The use of clays in fabric treatment compositions, and particularly detergents, is well known and examples and descriptions of clays in detergents can be found in a large number of publications. GB 1400898 discloses that smectic clays are preferred for this application, other publications have taught that the softening efficiency can be improved to that of simple addition of clay. EP 0299575 discloses using polymers additives; WO 92/07927 the use of polymer-polysiloxane and EP 0181508 discloses combining long alkyl chains containing quaternary amines with clay to give fabric softening.

DE 3833648 and EP 0203626 teach that clay can itself be processed with other ingredients and WO 00/60039 teaches that inclusion of a surfactant in an intimate mixture of clay, surfactant and polymer improves further the delivery of the clay softening agent.

The inclusion of polymers is, for the purpose of flocculating the clay, to aid efficiency of deposition of the clay and, typically, polyethylene oxide of molecular weight of 300,000 is used but is always in excess of 100,000. Long alkyl chain amines are themselves softening agents, as is polysiloxane, thus their combination with clay can be considered to be a combining of two softening agents.

The low molecular weight biodegradable polyamino acid polyaspartic acid has been used in detergent compositions, using aluminosilicates, but not using clay, to improve soil removal performance (WO 94/10282) but with no mention of softening performance, it has also been used to provide a sequesterant to maintain colour fidelity which can be compromised by deposition of Fe (WO 01/4632 A2). US patent 5, 658,872 describes the use of polyamino acids builders/sequestering agents, with aluminosilicates, but does not describe any fabric softening benefit.

US 6,407, 053 describes modified polyaspartic acid poly condensing aspartic acid with carboxylic acids, anhydride amines, alcohols, etc. or by polymerising monoethynically grafted unsaturated polymers in presence of polyaspartic acid and claim benefits are improvement in fabric overall appearance, pill/fuzz reduction, anti-fading, improved abrasion resistance and/or enhanced softening.

The inventors have unexpectedly found that mixing a polyamino acid with a clay unexpectedly has a synergistic effect and, for example, improves softening, and reduces creasing and wrinkles in fabrics. Whilst not wishing to be bound by the theory of the inventors, they believe that the clay and polymer chain interact to form a clay-polymer complex.

Accordingly, the first aspect of the invention provides a fabric treatment composition comprising : (i) a polyamino acid or a polyamino acid derivative, or a salt thereof; and (ii) a clay.

Preferably, the clay is a plate-like aluminosilicate clay, such as a smectic clay. Smectic clays are"swelling"clay minerals that can take up water between their layers. They also typically show cation exchange properties. Preferred clays include bentonite, montmorillonite, hectorite, nontronite, beidellite, saponite, laponite, vermicullite, kaolinite, illite and mixtures thereof.

Preferably, the clays are used with exchangeable cations present, preferably with a monovalent or divalent cation. Most preferably the counterions in the clay are protons, alkali metals and alkaline earth metals, most preferably the divalent cation is calcium or magnesium. Such calcium or magnesium salts are especially preferred because upon washing the calcium and magnesium cations exchange with sodium ions from within the washing solution. This results in the swelling of the clay and improves the dispersal of the clay.

The clay may be"activated". that is, some of the exchangeable cations, such as magnesium or calcium ions are replaced by monovalent cations such as potassium or especially sodium. This improves the softening effect of the clay. Not all of the exchangeable counterions are converted, however, as this will cause the clay to gel. Typical values are 15 to 50% of calcium and/or magnesium exchanged with sodium or potassium. Activated clays are discussed in, for example, GB 2, 138, 037. The polyamino acid is preferably a polyamino acid selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine.

The polyamino acid is most preferably polyaspartic acid or polyglutarnic acid. Polyamino acids may be produced by techniques well-known in the art. See, for example, US 5,658, 872 and US 6,407, 053. Polyamino acids such as polyaspartic acid may also be obtained commercially, such as Bayer and Donlar Biopolymers, Inc.

The polyamino acid may be a copolymer of two or more amino acids such as aspartic acid and glutamic acid.

Most preferably the fabric treatment composition preferably comprises a polyamino acid which has an alkali metal, ammonium or substituted ammonium salt. Preferably, the polyamino acid has an alkali metal cation such as sodium or potassium. The substituted ammonium may be mono-, di-or triethanolammonium.

