Abstract: A method of producing an aluminum substrate for a planographic printing plate is provided in which a recycled material including a used planographic printing plate having a planographic printing plate support obtained by treating an aluminum substrate is prepared, a recycled bare metal is obtained from the recycled material, and a new aluminum bare metal and a trace-metal master alloy of necessary amounts are mixed into the recycled bare metal to produce a new aluminum substrate.

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 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 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 presensitized plate having: on an aluminum support, a thermosensitive layer containing a photothermal conversion agent which absorbs infrared rays and generates heat and a water-insoluble and alkali-soluble resin, of which solubility to an alkali aqueous solution increases by heating, wherein the aluminum support has a grained structure with large undulation and a grained structure with small undulation on a surface thereof. This presensitized plate is excellent in damage resistance and sensitivity, and after the plate is processed into a lithographic plate, it is also excellent in scum resistance and press life.

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: 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 an infrared-sensitive photosensitive composition comprising (A?) a polyurethane resin having a specific diol as a constituent, (B) a light-to-heat converting agent, and (C) a novolak resin.

Abstract: An infrared-sensitive photosensitive composition comprising: (A) a resin; (B) a novolak resin; and (C) a light-to-heat converting substance, wherein the resin (A) has, as copolymer components, at least: (1) a (meth)acrylic acid or a monomer represented by formula (I) as defined herein; and (2) at least one compound selected from the group consisting of a (meth)acrylic ester, a (meth)acrylamide derivative, and a styrene derivative.

Abstract: A photosensitive resin composition containing a high molecular compound having at least a) a fluoro aliphatic group, and b) a group represented by formula —L—P (wherein L represents a divalent organic group connected to the skeleton of the high molecular compound, and P represents an aromatic group having a carboxyl group at the ortho-position).

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: 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 presensitized plate having: on an aluminum support, a thermosensitive layer containing a photothermal conversion agent which absorbs infrared rays and generates heat and a water-insoluble and alkali-soluble resin, of which solubility to an alkali aqueous solution increases by heating, wherein the aluminum support has a grained structure with large undulation and a grained structure with small undulation on a surface thereof. This presensitized plate is excellent in damage resistance and sensitivity, and after the plate is processed into a lithographic plate, it is also excellent in scum resistance and press life.

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 photosensitive resin composition containing a high molecular compound having at least a) a fluoro aliphatic group, and b) a group represented by formula —L—P (wherein L represents a divalent organic group connected to the skeleton of the high molecular compound, and P represents an aromatic group having a carboxyl group at the ortho-position).

Abstract: A photosensitive resin composition containing a high molecular compound having at east a) a fluoro aliphatic group, and b) a group represented by formula —L—P (wherein L represents a divalent organic group connected to the skeleton of the high molecular compound, and P represents an aromatic group having a carboxyl group at the ortho-position).