WO2002088292A1

WO2002088292A1 - Radical initiator composition

Info

Publication number: WO2002088292A1
Application number: PCT/EP2002/003846
Authority: WO
Inventors: Stephen Norman Batchelor; Andrew Paul Chapple; Lynette Fairclough; Jacqueline Williams
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 2001-04-27
Filing date: 2002-04-08
Publication date: 2002-11-07
Also published as: WO2002088292A8; GB0110414D0; AR033477A1

Abstract

The present invention relates to radical initiator composition which can be used in a novel colour care and stain treatment system. The present invention also relates to a method of preparing the composition and to its use. The invention provides a surfactant composition comprising a radical initiator, which is preferably a photo initiator and preferably selected from hydrogen abstraction photoinitiators, bond cleavage radical photoinitiators or mixtures thereof. The composition further comprises at least one detergency builder, and is characterised in that said radical initiator is adsorbed onto at least a portion of said builder.

Description

RADICAL INITIATOR COMPOSITION

Field of the Invention

The present invention relates to a radical initiator composition used for laundry colour care and stain treatment. The invention also relates to a method of preparing the composition and to its use.

Background of the Invention

It is known to include components in fabric care compositions which are specifically intended for colour care. These components may comprise dye transfer inhibitors, stain removers, photo-fading inhibitors, and fluorescence inhibitors. One disadvantage of these components is that many of the active ingredients are - expensive and this may preclude their use by many groups of consumers .

A possible solution to this cost barrier lies in the use of so-called 'radical initiators' . Radical initiators are well- known chemicals in the plastics and curing industry. These application have been widely discussed in the literature see e.g. H.F. Gruber Prog. Polym. Sci. 17 (1992), 953-1044 and references therein. They are typically organic chemicals which on exposure to light react to form neutral radicals that may initiate the polymerisation of alkenes . GB 909932 (Shell Research, 1960) , for example, discloses a finely divided filler which can be a simple salt or a metal alumina-silicate, onto which an organic, free-radical polymerisation initiator is adsorbed. This is used, preferably as a relatively coarse granular composition, in the production of rubber to achieve a degree of cross- linking.

Recently, radical initiators have been found to be effective laundry photo-bleaches: UK patent application 9917451.8 teaches their use from main wash detergent powders and liquids, where the initiators are intimately mixed into the powder or liquids.

These materials are effective at low levels as bleaching agents for dyes which have been removed from the fabric during the washing process. If these dyes are not bleached they may become transferred to other parts of the article being washed or to other articles being washed at the same time. This 'dye transfer' process can lead to the familiar problem of 'white' articles emerging from the wash with a significant colour. Radical initiators have been shown to provide a low cost mechanism by which vagrant dyes can be bleached, either during the wash or afterwards. These initiator materials are also effective against coloured components found in stains. In the present specification, vagrant dyes and coloured materials found in stains and soiling are, unless the context demands otherwise, referred to collectively as 'stains'. Several radical initiator mechanisms are known. Fabric care compositions comprising radical photo-initiator systems that operate by a hydrogen abstraction mechanism or a bond cleavage mechanism are described in our co-pending UK patent application no 9917451.8.

UK 9917451.8 discusses the potential problem of dye damage, in which the radical initiator is unable to distinguish between 'vagrant' dye and dye which has remained in situ. Clearly, it is important that any bleaching mechanism which is directed at unwanted stains is less effective and preferably ineffective against dyes which have been deliberately placed on the fabric to enhance its appearance.

One solution to this problem of selectivity is to ensure that the initiator only acts superficially. This can be accomplished by ensuring that the initiator, has a high log P value (where P is the octanol-water partition coefficient) . With a relatively hydrophobic initiator, less dye damage is likely to result on coloured fabric.

Unfortunately, such hydrophobic materials are difficult to formulate in conventional detergent compositions.

Thus, while it is possible to incorporate radical initiators in some liquid compositions, incorporation in solid or semi- solid forms such as bars, powders, tablets and granules has led to practical difficulties requiring the use of special mixing methods or commercially unfavourable levels of materials. For laundry powder or tablet production these modified processes are time-consuming and add extra cost to the incorporation of the radical-initiator. The present invention aims to provide effective and reproducible stain treatment compositions which contain radical initiators.

