GB1596545A

GB1596545A - Composition for dyeing and printing

Info

Publication number: GB1596545A
Application number: GB5208977A
Authority: GB
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1976-12-14
Filing date: 1977-12-14
Publication date: 1981-08-26
Also published as: CH629527A5; FR2374386B1; JPS5374528A; BR7708260A; FR2374386A1; JPS6113503B2; IT1089705B; IN146325B; DE2656503C2; CA1111209A; BE861843A; DE2656503A1

Abstract

The commercial, water-free, water-soluble dyeing preparations contain a diazotisable aromatic amine, a coupling component and an alkali metal nitrite. The aromatic amine or the coupling component, or both, have at least one water-solubilising, free acidic group and at least one fibre-reactive group. If the fibre-reactive group contains a water-solubilising, free acidic group, it can also function as that water-solubilising, free acidic group. The preparations are suitable for dyeing and printing fibre materials of natural or synthetic origin.

Description

(54) COMPOSITION FOR DYEING AND PRINTING (71) We, HOECHST AKTIENGESELLSCHAFT, a body corporate organised according to the laws of the Federal Republic of Germany, of 6230 Frankfurt/Main 80, Postfach 8003 20, Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to water-soluble dyeing compositions for the preparation of fibre-reactive azo dyestuffs, and their use for dyeing and printing.

Compositions for the dyeing and printing of fibrous materials of natural or synthetic origin, especially of textile materials or dyeing compositions for the dyeing and printing of similar materials, for example cellulose products, such as paper and cardboard, consist generally of pulverulent, pasty or liquid dyestuff compositions to which specific auxiliary agents for the various dyeing and printing processes may be admixed prior to the dyeing operation. With the exception of the developing and ice colour dyeing processes, in which stabilized diazonium compounds are made to react in the developing bath on the fibre material which has previously been impregnated with a solution of the coupling component, all other dyeing methods in the field of the azo dyestuffs are based upon the use of the dyestuffs themselves.

It has now been found that the colouring (dyeing and printing) of fibrous materials of natural and synthetic origin, especially of natural or regenerated cellulose, animal polyamide fibres, other natural or synthetic polyamides, by anionic fibre-reactive azo dyestuffs, may be conducted by using dyeing compositions which do not contain the azo dyestuffs themselves, but at least some of the starting materials for their preparation. The compositions may be used for dying a variety of materials for example viscose, cotton, linen, hemp, jute, silk, wool, furs, hides, skins, and synthetic polyamides such as polyamide 6, polyamide 66, polyamide 11, or polyamide 4.

The present invention provides a solid, dry, water-soluble composition which comprises a diazotizable aromatic amine and a coupling component therefor, one or each of the aromatic amine and the coupling component being substituted by a free-acid or anionic group, preferably a free-acid group, and a fibre-reactive group.

Certain fibre-reactive groups, for example the /3 - sulpatoethylsulfonyl group, themselves contain a free acid or anionic grouping. In such cases the presence of a further free acid or anionic group is not necessary.

The term "dry" as used herein is intended to mean that the composition contains substantially no free water. It is however possible, in many cases, for the composition to include inorganic salts or other compounds which contain water of crystallization, although it is preferred that any inorganic salts present be anhydrous.

The free acid group or anionic group acts as a solubilizer. Such groups include carboxy, sulfo, sulfato (--OSO,H) and phosphato (-OPO3H2) groups.

The fibre-reactive group is preferably a group of the general formula I (CH2)n(NR)pSO2Z I in which R represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, preferably an alkyl group of from 1 to 4 carbon atoms, and especially methyl or ethyl: n is zero, 1 or 2, preferably zero; p zero or 1, preferably zero; Z represents a vinyl group or a group of the formula -CH2-CH2-Z1, wherein Z, represents a hydroxy group or a group which can be split off with an alkali, for example a sulfato, phosphato, dimethylamino, diethylamino, methylsulfonyloxy, ptolylsulfonyloxy, acetoxy, sulfobenzoyloxy, phenoxy or trimethylammonium chloride group, or a chlorine or bromine atom.

The composition may also include an alkali metal or ammonium nitrite.

preferably an alkali metal nitrite, and especially sodiun nitrite.

The aromatic amine and the coupling component are preferably present in the composition in a stoichiometric or approximately stoichiometric amount. If a nitrite is present, it may also preferably be present in a stoichiometric or approximately stoichiometric amount based on the quantity of aromatic amine and/or couPling component. The term "approximately stoichiometric" means that the ratio of any two components differs from the stoichiometric ratio by not more than 10 mole percent, and is preferably within 10 mole percent of the stoichiometric ratio.

The nitrite may however be present in any proportion up to the approximate stoichiometric amount.

The compositions of the invention may also contain common auxiliary agents and substances which may be used for the dyeing of fibrous materials, for example, levelling auxiliaries, electrolytes, for example sodium chloride, potassium chloride, sodium sulfate, and optionally a siccative, for example anhydrous sodium sulfate or anhydrous calcium chloride or magnesium sulfate, In particular, the dyeing compositions may contain buffers.

The buffers used are salts which are able to bind the acid set free in the dyestuff preparation, especially alkali metal salts, such as sodium or potassium salts, of weak or medium-strength inorganic or organic acids, for example acetic acid, formic acid, tartaric acid, oxalic acid, phosphoric acid, boric acid, carbonic acid, such as sodium acetate, sodium or potassium hydrogen phosphate, disodiumhydrogen phosphate or trisodium phosphate, sodium borates, for example sodium metaborate, sodium or potassium carbonate or bicarbonate, as well as sodium- or sodiumpotassium tartrate or sodium oxalate, or mixtures of such buffer substances.

There may also be used the ammonium salts thereof sudh as ammonium acetate.

The water-free, dry dyeing compositions of the invention may be used in a simple manner for the preparation of dyestuff solutions, dye liquors, printing pastes and dye baths. The dyeing compositions are excellently suitable for quickly preparing high-quality pure dyestuff solutions which may subsequently be converted into the corresponding dye liquors, baths or pastes by adding corresponding dyeing and printing auxiliaries, and which can be used immediately in a dyeing or printing process.

The preparation of the dyestuff solutions may be effected by stirring a pulverulent dyeing composition of the invention into 5 to 1000 times, preferably 10 to 50 times its by weight of water having a temperature of from 0 to 800 C, preferably from 5 to 30"C, optionally while simultaneously or subsequently adding buffers especially in an amount of up to 1.5 equivalents, calculated on the coupling component, in order to obtain a pH value which is favourable for the coupling. The pH value of the aqueous dyeing composition solution which has been initially buffered should generally not exceed 5.5. If the starting components have more than one free acid group the proportion of these buffers is generally from about 0.8 to 1.3 equivalents per additional free acid group.In the course of this process the corresponding azo dyestuff is formed very rapidly and is susually complete within 5 to 30 minutes. The corresponding common dye liquors or baths or printing pastes are obtained by subsequently adding the dyeing and printing auxiliaries.

