CN108138084B

CN108138084B - Liquid laundry detergent compositions

Info

Publication number: CN108138084B
Application number: CN201680057139.7A
Authority: CN
Inventors: S·N·巴彻勒; J·M·伯德
Original assignee: Unilever NV
Current assignee: Unilever IP Holdings BV
Priority date: 2015-10-01
Filing date: 2016-08-16
Publication date: 2021-04-27
Anticipated expiration: 2036-08-16
Also published as: EP3356503B1; EP3356503A1; AR106190A1; CN108138084A; BR112018006161A2; BR112018006161B1; TR201906427T4; WO2017054983A1

Abstract

The present invention provides an isotropic detergent formulation for use in domestic laundry comprising an alkyl ether carboxylic acid, an anionic surfactant, a subtilisin-type serine protease and optionally a nonionic surfactant.

Description

Liquid laundry detergent compositions

Technical Field

The present invention provides enzyme and dispersant formulations for use in domestic laundry.

Background

Isotropic liquid laundry detergent formulations containing a high fraction (fraction) of anionic surfactant relative to nonionic surfactant are ubiquitous.

Proteases are used in isotropic laundry detergent formulations to remove protein-containing stains from fabrics.

WO2013/087286(Unilever) discloses liquid formulations containing alkyl ether carboxylic acids, betaines, anionic surfactants, nonionic surfactants for providing softening benefits.

US5269960(Clorox) discloses liquid aqueous enzyme detergents containing enzymes, nonionic surfactant, fatty acid and alkyl ether carboxylic acid, which have enhanced physical and enzyme stability.

DE 3320340 discloses laundry detergent formulations containing alkyl ether carboxylates having 4.5 ethoxylate units and a protease. In example a of DE 3320340, it is shown that such a formulation does not stabilize proteases during storage. In examples B, D and E of DE 3320340, formulations containing an alkyl ether carboxylate having 3.8 ethoxylate units and a protease are stabilized against some proteases.

There is a need to increase the detergency of isotropic laundry detergent formulations containing a high fraction of anionic surfactant relative to nonionic surfactant.

Disclosure of Invention

Surprisingly, the combination of protease with specific alkyl ether carboxylic acids provides enhanced cleaning and stain removal.

In one aspect, the present invention provides an isotropic laundry liquid detergent formulation comprising:

(i)10 to 40 wt% of a surfactant selected from anionic and nonionic surfactants, preferably 12 to 25 wt%, more preferably 14 to 21 wt%, wherein the weight fraction of nonionic surfactant/anionic surfactant is 0 to 0.3, preferably 0 to 0.15, most preferably 0 to 0.12;

(ii)2 to 10 wt%, preferably 3 to 8 wt%, most preferably 3 to 6 wt% of an alkyl ether carboxylic acid dispersant having the structure:

R-(OCH₂CH₂)_n-OCH₂-COOH，

wherein:

r is selected from saturated C8 to C18 linear alkyl chains, preferably C12 to C18 linear alkyl chains, more preferably C12 or C18 linear alkyl chains, most preferably C12 linear alkyl chains;

n is an average ethoxylation and n is selected from the group consisting of 5 to 20, preferably 7 to 14, more preferably 8 to 12, most preferably 9 to 11, and

(iii)0.002-0.2 wt% subtilisin protease, preferably 0.005-0.05 wt%.

Subtilisin proteases are members of the subtilase (subtilase) type serine protease family.

The weight% of anionic surfactant is calculated as sodium salt. The wt% of alkyl ether carboxylic acid dispersant is calculated as COOH form. The wt% protease is for the pure active protein.

In another aspect, the present invention provides a domestic method of treating a textile, the method comprising the steps of: the textile is treated with an aqueous solution of 0.5 to 20g/L of a laundry detergent composition as defined herein.

Preferably, the aqueous laundry detergent solution is left in contact with the textile for 10 minutes to 2 days, and then the textile is rinsed and dried.

