FABRIC TREATMENT COMPOSITION COMPRISING RADICAL INITIATORS

Abstract: The invention relates to bleaching compositions comprising radical initiators. More particularly the invention relates to laundry treatment compositions for the spot treatment of soiled articles and to a process using the said compositions. The invention provides a fabric treatment composition which comprises: a) a radical initiator, and b) neat surfactant.The present invention further provides a method for the treatment of fabrics, which comprises applying to the fabric a composition according to the invention.

Description: FABRIC TREATMENT COMPOSITION COMPRISING RADICAL INITIATORS Technical Field The present invention relates to bleaching compositions comprising radical initiators. More particularly the invention relates to laundry treatment compositions for the spot or other direct treatment of soiled articles and to a process using the said compositions. Background of the Invention Typical laundry stains contain chromophores based on carotenoids, phenolics and phytoestrogens. Radical photoinitiators are known as stain bleaches for laundry application. These are materials, which on exposure to light generate reactive radicals. In turn, these radicals cause chemical changes in the stain, which decolourise it. Radical photo-initiators are well known in the unrelated fields of polymerisation and curing reactions. Other types of radical initiators are known (such as thermal or chemical initiators) and use of these in bleaching and sewage or other effluent treatment has also been envisaged. It is a well established problem in the field of laundry bleaching that compounds which can bleach stains will also have the capacity to bleach dyes present in the cloth. Consequently, much effort has been spent in finding bleaches, which are effective against stains but are ineffective against dyes. This problem is especially difficult to solve in the context of porous fibres such as dyed cotton and other dyed cellulosics, particularly where these have been dyed with common dyestuffs based on strongly coloured azo-, anthroquinone or pthalocyanine compounds. UK Patent application no: 9917451.8, teaches that photoinitiators with high logarithm of octanol-water partition coefficient (logP) give good stain bleaching with little dye damage on the fabric. This is highly desirous as consumers wish to remove stains without damaging their coloured fabric. The most preferred photoinitiators are those with logP values in excess of 4.0. Many effective photoinitiators have logP values much lower than 4.0 and are known to give some fabric dye damage particularly when used at high levels. For example 1-hydroxy-cylcohexyl-phenyl-ketone has logP = 2.81, 2-hydroxy-4' -hydroxyethoxy-2-methyl-propiophenone has logP = 0.84. It would be advantageous if low logP initiators could be used without causing damage. A prior approach to this problem is disclosed in co-pending UK patent application UK 9929693.1. This teaches the use of radical terminators in conjunction with radical initiators to reduce dye damage. However the use of two active ingredients may not always be desirable, particularly for reasons of cost. Brief Description of the Invention We have found that application of initiators from neat surfactants reduces dye damage without a corresponding reduction of stain bleaching. The swelling behaviour of cotton is discussed in ^Cellulose -Structure Accessibility and Reactivity' , Gordon and Breach Science Publishers and references therein. Commonplace solvents such as water and ethanol are effective at swelling the amorphous regions of cotton and other cellulosics. It is believed that swelling is avoided by use of neat surfactant. Accordingly, the present invention provides a fabric treatment composition which comprises: a) a radical initiator, and neat surfactant It is believed that such formulations prevent the passage of the initiator into the regions of the fibres where the dye resides while allowing the initiator to come into contact with the stain, which is essentially superficial. By neat' surfactant in the present specification is meant a surfactant composition, which comprises less than about 10% water, and preferably less than about 5% water. The most preferred compositions are essentially free of water. The present invention further provides a method for the treatment of fabrics, which comprises applying to the fabric a composition according to the invention. Detailed Description of the Invention The preferred radical