WO2007093303A1

WO2007093303A1 - Laundry treatment compositions

Info

Publication number: WO2007093303A1
Application number: PCT/EP2007/000988
Authority: WO
Inventors: Stephen Norman Batchelor; Jayne Michelle Bird; Carol Meacock; Dawn Rigby; Jacqueline Williams
Original assignee: Hindustan Lever Ltd; Hindustan Unilever Ltd; Unilever NV
Current assignee: Hindustan Unilever Ltd; Unilever NV
Priority date: 2006-02-17
Filing date: 2007-02-02
Publication date: 2007-08-23
Anticipated expiration: 2008-08-17
Also published as: EP1984485B1; AR059511A1; CN101421385B; MY150083A; BRPI0708080A2; AR059607A1; ATE522596T1; EP1984485A1; CN101421385A; ES2367851T3; BRPI0708080B1

Abstract

The present invention provides a method of treating a textile with a composition comprising a hydrophobic dye.

Description

LAUNDRY TREATMENT COMPOSITIONS

TECHNICAL FIELD

The present invention relates to laundry treatment compositions with increased deposition of the dye to a substrate.

BACKGROUND OF THE INVENTION

Garments comprising polyester fibres are ubiquitous. Many garments are white but over the lifetime of these garments the whiteness is dulled reducing the aesthetic value of the garment. There is a need to maintain the white appearance of such garments such that the aesthetic value is retained as long as possible.

Bleach, fluorescers and shading agents are used in modern wash processes to maintain whiteness. The fluorescers and shading agents that are currently available, do not deposit on polyester fibres of garments to a significant degree. All fibres may be subjected to a bleaching process but over time such treatment can lead to the garment taking a yellow hue.

United States Patent 3,958,928 discloses a liquid dye composition together with methods for its use. The dye composition is a mixture of anthraquinone dyes suitable for use with liquid laundry detergents. The composition substantially reduces the undesirable fabric staining characteristic of a detergent in which the dye is employed, while still retaining the ability to blue the fabric. The composition is a combination of an oil soluble dye such as 1, 4-bis (2-ethylhexylamino) -anthraquinone (C.I. Solvent Blue 58) with a water soluble dye such as l-amino-2 -sulfo, 4- (2- sulfo-para toluidino) anthraquinone sodium salt (C.I. Acid Blue 145) and/or 1 , 4-bis (3 -sodium sulfonate mesitylidino) anthraquinone (CI. Acid Blue 80) . The dye disclosed has two eight carbon branched substituents . The dye levels disclosed are above 0.0005% of the formulation. Long alkyl chains aid the incorporation of the highly hydrophobic dye in water surfactant compositions. Surprisingly a wide range of disperse and solvent anthraquinone dyes without long alkyl chains are discovered which have much better function as shading dyes from homogeneous (isotropic) liquid laundry or granular formulations.

USP 6,521,581 discloses the use of anthraquinone dyes in a bi-phase (anisotropic) liquid detergent composition with high levels of coloured inorganic salts.

There is a need to provide technology that maintains and enhances the white appearance of polyester comprising garments .

DE 2557783 discloses water soluble dyes and also discloses hydrophobic dyes disperse blue 87 and disperse blue 7 at a level of 0.0001 wt%. Neither of these hydrophobic dyes is demonstrated as substantive to textiles.

Co-pending application PCT/EP2005/009884 discloses laundry formulations containing hydrophobic shading dyes in the range 0.0001 to 0.1 wt% which gives whitening benefits on synthetic fabrics. We have found that even lower levels of hydrophobic dyes which are disclosed in PCT/EP2005/009884 provide whitening benefits on fabrics upon multiple washing.

Co-pending application PCT/EP2005/009518 discloses laundry formulations containing dyes as low as 0.00005 wt% in a final laundry detergent composition.

JP 01/180,816 discloses a shampoo composition comprising 0.000001 wt% of an anthraquinone dye.

JP 2004/210961, to Lion Corporation, discloses the use of anthraquinone dyes in a liquid detergent composition purely for enhancing the aesthetic appearance of the liquid detergent composition. The compositions comprise alkanolamine, an anionic surfactant and a non- ionic surfactant. In all the examples in JP 2004/210961 alcohol is present as a solubilising agent for the dye, i.e., 5 wt % of ethanol is present. In some of the examples propylene glycol is also present to facilitate solubility of the dye.

