NO822433L - DETERGENT ADDITIVE AND DETERGENT MIXTURE CONTAINING IT - Google Patents

Abstract

A ternary builder system for detergent compositions comprises 25 to 97% by weight of an aluminosilicate cation-exchange material such as Zeolite A and 3 to 75% by weight, in total, of ( i) a soap containing at least 60% by weight of saturated material, and (ii) nitrilotriacetic acid or a water-soluble salt thereof, at a (i):(ii) ratio of 10:1 to 1:10, the proportion of soap in the ternary mix being at least 12%. The builder mix is advantageously used in detergent compositions containing less than 10% inorganic phosphate, and gives good results in zero-phosphate compositions.

Description

The invention relates to additives for detergent mixtures, as well as detergent mixtures containing them. These products are specially, but not essentially, adapted for :laundry washing. The invention relates more particularly to practically phosphate-free detergent mixtures.

Laundry preparations contain conventional phosphate washing ability builders. for example sodium tripolyphosphate. In some situations, it is believed that the use of phosphates in detergent mixtures can lead to environmental problems in waste water.

There is therefore a desire to reduce the phosphorus level, or to eliminate it completely in detergent mixtures.

Water-insoluble aluminosilicate ion-exchange materials have been proposed as alternative builders to phosphates, see, for example, British patents no...1 473 201 and 1 473 202. It is however-

time in practice found that these aluminosilicate materials, even in large quantities, tend to be undesirably slow in their exchange of cations, especially at low temperatures, resulting in poor detergency. The. consequently, it has been proposed to use supplementary water-soluble builders in combination with these aluminosiiicates to raise the washability to an acceptable level. These supplemental builders are generally materials which are effective sequestering builders in their own right, for example alkali metal tripolyphosphates, nitrile triacetates and poly-α-hydroxy acrylates. However, large quantities of these materials are not generally desirable in detergent mixtures for cost or environmental reasons.

We have now discovered that surprisingly good washing results are achieved by using, in combination with an aluminosilicate builder, relatively small amounts of both an organic sequestering builder

and an organic precipitating builder. The detergency results achieved by using ternary systems of this type have surprisingly been found to be better than. what one would expect based on consideration of the results obtained with the corresponding binary aluminosilicate/sequestering agent and aluminosilicate/precipitating systems, so that reduced quantities of the supplementary builders can be used, thereby achieving savings in costs and environmental benefits.

It is known that the detergency-building properties of aluminosilicates are improved by the addition of water-soluble complexing agents, for example sodium tripolyphosphate. This effect has been explained on the basis of it. so-called “carrier

molecule model", see for example P-. Berth, J. Am. Oil Chemists<1>Soc., 5J3, 52-53 (1978) . The complexing agent has the ability to absorb polyvalent water hardness ions (especially Ca 2+, but also Mg 2 +) from solid surfaces (such as the surface of a textile fiber) and carries them on to the aluminosilicate exchanger after transport through the aqueous medium.

agent forms a chelate complex with the hardness ion. which dissociates on arrival at the surface of the aluminosilicate.

It is not easy to be faced with a similar mechanism with precipitating builders, since these remove hard heat ions from the washing bath by the practically irreversible formation of a precipitation product (insoluble calcium or magnesium salt).

It is thus unexpected that the addition of a precipitating builder and an aluminosilicate/sequestering agent system provides a significant improvement in the detergency builder properties.

Accordingly, the present invention provides, in a first aspect, a detergent additive. which essentially consists of: (a) from approx. 25 to approx. 97% by weight of a crystalline or amorphous

aluminosilicate cation exchange material,

(b) from approx. 3,' to approx. 75% by weight, total, of

(i) an organic precipitating builder having a polyvalent anion, which builder forms an insoluble calcium salt, (ii) an organic builder which forms a soluble complex with

calcium,

as the weight ratio between (i) and (ii) is from approx. 10:1 to approx. 1:10.

The organic precipitating builder is preferably one that has

a divalent anion.

The aluminosilicate cation exchange material is a crystalline . or amorphous material with the general formula:

where Cat is a cation of valence ri that can be exchanged for calcium (for example, Na+ or K+); x is a number of 0.7-1.5; y is a number of 1.3-4; and z is such that the bound water content is from 10 to 28% by weight.

