AU667660B2

AU667660B2 - Liquid detergents

Info

Publication number: AU667660B2
Application number: AU64395/90A
Authority: AU
Inventors: Zia Haq; Frederik Jan Schepers; David Charles Steer; Johannes Cornelis Van De Pas; Rudolf Cornelis Stefanus Verheul
Original assignee: Unilever PLC
Current assignee: Unilever PLC
Priority date: 1989-10-12
Filing date: 1990-10-10
Publication date: 1996-04-04
Anticipated expiration: 2010-10-10
Also published as: AU6439590A; MX172775B; BR9007743A; JPH05500829A; WO1991005845A1

Description

LIQUID DETERGENTS

The present invention is concerned with structured detergent compositions which comprise detergent active material and an aqueous medium containing dissolved electrolyte material. In particular the present invention relates to structured liquid detergent compositions. Such structured liquids can be •internally structured' whereby the structure is formed by primary ingredients and/or they can be structured by secondary additives, which can be added as 'external structurants' to a composition.

Both forms of structuring are very well known in the art. External structuring is usually used for the purpose of suspending solid particles. Internal structuring is usually used to suspend particles and/or to endow properties such as consumer preferred flow properties and/or turbid appearance. The most common suspended particulate solids are detergency builders and abrasive particles. Examples of internally structured liquids without suspended solids are given in US patent 4 244 840 whilst examples where solid particles are suspended are disclosed in specifications EP-A-160 342; EP-A-38 101; EP-A-104 452 and also in the aforementioned US 4 244 840.

Some of the different kinds of internal surfactant structuring which are possible are described in the reference H.A.Barnes, 'Detergents', Ch.2. in K.Walters (Ed), 'Rheometry: Industrial Applications', J.Wiley & Sons, Letchworth 1980.In general, the degree of ordering of such systems increases with increasing surfactant and/or electrolyte concentrations. At very low concentrations, the surfactant can exist as a molecular solution, or as a solution of spherical micelles, both of these .being isotropic. With the addition of further surfactant and/or electrolyte, structured (anisotropic) systems can form. They are referred to respectively, by various terms such as rod-micelles, planar lamellar structures, lamellar droplets and liquid crystalline phases. Often, different workers have used different terminology to refer to the structures which are really the same. The presence of a surfactant structuring system in a liquid may be detected by means known to those skilled in the art for example, optical techniques, various rheometrical measurements, x-ray or neutron diffraction, and sometimes, electron microscopy.

One common type of internal surfactant structure is sometimes referred to as a dispersion of lamellar droplets (lamellar dispersion) These droplets consist of an onion-like configuration of concentric bilayers of surfactant molecules, between which is trapped water or electrolyte solution (aqueous phase) . Systems in which such droplets are close-packed provide a very desirable combination of physical stability and solid-suspending properties with useful flow properties.

When formulating internally structured compositions of the lamellar dispersion kind, there are limits to the types and amounts of ingredients compatible with having a stable, pourable product. The viscosity and stability of the product depend on the volume fraction of the liquid which is occupied b the droplets. Generally speaking, the higher is the volume fraction of the dispersed lamellar phase (droplets) , the better is the stability. However, higher volume fractions also lead to increased viscosity which in the limit can result in an unpourable product. This results in a compromise being reached. When the volume fraction is around 0.6, or higher, the droplets are just touching (spacefilling) . This allows reasonable stability with an acceptable viscosity. This volume fraction also endows useful solid suspending properties.

We have now found that increased stability and/or improved viscosity and/or improved solid suspending properties and/or improved alkalinity can be obtained if the composition comprises a combination of a deflocculating polymer and a structurant. Especially it has been found that silicates, especially when used in compositions having a relatively high pH, say 11.5 or less, are able to provide structuring to detergent compositions comprising deflocculating polymers.

