WO1995025842A1

WO1995025842A1 - Process for the coloration of textiles

Info

Publication number: WO1995025842A1
Application number: PCT/GB1995/000377
Authority: WO
Inventors: Mark Kenworthy; Andrew Hunter Morris Renfrew; Michael Gordon Hutchings; Aidan Joseph Lavery; Andrew Paul Shawcross
Original assignee: Zeneca Limited
Priority date: 1994-03-22
Filing date: 1995-02-23
Publication date: 1995-09-28
Also published as: AU1714295A; GB9405592D0

Abstract

A process for the coloration of a substrate comprising applying thereto a composition comprising a dye and a nucleophilic agent and heating and/or basifying the composition thereby joining the dye and nucleophilic agent together by the formation of covalent bonds, wherein: (i) the dye has at least one electrophilic group; and (ii) the nucleophilic agent has at least two groups selected from thiols and thiones. The dye and the nucleophilic agent form an oligomer or polymer which adheres strongly to the substrate.

Description

Process for the coloration of textiles

This invention relates to a process for dyeing textiles and to compositions.

Over the years there have been many different dyes and dyeing methods invented for textile materials. Reactive dyes, direct dyes, vat dyes and their uses are well known in dyestuff art.

A new process for colouring substrates has now been found in which a dye and a nucleophilic agent having specified groups join together or 'polymerise' when they are heated and/or basified. In this way the dye's molecular weight increases, its water solubility

decreases, and its affinity for any textile materials present increases, leading to high levels of exhaustion of the dye from the dyebath, good fixation to textiles and good wash-fastness properties for textiles dyed therewith.

According to the present invention there is provided a process for the coloration of a substrate comprising applying thereto a composition comprising a dye and a nucleophilic agent and heating and/or basifying the composition thereby joining the dye and nucleophilic agent together by the formation of covalent bonds, wherein:

(i) the dye has at least one electrophilic group; and

(ii) the nucleophilic agent has at least two groups selected from thiols and thiones.

Embodiments of the present invention and terms used are

illustrated by reference to the accompanying drawing in which:

Fig.1 is a flow chart showing schematically how a dye and

nucleophilic agent join together when basified.

Figure 1 illustrates what happens when an aqueous solution containing a composition comprising (i) a dye having two ß-sulphatoethylsulphonyl electrophilic groups; and (ii) a nucleophilic agent having two thiol groups is basified. On basification, or for that matter on heating, the dye and nucleophilic agent join together through the nucleophilic -S- groups forming a covalent bond with electrophilic -SO₂CH=CH₂ groups present on the dyes. Where the sulphato groups in the ß-sulphatoethylsulphonyl groups are the only or the major water-solubilising groups elimination thereof causes a decrease in water-solubility and this assists the affinity and/or fixation of the dye for or to any textiles which are present.

It is possible to check that the dye and nucleophilic agent have joined together by analysing a composition thereof using gel permeation chromatography (GPC) before and after heating and/or basification. A fall in the retention time shows that the dye and nucleophilic agent have joined together to give a higher molecular weight species. Alternatively, one may use ion spray mass spectrometry or high performance liquid chromatography instead of GPC.

A valuable feature of the present coloration process is that the dye and nucleophilic agent may be joined together without the need for free radical initiators, all that is needed is heating and/or

basification. The process can be operated using aqueous solutions of the composition at temperatures below 200°C using normal dyeing equipment.

As will be understood, the dye and nucleophilic agent used in the present process are different from one another. In one embodiment the molecular weight of the nucleophilic agent is at least 50 below that of the dye. In another embodiment the dye and nucleophilic agent are both free from sulpho groups (i.e. none of the carbon atoms in the dye and nucleophilic agent have a sulpho substituent).

The Dye

Preferably the dye has at least 2, more preferably from 2 to 6, electrophilic groups. This preference arises because dyes containing a plurality of electrophilic groups are capable of polymerising wnereas those having only one electrophilic group can only form oligomers with the nucleophilic agent.

The electrophilic group may be any group capable of forming a covalent bond with the nucleophilic agent when the composition is heated or basified. Preferably said electrophilic group is a group capable of undergoing 1) a substitution reaction, 2) an addition reaction or 3) an elimination and addition reaction with the aforementioned nucleophilic agent.

Preferred groups capable of undergoing a substitution reaction are of the formula -COCH₂-X¹, -COCHR¹CH₂-X¹, -COCHX¹CHX¹CO₂R², -COOHX¹CHX¹COR¹, -CH₂-X¹ and -NHCOCH₂-X¹

wherein:

X¹ is a labile group;

R¹ is H or a labile group;

R² is H or optionally substituted alkyl, aryl or heteroaryl; and

X¹ is preferably halo, especially chloro, bromo or lodo

A labile group is a group displaceable by the thiol or thione group in the aforementioned nucleophilic agent when the dye is heated or basified.