Definition of the Invention

We have determined that by pre-adsorbing the radical initiator onto at least a part of the builder it is possible to manufacture surfactant compositions suitable for laundry use and with improved effectiveness and reproducibility .

Accordingly, one aspect of the present invention provides a surfactant composition comprising at least one radical initiator and at least one detergency builder, wherein said radical initiator is adsorbed onto at least a portion of said builder.

Preferably this composition is a fabric care composition, i.e. it is effectively free of components which would harm fabrics .

A further aspect of the present invention provides a method of treating fabric with a surfactant composition comprising at least one radical initiator and at least one detergency builder, wherein said radical initiator is adsorbed onto at least a portion of said builder.

A further aspect of the present invention provides a process for the production of a fabric care surfactant composition which comprises forming a pre-mix of at least one builder and at least one radical initiator.

Preferably, the pre-adsorption is done in a liquid media. We have found that the liquid initiators can be adsorbed onto zeolites making granules that can be simply added to powder/tablet formulations or to detergent bars as part of an essentially standard production process.

Conveniently, solid/semisolid initiators can be made into a suitable liquid form by mixing with neat surfactant or a solvent .

Solid washing products (e.g. powders, bars, tablets) according to the present invention give excellent bleaching effects on stains with little colour damage. This can be accomplished with low levels of initiator.

To increase colour care and cleaning the formulations may also contain enzymes, perfumes, peroxygen based bleaches, singlet-oxygen photo bleaches, transition metal bleach catalysts, anti-dye transfer polymers, crystal growth inhibitors, modified polysaccharides, clays, cellulose mono- acetate and derivatives, fixers, reactive-cross-linking polymers, fluorescers and soil release polymers. These ingredients are all well-known in the art. For ease of application the radical initiator/builder combination can be co-granulated with these ingredients.

Preferably the builder/initiator granules are less than 700 microns in diameter (i.e. they will pass through a 700 micron sieve) . More preferably, the granules are 5-700 microns in diameter.

The radical-initiator/bleach granules of the present invention are particularly advantageous in formulations that cannot contain peroxygen bleaches (as other ingredients are present which would react with the peroxygen bleach on storage) or which cannot withstand the high pH of typical peroxygen bleach formulation (e.g. certain dye transfer polymers) . The granules as described herein may also be used to easily deliver radical initiators to polluted water for bleaching.

The granules may contain a single radical initiator or a mixture of radical initiators e.g. a 50:50 mixture of Lucirin TPO-L ™ and Esacure KIP-150 ™.

It has been found that the radical initiators of the present invention will act on stains without the need for agitation. This has the advantage that they can be used in simple application methods. Furthermore, mechanical damage to fabrics (such as fibrillation) can be avoided by reduction of agitation.

Detailed Description of the Invention

As described above, compositions according to the invention comprise :

a) radical initiator, b) builder, and,

c) surfactant .

Preferably the radical initiator and the builder are formed into a granule which is then mixed with the surfactant and with any other components present .

In order that the invention may be further understood it is described below with reference to preferred features thereof .

Radical Initiators:

Preferably the radical initiators are radical photoinitiators. Chemical and thermal radical initiators can be used but are less preferred.

It has been found that the preferred radical photo- initiators of the present invention have the advantage that they are stable in solution if kept in the substantial absence of light. It is found that they do not degrade spontaneously on storage .

Preferably the radical initiators are selected from hydrogen abstraction radical photoinitiators, bond-cleavage radical photoinitiators and mixtures thereof.

Oligomeric radical photoinitiators are preferred. Radical photoinitiators preferred for use in the present invention are components which produce radicals capable of attacking stains on fabric, on photo-excitation by one of the following routes:

Hydrogen Abstraction Photo Initiators:

Hydrogen abstraction radical photoinitiators operate according to the following reaction:

light kl

X τ> X* + R-H 7 X* + R»

where X is the radical photo-initiator and R-H is a hydrogen donating compound.

Suitable examples of hydrogen abstraction radical photoinitiators X include benzophenones, acetophenones, pyrazines, quinones and benzils.

