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:
Apr. 17, 2001
Filed:
Nov. 27, 1998
Applicant:
Inventor:
Keishin Handa, Kanagawa, JP;
Assignee:
Mitsubishi Chemical Corporation, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
B32B 7/02 ;
U.S. Cl.
CPC ...
B32B 7/02 ;
Abstract
The essence of the present invention lies in an optical sheet made of transparent resin having a visible light transmittance of not less than 80%, a glass transition temperature of not lower than 150° C. and a thickness of from 0.2 to 1.5 mm, which exhibits a birefringence index of not higher than 15 nm, a surface roughness Ra of not more than 0.1 &mgr;m and an impact strength of not less than 600 gf·cm as calculated in terms of dropping ball breakdown energy determined by Du Pont process impact resistance test.