THERMOPLASTIC POLYURETHANES AND THEIR USE

摘要

A thermoplastic polyurethane is provided to improve surface resistance and industrial processing possibility and to prevent the generation of surface defect in case of processing. A thermoplastic polyurethane is manufactured by reacting (a) at least one kind of organic diisocyanate; (b) a chain extender comprising at least one kind of low molecular weight polyol having 1.8-3.0 Zerewitinoff-active hydrogen atoms on average and a number average molecular weight Mn of 60 ~ 400 g/mole; and (c) at least one kind of polyol component having 1.8-3.0 Zerewitinoff-active hydrogen atoms on average and a number average molecular weight Mn of 450 ~ 10,000 g/mole (wherein the ratio of the number of isocyanate groups of (a) to the number of isocyanate reactive groups of (b) and (c) is 0.9:1 ~ 1.1:1); in the presence of (d) 0.4 ~ 10 weight% of a mixture of polyorganosiloxane represented by (R2SiO)n to the thermoplastic polyurethane (wherein R are independently a linear or branched organic hydrocarbon radical containing 1-27 carbon atoms, and n is an integer of 3 ~ 6000).