LIQUID LAUNDRY DETERGENT COMPOSITION

Description

FIELD OF INVENTION

[0001] The present invention provides a liquid laundry detergent composition. In particular, it relates to a concentrated liquid laundry detergent composition for use in domestic laundry.

BACKGROUND OF THE INVENTION

[0002] Laundry liquid formulations containing saturated long chain alkyl ether carboxylates with high degrees of ethoxylation are desirable as they provide enhanced cleaning particularly of sebum soil.

[0003] Saturated long chain alkyl ether carboxylates with high degrees of ethoxylation are solid waxy materials at room temperature.

[0004] To reduce weight in transportation it is desirable to have highly concentrated liquid laundry detergent with minimal contents of water. This may be used directly for washing or further mixed with other ingredients before washing. However it is highly desirable that the concentrated liquid detergent is a pourable liquid, both for ease of use for the consumer when using the concentrated liquid detergent, or when the concentrated liquid detergent is further processed into a more complex liquid detergent.

[0005] Accordingly, there is need for highly concentrated laundry detergents containing high levels of saturated long chain alkyl ether carboxylates that are pourable liquids at room temperature.

[0006] WO 2013/087286 (Unilever) discloses aqueous liquids formulations containing alkyl ether carboxylic acids, betaines, anionic surfactant, non-ionic surfactant for providing softening benefits.

[0007] WO 2014/060235 (Unilever) discloses an aqueous laundry detergent composition comprising (a) nonionic surfactant, (b) anionic surfactant, (c) alkyl ether carboxylic acid or carboxylate salt thereof, and, (d) a polyglucosamine or a copolymer of glucosamine and N-acetylglucosamine; and to its use to soften fabrics. Further liquid laundry detergents comprising a linear alkyl benzene sulfonate acid surfactant and an alkyl ether carboxylic acid surfactant are disclosed in US 2015/252294 A1.

SUMMARY OF THE INVENTION

[0008] In one aspect, the present invention provides a liquid laundry detergent composition comprising:

(i) from 50 to 80 wt.% of a linear alkyl benzene sulfonic acid surfactant;

(ii) from 15 to 45 wt.% of an alkyl ether carboxylic acid surfactant of the following structure:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wherein: R₁ is selected from saturated C₁₆ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 10 to 24;

(iii) less than 10 wt.% water;

(iv) from 0 to 20 wt.% non-ionic surfactant of the following structure

        R₂-(OCH₂CH₂)_n-OH,

wherein: R₂ is selected from saturated C₁₂ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 5 to 30, preferably 10 to 20;

wherein the pH of the formulation is from 0.3 to 2.0; and

wherein the weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant is from 1.5:1 to 5:1; and,

wherein the pH of the formulation is that of a 1 wt.% solution of the liquid laundry detergent composition dissolved in demineralised water at 293K.

[0009] Preferably the pH of the formulation is from 0.5 to 2.0, more preferably from 0.5 to 1.5.

[0010] A preferred liquid laundry detergent composition comprises:

(i) from 60 to 80 wt.% of a linear alkyl benzene sulfonic acid surfactant;

(ii) from 20 to 40 wt.% of an alkyl ether carboxylic acid surfactant of the following structure:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wherein: R₁ is selected from saturated C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 10 to 20;

(iii) less than 10 wt.% water;

(iv) from 0 to 20 wt.% non-ionic surfactant of the following structure

        R₂-(OCH₂CH₂)_n-OH,

wherein: R₂ is selected from saturated C₁₂ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 10 to 20;

wherein the pH of the formulation is from 0.5 to 2.0;

and wherein the weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant is from 1.5:1 to 4:1; and,

wherein the pH of the formulation is that of a 1 wt.% solution of the liquid laundry detergent composition dissolved in demineralised water at 293K.

DETAILED DESCRIPTION OF THE INVENTION

[0011] Water contents are measured by Karl Fischer Titration. This may be accomplished using an automated Karl Fischer titrators, available from MetroOhm, and Mettler Toledo.