Suitable examples of hydrogen donating compounds R-H include organic molecules containing an aliphatic C-H group and include propan-2-ol, and compounds comprising a cellulose, polyester, or nylon backbone, for example.

kl is the rate constant of the hydrogen abstraction reaction. Preferably, the rate constant kl is greater than

4 -l -i 10 mol Is when RH is propan-2-ol. Bond Cleavage Radical Photoinitiators:

Bond cleavage radical photoinitiators operate according to the following reaction:

light k2 Y 7 Y* 7 Rι«+ R2»

k2 is the rate constant of the bond-cleavage reaction.

& — 1 Preferably, k2 is greater than 10 s . These reactions are believed to produce carbon-centred radicals rather than the more familiar hetero-centred radical.

Bond cleavage radical photo-initiators are preferred over other types of radical photo-initiator.

Suitable bond cleavage radical initiators may be selected from the following groups. It should be noted that not all materials in these classes are themselves radical initiators:

(a) alpha amino ketones, particularly those containing a benzoyl moiety, otherwise called alpha-amino acetophenones, for example 2-methyl 1- [4 -phenyl] -2- morpholinopropan-1-one (Irgacure 907, trade mark), (2- benzyl-2 -dimethyl^' amino- 1- (4-morpholinophenyl) -butan-1- one (Irgacure 369, trade mark);

(b) alphahydroxy ketones, particularly alpha-hydroxy acetophenones, eg (1- [4- (2-hydroxyethoxy) -phenyl] -2- hydroxy-2 -methyl-1-propan-l-one) (Irgacure 2959, trade mark), 1 -hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, trade mark), oligo [2 -hydroxy 2-methyl-l- [4 (1- methyl) phenyl] propanone (Esacure KIP 150, trade mark);

(c) phosphorus-containing photoinitiators, including monoacyl and bisacyl phosphine oxide and sulphides, for example 2-4-6- (trimethylbenzoyl) diphenyl-phosphine oxide, bis (2 , 4, 6-trimethylbenzoyl) -phenyl -phosphine oxide (Irgacure 819, trade mark), (2,4,6- trimethylbenzoyl) henyl phosphinic acid ethyl ester (Lucirin TPO-L (trade mark) ex BASF) ;

(d) dialkoxy acetophenones;

(e) alpha-haloacetophenones; and

(f) trisacyl phosphine oxides.

(g) benzoin and benzoin based photoinitiators

Suitable radical photoinitiators are disclosed in WO 9607662 (trisacyl phosphine oxides) , US 5399782 (phosphine sulphides), US 5410060, EP-A-57474, EP-A-73413 (phosphine oxides), EP-A-088050, EP-A-0117233 , EP-A-0138754 , EP-A-0446175 and US 4559371.

Suitable photoinitiators are disclosed for example in EP-A-0003002 in the name of Ciba Geigy, EP-A-0446175 in the name of Ciba Geigy, GB 2259704 in the name of Ciba Geigy (alkyl bisacyl phosphine oxides) , US 4792632 (bisacyl phosphine oxides) , US 5554663 in the name of Ciba Geigy (alpha amino acetophenones) , US 5767169 (alkoxy phenyl substituted bisacyl phosphine oxides) and US 4719297 (acylphosphine compounds) .

Radical photoinitiators are discussed in general in A.F. Cunningham, V. Desorby, K. Dietliker, R. Husler and D.G. Leppard, Chemia 48 (1994) 423-426. They are discussed in H. F. Gruber Prog. Polym. Sci. 17(1992) 953-1044.

Without wishing to be bound by theory, it is preferred that the radical photoinitiators all react through their excited triplet state, to reduce the influence of the cage effect.

The radical photoinitiator suitably undergoes one of the reactions set out above when excited by radiation falling generally in the range 290-800 nm. For example, natural sunlight, which comprises light in this region, will be suitable for causing the radical photoinitiator to undergo one of the reactions described above. Preferably, the radical photo initiator has a maximum extinction coefficient in the ultraviolet range (290-400 nm) which is greater than

-l -l 100 mol 1cm . Suitably, the radical photo initiator is a solid or a liquid at room temperature. Preferably, the treated fabric is exposed to light until the stain is removed or all photo initiator has reacted. It will be appreciated that the time taken for stain removal and/or substantially complete reaction of the photo initiator will depend on the intensity of the light. In typical terrestrial light conditions, the time of exposure may, for example, range from a few seconds to a few days, preferably 1 second to 6 hours .

