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. 17, 1984
Filed:
Sep. 17, 1982
Applicant:
Inventors:
Stephen R Postle, Brentwood, GB;
Patrick D Thomas, Chelmsford, GB;
Assignee:
Ciba Geigy AG, Basel, CH;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
430566 ; 430959 ;
Abstract
Compounds of the formula ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are hydrogen or alkyl, X represents the atoms to complete an aromatic heterocyclic ring system and Y is hydrogen or the group ##STR2## where X is defined as above, are readily cleaved in alkaline solutions to release a hydroquinone derivative. The compounds can be incorporated into photographic materials used for activation processing.