GB2046777A - Basic azo dyes, a process for their manufacture and their use for the colouration of synthetic polymeric materials - Google Patents

Abstract

Blue cationic azo dyes for polyacrylonitrile are derived from a substituted 3-amino-2,1-benzisothiazole diazo component and a N-substituted p-aminophenyl coupling component containing a beta -hydroxy substituent on a C3-6 alkylene group linking a cationic moiety to the N- atom. Unlike Basic Blue 41, the dyes have excellent fastness to steam pleating and dry heat treatments and excellent hydrolytic stability. But like Basic Blue 41 they have excellent build-up properties. Thus they combine the good tinctorial strength and build-up properties of Basic Blue 41 and the excellent fastness of the anthraquinone dyes. They also exhibit excellent light fastness and pH stability.

Description

SPECIFICATION Basic azo dyes, a process for their manufacture and their use for the colouration of synthetic polymeric materials.

This invention relates to new water soluble azo dyestuffs, to a process for their manufacture and to their use for the colouration of synthetic pdlymeric materials, especially polymers and copolymers of acrylonitrile and dicyanoethylene and also acid modified polyesters and polyamides.

According to the present invention we provide water soluble azo dyestuffs free of carboxylic acid and sulphonic acid groups which have the formula:

wherein the benzene ring A is optionally substituted: R is hydrogen or an optionally substituted alkyl group containing from 1 to 6 carbon atoms or an optionally substituted cycloalkyl, aralkyl or aryl group; R1 is hydrogen, lower alkyl, especially methyl, lower alkoxy, especially methoxy, acylamino, especially acetylamino, carbamido, alkyl mercapto, especially methylmercapto, or hydroxyl; R2 is hydrogen, lower alkyl, especially methyl, or lower alkoxy, especially methoxy;D is a branched or unbranched alkylene chain containing from 3 to 6 carbon atoms and carrying a ss-hydroxyl substituent; 0+ is a cationic group attached to either the y-carbon atom or a more remote carbon atom of the alkylene chain, and X- is an anion which may be inorganic or organic in character.

By "lower alkyl" and "lower alkoxy" we mean alkyl and hydroxy groups containing from 1 to 4 carbon atoms.

Preferred substituents which the benzene ring A may carry are chlorine, bromine and fluorine, nitro, cyano, trifluoromethyl, alkyl sulphonyl, aryl sulphonyl, sulphonamido, N-alkyl or N,Ndialkyl sulphonamido, lower alkoxy, especially methoxy and ethoxy, alkyl mercapto, especially methyl mercapto, acylamino, especially acetylamino, lower alkyl, aralkyl, aryl and groups of the formula COOR3 wherein R3 is lower alkyl or aryl.

As examples of D we would mention

and, in particular,

The cationic group Q+ is suitably a cyclammonium group such as a pyridinium group, a quaternary ammonium group which may be for example a trialkylammonium, especially trimethyl ammonium, group, an isothiouronium group, for example

a hydrazonium group, for example

or a sulphonium or phosphonium group. Such cationic groups are well known in the art and are more particularly described in, for example, our UK Patent Specification No. 1482234.

Of particular value are the dyestuffs of the formula:

wherein R4 is hydrogen, fluorine, chlorine or bromine; R5 is hydrogen, lower alkyl, especially methyl, lower alkoxy, especially methoxy or acylamino, especially acetylamino; R6 is an optionally substituted lower alkyl group; and Q+ and X have the meanings hereinbefore defined. Conveniently Q+ is a cycloammonium or quaternary ammonium group and the anion X associated with the cationic group is chloride, bromide, sulphate, bisulphate, phosphate, tetrachlorozincate, nitrate, acetate or methyl sulphate. In those cases where the anion is polyvalent the dyestuff will contain a corresponding molar proportion of the cationic moiety.