The method of the invention preferably comprises a step of exposing the treated fabric to light, more preferably sunlight, even more preferably direct sunlight. When the method is carried out as part of a laundering process, the exposure to light conveniently involves drying the fabric in sunlight. However, the treated fabric can be exposed to light in other ways, such as, for example, using a source of artificial light.

Suitably, the radical photo-initiator is substantially colourless and gives non-coloured photo products upon undergoing one of the reactions set out above.

Optionally, the compositions comprise sensitisers such as thioxanthones, for example as described in EP-A-0088050 , EP- A-0138754.

Preferred Radical Photo-initiator Systems:

The present inventors have determined that radical photoinitiators having a specified hydrophobicity, measured by their log P value, have a particularly preferred effect. As noted above, all materials for the removal of stains also have a tendency to attack dye. The preferred radical photoinitiator systems have a beneficial balance of stain removal versus dye attack tendency. Preferably, the radical photoinitiators have a high log P value, where log P is the octanol-water partition coefficient. It is preferred that the radical photoinitiators have a log P measured at 25°C in excess of 2.5 and more preferably in excess of 4.0.

Clearly addition of the granule to the powder/tablet/bar should occur in the absence of significant levels of UV light to prevent photo-degradation of the product. Additionally the product container should not allow light below 440 nm to penetrate. This may be achieved by use of suitable optical barriers including plastics, sunscreens or dyes

Detergency Builders:

The compositions of the invention will contain one or more detergency builders. Some or all of the builder acts as a carrier for the radical initiator. Additional builder can be present which is essentially free of adsorbed radical initiator.

The builders present in compositions according to the invention may be organic or inorganic, or mixtures of the same.

It is preferred that the detergency builder which is pre- mixed with the initiator is an inorganic detergency builder. It is preferred that the detergency builder which is pre- mixed with the initiator is water insoluble. It is preferred that any additional organic builder present in the composition is not co-granulated with radical initiator.

For the preferred liquid initiators simple premixing of the initiator with the builder is sufficient to produce a granule .

For solid initiators, it is convenient to add a liquid phase material, preferably a solvent or a surfactant, to the premix. Nonionic surfactants have been found to be suitable for this purpose. Suitable liquids can be made by mixing surfactants with initiator in a 1:4 to 4:1 ratio. Ratios of around 1:1 on a weight basis have been found particularly effective .

Typical granules will contain builder and radical initiator at weight ratios of 1:1 to 100:1 with ratios of 1.5:1 to 40:1 being preferred.

Overall levels of radical initiator in the final product are preferably in the range 0.01-0.5wt% on total product.

The total amount of detergency builder in the compositions will suitably range from 5 to 80 wt%, preferably from 10 to 60 wt%.

Inorganic builders present in compositions of the invention may include : sodium carbonate, if desired in combination with a crystallisation seed for calcium carbonate, as disclosed in GB 1 437 950 (Unilever ) ; crystalline and amorphous aluminosilicate, for example, zeolites as disclosed in GB 1 473 202 (Henkel) ; mixed crystalline/amorphous aluminosilicate as disclosed in GB 1 470 250 (Procter & Gamble) ; and, layered silicates as disclosed in EP 164 514B (Hoechst) .

Inorganic phosphate builders, for example, sodium orthophosphate, pyrophosphate and tripolyphosphate are also suitable for use with this invention.

The compositions of the invention preferably contain an alkali metal, preferably sodium, aluminosilicate builder. Sodium aluminosilicate may generally be incorporated in amounts of from 10 to 70% by weight (anhydrous basis) , preferably from 25 to 50 wt%.

The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula:

0.8-1.5 Na 0. Al₂0₃. 0.8-6 Si0₂

These materials contain some bound water and, preferably, are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The most preferred sodium aluminosilicate contains 1.5-3.5 Siθ₂ units (in the formula above) . Both the amorphous and the crystalline materials can be prepared readily be reaction between sodium silicate and sodium aluminate, as amply described in the literature. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1 429 143 (Procter & Gamble) . The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A and X, and mixtures thereof .

The zeolite may be the commercially available zeolite 4A now widely used in laundry detergent powders. The zeolite builder incorporated in the compositions of the invention may be maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070A (Unilever) . Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20.

