Preparation of photographic silver halide emulsions

US4057429A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Luc A. De Brabandere · Lier, BE
• Robert J. Pollet · Vremde, BE
• Herman Alberik Pattyn · Kapellen, BE
• Hendrik Alfons Borginon · Mortsel, BE

Key dates

• Filing date: Mar 12, 1976
• Grant date: Nov 8, 1977
• Expiry date: Mar 12, 1996

Classification

• Technology area (CPC G): Physics
• CPC primary: G03C1/09
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

In the preparation of silver halide emulsions silver halide grain-growth is accelerated by the addition to the precipitation medium during or before silver halide precipitation of a compound of the formula ##STR1## wherein: N IS AN INTEGER FROM 1 TO 5 PA1 R.sup.1 is C.sub.1 -C.sub.5 alkyl or substituted alkyl PA1 R.sup.2 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, or a carboxylic acyl group PA1 R.sup.3 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl, and PA1 R.sup.4 is hydrogen or C.sub.1 -C.sub.5 alkyl or substituted alkyl group, aryl or substituted aryl or a salt-forming cation.