EP3390607A1

EP3390607A1 - Penta-built liquid detergent composition

Info

Publication number: EP3390607A1
Application number: EP16829240.7A
Authority: EP
Inventors: John O'donnell; William Shore
Original assignee: Henkel AG and Co KGaA
Current assignee: Henkel AG and Co KGaA
Priority date: 2015-12-18
Filing date: 2016-12-14
Publication date: 2018-10-24
Anticipated expiration: 2036-12-14
Also published as: EP3390607B1; AU2016372352B2; WO2017102868A1; AU2016372352A1

Abstract

An aqueous, phosphate-free, structured heavy duty liquid detergent composition comprising a surfactant system, a builder system and water, wherein the builder system comprises (A) at least one inorganic builder (sodium carbonate); (B) at least one polycarboxylic acid or salt thereof (citric acid); (C) at least one aminocarboxylate (GLDA tetrasodium salt); (D) at least one phosphonate (lysine tetra methylene phosphonate (LTMP)); and (E) at least one acrylate-containing water-soluble polymer or acid derivative or salts thereof (sodium salt of an acrylic acid copolymer). Method for cleaning textiles, wherein a washing liquor containing the detergent composition contacts the textile in at least one method step. Use of the detergent composition.

Description

"Penta-Built Liquid Detergent Composition"

The present invention relates to an aqueous, phosphate-free, structured liquid detergent composition, in particular a heavy duty liquid detergent (HDL) that comprises a builder system, a surfactant system and water, wherein the builder system comprises five separate builder components. The invention further relates to methods for washing of textiles using the detergents of the invention.

Liquid detergent compositions are well-known in the art and widely used. Over recent years, the have become more and more popular with the consumers because they offer a number of advantages over solid compositions, including, for example, the ease of dosing, dispensing and dissolving into a laundering liquor. In addition, they are perceived to be safer and less harsh to the textiles and environment compared to solid compositions. In particular for laundering colored fabrics they have gained popularity ever since their introduction on the market.

Recently, for environmental and regulatory reasons the demand for phosphate-free liquid detergents has increased. However, liquid detergent compositions, in particular phosphate-free heavy duty liquid (HDL) detergents suffer from physical and chemical instability and viscosity problems. This is particularly problematic for highly concentrated formulations. While HDL detergents have been introduced as early as the 1970's, the known stable formulations rely on the use of phosphates, in particular sodium tripolyphosphate (STPP), to form structured liquids containing high levels of builders and surfactants. In these built HDLs multilayered vesicles are formed that stabilize the formulation and prevent precipitation of the anionic surfactants by the builder components. These structures are stable and can be characterized by microscopic examination under polarized light and conductivity measurements. STPP was particularly suited to formation of vesicles with sodium alkylbenzene sulfonate (sodium LAS). In addition, STPP was well established as a builder in detergent powders and acts as a chelating agent, inhibits soil re- deposition during the wash and boosts overall detergency. The result of the use of STPP was the development of high performance and low cost HDL. However, as mentioned above, environmental concerns over the use of phosphates, including STPP, in laundry detergents have resulted in phosphate use being banned in some countries and a negative public image in most developed markets. While alternatives to STPP, such as zeolite, sodium citrate, and sodium carbonate, are known, these show poor performance relative to phosphate built HDL.

Therefore, there is still need in the art for phosphate-free, structured HDL detergents that have comparable performance as the previously used phosphate-based formulations. Accordingly, it is an object of the present invention to meet this need by providing an aqueous, phosphate-free, structured liquid detergent composition, in particular a HDL detergent that exhibits the desired performance.

It has surprisingly been found by the inventors that this object can be met by a composition that comprises a specific builder system, a surfactant system and water. It has been demonstrated that such a detergent shares a similar washing performance as the previously used STPP-containing compositions.

