| 摘要 |
PROBLEM TO BE SOLVED: To make handling in a bright room possible and to improve a problem on adhesiveness between a film and a printing plate material when an image is exposed by light, namely, problems such as vacuum suction time and blurring due to exposure by forming at least a photo-sensitive layer, an ink repellent layer and a protective film with a specified optical density in this order on a base plate. SOLUTION: A waterless lithographic printing original plate is obtd. by forming at least a photo-sensitive layer, an ink repellent layer and a protective film in this order on a base plate. In this case, the optical density of the protective film is made at least 1.0. The film with such an optical density as this can be obtd. by providing at least a layer with a high optical density of at least 1.0. The layer with a high optical density is obtd. by means of coating, metallizing and spattering. As compd. obtd. by coating, a compsn. contg. a metal oxide and a compsn. contg. an easily decomposable compd. and a photo- convertible substance can be cited. As the compd. for satisfying the easy decomposability, polyvinyl pyrrolidone and nitrocellulose are especially pref. |