SUMMARY OF THE INVENTION

Dyes disclosed herein are known to be used to dye textiles in industrial processes conducted at high temperatures together with high concentrations of dyes and dispersion agents. Surprisingly the dyes can be used to shade at low levels of dye and surfactant and at routine laundry temperatures . We have found that not only are hydrophobic dyes are substantive to polyester fibres under normal domestic wash conditions but also at low levels of dye a shading whiteness benefit is provided. Benefits are provided to a range of synthetic fibres in particular nylon and elastane. We have also found a synergy between dyes and specific fluorescent agents.

If the dyes are applied from main wash and rinse conditioner products the benefits are multiplied.

In one aspect the present invention provides a domestic method of treating a textile garment, the method including the following steps:

(i) adding a laundry treatment composition comprising between 0.0000001 to less than 0.00005 wt % of a hydrophobic dye, from 0.005 to 2 wt % of a fluorescent agent selected from: sodium 2 (4-styryl-3-sulfophenyl) -2H-napthol [1 , 2-d] triazole, disodium 4 , 4 ' -bis{ [ (4-anilino-6- (N methyl-N-2 hydroxyethyl) amino 1 , 3 , 5-triazin-2-yl) ] amino} stilbene-2-2 ' disulfonate, disodium 4, 4 ' -bis{ [ (4-anilino-6-morpholino-l , 3,5-triazin-2- yl)] amino} stilbene-2-2¹ disulfonate, and^" disodium 4,4'- bis (2-sulfostyryl) biphenyl , and between 2 to 60 wt % of a surfactant, the hydrophobic dye of an anthraquinone structure, to an aqueous medium to form a shading medium; (ii) treating the textile garment with the shading medium; (iv) rinsing the textile with an aqueous medium; and, (iii) drying the treated textile.

Preferably the anthraquinone is other than one having an alkyl branched or linear alkyl chain of more than seven carbon atoms. Preferably the alkyl chain does not have an OH or OMe substitutent found in disperse blue 87 and disperse blue 7. Most preferably the upper limit of a hydrophobic dye is 0.000049 wt%. To maintain whiteness it is preferred that the composition contains a sequesterant to remove transition metals. In this respect it is preferred that the composition contains less than 3 ppm of free transition metals.

In another aspect the present invention provides a method of treating a textile, the method comprising the steps of: (i) treating a textile with an aqueous solution of the hydrophobic dye, the aqueous solution comprising from 1 ppt (parts per trillion) to less than 1 ppb (part per billion) of the hydrophobic dye and from 0.2 g/L to 3 g/L of a surfactant; and, (ii) rinsing and drying the textile. Most preferably the upper limit of a hydrophobic dye is 999 ppt.

It is preferred that the hydrophobic dye is present in the range 100 ppt to 800 ppt. Preferably the aqueous solution has an ionic strength from 0.001 to 0.5. Most preferably In another aspect it is preferred that the aqueous solution also comprises from 1 ppb to 5 ppm, preferably 5 to 100 ppb one or more other dyes selected from cotton substantive shading dyes of group consisting of: hydrolysed reactive dye; acid dye; and direct dye.

The method of the present invention is preferably applied to a soiled textile garment that has been worn at least once. It is preferred that the temperature of treatment is 10 to 60 ⁰C, most preferably 15 to 40⁰C.

A "unit dose" as used herein is a particular amount of the laundry treatment composition used for a type of wash, conditioning or requisite treatment step. The unit dose may be in the form of a defined volume of powder, granules or tablet or unit dose detergent liquid.

DETAILED DESCRIPTION OF THE INVENTION

Hydrophobic dyes are defined as organic compounds with a maximum extinction coefficient greater than 1000 L/mol/cm in the wavelength range of 400 to 750 nm and that are uncharged in aqueous solution at a pH in the range from 7 to 11. The hydrophobic dyes are devoid of polar solubilizing groups. In particular the hydrophobic dye does not contain any sulphonic acid, carboxylic acid, or quaternary ammonium groups. The dye chromophore is an anthraquinone dye chromophore .

