WO1995002390A1

WO1995002390A1 - Surfactant system

Info

Publication number: WO1995002390A1
Application number: PCT/US1994/006943
Authority: WO
Inventors: Suzanne Powell
Original assignee: The Procter & Gamble Company
Priority date: 1993-07-12
Filing date: 1994-06-17
Publication date: 1995-01-26
Also published as: EP0708633A1; EP0708633A4; CA2166861A1; BR9407020A; AU7062494A; JPH09500409A

Abstract

According to one aspect of the present invention there is provided an anionic surfactant system containing: (a) alkyl sulfate surfactant derived from natural sources comprising a mixture of alkyl chain lengths wherein the weight distribution of the alkyl chain lengths is such that less than 20 % by weight of the alkyl chain lengths are C12, from 30 % to 80 % by weight of the alkyl chain lengths are C14, from 30 % to 50 % by weight of the alkyl chain lengths are C16 and less than 10 % by weight of the alkyl chain lengths are C18. Said anionic surfactant system preferably also contains alkyl ethoxysulfate surfactant. Said alkyl ethoxysulfate surfactant is preferably a water soluble C12-C18 alkyl ethoxysulfate salt containing an average of from 1 to 7 ethoxy groups per mole derived from the condensation product of a C12-C18 alcohol wherein said C12-C18 alcohol is most preferably derived from a natural source.

Description

SURFACTANT SYSTEM

This invention relates to a surfactant system derived from natural sources for incorporation into detergent compositions suitable for use in cleaning processes, especially fabric cleaning and more especially to high density granular detergent compositions comprising said surfactant system.

Granular detergent com ^sitions containing synthetic detergents, particularly linear alkyl benzene sulfonate salts are well known in the art and are in widespread commercial use. Conventionally the linear alkyl benzene sulfonate salt forms part of a surfactant mixture in association with one or more other anionic or nonionic surfactants.

Current environmental concern has focussed on the undesirability of deriving detergent components from non-renewable hydrocarbon sources. Interest has therefore increased in the formulation of well-performing detergent compositions comprising surfactant systems derived from natural sources.

An example of an anionic surfactant which is readily biodegradable and which could replace the alkyl benzene sulfonate component either partially or in toto is alkyl sulfate surfactant.

Detergent compositions including alkyl sulfate surfactant derived from naturally occuring fats and oils are known in the art. For example, GB- A-l, 399,966, in the name of the Procter & Gamble Company, discloses a detergent composition containing alkyl sulfate surfactant derived from tallow oil, or from coconut oil. Natural oils and fats provide feedstock material encompassing a range of alkyl chain lengths. The alkyl chains are predominantly linear, in contrast to the branched nature of feedstock obtained from synthetic sources. For example, tallow fat contains a high proportion (typically about 70%) of Ci8 alkyl chains. Coconut and palm oil on the other hand contain a high proportion of Cj2 alkyl chains (typically about 55%) and lesser proportions of C14, C and C18 alkyl chain lengths.

The detergency performance characteristics of surfactants having alkyl chains are known to depend on the nature and length of the alkyl chain. In general, surfactants having shorter alkyl chains are more hydrophillic, hence more water soluble, and thus tend to perform better at lower wash temperatures. Those with longer alkyl chains conversely tend to perform well at higher wash temperatures. The formulator of a natural surfactant system is hence faced with the problem of how to formulate a surfactant system which provides good detergency over a wide range of wash temperatures derived from feedstock material, which as provided by nature, contains a non-optimum distribution of alkyl chain lengths for this purpose.

EP-A-342,917 describes a surfactant system, derived preferably from natural feedstock material, comprising an anionic surfactant the major ingredient of which is an alkyl sulfate of mixed alkyl chain length such that at least 10% by weight of the alkyl chains present in the alkyl sulfate are C 12 chains and at least 20% by weight of the alkyl chains are Cig chains.

The Applicants have found that a surfactant system containing alkyl sulfate surfactant of mixed alkyl chain length such that the level of C12 and Ci8 alkyl chain lengths is minimised, and wherein the C14 and C16 alkyl chain lengths form the major part, provides good detergency performance over a wide range of temperatures.

The Applicants have also found that when formulated with an alkyl ethoxysulfate cosurfactant, and preferably a nonionic surfactant, such a surfactant system provides good detergency in the presence of cationic fabric softener compounds even when the total level of anionic surfactant in the composition is at a low level, namely from 5% to 10% by weight of the composition.

According to one aspect of the present invention there is provided surfactant system containing

(a) alkyl sulfate surfactant derived from natural sources comprising a mixture of alkyl chain lengths wherein the weight distribution of the alkyl chain lengths is such that less than 20% by weight of the alkyl chain lengths are C \2. from 30% to 80% by weight of the alkyl chain lengths are C 14, from 30% to 50% by weight of the alkyl chain lengths are C16 and less than 10% by weight of the alkyl chain lengths are Cis.

Said anionic surfactant system preferably also contains alkyl ethoxysulfate surfactant. Said alkyl ethoxysulfate surfactant is preferably a water soluble C12-C18 alkyl ethoxysulfate salt containing an average of from 1 to 7 ethoxy groups per mole derived from the condensation product of a C12-C18 alcohol wherein said C12-C18 alcohol is most preferably derived from a natural source.

To provide good dissolution characteristics for the alkyl sulfate surfactant and provide robust performance in the presence of cationic fabric softener components in the wash it is highly preferably that where present in said surfactant system the alkyl ethoxysulfate surfactant is most preferably in intimate admixture with the alkyl sulfate surfactant. The weight ratio of the alkyl sulfate surfactant to the alkyl ethoxysulfate surfactant is preferably from 2:1 to 19:1.

Most preferably said surfactant system is essentially free of alkyl benzene sulfonate.

The total level of alkyl sulfate and alkyl ethoxysulfate surfactant in the granular detergent composition is preferably from 5% to 10% by weight of the composition, more preferably from 6% to 9% by weight of the composition and most preferably from 6.5% to 8% by weight of the composition. Said granular detergent composition provides good detergency performance even when used in wash solutions where cationic fabric softener components are present. Examples of cationic fabric softener components include the well known quaternary ammonium compounds. Cationic fabric softeners are disclosed for example in EP-A- 0125,122, and co-pending European Application 91-202881.8 which discloses water-soluble quaternary ammonium compounds.

It is an essential aspect of the invention that the alkyl sulfate surfactant is derived from natural sources. By derived from natural sources it is meant herein that the alkyl chain portion of the surfactant is derived from naturally occuring fats and oil. Alkyl chains derived from such natural oils and fats are typically linear and have alkyl chains with even numbers of carbon atoms, most typically C12, C14, Ci6 and Ci8- The alkyl chains may contain a small proportion of unsaturated, e.g. : alkenyl, chains which if desired may be hydrogenated, or "hardened" to minimize these impurity levels. Typically the alkyl sulfate surfactant is produced from alcohols obtained by reduction of the natural oils and fats. Examples of natural oils and fats include those derived from coconut, babassu, palm kernel, beef tallow, kapok, olive, peanut, sesame and teaseed.

