| 摘要 |
PURPOSE:To effectively use both sides of a double-faced type PS plate (photosensitive planographic plate) by providing a photosensitive layer on the surface of each of two supports releasably adhered to each other on the back side thereof by a weak adhesive. CONSTITUTION:To produce a composite PS plate, two aluminum plates 1 are releasably adhered to each other on the back side thereof by a weak adhesive 3, each of the face sides of the plates 1 is subjected to a surface treatment such as graining and electrolytic oxidation, and a photosensitive composition is applied to each of the face sides of the plates 1, followed by drying. To use the composite PS plate, one side thereof is first subjected to imagewise exposure by an ordinary method according to the kind of the photosensitive layer on that side, then the other side is subjected to imagewise exposure, and both sides are simultaneously subjected to development. A developing liquid and a developing means are appropriately selected according to the type of the photosensitive layer to be developed. When images are formed, the supports 1 are released from each other, and each of the PS plates thus obtained is used for printing on an offset press or the like. |
