WO2001044424A1

WO2001044424A1 - Fabric care composition

Info

Publication number: WO2001044424A1
Application number: PCT/EP2000/011377
Authority: WO
Inventors: Stephen Norman Batchelor; Denise Angela Carr; Robert John Crawford; Lynnette Fairclough
Original assignee: Unilever Plc; Unilever Nv; Hindustan Lever Limited
Priority date: 1999-12-15
Filing date: 2000-11-14
Publication date: 2001-06-21
Also published as: CN1434853A; AU1702101A; EP1242571A1; GB9929693D0; BR0016437A; TR200201562T2; CA2394128A1

Abstract

A fabric care system comprising a radical initiator, which is preferably a photoinitiator and preferably selected from hydrogen abstraction photoinitiators, bond cleavage radical photoinitiators or mixtures thereof and a radical terminator is used to treat fabric, for example as a stain removal system in the washing or rinsing of fabric in a laundry process. The fabric treatment system can be incorporated into a fabric washing composition or a conditioner composition.

Description

FABRIC CARE COMPOSITION

The present invention relates to a fabric care composition comprising a novel colour care and stain treatment system. The present invention also relates to a method of treating fabric using the novel colour care and stain treatment system. The present invention further relates to the use of the novel colour care and stain treatment system in fabric care treatment.

Background of the Invention

The present invention is concerned with fabric treatment that takes place after use of the fabric, in particular to reverse degradation of fabric that occurs as a result of that use, for example soiling and staining. Such treatments are referred to herein as fabric care. Fabric care treatments include laundering and the application of non-detergent-based fabric care products, such as spray-on products. Considerable attention has been focused on components for inclusion in fabric care compositions which are specifically intended for colour care. For example, these components may comprise dye transfer inhibitors, stain removers, photofading inhibitors, and fluorescence inhibitors.

European patent application no. 97200107.7 discloses a fabric wash detergent composition in which a specific polymer system is included to provide stain removal benefits. International patent application no. PCT/EP 97/07289 discloses fabric treatment compositions comprising a sunscreen material for preventing sun damage to colour. WO 95/13354 discloses compositions comprising polymers such as PVPNO and N-vinyl pyrollidone/N- vinyl imidazole copolymers as dye transfer inhibitors. EP- A-0035470 discloses a textile treatment composition which comprises a photobleaching component. The photobleach material has some effect against stains, but can also attack dye.

Fabric care compositions comprising radical photoinitiator 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. If the photoinitiator has a high log P value (where P is the octanol- water partion coefficient) ie, it is relatively hydrophobic, then little dye damage is likely to result when the compositions are applied to coloured fabric but, in other cases, dye damage may result.

The present invention aims to provide further colour care and stain treatment compositions which contain radical initiators. The invention also aims to reduce the likelihood of damage to the dye in a coloured fabric when the compositions are used for the treatment of such a fabric.

Radical photoinitiators themselves are well-known and used in the unrelated fields of polymerisation, polymer cross-linking and curing reactions in materials. Radical terminators are also known in these, and other unrelated, technical fields. Definition of the Invention

The present invention accordingly provides a fabric care composition, comprising at least one radical initiator and at least one radical terminator.

The present invention further provides a fabric care treatment method, comprising treating the fabric with at least one radical initiator in the presence of at least one radical terminator.

The present invention further provides the use of a composition comprising at least one radical initiator and at least one radical terminator in a fabric care treatment method.

It has been found that the radical photoinitiators 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. Further, damage to fabrics such as fibrillation can be avoided.

The radical initiator systems according to the present invention are found to be soluble or dispersible in other media than water and can be used on dry-clean only garments.

The compositions of the invention have the surprising advantage that they reduce dye damage in coloured fabrics relative to corresponding compositions containing no radical terminator, whilst retaining effective stain bleaching properties. It was unexpected that the radical initiator and the radical terminator did not simply cancel each other out when used together in the composition to give substantially no stain bleaching properties.

Detailed Description of the Invention

Radical Initiators:

Preferably the radical initiators are radical photoinitiators. Chemical and thermal radical initiators are less preferred.

