Abstract: A laser-engravable flexographic printing element comprising an elastomeric, relief-forming, laser-engravable, thermally and/or photochemically crosslinkable layer comprising, as binder, at least 5% by weight of syndiotactic 1,2-polybutadiene having a content of 1,2-linked butadiene units of from 80 to 100%, a degree of crystallinity of from 5 to 30% and a mean molecular weight of from 20,000 to 300,000 g/mol on a flexible, dimensionally stable support.

Abstract: A thermosensitive plate material for lithographic plate formation according to the present invention includes a substrate (1) and a thermosensitive layer (2) formed thereon. The thermosensitive layer (2) includes an organic polymer (4) containing lipophilic portion forming particles (3). In the thermosensitive layer (2), a surface portion (21) having a thickness of 0.1 &mgr;m or more does not contain the lipophilic portion forming particles (3) but contains a metal oxide (5). The surface portion (21) includes a hydrophilic organic polymer (41), which has been cured with the metal oxide (5). A portion (22) of the thermosensitive layer (2) on the substrate side contains the lipophilic portion forming particles (3). The organic polymer (42) constituting the base portion (22) need not be the hydrophilic organic polymer.

Abstract: A method of designing a chemical amplification type photosensitive composition containing an acid generating agent, wherein the average distance between exposure particles in an exposure area of the photosensitive composition upon pattern exposure of the photosensitive composition or the average distance between the acids generated by the pattern exposure is calculated based on the sensitivity required of the photosensitive composition, and the composition of the photosensitive composition is set so that the diffusion length of the acid generated from the acid generating agent by the pattern exposure is greater than the calculated average distance.

Abstract: This invention relates to a photothermographic element comprising a support, at least one photothermographic imaging layer, and at least one filter layer, wherein the filer layer comprises a heat-bleachable composition comprising a benzothiazine arylidiene filter dye, which filter dye is in the presence of an effective amount of a base precursor.

Abstract: Positive-working thermally imageable elements, useful as printing plate precursors and having reduced ablation when thermally imaged, and methods for their preparation are disclosed. In one aspect, the elements contain a hydrophilic substrate, an underlayer, a barrier layer, and a top layer. The underlayer comprises a photothermal conversion material.

Abstract: In one embodiment, the present invention is directed to a method for preparing a printing member by coating a printing cylinder with a layer comprising ultraviolet-curable silicones and curing the layer using ultraviolet radiation.

Abstract: A method of graft polymerization which includes a step of forming a polymerization initiating layer in which a polymer having, on a side chain thereof, a crosslinking group and a functional group having polymerization initiating capability is immobilized on a support by a crosslinking reaction, and a step of conatacting a compound having a polymerizable functional group with the polymerization initiating layer, and then bonding the compound to the polymerization initiating layer supplying energy thereto, as well as a hydrophilic member, a printing plate precursor, a pattern forming material, a pattern forming method, a method of producing a particle-adsorbed material, and a method of producing a metal particle-dispersed thin layer film, to which the above-mentioned method of graft polymerization can be applied.

Abstract: The invention relates to a process and apparatus for forming a photopolymerizable element useful as a flexographic printing plate having at least one layer of particulate material. The process includes forming a layer of a molten photopolymerizable material onto a support; and applying the particulate material onto an exterior surface of the photopolymerizable layer opposite the support within 48 hours of forming the layer of photopolymerizable material. The process optionally includes heating of the surface of the photopolymerizable layer.

Abstract: A heat-sensitive composition which forms an image without the removal of material, which does not require any developing treatment after the stage of exposure to heat and comprises: (a) a switchable polymer, (b) an IR absorber, (c) a triazine compound, and (d) a novolak resin.

Abstract: A presensitized plate in which an image recording layer is formed on a support for a lithographic printing plate obtainable by performing a treatment with an aqueous solution containing one or more divalent or multivalent cations at a concentration ranging from 0.0001 mol/L to less than 0.020 mol/L is excellent in both scum resistance and press life when processed into a lithographic printing plate.

Abstract: A method for making a lithographic printing plate comprises the steps of imagewise exposing, to a laser beam, a PS plate comprising a substrate, a heat-sensitive layer containing at least one light-heat conversion agent and a binder polymer formed on the substrate and a hydrophilic or lipophobic layer applied onto the heat-sensitive layer; and then removing the hydrophilic or lipophobic layer on the laser-exposed area by developing the imagewise exposed printing plate within 120 seconds from the completion of the laser-exposure to thus give a lithographic printing plate, wherein the developing treatment comprises the step of rubbing the exposed printing plate surface with an abrasion means in the absence of any liquid. This method permits the production of a lithographic printing plate without causing any deterioration of the developing properties of the PS plate even when the imagewise exposed PS plate is developed within a short period of time after the completion of the laser-exposure.