Preferably, the polyamino acid (based on the acid form) has a molecular weight of less than 100,000, especially from about 700-90,000, more preferably 2,000-60, 000, especially 3,000-30, 000.

The polyamino acid may be a derivative of a polyamino acid. The polyamino acid may be derivatised by substituting or replacing one or more groups. For example, US 6,407, 053 discloses derivatised polyaspartic acids which are obtained by polycondensing (a) 1-99.9 mol % aspartic acid with (b) 99-0.1 mol % fatty acids, polybasic carboxylic acids, anhydrides of polybasic carboxylic acids, polybasic hydroxy carboxylic acids, monobasic poly-hydroxy carboxylic acids, alcohols, amines, alkoxylated alcohols and amines, amino sugars, carbohydrates, sugar carboxylic acids and/or non-proteiogenic aminocarboxylic acids, or by polymerising monoethylenically unsaturated monomers in the presence of polyaspartic acids. Most preferably, such derivatives of polyamino acids contain at least 50, at least 60, at least 70, at least 80, more preferably at least 90 mol % amino acid, such as aspartic acid.

The polyamino acid may be a polyamino acid or salt thereof having the formula wherein R is H or Cl-c4 alkyl, X and Y can be the same or different and are selected from Cl-C4 substituted alkylene or substituted phenylene, the substituent being selected from halogen, nitro and hydroxyl, m and n are the same or different and are 0 or 1, p is from 12 to 350 and M is hydrogen or a neutralizing cation.

The fabric treatment composition preferably uses a polyamino acid having the general formula: wherein M is hydrogen or a neutralising cation such as alkali metal (e. g. sodium or potassium), ammonium or substituted ammonium (e. g. mono-, di-, or triethanolammonium). The a and ß blocks in the above formula can vary in number of repeating units and can be randomly distributed along the chain provided that the total number of a + p is at least 2. The absolute configuration about the asymmetric carbon atoms can be d or 1.

It should be noted that the clay is not an aluminosilicate such as a zeolite. Such aluminosilicates are typically used as builders. They are not clays. It is the presence of a clay with the polyamino acid that has been found to unexpectedly improve the properties of the fabric treatment composition.

Preferably the clay and polyamino acid are intimately mixed.

However, the composition may additionally comprise one or more builders such as zeolite or sodium tripolyphosphate and may additionally comprise for example fillers, such as sodium sulphate, STPP, one or more of sodium carbonate, sodium silicate, layered silicate, sodium linear alkylbenzene sulphonate, non-ionic surfactants such as Donanol 45-7, cationic surfactants, anti-foaming agents, optical brighteners, photo bleaches, enzymes such as proteases or lipases, fabric bleaches such as perborate compounds, bleach activators such as TAED, chelating agents, other additives such as cmc, dye transfer inhibition compounds, perfume, speckles, and/or other additives typically found in fabric treatment compositions.

The fabric treatment composition may comprise a detergent, such as an amphoteric, non-ionic, cationic, anionic surfactant.

The fabric treatment composition is typically used at a pH range of 9-11. Accordingly, the fabric treatment composition may comprise one or more buffers or pH modifying agents.

However, the fabric treatment composition may also be produced without a detergent. This allows the fabric treatment composition to be combined with a detergent of choice, for example by the end user.

The polyamino acid, polyamino acid derivative or salt thereof and the clay may be intimately mixed. This may be achieved, for example, by dry mixing the polyamino acid and the clay as a powder, more preferably by intimately mixing them with water present to aid intimate contact between the clay and the polyamino acid.

The fabric treatment composition may also comprise a solvent or other liquid, such as water or an organic solvent. This allows the production of a liquid fabric treatment composition for convenient use by a consumer.

Alternatively, the fabric treatment composition may be tableted.

The ratio of the polyamino acid, polyamino acid derivative or a salt thereof: clay (s) is preferably 10: 1 to 1: 100, more preferably 1: 1 to 1: 100, especially 1: 1 to 1: 10 weight : weight.