Many examples of hydrophobic dyes are found in the classes of solvent and disperse dyes.

Shading of white garments may be done with any colour depending on consumer preference. Blue and Violet are particularly preferred shades and consequently preferred dyes or mixtures of dyes are ones that give a blue or violet shade on white polyester.

It is preferred that the dye(s) have a peak absorption wavelength of from 550nm to 650nm, preferably from 570nm to 630nm. A combination of dyes which together have the visual effect on the human eye as a single dye having a peak absorption wavelength on polyester of from 550nm to 650nm, preferably from 570nm to 630nm. This may be provide for example by mixing a red and green-blue dye to yield a blue or violet shade.

A wide range of suitable solvent and disperse dyes are available. However detailed toxicological studies have shown that a number of such dyes are possible carcinogens, for example disperse blue 1. Such dyes are not preferred. More suitable dyes may be selected from those solvent and disperse dyes used in cosmetics. For example as listed by the European Union in directive 76/768/EEC Annex IV part 1. For example disperse violet 27 and solvent violet 13.

A preferred anthraquinone are of the following structure (I) :

wherein R1, R4 , R5 , and R8 are independently selected from the groups consisting of -H, -OH, -NH₂, -NHR9, and -NO₂, such that a maximum of only one -N02 group and a maximum of two - H are present as Rl, R4 , R5, and R8 substituents ; where R9 is an branched or linear C1-C7-alkyl chain or an aryl group or substituted aryl groups, or a branched or linear C1-C7-alkyl chain, the branched or linear Cl-C7-alkyl chain is preferably not substituted by an -OH group or -OMe; R2, R3, R6, and R7 may be selected from -H, -F, -Br, -C1, SO3aryl or -NO₂, and -ORlO, wherein RlO is selected from the group consisting of branched or linear C1-C7-alkyl or aryl; and, R2 and R3 may together be joined to form a five membered non-aromatic 'ring of the form -C (=0) N (HRIl) C (=X) - , wherein X is 0 or NH and RIl is selected from the group consisting of C1-C6-alkyl optionally substituted with alkoxy groups. It is preferred that if R9 and/or RlO is a branched or linear alkyl chain then the chain has less than six carbon atoms and does not have an OH or OMe substitutent .

It is preferred that the R9 and RlO are not branched or linear alkyl chains; R9 and RlO may be methyl, i.e., not a chain. It is preferred that R2 and R3 are individual substituents and are not covalently bound together to form a ring. In particular, It is preferred that R2 and R3 are not joined to form a five membered non-aromatic ring of the form -C (=0) N (HRIl) C (=X) -, wherein X is 0 or NH and RIl is selected from the group consisting of C1-C6-alkyl optionally substituted with alkoxy groups.

It is preferred that Rl, R4 , R5 , and R8 are independently selected from the groups consisting of -H, -OH, -NH₂, and - NO₂, and R2 , R3 , R6 , and R7 is selected from -H, F, Br, C1 or -NO₂, and -Oaryl . It is also preferred that the aryl is an optionally substituted phenyl. Of the Rl, R4 , R5 and R8 it is most preferred that is -OH and one is selected from -NH2 and -NHR9.

It is preferred that R2 , R3 , R5 , R6 , R7 , and R8 are -H, R1 = -OH, R4 = -NHR9 or -NH2. It is preferred that R5, R6 , R7, and R8 = -H, R1 = R4 = - NH2, R2 = R3 = -Oaryl, or -C1.

Most preferred dyes are disperse blue 56, solvent violet 13, disperse violet 26 and disperse violet 28.

It is preferred that disperse blue 87 and disperse blue 7 are excluded from the hydrophobic dye of the anthraquinone structure .

The composition may also comprise between 0.0001 to 0.1 wt % of one or more other dyes selected from cotton substantive shading dyes of group consisting of: hydrolysed reactive dye; acid dye,- and direct dye. Example of preferred acid dyes are: acid blue 62, 40 and 290.

BALANCE CARRIERS AND ADJUNCT INGREDIENTS

The laundry treatment composition in addition to the dye comprises the balance carriers and adjunct ingredients to 100 wt % of the composition.

