Patent GB-479490-A (GB)
Title: Improvements in the dyeing of textile materials
Filed: 1936-08-05
Abstract: Cellulose esters or ethers, dyeing; azo dyes, forming on the material.--In the colouration of textile materials in package form made of or containing cellulose esters or ethers by applying thereto a diazotizable amine and a coupling component and forming an azo dye from these components upon the materials, at least one of the components is applied by passing through the package a solution thereof in an organic liquid, preferably one of boiling point below 150 DEG  C.  Specified liquids are petrol, benzene, toluene, xylene, carbon tetrachloride, per-, di- and tri-chlorethylenes, methyl, ethyl, propyl and butyl alcohols and ethyl, propyl and isopropyl acetates.  Mixtures of such liquids may be used (cf. Specification 460,575) e.g. liquids such as ethyl acetate or acetone, having a good solvent power for the dyestuff components may be incorporated in liquids having a limited solvent power therefor and organic bases, e.g. pyridine or trimethylbenzylammonium hydroxide may be present. Specified diazo components are m- and p-nitranilines, 5 : 2- and 3 : 4-nitroaminotoluenes, 5 : 2-, 4 : 2- and 3 : 4-nitroaminoanisoles, o-anisidine, 2- and 3-chloranilines, 2 : 5-dichloraniline, 4-, 5- and 6-chloro-2-aminotoluenes, 1- and 2-naphthylamines, aminoazobenzene, o-aminoazotoluene, 2-ethoxy- and 2-methoxy-benzene-azo-1-naphthylamine, p-aminobenzene - azo - dimethylaniline, p - aminobenzene-azo-1-naphthylamine, benzidine, dianisidine, 4 : 4<1>-diaminodiphenylamine, 1-aminoanthraquinone and its derivatives described in Specifications 396,412, 396,429, 396,430, and 396,431.  Specified coupling components are (a) as amine components, p-xylidine, p-cresidine, m-toluidine, alkyl-, aryl- and aralkyl-anilines, 1- and 2-naphthylamines and 1-naphthylamine-2-alkyl ethers, (b) as enolic components, phenol, cresols, resorcinol, 2-naphthol, 2 : 3-hydroxynaphthoic acid, aminophenols, alkyl- and aryl-aminophenols, e.g. m-hydroxydiphenylamine, arylides of 2 : 3- and 1 : 4-hydroxynaphthoic acids, arylides of o-hydroxycarboxylic acids of carbazole or anthracene, 1-phenyl-3-methyl-5-pyrazolone, arylides of acetoacetic and benzoylacetic acids, e.g. diacetoacetyl-o-tolidine.  In examples, (1) a solution at 70 DEG  C. of 5-nitro-2-aminotoluene and the m-nitranilide of 2 : 3-hydroxynaphthoic acid in a mixture of petrol and ethyl acetate is circulated through bobbins of cellulose acetate yarn wound with a quick traverse, the bobbins are washed with cold petrol and quickly dried by blowing warm air through them, diazotization is effected by circulating through them a solution at 18 DEG  C. containing sodium nitrite and acetic acid and, after washing with water, coupling is effected by circulating through them for \ba1/2\be hour a dilute sodium carbonate solution gradually heated to 80 DEG  C., whereupon the bobbins are rinsed and dried to obtain a fast red dyeing; if the diazo and coupling components are replaced by p-aminobenzene-azo-a -naphthylamine and 2 : 3-hydroxynaphthoic acid respectively, in which case coupling may be effected in acetic acid solution, the dyeing is navy blue or black; (2) a solution at 70 DEG  C. of 1-amino-4-(p-aminophenyl)-aminoanthraquinone in a mixture of petrol and ethyl acetate is circulated through bobbins of cellulose acetate yarn similarly wound, the bobbins are washed with cold petrol and quickly dried and the yarn is then treated for \ba1/4\be hour with an aqueous solution at 15 DEG  C. containing sodium nitrite and acetic acid, washed with cold water, treated with an aqueous solution containing phenol and sodium carbonate for 10 minutes in the cold and then for 30 minutes with heating to 70 DEG  C., washed with water and scoured with a hot soap solution to obtain a dark green dyeing, fast to rubbing, light and laundering; (3) the diazo component in (2) is replaced by m-nitroaniline to obtain a pale straw-coloured dyeing.