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:
Mar. 13, 2001
Filed:
Mar. 16, 1999
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
A process for producing a resin used for preparing an optical material. The process comprises curing a composition comprising an ultraviolet light absorbent and an epithio compound by polymerization in the presence of a catalyst, wherein the ultraviolet light absorbent and the catalyst are in amounts, each expressed as parts by weight per 100 parts by weight of the total amount of the epithio compound, which satisfy both of the following relationships (a) and (b): (a) 0.001≦ultraviolet light absorbent≦1,000, and (b) 0.001≦catalyst≦5,000. The process prevents coloration and clouding of optical material for a lens obtained by polymerization of an epithio compound caused by addition of an ultraviolet light absorbent.