These may be, for example, surfactants, builders, foam agents, anti-foam agents, solvents, fluorescers, bleaching agents, and enzymes. The use and amounts of these components are such that the composition performs depending upon economics, environmental factors and use of the composition.

The composition may comprise a surfactant and optionally other conventional detergent ingredients. The composition may also comprise an enzymatic detergent composition which comprises from 0.1 to 50 wt %, based on the total detergent composition, of one or more surfactants. This surfactant system may in turn comprise 0 to 95 wt % of one or more anionic surfactants and 5 to 100 wt % of one or more nonionic surfactants. The surfactant system may additionally contain amphoteric or zwitterionic detergent compounds, but this in not normally desired owing to their relatively high cost. The enzymatic detergent composition according to the invention will generally be used as a dilution in water of about 0.05 to 2 wt%.

It is preferred that the composition comprises between 2 to 60 wt % of a surfactant, most preferably 10 to 30 wt %. In general, the nonionic and anionic surfactants of the surfactant system may be chosen from the surfactants described "Surface Active Agents" Vol. 1, by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the current edition of "McCutcheon¹ s Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in "Tenside-Taschenbuch" , H. Stache, 2nd Edn. , Carl Hauser Verlag, 1981.

Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are C₆ to C₂₂ alkyl phenol -ethylene oxide condensates, generally 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule, and the condensation products of aliphatic C₈ to C₁₈ primary or secondary linear or branched alcohols with ethylene oxide, generally 5 to 40 EO.

Suitable anionic detergent compounds which may be used are usually water-soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher C₈ to C₁₈ alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl C₉ to C₂o benzene sulphonates, particularly sodium linear secondary alkyl C₁₀ to C₁₅ benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum. The preferred anionic detergent compounds are sodium Cu to C₁₅ alkyl benzene sulphonates and sodium C₁₂ to C₁₈ alkyl sulphates. Also applicable are surfactants such as those described in EP-A-328 177 (Unilever) , which show resistance to salting-out, the alkyl polyglycoside surfactants described in EP-A- 070 074, and alkyl monoglycosides .

Preferred surfactant systems are mixtures of anionic with nonionic detergent active materials, in particular the groups and examples of anionic and nonionic surfactants pointed out in EP-A-346 995 (Unilever) . Especially preferred is surfactant system that is a mixture of an alkali metal salt of a C₁₆ to C₁₈ primary alcohol sulphate together with a

C₁₂ to C₁₅ primary alcohol 3 to 7 EO ethoxylate. The nonionic detergent is preferably present in amounts greater than 10%, e.g. 25 to 90 wt % of the surfactant system. Anionic surfactants can be present for example in amounts in the range from about 5% to about 40 wt % of the surfactant system.

CATIONIC COMPOUND

When the present invention is used as a fabric conditioner it needs to contain a cationic compound.

Most preferred are quaternary ammonium compounds.

It is advantageous if the quaternary ammonium compound is a quaternary ammonium compound having at least one Ci₂ to C₂₂ alkyl chain.

It is preferred if the quaternary ammonium compound has the following formula:

in which R¹ is a Ci₂ to C₂₂ alkyl or alkenyl chain; R², R³ and

R⁴ are independently selected from Ci to C₄ alkyl chains and X- is a compatible anion. A preferred compound of this type is the quaternary ammonium compound cetyl trimethyl quaternary ammonium bromide.

A second class of materials for use with the present invention are the quaternary ammonium of the above structure in which R¹ and R² are independently selected from C₁₂ to C₂₂ alkyl or alkenyl chain; R³ and R⁴ are independently selected from Ci to C₄ alkyl chains and X^" is a compatible anion.

A detergent composition according to claim 1 in which the ratio of (ii) cationic material to (iv) anionic surfactant is at least 2:1.

Other suitable quaternary ammonium compounds are disclosed in EP 0 239 910 (Proctor and Gamble) .

It is preferred if the ratio of cationic to nonionic surfactant is from 1:100 to 50:50, more preferably 1:50 to 20:50.

The cationic compound may be present from 0.02 wt % to 20 wt % of the total weight of the composition.

Preferably the cationic compound may be present from 0.05 wt % to 15 wt %, a more preferred composition range is from 0.2 wt % to 5 wt %, and most preferably the composition range is from 0.4 wt % to 2.5 wt % of the total weight of the composition.

