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:
Aug. 28, 1979
Filed:
Dec. 23, 1974
Donald R Uhlmann, Newton, MA (US);
Elias Snitzer, Wellesley, MA (US);
Richard J Hovey, Sturbridge, MA (US);
Nori Y Chu, Southbridge, MA (US);
Joseph T Fournier, Jr, Storrs, CT (US);
American Optical Corporation, Southbridge, MA (US);
Abstract
Organic photochromic materials comprising a photochromic dye and a resinous material can be stabilized with a protective coating which will protect them from deactivation by exposure to moisture, oxygen, various plastic host materials, reactive chemicals or even normal atmospheric conditions. Useful organic photochromic dyes include the spiropyrans, the spirooxazines, the metal dithizonates, the phenazines, the phenothiazines and other known photochromic compositions. Useful resinous materials include vinyl-type thermoplastics, cellulosic materials, polyesters, epoxy resins and aminoplast resins. The encapsulated photochromic materials of the invention comprise an organic photochromic dye in combination with an organic resinous material enclosed within an outer shell of an inorganic material and find use in the preparation of photochromic plastic films, sheets, ophthalmic lenses such as lenses for sunglasses and in camera lenses and filters.