Abstract: Flexographic printing plates are produced by thermal development by a process in which an imagewise exposed flexographic printing element is developed by heating and removing the softened, unpolymerized parts of the relief-forming layer, the flexographic printing element used comprising an olefin/(meth)acrylate copolymer having an olefin content of from 50 to 94 mol %. The photopolymerizable flexographic printing element comprises an olefin/(meth)acrylate copolymer having a content of from 50 to 94 mol % of olefin monomers, from 6 to 50 mol % of (meth)acrylate monomers and from 0 to 5 mol % of further comonomers. This flexographic printing element is used for the production of flexographic printing plates both by thermal development and by development by means of washout compositions.

Abstract: Disclosed is a thermally sensitive imagable article and compositions therefor. The imagable article comprises a coating on a substrate, the coating comprising an amino acid or amide, and a compound capable of generating an acid upon heating. The coating optionally comprises a radiation absorbing compound. When imagewise exposed the coating has the property that exposed regions become relatively insoluble in a developer liquid whereas regions that have not been exposed remain relatively soluble in the developer and dissolve in the developer, leaving the exposed substrate in those regions.

Abstract: The present invention relates to a heat mode-compatible planographic printing plate comprising a photosensitive layer which is capable of recording with an infrared laser and formed by applying a photosensitive layer coating solution onto a hydrophilic support and then drying the photosensitive layer coating solution, the photosensitive layer coating solution being obtained by dissolving or dispersing I) an IR absorber, II) a polymerization initiator, and III) a compound having a polymerizable unsaturated group in a solvent, wherein the residual solvent in the photosensitive layer is 5% by weight or less relative to the weight of the photosensitive layer.

Abstract: Thermally imageable elements useful in lithographic printing are disclosed. The element has a layer of an imageable composition over a support. The imageable composition contains a supramolecular polymer that includes QHB-modified polymeric molecules having the structure A-L-B. A and B are each different QHB-modified portions selected from QHB-modified phenolic portions, QHB-modified acrylic portions, QHB-modified polyester portions, and QHB-modified polyurethane portions. L is a joining group. The elements are suitable for the preparation of lithographic printing plates.

Abstract: Negative thermosensitive lithographic printing plates developable with a non-alkaline aqueous developer and method of developing such plates. The plate comprises on a substrate a thermosensitive layer comprising an ethylenically unsaturated monomer, a free radical initiator, and an infrared absorbing dye. The plate can be imagewise exposed with an infrared laser to cause hardening in the exposed areas and then developed with a non-alkaline aqueous developer to remove the non-exposed areas. The non-alkaline aqueous developer can be water or an aqueous solution comprising at least 60% of water and having a pH of 2.0 to 10.0.

Abstract: Aqueous-based photothermographic materials comprise a hydrophilic binder, preformed silver halides, an organic silver salt other than a silver carboxylate, a reducing agent composition, and one or more mercaptotriazoles as toners in one or more thermally developable imaging layers. These layers have a pH less than 7. These photothermographic materials can be used in combination with phosphor intensifying screens for radiographic imaging.

Abstract: Thermally imageable elements and methods for their preparation and use are disclosed. The elements contain, in order, a substrate; an underlayer; and an ink-repellent layer. The underlayer contains a crosslinked allyl functional polyurethane. A photothermal conversion material is present in either in the underlayer or in an absorber layer between the underlayer and the ink-repellent layer. Thermal imaging and development removes the ink-repellent layer and reveals the underlayer in the exposed regions to form an imaged element useful as a waterless lithographic printing plate.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, comprises latex polymer-carbon black composite particles. Such imaging members can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic polymer having ionic moieties and the latex polymer-carbon black composite particles as a photothermal conversion material. The latex polymer-carbon black composite particles can be formulated in water or water-miscible solvents without agglomeration with other components such as charged polymers.

Abstract: A support material for photographic and non-photographic imaging processes which includes a raw paper and a thermoplastic layer arranged on the front side, the thermoplastic layer features at least one polyolefin layer arranged on the raw paper, at least one polyethylene layer arranged over the polyolefin layer and at least one of these layers contains a polyethylene obtained by means of metallocene catalysts.