If the product is a liquid it is preferred if the level of cationic surfactant is from 0.05 wt % to 10 wt % of the total weight of the composition. Preferably the cationic compound may be present from 0.2 wt % to 5 wt %, and most preferably from 0.4 wt % to 2.5 wt % of the total weight of the composition. If the product is a solid it is preferred if the level of cationic surfactant is 0.05 wt % to 15 wt % of the total weight of the composition. A more preferred composition range is from 0.2 wt % to 10 wt %, and the most preferred composition range is from 0.9 wt % to 3.0 wt % of the total weight of the composition.

It is most preferred that the present composition contains less than 0.1 wt % of any coloured inorganic electrolytes such as nickel or cupric sulphate. Most preferably the present composition is devoid of any coloured inorganic electrolytes .

BLEACHING SPECIES

The laundry treatment composition may comprise bleaching species. The bleaching species, for example, may selected from perborate and percarbonate . These peroxyl species may be further enhanced by the use of an activator, for example, TAED or SNOBS. Alternatively or in addition to, a transition metal catalyst may used with the peroxyl species. A transition metal catalyst may also be used in the absence of peroxyl species where the bleaching is termed to be via atmospheric oxygen, see, for example WO02/48301. Photobleaches, including singlet oxygen photobleaches, may be used with the laundry treatment composition. A preferred photobleach is vitamin K3.

FLUORESCENT AGENT

The laundry treatment composition comprises a fluorescent agent (optical brightener) . We have found that the presence of a fluorescent agent enhances the deposition of the dye. Fluorescent agents are well known and many such fluorescent agents are available commercially. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in laundry treatment composition is from 0.005 to 2 wt %, more preferably 0.01 to 0.1 wt %. Preferred fluorescers are: sodium 2 (4-styryl-3-sulfophenyl) -2H-napthol [1 , 2-d] triazole, disodium 4 , 4 ^■ -bis{ [ (4-anilino-6- (N methyl-N-2 hydroxyethyl) amino 1 , 3 , 5-triazin-2-yl) ] amino}stilbene-2-2 ' disulfonate, disodium 4, 4 ' -bis{ [ (4-anilino-6-morpholino-l , 3, 5-triazin-2- yl)] amino} stilbene-2-2 ' disulfonate, and disodium 4,4'- bis (2-sulfostyryl) biphenyl .

PERFUME

Preferably the laundry treatment composition comprises a perfume. The perfume is preferably in the range from 0.001 to 3 wt %, most preferably 0.1 to 1 wt %. Many suitable examples of perfumes are provided in the CTFA (Cosmetic, Toiletry and Fragrance Association) 1992 International Buyers Guide, published by CFTA Publications and OPD 1993 Chemicals Buyers Directory 80th Annual Edition, published by Schnell Publishing Co.

Examples

Example 1 White Nylon Elastane French knickers (65% polyamide, 33% elastane, 2% viscose gusset) were purchased from Marks and Spencers (UK) . The knickers were washed 20 times in a Brazilian top loading washing machine as part of a whites only load containing cotton, polyester and nylon. The L: C was 30:1, 2g/L of Brihlante™ washing powder was used and the water temperature was ambient . The experiment was repeated but with the addition of varying levels of the dye solvent violet 13 to the washing powder. The dye was added via a zeolite/non-ionic (7EO) granule, which contained 0.25% by weight solvent violet 13 dissolved in the non- ionic.

The build up of the dye on the fabric was monitored by measuring the reflectance of the fabric at 600nm. This was converted to the remission function K/S which is proportional to the dye loading on the cloth. K/S is calculated using the equation

K/S = (1-R)²/2R

Where is the R is the reflectance in % divided by 100. It was found that the build of dye on the cloth, expressed as deltaK/S (600nm) compared to control, per wash was constant, such that plots of K/S(600nm) verses wash number were linear with very good correlation coefficients (R²= 0.99). It was also found that deltaK/S (600nm) per wash correlated very well with the concentration of dye in the wash liquor expressed in ppb, such that: deltaK/S (600nm) per wash = 1.47xlO^-4x ppb dye in wash liquor R² = 0.98, 4 points in range 0 to 200ppb.