It is also an essential aspect of the present invention that the alkyl sulfate surfactant comprises a mixture of alkyl chain lengths. It is preferred that the level of C12 and Ci8 alkyl chain lengths is minimized and that the major proportion of the alkyl sulfate surfactant comprises C14 and Ci6 alkyl chain lengths. More particularly the alkyl sulfate surfactant comprises such surfactant with a mixture of alkyl chain lengths wherein the weight distribution of the alkyl chain lengths is such that less than 20%, most preferably less than 15% of the alkyl chains are C 12, from 30% to 80%, preferably from 35% to 70%, most preferably from 40% to 60% of the alkyl chains are C 14, from 30% to 50%, preferably from 30% to 40%, most preferably from 32% to 38% of the alkyl chains are Ci6, less than 10%, preferably less than 5%, most preferably less than 3% of the alkyl chains are Ci8-

Alkyl sulfate surfactant of the desired alkyl chain length distribution is obtained from natural feedstock, meaning natural oils or fats, or any mixtures thereof, or the natural alcohols derived therefrom, by any suitable physical process which allows for the separation of such feedstock into different components with the desired alkyl chain length distributions. Suitable physical processes would include, for example, distillation processes. The separation of feedstock material into different components of desired composition is often referred to in the industry as "cutting" of the feedstock (into desired "cuts"). The different components (or cuts) may then be used as such, or blended, as appropriate to allow for derivation of the alkyl sulfate surfactant with the desired alkyl chain length distribution in accord with the invention.

In a preferred execution of the invention the surfactant system also contains alkyl ethoxysulfate surfactant, preferably C12-C18 alkyl ethoxysulfate surfactant containing an average of from 1 to 7 moles ethylene oxide per mole derived from the condensaion product of a C 12- Ci8 alcohol wherein said C12-C18 alcohol is most preferably derived from natural sources. Examples of naturally occurring materials from which the alcohols can be derived are coconut oil and palm kernel oil and the corresponding fatty acids. Preferred are C12-C14 alkyl ethoxysulfate salts with an average of from one to five ethoxy groups per mole, and most preferably with an average of from one to three ethoxy groups per mole.

The weight ratio of the alkyl sulfate surfactant to the alkyl ethoxysulfate surfactant is preferably from 2:1 to 19:1 more preferably from 3:1 to 12: 1 and most preferably from 3.5:1 to 10:1.

It is preferred that the alkyl sulfate surfactant and the alkyl ethoxysulfate surfactant are in intimate admixture. Where incorporated in a particulate composition they should be mixed prior to the formation of any particulate component of which they may form a part. In the case of a spray dried granule, this mixing can take place in the slurried mixture fed to the spray drying equipment. Where another type of granule is formed an intimate mixture of the surfactants should be made before agglomeration, milling, flaking, prilling or any other particulate forming process takes place. The surfactant system of the invention may contain as non-essential components other anionic surfactant components including alkane sulfonate and alkyl ester sulfonate surfactants.

Use of alkane sulfonate salts as anionic surfactants is well known in the art, being disclosed for example in US Patent 3 929 678. Aliphatic alkane sulfonate salts may be obtained from the reaction of an aliphatic hydrocarbon, which may include the iso-, neo-, meso- and n-paraffms, having 12 to 24 carbon atoms and a sulfonating agent which may for example be SO3, H2SO4 or oleum the reaction being carried out according to known sulfonation methods, including bleaching and hydrolysis. In accord with the present invention the aliphatic C12-C20 alkane sulfonate salts are preferred with the aliphatic C14-C20 alkane sulfonate salts being most preferred. Preferred as cations are the alkali metal and ammonium cations.

Alkyl ester sulfonate surfactants hereof include linear esters of C12-C20 carboxylic acids (ie. fatty acids) which are sulfonated with gaseous SO3 according to "The Journal of the American Oil Chemists Society," 52 (1975), pp. 323-329. Suitable starting materials include natural fatty substances as derived from tallow, palm oil, etc.

The preferred alkyl ester sulfonate surfactants in accord with the invention comprise methyl ester sulfonate surfactants of the structural formula:

O

R3— CH— C — OR i S03M

wherein R3 is a C12-C20 alkyl, R4 is methyl and M is a cation which forms a salt with the methyl ester sulfonate. Suitable salt-forming cations include metals such as sodium, potassium, and lithium, and substituted or unsubstituted ammonium cations, such as monoethanolamine, diethanolamine, and triethanolamine. Most preferably, R3 is C14-C20 alkyl. The surfactant system of the invention is desirably incorporated as part of a detergent or cleaning composition for use in, for example, laundry, manual and automatic dishwashing, and hard-surface cleaner applications. The level of incorporation of the surfactant system, and of any further ingredients, will depend upon the nature of the detergent or cleaning composition, and in particular its de .ired application.

The compositions may in addition comprise in general terms those ingred ients commonly found in detergent products which may inc lude organic surfactants, detergent builders, anti-redeposition and soil suspension agents, suds suppressors, enzymes, optical brighteners, photoactivated bleaches, perfumes, filler salts, anti-corrosion agents and colours.

Laundry detergent compositions may also comprise fabric softening and antistatic agents.

The surfactant system of the invention may include as a preferred additional component a nonionic surfactant. Preferably the nonionic surfactant is incorporated such that the weight ratio of nonionic surfactant to anionic surfactant is from 1:4 to 4:1, preferably 1 :2 to 2: 1.

In one preferred aspect of the invention the surfactant system of the invention is incorporated within a laundry detergent composition at a level of from 3 % to 50% by weight, preferably from 5% to 30%, most preferably from 7% to 15% by weight of the detergent composition.

Machine dishwashing detergent compostions incorporating the anionic surfactant system of the invention comprise from 0.5% to 10% by weight, preferably from 1 % to 10% by weight, most preferably from 1 % to 5% of the surfactant system by weight of the invention. Preferably said machine dishwashing compositions also contain a nonionic surfactant system. Most preferred are low-foaming nonionic surfactants, especially the water soluble ethoxy leted C6-C]_.6 fatty alcohols and C6-C16 mixed ethoxy lated/propoxylated fatty alcohols and mixtures thereof. Preferably, the ethoxylated fatty alcohols are the C10-C16 ethoxylated fatty alcohols with a degree of ethoxylation of from 5 to 50, most preferably these are C12-C16 ethoxylated fatty alcohols with a degree of ethoxylation from 8 to 40. Preferably the mixed ethoxy lated/propoxylated fatty alcohols have an alkyl chain length of from 10 to 16 carbon atoms, a degree of ethoxylation of from 3 to 30 and a degree of propoxylation of from 1 to 10.

Suitable nonionic surfactants for incorporation as part of a nonionic surfactant system include polyhydroxy fatty acid amide surfactants, alcohol ethoxylate surfactants and alkyl polyglucoside surfactants.

Additionally detergent compositions in accord with the invention may optionally contain cationic, amphoteric, zwitterionic and semi-polar surfactants.

The polyhydroxy fatty acid amide surfactants in accord with the present invention comprise compounds of the structural formula:

O R5

R6- C — N — Z

wherein: R-5 is H, C1-C4 hydrocarbyl, 2-hydroxy ethyl, 2- hydroxypropyl, or a mixture thereof, preferably Ci or C2 alkyl, most preferably C1 alkyl (ie. methyl); and R6 is a C11-C31 hydrocarbyl, preferably straight chain C11-C19 alkyl, or alkanyl most preferably straight chain Cj6-Ci8 alkyl or alkenyl, or mixture thereof; and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxylated derivative (preferably ethoxylated or propoxylated) thereof. Z preferably will be derived from a reducing sugar in a reductive animation reaction; more preferably Z is a glycityl. Suitable reducing sugars include glucose, fructose, maltose, lactose, galactose, mannose, and xylose.

