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:
Jan. 16, 1996
Filed:
May. 19, 1995
Applicant:
Inventors:
Takeshi Sakashita, Iwakuni, JP;
Tomoaki Shimoda, Iwakuni, JP;
Kotaro Kishimura, Iwakuni, JP;
Shuichi Uchimura, Otake, JP;
Assignee:
GE Plastics Japan, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528198 ; 528125 ; 528126 ; 528171 ; 528199 ; 528204 ;
Abstract
The present invention relates to a method for preparing copolymeric polycarbonates which comprises melt polycondensing a mixture of an aromatic dihydroxy compound containing an amount of 2-90 mol % of hydroquinone or substituted hydroquinones and a diester carbonate in the presence of a catalyst containing an alkali metal compound or an alkaline earth metal compound in an amount of 1.times.10.sup.-8 to 5.times.10.sup.-6 mole per mole of the total amount of the aromatic dihydroxy compound, then adding an acidic compound to the melt polycondensation product.