IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR radiation-sensitive composition. This IR radiation-sensitive composition includes: a) free radically polymerizable component; an b) IR radiation absorber; c) an initiator composition; a d) borate compound; and a e) compound capable of forming a colored boronic complex during or after exposure of the infrared radiation-sensitive image-recording layer to infrared radiation. The resulting print-out image exhibits an excellent color contrast between the exposed and non-exposed regions. After IR imaging, these precursors can be developed off-press or on-press.

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 has a thickness comprised between 0.1 g/m.sup.2 and 1.75 g/m.sup.2 and includes an infrared absorbing compound which includes a thermocleavable group which transforms into a group which is a stronger electrondonor upon exposure to heat and/or IR radiation, and is capable of forming a printout image upon exposure to heat and/or IR radiation.

Provided are a planographic printing plate precursor including a support, and an image recording layer in this order, in which the image recording layer contains polymer particles containing an addition polymerization type resin, and the addition polymerization type resin contains a polymerizable group and a hydrophilic structure; a method of producing a planographic printing plate using the planographic printing plate precursor; a planographic printing method using the planographic printing plate precursor; and a curable composition containing the polymer particles.

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.

Provided are a planographic printing plate precursor including an aluminum support, and an image recording layer and a protective layer which are provided on the aluminum support in this order, in which a thickness of the protective layer is 0.2 μm or greater, and Expression (1) is satisfied in a case where a Bekk smoothness of a surface of an outermost layer on a side opposite to a side where the image recording layer is provided is denoted by b seconds; a planographic printing plate precursor laminate; a plate-making method for a planographic printing plate; and a planographic printing method.

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.

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 an leuco dye and a hydrophobic binder.

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.

An object of the present invention is to provide a flexographic printing plate precursor in which occurrence of wrinkles in an infrared ablation layer is suppressed and reproducibility of microcells is improved in a case of being made into a flexographic printing plate, and a manufacturing method of a flexographic printing plate using the flexographic printing plate precursor. The flexographic printing plate precursor of the present invention is a flexographic printing plate precursor including, in the following order, a support, a photosensitive layer, an interlayer, and an infrared ablation layer, in which the interlayer contains a rubber component and a resin component, and the resin component contains at least one of an acrylic resin or a methacrylic resin.