In a first aspect, the present invention therefore relates to an aqueous, phosphate-free, structured liquid detergent composition comprising a surfactant system, a builder system and water, wherein the builder system comprises

(A) at least one inorganic builder, preferably a carbonate, more preferably sodium

carbonate;

(B) at least one polycarboxylic acid or salt thereof, preferably a hydroxyl group-containing polycarboxylic acid or salt thereof, more preferably citric acid or citrate;

(C) at least one aminocarboxylate, preferably selected from the group consisting of L- glutamic acid Ν,Ν-diacetic acid (GLDA), methyl glycine diacetic acid (MGDA), imino disuccinic acid (IDS), ethylenediamine Ν,Ν'-disuccinic acid (EDDS), diethylenetriamine pentaacetic acid (DTPA), beta-alanine Ν,Ν-diacetic acid, hydroxyethylenediamine triacetic acid (HEDTA), and alkali metal salts thereof, more preferably GLDA tetrasodium salt;

(D) at least one phosphonate, preferably lysine tetra methylene phosphonate (LTMP); and

(E) at least one acrylate-containing water-soluble polymer or acid derivative or salts

thereof, preferably a sodium salt of an acrylic acid copolymer.

In a further aspect, the invention relates to methods for cleaning textiles, wherein a washing liquor containing the liquid detergent composition of the present invention contacts the textile in at least one method step.

In still another aspect, the invention also encompasses the use of a composition comprising

carbonate;

(E) at least one acrylate-containing water-soluble polymer or acid derivative or salts thereof, preferably a sodium salt of an acrylic acid copolymer,

as a builder system in an aqueous, phosphate-free, structured liquid detergent composition.

"At least one", as used herein, relates to one or more, i.e. 1 , 2, 3, 4, 5, 6, 7, 8, 9, or more. If used in combination with a compound, the term does not relate to the absolute number of molecules but rather to the number of different types of said compound. "At least one inorganic builder" thus means that at least one type but that also 2 or more different inorganic builder types can be present.

If not indicated otherwise, all viscosities referred to herein are viscosities measured at 20°C by a Brookfield LVT, Spindle No. 3 at 12 rpm.

If not indicated otherwise, all percentages are by weight relative to the total weight of the composition.

"Free of", as used herein in relation to a specific type of component, means that the referenced composition does not contain more than 0.5 wt.%, preferably no more than 0.1 wt.%, more preferably no more than 0.05 wt.% of said component relative to the total weight of the composition. Most preferably, said component is not contained at all.

The detergent compositions of the present invention can be used as detergents for textiles, carpets or natural fibers. In preferred embodiments, the detergents disclosed herein are heavy duty liquid (HDL) detergents.

The present invention is based on the inventors' surprising finding, that by use of the disclosed builder system structured liquid detergent compositions may be formed that have the desired washing performance.

"Washing performance", as used herein, relates to the removal of stains, in particular stains sensitive to surfactants. The removal can be evaluated by measuring a brightening of the stain either instrumentally or by visual inspection.

Structured liquids are widely used in the field of detergents. They can either be internally structured by one or more of the primary ingredients, such as the surfactants, and/or by using secondary additives, such as certain polymers and/or silicates. Structuring is used to endow the composition with properties such as a turbid appearance or certain flow properties. Such structured liquids may also contain suspended solids. While structured liquids provide more formulation flexibility compared to isotropic liquids, they often suffer from stability and viscosity problems. The presently disclosed formulations, however, provide for compositions that have the desired viscosities while at the same time showing good stability.

In various embodiments, the liquid detergent compositions of the invention are internally structured in that the surfactant system leads to formation of multilayered vesicles. "Structured", as used herein, therefore means that the compositions are preferably internally structured by formation of multilayered vesicles. "Multilayered vesicles" preferably relates to essentially spherical vesicles that have a multilayered, typically double-layered, shell formed of molecules comprising hydrophobic moieties, with said hydrophobic moieties arranged such that they face each other while the more hydrophilic parts of the molecules face outwards. Said shell can form a vesicle lumen.

The compositions of the invention comprise a builder system. The builder system is a phosphate- free builder system, as the composition is free of phosphates. However, the composition comprises phosphonates. Accordingly, the term "phosphate-free", as used herein does not include phosphonates.

The phosphonates included in the builder system are preferably phosphonates based on hydroxyl alkanes, amino alkanes or amino acids, such as 1-hydroxyethane-1 , 1-diphosphonate (HEDP), ethylenediamine tetramethylene phosphonate (EDTMP), diethylenetriamine pentamethylene phosphonate (DTPMP), and lysine tetramethylene phosphonate (LTMP). Preferred are

phosphonates that are readily water-soluble, in particular lysine tetramethylene phosphonate.

"Water-soluble", as used herein, relates to a solubility in water at 20°C of at least 1 g/L, preferably at least 10 g /L.

Phosphonates are used in amounts of 0.5 to 5.0 wt.%, preferably 2.0 to 3.0 wt.%.

