Abstract: The positive type photosensitive composition of the present invention comprises a polymer compound (A) having, in a side chain thereof, a polymerizable group or a cross-linkable group, and an infrared absorbent (B). Preferably, the polymerizable group or cross-linkable group is incorporated into molecules of the polymer compound (A) through a structural unit having this group in a side chain thereof. Specifically, the structural unit is preferably a structural unit having any one of structures represented by the following general formulae (1) to (4): wherein A, B, X each independently represents a single bond, an oxygen atom, a sulfur atom or the like; L and M each independently represent a bivalent organic group; R1 to R12 represents a hydrogen atom or a monovalent organic group; R13 to R24 each independently represents a monovalent organic group; and Y represents an oxygen atom, a sulfur atom, or a phenylene group which may have a substituent.

Abstract: The present invention provides an image recording material comprising a substrate, an intermediate layer, and a photosensitive layer containing a novolac phenol resin and a light to heat conversion agent and being recordable with an infrared laser. The intermediate layer and photosensitive layer are sequentially provided on the substrate. The intermediate layer contains a polymer having an acidic group and being capable of interacting with the novolac phenol resin contained in the photosensitive layer. A planographic printing plate excellent in chemical resistance and printing durability is obtained by heat-treating the image recording material at 150 to 300° C. after effecting image-wise exposure with an infrared laser and development.

Abstract: An image recording material of the present invention comprises an anodized aluminum support, an intermediate layer containing a polymer having a carboxylic acid group in a side chain thereof and formed on the aluminum support, and a photosensitive layer containing at least 50% by weight or more of novolak type phenol resin and a photothermal conversion agent and recordable by IR laser beam. A planographic printing plate excellent in printing durability can be obtained by subjecting the image recording material imagewise to IR laser exposure treatment and to development treatment, and then heating the image recording material at 150 to 300° C.

Abstract: The present invention relates to a positive-type planographic printing plate precursor comprising: a hydrophilic substrate; an image recording layer including a novolak resin (A) and a light-to-heat conversion agent (B), disposed on the substrate, the image recording layer increasing in solubility in an aqueous alkali solution when exposed to light emitted from an infrared laser, wherein the weight average molecular weight (Mw) of the novolak resin (A) is in a range of 500 to 10000 based on polystyrene, the molecular weight being found by a gel permeation chromatographic (GPC) method using monodispersion polystyrene as a standard, and the degree of dispersion (Mw/Mn) is 1.7 or less when the weight average molecular weight (Mw) is 500 to 3000, the degree of dispersion (Mw/Mn) is 2.

Abstract: A support for a lithographic printing plate, wherein scum resistance is improved when processed into a lithographic printing plate by performing treatment for water wettablity and, in addition, press life is excellent. A support for a lithographic printing plate, which is obtained by performing at least anodizing treatment and silicate treatment on an aluminum plate, wherein a ratio of the number of atoms of alkali-earth metal and silicon existing on a surface thereof is 0.1 to 0.95.

Abstract: A planographic printing plate precursor of the present invention includes a hydrophilic support, and a lower layer and an image recording layer disposed on the hydrophilic support in this order. The lower layer includes a water-insoluble and alkali-soluble resin, and wherein the image recording layer includes a novolak type phenolic resin containing phenol as a structural unit thereof and a light-to-heat conversion agent, and exhibits increased solubility in an alkaline aqueous solution when exposed to an infrared laser.

Abstract: A heat-sensitive lithographic printing plate precursor comprising a support having thereon two image-forming layers each containing a polymer insoluble in water and soluble in an aqueous alkaline solution, wherein an upper layer of the image-forming layers contains a copolymer including a monomer unit represented by formula (A) defined in the specification.

Abstract: There is provided an infrared-sensitive lithographic printing plate capable of direct plate-making based on digital data from a computer or the like, and excellent in development latitude and scratch resistance, which is an infrared-sensitive lithographic printing plate comprising a support and a heat-sensitive layer, the heat-sensitive layer comprising (A) a copolymer having a specific monomer unit having a carboxyl group, (B) an alkali-soluble high molecular weight compound having a sulfonamide group, and (C) a light-heat conversion material.

Abstract: A process for producing a heat mode-compatible positive planographic printing plate precursor comprising a support and a photosensitive layer whose solubility in an aqueous alkali solution increases upon heat-mode exposure, which includes: applying a photosensitive layer coating solution onto the support, and drying the photosensitive layer coating solution at a drying temperature not less than 150° C. and not greater than 200° C. and for a drying time of 110 seconds or less.

Abstract: A planographic printing plate precursor includes a photosensitive layer obtained by coating and drying on a support a photosensitive layer coating solution formed of a photosensitive composition, which contains a cyanine dye represented by general formula (I) below and a polymer insoluble in water and soluble in an aqueous alkali solution, dissolved or dispersed in a solvent system containing 80% by weight or more of a solvent having a boiling point lower than 100° C. in a solvent having a boiling point lower than 200° C.; wherein a solubility in an aqueous alkali solution of the photosensitive layer is increased by exposure to an infrared laser.

