Flatting agents for thermoplastic polyurethane elastomers - comprise non-polar homo- or co-polyolefin(s) which are incompatible with the elastomers and provide improved anti-blocking properties

摘要

Largely non-polar homo- or co-polyolefins (I) which are incompatible with thermoplastic polyurethane elastomers (TPU) are useful as flatting agents for TPU elastomers (II). (I) comprise homo- or co-polystyrene, EPDM rubber, PE, PP and mixts. of at least 2 or these, pref. impact copolystyrene (esp. SB copolymer contg. not above 25 wt.% butadiene), or ethylene/propylene/dicyclopentadiene and/or ethylene/propylene/ ethylidenenorbornene rubber. Amt. of (I) is more than 5-20 pts. wt. per 100 pts.wt. TPU. (I) is used as a concentrate contg. up to 30 wt.% thermoplastic elastomer and at least 70 wt.% (I). (II) are thermoplastic polyether- or polyester-urethane elastomers, pref. obtd. by reaction of high-mol. wt. polyesterdiol(s) or polyoxytetramethylene glycol (PTMG) with 4,4'-MDI and 1,4-butanediol by the strip or extruder process. USE/ADVANTAGE - Enables the prodn. of matt, non-reflecting TPU surfaces (as required, e.g. for cable and film prodn.) with improved non-blocking properties, without adversely affecting the mechanical properties of the TPU.