Patent GB-555791-A (GB)
Title: Manufacture of new azo dyestuffs
IPC: C09B43/14
Filed: 1941-11-24
Abstract: 555,791. Dyes. SOC. OF CHEMICAL INDUSTRY IN BASLE. Nov. 24, 1941, Nos. 15105 and 15106. Convention dates, Nov. 22, 1940 and Oct. 10, 1941. [Classes 2 (iii) and 15 (ii)] Disazo dyes are obtained by condensing with phosgene two proportions of the same or different aminoazo dyestuffs of the general formula R-N =N-R<SP>1</SP>-NH-CO-R<SP>11</SP>-NH 2  wherein R represents a sulphosalicylic acid residue and R<SP>1</SP> and R" represent benzene residues, substituted or not, or one molecular proportion of such an aminoazo, dyestuff and one molecular proportion of an aminoazo dyestuff of the general formula R<SP>111</SP>- NH 2 , wherein R<SP>111</SP> represents an azobenzene residue carrying at least one water-solubilizing group. The products dye natural or regenerated cellulose fibres, e.g. cotton, ramie, flax, viscose or cuproammonium artificial silk or mixtures thereof with animal fibres, e.g. wool or silk, yellow shades of which the fastness to wet treatments and to light is improved by aftertreatment with salts of metals, e.g. of chromium, copper, cobalt or nickel. Specified dyestuffs of the first general formula are 4<SP>1</SP>-(4<SP>11</SP>-amino)- benzoylamino - azobenzene - 4 - hydroxy - 3 - sulpho - 5 - carboxylic acid and its 2<SP>1</SP> - methyl - 51 - methoxy, 2<SP>1</SP>:5<SP>1</SP> - dimethoxy, 2<SP>1</SP>:5<SP>1</SP>-dimethyl and 3<SP>1</SP> - methoxy derivatives, 4<SP>1</SP> - (3<SP>11</SP>- amino) - benzoylamino - azobenzene 4 - hydroxy - 3 - sulpho - 5 - carboxylic acid and its 2<SP>1</SP> - acetylamino - 5<SP>1</SP> - methoxy, 2<SP>1</SP>:5<SP>1</SP> - dimethoxy and 2<SP>1</SP>:5<SP>1</SP> - dimethyl derivatives, 4<SP>1</SP> - (3<SP>11</SP>- or 4<SP>11</SP> - amino) - benzoylamino - azobenzene - 2 - hydroxy - 5 - sulpho - 3 - carboxylic acid or their 2<SP>1</SP> - methyl, 2<SP>1</SP> - methyl - 5 - methoxy or 2<SP>1</SP>:5<SP>1</SP> - dimethyl derivatives and 4<SP>1</SP> - (4<SP>11</SP> - amino) - benzoylamino - azobenzene - 21 - methyl - 5<SP>1</SP> - methoxy - 2 - hydroxy - 4 - sulpho - 3 - carboxylic acid. Specified other dyestuffs of the second general formula are 4<SP>1</SP> - amino - azobenzene - 4 - hydroxy - 3 - carboxylic acid and its 2<SP>1</SP> - and 3<SP>1</SP> - methyl, 5 - methyl and 3<SP>1</SP> - methoxy derivatives, 4<SP>1</SP> - amino - 51 - methoxy - 2<SP>1</SP> - methyl - azobenzene - 2 - carboxylic acid, the 3<SP>1</SP> - methyl and 2<SP>1</SP> - methoxy derivatives of 5<SP>1</SP> - amino - azobenzene - 4 - hydroxy - 3 - carboxylic acid, 4<SP>1</SP> - amino - 2<SP>1</SP> - methyl - azobenzene - 3 - and 4 - sulphonic acid, 4<SP>1</SP> - amino - 3<SP>1</SP> - methoxy - azobenzene - 3 - sulphonic acid, and 4<SP>1</SP>-amino - 5<SP>1</SP> - methoxy - 2<SP>1</SP> - methyl - azobenzene - 4 - chloro - 3 - sulphonic acid. Examples relate to the condensation with. phosgene (1 mol.) of (1) 2 mols. of the product obtained by reduction of the nitro group in the product of condensation of p - or m - nitro - benzoyl chloride with 1 - amino - 4 - hydroxy - benzene - 3 - carboxy - 5 - sulphonic acid # cresidine, m - toluidine, 2:5 - dimethoxy - aniline or p - xylidine, (2) 2 mols. of the product obtained by reduction of the nitro group in the product of condensation of p- or m - nitrobenzoyl chloride with 1 - amino - 2 -. hydroxybenzene - 3 - carboxy - 5 - sulphonic acid # m - toluidine, cresidine or 2:5 - di - methoxyaniline, (3) 1 mol. -of the product obtained by reduction of the nitro group in the product of condensation of p-nitrobenzoyl chloride with 1 - amino -. 4.- hydroxybenzene - 3 - carboxy - 5 - sulphonic acid # cresidine and 1 mol. of 4<SP>1</SP> - (4<SP>11</SP> - or 3<SP>11</SP> - amino) - benzoyl - amino - azobenzene - 4 - hydroxy -,3 - carboxy - lic or of the 2<SP>1</SP>-methvl derivative of the 3<SP>11</SP>- amino compound, (4) 1 mol. of the product obtained by reduction of the nitro group in the product of condensation of p - nitrobenzoyl chloride with 1-amino-2- or 4-hydroxybenzene- 3-carboxy-5-sulphonic acid # m-toluidine, cresidine, or 2:5 - dimethoxyaniline and 1 mol. of 4-amino-4<SP>1</SP>-hydroxy-azobenzene-3<SP>1</SP>-carboxylic acid or its 2- or 5<SP>1</SP>-methyl derivative or 4 - amino - 3 - methoxy - azobenzene - 3<SP>1</SP> - sulphonic acid, (5) 1 mol. of the product obtained by reduction of the nitro group in the product of condensation of p-nitrobenzoyl chloride with 1-amino-4-hydroxybenzene-3-carboxy - 5 - sulphonic acid # cresidine and 1 mol. of 4 - amino - 4<SP>1</SP> - hydroxy - azobenzene - 3<SP>1</SP> - carboxylic acid or its 2 - methyl derivative, (6) 1 mol. of the product obtained by reduction of the nitro group in the product of condensation of m- or p-nitrobenzoyl chloride with 1 - amino - 2 - hydroxybenzene - 3 - carboxy - 5 - sulphonic acid # cresidine or aniline and 1 mol. of 4-amino-4<SP>1</SP>-hydroxyazobenzene-3<SP>1</SP>-carboxylic acid or its 2-methyl derivative. An example is also given of the process of dyeing cotton with one of the dyestuffs with subsequent addition to the dyebath of copper sulphate and sodium tartrate and heating for ¢ hour at 95‹C. to obtain a fast shade. The dyeing of a mixed fabric of wool and viscose artificial silk staple fibres is advantageously effected in a neutral bath in presence of sodium or potassium chromate.