initiators are photo and thermal initiators. The use of photo initiator systems is preferred as sunlight and other suitable sources of illumination are generally freely available. It is commonplace, for example, to dry laundered articles in sunlight. Mode of application: The surfactant may be contained in a wipe and the wipe used to physically remove stain and apply photo-initiator to it. Alternatively, the composition may be applied directly to the substrate being treated. Surfactants may be employed in solid or liquid form. In some markets, liquid surfactants are preferred for ease of application. In other markets solid forms, particularly soft solid forms, will be preferred. Preferably, these can take the form of soap or other non-soap detergent bars, although embodiments of the invention may take the form of other applicator sticks. A range of suitable application forms can be found in the art of deodorant sticks and other applicators. The initiator may be a perfume material or the carrier of a perfume material. Inclusion of the initiator in a final composition together with the perfume is advantageous as both classes of materials may require careful dosing and the composition is generally not subjected to heating once the perfume has been added. The photo-initiator system must generally be stored in the absence of light of wavelength below 500nm, to avoid photo- reaction. An opaque packaging is sufficient for this purpose. Surfactant: The surfactant may be chosen from soap and non-soap anionic, cationic, non-ionic, a photeric and zwitterionic detergent active compounds, and mixtures thereof. Many suitable detergent active compounds are available and are fully described in the literature, for example, in "Surface-Active Agents and Detergents", Volumes I and II, by Schwartz, Perry and Berch. The preferred textile-compatible carriers that can be used are soaps and synthetic non-soap anionic and nonionic compounds. Nonionic surfactants, particularly alkoxylated nonionics are preferred. Nonionic surfactants that may be used include the primary and secondary alcohol ethoxylates, especially the Cs-C 2 o aliphatic alcohols ethoxylated with an average of from 1 to 20 moles of ethylene oxide per mole of alcohol, and more especially the Cι 0 -Cι 5 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 alkylpolyglycosides, glycerol monoethers, and polyhydroxyamides (glucamide) . Anionic surfactants are well-known to those skilled in the art. Examples include alkylbenzene sulphonates, particularly linear alkylbenzene sulphonates having an alkyl chain length of Ca-Cis; primary and secondary alkylsulphates, particularly C 8 -Cι S primary alkyl sulphates; alkyl ether sulphates; olefin sulphonates; alkyl xylene sulphonates; dialkyl sulphosuccinates; and fatty acid ester sulphonates. Sodium salts are generally preferred. Cationic surfactants that may be used include quaternary ammonium salts of the general formula RιR 2 R 3 RN + X ~ wherein the R groups are independently hydrocarbyl chains of Cι-C 22 length, typically alkyl, hydroxyalkyl or ethoxylated alkyl groups, and X is a solubilising cation (for example, compounds in which Ri is a C 8 -C 2 2 alkyl group, preferably a Ca-Cio or Cι 2 -Cι 4 alkyl group, R 2 is a methyl group, and R 3 and R 4 , which may be the same or different, are methyl or hydroxyethyl groups) ; and cationic esters (for example, choline esters) and pyridinium salts. Amphoteric surfactants may also be used, for example amine oxides or betaines. Radical Initiators: The photo-initiators can be hydrogen abstraction radical photoinitiators. These include benzophenones, acetophenones, pyrazines, quinones and benzils. Bond cleavage photoinitiators are preferred. 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 1- [4-phenyl] -2- morpholinopropan-1-one (Irgacure 907, trade mark, ex CIBA) , (2-benzyl-2-dimethyl amino-l-(4- morpholinophenyl) -butan-1-one (Irgacure 369, trade mark, ex CIBA) ; (b) alphahydroxy ketones, particularly alpha-hydroxy acetophenones, eg (1- [4- (2-hydroxyethoxy) -phenyl] -2- hydroxy-2-methyl-l-propan-l-one) (Irgacure 2959, trade mark, ex CIBA) , 1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, trade mark, ex CIBA); 2-hydroxy-2-methyl- 1-phenylpropan-l-one (Esacure ™ KL200 ex Lamberti SPA) ; and, oligomeric polyfunctional alpha-hydroxyketones (such as Esacure KIP150 ex Lamberti SPA) ; (c) phosphorus-containing photoinitiators, including monoacyl and bisacyl phosphine oxide and sulphides, for example 2-4-6- (tri