Okamoto Chemical Industry Co., Ltd.

Jun Ozaki

Masaro Nakatsuka

Keiko Yonezawa

Naoya Sato

Yasuhiro Uozumi

A thermal negative type lithographic printing original plate has a photosensitive layer featuring high sensitivity, excellent reproducibility in FM screening, and excellent print durability and chemical resistance at a minute image portion. A photosensitive composition for the photosensitive layer contains an alkali soluble resin having a monomer unit represented by the formula (I), a silane coupling agent represented by the formula (II), an infrared absorber, a radical polymerization initiator, and a polymerizable compound having an ethylenic double bond and an amount of the silane coupling agent is from 15 to 40% of the photosensitive composition by mass.

Photosensitive composition and lithographic printing original plate using the composition

An object of the present invention is to provide a support for lithographic printing plates provided with a photosensitive layer containing an acid generator and an acid-decomposable compound, that offers superior sensitivity, chemical resistance, print durability, and little scumming during printing. The present invention provides an aluminum support for a lithographic printing plate, the support being obtainable by treating a surface of an anodized aluminum plate with a treatment liquid comprising metal fluoride, metal phosphate salt, and perchlorate, and a base plate for a lithographic printing plate using the same.

Aluminum support for lithographic printing plate and base plate for lithographic printing plate

The present invention provides image-forming compositions and photosensitive lithographic plates which are excellent in sensitivity to infrared radiation, latitude of development, treatable area in m, and printing durability. Specifically, the present invention provides an image-forming composition comprising (A) a polymeric compound obtainable by the addition reaction of a resinous polymer having one or more phenolic hydroxyl groups with a silane coupling agent of the following general formula (1) or (2), (B) an acid generator, (C) an infrared absorber, and (D) an alkali-soluble resin, and a photosensitive lithographic plate having this image-forming composition applied onto a substrate. wherein Xand Xeach represent a trimethoxysilyl group or the like; Grepresents O or COO; Rand Reach independently represents a hydrogen atom or a methoxy group; Rrepresents (CH)which may have a hydrocarbon side chain; Grepresents O or COO; Rrepresents a hydrogen atom or a straight-chain or branched alkyl group; and Rrepresents (CH)which may have a hydrocarbon side chain.

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Warabi, Japan

Jun Ozaki