Abstract:
A method for producing a planographic printing plate is provided, which includes: subjecting a planographic printing plate precursor to image-wise exposure, wherein the precursor includes plural recording layers at least one of which contains (A) an infrared absorbing agent on a support, the upper recording layer contains (B) a water-insoluble and alkali-soluble polymer compound having a repeating unit containing a fluoroalkyl group or a siloxane structure; and developing the precursor using an alkali developer containing (C)an ammonium salt compound of Formulae (C-1) to (C-3), wherein R1 represents a methyl group or an ethyl group, R2 and R3 represent a hydrocarbon group having 3 to 20 carbon atoms, R4 represents a hydrocarbon group, A represents an atomic group which forms a nitrogen-containing aliphatic ring with N+, B represents an atomic group which forms a nitrogen-containing aromatic ring with N+, and X−represents a counter anion.
Abstract:
A lithographic printing plate precursor in a positive-type with an infrared-sensitivity, having a support and an image recording layer provided on the support, the support having a hydrophilic surface, the recording layer having a particular resin, an amphoteric surfactant and/or an anionic surfactant, and an infrared absorbing agent, wherein the particular resin being at least one of resins selected from the group consisting of a polyurethane resin, a poly(vinyl acetal) resin, and maleimide resin A.
Abstract:
A method of making a planographic printing plate includes exposing, to infrared light, a planographic printing plate precursor including a recording layer provided on a substrate, and developing the precursor using an aqueous alkaline solution. The recording layer comprises a copolymer containing a structural unit derived from (meth)acrylonitrile and at structural unit derived from styrene, a water-insoluble and alkali-soluble resin, and an infrared absorbing agent, the solubility of the recording layer in the aqueous alkaline solution being increased by the exposure. The aqueous alkaline solution has a pH of 8.5 to 10.8 and contains a betaine-based amphoteric surfactant and an ammonium salt represented by Formula (I): R1, R2, R3, and R4 each independently represent an alkyl or aryl group; the total number of carbon atoms in R1, R2, R3, and R4 is not more than 20; and X− represents a counter anion.
Abstract:
A positive-working lithographic printing plate precursor for infrared laser is provided that includes, layered sequentially above a support, a lower layer and an upper layer, the lower layer and/or the upper layer including an infrared absorbing agent, either the lower layer comprising an alkali-soluble group-containing graft copolymer or the upper layer comprising a sulfonamide group-, active imide group-, and/or amide group-containing graft copolymer, and the graft copolymer being a polyurethane resin having as a graft chain an ethylenically unsaturated monomer-derived constitutional unit. There is also provided a process for making a lithographic printing plate, the process including in sequence an exposure step of imagewise exposing by means of an infrared laser the positive-working lithographic printing plate precursor for infrared laser and a development step of developing using an aqueous alkali solution with a pH of 8.5 to 10.8.