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:
May. 05, 1992
Filed:
Jan. 10, 1991
Douglas S McBain, Norton, OH (US);
John C Crano, Akron, OH (US);
PPG Industries, Inc., Pittsburgh, PA (US);
Abstract
A photochromic article having improved pohotochromic equilibrium response is described. In particular, a phtochromic compound is incorporation into or applied to an article, e.g., matrix, of a synthetic organic resin prepared from a composition comprising from about 55 to about 90 weight percent of a polyol(allyl carbonate), e.g., diethylene glycol bis(allyl carbonate), from about 10 to about 40 weight percent of an aliphatic polyurethane having terminal ethylenic unsaturation, e.g., an aliphatic polyesterurethane diacrylate, and from about 0 to about 5 weight percent of a difunctional monomer selected from the group consisting of allyl methacrylate and allyl acrylate. Such photochromic articles have an improved photochromic equilibrium response at ambient temperatures compared to the response of a comparable photochromic article prepared from a polyol(allyl carbonate) homopolymer, e.g., homopolymers of diethylene glycol bis(allyl carbonate), at the same ambient temperatures.