A lithographic printing plate precursor including a photopolymerisable coating and an overcoat layer provided on top of said layer, characterized in that the overcoat layer includes a compound comprising at least one moiety having a structure according to Formula (I): (I). ##STR00001##

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.

Provided is an on-press development type lithographic printing plate precursor having a support, an image-recording layer, and an outermost layer in this order, in which the image-recording layer contains an infrared absorber, an electron-accepting polymerization initiator, and a polymerizable compound, LUMO of the electron-accepting polymerization initiator-LUMO of the infrared absorber is 0.45 eV or more, and the outermost layer contains a discoloring compound. Also provided is a method of preparing a lithographic printing plate and a lithographic printing method in which the on-press development type lithographic printing plate precursor is used.

A lithographic printing plate precursor includes a photopolymerizable coating and an overcoat which is deactivated after imagewise exposure and preheating of the precursor.

Provided are a planographic printing plate precursor including a support, and an image recording layer on the support, in which the image recording layer contains an infrared absorbing agent, a polymerization initiator, and a core-shell particle, a core portion of the core-shell particle contains a resin A containing a functional group A, and a shell portion of the core-shell particle contains a resin B containing a functional group B that is bondable to or interactable with the functional group A and a dispersion group; a method of preparing a planographic printing plate using the planographic printing plate precursor; and a planographic printing method carried out using the planographic printing plate precursor.

Lithographic printing plates are provided by imagewise exposing negative-working lithographic printing plate precursors having one or more radiation-sensitive imageable layers, followed by contacting with a processing solution that contains up to 10 weight % of one or more compounds represented by Structure (I) shown as follows:
R.sup.1—C(═O)—N(R.sup.2)—R.sup.3   (I)
wherein R.sup.1, R.sup.2, and R.sup.3 independently represent hydrogen or a substituted or unsubstituted hydrocarbon group, or two or three of R.sup.1, R.sup.2, and R.sup.3 are combined to form one or more cyclic rings, and the total number of carbon atoms in the Structure (I) molecule is at least 7 and up to and including 33. Both negative-working and positive-working lithographic precursors can be imaged and processed using this processing solution using one or more successive applications of the same or different processing solution. The processing solution can be derived from a corresponding processing solution concentrate that can also be used for replenishment.

An object of the present invention is to provide a lithographic printing plate precursor which has excellent on-press developability and is capable of suppressing generation of slip stains and from which a lithographic printing plate with satisfactory printing durability is obtained, and a method of producing a lithographic printing plate and a printing method using the lithographic printing plate precursor. The lithographic printing plate precursor of the present invention is a lithographic printing plate precursor including an aluminum support, and an image recording layer, in which the aluminum support includes an aluminum plate and an anodized aluminum film disposed on the aluminum plate, the anodized film is positioned on a side of the image recording layer with respect to the aluminum plate, the anodized film has micropores extending from a surface of the anodized film on the side of the image recording layer in a depth direction, the micropores have an opening ratio of 20% to 70%, a steepness a45 on the surface of the anodized film on the side of the image recording layer is in a range of 3% to 25%, and an arithmetic average roughness Ra on the surface of the anodized film on the side of the image recording layer is in a range of 0.25 to 0.60 μm.

A planographic printing plate precursor containing in the following order: an aluminum support; an image recording layer; and a protective layer, in which a thickness of the protective layer is 0.2 μm or greater, and in a case where a Bekk smoothness of a surface of an outermost layer at a side where the image recording layer is provided is 1000 seconds or less.

A lithographic printing plate precursor is disclosed including a support and a coating comprising (i) a photopolymerisable layer including a polymerisable compound and a photoinitiator, and a top layer provided above the photopolymerisable layer; characterized in that the top layer includes a non-polymeric polyfunctional compound in an amount between 2 mg/m.sup.2 and 80 mg/m.sup.2 which comprises at least two carboxyl and/or carboxylate groups.