, such as sodium percarbonate, sodium perborate and peracids.

The liquid laundry detergent composition may be present in a water-soluble unit dose article. In such embodiments, the water-soluble unit dose article comprises at least one water-soluble film shaped such that the unit dose article comprises at least one interior compartment surrounded by the water-soluble film. At least one compartment contains a liquid laundry detergent composition. The water-soluble film is sealed so that the liquid laundry detergent composition does not leak out of the compartment during storage. However, when the water-soluble unit dose article is added to water, the water-soluble film dissolves and releases the contents of the internal compartment into the wash liquor.

Examples

An aqueous liquid laundry detergent was prepared having the following formulation:

surfactants other than AEC are Linear Alkylbenzene Sulfonate (LAS), sodium lauryl ether sulfate with 3 moles of ethoxylation (SLES), and nonionic with 7 moles of ethoxylation (NI) C₁₂-C₁₅A straight chain alcohol. The surfactant levels given in the table are the sum of LAS, SLES and NI. The ratios of the three are given in the table of results below. The formulations were prepared with and without the addition of 4 wt% of an Alkyl Ether Carboxylate (AEC). The AEC used had 10 moles of ethoxylated and oleyl alkyl chains.

The formulation was used to wash 8 pieces of 5 x 5cm EMPA 117 stain monitor (blood/milk/ink stain on polyester cotton) in a tergitometer set at 200 rpm. A60 minute wash was carried out with 2.3g/L of the formulation in 800ml of 26o French hard water at room temperature (293K). To simulate oily soil, SBL2004 soil strips (from WarwickEquest) of (7.5g) were cut into 4 aliquots and added to the wash liquor.

Once the wash was complete, the cotton monitor was rinsed once in 400ml of clear water, removed, dried, and the color measured on a reflectometer as% reflectance at R460, i.e. 460nm (excluding UV).

The greater the Δ of the R460 value, the cleaner the fabric compared to the control.

The Δ R460 value is thus calculated:

Δ R460 ═ L (AEC) -L (control without AEC)

The greater the Δ R460 value, the greater the formulation performance improvement brought about by the introduction of the Alkyl Ether Carboxylate (AEC). The 95% confidence limits were calculated based on 8 individual EMPA 117 blocks.

The results are shown below:

comparative example A, which is believed to fairly reflect the disclosure of prior art WO2016/180552 (example 1) and DE 102013218614A (example B), discloses exemplary formulations of LAS: NI: SLES in a weight ratio of 4:1:5(WO2016/180552) and 4:2:5(DE 102013218614A).

The inventive formulations with a high proportion of LAS relative to other surfactants (e.g., NI and SLES surfactants) show much greater benefit from AEC addition than formulations with a much lower proportion of LAS.

Claims

1. An aqueous liquid laundry detergent composition comprising:

(i)5-19 wt% of a linear alkylbenzene sulphonate anionic surfactant,

R₂-(OCH₂CH₂)_n-OCH₂-COOH，

wherein:

(iii) at least 60% by weight of water;

(v)0-1 wt% of a phosphorus-containing chemical;

2. An aqueous liquid laundry detergent composition according to claim 1, wherein the composition comprises an additional anionic surfactant, wherein the weight ratio of additional surfactant to linear alkylbenzene sulphonate is from 0.01 to 0.55, preferably from 0.01 to 0.1.

3. An aqueous liquid laundry detergent composition according to claim 1 or claim 2 wherein the composition comprises from 0.5 to 6 wt%, preferably from 1 to 6 wt%, more preferably from 2 to 6 wt% of alkyl ether carboxylic acid anionic surfactant.

4. An aqueous liquid laundry detergent composition according to any preceding claims wherein the weight ratio of alkyl ether carboxylic acid to linear alkylbenzene sulphonate surfactant is from 0.1 to 0.6.

5. An aqueous liquid laundry detergent composition according to any preceding claims wherein the linear alkylbenzene sulphonate surfactant is present in an amount of from 6 to 19 wt%, preferably from 7 to 19 wt%, more preferably from 8 to 19 wt%, most preferably from 9 to 19 wt%.

6. An aqueous liquid laundry detergent composition according to any preceding claims wherein the weight percentage of linear alkylbenzene sulphonate surfactant to total non-alkyl ether surfactant is from 50 to 100 wt%, preferably from 60 to 100 wt%, more preferably from 70 to 10 wt%, most preferably from 80 to 100 wt%.

7. An aqueous liquid laundry detergent composition according to any preceding claim having a pH of from 7 to 11, preferably from 7 to 10.

8. A domestic method of treating a textile, the method comprising the steps of:

a) treating a textile with at least 1g/L of an aqueous solution of a laundry detergent composition as defined in any preceding claim; and