Patent GB-582977-A (GB)
Title: Manufacture of dyestuffs
IPC: C09B43/16
Filed: 1941-07-14
Abstract: Polyazo dyes, giving dyeings of which the fastness to wet treatments is improved by an after-treatment with a copper compound, are obtained by coupling in an alkaline medium the reaction product from 1 mol. of one of certain heterocyclic compounds containing 2 or 3 replaceable halogen atoms, 1 mol. of 1 : 8-aminonaphthol-4-sulphonic acid or -3 : 6-, -4 : 6-or -2 : 4-disulphonic acid, 1 mol. of 4-amino-41-hydroxy - azobenzene - 31 - carboxylic acid or a substitution product thereof and (in the case of 3 replaceable halogen atoms) 1 mol. of a primary or secondary amine, with a diazotised aminoazo compound of the general formula R1-N = N-R2-NH2, wherein R1 represents a residue of a mononuclear compound of the benzene series carrying an o-hydroxycarboxylic acid grouping and R2 represents a phenylene residue having the -N = N- and -NH2 groups in p-position to each other; or by coupling the diazotised aminoazo dyestuff in alkaline solution with the 1 : 8-aminonaphtholsulphonic acid, and reacting the resulting disazo-dyestuff, the 4-amino-41-hydroxy - azobenzene - 31 - carboxylic acid and (when necessary) the primary or secondary amine in any order with the halogenated heterocyclic compound; or by coupling the diazotised aminoazo dyestuff with a primary or secondary condensation product from the 1 : 8-aminonaphtholsulphonic acid and then performing the further condensation or condensations.  The halogenated heterocyclic compounds are such as comprise a 6-membered ring of 3 or 4 carbon atoms and 3 or 2 nitrogen atoms with not more than 2 nitrogen atoms linked together directly and containing at least twice the group <FORM:0582977/IV/1> , e.g. cyanuric halides, 1-phenyl- and 1-methyl-3 : 5-dichloro-2 : 4 : 6-triazine, 2 :4-dichloroquinazoline, 2 : 4 : 6 - tribromopyrimidine and 4 - methyl - 2 : 6 - dichloropyrimidine. Specified substitution products of 4-amino-41-hydroxy-azobenzene-31-carboxylic acid are the 2- and 51-methyl, 3-chloro, 3-methoxy and 3-sulphonic acid derivatives, specified primary and secondary amines are monomethylamine, monoethylamine, monopropylamine, diethylamine, aniline, N-methylaniline, p-toluidine, a -and b -naphthylamine and their sulphonic or carboxylic acid derivatives, e.g. 4-aminophenol-2-carboxylic acid, aminoazo compounds, e.g. of the type of 4-amino-41-hydroxy-azobenzene-31-carboxylic acid, and polynuclear compounds such as 4-(41-aminobenzoyl)-aminophenol-2-carboxylic acid. Specified aminoazo compounds of the above general formula R1-N = N-R2-NH2 are those obtainable by coupling a diazotised aminosalicylic acid, e.g. 4-aminophenol-2-carboxylic acid or its 6-sulphonic acid, with 3-aminotoluene or a 4-alkoxy (e.g. methoxy or ethoxy) derivative thereof, or with an ether of an o-aminophenol, e.g. o-anisidine or o-phenetidine, preferably in the form of its o -methanesulphonic acid.  In examples, the production is described of the following dyestuffs (1) and (2) 4-aminophenol-2-carboxylic acid --> cresidine or 4-aminophenol-2-carboxylic-6-sulphonic acid --> m-toluidine or cresidine --> (alkaline) the condensation product from cyanuric chloride (1 mol.), 1 : 8 : 3 : 6-aminonaphtholdisulphonic acid (1 mol.), 4-amino-41-hydroxy-azobenzene-31-carboxylic acid (1 mol.) and aniline (1 mol.); (3) 4-aminophenol-2-carboxylic-6-sulphonic acid --> cresidine --> (alkaline) 1 : 8 : 3 : 6-aminonaphtholdisulphonic acid, condensed with the condensation product from cyanuric chloride (1 mol.) and 4-amino-41-hydroxy-azobenzene-31-carboxylic acid (1 mol.) and the product further condensed with 4-aminophenol-2-carboxylic acid (1 mol.); (4) 4-aminophenol-2-carboxylic-6-sulphonic acid --> cresidine --> (alkaline) the condensation product from 1-methyl-3 : 5-dichloro-2 : 4 : 6-triazine (1 mol.), 1 : 8 : 3 : 6 - aminonaphtholdisulphonic acid (1 mol.) and 4-amino-41-hydroxy-azobenzene-31-carboxylic acid (1 mol.).  A table is also given showing the shades obtainable on cotton in a weakly alkaline bath in the presence of copper sulphate and sodium tartrate with the dyestuffs from various combinations of components, additional aminoazo compounds of the above general formula R1-N = N-R2-NH2 being 4-aminophenol-2-carboxylic acid --> 2-anisidine and 4-nitroaniline-2-carboxylic acid --> salicylic acid (nitro group reduced).  An example is also given of the dyeing of cotton by the process indicated, using the first dyestuff of (1).  Specification 460,378 is referred to.  The Specification as open to inspection under Sect. 91 comprises also a reference to the use of the products for dyeing mixed fabrics, e.g. of wool and viscose artificial wool, advantageously in a neutral bath in the presence of sodium or potassium chromate. The table includes additional dyestuffs in which 3-amino-41-hydroxyazobenzene-31-carboxylic acid is employed instead of the 4-amino compound.  This subject-matter does not appear in the Specification as accepted.