Abstract:
Negative-working imageable elements that can be imaged using infrared radiation comprise an imageable layer and a protective overcoat on a hydrophilic substrate. The imageable layer includes an IR-sensitive cyanine dye. The protective overcoat predominantly comprises one or more poly(vinyl alcohol) resins, each of which has a hydrolysis level of 85% or less. The use of this particular overcoat composition used in combination with the IR-sensitive cyanine dye provides improved tolerance to fogging by white light while maintaining desired imaging speed.
Abstract:
A lithographic printing plate precursor includes: a support; and a photosensitive layer containing a binder polymer containing a positively charged nitrogen atom in at least one of a main chain and a side chain of the binder polymer, a compound containing an ethylenically unsubstituted bond; and a radical polymerization initiator.
Abstract:
A lithographic printing plate precursor includes: a support having a surface, a contact angle of water droplet in air on which is 70° or more; and a photosensitive layer, wherein the support has, on a surface of the support, a compound having a functional group X, the functional group X is a functional group capable of forming a chemical bond with a compound having a functional group Y which can interact with the functional group X, when the functional group X is brought into contact with the compound having a functional group Y, to adsorb the compound having a functional group Y on the surface of the support so as to decrease the contact angle of water droplet in air on the surface of the support to 30° or less.
Abstract:
A method of on-press developing a laser sensitive lithographic printing plate with ink and/or fountain solution is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and on-press developed with ink and/or fountain solution. The exposure and development are performed with the plate under lightings that contain no or substantially no radiation below a wavelength selected from 400 to 650 nm, or in the dark or substantially dark.
Abstract:
An objective is to provide a planographic printing plate material capable of being exposed to infrared laser, which exhibits excellent printing durability and storage property (specifically at high humidity). Also disclosed is a planographic printing plate material comprising a hydrophilic support and provided thereon, a lower layer and an upper layer each possessing an alkali soluble resin, wherein the upper layer possesses a compound represented by Formula 1: wherein R1 represents an alkyl group having 1-6 carbon atoms, each of R2 and R3 independently represents a hydrogen atom or an alkyl group, and X− represents a non-nucleophilic anion group.
Abstract:
A polymerizable composition contains a binder polymer containing a functional group having a dipole moment of 3.8 debye or more and being represented by the formula (1), (2), (3), (4) or (5) as defined herein, a radical polymerizable compound and a radical polymerization initiator.
Abstract:
A method of deactivating and on-press developing an exposed lithographic printing plate is disclosed. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is exposed with the radiation, deactivated, and then on-press developed with ink and/or fountain solution. The deactivation of the exposed plate allows the handling of the plate under regular office light or any other light without causing the hardening of the non-exposed areas of the photosensitive layer.
Abstract:
A lithographic printing plate precursor capable of forming an image upon irradiation with an infrared laser comprising a support, a first layer containing as the main component an alkali-soluble resin and a second layer containing as the main component an alkali-soluble resin that is different from the alkali-soluble resin contained as the main component in the first layer in this order, and at least one of the first layer and the second layer contains a mixture comprising at least two kinds of infrared absorbing agents.
Abstract:
The present invention provides a planographic printing plate precursor including on a support a photosensitive layer that contains a polymerizable composition containing a specific binder polymer having a repeating unit of formula (I), an infrared absorbent, a polymerization initiator and a polymerizable compound, wherein R1 represents a hydrogen atom or a methyl group; R2 represents a linking group which includes two or more atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom and a sulfur atom and has a number of atoms of 2 to 82; A represents an oxygen atom or —NR3— in which R3 represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; and n represents an integer of 1 to 5. The invention also provides a planographic printing plate precursor provided with a specific photosensitive layer with respect to an alkaline developer.
Abstract:
A lithographic printing plate precursor comprising: a support; an image recording layer comprising (A) an actinic ray absorber, (B) a polymerization initiator, and (C) a polymerizable compound, wherein the image recording layer is capable of being removed with at least one of a printing ink and a fountain solution; and an overcoat layer comprising an inorganic laminar compound. And a lithographic printing method comprising: mounting a lithographic printing plate precursor on a printing press; imagewise exposing the lithographic printing plate precursor with laser beams; and feeding at least one of a printing ink and a fountain solution to the lithographic printing plate precursor to remove a laser beams non-exposed area in an image recording layer; and performing printing.