Process for producing thermoplastic resins

摘要

A process is claimed for the prodn. of impact-modified thermoplastics (I) by mixing a moist elastomer component (A) contg. up to 60 wt% residual water with a thermoplastic polymer (B) and other polymers (C) and additives (D) in a screw machine, with mechanical dehydration of component (A). The process is carried out in a synchronous twin screw extruder with the following sequence of sections in the direction of feed: (1) metering section(s) for introducing component (A) into the extruder by means of a metering device, (2) squeezing section(s) for removing the water, with accumulator element(s) and associated water outlet(s), (3) section(s) in which polymer (B) is added as a melt, (4) section(s) fitted with mixing, kneading and/or other plasticising elements, (5) degassing section(s) with gas outlets, in which residual water is removed as vapour, and (7) a discharge zone. The water emerging from the outlets in section (2) is partly or completely in the liq. phase; components (C) and/or (D) are added in one or more of the above sections, either together or separately and together with or apart from (A) and/or (B). Also claimed are impact-modified thermoplastic moulding materials (I) obtd. by this process.