Preferably, a crystalline material is used which can be described by the unit cell content:

where x and y are whole numbers of at least 6, the ratio between x and: y being in the range from 1:1 to 1:2; and z is such that the bound water content is from 10 to 28% by weight.

The aluminosilicate preferably has a particle size of 0.1-100 ym, ideally between 0.1 and 10 ym, and an ion exchange capacity of at least 200 mg CaCO^pr. grams of aluminosilicate (anhydrous basis).

In a preferred embodiment, the water-insoluble aluminosilicate is a crystalline material of the formula described by the unit cell content:

where z is 20-30, preferably approx. 27.

An example of this material is the commercially available product known as Zeolite, type A, which is typically: and is also described by its unit-cell content:

The organic precipitating builder is a water-soluble material which forms an insoluble calcium salt and which has a multivalent, preferably divalent, anion. Materials that have a divalent anion are generally significantly more weight-efficient as builders than

2+ soaps are; only one mole is consumed by each gram ion of Ca

2+

or Mg -hardness ions, compared to 2 moles of soap.

The solubility product of the calcium salt in the organic precipitating building having a divalent anion is preferably

-8

less than 10

The organic precipitating builder is advantageously a compound of formula I:

where:

Rler C10~ C24^~ a^ Y^ e^ is alkenyl, or an arylalkyl- or

alkylaryl group of equivalent chain length;

X is CH, CR 2 , N or CON;

R 2 is C 1 -C 4 -alkyl;

Y is hydrogen or a solubilizing cation, preferably alkali metal and especially sodium;

. n and m, which may be the same or different, are 0 or whole numbers 1-4; and

Z is COOY or S03Y.

A preferred group of compounds within this definition consists of those whose X is CH, X n is zero and m is 0 or 1. Thus, according to a first preferred embodiment of the invention, the organic precipitating builder is a compound of formula II :

where R^, Y and Z have the same meanings as given above, and p is 0 or 1.

Particularly preferred classes of compounds within the general formula II are the following:

(i) substituted malonates of formula III:

(ii) substituted succinates of formula IV:

- and -

(iii) α-sulfofatty acid salts of formula V:

Compounds of formulas III and IV are described, for example, in British Patent Nos. 1 293 753, 1 342 247 and 1 342 340. Examples of such compounds include disodium dodecyl malonate (C-^2<_>AKM), disodium hexadecenyl succinate (C16 . -j^-AKS).. and disodium mixed-C^-C^g-succinate- (C15_lg-AKS) .

Compounds of formula V are described, for example, in British Patent Nos. 1,368,736' and 1,380,390. A typical example is disodium α-sulfostearate (C18-SFAS). Mixtures of compounds with different chain lengths, for example the α-sulfoslate of coconut fatty acids' (coconut SFAS). , or of tallow fatty acids (tallow-SFAS), or of mixed coconut and tallow fatty acids, can also be used with advantage.

According to another preferred embodiment of the invention, the organic precipitating builder is a compound of formula VI: or of formula VII:

where R^ and Y have the meanings given above, and v and w are each 1-4, preferably 1 or 2.

Compounds of formula VI where v and w are both 1, i.e. the N-alkyl iminodiacetates, are of particular interest.

Compounds of formula VI where v and w are both the 2,3-imino-dipropionates are known amphoteric surfactants, for example disclosed in British Patent No. 1,296,793. These materials are also known as foaming agents in soap bars, for example known from European patent 0 02 5 242,

and as anti-corrosive agents, for example from US patent no.

2 926 108. Compounds of formula VI where v and w are both 1, the iminodiacetates, are also obvious, for example as lime-soap dispersants in soap products, see US patent no.

3,630,927,<p>g as anti-corrosive agents, see US patent no.

2,368,604. US Patent No. 3,981,779 discloses compounds of. both formulas VI and VII for use as "chelating surface-active agents" for reducing fouling of metals in aqueous systems.

British Patent No. 761,384 discloses detergent compositions containing 10-50% by weight of alkylbenzene sulphorate and 5-20% by weight of a water-soluble salt of an N-(C 6 -C 6 -alkyl)iminodiacetic acid, the latter component serving as a suds agent. Likewise, British Patent No. 761,383 discloses combinations of alkyl sulfates and N-(C 8 -C 8 -alkyl)-iminodicarboxylic acids. Other patents relating to the use of compounds of formula VI in detergent compositions are British Patent Nos. 446,737 and 446,813. Compounds analogous to those of formula VI but having shorter alkyl chains (C 6 or less) are known as

sequestering builders, as stated in British patent document no.