When R¹ is a labile group it is preferably halo, especially chloro.

The optional substituents which may be present on R² are

preferably as mentioned hereinafter for L. R² is preferably H, phenyl or C_1-4-alkyl, especially methyl or ethyl.

A further group capable of undergoing a substitution reaction is a labile group attached to a heterocycle, for example a triazine ring.

Groups which are capable of undergoing an addition reaction preferably comprise an epoxide group, an aziridine, aziridinium, azetidine or cyclopropane group or, more preferably, an activated alkene (e.g. alkenyl sulphone) or alkyne capable of undergoing a Michael-type addition with the aforementioned nucleophilic group.

A preferred activated alkene is or comprises a group of formula -Z¹-CR³=CR⁴R⁵, -CR³=CR⁵-Z² or -CZ²=CR³R⁵ wherein Z¹ and Z² are electron withdrawing groups and R³, R⁴ and R⁵ are each independently H, C_1-4-alkyl or halo. Z¹ is preferably -SO-, -SO₂-, -CO-, especially -SO₂-, and Z² is preferably -CN, -NO₂ or an alkyl- or arylsulphonyl group or an acyl group. The activated alkene of formula -Z¹-CR³=CR⁴R⁵ may be attached to a group of formula -NR²- (wherein R² is as hereinbefore defined) to give a group of formula -NR²-SO-CR³=CR⁴R⁵, -NR²-SO₂-CR³=CR⁴R⁵ or -NR²-CO-CR³=CR⁴R⁵. Preferred alkylsulphonyl groups are -SO₂- (C_1-4-alkyl) and preferred arylsulphonyl groups are phenylsulphonyl and tosyl. Preferred acyl groups are of the formula -CO-R² wherein R² is as hereinbefore defined, especially C_1-4-alkyl or phenyl. It is preferred that R³ and R⁴ are both H.

A preferred group capable of undergoing an elimination and addition reaction is or comprises a group of the formula -Z¹-NR²- (CR⁶R⁶)_m-X² or -Z¹(CR⁶R⁶)_m-X², especially -Z¹-NH-CH₂-CH₂-X² and -Z¹-CH₂-CH₂-X² wherein X² is a labile group; Z¹ and R² are as hereinbefore defined; each R⁶ independently is halo, -NH₂, carboxy or a group described above for R²; and m is 2, 3 or 4. Preferably the labile group represented by X² is -OSO₃H, -SSO₃H, -OPO₃H₂, or a salt thereof, halo (especially chloro) or acetoxy. The groups of formula -Z¹(CR⁶R⁶)_m-X² may be attached to a group of formula -NR²- as defined above, in which case the CR⁶R⁶ groups may be replaced by CHR⁶ groups.

Examples of groups capable of undergoing an elimination and addition reaction include the following:

-SO₂CH₂CH₂OSO₃H, -SO₂(CH₂)₃OSO₃H, -SO-CH₂CH₂Cl, -SO₂CH₂CH₂OPO₃H₂,

-NHCOCH₂CH₂OSO₃H, -SO₂CH₂CH₂OCOCH₃ , -SOCH₂CH₂OSO₃H,

-SO₂CH₂CH₂SSO₃H, -NHSO₂ CH₂OSO₃H, -NHSO₂ (CH₂)₃SSO₃H, -NHSO₂ (CH₂) ₄OSO₃H, -N(CH₃ ) SO₂C H₂CH₂OSO₃H, -SO₂ -CH (CH₃ ) CH₂-OSO₃H,

-SO₂NH-CH (CH₂CH₃ ) CH₂-OSO₃H, -SO₂NH-C (OH) (CH₃) CH₂-OSO₃H,

-SO₂NH-CH (CH₃) CH (Ph) -OSO₃H, -SO-NHCH(OSO₃H) CH₂-OSO₃H,

-SO₂NHCH (COOH) CH₂OSO₃H, -SO₂NHCH (Ph) CH₂OSO₃H,

-SONHC (CH₃) ₂CH₂OSO₃H, -SO₂NHC (CH₂OSO₃H) ₃ ,

-SO-NHC (CH₃) (OH) CH₂OSO₃H and -SO₂NH (CH₂ )₃-OSO₃H.