Also it has been found that the combination of deflocculating polymers and high pH buffering agents provides a surprisingly good stability to structured detergent compositions. Especially it has been found that silicate, especially when used in compositions of relatively high pH, say 11.5 or above, is an excellent buffering material.

Accordingly the first embodiments of the present invention relates to a structured aqueous detergent composition comprising detergent active material and an aqueous medium optionally containing dissolved electrolyte material, said composition comprising a deflocculating polymer and a structurant.

Preferably the structurant comprises a silicate material.

Accordingly the second embodiment of the present invention relates to a structured aqueous detergent composition comprising detergent active material and an aqueous medium optionally containing dissolved electrolyte material, said composition comprising a deflocculating polymer and a high pH buffering material. In this specification the term high pH buffering material refers to any material capable of buffering an aqueous composition at a pH above 9.0 preferably above 10.0, more preferred from 11.0 to 14.0. Preferably the high pH buffering material comprises a silicate material.

Without being bound by any particular interpretation or theory, Applicants have hypothesised that the advantages of using a deflocculating polymer in combination with a structurant can be explained as follows.

Often, liquid detergent composition comprising active materials dispersed in an aqueous phase containing dissolved electrolyte are unstable and/or highly viscous due to flocculation of the dispersed phase. By adding a deflocculating polymer to such a system, flocculation may be reduced, resulting in an improved viscosity and/or stability. Sometimes, however, the use of deflocculation polymers alone is not sufficient to obtain a fully stable composition. In particular, sometimes the deflocculated detergent structure of dispersed lamellar droplets in an aqueous continuous phase will be too weak to provide long term physical stability and/or sufficient solid suspending properties. By using a structurant in combination with a deflocculating polymer an external structure is formed which provides stability to the weak deflocculated dispersion.

Therefore, preferred compositions of the present invention contain a dispersion of lamellar droplets of detergent active material in an aqueous continuous phase. More preferably said compositions are also externally structured, whereby the composition comprises a deflocculating polymer and a structurant and whereby the corresponding composition minus the structurant is less stable and/or has reduced solid suspending properties.

Applicants have hypothesised that the advantages of using silicates in combination with deflocculating polymers can be explained as follows.

When compositions of the invention contain a silicate material, it is believed that at pH values below a certain value (hereafter referred to as the critical pH value) , the silicate acts both as a buffering material and as a structurant in accordance with the mechanism as described hereabove.

At pH values above the critical value the structurant function of the silicate will be less pronounced and the main functions of the silicate will be to buffer the system and to provide an electrolyte effect. The electrolyte effect is caused by the solubilisation of the silicate, whereby the ionic strength of the aqueous phase is increased. The combination of silicate and deflocculating polymers will then provide the desired product properties as the electrolyte will promote the formation of a suitable lamellar droplet phase structure and the deflocculating polymer will reduce the flocculation via the mechanism as described hereinbelow.

It is believed that the critical pH at which the function of the silicate may change is dependant on the type of silicate that will be used. For sodium silicates, it is believed that the critical pH value is between about 11 and 12, generally about 11.5.

The deflocculating polymer

Suitable deflocculating polymers for use in compositions of the present invention are for instance described in our copending European patent application 89201530.6. Polymers as described in this document have a hydrophilic backbone and at least one hydrophobic side chain. Generally the hydrophilic backbone of the polymer is predominantly linear (the main chain of the backbone constitutes at least 50 %, preferably more than 75 %, most preferred more than 90% by weight of the backbone) , suitable monomer constituents of the hydrophilic backbone are for example unsaturated C -_β acids, ethers, alcohols, aldehydes, ketones or esters, sugar units, alkoxy units, aleic anhydride and saturated polyalcohols such as glycerol. Examples of suitable monomer units are acrylic acid, methacrylic acid, maleic acid, vinyl acetic acid, glucosides, ethylene oxide and glycerol. The hydrophilic backbone made from the backbone constituents in the absence of hydrophobic side-groups is relatively water-soluble at ambient temperature and a pH of between 6.5 and 14.0. Preferably the solubility is more than 1 g/1, more preferred more than 5 g/1 most preferred more than 10 g/1.