Suitable inorganic builders include, without limitation, silicates, aluminosilicates (particularly zeolite), and carbonates, with water-soluble inorganic builders and in particular carbonates being preferred.

Suitable carbonates include alkali metal carbonates, hydrogen carbonates and sesquicarbonates, with alkali metal carbonates, in particular sodium carbonate being preferred. In various embodiments, inorganic builders, in particular water-soluble inorganic builders, preferably carbonates, are used in amounts of up to 8 wt.%, preferably up to 5 wt.% relative to the total weight of the composition. In preferred embodiments, carbonate, preferably sodium carbonate, is used in amounts of 1.0 to 8.0 wt.%, preferably 3.0 to 5.0 wt.%.

Suitable polycarboxylic acids, which can be used as free acids or in form of their salts, include, but are not limited to, citric acid, adipic acid, succinic acid, glutaric acid, malic acid, tartric acid, maleic acid, fumaric acid, and sugar acids. In addition to their builder properties, the free acids can also be used for pH control. Preferred are citric acid, succinic acid, glutaric acid, adipic acid and gluconic acid, and combinations thereof.

Particularly preferred are citric acid and their salts, i.e. citrates. In various embodiments, the polycarboxylic acids, in particular citric acid/citrate, are contained in the compositions of the invention in amounts of 3.0 to 15.0 wt.%, preferably 6.0 to 10.0 wt.%.

Suitable aminocarboxylic acids or salts thereof, i.e. aminocarboxylates, are selected from the group consisting of L-glutamic acid Ν,Ν-diacetic acid (GLDA), methyl glycine diacetic acid (MGDA), imino disuccinic acid (IDS), ethylenediamine Ν,Ν'-disuccinic acid (EDDS), diethylenetriamine pentaacetic acid (DTPA), beta-alanine Ν,Ν-diacetic acid, hydroxyethylenediamine triacetic acid (HEDTA), and salts, preferably alkali metal salts thereof as well as combinations of any one of more of the aforementioned. Particularly preferred is GLDA tetrasodium salt.

The aminocarboxylates are preferably used in amounts of 2.0 to 10.0 wt.%, preferably 3.0 to 5.0 wt.% relative to the total weight of the composition.

Finally, the fifth builder component are acrylate-containing water-soluble polymers, such as alkali metal salts of polyacrylic acid or polymethacrylic acid, for example those having a molecular weight Mw in the range of 600 to 750,000 g / mol, as determined by gel permeation chromatography (GPC) according to DIN 55672-1 :2007-08 with THF as an eluent.

Preferred polymers are polyacrylates with a molecular weight M_w of 1 ,000 to 15,000 g / mol, more preferred, due to their solubility, are short-chain polyacrylates with a molecular weight M_w of 1 ,000 to 10,000 g / mol, most preferred from 1 ,000 to 5,000 g / mol.

Also suitable are copolymers of acrylates, in particular those of acrylic acid and methacrylic acid, and acrylic acid or methacrylic acid and maleic acid. To further improve solubility, such copolymers can also contain monomers of allyl sulfonic acids, such as allyloxybenzene sulfonic acid and methallyl sulfonic acid. Preferred acrylates for use in the present invention are alkali metal salts of polymers of acrylic acid, preferably the sodium salts, in particular those with molecular weights in the range of 1 ,000 to 10,000 g / mol or 1 ,000 to 5,000 g / mol. Suitable acrylates are commercially available, for example under the tradename Acusol^® from Dow Chemical, preferred is, for example, Acusol^® 420N.

In various embodiments, the builder system comprises relative to the total weight of the detergent composition:

(a1 ) 1.0 to 8.0 wt.-%, preferably 3.0 to 5.0 wt.-% of the at least one inorganic builder, preferably a carbonate, more preferably sodium carbonate;

(a2) 3.0 to 15.0 wt.-%, preferably 6.0 to 10.0 wt.-% of the at least one polycarboxylic acid or salt thereof, preferably a hydroxyl group-containing polycarboxylic acid or salt thereof, more preferably citric acid or citrate, most preferably preferably sodium citrate;

