Dai-ichi Kogyo Seiyaku Co., Ltd.

Sumio Goto

Kazuo Sato

Takeshi Doi

Kazuhiko Ishihara

Akio Watanabe

Masahiro Komori

Tamotu Hamamura

Synthetic fiber-containing fabrics are post-treated by impregnating the fabrics with an aqueous solution or dispersion of a thermally reactive blocked isocyanate group-containing polysaccharide derivative and then baking the impregnated fabrics. The blocked isocyanate group-containing polysaccharide derivative is produced by reacting a hydroxy-alkylated natural polysaccharide with a polyisocyanate compound to form a urethane polymer having at least one free isocyanate group, and then blocking the free isocyanate group with a blocking agent. The hydroxyalkylate natural polysaccharide may be directly reacted with a polyisocyanate compound having at least one blocked isocyanate group.

Post-treatment of synthetic fiber fabrics

A process for improving the abrasion resistance of textile belts without decreasing the flexibility and with a good workability, which comprises applying an aqueous composition comprising a water soluble or dispersible, thermally reactive blocked urethane prepolymer to textile belts, and then subjecting the textile belts to heat treatment, thereby converting the blocked urethane prepolymer into a high molecular weight urethane resin.

Process for improving abrasion resistance of textile belts

A thermally reactive water-soluble urethane prepolymer having a plurality of masked isocyanate groups capable of regenerating free isocyanate groups at an elevated temperature, said urethane prepolymer having the formula: ##STR1## wherein A is an organic bridging group having a valency from 3 to 5,

Thermally reactive water-soluble blocked urethane prepolymer

A hydrophilic and thermoreactive urethane composition having improved properties such as stability in solution, non-tackiness, water resistance and strength and useful in treating and finishing fibrous products prepared by forming a urethane prepolymer containing free isocyanate groups from (a) (1) a compound containing at least 2 active hydrogen atoms, containing an oxyethylene chain, and having a molecular weight of about 200 to 20,000, or (2) a compound containing at least 2 active hydrogen atoms, not containing an oxyethylene chain, and having a molecular weight of about 200 to 20,000 and a compound containing at least 2 active hydrogen atoms, containing an oxyethylene chain and having a molecular weight of about 200 to 200,000; and (b) an excess of a polyisocyanate; and if desired, (c) a chain extender containing at least 2 active hydrogen atoms; whereby the prepolymer has an oxyethylene chain content of 10 to 40% by weight, and then reacting the prepolymer or a solution thereof with not more than 3 times the equivalent of the free isocyanate groups in the prepolymer of an aqueous solution of a bisulfite salt having a concentration of at least 15% by weight. Where the urethane prepolymer contains at least 1% by weight ester groups, the hydrophilic and thermoreactive urethane composition is particularly valuable as a high strength adhesive composition and is useful as an adhesive in bonding a sheet-like material as a top-coat to a fabric as a base in producing an artificial leather.

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Moriyama, Japan

Sumio Goto