GB2301118A - Combination of dye having at least two electrophilic groups and a nucleophilic agent having at least one primary or secondary aliphatic amine - Google Patents

Abstract

A process for the coloration of a substrate comprises applying thereto a dye having at least two electrophilic groups (eg a beta-sulphatoethylsulphonyl group) and a nucleophilic agent having a molecular weight of at least 600 and at least one group selected from aliphatic primary amino groups and aliphatic secondary amino groups, wherein said dye and said nucleophilic agent are such that if they are applied to cotton by exhaust dyeing at least 90% of the dye is immobilised. Compositions comprising the dye and agent are also claimed, where the amino group(s) of the agent may optionally be masked by a protecting group.

Description

CHEMICAL PROCESS This invention relates to a process for dyeing substrates, to dyes and to compositions.

In conventional dyeing processes using water-soluble dyes, not all dye fixes to a substrate and, after dyeing, the dyehouse has the expensive problem of disposing of highly coloured solutions containing unfixed dye. For example, during normal exhaust dyeing some unfixed dye remains in the dyebath, whilst sane only loosely adheres to textiles and has to be washed-off in the dyehouse to avoid later cross-staining of adjacent fibres during damestic washing. This can result in large volumes of coloured effluent which often contains cansiderable amounts of dissolved dye. There is a need for a dyeing process which results in colourless or weakly coloured effluent and, ideally, coloured textiles which require less or no washing after dyeing is complete.Such a process wculd make dyehouses more environmentally friendly and reduce their effluent disposal costs.

According to the present invention there is provided a process for the coloration of a substrate comprising applying thereto a water-soluble dye having at least two electrophilic groups and a nucleophilic agent having a molecular weight of at least 600 and at least one group selected from aliphatic primary amino groups and aliphatic secondary amino groups, wherein said dye and said nucleophilic agent are such that if they are applied to cotton by exhaust dyeing at least 90% of the dye is immobilised.

The nucleophilic agent having a molecular weight of at least 600 and at least one group selected from aliphatic primary amino groups and aliphatic secondary amino groups is hereinafter abbreviated to "the nucleophilic agent".

The dye and the nucleophilic agent react together during the process to form a highly substantive species which has great affinity for the substrate. The precise mechanism is not fully understood, but the species might exist as some form of oligomer or polymer wherein the agent and dye are joined together by either covalent bonds formed between the electrophilic groups of the dye and aliphatic primary/secondary group(s) in the nucleophilic agent, or by anion-cation attractian between anionic groups in the dye (when present) and cationic protonated aliphatic primary and secondary amino groups. Possibly both of these mechanisms play a part in formation of the highly substantive species.

It is possible to select appropriate combinations of dyes and nucleophilic agents for use in the process by measuring how much dye is immobilised under exhaust dyeing conditions. Very high immobilisation under these conditions indicates that the dye and nucleophilic agent form the highly substantive species and this behaviour is reflected in other dyeing processes, e.g. printing, continuous and semi - continuous dyeing.

Preferably the dye and the nucleophilic agent used in the process are such that if they are applied to cotton by exhaust dyeing at least 95%, more preferably at least 97t, especially from 99% to 100t of the dye is immobilised.

words "such that if they are applied to cotton by exhaust dyeing at least 90% of the dye is immabilisedt are not intended to limit processes of the invention to exhaust dyeing, but this definition serves as a useful test for identifying combinations of dyes and nucleophilic agents which can react together and form a highly substantive species under a whole variety of different dyeing conditions.

The extent of immcbilisation of the dye may be determined by dissolving 0.100 grammes ("WI") of dye in a dyebath containing 30ml of water buffered at pH 7, adding 0.75g of sodium sulphate and 5g of cotton, heating to 950C over one hour, maintaining the temperature at 950C for on hour, then adding nucleophilic agent such that the ratio of electroohilic groups in the dye to the total amount of aliphatic primary amino groups and aliphatic secondary amino groups in the nucleophilic agent is 2::3, heating for one further hour at 950C, followed by removing the dyed cotton from the dyebath and stirring the dyed cotton for 15 minutes with each of (i) 50ml of water containing 0.03 grammes of acetic acid, and (ii) three lots of 50ml of boiling water, wherein the total weight in grammes of dye dissolved in the dyebath and washes is determined using a spectrophotometer ("w2") and the % immobilisation is given by the calculation [(W1 - w2) - W1] x 100% When sane combinations of dye and agent are heated under exhaust dyeing conditions in the presence of a substrate they form not only a highly substantive species on the substrate but also a solid precipitate which can fall to the bottom of the dyebath.Under these circumstances the immobilisation is still calculated as described above because the precipitate is not actually dissolved in the dyebath.

