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:
Nov. 09, 1999
Filed:
Jul. 22, 1998
Robert A Smith, Murrysville, PA (US);
Christopher D Selvig, Pittsburgh, PA (US);
PPG Industries Ohio, Inc., Cleveland, OH (US);
Abstract
A method of preparing photochromic materials useful for optical applications, and photochromic materials prepared by such method, are described. Such method comprises polymerizing a blend of a polyol[(meth)acryloyl terminated carbonate] monomer and a photochromic amount of an organic photochromic substance, thereby forming a photochromic material. A preferred polyol[(meth)acryloyl terminated carbonate] monomer is diethylene glycol bis[(methacryloyloxy)ethylene carbonate]. Polymerization may be performed by free radical initiation using thermal initiators, photoinitiators or a combination of such initiators. Photochromic materials prepared by such method may be used in optical applications, e.g., photochromic lenses.