(a3) 2.0 to 10.0 wt.-%, preferably 3.0 to 5.0 wt.-% of the at least one aminocarboxylate, preferably selected from the group consisting of L-glutamic acid Ν,Ν-diacetic acid (GLDA), methyl glycine diacetic acid (MGDA), imino disuccinic acid (IDS), ethylenediamine Ν,Ν'-disuccinic acid (EDDS), diethylenetriamine pentaacetic acid (DTPA), beta-alanine Ν,Ν-diacetic acid,

hydroxyethylenediamine triacetic acid (HEDTA), and alkali metal salts thereof, more preferably GLDA tetrasodium salt;

(a4) 0.5 to 5.0 wt.%, preferably 2.0 to 3.0 wt.-% of the at least one phosphonate, preferably lysine tetra methylene phosphonate (LTMP); and

(a5) 0.5 to 5.0 wt.%, preferably 1.0 to 2.0 wt.% of the at least one acrylate-containing water-soluble polymer or acid derivative or salts thereof, preferably a sodium salt of an acrylic acid copolymer.

Further organic builders include polyacetals, dextrins and others. It is however preferred that the compositions are free of these other types of organic builders.

In various embodiments, the builder system is comprised in the compositions in an amount of 10.0 to 30.0 wt.%, preferably 15.0 to 25.0 wt.%.

The detergent compositions of the invention further comprise a surfactant system. Said surfactant system preferably comprises at least one alkyl ether sulfate. Preferred alkyl ether sulfates are those of formula (I)

R -0-(AO)n-S0₃- X⁺ (I).

In formula (I) R represents a linear or branched, substituted or unsubstituted alkyl group, preferably a linear, unsubstituted alkyl group, more preferably a fatty alcohol moiety. Preferred R moieties are selected from the group consisting of decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl moieties and mixtures thereof, wherein those groups with an even number of carbon atoms are preferred. Particularly preferred R moieties are derived from C10-C18 fatty alcohols, such as those derived from coconut oil alcohols, tallow fatty alcohols, lauryl, myristyl, cetyl or stearyl alcohol or from Cio-C2o oxoalcohols.

AO represents an ethyleneoxide (EO) or propyleneoxide (PO) group, preferably an ethyleneoxide group. The index n represents an integer from 1 to 50, preferably from 1 to 20 and more preferably from 1 to 10. Particularly preferably, n is 1 , 2, 3, 4, 5, 6, 7 or 8. X represents a monovalent cation or the n-th part of an n-valent cation, preferred are alkali metal cations, specifically Na⁺ and K⁺, most preferably Na⁺. Further cations X⁺ may be selected from NH₄ ⁺, ½ Zn²⁺,½ Mg²⁺,½ Ca²⁺,½ Mn²⁺, and combinations thereof.

In various preferred embodiments, the detergent compositions comprise an alkyl ether sulfate selected from fatty alcohol ether sulfates of formula (II)

wherein k = 9 to 19, and n = 1 , 2, 3, 4, 5, 6, 7 or 8. Preferred are C10-16 fatty alcohol ether sulfates with 1-7, more preferably 1-3 EO (k = 9-15, n = 1-7, 1 -3), even more preferred the C12-14 fatty alcohol ether sulfates with 1 -3, particularly 2 EO (k = 1 1-13, n = 1-3 or 2), more particularly the sodium salts thereof. Particularly preferred is lauryl ether sulfate sodium salt with 2 EO, as it is particularly advantageous for achieving the desired viscosity ranges. The level of ethoxylation is an average value and can, for a specific compound, be an integer or fractional number.

The alkyl ether sulfate is preferably contained in the compositions of the invention in an amount of 2.0 to 8.0 wt.% relative to the total weight of the composition, preferably 3.0 to 7.0 wt.%.

In various embodiments, the surfactant system comprises at least one alkyl benzene sulfonate. Said alkyl benzene sulfonate may be present alternatively to the above alkyl ether sulfate or, preferably, in addition to it.

Exemplary alkyl benzene sulfonates include, but are not limited to linear and branched alkyl benzene sulfonates, preferably linear alkyl benzene sulfonates. Exemplary compounds are those of formula (III)

wherein R^' and R^" are independently H or alkyl and combined comprise 9 to 19, preferably 9 to 15 and more preferably 9 to 13 carbon atoms. Particularly preferred are dodecyl and tridecyl benzene sulfonates, in particular the sodium salts thereof. Preferred contents of the alkyl benzene sulfonates range from 3.0 to 22.0 wt.%, preferably 10.0 to 15.0 wt.%, relative to the total weight of the composition.

