Thermoplastic elastomer with high resistance, elasticity and good paintability and high impact resistant polymer blends prepared therefrom

Thermoplastic elastomers with high strength and elasticity combined with good coloring properties are obtained by melt-compounding mixtures of propylene homo- and/or co-polymers and elastomeric olefin co- and/or ter- polymers with diene monomers and radical initiators in presence of auxiliary substances. Thermoplastic elastomers (TPE), with high strength and elasticity and good pigmentability, in which the embedded elastomer has an average particle size of 0.05-5 (preferably 0.1-1) microns, are obtained by reacting, in the melt, mixtures of: (A) 20-80 (preferably 40-60) wt% propylene homo- and/or co-polymers, and (B) 80-20 (preferably 60-40) wt% elastomeric 2-8C olefin co- and/or ter-polymers with (based on total polymer) (C) 0.10-4.0 (preferably 0.2-1.5) wt% volatile 4-7C dienes, and (D) 0-4.0 (preferably 0.2-1.5) wt% acyl peroxides, alkyl peroxides, hydroperoxides, peroxycarbonates, peresters, ketone peroxides, peroxy-ketals and/or azo compounds as radical initiators, with the addition of: (E) 0.01-40 wt% auxiliary substances before and/or after the reaction. Independent claims are also included for: (a) high-impact polymer blends comprising (i) 5-95 (preferably 10-50) wt% TPE as above and (ii) 95-5 (preferably 90-50) wt% of (iia) unmodified polyolefins, preferably isotactic homopolypropylene, copolymers of propylene with ethylene or 4-18C alpha -olefins (especially statistical copolymers, block copolymers and/or statistical block copolymers), non-isotactic homopolypropylene, amorphous polypropylene or non-linear propylene polymers and/or (iib) blends of (iib1) 60-98 wt% crystalline copolymer of 85- 99.5 wt% propylene and 15-0.5 wt% ethylene and/or alpha -olefin of formula H2C=CHR in which, (iib2) 2-40 wt% elastic copolymer of 20-70 wt% ethylene and 80-30 wt% propylene and/or alpha -olefin as above; and (b) the process as above for the production of TPE, carried out in a continuous kneader at 150-300 (preferably 185-245) degrees C with residence times of 1-35 (preferably 2.5-6) minutes. R = 2-8C linear or branched alkyl