Provided are a color developing composition including a compound represented by Formula 1, a lithographic printing plate precursor having at least a layer including the color developing composition, a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used, and a compound represented by Formula 1.

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The invention relates to an imageable coating layer, thermal negative-working lithography printing plate, and platemaking method. The coating layer includes constituents in parts by weight: a radically polymerizable compound 20-60 parts, a radiation-absorbing compound 0.5-12 parts, a free radical initiator 1-25 parts, a binding agent 10-70 parts, and a development accelerator 0.5-15 parts. The platemaking method includes the steps: S1, preparing a printing plate precursor that includes a substrate having a hydrophilic surface or is provided with a hydrophilic layer and imageable coating layer covering the substrate; S2, patternedly exposing the printing plate precursor, forming an exposed area and an unexposed area; and S3, removing the unexposed area via a development process. The employment of the imageable coating layer and the plate making method allows the implementation of a flexible development process of on-press development or off-press development and produces a printing plate provided with great printing performance.

Provided are a positive type planographic printing plate precursor including: a support which has a hydrophilic surface; and an image recording layer on the support, the image recording layer containing: a polymer compound 1 having at least one bond selected from the group consisting of a urea bond, a urethane bond, and a carbonate bond in a main chain and containing a sulfonamide group in the main chain; a polymer compound 2-1 having at least one of a constitutional unit represented by Formula S-1 or a constitutional unit represented by Formula S-2 or a polymer compound 2-2 having a constitutional unit represented by Formula EV-1 and a constitutional unit represented by Formula EV-2; and an infrared absorbent, and a method of producing a planographic printing plate obtained by using the positive type planographic printing plate precursor.

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A curable composition includes an infrared absorber having at least one element in Group XIII of the periodic table on a mother nucleus structure and having a chain-like polymethine structure, in which two or more hetero atoms are bonded to carbon atoms at non-meso positions. Also, a lithographic printing plate precursor in which the curable composition is used, and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used are provided.

The present invention aims at providing a lithographic printing plate precursor, a lithographic printing plate manufacturing method, a printing method and an aluminum support manufacturing method that enable the resulting lithographic printing plate to have a long tiny dot press life. The lithographic printing plate precursor of the invention is a lithographic printing plate precursor having an aluminum support and an image recording layer disposed above the aluminum support. When measured over a 400 m400 m region of a surface of the aluminum support on the image recording layer side using a three-dimensional non-contact roughness tester, pits with a depth from centerline of at least 0.70 m are present at a density of at least 3,000 pits/mm.sup.2; and a surface area ratio S is not less than 35%, the surface area ratio S being determined using an actual area S.sub.x obtained, through three-point approximation, from three-dimensional data acquired by measurement at 512512 points in 25 m square of the surface of the aluminum support on the image recording layer side by means of an atomic force microscope and a geometrically measured area S.sub.o.

Provided is a precursor for lithographic printing having excellent printing durability and ink repellency as well as high reproducibility of the high definition images. The precursor for lithographic printing includes, at least a heat sensitive layer and an ink repellent layer wherein the ink repellent layer has an elastic modulus of the plate surface under the surface load of 14000 N/m2 of at least 25 MPa and up to 35 MPa.

Negative-working, radiation-sensitive printing plates include or consist of a hydrophilic first layer or substrate and, thereover, an oleophilic imaging layer that includes an iodonium borate free-radical initiators in accordance herewith have the structure

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where X and Y are alkoxy, p and q range independently from 0 to 5, and p+q5; or p and q may range independently from 0 to 4, with p+q4.

Please replace the Abstract of the Disclosure originally filed with the above-identified patent application with the following amended Abstract of the Disclosure:

Thermoplastic polymer particles including at least one polymer including monomeric units derived from the monomers selected from ethylene, (vinyl)chloride, methyl(meth)acrylate, ethyl (meth)acrylate, vinylidene chloride, (meth)acrylonitrile, vinylcarbazole and/or styrene, characterized in that the polymer further includes at least one monomeric unit including an oxalylamido moiety.

Provided is a positive type photosensitive resin composition including: a polymer compound which contains, in a main chain thereof, a sulfonamide group and a structure represented by Formula A-1; and an infrared absorbent. In Formula A-1, X represents NR.sup.1, S, or O, R.sup.1 represents a hydrogen atom or an alkyl group, and each symbol * independently represents a bonding position with respect to another structure.

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A lithographic printing plate precursor including an image recording layer containing an infrared absorber represented by Formula I, on a support, and a method of producing a lithographic printing plate and a lithographic printing method using the lithographic printing plate precursor.

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