In addition, the compositions of the invention may further comprise one or more nonionic surfactants. Preferred nonionic surfactants are those of formula (IV)

wherein R² represents a linear or branched substituted or unsubstituted alkyl moiety, AO represents an ethylene oxide (EO) or propylene oxide (PO) group and m is an integer from 1 to 50.

In formula (IV) R² preferably represents a linear or branched, substituted or unsubstited alkyl group, preferably a linear, unsubstituted alkyl group, particularly preferred a fatty alcohol group. Preferred groups are R² are selected from decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl groups and combinations thereof, wherein those groups with an even number of carbon atoms are preferred. Particularly preferred are R² groups derived from C12-C18 fatty alcohols, such as coconut oil alcohol, tallow oil alcohol, lauryl, myristyl, cetyl or stearyl alcohol or from C10-C20 oxoalcohols.

AO represents an ethyleneoxide (EO) or propyleneoxide (PO) group, preferably an ethyleneoxide group. The index m represents an integer from 1 to 50, preferably from 1 to 20 and more preferably from 1 to 6. Particularly preferably, m is 1 , 2, 3, 4 or 5, most preferably 3-5, as higher degrees of ethoxylation may negatively influence viscosity and stability.

In various preferred embodiments, the detergent compositions comprise an alkyl ether selected from fatty alcohol ethers of formula (V)

wherein k = 1 1 to 19, m = 1 , 2, 3, 4, 5, 6, 7 or 8. Preferred are C12-18 fatty alcohols with 1-6 EO (k = 1 1-17, m = 1 -5 in formula (V)). More preferred are C12-14 alcohols having 1-5 EO, most preferred are C12-14 alkyl ethers with 3-5 EO, in particular lauryl ether with 5 EO.

Such nonionic alkyl ethers may be contained in the formulation in amounts of 0.0 to 5.0 wt.%, preferably 2.0 to 3.0 wt.%.

The detergents may further include other nonionic surfactants, such as alkyl glucosides of the general formula RO(G)x, where R is a primary linear or 2-methyl-branched aliphatic radical containing 8 to 22 and preferably 12 to 18 carbon atoms and G stands for a glucose unit. The degree of oligomerization x, which indicates the distribution of monoglucosides and oligoglucosides, is a number of 1 to 10 and preferably a number of 1.2 to 1 .4. However, in preferred embodiments, the compositions do not include such alkyl glucosides.

In various embodiments, the surfactant system comprises at least two anionic surfactants, namely at least one alkyl ether sulfate and preferably at least one alkyl benzene sulfonate, and optionally an alkyl ether.

The compositions may comprise, for example, 5.0 to 25.0, preferably 13.0 to 20.0 wt.% of the surfactant system. Said surfactant system may comprise or consist of anionic surfactants, preferably (1 ) 2.0 to 8.0 wt.%, preferably 3.0 to 7.0 wt.% C10-16 alkyl ether sulfates with 1 to 7 EO, preferably C12-14 fatty alcohol ether sulfates with 1-3 EO, more preferably lauryl ether sulfate with 2 EO; (2) 3.0 to 22.0, preferably 10.0 to 15.0 wt.%, of a linear alkyl benzene sulfonate, preferably dodecyl or tridecyl benzene sulfonate; and (3) 0.0 to 5.0 wt.%, preferably 2.0 to 3.0 wt.%, C12-18 alkyl ethers with 1-6 EO, preferably C12-14 alkyl ethers having 1-5 EO, most preferably lauryl ether with 5 EO. All afore-mentioned percentages relate to the total weight of the composition.

The detergent compositions of the invention are aqueous liquid compositions and as such comprise significant quantities of water, typically 35.0 to 85.0 wt.%, preferably 50.0 to 70.0 wt.%.

The pH value of the detergents according to the invention is generally in the range of from pH 9 to 12, preferably in the range from 10.0 to 1 1.0. Relatively high pH values, for example above 9, may be adjusted by the use of small quantities of sodium hydroxide or alkaline salts, such as sodium carbonate. The liquid detergents are typically opaque, are flowable, and may be poured under the sole effect of gravity without any need for other shear forces to be applied. Their viscosity is generally greater than 1 ,000 mPas (Brookfield viscosimeter, spindle 3, 12 rpm, 20° C), namely in the range of between 1 ,000 and 10,000 mPas, preferably between 2,000 and 6,000 mPas.

