Silver halide recording material

US5667956A · kind A · utility

Assignee

• Agfa NV · BE

Inventors

• Michael Missfeldt · Leichlingen, DE
• Johannes Willsau · Leverkusen, DE
• Ralf Buscher · Lohmar, DE
• Peter Bell · Neunburg vorm Wald, DE
• Hans-Ulrich Borst · Elsdorf, DE

Key dates

• Filing date: Aug 19, 1996
• Grant date: Sep 16, 1997
• Expiry date: Aug 19, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C1/06
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

The grain/sensitivity ratio of a photographic silver halide material may be improved by adding a compound of the formula I to one of its layers. The material moreover exhibits a low increase in fog on storage. ##STR1## in which: Y.sub.1, Y.sub.2, Y.sub.3 each mean one of the following residues ##STR2## R.sub.1 to R.sub.34 mean H, alkyl or aryl; two residues (R.sub.1 to R.sub.34) located on the same N atom may complete a 5-, 6- or greater-membered ring containing at least one N atom and optionally further heteroatoms; two residues (R.sub.1 to R.sub.34) located on adjacent N atoms may complete a ring involving both N atoms and at least one P atom; PA1 X.sup.- means an anion required to balance the charge, for example Cl.sup.-, Br.sup.- or tosylate (TosO.sup.-).