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:
Jun. 27, 1995
Filed:
Sep. 24, 1993
Hans-Ulrich Borst, Elsdorf, DE;
Lothar Endres, Bergisch Gladbach, DE;
Hans hlschlager, Bergisch Gladbach, DE;
Agfa-Gevaert AG, Leverkusen, DE;
Abstract
Emulsions having an improved sensitivity/grain ratio are obtained when a silver halide emulsion containing up to 20 mol % of AgI is prepared by the precipitation of a silver halide emulsion A containing up to 100 mol % of AgI and the addition of a silver halide emulsion B which contains up to 40 mol % of AgI, has an average grain size of at most 0.25 .mu.m and is always more soluble in aqueous gelatine solution than emulsion A either due to its grain size or due to its iodide content, this being carried out in the presence of at least two compounds selected from imidazole, histidine (.alpha.-amino-.beta.-imidazolyl-(5)-propionic acid) and other monocyclic, 5- or 6-membered heterocyclic compounds which have at least one ring nitrogen atom, are free from SH groups and form sparingly soluble silver salts in weak acid to neutral aqueous solutions, which salts redissolve at pH>9 when ammonia is added, one of the at least two compounds being imidazole or histidine and at least one other compound being a compound other than imidazole or histidine.