If as starting product there is used a dyeing composition which contains the three components not in a stoichiometric amount, but a mixture of the aromatic amine and the coupling component in a stoichiometric or approximately stoichiometric amount and no alkali metal nitrite or a small amount of alkali metal nitrite, the dyeing composition may also be dissolved by being stirred into water, and the total stoichiometric amount of alkali metal nitrite, or the residual amount still required, may be added. The dyestuff formation is then effected as rapidly as in the above case.

However, it is favourable from the economic point of view and especially advantageous for the user (dyer, printer) if for the preparation of the dyestuff solutions and the subsequent preparation of the dye liquors or baths or printing pastes from these solutions use is made of those dyeing compositions according to the invention which contain the three components in a stoichiometric or approximately stoichiometric amount, or which consist of the same.

As a rule it is advantageous for the dyeing compositins to contain the buffers, so that it is convenient for the user to adjust the pH range required for the coupling without difficulty (this pH is determined by the choice of the diazo and coupling components) and to maintain the pH during the coupling. Therefore the buffers are advantageously present in the dyeing compositions of the invention especially where more than one free-acid group is present either or both of the amine and coupling component, in the above proportion. The content of buffer substance in the composition should preferably be such that the initial pH value of the solution does not exceed 5.5.

The pH value of the solution of the dyeing composition which is required for the dyestuff formation should be adjusted by the buffers to a value of from 2 to 6, preferably from 3.5 to 5.

The dyeing compositions of the invention are extremely suitable for the preparation of aqueous solutions of anionic azo dyestuffs which have one or more substituents having fiber-reactive properties. Fiber-reactive groups of this kind may be contained in the diazo as well as in the coupling component.

Compared with other processes, the use of dyeing compositions of the present invention for the preparation of aqueous solutions of fiber-reactive azo dyestuffs has the advantage that the formation of the dyestuffs is effected with a small amount of by-products, since by using the dyeing compositions of the invention the synthesis of the azo dyestuffs can be carried out at an optimum pH range for example from 3.5 to 5. A consequential advantage of the compositions of the invention are that waste is no longer obtained in contrast to other preparations of azo dyes.Also, in the synthesis of the dyestuffs there is no, or practically no, inert salt formation by the neutralization of acids, as is the case a considerable degree in other processes, and that a separate preparation and isolation of the dyestuffs which are to be used subsequently in dyeing and printing processes, is no longer required. Moreover, the dyeing compositions of the invention are marked by a very good fastness to storage, and their volume and weight has been reduced by about 50 ZO compared with corresponding fiber-reactive anionic, water-soluble commercial dyestuffs which may contain up to 70% by weight of electrolytes as extenders.In the preparation of anionic azo dyestuffs which have one or several reactive groups of the vinyl sulfone series, especially the p - sulfatoethylsulfonyl group, there is no deactivation of the fiber reactivity of the reactive group. Such a deactivation is possible, for example, in the case of the p - sulfatoethylsulfonyl reactive group by its reaction with water to form the p - hydroxyethylsulfonyl compound.

The dyeing compositions of the invention may be prepared by mechanically mixing the components (aromatic amine, coupling component, and optionally alkali metal nitrite, buffer and other auxiliaries) with the exclusion of water, preferably under grinding conditions, with one another to form a homogeneous mixture, or by grinding said components with one another. In the process of homogeneous mixing, the components themselves should already have a fine pulverulent consistency. The aromatic amine and the coupling component are advantageously initially mixed with each other, preferably being finely ground, and subsequently the nitrite and optionally buffer substances and other auxiliaries especially electrolytes and siccatives, are added, are mixed homogeneously or optionally ground with one another.In this fine pulverulent homogeneous mixtures of the components are obtained in the dyeing composition. Especially in cases where one of the diazo or coupling components is liquid, it is favorable to grind these two components first with each other in order to obtain a homogeneous solid mixture.

For the dyeing compositions of the invention, a great number of diazo components and coupling components may be used.

For the present novel compositions for the preparation of water-soluble anionic fiber-reactive azo dyestuffs there may generally be used a great number of aromatic amines as diazo components and of coupling components containing enolic groups or tertiary amino groups, provided that one or both of these components contain at least one free acid group.

