Abstract: A platemaking method for a lithographic printing plate, comprises: imagewise exposing a lithographic printing plate precursor comprising: a hydrophilic substrate; and a negative image recording layer containing a water-insoluble polymer; and removing a non-exposed area of the image recording layer with an aqueous solution, wherein a temperature of the aqueous solution is higher than a glass transition temperature (Tg) of the water-insoluble polymer.

Abstract: A method for preparing a lithographic printing plate includes: exposing a lithographic printing plate precursor including a hydrophilic support, a photosensitive layer containing (A) a sensitizing dye having an absorption maximum in a wavelength range of from 350 to 450 nm represented by the formula (I) as defined herein, (B) a polymerization initiator, (C) a polymerizable compound and (D) a binder polymer and a protective layer in this order with laser of from 350 to 450 nm; and removing the protective layer and an unexposed area of the photosensitive layer in the presence of a developer having pH of from 9 to 11 and containing a carbonate ion, a hydrogen carbonate ion, a surfactant and a water-soluble polymer compound by an automatic processor.

Abstract: A method for preparing a lithographic printing plate includes: exposing a lithographic printing plate precursor including a hydrophilic support, a photosensitive layer containing (A) a sensitizing dye having an absorption maximum in a wavelength range of from 350 to 450 nm represented by the formula (I) or (II) as defined herein, (B) a polymerization initiator, (C) a polymerizable compound and (D) a binder polymer and a protective layer in this order with laser of from 350 to 450 nm; and removing the protective layer and an unexposed area of the photosensitive layer in the presence of a developer having pH of from 9 to 11 and containing an alkali agent, a surfactant and a water-soluble polymer compound by an automatic processor.

Abstract: A method for preparing a lithographic printing plate includes: exposing imagewise a lithographic printing plate precursor comprising, in the following order, a hydrophilic support, a photosensitive layer containing (A) a sensitizing dye, (B) a polymerization initiator, (C) a polymerizable compound and (D) a binder polymer and a protective layer containing at least one acid-modified polyvinyl alcohol in an amount of 50% by weight or more based on a total solid content of the protective layer; and removing the protective layer and an unexposed area of the photosensitive layer with a developer having pH of from 2 to 8.

Abstract: A lithographic printing process comprises the steps of: imagewise exposing to infrared light a presensitized lithographic plate which comprises a hydrophilic support and an image-forming layer containing an infrared absorbing agent, a polymerization initiator and a binder polymer to polymerize the polymerizable compound within the exposed area; removing the image-forming layer within the unexposed area while mounting the lithographic plate on a cylinder of a printing press; and then printing with the lithographic plate while mounting the lithographic plate on the cylinder of the printing press. The polymerization initiator is a salt of an anion with a sulfonium ion. According to the present invention, a specific anion or a specific sulfonium ion is used in the polymerization initiator.

Abstract: A lithographic printing plate precursor comprising an image recording layer containing a sensitizing dye, a polymerization initiator, a polymerizable compound and a binder polymer and a hydrophilic support, wherein the image recording layer or a layer optionally provided between the image recording layer and the hydrophilic support contains a compound capable of forming an adsorptive group to the hydrophilic support due to heat, an acid or a radical.

Abstract: A method for preparation of a lithographic printing plate including: exposing with a laser a lithographic printing plate precursor including a support and a photosensitive layer containing a sensitizing dye, a radical polymerization initiator, a radical polymerizable compound and a binder polymer; and subjecting the exposed lithographic printing plate precursor to development processing with a developer having pH of from 3 to 9 to remove an unexposed area of the photosensitive layer, wherein the binder polymer is a polymer having an acid value of from 10 to 250 mg-KOH/g and the developer contains a compound represented by one of the formulae <1>, <2> and <3> defined herein.

