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.

Provided are a lithographic printing plate precursor having an image-recording layer on an aluminum support, in which the image-recording layer contains a polymerization initiator, an infrared absorber, a polymer particle, and a polymerizable compound, and the polymerizable compound has a) a molecular weight of 1,500 to 3,000, b) a double bond equivalent of 200 or less, and c) a CLog P of 9 or less and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used.

A lithographic printing plate precursor is disclosed including a support and a coating comprising a polymerisable compound, an initiator and an infrared absorbing dye wherein the initiator and the infrared absorbing dye are capable of inducing a print-out image.

Provided is a positive type lithographic printing plate precursor including at least: a support which has a hydrophilic surface or a hydrophilic layer; and an underlayer, an interlayer, and an upper layer on the support in this order, in which the underlayer contains a polymer compound 1 which has at least one structure selected from the group consisting of a urethane bond, an acetal structure, and a urea bond in a main chain, the interlayer contains a polymer compound 2 which has at least one structure selected from the group consisting of a sulfonamide group, an active imide group, and a urea bond in a side chain, the upper layer contains a polymer compound 3 which has a phenolic hydroxy group, and one or more layers among the underlayer, the interlayer, and the upper layer contain an infrared absorbent. Further, provided are a method of producing the positive type lithographic printing plate precursor and a method of preparing a lithographic printing plate using the positive type lithographic printing plate precursor.

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; 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 are a lithographic printing plate precursor having 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 and a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used.

A method of imaging printing plates uses a single imaging device having at least one laser delivering, in an imagewise manner, pulsed electromagnetic energy of pulse duration not greater than 110.sup.6 seconds. Such an imaging method permits the imaging of a plurality of types of printing plates irrespective of any sensitised imaging chemistry contained in their coatings.

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 particle including an addition polymerization-type resin having a hydrophilic structure and a crosslinking structure, a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used, a polymer particle including an addition polymerization-type resin having a hydrophilic structure and a crosslinking structure, and a composition including the polymer particle.

A photosensitive resin composition contains a polymer compound having a linking group represented by Formula A-1 in the main chain; and an infrared absorbing material. In Formula A-1, R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a monovalent organic group, and X.sup.1 is a specific linking group. ##STR00001##

Provided are a curable composition including a sail compound having a) an organic anion in which, in Hansen, solubility parameter, d is 16 or more, p is 16 or more and 32 or less, and H is 60% or less of p and b) a counter cation, a lithographic printing plate precursor having an image-recording layer containing the curable composition, a method for producing a lithographic printing plate using the lithographic printing plate precursor, and a compound that is used in the image-recording layer in the lithographic printing plate precursor.