Photographically useful chalcogenazoles, chalcogenazolines, and chalcogenazolinium and chalcogenazolium salts

US4576905A · kind A · utility

Assignee

• EASTMAN KODAK COMPANY · US

Inventors

• Wolfgang H. H. Gunther · Hersbruck, DE
• Ronald E. Leone · Rochester, US
• Rosemary Przyklek · Rochester, US

Key dates

• Filing date: Oct 12, 1984
• Grant date: Mar 18, 1986
• Expiry date: Oct 12, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S430/141
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Compounds containing an aromatic ring portion fused with a tellurazolium or derivative tellurazole, tellurazoline (including tellurazolinylidene), or tellurazolinium ring portion are disclosed together with processes and intermediates for their preparation. With properly selected pendant groups these tellurazolium and derivative compounds can be usefully employed as dyes, antifoggants or stabilizers, nucleating agents, latent image keeping addenda, or speed or contrast altering addenda in silver halide photographic systems.