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. 07, 1998
Filed:
Mar. 14, 1996
Katsushige Hayashi, Ibaraki, JP;
Tsutomu Kawakami, Ibaraki, JP;
Yuji Takeda, Ibaraki, JP;
Katuhiro Iura, Ibaraki, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A method of producing a polycarbonate excellent in the hue, the thermal stability, and the electrolysis stability by supplying a polycarbonate obtained by a transesterification method to an extruder having vent(s), melting the polycarbonate, and adding an acidic compound to the molten polycarbonate followed by kneading to continuously devolatilize low molecular weight compounds remaining in the polycarbonate. Better result is obtained by adding water to the kneaded mixture of the polycarbonate and the acidic compound before devolatilizing the low molecular weight compounds.