Patent · US Expired

Photographically useful chalcogenazoles, chalcogenazolines, and chalcogenazolinium and chalcogenazolium salts

US4874866A · kind A · utility

3Cited by

12References

45Claims

0Family size

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 3, 1985
Grant date	Oct 17, 1989
Priority date	—
Expiry date	Oct 3, 2005

Classification

Technology area (CPC G)Physics
CPC primaryG03G5/09
WIPO fieldOptics
WIPO sectorInstruments

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 derivatives 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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.