Detailed Description

Detergent forms

The laundry detergent formulation is a non-phosphate laundry detergent formulation, i.e. containing less than 1 wt% phosphate. In the art, the term "phosphate" encompasses diphosphate, triphosphate and phosphonate species.

The laundry detergent is an aqueous isotropic liquid laundry detergent, preferably having a pH of 7 to 9.

The detergent formulation may be present in a polyvinyl alcohol pouch for ease of dispensing.

Protease enzyme

Subtilisin proteases (EC 3.4.21.62) hydrolyze both peptides and bonds within proteins, which results in enhanced removal of protein-or peptide-containing stains in a laundry environment. Subtilisin proteases are members of the subtilisin-type family of serine proteases. The serine protease family is described in the MEROPS peptidase database (http:// polymers. sanger. ac. uk /). The term "subtilase" refers to the subgroup of serine proteases according to Siezen et al, Protein Engng.4(1991)719-737 and Siezen et al, Protein Science 6(1997) 501-523. Serine proteases are a subset of proteases characterized by a serine at the active site, which forms a covalent adduct with a substrate. Subtilases can be divided into 6 sub-classes, of which the subtilisin family is one.

Examples of subtilases are those derived from Bacillus such as Bacillus lentus, Bacillus alkalophilus, Bacillus subtilis, Bacillus amyloliquefaciens, Bacillus pumilus and Bacillus gibsonii described in US7262042 and WO09/021867, as well as subtilisin (subtilisin lentius), subtilisin Novo, subtilisin Carlsberg, Bacillus licheniformis, subtilisin BPN', subtilisin 309, subtilisin 147 and subtilisin 168 described in WO89/06279, and the protease PD138 described in WO 93/18140. Further proteases are described in WO92/19729, WO96/034946, WO98/20115, WO98/20116, WO99/011768, WO01/44452, WO03/006602, WO04/03186, WO04/041979, WO07/006305, WO11/036263, WO11/036264, in particular in one of the following positions using BNP' numbering or in the case of the above-mentioned proteasesMultiple variants with substitutions: 3, 4, 9, 15, 27, 36, 57, 68, 76, 87, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 106, 118, 120, 123, 128, 129, 130, 160, 167, 170, 194, 195, 199, 205, 206, 217, 218, 222, 224, 232, 235, 236, 245, 248, 252, and 274. More preferred subtilase variants may comprise the following mutations: S3T, V4I, S9R, A15T, K27R,^*36D,V68A,N76D,N87S,R,^*97E, a98S, S99G, D, a, S99AD, S101G, M, R S103A, V104I, Y, N, S106A, G118V, R, H120D, N123D, S128D, P129D, S130D, G160D, Y167D, R170D, a 194D, G195D, V199D, V205D, L217D, N218D, M222D, a 232D, K235D, Q236D, Q245D, N252D, T274D (using BNP' numbering).

Most preferably, the subtilisin is derived from Bacillus gibsonii or Bacillus lentus.

Subtilisins are commercially available from, for example, Novozymes^TMAnd Genencor^TM。

Alkyl ether carboxylic acids

In the context of the present invention, alkyl ether carboxylic acid dispersants are not included as anionic surfactants. The weight of the alkyl ether carboxylic acid is calculated as the protonated form R- (OCH)₂CH₂)_n-OCH₂COOH. They may be used as salts, for example sodium or amine salts.

The alkyl chain is aliphatic and linear and may be selected from CH₃(CH₂)₇-；CH₃(CH₂)₈-；CH₃(CH₂)₉-；CH₃(CH₂)₁₀-；CH₃(CH₂)₁₁-；CH₃(CH₂)₁₂-；CH₃(CH₂)₁₃-；CH₃(CH₂)₁₄-；CH₃(CH₂)₁₅-；CH₃(CH₂)₁₆-and CH₃(CH₂)₁₇-。

The alkyl chain is preferably selected from CH₃(CH₂)₁₁-and CH₃(CH₂)₁₇-。

The alkyl ether carboxylic acids most preferably have the following structure:

CH₃(CH₂)₁₁(OCH₂CH₂)₁₀OCH₂COOH。

the alkyl ether carboxylic acid can be selected from Kao (R), (G), (B), (C), (D), (

)、Huntsman(

) And Clariant (

) And (4) obtaining.