[0012] The pH of the formulation is that of a 1 wt.% solution of the liquid laundry detergent composition dissolved in demineralised water at 293K.

[0013] Room temperature as used herein is defined as 293K.

Linear alkyl benzene sulfonic acid surfactant

[0014] The liquid laundry composition comprises from 50 to 80 wt.%, preferably from 55 to 80 wt.%, more preferably from 55 to 75 wt.%, most preferably from 60 to 75 wt.% of the linear alkyl benzene sulfonic acid surfactant. Weights are expressed as the protonated form (i.e. the linear alkyl benzene anionic sulfonic acid form).

[0015] They may be used as salt version, for example alkali metal salt (preferably sodium salt), triethanolamine, monoethanol amine salt. The sodium salt is most preferred. Preferably the non-neutralised acid form is used.

[0016] Linear alkyl benzene sulfonic acid has the structure:

where x + y = 7, 8, 9 or 10.

[0017] Preferably x + y = 8 is present at a weight level greater than 28 wt.% of the total level of the linear alkyl benzene anionic surfactant.

[0018] Preferably x + y = 9 is present at greater than 28 wt.% of the total level of the linear alkyl benzene anionic surfactant. Weights are expressed as the protonated form.

[0019] The surfactant may be produced by a variety of different routes. Synthesis is discussed in Anionic Surfactants Organic Chemistry edited by H.W. Stache (Marcel Dekker, New York 1996).

[0020] Linear alkyl benzene sulfonic acid may be made by the sulfonation of linear alkyl benzene. The sulfation can be carried out with concentrated sulphuric acid, oleum or sulphur trioxide. Linear alkyl benzene sulfonic acid produced by reaction of linear alkyl benzene with sulphur trioxide is preferred.

[0021] Linear alkyl benzene may be produced by a variety of routes. Examples include:
Benzene may be alkylated with n-alkenes using HF catalyst.

[0022] Benzene may be alkylated with n-alkenes in a fixed bed reactor with a solid acidic catalyst such as Alumosilicate (DETAL process).

[0023] Benzene may be alkylated with n-alkenes using an aluminium chloride catalyst. Benzene may be alkylated with n-chloroparaffins using an aluminium chloride catalyst.

Alkyl ether carboxylic acid

[0024] The liquid laundry composition comprises from 15 to 45 wt.%, preferably from 15 to 40 wt.%, more preferably from 17.5 to 40 wt.%, most preferably from 20 to 40 wt.% of the alkyl ether carboxylic acid anionic surfactant.

[0025] Weights of alkyl ether carboxylic acid are calculated as the protonated form, R₂-(OCH₂CH₂)_n-OCH₂COOH, where n is from 10 to 24. They may be used as salt version for example sodium salt, triethanolamine, monoethanol amine salt. The sodium salt is most preferred.

[0026] n may be from 10 to 24, preferably from, 10 to 20, more preferably from 15 to 20.

[0027] Alkyl ether carboxylic acids synthesis is discussed in Anionic Surfactants Organic Chemistry edited by H.W. Stache (Marcel Dekker, New York 1996). They may be synthesised via the reaction of the corresponding alcohol ethoxylate with chloroacetic acid or monochloro sodium acetate in the presence of NaOH:-

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

[0028] In this synthesis residual R₂-(OCH₂CH₂)_n-OH may be present, preferably levels of R₂-(OCH₂CH₂)_n-OH are from 0 to 10 wt.% in the alkyl ether carboxylic acid. Low levels of diglycolic acid and glycolic acid may be present as bi products.

[0029] The alkyl ether carboxylic acid may also be synthesised via an oxidation reaction:-

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

[0030] The oxidation is typically conducted using oxygen as the oxidant under basic conditions in the presence of metal catalyst such as Pd/Pt, as described in DE3135946; DE2816127 and EP0304763.

[0031] The alkyl chain may be linear or branched, preferably it is linear.