To ensure stability and the desired viscosity, the compositions may further comprises stabilizers and/or rheology modifiers (thickeners), preferably both. These compounds are typically polymers, such as polymers based on acrylates or methacrylates. Examples of suitable acrylate polymers comprise, but are not limited to, polymers of the Acusol® series (Dow Chemicals, Midland, USA), Alcosperse® series, Aquatreat® series (both Akzo Nobel, Amsterdam, The Netherlands), Good- rite® series (Emerald Performance Materials, Cuyahoga Falls, USA), Junlon® series, Jurymer® series, Rheogic® series, Aran® series (all Toagosei Co., Ltd., Tokyo, Japan), Glascol® series (BASF, Ludwigshafen, Germany), Aqualic® series (Nippon Shokubai Co., Ltd., Osaka, Japan), Carbopol® series and Carboset® series (both The Lubrizol Corporation, Wickliffe, USA). Preferred are, for example, Alcosperse® 325 (Akzo nobel), as a stabilizer, and Acusol® 810 (Dow Chemical), as a thickener. These components are typically used in amounts of up to 1 wt.%, typically 0,1 to 0.5 wt.%. In addition to the ingredients mentioned above, however, the detergents may commonly contain at least one, preferably two or more other substances selected from the group consisting of soaps, pH adjusting agents, perfumes, fluorescing agents (optical brighteners), dyes, colorants, antimicrobial active substances, germicides, fungicides, antioxidants, preservatives, and softening compounds.

Further possible ingredients include silicone oils, anti-redeposition agents, anti-greying agents, shrinkage preventers, wrinkle protection agents, dye transfer inhibitors, corrosion inhibitors, antistatic agents, bittering agents, ironing adjuvants, proofing and impregnation agents, swelling and anti-slip agents, complexing agents and UV absorbers.

Also included may be bleaching agents, bleach activators, bleach catalysts, and enzymes, however, in various embodiments, the compositions are free of those.

For cold wash properties, it can be beneficial to additionally include soaps. Accordingly, in some embodiments, the detergent compositions further comprise relative to their total weight 0.25 to 15 wt.%, preferably 0.5 to 12.5 wt.%, preferably 2.0 to 6.0 wt.% soaps. Preferred are soaps from C12- C18 fatty acids, i.e. the salts of lauric acid, myristic acid, palmitic acid, stearic acid, or mixtures derived from natural fatty acids, for example coconut, palm kernel, olive oil, or tallow fatty acids.

Further ingredients that are commonly used include colorants, perfumes and optical brighteners, as well as pH adjusting agents. All of these ingredients are well-known in the art and readily available.

The present invention further relates to methods for cleaning textiles, wherein a washing liquor containing the liquid detergent composition of the present invention contacts the textile in at least one method step. The methods are preferably carried out in an automatic washing machine.

Methods for cleaning of textiles are generally characterized by the fact that in several different process steps various cleaning-active substances are applied to the textiles and after the contact time said cleaning-active substances are washed off, or that the textiles are treated in any other way with a detergent or a solution of said substance.

Also encompassed by the present invention is the use of the builder compositions disclosed herein for providing builder properties to aqueous, phosphate-free, structured liquid detergent compositions.

All embodiments described herein in relation to the compositions of the invention are similarly applicable to the methods and uses of the invention and vice versa. Examples

Example 1 :

Wash performance testing was conducted in top load domestic washing machines under the following conditions:

Table 1 : Wash conditions

Table 2: Technical stain

Measurement of soil removal

Washed swatches are read using a Hunter Lab Reflectometer thereby the Lightness (L^*) is recorded. The reflectometer is standardized with black (L^* = 0) and white (L^* = 100) standards. The resultant L^* value for washed stains can be compared to estimate wash performance.

Measurements are in triplicate and student t-test is applied at a 95% confidence interval. For individual stains the following criteria is applied:

Statistically better: Test statistic > 2.67 and delta L^* >1

Statistically worse: Test statistic <-2.67 and delta L^* <-1

In general, the criteria of +/-1 can be applied for top load wash performance.

A snap-shot of overall performance can be made by comparing the total L^* score for all 13 technical stains and applying the following criteria:

Top load: >5L^* is statistically better and <-5L^* is statistically worse. However, L^* scores for individual stains must be evaluated to obtain an accurate estimation of performance.

In all wash studies the phosphate-based formula was used as a benchmark and in Table 3 is used as a reference.

