Mitsubishi Paper Mills Limited

Euji Kanada

Yoshikazu Takaya

Hiroshi Nishinoiri

Masahiko Saikawa

There is provided a method for making a lithographic printing plate having high sensitivity, resolving power and printing endurance and free from scumming utilizing silver complex diffusion transfer process which comprises subjecting to scanning exposure of high-intensity short-time a light sensitive material comprising a support and, provided thereon, at least a silver halide emulsion layer and a physical development nuclei layer as a surface layer and then developing it with a silver complex diffusion transfer developer, the improvement which comprises subjecting the light sensitive material to imagewise exposure with scanning light of at least 700 nm, said emulsion layer containing silver halide grains mainly composed of silver chloride and a sensitizing dye having a sensitivity maximum in the long wavelength region of at least 700 nm in an amount of 3.times.10.sup.-5 -3.times.10.sup.-4 mol for 1 mol of silver halide and an antihalation means being provided below said emulsion layer to provide a reflectance of 13-40% for the scanning exposure light of at least 700 nm.

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Nagaokakyo, Japan

Euji Kanada