[0032] The alkyl chain is preferably selected from CH₃(CH₂)₁₅ and CH₃(CH₂)₁₇

[0033] The alkyl ether carboxylic acid is most preferably of the structure:

        CH₃(CH₂)₁₇(OCH₂CH₂)₂₀OCH₂COONa

[0034] Alkyl ether carboxylic acids are available from Kao (Akypo ^®), Huntsman (Empicol^®) and Clariant (Emulsogen ^®).

[0035] The alkyl ether carboxylic acid is preferably used directly form the synthesis without further purification.

[0036] The weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant is from 1.5:1 to 5:1. The weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant may preferably be from 1.5:1 to 4.5:1, for example from 1.5:1 to 4:1; or from 2:1 to 4.5:1; or 2:1 to 4:1; or even 2.5:1 to 4.25:1; or even 2.5:1 to 4:1.

[0037] Water may be absent from the formulation, or present at a level of less than 10 wt.%, preferably less than 9 wt.%. If water is present, then it is present preferably at a level of from 0.01 to 8 wt.%, more preferably from 0.1 to 8 wt.%, most preferably from 1 to 8 wt.%.

[0038] Non-ionic surfactant may be absent from the formulation, or present at a level of less than 20 wt.%, preferably less than 15 wt.%, more preferably less than 12 wt.%. If non-ionic surfactant is present, then it is present preferably at a level of from 0.1 to 20 wt.%, more preferably from 0.1 to 15 wt.%, most preferably from 0.25 to 12 wt.%.

[0039] The non-ionic surfactant has the following structure:

        R₂-(OCH₂CH₂)_n-OH,

wherein: R₂ is selected from saturated C₁₂ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 5 to 30, preferably 10 to 20.

[0040] The liquid detergent composition of the invention can be considered a concentrated liquid detergent composition. It may be used directly, or more preferably used as an ingredient to formulate further liquid detergent compositions.

[0041] Such further liquid detergent compositions may comprise further ingredients such as: fatty acids or salts thereof, shading dyes, enzymes (such as lipase, protease, amylase, cellulase), antiredeposition polymers, dye transfer inhibiting polymers, builders, structurants or thickening polymers, sequestrants, perfumes, and/or soil release polymers.

Experimental

[0042] The following mixtures containing 20 wt.% of alkyl ether carboxylate (R₁ = stearyl, n = 20, used as Na salt) and 80 wt.% second surfactant were prepared at 333K. At this temperature, all ingredients were liquid. They were then cooled to 293K. The phase results are shown in the table. The pH of the formulation is between 0.3 to 2.0

Second surfactant	Phase at 293K
linear alkyl benzene anionic sulfonic acid inventive	Pourable Liquid
Sodium lauryl ether sulfonate with 1 mole of ethoxylation comparative	Solid
Sodium lauryl ether sulfonate with 3 mole of ethoxylation comparative	Soft Gel
Non-ionic surfactant: alcohol ethoxylate with C13-15 and 7 moles of ethoxylation comparative	Soft Gel

[0043] The experiment with was repeated with different ratios of linear alkyl benzene anionic sulfonic acid to the alkyl ether carboxylate. The results are shown in the following table, along with the entry for the previous example:-

Wt% alkyl ether carboxylate	Wt% linear alkyl benzene anionic sulfonic acid	Phase at 293K
100 comparative	0	solid
50 comparative	50	Soft gel
40 inventive	60	Pourable Liquid
30 inventive	70	Pourable Liquid
20 inventive	80	Pourable Liquid

Claims

1. A liquid laundry detergent composition comprising:

(i) from 50 to 80 wt.% of a linear alkyl benzene sulfonic acid surfactant;

(ii) from 15 to 45 wt.% of an alkyl ether carboxylic acid surfactant of the following structure:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wherein: R₁ is selected from saturated C₁₆ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 10 to 24;

(iii) less than 10 wt.% water;

(iv) from 0 to 20 wt.% non-ionic surfactant of the following structure

        R₂-(OCH₂CH₂)_n-OH,

wherein: R₂ is selected from saturated C₁₂ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 5 to 30, preferably 10 to 20;

wherein the pH of the formulation is from 0.3 to 2.0; and

wherein the weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant is from 1.5:1 to 5:1; and,

wherein the pH of the formulation is that of a 1 wt.% solution of the liquid laundry detergent composition dissolved in demineralised water at 293K.