Especially preferred is zeolite MAP having a silicon to aluminium ratio not exceeding 1.07, more preferably about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per g of anhydrous material.

Organic builders that may also be present include: polycarboxylate polymers such as: polyacrylates, acrylic/maleic copolymers, and acrylic phosphinates; monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and tri-succinates, carboyxmethyloxysuccinates, carboxy ethyloxymalonates , dipicolinates , hydroyxethyliminodiacetates , alkyl- and alkenyl-malonates and succinates, and, sulphonated fatty acid salts. This list is not intended to be exhaustive.

Especially preferred organic builders are citrates, suitable used in amounts of from 5 to 30 wt%, preferably from 10 to 25 wt%; and acrylic polymers, more especially acrylic/maleic copolymers, suitably used in amounts of from 0.5 to 15 wt%, preferably from 1 to 10 wt%.

Builders, both inorganic and organic, are preferably present in alkali metal salt, especially sodium salt, form.

Radical Terminators:

Radical terminators may optionally be present in the compositions of the present invention.

The radical terminators which are used in the compositions and methods of the invention react rapidly with reactive free radicals to give non-reactive products. "Reactive free radicals" are the free radicals which are formed from the radical initiator or by the reaction of these free radicals with molecules which are present in the environment in the region of the stain.

The reaction of the radical terminators (T) with reactive free radicals (R) to give non-reactive products can be summarised by the following equation: k3 R • + T ► non-reactive products

The non-reactive products can, for example, be relatively stable (and relatively unreactive) radicals or non-radical molecules or ions .

The rate constant k3 for the above reaction is preferably

4 -i -l greater than 10 M s , more preferably greater than

10 M s . It is preferably at or near to the diffusion controlled limit (ie, close to 8RT/3η, where T is the temperature, R is the gas constant and rj is the viscosity)

Suitable radical terminators include, for example, stable (ie, non-reactive) radicals eg, compounds containing nitroxide (N-O*) radicals, radicals derived from hindered semiquinones or radicals derived from hindered phenols. These act as radical terminators by reaction with the reactive free radicals to form a non-radical molecule or ion.

Suitable radical terminators also include, for example, compounds which react with reactive free radicals to form the stable radicals mentioned in the preceding paragraph. Thus, hindered amines (HALS; hindered amine light stabilisers) which are capable of forming nitroxide radicals, hindered phenols and hindered hydroquinones can also act as effective terminators. Preferred radical terminators for use in the invention include ascorbic acid (vitamin C) and chromanols such as vitamin E.

The chemistry of radical terminators is well-known and is described in, for example, Pospisil et al, "Oxidation Inhibition in Organic Materials", Volumes I and II, CRC Press, 1990. Rate constants k3 for the reactions of radical terminators with reactive free radicals are given in, for example, Landolt-Bornstein, "Radical Reaction Rates in

Liquids", Fisher H, Hellwege K-H, (Springer-Verlag) 1963- 1997.

The radical terminators which may be used in the compositions and methods of the invention can be single radical terminator compounds or mixtures containing two or more different radical terminators.

When radical terminators are used in conjunction with radical initiators, the two do not merely cancel each other out but, instead, still give effective stain bleaching whilst reducing damage to the dye in a coloured fabric. This benefit is particularly, although not exclusively, observed when the radical terminator is water soluble and the use of water soluble radical terminators is therefore preferred.

The ratio of the amounts (by weight) of radical terminator to radical initiator used in the compositions and methods of the invention can be, for example, from 100:1 to 1:100, preferably 10:1 to 1:10, more preferably 5:1 to 1:5. Form of Compositions:

The present invention is suitable for use in industrial or domestic fabric wash compositions, fabric conditioning compositions and compositions for both washing and conditioning fabrics (so-called through the wash conditioner compositions) . The present invention can also be applied to industrial or domestic non-detergent based fabric care compositions.

Fully formulated fabric wash compositions according to the present invention may be in any suitable solid form, for example, tablets, powders (including such forms as grains, flakes and granules) and/or bars. Powders and bars are preferred for 'low cost' markets.

Typically, fabric wash compositions according to the present invention comprise a surfactant which is a fabric wash detergent material selected from non-soap anionic surfactant, nonionic surfactants, soap, amphoteric surfactants, zwitterionic surfactants and mixtures thereof.

