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. 13, 1999
Filed:
Sep. 24, 1997
Applicant:
Inventors:
Keigo Nishihira, Ube, JP;
Shuji Tanaka, Ube, JP;
Katsumasa Harada, Ube, JP;
Ryoji Sugise, Ube, JP;
Akinori Shiotani, Ichihara, JP;
Katsutoshi Washio, Ichihara, JP;
Assignee:
UBE Industries, Ltd., Ube, JP;
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528196 ; 560190 ;
Abstract
A diaryl carbonate is produced by decarbonylating a diaryl oxalate, which can be prepared by transesterification of a dialkyl oxalate with a hydroxyaryl compound, in the presence of a catalyst, while removing the resultant carbon monoxide as a by-product, and then optionally refined by an evaporation and/or distillation, and then the resultant diaryl carbonate is condensation-polymerized with a polyhydroxyl compound, while recovering a resultant hydroxyaryl compound from the reaction system, to produce a polycarbonate.