Abstract:
The invention provides a photosensitive composition including (A) a vinyl polymer containing a copolymerization component having a carboxyl group, having a content of the carboxyl group in a molecule of 2.0 meq/g or higher and having a solubility parameter less than 21.3 MPa1/2, (B) a polymer compound including a phenolic hydroxyl group, and (C) an IR absorber.
Abstract:
A method for preparing a negative-working lithographic printing plate is provided which comprises the steps of (1) providing a lithographic printing plate precursor comprising on a grained and anodized aluminum support, having a hydrophilic surface, a coating comprising (i) polymer particles which are core-shell particles having a hydrophobic heat-softenable core and a hydrophilic shell and (ii) an infrared light absorbing agent, (2) exposing said coating to heat, thereby inducing coalescence of said polymer particles at exposed areas of said coating, and (iii) developing said precursor by applying a gum solution to said coating, thereby removing non-exposed areas of said coating from said support. According to the above method the printing plates exhibit after ageing an improved clean-out and a reduced background stain, resulting in toning-free printing.
Abstract:
A polymer compound includes i) a polymerization unit represented by —(CHR3—CR4(-L1-Y1))x—(CHR5—CR6(-L2-Y2))y-; and ii) a silane coupling group represented by —S—(CH2)n—Si—(R1)m(OR2)3-m, as a terminal of the polymer, wherein R1, R2, R3, R4, R5, R6, n, x, y, L1, L2, Y1 and Y2 are defined in the specification. A lithographic printing plate base includes: a support; and a hydrophilic layer containing solid particles to a surface of which a hydrophilic polymer is chemically bonded.
Abstract:
The present invention provides a planographic printing plate precursor including a support and a positive recording layer formed on the support and containing: (A) a polymer having a structural unit represented by the following general formula (1), (B) a photo-thermal converting agent, and (C) an amino compound having a methylol group or an alkoxymethyl group; and a positive recording layer whose solubility in an alkaline developer is improved by exposure to light or by heating. In general formula (1), R1 represents an alkyl group or a cyclic group, x represents 0 or 1, and A represents a bivalent bonding group. According to the invention, a positive planographic printing plate precursor for use with infrared lasers having excellent chemical resistance and wide image development latitude can be obtained.
Abstract:
The present invention provides a polymerizable composition comprising (A) a compound represented by the following formula (I), (B) an infrared absorbent, and (C) a compound having at least one addition-polymerizable ethylenically unsaturated bond, and a negative planographic printing plate precursor having a recording layer containing the polymerizable composition. In the formula (I), R1, R2, R3, R4, R5, and R6 each independently represent a hydrogen atom or a monovalent organic group; and X− represents an anion.
Abstract:
Radiation-sensitive element comprising (a) a substrate with at least one hydrophilic surface and (b) a radiation-sensitive coating on at least one hydrophilic surface of the substrate, wherein the coating comprises: (i) at least one free-radical polymerizable monomer and/or oligomer and/or polymer with at least one ethylenically unsaturated group each, (ii) at least one absorber selected from photoinitiators and sensitizers, which is capable of absorbing radiation of a wavelength in the range of 250 to 1,200 nm and (iii) at least one stabilizer comprising in its molecule at least one group capable of inhibiting free-radical polymerization, and at least one other group capable of sorption at the hydrophilic surface of the substrate.
Abstract:
A presensitized lithographic printing plate comprises a hydrophilic support and an image-forming layer. The image-forming layer contains microcapsules and a hydrophilic compound. The microcapsules are dispersed in the image forming layer. The hydrophilic compound is arranged outside of the microcapsules. The microcapsules comprise a core and a shell. The core comprises a polymerizable compound. The shell comprises a polymer. The polymer of the shell has adherence to a surface of the hydrophilic support.
Abstract:
An on-press developable heat-sensitive lithographic printing plate precursor comprising: a support having a water-wettable surface; and an image forming layer, wherein the image forming layer comprises microcapsules containing a lipophilic compound and one of a leuco dye which forms a color by an action of an acid and a dye which reduces the maximum absorption intensity in a visible region by an action of an acid, an acid generator capable of generating an acid on heat application, and a light-heat converting substance.
Abstract:
A photosensitive composition containing: (A) a sensitizing dye; (B) a photopolymerization initiator; (c) a polymerizable compound having an ethylenically unsaturated bond; and (D) a polymer binder, wherein the photopolymerization initiator exhibits a reaction rate constant with a semiquinone radical anion in the range of 2.0×102 to 1.0×108 (mol−1·l·s−1).
Abstract:
The invention is a directly imageable waterless planographic printing plate precursor comprising: at least a heat insulating layer, a heat sensitive layer, and an ink repellent layer that are provided in that order on a substrate, wherein a transmittance of the heat insulating layer for a light having a wavelength within a range of 400 to 650 nm is at most 15% over the entire range of the wavelength. The invention provides a directly imageable waterless planographic printing plate precursor that allows measurement of the dot area ratio on the printing plate with a densitometer or the like.