| 摘要 |
PURPOSE:To obtain an offset press plate capable of being photoengraved by a simple apparatus without necessitating a light source and development treatment, by a method wherein a specific wax-containing layer is provided on a water resistant support and the surface thereof is subjected to thermal printing by thermal head. CONSTITUTION:On a water resistant support such as paper, a film or synthetic paper subjected to water resistance imparting treatment, a layer containing wax with a m.p. of 60-180 deg.C and a particle size of 0.1-10mum, a hydrophilic binder and a pigment is provided and the surface thereof is printed under heating by a thermal head to obtain an image part. The wax of the thermally printed part is melted and the surface of a press plate becomes oleophilic and comes to an ink receivable surface. On the other hand, because the wax of a non-image part is covered with the hydrophilic binder, said non-image part shows hydrophilicity and functions as the water holding surface of damping water in printing. |
