Multi-stage process for producing heat resistant dimensionally stable polymethacrylate moulding compounds

US6214942A · kind A · utility

Assignee

• Roehm GmbH · DE

Inventors

• Werner Siol · Pfungstadt, DE
• Heinz Vetter · Weiterstadt, DE
• Michael Wicker · Seeheim-Jugenheim, DE

Key dates

• Filing date: Sep 14, 1998
• Grant date: Apr 10, 2001
• Expiry date: Sep 14, 2018

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2333/12
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention concerns a process for producing polymethacrylate moulding compounds, which have high thermal dimensional stability and high stability with respect to thermal decomposition, by the radical polymerization of methylmethacrylate monomers and optionally comonomers in at least two reactors operated successively, ensuring a high degree of blending. The process is characterized in that: a) a first reactor is operated at a temperature of less than 120.degree. C.; and b) a second reactor or further successive reactors is/are operated in a temperature range of more than 130.degree. C. and at most 200.degree. C.