Abstract: There are provided a coating liquid for providing an infrared sensitive layer on a photosensitive resin surface, which is obtained by dissolving or dispersing in a specific ester solvent a binder polymer soluble in the solvent, an infrared absorbing substance and, if desired, a non-infrared opaque substance, and a process for obtaining a seamless photosensitive resin sleeve printing plate, which comprises using the same.

Abstract: A lithographic printing plate precursor which comprises a support having provided thereon a layer comprising a hydrophilic medium, wherein the layer comprising a hydrophilic medium contains a hydrophobitization precursor having a hydrophilic surface and a light/heat converting agent which is hydrophilic in itself, or at least on the surface.

Abstract: A method for preparation of a lithographic printing plate, which comprises the steps of: imagewise recording on a lithographic printing plate precursor comprising a support having a hydrophilic surface and a thermosensitive layer, the thermosensitive layer comprising at least one of polymer particles and a microcapsule encapsulating an oleophilic compound therein; and rubbing the printing plate precursor by a rubbing member in the presence of a processing liquid to remove the thermosensitive layer of non-image portions.

Abstract: An aqueous developer for lithographic printing plates and a method for developing the printing plates are disclosed. The developer comprises an organic dispersing agent. The developer develops multi-layer printing plates quickly, with high throughput, but with no sludge formation in the developing process.

Abstract: A photopolymerizable composition which is highly sensitive to light in the visible region and long-wavelength regions including the near infrared region, is not sensitive to light in the ultraviolet region, and has excellent handling efficiency under day light fluorescent lamps. The composition contains an ethylenically unsaturated compound, a dye which has a basic structure, a photopolymerization initiator, and a photopolymerizable lithographic printing plate which has a support and a layer of the photopolymerizable composition on its surface.

Abstract: A method of making a negative-working heat-sensitive lithographic printing plate precursor is disclosed, the method comprising the steps of (a) preparing an aqueous dispersion comprising particles of a hydrophobic thermoplastic polymer A which is not soluble or swellable in an aqueous alkaline developer and particles of a polymer B which is soluble or swellable in an aqueous alkaline developer but not soluble or swellable in water, wherein the glass transition temperature of polymer A is higher than the softening temperature of polymer B; (b) applying the aqueous dispersion on a lithographic substrate having a hydrophilic surface, thereby obtaining an image-recording layer; (c) overall heating the image-recording layer at a temperature which is higher than the softening temperature of polymer B without inducing coalescense of the particles of polymer A. The printing plate precursor has improved mechanical resistance.

Abstract: A method for preparing a lithographic printing plate involving the steps of subjecting, to imagewise exposure, a presensitized plate for use in making a lithographic printing plate comprising an aluminum substrate provided thereon with a light-sensitive layer formed from a photopolymerizable light-sensitive composition, which comprises a compound having an ethylenically unsaturated double bond, a photopolymerization initiator and a polyurethane resin binder and then developing the imagewise exposed plate with a developer containing an inorganic alkaline agent and a nonionic surfactant, carrying a polyoxyalkylene ether group, having a pH value ranging from 10.0 to 12.5 and an electrical conductivity ranging from 3 to 30 mS/cm.

Abstract: A method for treating a photosensitive lithographic printing plate, which comprises exposing the photosensitive lithographic printing plate to laser light, developing with a developer containing an alkali metal silicate and then carrying out post-exposure treatment, said photosensitive lithographic printing plate being prepared by forming a photopolymerizable photosensitive layer having a film thickness of from 1.2 to 4 g/m2 and further forming a protective layer having a film thickness of from 2 to 8 g/m2 on a support having a centerline average height (Ra) of at least 0.35 &mgr;m.

Abstract: A hydrophilic layer and an overcoat layer are provided in this order on a heat-sensitive layer having an ink receiving surface, so as to form an original (plate) for a lithographic printing plate. The overcoat layer can be removed during printing. A system capable of forming an inorganic hydrophilic matrix by sol-gel conversion is provided in the hydrophilic layer. Adhesion between the heat-sensitive layer and the hydrophilic layer decreases in a heated region through image processing. Emulsion ink is supplied to the plate surface during printing, whereby the overcoat layer and the hydrophilic layer at an image portion are removed with a hydrophilic component of the emulsion ink. Thus, with a heat-sensitive original that can be subjected to heat-mode prepress using laser exposure, good printed matter can be stably obtained, irrespective of balance between image and non-image portions, without using wetting water.