It has been found that the radical photoinitiators 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.

Radical photoinitiators preferred for use in the present invention are components which produce radicals capable of attacking stains on fabric, on photoexcitation by one of the following routes: Hydrogen Abstraction

Hydrogen abstraction radical photoinitiators operate according to the following reaction:

light kl X X* + R-H >X« + R«

where X is the radical photoinitiator 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 10⁴ mol^"1 Is^"1 when RH is propan-2-ol.

Bond Cleavage Radical Photoinitiators

Bond cleavage radical photoinitiators operate according to the following reaction: light k2

k2 is the rate constant of the bond-cleavage reaction. Preferably, k2 is greater than 10⁶ s^"1.

Suitable bond cleavage radical initiators may be selected from the following groups:

(a) alpha amino ketones, particularly those containing a benzoyl moiety, otherwise called alpha-amino acetophenones, for example 2-methyl l-[4-phenyl]-2-morpholinopropan-l-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- 1 - one) (Irgacure 2959, trade mark), 1-hydroxy-cyclohexyl-phenyl- ketone (Irgacure 184, 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)phenyl phosphinic acid ethyl ester (Lucerin 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 photoinitiator has a maximum extinction coefficient in the ultraviolet range (290-400 nm) which is greater than 100 mol^lcm^"1. Suitably, the radical photoinitiator is a solid or a liquid at room temperature. Preferably, the treated fabric is exposed to light until the stain is removed or all photoinitiator has reacted. It will be appreciated that the time taken for stain removal and/or substantially complete reaction of the photoinitiator 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 photoinitiator 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 Photoinitiator Systems

The present inventors have discovered that radical photoinitiators having a specified hydrophobicity, measured by their log P value, have a particularly preferred effect. All materials for the removal of stains also have a tendency to attack dye. The preferred radical photoinitiator systems have a particularly 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. Radical Terminators

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 greater than 10⁴ M^"1 s^"1, more preferably greater than 10⁶ M^"1 s^"1 or even more preferably at or near to the diffusion controlled limit (ie, close to 8RT/3E, where T is the temperature, R is the gas constant and E 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 radicals 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.

It is surprising that, in the present invention, 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.

Fabric Care 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, for example spray-on compositions.

Fabric Wash Compositions

Fabric wash compositions according to the present invention may be in any suitable form, for example powdered, tableted powders, liquid or solid detergent bars. Fabric wash compositions according to the present invention comprise 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 Cs-Cis 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 C8-C20 aliphatic alcohol ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the C10-C15 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 poly gly cosides, 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.

Detergency Builder

The detergent compositions of the invention will generally also contain one or more detergency builders. 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 that may be present 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 alummosilicates, for example, zeolites as disclosed in GB 1 473 202 (Henkel) and mixed crystalline/amorphous alummosilicates 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 detergent compositions of the invention preferably contain an alkali metal, preferably sodium, aluminosilicate builder. Sodium alummosilicates may generally be inco porated 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 O. AI2O3. 0.8-6 Si0₂

These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium alummosilicates contain 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 alummosilicates 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 384 070 A (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 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 trisuccinates, carboyxmethy loxy succinates , carboxymethyloxy malonates , dipicolinates , hydroyxethyliminodiacetates, alkyl- and alkenylmalonates 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.

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 photobleach system as described, for example, in EP- A-0035470.

Fabric Softening Composition

The fabric treatment composition of the present invention may be a fabric conditioning composition or it may comprise fabric conditioner.

Fabric Softening Compound

The fabric softening compound is preferably a cationic nonionic or anionic fabric softening compound.

The fabric softening compound may be a quaternary ammonium material comprising a polar head group and one or two alkyl or alkenyl chains. The fabric softening compound may also be a nonionic fabric softening compound such as a fabric softening oil, a fabric softening silicone composition or a fabric softening ester composition such as sugar esters.

Particularly preferably, the fabric softening compound has two long chain alkyl or alkenyl chains with an average chain length greater than C14, more preferably each chain has an average chain length greater than C14, more preferably at least 50% of each long chain alkyl or alkenyl group has a chain length of Cis. It is preferred if the long chain alkyl or alkenyl groups of the fabric softening compound are predominantly linear.

