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:
Feb. 22, 1977
Filed:
Dec. 09, 1974
Applicant:
Inventors:
Manfred Becker, Leverkusen, DT;
Roswitha Ullrich, Burscheid, DT;
Assignee:
AGFA-Gevaert A.G., Leverkusen, DT;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03C / ;
U.S. Cl.
CPC ...
96 663 ;
Abstract
A black and white developer solution containing o- or p-N-(2-hydroxyethyl)aminophenol as developer substance and a piperazine derivative of the formula ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 denotes substituents as described hereinafter capable of developing a certain quantity of film e.g. 10 roll films per liter successively to substantially constant gamma values.