As raw materials, high dextrose com syrup, high fructose corn syrup, and high maltose com syrup can be utilised as well as the individual sugars listed above. These com syrups may yield a mix of sugar components for Z. It should be understood that it is by no means intended to exclude other suitable raw materials. Z preferably will be selected from the group consisting of -CH2-(CHOH)_n-CH₂OH, -CH(CH2θH)-(CHOH)_n_ι- CH₂OH, i-CH₂-(CHOH)2(CHOR')(CHOH)-CH2θH, where n is an integer from 3 to 5, inclusive, and R' is H or a cyclic or aliphatic monosaccharide, and alkoxylated derivatives thereof. Most preferred are glycityls wherein n is 4, particularly -CH2-(CHOH)4-CH2θH.

R-5 can be, for example, N-methyl, N-ethyl, N-propyl, N-isopropyl, N- butyl, N-2-hydroxy ethyl, or N-2-hydroxypropyl.

R6-CO-N < can be, for example, cocamide, stearamide, oleamide, lauramide, myristamide, capricamide, palmitamide, tallowamide, etc.

Z can be 1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl, 1- deoxylactityl, 1-deoxygalactityl, 1-deoxymannityl, 1-deoxymaltotriotityl, etc.

The most preferred polyhydroxy fatty acid amide has the general formula

R6—

CH2 (CHOH)4CH2θH

wherein R6 is a C11-C19 straight-chain alkyl or alkenyl group.

Methods for making polyhydroxy fatty acid amides are known in the art. In general, they can be made by reacting an alkyl amine with a reducing sugar in a reductive animation reaction to form a corresponding N-alkyl poly hydroxy amine, and then reacting the N-alkyl polyhdroxy amine with a fatty aliphatic ester or triglyceride in a condensation/amidation step to form the N-alkyl, N-polyhydroxy fatty acid amide product. Processes for making compositions containing polyhydroxy fatty acid amides are disclosed, for example, in GB Patent Specification 809 060 , published February 18, 1959, by Thomas Hedley & Co Ltd, US Patent 2 965 576, issued December 20, 1960 to E R Wilson, and US Patent 1 985 424, issued December 25, 1934 to Piggott, each of which is incorporated herein by reference. One class of nonionic surfactants useful in the present invention comprises condensates of ethylene oxide with a hydrophobic moiety, providing surfactants having an average hydrophilic-lipophilic balance (HLB) in the range from 8 to 17, preferably from 9.5 to 13.5, mere preferably from 10 to 12.5. The hydrophobic (lipophilic) moiety may be aliphatic or aromatic in nature and the length of the polyoxyethylene group which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired degree of balance between hydrophilic and hydrophobic elements.

Especially preferred additional nonionic surfactants of this type are the C12-C20 primary alcohol ethoxylates containing an average of from 3-11 moles of ethylene oxide per mole of alcohol, particularly the C12-C16 primary alcohol ethoxylates containing an average of from 3-7 moles of ethylene oxide per mole of alcohol and most preferably the C12-C16 primary alcohol ethoxylates containing an average of 3 moles of ethylene oxide per mole of alcohol.

Another class of nonionic surfactants comprises alkyl polyglucoside compounds of general formula

RO (C_nH_2nO)_tZ_x

wherein Z is a moiety derived from glucose; R is a saturated hydrophobic alkyl group that contains from 12 to 18 carbon atoms; t is from 0 to 10 and n is 2 or 3; x is from 1.3 to 4, the compounds including less than

10% unreacted fatty alcohol and less than 50% short chain alkyl polyglucosides. Compounds of this type and their use in detergent compositions are disclosed in EP-B 0 070074,

0 070 077, 0 075 996 and 0 094 118.

A further class of surfactants are the semi-polar surfactants such as amine oxides. Suitable amine oxides are selected from mono C8-C20. preferably C10-C14 N-alkyl or alkenyl amine oxides and propylene- 1,3- diamine dioxides wherein the remaining N positions are substituted by methyl, hydroxy ethyl or hydroxpropyl groups. Cationic surfactants can also be used in the detergent compositions herein and suitable quaternary ammonium surfactants are selected from mono ^c8^_Cl6> preferably C10-C14 N-alkyl or alkenyl ammonium surfactants wherein remaining N positions are substituted by methyl, hydroxy ethyl or hydroxypropyl groups.

Where formulated as a granular composition any particulate components may have any suitable physical form, i.e. it may take the form of flakes, prills, marumes, noodles, ribbons, or granules which may be spray-dried or non spray-dried agglomerates.

Another highly preferred component detergent or cleaning compositions in accord with the invention is a detergent builder system comprising one or more other detergent builders. These can include, but are not restricted to, phosphates, crystalline layered sodium silicates, carbonates borates, alkali metal aluminosilicates, monomeric polycarboxylates, homo or copolymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxylic radicals seperated from each other by not more than two carbon atoms, carbonates, silicates and mixtures of any of the foregoing.

The builder system is preferably present in the detergent or cleaning compositions in an amount from 1 % to 95 % by weight.

When the detergent composition is a laundry or machine dishwashing detergent composition the level of builder system is preferably from 1 % to 80% by weight, more preferably 20% to 70% by weight of the compostion.

Suitable silicates are those having an Siθ2:Na2θ ratio in the range from 1.6 to 3.4, the so-called amorphous silicates of Siθ2 : Na2θ ratios from 2.0 to 2.8 being employed where addition to the mixture of ingredients that are spray dried is required. Where aluminosilicates constitute an ingredient of the mixture to be spray dried, silicates should not be present in the mixture but can be incorporated in the form of an aqueous solution serving as an agglomerating agent for other solid components, or, where the silicates are themselves in particulate form, as solids to the other particulate components of the composition. However, for compositions in which the percentage of spray dried components is low i.e. 30%, it is preferred to include the amorphous silicate in the spray-dried components.

Whilst a range of aluminosilicate ion exchange materials can be used, preferred sodium aluminosilicate zeolites have the unit cell formula Na_z [(A102 ) z (Si0₂ )_y ] xH ₂0

wherein z and y are at least 6; the molar ratio of z to y is from 1.0 to 0.5 and x is at least 5, preferably from 7.5 to 276, more preferably from 10 to 264. The aluminosilicate materials are in hydrated form and are preferably crystalline, containing from 10% to 28%, more preferably from 18% to 22% water in bound form.

