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:
Sep. 20, 1994
Filed:
Jun. 01, 1993
Applicant:
Inventors:
Assignee:
Idemitsu Petrochemical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528200 ; 528196 ; 528198 ; 526 62 ;
Abstract
A polycarbonate having desirable color tone or transparency, as well as desirable heat resistance and water resistance, in which the amounts of residual metals in the polycarbonate are 10 ppm or less in total of Fe, Cr and Mo and 50 ppm or less in total of Ni and Cr. The polycarbonate is obtained by transesterification of (A) a dihydroxy compound and (B) a carbonic diester in a reactor made of a metallic material containing at least one metal selected from the group consisting of Fe, Cr, Mo, Ni and Cu, and controlling the water content in the reactor to 500 ppm or less.