Preferably the hydrophobic sidegroups are composed of relatively hydrophobic alkoxy groups for example butylene oxide and/or propylene oxide and/or alkyl or alkenyl chains having from 5 to 24 carbon atoms. The hydrophobic groups may be connected to the hydrophilic backbone via relatively hydrophilic bonds for example a poly ethoxy linkage. Preferred polymers are of the formula:

wherein:

Q² is a molecular entity of formula (la) :

wherein:

R¹ represents -C0-0-, -0-, -0-C0-, -CH₂-, -CO-NH- or is absent;

R² represents from 1 to 50 independently selected alkyleneoxy groups preferably ethylene oxide or propylene oxide groups, or is absent , provided that when R³ is absent and R⁴ represents hydrogen or contains no more than 4 carbon atoms, then R² must contain an alkyleneoxy group preferably more than 5 alkyleneoxy groups with at least 3 carbon atoms;

R³ represents a phenylene linkage, or is absent;

R⁴ represents hydrogen or a C₁_₂₄ alkyl or C₂_₂₄ alkenyl group, with the provisos that a) when R¹ represents -O-CO-, R² and R³ must be absent and R⁴ must contain at least 5 carbon atoms; b) when R² is absent, R⁴ is not hydrogen and when also R³ is absent, then R⁴ must contain at least 5 carbon atoms;

R⁵ represents hydrogen or a group of formula -COOA⁴;

R⁶ represents hydrogen or Ci_4 alkyl; and

A¹, A², A³ and A⁴ are independently selected from hydrogen, alkali metals, alkaline earth metals, ammonium and amine bases and C₁_₄, or (C₂H4θ)tH wherein t is from 1-50, and wherein the monomer units may be in random order.

Q¹ is a multifunctional monomer, allowing the branching of the polymer, wherein the monomers of the polymer may be connected to Q¹ in any direction, in any order, therewith possibly resulting in a branched polymer.

Preferably Q¹ is trimethyl propane triacrylate (TMPTA) , ethylene bisacrylamide or divinyl glycol.

z and v are 1; n is at least 1; (x + y + p + q + r) : z is from 4 : 1 to 1,000 : 1, preferably from 6 : 1 to 250 : 1; in which the monomer units may be in random order; and preferably p and q are zero and/or r is zero; most preferably p, q, y and r are zero.

R⁷ and R⁸ represent -CH₃ or -H;

R⁹ and R¹⁰ represent substituent groups such as amino, amine, amide, sulphonate, sulphate, phosphonate, phosphate, hydroxy, carboxyl and oxide groups, preferably they are selected from -S0₃Na, -CO-O-C₂ ^H4~ OS0₃Na, -CO-0-NH-C(CH₃)₂-S0₃Na, -CO-NH₂, -0-CO-CH₃, -OH;

Preferably polymers for use in compositions of the invention which are of relatively high pH (say 10 or more) are substantially free of hydrolysable groups such as carbonyl groups for increased polymer stability at high pH values. Particularly preferred polymers for use in high pH compositions of the invention comprise hydrophilic backbones constituted by acid groups such as acrylic acid and at least one hydrophobic side chain which is constituted of from 5 to 75 relatively water- insoluble alkoxy groups such as propoxy units optionally linked to the hydrophylic backbone via an poly-alkoxy linkage constituted of from 1-10 relatively watersoluble alkoxy groups such as ethoxy units.

