Abstract:
A lithographic printing plate for infrared laser is provided which shows an excellent coated surface state and an excellent stability with time against scratch, and which has a heat-sensitive layer containing the following (A) to (D): (A) a substance which absorbs a light to generate heat; (B) an alkaline aqueous solution-soluble resin having phenolic hydroxyl groups; (C) a polymer containing as a polymerizable component (meth)acrylate monomer having within the molecule 2 or 3 perfluoroalkyl groups containing 3 to 20 carbon atoms; and (D) a fluorine-containing polymer containing at lease a specific monomer as a copolymerizable component.
Abstract:
A positive image recording material applicable to infrared laser comprising a support whereon is formed a photosensitive/heatsensitive layer containing (A) an alkali-soluble resin, (B) a photothermal conversion substance, and (C) at least one compound selected from a group of compounds defined by the formulae (I), (II), (III), and (IV) exhibiting improved solubility to an alkaline developer following exposure with an infrared laser wherein the substituent groups of the formulae (I) to (IV) are specified in the specification for this invention.
Abstract:
The present invention relates to a method for forming images which comprises imagewise exposing a photopolymerizable image-forming material comprising a substrate provided thereon with an image-recording layer which comprises a specific photopolymerization initiator system, a polymerizable compound carrying at least one ethylenically unsaturated group and a binder polymer and then developing the imagewise exposed material with a developer containing at least one carbonate and at least one hydrogen carbonate and a specific surfactant in an amount ranging from 1.0 to 10% by weight, and having a specific pH and a specific electrical conductivity. The image-forming method permits the achievement of a sufficient developing ability even at a relatively low pH at which the image-forming material is not damaged so much and the preparation of a printing plate having good printing durability.
Abstract:
A positive working lithographic printing plate precursor comprising a lower layer containing a water-insoluble and alkali-soluble resin, and an upper heat-sensitive layer containing a water-insoluble and alkali-soluble resin and an infrared absorbing dye and increasing the solubility in an alkaline aqueous solution by heating, provided in this order on a hydrophilic support, and (a) the upper heat-sensitive layer containing at least two kinds of surface active agents, or (b) the lower layer and upper heat-sensitive layer each containing a surface active agent different from each other.
Abstract:
A lithographic printing plate precursor comprising, in this order, a support, an undercoat layer and a photosensitive layer containing an infrared absorber, a polymerization initiator, a polymerizable compound and a binder polymer, wherein the undercoat layer contains a polymer compound having an acid group, and Ra, ΔS and a45 of a surface of the support are satisfied with the following conditions (i) to (iii), respectively: (i) Ra: 0.2 to 0.40 μm, (ii) AS: 35 to 85%, (iii) a45: 25 to 55%, in which Ra, ΔS (%) and a45 are defined herein.
Abstract:
The present invention provides an image recording material comprising a substrate, an intermediate layer, and a photosensitive layer containing a novolac phenol resin and a light to heat conversion agent and being recordable with an infrared laser. The intermediate layer and photosensitive layer are sequentially provided on the substrate. The intermediate layer contains a polymer having an acidic group and being capable of interacting with the novolac phenol resin contained in the photosensitive layer. A planographic printing plate excellent in chemical resistance and printing durability is obtained by heat-treating the image recording material at 150 to 300° C. after effecting image-wise exposure with an infrared laser and development.
Abstract:
The heat mode image recording material of the present invention comprises an infrared absorbent (A), and a polymer (B) comprising a polyfunctional monomer component. The material can be exposed to an infrared laser, whereby an image can be formed thereon. The heat mode image recording material of the invention has superior film-formability and superior film strength, and is useful for a the recording layer of a planographic printing plate precursor having wide development latitude and excellent scratch resistance.
Abstract:
A lithographic printing process which comprises the steps of: imagewise exposing to infrared light a presensitized lithographic plate which comprises a hydrophilic support and a removable image-forming layer containing an infrared absorbing agent having the absorption maximum within an infrared region and a visible dye having the absorption maximum within a visible region to shift the absorption maximum of the visible dye within the exposed area with a change of at least 50 nm in the wavelength and a change of at least 15 in color in terms of ΔE, and to make the image-forming layer irremovable within the exposed area; removing the image-forming layer within the unexposed area of the lithographic plate mounted on a cylinder of a printing press; and then printing an image with the lithographic plate mounted on the cylinder of the printing press. The other processes are also disclosed.
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 requiring no fountain solution, comprising, in this order: a back layer containing a particle having an average particle size of 0.2 to 4.0 nullm; a support; a light-to-heat conversion layer; and a silicone rubber layer, wherein a dynamic friction coefficient between a surface of the back layer and a surface of a plate cylinder of a press on which the lithographic printing plate precursor is to be loaded is from 0.17 to 0.26.