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.

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.

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.

A method for making a lithographic printing plate is disclosed including the steps of (i) image-wise exposing a printing plate precursor to heat and/or IR radiation; said precursor including a support and a coating comprising a polymerisable compound, an infrared absorbing compound, a borate compound and a photoinitiator including a trihaloalkyl group; (ii) developing the exposed precursor by treating the coating of the precursor with a gum solution thereby removing the coating from the support at the non-image areas; and/or by mounting the precursor on a plate cylinder of a lithographic printing press and rotating the plate cylinder while feeding dampening liquid and/or ink to the precursor.

A lithographic printing plate precursor is disclosed including a coating comprising a polymerisable compound, an infrared absorbing dye, a photoinitiator including a trihaloalkyl group and a borate compound.

Provided are a planographic printing plate precursor including a support and an image recording layer formed on the support, in which the image recording layer contains a polymer A which includes a constitutional unit A1 having an ethylenically unsaturated group, a weight-average molecular weight of the polymer A is in a range of 2,500 to 35,000, and a content of the constitutional unit A1 in the polymer A is 15 mol % or more, and a method of producing a planographic printing plate using the planographic printing plate precursor.

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 is a lithographic printing plate precursor having: a support; and an image-recording layer as an outermost surface layer on the support, in which the image-recording layer includes a hydrophilic polymer, an ion intensity derived from the hydrophilic polymer has a maximum value I1, the ion intensity being measured by a time-of-flight secondary ion mass spectrometry in such a manner that cutting is carried out from an image-recording layer surface in a direction of the support by an Ar gas cluster ion beam method, a ratio d0/d1 of a thickness d0 of the image-recording layer to a depth d1 from an outermost layer at which the I1 is obtained is 2.0 or more, and a ratio I1/I0 of the I1 to an ion intensity I0 derived from the hydrophilic polymer at a depth from the outermost layer of the d0 is 1.5 or more.

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.