Abstract: A heat-sensitive lithographic printing plate of the present invention, which enables image recording by infrared-ray scanning exposure based on digital data and has excellent on-press developability, high resistance to scumming and a long press life, the heat-sensitive lithographic printing plate having on a support with a hydrophilic surface an image-forming layer made up of microcapsules in which a reactive group-containing hydrophobic compound is enclosed, a light-to-heat converting agent and a water-soluble compound which has a reactive group capable of reacting with the hydrophobic compound and is situated outside the microcapsules.

Abstract: A method for preparation of a lithographic printing plate including: exposing imagewise a lithographic printing plate precursor including a hydrophilic support, a photosensitive layer containing a sensitizing dye, a radical polymerization initiator, a radical polymerizable compound and a binder polymer and a protective layer provided in this order, to laser radiation; conducting development processing to remove the protective layer and an unexposed area of the photosensitive layer; covering the exposed area of the photosensitive layer remaining on a surface of a lithographic printing plate with a layer of liquid; and performing overall exposure of the lithographic printing plate to light having a wavelength capable of causing radical polymerization.

Abstract: An image forming method in which a planographic printing plate precursor having, on a support, an image recording layer containing (A) a polymerization initiator, (B) a polymerizable compound, and (C) a binder polymer, and having photosensitivity in a wavelength range of 250 nm to 420 nm, is subjected to exposure using laser light in the wavelength range of 250 nm to 420 nm, and a one-pixel drawing time is one millisecond or less, a planographic printing plate precursor having the image recording layer which further contains (D) a compound having a polymerizable group and a support adsorptive group, or (F) a filler, and a planographic printing method including development-on-machine, are provided.

Abstract: A method for preparing a lithographic printing plate comprising: exposing a lithographic printing plate precursor comprising a hydrophilic support, a photosensitive layer containing a sensitizing dye having an absorption maximum in a wavelength range of from 350 to 450 nm represented by the formula (I) as defined herein, a polymerization initiator, a polymerizable compound and a hydrophobic binder polymer having an acid value of 0.3 meq/g or less and a protective layer provided in this order with a laser beam of from 350 to 450 nm; and rubbing a surface of the exposed lithographic printing plate precursor with a rubbing member in the presence of a developer having pH of from 2 to 10 in an automatic processor equipped with the rubbing member to remove the protective layer and an unexposed area of the photosensitive layer.

Abstract: The invention provides an image recording method and a lithographic printing method in which both high image quality and good fine line reproducibility can be achieved, and high sensitivity and safety under white light can be obtained, and the image recording method for a lithographic printing plate, which comprises imagewise exposing with an imaging time per pixel of 1 millisecond or less using a laser light with an emission wavelength of from 250 nm to 420 nm, wherein the lithographic printing plate precursor comprises a support and an image recording layer, in which the image recording layer contains (A) a polymerization initiator and (B) a polymeric compound and has an image recording layer which is photosensitive in a wavelength of from 250 nm to 420 nm, and the support has an anodized film with sealed micropores on the surface; and a lithographic printing method utilizing the same.

Abstract: A method for preparing a lithographic printing plate comprising: exposing a lithographic printing plate precursor comprising a hydrophilic support, a photosensitive layer containing (A) a sensitizing dye having an absorption maximum in a wavelength range of from 350 to 450 nm represented by the formula (I) or (II) as defined herein, (B) a polymerization initiator, (C) a polymerizable compound and (D) a hydrophobic binder polymer having an acid value of 0.3 meq/g or less and a protective layer provided in this order with a laser beam of from 350 to 450 nm; and rubbing a surface of the exposed lithographic printing plate precursor with a rubbing member in a presence of a developer having pH of from 2 to 10 in an automatic processor equipped with the rubbing member to remove the protective layer and an unexposed area of the photosensitive layer.

