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:
Sep. 20, 2016
Filed:
Sep. 06, 2013
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Hiroyuki Okada, Osaka, JP;
Hiroshi Horikoshi, Chiba, JP;
Eiji Koshiishi, Chiba, JP;
Teruo Kamura, Chiba, JP;
MITSUBISHI GAS CHEMICAL COMPANY, INC., Tokyo, JP;
Abstract
A composition for an optical material includes (a) a compound having two β-epithiopropyl groups and having a specific structure, (b) a compound having one β-epithiopropyl group and one glycidyl group and having a specific structure, (c) polyisocyanate and (d) polythiol, enables the prevention of the occurrence of such a defect that peeling traces linger on a lens. In the composition for an optical material, an embodiment in which (e) sulfur is additionally contained is preferred. Another embodiment of the present invention is a method for producing an optical material, characterized by adding an onium salt as a polymerization catalyst to the composition for an optical material in an amount of 0.0001 to 10% by mass relative to the total amount of the compound (a), the compound (b), polyisocyanate (c) and polythiol (d) and then polymerizing and curing the resultant mixture.