The above aluminosilicate ion exchange materials are further characterised by a particle size diameter of from 0.1 to 10 micrometers, preferably from 0.2 to 4 micrometers. The term "particle size diameter" herein represents the average particle size diameter of a given ion exchange material as determined by conventional analytical techniques such as, for example, microscopic determination utilizing a scanning electron microscope or by means of a laser granulometer. The aluminosilicate ion exchange materials are further characterised by their calcium ion exchange capacity, which is at least 200 mg equivalent of CaCθ3 water hardness/g of aluminosilicate, calculated on an anhydrous basis, and which generally is in the range of from 300 mg eq./g to 352 mg eq./g. The aluminosilicate ion exchange materials herein are still further characterised by their calcium ion exchange rate which is at least 130 mg equivalent of CaC03/litre/minute/(g/litre) [2 grains Ca+ +/ gallon/minute/gram/gallon)] of aluminosilicate (anhydrous basis), and which generally lies within the range of from 130 mg equivalent of CaC03/litre/minute/(gram/litre) [2 grains/gallon/minute/ (gram/gallon)] to 390 mg equivalent of CaCθ3/litre/minute/ (gram/litre) [6 grains/gallon/minute/(gram/gallon)], based on calcium ion hardness. Optimum aluminosilicates for builder purposes exhibit a calcium ion exchange rate of at least 260 mg equivalent of CaC03/litre/ minute/ (gram/litre) [4 grains/gallon/minute/(gram/gallon)].

Aluminosilicate ion exchange materials useful in the. practice of this invention are commercially available and can be naturally occurring materials, but are preferably synthetically derived. A method for producing aluminosilicate ion exchange materials is discussed in US Patent No. 3,985,669. Preferred synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite B, Zeolite X, Zeolite HS and mixtures thereof. In an especially preferred embodiment, the crystalline aluminosilicate ion exchange material is Zeolite A and has the formula

Na 12 [(A102 ) 12 (Si0₂)l2 ]• xH₂ O

wherein x is from 20 to 30, especially 27. Zeolite X of formula Na86 [(Alθ2)86(^Si°2)l06]- 276 H2O is also suitable, as well as Zeolite HS of formula Na6 [(Alθ2)6(Siθ2)6l 7.5 H2 O).

Suitable water-soluble monomeric or oligomeric carboxylate builders can be selected from a wide range of compounds but such compounds preferably have a first carboxyl logarithmic acidity /constant (pKi) of less than 9, preferably of between 2 and 8.5, more preferably of between 4 and 7.5.

The logarithmic acidity constant is defined by reference to the equilibrium

H+ + A- . ' H A where A" is the fully ionized carboxylate anion of the builder salt.

The equilibrium constant is therefore

Ki = (H A)

(H+) (A") and pKi = logioK.

For the purposes of this specification, acidity constants are defined at 25 °C and at zero ionic strength. Literature values are taken where possible (see Stability Constants of Metal-Ion Complexes, Special Publication No. 25, The Chemical Society, London): where doubt arises they are determined by potentiometric titration using a glass electrode.

Preferred carboxylates can also be defined in terms of their calcium ion stability constant (pKca+ +) defined, analogously to pKi, by the equations pKca+ + = loglθKCa+ +

where Kca+ + = (Ca+ + A)

(Ca+ +) (A)

Preferably, the polycarboxylate has a pK Ca- + ^m the range from about 2 to about 7 especially from about 3 to about 6. Once again literature values of stability constant are taken where possible. The stability constant is defined at 25 °C and at zero ionic strength using a glass electrode method of measurement as described in Complexation in Analytical Chemistry by Anders Ringbom (1963).

The carboxylate or polycarboxylate builder can be momomeric or oligomeric in type although monomeric polycarboxylates are generally preferred for reasons of cost and performance.

Monomeric and oligomeric builders can be selected from acyclic, alicyclic, heterocyclic and aromatic carboxylates having the general formulae

n

wherein Ri represents H,Cι_30 alkyl or alkenyl optionally substituted by hydroxy, carboxy, sulfo or phosphono groups or attached to a polyethylenoxy moiety containing up to 20 ethyleneoxy groups; R2 represents H,Cι_4 alkyl, alkenyl or hydroxy alkyl, or alkaryl, sulfo, or phosphono groups;

X represents a single bond; O; S; SO; SO2; or NRi;

Y represents H; carboxy;hydroxy; carboxy methyloxy; or

Cι_30 alkyl or alkenyl optionally substituted by hydroxy or carboxy groups;

Z represents H; or carboxy; m is an integer from 1 to 10; n is an integer from 3 to 6; p, q are integers from 0 to 6, p + q being from 1 to 6; and wherein, X, Y, and Z each have the same or different representations when repeated in a given molecular formula, and wherein at least one Y or Z in a molecule contain a carboxyl group.

Suitable carboxylates containing one carboxy group include lactic acid, glycolic acid and ether derivatives thereof as disclosed in Belgian Patent Nos. 831 368, 821 369 and 821 370.

Polycarboxylates containing two carboxy groups include the water-soluble salts of succinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid, diglycolic acid, tartaric acid, tartronic acid and fumaric acid, as well as the ether carboxylates described in German Offenlegenschrift 2 446 686, and 2 446 687 and US Patent No.

3 935 257 and the sulfmyl carboxylates described in Belgian Patent No. 840 623. Polycarboxylates containing three carboxy groups include, in particular, water-soluble citrates, aconitrates and citraconates as well as succinate derivatives such as the carboxymethyloxysuccinates described in British Patent No. 1 379 241, lactoxysuccinates described in British Patent No. 1 389 732, and aminosuccinates described in Netherlands Application 7 205 873, and the oxypolycarboxylate materials such as 2-oxa- 1,1,3- propane tricarboxylates described in British Patent No. 1 387 447.

Polycarboxylates containing four carboxy groups include oxydisuccinates disclosed in British Patent No. 1 261 829, 1,1,2,2-ethane tetracarboxylates, 1,1,3,3-propane tetracarboxylates and 1,1,2,3-propane tetracarboxylates. Polycarboxylates containing sulfo substituents include the sulfosuccinate derivatives disclosed in British Patent Nos. 1 398 421 and 1 398 422 and in US Patent No.

3 936 448, and the sulfonated pyrolysed citrates described in British Patent No. 1 439 000.

Alicyclic and heterocyclic polycarboxylates include cyclopentane- cis,cis,cis-tetracarboxylates, cyclopentadienide pentacarboxylates, 2,3,4,5-tetrahydrofuran - cis, cis, cis-tetracarboxylates, 2,5- tetrahydrofuran - cis - dicarboxylates, 2,2,5,5-tetrahydrofuran - tetracarboxylates, 1, 2,3,4,5, 6-hexane - hexacarboxylates and carboxy methyl derivatives of polyhydric alcohols such as sorbitol, mannitol and xylitol. Aromatic polycarboxylates include mellitic acid, pyromellitic acid and the phthalic acid derivatives disclosed in British Patent No. 1 425 343.

Of the above, the preferred polycarboxylates are hydroxy carboxylates containing up to three carboxy groups per molecule, more particularly citrates.

The parent acids of the monomeric or oligomeric polycarboxylate chelating agents or mixtures thereof with their salts, e.g. citric acid or citrate/citric acid mixtures are also contemplated as components of builder systems of detergent compositions in accordance with the present invention.

Other suitable water soluble organic salts are the homo- or co-polymeric polycarboxylic acids or their salts in which the polycarboxylic acid comprises at least two carboxyl radicals separated from each other by not more than two carbon atoms. Polymers of the latter type are disclosed in GB-A-1 596 756. Examples of such salts are polyacrylates of MWt 2000- 5000 and their copolymers with maleic anhydride, such copolymers having a molecular weight of from 20 000 to 100 000, especially from 70 000 to 90 000. These materials are normally used at levels of from 0.5% to 10% by weight more preferably from 0.75% to 8% , most preferably from 1 % to 6% by weight of the composition.