2. A liquid laundry detergent composition according to claim 1, wherein the pH of the formulation is from 0.5 to 2.0, preferably from 0.5 to 1.5.

3. A liquid laundry detergent composition according to claim 1 or claim 2, wherein the non-ionic surfactant is present at a level of from 0.1 to 20 wt.%, preferably from 0.1 to 15 wt.%, more preferably from 0.25 to 12 wt.%.

4. A liquid laundry detergent composition according to any preceding claim, wherein the composition comprises from 55 to 80 wt.%, preferably from 55 to 75 wt.%, more preferably from 60 to 75 wt.% of the linear alkyl benzene sulfonic acid surfactant.

5. A liquid laundry detergent composition according to any preceding claim, wherein the composition comprises from 15 to 40 wt.%, preferably from 17.5 to 40 wt.%, more preferably from 20 to 35 wt.% of the alkyl ether carboxylic acid anionic surfactant.

6. A liquid laundry detergent composition according to any preceding claim, wherein the level of water is from 0 to less than 9 wt.%, preferably from 0.01 to 8 wt.%, more preferably from 0.1 to 8 wt.%, most preferably from 1 to 8 wt.%.

7. A liquid laundry detergent composition according to claim 1, comprising:

(i) from 60 to 80 wt.% of a linear alkyl benzene sulfonic acid surfactant;

(ii) from 20 to 40 wt.% of an alkyl ether carboxylic acid surfactant of the following structure:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wherein: R₁ is selected from saturated C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 15 to 20;

(iii) less than 10 wt.% water;

(iv) from 0 to 20 wt.% non-ionic surfactant of the following structure

        R₂-(OCH₂CH₂)_n-OH,

wherein: R₂ is selected from saturated C₁₂ to C₂₂ linear or branched alkyl chains, preferably C₁₆ to C₁₈ linear alkyl chains, and wherein n is selected from 10 to 20;

wherein the pH of the formulation is from 0.5 to 2.0;

and wherein the weight ratio of linear alkyl benzene sulfonic acid surfactant to the alkyl ether carboxylic acid surfactant is from 1.5:1 to 4:1; and,

wherein the pH of the formulation is that of a 1 wt.% solution of the liquid laundry detergent composition dissolved in demineralised water at 293K.

Ansprüche

1. Flüssige Waschmittelzusammensetzung, umfassend:

(i) 50 bis 80 Gew.-% eines linearen Alkylbenzolsulfonsäure-Tensids;

(ii) 15 bis 45 Gew.-% eines Alkylethercarbonsäure-Tensids der folgenden Struktur:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wobei: R₁ aus gesättigten linearen oder verzweigten C₁₆- bis C₂₂-Alkylketten, vorzugsweise aus linearen C₁₆- bis C₁₈-Alkylketten ausgewählt ist, und wobei n aus 10 bis 24 ausgewählt ist;

(iii) weniger als 10 Gew.-% Wasser;

(iv) 0 bis 20 Gew.-% nicht-ionisches Tensid der folgenden Struktur

        R₂-(OCH₂CH₂)_n-OH,

wobei: R₂ aus gesättigten linearen oder verzweigten C₁₂- bis C₂₂-Alkylketten, vorzugsweise aus linearen C₁₆- bis C₁₈-Alkylketten ausgewählt ist, und wobei n aus 5 bis 30, vorzugsweise 10 bis 20, ausgewählt ist;

wobei der pH-Wert der Formulierung 0,3 bis 2,0 beträgt und

wobei das Gewichtsverhältnis von linearem Alkylbenzolsulfonsäure-Tensid zu dem Alkylethercarbonsäure-Tensid 1,5:1 bis 5:1 beträgt und

wobei der pH-Wert der Formulierung derjenige einer 1 gewichtsprozentigen Lösung der flüssigen Waschmittelzusammensetzung, gelöst in entmineralisiertem Wasser, bei 293 K ist.