ethylbenzoyl) diphenyl-phosphine oxide, bis (2,4, 6-trimethylbenzoyl) -phenyl-phosphine oxide (Irgacure 819, trade mark ex CIBA), (2,4,6- trimethylbenzoyl) phenyl phosphinic acid ethyl ester (Lucerin TPO-L (trade mark) ex BASF) ; (d) dialkoxy acetophenones; particularly Benzildimethylketal (Esacure ™ KBl ex Lamberti SPA) ; (e) alpha-haloacetophenones; (f) trisacyl phosphine oxides; and, (g) benzoin and benzoin-based photoinitiators. Further 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. Other suitable radical photoinitiators are disclosed 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, Che ia 48 (1994) 423-426 and H.F.Gruber, Prog. Polym. Sci . , 17, (1992), 953-1044. The preferred radical photoinitiators become active 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 ~1 lcm ~1 . Suitably, the radical photoinitiator is a solid or a liquid at room temperature. Particularly preferrred photo-initiators include alpha hydroxy ketones, particularly those containing a benzoyl moiety. 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. The radical photoinitiators are preferably activated by ambient light eg, domestic lighting or sunlight. However, a separate light source (for example a tungsten filament or gas discharge tube) may be employed for activation of the photoinitiator. In the alternative, the initiator may be a thermal initiator, which decomposes to form radicals on heating. As will be apparent, there will be some degree of overlap between the classes of initiator, which may be used in these two aspects of the invention. Some radical photoinitiators also decompose by heating (particularly at higher temperatures), and some thermal initiators decompose on exposure to light (particularly at shorter wavelengths) . Suitable thermal initiators include compounds comprising an azo group or a peroxygen group. Preferred materials exclude those containing a peroxygen group and include those forming a carbon-centred radical rather than an oxygen-centred radical. The thermal initiators are preferably stable at ambient temperature. Temperatures to which the thermal initiators should be heated to cause them to decompose are preferably in the range of up to 100°C, more preferably from 35°C to 90°C, most preferably 35°C to 40°C. Heat may conveniently be applied by means available in the laundering environment such as by use of an iron or tumble drier. The invention will be further described with reference to the following non-limiting examples. Examples For all the examples, values given are the average of 4 experiments. Example 1 : Cotton cloth samples were reactively dyed with Remazol Black B ™ so that the cloth contained 1.5xl0 -4 mol kg -1 of dye. This cloth is a sensitive monitor of dye damage. Separate samples of white cloth were heavily stained with β-carotene (ex. Equest, Newcastle GB) . These cloths served as monitors of bleaching activity. 1% of the radical initiator 1-hydroxy-cylcohexyl-phenyl- ketone (Irgacure 184 ex Ciba Speciality Chemicals) was dissolved in the C12-E5 ethoxylated nonionic liquid surfactant Cι 2 H 25 -0- (CH 2 CH 2 0) 5 H (Genopol C-050 ex. Clariant, CAS no. 61791-13-7) . This product was applied both to white cotton cloth stained with beta-carotene and cotton cloth dyed with Remazol Black B. The cloths were irradiated for 18 minutes in a Weatherometer™, then rinsed in de-mineralised water, dried and the ΔE values measured. CIELAB ΔE values of the cloths compared to the original untreated fabric were measured using a reflectance spectrometer. Control experiments using the surfactants and irradiation in the absence the initiator were also performed. The results are shown in Table 1 and compared to controls using Genopol alone and applying 1% Irgacure 184 from ethanol. Results are also shown for a lower level of radical initiator. Table 1 Table 1 Stain Bleaching and Dye damage from Irgacure 184 (initiator) applied from Genopol C-050 (surfactant) The results show that the presence of the radical initiator led to a significant improvement in the removal of the stain without corresponding dye damage. Example 2 : Example 1 was repeated using the radical initiator Lucirin TPO-L™ (ex. BASF) , again excellent stain bleaching was observed with little dye damage. Results are shown in Table 2 below. Table 2 Table 2 Stain bleaching and Dye damage from Lucirin TPO-L applied from a solution of Genapol C-050. Example 3 : The experiments of example 1 & 2 were repeated except the cloths were treated, rinsed with water, dried, then irradiated in a Weatherometer™. Although more bleaching is observed, more dye damage is also found. Results are given in the table below. Table 3 Table 3 Stain bleaching and Dye damage from Lucirin TPO-L and Irgacure 184 applied from a solution of Genapol C-050, Here stain is treated, rinsed, dried then irradiated. Example 4 : This example uses a solid surfactant. The waxy solid, ethoxylated alcohol, surfactant Synperonic A20™ (ex ICI surfactants) was melted by heating. 