EP2334777B1

EP2334777B1 - Elastane substantive dyes

Info

Publication number: EP2334777B1
Application number: EP09812689.9A
Authority: EP
Inventors: Stephen Norman Batchelor; Jayne Michelle Bird; Susan Barbara Joyce
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2008-09-12
Filing date: 2009-07-17
Publication date: 2013-05-01
Anticipated expiration: 2029-07-17
Also published as: AR077158A1; CL2011000517A1; ES2422555T3; CN102149804B; CN102149804A; WO2010028893A1; ZA201101006B; EP2334777A1; MY153978A

Description

FIELD OF INVENTION

The present invention relates to the delivery of dyes to fabrics.

BACKGROUND

Shading dyes may be used to enhance the whiteness of garments in the laundry process. WO2005/003276 WO2006/010472 and WO2008/017570 (all Unilever) teaches the use of specific acid azo, anthraquinone, triphenylmethane and azine dyes for shading garments. WO2006/004870 WO2007/084729 (Proctor and Gamble) and co-pending EP08150172 (Unilever) teaches the use of specific basic triphenylmethane, thiazolium, anthraquinone and methane dyes for shading garments. The advantage of these dyes is that they deposit in the first washes and then do not build up further on the fabrics in subsequent washes. This prevents overshading of garments.
Wash loads typically consist of a range of fabrics made from different fibers, particularly cotton, polyester, nylon and elastane. Elastane containing fabrics are prone to yellow much more than other fibers due to oxidation. It would thus be desirable to have a shading dye that build up slowly on elastane fabrics over multiple washes but not on cotton or polyester. This would provide optimal whiteness over the lifetime of all garments in the wash.

SUMMARY OF INVENTION

Blue or violet cationic naptholactam dyes build up slowly on elastane fabrics over multiple washes but not on cotton or polyester when applies in domestic washing.
In one aspect the present invention provides a laundry treatment composition comprising:

(i) from 2 to 70 wt% of a surfactant, and from 0.0001 to 0.1 wt% of a cationic blue or violet naptholactam dye of the following structure:
wherein:
- X^- is a counter ion;
- R1 is an optionally substituted alkyl which may form an alkylene bridge at the 1 position;
- R2 is a group having at least one benzene moiety directly bound to a nitrogen atom, wherein the benzene moiety is between 1 and 4 bonds removed from the naptholactam and in conjugation with the naptholactam and rings A and B are optionally substituted.

In another the present invention provides a domestic method of treating a textile, the method comprising the steps of:

(i) treating a textile with an aqueous solution of the cationic blue or violet naptholactam, the aqueous solution comprising from 1 ppb to 1 ppm of the cationic blue or violet naptholactam dye, and from 0 ppb to 1 ppm of another dye or pigment selected from: pigments, hydrophobic dyes and direct dyes; and, from 0.0 g/L to 3 g/L of a surfactant;
(ii) optionally rinsing the textile; and, (iii) drying the textile. Prefereably, the aqueous solution comprises 0.1 to 50 ppm of fluorescer.

DETAILED DESCRIPTION OF THE INVENTION

The naptholactam dyes as used in the present invention are blue or violet. In this regard, the naptholactam dyes gives a blue or violet colour to a white cloth with a hue angle of 240 to 345, more preferably 260 to 320, most preferably 270 to 300.
R is an uncharged group selected from: C1-C8-alkyl which may be substituted by -OH, -Cl, and -F, -CN; -CONHC1-C6-alkyl; - OCOC1-C6-alkyl; -CO2C1-C6-alkyl; -OC1-C6-alkyl;
and -C(O)NH2 groups; benzyl; phenyl; wherein the benzyl and phenyl may be substituted by a group selected from: -OC1-C6-alkyl, -C1-C6-alkyl and, R1 may form together with ring A at position 1 a five or six membered ring linked by a C3-C4-alkyl chain;
R2 is selected from:

and,
wherein R3 and R4 are selected from: H; polyethers, C1-C8-alkyl which may be substituted by -OH, -Cl, and -F, -CN; -CONHC1-C6-alkyl; - OCOC1-C6-alkyl; -CO2C1-C6-alkyl; -OC1-C6-alkyl;and -C(O)NH2 groups; benzyl; phenyl; wherein the benzyl and phenyl may be substituted by a group selected from: -OC1-C6-alkyl, -C1-C6-alkyl; and, R3 and R4 together form a morpholine group,
a group of the form:
wherein R5 is selected from: H, CN, -C(O)OC1-C8-alkyl; -C1-C8-alkyl, phenyl, napthyl; phenyl-C1-C8-alkyl(O)O-C1-C8-alkyl; naphthyl-C1-C8-alkyl(O)O-C1-C8-alkyl; and, -C1-C8-alkylC(O)N(R7)2, wherein R7 may be the same or different and is selected from: C1-C8-alkyl; benzyl; and, phenyl,
D together with C-N represents a 5 or 6 membered nitrogen containing ring which may be further condensed to a benzene ring and may carry C1-C8-alkyl and -OC1-C6-alkyl groups;
R6 is selected from the groups as defined in R3 and R4, rings A and B may carry up to two groups R7 which are independently selected from: H; -Br; -Cl; -F; -NO₂; -CN; - SO2-benzyl; -C(O)O-C1-C8-alkyl; -C(O)-C1-C8-alkyl; - NHC(O)C1-C4-alkyl, -SO2-C1-C8-alkyl; -SO2-phenyl; -S02-phenyl and, one of rings A or B may be linked via a -CH2- or -NH- unit to another naptholactam dye unit;
alkyl rings and aromatic rings other than rings A and B of the naptholactam dye as defined may carry up to six R8 groups selected from: -C1-C6-alkyl and -OC1-C6-alkyl that are same or different.
Where -C1-C6-alkyl is found as a terminal group it is preferred that these groups are C1 or C2 alkyl, more preferably CH3 or C2H5. Where -C1-C6-alkyl is found as a spacer group, for example -C1-C8-alkylC(O)N(R7)2, it is preferred that these groups are C1 or C2 alkyl, more preferably methylene or ethylene spacers.
Preferably, R1 is selected from: Methyl and Ethyl.
Preferably, R3 and R4 are selected from: C1-C6-alkyl, hydroxyl substituted C1-C6-alkyl; chloro substituted C1-C6-alkyl; flouro substituted C1-C6-alkyl; cyano substituted C1-C6-alkyl; phenyl substituted C1-C6-alkyl; phenyl; and optionally substituted phenyl.
Most preferably, R3 and R4 are selected from: CH₃, C₂H₅; CH₂CH₂OH; CH₂CH₂CN; CH₂CH₂Cl; CH₂Ph; Ph; and p-MeOPh-.
Most preferably, there is a single R7 subsistent, which is present at position 3 as indicated on the A ring or rings A and B are unsubstituted.
The naptholactam dyes and substituents thereof may be or carry a polyether chain. A polyether chain is defined as at least two repeating units that are chemically bound via the ether's oxygen. Preferred polyether chains are selected from ethylene oxides or propylene oxides. Where an alkyl and/or polyether chain is present the chain preferably has a molecular weight of less than 1000, more preferably less than 400, even more preferably less than 200. Preferably R3 and/or R4 is a polyether chain as defined above.
The naptholactam dyes may be further substituted by uncharged organic groups. If the naptholactam dyes is further substituted it is preferred that the uncharged organic groups should have a total molecular weight of less than 400, preferably less than 150. Preferred uncharged organic groups may be selected from NHCOCH₃, CH₃, C₂H₅, CH₃O, C₂H₅O, amine, Cl, F, Br, I, NO₂, CH₃SO₂, and CN. It is preferred that any uncharged organic groups of the naptholactam dyes do not have more than three carbon carbon double bonds (C=C).
X- is not essential aspect of the invention and may be varied widely. X- may be an anion such as RCOO^-, BPh₄ ^-, ClO₄ ^-, BF₄ ^-, PF₆ ^-, RSO₃ ^-, RSO₄ ^-, SO₄ ^2-, NO₃ ^-, F^-, Cl^-, Br^-, or I^-, with R being hydrogen, optionally substituted alkyl or optionally substituted aryl. Preferably X- is selected from: CH₃SO₃ ^-, CH₃CO₂ ^-, BF₄ ^-, Cl^-, F^-, Br^-, and I^-.
Examples of naptholactam dyes suitable for use in the present invention are given below:

SURFACTANT

The composition comprises between 2 to 70 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 "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Preferably the surfactants used are saturated.
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 C₂₀ 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 C₁₁ 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.
In another aspect which is also preferred the surfactant may be a cationic such that the formulation is a fabric conditioner.

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 C₁₂ to C₂₂ alkyl chain.
It is preferred if the quaternary ammonium compound has the following formula:
in which R¹ is a C₁₂ to C₂₂ alkyl or alkenyl chain; R², R³ and R⁴ are independently selected from C₁ 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 C₁ 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 1.5 wt % to 50 wt % of the total weight of the composition. Preferably the cationic compound may be present from 2 wt % to 25 wt %, a more preferred composition range is from 5 wt % to 20 wt %.
The softening material is preferably present in an amount of from 2 to 60% by weight of the total composition, more preferably from 2 to 40%, most preferably from 3 to 30% by weight.
The composition optionally comprises a silicone.

Builders or Complexing agents:

Builder materials may be selected from 1) calcium sequestrant materials, 2) precipitating materials,
3) calcium ion-exchange materials and 4) mixtures thereof.
Examples of calcium sequestrant builder materials include alkali metal polyphosphates, such as sodium tripolyphosphate and organic sequestrants, such as ethylene diamine tetraacetic acid.
Examples of precipitating builder materials include sodium orthophosphate and sodium carbonate. Preferably, the laundry treatment composition comprises sodium carbonate in the range from 5 to 50 wt%, most preferably 10 to 35 wt%.
Examples of calcium ion-exchange builder materials include the various types of water-insoluble crystalline or amorphous aluminosilicates, of which zeolites are the best known representatives, e.g. zeolite A, zeolite B (also known as zeolite P), zeolite C, zeolite X, zeolite Y and also the zeolite P-type as described in EP-A-0, 384, 070 .
The composition may also contain 0-65 % of a builder or complexing agent such as ethylenediaminetetraacetic acid, diethylenetriamine-pentaacetic acid, alkyl- or alkenylsuccinic acid, nitrilotriacetic acid or the other builders mentioned below. Many builders are also bleach-stabilising agents by virtue of their ability to complex metal ions.
Zeolite and carbonate (carbonate (including bicarbonate and sesquicarbonate) are preferred builders.
The composition may contain as builder a crystalline aluminosilicate, preferably an alkali metal aluminosilicate, more preferably a sodium aluminosilicate. This is typically present at a level of less than 15%w. Aluminosilicates are materials having the general formula:

0.8-1.5 M₂O. Al₂O₃. 0.8-6 SiO₂

₂

Alternatively, or additionally to the aluminosilicate builders, phosphate builders may be used. In this art the term 'phosphate' embraces diphosphate, triphosphate, and phosphonate species. Other forms of builder include silicates, such as soluble silicates, metasilicates, layered silicates (e.g. SKS-6 from Hoechst).
Preferably the laundry detergent formulation is a non-phosphate built laundry detergent formulation, i.e., contains less than 1 wt% of phosphate.

Enzymes

The composition may comprise one or more enzymes, which provide cleaning performance, fabric care and/or sanitation benefits.

FLUORESCENT AGENT

The composition preferably comprises a fluorescent agent (optical brightener). 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 the composition is generally from 0.005 to 2 wt %, more preferably 0.01 to 0.1 wt %. Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. 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-1,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'-bis(2-sulfostyryl)biphenyl.

PERFUME

Preferably the 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.
It is commonplace for a plurality of perfume components to be present in a formulation. In the compositions of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components.
In perfume mixtures preferably 15 to 25 wt% are top notes. Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Preferred top-notes are selected from citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol.
Perfume and top note may be used to cue the whiteness benefit of the invention.
It is preferred that the laundry treatment composition does not contain a peroxygen bleach, e.g., sodium percarbonate, sodium perborate, and peracid.

