GB417489A - Improvements in the manufacture and production of azo dyestuffs - Google Patents

Abstract

Azo dyes; cellulose esters and regenerated celluloses, dyeing; mordant dyes, dyeing with.--Monoazo or disazo dyes are manufactured by coupling, with diazo or tetrazo compounds, 8-aminoquinoline or its homologues or substitution products unsubstituted in the 8-amino group, e.g. 5-methyl-, 5-chloro- or 5-alkoxy-8-aminoquinolines or 8 - aminoquinoline - 5 - sulphonic p acid. The products dye leather, wool, cotton, viscose, acetate artificial silk, natural silk or lacquers. Those derived from 8-aminoquinolines having a free p-position to the amino group or from diazotized o-aminophenols may be after-chromed and may also be converted in substance into complex metal compounds. Examples describe the manufacture of the following dyestuffs: (1) metanilic acid --> 8-aminoquinoline, which dyes wool orange shades becoming brown on after-chroming; treatment in substance with chromium formate yields a dyestuff which dyes wool and leather brown shades; (2) 3 : 4 - dichloraniline - 6 - sulphonic acid --> 8-aminoquinoline, which dyes wool orange shades; by after-chroming or by dyeing chrome-mordanted wool, yellow brown shades are obtained; chroming in substance yields a chromium compound which dyes wool and leather; the copper compound may be obtained by boiling with copper sulphate or tetrammine cupric sulphate, whilst other metal compounds, e.g. iron or nickel compounds, may also be prepared; (3) 2 : 5-dichloraniline --> 8-aminoquinoline-5-sulphonic acid, which dyes wool orange shades; (4) aniline --> 8-aminoquinoline, which dyes acetate artificial silk orange shades and also colours cellulose ester lacquers; (5) p-nitraniline --> 8-aminoquinoline, which dyes acetate artificial silk red shades and also colours cellulose ester lacquers; (6) 4 : 4<1>-diaminodiphenylurea-3 : 3<1>-disulphonic acid \sQ 8-aminoquinoline, which dyes silk brown shades and cotton brown shades which become blue on after-coppering. A table shows the shades obtained with and without after-chroming or chrome-mordanting with the dyestuffs obtained by coupling diazotized sulphanilic acid, 4-chloraniline-2- or 3-sulphonic acid, 3-chloraniline-6-sulphonic acid, 6-chloro-3-toluidine-4-sulphonic acid, 4-toluidine-2-sulphonic acid, 2-anisidine-4-sulphonic acid, p-nitraniline-o-sulphonic acid, naphthionic acid or 2 : 6 : 8-naphthylamine-disulphonic acid with 8-aminoquinoline or diazotized picramic acid with 8-aminoquinoline-5-sulphonic acid. The Specification as open to inspection under Sect. 91 refers also to the manufacture of polyazo dyes. This subject-matter does not appear in the Specification as accepted. 5-Methyl-8-aminoquinoline is obtainable by converting 1-methyl-3-amino-4-hydroxybenzene by Skraup s method into 5-methyl-8-hydroxyquinoline and treating this with ammonia at elevated temperature and pressure. 5-Alkoxy-8-aminoquinolines are obtainable by subjecting 1-alkoxy-3-amino-4-nitrobenzenes to the Skraup synthesis and reducing the nitro group. 8-Aminoquinoline-5-sulphonic acid is obtainable by sulphonating 8-aminoquinoline, e.g. by means of fuming sulphuric acid.