Suitable anionic surfactants are well known to the person skilled in the art and include alkyl benzene sulphonate, primary and secondary alkyl sulphates, particularly C₈-C₁₅ primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates, dialkyl sulphosuccinates; ether carboxylates ; isethionates; sarcosinates; fatty acid ester sulphonates and mixtures thereof. The sodium salts are generally preferred. Nonionic surfactants are also well known to the person skilled in the art and include primary and secondary alcohol ethoxylates, especially Ce-C₂o aliphatic alcohol ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C^Q- IS primary and secondary aliphatic alcohols ethoxylated with an average of from 1 to 10 moles of ethylene oxide per mole of alcohol. Non-ethoxylated nonionic surfactants include alkyl polyglycosides, glycerol monoethers and polyhydroxy amides (glucamide) .

Mixtures of nonionic surfactant may be used.

Detergent compositions suitable for use in domestic or industrial automatic fabric washing machines generally contain anionic non-soap surfactant or nonionic surfactant, or combinations of the two in suitable ratio, as will be known to the person skilled in the art, optionally together with soap.

Many suitable detergent-active compounds are available and fully described in the literature, for example in "Surface- Active Agents and Detergents", Volumes I and II, by Schwartz, Perry & Berch.

Anionic surfactant is suitably present at a level of from 5 wt% to 50 wt%, preferably 10 wt%-40 wt% based on the fabric treatment composition. Nonionic surfactant is suitably present at a level of 1-20 wt%, preferably 5-15 wt%. The total amount of surfactant present will depend upon the intended end use and may be as high as 60 wt% for example in a composition for washing fabrics by hand. In compositions for machine washing of fabric, an amount of from 5 to 40 wt% is generally appropriate.

Bleach Components :

Detergent compositions according to the invention may also suitably contain a peroxy bleach system for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution.

Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates . Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate .

Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB 2 123 044B (Kao) .

The compositions may further comprise a non-radical initiating photo-bleach system as described, for example, in EP-A-0035470. Other Ingredients :

The compositions of the invention can also contain one or more optional ingredients, selected from pH buffering agents, perfume carriers, fluorescers, colorants, hydrotropes, antifoaming agents, antiredeposition agents (including both soil and dye transfer inhibitors) , enzymes, bleaches, crystal growth inhibitors, optical brightening agents, opacifiers, anti-shrinking agents, anti-wrinkle agents, anti-spotting agents, cotton repair agents, germicides, fungicides, anti-corrosion agents, drape imparting agents, antistatic agents, clays and ironing aids.

Fabric wash detergent compositions according to the present invention may further include through the wash softening material, such as cationic fabric softener.

Method of Use:

Conveniently, the compositions of the invention are used in essentially the same manner as known laundry detergent compositions. That is, the composition are either applied to the fabric in a dissolved form (using a washing machine or some suitable vessel) or applied 'directly' in the form of a bar and in the presence of water. After rinsing to remove surfactants and soils the fabric is dried under suitable illumination and it is believed that it is at this stage that the initiators are most effective. Sufficient illumination can be provided by artificial light but drying under sunlight is preferred. While the preferred method of use is an essentially standard process, it is possible to envisage variants on this standard process which would more effectively utilise the photo-initiator. Such variant methods include extended exposure to light prior to a final rinsing step, or a pre- treatment of stains with a composition according to the invention. Where a composition of the present invention is intended for use in one of these variant methods, it will typically be packaged together with instructions relating to that method.

The present invention will be further described by way of example only, with reference to the following examples.

EXAMPLES

Example 1 :

The liquid radical photo-initiator Lucirin TPO-L (ex BASF) was gradually added to zeolite A24 (Doucil A24 ex

Crossfield) with vigorous mixing. When the weight percent of zeolite was 66% and Lucirin 34% a good granule was created.

The so-formed granules were added to a fully formulated washing powder (Persil™ Colour containing amongst others surfactant (LAS, nonionic) enzymes, builders, anti-dye transfer polymer) to give powders containing 0.1 and 0.2% by weight of Lucirin TPO-L. Five tomato stains on white cotton were created by mixing a tomato paste with olive, sunflower, rape seed, mixed vegetable or soybean oil, then applying the paste to 10 by 10 cm pieces of cotton sheeting. The stains were aged for 3 days under ambient conditions. This method created dark red stains. The severity of the stain was measured using a Reflectometer™ and expressed as the CIELAB™ ΔE value relative to a clean white piece of cloth.