Diazo components of this kind are, for example, the following: Aniline, 4,4' - methylene - di(m - toluidine), o - anisidine, o~- phenetidine, 4 - nitro - 2 - aminoanisole, 5 - nitro - 2 - aminoanisole, 4 - chloro - 2 - aminoanisole, p - phenetidine, p - anisidine, 4 - amino - 4 - methoxydiphenyl amine, 2 - nitro - 4 - aminoanisole, 3 - nitro - 4 - aminoanisole, 4 - amino diphenylether, 5 - methyl - o - anisidine, 4 - nitroaniline, 2 - chloro - 4 - nitroaniline, 2,6 - dichloro - 4 - nitroaniline, 2,6 - dibromo - 4 - nitroaniline, 4 aminoacetanilide, 2 - nitro - 4 - methylaniline, 4 - (o - tolylazo) - 2methylaninine, 4 - aminoazobenzene, 4 - nitrophenyl - azo - I - naphthylamine 2,4 - dinitroaniline, 2,5 - dimethoxyaniline, p - xylidine, 2,4 - xylidine, p butvl - aniline, p - amino - diphenylamine, p - aminoacetanilide, aminobenzyl alcohol, 4' - amino - methyl - 3 - nitrobenzophenone, 4 - amino - 4' propoxybenzophenone, 2 - amino - 4' - fluorobenzophenone, 2 - amino - 4,5 di - propoxybenzophenone, 2 - amino - 5 - bromobenzophenone, 4 - amino - 3 chlorobenzophenone, 2 - amino - 4,5 - dichiorobenzophenone, 4 - amino - 2 - methylbenzophenone, 3 - amino - 2,4 - dimethylbenzophenone, 2 - amino - 4 acetylaminotoluene, benzidine (reference is made to the Carcinogenic Substances Regulations, 1967), 3,3' - dichlorobenzidine, 2 - nitrobenzidine, 2 - amino - 4 methoxybenzophenone, 2 - cyano - 4 - nitroaniline, 2,4 - dinitro - 6 chloroaniline, 2,5 - diethoxyaniline, 4 - cyanoaniline, 2 - chloroaniline, 3 chloroaniline, 4 - chloroaniline, 2,5 - dichloroaniline, 4 - chloro - 2 - nitroaniline, o - toluidine, p - toluidine, 5 - chloro - 2 - aminotoluene, 6chloro - 2 - aminotoluene, 4- chloro - 2- aminotoluene, 4- chloro - 2- (p chlorophenylsulfonyl)aniline, p - (p' - tolylsulfonyl)aniline, p - (p' ethoxyphenylsulfonyl)aniline, 2 - ethoxy - 1 - naphthylamine, I - naphthylamine, dianisidine, 4 - carbomethoxyamino - 2,5 - diethoxyaniline, 4 - benzoylamino 2,5 - diethoxyaniline, 3 - amino -4 - methylbenzonitrile, 1 - (m - aminophenyl) - 3 - methyl - 5 - pyrazolone, 2- cyano - 4- nitroaniline, 4,4' diaminodiphenylsulfone, 4 - methylsulfonylaniline, 2 - (o - aminophenyl) - 2,1,3 benzotriazole, 4 - aminobenzophenone, 3 - chloro - 4 - cyanoaniline, o aminobenzotrifluoride, 5 - chloro - 2 - aminobenzotrifluoride, dehydrothio - p toluidine, 4' - amino - 2,4 - dichlorobenzophenone, 4- amino - 4' ethylbenzophenone, 1 - aminoanthraquinone - 3 - sulfonic acid, 2 - amino benzosulfdnic acid, 2,5 - dichloro - 6 - sulfoaniline, 2,4 - dichloro - 5 carboxyaniline, p - amino - benzenesulfonic acid, 2 - methyl - 5 - or - 4 sulfoaniline, 2 - methoxy - 4 - sulfoaniline, 2,5 - dimethyl - 4 - sulfoaniline, 2,5 dimethoxy -4-suffoaniline, 2 - methyi - 5 - methoxy - 4 - sulfoaniline, 3 acetyl - amino - 4 - sulfonaniline, 4' - sultbbenzoylamino - 2 - sulfoaniline, 2 aminonaphthalene - 6,8 - disulfonic acid, 1 - aminonaphthalene - 4 - sulfonic acid, 2- amino - naphthol(8)- 4,6- disulfonic acid, 4- methoxy - 5sulfoaniline, 4 - ethyl - 5 - sulfoaniline, 2 - aminobenzthiazole, 2 - amino - 4 chlorobenzthiazole, 2 - amino - sulfobenzthiazole, 2 - amino - 5 - methyl sulfobenzthiazole, 4- chloroanthranilic acid, 2- aminobenzoic acid, 4 aminobenzoic acid, sulfanilic acid, 2A - disulfoanfline, 2,5 - disulfoaniline, 6 chlorometanilic acid, 2 - amino - 5 - chlorobenzene - sulfonic acid, 2 - amino 5 - nitrobenzene - sulfonic acid, 3 - chloroaniline - 5 - sulfonic acid, 3 - amino 5 - chloro - o - toluene - sulfonic acid, 2 - amino - 6 - chlorotoluene - 3 sulfonic acid, 5 - aminotoluene - 4 - sulfonic acid, 3 - aminotoluene - 6 - sulfonic acid, 4 - acetylaminoaniline - 2 - sulfonic acid, 2 - (p - aminoanilino)- 5 nitrobenzene - sulfonic acid, 5 - amino - 1 - naphthalene - sulfonic acid, 5 amino - 2 - naphthalene - sulfonic acid, 8 - amino - 2 - naphthalene - sulfonic acid, 5 - acetamido - 8 - amino - 2 - naphthalene - sulfonic acid, 8 - acetamido 5 - amino - 2- naphthalene - sulfonic acid, 6 - amino - 2- naphthalene sulfonic acid, 7 - amino - 1,3 - naphthalene - disulfonic acid, 6 - amino - 1,3 naphthalene - disulfonic acid, 4,4' - diamino - 2,2' - stilbene - disulfonic acid.

4,4' - diaminodiphenyl - 2,2' - disulfonic acid, 3,3' - dimethyl - 4,4' diaminodiphenyl - 6,6' - disulfonic acid, 2 - ethoxy - I - naphthylamine - 6 sulfonic acid, p - (p' - aminophenyl- azo)benzene - sulfonic acid, p- (4- amino - 3 - methoxyphenylazo)benzene - sulfonic acid, 4 - (p sulfatoethylsulfonyl)aniline, 4 - (p - sulfatoethylsulfonyl) - 2 - hydroxyaniline, 4 (p - phosphatoethylsulfonyl)aniline, 3 - (,5 - sulfatoethylsulfonyl)aniline, 3 - (A - chloroethylsulfonyl)aniline, 3 - (,B - dimethylamino - ethylsulfonyl)aniline, 2,5 disulfo - 4 - vinylsulfonylaniline, 4 - methyl - 5 - (,B - sulfatoethylsulfonyl)aniline.

