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:
Jul. 14, 1992
Filed:
Jan. 30, 1991
Applicant:
Inventor:
Reinhold Ruger, Rodermark, DE;
Assignee:
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
564151 ;
Abstract
Photographic silver halide elements containing aryl hydrazides as defined for the production of images with ultrahigh contrast and a new class of aryl hydrazides with a cationic group in the aryl radical as defined. The photographic silver halide elements can be developed at relatively low pH values and have low fog and low tendency to form black spots in unexposed or slightly exposed areas.