Patent GB-530169-A (GB)
Title: Manufacture of azo dyestuffs
IPC: C09B35/56
Filed: 1939-06-05
Abstract: 530,169. Azo dyes. IMPERIAL CHEMICAL INDUSTRIES, Ltd. June 5, 1939, No. 16508. Convention date, June 4, 1938. [Classes 2 (iii) and 15 (ii)] Tetrakisazo dyes are obtained by tetrazotizing a chloro-substituted diaminodiphenyl, which may be further substituted by alkyl, aryl, aralkyl, alkoxy, nitro, sulphonic acid, carboxylic acid or cyano groups (referred to below as R groups) coupling the tetrazo compound with an aminophenylpyrazolone, an aminobenzene which may be substituted by alkyl or alkoxy except in p-position to the amino group, a 1-aminonaphthalene or a sulphonic acid thereof having a free 4-position but otherwise substituted, if desired, substituents in the 2- or 3- positions being alkyl or alkoxy, and substituents in the 5-, 6-, 7- or 8- positions being R groups as above, a 1-, 2-, 3- or 4-aminonaphthol-6- or 7-sulphonic acid in which the hydroxy group is in position 5, 6, 7 or 8, and which may carry an R group in any free 1, 2, 3 or 4 position and an alkyl or alkoxy group in any free 5, 6, 7 or 8 position, or an aminobenzoylatninonaphtholsulphonic acid, tetrazotizing the resulting disazo dyestuff and coupling with 1:3-dihydroxybenzene or a derivative thereof substituted in 5-position by hydroxy, alkyl, alkoxy, amino, sulphonic acid, carboxylic acid, halogen or cyano. An example is given of the production of the dyestuff, 2:2<SP>1</SP>-dichloro-3:3<SP>1</SP>-dimethyl- 4:4<SP>1</SP>-diaminodiphenyl ## 2-(4<SP>1</SP>-aminobenzoyl)- amino - 5 - naphthol - 7 - sulphonic acid (2 mols.) ## 1:3-dihydroxybenzene (2 mols.), which dyes viscose rayon from a bath containing sodium carbonate and Glauber salt, the dyeing on after-treatment in the same or a separate bath with formaldehyde being a bright orange fast to washing and yielding white discharges with sodium formaldehydesulphoxylate. A table is also given showing the shades obtainable with the dyestuffs from various combinations of components, additional first components being the 2:2<SP>1</SP>-dichloro-, and 6:6<SP>1</SP>- dichloro-3:3<SP>1</SP>-dimethoxy derivatives of 4:41- diaminodiphenyl, additional second components being 1-(31-amino) phenyl-5-pyrazolone - 3-carboxylic acid, and 2:5:7-aminonaphtholsulphonic acid and an additional third component being 1:3-dihydroxybenzene-5-sulphonic acid. The fastness of the dyeings to light may be improved by after-treatment with copper salts before, during or after the treatment with formaldehyde. Specifications 2789/92, 13743/96, 1145/97, [all in Class 2], 14150/12, 1435/13, [both in Class 2 (iii)], and 432,355 are referred to. The Specification as open to inspection under Sect. 91 comprises also the use as tetrazo component of any diaminodiphenyl in which the amino groups are in different nuclei and which may be substituted by halogen or by R groups as above, additional tetrazo components specified being 4:4<SP>1</SP>-diaminodiphenyl and its 3:3'- dimethyl-, 3:3<SP>1</SP>-dimethoxy-, 2:2<SP>1</SP>-dimethyl-5:5<SP>1</SP>- dimethyl-5:5<SP>1</SP>-dimethoxy- and 2:2<SP>1</SP>-disulphoderivatives. The use as second components of 1-(31-amino)phenyl -5-pyrazolone-3-carboxylic acid 2:8:6-, 1:5:7-, and 2:5:7-aminoanaphtholsulphonic acids, 1-aminonaphthalene, its 6- sulphonic acid and 3-amino-4-methoxytoluene is also specified. This subject-matter does not appear in the Specification as accepted.