Toray Industries, Inc.

Mikio Tsuda

Norimasa Ikeda

Ken Kawamura

Norio Kawabe

Masanao Isono

Shigeo Abiko

Yoichi Mori

Chikara Ichijo

Sadao Kobashi

Water-less lithographic raw plate

According to the present invention there is provided a laminate comprising a photosensitive layer and a silicone rubber layer both laminated successively onto a base substrate, in which a main component of the photosensitive layer is formed by an adduct obtained by an addition reaction of a photopolymerizable glycidyl (meth)acrylate and a monoglycidyl ether compound not having a photopolymerizable group with a diamine compound. Because of using a photosensitive layer having such a specific composition as mentioned above, the dry planographic printing plate obtained from the present invention is suitably employable in commercial web offset printing and newspaper web offset printing.

Laminate used for the production of a dry planographic printing plate

A printing plate formed of a substrate and laminated thereon in the following order a primer layer and a photosensitive layer containing a quinonediazide compound and a silicone rubber layer, wherein the primer layer contains 0.1 to 25% by weight of a quinonediazide group. The printing plate of the present invention is excellent in dot reproduction, hardly causes cracking in the photosensitive layer, and has a wide latitutde in production.

Printing plate

An image-forming laminated plate, particularly a dry planographic printing unprocessed plate, comprising a base substrate, a photosensitive layer containing a substance with quinonediazide structure and a silicone rubber layer in laminating order is treated with a base after imagewise exposure. In addition, the image-forming laminated plate may be subjected to a whole surface slight exposure to the extent that 5 to 60 molar % of the quinonediazide structure in the photosensitive layer to be exposed is photo-decomposed into carboxylic acid structure before or after the usual imagewise exposure for obtaining a negative working plate, or the image-forming laminated plate may be subjected to a imagewise slight exposure to the same extent without the usual imagewise exposure for obtaining a positive working plate. The base-treatment alone or in combination with the slight exposure enhances both the adhesion of the photosensitive layer to the silicone rubber layer and the solvent resistance of the photosensitive layer in non-image areas.

Treatment of image-forming laminated plate

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Ohmihachiman, Japan

Mikio Tsuda