The fabric treatment compositions may be in the form of a liquid or a solid. They may be impregnated into a non-woven sheet of fabric material, for example for use in tumble-driers as a softener in the drying process or for use in the machine wash. The composition may be in the form of a powder, granule, slurry or tablet.

Detergent compositions comprising the fabric treatment compositions are also provided.

These may be in the form of a powder, a granule, a slurry or a tablet.

Preferably, the composition contains 55 to 90% by weight of clay compared to the total amount of clay and polyaspartic acid.

A further aspect of the invention provides a method of treating a fabric comprising combining: (i) a polyamino acid or a polyamino acid derivative or a salt thereof ; and (ii) a clay ; in a liquid to form a liquid treatment agent; and (iii) contacting a fabric with a liquid treatment agent.

The liquid may typically be water, for example the water used to wash the fabric. The clay typically disperses within the liquid and does not truly dissolve within the liquid.

However, it may be possible to use other liquids, such as organic solvents, instead of an aqueous liquid such as water.

Preferably, the fabric treatment composition is as defined above for the first aspect of the invention.

The polyamino acid, polyamino acid derivative or salt may be added separately to the clay, or alternatively added together, for example in an intimately mixed state. The intimately mixed components may be mixed, for example, in a dry state prior to adding to the liquid.

Typically, the fabric treatment agent is used at a pH range of 5 to 10.

Typical concentrations of the fabric conditioners are 0.2 to 4%.

They may be used at a temperature range of 5 to 100°C, especially 30 to 92°C, more preferably 40 to 70°C, especially 60°C.

The invention also includes within its scope fabric treated with a fabric treatment agent according to the first aspect of the invention or treated by a method according to the second aspect of the invention.

Combinations of a mixture of 1) the polyamino acid, polyamino acid derivative, or a salt thereof, with 2) a clay, as defined above, are also provided.

The invention will now be described by reference to the following Figure and examples: Figure 1 shows the arrangement of stains on a test sample for stain release tests.

Except where otherwise indicated, the clay/polyaspartic acid sodium salt were tested primarily in a simple detergent formulation that consisted of Zeolite A (48%), 80-100% sodium alkylaryl sulphonate (Unger Ufaryl) (24.2%), sodium carbonate (24.2%) and Antifoam C133 (Basildon Chemicals) (3.2%).

The clay and polyaspartic acid were either added as two discrete individual powders ("two") to the detergent formulation or the clay and polyaspartic acid had been premixed ("intimately mixed") in the presence of water to ensure their intimate contact. The intimate mixtures were dried and milled to a powder before being evaluated. The ratio of clay to polyaspartic acid were varied (Example 1). Where not indicated otherwise, the clay and polyaspartic acid were intimately mixed. The clay (e. g. CSM. Vol. 1), unless otherwise indicated, was an Eastern Mediteranean calcium type of bentonite clay from Turkey.

The washing tests were conducted with Miele Novotronic W864 washing machines at 60°C, cotton wash and 1200 rpm spin speed for drying washing. 8 washing cycles were carried out before the Terry towel swatches were tested for softness. The water had a typical total hardness of 25 mg. For each wash cycle lOOg of basic detergent plus lOg of additive was used. 1 l Og detergent was used as a reference without additive.

Unless otherwise indicated, the polyaspartic acid was 3000 mol. wt. from Donlar and ratios of e. g. clay: polyaspartic acid are on a weight: weight basis.

Unless otherwise indicated, the ratio of clay: polyaspartic acid additive was 90: 10, and the components were intimately mixed.

Softness testing was by panel comparing to a standard swatch, the test was carried out in duplicate on a scoring system of +2 for much softer, +1 for slightly softer, 0 for no difference, -1 for slightly worse and-2 for much worse.

All swatches were allowed to dry in the same atmosphere for 24 hours to allow moisture contents to normalise prior to panel testing.

Upon final air drying there was a difference noted in the propensity to leave creases and wrinkles in the dried swatch. The difference was marked and beneficial for intimately mixed polyaspartic acid sodium salt (NaPASP) /clay and not so for other systems.