In particular we would mention dyestuffs of the formula:

wherein R7 is hydrogen or methyl; Rs is methyl, ethyl or fi-hydroxyethyl and Q+ and X have the meanings hereinbefore defined. Preferably Q+ is

wherein R9 is hydroxyethyl, or hydrogen, methyl, hydroxymethyl hydroxyethyl, or dimethylamino, or-N+(CH3), -N+(C2K4OH)3,

wherein RXo, R11 and R,2 are lower alkyl groups. Most conveniently the anion X is chloride, bromide, sulphate, bisulphate or tetrachloro zincate.

In a further aspect of our invention we provide a process for the manufacture of water soluble azo dyestuffs which comprises either (a) coupling a diazotised amine of the formula

with a coupling component of the formula

or (b) reacting a compound of the formula:

wherein Z is a removable radical of an organic or inorganic acid, especially a halogen atom or sulphato group, with a compound Q capable of conversion to a cationic group 0+ and if the anion of Z is not the same as the anion X, replacing the anion of Z by anion X by further reaction with an acid HX; A, D, R, R1, R2, 0+ and X- having the meanings hereinbefore defined.

As examples of suitable diazotisable amines which may be used in method (a) we would mention 3-amino-2, 1-benzisothiazole, its 4-lower alkyl, lower alkoxy, halogeno or nitro, 5-alkyl, halogeno, nitro, alkyl or aryl sulphonyl, N-alkyl or N,N-dialkylsulphonamido or acylamino, 6halogeno, nitro or cyano, 7-halogeno or nitro, 4,7-dialkyl, 5,7-dihalogeno or dinitro, 4-alkyl-6cyano, 5-haíogeno-7-cyano or 5-cyano-7-halogeno derivatives and especially its 5-nitro derivatives and its 5-nitro-7-halogeno derivatives.

The amine is diazotised in the normal way using mineral acid and sodium nitrite or nitrosyl sulphuric acid in concentrated sulphuric acid. Coupling is carried out in a neutral to acid medium, for example, in acetic acid.

As examples of suitable coupling components which may be used in method (a) we would particularly mention, N, S or P (as appropriate)-[y-(N'-phenyl-N'-methyl, ethyl- or hydroxyethyl amino)-ss-hydroxypropyl]pyridinium, trimethylammonium, dimethyl hydroxyethyl ammonium, methyl di(hydroxyethyl)ammonium, N-amino dimethyl ammonium, dimethyl sulphonium, tetramethyl isothiouronium, or dimethyl phenyl phosphonium chlorides, bisulphates or methyl sulphates in which the N'-phenyl group may bear a 3-methyl, 3-methoxy or 3-acetylamino substituent and, in the case of the pyridinium salt, in which the pyridine ring may bear a methyl, hydroxymethyl, hydroxyethyl, hydroxyl or dimethylamino group in the 2, 3 or 4 position.

In method (b), the compound

in which "Dye" is

is conveniently prepared by reacting a compound Dye-NHR with a halogeno epoxyalkane as exemplified by the following reactions:

Ci) Dye - NHR + N (i) Dye - Cl + - > C1 , Dye - N\ 0 Cii) Dye-NHR + ~~~ cH3 -CH.CH-Br ) II2-H.CB-Br . I cH .CH.CH - Br OH 0 R ~~ OH (iii) Dye-NHR + CH3-CII-CH-CH2Br ) Dye-N\ CE-CH-CH2Br cH3 0 cN (iv) Dye-WlIR + CH2-CH.CH2.CH2.CH.CH34 Dye-N 2t OH CN.CH OH CNCi ci 2 2 2 OH The cationic dyestuff may then be obtained from the halogeno precursor by direct reaction with the compound Q which is capable of conversion to the cationic group Q+, e.g. with pyridine which reacts to form a pyridinium cation.

The dyestuffs of the present invention may be used to colour polymeric materials by application from an aqueous dyebath. They give valuable mid-blue to greenish blue shades of high tinctorial strength. In particular, the dyestuffs of the invention are valuable dyeing and printing polyacrylonitrile materials and may be applied from acid, neutral or slightly alkaline dyebaths (pH from 3 to 7) at temperatures of between 40 to 1 20 C and ideally between 80 to 1 20"C or by printing techniques using thickened print pastes or by a wet transfer printing process.