2. Flüssige Waschmittelzusammensetzung nach Anspruch 1, wobei der pH-Wert der Formulierung 0,5 bis 2,0, vorzugsweise 0,5 bis 1,5, beträgt.

3. Flüssige Waschmittelzusammensetzung nach Anspruch 1 oder Anspruch 2, wobei das nicht-ionische Tensid in einer Menge von 0,1 bis 20 Gew.-%, vorzugsweise von 0,1 bis 15 Gew.-%, bevorzugter von 0,25 bis 12 Gew.-%, vorliegt.

4. Flüssige Waschmittelzusammensetzung nach irgendeinem vorhergehenden Anspruch, wobei die Zusammensetzung 55 bis 80 Gew.-%, vorzugsweise 55 bis 75 Gew.-%, bevorzugter 60 bis 75 Gew.-% des linearen Alkylbenzolsulfonsäure-Tensids umfasst.

5. Flüssige Waschmittelzusammensetzung nach irgendeinem vorhergehenden Anspruch, wobei die Zusammensetzung 15 bis 40 Gew.-%, vorzugsweise 17,5 bis 40 Gew.-%, bevorzugter 20 bis 35 Gew.-% des anionischen Alkylethercarbonsäure-Tensids enthält.

6. Flüssige Waschmittelzusammensetzung nach irgendeinem vorhergehenden Anspruch, wobei die Menge des Wassers 0 bis weniger als 9 Gew.-%, vorzugsweise 0,01 bis 8 Gew.-%, bevorzugter 0,1 bis 8 Gew.-%, höchst bevorzugt 1 bis 8 Gew.-%, beträgt.

7. Flüssige Waschmittelzusammensetzung nach Anspruch 1, umfassend:

(i) 60 bis 80 Gew.-% eines linearen Alkylbenzolsulfonsäure-Tensids;

(ii) 20 bis 40 Gew.-% eines Alkylethercarbonsäure-Tensids der folgenden Struktur:

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

wobei: R₁ aus gesättigten linearen C₁₆- bis C₁₈-Alkylketten ausgewählt ist und wobei n aus 15 bis 20 ausgewählt ist;

(iii) weniger als 10 Gew.-% Wasser;

(iv) 0 bis 20 Gew.-% nicht-ionisches Tensid der folgenden Struktur

        R₂-(OCH₂CH₂)_n-OH,

wobei: R₂ aus gesättigten linearen oder verzweigten C₁₂- bis C₂₂-Alkylketten, vorzugsweise aus linearen C₁₆- bis C₁₈-Alkylketten, ausgewählt ist und wobei n aus 10 bis 20 ausgewählt ist;

wobei der pH-Wert der Formulierung 0,5 bis 2,0 beträgt;

und wobei das Gewichtsverhältnis von linearem Alkylbenzolsulfonsäure-Tensid zu dem Alkylethercarbonsäure-Tensid 1,5:1 bis 4:1 beträgt; und

wobei der pH-Wert der Formulierung derjenige einer 1 gewichtsprozentigen Lösung der flüssigen Waschmittelzusammensetzung, gelöst in entmineralisiertem Wasser, bei 293 K ist.