Other preferred polymers for use in compositions of the invention are described in our copending British patent applications 8924479.2, 8924478.4 and 8924477.6. Of the polymers described in those patent applications, especially the use of polymers in accordance with GB patent application 8924478.4 is preferred. These polymers are constituted of nonionic monomers and ionic monomers, wherein the ionic monomer is from 0.1 to 50 % by weight of the polymer. Especially preferred polymers of this type are of the formula:

wherein: x, z and n are as above;

R³ and R⁴ represent hydrogen or C-_j^ alkyl;

R² represents -CO-0-, -0-, -0-CO-,

-CH₂-, -CO-NH-, or is absent;

R¹ represents -C₃H₆-N⁺-(CH₃)₃(Cl") ,

-C₂H₄-OS0₃-(Na⁺), -S0₃"(Na⁺),

-C₂H₄ N⁺(CH₃)₂ Cl", -C₂H₄ N+ (C₂H₆)₂ Cl^",

-CH₂ N⁺ (CH₃)₂ Cl", -CH₂ N+ (C₂H₆)₂ Cl" or benzyl-S0₃" (Na⁺) ; R^a is CH₂, C2H , C₃Hg or is absent; R^b represents form 1 to 50 independently selected alkylene oxide groups, preferably ethylene oxide groups or is absent; R^c represents -OH or -H; and wherein if R²,R^a and R^b are absent, then R^c is not -H. Other preferred polymers have the formula:

(HI)

Wherein:

- x = X! + x₂

- x,z and n are as defined above

- R¹ represents -CH₂0- or -0-;

- R² represents -CH₂COO^"Na+ or -C₃H₆ON⁺(CH₃)₃C1~ - R³ and R⁴ represents -OH, CH₂OH, -0(C₃H₆0)_p-H,

-CH₂-0(C₃H₆0)_p-H or -OCH₂C0O~Na⁺ or -0-C₃H₆ON+(CH₃)₃Cl-

- R⁵ represents -OH, -NH-COr-CH₃ or -0(C₃H₆0)_p-H

- R⁶ represents -OH,-CH₂OH, -CH₂-OCH₃, -0(C₃H₆0)_p-H or -CH₂-0-(C₃H₆0)_p-H

- p is from 1 - 10.

Preferably polymers for use in compositions have a molecular weight (as determined as in our co-pending european patent application 89201530.6) of between 500 and 100,000, more preferred from 1,000 to 20,000, especially preferred from 1,500 to 10,000 most preferred from 2,800 to 6,000. Polymers for use in compositions of the invention may for example be prepared by using conventional aqueous polymerisation procedures, suitable methods are for example described in the above mentioned co-pending european patent application.

Generally the deflocculating polymer will be used at from 0.01 to 5 % by weight of the composition, more preferably from 0.1 to 3.0, especially preferred from 0.25 to 2.0 %.

Without being bound by any particular interpretation or theory, the Applicants have hypothesised that the deflocculating polymers exert their action on the composition by the following mechanism. The hydrophobic side-chain(s) or ionic groups could be incorporated in or onto the outer bi-layer of the droplets, leaving the hydrophilic or nonionic backbone over the outside of the droplets and/or the polymers could be incorporated deeper inside the droplet.

When the hydrophobic or side chains or ionic groups are mainly incorporated in or onto the outer bilayer of the droplets, this has the effect of decoupling the inter- and intra-droplet forces i.e. the difference between the forces between individual surfactant molecules in adjacent layers within a particular droplet and those between surfactant molecules in adjacent droplets could become accentuated in that the forces between adjacent droplets are reduced. This will generally result in an increased stability due to less flocculation and a decrease in viscosity due to smaller forces between the droplets resulting in greater distances between adjacent droplets.

When the polymers are incorporated deeper inside the droplets also less flocculation will occur, resulting in an increase in stability. The influence of these polymers within the droplets on the viscosity is governed by two opposite effects : firstly the presence of deflocculating polymers will decrease the forces between adjacent droplets resulting in greater distances between the droplets, generally resulting in a lower viscosity of the system; secondly the forces between the layers within the droplets are equally reduced by the presence of the polymers in the droplet, this generally result in an increase in the layer thickness, therewith increasing the lamellar volume of the droplets, therewith increasing the viscosity. The net effect of these two opposite effects may result in either a decrease or an increase in the viscosity of the product.