The presence of a precipitate in the dyebath is usually acceptable because it can easily be removed by filtration, thereby lowering the chemical content of dye liquors which are disposed of after dyeing.

However, to avoid wasting dye it is preferred that the amount of precipitate formed in the dyebath is less than 10%, more preferably less than 5%, especially less than 2%, more preferably 0% by weight relative to the weight of dye used.

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. The process can operate using aqueous solutions of the dye and nucleophilic agent at practical temperatures using normal dyeing equipment. In one embodiment the molecular weight of the nucleophilic agent is at least 600 and at least 50 above or below that of the dye.

As will be understood, the electrophilic groups in the water-soluble dye are required to react with aliphatic primary and/or secondary amino groups in the nuclecohilic agent (this allows formatian of a highly substantive species). Thus where the water-soluble dye is a reactive dye the process for coloration is performed under conditions such that said dye does not react to a significant extent with the substrate (e.g. < 10% reacts, preferably < 5t) before said dye reacts with the nucleophilic agent. Hence the present process is distinct from a simple post-dyeing after treatment involving contacting a substrate dyed with a reactive dye (wherein dye has lost its reactive groups) with a nucleophilic agent.Conditions where the water-soluble dye does not react to a significant extent with the substrate before it can react with the nucleophilic agent can be selected by dyers without difficulty, for example high pH and high temperatures tend to encourage covalent band formation between reactive dyes and cellulosic substrates and would therefore be avoided.

The Dye Preferably the dye has from 2, 3, 4, 5, or 6 electroohilic groups. The electrophilic groups may be any group capable of forming a covalent bond with the nucleophilic agent during the coloration process.

Preferably said electroohilic 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, -COCHX1-CHX1CO2R2, -COCHX1CHX1COR1, -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 iodo.

A labile group is a group displaceable by the aliphatic primary or secondary amino 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 e optional substituents which may be present on R2 are preferably as mentioned hereinafter for L2. R2 is preferably H, phenyl or C1-4 -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. The labile group is preferably chloro or fluoro, or a quaternary ammonium group such as optionally substituted pyridinium.

Gratis which are capable of undergoing an addition reaction preferably ccmprise 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, Cl4-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 -NRE- (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-(C1-4-alkyl) and preferred arylsulphonyl groups are phenylsulphonyl and tosyl.Preferred acyl groups are of the formula -CO-R2 wherein R7 is as hereinbefore defined, especially Cl4-alkyl or phenyl. It is preferred that R3 and are both H.

Examples of activated alkenes include the following:

-NHCOCBr=CH2, -CO-CBr=CHBr,

-SO2-CH=CH2, -SO-CH=CH2, -COCCl=CCl2, -SO2CH=CHCl, -CH=CH-CN, -CH=CH-NO2, -C(CN)=CH2, -NHSO2-CH=CH2, -N(CH3)SO2CH=CH2, -C(NO2)=CH2 and

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, -SS4H, -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, -SO2CH2CH2Cl, -SO2CH2CH2OPO3H2, -NHCOCH2CH2OSO3H, -SO2CH2CH2OCOCH3, -SOCH2CH2OSO3H, -SO2CH2CH2SSO3H, -NHSO2CH2CH2OSO3H, -NHSO2 (CH2)3SSO3H, -NHSO2 (CH2)4OSO3H, -N (CH3) SO2CH2CH2OSO3H, -SO2NH-CH (CH3) CH2-OSO3H, -SO2NH-CH (CH2CH3) CH2-OSO3H, -SO2NH-C (CH) (CH3) CH2-OSO3H, -SO2NH-CH (CH3) CH (Ph) -OSO3H, -SO2NHCH (OSO3H) CH2-OSO3H, -SO2NHCH (COCH) CH2OSO3H, -SO2NHCH (Ph) CH2OSO3H, -SO2NHCH2CH2Cl, -SO2NHC (CH3)2CH2OSO3H, -SO2NHC (CH2OSO3H)3, -SO2NHCH2CH2Br, -SO2NHCH2CH2OSO3H, -SO2NHC (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.