Revendications

1. Composition de détergent de lessive liquide comprenant :

(i) de 50 à 80 % en masse d'un tensioactif d'acide alkylbenzène sulfonique linéaire ;

(ii) de 15 à 45 % en masse d'un tensioactif d'acide alkyléther carboxylique de la structure suivante :

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

dans laquelle : R₁ est choisi parmi des chaînes alkyle linéaires ou ramifiées en C₁₆ à C₂₂ saturées, de préférence des chaînes alkyle linéaires en C₁₆ à C₁₈, et dans laquelle n est choisi de 10 à 24 ;

(iii) moins de 10 % en masse d'eau ;

(iv) de 0 à 20 % en masse de tensioactif non-ionique de la structure suivante

        R₂-(OCH₂CH₂)_n-OH,

dans laquelle : R₂ est choisi parmi des chaînes alkyle linéaires ou ramifiées en C₁₂ à C₂₂ saturées, de préférence des chaînes alkyle linéaires en C₁₆ à C₁₈, et dans laquelle n est choisi de 5 à 30, de préférence de 10 à 20 ;

dans laquelle le pH de la formulation est de 0,3 à 2,0 ; et

dans laquelle le rapport massique de tensioactif d'acide alkylbenzène sulfonique linéaire au tensioactif d'acide alkyléther carboxylique est de 1,5:1 à 5:1 ; et,

dans laquelle le pH de la formulation est celui d'une solution à 1 % en masse de la composition de détergent de lessive liquide dissoute dans de l'eau déminéralisée à 293 K.

2. Composition de détergent de lessive liquide selon la revendication 1, dans laquelle le pH de la formulation est de 0,5 à 2,0, de préférence de 0,5 à 1,5.

3. Composition de détergent de lessive liquide selon la revendication 1 ou revendication 2, dans laquelle le tensioactif non-ionique est présent à une teneur de 0,1 à 20 % en masse, de préférence de 0,1 à 15 % en masse, encore mieux de 0,25 à 12 % en masse.

4. Composition de détergent de lessive liquide selon l'une quelconque des revendications précédentes, dans laquelle la composition comprend de 55 à 80 % en masse, de préférence de 55 à 75 % en masse, encore mieux de 60 à 75 % en masse du tensioactif d'acide alkylbenzène sulfonique linéaire.

5. Composition de détergent de lessive liquide selon l'une quelconque des revendications précédentes, dans laquelle la composition comprend de 15 à 40 % en masse, de préférence de 17,5 à 40 % en masse, encore mieux de 20 à 35 % en masse du tensioactif anionique d'acide alkyléther carboxylique.

6. Composition de détergent de lessive liquide selon l'une quelconque des revendications précédentes, dans laquelle la teneur en eau est de 0 à moins de 9 % en masse, de préférence de 0,01 à 8 % en masse, encore mieux de 0,1 à 8 % en masse, bien mieux encore de 1 à 8 % en masse.

7. Composition de détergent de lessive liquide selon la revendication 1, comprenant :

(i) de 60 à 80 % en masse d'un tensioactif d'acide alkylbenzène sulfonique linéaire ;

(ii) de 20 à 40 % en masse d'un tensioactif d'acide alkyléther carboxylique de la structure suivante :

        R₁-(OCH₂CH₂)_n-OCH₂-COOH,

dans laquelle : R₁ est choisi parmi des chaînes alkyle linéaires en C₁₆ à C₁₈ saturées, et
dans laquelle n est choisi de 15 à 20 ;

(iii) moins de 10 % en masse d'eau ;

(iv) de 0 à 20 % en masse de tensioactif non-ionique de la structure suivante

        R₂-(OCH₂CH₂)_n-OH,

dans laquelle : R₂ est choisi parmi des chaînes alkyle linéaires ou ramifiées en C₁₂ à C₂₂ saturées, de préférence des chaînes alkyle linéaires en C₁₆ à C₁₈, et dans laquelle n est choisi de 10 à 20 ;

dans laquelle le pH de la formulation est de 0,5 à 2,0 ;

et dans laquelle le rapport de masse de tensioactif d'acide alkylbenzène sulfonique linéaire au tensioactif d'acide alkyléther carboxylique est de 1,5:1 à 4:1 ; et,

dans laquelle le pH de la formulation est celui d'une solution à 1 % en masse de la composition de détergent de lessive liquide dissoute dans de l'eau déminéralisée à 293 K.