GB653698A - Improvements relating to the development of colour on sheet materials such as textiles - Google Patents

Abstract

653,698. Multicolour decoration. CALICO PRINTERS' ASSOCIATION, Ltd., ISHERWOOD, F., and MILLER, W. S. July 14, 1948, No. 18894. [Class 98 (ii)] Sheet material such as textile fabrics or paper is provided with a multicolour design with avoidance of registration difficulties caused by dimensional changes of the material in washing it between production of the several colours, by sensitizing the material with a composition to produce a dye on light-exposure, exposing to light in selected areas as by use of a stencil, and treating with a desensitizer, the cycle of operations being repeated for each further colour required, the material being fixed as regards dimensions as in a frame by means of pins, or by use of frictional forces, pressure, suction, adhesive, by stiffening the material or by use of a stentor, on or after application of the first sensitizer, without washing the material before the last exposure. Sensitizers may comprise sulphuric esters of leuco vat dyes, diazo compounds used with coupling components, or in the case of the last of the cycles, alkali chromates by use of which a dye can be fixed to the material after it is washed; and may be applied as by spraying or brushing in aqueous or aqueous-solvent solution which may contain hygroscopic agents or catalysts for fixing colours. Usually the desensitizer consists of, or is incorporated with, the sensitizer applied for the next colour. In example (1) cotton cambric is padded with aqueous sodium salt of 4.4<SP>1</SP>-dimethyl-6.6<SP>1</SP>-dichloro-thioindigo, stretched on a frame and fixed with pins, dried, exposed through a red separation negative, sprayed with an aqueous alkaline solution containing 2- sodium diazo-sulpho-4-chloro-toluene and diaceto-acetic-o-tolidide which serves as red desensitizer and yellow sensitizer, exposed through the yellow printer, sprayed with aqueous sodium chromate, hydroxide, thiosulphate and sulphite, dried, exposed through the blue printer, removed from the frame, rinsed, soaped, boiled, dyed with chromazurine G and again soaped and rinsed, to show a colour picture. In example 2 a viscose taffeta cloth is treated by a similar series of operations with the sodium salt of the disulphuric ester of leuco 5.7-51.71-tetrabromo-indigo containing copper acetate as catalyst for the blue colour, alkaline 2-hydroxy-3-naphthoic-2.4-dimethoxy- 5-chloranilide and 2-sodium diazo-sulpho-6- chlorotoluene for red, and chromate treatment with dyeing by Persian Berry extract for yellow. Three further examples specify similar colour-producing cycles.