The present invention provides a planographic printing plate original including, in the order mentioned below: a substrate; and at least a heat sensitive layer and a silicone rubber layer provided on the substrate, wherein the heat sensitive layer contains a polyurethane having a carbonate structure. The present invention also provides a method of producing a planographic printing plate using the same, and a method of producing a printed matter. An object of the present invention is to provide: a planographic printing plate original which has an excellent halftone dot reproducibility and printing durability, and in which the occurrence of scumming can be prevented; a method of producing a planographic printing plate using the same; and a method of producing a printed matter.

An on-press development type lithographic printing plate precursor having 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 a color-developing substance precursor, and in a case where the image-recording layer is exposed to an infrared laser having a wavelength of 830 nm at an energy density of 110 mJ/cm.sup.2, a loss of ethylenically unsaturated bonds in an exposed area in the image-recording layer is 10% to 40% of ethylenically unsaturated bonds in a non-exposed area in the image-recording layer, and a method for preparing a lithographic printing plate or a lithographic printing method using the on-press development type lithographic printing plate precursor.

A method of forming printing sleeve for mounting on a cylinder in a printing press is provided. The method includes providing a permanent hydrophilic tubular layer on a tubular base; selectively providing a first temporary hydrophobic layer on the hydrophilic tubular layer to form a first imaged printing sleeve, the temporary hydrophobic layer forming a first image; printing, by the first imaged printing sleeve, a first print job including the first image on a substrate; and removing the first temporary hydrophobic layer from the permanent hydrophilic layer such that the permanent hydrophilic layer remains intact on the tubular base. A lithographic printing sleeve for a printing press is also provided.

A negative-working lithographic printing plate precursor has a negative-working infrared radiation-sensitive image-recording layer that has a) two or more free radically polymerizable components; b) an initiator composition capable of generating free radicals; and c) one or more infrared radiation absorbing cyanine dyes. The a) two or more free radically polymerizable components comprise a combination of a urethane (meth)acrylate and a polyester (meth)acrylate, which together, comprise 75-100 weight % of all free radically polymerizable components. The weight ratio of the urethane (meth)acrylates to the polyester (meth)acrylates is from 90:10 to and including 35:65. The urethane (meth)acrylates comprise one or more urethane linkages and at least 4 acrylate or methacrylate ester groups. Each of the one or more polyester (meth)acrylates is free of a urethane linkage and is represented following structure (I). These precursors are less sensitive to ambient ozone and can be infrared radiation imaged and developed on-press during lithographic printing.

A system for preparing a photopolymer printing plate includes exposure unit comprising a plurality of UV light emitting diodes (UV LEDs), a holder comprising a UV translucent material configured to receive the printing plate, and a controller configured to activate the plurality of UV LEDs. The UV LEDs include a plurality of stationary back UV LEDs configured to emit UV radiation toward the non-printing back side of the printing plate through the holder with the printing plate disposed in a stationary position on the holder, the plurality of stationary back UV LED sources together defining at least one back array having a collective irradiation field covering an area at least coextensive with the lateral length and lateral width of the plate.

Provided is an imageable composition for a photosensitive negative-working lithographic printing plate, and a platemaking method therefor. The imageable composition includes the following components in parts by mass: 25-65 parts of a free radical polymerizable compound, 0.5-25 parts of a photoinitiator, 10-60 parts of a binder, and 1-20 parts of a development accelerator. The platemaking method may comprise coating a substrate, which may have a hydrophilic surface or a hydrophilic layer, with an imageable composition to obtain a photosensitive negative-working lithographic printing plate precursor. The method may additionally include exposing the lithographic printing plate precursor by using laser light and according to a required image, so as to form an exposed region and an unexposed region. Further the method may include removing the unexposed region from the exposed printing plate precursor by means of a development process, so as to obtain a required lithographic printing plate.

Provided are a planographic printing plate precursor for furnishing a planographic printing plate in which edge stain does not occur, adhesion to interleaving paper is prevented, and the water width with respect to edge stain at the time of printing is wide; a method of producing the same, and a printing method using the same. The planographic printing plate precursor including: a support; an image recording layer formed on the support; and a water-soluble compound having a molecular weight in a range of 60 to 300 and a solubility of 10 g/L or greater in water at 20 C., in which a content of the compound per unit area in a region on the image recording layer side from an end portion of the planographic printing plate precursor to a portion inside the end portion by 5 mm is greater than a content of the compound per unit area in a second region other than the first region by an amount of 50 mg/m.sup.2 or greater.

Provided is a planographic printing plate precursor including: a support; and an image recording layer formed on the support, in which the content of fine particles per unit area in a region on a plate surface on the image recording layer side from an end portion of the planographic printing plate precursor to a portion inside the end portion by 5 mm is greater than the content of the fine particles per unit area in a region other than the region by an amount of 10 mg/m.sup.2 or greater, edge stains are not generated therein, and transferring of the image recording layer is prevented even in a case where planographic printing plate precursors are stored in a stacked state. Further, provided are a method of producing the same and a printing method using the same.

There are free radical scavengers of formula (P.sub.m-L).sub.n-T.sub.q. Also provided are negative-working lithographic printing plate precursors comprising a hydrophilic substrate and a NIR photopolymerizable or UV-violet photopolymerizable imageable layer coated on the hydrophilic layer, the imageable layer also being photopolymerizable by visible light, the imageable layer having an outer surface and a thickness, the outer surface of the imageable layer being uniformly, and partially or completely crosslinked down to a depth corresponding to at most about 70% of the thickness of the imageable layer.

Provided are a photosensitive resin composition which enables production of a lithographic printing plate precursor having a non-image portion which has good solubility in an alkali aqueous solution and which enables production of a lithographic printing plate having excellent chemical resistance and excellent printing durability, a lithographic printing plate precursor obtained by using the photosensitive resin composition, a method for producing a lithographic printing plate, and a new polymer compound. The photosensitive resin composition of the present invention contains: a polymer compound which has an amine bond or a quaternary ammonium salt bond, and at least one bond selected from the group consisting of a urea bond, a urethane bond, and a carbonate bond in the main chain and has a sulfonamide group or a phenolic hydroxyl group in the main chain and/or the side chain; and an infrared absorbing material.