| 摘要 |
PURPOSE:To permit exposure of a negative and plate material without using a vacuum device and the easy discrimination of a latent image by naked eyes in the exposing stage by using a photosensitive resin layer contg. a dye which is faded in color by active radiations and form the color again in the developing stage and having surface tackiness. CONSTITUTION:This plate material consists of a base, the photosensitive layer and film-like protective layer. The photosensitive layer is formed by uniformly compounding the dye which is faded in color by the active radiations in UV to visible parts and forms the color again in the developing stage with a compsn. consisting of a polymer having rubber elasticity, addition polymerizable unsatd. monomer and photopolym. initiator. The dye which is incorporated into the photosensitive layer and is faded in color by the radiations of the UV to visible parts is colored again when treated with a developer. The exposed part is colored again in the eluting stage by the developer; therefore, the development is substantially controlled and executed even with the image contg. fine dot or lines. The removal of such dots or lines by brushing during the development is averted and the exposed part is faithful to the original picture. The printing plate having the shoulder-shaped excellent relief image is thus obtd. |
