| 摘要 |
PURPOSE:To improve sensitization rate and to prevent stains due to remaining dyes, by sensitizing an emulsion with a dimethine dye having pyrazolo[1,5-a] pyrazine ring. CONSTITUTION:A direct positive type photographic emulsion is sensitized with a die characterized by combining the 3-position of the pyrazolo-[1,5-a]pyrazine ring with the 1,2,3,4, or 9-position of an N-contg. hetero ring through a dimethine chain, represented by the shown general formula in which R0 is alkyl, alkoxyalkyl, carboxyalkyl, sulfoalkyl, or the like; R1-R3 are each H, alkyl, alkoxy, amino, cyclic amino, or the like, and R2 and R3 may form a benzene ring together with each other; and Z is an atomic group necessary to complete a 5- or 6-membered N- contg. hetero ring, such as oxazoline, oxazole, thiazole, or selenazole. |
