| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat-sensitive original plate for lithographic printing plate, which can perform printing by directly being installed on a printing machine without a post-exposure treatment, with which the pollution of a laser exposure device and of a light source by flying abrasion work-up is prevented from developing, which is excellent in a hardness to be tinted during printing and the plate wearability of which is improved. SOLUTION: In this heat sensitive original plate for lithographic printing plate, (1) an ink accepting layer, (2) a hydrophilic layer including the colloidal particle-like oxide or hydroxide of at least one element selected from the group consisting of beryllium, magnesium, aluminum, silicon, titanium, boron, germanium, tin, zirconium, iron, vanadium, antimony and transition metal and (3) a hydrophilic over-coating layer removable as the plate is installed on the printing machine are provided in the order named on a support. Further, the dry spread of the ink accepting layer is less than 0.5 g/m<2> and the center-line surface roughness Ra of the surface of the ink accepting layer is 0.4 to 0.65 μm. |
