Patent ID: 6165399
Filing Date: 2000-12-26
Classification: B29B,B29C,C08J,C08L

Abstract:
A process for the preparation of toughened thermoplastics or polymer blends containing toughened thermoplastics, the thermoplastics or the polymer blends comprisingA) from 5 to 95% by weight of at least one water-moist elastomer component A containing up to 60% by weight of residual water,B) from 5 to 95% by weight of at least one thermoplastic polymer B,C) from 0 to 95% by weight of at least one further polymer C, andD) from 0 to 70% by weight of additives D,by mixing the elastomer component A with the thermoplastic polymer B and, if present, the further polymer C and, if present, the additives D in an extruder with mechanical dewatering of the elastomer component A, whereinthe components A, B, C and D are fed to an extruder which has at least two screws rotating in the same direction or in opposite directions and having a screw diameter D.sub.Screw, and, in the conveying direction, the extruder being essentially composed ofat least one metering section into which elastomer component A is fed to the extruder by a metering device,at least one squeeze section which serves for dewatering the elastomer component A and contains at least a first retarding element and at least one dewatering orifice which is present upstream of the first retarding element by a distance corresponding to at least one screw diameter D.sub.Screw,at least one feed section in which the thermoplastic polymer B is introduced as a melt into the extruder,at least one plastication section provided with mixing or kneading elements,at least a last devolatilization section which is provided with at least one devolatilization orifice and in which the remaining water is removed as steam, anda discharge zone,wherein some or all of the water emerging from the dewatering orifices is present in the liquid phase,wherein the components C and/or D are fed to the extruder together or separately from one another, either together with the components A and/or B or separately from A and B andwherein the screws of the extruder have a flight depth ratio D.sub.Screw, external /D.sub.Screw, internal of from 1.2 to 1.8.