Abstract: The invention provides a waterless offset lithographic printing plate precursor that is mountable on a magnet type printing cylinder and has high durability and halftone dot reproducibility. The waterless offset lithographic printing plate precursor contains at least a heat-sensitive layer and a silicone rubber layer disposed on a substrate, the substrate being of a ferromagnet material.

Abstract: A method is provided for production of a flexographic printing plate precursor for laser engraving including at least the following steps to be carried out in this order: (1) a step for separately preparing a plurality of fluids that are reactive with each other, (2) a step for carrying out in-line mixing of the plurality of fluids to form a reactive resin composition, (3) a step for casting the reactive resin composition onto a release material to form a cast film, (4) a step for heating the cast film, and (5) a step for removing the cast film from the release material to form an independent sheet made of the reactive resin composition.

Abstract: A photosensitive resin printing plate precursor including: a photosensitive resin layer (A) containing a water-soluble or water-dispersible resin and an ultraviolet-curable monomer; and a water-insoluble heat-sensitive mask layer (C) containing an infrared-absorbing material, deposited in that order on a support is disclosed. By introducing a crosslinked structure or a hydrophobic constituent to the heat-sensitive mask layer (C) so as to be insoluble in water, a difference in polarity is produced between the layers (A) and (C) and, thus, mass transfer between the two layers can be prevented. Also, the scratch resistance of the heat-sensitive mask layer (C) can be dramatically enhanced and, thus, the printing plate precursor becomes easy to handle.

Abstract: An object of the present invention is to provide a photosensitive resin printing plate precursor capable of forming a protruding relief pattern without using any original pattern film. Specifically, the present invention relates to a photosensitive resin printing plate precursor including: a photosensitive resin layer (A) containing a water-soluble or water-dispersible resin and an ultraviolet-curable monomer; and a water-insoluble heat-sensitive mask layer (C) containing an infrared-absorbing material, deposited in that order on a support. By introducing a crosslinked structure or a hydrophobic constituent to the heat-sensitive mask layer (C) so as to be insoluble in water, difference in polarity is produced between the layers (A) and (C) and, thus, mass transfer between the two layers can be prevented. Also, the scratch resistance of the heat-sensitive mask layer (C) can be dramatically enhanced and, thus, the printing plate precursor becomes easy to handle.

Abstract: A directly imageable planographic printing plate precursor, which may be of the positive or negative type, has at least a heat sensitive layer on a substrate. The heat sensitive layer contains a light-to-heat conversion material and a metal-containing organic compound.

Abstract: A directly imageable planographic printing plate precursor which may be of the positive or negative type, has at least a heat sensitive layer on a substrate. The heat sensitive layer contains a light-to-heat conversion material and a metal-containing organic compound.

Abstract: A directly imageable waterless planographic printing plate, which has at least the heat sensitive layer and an ink repellent layer in this order on a substrate, having a high sensitivity and good image reproducibility and allowing a heat sensitive layer to remain even after development is produced by imagewisely irradiating a precursor of the printing plate with a laser beam, pre-treating the precursor by a pre-treatment liquid containing an amine compound by 0.1 to 30 wt % based on the weight of the entire pre-treatment liquid, and removing the ink repellent layer at the laser beam irradiated area, in this order, such that the heat sensitive layer is at least partially left on the printing plate after completion of the above steps.

Abstract: A directly imageable waterless planographic printing plate precursor is a laminate of, in turn, at least a heat sensitive layer and a silicon rubber layer on a substrate. The heat sensitive layer includes (A) a light-to-heat converting material and (B) a compound which contains N—N bonds.

Abstract: A directly imageable raw plate for waterless planographic printing plate, in which a heat insulating layer, heat sensitive layer and ink repellent layer are formed in this order on a substrate, comprising physical properties of 5 to 100 kgf/mm.sup.2 in initial elastic modulus and 0.05 to 5 kgf/mm.sup.2 in 5% stress as tensile properties of the heat sensitive layer or the heat insulating layer or the laminate consisting of both the layers.It can be suitably used also for large printing presses and web offset printing presses requiring high printing durability, and makes it possible to obtain an economically advantageous printing plate.