Alkyl ether carboxylic acids can be prepared by a modified Williamson synthesis:

R-(OCH₂CH₂)_n-OCH₂COOH+NaOH+ClCH₂COONa→

R-(OCH₂CH₂)_n-OCH₂COONa+NaCl+H₂O

an alternative is by oxidation using Pt or Pd catalysts as described in DE3135946, DE2816127 and EP 0304763.

Surface active agent

The laundry composition comprises an anionically charged surfactant (which includes mixtures of anionically charged surfactants).

Suitable anionic detergent compounds which may be used are typically water-soluble alkali metal or amine salts of fatty acids (soaps), organic sulphates and sulphonates having alkyl groups containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher alkyl groups.

Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially by reacting higher C's, for example prepared from tallow or coconut oil₈To C₁₈Those obtained by sulfating alcohols, alkyl C₉To C₂₀Sodium and potassium benzene-sulphonates, especially linear secondary alkyl C₁₀To C₁₅Sodium benzenesulfonate; and sodium alkyl glyceryl ether sulfates, particularly those ethers of higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum.

The anionic surfactant is preferably selected from: linear alkyl benzene sulfonate; an alkyl sulfate; alkyl ether sulfates; soap; alkyl (preferably methyl) ester sulfonates and mixtures thereof.

Most preferred anionic surfactants are selected from: linear alkyl benzene sulfonate; an alkyl sulfate; soap; alkyl ether sulfates and mixtures thereof. Preferably, the alkyl ether sulphate is C with an average of 1 to 3 EO (ethoxylate) units₁₂-C₁₄N-alkyl ether sulfates. Sodium lauryl ether sulphate is particularly preferred (SLES). Preferably, the linear alkylbenzene sulfonate is C₁₁To C₁₅Sodium alkyl benzene sulfonate (LAS). Preferably, the alkyl sulfates are linear or branched C₁₂To C₁₈Sodium alkyl sulfate. Sodium dodecyl sulfate is particularly preferred (SDS, also known as primary alkyl sulfate). The soap is preferably C₁₂To C₁₈Saturated fatty acids, preferably they are present at a level of less than 3% by weight of the formulation.

The level of anionic surfactant in the laundry composition is from 10 to 40 wt% of the formulation (i). Preferably, LAS is the predominant anionic surfactant present.

In isotropic laundry detergent formulations, preferably two or more anionic surfactants are present, preferably linear alkyl benzene sulphonate together with alkyl ether sulphate.

The nonionic surfactant may be present in a surfactant mixture.

Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having an aliphatic hydrophobic group and a reactive hydrogen atom, such as fatty alcohols, acids or amides, with ethylene oxide, in particular (alone or together with propylene oxide). Preferred nonionic detergent compounds are aliphatic C₈To C₁₈Condensation products of linear or branched primary or secondary alcohols with ethylene oxide.

Preferably, a non-ionic surfaceThe active agent is an alkyl ethoxylated nonionic surfactant and is C₈To C₁₈Primary alcohols, most preferably C₁₂To C₁₆Primary alcohols, having an average ethoxylation of from 7EO to 9EO units.

Builders or complexing agents

The builder material may be selected from 1) calcium sequestrant materials, 2) precipitation materials, 3) calcium ion exchange materials and 4) mixtures thereof.

Examples of calcium sequestrant builder materials include alkali metal polyphosphates, such as sodium tripolyphosphate, and organic sequestrants, such as ethylenediaminetetraacetic acid.

The builder is preferably an organic chelant containing carboxylic acid groups. The most preferred builder is citric acid.

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. The total amount of fluorescer or fluorescers used in the composition is typically from 0.005 to 2 wt%, more preferably from 0.01 to 0.1 wt%. Preferred classes of fluorescers are: distyrylbiphenyl compounds, such as Tinopal (trade mark) CBS-X, diaminostilbene disulphonic 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.

