Impact resistant thermoplastic rubber particulate mixt. - prepd. by presence of adhesion promoting polymer for processing by injection moulding or extrusion

摘要

An impact resistant thermoplastic polymer mixt. is prepd. by: (a) mixing rubber particles dispersed in a matrix of an irradiation resistant thermoplastic in the presence of a cpd. that promotes adhesion of the particles in the matrix; (b) solidifying the mixt.; and (c) irradiating the mixt. either before or after solidification. The thermoplastic polymer mixt. comprises: (i) 50-95 pts.wt. of polystyrene or a copolymer of styrene and acrylonitrile or maleic anhydride as matrix, (ii) 50-5 pts.wt. of a particulate, at least partially crosslinked rubber phase of av. particle size 0.1-1.0 microns chosen from polybutadiene, butadiene-acrylonitrile copolymer, butadiene-styrene copolymer, acrylate rubber, butyl rubber, EVA copolymer, ethylene-propylene copolymer, chlorinated polyethylene and/or EP copolymer contg. other copolymerised polyunsatd. monomer and (iii) 0.5-10 pts.wt. adhesion promoting polymer comprising portions soluble in the matrix or rubber phases. An impact resistant polymer compsn. consisting of 10-90 pts.wt. of the above polymer mixt. and 90-10 pts. wt. polyphenylene oxide is also claimed.