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:
Feb. 05, 1991
Filed:
Apr. 07, 1989
Applicant:
Inventors:
Junichiro Washiyama, Kanagawa, JP;
Motoyuki Hirata, Kanagawa, JP;
Tetsuo Yasuda, Kanagawa, JP;
Shigenobu Ishihara, Kanagawa, JP;
Assignee:
Showa Denko Kabushiki Kaishi, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428 64 ; 428 65 ; 428412 ; 428913 ; 369288 ; 346 / ; 3461351 ; 430945 ;
Abstract
An optical disk substrate is disclosed, which is molded from a terpolymer composed of (A) an aromatic vinyl monomer, (B) cyclohexylmaleimide, and (C) at least one compound selected from the group consisting of (meth)acrylonitrile, isobornyl (meth)acrylate and cyclohexyl (meth)acrylate, with the cyclohexyl maleimide being copolymerized in an amount of from 5 to 60 wt % of said terpolymer. The optical disk substrate exhibits high heat resistance, low water absorption and low birefringence.