2,5 - dimethoxy - 4- (,B - phosphatoethylsulfonyl)aniline, 2 - methyl - 4methoxy - 5 - (p- vinylsulfonyl)aniline, 4- [N - methyl - N - (fi- sulfatoethylsulfonyl)]amino - aniline, 4 - ethoxy - 5 - (p sulfatoethylsulfonyl)aniline, 2 - chloro - 4 - ( - sulfatoethylsulfonyl)aniline. 2 amino - 8 - ( - sulfatoethylsulfonyl)naphthalene, 2 - amino - 6 - ( - phosphatoethylsulfonyl)naphthalene, 2- and 3 - amino - pyridine or 2 - bromo 4 - ( - sulfatoethylsulfonyl)aniline. Coupling components which may be used in the compositions of the invention are, for example, the following: Naphthol compounds, for example 1- or 2 - naphthol, 1 - naphthol - 4 suifonic acid, 1 - naphthol - 2 - sulfonic acid, 1 - naphthol - 3,6 - disulfonic acid, 2 - naphthol - 5,7 - disulfonic acid, 1 - naphthol - 3,6,8 - trisulfonic acid, 1 acetylamino - naphthol(8) - 3,6 - disulfonic acid and -4,6 - disulfonic acid, 1 benzoylamino - naphthol(8) - 3,6 - disulfonic acid and -4,6 - disulfonic acid, 2 acetylamino - 5 - naphthol - 7 - sulfonic acid, 2 - benzoylamino - 8 - naphthol - 6 sulfonic acid, 2 - tosylamino - 5 - naphthol - 7 - sulfonic acid, 2 - acetylamino 8 - naphthol - 3,6 - disulfonic acid, 2 - acetylamino - 5 - naphthol - 1,7 disulfonic acid, 2 - benzoylamino - 8 - naphthol - 6 - sulfonic acid, 2 phenylsulfonylamino - 5 - naphthol - 7 - sulfonic acid, 2 - (N - methyl - N acetyl)amino - 8 - naphthol - 6 - sulfonic acid, furthermore aromatic tertiary amines, especially aniline compounds, such as N,N - dimethylaniline, diethyl - m - toluidine, di - N,N - (n - propyl) - o toluidine, N - methyl - N - (2' - cyanoethyl)aniline, N,N - bis(2' cyanoethyl)aniline, N - methyl - N - (3' - cyanopropyl) - m - toluidine, Ncyanomethyl - N - (2' - acetoxyethyl)aniline, N,N - bis(2' - acetoxyethyl)aniline, N,N - bis(3' - butyryloxypropyl) - m - toluidine, N,N - bis(2' - benzoyloxyethyl) m - toluidine, N - (2' - cyanoethyl) - N - benzoylmethyl - aniline, N - ethyl N - (2' - cyanoethyl)aniline, N - ethyl - N - (2' - cyanoethyl) - m - toluidine, N (2' - cyanoethyl) - N - (2' - hydroxyethyl)aniline, 2 - (N - ethylanilino)ethanol, phenyldiethanolamine, N,N - bis(2 - hydroxyethyl) - m - toluidine, m - chloro N,N - dimethyl - aniline, N,N - bis(2' - acetoxyethyl) - N' - benzoyl - m - phenylene - diamine, 2 - methoxy - 5 - benzoylamino - N,N - diethylaniline, N,N bis(2' - benzoylethyl)- N' - methylsulfonyl: m - phenylene - diamine, N,N dimethyl - 2 - methoxy - 5 - methylaniline, N,N - bis(2' - hydroxyethyl) - 2 methoxy - 5 - chloraniline, N,N - dimethyl- 2,5 - dimethoxy - aniline, Nmethyl - N - (2',3' - dihydroxypropyl) - 2 - chloro - 5 - methyl - aniline, N methyldiphenylamine, N,N - (2' - hydroxyethyl)- 2 - chloro - 5 - (p nitrobenzamido)aniline, N - (2' - cyanoethyl)- 2,5 - dimethoxyaniline, Nethyl - N - (2' - cyanoethyl)cresidine, N,N - bis(2' - cyanoethyl) - m - anisidine, N - (2' - cyanoethyl)- o - chloroaniline;; N - (2' - cyanoethyl) - N (benzoyloxyethyl)aniline, N - ethyl - N - (2' - cyanoethyl)aniline, furthermore, pyrazolone compounds, wherein the keto group may be present in the 4- or 5 position, for example, 3 - methyl- or 3 - carboxy- or 3 - carbonamido - pyrazolone, 3 - carboxy- or 3 - carbethoxy- or 3 - carbomethoxy- or 3 - methyl - 1 - (4' - sulfophenyl)pyrazolone, I - (4' - fi - sulfatoethylsulfonyl)phenyl - 3 - methyl- or 3 - carboxy - pyrazolone - (5), 1 - (2' - naphthyl) - 3 - methyl - pyrazolone - (5), 1 - (2' - naphthyl) - 3 - methyl - pyrazolone - (5) - 5',7' - disulfonic acid, 1 - (2' - naphthyl) - 3 - carboxy - pyrazolone - (5) - 5' - (,B - phosphatoethyl)sulfone, 1 - (3' - ,B- sulfatoethylsulfonyl - 6' - methoxy)phenyl- 3 - carbethoxy pyrazolone - (5), 1 - (2,5' - dichloro - 4' - sulfo)phenyl- or 1 - (2,5' - dichloro 4' - '3 - sulfatoethylsulfonyl)phenyl - 3 - methyl - pyrazolone - (5), 1 - (2',5' dimethoxy - 4' - ,B - sulfatoethylsulfonyl) - 3 - carbonamido - pyrazolone - (5), I - (3' - carboxy)phenyl- or I - (3' - acetylamino)phenyl- 3 - carboxy - pyrazolone - (5), 1 - (4' - nitro)phenyl - 3 - methyl - pyrazolone - (5), moreover, other generally known coupling components which carry active methylene groups, such as barbituric acid, derivatives of malonic acid, derivatives of acetoacetylarylides, for example, acetoacetyl - 5 - - sulfo - 2- naphthyl- amide, acetoacetylanilide, acetylacetylanilide - 4 - sulfonic acid, acetylacetyl - 2,5 - dimethoxyanilide - 4 sulfonic acid, acetoacetyl - 2,5 - dimethoxy - anilide - 4 - fi - sulfatoethylsulfone, acetoacetyl - 4 - chloroanilide, acetoacetyl - 2 - chloroanilide - 4 - sulfonic acid, furthermore 8 - hydroxyquinoline, 2 - hydroxy - quinoline, 2,5 - bis(N,N diethylamino)pyridine, hydroxy - carbazole, cresol, phenol, 2 - methylindole, 5 - chloro - 2 - hydroxy - benzoic acid and 2,3 - hydroxynaphthoic acid or 2 hydroxycarbazole - 3 - carboxylic acid.

Preferred diazo components may be specified by the following general formulae II to V:

in which the formula radicals have the following meanings: R1 is hydrogen, fluorine, chlorine, bromine, trifluoromethyl, alkyl of from I to 4 carbon atoms, alkoxy of from I to 4 carbon atoms, alkoxyalkylene of from 2 to 6 carbon atoms altogether, alkanoyl of from 2 to 4 carbon atoms, alkanoylamino of from 2 to 4 carbon atoms, benzoylamino, chlorobenzoylamino, nitrobenzoylamino, methylbenzoylamino, sulfobenzoylamino, chloroacetylamino, acryloylamino.

