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. 17, 2001
Filed:
Jul. 14, 2000
Ralf Wirowski, Köln, DE;
Hans-Ulrich Borst, Elsdorf, DE;
Detlev Kapitza, Köln, DE;
Jörg Siegel, Köln, DE;
Peter Bergthaller, Bergisch Gladbach, DE;
Heinrich Odenwälder, Leverkusen, DE;
Agfa-Gevaert, , BE;
Abstract
The production of tabular silver bromide-iodide emulsions and silver bromide-chloride-iodide emulsions with an aspect ratio,, an iodide content from 1 to 40 mol % and a chloride content from 0 to 20 mol %, by the process steps of (a) silver halide nucleus precipitation, and (b) at least one further precipitation of silver halide, wherein rein at least one aromatic five- or six-membered, heterocyclic compound, which is free from—SH—,—SSO,H— and—SSO,R groups, is added in an amount from 10,to 10,mol/mol silver during nucleus precipitation or during the precipitation of an inner zone of the silver halide grain which is different from the nucleus precipitate, results in an improved speed/grain size ratio and in an increased stability of a photographic material which contains an emulsion produced in this manner.