Process for the preparation of tetramethylated bisphenol polycarbonates

US4316980A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Karsten-Josef Idel · Krefeld, DE
• Volker Serini · Krefeld, DE
• Dieter Freitag · Krefeld, DE
• Gerd Fengler · Krefeld, DE

Key dates

• Filing date: Jan 14, 1980
• Grant date: Feb 23, 1982
• Expiry date: Jan 14, 2000

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G64/24
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the preparation of thermoplastic, aromatic polycarbonates which contain structural units of the formulae 1 and/or 2 ##STR1## in which R denotes C.sub.1 -C.sub.3 -alkyl, preferably CH.sub.3, and PA1 X denotes a single bond, C.sub.1 -C.sub.5 -alkylene, C.sub.2 -C.sub.5 -alkylidene, cyclohexylene, cyclohexylidene, --O-- or --S--.