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AssigneeFuji Photo Film Co., Ltd.
InventorsKazuo Fujita, Shiro Tan, Akira Nagashima
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The present invention relates to a positiive-working presensitized plate useful for preparing a lithographic printing plate comprising a positive-working photosensitive composition comprising at least one ester of 1,2-naphthoquinone-2-diazide-5-sulfonic acid, at least one ester of 1,2-naphthoquinone-2-diazide-4-sulfonic acid, and at least one polymer which is insoluble in water and soluble in an aqueous alkaline solution and which comprises at least one group or bond selected from sulfonamide group, urea bond or urethane bond. A lithographic printing plate prepared from the presensitized plate of the present invention shows improvement of chemical-resistance and printing durability, and good sensitivity, coupling property, adaptability to ball-point pen, shelf stability, and stability of sensitivity with time after exposure.
A positive-working presensitized plate useful for preparing a lithographic printing plate comprising a positive-working photosensitive composition coated on a substrate, wherein the composition comprises (a) at least one ester of 1,2-naphthoquinone-2-diazide-5-sulfonic acid, (b) at least one ester of 1,2-naphthoquinone-2-diazide-4-sulfonic acid, and (c) at least one polymer which is insoluble in water and soluble in an aqueous alkaline solution and which comprises at least one sulfonamide group.
A positive-working presensitized plate useful for preparing a lithographic printing plate comprising a positive-working photosensitive composition coated on a substrate, wherein the composition comprises (a) at least one ester of 1,2-naphthoquinone-2-diazide-5-sulfonic acid, (b) at least one ester of 1,2-naphthoquinone-2-diazide-4-sulfonic acid, and (c) at least one polymer which is insoluble in water and soluble in an aqueous alkaline solution and which comprises at least one urea bond or urethane bond.
Dependencies are inferred from the claim text.