GB1062564A - Process for modifying the characteristics of structures containing keratin fibres and product thereof - Google Patents

Abstract

Structures containing keratin fibres are shrinkproofed and permanent configurations and mechanical effects, e.g. pleating, crimping and calendering, are set therein by reacting them with a polyfunctional isocyanate compound containing at least two groups which are isocyanate or isothiocyanate groups and a polymeric polyhydroxy compound which is a polyether polyol containing more than one ether linkage and having terminal hydroxy groups. The isocyanate compounds and the polymeric polyhydroxy compound may be reacted together to an extent below which a gel is produced which is insoluble in a non-reactive organic solvent to form a prepolymer and the prepolymer then applied to the fibres. The isocyanate compound may be an aryl, alicyclic or alkylene diisocyanate or diisothiocyanate and suitable polymeric polyhydroxy compounds are polyalkylene ether glycols, polyalkylenearyleneether-thioether glycols and polyalkylene ether p triols. The isocyanate compound and polymeric polyhydroxy compound or prepolymer thereof may be applied to the fibres as a solution in a non-reactive organic solvent e.g. a halogenated hydrocarbon, an aromatic hydrocarbon, n-butyl acetate ether or phosphate p-dioxane, ethyl oxalate, methyl isobutyl ketone pyridine, quinoline, N, N-dimethyl-formamide or-acetamide or 2, 2, 4-trimethyl pentane by padding, immersing or spraying or from applicator rolls, or as aqueous emulsions or dispersions when the isocyanate groups are blocked by reaction with tertiary alcohols, secondary aromatic amines which contain only one group having a hydrogen atom reactive with the isocyanate group, mercaptans, lactams, imides, monohydric phenols or compounds containing enolizable hydrogen. The treating solution may also contain a catalyst and a co-reactant containing at least two -OH, -NH2, -NRH, -COOH or SH groups or the coreactant may be applied from a separate solution. Numerous examples of suitable isocyanate compounds, polymeric polyhydroxy compounds, catalysts, coreactants and isocyanate group blocking compounds are given. After impregnation the fibres may be dried and cured by heating to 220 DEG - 260 DEG F, aged for 12-24 hours, scoured and dyed with premetallized or acid dyes. During the impregnation the fibres and solutions are preferably maintained at a pH value of 3-9. Fabrics comprising wool alone or in admixture with synthetic polyamide, polyester, acrylic, cellulose acetate, viscose rayon or cotton fibres may be treated. Other suitable keratin fibres are mohair, alpaca, cashmere, vicuna, guanaco, camel hair and llama. In inserting a desired configuration, e.g. pleat, in a fabric, the fabric may be impregnated, arranged in the configuration and cured. Alternatively the fabric may be impregnated, dried, made into garments, pressed to the desired configuration and cured. Reference is also made to crimped yarns and crimped stretch fabrics. Crimped yarn may be obtained by knitting a yarn, impregnating, curing and unravelling the knitted fabric.