Patent GB-435171-A (GB)
Title: Improvements in or relating to the colouring of materials
IPC: D06P1/12
Filed: 1933-12-08
Abstract: Azo dyes, forming on the material; printing.--In the production of azo dyestuffs on textile fibres by processes in which the development of the colour is effected by treatment with an acid hydrolyzing agent, the material is treated immediately before or during the hydrolysis with a strong solution of an inert salt. Specified salts are chlorides or sulphates of the alkali metals, aluminium or zinc, chlorides of the alkaline earth metals and sodium phosphates.  The process is applicable to material impregnated or printed with the coupling component and with a diazo component in the form either of a diazoamino compound obtainable by coupling a diazo salt with a secondary amine or in the form of a nitrosamine alkali metal salt. The dyeings are of exceptional brightness and especially fast to light and washing. The following examples are specified.  (1) Cotton piece goods are printed with an aqueous paste containing the diazoamino compound from diazotized 4-chloro-2-toluidine and methylglucamine, turkey red oil, the o-toluidide of 2 : 3-oxynaphthoic acid, caustic soda and a thickener and the printed goods are dried, immersed for 20 seconds in an aqueous solution at 220 DEG  F. containing 1,0 per cent of acetic acid, 0,5 per cent of formic acid and 28 per cent of sodium chloride, rinsed, treated with a hot soap solution, again rinsed and dried to obtain a bright red pattern.  (2) A brilliant orange pattern is similarly obtained using as diazoamino compound that from diazotized m-aminobenzotrifluoride and ethylxylamine and as coupling component the o-anisidide of 2 : 3-oxynaphthoic acid.  (3) A yellow pattern is similarly obtained using the diazoamino compound from diazotized 2 : 5-dichloraniline and diethanolamine and as coupling component diacetoacetyltolidine. (4) Cotton piece goods are printed with an aqueous paste containing the bis-diazoamino compound from tetrazotized dianisidine and sarcosin, turkey red oil, the anilide of 2 : 3-oxynaphthoic acid, caustic soda and a thickener and the printed goods are immersed in a cold saturated sodium chloride solution, exposed to the action of steam carrying acetic acid vapour, washed, soaped, rinsed and dried to obtain a bright blue pattern.  (5) Cotton piece goods are impregnated with an aqueous paste containing the diazoamino compound from diazotized p-toluene-azo-2 5-dimethoxyaniline and proline, turkey red oil, the o-toluidide of 2 3-oxynaphthoic acid, caustic soda and a thickener and the impregnated goods are immersed in an aqueous solution at 60 DEG  F. containing acetic and formic acids and sodium chloride as in (1), passed over a metal roll heated to 220 DEG F., washed, soaped, rinsed and dried to obtain a deep blue-black dyeing.  (6) Cotton piece goods are printed with an aqueous paste containing the diazoamino compound from diazotized 2 : 5-diethoxy-4-benzoylaminoaniline and nipecotinic acid, the o - toluidide of 2 : 3 - oxyanthracenecarboxylic acid, caustic soda and a thickener and the printed goods are dried, immersed in a cold acid sodium chloride solution as in (5), subjected to the action of live steam, washed, soaped, rinsed and dried to obtain a green pattern. (7) Cotton piece goods are printed with an aqueous paste containing the diazoamino compound from diazotized 4<1>-ethoxy-4-aminodiphenylamine and benzyltaurine, turkey red oil, the anilide of 2 : 3-oxynaphthoic acid, caustic soda and a thickener and the printed goods are dried, immersed for about 30 seconds in a boiling saturated potassium chloride solution containing 2 per cent of acetic acid, washed, soaped, rinsed and dried to obtain a fast navy blue print.  (8) Cotton piece goods are printed with an aqueous paste containing the diazoamino compound from diazotized 1 - aminoanthraquinone and monoethyl - o - toluidine-4-sulphonic acid, turkey red oil, the anilide of 2 : 3-oxynaphthoic acid, caustic soda and a thickener and the printed goods are dried, immersed for 1 minute in a boiling saturated sodium sulphate solution containing acetic and formic acids, washed, soaped, rinsed and dried to obtain a bright red pattern. (9) Cotton piece goods are impregnated with an aqueous paste containing the diazoamino compound from diazotized 1-naphthylamine and 1 - methylaminonaphthalene - 2 : 4 - disulphonic acid, the anilide of 7-oxy-8-carboxy-a -naphthocarbazole, caustic soda and a thickener and the impregnated goods are immersed in a saturated potassium chloride solution, treated with steam containing formic acid vapour, washed, soaped, rinsed and dried to obtain a uniform black dyeing.  (10) Cotton piece goods are printed over the whole surface with an aqueous paste containing the diazoamino compound from diazotized m-nitro-p-toluidine and p-toluidine-w-methanesulphonic acid, the o-toluidide of 2-oxycarbazole-3-carboxylic acid, caustic soda and a thickener, and the printed goods are further treated as in (1) to obtain a brown dyeing.  The diazoamino compounds used may be any of the general formula Ar--N = N--R in which Ar is an aromatic residue of the benzene, naphthalene, diphenyl, diphenylamine, anthraquinone or carbazole series free from solubilizing groups such as sulphonic or carboxylic groups and carrying, if desired, substituents such as alkyl, alkoxy, halogen, nitro, trifluoromethyl or acylamino groups and R is the residue of a secondary amine containing at least one solubilizing group such as a sulphonic, carboxylic or hydroxyl group. In general, the coupling components may be the arylides of 2 : 3-oxynaphthoic acid, oxycarbazole-, oxynaphthocarbazole- and oxyanthracene-carboxylic acids, a  or b -naphthol, acylaceto derivatives of aromatic amines, 2-methylindole and arylmethylpyrazolones.  In an example of the use of a nitrosamine, cotton goods are printed with an aqueous paste containing a nitrosaminealkali metal salt of p-nitraniline, the anilide of 2 : 3-oxynaphthoic acid, sodium ricinoleate, caustic soda and tragacanth thickening and the printed goods are immersed in a boiling saturated sodium chloride solution containing acetic acid, rinsed, soaped, rinsed and dried to obtain a fast red pattern.  Additional acid substances specified for use in the development are citric, tartaric, oxalic and monochloracetic acids, sodium dihydrogen phosphate, potassium hydrogen oxalate and sodium hydrogen sulphate.