Abstract:
A method of lithographic printing is disclosed which comprises the steps of unwinding a web of an imaging material from a supply spool, the imaging material comprising (1) a flexible lithographic base having a hydrophilic surface and (2) an image-recording layer which is removable in a single-fluid ink or can be rendered removable in a single-fluid ink by exposure to heat or light, wrapping the imaging material around a cylinder of a printing press, image-wise exposing the image-recording layer to heat or light, processing the image-recording layer by supplying single-fluid ink, thereby obtaining a printing master, printing by supplying single-fluid ink to the printing master which is mounted on a plate cylinder of the printing press, removing the printing master from the plate cylinder, preferably by winding up on an uptake spool. Since the image-recording layer can be processed by single-fluid ink, the imaging material is suitable for on-press processing in printing presses wherein no fountain solution is supplied to the plate. The method allows a rapid, fully automatic plate change with reduced press down time.
Abstract:
A heat mode-applicable image-formation material having high sensitivity and excellent image-forming property, and a novel infrared absorber which can be suitably used in this material. The present invention relates to a substrate carrying thereon an image-formation layer which contains an infrared absorption agent. The agent has at least one surface orientation group in the molecule, and solubility of the image-formation layer in an alkaline aqueous solution is changed by action of radiation in the near-infrared range. Preferable as the infrared absorbing agent is an infrared absorber comprising, in a molecule thereof, a fluorine-containing substituent which have at least 5 fluorine atoms, or a polymethine chain of at least 5 carbon atoms and an alkyl group of at least 8 carbon atoms, said alkyl group being connected to the polymethine chain via any of nitrogen, oxygen and sulfur.
Abstract:
The present invention provides a resin composition that includes (A) a polymer compound that has, on a side chain of a main chain polymer, through a linkage group containing a hydrogen-bonding group and a ring structure, a terminal ethylenic unsaturated bond, and is soluble or swelling in water or an alkali aqueous solution, and (B) a compound that generates radicals when exposed to light or heat. The invention further provides a thermo/photosensitive composition that includes (Anull) a polymer compound that has a non-acidic hydrogen-bonding group on a side chain and is soluble or swelling in water or an alkali aqueous solution, and (Bnull) a compound that generates radicals when exposed to light or heat.
Abstract:
A lithographic printing plate precursor is disclosed, comprising a hydrophilic support having thereon a heat-sensitive layer containing either a microcapsule containing a compound having a functional group capable of reacting by heat or a fine particulate polymer, wherein (1) when the heat-sensitive layer contains a fine particulate polymer, the fine particulate polymer may be a fine particulate polymer capable of combining or incapable of combining by heat used for the image formation and the fine particulate polymer has a functional group capable of reacting with a functional group present in another fine particulate polymer or with a functional group present in another component in the heat-sensitive layer; or (2) when the heat-sensitive layer contains a microcapsule containing a compound having a functional group capable of reacting by heat, the microcapsule may be a microcapsule having an outer wall capable of rupturing or incapable of rupturing by heat used for the image formation and a light-to-heat converting material is contained in the heat-sensitive layer or in a layer adjacent thereto.
Abstract:
Disclosed is a printing plate precursor comprising a substrate and provided thereon, a layer containing a light heat conversion material, wherein the light heat conversion material does not substantially change in nature when allowed to stand in a temperature atmosphere of 400 to 500° C. for 10 minutes or a printing plate precursor comprising a substrate and provided thereon, a hydrophilic layer which is porous, wherein the hydrophilic layer contains a carbon atom-free material in an amount of not less than 91% by weight.
Abstract:
QHB-Modified free radical polymerizable compounds and free radical polymerizable compositions that comprise these compounds are disclosed. A QBH-modified free radical polymerizable compound has at least one moiety that comprises at least one free radical polymerizable group; a supporting backbone, and at least one and preferably at least two moieties capable of forming four or more, typically four, hydrogen bonds with similar or complementary units on other molecules or portions of molecules. Free radical polymerizable compositions that contain these compounds may be used in any of the well-known applications for free radical polymerizable compositions. They are especially useful for the formation of imageable elements useful as lithographic printing plate precursors.
Abstract:
An IR-sensitive composition comprising, in addition to a polymeric binder, a free radical polymerizable system consisting of at least one member selected from unsaturated free radical polymerizable monomers, oligomers which are free radical polymerizable, and polymers containing CnullC bonds in the back bone and/or in the side chain groups and an initiator system, wherein the initiator system comprises the following components: (a) at least one material capable of absorbing IR radiation, (b) at least one compound capable of producing radicals and (c) at least one hereto-substituted arylacetic acid co-initiator compound indicated by the following general structures: 1 where X is either nitrogen, oxygen or sulfur, Ar is any substituted or unsubstituted aryl ring and R is any subconstituent.
Abstract:
Lithographic printing plates having on a hydrophilic substrate an oleophilic photosensitive layer comprising an oleophilic polymer, a free radical polymerizable monomer, and 4-piperonyl-2,6-bis(trichloromethyl)-s-triazine as free radical initiator and/or leucomalachite green as exposure indicating dye; wherein the weight ratio of the monomer to the polymer is larger than 1.0. The plates can be developed with ink and/or fountain solution on a lithographic printing press or with a non-alkaline aqueous developer comprising 60-99% by weight of water and 0.5 to 40% by weight of an alcohol solvent. A photosensitive dye can be added in the photosensitive layer to provide photosensitivity to a specific wavelength between 200 and 1200 nm. Unlike commonly used s-triazine initiator or leuco dye, 4-piperonyl-2,6-bis(trichloromethyl)-s-triazine or leucomalachite green does not insolubilize from the photosensitive layer.
Abstract:
The present invention provides an image recording material onto which images can be recorded with an infrared ray, the material comprising an infrared absorbent (A), a radical-generating agent (B) and a radically polymerizable compound (C), wherein the infrared absorbent is a cyanine dye in which at least one substituent on a nitrogen atom in a heterocyclic ring at each end forms a cyclic ring which includes a methine chain.
Abstract:
There is provided a negative planographic printing plate which can be directly recorded based on digital data from computers and the like, excellent in storage stability, shows no reduction in sensitivity with the lapse of time, and has excellent face flatness. It comprises a substrate having disposed thereon a photosensitive layer which is obtained by applying a photosensitive layer application solution containing an infrared absorber, a compound which generates a radical or acid due to heat, a polymerizable compound or a crosslinking compound, and a silicon-based surfactant such as a siloxane/oxyethylene copolymer and the like, onto the substrate and drying the solution, and which is hardened by exposure to an infrared laser ray.