carbalkoxy of from 2 to 5 carbon atoms, carboxy, carbamoyl, sulfamoyl, N - alkylor N,N - dialkyl - sulfamoyl of from 1 to 4 carbon atoms, in each alkyl radical, N alkyl- or N,N - dialkylcarbamoyl of from 1 to 4 carbon atoms in each alkyl radical, hydroxy, sulfo, alkylsulfonyl of from 1 to 3 carbon atoms, cyano, nitro or a fiberreactive radical (group), especially a radical of the formula hCH2)n(NR)pSO2Z in which R is hydrogen or alkyl of from 1 to 4 carbon atoms, n is the integer 0, 1 or 2, and p is the integer 0 or 1, Z is the vinyl group or a radical of the formula -CH2-CH2-Z1 in which Zl is the hydroxy group or a radical which can be split off by an alkali, for example sulfato, phosphato, dimethylamino, diethylamino, methylsulfonyloxy, p tolylsulfonyloxy, acetoxy, sulfobenzoyloxy, phenoxy, chlorine, bromine or trimethylammonium chloride, R2 is hydrogen, carboxy, sulfo, chlorine, bromine, alkyl of from 1 to 4 carbon atoms, alkoxy of from 1 to 4 carbon atoms, cyano, sulfamoyl, carbamoyl or a fiberreactive radical (group), especially a radical of the formula -(CH2)n--hNR)p-SO2--Z of the above definition, (CH2)nNR)pSO2Z R3 is hydrogen, sulfo, sulfamoyl, chlorine. alkvl of from 1 to 4 carbon atoms or alkoxy of from I to 4 carbon atoms, R4 is hydrogen, chlorine, bromine, alkyl of from 1 to 4 carbon atoms, aikoxy of from 1 to 4 carbon atoms, alkoxyalkylene of, in total, from 2 to 4 carbon atoms, alkanoyl of, in total, from 2 to 4 carbon atoms, alkanoylamino of, in total, from 2 to 4 carbon atoms, benzoylamino, chlorobenzoylamino, nitrobenzoylamino, methylbenzoylamino, sulfobenzoylamino, chloroacetylamino. acryloylamino, carbalkoxy of from 2 to 5 carbon atoms, carboxy, carbamoyl, sulfamoyl, N - alkylor N,N - dialkyl - carbamoyl or N - alkyl- or N,N - dialkyl - sulfamoyl of from 1 to 4 carbon atoms in each alkyl radical, hydroxy, sulfo, alkylsulfonyl with from 1 to 3 carbon atoms, cyano, nitro or a fiber-reactive radical (group), especially a radical of the formula (CH2)n(N R)pSO2Z of the above definition, R5 is hydrogen. chlorine, sulfo, or a fiber-reactive radical (group) of the formula (CH2)n(NR)pSO2Z of the above definition, R6 is hydrogen or sulfo, R7 is hydrogen or sulfo, R6 being different from R7, A is a benzene or naphthalene nucleus, X is a ground of the formula -S-, -O-, -SO,-, -NH-CO-, -CO- NH-, -NH-CO-NH-, -CH1-, -CH2-CH3-, -SO2-NH- or -NH- SO'-, m is zero or 1, and B is an aromatic heterocyclic ring which may contain 1 or 2 fused benzene rings, for example a pyridine. triazole, imidazole, benzotriazole ring, a benzthiazole ring, a carbazole ring, a benzoxazole, benzoxazolone, benzimidazole, benzimidazolone, or a phthalimide ring.

Preferred coupling components may be specified by the following general formulae VI to XI:

in which R, R2, R3, R4 R5, R6, A, X and m are defined as above and R8 stands for methyl, carboxy, carbalkoxy of from 2 to 5 carbon atoms, carbamoyl or phenyl, and R9 is alkyl of from 1 to 3 carbon atoms or phenyl optionally substituted by methyl, methoxy, chlorine or sulfo, and the radicals R10 are identical or different to each other and each stands for alkyl of from 1 to 4 carbon atoms, cyanoethyl, cyanopropyl, hydroxyethyl or hydroxypropyl, alkanoyloxyethyl or alkanoyloxypropyl each having an alkanoyl radical of from 2 to 4 carbon atoms, benzoyloxyethyl benzoyloxypropyl, or alkoxyalkylene having from 2 to 6 carbon atoms altogether.

By means of the dyeing compositions of the invention there may be prepared not only aqueous solutions of metal-free dyestuffs, but also metal complex compounds of azo dyestuffs, if as starting compounds there are used diazo and coupling components which already contain functional groups capable of the metal complex formation, such as carboxy, preferably hydroxy group, and if during the introduction of the dyeing composition into the water by stirring there is added simultaneously or subsequently the corresponding heavy metal salt, such as a copper, cobalt or chromium salt, which is common for metallization processes of this kind. Such metal compound metallizing azo dyestuffs are generally known in a great number in literature.However, it is also possible to use as starting dyeing compositions such which already contain the heavy metal salts in stoichiometric amounts or which contain as functional diazo or coupling component already a compound which is a metal-complex monoazo dyestuff, by which measure metalcontaining disazo dyestuffs are obtained.

The dyeing compositions of the invention are not restricted to the use of aromatic monoamines as diazo components, although their use is preferred. For the preparation of disazo dyestuffs the use of diamines is also possible, unless as starting compound, as has been indicated before, there is already used another monoazo dyestuff which can be coupled, or is used a diazotizable monoazo dyestuff. As bis-diazotizable diamines of this kind there may be mentioned, for example, the 2,2' - disulfodiphenylene - 4,4' - diamine and 1,4 - diamino - benzene.Starting amines or coupling components which already contain an azo group are, for example 5,7 - disulfonaphthyl - (2) - 2' - azo - 3' - amino - 6' sulfo - 1' - naphthol or -l - (8' - hydroxy - 5' - sulfonaphthyl - 2') - 3 - methyl pyrazolone - (5) - 7' - azobenzene. However, also coupling components which can be coupled twice may be used for the dyeing compositions of the invention for example, resorcinol, p - phthaloyl - bis(4' - sulfo - acetic acid - anilide) and 1,8 dihydroxynaphthalene - 3,6 - disulfonic acid. However, preference is given to dyeing compositions which have as diazo component a monoamine and as coupling component a compound that possesses one position capable for coupling.

Together with the use of the novel dyeing compositions in accordance with the invention for the preparation of azo dyestuffs in an aqueous solution there has accordingly also been found a novel process for the colouring (dyeing and printing) of fibrous materials of natural or synthetic origin of the kind mentioned at first, which comprises dissolving the dyeing compositions of the invention in water having a temperature of from 0 to 800C, preferably from 5 to 300 C, optionally adding buffer substances and heavy metal salts, allowing these solutions to stand (for example, while stirring) for the formation of the dyestuff at a tempeature of from 0 to 800 C, preferably from 5 to 30"C, for 5 minutes up to about 2 hours, preferably from 5 to 30 minutes and using the dyestuff solution thus obtained subsequently for the preparation of dye liquors or dye baths or printing pastes by mixing it with the dyeing and printing auxiliaries common for thos liquors, baths or pastes, optionally-if required-after or while diluting with water, then applying the dyestuff liquors, baths or printing pastes thus prepared on the material according to common methods (such as padding, printing, moving in the liquor (bath)), and fixing the dyestuff as usual for fiber-reactive dyestuffs, such as by means of an alkaline reacting agent.

