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. ##STR00001##

There are free radical scavengers of formula (P.sub.m-L).sub.n-T.sub.q. Also provided are negative-working lithographic printing plate precursors comprising a hydrophilic substrate and a NIR photopolymerizable or UV-violet photopolymerizable imageable layer coated on the hydrophilic layer, the imageable layer also being photopolymerizable by visible light, the imageable layer having an outer surface and a thickness, the outer surface of the imageable layer being uniformly, and partially or completely crosslinked down to a depth corresponding to at most about 70% of the thickness of the imageable layer.

A lithographic printing plate precursor having an image-recording layer on a hydrophilic support, in which the image-recording layer includes an organic polymer particle, and the organic polymer particle is a reaction product obtained by at least reacting an aromatic polyvalent isocyanate compound having a structure represented by Formula PO and water, a method for making a lithographic printing plate having excellent printing resistance in the case of using an ultraviolet-curable ink in printing, a new organic polymer particle, and a resin composition including the organic polymer particle. ##STR00001##

An on-machine development lithographic printing plate precursor includes an image-recording layer on an aluminum support having an anode oxide film, wherein an end portion of the lithographic printing plate precursor has a shear droop shape, the image-recording layer contains a compound having a support adsorptive property, having a molecular weight of 1,000 or less, and not having an unsaturated double bond group in a molecule, and a content of the compound is substantially the same in a plane of the image-recording layer.

A lithographic printing plate precursor is disclosed including a support and a coating comprising (i) a photopolymerisable layer including a polymerisable compound, a photoinitiator and an asymmetrically substituted infrared absorbing compound.

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 including a support and a coating comprising a polymerisable compound, optionally a sensitizer, a photoinitiator and discrete particles is disclosed wherein the discrete particles comprise a crosslinked hydrophobic polymer backbone and a plurality of hydrophobic pendant grafts.

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.

IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR radiation-sensitive composition in an infrared radiation-sensitive image-recording layer. This IR radiation-sensitive composition includes: (1) a free radical initiator composition comprising a borate compound; (2) a free radically polymerizable composition; (3) an acid-sensitive color-changing compound that is represented by the Formula (I) identified herein; (4) an infrared absorber material; and a (5) color-changing compound of Formula (III) or Formula (IV) identified herein. After IR imaging, the exposed precursors exhibit desirable printout images especially in the 600-700 nm region of the electromagnetic spectrum and especially for observation using electronic sensing devices. The imaged precursors can be developed off-press or on-press.