摘要:
Thermoplastic moulding compositions ofA. 90 to 30 parts by weight of a copolymer prepared by solution or bulk polymerization of a.sub.1 30 to 45% by weight of .alpha.-methylstyrene, a.sub.2 26 to 35% by weight of acrylonitrile and a.sub.3 44 to 20% by weight of styrene and/or p-methylstyrene, and with a content of incorporated acrylonitrile of 27-30% by weight,B. 5 to 60 parts by weight of a random copolymer of b.sub.1 18 to 24% by weight of maleic anhydride and b.sub.2 82 to 76% by weight of styrene and/or p-methylstyrene andC. 5 to 40 parts by weight of a graft polymer of 70 to 30% by weight of a mixture of c.sub.1 a vinylaromatic and/or C.sub.1 -C.sub.4 -alkyl and c.sub.2 acrylonitrile, on 30 to 70% by weight of a rubber with a glass transistion temperature of less than -10.degree. C.
摘要:
Process for the preparation of thermoplastic copolymers of .alpha.-methylstyrene and acrylonitrile by continuous bulk copolymerization ofA. 30 to 50 mol % of .alpha.-methylstyrene andB. 70 to 50 mol % of acrylonitrileat temperatures from 60.degree. to 120.degree. C. with average residence times of 4 to 12 hours in the presence of initiators which supply free radicals, carried out in at least two continuously operated mixed tank reactors, characterized in that 100 molar parts of a monomer mixture ofA.sub.0. 34 to 52 mol % of .alpha.-methylstyrene andB.sub.0. 66 to 48 mol % of acrylonitrileare fed continuously into the first tank reactor per unit time, and, with back-mixing, are copolymerized up to a conversion of 5 to 30 molar parts to give a copolymer of the compositionA.sub.1. 49 to 53 mol % of .alpha.-methylstyrene andB.sub.1. 51 to 47 mol % of acrylonitrile,and the mixture consisting of 70 to 95 molar parts of the monomers A and B and 5 to 30 molar parts of the copolymer of the composition A.sub.1 -B.sub.1 is transferred continuously to the second tank reactor and is polymerized there up at a further conversion of 5 to 55 molar parts to a total conversion of 20 to 60 molar parts to give further copolymer of the compositionA.sub.1. 49 to 53 mol % of .alpha.-methylstyrene andB.sub.1. 51 to 47 mol % of acrylonitrile,0,5 to 11.5 molar parts of acrylonitrile being removed from the vapor condenser of the second tank reactor and recycled to the first tank reactor per unit time.
摘要:
The invention relates to the use of mixtures consisting of 5 to 95% by weight of an aromatic polycarbonate of which the linear chains contain from 0.1 mol-% to 50 mol-% bifunctional structural units corresponding to formula (1) ##STR1## and 95 to 5% by weight of a thermoplastic styrene polymer and, optionally, standard additives as substrates for optical storage media.