Abstract: An image forming method using a negative type image forming material is disclosed, and said method comprises the steps of exposing a negative type image forming material to infrared laser imagewise, which image forming material comprises a substrate and an image recording layer formed thereon, comprising (A) a radical generator, (B) a radical-polymerizable compound, (C) an infrared absorbing agent, and (D) a binder polymer; and developing the image forming material with an alkaline developing solution comprising a weak acid or a salt thereof having a dissociation constant pka of from 10 to 13.

Abstract: Graft copolymers are used for the production of laser-engravable relief printing plates, the graft copolymers being obtained by free radical polymerization of vinyl esters in the presence of polyalkylene oxides and subsequent hydrolysis of the ester function. Processes for the production of transparent flexographic printing plates by means of laser engraving using said graft copolymers are described.

Abstract: A lithographic printing precursor for lithographic offset printing comprises, a layer of imageable medium on a hydrophilic base. The imageable medium comprises hydrophobic polymer particles in an aqueous medium, a substance for converting light into heat, and a non-crosslinkable aqueous-soluble composition. The lithographic printing precursor may be used to make lithographic printing surfaces that obtain long run lengths on lower quality paper and in the presence of press-room chemicals. The lithographic printing precursor can be imaged and developed on-press and the imageable medium can also be sprayed onto a hydrophilic surface to create a printing surface that may be processed wholly on-press. It can also be processed in the more conventional fully off-press fashion. The hydrophilic surface can be a printing plate substrate or the printing cylinder of a printing press or a sleeve around the printing cylinder of a printing press. The cylinder can be conventional or seamless.

Abstract: The invention relates to a process for preparing a flexographic printing plate from a photosensitive element having a photopolymerizable layer and a thermally removable layer on the photopolymerizable layer. The process includes imagewise exposing the photosensitive element and thermally treating the exposed element to form a relief suitable for use in flexographic printing. The thermally removable layer can be transparent or opaque to actinic radiation. The invention also relates to a photosensitive element for use in this process. The photosensitive element includes a photopolymerizable layer and at least one thermally removable layer having a filler and a binder, wherein the binder is less than 49% by weight, based on the total weight of the binder and filler.

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, has an imaging layer comprised of a thermally sensitive ionomer (charged polymer) and a photothermal conversion material that is a bis(aminoaryl)polymethine dye that is soluble in water or a water-miscible organic solvent, and that has a &lgr;max greater than 700 nm as measured in water or the water-miscible organic solvent.

Abstract: A negative-working heat-sensitive material for making a lithographic printing plate by direct-to-plate recording is disclosed which comprises in the order given a lithographic base having a hydrophilic surface, an oleophilic imaging layer and a cross-linked hydrophilic upper layer, characterize in that the oleophilic imaging layer comprises at least one transition metal complex of an organic acid. Materials according to the invention are characterized by an increased run length and can be used as a printing plate immediately after exposure.

Abstract: A heat-sensitive composition of the positive type comprising a polymeric binder and a solubility inhibitor, wherein the said solubility inhibitor consists of an organometallic compound, with the exclusion of the metallocenes, an organic salt or an organic complex of an inorganic salt of a metal belonging to the group IIIA or transition group of the periodic system of the elements.

Abstract: A method of making a lithographic printing plate is disclosed which comprises the steps of

Abstract: A method for forming a dampening-waterless lithographic plate comprising an irradiation step of irradiating a dampening-waterless lithographic blank plate imagewise with a laser beam, the blank plate comprising a support, a photothermal conversion layer provided on the support for converting laser beam energy to heat, and an ink-repellent layer provided on the photothermal conversion layer a first rubbing step of rubbing the surface of the ink-repellent layer without use of a liquid so as to remove at least a portion of the ink-repellent layer in areas irradiated with a laser beam and a second rubbing step of rubbing the surface of the partially removed ink-repellent layer through use of a liquid.

Abstract: A positive working, multi-layer thermally imageable element is disclosed. The element comprises a substrate, an underlayer, and a top layer. The top layer comprises a crosslinked polymeric material. The element may be thermally imaged and developed to form a lithographic printing plate.

Abstract: A direct-to-press imaging method comprises: (a) applying an imageable coating to a printing cylinder, wherein the imageable coating comprises a composition such as a thermally switchable polymer which changes affinity for a printing fluid upon exposure to imaging radiation such as infrared radiation delivered imagewise via a laser, and the imageable coating is substantially insoluble in the printing fluid; (b) imagewise exposing the imageable coating to actinic radiation to obtain an imaged coating; (c) printing a plurality of copies of an image from the imaged coating; and (d) reapplying the imageable coating as desired by repeating steps (a) through (c) at least once without substantially removing the prior imaged coating before reapplying the imageable coating.

