| 摘要 |
PURPOSE:To improve stroage stability by using a specified compd. as a fogging agent in a silver halide photographic element having an emulsion layer and forming a positive type image. CONSTITUTION:A compd. to be used as a fogging agent in a hydrophilic colloid for composing an emulsion layer is represented by the formula shown here in which R1 is H, alkyl, cycloalkyl, aryl, or heterocyclic, and R2, R3 are each H, alkyl, cycloalkyl, or aryl. The fogging agent used in this invention is obtained by the ordinarily known reactions, that is, by reacting thiosemicarbazide or the like with acid anhydride or formic acid or ethyl formate. |
