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:
Dec. 23, 1986
Filed:
Apr. 10, 1985
Mituhiko Masumoto, Osaka, JP;
Shigeo Yanada, Osaka, JP;
Toshiaki Izumida, Hyogo, JP;
Kazuyuki Akahori, Osaka, JP;
Abstract
A transparent optical article is disclosed, which is produced by molding a branched polycarbonate resin having a viscosity average molecular weight of from 13,000 to 20,000 as prepared from at least one dihydric phenol compound in the presence of a polyfunctional organic compound having at least two phenolic hydroxyl groups as a branching agent in an amount of from 0.02 to 3 mol % based on the total amount of the dihydric phenol compound. The transparent molded optical article includes digital audio discs, video discs, memory discs and lenses used in the optical reading system. The optical article is greatly reduced in double refraction and has a high mechanical strength.