GB664993A - Improvements in or relating to cellulosic textile materials - Google Patents

Abstract

Cellulosic textile materials are rendered crease-resistant by impregnating with (a) a melamine-formaldehyde composition, which is at least partly soluble in water, comprising one or more methylol melamines or alkylated methylol melamines, and (b) a film-forming, water-insoluble thermoplastic polymerization product of one or more alkyl acrylates in which the alkyl group contains not more than 5 carbon atoms, with or without one or more monomers containing a CH2: C: group. From 1 to 3 parts of product (b) are used for each part of product (a), and (a) is cured in contact with (b) to a water-insoluble state, the amount of (a) and (b) used being such that the finished textile contains from 8-40 per cent by weight of impregnating composition. Di-, tri-, tetra-, penta- or hexamethylol melamine, or methylated methylol melamines may be used. The thermoplastic polymerization product may be polymerized methyl, ethyl, propyl, tert.-butyl or amyl acrylate or copolymers of these acrylates with monovinyl compounds such as vinyl acetate, propionate and butyrate; monovinyl substituted cyclic compounds such as styrene, mono-and dimethyl-styrenes, halogenated styrenes, cyano styrenes and a -p-dimethyl styrene; vinyl pyridines, vinyl thiophenes, vinyl fluorenes and vinyl and vinylidene halides; acrylic acid and its amides, for example acrylamide, N-methyl acrylamide and N-diethyl acrylamide; acrylonitrile; alkacrylic compounds such as methacrylic and ethacrylic acids, methacrylamide and ethacrylamide, methacrylonitrile and ethacrylonitrile; methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl and amyl methacrylates and ethacrylates; allyl and methallyl esters such as the acetates, propionates and laurates; and 1,3-butadiene and similar compounds. Preferred copolymers are those of ethyl acrylate and styrene or acrylonitrile. The curing of the melamine-formaldehyde or similar reaction product may be accelerated by addition of a catalyst such as oxalic, acetic or phosphoric acid, diammonium hydrogen phosphate, ethyl ammonium phosphate, diammonium phthalate and ammonium or zinc chloride. Textile materials which may be treated are cotton, linen, hemp, jute, ramie, sisal, regenerated cellulose, cellulose acetate or acetate-butyrate rayons, saponified acetate rayons, viscose rayons, cuprammonium rayons and ethyl cellulose, or mixtures of such materials. Mercerized cotton cloth is especially mentioned. In one example an aqueous impregnating bath is prepared containing 10 per cent of methylated methylol melamine, 20 per cent of a thermoplastic polymerization product and 0.35 per cent of a mixture of diammonium hydrogen phosphate and hexamethylene tetramine. The fabric is soaked in this bath and then squeezed through a padder so that 90 per cent of the liquid (by weight of the dry fabric) is retained by the fabric. The fabric is then heated for 6 minutes at 290 DEG F. and the dried and cured textile washed in an aqueous solution containing 0.1 per cent soap and 0.1 per cent sodium bicarbonate, rinsed in water and dried. Cotton percale and mercerized cotton twill may be treated in this way, using as the thermoplastic polymerization product various additives such as a copolymer of 70 per cent ethyl acrylate and 30 per cent styrene, a copolymer of 90 per cent ethyl acrylate and 10 per cent acrylonitrile, or a copolymer of 79 per cent ethyl acrylate and 21 per cent a -para-dimethylstyrene. The Specification as open to inspection under Sect. 91 refers also to the use as the thermoplastic polymerization product of polymers or copolymers of the monomeric compounds mentioned above. This subject-matter does not appear in the Specification as accepted.