Suitable external structurants can be any materials capable of providing secondary structuring to the compositions of the invention. Suitable structurants include for example structuring or thickening polymeric ingredients such as water-swellable polymers and/or organic colloids, or filamentary soap crystals or cellulose. Examples of these materials are the water- soluble polymers of acrylic acid, cross-linked with about 1 % of a poly-allyl ether of sucrose having an average of about 5.8 allyl groups for each sucrose molecule, the polymer having a molecular weight in excess of 1,000,000. Well-known structurants of this type are marketed under the trade-names CARBOPOL 934,

940 and 041. The level of Carbopol-type structurants is preferably from 0.05-5% by weight of the composition, more preferred from 0.1 to 2.0%. Other suitable structurants are clay materials.

Suitable structuring clays include low, medium or high swelling clays. Preferred clay materials for use in compositions of the invention are montmorrilonite clays, more preferably bentonite clays, especially preferred white bentonite clays. The level of clay materials is preferably from 0.1 to 20% by weight of the composition, more preferred from 0.3 to 10%.

Also mixtures of structurants may be used.

For compostions of the invention it is preferred that at least part of the external structurants are silicate structurants. For obtaining the structuring effect of the silicate it is preferred that the pH of the composition if below the critical pH value for the silicate used, more preferred at least 0.5 pH unit below this pH. Especially preferred pH values for obtaining a silicate structuring effect are below 11.5, more preferred less than 11.0. As described hereabove silicates may also advantageously included for obtaining high pH buffering.

Preferably sodium silicates are used. Other suitable silicates include potassium silicates. For example ortho-, meta-, di- and tri-silicates or mixtures thereof may be used. Depending on the pH of the composition, silicates may react with alkali metal hydroxides and be converted to more acid or alkaline versions. Especially preferred is the use of silicates wherein the molar ratio of Na₂0 to Si0₂ is between 1 : 1.6 and 1 : 3.9, more preferably from 1 : 1.65 to 1 : 3, most preferably from 1 : 1.7 to 1 : 2.5. Particularly preferred silicates are di-silicates.

The amount of silicate is preferably from 0.1 to 20 % by weight, more preferably from 1 to 15 %, most preferably from 2 to 13. These percentages preferably represent the amount of metasilicate corresponding to the silicate present in the composition. Especially preferably the silicates are used at pH's between 9 and 12.5. Especially advantageous is the use of silicate material in compositions of relatively high pH values say from 8- 13, more preferred from 9 to 12.5, most preferred from 10-12.0.

Additional advantages of using silicates may be that possibly they provide high foaming products having building properties, said products being suitable for pouring and quick dispersing.

Although compositions of the invention may be in the form of pastes or gels, preferred embodiments of the invention are liquid detergent compositions. Preferably a corresponding composition minus the structurant and/or the deflocculating polymer is less stable and/or has a higher viscosity and/or has decreased solid suspending properties.

Compositions of the invention preferably are physically stable.In the context of the present invention, physical stability for these systems can be defined in terms of the maximum separation compatible with most manufacturing and retail requirements. That is, the 'stable' compositions will yield no more 10 %, preferably no more than 5 %, most preferred no more than 2% by volume phase separation as evidenced by appearance of 2 or more separate phases when stored at 25°C for 21 days from the time of preparation. Especially preferred are compositions which do not yield any phase separation upon storage for 21 days at 25 °C.

Preferably compositions of the invention have solid suspending properties. Preferably less than 10 wt % of the suspended solids sediment within 21 days at 25 °C from the day of preparation, more preferably less than 5 %, especially preferably less than 2 %. Most preferably substantially no sedimentation takes place upon storage for three weeks at 25°C.