In one embodiment the aforementioned groups of formula -Z¹-NR²- (CR⁶R⁶)_m-X², -NR²-Z¹(CR⁶R⁶)_m-X², -Z¹-CR³=CR⁴R⁵, -CR³=CR⁵-Z² and -CZ²=CR³R⁵ are attached directly to an aromatic carbon atom, for example the carbon atom of an aromatic ring such as a benzene ring, in molecules of the dye.

Preferably the dye is capable of absorbing radiation at a wavelength in the region from the ultraviolet to the infra-red, preferably in the visible region of the spectrum, especially light of a wavelength from 400 to 700nm. Preferably the dye has an extinction coefficient of at least 5,000, more preferably at least 10,000, especially from 10,000 to 300,000, more especially from 10,000 to

150,000.

The dye is preferably an azo, anthraquinone, phthalocyanine, triphenodioxazine, triphenylmethane, formazan, xanthene or

benzdifuranone dye or a dye which contains a combination of these chromophores, especially an azo dye.

In one aspect of the invention the dye has a mildly solubilising group, for example such that when any temporary solubilising group (s) are removed the remaining dye is not so insoluble that it instantly precipitates before reaction with the nucleophilic agent occurs and not so soluble that it can easily be washed from the substrate. We have found that certain groups having a pKa in the range 1 to 10, preferably

2 to 9, may be used as mildly solubilising groups.

A preferred group having a pKa in the range 1 to 10 is of the

Formula (1):

wherein:

R⁷ is H or alkyl.

Groups of Formula (1) may be incorporated into the dye by reacting a dye having a substituent of formula -NHR¹ with cyanuric chloride and replacing the two chlorine atoms with hydroxy groups by hydrolysis, for example by heating at 30-50°C with aqueous sodium carbonate for 5-24 hours. One preferred class of dyes used in the process is of the Formula (2):

wherein:

X and R⁷ are as hereinbefore defined;

n has a value of at least one; and

D is a chromophore, preferably of the azo,

anthraquinone, phthalocyanine, triphenodioxazine, triphenylmethane, formazan, xanthene or benzdifuranone series or a combination thereof.

It is especially preferred that D is an azo chromophore. The preferred azo chromophore represented by D is a monoazo, disazo or trisazo chromophore.

Formulae (1) and (2) shown above naturally include tautomers thereof. The Nucleophilic Agent

The nucleophilic agent is preferably water-soluble. In one embodiment the nucleophilic agent has a molecular weight in the range 95 to 2000, more preferably 100 to 1900.

The thiol (i.e. -SH) group in the nucleophilic agent may, for example, be present in a substituent of formula -CO-SH or -NH-CO-SH.

The thione group which may be present in the nucleophilic agent is of the formula =S, for example as found in -PS(-OH)₂ and -O-PS(-OH), and -O-PS(-OH)₂. A particularly preferred thione group is of the formula >C=S, for example the agent may have a -CS-OH, -CS-NH-, -NH-CS-OH or thiourea substituent. Preferred thione groups are of the formula -NR²-CS-NR²R² or -NR²-CS-NR²- wherein each R² independently is as hereinbefore defined, provided at least one R² is H.

In one embodiment of the invention the nucleophilic agent has, in addition to the two or more groups selected from thiols and thiones, a quaternary amine group. The quaternary amine group increases affinity of the nucleophilic agent for substrates such as cotton leading to stronger dyeings and higher wash fastness. Examples of quaternary amine groups include dialkyl phenyl ammonium, e.g. Ph(CH₃)₂N⁺-,

Ph(CH₃CH₂)₂N⁺-; optionally substituted pyridinium, e.g. 2-, 3- and 4-methyl pyridinium, 2-, 3-, 4- carboxy pyridinium; N-alkyl-pyridinyloxy, e.g. N-methyl-4-pyridinyloxy, N-methyl-2-pyridinyloxy and N-ethyl-4- pyridinylαxy; tri(alkyl)ammonium, e.g. (CH₃)₃N⁺-, (CH₃CH₂)₃N⁺-,

CH₃(CH₃CH₂)₂N⁺-; (CH₂)₅N⁺-; (CH₂CH₂OCH₂CH₂)N⁺-; and those derived from quinuclidine and diazobicyclo octane.