It is highly preferred if the fabric softening compounds are substantially water-insoluble. Substantially insoluble fabric softening compounds in the context of this invention are defined as fabric softening compounds having a solubility less than 1 x 10^"3 wt% in demineralised water at 20 °C, preferably the fabric softening compounds have a solubility less than 1 x 10^"4, most preferably the fabric softening compounds have a solubility at 20°C in demineralised water from 1 x 10^"3 to 1 x 10^"6.

Well-known species of substantially water-insoluble quaternary ammonium compounds having the formula:

wherein R¹ and R² represent hydrocarbyl groups having from 12 to 24 carbon atoms; R³ and R⁴ represent hydrocarbyl groups containing 1 to 4 carbon atoms; and X is an anion, preferably selected from halide, methyl sulphate and ethyl sulphate groups are preferred.

Representative examples of these quaternary softeners include di(tallow alkyl) dimethyl ammonium methyl sulphate; dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow alkyl) dimethyl ammonium chloride; dioctadecyl dimethyl ammonium chloride; di(hydrogenated tallow alkyl) dimethyl ammonium methyl sulphate; dihexadecyl diethyl ammonium chloride; di(coconut alkyl) dimethyl ammonium chloride, ditallow alkyl dimethyl ammonium chloride and di(hydrogenated tallow alkyl) dimethyl ammonium chloride (Arquad 2HT Trade Mark).

Other preferred softeners contain esters or amide links, for example those available under the trade names Accosoft 580, Varisoft 222, and Stepantex.

Particularly preferred fabric softening compounds are water-insoluble quaternary ammomum materials which comprise a compound having two C 12-18 alkyl or alkenyl groups connected to the molecule via at least one ester link. It is more preferred if the quaternary ammomum material has two ester links present. The preferred ester-linked quaternary ammonium material for use in the invention can be represented by the formula:

R¹

wherein each R¹ group is independently selected from C1-4 alkyl, hydroxy alkyl or C2-4 alkenyl groups; and wherein each R² group is independently selected from Cs-28 alkyl or alkenyl groups; T is -C(O)- O- or -O-C(O)-; X^" is any suitable anion and n is an integer from 0-5. Particularly preferred is di(ethyl ester) dimethyl ammonium chloride (DEEDMAC).

A second preferred type of quaternary ammonium material can be represented by the formula:

OOCR²

wherein Ri, n, X^" and R2 are as defined above.

It is advantageous for environmental reasons if the quaternary ammonium material is biologically degradable.

Preferred materials of this class such as 1 ,2 bis[hardened tallowoyloxy]-3- trimethylammonium propane chloride and their methods of preparation are, for example, described in US 4 137 180 (Lever Brothers). Preferably these materials comprise small amounts of the corresponding monoester as described in US 4 137 180 for example 1 -hardened tallowoyloxy-2- hydroxy trimethylammonium propane chloride. The fabric softening agent may also be a polyol ester quat (PEQ) as described in EP 0 638 639 (Akzo).

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, enzymes, optical brightening agents, opacifiers, anti-shrinking agents, anti-wrinkle agents, anti-spotting agents, germicides, fungicides, anti-corrosion agents, drape imparting agents, antistatic agents and ironing aids.

The present invention may be in the form of a dilute or concentrated aqueous solution or suspension, for example as described in WO

97/15651 , WO 95/27769. Alternatively, the fabric softening composition may be in the form of a powder for use in the rinse cycle of an automatic washing machine. Alternatively, the fabric softening composition may be in the form of a sheet comprising fabric conditioning compositions for use in a tumble dryer, for example as disclosed in WO 95/27777.

Alternatively, the fabric conditioning composition may be in the form of a substantially non-aqueous concentrate as described in international patent application no. PCT/EP99/00497. Fabric wash detergent compositions according to the present invention may further include through the wash softening material, such as cationic fabric softener.