Organic phosphonates and amino alkylene poly (alkylene phosphonates) include alkali metal ethane 1 -hydroxy d^: hosphonates, nitrilo trimethylene phosphonates, ethylene diamine tetra methylene phosphonates and diethylene triamine penta methylene phosphonates, although these materials are less preferred where the minimisation of phosphorus compounds in the compositions is desired.

These phosphonate materials are normally present at levels less than 5 % by weight, more preferably less than 3 % by weight and most preferably less than 1 % by weight of the compositions. The detergent compositions can also include miscellaneous ingredients preferably in a total amount of from 0% to 45% by weight, examples of such ingredients being optical brighteners, anti-redeposition agents, photoactivated bleaches (such as tetrasulfonated zinc phthalocyanine) and heavy metal sequestering agents.

When formulated as a granular compostion the particle size of the particulate components of any detergent or cleaning composition containing the surfactant system of the invention is conventional and preferably not more than 5% by weight should be above 1.4mm, while not more than 10% by weight should be less than 0.15 mm in maximum dimension. Preferably at least 60%, and most preferably at least 80%, by weight of the powder lies between 0.7 mm and 0.25 mm in size. Preferred granular detergent compositions in accordance with the invention comprise at least one spray dried granular surfactant-containing particulate component and at least one surfactant- containing particulate agglomerate component.

For spray dried powders, the bulk density of the particles from the spray drying tower is conventionally in the range from 400 to 450 g/litre and this is then enhanced by further processing steps such as size reduction in a high speed cutter/mixer followed by compaction preferably to achieve a final density of greater than 550 g/litre. Alternatively, processes other than spray drying may be used to form a high density particulate directly.

Where the particulate components are particulate agglomerates the bulk density of these components will be a function of their mode of preparation. However, the preferred form of such components is a mechanically mixed agglomerate which may be made by adding the ingredients dry or with an agglomerating agent to a pan agglomerator, Z blade mixer or more preferably an in-line mixer such as those manufactured by Schugi (Holland) BV, 29 Chroomstraat 8211 AS, Lelystad, Netherlands and Gebruder Lodige MaschinenbanGmbH, D- 4790 Paderbom 1, Elsenerstrasse 7-9, Postfach 2050 F.R.G. By this means the second component can be given a bulk density in the range from 650 g/litre to 1190 g/litre more preferably from 700 g/litre to 850 g/litre. Preferably any particulate agglomerate components include sodium carbonate at a level of from 20% to 40% by weight of the component. Preferably, the composition includes from 3 % to 18% sodium carbonate by weight of the composition, more preferably from 5% to 15% by weight.

A highly preferred ingredient of any particulate agglomerate components is also a hydrated water insoluble aluminosilicate ion ^• change material of the synthetic zeolite type, described hereinbefore, present at from 10% to 55 % by weight of the second component. The amount of water insoluble aluminosilicate material incorporated in this way is from 1 % to 15% by weight of the composition, more preferably from 2% to 10% by weight.

In one process for preparing the particulate agglomerate component, the surfactant salt is formed in situ in an inline mixer. The liquid acid form of the surfactant is added to a mixture of particulate anhydrous sodium carbonate and hydrated sodium aluminosilicate in a continuous high speed blender, such as a Lodige KM mixer, and neutralised to form the surfactant salt whilst maintaining the particulate nature of the mixture. The resultant agglomerated mixture forms the second component which is then added to other components of the product. In a variant of this process, the surfactant salt is pre-neutralised and added as a viscous paste to the mixture of the other ingredients. In the variant, the mixer serves merely to agglomerate the ingredients to form the second component.

Where there is only one surfactant-containing component in the composition one or more other ingredients will be added as particulate components and will preferably also be present where more than one surfactant-containing particulate components forms part of the composition. Thus one or more of oxygen bleaches, photoactivated bleaches, bleach activators, builder salts, detergent enzymes, suds suppressors, fabric softening agents, soil suspension and anti-redeposition agents, soil release polymers, and optical brighteners can be added as solids. Suitable oxygen bleaches include the inorganic perhydrates such as sodium perborate monohydrate and tetrahydrate, sodium percarbonate, sodium perphosphate and. sodium persilicate. Sodium percarbonate and the sodium perborate salts are most preferred. These materials are normally added as crystalline solids and, in the case of sodium percarbonate, may be coated with e.g. silicate in order to aid stability. Usage levels range from 3% to 22% by weight, more preferably from 8% to 18% by weight.

Photoactivated bleaches include the zinc and aluminium salts of tri and tetra sulfonated phthalocyanine which are normally added as dispersions in other materials because of their low levels of usage, typically from 0.0005 to 0.01 % by weight of the composition.

Bleach activators or peroxy acid bleach precursors can be selected from a wide range of classes and are preferably those containing one or more N- or O- acyl groups.

Suitable classes include anhydrides, esters, imides and acylated derivatives of imidazoles and oximes, and examples of useful materials within these classes are disclosed in GB-A-1586789. The most preferred classes are esters such as are disclosed in

GB-A-836 988, 864 798, 1 147 871 and 2 143 231 and imides such as are disclosed in GB-A-855 735 & 1 246 338. Levels of incorporation range from 1 % to 10% more generally from 2% to 6% by weight of the composition.

Particularly preferred precursor compounds are the N-,N,N**-Nl tetra acetylated compounds of formula

wherein x can be O or an integer between 1 & 6.

Examples include tetra acetyl methylene diamine (TAMD) in which x= 1, tetra acetyl ethylene diamine (TAED) in which x=2 and tetraacetyl hexylene diamine (TAHD) in which x=6. These and analogous compounds are described in GB-A-907 356. The most preferred peroxyacid bleach precursor is TAED.

Solid peroxyacid bleach precursors useful in compositions of the present invention have a Mpt> 30°C and preferably >40°C. Such precursors will normally be in fine powder or crystalline form in which at least 90% by weight of the powder has a particle size > 150 micrometers.

This powder is usually agglomerated to form particulate material, at least 85 % of which has a particle size between 400 and 1700 micrometers. Suitable agglomerating agents include aliphatic mono and polycarboxylic acids,Ci2~Ci8 aliphatic alcohols condensed with from 10 to 80 moles of ethylene oxide per mole of alcohol, cellulose derivatives such as methyl, carboxymethyl and hydroxyethyl cellulose, polyethylene glycols of MWt 4,000 - 10,000 and polymeric materials such as polyvinyl pyrrolidone.

The precursors are preferably coated with an organic acid compound such as citric or glycolic acid, as disclosed in the commonly assigned copending British Patent Application No. 9102507.2 filed February 6 1991.

Builder salts that can advantageously be added as solid particulates include silicates and certain polycarboxylate builders such as citrates.