Abstract: The present invention provides an exposure processing method of a planographic printing plate including: providing an image recording layer containing a polymerizable compound which is solid at room temperature, a polymerization initiator, and a light-to-heat converting agent, and a microcapsule encapsulating at least one of the monomer and the polymerization initiator, such that the light energy quantity absorbed in the lower part of the image recording layer is more than the light energy quantity absorbed in the upper and middle parts of the image recording layer; exposing the image recording layer; and thereafter post-heating the image recording layer at a temperature in a range equal to or above the melting point of the monomer and below the glass transition point of the wall of the microcapsule. As a result, the printing resistance of a planographic printing plate is enhanced.

Abstract: An on-press development or non-processing (non-development) type lithographic printing plate precursor capable of giving a printout image having a large lightness difference, and a lithographic printing method using this lithographic printing plate precursor are provided, a lithographic printing plate precursor comprising a support and a photosensitive-thermosensitive layer capable of recording an image by infrared laser exposure, the lithographic printing plate precursor being capable of performing a printing by loading on a printing press without passing through a development processing step after recording an image, or by recording an image after loading on a printing press, wherein said photosensitive-thermosensitive layer comprises (1) an infrared absorbent and (2) a discoloring agent or discoloration system capable of generating a color change upon exposure; and the lithographic printing method performing a printing using the above-described lithographic printing plate precursor.

Abstract: A method for preparation of a lithographic printing plate, which comprises the steps of: imagewise recording on a lithographic printing plate precursor comprising a support having a hydrophilic surface and a thermosensitive layer, the thermosensitive layer comprising at least one of polymer particles and a microcapsule encapsulating an oleophilic compound therein; and rubbing the printing plate precursor by a rubbing member in the presence of a processing liquid to remove the thermosensitive layer of non-image portions.

Abstract: A lithographic printing plate precursor comprises an image-forming layer containing a polymerization initiator and a polymerizable compound, and a hydrophilic support, wherein the lithographic printing plate precursor comprises a compound containing at least one functional group having an interaction with a surface of the hydrophilic support.

Abstract: The present invention provides an exposure processing method of a planographic printing plate comprising: providing an image recording layer containing a polymerizable compound which is solid at the room temperature, a polymerization initiator, and a light-to-heat converting agent, and a microcapsule encapsulating at least one of the monomer and the polymerization initiator, such that the light energy quantity absorbed in the lower part of the image recording layer is more than the light energy quantity absorbed in the upper and middle parts of the image recording layer; exposing the image recording layer, and thereafter post-heating the image recording layer at a temperature in a range equal to or above the melting point of the monomer and below the glass transition point of the wall of the microcapsule. As a result, the printing resistance of a planographic printing plate is enhanced.

Abstract: A method for preparation of a lithographic printing plate comprising: exposing a lithographic printing plate precursor comprising a hydrophilic support, a photosensitive layer containing (A) a sensitizing dye having an absorption maximum in a wavelength range of from 350 to 450 nm, (B) a hexaarylbiimidazole compound, (C) a polymerizable compound, (D) a hydrophobic binder polymer and (E) a chain transfer agent and a protective layer in this order, with a laser beam of from 350 to 450 nm; and rubbing a surface of the exposed lithographic printing plate precursor with a rubbing member in a presence of a developer having pH of from 2 to 10 in an automatic processor equipped with the rubbing member to remove the protective layer and an unexposed area of the photosensitive layer.

Abstract: Disclosed is a method of carrying out lithographic printing using a plate having an image recording layer capable of being developed with dampening water and/or ink, the method including: a development step in which a plate bearing a recorded image, mounted on a plate cylinder and having a given surface speed is subjected to contact with a dampening roller and/or a form roller having a surface speed differing from the surface speed of the plate, and is thereby supplied with dampening water and/or ink; and a printing step in which ink is transferred to a printing material while the dampening roller and form roller remain in contact with the plate. The method of the present invention is a lithographic printing method which uses on-machine development type plates and has a very high productivity because the amount of paper spoilage at the start of printing is low and the time until scum-free impressions are obtained is short.