Patent ID: 6506846
Filing Date: 2003-01-14
Classification: C08F

Abstract:
A process for preparing impact-modified thermoplastic molding compositions which comprise a soft phase made from a rubber dispersed in a hard matrix composed of vinylaromatic monomers, wherein, in a first step, a diene rubber is polymerized in the presence of an organometallic compound of an alkali metal, until the content of residual butadiene is less than 200 ppm, and in a second step, vinylaromatic monomers are polymerized by anionic polymerization in the presence of the diene rubber, wherein the anionic polymerization of the vinylaromatic monomers is initiated by the addition of an organometallic compound of magnesium, aluminum or mixtures thereof, and optionally by further addition of an organometallic compound of an alkali metal.