1,383,025, and as anti-rancidity agents in soap and non-soap detergents, as stated in British Patent No. 574,504.

The organic sequestering builder is a water-soluble material which forms soluble complexes with calcium, preferably with pK 'Ca values above 3.0, preferably above 4.0 dg, preferably above 4.5. The sequestering builder also advantageously forms complexes with magnesium, preferably with -pK^ values above 4.0.

Examples of suitable materials include alkali metal (especially sodium) salts of the following acids: nitrile triacetic acid, ethylenediaminetetraacetic acid, polyacrylic acid, poly(a-hydroxy-acrylic acid, carboxymethyloxymalonic acid, carboxymethyloxysuccinic acid, oxydiacetic acid, oxydiacetic acid, citric acid, dipicolic acid and many more. The polyacetal carboxylates which are disclosed in US Patent Nos. 4,144,126 and 4,146,495, and the oxidized polysaccharides which are disclosed in British Patent Nos. 1,330,121, 1,330,122 and 1,330,123 can also be used with advantage.

However, alkali metal salts of nitrile triacetic acid (NTA), especially the trisodium salt, are the preferred organic sequestering agents used according to the present invention. Use of NTA salts in combinations with precipitating builders which have a divalent anion is particularly preferred.

The nitrile triacetic acid compounds which are preferably used according to the present invention are known sequestering agents and can be represented by the following structural formula:

N==(CH 2 COOX) 3

where X as previously is hydrogen or a solubilizing cation. These compounds further contain C-bonded substituents of an inert and non-toxic nature, for example alkyl, for example methyl or ethyl, or haloalkyl, for example chloromethyl. The nature of the aforementioned compounds is not particularly critical, with the implicit limitation that such substituents

must be devoid of any tendency to adversely affect the desirable properties of the nitrile-acetic acid compound.

Preferred compounds that fall within the scope of the above described definition and formula are nitrile triacetic acid, trisodium nitrile triacetate monohydrate, tripotassium nitrile triacetate, disodium nitrile triacetate and dipotassium nitrile triacetate.

The organic precipitating building and the organic sequestering building make up from approx. 3 to approx. 75% by weight of the builder mix (washing additive) according to the invention, preferably from approx. 10 to approx. 60% and especially from approx. 20 to approx.

50%. The ratio between precipitating agent and sequestering agent is from 10:1 to 1:10, preferably from 3:1 to 1:3' and preferably

from 3:1 to 1:1.

The washing additive according to the present invention is

an efficient building system that gives good washability results

when incorporated, together with detergent active materials, in a detergent mixture.

Accordingly, in another aspect of the invention, there is provided a detergent mixture comprising from approx. 3 can withstand approx. 90% by weight of at least one synthetic detergent-active material and from approx. 10 to approx. 97% by weight of a washing additive as previously defined.

The detergent mixture according to the invention contains from approx. 10. to approx. 97% by weight of the washing additive according to the invention, preferably from approx. 10 to approx. 80, preferably from approx. 25% to approx. 70% and especially from approx. 28 to approx. 67%.

Since the washing additive contains from approx. 25 to approx. 97% by weight aluminosilicate, the aluminosilicate content in the detergent mixture can vary from approx. 2.5 to approx. 94%. An aluminosilicate content of from approx. 10 to approx. 60%, especially from approx. 17 to approx.

4 7%, preferred.

Likewise, the content of organic builders (precipitating agent plus sequestering agent) can vary from approx. 0.3 to approx. 73%, as an area of from approx. 5 to approx. 40%, especially from approx. 7 to approx. 27. %, preferred. The preferred area for the content of the precipitating build is from approx. 3 to approx. 20%,

especially from approx. 5 to approx. 10%; for the sequestering builder, the preferred area is from approx. 1 to approx. 15%, especially from approx. 2 to approx. 10%,

The detergent mixtures according to the invention are, for stages, practically free of inorganic phosphate. This is highly desirable for environmental reasons, as mentioned earlier. Products according to the invention which do not contain any inorganic phosphate have been shown to exhibit detergency properties comparable to those of sodium tripolyphosphate-based products.