Particularly good results are found where the two or more electrophilic groups are selected fran activated alkenes and groups capable of undergoing an elimination and addition reaction, especially vinyl sulphones and groups which are convertible to vinyl sulphones an treatment with aqueous alkali.

Preferably the dye is capable of absorbing radiation at a wavelength in the region from the ultraviolet to the inf ra-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 can contain any chromophore. The dye is preferably an azo, anthraquinone, phthalocyanine, triphenodiaxazine, triphenylmethane, formazan, xanthene or benzdifuranone dye or a dye which contains a combination of these chromophores, especially an azo dye.

Preferred azo dyes contain 1,2,3 or 4 azo (-N=N-) groups.

Preferably the dye has high substantivity as this greatly enhances immobilisation of the dye when it reacts with the nucleophilic agent.

The Nucleophilic Agent The nucleophilic agent is preferably water-soluble or waterdispersible. In one embodiment the nucleophilic agent has a molecular weight in the range 600 to 1,000,000 more preferably 600 to 200,000.

Preferably the nucleophilic agent has at least two aliphatic primary or secondary amino groups because this is believed to give a highly substantive polymer in which the dye and agent constitute alternative omits. However in some cases, depending on the dye and agent, reaction of the two or more electrophilic groups in the dye with nuclesphilic agents having only one aliphatic primary or secondary amino group can produce a highly substantive species.

The aliphatic primary amino group is an amino of group formula -NEW attached to a nitrogen atom or an aliphatic carbon atom and an aliphatic secondary amino group is a group of formula -NH- attached to two aliphatic carbon atoms or to one aliphatic carbon atom and one nitrogen atom.

It is believed important that the -NEL and -NH- groups in aliphatic primary and secondary amino groups are attached to aliphatic carbon atcms because attachment to aromatic species (e.g. phenyl or naphthyl) or to a carboxyl group (-CO-) lowers the nucleophilicity of the -NEL or -NH- group thereby rendering them less reactive towards electrophilic groups in the dye under practical conditions. There may of course be amine groups in the nucleophilic agent which are not aliphatic primary or secondary amino groups provided the nucleophilic agent has at least one group, preferably at least two groups, selected from aliphatic primary amino and aliphatic secondary amino groups.

The aliphatic primary amino groups and secondary amino groups may be attached to the same carbon atom, for example as found in guanidine groups such as -NH-C (=NH) -NH2 and -NH-C (=NH) -NH- . In hydrazines there can be me aliphatic primary amino group and one aliphatic secondary amino group, for example as in -CH2NH-NH2, two aliphatic secondary amino groups, for example as in -CH2NH-NHCH2-, or two aliphatic primary amino groups.

Preferred aliphatic primary amino groups are of the formula -CH2-NH2, -CH (R1) -NH2 and -C(R1)2-NH2 and preferred aliphatic secondary amino groups are of the formula -CH2-NH-CH2-, -CH(R1)-NH-CH2- and -CH (R1) NH-CH (R1)- wherein each R1 independently is H or optionally substituted alkyl, aryl or aralkyl, more preferably H or C1.4-alkyl, especially H or methyl.

Examples of the nucleophilic agents include polyethylene imine ("PEI") 600, ea1 1000, PEI 1800, PEI 60,000, PEI 100,000, polypropylene imines having a molecular weight of at least 600, cyclocopolymers of dialkylamine and sulphur dioxide having a molecular weight of at least 600, and polyaihes having a MWT of at least 600 derived from allylamines and amine terminated dendrimers. Commercially available products which may be used as nucleophilic agents include JEFFAMINE D2000, ED 2001, ED 900 and T5000.

The dye having at least two electrphilic groups and the nucleophilic agent may be applied to the substrate in either order or simultaneously. Preferably said dye is applied to the substrate before the nucleophilic agent as this allows the dye to colour the substrate evenly before being fixed by the nucleophilic agent.