Dry mix addition of amorphous sodium silicates, particularly those of Siθ2:Na2θ ratio of from 2.0: 1 to 3.2: 1 is employed where aluminosilicates form part of a spray dried component, in order to avoid the formation of insoluble reaction products. Furthermore the incorporation of crystalline, so called 'layered' silicates into detergent compositions necessitates their addition as solids. These crystalline layered sodium silicates have the general formula

NaMSi_xθ2χ+ ι.yH₂0

wherein M is sodium or hydrogen, x is a number from 1.9 to 4 and y is a number from 0 to 20. Crystalline layered sodium silicates of this type are disclosed in EP-A-0 164 514 and methods for their preparation are disclosed in DE-A-3 417 649 and DE-A-3 742 043. For the purposes of the present invention, x in the general formula above has a value of 2, 3 or 4 and is preferably 2. More preferably M is sodium and y is 0 and preferred examples of this formula comprise the_<T and £ forms of Na2Si2θ5. These materials are available from Hoechst AG FRG as respectively NaSKS-11 and NaSKS-6. The most preferred material is -Na2Si2θ5, (NaSKS-6). Crystalline layered silicates are incorporated either as dry mixed solids, or as solid components of agglomerates with other components.

Anti-redeposition and soil-suspension agents suitable herein include cellulose derivatives such as methylcellulose, carboxymethylcellulose and hydroxy ethy cellulose, and homo-or co-polymeric polycarboxylic acids or their salts. Polymers of this type include copolymers of maleic anhydride with ethylene, methylvinyl ether or methacrylic acid, the maleic anhydride constituting at least 20 mole percent of the copolymer. These materials are normally used at levels of from 0.5% to 10% by weight, more preferably from 0.75% to 8%, most preferably from 1 % to 6% by weight of the composition.

Other useful polymeric materials are the polyethylene glycols, particularly those of molecular weight 1000-10000, more particularly 2000 to 8000 and most preferably about 4000. These are used at levels of from 0.20% to 5% more preferably from 0.25% to 2.5% by weight. These polymers and the previously mentioned homo- or co-polymeric polycarboxylate salts are valuable for improving whiteness maintenance, fabric ash deposition, and cleaning performance on clay, proteinaceous and oxidizable soils in the presence of transition metal impurities. Preferred optical brighteners are anionic in character, examples of which are disodium 4,4l-bis-(2-diethanolamino-4-anilino -s- triazin-6- ylamino)stilbene-2:2l disulphonate, disodium 4,4 -bis-(2-morpholino -4- anilino-2-triazin-6-y laminostilbene-2 : 21 -disulphonate , disodium 4, 4! -bis- (2,4-dianilino-s-triazin-6-ylamino)stilbene-2:2l - disulphonate, monosodium 4l >4l l-bis-(2,4-dianilino-s-triazin-6 ylamino)stilbene-2- sulphonate, disodium 4,4l-bis-(2-anilino-4-(N-methyl-N-2- hydroxyethylamino)-2-triazin-6-ylamino)stilbene-2,21 - disulphonate, disodium 4,4¹-bis-(4-phenyl-2, l,3-triazol-2-yl)stilbeιιe-2,2l disulphonate, disodium 4,4¹bis(2-anilino-4-( 1 -methyl-2-hydroxyethylamino)-s-triazin-6- ylamino)stilbene-2,2ldisulphonate and sodium 2(stilbyl-4H-(naphtho- l -l,2l'A,5)-l,2,3 - triazole-2¹!- sulphonate.

Soil-release agents useful in detergent or cleaning compositions in accord with the present invention are conventionally copolymers or terpolymers of terephthalic acid with ethylene glycol and/or propylene glycol units in various arrangements. Examples of such polymers are disclosed in the commonly assigned US Patent Nos. 4 116 885 and 4 711 730 and European Published Patent Application No. 0 272 033. A particular preferred polymer in accordance with EP-A-0 272 033 has the formula

(CH3(PEG)43)o.75(POH)o.25(T-PO)2.8(T-PEG)o.4)T(PO-H)o.25((PEG)43CH₃)o.75 where PEG is -(OC2H₄)O-,PO is (OC3H6O) and T is (pCOC6H₄CO).

Certain polymeric materials such as polyvinyl pyrrolidones typically of MWt 5000-20000, preferably 10000-15000, also form useful agents in preventing the transfer of labile dyestuffs between fabrics during the washing process.

Another optional detergent composition ingredient is a suds suppressor, exemplified by silicones, and silica-silicone mixtures. Silicones can be generally represented by alkylated polysiloxane materials while silica is normally used in finely divided forms, typified by silica aerogels and xerogels and hydrophobic silicas of various types. These materials can be incorporated as particulates in which the suds suppressor is advantageously releasably incorporated in a water-soluble or water- dispersible, substantially non-surface-active detergent-impermeable carrier. Alternatively the suds suppressor can be dissolved or dispersed in a liquid carrier and applied by spraying on to one or more of the other components.

As mentioned above, useful silicone suds controlling agents can comprise a mixture of an alkylated siloxane, of the type referred to hereinbefore, and solid silica. Such mixtures are prepared by affixing the silicone to the surface of the solid silica. A preferred silicone suds controlling agent is represented by a hydrophobic silanated (most preferably trimethyl- silanated) silica having a particle size in the range from 10 nanometers to 20 nanometers and a specific surface area above 50 m-2/g, intimately admixed with dimethyl silicone fluid having a molecular weight in the range from about 500 to about 200,000 at a weight ratio of silicone to silanated silica of from about 1:1 to about 1:2.

Suitable silicone suds controlling agents are disclosed in US Patent 3 933 672 and DTOS 2 646 126, an example of the latter being DC0544, a self emulsifying siloxane/glycol copolymer commercially available from Dow Corning. A particularly preferred suds suppressor system based on a silica silicone mixture comprises 78% starch, 12% stearyl alcohol binder and 10% of a silica/silicone blend available from Dow Corning under the reference X2/3419. This system is the subject of European Patent No. 0 210 721.

The preferred methods of incoφoration comprise either application of the suds suppressors in liquid form by spray-on to one or more of the major components of the composition or alternatively the formation of the suds suppressors into separate particulates that can then be mixed with the other solid components of the composition. A preferred example of such a particulate is a crystalline or amoφhous aluminosilicate zeolite on to which the suds suppressor is absorbed. Suds suppressor particulates of this type are the subject of the commonly assigned copending European Application No. 91201343.0. The incoφoration of the suds modifiers as separate particulates also permits the inclusion therein of other suds controlling materials such as C20-C24 fatty acids, microcrystalline waxes and high MWt copolymers of ethylene oxide and propylene oxide which would otherwise adversely affect the dispersibility of the matrix. Techniques for forming such suds modifying particulates are disclosed in the previously mentioned US Patent No. 3 933 672.

An especially preferred suds suppressor system comprises in combination a particulate suds suppressing component and a spray-on suds-suppressing component.

The suds suppressors described above are normally employed at levels of from 0.01 % to 5.0% by weight of the composition, preferably from 0.01 % to 1.5% by weight, and most preferably from 0.1 % to 1.2% by weight.

Another optional ingredient useful in the present invention is one or more enzymes.

Preferred enzymatic materials include the commercially available amylases, neutral and alkaline proteases, lipases, esterases and cellulases conventionally incoφorated into detergent compositions. Suitable enzymes are discussed in US Patents 3 519 570 and 3 533 139.

Fabric softening agents can also be incoφorated into detergent compositions in accordance with the present invention. These agents may be inorganic or organic in type. Inorganic softening agents are exemplified by the smectite clays disclosed in GB-A-1 400 898. Organic fabric softening agents include the water insoluble tertiary amines as disclosed in GB-A-1 514 276 and EP-B-0 011 340.