If desired, however, the compositions may contain inorganic phosphate, but preferably at a level not exceeding 10%, based on the whole product - A level below 5% is advantageous, and a level below 3% is particularly preferred. Any phosphate that is present can, for example, be in the form of alkali metal (preferably sodium) tripolyphosphate, -orthophosphate, -pyrophosphate or polymeric phosphate.

The detergent mixtures according to the invention necessarily include from approx. 3 to approx. 90% by weight, preferably from approx.

5 to approx. 40% by weight, preferably from approx. 10 to approx. 25% by weight, of a

synthetic anionic, nonionic, amphoteric or zwitterionic detergent compound or mixture thereof. Many suitable detergent active compounds are commercially available and are fully described in the literature, for example in "Surface Active Agents and Detergents", Vols. I and II, by Schwartz, Perry and Berch.

The preferred detergent compounds that can be used are synthetic anionic and nonionic compounds. The former are usually water-soluble alkali metal salts of organic sulfates

and sulfonates having alkyl radicals containing from approx. 8

to approx. 22 carbon atoms, the term alkyl being used to include the alkyl part in higher aryl radicals. Examples of suitable anionic washing compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher (C 8 -C 8 ) alcohols, for example produced from tallow or coconut oil; sodium and potassium alkyl(C 8 -C 20 1 benzenesulfonates, especially sodium linear secondary alkyl(C 2 -C 20 )benzenesulfonates; sodium alkyl glyceryl ether sulfates, especially such ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols such as derived from petroleum; sodium coconut oil fatty acid mono-glyceride sulfates and sulfonates; sodium and potassium salts of sulfuric acid esters of higher (Cg-C^g)-fatty alcohol-alkylene oxide, especially ethylene oxide reaction products; the reaction products of such fatty acids as coconut fatty acids esterified with isethion-

acid and neutralized with sodium hydroxide; sodium and potassium salts of fatty acid amides of methyl taurine; alkane monosulfonates, for example those derived from the reaction of α-olefins {Cq-C^ qX with sodium bisulfate and those derived from the reaction of paraffins with SO 2 and Cl 2 and then hydrolysis with a base to produce a randomized sulfonate; olefin sulfonates., this term being used to describe the material produced by reacting olefins, especially C^Q-C2Q-a-olefins, with SO^ and then neutralizing and hydrolyzing the reaction product. The preferred anionic washing compounds are sodium (Ci-C]-5) alkylbenzenesulfonates and sodium (Ci6-Ci8^ ~ alkyl sulfates.

Examples of suitable non-ionic washing compounds which can be used include in particular the reaction products of alkylene oxides, usually ethylene oxide, with alkyl(C8-C22)phenols, usually 5-25 EO, i.e. 5-25 units of ethylene oxide per molecule; the condensation products of aliphatic (Cg-C^g )-prim.-. or sec.-linear or branched alcohols with ethylene oxide, usually 6-30 EO, and products prepared by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called non-ionic detergents include long-chain tertiary amine oxides, long-chain tertiary phosphine oxides and dialkyl sulfoxides.

Mixtures of detergent-active compounds, for example mixed anionic or mixed anionic and non-ionic compounds, can be used in the detergent mixtures, especially in the latter case to provide regulated low-foaming properties. This is to the advantage of mixtures intended for use in suds-intolerant automatic washing machines. Anionic and non-ionic washing compounds are advantageously used together in ratios of from 3:1 to 1.5:1.

Certain amounts of amphoteric or zwitterionic detergent-active compounds can also be used in the mixtures according to the invention, but this is not normally desired because they are relatively expensive. If any amphoteric or zwitterionic detergent compounds are used, it is usually in small amounts in mixtures based on the very commonly used synthetic anionic and/or nonionic. detergent-active compounds.

If desired, the product according to the invention can also include soap. The presence of small amounts of soap is advantageous with respect to foam control and washability. Soaps which can be used are especially the sodium or, less desirable, the potassium salts of C-^-C^-f acetic acids. Soaps that are mainly based on

the longer chain fatty acids within this range, i.e. with at least half of the soap having a chain length of C 2 g or more, are particularly preferred. This preferred chain length distribution can conveniently be achieved by using soaps from natural sources, such as tallow, palm oil or rapeseed oil, which may be hydrogenated if desired, with smaller amounts of other, shorter chain soaps made from nut oils, such as coconut oil or palm kernel oil .