It has already been described in numerous pulications how to prepare those dye liquors or baths or printing pastes from dyestuff solutions which are commonly prepared by dissolving a dyestuff isolated following the synthesis in water and how to carry out dyeing and printing processes with the same. It is therefore not necessary to provide any kind of instruction in the present patent application, as it would only refer to process steps already known to the person skilled in the art.

The following examples serve to illustrate the subject of the invention. The parts are parts by weight.

EXAMPLE 1 400 parts of 4' - amino - benzoylamino - 3 - fi - sulfatoethylsulfonylbenzene.

405 parts of 1 - acetylamino - 8 - naphthol - 3,6 - disulfonic acid as disodium salt and 69 parts of sodium nitrite are finely ground together, until a homogeneous mixture has been formed. (The components may also first be finely ground individually and then be mixed with one another to give a homogeneous mixture.) 87.4 parts of this mixture are dissolved in 1000 parts of water of 15"C, and the solution is allowed to stand for 30 minutes at room temperature; it shows a pH value of 5.0.

With this solution, dye liquors, dye baths or printing pastes can be prepared for the production of cotton dyeings according to the dyeing or printing methods for reactive dyestuffs. Thus, this dyestuff solution may be used directly for padding a cotton fabric with a liquor pick-up of 80% by weight, calculated on the material weight; the fabric which has subsequently been dried is then padded over with an aqueous alkaline solution containing sodium hydroxide and sodium sulfate, and is thereafter steamed with saturated steam of a temperature of from 102 to 1030C for 5 minutes, and then it is washed thoroughly.In this manner a red cotton dyeing is obtained which shows the same color depth as a dyeing which has been prepared in the same manner, but using 77 parts of a dyestuff-which has been obtained in a conventional way by diazotizing the amine in a hydrochloric acid solution and coupling it with the above-mentioned component, neutralizing the dyestuff solution and salting the dyestuff out--dissolved in 1000 parts of water, applying it by padding, drying the padded fabric, padding the alkaline solution over, and steaming.

EXAMPLE 2 A dyeing composition is prepared by a homogeneous grinding of 311 parts of A- - sulfatoethylsulfonyl - 3 - amino - 4 - methoxybenzene, 405 parts of I - acetylamino - 8 - naphthol - 3,6 - disulfonic acid as disodium salt and 69 parts of sodium nitrite. This mixture may be stored, in the same manner as the composition according to Example 1, for several months without any alteration (decomposition). 78.5 parts of this mixture are dissolved in 1000 parts of water of 10"C, and the solution is allowed to stand for 20 minutes; a pH value of 4.9 is thereafter established.By means of this solution, dye liquors, dye baths and printing pastes can be prepared in common manner; under the conditions of fixation for reactive dyestuffs-as they are known from literature for numerous cases (in the presence of an alkali and optionally heat)-bluish red dyeings are obtained which show the same color intensity as dyeings obtained in the same manner, while using 68 parts of a dyestuff prepared from the above-mentioned components according to conventional methods.

EXAMPLE 3 281 parts of 1 - amino -4 -P - sulfatoethylsulfonyl - benzene, 423 parts of 1 benzoylamino - 8 - naphthol - 4,6 - disulfonic acid and 7 parts of sodium nitrite are ground separately and are then mechanically mixed to give a homogeneous mixture. 71.1 parts of the dyeing composition thus prepared are introduced, while stirring, into 750 parts of water of 10 C; subsequently a solution of 6.2 parts of sodium nitrite and 38 parts of trisodium-phosphate-dodecahydrate in 200 parts of water is added (it is also possible to dissolve the dyeing composition first in 950 parts of water at 100C and then to add 6.2 parts of finely ground sodium nitrite and 38 parts of finely ground trisodium-phosphate-dodecahydrate in substance).After 30 minutes of stirring the dyestuff solution thus obtained is used as dyebath for the dyeing of cotton fabric, for which 30 g of anhydrous sodium sulfate and 3 g of sodium carbonate as well as 1 cm3 of an aqueous 32.5% sodium hydroxide solution are added to the dyestuff solution; then 30 g of a fabric of mercerized cotton are introduced, and the material is dyed for one hour at 600 C. In this manner, a yellowish red cotton dyeing of a high color intensity is obtained, as it is also obtained according to the methods which have been common so far while maintaining the above-mentioned dyeing conditions and while using 71.5 parts of a dyestuff which had been prepared in conventional manner by diazotizing in the presence of an excess of acid and coupling the diazo and coupling components, neutralizing the azo dyestuff solution and isolating the dyestuff by salting out.

EXAMPLE 4 325 parts of 1 - amino - 2- methoxy - 5 - methyl - 4- 13- sulfatoethylsulfonylbenzene, 318 parts of the ammonium salt of N acetoacetylamino - 2 - methoxy - 5 - methylbenzene - 4 - sulfonic acid and 69 parts of sodium nitrite are ground together to form a homogeneous mixture. With this dyeing composition, a dyestuff solution can be prepared very fast, when 71.2 parts of this composition are dissolved, for example, in 1500 parts of water of 20"C, and this solution is allowed to stand for 15 minutes. In the course of this process a pH value of 5.4 is established.

This dyestuff solution may be used in order to prepare a dye liquor, a dye bath or a printing paste in common manner, with which a cotton fabric is coloured (dyed or printed) according to the dyeing condition common for reactive dyestuffs, whereupon the dyestuff is fixed on the cellulose fiber. In this manner a greenish yellow dyeing is obtained which shows a high color intensity which is equal to a dyeing or print that has been prepared with the use of 53.9 parts of a dyestuff synthetized from the above diazo and coupling components according to conventional methods, while maintaining the same application and fixation conditions in the colouring process.

EXAMPLE 5 325 parts of 1 - amino - 2 - methoxy - 5 - methyl - 4 - A sulfatoethylsulfonylbenzene, 254 parts of 1 - (4' - sulfophenyl)- 3 - methyl pyrazolone (5), 160 parts of anhydrous sodium acetate and 69 parts of sodium nitrite are finely ground and are subsequently mixed in a high-speed stirrer to give a homogeneous mixture. 80.8 parts of the dyeing composition thus prepared are dissolved in 1500 parts of water of 15"C; after 15 minutes a yellow dyestuff solution having a pH of 4.8 is obtained, which solution may be used in common manner, for example as has been described in the above Examples, to prepare yellow dyeings of a high color intensity.