A preferred process according to the invention for coloration of a substrate comprises the steps: (a) applying an aqueous solution of a dye having at least two electrophilic groups to the substrate; (b) bringing the nucleophilic agent into contact with the substrate.

A convenient way of performing step (a) is to immerse the substrate in an aqueous solution of said dye. Step (b) may be achieved by adding the nuclecililic agent to the aqueous solution.

In another process, steps (a) and (b) are employed as described above except that said dye is used in step (b) in place of the nucleophilic agent, and said nucleophilic agent is used in step (a) in place of the dye.

The simultaneous application of the dye having at least two electrophilic groups and the nucleophilic agent is particularly useful where said dye and the nucleophilic agent do not react together very quickly at ambient temperature or neutral pH and an elevated temperature and/or pH is required to make the two species react. In this case said dye has the opportunity to colour the substrate evenly before fixing by raising the temperature and/or pH.

Amine groups in the nucleophilic agent can be masked using a protecting group if so desired. In this way, particularly storage stable compositions comprising the dye having at least two electrophilic groups and a masked nucleophilic agent can be provided. The protecting group can be removed from the nucleophilic agent before, during or after it has been applied to a substrate, for example by treating the agent with acid, base or by heating it. Examples of protecting groups which can be used to mark the nucleophilic agent include CF3CO, CH3CO and all other known protecting groups for nitrogen.

The amount of said dye in the aqueous solution will depend upon the depth of she required and solubility of the dye. Typically the aqueous solution contains 0.001t to 40% by weight of the dye relative to the weight of water, preferably 0.01 to 30% more preferably 0.01% to 5%.

The ratio of dye to the nucleophilic agent or marked nucleophilic (by weight) applied to the substrate is preferably in the range 100:1 to 1:100, more preferably 20:1 to 1:20, especially 9:1 to 1:9, more 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 aliphatic primary and secondary amino groups in the nucleophilic agent.

Because the dye and nucleophilic agent are believed to join together by reaction of the electrophilic groups in the dye and the amino groups in the nucleophilic agent it is preferred that the relative amounts (in moles) of dye and nucleophilic agent is chosen such that the total number of aliphatic primary and secondary amino groups is about equal to or exceeds the number of electroohilic groups. However, if one wishes the dye may be used in excess such that fibre-reactive electroohilic groups remain present which can form covalent bonds with cellulosic substrates in a conventional manner.

The dye and the nucleophilic agent are preferably applied to the substrate as an aqueous solution, more preferably as a solution in water.

During the process for coloration of a substrate it is preferred to heat and/or basify the substrate either before step (a), during step (a), between step (a) and step (b), during step (b), after step (b), or any combination thereof. Heating and/or basifying during step (a) can be useful to exhaust dye onto the substrate before bringing the nuclesphilic agent into contact with the product of step (a), for example at the same temperature or, for econany, at a lower temperature.

Preferably the aqueous solution of dye containing at least two electrophilic groups is applied to the substrate at an elevated temperature, (e.g. at a temperature between 40"C and 300"C, preferably 45"C and 200"C, especially 45"C and 140"C) and the nucleophilic agent is applied to the substrate at a lower temperature (e.g. at a temperature between 0 C and llO"C, preferably 10 C and 85"C).

The heating may be achieved by any means, for example by an electrical means such as a heating mantle, infra-red, microwave or ultrasound or by using steam.

When the present process is performed by basifying a mixture of said dye and nuclecphilic agent it is preferred that the basifying is from a first pH to a secand 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. E 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.

Preferably basification is achieved using an alkaline earth or alkali metal, base or salt, more preferably an alkali metal hydrcxide, carbonate or bicarbonate, especially a sodium or potassium hydroxide, carbonate, bicarbonate or composition thereof. In sane cases the nucleophilic agent is sufficiently basic to avoid the need for any other base being added.

Although formulae have been shown in their unionised or free acid form in this specification, for example -SEH, these formulae include the ionised and salt forms, particularly salts with alkali metals such as sodium, potassium or lithium or mixed sodium/lithium salts, ammonium salts and salts where the nucleophilic agent acts as a cation.

A further feature of the present invention provides a composition, preferably a solid composition, ccmprising: (i) a dye having at least two electroohilic groups; and (ii) the nucleophilic agent or masked nucleophilic agent.

