A curable composition includes a salt compound having a) an organic anion in which, in Hansen solubility parameter, δd is 16 or more, δp is 16 or more and 32 or less, and δH is 60% or less of δp 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 are also set out.

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.

Disclosed is a infrared radiation sensitive positive-working imageable element. The imageable element comprises: (a) a substrate, (b) an inner coating covering the substrate, and (c) an outer coating covering the inner coating. The inner coating comprises a repeating unit derived from a maleimide monomer and a (meth)acrylamide monomer, and a polymer hinder P that is soluble in an alkaline developing solution; and the outer coating comprises an infrared radiation absorbing compound and a polymer binder Q which is different from that in the inner coating. The imageable element is designed such that same is not only sensitive to radiation with a maximum wavelength of 700-1200 nm, but also has a good resistance to chemical solvents when used as a lithographic printing plate precursor, and same is not easily corroded and dissolved by printing chemicals during use, thus facilitating the prolonging of the service life of a lithographic printing plate.

The invention relates to an imageable coating layer, thermal negative-working lithography printing plate, and platemaking method. The coating layer includes constituents in parts by weight: a radically polymerizable compound 20-60 parts, a radiation-absorbing compound 0.5-12 parts, a free radical initiator 1-25 parts, a binding agent 10-70 parts, and a development accelerator 0.5-15 parts. The platemaking method includes the steps: S1, preparing a printing plate precursor that includes a substrate having a hydrophilic surface or is provided with a hydrophilic layer and imageable coating layer covering the substrate; S2, patternedly exposing the printing plate precursor, forming an exposed area and an unexposed area; and S3, removing the unexposed area via a development process. The employment of the imageable coating layer and the plate making method allows the implementation of a flexible development process of “on-press development” or “off-press development” and produces a printing plate provided with great printing performance.

A lithographic printing plate precursor is disclosed including a support and a coating comprising a photopolymerisable layer including a polymerisable compound, a photoinitiator, and an infrared absorbing compound including a long chain linear or branched alkyl group.

A lithographic printing plate precursor is disclosed including a support and a coating comprising a photopolymerisable layer including a polymerisable compound and a photoinitiator, characterized in that the coating comprises a hydrophilic adhesion promoting copolymer including at least one monomeric unit according to Formula I and at least one monomeric unit according to Formula II; and at least one group and/or moiety including a phosphor atom.

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A method for processing a heat-sensitive positive-working lithographic printing plate material is disclosed which comprises at least two layers: —a first layer comprising an oleophilic resin and/or a vinyl acetal (co)polymer; —a second layer comprising a (co)polymer which is located between the support and the first layer; comprising the steps of: —treating the plate material with an alkaline development solution, —treating the plate material with a first gum solution and consecutively with a second gum solution which are configured as a cascade whereby the second gum solution overflows into the first gum solution; and which gum solutions include a buffer; characterized in that the pH of the first gum solution reaches a steady state value above the pKa value of the (co)polymer present in the second layer.

A lithographic printing plate precursor is disclosed including a support and a coating including a polymerisable compound, an optionally substituted trihaloalkyl sulfone initiator, a leuco dye and a specific infrared absorbing compound including a six membered ring in the central position.

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 opposite to a side where the image recording layer is provided is in a range of 0.3 m to 20 m; a method of producing the lithographic printing plate precursor; a lithographic printing plate precursor laminate formed of the lithographic printing plate precursor; and a lithographic printing method.

Provided are a planographic printing plate precursor and a method of producing a planographic printing plate precursor, in which an image forming region during printing on newspaper page is ensured and edge stains are eliminated. Provided are a planographic printing plate precursor (10b) including an aluminum support (12) which has an anodized film (14), and an image recording layer (16) on the aluminum support (12), in which an end portion of the planographic printing plate precursor (10b) has a sagging shape having a sagging amount (X) of 25 m to 150 m and a sagging width (Y) of 70 m to 300 m, the image recording layer (16) contains an infrared absorbing agent, and a part or an entire side surface of two sides of the aluminum support (12), the two sides having the sagging shape and opposing each other contains an ink repellent agent (44); and a method of producing the planographic printing plate precursor (10b).