EXAMPLE 6 400 parts of 4' - aminobenzoylamino - 3 - F - sulfatoethylsulfonylbenzene and 405 parts of the disodium salt of 1 - acetylamino - 8 - naphthol - 3,6 disulfonic acid are finely ground and are mixed in a high-speed stirrer to give a homogeneous mixture. 80.5 parts of the dyeing composition thus obtained are stirred with 1000 parts of water of 25"C; then 6.9 parts of sodium nitrite are introduced into this solution. The mixture is continued to be stirred for 30 minutes at the resulting pH value of 5.0 , thus yielding a dyestuff solution which may be used as dye bath, dye liquor or printing paste after the addition of the corresponding dyeing and printing auxiliaries and substances.With these compositions, red dyeings or prints of a high color intensity are obtained, which are equal to those dyeings and prints which have been produced under the same conditions, however, while using 77.2 parts of a dyestuff prepared and isolated according to conventional methods from the above diazo and coupling components.

EXAMPLE 7 29.7 parts of 3 - amino - 4 - hydroxy - 1 - - sulfatoethylsulfonyl - benzene, 36.1 parts of 1 - acetylamino - 8 - naphthol - 3,6 - disulfonic acid as disodium salt, 18.2 parts of copper(II) - acetate and 6.9 parts of sodium nitrite are at first finely ground separately and are then mixed together, while being ground, to give a homogeneous mixture.The dyeing composition thus prepared is thereafter stirred into 11 of water of 35"C, and stirring is continued for a reaction period of 2 hours, yielding a dyestuff solution with which, upon adding dyeing auxiliaries and fixing agents common for reactive dyestuffs and according to the dying conditions common for reactive dyestuffs, a red-violet dyeing is obtained on a cotton fabric which corresponds to a dyeing having been obtained in the same manner, however, while using 73.1 parts of a dyestuff prepared from the above-mentioned diazo and coupling components according to a conventional synthesis by diazotization in a strongly hydrochloric solution, subsequent coupling, metallization with a copper salt, neutralization and salting-out the dyestuff.

EXAMPLE 8 93 parts of aniline are intimately mixed with 392 parts of I - (4' - p sulfatoethylsulfonyl)phenyl - 3 - carboxy - pyrazolone - (5), in the course of which the salt is formed, under self-heating. The mixture obtained is finely ground and is thereafter mixed mechanically with 69 parts of ground sodium nitrite to give a homogeneous mixture. 55.4 parts of this mixture are introduced into 1000 parts of water of 15"C and are stirred for 30 minutes. Subsequently a cotton fabric is dyed.

as has been described in Example 3. The same greenish yellow dyeing is obtained, as is produced with 49.6 parts of the chemically identical dyestuff which has been prepared in a conventional manner of a diazotization and coupling process.

WHAT WE CLAIM IS: 1. A dry, solid, water-soluble composition which comprises a diazotizable aromatic amine and a coupling component therefor, one or each of the aromatic amine and the coupling component being substituted by a free acid or anionic group and a fiber-reactive group.

2. A composition as claimed in Claim 1, wherein the fiber-reactive group, if containing a free acid or anionic group, comprises said free acid or anionic group.

3. A composition as claimed in Claim 1 or Claim 2, wherein the said free acid or anionic group is a sulfonic acid group.

4. A composition as claimed in Claim 2 wherein the fibre-reactive group containing a free acid or anionic group is a fi - sulfatoethylsulfonyl group.

5. A composition as claimed in any one of Claims 1 to 3, wherein the fiberreactive group has the general formula I (CH2)n(NR)pSO2Z (I) in which R represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms; Z represents a vinyl group or a group of the formula -CH,-CH,-Z1, in which Z1 represents a hydroxy group or a group or atom capable of being split off by alkali; n is zero, one or two: and p is zero or one.

6. A composition as claimed in Claim 5, wherein R represents an alkyl group having from 1 to 4 carbon atoms.

7. A composition as claimed in Claim 5 or Claim 6, wherein Z represents a vinyl group or a group of the formula -CH2CH2-Z1, in which Z1 represents a hydroxy group or a sulfato, phosphato, dimethylamino, diethylamino, methylsulfonyloxy, p - tolylsulfonyloxy, acetoxy, sulfobenzoyloxy, phenoxy or trimethylammonium chloride group, or a chlorine or bromine atom.

8. A composition as claimed in Claim 7, wherein Z represents a vinyl group.

9. A composition as claimed in Claim 7, wherein Z represents a ,B-sulfatoethyl group.

10. A composition as claimed in any one of Claims 5 to 9, wherein n is zero.

11. A composition as claimed in any one of Claims 5 to 10, wherein p is zero.

12. A composition as Claim 1, wherein the aromatic amine has one of the general formulae II, III, IV or V

in which Rl represents a hydrogen, fluorine, chlorine or bromine atom, a trifluoromethyl group, an alkyl or alkoxy group having from 1 to 4 carbon atoms, an alkoxyalkylene group having a total of from 2 to 6 carbon atoms, an alkanoyl group having from 2 to 4 carbon atoms, an alkanoylamino group having from 2 to 4 carbon atoms, a benzoylamino, chlorobenzoylamino, nitrobenzoylamino, methylbenzoylamino, sulfobenzoylamino, chloroacetylamino, acryloylamino group or a carbalkoxy group having from 2 to 5 carbon atoms, a carboxy group, a carbamoyl or sulfamoyl group which may be N-substituted by one or two alkyl groups having from 1 to 4 carbon atoms, a hydroxy or sulfo group, an alkylsulfonyl group having from 1 to 3 carbon atoms, a cyano or nitro group or a fiber-reactive group; R2 represents a hydrogen, chlorine or bromine atom, a carboxy or sulfo group, an alkyl or alkoxy group having 1 to 4 carbon atoms, a cyano, sulfamoyl, carbamoyl or a fiber-reactive group; R, represents a hydrogen or chlorine atom, a sulfo or sulfamoyl group, or an alkyl or alkoxy group having 1 to 4 carbon atoms; R4 represents a hydrogen, chlorine or bromine atom, an alkyl or alkoxy group having from 1 to 4 carbon atoms, an alkoxyalkyl group having a total of from 2 to 4 carbon atoms, an alkanoyl group having from 2 to 4 carbon atoms, an alkanoylamino group having from 2 to 4 carbon atoms, a benzoylamino, chlorobenzoylamino, nitrobenzoylamino, methylbenzoylamino.

