The present disclosure provides an on-press development type lithographic printing plate precursor having a support, an image-recording layer, and an outermost layer in this order, in which a contact angle of a water droplet on a surface of the outermost layer that is measured 2 seconds after the water droplet is landed by an airborne water droplet method is greater than 36°. The present disclosure also provides applications of the on-press development type lithographic printing plate precursor.

IR-sensitive lithographic printing plate precursors provide a stable print-out image using a unique IR radiation-sensitive composition in an infrared radiation-sensitive image-recording layer. This IR radiation-sensitive composition includes: (1) a free radical initiator composition that comprises an electron-donating agent; (2) a free radically polymerizable composition; and (3) a color-changing compound that is represented by the Structure (I) having an indene ring in the conjugated chain between the aromatic terminal groups. The compound can also have a —C(═O)—OR.sup.7, —SO.sub.2—R.sup.3, or —SO.sub.2NR.sup.8R.sup.9 group wherein R.sup.7 represents a substituted or unsubstituted alkyl group having a secondary or tertiary connecting carbon that connects to the rest of the —C(═O)—OR.sup.7 group; and R.sup.8, R.sup.9, and R.sup.10 independently represent substituted or unsubstituted alkyl, aryl, or heteroaryl groups. After IR imaging, these precursors exhibit desirable printout images both fresh and after dark storage. The precursors can be developed off-press or on-press.

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.

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.

The present disclosure provides an on-press development type lithographic printing plate precursor having a support, an image-recording layer, and an outermost layer in this order, in which the outermost layer contains a hydrophobic polymer, and a contact angle of a water droplet on a surface of the outermost layer that is measured 2 seconds after the water droplet is landed by an airborne water droplet method is less than 36°. The present disclosure also provides applications of the on-press development type lithographic printing plate precursor.

Provided is an on-press development type lithographic printing plate precursor having two or more maximal absorption wavelengths in a wavelength range of 760 nm to 900 nm, in which in a case where the on-press development type lithographic printing plate precursor is subjected to exposure to infrared having a wavelength of 830 nm at an energy density of 110 mJ/cm.sup.2, in a portion subjected to the exposure, a brightness change ΔL before the exposure and after storage subsequent to the exposure for 24 hours under conditions of 25° C. and 70% RH is 3.0 or more. Also provided are a method of preparing a lithographic printing plate and a lithographic printing method in which the on-press development type lithographic printing plate precursor is used.

Provided is a laminate including a lithographic printing plate precursor and interleaving paper, in which the lithographic printing plate precursor is an on-press development type lithographic printing plate precursor containing an acid color developing agent in at least any of layers, and a pH of the interleaving paper is 5 or more.

Provided are a lithographic printing plate precursor comprising: an image-recording layer on a support, in which the image-recording layer includes a dye compound having a decomposable group that is decomposed by an acid, heat, or both and a structure in which decomposition of the decomposable group opens a ring or desorbs a leaving group and an electron-donating polymerization initiator, a method for producing a lithographic printing plate in which the lithographic printing plate precursor is used, and a color-developing composition including a dye compound having a decomposable group that is decomposed by an acid, heat, or both and a structure in which decomposition of the decomposable group opens a ring or desorbs a leaving group and an electron-donating polymerization initiator.

A system for exposing a heat and/or light sensitive printing plate precursor including a coating on a support includes a platesetter including a laser head for generating a laser beam to create an image, and the platesetter further includes an electrostatic generator capable of electrostatically charging the surface of the coating.

Provided is a photosensitive resin composition, including: a polymer compound which has a polycyclic structure and a sulfonamide group in a main chain thereof; and an infrared absorbent, wherein the polycyclic structure has at least one structure selected from the group consisting of a fused cyclic hydrocarbon structure and a fused polycyclic aromatic structure.