GB541047A - Improvements in the production of coloured textile materials - Google Patents

Abstract

541,047. Dyeing textiles. BRITISH CELANESE, Ltd. May 8, 1940, No. 8257. Convention date, May 10, 1939. [Classes 2 (iii) and 15 (ii)] Pattern effects are obtained upon textile materials, especially such materials made of or containing a cellulose ester or ether, by discharging a ground colour thereon by means of thiourea dioxide or a substitution product thereof, e.g. a dioxide of an N-alkyl-; N-aryl- or N-aralkyl-thiourea. These may be used as such or in the form of their salts, e.g. their calcium, zinc or sodium salts, and other discharge agents, such as sulphoxylates, may also be present. In the application to cellulose ester or ether materials the discharge preparation advantageously contains one or more swelling agents for such materials such as thiocyanates, monoacetin, glycerol formal or thiodiglycol. The preparation may also be buffered by the addition of an acid, e.g. acetic, citric or tartaric acid, or of an alkaline salt, e.g. disodium phosphate or sodium acetate. Coloured discharges are obtainable by incorporating dyes resistant to the action of the thiourea dioxide, e.g. amino-, hydroxy- and mercapto-anthraquinones and their substitution products and vat dyes, e.g. of the Indanthrene series, which, when applied to a mixed material containing a cellulose ester or ether and natural or regenerated cellulose, are preferably used in their leuco form. Specified dischargeable ground colours are Setacyl direct discharge blue G, Setacyl direct yellow 5G, Setacyl direct orange GH, Setacyl direct red GN, Celliton discharge yellow 3GN or GRL, Celliton discharge blue 5G, Celliton discharge red BBL and the disazo dye, formed on the material, by coupling thereon diazotized 4-nitro-4<SP>1</SP>-amino- 3<SP>1</SP>-acetyl-amino-6-methoxy-azo-benzene or its 2-chloro derivative with 3-acetyl-amino- 1-di-(#-hydroxyethyl)-aminobenzene. In examples, (1) a fabric of cellulose acetate yarn, dyed with the dyestuff, 2:4-dinitro-6-chloroaniline#3-acetylamino-6 -methoxy-1-di-(#- hydroxyethyl)-aminobenzene is printed with an aqueous paste containing gum tragacanth, thiourea dioxide, monoacetin and disodium phosphate and the printed material is steamed for 5-20 minutes at 211-212‹ C. and washed to obtain a white pattern on a blue ground ; (2) the discharge paste in (1) is coloured with Indanthrene scarlet B and after the steaming the material is washed, scoured with neutral soap or a salt of an acid sulphate of a higher fatty alcohol and finally oxidized to obtain a scarlet pattern on a blue ground. Thiourea dioride is obtained by the action of hydrogen peroxide on thiourea.