According to a preferred embodiment of the invention, the detergent mixture also contains a bleaching system. .The bleaching system preferably comprises a peroxy-bleach compound which is an inorganic persalt, which is preferably used in connection with an activator for this. The persalt can be, for example, sodium perborate (either the monohydrate or the tetrahydrate) or sodium percarbonate. The activator makes the bleaching more effective at lower temperatures, i.e. in the range from ambient temperature to approx. 60°C, so that such bleaching systems are generally known as low-temperature bleaching systems and are well known in the field. The inorganic persalt serves to release active oxygen in solution, and the activator is usually an organic compound having one or more reactive acyl residues, which cause the formation of peracids, the latter providing a more effective bleaching effect at lower temperatures than can is achieved by using the peroxy bleach compound alone. The weight ratio between the peroxy bleach compound and the activator is generally from approx. 20:1 to approx. 1:1, preferably approx. 15:1 to approx. 2:1.

The detergent mixtures according to the invention preferably contain from approx. 5 to approx. 30% by weight of the peroxy bleach compound and approx. 0.1 to approx. 15% by weight of the activator. The total amount of the bleaching system ingredients is preferably in the range from 5 to 35% by weight. especially from approx. 6 to approx. 30% by weight.

Typical examples of suitable peroxy bleaching compounds are alkali metal perborates, both tetrahydrates and monohydrates, alkali metal percarbonates, persilicates and perphosphates, of which sodium perborate is preferred,

Activators.for.peroxybleaching compounds are abundantly described in the literature, including in British Patents 836,988, 855,735, 907,356, 907,358, 970,950, 1,003,310 and

1 246 339, US Patents 3 332 882 and 4 128 494, Canadian Patent 844 481 and South African Patent 68/6 344. Specific suitable activators include: (a) N-diacylated and N,N'-polyacylated amines, f .ex. N,N,N',N'-tetraacetylmethylenediamine and N,N,N',N'-tetraacetylethylenediamine, N,N-diacetylaniline, N,N-diacetyl-p-toluidine; 1,3-diacylated hydantoins, e.g. 1,3-diacetyl- 5,5-dimethylhydantoin and 1,3-dipropionylhydantoin; α-acetoxy-(N,N,N1)-polyacylmalonamide, e.g. α-acetoxy-(N,N')-diacetylmalonamide; (b) N-alkyl-^-N-sulfonylcarbonamides, e.g. the compounds N-methyl-N-mesyl-acetamide, N-methyl-N-mesyl-benzamide,. .N-methyl-N-mesyl-p-nitrobenzamide and N-methyl-N-mesyl-p-methoxybenzamide; (c) N-acylated cyclic hydrazides, acylated triazones or urazoles, e.g. monoacetylmaleic acid hydrazide; (d) 0,N,N-trisubstituted hydroxylamines, e.g. 0-benzoyl-N,N-succinylhydroxylamine, 0-acety1-N,N-succinylhydroxylamine, O-p-methoxybenzoyl-N,N-succinylhydroxylamine, 0-p-nitro-benzoyl-N,N-succinylhydroxylamine and 0,N,N^ triacet.yl-hydroxylamine; (e) N,N'-diacylsulfuryl amides, e.g. N,N'-dimethyl-N,N'-diacetyl-sulfurylamide and N,N'-diethyl-N,N'-dipropionylsulfurylamide; (f) . Triacylcyanurates, e.g. triacetyl cyanurate and tribenzoyl cyanurate; (g) Carboxylic anhydrides, e.g. benzoic anhydride, m-chloro-. benzoic anhydride, phthalic anhydride and 4-chlorophthalic anhydride. (h) Sugar residues, e.g., glycosepentaacetate; (i) 1,3-diacyl-4,5-diacyloxy-imidazolidine, e.g. 1,3-diformyl-4,5-diacetoxy-imidazolidine, 1,3-diacetyl-4,5-diacetoxy-imidazoline, 1,3-diacetyl-4,5-dipropionyloxy-imidazoline; (j) Tetraacetyl glycoluril and tetrapropionyl glycoluril; (k) Diacylated 2,5-diketopiperazines, e.g. 1,4-diacetyl-2,5-diketopiperazine, 1,4-dipropionyl-2,5-diketopiperazine and 1,4-dipropionyl-3,6-dimethyl-2,5-diketopiperazine; (1) Acylation products of propylenediurea or 2,2-dimethyl-propylenediurea (2,4,6,8-tetraazabicyclo-(3,3,1)-ironane-3,7-dione or its 9,9-dimethyl derivative), especially tetraacetyl or tetrapropionyl propylene diurea or their dimethyl derivatives; (m) Carbonic acid esters, f . e.g. the sodium salts of p-(ethoxy-carbonyloxy)-benzoic acid and p-(propoxy-carbonyloxy)-benzenesulfonic acid;

