Thermoplastic polymer blends useful for prodn. of mouldings, etc. - contain thermoplastic polyurethane obtd. from di:isocyanate, short-chain extender and high mol.wt. cpd. contg. hydroxy or amino gps., opt. fillers or fibres, etc.

摘要

Thermoplastic polymer blends (I) contain (A) 90-40% thermoplastic polyurethane (TPU) obtd. by reaction of (a) not above 50 wt.% di-isocyanate (Aa), (b) short-chain chain-extender(s) (Ab), esp. a diol with mol. wt. at least 63 (pref. 76-399) and (c) a high-mol. wt. OH or amino gp.-contg. cpd. (Ac), pref. with mol.wt. 600-6000; (B) at least 10-60 (pref. 20-50)% thermoplastic aromatic polyester with mol.wt. at least 20,000-100,000 (pref. 25,000-60,000) (with wt. ratio A:B = (90:10)-(40:60)); opt. (C) other thermoplastic component(s) other than polycarbonate (with wt. ratio (A+B):C = (95:5)-(50:50)); opt. (D) normal additives other than vulcanisation aids and opt. (E) fillers and/or fibres. The amt. of component (Ac) is 30-80 wt.% w.r.t. total (Aa-Ac), and the ratio (NCO gps. in Aa):(NCO-reactive gps. in Ab and Ac) = 0.9-1.1. More specifically, (B) is a terephthalate ester, esp. PBT or a polyester obtd. by reaction of terephthalic acid or a deriv. with a short-chain diol and a high-mol. wt. hydroxy cpd., pref. with mol.wt. 600-6000; (Aa) is 4,4'-MDI contg. not above 5 wt.% of the 2,4' isomer, (Ab) is a polyalcohol, polyamine or aminoalcohol with mol. wt. as above and (Ac) is a polyester-diol with mol. wt. 600-6000; (C) is ABS, SAN, polyamide or polystyrene; (I) contains, as component (E), up to 50 wt.% (in)organic fibre and/or other inorganic fillers such as mica or talcum, pref. 10-40 wt.% PU-coated glass fibres; components (Aa-Ac) are injected into a twin-screw kneader at a first feed point, and component (B) (and opt. C and E) is added to the incompletely reacted TPU at a subsequent feed pt. USE/ADVANTAGE - (I) are useful for the prodn. of film, coatings, mouldings, and composites TPU-polyester blends with improved tear resistance, oil and petrol resistance and cold impact strength, high thermal dimensional stability, improved resistance to hot air ageing, low tendency to yellowing and improved high-temp. compression set are prepd. blends (I) are easily processable, even with Shore Hardness D below 72.