| 摘要 |
PURPOSE:To largely improve printing durability of a plate with high ink accepting property and no surface staining by incorporating a specified mesoion compd. into a diffusion transfer treating liquid. CONSTITUTION:A planographic printing plate is obtd. from a photosensitive member having a silver halide emulsion layer and a physical developing core layer on a supporting body by silver complex salt diffusion transfer method using a diffusion transfer treating liquid. The diffusion transfer treating liquid incorporates a mesoion compd. expressed by formula I as a silver halide chelating agent. In formula, R1 and R2 are alkyl groups, cycloalkyl groups or heterocyclic groups. R2 may be hydrpogen atom. Y is -O-, -S-, or -N(R3)-, wherein R3 is an alkyl group, amino group, or sulfamoil amino group. R1 and R2, or R2 and R3 may be coupled with each other to form a ring. The mesoion compd. expressed by formula I is added by 1X10<-5>mol/1 to 10mol/1 to the treating liquid. |