Example 1 : Sodium carbonate built HDL

In this series, sodium tripolyphosphate was removed, the builder sodium carbonate was kept constant, while the surfactant active levels were increased. Tetrasodium GLDA and polyacrylate were included to compensate for the removal of sodium tripolyphosphate. The wash data shows that a simple builder/surfactant combination cannot deliver the same wash performance as the reference phosphate-based detergent.

Table 3: Sodium carbonate built HDL Wash Performance and Composition

Phosphate

Product description A B C D E F

Reference

Delta L^* 0 -21 -20 -19 -14.6 -18.5 -9.6

Total surfactant (g/wash) 7.08 5.05 7.57 10.08 12.61 15.13 20.19

Total builder (g/wash) 13.29 4.82 4.82 4.82 4.82 4.82 4.82

Ingredient Composition of formulations (grams/wash)

Deionised Water QS QS QS QS QS QS QS

Sodium LAS 5.37 2.34 3.51 4.67 5.84 7.01 9.35

Sodium laureth-2 sulfate 1.71 1.45 2.17 2.89 3.62 4.34 5.79

Laureth-8 0.00 1.26 1.89 2.52 3.15 3.78 5.05

Sodium Tripolyphosphate 10.43 0.00 0.00 0.00 0.00 0.00 0.00

Soda ash 2.75 3.71 3.71 3.71 3.71 3.71 3.71

Sodium Bicarbonate 0.1 1 0.00 0.00 0.00 0.00 0.00 0.00

Tetrasodium GLDA 0.00 0.37 0.37 0.37 0.37 0.37 0.37 Polyacrylate builder 0.00 0.74 0.74 0.74 0.74 0.74 0.74

Total L^* scores relative to the Phosphate reference demonstrate that replacement of phosphate by increasing surfactant active does not compensate for the low in top load wash performance. Increasing the surfactant concentration by almost 3-fold still resulted in lower top load wash performance.

Example 2: Penta-built HDL

Changing the focus from the surfactant to the builder system was carried out and much better top load wash performance wash results were obtained. A system comprising of 5 builders in combination with anionic surfactants alone gave surprising results:

Table 4 - Wash Performance and Composition of Pentabuilt Formulations

In the system comprising of anionic and nonionic surfactants reducing the surfactant concentration resulted in reduced top load wash performance. However, in systems where nonionic surfactants were excluded the wash performance did not reduce as the anionic surfactant concentration was also reduced. Example L is an efficient replacement for the phosphate builder. It does have a higher surfactant dose per wash but the builder dose per wash is significantly lower.

This correlated with previous testing on phosphate built formulations where the inclusion of nonionic surfactants does not contribute significantly to wash performance in top load machines. Additionally, if this builder system is contributing to performance the same way as a phosphate built system, then there should also be a corresponding loss of wash performance when the builders are reduced.

Example 5: Wash performance effect of builders

Another wash study was conducted to examine the effect of removing individual builders from the formulation.

The results confirm performance found in the previous wash study and show that each builder has a significant effect on the overall wash performance.

Table 5: Wash performance effect of builders

Product description Phosphate L M N O P Q

Reference

Delta L^* 0 -2.3 -16.6 -14.8 -5.9 -7.1 -8

Total surfactant (g/wash) 7.08 7.56 7.56 7.56 7.56 7.56 7.56

Total builder (g/wash) 13.29 9.46 5.65 7.57 8.33 8.70 7.57

Ingredient Composition of formulations (grams/wash)

Deionised Water QS QS QS QS QS QS QS

Sodium C13 LAS 5.37 6.05 6.05 6.05 6.05 6.05 6.05

Sodium laureth-2 sulfate 1.71 1.51 1.51 1.51 1 .51 1.51 1.51

Sodium Tripolyphosphate 10.43 0.00 0.00 0.00 0.00 0.00 0.00

Sodium Carbonate 2.75 1.89 1.89 0.00 1 .89 1.89 1.89

Sodium Bicarbonate 0.1 1 0.00 0.00 0.00 0.00 0.00 0.00

Citric acid monohydrate 0.00 2.84 0.00 2.84 2.84 2.84 2.84

Sodium hydroxide 50% 0.00 0.95 0.00 0.95 0.95 0.95 0.95

Tetrasodium GLDA 0.00 1.89 1.88 1.89 1 .89 1.89 0.00

Lysine tetramethylene 0.00 1.13 1.13 1.13 0.00 1.13 1.13 phosphonate

Polyacrylate builder 0.00 0.76 0.75 0.76 0.76 0.00 0.76 Examples M and N show a very significant performance effect due to citrate and carbonate while O, P and Q show smaller but still significant effects due to Phosphonate, Polyacrylate and GLDA.