Non-Detergent-Based Fabric Care Products

The present invention can also be used in non-detergent-based fabric care products. For example, the product may comprise the stain removal system as the principal ingredient. For example, non-detergent based compositions may comprise solutions of the stain removal system of the present invention in a suitable solvent, such as isopropanol, alcohol etc. The compositions may comprise aerosol or spray-on compositions. They may be in the form of sticks, bars, dab-on compositions, for example absorbed into sponges for application to the surface etc.

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

Examples

All quantities are in percent or parts by weight unless indicated otherwise.

The following radical initiators are used in the present examples. They are available commercially as initiators for free radical polymerisation under the trade marks set out below from Ciba Specialty Chemicals. Irgacure 184 - an α-hydroxyacetophenone photoinitiator.

Irgacure 819 - bis(2,4,6-trimethyl benzoyl) - phenyl phosphine oxide (log P = 5.8, measured at 25°C).

The radical terminator used was 4-hydroxy-2,2,6,6-tetramethyl-l- piperidinyloxy free radical (TEMPOL ex Aldrich)

Example 1

Curry, chilli, bolognese and β -carotene stained cotton cloth was purchased from Equest (aged 3 days and packed under nitrogen). The amounts of Irgacure 184 and TEMPOL listed in the table, were dissolved in ethanol and applied to the stained cloth. The cloth was dried, and then irradiated in a Weatherometer (WOM), with the WOM operated at the outside Florida sunlight setting, for 12 minutes. In separate experiments the stained cloth was wetted before placing in the WOM. The results are listed in Tables 1 and 2 below. Addition of TEMPOL did not reduce the efficiency of bleaching (bleaching was above that of light alone, which gave an average reduction of approximately 9 ΔE units dry and 12 ΔE units wet) and TEMPOL on its own did not provide significant extra bleaching. Stain bleaching was measured on a reflectometer and expressed in CIELAB ΔE values. The bleaching and protection were also observed when the stained cloth was exposed to ambient light in the UK.

Table 1 , values for dry cloth. ΔE calculated compared to white original cloth.

Table 2 Values for dry cloth

The padding procedure above was then repeated using cloth dyed with the dyes listed in Table 4 (cloths obtained from Veebee Tech, Harrogate, UK). Dye damage was measured on a reflectometer and expressed in CIELAB ΔE values compared to the original. The results are shown in Table 3, and show that dye damage is significantly reduced in the presence of TEMPOL. Thus the combination of radical initiator and TEMPOL provides a better cleaning to care effect.

Table 3 effect of TEMPOL on dye damage.

Table 4 Dye set used. Example 2

The experimental procedure of Example 1 was repeated using Irgacure 819. The results are summarised in Table 5, stain reduction and dye damage are quoted in ΔE values. Again, there is little effect on bleaching but the dye damage is greatly reduced, ie, a better clean/care regime. The initial average staining was 40 ΔE units, and irradiation was performed wet.

Table 5

*values are quoted above a control irradiated without initiator.

Example 3

The experiments were repeated using Irgacure 184 and, instead of TEMPOL, Vitamin C (ascorbic acid, Sigma). Again, dye damage was reduced but stain bleaching was not. (In this case Irgacure 184 was applied from ethanol, dried then Vitamin C was applied from water). Thus, 0.1 % 184 and 0.1 % Vitamin C gave an average stain reduction of 19.6 and dye damage of 1.1 when irradiated wet for 12 minutes. Example 4

The experiments were repeated using Vitamin E(Sigma) and Irgacure 184. Again dye damage was reduced, however in this case there was some decrease in stain bleaching. Vitamin E is not water soluble.

Example 5

The following rinse conditioner formulation was prepared:

HEQ ¹ - 4%

Perfume - 0.3%

Ascorbic acid - 0.66%

Irgacure 819 (trade mark) - 0.66%

Water - to 100%

1 HEQ = 1,2 bis [hardened tallowoyloxy]-3-trimethylammonium propanechloride, ex Hoechst.

3 grams of this rinse conditioner were dissolved in 600 grams of cold water. 18 grams of cotton sheeting were placed in it for 5 minutes. At the end of this time, the cotton was removed and dried. The reflectance spectrum of the cotton sheeting was studied at 320 nm using a Spectraflash SF60 (trade mark) reflectometer.