The thiol or thione group in the nucleophilic agent can be attached to a heterocyciic ring, preferably a 5 or 6 membered ring containing 1, 2 or 3 atoms selected from nitrogen, oxygen and sulphur, to give what are hereinafter referred to as heterocyciic thiol or thione groups respectively. The preferred heterocyciic thiol or thione group contains 1, 2 or more preferably 3 nitrogen atoms. Preferred

heterocyciic thiol or thione groups carry 1 or 2 groups selected from -SH and =S. Examples of heterocyciic thiols and thiones include groups for Formula (3) and (4):

The groups of Formula (3), Formula (4) and the thioureas may exist in tautomeric forms other than those illustrated and these are included in the present invention. By way of illustration tautomers of groups of Formula (3) include those illustrated below by Formulae (3a) and (3b) and tautomers of groups of Formula (4) include those illustrated by (4a), (4b), (4c) and (4d):

The nucleophilic agent is preferably a triazine compound having 1,

2 or 3 groups selected from thiols and thiones, especially

trithiotriazine (i.e. s-triazine having three -SH groups) or a group of the formula:

A-X-L-X-A

wherein: each A is a group of Formula (4) as hereinbefore defined;

each X independently is oxygen, sulphur or -NR⁸-;

each R⁸ independently is H or alkyl; and

L is a divalent organic linker group.

R⁸ is preferably H or C_1-4-alkyl.

L is preferably an alkylene, arylene or aralkylene group. The preferred alkylene group is optionally substituted C_2-4-alkylene. The preferred arylene group is optionally substituted phenylene or

naphthylene. The preferred aralkylene group is optionally substituted benzylene or xylylene. When L is substituted the substituent (s) are preferably selected from halo, especially chloro; nitro; alkoxy, especially C_1-4-alkoxy; alkyl, especially C_1-4-alkyl; cyano; hydroxy; -SH; amino; L may contain or be free from chromophores, for example the chromcphores mentioned above for D.

A further preferred nucleophilic agent is of Formula (5) or (6):

Wherein each R⁷ independently is H or optionally substituted alkyl, preferably H or C_1-4-alkyl; each L independently is as

hereinbefore defined; and each Q is a quaternary amine group.

Preferred quaternary amine groups are as hereinbefore described.

Another preferred nucleophilic agent is of formula Q-L-CH₂SH wherein Q and L are as hereinbefore defined.

The ratio of dye to nucleophilic agent (by weight) is preferably in the range 19:1 to 1:19, more preferably 9:1 to 1:9, especially 3:1 to 1:3. Factors influencing the preferred ratio include the relative molecular weights of the dye and nucleophilic agent, the number of electrophilic groups in the dye and the number of thiol and thione groups in the nucleophilic agent. Because the dye and nucleophilic agent join together by reaction of the electrophilic groups in the dye and the thiol or thione groups in the nucleophilic agent it is preferred that the relative amounts (in moles) of dye and nucleophilic agent is chosen such that the number of electrophilic and thiol/thione groups is about equal, e.g. in the range 5:4 to 4:5. However, if one wishes the dye may be used in excess such that fibre-reactive electrophilic groups are present on the resultant oligomer or polymer which can form covalent bonds with cellulosic substrates in a conventional manner. In one embodiment the ratio of dye to nucleophilic agent is not 95:5 or 5:95.

The composition is preferably applied to the substrate as an aqueous solution, more preferably as a solution in water.

A further feature of the present invention provides a composition comprising:

(i) a dye having at least one electrophilic group; and

(ii) a nucleophilic agent having at least two groups selected from thiols and thiones.

The preferred dye and nucleophilic agents contained in the composition are. as hereinbefore described in relation to the present process. The preferred ratio of dye to nucleophilic agent is as hereinbefore described. The composition may contain one or more of the dyes and one or more of the nucleophilic agents.

In the present process it is preferred that the composition is heated from a first temperature to a second temperature at least 20°C higher than the first temperature, more preferably at least 30°C higher, especially at least 40°C higher and optionally up to 200°C or 300°C higher than the first temperature. The first temperature is preferably between 0°C and 40°C, more preferably between 5°C and 40°C, especially between 10°C and 40°C. The composition may be heated by any means, for example by an electrical means such as a heating mantle, infra-red, microwave- or ultrasound or by using steam. The heating may be done at neutral, acid or alkali pH, preferably at a pH above 7.

When the present process is performed by basifying the composition it is preferred that the basifying is from a first pH to a second pH at least 0.5 pH units higher than the first pH, more preferably at least 1 pH unit higher, especially at least 2 pH units higher, more especially at least 3 pH units higher and optionally up to 7 pH units higher than the first pH. The first pH is preferably between pH 0 and pH 8.5, more preferably between pH 2 and pH 8, especially between pH 4 and pH 8, more especially between pH 6 and pH 8 and especially preferably approximately pH 7.

The composition is preferably basified using an alkaline earth or alkali metal, base or salt, more preferably an alkali metal hydroxide, carbonate or bicarbonate, especially a sodium or potassium hydroxide, carbonate, bicarbonate or composition thereof.