(n) α-acyloxy-(N,N')-polyacylmalonamides, e.g. α-acetoxy-(N,N1)-diacetylmalonamide.

The N-diacetylated and N,N<1->polyacylated amines mentioned below

(a), is of particular interest, especially N,N,N',N'-tetraacetyl-ethylenediamine (TAED).

It is preferred to use the activator in granular form, preferably where the activator is finely divided, as described in our British Patent Application No. 80 21979. Specifically, it is preferred to have an activator with an average particle size of less than 150 ym, which provides significant improvement in bleaching efficiency . The sedimentation losses, when using an activator with an average particle size of less than 150 ym, are significantly reduced. Even better bleaching performance is achieved if the average particle size of the activator is less than 100 µm. However, too small a particle size results in increased decomposition, dust formation. and handling problems, and although particle sizes below 100 ym can provide improved bleaching efficiency, it is desirable that the activator has no more than 20% by weight particles of size less than 50 ym. On the other

side, the activator may have a certain amount of particles with a size above 150 ym, but it should not contain more than 5% by weight of particles

> 300 ym, and no more than 20% by weight particles > 200 ym, preferably > 150 ym. The. it should be understood that these particle sizes refer to the activator present in the granules, and not to the granules themselves. The latter has a particle size where the main part varies from 100 to 2000 ym, preferably 250-1000 ym. Up to 5% by weight granules of particle size

> 1700 ym and up to 10% by weight of granules < 250 ym is tolerable. The granules which incorporate the activator, preferably in this finely divided form, can be obtained by granulating the activator with a suitable carrier material, for example sodium tripolyphosphate. and/or potassium tripolyphosphate. Other granulation methods, for example the use of organic and/or inorganic granulation aids, can also be used usefully. The granules can then be dried, if necessary. Basically, any granulation process is applicable, when only the granule contains the activator and

when only the other materials present in the granule do not adversely affect the activator.

It is particularly preferred to include in the detergent mixtures a stabilizer for the bleaching system, for example ethylenediaminetetramethylenephosphonate and diethylenediaminetriaminepentamethylenephosphonate. These stabilizers can be used in acid or salt form, especially in the form of calcium, magnesium, zinc or aluminum salt form, as described in our British patent application No. 2 04 8 93 0...

Apart from the components already mentioned, the detergent mixtures according to the invention may contain any of the conventional additives in the quantities in which such materials are normally used in laundry detergent mixtures. Examples of these additives include foam enhancers, for example alkanolamides, especially the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids; foam suppressants, for example alkyl phosphates, silicones, or alkylphosphonic acids which are incorporated in petroleum jelly, wax • or mineral oil; soil carriers, for example sodium carboxymethyl cellulose and cellulose ethers; fabric softeners; inorganic salts, such as sodium sulfate and sodium carbonate; and, usually present in very small amounts, fluorescing agents, perfume, enzymes, such as proteases and amylases.

It may be desirable to include in the product a quantity of an alkali metal silicate', especially sodium ortho-, -meta- or preferably neutral or alkaline silicate. The presence of

such alkali metal silicates at levels that are at least approx.

1%, and preferably from approx. 5 to approx. 15% by weight of the mixture, is advantageous with regard to reducing corrosion of metal parts in washing machines, in addition to providing processing advantages and generally improved powder properties. The stronger alkaline ortho- and metasilicates would normally only be used in lower amounts within this range, in admixture with the neutral or alkaline silicates.