Scores from panel test: Example 1-Basic detergent formulation plus additive Ratio of clay CSMVOL 1 Intimately mixed Added as two 100 : 0-0. 5 55 45 +1.2 +1.6 62 38-+0. 05 79 21 +1.6 +0.25 86 14 +1.6 +0.8 93 7 +1.6-0. 2 0 100--0. 2 0 : 0-0. 8 Ratio of clay CSMVOL 2 55 : 45-+0. 3 79 : 21-+0. 15 100 : 0-+0. 5 0 100--0. 2 Example 2-Fully formulated detergents + CSMVOL1 and NaPASP Commercial detergent 1-0.7 Commercial detergent 1 + intimately mixed 55: 45 +1.6 Commercial detergent 1 + separately mixed 55: 45 +1.1 Commercial detergent 2-0.7 Commercial detergent 2 + intimately mixed 55: 45 +0.8 Commercial detergent 2 + separately mixed 55: 45 +0.8 Commercial detergent 3 includes a clay softener Commercial detergent 3-0.5 Commercial detergent 3 + intimately mixed 55: 45 +0.9 Commercial detergent 3 + separately mixed 55: 45 +1.5 The polyaspartic acid sodium salt/clay interaction leading to enhanced softening compared to clay alone is not due to flocculation of the clay as is the mechanism noted in previous patents teaching the benefits of polymer addition to clay. The current mechanism was shown not to be due to flocculation by comparing the rate of settling of clay from a uniform suspension in water (achieved through shaking).

Clay wherein the exchangeable cations are calcium and magnesium, i. e. the form normally used in commercial detergents containing clay for through the wash softening settled at an identical rate with or without NaPASP present and visually there was no evidence of flocculation. As the calcium/magnesium exchangeable cations are replaced by sodium cations in situ during the washing process so the experiment was repeated with the clay now containing sodium exchangeable cations. The rate of settling was slower than with clay in the calcium/magnesium form but the presence or absence of NaPASP did not influence the settling rate and there was no visual evidence of flocculation.

When either sodium form or calcium/magnesium form clay was mixed with 300,000 molecular weight polyethylene oxide (a polymer claimed in EP 0299575) the clay visibly flocculates and rapidly settles in a manner not observed in the NaPASP containing experiments.

The anti-creasing/anti-wrinkle behaviour noted on air drying the swatches was assessed by comparing pairs of swatches that had been air dried-hanging vertically pegged to a drying frame. Swatches from intimately mixed NaPASP/clay washing was compared with swatches from separately mixed NaPASP/clay washing. The swatch with least creases was scored +1 and if no difference noted was scored 0. It was noted that both the clay alone and NaPASP alone gave more creases than the intimately mixed NaPASP/clay swatches.

Example 3 Anticreasing/Antiwrinkle behaviour Ratio of clay to NaPASP Intimately mixed Added as two 55 45 +1- 62 38 0 0 79 21 +1 86 14 +1 93 7 +l Swatches washed with commercial detergents 1 and 2 were compared respectively with swatches washed with NaPASP/clay using the same scoring system and also scoring-1 if creasing was worse.

Commercial detergent 1 + intimately mixed 55: 45 +1 Commercial detergent 1 + separately mixed 55: 45-1 Commercial detergent 2 + intimately mixed 55: 45 +1 Commercial detergent 2 + separately mixed 55: 45 0 Example 4. The effect of different sources of polyaspartic acid: 70: 21 Clay: poly aminoacid ratio 86: 24 Clay: poly aminoacid ratio Softness score Donlar +2 +2 Softness score Bayer +1.75 +1.75 This shows that the source of the polyaspartic acid does not have a significant effect on the softening effect of polyaspartic acid.

Example 5. The effect of clay concentration: Percentage clay* 55% 79% 86% 90% 93% Softness score +1.5 +2 +2 +1.5 +1.03 * percentage of clay + polyaspartic acid by weight.

This shows that concentrations of 55% to 90% clay have improved softness.

Example 6. Comparison of commercially available brands of detergents against a standard detergent: Detergent Persil Bold Home-made + 10% additive Softness score +0.3 +0. 5 +2 Example 7. The effect of wash temperature.

Varying the wash temperature showed improvements at about 60°C : Wash Temperature (°C) 30 40 60 92 Softness score +1 +1.2 +1.8 +1.2 Example 8. The effect of molecular weight.

