GB552145A - Manufacture of azo dyestuffs - Google Patents

Abstract

552,145. Dyes and dyeing. IMPERIAL CHEMICAL INDUSTRIES, Ltd. (Du Pont de Nemours & Co., E. I.). Sept. 19, 1941, No. 12122. [Classes 2 (iii) and 15 (ii)] Trisazo dyes, substantive to cotton and regenerated cellulose, on which they produce brown dyeings which can be made fast to washing by tetrazotization on the fibre and development with a coupling component, are obtained by diazotizing an amine of the benzene or naphthalene series, coupling with a primary amine of the benzene series coupling in p-position to the amino group or a 1-aminonaphthalene coupling in 4-position, rediazotizing and coupling with a similarly defined primary amine, rediazotizing and coupling with 3:3<SP>1</SP>-diamino-sym-diphenylurea or a substitution product thereof, the components being so chosen that the product contains a sufficiency of solubilizing groups. The m- or p-aminobenzoyl group may be introduced into a middle component by condensation at the appropriate stage with m- or p-nitrobenzoyl chloride, followed by reduction of the nitro group. The products may be tetrazotized on the fibre and developed with a coupling component. Specified first components are aniline- 3- or 4-sulphonic acid, aniline-2:5-disulphonic acid, 1 - amino - 4 - methylbenzene - 3 - sulphonic acid, 1 - amino - 2 - chlorobenzene - 5 - sulphonic acid, 1 - amino - naphthalene - 4 - or 6 - sulphonic acid, 1 - aminonaphthalene - 3:8 - disulphonic acid, 2-aminophthalene-6-sulphonic acid and 2 - aminonaphthalene - 3:6 -, 4:8 -, 5:7- or 6:8-disulphonic acid. Specified middle components are aniline, o- and m-toluidines, o- and m-anisidines, 1-amino-3-chloro-6-methylbenzene, p-xylidine, cresidine, 2:5-dimethoxyaniline, 1 - (4<SP>1</SP> - aminobenzoylamino) - 3 - methylbenzene, 1 - aminonaphthalene and its 6- or 7-sulphonic acid and 1-(41-aminobenzoylamino)-naphthalene and its 6-sulphonic acid. Examples relate to (1) production of the dyestuff, 2-aminonaphthalene-6:8-disulphonic acid # m-toluidine# m-toluidine# 3:3<SP>1</SP>-diamino-symdiphenylurea, of which the dyeing on cotton is tetrazotized and developed with #-naphthol to a dischargeable red chocolate brown shade, fast to washing ; (2) condensation of the disazo dyestuff, 2 - aminonaphthalene - 6:8 - disulphonic acid # m-toluidine # m-toluidine, with p-nitrobenzoyl chloride, followed by reduction of the nitro group, rediazotization and coupling with 3:3<SP>1</SP>-diamino-sym.-diphenylurea; (3) condensation of the monoazo dyestuff, 2 - aminonaphthalene - 6:8 - disulphonic acid # m-toluidine, with m-nitrobenzoyl chloride, followed by reduction of the nitro group, rediazotization; coupling with m-toluidine, rediazotization and coupling with 3:3<SP>1</SP>-diamino-sym.- diphenylurea. Tables are also given showing the shades obtainable on cotton with the dyes from various combinations of components tetrazotized on the fibre and developed with # - naphthol, 1 - phenyl - 3 - methyl - 5 - pyrazolone, m-toluylenediamine or acetoacetanilide.