The preferred dye and the nucleophilic agent contained in the composition are as hereinbefore described in relation to the present process. The preferred ratio of the dye to the 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 one embodiment the present process and the composition contain a buffer which maintains the pH in the range 5 to 8.5, more preferably 6 to 8. The use of a buffer can lead to dyeings which are more level. As examples of suitable buffers there may be mentianed phosphate, borate and citrate buffers, especially Na2HPO4, g;Hi04 and sodium tripolyphosphate.

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 groups.

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

The substrate used in the process is preferably leather or 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.

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

A further feature of this invention comprises a polymer or oliganer 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 fran first to second temperatures and pHs as described hereabove.

The invention is fur illustrated by the following examples in which all parts and percentages are by weight unless otherwise stated.

In the following Examples the extent of immobilisation (e) was determined by the method described earlier in the specification.

All Amax were recorded in water.

Example 1 Stave a) - Dye Preparation Preparatian of Dye 1

A solution of 4-(ss-sulphatoethylsulphQnyl) aniline (6.2g) in water (50ml) was adjusted to pH 6 using 2N sodium carbonate. 2N sodium nitrite (12ml) was added and the solution was cooled in ice, then added to a mixture of ice and concentrated hydrochloric acid (6ml). After stirring at 0-50C for 2 hours excess nitrous acid was destroyed by the addition of sulphamic acid to give a diazo component.

The suspension of diazo component was added to a solution of 5,5' -dihydroxydinaphth-2, 2'-yl-urea-7,7'-disulphonic acid (5.5g) in water (150ml) at pH 3 and 0-50C. After stirring for 30 minutes, the solution was allowed to warm to room temperature. An approximately equal volume of iso-propanol was added to the mixture and the resultant orange precipitate was filtered off to give the title product (6.7g) having two electrophilic groups and a Amax at 482nm.

Stave b) - Dveinq Process The title product (0. lOg) was dissolved in water (30ml) containing pH 7 buffer and sodium sulphate (0.75g). A piece of cotton (5g) was added and the solution was heated from 300C to 900C at the rate of ldegC min~l. After 30 minutes at 900C polyethyleneimine 600 (0.05M solution, 1.2ml, a nucleophilic agent) was added and heating was continued at 900C for a further hour. The resultant dyebath was colourless and the cotton was dyed bright orange with excellent washfastness.

Stare c) - Further Dveing Processes The method stage b) was varied as indicated below to give high wash fastness dyeings - as stage b) but using PEI 60,000 in place of PEI 600, - as stage b) but using JEFFxMINE D2000 in place of PEI 600, - as stage b) but using NaCl in place of sodium sulphate, - as stage b) but heating to 600C instead of 900C, - as stage b) but heating to 1300C instead of 90 C.

Examples 2 to 15 Preparation of Dve 2

Cyanuric chloride (3.53g) was dissolved in acetane (30ml) and added to ice water (50ml). l-hydrty-3-sulpho-6-amino naphthalene ("J-acid", 5g) was dissolved in water (50ml) at pH 6.5 and added dropwise to 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 Jacid in water (50ml) at pH 6.5 was added and the resultant mixture was stirred at room temperature and pH 6 overnight, and finally at 400C for 2 hours. The mixture was cooled and the product salted out to give 18.5g of a coupling component.

4-(ss-sulphatoethylsulphonyl) aniline (3.55g) was dissolved in water (50ml) at pH 7, and 7ml of a 2M solution of sodium nitrite was added. This solutian was added to ice water (50ml) and concentrated HC1 (4ml) and diazotised at 0-50C 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 (loom) and added dropwise at pH 3. After stirring at 0-50C for 2 hours, the solution was allowed to warm to room temperature overnight. Propan-2-ol was added and the precipitate filtered off and dried to give the title dye having two electroohilic groups (4.9g) and Imax at 481nm.

Preparatian of Dye 3 The method described above for Dye 2 was followed except that in place of 4-(ss-sulphatoethylsulphonyl) aniline there was used 2methoxy-5-(ss-sulphatoethylsulphonyl) aniline.

Preparatisn of Dve 4

4-Nitroaniline (2.76g) was stirred in ice water (loom) containing concentrated HC1 (6ml) and 2M NaNO3 solutian (limy) was slowly added. The solution was stirred at 0-50C for 1.5 hours and excess nitrous acid was destroyed by the addition of sulphamic acid.