It is preferred that the aqueous solution used in the method has the fluorescent agent present. When the fluorescent agent is present in the aqueous solution used in the method, it is preferably from 0.0001 to 0.1g/L, preferably from 0.001 to 0.02 g/L.

Perfume

Preferably, the composition comprises a perfume. The perfume is preferably 0.001 to 3 wt%, most preferably 0.1 to 1 wt%. Many suitable examples of fragrances are provided in the CTFA (Cosmetic, Toiletry and Fragrance Association)1992International layers Guide, published by CFTA Publications, and the OPD 1993Chemicals layers Directory 80th annular Edition, published by Schnell Publishing Co.

The presence of multiple perfume components in a formulation is common. In the compositions of the present invention, it is envisaged that four or more, preferably five or more, more preferably six or more, or even seven or more different perfume components will be present.

In the perfume mixture, preferably 15 to 25% by weight is top notes. Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80[1955 ]). Preferred top notes are selected from citrus oil, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol.

Perfumes and top notes can be used to cue the cleaning and whitening benefits of the present invention.

It is preferred that the detergent formulations of the invention are free of peroxygen bleaching agents, such as sodium percarbonate, sodium perborate and peracids.

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 and lauryl methacrylate/acrylic acid copolymers.

Additional enzymes

One or more additional enzymes are preferably present in the laundry composition of the present invention and when carrying out the method of the present invention.

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

The additional enzyme is preferably selected from: amylases, mannanases, lipases, and cellulases, most preferably amylases and lipases. Suitable lipasesIncluding Novozymes, Bagsvaerd Denmark under the trade name

And

those that are sold.

Any enzyme present in the composition may be stabilised using conventional stabilisers, for example, a polyol such as propylene glycol or glycerol, a sugar or sugar alcohol, lactic acid, boric acid or a boric acid derivative (e.g. an aromatic borate ester) or a phenyl boronic acid derivative such as 4-formylphenyl boronic acid, and the composition may be formulated as described in, for example, WO92/19709 and WO 92/19708.

Shading dye

Shading dye (shading dye) is preferably present in the formulation at a level of 0.002 to 0.2 wt%.

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

Hueing dyes for laundry detergents preferably have an absorption maximum in the visible range (400-700nm) of greater than 5000Lmol^-1cm^-1Preferably greater than 10000Lmol^-1cm^-1The extinction coefficient of (a). The color of the dye is blue or violet.

Preferred shading dye chromophores are azo, azine, anthraquinone and triphenylmethane.

Azo, anthraquinone, phthalocyanine and triphenylmethane dyes preferably carry a net anionic charge or no charge. Azines preferably carry a net anionic or cationic charge.

During the washing or rinsing step of the washing process, a blue or violet shading dye is deposited onto the fabric, providing a visible shade to the fabric. In this regard, the dye imparts a blue or violet colour to the white cloth with a hue angle of 240 to 345, more preferably 250 to 320, most preferably 250 to 280. The white cloth used in this test was a bleached, non-mercerized woven cotton sheet.

Hueing dyes are discussed in WO2005/003274, WO2006/032327(Unilever), WO2006/032397(Unilever), WO2006/045275(Unilever), WO06/027086(Unilever), WO2008/017570(Unilever), WO2008/141880(Unilever), WO2009/132870(Unilever), WO2009/141173(Unilever), WO2010/099997(Unilever), WO2010/102861(Unilever), WO2010/148624(Unilever), WO2008/087497(P & G), WO2011/011799(P & G), WO2012/054820(P & G), WO2013/142495(P & 151g) and WO2013/151970(P & G).