Unlike Basic Blue 41, the dyes have excellent fastness to steam pleating and dry heat treatments and excellent hydrolytic stability. But like Basic Blue 41 they have excellent build-up properties. Thus they combine the good tinctorial strength and build-up properties of Basic Blue 41 and the excellent heat fasteness of the anthraquinone dyes. They also exhibit excellent light fastness and pH stability.

It is surprising that the presence of a hydroxy methylene (CHOH) substituent in the ssposition of the alkylene chain linking the cationic group to the anilino moiety of the coupling component should give mid-blue to greenish blue shades similar to Basic Blue 41 instead of the less useful reddish-blue shades obtained from the equivalent dyes which do not contain the hydroxyl substituent. A wider gamut of shades of mixed dyes is obtainable with mid-blue dyes making them more desirable than the reddish-blues.

It is a further advantage that the dyes of the present invention have superior Compatability Values to the equivalent dyes not having the hydroxyl substituent on the alkylene chain.

The invention is illustrated by the following Examples in which parts and percentages are by weight unless otherwise stated. Where parts by volume are given, the relationship of weight to volume is the same as that between gram and millilitre.

Example 1 1.92 parts of 5-nitro-3-amino-2,1-benzisothiazole were dissolved in 40 parts by volume of 85% sulphuric acid (i.e. 85 parts of sulphuric acid and 1 5 parts of water by volume) and the temperature maintained at 0-5"C while 5 parts by volume of nitrosyl sulphuric acid were added dropwise. The diazotisation mixture was stirred at this temperature for 2 hours.

3.8 Parts of N-[3-(nXmethylphenylethylamino)-2-hydroxypropyl]-4-methyl pyridinium chloride, i.e. 20% molar excess over the diazo component, was dissolved in 10 parts by volume of water and the solution added to 30 parts by volume of glacial acetic acid. The resulting solution was stirred at O to 5"C and the diazo solution added dropwise, the temperature being maintained at 5-10" throughout. On completion of the addition, the coupling mixture was stirred at O to 5"C for 1 hour, run into 100 parts by volume of iced water and neutralised by the addition of sodium acetate.

The precipitated solid, which included much inorganic material, was collected by filtration and washed with a little cold water. The cake was slurried in acetone and the mixture filtered: the inorganic material remained as the filter cake whilst the required dye was in solution in acetone as a blue filtrate.

The acetone filtrate was evaporated to dryness and the residual dark blue solid dissolved in hot water, filtered, and the dyestuff precipitated by the addition of sodium chloride. The resalting process was repeated to remove traces of a yellow impurity. The blue solid was dissolved in hot methanol, filtered, and the methanol evaporated off to give a dark blue solid. Analysis of the solid by thin layer chromatography on a silica gel plate using as eluent, chloroform 1 5 parts:methanol 5 parts:and acetic acid 1 part, showed a homogeneous mid-blue band.

The product dyed "Orlon" (Registered Trade Mark) from an acid dyebath a mid-blue shade, of almost identical hue to Basic Blue 41. The dyes cloth had excellent light fastness, pH stability, fastness to dry heat and steam pleating.

This experiment was repeated except that pyridine was used as the quaternising group. A dye with very similar properties was obtained.

Examples 2 to 21 The procedure of Example 1 was used to obtain dyes of the formula

in which R20 to R23, Q+ and X- have the meanings given in the following table, the amine and coupling components being chosen appropriately.