Compositions of the invention preferably have a viscosity of less than 5,000 mPas at 21 s-1, more preferred less than 4000 mPas, most preferred less than 3000 mPas, especially preferred between 100 and 1,000 mPas at 21 s-1.

Compositions of the invention also comprise detergent active materials, preferably at a level of from 1 to 70% by weight of the composition, more preferred a level of 5 to 60 % by weight, most preferred from 10 to 50 % by weight.

In the case of blends of surfactants, the precise proportions of each component which will result in the desired structures will depend on the type(s) and amount(s) of the electrolytes, as is the case with conventional structured liquids.

In the widest definition the detergent-active material in general, may comprise one or more surfactants, and may be selected from anionic, cationic, nonionic, zwitterionic and amphoteric species, and (provided mutually compatible) mixtures thereof. For example, they may be chosen from any of the classes, sub-classes and specific materials described in 'Surface Active Agents' Vol.I, by Schwartz & Perry, Interscience 1949 and 'Surface Active Agents' Vol.II by Schwartz, Perry & Berch (Interscience 1958) , in the current edition of "McCutcheon's Emulsifiers & Detergents" published by the McCutcheon division of Manufacturing Confectioners Company or in 'Tensid-Taschenbuch* , H.Stache, 2nd Edn. , Carl Hanser Verlag, Mϋnchen & Wien, 1981.

Suitable nonionic surfactants include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide, either alone or with propylene oxide. Specific nonionic detergent compounds are alkyl (Cg-C₁₈) primary or secondary linear or branched alcohols with ethylene oxide, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long-chain tertiary phospine oxides and dialkyl sulphoxides.

Preferably the level of nonionic surfactants is more than 1 % by weight of the composition, preferably.from 2.0 to 20.0% by weight of the composition.

Compositions of the present invention may contain synthetic anionic surfactant ingredients, which are preferably present in combination with the above mentioned nonionic materials. Suitable anionic surfactants are usually water-soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher (Cs-C^s) alcohols produced, for example, from tallow or coconut oil, sodium and potassium alkyl (Cg-C₂o) benzene sulphonates, particularly sodium linear secondary alkyl (Cιo" ιs) benzene sulphonates; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium coconut oil fatty monoglyceride sulphates and sulphonates; sodium and potassium salts of sulphuric acid esters of higher (Cg-C^g) fatty alcohol-alkylene oxide, particularly ethylene oxide, reaction products; the reaction products of fatty acids such as coconut fatty acids esterified with isethionic acid and neutralized with sodium hydroxide; sodium and potassium salts of fatty acid amides of methyl taurine; alkane monosulphonates such as those derived by reacting alpha-olefins (Cg- ø) with sodium bisulphite and those derived from reacting paraffins with S0₂ and Cl₂ and then hydrolyzing with a base to produce a random sulphonate; and olefin sulphonates, which term is used to describe the material made by reacting olefins, particularly C₁₀-C₂₀ alpha-olefins, with S0₃ and then neutralizing and hydrolyzing the reaction product. The preferred anionic detergent compounds are sodium (C -.-C 5) alkyl benzene sulphonates and sodium (Ci₆-C₁₈) alkyl sulphates.

Generally the level of the above mentioned non-soap anionic surfactant materials is from 1-40 % by weight of the composition.

Preferred compositions according to the present invention are anionic rich, preferably the weight ratio of synthetic anionic surfactants to nonionic surfactants is from 10 : 1 to 1 : 10, more preferred from 8:1 to 1:2, most preferred from 6 : 1 to 1 :1.

It is also possible, and sometimes preferred, to include an alkali metal soap of a mono- or di-carboxylic acid, especially a soap of an acid having from 12 to 18 carbon atoms, for example oleic acid, ricinoleic acid, and fatty acids derived from castor oil, rapeseed oil, groundnut oil,coconut oil, palmkernel oil, alk(en)yl succinates e.g. dodecyl succinate or mixtures thereof. The sodium or potassium soaps of these acids can be used. Preferably the level of soap in compositions of the invention is from 1-40 % by weight of the composition, more preferred from 5-25 %.