The monoazo dyes preferably contain a heterocyclic ring, and are most preferably thiophene dyes. The monoazo dyes are preferably alkoxylated and are preferably uncharged or anionically charged at pH 7. Alkoxylated thiophene dyes are discussed in WO/2013/142495 and WO/2008/087497. Preferred examples of thiophene dyes are shown below:

the disazo dye is preferably a sulfonated disazo dye. Preferred examples of sulfonated bisazo compounds are direct violet 7, direct violet 9, direct violet 11, direct violet 26, direct violet 31, direct violet 35, direct violet 40, direct violet 41, direct violet 51, direct violet 66, direct violet 99 and alkoxylated forms thereof. Alkoxylated disazo dyes are discussed in WO2012/054058 and WO 2010/151906.

Examples of alkoxylated disazo dyes are:

the azine dye is preferably selected from sulphonated phenazine dyes and cationic phenazine dyes. Preferred examples are acid blue 98, acid violet 50, dyes having CAS number 72749-80-5, acid blue 59, and phenazine dyes selected from the group consisting of:

wherein:

X₃selected from: -H, -F, -CH₃，-C₂H₅，-OCH₃and-OC₂H₅；

X₄Selected from: -H, -CH₃，-C₂H₅，-OCH₃and-OC₂H₅；

Y₂Selected from: -OH, -OCH₂CH₂OH，-CH(OH)CH₂OH，-OC(O)CH₃And C (O) OCH₃。

The hueing dye is present in the composition at 0.0001 to 0.5 wt%, preferably 0.001 to 0.1 wt%. Depending on the nature of the hueing dye, there is a preferred range depending on the potency of the hueing dye, which depends on the class and the specific potency within any particular class. As mentioned above, the hueing dye is a blue or violet hueing dye. Mixtures of hueing dyes may be used.

Most preferably, the hueing dye is a reactive blue anthraquinone dye covalently linked to an alkoxylated polyethyleneimine. The alkoxylation is preferably selected from ethoxylation and propoxylation, most preferably propoxylation. Preferably, 80 to 95 mole% of the N-H groups in the polyethyleneimine are replaced by isopropanol groups by propoxylation. Preferably, the molecular weight of the polyethyleneimine is 600 to 1800 prior to reaction with the dye and propoxylation.

An example structure of a preferred reactive anthraquinone covalently linked to a propoxylated polyethyleneimine is:

preferred reactive anthraquinone dyes are: reactive blue 1, reactive blue 2, reactive blue 4, reactive blue 5, reactive blue 6, reactive blue 12, reactive blue 16, reactive blue 19, reactive blue 24, reactive blue 27, reactive blue 29, reactive blue 36, reactive blue 44, reactive blue 46, reactive blue 47, reactive blue 49, reactive blue 50, reactive blue 53, reactive blue 55, reactive blue 61, reactive blue 66, reactive blue 68, reactive blue 69, reactive blue 74, reactive blue 86, reactive blue 93, reactive blue 94, reactive blue 101, reactive blue 103, reactive blue 114, reactive blue 117, reactive blue 125, reactive blue 141, reactive blue 142, reactive blue 145, reactive blue 149, reactive blue 155, reactive blue 164, reactive blue 166, reactive blue 177, reactive blue 181, reactive blue 185, reactive blue 188, reactive blue 189, reactive blue 206, reactive blue 208, reactive blue 247, reactive blue 258, reactive blue 261, reactive blue 262, reactive blue 263 and reactive blue 172.

The dyes are listed according to the colour index (Society of Dyers and Colourists/American Association of Textile Chemists and Colourists) classification.

For ease of use, it is preferred if the isotropic laundry detergent formulation is present in a package of 0.5 to 5 kg.

Examples

Example 1

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

composition (I)	By weight%
		Monopropylene glycol	2
Triethylamine	1.5
		C12-C15 alcohol ethoxylates with 7 moles of ethylene oxide	2.1
Straight chain alkyl benzene sulfonate	8.4
		Sodium laureth sulfate with 3 moles of ethylene oxide	10.5
Citric acid	0.5
		Perfume	0.3
Sodium hydroxide	To pH 8.4
		Water (W)	Balance of

The weight fraction of nonionic/anionic surfactant was 2.1/(8.4+10.5) ═ 1/9 ═ 0.11.

