BIS-QUATERNARY PYRIDINE SALTS AS ANTIFOGGING STABILIZING AGENT OF SILVERHALIDE PHOTOGRAPHIC EMULSIONS SENSIBILIZED WITH CARBOCYANINE DYES AND METHOD OF SENSITIZATION OF SILVERHALIDE EMULSIONS WITH THEIR USE Russian patent published in 2002 - IPC

FIELD: organic chemistry. SUBSTANCE: invention describes bis-quaternary pyridine salt (I) where A is (CH₂)_m; m = 0-8; (CH₂OCH₂)_n; n = 0-2; R is lower alkyl; X is a residue of indicated formula where Y is NH, O which are used as an antifogging stabilizing agent of silverhalide photographic emulsions and method of sensitization of silverhalide photographic emulsions with their use. Compounds (I) containing carbocyanine dyes of anionic or cationic-anionic structure or their compositions and supersensitizing agent ensure to enhance or retain the level of photosensitivity at decrease of fog optical level or in retention of permissible fog level (D_O ≤ 0.20) in the molar ratio of supersensitizing agent to compound (I) = 1:(0.05-0.4). EFFECT: improved method of sensitizing, valuable photographic properties of compounds. 2 cl, 2 tbl, 13 ex