The product according to the invention is preferably

.alkaline, but not too strongly alkaline, as this could result in frost<y>damage and also be dangerous for household use. In practice, the product should ideally give a pH value of from approx. 8.5 more

about. 11 in use in a watery wash bath. It is particularly preferred for household products that they have a pH value of from approx. 9.0 to c. 10.5 , ■ as lower pH values tend to be less effective for optimum detergency, and stronger alkaline products.'can be dangerous if misused. The pH value is measured at the lowest normal use concentration of 0.1 wt/vol..% of the product in water of 12°H (Ca), (French permanent hardness, calcium only) at 50°C so that a satisfactory degree of alkalinity can be ensured in use at all normal product concentrations. If necessary, up to 10% by weight of alkali metal carbonate, preferably sodium carbonate, may be included in order to raise the pH and maintain adequate buffering capacity in the presence of acidic soil.

If carbonates or phosphates are present, it may be desirable to include in the product according to the invention one or more anti-deposition agents, in order to reduce any tendency to form inorganic deposits on washed clothes. The amount of any such anti-deposition agent is normally from approx. 0.1 to approx. 5% by weight, preferably from approx. 0.2 to approx. 1.5% by weight, calculated on the mixture. The preferred antifouling agents are anionic polyelectrolytes, especially polymeric ones

aliphatic carboxylates, or organic phosphonates.

The detergent mixtures according to the invention should preferably be in free-flowing particle form, for example as powder or granules, and can be produced by any of the techniques that are usually used in the production of such detergent preparations, for example by slurry and spray drying processes. It is preferred that the method used to make the mixtures should result in a product that has a moisture content of no more than approx. 12%, preferably from approx. 4 to approx. 10%, by weight.

The detergent mixtures according to the invention can also be in the form of bars or tablets, or in liquid form.

In the following, the invention will be illustrated by means of the non-limiting examples.

EXAMPLES

In the examples that follow, the washability of laundry detergents containing different builder systems was compared by measuring the reflectivity of a clay soiled polyester/cotton fabric sample before and after washing in the Tergotometer. The reflectivity was measured with a Carl Zeiss Eirepho Reflecto-meter, and the increase in reflectivity upon washing (AR) was calculated as a measure of washability.

In each case, a wash bath was created by application. of the ingredients listed below, in the concentrations listed, in water of 40°FH (Ca) or 20°FH (Ca). The washing bath was allowed to equilibrate for 15 minutes. Fabric samples (four pieces per liter, each measuring 76.2 mm x 76.2 mm) were then added, and a 20 minute wash, at 80°C, pH 10.0 and 55 rpm. agitation was carried out, followed by rinsing in water of the same hardness as the water used to make the wash bath..

The ingredients and concentrations were as follows:

It will be seen that the washing additive according to the invention was used in concentrations of from 1.00 to 5.00 g/litre, and the other components in the mixtures were used in a constant total concentration of 2.495 g/litre, so that the total concentration varied from 3.495 to 7.495 g/liter. The percentage of the total mixture that the washing additive according to the invention constituted was therefore at each concentration of the latter as follows:

All percentages given in the examples are by weight and are based on the anhydrous materials.

EXAMPLE 1

The washing capabilities of mixtures containing a ternary builder system (washing additive). according to the invention were compared at two different concentrations and water hardnesses, with the values for control mixtures containing simple or binary builder systems. The aluminosilicate used was Zeolite A, the organic precipitating agent was disodium dodecyl malonate (C2AKM), and the organic sequestering agent was trisodium nitrile triacetate (NTA). The results were as follows:

EXAMPLE 2

A similar procedure to that in example 1 was carried out with the organic sequestering agent trisodium carboxymethyl oxysuccinate (CMOS) instead of NTA. The results were as follows:

EXAMPLE 3

A similar method to that in example 1 was carried out with the organic sequestering agent poly(α-hydroxyacrylate)

(PHAC) instead of NTA. The tests at 2.5 g/l and in water of 40°FH

2+

(Ca ) was carried out with another piece of test cloth, one with a predominantly greasy soil. The results were as follows:

EXAMPLE 4

A similar procedure to that in example 1 was carried out with an organic sequestering agent which was a polyacrylate (Versicol E7) instead of NTA. The tests were carried out at 3.0 g/l and in water of 40°FH (Ca ), and the results were as follows:

EXAMPLE 5

A similar procedure to that in example 1 was carried out with, as organic sequestering agent, tetrasodium-ethylene-diaminetetraacetate (EDTA) instead of NTA, at 3.0 g/l and in water of 40°FH (Ca2+). The results were as follows:

EXAMPLE 6

A similar procedure to that in example 1 was carried out with, as organic sequestering agent, tetrasodium oxydisuccinate (ODS) instead of NTA<*>, at 3.0 g/l and in water of 40°FH

2+

(Approx. The results were as follows:

EXAMPLE 7 A similar method to that in example 1 was carried out with, as organic sequestering agent instead of NTA, a . oxidized starch as described in British Patent No. 1 330 121. The tests were carried out at 3.0 g/l and in water of 40°FH (Ca ) and the results were as follows:

EXAMPLE 8

A similar procedure to that in example 1 was carried out with, as organic precipitant, instead of C-^-AKM, disodium hexadecenyl succinate (Clg-AKS). The tests were carried out in

Water of 40°FH (Ca2 + ). , and the results were as follows:

EXAMPLE 9

A similar method to that in example 1 was carried out with, as organic precipitating agent, instead of C^2 AKM, di-sodium-α-sulfostearate' (C, 0-SFAS). The tests were carried out in water of 4 0 FH (Ca ), and the results were as follows:

EXAMPLE 10

A similar procedure to that in example 1 was carried out with, as organic precipitant, instead of C₂AKM, disodium hexadecyl iminodiacetate (C₂IMA). The tests were carried out at a total builder concentration of 4 g/l in water of 40°FH (Ca }. Tests were carried out with both a clay-soiled test cloth

and a piece of test cloth that was soiled with a mixture of organic and particulate dirt. The results are as follows:

Claims (13)

1. Washing additive, characterized in that it essentially consists of: (a) from 25 to 97% by weight of a crystalline or amorphous aluminosilicate cation exchange material, (b) from 3 to 75% by weight, in total, of (i), a organic precipitating builder having a polyvalent anion, which builder forms an insoluble calcium salt, (ii). an organic builder that forms a soluble complex with calcium, the weight ratio between (i) and (ii) being from 10:1 to 1:10. 2. Washing additive as stated in claim 1, characterized in that the organic precipitating building has a divalent anion. 3. Washing additive as stated in claim 2, characterized in that the organic precipitating builder is a compound of formula I where R 1 is C 1 -C 2 -C 4 -alkyl or alkenyl, or an arylalkyl or alkylaryl group of equivalent chain length; X is CH, CR 2 , N or CON; R 2 is C 1 -C 4 alkyl; Y is hydrogen or a solubilizing cation; n and m, which may be the same or different, are 0 or integers numbers of 1-4; and Z is COOY or S03Y.. 4. Washing additive as stated in claim 3, characterized in that the organic precipitating builder is a compound of formula II where R^, Y and Z have the meanings given in claim 3, and p_ is 0 or 1. 5. Washing additive as stated in claim 4, k. fa r a c t e r i s e r t in that the organic precipitating builder is a compound of formula III where R^ and Y have the meanings given in claim 3. 6. Washing additive as stated in claim 4, characterized in that the organic precipitating builder is a compound of formula IV where R^ and Y have the meanings given in claim 3. 7. Washing additive as stated in claim 4, characterized in that the organic precipitating builder is a compound of formula V where R^ and Y have the meanings given in claim 3. 8. Washing additive as stated in any of the claims to 7, characterized in that the organic sequestering builder is an alkali metal salt of an organic carboxylic acid with 3 or more carboxyl groups. 9. Washing additive as specified in claim 8, characterized in that the organic sequestering builder or an alkali metal salt of nitrile triacetic acid. 10. Washing additive as stated in claims 1 to 9, characterized in that the aluminosilicate cation exchange material is a crystalline material with a unit cell of formula X where z is from 20 to 3 0.. 11. Washing additive as stated in any one of claims 1 to 10, characterized in that the weight ratio between the organic-precipitating builder and the organic sequestering builder is from 3:1 to 1:3. 12. Detergent mixture, characterized in that it comprises 3-90% by weight of at least one synthetic detergent-active material and 10^-97% by weight of a detergent additive as specified in any of claims 1 to 11. . 13. Detergent mixture as stated in claim 12, characterized in that it contains less than 5% by weight of inorganic phosphate.