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:
Jan. 22, 2008
Filed:
Mar. 20, 2003
Anil Kumar, Allegheny County, PA (US);
Barry Van Gemert, Westmoreland County, PA (US);
Forrest R. Blackburn, Allegheny County, PA (US);
Clara E. Nelson, Allegheny County, PA (US);
Anil Kumar, Allegheny County, PA (US);
Barry Van Gemert, Westmoreland County, PA (US);
Forrest R. Blackburn, Allegheny County, PA (US);
Clara E. Nelson, Allegheny County, PA (US);
PPG Industries Ohio, Inc., Cleveland, OH (US);
Abstract
Described are photochromic articles that include a substrate, a temperature dependent reducing amount of at least one organic photochromic material (b) that changes from more absorbing to less absorbing of radiation in its activating spectral absorbance as the temperature increases from 10° C. to 35° C. and at least one other photochromic material (c) that is different from photochromic material (b). In the article, photochromic material (b) is interposed between photochromic material (c) and a source of activating radiation. The photochromic article demonstrates a more consistent photochromic response, for example, an optical density response loss of 50 percent or less over a temperature range of from 10° C. to 35° C. as measured in the Photochromic Temperature Dependence Test. Methods for producing the aforedescribed articles are also disclosed.