Also possible is the use of salting out resistant active materials such as for example described in EP 328 177, especially the use of alkyl poly glycoside surfactants such as for example disclosed in EP 70 074. Also alkyl mono glucosides may be used.

The compositions optionally also contain electrolyte in an amount sufficient to bring about lamellar structuring of the detergent-active material. Preferably the compositions contain from 1% to 60%, especially from 10 to 45% of a salting-out electrolyte. Salting-out electrolyte has the meaning ascribed to in specification EP-A-79 646, that is salting-out electrolytes have a lyotropic number of less than 9.5. Optionally, some salting-in electrolyte (as defined in the latter specification) may also be included.

In any event, it is preferred that compositions according to the present invention include detergency builder material, some or all of which may be electrolyte. In this context it should be noted that some detergent active materials such as for example soaps, also have builder properties. Preferably compositions of the invention comprise suspended particles of solid material, all or part of which may be builder material.

Examples of phosphorous-containing inorganic detergency builders include the water-soluble salts, especially alkali metalpyrophosphates, orthophosphates, polyphosphates and phosphonates. Specific examples of inorganic phosphate builders include sodium and potassium tripolyphosphates, phosphates and hexametaphosphates. Phosphonate sequestrant builders may also be used. Sometimes it is however preferred to minimise the amount of phosphate builders.

Examples of non-phosphorus-containing inorganic detergency builders, when present, include water-soluble alkali metal carbonates, bicarbonates, silicates and crystalline and amorphous aluminosilicates. Specific examples include sodium carbonate (with or without calcite seeds) , potassium carbonate, sodium and potassium bicarbonates, silicates and zeolites.

As described above especially preferred if the use of silicate materials in compositions of the invention. These builders are able to buffer the composition at relatively high pH values. Furthermore silicates have been found to be useful structurants at certain pH values. Applicants believe that this structuring effect may be explained by the polymerisation of the silicate builder materials, whereby a structuring network is formed, which provides increased stabiltiy and/or viscosity and/or solid suspending properties to compositions of the invention. The presence of such a network may be detected with NMR.

Most preferably silicate materials are used in combination with other builder materials. Especially advantageous is the combined use of silicates with builders, which -at least partially- are present as suspended particles of solid material.

Examples of organic detergency builders, when present, include the alkaline metal, ammonium and substituted ammonium polyacetates, carboxylates, polycarboxylates, polyacetyl carboxylates and polyhydroxysulphonates. Specific examples include sodium, potassium, lithium, ammonium and substituted ammonium salts of ethylenediaminetetraacetic acid, nitrilitriacetic acid, oxydisuccinic acid, melitic acid, benzene polycarboxylie acids, CMOS, tartrate mono succinate, tartrate di succinate and citric acid.

In the context of organic builders, it is also possible to incorporate polymers which are only partly dissolved, in the aqueous continuous phase as described in EP 301.882. This allows a viscosity reduction (due to the polymer which is dissolved) whilst incorporating a sufficiently high amount to achieve a secondary benefit, especially building, because the part which is not dissolved does not bring about the instability that would occur if substantially all were dissolved. Typical amounts are from 0.5 to 4.5% by weight.

It is further possible to include in the compositions of the present invention, alternatively, or in addition to the partly dissolved polymer, yet another polymer which is substantially totally soluble in the aqueous phase and has an electrolyte resistance of more than 5 grams sodium nitrilotriacetate in 100ml of a 5% by weight aqueous solution of the polymer, said second polymer also having a vapour pressure in 20% aqueous solution, equal to or less than the vapour pressure of a reference 2% by weight or greater aqueous solution of polyethylene glycol having an average molecular weight of 6000; said second polymer having a molecular weight of at least 1000. Use of such polymers is generally described in our EP 301,883. Typical levels are from 0.5 to 4.5% by weight.