Polymers

The composition may comprise one or more polymers. Examples are carboxymethylcellulose, poly (ethylene glycol), poly(vinyl alcohol), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers.
Polymers present to prevent dye deposition, for example poly(vinylpyrrolidone), poly(vinylpyridine-N-oxide), and poly(vinylimidazole), are preferably absent from the formulation.

Examples

Example 1

Synthesis of cationic naptholactams are well documented in the literature: GB1520828 (Bayer), GB987828 (Bayer) and GB1371 178 (Bayer) GB973259 (Bayer), and GB1583160 (Ciba). The exemplified cationic naptholactam dyes suitable for use as given above were synthesised following these literature procedures. All were found to give blue or violet in colour in aqueous solution and when deposited on cloth gave a blue or violet hue to the cloth.

Example 2

The following dye was synthesised from literature procedures:
0.005wt% of the dye was added to a washing powder contained 20% LAS surfactant, 30% Na₂CO₃, 40% NaCl, remainder minors included calcite and fluorescer and moisture. The washing powder was used to wash a variety of white fabric types.
Washes were conducted in 26 French Hard water at 293K with a liquor to cloth ratio of 10:1. Washes took 30 minutes and were followed by 2, 1 minute rinsed in 26 French Hard water at 293K. Following the 1^st, 3^rd, 5^th and 10^th wash the fabrics were dried and their colour measured using a reflectometer (UV-excluded) and the colour expressed as CIE L*a*b* values. The Δb values wash calculated from this, which is given by Δb = b(control wash without dyes) - b(wash with dye).
The table below shows the Δb values obtained in the experiment for the naptholactam dye and compares it to other dyes.
3 cottons (woven knitted and towelling), 4 different polycottons and 2 elastanes (nylon-elastane, cotton-elastane) were used in the experiment. Average values are given.

Naptholactam dye Wash number

0 1 3 5 10

Cottons 0.00 0.22 0.68 0.88 0.99

Polycottons 0.00 0.21 0.37 0.44 0.47

elastanes 0.00 0.19 0.59 0.81 1.32

Comparative example:

Basic blue 159	Wash number
	0	1	3	5	10
Cottons	0.00	0.27	0.44	0.56	0.58
Polycottons	0.00	0.14	0.21	0.24	0.29
elastanes	0.00	0.29	0.45	0.56	0.70

Basic Blue 159 is an azo dye as described in W02006/004870 .

Comparative example:

Thiazolium dye	Wash number
	0	1	3	5	10
Cottons	0.00	0.36	0.63	0.68	0.77
Polycottons	0.00	0.30	0.39	0.40	0.47
elastanes	0.00	0.43	0.75	0.88	1.05

The thiazolium dye use was:
As described in WO2007/084729 . It was used at 0.002wt% on formulation.
The naptholactam dye builds up more strongly on the elastane containing fabrics than the other dyes.

Claims

A laundry treatment composition comprising:
(i) from 2 to 70 wt% of a surfactant, and from 0.0001 to 0.1 wt% of a cationic blue or violet naptholactam dye of the following structure:
wherein:
X^- is a counter ion;

R1 is an optionally substituted alkyl which may form an alkylene bridge at the 1 position;

R2 is a group having at least one benzene moiety directly bound to a nitrogen atom, wherein the benzene moiety is between 1 and 4 bonds removed from the naptholactam and in conjugation with the naptholactam and rings A and B are optionally substituted.
A laundry treatment composition according to claim 1, wherein:
R₁ is an uncharged group selected from: C1-C8-alkyl which may be substituted by -OH, -Cl, and -F, -CN; -CONHC1-C6-alkyl; - OCOC1-C6-alkyl; -CO2C1-C6-alkyl; -OC1-C6-alkyl;

and -C(O)NH2 groups; benzyl; phenyl; wherein the benzyl and phenyl may be substituted by a group selected from: -OC1-C6-alkyl, -C1-C6-alkyl and, R1 may form together with ring A at position 1 a five or six membered ring linked by a C3-C4-alkyl chain;

