An object of the invention is to provide an aluminum support for a planographic printing plate and a planographic printing plate precursor which can be used to obtain a plate precursor for a planographic printing plate that is excellent in terms of plate wear resistance in the case of being used to produce a planographic printing plate and exhibits excellent on-machine developability. In an aluminum support for a planographic printing plate of the embodiment of the invention, an average value of surface area-increase rates S.sub.SEM (%) is 200% or more, and an average value of pit depths h.sub.SEM (nm) is 400 nm 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 toplayer provided above the photopolymerisable layer: characterized in that the toplayer includes a halogenated polymer and a nitrite and/or nitrate salt.

The present invention provides a lithographic printing plate precursor that enables a lithographic printing plate formed therefrom to have excellent image visibility and a long press life, as well as a lithographic printing plate manufacturing method and a printing method. The lithographic printing plate precursor of the invention is a lithographic printing plate precursor including an aluminum support and an image recording layer, the aluminum support includes an aluminum plate and an anodized film of aluminum formed on the aluminum plate, the anodized film is positioned closer to the image recording layer than the aluminum plate is, the anodized film has micropores extending in a depth direction of the anodized film from a surface of the anodized film on the image recording layer, the micropores have an average diameter of more than 10 nm but not more than 100 nm at the surface of the anodized film, and the surface of the anodized film on the image recording layer side has a lightness L* of 70 to 100 in a L*a*b* color system.

Provided is a method for production of an aluminium strip for lithographic printing plate supports from an aluminium alloy including (in wt %): 0.05%Si0.25%, 0.2%Fe1%, Cu max. 400 ppm, Mn0.30%, 0.10%Mg0.50%, Cr100 ppm, Zn500 ppm, Ti<0.030%, the remainder aluminium and unavoidable impurities individually at most 0.03%, in total at most 0.15%. In the method, a rolling ingot is cast from an aluminium alloy, and the rolling ingot is homogenised. Further, the rolling ingot is hot rolled to a hot strip final thickness, and the hot strip is cold rolled to final thickness of between 0.1 mm and 0.5 mm. The product of the relative final thicknesses of the aluminium strip after the first and after the second cold rolling pass of the aluminium strip is 15% to 24%.

Provided are a planographic printing plate precursor, a laminate thereof, and a method of producing a planographic printing plate precursor capable of satisfying all purposes for eliminating interleaving paper used for preventing scraping and peeling, preventing adhesion, imparting a plate-separating property for preventing multiple-plate feeding, and preventing scratches. The planographic printing plate precursor which includes a polymer layer on a surface of a belt-like support 12 includes a back coat layer 70 having an arithmetic average surface roughness Ra of 0.5 m or greater due to a surface roughness structure in which thin film portions 60 and thick film portions 62 are continuously formed on a rear surface of the belt-like support 12.

Provided are a planographic printing plate precursor for on-press development, including: an aluminum support; an interlayer which contains a compound containing a support absorptive group and a hydrophilic group; and an image recording layer which contains an infrared absorbing agent, a polymerization initiator, a polymerizable compound, and polymer particles formed of a styrene copolymer, on the aluminum support, in which the aluminum support is an aluminum plate having an anodized film on a surface in contact with the interlayer and the anodized film has micropores extending in a depth direction from a surface in contact with the interlayer, and an average pore diameter of the micropores in the surface of the anodized film is in a range of 20 to 40 nm; a method of preparing a planographic printing plate and a planographic printing method obtained by using the planographic printing plate precursor for on-press development.

The present invention provides a printing plate precursor including a layer which includes a polymer and is provided on a printing surface side of an aluminum support, and a layer which includes particles and is provided on a side opposite to the printing surface side, 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 on the side opposite to the printing surface side is denoted by b second, a specific expression (1) is satisfied; a printing plate precursor laminate; a method for making a printing plate; and a printing method.

This application relates to coating and inks compositions comprising starch derivatives, their uses and substrates comprising such compositions.

An on-press development type lithographic printing plate precursor including a support, and an image-recording layer on the support, in which the image-recording layer contains an infrared absorber, a polymerization initiator, a polymerizable compound, and one or more compounds selected from the group consisting of a compound represented by Formula (1) and a compound represented by Formula (2) (in Formula (1) and (2), Ra.sub.1 and Ra.sub.2 represent an alkyl group, Rb.sub.1 and Rb.sub.3 represent an alkyl group, Rb.sub.2 and Rb.sub.4 represent an alkyl group, and EDG's each independently represent a hydrogen atom or an electron-donating group, provided that at least one of the four EDG's in Formula (1) represents an electron-donating group).

Lithographic printing plate precursors are prepared with a unique substrate and one or more radiation-sensitive imageable layers. The substrate is prepared by two separate anodizing processes to provide an inner aluminum oxide layer having an average dry thickness (T.sub.i) of 650-3,000 nm and a multiplicity of inner micropores having an average inner micropore diameter (D.sub.i) of 15 nm. A formed outer aluminum oxide layer comprises a multiplicity of outer micropores having an average outer micropore diameter (D.sub.o) of 15-30 nm; an average 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, and D.sub.o in nanometers and the outer aluminum oxide layer micropore density (C.sub.o) in micropores/m.sup.2, are further defined by the outer aluminum oxide layer porosity (P.sub.o) according to the following equation:

0.3P.sub.o0.8

where P.sub.o is 3.14(C.sub.o)(D.sub.o.sup.2)/4,000,000.