Abstract: The present invention relates to a heat mode-compatible planographic printing plate comprising a photosensitive layer which is capable of recording with an infrared laser and formed by applying a photosensitive layer coating solution onto a hydrophilic support and then drying the photosensitive layer coating solution, the photosensitive layer coating solution being obtained by dissolving or dispersing I) an IR absorber, II) a polymerization initiator, and III) a compound having a polymerizable unsaturated group in a solvent, wherein the residual solvent in the photosensitive layer is 5% by weight or less relative to the weight of the photosensitive layer.

Abstract: The invention provides a photosensitive composition including (A) a vinyl polymer containing a copolymerization component having a carboxyl group, having a content of the carboxyl group in a molecule of 2.0 meq/g or higher and having a solubility parameter less than 21.3 MPa1/2, (B) a polymer compound including a phenolic hydroxyl group, and (C) an IR absorber.

Abstract: A photosensitive lithographic printing plate which comprises a photosensitive layer comprising: (A) a resin prepared by condensing substituted phenols represented by the following formula (I) with aldehydes; (B) a resin prepared by condensing phenols selected from cresol, phenol and xylenol with aldehydes; and (C) a light-heat converting substance: 1

Abstract: An infrared-sensitive photosensitive composition comprising:

Abstract: An infrared-sensitive photosensitive composition comprising (A) an alkali-soluble resin containing a repeating unit having an alkylene oxide group, and (B) a light-to-heat converting agent; and

Abstract: A positive planographic printing plate precursor includes a support having disposed thereon a lower thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound and an upper thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound, with alkali-solubility increasing under heat, wherein (i) both the upper thermosensitive layer and the lower thermosensitive layer contain an IR absorbing dye, with the ratio of the IR absorbing dye concentration in the upper thermosensitive layer to the IR absorbing dye concentration in the lower thermosensitive layer is 1.6 to 10.0, and/or (ii) the upper thermosensitive layer and the lower thermosensitive layer contain different IR absorbing dyes, and/or (iii) at least one of the upper thermosensitive layer and the lower thermosensitive layer contains an IR absorbent having, in one molecule, at least two chromophoric groups that absorb IR light, with the chromophoric groups bonding to each other via a covalent bond.

Abstract: A positive working lithographic printing plate precursor comprising a lower layer containing a water-insoluble and alkali-soluble resin, and an upper heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared absorbing dye and increasing the solubility in an alkaline aqueous solution by heating, provided in this order on a hydrophilic support, and (a) the upper heat-sensitive layer containing at least two kinds of surface active agents, or (b) the lower layer and upper heat-sensitive layer each containing a surface active agent different from each other.

Abstract: A positive image-forming material for use with infrared laser is provided. The material includes a substrate, a layer (A) containing not less than 50% by weight of a copolymer which contains, as a copolymerization component, not less than 10% by mol of at least one of the following monomers (a-1) to (a-3), wherein (a-1) is a monomer having in the molecule a sulfonamide group wherein at least one hydrogen atom is linked to a nitrogen atom, (a-2) is a monomer having in the molecule an active imino group represented by the following general formula (I): and (a-3) is a monomer selected from acrylamide, methacrylamide, acrylate, methacrylate and hydroxystyrene, which respectively have a phenolic hydroxyl group; and a layer (B) containing not less than 50% by weight of an aqueous alkali solution-soluble resin having a phenolic hydroxyl group. The layer (A) and the layer (B) contain a compound which generates heat upon absorbing light.

Abstract: A support for a lithographic printing plate, wherein scum resistance is improved when processed into a lithographic printing plate by performing treatment for water wettablity and, in addition, press life is excellent. A support for a lithographic printing plate, which is obtained by performing at least anodizing treatment and silicate treatment on an aluminum plate, wherein a ratio of the number of atoms of alkali-earth metal and silicon existing on a surface thereof is 0.1 to 0.95.

Abstract: A planographic printing original plate which comprises an intermediate layer which contains a polymer including, as a monomer unit, at least a monomer having an acid group and a monomer having an onium group; and a photosensitive layer comprised of a positive-type photosensitive composition for an infrared laser which contains: (A) at least an alkali-soluble polymeric compound; (B) a compound which has a function to deteriorate the solubility of the alkali-soluble polymeric compound in an alkaline aqueous solution due to compatibility with the alkali-soluble polymeric compound, the function being deteriorated by compound (B) being heated; and (C) a compound which generates heat by absorbing light, the intermediate layer and the photosensitive layer being formed sequentially on a support which has been subjected to a hydrophilizing treatment.