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, 2007
Filed:
Mar. 20, 2003
Robert W. Walters, County of Westmoreland, PA (US);
Anil Kumar, County of Allegheny, PA (US);
Clara E. Nelson, County of Allegheny, PA (US);
Anu Chopra, County of Allegheny, PA (US);
Robert W. Walters, County of Westmoreland, PA (US);
Anil Kumar, County of Allegheny, PA (US);
Clara E. Nelson, County of Allegheny, PA (US);
Anu Chopra, County of Allegheny, PA (US);
Transitions Optical, Inc., Pinellas Park, FL (US);
Abstract
Described are photochromic materials of indeno [2',3′:3,4]naphtho[1,2-b]pyran structure, characterized in that they have a nitrogen or sulfur containing substituent at the 11-position ring atom, are substantially free of spiro-substituents at the 13-position and have been adapted to provide an increase in the sensitivity, visible lambda max or a combination thereof as measured in the Indenonaphthopyran Photochromic Performance Test. Optional substituents can be present at the other positions of the indeno [2′,3′:3,4]naphtho [1,2-b]pyran structure. Also described are naphthols used to produce the photochromic materials and photochromic articles that contain or that have coatings containing at least one of the novel photochromic materials or combinations thereof with other photochromic materials.