Carboxyl J-acid (5.48g) was dissolved in water (200ml) and added dropwise to the diazo solution at pH 3-4. The reaction was then stirred at pH 3-4 and 0-50C for 3 hours before allowing to warm to roan temperature overnight. The resultant precipitate was filtered off, washed with a small amount of water and dried to give 10g of a diazo dinitro compound.

The diazodinitro compound (5g) was stirred in water (loom) at pH 8 and room temperature. Sodium sulphide nonahydrate (7.09g) and sodium bicarbonate (2.5g) were mixed in water and added to the solution.

After stirring for 2 hours, the solution was carefully acidified to pH 2 with concentrated HC1 and the precipitate filtered off and dried to give 5.0g of a diamino diazo compound.

Cyanuric chloride (1. 72g) was dissolved in acetone (30ml) and added to ice water (50ml). 3-(ss-sulphatoethylsulphonyl) aniline (2.5g) was dissolved in water (50ml) at pH 7 and added dropwise to the cyanuric chloride dispersion at pH 2-3 and 0-5 C. The reaction was stirred at 0-50C and pH 2 for 2 hours. The above diamino diazo compound (3.5g) was dissolved in water (lOOml) at pH 7 and was added at pH 7 and room temperature. The reaction was stirred at pH 7 overnight, then 10% w/v NaCl was added. The precipitate was filtered off and dried to give the title product (4g) as a bluish-red dye having a #max at 509nm.

Prenaration of Dve 5 The method described above for Dye 4 was repeated except that in place of 3-(ss-sulphatoethylsulphonyl) aniline there was used 4 (ss-sulphatoethylsulphanyl) aniline. The resultant dye had a Arnax at 517 nm.

Preraration of Dve 6

The title dye was prepared by the method used for Dye 1 except that in place of 4-(ss-sulphatoethylsulphonyl) aniline there was used 6-(ss-sulphatoethylsulphonyl)-2-naphthylamine. The title dye had a Amax at 504 nm.

Preparation of Dve 7

Stave a) 4-(ss-sulphatoethylsulphonyl) aniline (28.1g) was dissolved in water (150ml), adjusted to pH 6 and 55ml of 2N sodium nitrile was added.

This solutian was added to a mixture of ice and concentrated HC1 (25ml) and diazotised at 0-50C for 2 hours. Excess nitrous acid was destroyed by the addition of sulphamic acid. M-Toluidine (10.7g) in ethanol (loom) was added to the diazo suspension and the mixture was stirred at 0-50C, pH 3-4 for 2 hours before warming to room temperature. The product was filtered-off and dried to give 4-amino-2-methyl-4'-(P- sulphatoethylsulphonyl) azobenzene (31.9g).

The above product (4.80g) was dissolved in a mixture of water (75ml) and tetrahydrofuran (50ml) at pH 6.5. 2N Sodium nitrite was added (6.5ml) and the solution was poured onto ice and concentrated HC1 (4ml) and diazotised at 10-200C for 2 hours. Excess nitrous acid was destroyed using sulphamic acid to give a disazo solutian. as 5,5' Dihydroxydinaphth-2,2'-urea-7,7'-disulphonic acid (2.75g) was dissolved in water (75ml) and tetrahydrofuran (50ml), added to the above diazo solution and stirred at room temperature, pH 6.5 overnight. The solution was acidified to pH 2.5 and screened to remove excess diazo, and the product was precipitated out by the addition of iso-prapanol.

On drying this gave the title product as a dark red solid (6.60g) with a Amax at 540 nm.

Preoaration of Dve 8 The method of preparation for Dye 7 was repeated except that in place of m-toluidine there was used 3-acetamido-6-sulphoaniline, and in place of 5,5'-dihydroxydinaphth-2,2'-urea-7,7'-disulphonic acid was used the coupling component from Example 2. The resultant bluish-red solid had a Amax at 537 nm.