The composition may be basified by adding an alkaline solution of dye to nucleophilic agent, by adding an alkaline solution nucleophilic agent to dye, or by adding alkaline earth or alkali metal, base or salt to a solution of the coπposition.

Nucleophilic agents which contain a thiol or thione heterocycle of Formula (3) or (4) are preferably prepared by heating the corresponding compound having a chlorotriazine group (for example a compound

containing a group of Formula (3) or (4) where instead of -SH or =S groups there is a chloro atom) with sodium hydrosulphide in aqueous medium at 0-30°C, or preferably with sodium thiosulphate at 0-100°C, especially 25-60°C. The aqueous medium may contain a water-miscible organic solvent, for example an alcohol or ketone.

Although formulae have been shown in their unionised or free acid form in this specification, for example -SO₂H or -SH, these formulae include the ionised and salt forms, particularly salts with alkali metals such as sodium, potassium or lithium or mixed sodium/lithium salts.

As there is no need to use a free-radical initiator in the present process it is preferred that the process is performed in the absence of such an initiator.

Dyes used in the process may be prepared by analogous methods to those described in the dyestuff art except that intermediates are selected which will result in the dye having the aforementioned electrophilic group.

Alternatively dyes according to the invention containing an azo chromophore may be prepared by coupling two suitable precursors.

The substrate used in the process is preferably a textile material, especially a natural, semi-synthetic or synthetic material.

Examples of natural textile materials include wool, silk, hair and cellulosic materials, particularly cotton, jute, hemp, flax and linen. Preferred cotton materials are Sea Island, Egyptian, American,

Peruvian, Asiatic and Indian cottons, for example cottons having a staple length of 2.5 to 5cm, a denier of 1 to 2 and a moisture content of at least 8%.

Examples of synthetic and semi-synthetic materials include polyamides, polyesters, polyacrylonitriles and polyurethanes.

The preferred dyeing process comprises immersing a textile material in a vessel containing the aforementioned composition and water and heating, basifying or heating and basifying the composition thereby causing the dye and nucleophilic agent to join together.

Alternatively both the pH and temperature may be raised during dyeing, preferably from the first to second temperatures and from the first to second pHs described in the preceding two paragraphs.

Conventional dye bath additives may be added to assist coloration of the substrate, for example salt or dyeing auxiliaries.

Compositions of the invention may also be applied to textile substrates, paper or transparent sheets by ink jet printing. Preferably the substrate is alkaline.

It is preferred that the joining together of the dye and

nucleophilic agent gives a product of lower water-solubility, more preferably less than 80%, especially less than 50%, more especially less than 25% and especially preferably less than 10% of the water-solubility of the original dye. In a particularly preferred embodiment joining together of the dye and nucleophilic agent results in a product having less than 5%, more preferably less than 1%, especially negligible solubility in water (at 20°C), wherein all percentages are by weight.

The aforementioned product will be oligomeric or polymeric, depending on the conditions, dye and nucleophilic agent used.

The joining together of the molecules to give a product having lower solubility than the original dye may be achieved by the presence of temporary solubilising groups in the dye, that is to say groups which enhance solubility of the dye in water which are convertible by heating or basifying the dye into a group which does not enhance the solubility of the dye in water. It is preferred that at least 50%, more preferably at least 75% and especially that all acid groups, e.g. carboxy, sulpho and sulphato groups, in the dye are temporary solubilising groups because the lowering of water-solubility which occurs when the temporary solubilising groups are removed can greatly enhance exhaustion of the dye from a dyebath leading to high depths of shade and high wash- fastness.

Preferred examples of such a temporary solubilising groups are ß-sulphatoethylsulphonyl, ß-thiosulphatoethylsulphonyl and

β-phosphatoethylsulphonyl, which may also act as electrophilic groups. Basification and/or heating causes elimination of a solubilising group, for example an inorganic solubilising group such as a sulpho group (in the form of sulphate), bisulphate, thiosulphate or phosphate, to give a dye having fewer solubilising groups.

A further feature of this invention comprises a polymer or oligomer obtained or obtainable by heating or basifying or heating and basifying a composition according to the present invention. Preferably the heating and/or basifying is from first to second temperatures and pHs as described hereabove.