Samples of polyaspartic acid of 3,000 and 50,000 molecular weight from Donlar were tested with clay: Molecular weight (Mw) 3K 50K Softness score +2 +1.625 This shows that a variety of molecular weights may be used.

Example 9. Stain Removal.

The assessment of clay/polyamino acid using a detergent with no bleaching agents was assessed using EMPA 102 cotton test samples and the above wash cycle, comparison with detergent alone single wash cycle.

RESULT, no difference in stain intensity after washing could be determined between test pieces washed with modified clay (clay + additive) /detergent and those washed in detergent alone (reference).

Example 10. Soil Release.

The assessment was made using pre-conditioned cotton and polycotton fabrics (pre-washed - 8 cycles with and without modified clay). Test pieces had stains uniformly added as in Figure 1. The test pieces were washed in detergent alone (with no bleaching agent or modified clay) in wash cycle above.

RESULT, no difference in the intensity of residual stains between test pieces washed with and without modified clay with additive.

Example 11. Brightness assessment.

Terry towel swatches washed (8 cycles) with modified clay (clay + additive) and detergent and in detergent alone were assessed for affect on brightness of fabric by measuring 457 nm light reflected from the swatches compressed and at various orientations 18 readings per measurement.

RESULTS: SWATCH REFLECTION OF 457 nm LIGHT UNWASHED 88.7 and 88.3 DETERGENT ALONE 88.6 and 88.6 DET + Modified Clay 89.3 and 91.1 Example 12. Deposition of material on fabric surface.

An average from 3 runs of % ash residue from swatches compared to initial weight.

Swatches were washed 8 cycles with different additives present and ashed at 950°C (it might have been at a slightly different temp) 1. Own detergent* alone 0. 31% 2. Own detergent* alone + polyaspartic acid (4. 5g) 0.28% 3. Own detergent* alone + Clay (CSMVOL1) (5. 5g) 0.58% 4. Own detergent* alone + intimately mixed PASP/clay (lOg) 0.55% 5. Own detergent* alone + added as separate PASP/clay (lOg) 0.44% 6. No additives 0.09% * The simple detergent described above. Wherever clay is added ash residue is higher.

XRay Fluorescence on ash residues at 3. 7% made up with Ti02 show the following : Element 1 2 3 4 5 3. 7% clay in 100% TiO2 TiO2 control O 40. 12 40.12 40.05 40.10 40.07 40.13 40.03 Na 0.37 0.24 0.09 0.10 0.10 0.05 0.08 Mg 0.08 0.11 0.07 0.14 0.08 0.10 0.06 Al 0. 39 0. 38 0.06 0.15 0.10 0.10 0.00 Si 0. 39 0. 39 0.11 0.28 0.19 0. 36 0.00 P 0.07 0.07 0 ; 07 0.07 0.07 0.06 0.06 S 0.02 0.01 0.01 0.01 0.01 0.00 0.00 K 0.12 0.12 0.12 0.10 0.10 0.09 0.09 Ca 0.12 0.22 0.05 0.12 0.11 0.08 0.00 Ti 58. 30 58. 30 59. 32 58.87 59.12 58.94 59.66 Fe 0.03 0.04 0.05 0.06 0.06 0.07 0.02 XRF from 1 indicates zeolite deposited on fabric as only Si and Al material present.

XRF from 2 polyaspartic only zeolite still laid on fabric.

XRF from 3,4 and 5 where clay present show lower Al and Si suggests clay cometes successfully for fabric surface. Unfortunately, the ratio of clay to zeolite cannot be determined but by taking the Fe and Na data into account also it would seem that the majority of the inorganic deposited is clay.

Example 13. Alternative sources of clay.

Another source of bentonite clay (CGS-a non-gelling clay) was tested to ensure that the effects seen were not limited to the source of the clay. "Persil"is a commercially available brand of detergent.

Persil + (intimately mixed CGS/polyaspartic acid 90: 10) scored +1, compared to Persil alone. The softness was measured whilst adding lOg granulated additive to 100g Persil.

Persil + CGS alone scored +0.5 (lOg additive + 100g Persil), showing that the softness increase is not just due to the clay alone.