GB956509A - Stretchable fabrics - Google Patents

Abstract

Breathable fabrics having a high covering power are produced by treating a normally stretchable fabric with an emulsion comprising a minor proportion by weight of water and a major proportion by weight of a solution of a normally tacky polyurethane resin intermediate reaction product which is a polyester-diisocyanate or polyether-diisocyanate reaction product in an organic solvent for the resin so that each yarn of the fabric becomes coated with the emulsion, curing the coated fabric and then stretching it to break the polymeric webs between the yarns of the fabric. Circular knit, tricot knit and woven fabrics made from cotton, wool, linen, nylon, polyester, polyacrylonitrile, polyurea or polyurethane fibres may be treated, those made from bulked or textured filaments, such as yarn sold under the Registered Trade Mark "Helanca", being preferred. Suitable polyesters used in preparing the polyurethanes are those having molecular weights between 1500 and 5000 formed from glycols, e.g. ethylene glycol, diethylene glycol, triethylene glycol, decamethylene glycol and 1,12-octadecamediol, and dicarboxylic acids, e.g. adipic, succinic, glutaric, pimelic, suberic, azelaic, sebacic, malonic, isophthalic, hexahydroterephthalic and p.phenylene-diacetic acid, and suitable polyethers are those having the formula H(OR)nOH in which R is a hydrocarbon radical and n is an integer sufficiently high to give the product a molecular weight of 500-5000. The diisocyanate used to prepare the polyurethane may be hexamethylene diisocyanate, a toluene diisocyanate, a naphthalene diisocyanate or p,p1-diphenyl-methane diisocyanate. The organic solvent used to prepare the emulsion may be 1,1,1-trichloroethane, carbon tetrachloride, chloroform or other halogenated hydrocarbon or an ether. The fabric may be cured by heating to 50-200 DEG C. and may be stretched by from 5-70% to break the polymeric webs between the yarns of the fabric.