This formulation was used to wash 8 EMPA 117 stain monitors (blood/milk/ink stains on polyester cotton) of 5 x 5cm in a tester (tergitometer) set at 200 rpm. The wash was carried out with 2.3g/L of the formulation at room temperature (293K) in 800ml of 26 ° french hard water for 60 minutes. To simulate oily soil, 7.5g SBL2004 soil strips (from Warwick Equest) cut into 4 equal pieces were added to the wash.

Once the wash had been completed, the cotton surveillants were rinsed once in 400ml of clear water, taken out of the dry, and the color was measured on a reflectometer and expressed as CIE L a b values.

An equivalent formulation but incorporating 8.7 wt% of an alkyl ether carboxylic acid wherein the alkyl group is linear C12 (lauryl) was tested. The average number of ethoxy groups was 10.

(iv) addition and non-addition of subtilisin serine protease (EC No. 232-

16L from Novozymes), repeat the experiment. The enzyme was added to give the formulation 0.018 wt% pure active protein.

Stain removal was measured as Δ L, where

Δ L ═ L (test formulation) -L (control)

A larger Δ L value indicates more stain removal.

Also calculated from the standard deviation of the measurements of the 8 monitors, a 95% confidence limit is given.

The results are given in the table below.

The ratio of the combination of protease and alkyl ether carboxylic acid is expected from the combination of the effects of the individual components. For the combination, Δ L ═ 5.4+3.2 ═ 8.6 was expected, but 12.0 was obtained.

By adding amylase, mannanase and pectinase: (

Novozyme，

Novozymes，

Novozymes) to produce a formulation,

examples of Isotropic liquid formulations

NI (9EO) is a C12-C15 alcohol ethoxylate with 9 moles of ethylene oxide.

The perfume comprises core shell melamine formaldehyde encapsulates of perfume.

Claims

1. An aqueous isotropic liquid laundry detergent formulation comprising:

(i)10 to 40 wt% of a surfactant selected from anionic and nonionic surfactants, wherein the weight fraction of nonionic surfactant/anionic surfactant is from 0 to 0.3, wherein the anionic surfactant comprises C11 to C15 linear alkylbenzene sulphonate;

(ii)2 to 10 weight percent of an alkyl ether carboxylic acid dispersant having the structure:

R-(OCH₂CH₂)_n-OCH₂-COOH，

wherein:

r is selected from the group consisting of saturated C8-C18 linear alkyl chains, and wherein n is selected from 7-20; and the combination of (a) and (b),

(iii)0.002-0.2 wt% of a subtilisin-type serine protease, wherein the laundry detergent formulation contains less than 1 wt% phosphate.

2. An isotropic liquid laundry detergent formulation according to claim 1, wherein the nonionic surfactant is selected from alkyl ethers having 7-9 ethoxy groups and C12-C16 linear alkyl chains.

3. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein two or more anionic surfactants are present, including the linear alkylbenzene sulphonate and alkyl ether sulphate.

4. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein R is selected from CH₃(CH₂)₁₁-and CH₃(CH₂)₁₇-。

5. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the formulation comprises from 0.002 to 0.2 wt% of hueing dye.

6. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein n is selected from 8 to 12.

7. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the alkyl ether carboxylic acid dispersant is selected from:

CH₃(CH₂)₁₁(OCH₂CH₂)₁₀OCH₂COOH。

8. an aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the anionic and nonionic surfactants are present in the range from 12 to 25 wt% and the level of subtilisin-type serine protease is from 0.005 to 0.05 wt%.

9. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the weight fraction of nonionic/anionic surfactant is from 0 to 0.12.

10. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the alkyl ether carboxylic acid dispersant is present in the range of 3 to 8 wt%.

11. An aqueous isotropic liquid laundry detergent formulation according to claim 1 or 2, wherein the linear alkylbenzene sulphonate is the predominant anionic surfactant present.

12. A domestic method of treating a textile, the method comprising the steps of: treating the textile with 0.5 to 20g/L of an aqueous solution of a laundry detergent formulation as defined in any preceding claim.