Process for the preparation of binary .alpha.-methylstyrene/acrylonitrile resins by multi-stage bulk polymerization

US4795780A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Frank Wingler · Leverkusen, DE
• Klaus Summermann · Cologne, DE
• Gerd Wassmuth · Leverkusen, DE
• Alfred Pischtschan · Gundelsheim, DE
• Joachim Doring · Cologne, DE

Key dates

• Filing date: Jul 20, 1987
• Grant date: Jan 3, 1989
• Expiry date: Jul 20, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F220/44
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Process for the preparation of thermoplastic copolymers of .alpha.-methylstyrene and acrylonitrile by continuous bulk copolymerization of PA1 A. 30 to 50 mol % of .alpha.-methylstyrene and PA1 B. 70 to 50 mol % of acrylonitrile at temperatures from 60.degree. to 120.degree. C. with average residence times of 4 to 12 hours in the presence of initiators which supply free radicals, carried out in at least two continuously operated mixed tank reactors, characterized in that 100 molar parts of a monomer mixture of PA1 A.sub.0. 34 to 52 mol % of .alpha.-methylstyrene and PA1 B.sub.0. 66 to 48 mol % of acrylonitrile are fed continuously into the first tank reactor per unit time, and, with back-mixing, are copolymerized up to a conversion of 5 to 30 molar parts to give a copolymer of the composition PA1 A.sub.1. 49 to 53 mol % of .alpha.-methylstyrene and PA1 B.sub.1. 51 to 47 mol % of acrylonitrile, and the mixture consisting of 70 to 95 molar parts of the monomers A and B and 5 to 30 molar parts of the copolymer of the composition A.sub.1 -B.sub.1 is transferred continuously to the second tank reactor and is polymerized there up at a further conversion of 5 to 55 molar parts to a total c…