A lithographic printing plate precursor has an image-recording layer on a hydrophilic support, in which the image-recording layer contains an infrared absorbing dye that decomposes by exposure to an infrared ray and a color developer that develops color due to the exposure to an infrared ray. A method for producing a lithographic printing plate includes image-exposing the lithographic printing plate precursor using an infrared laser.

A lithographic printing plate precursor has an image-recording layer on a hydrophilic support, wherein the image-recording layer includes a polymer particle including an addition polymerization resin having a hydrophilic structure and a crosslinking structure. A method for producing a lithographic printing plate uses the lithographic printing plate precursor. A polymer particle includes an addition polymerization resin having a hydrophilic structure and a crosslinking structure. A composition includes the polymer particle.

A lithographic printing plate precursor including a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side where the image recording layer is provided is in a range of 0.3 μm to 20 μm; a method of producing a lithographic printing plate precursor; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; a plate-making method for a lithographic printing plate; and a lithographic printing method.

Provided is a lithographic printing method including a preparing step of preparing a lithographic printing plate precursor which includes an aluminum support, and an image recording layer containing an acid color developing agent and an acid generator on the aluminum support, an exposing step of exposing the lithographic printing plate precursor, a developing step of supplying acidic dampening water to the exposed lithographic printing plate precursor and removing a non-image area of the image recording layer, and a printing step, in which the aluminum support includes an anodized aluminum film, the anodized film has micropores, and a value ΔS is 15% or greater and 60% or less.

A planographic printing plate precursor includes: a support; and an image recording layer which includes a radical initiator, a radical polymerizable component, and a radiation absorption compound, and in which the image recording layer shows two or more peaks of a radical generation amount in a radical generation amount-versus-time curve after exposure to image forming radiation, in which the radical initiator includes an electron-donating radical initiator and an electron-accepting radical initiator, and the radiation absorption compound comprises a compound represented by the following Formula 1. ##STR00001##

Provided are a planographic printing plate precursor including a support and an image recording layer formed on the support, in which the image recording layer contains a polymer A which includes a constitutional unit A1 having an ethylenically unsaturated group, a weight-average molecular weight of the polymer A is in a range of 2,500 to 35,000, and a content of the constitutional unit A1 in the polymer A is 15 mol % or more, and a method of producing a planographic printing plate using the planographic printing plate precursor.

Provided are a planographic printing plate precursor having an image recording layer on a support, and an overcoat layer in this order, in which the overcoat layer includes particles, the overcoat layer is an outermost layer, and an occupation area ratio of the particles in a surface of the overcoat layer is 30% by area or more; and a method of producing a planographic printing plate obtained by using the planographic printing plate precursor.

Provided are a lithographic printing plate precursor including a hydrophilized aluminum support, and a water-soluble or water-dispersible negative type image recording layer provided on the aluminum support, in which an arithmetic average height Sa of a surface of an outermost layer on a side where the image recording layer is provided is in a range of 0.3 m to 20 m or in which Expression (1) and Expression (2) are satisfied in a case where a Bekk smoothness of a surface of an outermost layer on a side where the image recording layer is provided is set as a seconds and a Bekk smoothness of a surface of an outermost layer on a side opposite to a side where the image recording layer is provided is set as b seconds; a method of producing the same; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; a plate-making method for a lithographic printing plate; and a lithographic printing method.

a1000, b1000(1)

1/a+1/b0.002(2)

The present invention provides a printing plate precursor, a method of producing a printing plate, and a printing method with excellent stain resistance and deinking capability after being left to stand at the time of obtaining a printing plate. The printing plate precursor of the present invention is a printing plate precursor including an aluminum support, and a functional layer which is disposed on the aluminum support, in which the aluminum support includes an aluminum plate and an aluminum anodized film disposed on the aluminum plate, the anodized film is positioned closer to the functional layer than the aluminum plate is, the anodized film has micropores extending in a depth direction from a surface of the functional layer side, and an average diameter of the micropores in the surface of the anodized film is in a range of 13 nm to 100 nm, the printing plate precursor contains a hydrophilizing agent in a region on a plate surface of the functional layer side which extends to a distance of 5 mm inward from two facing end portions of the printing plate precursor, and a content of the hydrophilizing agent per unit area in the region is greater than a content of the hydrophilizing agent per unit area in a region other than the region by 10 mg/m.sup.2 or greater.

Provided are a lithographic printing plate precursor having an image-recording layer on a hydrophilic support, in which the image-recording layer includes a. polymer having a constituent unit derived from a monomer having a solubility parameter of 20 MPa.sup.1/2 or more, an infrared absorber, and a polymer particle; a resin composition for producing a lithographic printing plate precursor including the polymer, an infrared absorber, and a polymer particle; and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used.