Patent ID: 6197915
Filing Date: 2001-03-06
Classification: C08G,D01F,Y10S

Abstract:
A thermoplastic polyurethane obtained by reacting;[1] a polyol composition (A) which consists essentially of a polyester-polyol (A-1) having a crystallization enthalpy of at most 70 J/g and a number-average molecular weight of from 1000 to 5000 and a polyether-polyol (A-2) having a number-average molecular weight of from 500 to 2500, and in which the average number, f, of the functional hydroxyl groups existing therein and represented by the following formula (I):f={number of all hydroxyl groups in the polyols constituting the polyol composition}/{number of molecules of all polyols constituting the polyol composition} (I),falls between 2.006 and 2.100,[2] an organic diisocyanate (B), and[3] a chain extender (C),at a ratio that satisfies the following formula (II):1.00.ltoreq.b/(a+c).ltoreq.1.10 (II)wherein a indicates the number of moles of all polyols constituting the polyol composition (A), b indicates the number of moles of the organic diisocyanate (B), and c indicates the number of moles of the chain extender (C).