GB586549A - Improvements in or relating to the chemical modification of organic textile and other materials - Google Patents

Abstract

Textile and other materials having a basis of substances consisting of long chain molecules containing hydroxy, thio, amino or other groups reactive with the isocyano or isothiocyano radical are caused to react with organic di- or poly-isocyanates or isothiocyanates. The treatment of materials of resinous condensation products of formaldehyde with an amide or phenol or of synthetic linear polyamides is excluded. The treatment of cellulose derivative materials, soluble in organic solvents, with di- or poly-isocyanates is also excluded. Textile filaments or yarns or films, foils, or other moulded articles may be treated. They may be of cotton, regenerated cellulose, acetone-soluble cellulose acetate or other incompletely esterified or etherified cellulose derivative, polyvinyl alcohol or a partially esterified or acetalised derivative thereof, polymethacrylic acid, alginic acid, casein, natural silk or wool. Wool in which the disulphide cross-linkages have been broken down to thiol groups may be subjected to the treatment. Tetra-, hexa-and octa-methylene di-isocyanates and di-isothiocyanates, and pentane - 1,3,5 - tri - iso - cyanate may be used. Meta- and paraphenylene - di - isocyanates and di - isothio - cyanates, the 4,41-di-isocyanate of diphenyl, adipyl di-isocyanate, 4,41-di-isocyanate of didiphenyl methane, and 4,41,411 - tri - isocyanotriphenyl-methane are also specified. The treatment is believed to result in the formation of cross-linkages between long molecular chains through radicals containing a plurality of -Y.CX.NH- groups, Y being = N-, -NH-, -S-, -O-, or a direct linkage, and X being -S- or -O-. The treatment reduces or removes the solubility of cellulose acetate yarns and other materials in organic solvents and increases the melting point and heat resistance. The affinity for dyes is modified. The treatment increases the hydrophobic character of the materials and raises the ratio of the wet to the dry strength. The treatment may be effected by impregnating the materials, e.g. yarns in hank or fabric form, with the reagent and then heating to effect the desired reaction. The reagent may be applied in solution in a non-solvent liquid. The heating may be effected at 110-130 DEG C. Materials of regenerated cellulose and alginic acid may be rendered more receptive to the reagent by first wetting them with water, replacing the water by benzene or other inert organic solvent, removing the solvent and then applying the reagent. Alternatively, when treating these materials, pyridine may be used as a solvent for the reagent. In examples, hanked cotton yarn, regenerated cellulose yarn from stretched and saponified cellulose acetate yarn, wool yarn, viscose yarn and cellulose acetate yarn are rendered water-repellent by treatment with octamethylene-and hexamethylene-di-isocyanate or di-isothiocyanate.