Presaraticn of Dve 9

Stave a) J-Acid (23.4g) was dissolved in water (250ml) at pH 7 and cooled to 0-50C. Terephthaloyl chloride (10.2g) in acetone (lOOml) was added dropwise to this solution, and after stirring at 0-50C and pH 6 for 4 hours, the mixture was allowed to warm to room temperature. A small additional portion of terephthaloyl chloride (0.50g) in acetone (20ml) was added and after stirring for a further hour the product was filtered off and washed with acetone. This gave 33.5g of the coupler.

3-(P- sulphatoethylsulphcyl )aniline (1.55g) was dissolved in water (50ml) at pH 6, and 2N sodium nitrite (3ml) was added. This was added to ice and concentrated HC1 (1.6ml) and diazotised at 0-50C for 1 hour. Excess nitrous acid was destroyed by adding sulphamic acid.

The above coupler (1.80g) was dissolved in a mixture of water (75ml) and acetone (75ml) and added dropwise to the diazo at pH 3.

The solution was stirred at 0-5 C. pH 3-3.5 for 4 hours then allowed to warm to roan temperature. Sufficient isopropanol was added to cause precipitation and the product was filtered off and dried to give the title dye (3.0g) havng a Amax at 478 nm.

Preoration of Dye 10 The method of preparatian for Dye 9 was repeated except that in place of 3-(ss-sulphatoethylsulphonyl) aniline there was used 4-(B- sulphatoethylsulphcaryl )aniline.

Preparation of Dye 11 The method of preparation for Dye 7 was repeated except that in place of 4-(ss-sulphatoethylsulphonyl) aniline there was used 3-(ss- sulphatoethylsulphonyl) aniline.

Preparation of Dye 12

Stave a) Cyanuric chloride (4.06g) was dissolved in acetone (30ml) and added to ice/water (50ml). A solutian of J-acid in water (lOOml) at pH 7 was added dropwise and the reaction was stirred, maintaining the mixture at 0-50C, pH 2-2.5 until it was negative to Ehrlich's reagent.

4-(ss-sulphatoethylsulphonyl) aniline (5.62g) was dissolved in water (50ml) at pH 7 and 2N sodium nitrite (llml) was added. This solution was poured onto ice and concentrated HC1 (6ml) and diazotised for 1 hour before destroying excess nitrous acid using sulphamic acid.

The diazo product was then added to the above suspensian of J-acid dichlorotriazine and the mixture was stirred at pH 3-4, 0-50C for 3 hours. A solid was isolated by precipitation with isopropanol and filtering.

The above solid (5g) was dissolved in water (iooml).

p-Phenylenediamine (0.37g) in water (50ml) was added and the solution was stirred at pH 4-5 and room temperature for 20 hours. Sufficient ethanol was added to cause precipitation and the dye was filtered-off and dried. The title product was abtained as an orange solid with a Xmax at 480 nm.

Preparation of Dye 13 The method of preparation for Dye 2 was repeated except that in place of 4-(ss-sulphoatoethylsulphonyl) aniline there was used 2-amino6-(ss-sulphatoethylsulphonyl) naphthalene. The product had a Amax at 493 nm.

Preparation of Dye 14 The method of preparation for Dye 1 was repeated except that in place of 4-(ss-sulphatoethylsulphonyl) aniline there was used 4methoxy-3-(ss-sulphatoethylsulphonyl) aniline.

Preparation of Dye 15

Stave a) Cyanuric chloride (3.69g) was dissolved in acetone (30ml) and added to ice/water (50ml). A solution of 4- (ss- sulphatoethylsulphonyl) aniline (5.62g) in water at pH 6 was added dropwise keeping the reaction mixture at pH 2. This was stirred for 2 hours at 0-50C. The mixture was allowed to warm to rocm temperature and a pH 6 solution of J-acid (4.70g) in water (50ml) was added dropwise.

The solution was stirred at pH 6 overnight, and the coupler was isolated by removing the water under reduced pressure.

Stare b) 4-(ss-sulphatoethylsulphonyl) aniline (28.1g) was dissolved in water (150ml) at pH 6, 2N sodium nitrite was added (55 ml) and the mixture was poured slowly onto ice and concentrated HC1 (25ml). After diazotising at 0-50C for 2 hours, excess nitrous acid was destroyed by the addition of sulphamic acid. 5-Acetamidoaniline-2-sulphonic acid (23.0g) was dissolved in water (150ml) at pH 6 and cooled in ice. This was slowly added to the diazo solution and the mixture was stirred at pH 3.5, 0-5 C for 2 hours before allowing to warm to roam temperature. The solution was adjusted to pH 1.5, and the product was filtered off and dried.