The invention is further illustrated by the following examples in which all parts and percentages are by weight unless otherwise stated. Example 1 a) Preparation of Agent (A)

Trithiotriazine (Agent (A)) was obtained from Aldrich Chemical

Company Limited, Gillingham, England. b) Preparation of Dye (A)

Stage (i)

Cyanuric chloride (5g) was added to a mixture of N-ethyl-N- gamma-aminopropylaniline (4g), acetone (200ml) and calcium chloride (3g) at 5°C. The mixture was stirred for 3 hours, the solid filtered off, and water (200ml) added to the filtrate. Sodium sulphite (2g) was added. After 5 hours at 30-40°C sodium carbonate (5g) was added and the mixture was stirred for a further 10 hours. Addition of sodium chloride (20g) gave a white precipitate of a dihydroxytriazine intermediate (9g). Stage (ii) - Coupling

To p-aminophenylsulphatoethylsulphone (1.8g) in water (150ml) at 0-5°C was added 2N sodium nitrite (3.5ml) and concentrated hydrochloric acid (5ml). The mixture was stirred for 20 minutes before it was added dropwise to a solution of the product from stage d) (5.5g) in water (50ml) at pH 5.5 and 0-5°C. After stirring for 2 hours salt (30g) was added at the resultant orange solid filtered-off to give the title product (4.2g). An infra-red absorption spectrum showed peaks at 3447, 1734, 1685, 1654, 1601, 1516, 1375, 1258, 1132, 1000, 823 and 754 cm¹. c) Dyeing

A composition was prepared comprising the title Dye A (0.1g), water (50ml) and trithiotriazine (0.0072g) as nucleophilic agent

Cotton (5g) was added and the temperature raised to 50°C. Salt (1g) and sodium bicarbonate were added and the temperature was raised to 58°C and held at this temperature for 1 hour thereby causing the dye and nucleophilic agent to join together. The cotton was removed, rinsed in water then boiled in detergent to give cotton having a deep orange colour (integ value of 18.3).

d) Comparative Dyeing

The method of step c) was repeated except that the trithiotriazine was omitted. The cotton was dyed only weakly (integ. value of 9.1). Example 2

Preparation of Dye (B)

A solution of cyanuric chloride (26.9g, 0.2mole) in acetone (300ml) was added dropwise to ice/water (200g) at 0-5°C to give a slurry.

H-Acid (70.27g, 0.18mole) was dissolved in water (200ml) by adding 2N NaOH to pH 6. This solution was added dropwise to the above mentioned slurry at 0-5°C, allowing the pH to drop to 0.5. The mixture was then stirred for 1.5 hours at 0-5°C to give a solution of a dichlorotriazinyl compound.

P-Aminophenyl-β-sulphatoethylsulphone (56.2g, 0.2mole) was stirred in ice/water (200g). Concentrated HCl (110ml) was added followed by 2N NaNO₂ (aq) (110ml). This mixture was stirred for 30 minutes at 0-5°C and excess nitrous acid was then destroyed using solid sulphamic acid. The resultant diazonium salt solution was added to the above

dichlorotriazinyl solution and the pH was raised to 5.0 by adding solid Na₂CO₃. wke mixture was stirred for 1 hour and then allowed to warm to room temperature. The pH was raised to 6.0, HCl .NH₂C₂H₄SO₂C₂H₄Cl

(0.2mole, 41.62g) was added and the mixture was stirred at room temperature for a further 4 hours. The resultant solution was salted to 20% w/v with KCl and the resultant red precipitate filtered off, washed and dried to give the title product.

Dyeing

A dyeing vessel was charged with Dye (B) (0.20g, 1.7×10^-4 moles), trithiotriazine (0.0125g, 7.1×10^-5 moles) and water (50ml), followed by sodium chloride (2.0g) and sodium hydrogen carbonate (1.0g).

Cotton (5.0g) was added and the mixture heated to 50°C for 1 hour. Sodium carbonate (1.0g) followed by caustic liquor (0.1g) were added and heating continued at 60°C for a further 1.5 hours. Very high levels of exhaustion of the dye onto cotton were observed. Example 3

a) Preparation of Agent (B)

A solution of cyanuric chloride (5.4g) in acetone (50ml) was added dropwise over 5 minutes at 0-5°C to a solution of (2-aminoethyl) trimethyl ammonium chloride hydrochloride (5g) in water (100ml). The mixture was stirred for 1 hour to give a solution.

Sodium sulphide (56g) was dissolved in water (100ml), the pH was adjusted to 8 using 2M hydrochloric acid and then added to the above mentioned solution. The reaction mixture was stirred at room

temperature for 2 hours whilst maintaining the pH at 8 (using 2M sodium carbonate). The resultant white precipitate was collected by

filtration, washed with isopropanol and dried to give title Agent (B). b) Preparation of Dye (C)

Cyanuric chloride (3.53g) was dissolved in acetone (30ml) and added to ice water (50ml). 1-hydroxy-3-sulpho-6- amino naphthalene ("J-acid",5g) was dissolved in water (50ml) at pH 6.5 and added dropwise th the cyanuric chloride suspension, maintaining the mixture at pH 2 and a temperature of 0-5°C. After stirring for 3 hours, a further 5g of J- acid in water (50ml) at pH 6.5 was added and the resultant mixture was stirred at room teπperature and pH 6 overnight, and finally at 40°C for 2 hours. The mixture was cooled and the product salted out to give 18.5g of a coupling component.