Preferably the level of non-soap builder material is from 5-50 % by weight of the composition, more preferred from 5 to 35 % by weight of the composition.

Apart from the ingredients already mentioned, a number of optional ingredients may also be present, for example lather boosters such as alkanolamides, particularly the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids, lather depressants, oxygen-releasing bleaching agents such as sodium perborate and sodium percarbonate, peracid bleach precursors, chlorine-releasing bleaching agents such as trichloroisocyanuric acid, inorganic salts such as sodium sulphate, and, usually present in very minor amounts, fluorescent agents, perfumes, enzymes such as proteases, amylases and lipases (including Lipolase (Trade Mark) ex Novo) , anti-redeposition agents, germicides and colourants.

The level of water is preferably from 10-90% by weight, more preferably 15-70%, most preferably 20-50%. Compositions of the invention may be prepared by any conventional method for the preparation of liquid detergent compositions. A preferred method involves the dispersing of the electrolyte ingredient together with the minor ingredients except for the temperature sensitive ingredients -if any- in water of elevated temperature, followed by the addition of the builder material- if any-, the detergent active material (optionally as a premix) under stirring and thereafter cooling the mixture and adding any temperature sensitive minor ingredients such as enzymes perfumes etc. The deflocculating polymer may advantageously be added after the electrolyte ingredients, the builder ingredients or just before cooling.

In use the detergent compositions of the invention will be diluted with wash water to form a wash liquor for instance for use in a washing machine. The concentration of liquid detergent composition in the wash liquor is preferably from 0.1 to 10 %, more preferred from 0.1 to 3% by weight. The invention will now be illustrated by way of the following Examples.

EXAMPLE I

The following compositions were prepared by adding the electrolyte ingredients except for the silicate KOH to the water under stirring followed by addition of the polymer, the silicates the detergent active ingredients and the remaining ingredients.

INGREDIENT %(wt) Water

SCMC

Fluorescer¹)

STP

KOH deflocculating polymer²) silicate³)

LAS-acid

Dobanol 91.6

Perfume

¹)Tinopal CBS-X

²)polymer A-ll as described in EP 89201530.6.

(deflocculating polymer of formula I, wherein q, p and r are 0, v=l, x=25, y=0, R¹ is - CO - O -, R² is absent R³ is absent, R⁴ is - C₁₂H₂₅, R⁵ is -H, R⁶ is - CH₃ and A¹ is Na. The molecular weight of the polymer is about 3.5 K) . ³)sodium disilicate (ex Crossfields)

Both compositions had a pH of 11.5. Composition A had a viscosity of 400 mPas at 21s-l, composition B had a viscosity of 1,050 at 21s-l. Both compositions did not show any phase separation upon storage for 3 months at 25 °C.

The corresponding composition minus the deflocculating polymer was too viscous to be pourable. EXAMPLE 2

The following composition was made substantially as in example I.

INGREDIENT % (Wt C

The composition had a viscosity of 200 mPas at 21 s-1 and was physically stable for at least 3 months at 25 °C.

The corresponding composition minus the deflocculating polymer had an unacceptable high viscosity.

EXAMPLE III

The following compostion was prepared substantially as in example I.

INGREDIENT %fwtϊ

The composition had a pH of 11.5 and a viscosity of 600 mPas at 21 s"¹ and was fully stable for a period of 3 months ar 25 °C. The corresponding composition minus the deflocculating polymer was highly viscous and not pourable.

Claims

1. A structured aqueous detergent composition comprising detergent active material and an aqueous medium optionally containing dissolved electrolyte material, said composition comprising a deflocculating polymer and a structurant.

2. A structured aqueous detergent composition comprising detergent active material and an aqueous medium optionally containing dissolved electrolyte material, said composition comprising a deflocculating polymer and a high pH buffering material.