COMPOSITION FOR THERMOPLASTIC POLYURETHANE RESIN EXCELLENT IN SOLUBILITY, PRODUCTION OF RESIN THEREFROM, AND MOLDED ITEM MADE THEREFROM

摘要

PROBLEM TO BE SOLVED: To obtain a thermoplastic polyurethane excellent in physical properties and solubility in solvents by reacting a specific long-chain polyol with a mixture of 4,4'-diphenylmethane diisocyanate and its isomer. SOLUTION: This compsn. for a thermoplastic polyurethane resin comprises an isocyanate component comprising 50-98wt.% 4,4'-diphenylmethane diisocyanate and 50-2wt.% its isomer and a long-chain polyol having a hydroxyl value of 50-150mgKOH/g in a molar ratio of NCO/OH of 0.85-1.15. Pellets and thermally molded items are obtd. from the compsn. The isocyanate component may contain another isocyanate. The polyol may be a polyester polyol, a polyether polyol, or an another-type polyol and pref. has a mol.wt. of 850-5,000. The compsn. may futher contain a chain extender such as ethylene glycol. A polyurethane resin obtd. from the compsn. can be used not only for molded items but also as solns. for adhesives or coating materials.