Patent GB-489934-A (GB)
Title: Improvements in the manufacture and production of azo dyestuffs
IPC: C09B39/00
Filed: 1937-01-04
Abstract: Azo dyes are made in substance or on the fibre by coupling diazotized aromatic amines with such o-hydroxyaryl carboxylic acid arylides capable of coupling as are derived from an amino-benzene or diphenyl and are substituted at least once in an aryl nucleus of the arylide radicle by an alkoxy group containing at least one free alcoholic hydroxy group. In example (6) 3.31-dimethoxybenzidine \sQ 2 - hydroxynaphthalene - 3 - carboxylic acid -21.b  - hydroxyethyloxyanilide and 4 - chlor-2 - nitraniline --> 2 - hydroxynaphthalene-3 - carboxylic acid - 21.b  - hydroxyethyloxy-51-methylanilide are prepared as insoluble dyes, useful as pigments; if the diazo compounds contain sulphonic acid groups, e.g. sulphanilic acid, the products dye wool.  In the other examples, dyes from the following pairs of components are prepared on fabrics of cotton, viscose artificial silk, wool or mixtures of the last two, by impregnating the fabric with a weakly alkaline solution of the coupling component in the presence of the usual dyeing assistants, and treating with the diazotized amine : 2 - hydroxynaphthalen-3-carboxylic acid - 21-, 31- or 41-(b -hydroxyethyloxy)anilide and 4-chlor - 2 - nitraniline; 2 - hydroxynaphthalene - 3 - carboxylic acid -21 - (HO.CH2.CH2.O.CH2.CH2.O) - 51 - methylanilide and 4-amino-41-methoxydiphenylamine; bis - 2 - hydroxynaphthalene - 3 - carboxylic acid - 31.311 - di-(b -hydroxyethyloxy)-benzidide and 2.5-dichloraniline; 2-hydroxyanthracene-3 - carboxylic acid - 21 - b .hydroxyethyloxy-51-methylanilide and 4-amino-3-methoxydiphenylamine; 2 - hydroxynaphthalene - 3-carboxylic acid - 21.51 - di-(b -hydroxyethyloxy)-anilide and 5-nitro-2-toluidine; 2-hydroxynaphthalene - 3 - carboxylic acid - 21-(b .g  - dihydroxypropyloxy)anilide and 4-amino - 41 - methoxydiphenylamine; 3-hydroxydiphenyleneoxide - 2 - carboxylic acid-21 - (b .g  - dihydroxypropyloxy)anilide and 2.5-dichloraniline.  In some of the above arylides the -O.CH2.CH2.OH radicle may be replaced by -O.CH2.CH2.O.CH2.CH2.OH, -O.(CH2. CH2.O)2CH2.CH2OH and -O.(CH2.CH2.O)4 CH2.CH2OH, and when two radicles of this last formula are present the dye can be prepared in neutral solution.  Arylides derived from salicylic, methylsalicylic, 2-hydroxy-6-methoxynaphthalene - 3 - carboxylic, 2-hydroxytriphenylene - 3 - carboxylic, 2-hydroxycarbazole - 3 - carboxylic and 7.8-benzocarbazole - B2.3 - hydroxy - 2 - carboxylic acids are also specified.  Other diazo components specified are aniline, nitranilines, nitroaminophenols, aminodiphenylamines and aminoazobenzenes which may contain halogen, alkyl, fluoralkyl, alkoxy, alkylsulphonic, carboxylic and sulphonic groups.  Samples of the following insoluble dyestuffs have been furnished: (1) 4-nitraniline --> 3 - hydroxydiphenyleneoxide - 2 - carboxylic acid p - 21-(b .g .-dihydroxypropyloxy) - anilide; (2) 4-nitraniline --> 2 - hydroxycarbazole - 3 - carboxylic acid - 21 - (b .g -dihydroxypropyloxy)-anilide; (3) 2-chloraniline --> 3-hydroxydiphenyleneoxide - 2 - carboxylic acid - 21-b  - hydroxyethyloxy - 51 - methylanilide. Specifications 6379/12, [Class 2 (iii)], 17279/13, [Class 15 (ii)], and 421,117 are referred to.  In the Provisional Specification the arylide radicle of the coupling component is not restricted to benzene and diphenyl derivatives and naphthalene and stilbene derivatives are specified.  Additional coupling components specified are 2-hydroxynaphthalene-3-carboxylic acid - 21 - (HO.CH2.CH2.O.CH2.CH2.O) or -(HO.CH2.CH2.O) - 41 - methylanilide.  Hydroxyalkoxyaminobenzenes and diphenyls are prepared by reacting nitrophenols with ethylene oxide, ethylene chlorhydrin, epichlorhydrin, propylene oxide or butylene dioxide and subsequently reducing.