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. 05, 1993
Filed:
Jan. 10, 1991
Walter Fischer, Reinach, CH;
Evelyn Fischer, Weil am Rhein, DE;
Ernst Minder, Sissach, CH;
Manfred Hofmann, Marly, CH;
Jurgen Finter, Freiburg, DE;
Heinz Spahni, Frenkendorf, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
Compounds of formula I or V, or mixtures thereof, ##STR1## wherein R is unsubstituted C.sub.6 -C.sub.14 aryl or C.sub.6 -C.sub.14 aryl which is substituted by C.sub.1 -C.sub.12 alkyl, C.sub.1 -C.sub.12 alkoxy, C.sub.1 -C.sub.12 alkylthiol, phenyl, benzyl, --CN,--CF.sub.3, halogen or --COOR.sub.5, and R.sub.5 is H, C.sub.1 -C.sub.18 alkyl, cyclohexyl, cyclopentyl, phenyl, C.sub.1 -C.sub.12 alkylphenyl, benzyl or C.sub.1 -C.sub.12 alkylbenzyl, and at least one of the substituents R.sub.1 to R.sub.4 is an organic thiol, sulfoxyl or sulfonyl group, and the other members R.sub.1 to R.sub.4 are H, F, Cl or Br, are reversible photochromic systems which can be used for contrast formation or light absorption.