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. 13, 2001
Filed:
Mar. 02, 2001
Applicant:
Inventors:
Assignee:
Optische Werke G. Rodenstock, Munich, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ; G02B 5/23 ; C08K 5/15 ;
U.S. Cl.
CPC ...
C07D / ; C07D / ; C07D / ; G02B 5/23 ; C08K 5/15 ;
Abstract
The present invention relates to specific photochromic 3H-naphtho[2,1-b]pyran derivatives and to their use in plastics of all types, especially for ophthalmic purposes. In particular, the present invention relates to spiro compounds derived from naphthopyrans and having a fluorene structure, referred to as spirofluorenopyrans, in which an annelated ring system is joined by a spiro bond to the central carbon atom of the fluorene structure.