1% of Lucirin TPO-L or Irgacure 184 was dissolved in the hot liquid and then the solution poured into a plastic mould and allowed to solidify by cooling. The so-formed solid was wiped across the surface of β-carotene-stained cotton and cotton dyed with Remazol Black B (as in example 1) then irradiated in a Weatherometer for 6 minutes. Control experiments were also carried out using pure surfactant. After irradiation the stained cloth treated with initiator was clearly bleached and no dye damage on the dyed cloth above control could be observed. The control stained cloth showed no bleaching. Table 4 Table 4 Stain bleaching and Dye damage from Lucirin TPO-L applied from Synperonic A20. Example 5 PEG-50 Hydrogenated Tallow Amide—a waxy solid at room temperature (ex Akzo Nobel Chemicals) was melted by heating. 1% of Lucirin TPO-L or Irgacure 184 was dissolved in the hot liquid and then the solution poured into a plastic mould and allowed solidified by cooling. The so-formed solid was wiped across the surface of β-carotene stained cotton and cotton dyed with Remazol Black B (as per examples 1) then irradiated in a Weatherometer for 6 minutes. Control experiments were also carried out using pure surfactant. After irradiation the stained cloth treated with initiator was clearly bleached and no dye damage on the dyed cloth above control could be observed. The control stained cloth showed no bleaching. Table 5 Table 5 Stain bleaching and Dye damage from Lucirin TPO-L applied from PEG-50 Hydrogenated Tallow Amide. Example 6 : 0.2% initiator was dissolved in Genapol C-050 at room temperature. Water was added to this solution until the initiator precipitated. For both Irgacure 184 and Lucirin TPO-L precipitation occurred with less than 10% added water. Example 7 0.2% initiator was dissolved in Synperonic A20 at its melting point. Water was added to this solution until the initiator precipitated. For both Irgcaure 184 and Lucirin TPO-L precipitation occurred with less than 10% added water.

Claims: CLAIMS 1. A fabric treatment composition, which comprises: a) a radical initiator, and b) neat surfactant. 2. A composition according to claim 1 wherein the surfactant is a liquid or soft solid. 3. A composition according to any preceding claim, wherein the surfactant is an alkoxylated nonionic. 4. A composition according to claim 3, wherein the surfactant is a liquid ethoxylated alcohol. 5. A composition according to any proceeding claim, where the radical initiator is a photo or thermal initiator. 6. A composition according to any preceding claim, wherein the initiator is a bond cleavage photoinitiator. 7. A composition according to claim 7, wherein the initiator is selected from: (a) alpha amino ketones, (b) alphahydroxy ketones, (c) phosphorus-containing photoinitiators, (d) dialkoxy acetophenones; (e) alpha-haloacetophenones; (f) trisacyl phosphine oxides; (g) benzoin and benzoin-based photoinitiators, and, (h) mixtures thereof. 8. A composition according to claim 7, wherein the radical photoinitiator becomes active when excited by radiation falling generally in the range 290-800 nm. 9. A composition according to claim 7, wherein the radical photo-initiator has a maximum extinction coefficient in the ultraviolet range (290-400 nm) which is greater than 100 mol "1 lcm "1 . 10. A composition according to any preceding claim, in combination with a wipe or swab. 11. A composition according to any preceding claim, further comprising one or more perfume components. 12. A composition according to any preceding claim, further comprising a radical terminator. 3. A method for the treatment of fabrics which comprises applying to the fabric a composition according to any of claims 1-12.

Inventors: BATCHELOR STEPHEN NORMAN, WILLIAMS JACQUELINE, BATCHELOR, STEPHEN, NORMAN, WILLIAMS, JACQUELINE
Applicants: BATCHELOR STEPHEN NORMAN, LEVER HINDUSTAN LTD, UNILEVER NV, UNILEVER PLC, WILLIAMS JACQUELINE, BATCHELOR, STEPHEN, NORMAN, HINDUSTAN LEVER LIMITED, WILLIAMS, JACQUELINE
Application year: 2001
Main classification: C11D3
IPC codes: C11D1, C11D3, C11D17