Shade on ample B20 B21 22 Bg Q+ i polyacrylo N02 H II C2Hs +NCH 2 Ci Hid-blu HSO- II N02 BF H CIII 4 N02 H H C2H5 ci I. 5 N02 11 Cg3 C2H4021 - 3 CE3 Cl C 6 N02 H H .. Cl Cl 7 N02 H cH3 C2H5 - Cl , 8 N02 H CH3 'I - N(CH3)2 CL Gblueoni8h~ 9 1102 H cH II - Cm201 Cl Mid-blue 10 NO2 H CH3 C2"5 - +lox Cl Mid-blue cH20H 11 N02 H CH3 .. - +N; 3 C1 3 2OH 12 N02 H H . - IOcg20H Ci 13 2 H 4:H3 " +N/r C1 Ig C2H40H 14 . 102 H CH3 -+n(ci-) CH3S0 3 33 3 4

Table (continued)

r5hade on E can ple 20 H21 H22 R23 x X Polyacrylo 15 NO2 H CH3 C2H5 1 3 Cl Mid-blue -z3- C2H40H 16 N02 H CH3 " H4OH Cl 12 J(OH c2H4oH 17 N02 H H ., - +M(cH3)3 CH4 .. .

18 102 H CH3 " NH Cl + 2 CR3 19 N02 H CH3 .. - a (CR ) CR SO I' 3 + 32 3 4 20 N02 H CH3 i C2H5 r(CH)2 Cl Mid-blue + ,r 32 -s=C N(OH ) 32 21 N02 H CH3 ll CH3 ci -p CH3

Claims (11)

1. A water soluble azo dyestuff free of carboxylic acid and sulphonic acid groups which has the formula:

wherein the benzene ring A is optionally substituted; R is hydrogen or an optionally substituted alkyl group containing from 1 to 6 carbon atoms or an optionally substituted cycloalkyl, aralkyl or aryl group; R1 is hydrogen, lower alkyl, lower alkoxy, acylamino, carbamido, alkyl, mercapto, or hydroxyl; R2 is hydrogen, lower alkyl or lower alkoxy; D is a branched or unbranched alkylene chain containing from 3 to 6 carbon atoms and carrying a ss-hydroxyl substituent; Q+ is a cationic group attached to either the y-carbon atom or a more remote carbon atom of the alkylene chain, and X- is an anion.

2. A dyestuff as claimed in claim 1 in which the benzene ring A carries one or more substituents selected from chlorine, bromine, fluorine, nitro, cyano, trifluoromethyl, alkyl sulphonyl, aryl sulphonyl, sulphonamido, N-alkyl or N,N-dialkyl sulphonamido, lower alkoxy, alkyl mercapto, acylamino, lower alkyl, aralkyl, aryl and groups of the formula COOR3 wherein R3 is lower alkyl or aryl.

3. A dyestuff as claimed in claim 1 which has the formula:

wherein R4 is hydrogen, fluorine, chlorine or bromine; R5 is hydrogen, lower alkyl, lower alkoxy, or acylamino; and R8 is an optionally substituted lower alkyl group.

4. A dyestuff as claimed in claim 3 which has the formula:

wherein R7 is hydrogen or methyl and R8 is methyl, ethyl or ss-hydroxyethyl.

5. A dyestuff as claimed in claim 4 in which Q+ is

wherein R9 is hydrogen, methyl, hydroxymethyl, hydroxyethyl, or dimethylamino, or -N+(CH3)3, -N +(C2H4OH)3,

wherein-R10, R" and R,2 are lower alkyl groups.

6. A dyestuff as claimed in claim 1 substantially as herein described with reference to any one of Examples 1 to 21.

7. A process for the manufacture of water soluble azo dyestuffs as claimed in claim 1, which comprises either (a) coupling a diazotised amine of the formula

with a coupling component of the formula

or (b) reacting a compound of the formula:

wherein Z is a removable radical of an organic or inorganic acid with a compound 0 capable of conversion to a cationic group Q+ and if the anion of Z is not the same as the anion X, replacing the anion of Z by anion X by further reaction with an acid HX.

8. A process as claimed in claim 7 substantially as herein described with reference to any one of Examples 1 to 21.

9. A process for the colouration of polymeric materials which comprises applying to a polymeric material a dyestuff as claimed in any one of claims 1 to 6.

10. A process as claimed in claim 9 in which the polymeric material is polyacrylonitrile.

11. Polymeric materials whenever coloured by a dyestuff as claimed in any one of claims 1 to 6.