The five stains created with the different oils were washed in a European-type, horizontal axis, washing machine with clean cotton ballast such that the liquor to cloth ratio was 8:1. Washing powder was added via the dispenser to give 4g powder per litre water. A 40 C colour wash program was chosen.

After washing the stained cloths were placed in a Weatherometer™ for 6 minutes irradiation with simulated sunlight, then dried. The CIELAB ΔE was then remeasured. The results are presented in Table 1 below. Lower figures in the results show improved bleaching.

Table 1: Zeolite/Lucirin on Tomato stains.

Clearly the two powders with the added zeolite/Lucirin TPO-L granule show improved bleaching effects as compared with the control powder without the added granule.

Example 2 :

A viscous liquid suitable for mixing with zeolite to form a granule was prepared. This comprised the semi-solid radical photo initiator Esacure™ KIP-150 (ex. Lamberti spa) which was mixed with the non-ionic surfactant Synperionic™ A7

(ex ICI surfactants) to give a 50:50 weight mixture. The so- formed mixture was then gradually added to zeolite A24 (Doucil A24 ex Crossfield) . When the weight percent of zeolite was 69% and the Esacure™ KIP-150/A7 mixture 31% a good granule was created.

The granules were added to a fully formulated washing powder (Persil ™ Colour, ex Lever Bros.) as per Example 1 to give powders containing 0.2 and 0.5% of the initiator. The wash test of example 1 was then repeated. Both powders that contained Esacure KIP-150 bleached the tomato stains unlike the control powder.

Example 3

To demonstrate that the current granulation method gives equivalent effects to intimately mixing the initiator into a liquid detergent, Lucirin TPO-L was intimately mixed with Persil™ Liquid (ex Lever Faberge GB) and Wisk™ (ex Lever Bros. USA) to give 0.2% on weight formulation. The Esacure KIP-150/A7 was added to Persil Liquid to give 0.5% of the initiator on weight formulation. These formulation were used to wash the stains outlined in example 1. Within experimental error equivalent bleaching effects were found to that from the powder with the granule.

Example 4 :

A granule was created by slowly adding 10% weight of Lucirin TPO-L to the zeolite Doucil™ A24 with vigorous mixing. The organic builder Sokalam CP5 (ex BASF) , a maleic Anhydride and acrylic acid copolymer, was then added till a good granule was created. The resulting granule had the following weight composition:

Doucil A24 69.6%, Sokalam CP5 23.1%, Lucirin TPO-L 7.3%.

Example 5 :

The experiment of example 4 was repeated but the Esacure/Synperonic A7 mixture of example 2 used instead of Lucirin TPO-L. The resulting granule had following weight composition

Doucil A24 70.1%,

Sokalam CP5 23.1%,

Esacure KIP-150 3.4%,

Synperionic A7 3.4%. Example 6 :

Esacure KIP150 was cooled to 0 C and then pulverised by hammer. The resulting powder was mixed with dry ice to obtain a cold mixture. This mixture was mixed with powdered sodium sulphate and then granulated with Sokalam CP5 and warmed to room temperature. The granules were then dried at

50 C. The granule composition was:

Esacure KIP150 8.0%, sodium sulphate 84.5%, Sokalam CP5 7.2%

Example 7 :

The granules of examples 1,2 & 4-6 were added to Persil Colour Care Powder to give 0.1% weight initiator in the powder. The powders were used to wash the tomato stains of example 1, (30 mins, 40 C wash, 5g/l powder, 2 rinses, a liquor to cloth ratio of 10:1 and wash only contained stained cloth) and then irradiated in a Weatherometer™ ('WOM') for 12 minutes. The results are given in table 2.

Table 2

From the above results it can be seen that all the granules according to the invention gave good bleaching benefits above control .

