Thermoplastic molding materials based on special graft rubber components

US6828380B2 · kind B2 · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Liqing-Lee Sun · Irvine, US
• Eckhard Wenz · Neunburg vorm Wald, DE
• Herbert Eichenauer · Dormagen, DE
• Stefan Moss · Haan, DE
• Heinrich Alberts
• Hans-Bernhard Hauertmann · Dormagen, DE
• Karl Zabrocki · Waldbröl, DE
• Hans-Erich Gasche · Odenthal, DE
• Ulrich Jansen · Düsseldorf, DE

Key dates

• Filing date: Nov 21, 2002
• Grant date: Dec 7, 2004
• Expiry date: Dec 22, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08L55/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A molding composition having good surface gloss, high elongation at break and good thermoplastic processability is disclosed. The composition contains (A) a graft polymer that is obtained by free-radical polymerization of resin-forming vinyl monomers in the presence of rubber in latex form, (B) a copolymer of styrene and acrylonitrile and an optional (C) a resin selected from the group consisting of polycarbonates, polyester-carbonates, polyesters and polyamides. The preparation of the graft polymer is characterized in that (i) before the start of the grafting polymerization reaction the rubber latex is brought to a pH of 9 to 11, (ii) the redox initiator components are employed in amounts of 0.1 to 2.5 wt. % (based on the monomers metered in) and (iii) during the entire grafting polymerization reaction the pH remains constant±0.5 and in the range of 11.0 to 8.8, and (iv) the temperature difference between the start and end of the reaction is at least 10° C.