| 摘要 |
PURPOSE:To obtain a direct positive photosensitive material showing sufficient reversibility in a processing solution comparatively low in pH by incorporating a specified heterocyclic quaternary ammonium salt in a photographic emulsion layer or its adjacent hydrophilic colloidal layer. CONSTITUTION:At least one of the photographic emulsion layers or its adjacent hydrophilic colloidal layer contains at least one of the alkynyl-substituted quaternary ammonium salts represented by formula I in which Z is a nonmetallic atomic group necessary to form a 5- or 6-membered hetero ring; R<1> is an aliphatic group; R<2> is H, aryl, or the like; Y is a valency electron-balancing counter ion; n is 1 or 0; and m is 0 or 1. This salt of formula I is added to the photographic sensitive material by dissolving it in water or an organic solvent miscible with water, such as alcohols and ketones, and adding this solution into a hydrophilic colloidal solution, in an amount of approximately 1X10<-6>-1X10<-3>mol per mol of silver halide in the silver halide emulsion layer. |