To obtain a good visible whiteness benefits over control without dye (corresponding to a colour change of 1 deltaE points), required a total increase in K/S(600nm) of 0.009. From the above data the number of washes required to achieve this result may be obtained as given in the table below:

Example 2

Experiments were conducted to see how deposition to nylon and polyester fabrics varied with dosage of powder (2 and 6g/L) ; type of powder (Brihlante™ LAS/STPP based product and Persil Colour™ LAS/NI/Zeolite based product) ; and temperature (20 and 40 ⁰C) .

For solvent violet 13 deposition did not vary greatly with temperature for polyester but doubled for nylon. The two formula's behaved similarly. Increasing the powder dose decreased deposition by about 30 to 40%.

Example 3

From the data in example 1 and 2, good benefits could be expected in the lifetime of the garment (2 years, wearing once per week, 104 washes), for levels of 0.5 ppb at 20⁰C for Brihlante and 0.8 ppb solvent violet 13 in the wash liquor for Persil Colour type formulations. Raising the temperature by 20⁰C doubles the deposition, thus at 40⁰C, levels of 0.25ppb for Brihlante and 0.4 ppb for Persil Colour type formulations. At 60 ⁰C levels of 0.12ppb for Brihlante and 0.2 ppb for Persil Colour type formulations.

Formulations are typically dosed in the range 1 to 12 g/L, to obtain the levels of dye required in the wash liquor the following levels of dye are required in the formulation.

Example 4

Experiments were performed to compare the relative performance, in terms of delivery to polyester fabrics in the wash from granular detergent formulations, of different anthraquinone dyes. Dyes without alkyl chains performed better. The best performing dyes were disperse blue 56, disperse violet 26, disperse violet 28 and solvent violet 13. Example 5

A standard fabric conditioner was created containing 5% of a C16 to C18 dialkyl quaternary salt and a fatty co-active. To this was added 0.005% of solvent violet 13. Washing polyester and nylon cloth with this fabric conditioner at 10g/L showed clear deposition of the dye to the polyester. The example demonstrates that the dyes may be used at much lower levels than exemplified.

Example 6

A liquid detergent was formulated containing 3%LAS, 6% alcohol ethoxylate (9EO) , 6% sodium lauryl sulfate (3EO) and 0.00002% solvent violet 13. The solvent violet was added via a concentrated non- ionic solution.

The 1.8 g/L detergent was used to wash a piece of white nylon-elastane (80 : 20) fabric with a L:C of 100:1 at ambient temperatures. The fabric was washed 10 times in this manner and compared to a control . The colour of the fabric was measured with a reflectometer and expressed as the L*, a* and b* values. The cloth washed in solvent violet 13 control has delta L*, delta a* and delta b* of -0.2, 0.2 and -0.9 respectively relative to the control. The decrease in b* reflecting a bluing of the cloth indicates the effective deposition of the dye.

The level of dye in the wash solution is 0.36 ppb^'. This examples illustrates that benefits from liquids may occur at lower wash numbers than powders. Example 7

65:35 pieces of woven polyester-cotton was washed in water containing 0.5 g/L SDS surfactant and 0.5g/L NaC1 for 30 minutes at room temperature (20⁰C) . To this was added varying levels of the fluorescers Tinopal CBS-X (ex Ciba Speciality Chemicals, Basel) and solvent violet 13. The solvent violet 13 was added with vigorous agitation from a 50 ppm ethanol stock solution. After the wash the clothes were dried and their reflectance spectra recorded with UV light excluded from below 420nm. The level of solvent violet 13 deposited to the cloth may be conveniently measured via the reflectance at 580nm.

The results are shown in the table below, where the K/S value at 580 nm is given.

K/S = (1-R)²/(2R) and is proportional to the dye loading on the cloth.

As expected the CBS-X does not significantly change the baseline value of K/S (580) as UV light is excluded and the molecules does not absorb or emit at this wavelength.

The adsorption of solvent violet 13 to the cloth is clearly- seen by the increase in K/S(580) . Surprisingly the adsorption increases as the CBS-X level is increased, so that there is more dye on the cloth. This is completely unexpected as CBS-X deposits to the cotton fibres and solvent violet 13 to the polyester fibres in the cloth. The fluorescer makes the deposition of solvent violet 13 more efficient.

