| 摘要 |
<p>of the disclosure: There is disclosed a process for preparing impact resistant styrene graft copolymers having improved properties, especially an excellent combination of toughness, hardness and gloss. They are obtained by polymerizing a solution of an ethylene-propylene-tercomponent rubber in a mixture of styrene and acrylonitrile in one step (mass polymerization) or two steps (mass/suspension polymerization) in the presence of an organic peroxide and subjecting the copolymer obtained to a shear extrusion yielding rubber particles with an average size below 1 .mu.m and thereafter crosslinking said rubber particles, care being taken that an amount of 0.02 to 0.5 weight % of a cross-linking initiator is present when cross-linking starts.</p> |
