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AssigneeTokyo Ohka Kogyo Co., Ltd.
InventorsToshiya Takagi, Takashi Fujimoto
Estimating the term…
A photosensitive laminated original printing plate for letterpress printing that does not contaminate developers, being capable of suppressing a cost increase due to developer replacement and is of high quality; and a process for producing a letterpress printing plate using the photosensitive laminated original printing plate for letterpress printing. There is provided a photosensitive laminated original printing plate for letterpress printing, comprising a support and, at least sequentially superimposed thereon, a photosensitive resin layer which is sensitive to ultraviolet radiation and is developable with water or a mixture of water and alcohol and a mask material layer which contains at least a nonultraviolet-absorbing organic dye and ultraviolet-absorbing organic dye and a binder soluble or dispersible in water or a mixture of water and alcohol and is removable by means of water or a mixture of water and alcohol, wherein the nonultraviolet-absorbing and ultraviolet-absorbing materials are of compositions having compatibility with the binder.
A photosensitive laminated original printing plate for letterpress printing comprising:
In a process for producing letterpress printing plate comprising irradiating a pattern light with a chemical ray to a photosensitive resin layer for the original printing plate in which a photosensitive resin layer is at least formed on a support, and then obtaining the printing plate for letterpress printing by developing with a developing solution consisting of water or a mixture of water and an alcohol to form a resin layer having a relief pattern on the support for printing, the process comprising steps of irradiating a non-ultraviolet ray on a mask material layer of a photosensitive laminated original printing plate for letterpress printing using the photosensitive laminated original printing plate for letterpress printing as an original plate for letterpress printing to allowing the irradiated part of the mask material layer to sublimate by the irradiation, thereby changing into a mask image layer which corresponds to an ultraviolet transmissive region;
Dependencies are inferred from the claim text.