Formulations

Initial formulation work has been conducted and it was found that a multi-layered vesicle structure could be formed but these were found to be unstable. Addition of a C9 hydrophobically modified polyacrylate, Alcosperse® 325, was required to achieve a stable formulation. Additionally, a polyacrylate thickener such as Acusol® 81 OA, could be incorporated to achieve a more viscous product.

Formulations are summarized in Table 6, which shows that the grams per wash of each raw material are kept constant but the percentage in the formula is adjusted to achieve the required dose.

Table 6: Prototype penta-built HDL formulation

Formula "% m/m" is the concentration of each raw material based on 100% active ingredient.

Claims

1. Aqueous, phosphate-free, structured liquid detergent composition comprising a surfactant system, a builder system and water, wherein the builder system comprises

carbonate;

thereof, preferably a sodium salt of an acrylic acid copolymer.

2. The detergent composition according to claim 1 , wherein the composition comprises relative to the total weight of the composition

(a) 10.0 to 30.0 wt.-%, preferably 15.0 to 25.0 wt.-% of the builder system,

(b) 5.0 to 25.0 wt.-%, preferably 13.0 to 20.0 wt.-% of the surfactant system

(c) 35.0 to 85.0 wt.-%, preferably 55.0 to 70 wt.-% water.

3. The detergent composition according to claim 1 or 2, wherein the builder system comprises relative to the total weight of the detergent composition:

hydroxyethylenediamine triacetic acid (HEDTA), and alkali metal salts thereof, more preferably GLDA tetrasodium salt; (a4) 0.5 to 5.0 wt.%, preferably 2.0 to 3.0 wt.-% of the at least one phosphonate, preferably lysine tetra methylene phosphonate (LTMP); and

4. The detergent composition according to any one of claims 1 to 3, wherein the surfactant system comprises at least one, preferably two anionic surfactants, preferably being selected from the group consisting of alkyl ether sulfates and linear alkyl benzene sulfonates.

5. The detergent composition according to claim 4, wherein

(1 ) the at least one alkyl ether sulfate comprises C10-16 alkyl ether sulfates with 2 to 7 EO, preferably sodium lauryl ether sulfate with 2 EO; and/or

(2) the at least one linear alkyl benzene sulfonate (LAS) comprises linear C9-13 alkyl benzene sulfonates, preferably tridecyl benzene sulfonate sodium salt or dodecyl benzene sulfonate sodium salt; and/or

(3) the surfactant system further comprises a nonionic surfactant.

6. The detergent composition according to any one of claims 1 to 5, wherein the surfactant system comprises relative to the total weight of the detergent composition:

(1 ) 2.0 to 8.0 wt.%, preferably 3.0 to 7.0 wt.% C10-16 alkyl ether sulfates with 1 to 7 EO, preferably C12-14 fatty alcohol ether sulfates with 1-3 EO, more preferably lauryl ether sulfate with 2 EO;

(2) 3.0 to 22.0, preferably 10.0 to 15.0 wt.%, more preferably 10.0 to 15.0 wt.% of a linear alkyl benzene sulfonate, preferably dodecyl or tridecyl benzene sulfonate; and

(3) 0.0 to 10 wt.%, preferably 2.0 to 3.0 wt.%, C12-18 alkyl ethers with 1-6 EO, preferably C12-14 alkyl ethers having 1-5 EO, most preferably lauryl ether with 5 EO.

7. The detergent composition according to any one of claims 1 to 6, wherein the detergent composition further comprises at least one polymeric thickener and/or at least one polymeric stabilizer.

8. The detergent composition according to any one of claims 1 to 7, wherein the detergent composition comprises at least one, preferably two or more other substances selected from the group consisting of soaps, pH adjusting agents, perfumes, fluorescing agents (optical brighteners), dyes, colorants, antimicrobial active substances, germicides, fungicides, antioxidants, preservatives, and softening compounds.

9. Method for cleaning textiles, wherein a washing liquor containing the detergent composition according to any one of claims 1 to 8 contacts the textile in at least one method step.

10. Use of a composition comprising

carbonate;

thereof, preferably a sodium salt of an acrylic acid copolymer.