The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 1978
Filed:
Dec. 11, 1975
Dieter Neuray, Rumeln-Kandenhausen, DE;
Hugo Vernaleken, Krefeld-Bockum, DE;
Claus Wulff, Krefeld, DE;
Ralf Lange, Krefeld, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
The present invention is concerned with a process for the production of high molecular weight thermoplastic ppolycarbonates having improved flame resistance and in conjunction with glass fibres, improved mechanical properties and the polycarbonates so produced. A solution polycarbonate is reacted with an alkali metal salt soluble in the melt of the polycarbonate until the Staudinger Index has increased by about 3 to 30 cm.sup.3 /g. This usually requires about 0.0001 to 0.1 wt. % of the salt, based on the weight of polycarbonate and a temperature of about 250.degree. to 400.degree. C for between about 1 and 30 minutes. In a preferred embodiment the reaction is conducted in a self-cleaning twin screw extruder.