A lithographic printing plate precursor is disclosed including on a support a coating comprising (i) a photopolymerisable layer including a polymerisable compound, a first infrared absorbing dye including at least one electron withdrawing substituent and a photoinitiator; and (ii) a top layer provided above the photopolymerisable layer which includes a second infrared absorbing compound which includes a thermocleavable group which transforms into a group which is a stronger electron-donor upon exposure to heat and/or IR radiation, and is capable of forming a print-out image upon exposure to heat and/or IR radiation.

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.

Provided is an on-press development type lithographic printing plate precursor having a support and an image-recording layer on the support, in which the image-recording layer contains a compound A that has a partial structure satisfying Δd≥15.5 wherein δd is a value of a dispersion element in the Hansen solubility parameters, and a content of the partial structure satisfying Δd≥15.5 in the compound A is 50% by mass or more with respect to a total mass of the compound. Also provided is a method of preparing lithographic printing plate or a lithographic printing method using the lithographic printing plate precursor.

Lithographic printing plate precursors are prepared with a unique aluminum-containing substrate prepared using two separate anodizing processes to provide an inner aluminum oxide layer of average dry thickness (T.sub.i) of 300-3,000 nm and a multiplicity of inner micropores of average inner micropore diameter (D.sub.i) of ≤100 nm. An outer aluminum oxide layer is also provided to have a multiplicity of outer micropores of average outer micropore diameter (D.sub.o) of 15-30 nm and a dry thickness (T.sub.o) of 30-650 nm. A hydrophilic layer disposed on the outer aluminum oxide layer at 0.0002-0.1 g/m.sup.2 has at least a hydrophilic copolymer composed of (a) recurring units having an amide group and (b) recurring units comprising an —OM group directly connected to a phosphorus atom, wherein M represents a hydrogen, sodium, potassium, or aluminum atom.

Provided herein is a topcoat composition comprising at least one fluorosilicone, a hydride-functional crosslinking agent, an infrared-absorbing filler, and at least one dispersant that is non-reactive with the hydride-functional crosslinking agent, by weight based on a total weight of the topcoat composition, wherein the topcoat composition has a degree of crosslinking between about 10 micrograms/hour/milligrams to about 20 micrograms/hour/milligrams. Further provided herein are methods of making the topcoat composition, as well as an imaging blanket and methods of reducing coating defects on a media coated using the imaging member.

A lithographic printing plate precursor has an infrared radiation-sensitive image-recording layer containing an IR absorber, and an ozone-blocking material of 1500 or less molecular weight and has structure (I), (II), or (III): ##STR00001##
wherein R is a hydrocarbon having 14-30 carbon atoms; m is 1 or 2; n is 1-6; the sum of m and n is >2 and <8; and A is a multivalent organic moiety free of R and OH groups and has a valence m+n; ##STR00002##
wherein R.sub.1 and R.sub.2 are alkyl groups of 14-22 carbon atoms, and o is 1-3;
R.sub.3C(═O)NR.sub.4R.sub.5   (III)
wherein R.sub.3 is an alkenyl with a C═C bond within a carbon-carbon chain of 16-30 carbons, and R.sub.4 and R.sub.5 are hydrogen or unsubstituted alkyls of 1-4 carbon atoms. Such ozone-blocking materials can be used to protect infrared radiation-sensitive dyes that may be degraded by ozone and thus improve imaging sensitivity.

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 toplayer provided above the photopolymerisable layer; characterized in that the toplayer includes a hydrophobic binder.

Provided are a lithographic 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 core-shell particles, a core portion of each 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 polymerizable group: a method of preparing a lithographic printing plate using the lithographic printing plate precursor; and a lithographic printing method carried out using the lithographic printing plate precursor.

A negative-working lithographic printing plate precursor includes a coating including vinylogous vitrimer particles. The vinylogous vitrimer particles include a resin having at least one moiety of formula (I), (II), and/or (III):

##STR00001##

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 organic particle containing a resin that has a constitutional unit A having a cation moiety and a constitutional unit B having an anion moiety; and a method of preparing a planographic printing plate using the planographic printing plate precursor.