A lithographic printing plate precursor is disclosed including a support and a coating comprising (i) a photopolymerisable layer including a polymerisable compound and an optionally substituted trihaloalkyl sulfone photoinitiator, and (ii) a toplayer provided above the photopolymerisable layer; characterized in that the toplayer includes an infrared absorbing dye capable of forming a print-out image upon exposure to heat and/or IR radiation.

Lithographic printing plate precursors are prepared with a unique aluminum-containing substrate and one or more radiation-sensitive imageable layers. The aluminum-containing substrate is prepared by three separate and sequential anodizing processes to provide an inner aluminum oxide layer having an average dry thickness (T.sub.i) of 500-1,500 nm and a multiplicity of inner pores having an average inner pore diameter (D.sub.i) larger than 0 and <15 nm. A formed middle aluminum oxide layer has a dry thickness (T.sub.m) of 60-300 nm and a multiplicity of middle pores of average middle pore diameter (D.sub.m) of 15-60 nm, arranged over the inner aluminum oxide layer. A formed outer aluminum oxide layer comprises a multiplicity of outer pores having an average outer pore diameter (D.sub.o) of 5-35 nm and an average dry thickness (T.sub.o) of 30-150 nm, arranged over the middle aluminum oxide layer. D.sub.m is larger than D.sub.o that is larger than D.sub.i.

Disclosed is a heat-sensitive processless planographic printing plate material containing a thermosensitive protection layer. The planographic printing plate material sequentially comprises a supporting body, a hydrophilic layer, a heat-sensitive layer and a thermosensitive protection layer from the bottom up. The thermosensitive protection layer therein can not only isolate oxygen and protect the heat-sensitive layer from oxygen inhibition, but can also sense heat and allow a polymerization reaction to take place. Thus the binding force between same and the next layer is improved, so that the precision of printing plate images is high, the development performance is good, and the pressrun is high.

The present invention relates to a printing plate including a first silicone layer and a second silicone layer which have different ink acceptabilities on a support. An object of the present invention is to provide a printing plate that dispenses with a development step and that has excellent image reproducibility, ink repellency, ink acceptability, and printing durability.

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.

A negative-working infrared radiation-sensitive lithographic printing plate precursor can be imaged and developed on-press to provide a lithographic printing plate. Such precursor has an initiator composition that contains compound A of Structure (I) and one or more compounds collectively as compound B of Structure (II) or Structure (III): ##STR00001##
wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 are independently alkyl groups each having 3 to 6 carbon atoms; at least one of R.sub.3 and R.sub.4 is different from R.sub.1 or R.sub.2; the difference of total number of carbon atoms in R.sub.1 and R.sub.2 and the total number of carbon atoms in R.sub.3 and R.sub.4 is 0, 1, or 2; the difference of total number of carbon atoms in R.sub.1 and R.sub.2 and the total number of carbon atoms in R.sub.5 and R.sub.6 is 0, 1, or 2; and X.sub.1, X.sub.2 and X.sub.3 are the same or different anions.

IR-sensitive lithographic printing plate precursors provide a high contrast and stable printout image using an IR radiation-sensitive composition. This composition includes: a free radically polymerizable component, an IR absorber, an initiator composition, color-forming compound(s) such as a specific leuco dye, and compound(s) represented by the following Structure (P):

##STR00001##

wherein X is O, S, NH, or CH.sub.2, Y is >N or >CH, R.sup.1 is hydrogen or an alkyl, R.sup.2 and R.sup.3 are independently halo, thioalkyl, thiophenyl, alkoxy, phenoxy, alkyl, phenyl, thioacetyl, or acetyl, and m and n are independently 0 or an integer of 1 to 4. The printout image exhibits a color contrast between the exposed and non-exposed regions of a E greater than 8. A E of at least 5 is maintained between the exposed and the non-exposed regions with exposure to white light for at least one hour. These precursors, when IR-exposed, can be developed on-press.

Lithographic printing plate precursors are prepared with a unique substrate using two separate anodizing processes to provide an inner aluminum oxide layer of average dry thickness (T.sub.i) of 650-3,000 nm and a multiplicity of inner micropores of average inner micropore diameter (D.sub.i) of 15 nm. An outer aluminum oxide layer comprises a multiplicity of outer micropores of average outer micropore diameter (D.sub.o) of 15-30 nm; dry thickness (T.sub.o) of 130-650 nm; and a micropore density (C.sub.o) of 500-3,000 micropores/m.sup.2. The ratio of D.sub.o to D.sub.i is greater than 1.1:1. A hydrophilic layer disposed on the outer aluminum oxide layer has a copolymer composed of (a) recurring units and (b) recurring units, wherein the (a) recurring units have an amide group, and the (b) recurring units have at least a phosphonic acid, a phosphoric acid, a salt of a phosphonic acid, or a salt of a phosphoric acid group.

The present invention provides a lithographic printing plate precursor including at least a heat-sensitive layer and an ink repellent layer disposed on a substrate, the rate of gas generation therefrom being 6.510.sup.5 g/m.sup.3 to 12.510.sup.5 g/m.sup.3 as determined by GC-MS analysis in which the lithographic printing plate precursor is heated in a nitrogen stream at 450 C. for 5 minutes, and also provides a method for producing a lithographic printing plate and a method for producing printed matter therefrom.

The present invention provides a printing plate precursor including a layer which includes particles and is provided at a printing surface side of an aluminum support, in which a modulus of elasticity of the particles is 0.1 GPa or more, and in a case where a Bekk smoothness of an outermost layer surface at the printing surface side is denoted by A second, a specific expression (1) is satisfied; a printing plate precursor laminate; a method for making a printing plate; and a printing method.