Abstract:
Provided are, as a lithographic printing plate precursor that enables good development with a developer having a pH from 2 to 10 and is excellent in runlength and stain resistance and a production process of a lithographic printing plate using the precursor, a lithographic printing plate precursor whose photosensitive layer contains the following components (A), (B), and (C): (A) a copolymer having a repeating unit of the formula (1) and at least one of a repeating unit of the formula (2) and a repeating unit of the formula (3): wherein each of A and B independently represents a hetero atom, each of R and R 1 to R 9 represents a monovalent substituent, L represents a divalent linking group, X represents a hydroxyl group, a monovalent group containing an acid group, an alkyleneoxy group, an amide group, or an ether group, an amino group, an ammonium group, or a salt obtained by neutralizing an acid group, and L 0 represents a single bond or divalent hydrocarbon group, (B) a compound having an ethylenically unsaturated bond, and (c) a polymerization initiator; and a production process of a lithographic printing plate by using the precursor.
Abstract:
The present invention provides method for preparing a lithographic printing plate comprising: (i) exposing to laser light having a wavelength of 350-450 nm a lithographic printing plate precursor comprising a hydrophilic support; a photosensitive layer containing (A) a sensitising dye having a maximum absorption wavelength of 350-450 nm, (B) a hexaarylbiimidazole compound, (C) a polymerizable compound, (D) a hydrophobic binder polymer having a crosslinkable functional group in a side chain, and (E) a chain transfer agent; and a protective layer in this order; and (ii) rubbing a surface of the exposed lithographic printing plate precursor with a rubbing member in an automatic processor in the presence of a developer having a pH of 2-10 to remove the protective layer and unexposed areas of the photosensitive layer. A lithographic printing plate precursor as defined above is also provided, wherein the hydrophobic binder polymer has an acid value of 0.3 meq/g or less.
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 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:
To provide a developer for processing of a lithographic printing plate precursor, containing a non-reducing sugar having bonded therein two or more monosaccharides and having a pH of 6 to 14 and thereby provide a developer having a pH stable to aging and an excellent film-forming property, a method for manufacturing a lithographic printing plate, where a lithographic printing plate excellent in developability and dispersibility of development scum and kept from staining of the non-image area can be manufactured even by simple processing of one solution and one step requiring no water washing step, a developer used therefor, and a printing method of performing printing by using the manufacturing method of a lithographic printing plate.
Abstract:
By a method of preparing a lithographic printing plate having exposing a lithographic printing plate precursor including a photosensitive layer containing (A) a polymerization initiator, (B) a polymerizable compound, (C) a sensitizing dye and (D) a binder polymer and a protective layer in this order on a hydrophilic support with laser and then removing the protective layer and an unexposed area of the photosensitive layer in the presence of a developer, in which the developer is a developer which has pH of from 2 to less than 10 and contains an amphoteric surfactant and a nonionic surfactant having an alkylene oxide chain, a simple processing of one solution and one step which does not require a water washing step becomes possible, excellent development property is achieved and a lithographic printing plate which has good printing durability and does not cause printing stain can be provided.