IMPACT MODIFIED THERMOPLASTIC POLYURETHANE MOLDING COMPOSITIONS, A PROCESS FOR THEIR PREPARATION AND THEIR USE

摘要

IMPACT MODIFIED THERMOPLASTIC POLYURETHANE MOLDING COMPOSITIONS, A PROCESS FOR THEIR PREPARATION AND THEIR USE The subject of the instant invention is impact modified thermoplastic polyurethane molding compositions, comprising: A) 70 to 99 parts by weight of at least one thermoplastic polyurethane elastomer (A); B) 1 to 30 parts by weight of at least one graft polymer (B), comprising: B1) an elastomer (B1) serving as a grafting basis having a glass temperature less than -40.degree. C; and, B2) a grafting basis (B2) prepared in one or two steps, comprising; .alpha.-methylstyrene and acrylonitrile; or .alpha.methylstyrene, styrene, and acrylonitrile; whereby in grafting basis (B2); i) the amount of .alpha.-methylstyrene units polymerized in situ is greater than the styrene units, ii) the weight ratio of the .alpha.-methylstyrene units or .alpha.methylstyrene styrene units polymerized in situ to the acrylonitrile units is from 60:40 to 90:10; and, iii) the grafting degree lies between 15 and 30, the parts by weight of (A) and (B) total 100 parts by weight, C) 0 to 60 weight percent of at least one additive, based on the weight of (A) and (B). , .. . .. .. . .. . .. .