Abstract: An image-forming material which has high sensitivity and is excellent in image-forming performance and which does not produce smudges on an optical system of an exposing apparatus, and a planographic printing original plate which uses this image-forming material and can produce images by an infrared laser for a direct plate-making process. These can be achieved by an image-forming material containing an infrared absorber having in the same molecule thereof two or more chromophoric groups which can absorb infrared radiation and are each bonded by a covalent bond.

Abstract: A lithographic printing method is disclosed which comprising the steps of providing an imaging material which comprises a support and an image-recording layer that is not removable with a single-fluid ink which comprises an ink phase and a polar phase; image-wise exposure of the image-recording layer to heat or light without substantially ablating said image-recording layer, thereby switching the affinity of the image-recording towards ink or an ink-abhesive fluid and thereby creating a printing master comprising a lithographic image which consists of unexposed areas that have affinity for one phase of said ink phase and polar phase and of exposed areas that have affinity for the other phase of said ink phase and polar phase; printing, wherein the single-fluid ink is supplied to the printing master.

Abstract: A positive photosensitive printing plate is prepared wherein the photosensitivity is to near-infrared rays which do not induce a chemical change in a photosensitive component. The photosensitive material has an inclined structure from the viewpoint of dissolution of the irradiated portion in an alkali developer. The dissolution rate is such that it continuously increases from the upper, surface part of the photosensitive material to the lower part of the photosensitive material. This effect may be enhanced by diffusion of a material, preferably a polar compound, such as H2O, from the surface toward the inner lower part of the photosensitive material. Techniques for accomplishing the diffusion include contacting the surface of the photosensitive material with an atmosphere of high humidity or overlaying the photosensitive material with a layer of protective material (paper) containing moisture and heating the resultant composite.

Abstract: A printing plate element is disclosed, comprising a substrate and a component layer containing a first material which is water-insoluble or capable of varying from being water-soluble to being water-insoluble at a prescribed temperature of not less than 60° C. and a second material which is water-soluble and has a melting point of 60 to 300° C. A method of preparing a printing plate is also disclosed, comprising imagewise exposure of the printing plate element and removing an unexposed area of the printing plate element with aqueous solution.

Abstract: An offset plate sensitive to UV or visible light, prepared simply and imaged digitally therewith in a CTP method, and also processed in a simple manner. The plate is provided as a photopolymer plate with increased sensitivity, and is used in a simple imaging-on-press system, using the surface of a lithographic printing cylinder itself as a plate substrate.

Abstract: Provided is a heat-sensitive lithographic printing plate comprising a support having thereon an undercoat layer and a heat-sensitive layer in this order, with at least one of the undercoat layer and the heat-sensitive layer comprising polymer hollow microspheres having voids on the inside, or a heat-sensitive lithographic printing plate comprising a support having thereon a heat-sensitive layer, with the heat-sensitive layer comprising polymer hollow microspheres having voids on the inside.

Abstract: Provided is a planographic printing plate precursor having the advantages of good developability in printers, high sensitivity and a long press life. On a support having a hydrophilic surface with hydrophilic graft polymer chains existing therein, formed is a thermosensitive layer containing a polymer having, in the molecule, a functional group capable of interacting with the hydrophilic graft polymer and a functional group that undergoes hydrophilicity/hydrophobicity conversion through exposure to heat, acid or radiation to fabricate the planographic printing plate precursor.

Abstract: A positive working printing form precursor comprises a thermally imagable composition which includes a hydroxyl group-containing polymer, for example a novolak resin. The composition has a weight of less than 1.1 gm−2. It has been found that using a low weight of the composition on the precursor improves the properties of the precursor, in particular by rendering the sensitivity of the precursor to imaging radiation less variable over time.

Abstract: A process for making thermally imageable negative working compositions comprising the steps of:

Abstract: An imaging member, such as a negative-working printing plate or on-press cylinder, can be prepared with a hydrophilic imaging layer comprised of a heat-sensitive hydrophilic charged polymer (ionomer) and an infrared radiation sensitive negatively-charged oxonol dye that has a &lgr;max of greater than 700 nm. The heat-sensitive polymer and IR dye can be formulated in water or water-miscible solvents to provide highly thermal sensitive imaging compositions. In the imaging member, the polymer reacts to provide increased hydrophobicity in areas exposed to energy that provides or generates heat. For example, heat can be supplied by laser irradiation in the IR region of the electromagnetic spectrum. The heat-sensitive polymer is considered “switchable” in response to heat, and provides a lithographic image without conventional alkaline processing.