sulfobenzoylamino, chloroacetylamino or acryloylamino group, a carbalkoxy group having from 2 to 5 carbon atoms, a carboxy group, a carbamoyl or sulfamoyl group which may be N-substituted by dne or two alkyl groups having from 1 to 4 carbon atoms, a hydroxy or sulfo group, an alkylsulfonyl group having from 1 to 3 carbon atoms, a cyano or nitro group or a fiber-reactive group; R5 represents a hydrogen or chlorine atom, a sulfo group or a fiber-reactive group; R6 represents a hydrogen atom or a sulfo group; R7 represents a hydrogen atom or a sulfo group, R6 being different from R7; A represents a benzene or naphthalene nucleus; X represents a group of the formula -S-, -0--SO,-, -NH-CO-, --COO-NNH-, -NH-CO-NH-, -CH2-, -CH2-CH,-,-SO2-NH- or -NH-SO,-; m is zero or 1; and B represents an aromatic heterocyclic ring which may contain 1 or 2 fused benzene rings.

13. A composition as claimed in Claim 12, wherein any fiber-reactive group is defined as in any one of Claims 5 to 11.

14. A composition as claimed in Claim 12 or Claim 13, wherein B represents a pyridine, triazole, imidazole, benzotriazole, benzthiazole, carbazole, benzoxazole, benzimidazole, benzimidazolone or phthalimide nucleus.

15. A composition as claimed in Claim 1, wherein the coupling component has one of the general formulae VI, VII, VIII, IX, X or XI.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

R4 represents a hydrogen, chlorine or bromine atom, an alkyl or alkoxy group having from 1 to 4 carbon atoms, an alkoxyalkyl group having a total of from 2 to 4 carbon atoms, an alkanoyl group having from 2 to 4 carbon atoms, an alkanoylamino group having from 2 to 4 carbon atoms, a benzoylamino, chlorobenzoylamino, nitrobenzoylamino, methylbenzoylamino.

sulfobenzoylamino, chloroacetylamino or acryloylamino group, a carbalkoxy group having from 2 to 5 carbon atoms, a carboxy group, a carbamoyl or sulfamoyl group which may be N-substituted by dne or two alkyl groups having from 1 to 4 carbon atoms, a hydroxy or sulfo group, an alkylsulfonyl group having from 1 to 3 carbon atoms, a cyano or nitro group or a fiber-reactive group; R5 represents a hydrogen or chlorine atom, a sulfo group or a fiber-reactive group; R6 represents a hydrogen atom or a sulfo group; R7 represents a hydrogen atom or a sulfo group, R6 being different from R7; A represents a benzene or naphthalene nucleus; X represents a group of the formula -S-, -0--SO,-, -NH-CO-, --COO-NNH-, -NH-CO-NH-, -CH2-, -CH2-CH,-,-SO2-NH- or -NH-SO,-; m is zero or 1; and B represents an aromatic heterocyclic ring which may contain 1 or 2 fused benzene rings.

13. A composition as claimed in Claim 12, wherein any fiber-reactive group is defined as in any one of Claims 5 to 11.

14. A composition as claimed in Claim 12 or Claim 13, wherein B represents a pyridine, triazole, imidazole, benzotriazole, benzthiazole, carbazole, benzoxazole, benzimidazole, benzimidazolone or phthalimide nucleus.

15. A composition as claimed in Claim 1, wherein the coupling component has one of the general formulae VI, VII, VIII, IX, X or XI.

in which R1, R,, R3 R4, Rs, R6, A, X and m are as defined in Claim 13 or Claim 14

and Ra represents a methyl or carboxy group, a carbalkoxy group having from 2 to 5 carbon atoms, a carbamoyl or a phenyl group; R9 represents an alkyl group having from 1 to 3 carbon atoms, or a phenyl group which is optionally substituted by one or more chlorine atoms or methyl, methoxy, or sulfo groups; and the groups Rao, which may be the same or different each represents an alkyl group having from 1 to 4 carbon atoms, a cyanoethyl, cyanopropyl, hydroxyethyl or hydroxypropyl group, an alkanoyloxyethyl or alkanoyloxypropyl group having an alkanoyl radical of from 2 to 4 carbon atoms, a benzoyloxyethyl or benzoyloxypropyl group, or an alkoxyalkylene group having a total of from 2 to 6 carbon atoms.

16. A composition as claimed in Claim 1, wherein the aromatic amine is one of those specifically mentioned herein.

17. A composition as claimed in Claim 1, wherein the coupling component is one of those specically mentioned herein.

18. A composition as claimed in any one of Claims 1 to 17, which includes an alkali metal nitrite or ammonium nitrite.

19. A composition as claimed in Claim 18, which includes an alkali metal nitrite.

20. A composition as claimed in Claim 18 or Claim 19, wherein the ratio of the quantity of coupling component and/or aromatic amine to the quantity of nitrite is within 10 mole percent of the stoichiometric ratio.

21. A composition as claimed in any one of Claims 1 to 20, wherein the ratio of the quantity of aromatic amine to the quantity of coupling component is within 10 mole percent of the stoichiometric ratio.

22. A composition as claimed in any one of Claims 1 to 21, which includes one or more levelling auxiliaries, electrolytes, siccatives and/or buffers.

23. A composition as claimed in Claim 22, which includes any one or more of those electrolytes, siccatives and/or buffers specifically mentioned herein for the purpose.

24. A composition as claimed in Claim 22 ot Claim 23, which includes a buffer, wherein the aromatic amine and/or the coupling component is substituted by more than one free acid group.

25. A composition as claimed in Claim 22 or Claim 23, which includes up to 1.5 equivalents of a buffer per mole of the coupling component.

26. A composition as claimed in Claim 24, which includes 1.5 equivalents of the buffer per mole of the coupling component plus from 0.8 to 1.3 equivalents of the buffer per mole of additional free acid group.

27. A composition as claimed in any one of Claims 1 to 27, which includes one or more heavy metal salts.

28. A composition as claimed in Claim 1, substantially as hereinbefore described in any one of the Examples.

29. A process for coloring a fibrous material, which comprises dissolving a composition as claimed in any one of Claims 1 to 28 in water and dissolving a buffer, a heavy metal salt, or a nitrite if required, and contacting the fibrous material with the resulting solution.

30. A process as claimed in Claim 29, wherein fibrous material is contacted with the said resulting solution at least five minutes after dissolution of the composition in water.

31. A process as claimed in Claim 29, substantially as hereinbefore described in any one of the Examples.

32. A fibrous material having been colored by a process as claimed in any one of Claims 29 to 31.