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:
Sep. 20, 1977
Filed:
Aug. 13, 1975
Immo Boie, Cologne, DT;
Dieter Lowski, Bergheim Erft, DT;
AGFA-Gevaert, A.G., , DT;
Abstract
Desirable 2-equivalent yellow couplers carry at the coupling position a monocyclic pyrrole, diazole or triazole ring attached to the coupling position of the yellow coupler by a nitrogen atom, which ring can be split off in the coupling reaction. Photographic 2-equivalent yellow couplers with nitrogen-containing heterocyclic splittable groups having such nitrogen bonded to the coupling position of the couplers, are prepared by reacting a corresponding 2-equivalent yellow coupler containing a halogen such as chlorine in the coupling position with the nitrogen-containing heterocyclic compound that supplies the splittable group, in the presence of base and in the further presence of hexamethylphosphoric acid triamide as solvent.