It was calculated from the reflectance results that approximately 0.003 % of radical photoinitiator (based on the weight of the cloth) had been delivered.

Example 6

An oily tomato stain was created by smearing an oily tomato paste (ex Sacla; ingredients :-rehydrated sun dried tomatoes, sunflower seed oil, white wine vinegar, salt, sugar, flavourings, garlic, black pepper and lactic acid) on white cotton. Once the paste was applied, it was left for 30 minutes then washed in detergent without bleach or fluorescer (Persil Colour (trade mark) powder) at 20 °C then rinsed. (All water was demineralised). The wash did not remove all the stain.

Ethanol solutions containing 0.0019 mol l^"1 Irgacure 819 (trade mark) and:- (a) nothing else

(b) 0.0035 mol l ¹ TEMPOL

(c) 0.0037 mol l^"1 10-DOXYL nonadecane (Sigma) were padded onto the stains and onto the dyed cotton (according to the procedure outlined in Example 1); the cloths were dried then wet with water then irradiated in a WOM for 6 minutes. The results are summarised in the table below.

although the less water soluble 10-DOXYL nonadecane does reduce dye damage it is not as effective as TEMPOL.

Example 7

A base washing powder was produced containing:

Powders were also created as above further containing 9.5 % Irgacure 819 (trade mark) and 9.5 % Irgacure 819 (trade mark) with 10% TEMPOL. The three powders were dissolved in water and used to wash cotton dirtied by an oily tomato stain (as per Example 5) and cotton dyed with cibacron red and cibacron mrquoise at 0.1 % owf. After washing, the clothes were irradiated wet in a WOM for 6 minutes. Both Irgacure 819 (trade mark) containing formulations gave better cleaning than the control. The formulation containing TEMPOL gave less dye damage.

Claims

1. Fabric care composition comprising at least one radical initiator and at least one radical terminator.

2. The composition of Claim 1, wherein the radical terminator has a rate constant for reaction with reactive free radicals of at least 10⁴ M ¹ s ¹.

3. The composition of Claim 2, wherein the radical terminator has a rate constant for reaction with reactive free radicals of at least

10⁶ M ¹ s ¹.

4. The composition of any preceding claim wherein the radical initiator is a radical photoinitiator.

5. The composition of claim 4 wherein the radical initiator is selected from hydrogen abstraction photoinitiators, bond-cleavage radical photoinitiators and mixtures thereof,

6. The composition of claim 5, wherein the radical terminator is selected from hindered amines, nitroxides formed from said hindered amines, hindered phenols, hindered hydroquinones, radicals formed from said phenols or hydroquinones, and mixtures thereof.

7. The composition of claim 1 , wherein the radical terminator is ascorbic acid.

8. The composition of claim 1 , wherein the radical terminator is a chromanol.

9. The composition of claim 8, wherein the radical terminator is Vitamin E.

10. The composition of any preceding claim, being a fabric conditioner composition, the composition further comprising fabric conditioner.

11. The composition of claim 10, being a rinse conditioner.

12. The composition of any preceding claim, being a fabric wash composition, the composition further comprising fabric wash detergent.

13. The composition of claim 12, wherein the fabric wash detergent is selected from non-soap anionic, nonionic, amphoteric and zwitterionic surfactants and mixtures thereof.

14. The composition of claim 1 , further comprising a builder material.

15. The composition of any preceding claim, wherein the radical photoinitiator is a hydrogen abstraction radical photoinitiator selected from the group consisting of benzophenones, acetophenones, pyrazines, quinones, benzils and mixtures thereof.

16. The composition of any preceding claim wherein the radical photoinitiator 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.

17. The composition of any preceding claim, wherein the radical initiator is a photo-initiator excitable by light substantially in the range 290- 460 nm.

18. A method of treating fabric which comprises treating the fabric with a composition according to any preceding claim.

19. A method according to claim 18, wherein the treatment of fabric takes place during a fabric washing step.

20. A method according to claim 18, wherein the treatment takes place during a fabric rinsing step, in the presence of fabric conditioner.

21. Use of a composition according to any one of claims 1-17 in a fabric care treatment method.