Their combination with mono C12-C14 quaternary ammonium salts is disclosed in EP-B-0 026 527 & 0 026 528. Other useful organic fabric softening agents are the dilong chain amides as disclosed in EP-B-0 242 919. Additional organic ingredients of fabric softening systems include high molecular weight polyethylene oxide materials as disclosed in EP-A- 0 299 575 and 0 313 146.

Levels of smectite clay are normally in the range from 5% to 15% , more preferably from 8% to 12% by weight, with the material being added as a dry mixed component to the remainder of the formulation. Organic fabric softening agents such as the water-insoluble tertiary amines or dilong chain amide materials are incoφorated at levels of from 0.5% to 5% by weight, normally from 1 % to 3 % by weight, whilst the high molecular weight polyethylene oxide materials and the water soluble cationic materials are added at levels of from 0.1 % to 2 % , normally from 0.15% to 1.5% by weight. Where a portion of the composition is spray dried, these materials can be added to the aqueous slurry fed to the spray drying tower, although in some instances it may be more convenient to add them as a dry mixed particulate, or spray them as a molten liquid on to other solid components of the composition.

In a particularly preferred process for making detergent compositions in accordance with the invention, part of the spray dried product comprising one of the granular components is diverted and subjected to a low level of nonionic surfactant spray on before being reblended with the remainder. A second granular component is made using the preferred process described above. The first and second components together with perhydrate bleach, bleach precursor particulate, other dry mix ingredients such as any carboxylate chelating agent, soil-release polymer, silicate of conventional or crystalline layered type, and enzyme are then fed to a conveyor belt, from which they are transferred to a horizontally rotating drum in which perfume and silicone suds suppressor are sprayed on to the product. In highly preferred compositions, a further drum mixing step is employed in which a low (approx. 2% by weight) level of finely divided crystalline material is introduced to increase density and improve granular flow characteristics.

The concentrated granular compositions of the present invention have a bulk density of at least 550g/litre, preferably at least 650g/litre more usually about 700 g/litre.

Bulk density is measured by means of a simple funnel and cup device consisting of a conical funnel moulded rigidly on a base and provided with a flap valve at its lower extremity to allow the contents of the funnel to be emptied into an axially aligned cylindrical cup disposed below the funnel. The funnel is 130 mm and 40 mm at its respective upper and lower extremities. It is mounted so that the lower extremity is 140 mm above the upper surface of the base. The cup has an overall height of 90 mm, an internal height of 87 mm and an internal diameter of 84 mm. Its nominal volume is 500 ml.

To carry out a measurement, the funnel is filled with powder by hand pouring, the flap valve is opened and powder allowed to overfill the cup. The filled cup is removed from the frame and excess powder removed from the cup by passing a straight edged implement e.g. a knife, across its upper edge. The filled cup is then weighed and the value obtained for the weight of powder doubled to provide the bulk density in g/litre. Replicate measurements are made as required.

Subject to the above bulk density limitations, the compositions of the invention can be made via a variety of methods including dry mixing, spray drying, agglomeration and granulation. A preferred method of making the compositions involves a combination of spray drying, agglomeration in a high speed mixer and dry mixing.

Compositions in accordance with the present invention comprise a plurality of separate particulate components. The particulates can have any suitable form such as granules, flakes, prills, marumes or noodles but are preferably granular. The granules themselves may be agglomerates formed by pan or drum agglomeration or by an in-line mixer and also may be spray dried particles produced by atomising an aqueous slurry of the ingredients in a hot air stream which removes most of the water. The spray dried granules are then subjected to densification steps, e.g. by high speed cutter mixers and/or compacting mills, to increase density before being reagglomerated.

Preferred compositions in accordance with the invention comprise at least one spray dried granular surfactant-containing component and at least one surfactant-containing particulate agglomerate component.

Where one or more surfactant-containing particulate components are spray dried granules these will preferably comprise in total at least 15%, more preferably from 25% to 45%, by weight of the composition. Where one or more surfactant-containing particulate components are particulate agglomerates these will preferably comprise in total from 1 % to 50%, more preferably from 10% to 40% by weight of the composition.

Where the surfactant-containing particulates are the only multi ingredient components, the remainder of the ingredients can be added individually as dry solids, or can be sprayed on to either the particulate components or on to any or all of the solid ingredients.

In preferred concentrated detergent products incoφorating an alkali metal percarbonate as the perhydrate salt it has been found necessary to control several aspects of the product such as its heavy metal ion content and its equilibrium relative humidity. Sodium percarbonate-containing compositions of this type having enhanced stability are disclosed in the commonly assigned British Application No. 9021761.3 filed October 6 1990 Attorney's Docket No. CM343.

Preferred laundry detergent compositions of the invention are formulated to be used with delivery systems that provide transient localised high concentrations of product in the drum of an automatic washing machine at the start of the wash cycle. These delivery systems avoid problems associated with loss of product in the pipework or sump of the machine and the high transient concentrations provide fabric cleaning benefits.

High transient concentrations require rapid dissolution/dispersion of the composition but this is difficult with surfactant containing particulate components in which the alkyl sulfate surfactant is relatively insoluble and hence make the component hydrophobic in nature. The incoφoration of a low level of a water soluble ethoxysulfate surfactant into the alkyl sulfate surfactant containing particulate has however been found to enable acceptable rate of dissolution characteristics to be achieved whilst retaining the detergency provided by surfactant.

Delivery systems for introducing laundry detergent compositions in accord with the invention into an automatic washing machine can take a number of forms. Thus a composition can be incoφorated in a bag or container from which it is rapidly releasable at the start of the wash cycle in response to agitation, a rise in temperature or immersion in the wash water in the drum. Alternatively the washing machine itself may be adapted to permit direct addition of the composition to the drum e.g. by a dispensing arrangement in the access door.

Products comprising a laundry detergent composition enclosed in a bag or container are usually designed in such a way that container integrity is maintained in the dry state to prevent egress of the contents when dry, but are adapted for release of the container contents on exposure to a washing environment, normally on immersion in an aqueous solution.

Usually the container will be flexible, such as a bag or pouch. The bag may be of fibrous construction coated with a water impermeable protective material so as to retain the contents, such as is disclosed in European published Patent Application No. 0 018 678. Alternatively it may be formed of a water-insoluble synthetic polymeric material provided with an edge seal or closure designed to rupture in aqueous media as disclosed in European published Patent Application Nos. 0 Oil 500, 0 011 501, 0 011 502, and 0 011 968. A convenient form of water frangible closure comprises a water soluble adhesive disposed along and sealing one edge of a pouch formed of a water impermeable polymeric film such as polyethylene or polypropylene. In a variant of the bag or container form, laminated sheet products can be employed in which a central flexible layer is impregnated and/or coated with a composition and then one or more outer layers are applied to produce a fabric-like aesthetic effect. The layers may be sealed together so as to remain attached during use or may separate on contact with water to facilitate the release of the coated or impregnated material.

