Patent GB-523304-A (GB)
Title: Improvements in or relating to colouring cellulose ester or ether materials
IPC: C09B31/06
Filed: 1938-12-30
Abstract: 523,304. Dyes. STANLEY, E., ELLIS, G. H., and OLPIN, H. C. Dec. 30, 1938, No. 37863. [Classes 2 (ii), 2 (iii) and 15 (ii)] Cellulose ester or ether textile materials, straws, foils and the like are coloured yellow to orange shades fast to water and to light by forming thereon an azo dye obtainable by coupling a diazotized aminoazo compound of the general formula R<SP>1</SP>-N=N-R 2 -NH 2  with a non-nitrogenous phenolic component of the general formula R 3 OH, wherein R 2  represents a benzene or naphthalene residue, R 1  and R 3  represent aryl residues selected from the group consisting of benzene and naphthalene residues and at least one of the residues R 1 , R  3  comprises two such aryl nuclei united directly or through carbon alone by a single linkage. Alternatively, such an azo dye is incorporated in a cellulose ester or ether solution prior to the shaping and setting of the materials. The residues R 1 , R 2  and R  3  may carry other substituents such as acylamino, alkyl and alkoxy groups but are free from sulphonic, carboxylic and like acid groups. Specified aminoazo compounds are : (a) those obtainable by coupling a diazotized aminodiphenyl, such as 4-aminodiphenyl or its 3- nitro-, 4<SP>1</SP>-chloro-3-nitro-, 4<SP>1</SP>-acetylamino-, 3:3<SP>1</SP>- dimethyl-4'-acetylamino- and 3:3<SP>1</SP>-dimethoxy- 41-acetylamino derivatives, with a primary aromatic amine coupling in p-position to the amino group, such as aniline and o-toluidine (coupled in the form of their formaldehyde bisulphite compounds), m-toluidine, p-xylidine, cresidine, 2:5-dimethoxyaniline, monoacetylm-phenylenediamine, 1-naphthylamine and its 2-ethoxy derivative ; (b) those obtainable by coupling diazotized 4-amino-4<SP>1</SP>-acetylaminodiphenylmethane, 4-amino-41-acetylaminodiphenyldimethylmethane, 4-benzoylaminoaniline, 4-aminodiphenyl ether or 4-aminodiphenyl sulphone with a p-coupling amine as above ; (c) 4-aminoazobenzene and its 2<SP>1</SP>:3-dimethyl-, 2:5:dimethoxy-, 4'-nitro-2-methyl-, 4<SP>1</SP>- nitro-2-methyl-5-methoxy- and 4<SP>1</SP>-nitro-2:5-dimethoxy derivatives, and 4-amino-1:1<SP>1</SP>-azonaphthalene and its nuclear substitution products. Specified phenolic components are phenol, cresols, 2-and-4-hydroxydiphenyls, 4- hydroxydiphenyl-methane, 4-benzoylaminophenol and 2-naphthol. In dyeing mixed textile materials containing a cellulose ester or ether and cotton or regenerated cellulose by applying the aminoazo component and diazotizing and developing with the phenolic component, the cellulosic fibres remain uncoloured and may be dyed with a suitable dyestuff before or after the development of the azo dye and, if such dyestuff is diazotizable, it may be diazotized and developed with the same or a different component. In examples, (1) the dyestuff 4<SP>1</SP>-acetylamino-4-aminodiphenyl # aniline# phenol, is incorporated in a solution of cellulose acetate in acetone which is then spun into bright golden yellow filaments ; (2) a cellulose acetate knit fabric is dyed from a soap bath with the dyestuff 4<SP>1</SP>-acetylamino-4-aminodiphenyl # aniline, and the dyeing is diazotized and developed with an aqueous solution of phenol at 70-75‹C. to obtain a golden yellow shade ; (3) a cellulose acetate knit fabric is dyed from a soap bath with the dyestuff, 4<SP>1</SP>- acetylamino-4-aminodiphenyl # m-toluidine and the dyeing is diazotized and developed to a yellow shade with 4-hydroxydiphenyl or pcresol, dispersed with soap ; (4) cellulose acetate artificial silk is dyed with the dyestuff, 4-benzoylaminoaniline # aniline, and the dyeing is diazotized and developed to a yellow shade with 2-hydroxydiphenyl dispersed with soap. According to the Provisional Specification the diazo components may be applied to the materials from solutions in organic solvents as described in Specification 479,490.