R2 is selected from:

and,
wherein R3 and R4 are selected from: H; polyethers, C1-C8-alkyl which may be substituted by -OH, -Cl, and -F, -CN; -CONHC1-C6-alkyl; - OCOC1-C6-alkyl; -CO2C1-C6-alkyl; -OC1-C6-alkyl;and -C(O)NH2 groups; benzyl; phenyl; wherein the benzyl and phenyl may be substituted by a group selected from: -OC1-C6-alkyl, -C1-C6-alkyl; and, R3 and R4 together form a morpholine group,

a group of the form:
wherein R5 is selected from: H, CN, -C(O)OC1-C8-alkyl; -C1-C8-alkyl, phenyl, napthyl; phenyl-C1-C8-alkyl(O)O-C1-C8-alkyl; naphthyl-C1-C8-alkyl(O)O-C1-C8-alkyl; and, -C1-C8alkylC(O)N(R7)2, wherein R7 may be the same or different and is selected from: C1-C8-alkyl; benzyl; and, phenyl,

D together with C-N represents a 5 or 6 membered nitrogen containing ring which may be further condensed to a benzene ring and may carry C1-C8-alkyl and -OC1-C6-alkyl groups;

R6 is selected from the groups as defined in R3 and R4, rings A and B may carry up to two groups R7 which are independently selected from: H; -Br; -Cl; -F; -NO₂; -CN; - SO2-benzyl; -C(O)O-C1-C8-alky -C(O)-C1-C8-alkyl; - NHC(O)C1-C4-alkyl, -SO2-C1-C8-alkyl; -SO2-phenyl; -SO2-phenyl and, one of rings A or B may be linked via a -CH2- or -NH- unit to another naptholactam dye unit;

alkyl rings and aromatic rings other than rings A and B of the naptholactam dye as defined may carry up to six R8 groups selected from: -C1-C6-alkyl and -OC1-C6-alkyl that are same or different.
A laundry treatment composition according to claim 2, wherein the R3 and R4 are selected from: C1-C6-alkyl, hydroxyl substituted C1-C6-alkyl; chloro substituted C1-C6-alkyl; flouro substituted C1-C6-alkyl; cyano substituted C1-C6-alkyl; phenyl substituted C1-C6-alkyl; phenyl; and optionally substituted phenyl.
A laundry treatment composition according to any preceding claim, wherein R1 is selected from: Me and Ethyl.
A laundry treatment composition according to any preceding claim, wherein at least one of R3 and R4 is selected from: Me, C2H5; CH₂CH₂OH; CH₂CH₂CN; CH₂CH₂Cl; CH₂Ph; Ph; and p-MeOPh-.
A laundry treatment composition according to any preceding claim, wherein there is a single R7 subsistent, which is present at position 3 as indicated on the A ring or rings A and b are unsubstituted.
A laundry treatment composition according to claim 1, wherein the naptholactam dye is selected from:
A laundry treatment composition according to claim 1, wherein the naptholactam dye is selected from:
A laundry treatment composition according to any preceding claim wherein the composition comprises a fluorescer selected from the group consisting of: 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-1,3,5-triazin-2-yl)]amino) stilbene-2-2' disulfonate, and disodium 4,4'-bis (2-sulfostyryl)biphenyl.
A domestic method of treating a textile comprising elastane fibers, the method comprising the steps of:
(i) treating a textile with an aqueous solution of a cationic blue or violent naptholactam dye as defined in any one of claims 1 to 8, the aqueous solution comprising from 1 ppb to 1 ppm of the cationic blue or violet naptholactam dye, and from 0 ppb to 1 ppm of another dye or pigment selected from: pigments, hydrophobic dyes and direct dyes; and, up to 3 g/L of a surfactant;

(ii) optionally rinsing the textile; and,

(iii) drying the textile.
A domestic method of treating a textile according to claim 10, wherein the aqueous solution comprises 0.1 to 50 ppm of fluorescer.