Thermoplastische Formmassen mit geringer Vergelbungsneigung

摘要

Thermoplastic moulding materials with reduced tendency to yellowing are obtained by (i) polymerising a monomer mixture A which contains (in relation to A): (a1) 1 to 100 % by weight acrylonitrile and (a2) 0 to 99 % by weight of one or several monomers which can be copolymerised with acrylonitrile, in the presence of 0.01 to 5 % by weight (in relation to the monomer mixture A), of an additive B which contains: (b1) at least one compound containing at least one silicon-hydrogen bond ("silyl hydrides"); (b2) orthocarbonates, orthocarboxylic acid esters or orthosilicates ("ortho compounds"), or mixtures of said ortho compounds; or (b3) mixtures of silyl hydrides (b1) and ortho compounds (b2); or by (ii) adding 0.01 to 5 % by weight (in relation to the monomer mixture A) of additive B when subsequently processing the polymers which correspond to the monomer mixture A.