4-(β-sulphatoethylsulphonyl) aniline (3.55g) was dissolved in water (50ml) at pH 7, and 7ml of a 2M solution of sodium nitrite was added. This solution was added to ice water (50ml) and concentrated HCl (4ml) and diazotised at 0-5°C for 2 hours. Excess nitrous acid was destroyed using sulphamic acid and the suspension was adjusted to pH 3. The above coupling component (4.0g) was dissolved in water (100ml) and added dropwise at pH 3. After stirring at 0-5°C for 2 hours, the solution was allowed to warm at room temperature overnight. Propan-2- ol was added and the precipitate filtered off and dried to give title Dye (C) having two electrophilic groups (4.9g) and λmax at 481nm.

c) Dyeing Process

A vessel was charged with Agent (B) (0.1g), Dye (C) (0.1g), a pH 7 buffer solution (50ml) and sodium sulphate (1.0g). The vessel was warmed from 20°C to 30°C and cotton (5.0g) was added. The mixture was heated to 95°C over the course of 1 hour, NaHCO₃ (1g) was added and the temperature of 95°C was maintained for one hour further.

The cotton was removed from the vessel, boiled in water followed by detergent to give cotton having a deep orange colour. Measurement of the depth of shade on a reflectance spectrophotometer gave an integ value of 37.6.

d) Comparative Dyeing

The process of step c) was repeated except that Agent (B) was omitted. The cotton was dyed to a weaker depth of shade with an integ value of 28.6.

Example 4

a) Preparation of Agent (C)

Pyridine (250ml) was added to a solution of 2-chloroethylamine hydrochloride (83.5g) in water (250ml) and the mixture stirred under reflux for 2 hours. The mixture was cooled to room temperature and washed with dichloromethane (2 × 400ml).

The aqueous solution was acidified to pH 2 with concentrated hydrochloric acid and evaporated to dryness. The resultant quaternary ammonium intermediate was re-slurried with isσpropanol, collected by filtraton and dried.

A solution of cyanuric chloride (38g) in acetone (100ml) was added dropwise over 5 minutes at 0-5°C to a solution of the above described quaternary ammonium intermediate (41.4g) in water (200ml). The mixture was stirred for 1 hour to give a solution.

p-Phenylene diamine (10.8g) was added to the above solution and the mixture was stirred at 30-40°C for 16 hours with the pH maintained between 6 and 7 (using 2M sodium carbonate). Acidification to pH 2 with concentrated hydrochloric acid gave a bis-monochloro compound which was collected by filtration, washed with water and isopropanol and dried.

The dry bis-monochloro compound (19.3g) was dissolved in a mixture of water (200ml) and acetone (100ml). To this solution was added sodium sulphide (60g) followed by concentrated hydrochloric acid to pH 8. The reaction mixture was stirred for 2 hours at room temperature, whilst maintaining the pH at 8 (using 2M sodium carbonate). The resultant white precipitate was collected, washed with isopropanol and dried to give title Agent (C).

b) Dyeing Process

A vessel was charged with Agent (C) (0.24g), Dye (B) from Example 2 (0.1g), a pH 7 buffer solution (50ml) and sodium sulphate (1g). The vessel was warmed from about 20°C to 30°C and cotton (5g) was added. The mixture was heated to 95°C over 1 hour, NaHCO₃ (1g) was added and the temperature was maintained at 95°C for one hour further, after which the very high level of exhaustion of dye onto the cotton was observed.

Example 5

The dyeing process of Example 3, step C, was followed except that in place of Agent (B) there was used Agent (C) (0.18g) described in Example 4. The dye was exhausted onto the cotton to a very high degree.

Example 6

a) Preparation of Agent (D)

2-chloroethylamine hydrochloride (83.5g), pyridine (250ml) and water (250ml) were stirred under reflux for 2 hours. The mixture was allowed to cool to room temperature and was washed with CH₂Cl₂ (2x 400ml). The aqueous layer was acidified to pH 2 using concentrated hydrochloric acid and evaporated to dryness. The product was slurried in isopropanol and dried to give an intermediate product.

A solution of cyanuric chloride (5.4g) in acetone (50ml) was added dropwise over 5 minutes, at 0-5°C, to a solution of the above mentioned intermediate product (5.9g) in water (100ml). The mixture was stirred for 1 hour until a solution resulted.