Stave c) The product fan stage b) (2.35g) was dissolved in water at pH 6 and 2N sodium nitrite (2.4ml) was added. The solution as added to ice and concentrated HC1 (1.5ml) and diazotised for 1 hour at 0-50C.

Excess nitrous acid was destroyed using sulphamic acid.

The coupler fran stage a) (2.93g) was dissolved in water (50ml), and the diazo was added to this and then stirred at 0-50C, pH 34 for 2 hours. The solution was warmed to room temperature adjusted to pH 2.5 and filtered. The product was purified by redissolving in water (lOOml) and adding salt (206 w/v). The resultant title product was filtered off and dried to give a bluish-red solid with #max at 526 nm Dyeing The method of Example 1, stage b), may be repeated except that in place of Dye 1 there is used the Dye indicated in the second column of Table 1 and in place of polyethylene imine 600 there is used the nucleophilic agent stated in the third column of Table 1.

Table 1

Example Second Column Third Column (Dye) (nucleophilic agent) 2 Dye 2 PEI 100,000 3 Dye 3 PEI 60,000 4 Dye 4 H2N(C2H4O)20C2H4NH2 5 Dye 5 Polyallylamine (MWca 1000) 6 Dye 6 PEI 1800 7 Dye 7 H2N(C2H4O)20C2H4NH2 8 | Dye 8 PEI 1000 9 Dye 9 JEFFAMINE D2000 10 Dye 10 JEFFAMINE T5000 11 Dye 11 JEFFAMINE ED2001 12 Dye 12 PEI 6000 13 Dye 13 PEI 60,000 14 Dye 14 JEFFAMINE ED900 15 Dye 15 PEI 1800 Comparative Example The dyeing method of Example 1, stage b) was repeated except that in place of PEI 600 there was used PEI 1800 and in place of Dye 1 there was used the dye shown below having only one electrophilic group:

The resultant dyebath remained highly coloured after dyeing was completed and the cotton was not dyed to as deep a shade.

Claims (11)

1. A process for the coloration of a substrate comprising applying thereto a dye having at least two electrophilic groups and a nuclecphilic agent having a molecular weight of at least 600 and at least one group selected from aliphatic primary amino groups and aliphatic secondary amino groups, wherein said dye and said nucleophilic agent are such that if they are applied to cotton by exhaust dyeing at least 90% of the dye is immobilised.

2. A process according to Claim 1 wherein the nuclecohilic agent having a molecular weight of at least 600 has at least two groups selected fran aliphatic primary amino groups and aliphatic secondary amino groups.

3. A process according to any one of the preceding claims wherein the dye and the agent are such that if they are applied to cotton by exhaust dyeing at least 958 of the dye is immobilised.

4. A process according to any one of the preceding claims wherein said eleatroahilic groups are selected fran activated alkenes and groups which are capable of undergoing an elimination and addition reaction.

5. A process according to Claim 1 for the coloration of a substrate comprising the steps: (a) applying an aqueous solution of a dye having at least two electrophilic groups to the substrate; (b) bringing the nucleophilic agent into contact with the substrate.

6. A process according to any one of the preceding claims wherein the water-soluble dye is a reactive dye and the process for coloration is performed under conditions such that said dye does not react with the substrate to a significant extent before said dye can react with the nucleophilic agent.

7. A process according to claim 5 wherein the dye is a reactive dye and step (a) is performed under conditions such that the dye does not react with the substrate to a significant extent during step (a).

8. A process according to any one of claims 5 to 7 wherein step (a) is performed at a temperature between 40"C and 300 C.

9. A process according to anyone of claims 5 to 8 wherein step (b) is performed at a temperature between oOC and 1100C.

10. A commosition comprising (i) a dye having at least two electrophilic groups; and (ii) a nucleophilic agent having a molecular weight of at least 600 and at least one group selected from aliphatic primary amino groups and aliphatic secondary amino groups where said amino groups are optionally masked using a protecting group.

11. A composition according to claim 10 which is a solid composition.