Example 8 :

The nonionic surfactant Synperionic A20 is a waxy solid at room temperature. It was melted by heating and the semi- solid photo-initiator Esacure KIP 150 was added to give a 50:50 (weight) mixture. This was allowed to cool, and when the mixture became viscous, the zeolite Doucil A24 was added and the mixture mixed with a pestle and mortar. This produced granules which contained 12.5% weight photoinitiator. The granules were added to Persil Colour Care washing powder so that the powder contained 0.2% Esacure KIP 150. The powder was then used to wash oily (Soya) tomato stains on cotton (7g/l powder, 40 C, 30 min wash, lOOg cloth/1, (of which 12.5g stained)) . Following the wash and rinse the cloths were irradiated in a WOM for 12 minutes. Compared to a control powder without photoinitiators greatly increased stain removal was observed (ΔE_control ⁼ 32, ΔEKIP

150 = ⁷-⁶)

Example 9 :

Lucirin TPO-L granules were made according to example 1. Following their creation the granules were separated into different sizes by sieving. To see the effect of granule size in performance the granules added to Persil Powder and used to wash cotton stained with Palm oil in a manner analogous to example 8. A wash was also conducted without initiator added and with initiator added directly to the wash liquor. The results are given in table 3 below:

Table 3

Example 10

Granules were made according to examples 2, 5 and 7 and added to Persil Colour Care washing powder to give 0.2% of radical photoinitiator on weight of formulation. The powders were stored in an open container at 28 C and 70% relative humidity for 20 weeks. The performance of the powders was then tested by washing then irradiating oily tomato stains and comparing to a control that had also been stored but without photoinitiator present. The 3 powders which contained initiator gave excellent bleaching of the stain, compared to the control, showing that the granules store well .

Example 11:

Granules were made according to example 2 and stored in 2 washing powders which had zeolite and phosphate as the predominate builders respectively and percarbonate and perborate as a hydrogen peroxide source respectively. Bleach wash tests on tomato stains after 1 weeks storage at 37 C and 70% humidity in closed cardboard boxes showed that photo-bleaching due to the presence of Esacure KIP still occurred.

Claims

1. Surfactant composition comprising at least one radical initiator and at least one detergency builder,

CHARACTERISED in that said radical initiator is adsorbed onto at least a portion of said builder.

2. Composition according to claim 1 wherein the radical initiator is a radical photo-initiator, preferably an oligomeric radical photo-initiator.

3. Composition according to claim 2 wherein the radical initiator is selected from hydrogen abstraction photo- initiators, bond-cleavage radical photo-initiators and mixtures thereof .

4. Composition according to claim 3, wherein the radical photo-initiator is selected from the group consisting of benzophenones, acetophenones, pyrazines, quinones, benzils and mixtures thereof.

5. Composition according to claim 4, wherein the radical photo-initiator is selected from the group consisting of alpha amino ketones, preferably alpha-amino acetophenones, alpha-hydroxy ketones, preferably alpha- hydroxy acetophenones, monoacyl and bisacyl phosphine oxides and sulphides, dialkoxy acetophenones, alpha-halo acetylphenones, triacylphosphine oxides, benzoin and benzoin based photoinitiators and mixtures thereof.

6. Composition according to any preceding claim wherein the builder is inorganic.

7. Composition according to claim 6, wherein the builder is selected from the group consisting of sodium carbonate, crystalline and amorphous aluminosilicate, mixed crystalline/amorphous aluminosilicate, layered silicate, sodium orthophosphate, pyrophosphate and tripolyphosphate and mixtures thereof.

8. Composition according to claim 7 wherein the builder is an alkali metal having the general formula: 0.8-1.5

Na₂0. Al₂0₃. 0.8-6 Siθ

9. Composition according to claim 8 wherein the builder is an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20.

10. Composition according to any of claims 1-9 further comprising a detersive surfactant, a solvent or a mixture thereof .

11. Composition according to any of claims 1-10 further comprising a detergency builder which is essentially free of adsorbed radical initiator.

12. A method of treating fabric CHARACTERISED IN THAT it comprises treating the fabric with a composition according to any preceding claim.

13. A method according to claim 12, wherein the treatment of fabric takes place during a fabric washing step.

14. A method according to claim 12, wherein the treatment takes place during a fabric rinsing step, in the presence of fabric conditioner.

15. Process for the production of a composition according to any one of claims 1-11 CHARACTERISED IN THAT it comprises forming a pre-mix of at least one builder and at least one radical initiator.

16. Process according to claim 15 wherein the premix further comprises at least one of surfactant, solvent and mixtures thereof