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. 19, 1993
Filed:
Feb. 04, 1991
Applicant:
Inventors:
Nicola Casilli, Ravenna, IT;
Luciana Crisci, Sant'Angelo Lodigiano, IT;
Fiorenzo Renzi, Gorgonzola, IT;
Franco Rivetti, Schio, IT;
Assignee:
Enichem Synthesis S.p.A., Palermo, IT;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; F21V / ;
U.S. Cl.
CPC ...
252586 ; 252589 ;
Abstract
A photochromatic composition contains at least two photochromatic compounds, defined by the general formula: ##STR1## wherein the various substituents from R.sub.1 to R.sub.7 and X are as defined in the specification. In such a mixture, at least one photochromatic compound is defined by the general formula, wherein R.sub.7 represents a hydrogen atom, and at least one further compound is also defined by the general formula, wherein R.sub.7 represents an -NR.sub.8 R.sub.9, with R.sub.8 and R.sub.9 having the meaning as defined in the text.