Sodium sulphide (56g) was dissolved in water (100ml), the pH was adjusted to 8 (using 2M hydrochloric acid) and then added to the above mentioned solution. The reaction mixture was stirred at room temperature for 2 hours whilst maintaining the pH at 8 (using 2M sodium carbonate). The pH was adjusted to 2 (using concentrated HCl) and the resultant white precipitate was collected by filtration, washed with isopropanol and dried to give Agent (D) shown above.

b) Dyeing Process

The dyeing process of Example 3, step c), was repeated except that in place of Agent (B) there was used Agent (D) (0.08g).

The cotton was dyed a deep orange colour to an integ value of 35.7.

c) Comparative Dyeing

The process of step c) above was repeated except that Agent (D) was omitted. The cotton was dyed to a weaker depth of shade with an integ value of 28.6.

Example 7

a) Preparation of Agent (E)

δ-Bromobutanoyl chloride (9.9g) was added dropwise to a solution of dimercaptopropanol (6.7g) in toluene (50ml). The mixture was heated under reflux until the evolution of HCl gas ceased (approximately 2½ hours). Toluene was removed by evaporation and the resultant yellow oil was purified by flash column chromatography to give a bromo compound.

The above described bromo compound (4.0g), pyridine (8.8g) and water (17.5ml) were added and the mixture was heated under reflux for 2 hours. The reaction mixture was allowed to cool, washed with ether, and then solvent evaporated to give Agent (E) as a solid.

b) Preparation of Dye (D)

Dye (D) was prepared using the method described for Dye (B) in Example 2 except that in place of HCl .NH₂C₂H₄SO₂C₂H₄Cl there was used 4-(β- sulphatoethylsulphonyl)-N-methylaniline. The resultant dye has a λmax at 519nm.

c) Dveing Process

A vessel was charged with Agent (E) (0.08g), Dye (D) (0.1g), a pH 7 buffer solution (50ml) and sodium sulphate (1.0g). The vessel was warmed from about 20°C to 30°C and cotton (5g) was added. The mixture was heated to 95°C over 1 hour, NaHCO₃ (1g) was added and the temperature was maintained at 95°C for one hour further, after which the very high level of exhaustion of dye onto the cotton was noticed.

Example 8

The dyeing process of Example 7, step c), was repeated except that in place of Dye (D) there was used Dye (C) from Example 3 (0.1g). Very high levels of dye exhaustion onto the cotton were observed.

Examples 9 to 16

Example 3 may be repeated except that in step b), in place of the reagent given in the first column of Table 1, there is used an

equivalent amount of the reagent shown in the second column.

Examples 17 to 21

Example 2 may be repeated except that in place of the reagent given in the first column of Table 2, there is used an equivalent amount of the reagent shown in the second column.

Examples 22 to 25

Example 1 may be repeated except that in place of Dye (A) there is used the dye shown in Table 3.

Examples 26 to 34

Example 3 may be repeated except that in place of Agent (B) there is used the Agent shown in Table 4 below.

Claims

1. A process for the coloration of a substrate comprising applying thereto a composition comprising a dye and a nucleophilic agent and heating and/or basifying the composition thereby joining the dye and nucleophilic agent together by the formation of covalent bonds, wherein:

(i) the dye has at least one electrophilic group; and

2. A process according to Claim 1 wherein the dye has at least two electrophilic groups.

3. A process according to Claim 1 or 2 wherein the dye has a mildly solubilising group.

4. A process according to any one of the preceding claims wherein all acid groups in the dye are temporary solubilising groups.

5. A process according to any one of the preceding claims wherein the molecular weight of the nucleophilic agent is at least 50 below that of the dye.

6. A process according to any one of the preceding claims wherein the ratio of dye to nucleophilic agent is in the range 19:1 to 1:19.

7. A process according to any one of the preceding claims wherein the heating is from a first temperature in the range 10°C to 40°C to a second temperature at least 20°C higher than the first temperature.

8. a process according to any one of the preceding claims wherein said nucleophilic agent has a quaternary ammonium group .

9. A process according to any one of the preceding claims wherein the joining together of said dye and said nucleophilic agent gives a product having less than 25% of the solubility of the original dye.

10. A composition comprising:

(i) a dye having at least one electrophilic group; and

11. A composition according to Claim 10 wherein the nucleophilic agent does not contain a chromophore.

12. A composition according to Claim 10 wherein the nucleophilic agent has a quaternary amine group.

13. A polymer or oligomer obtained or obtainable by heating or basifying or heating and basifying a composition according to Claim 10.