Tinopal CBS-X is a di-styryl biphenyl compound of the following structure:

Claims

We claim :

1. A domestic method of treating a textile garment, the method including the following steps: (i) adding a laundry treatment composition comprising between 0.0000001 to less than 0.00005 wt % of a hydrophobic dye, from 0.005 to 2 wt % of a fluorescent agent selected from: sodium 2 (4-styryl-3-sulfophenyl) -2H-napthol [1 , 2-d] triazole, disodium 4 , 4 ' -bis{ [ (4-anilino-6- (N methyl-N-2 hydroxyethyl) amino 1 , 3 , 5-triazin-2-yl) ] amino}stilbene-2-2 ^■ disulfonate, disodium 4, 4 ' -bis{ [ (4-anilino-6-morpholino-l , 3, 5-triazin-2- yl) ] amino} stilbene-2-2 ' disulfonate, and disodium 4,4'- bis (2-sulfostyryl) biphenyl , and between 2 to 60 wt % of a surfactant, the hydrophobic dye of an anthraquinone structure, to an aqueous medium to form a shading medium; (ii) treating the textile garment with the shading medium; (iv) rinsing the textile with an aqueous medium; and, (iii) drying the treated textile.

2. A method according to claim 1, wherein the hydrophobic dye of the following anthraquinone structure (I) :

wherein Rl, R4 , R5 , and R8 are independently selected from the groups consisting of -H, -OH, -NH₂, -NHR9, and NO₂, such that a maximum of only one -N02 group and a maximum of two -H are present as R1, R4 , R5 , and R8 substituents ; where R9 is an branched or linear C1-C7-alkyl chain or an aryl group or substituted aryl groups; and, R2, R3, R6, and R7 may be selected from -H, -F, -Br, - C1, SO3aryl or -NO₂, and -ORlO, wherein RlO is selected from the group consisting of branched or linear C1-C7- alkyl or aryl .

3. A method according to claim 2, wherein the branched or linear alkyl chain of R9 and RlO has less than six carbon atoms and does not have an OH or OMe substitutent .

4. A method according to claim 2, wherein Rl, R4 , R5 , and

R8 are independently selected from the groups consisting of -H, -OH, -NH₂, and -NO₂, and

R2, R3, R6, and R7 is selected from -H, F, Br, C1 or -

NO₂, and -Oaryl .

5. A method according to any one of claims 2 to 4 , wherein aryl is an optionally substituted phenyl.

6. A method according to according to any one of claims 2 to 5, wherein at least one of R1, R4 , R5 and R8 is -OH and one of Rl, R4 , R5 and R8 is selected from -NH2 and - NHR9.

7. A method according to claim 2, wherein R2 , R3 , R5 , R6 , R7, and R8 are -H, R1 = -OH, R4 = -NHR9 or -NH2.

8. A method according to claim 2, wherein R5 , R6 , R7 , and R8 = -H, R1 = R4 = -NH2, R2 = R3 = -Oaryl, or -C1.

9. A method according to claim 1, wherein the dye is selected from the group consisting of: solvent violet 13, disperse blue 56, disperse violet 26 and disperse violet 28.

10. A method according to claim 9, wherein the dye is solvent violet 13.

11. A method according to any preceding claim, wherein the dye gives a blue or violet shade when deposited on white polyester.

12. A method according to any preceding claim, wherein the composition comprises between 0.0001 to 0.1 wt % of one or more other dyes selected from cotton substantive shading dyes of group consisting of: hydrolysed reactive dye,- acid dye; and direct dye.

13. A method of treating a textile, wherein a shading medium comprises from 1 ppt to less than 1 ppb of the hydrophobic dye as defined in any one of claims 1 to 10, and from 0.2 g/L to 3 g/L of a surfactant.

14. A method of treating a textile according to claim 13, wherein the hydrophobic dye is present in the range lppt ppb to 999 ppt.

15. A method of treating a textile according to claim 13 or 14, wherein the aqueous solution comprises from 1 ppb to 5 ppm one or more other dyes selected from cotton substantive shading dyes of group consisting of: hydrolysed reactive dye; acid dye; and direct dye.