An alternative laminate form comprises one layer embossed or deformed to provide a series of pouch-like containers into each of which the detergent components are deposited in measured amounts, with a second layer overlying the first layer and sealed thereto in those areas between the pouch-like containers where the two layers are in contact. The components may be deposited in particulate, paste or molten form and the laminate layers should prevent egress of the contents of the pouch-like containers prior to their addition to water. The layers may separate or may remain attached together on contact with water, the only requirement being that the structure should permit rapid release of the contents of the pouch-like containers into solution. The number of pouch-like containers per unit area of substrate is a matter of choice but will normally vary between 500 and 25,000 per square metre.

Suitable materials which can be used for the flexible laminate layers in this aspect of the invention include, among others, sponges, paper and woven and non-woven fabrics.

However the preferred means of carrying out the process of the invention is to introduce the composition into the liquid surrounding the fabrics that are in the drum via a reusable dispensing device having walls that are permeable to liquid but impermeable to the solid composition.

Devices of this kind are disclosed in European Patent Application Publication Nos. 0 343 069 & 0 343 070. The latter Application discloses a device comprising a flexible sheath in the form of a bag extending from a support ring defining an orifice, the orifice being adapted to admit to the bag sufficient product for one washing cycle of an automatic process. A portion of the washing medium flows through the orifice into the bag, dissolves the product, and the solution then passes outwardly through the orifice into the washing medium. The support ring is provided with a masking arrangement to prevent egress of wetted, undissolved, product, this arrangement typically comprising radially extending walls extending from a central boss in a spoked wheel configuration, or a similar structure in which the walls have a helical form.

Preferred dispensing devices are reusable and are designed in such a way that container integrity is maintained in both the dry state and during the wash cycle. Especially preferred dispensing devices for use in accord with the invention have been described in the following patents; GB-B- 2,157, 717, GB-B-2, 157, 718, EP-A-0201376, EP-A-0288345 and EP- A-0288346. An article by J. Bland published in Manufacturing Chemist, November 1989, pages 41-46 also describes especially preferred dispensing devices for use with granular laundry produts which are of a type commonly known as the "granulette". In the detergent compositions, the abbreviated component identifications have the following meanings:

246AS Sodium alkyl sulfate surfactant containing a alkyl chain length weight distribution of 15%

C12 alkyl chains, 45% C14 alkyl chains, 35%

Ci6 alkyl chains, 5% Cis alkyl chains

24AE3S C12-C14 alkyl ethoxysulfate containing an average of three ethoxy groups per mole

TAE_n Tallow alcohol ethoxylated with n moles of ethylene oxide per mole of alcohol

35E7 A Ci3_i5 primary alcohol condensed with an average of 7 moles of ethylene oxide

25E3 A C12-C15 primary alcohol condensed with an average of 3 moles of ethylene oxide

NaSKS-6 Crystalline layered silicate of formula -

Na2Si2θ5 (NaSKS-6)

Perborate Sodium perborate monohydrate

TAED Tetra acetyl ethylene diamine

Silicate Amoφhous Sodium Silicate (Siθ2:Na2θ ratio normally follows)

Carbonate Anhydrous sodium carbonate Bicarbonate Anhydrous sodium bicarbonate Zeolite A Hydrated Sodium Aluminosilicate of formula

Nai2(A10₂Si0₂)l2- 27H₂0 having a primary particle size in the range from

1 to 10 micrometers

Citrate Tri-sodium citrate dihydrate

MA/AA Copolymer of 1 :4 maleic/acrylic acid, average molecular weight about 80,000.

Enzyme Mixed proteolytic and amylolytic enzyme sold by Novo Industries AS. Example 1

The following low-sudsing granular detergent composition was prepared in accordance with the invention (percentage, parts by weight).

246 AS 8.8

24AE3S 2.2

35E7 4.5

Zeolite A 24.8

Carbonate 15.5

MA/AA 4.6

Sulphate 5.0

Silicate 2.5

Citrate 11.4

Bicarbonate 7.0

Enzyme 1.6

Suds suppressor system

Particulate antifoam component 2.1

Spray-on antifoam component 2.0

Misc, minors, moisture to balance

The particulate antifoam component was an agglomerate comprising 11 % by weight of the component of polydimethylsiloxane, 14% by weight TAE80, 5% by weight of a mixture of C12-C22 hydrogenated fatty acids and 70% by weight of starch.

The spray-on antifoam component comprised 30% by weight of the component of silicone/silica antifoam compound comprising 85 % by weight of the antifoam compound of polydimethylsiloxane and 15% by weight of the antifoam compound of silica, 3 % by weight of silicone glycol rake copolymer (DC0544 from DOW Corning), and 67% by weight of TAE11 carrier fluid. Example 2

The following laundry detergent compositions were prepared (parts by weight) in accordance with the invention.

A B ' C D

246AS 7.6 6.5 4.8 6.8

24AE3S 2.4 - 1.2 1.7

TAE11 1.10 - - -

TAE50 - 0.4 0.4 0.4

35E7 3.26 - - -

35E3 - 5.0 5.0 5.0

Zeolite A 19.5 13.0 13.0 13.0

Citrate 6.5 - - -

MA/AA 4.25 4.25 4.25 4.25

NaSKS-6* - 10.01 10.01 10.01

Citric Acid* - 2.73 2.73 2.73

TAE50* - 0.26 0.26 0.26

Carbonate 11.14 9.84 9.84 9.84

Perborate 16.0 16.0 16.0 16.0

TAED 5.0 5.0 5.0 5.0

Enzyme 1.4 1.4 1.4 1.4

Silicate (2.0 ratio) 4.38 - - -

Water and miscellaneous (Including suds suppressor, sodium sulphate, perfume) to balance

* Present as components of crystalline layered silicate particulates.

Claims

1. A surfactant system containing alkyl sulfate surfactant derived from natural sources comprising a mixture of alkyl chain lengths wherein the weight distribution of the alkyl chain lengths is such that less than 20% by weight of the alkyl chain lengths are C12, from 30% to 80% by weight of the alkyl chain lengths are C 14, from 30% to 50% by weight of the alkyl chain lengths are C 15 and less than 10% by weight of the alkyl chain lengths are Ci -

2. A surfactant system according to Claim 1 wherein the weight distribution of the alkyl chain lengths is such that less than 15% by weight of the alkyl chain lengths are C12, from 35% to 70% by weight of the alkyl chain lengths are C14, from 30% to 40% of the alkyl chain lengths are Ci6, and less than 5% of the alkyl chain lengths are Ci8-

3. A surfactant system according to either of Claims 1 or 2 containing alkyl ethoxysulfate surfactant wherein the weight ratio of alkyl sulfate surfactant to alkyl ethoxysulfate surfactant is from 2:1 to 19:1.

4. A surfactant system according to any of Claims 1 - 3 additionally containing a nonionic surfactant.

5. A surfactant system according to Claim 4 wherein the weight ratio of nonionic surfactant to anionic surfactant is from 1 :4 to 4: 1.

6. A surfactant system according to any of Claims 1 - 5 which is essentially free of alkyl benzene sulfonate.

7. A detergent or cleaning composition comprising the surfactant system of any of Claims 1 - 6.

8. A laundry detergent composition according to Claim 7 incoφorating the surfactant system at a level of from 3% to 50% by weight.

9. A machine dishwashing detergent composition according to Claim 7 incoφorating the surfactant system at a level of from 0.5% to 10% by weight.

10. A detergent composition according to either of Claims 8 or 9 containing a builder system at a level of from 1% to 80% by weight of the composition.