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:
May. 16, 1978
Filed:
Jul. 12, 1976
Applicant:
Inventors:
Ichiro Tokumitsu, Tokuyamashi, JA;
Hideo Konuma, Tokuyamashi, JA;
Shigeaki Mochizuki, Tokuyamashi, JA;
Kohichi Morotomi, Tokuyamashi, JA;
Norio Murai, Tokuyamashi, JA;
Mikio Koyama, Tokuyamashi, JA;
Assignee:
Idemitsu Petrochemical Co. Ltd., Tokyo, JA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
260463 ;
Abstract
Polycarbonate oligomer having uniform qualities is prepared by reacting an aqueous alkaline solution of 2,2-(4,4'-dihydroxydiphenyl) propane with phosgene in the presence of methylene chloride and as a characteristic point of this method, in the presence of an inert gas in an amount of 1 to 10 mol % based upon the phosgene.