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. 04, 1990
Filed:
Sep. 13, 1988
Yoshiro Hirose, Fussa, JP;
Takeshi Sakamoto, Akishima, JP;
Masahisa Kosaka, Itsukaichi, JP;
Mitsuo Sugimura, Hamura, JP;
Kazuo Inoue, Fussa, JP;
Eiichi Yajima, Fuchu, JP;
Kunio Sasaki, Akishima, JP;
Hoya Corporation, Tokyo, JP;
Abstract
A polyurethane lens is produced by (a) adding to a monomer mixture comprising a polyisocyanate and a polythiol, a phosphoric acid ester represented by the general formula (I) ##STR1## (R.sub.1 and R.sub.2 which may be the same or different are each an alkyl group of 1-8 carbon atoms) and then (b) subjecting the monomer mixture containing the phosphoric acid ester, obtained in the step (a) to cast polymerization in a mold for plastic lens production. Said polyurethane lens has good releasability from mold, is free from color unevenness after tinting and cloudiness, and possesses high refractive index (N.sub.D) and high optical dispersion.