Direct-positive silver halide emulsions having incorporated developers

US4026708A · kind A · utility

Assignee

• Agfa-Gevaert NV · BE

Inventors

• Willy Joseph Vanassche · Aartselaar, BE
• Robert J. Pollet · Vremde, BE
• Jozef Frans Willems · Wilrijk, BE
• Antoon L. Vandenberghe · Hove, BE
• Jules Robert Berendsen · Deurne, BE
• Herman Alberik Pattyn · Kapellen, BE

Key dates

• Filing date: Feb 21, 1975
• Grant date: May 31, 1977
• Expiry date: Feb 21, 1995

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/141
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Direct-positive emulsions are described comprising incorporated developing agents wherein the developing agents are 1,4-dihydroxybenzene compounds of which at least one of the hydroxyl groups has been esterified to form a hydrolyzable aliphatic acyloxy group comprising a quaternary ammonium group.