Abstract: A method for eliminating unwanted ink-receptive sections in positive working printing plates resulting from shading of the surface layer during exposure by the clamps holding the plate on the exposure apparatus following development of an imagewise exposed precursor. Accordingly the areas that are shaded are identified prior to development and the surface layer is scored in those areas to a depth and density sufficient to result in the scored layer being removed during development but not deep enough to damage the underlying hydrophilic layer.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including both constitutional units having a pendant cyano group attached directly to the hydrophobic backbone, and constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. When the imageable element is imaged and developed, the resulting printing plate may exhibit improved on-press solvent resistance and longer press life.

Abstract: Developer composition obtainable by (a) providing water, (b) dissolving such an amount of an alkaline component selected from alkali silicates, alkali hydroxides, Na3PO4, K3PO4, NR4OH, wherein each R is independently selected from C1C4 alkyl groups and C1-C4 hydroxyalkyl groups, and mixtures thereof in the water provided in step (a) that a pH of more than 12 is obtained, and (c) dissolving a stabilizer selected from M2CO3, MHCO3, or a mixture of 2 or more thereof, wherein each M is independently selected from Li, Na, K and NR?4 and each R? independently represents H or C1-C4 alkyl, in the solution obtained in step (b) wherein the amount of the added stabilizer is such that the amount of the added carbonate anion is 1.5 to 20 wt-%, based on the total weight of the developer composition.

Abstract: The present invention relates to a polymerizable coating composition suitable for the manufacture of printing plates, which may be developable on-press. The coating composition comprises (i) a polymerizable compound and (ii) a polymeric binder comprising polyethylene oxide segments, wherein the polymeric binder is selected from the group consisting of at least one graft copolymer comprising a main chain polymer and polyethylene oxide side chains, a block copolymer having at least one polyethylene oxide block and at least one non-polyethylene oxide block, and a combination thereof. The invention is also directed to an imageable element comprising a substrate and the polymerizable coating composition.

Abstract: The present invention provides methods of imagewise exposing a thermally sensitive composition formed from a nanopaste comprising inorganic nanoparticles, a carrier, and preferably certain polymeric binders. The composition has been applied to a substrate and treated to improve adhesion. Exposure affects the solubility of exposed portions of the applied and treated layer relative to unexposed portions of the applied layer. The imaged layer is then developed on-press with a fountain solution, lithographic ink, or both, to remove the exposed portions or unexposed portions of the layer to form an image in a printing plate.

Abstract: Multilayer thermally imageable elements useful as lithographic printing plate precursors are disclosed. The imageable elements comprise a substrate, an underlayer over the substrate, and a top layer over the underlayer. The top layer contains a polymer containing anhydride groups. This polymer is present in the top layer in an amount of at least 60% based on the dry weight of the layer. The imageable elements have excellent resistance to press room chemicals.

Abstract: Initiator system comprising: (a) at least one substance capable of absorbing IR radiation, (b) at least one compound capable of forming free radicals, and (c) at least one 1,4-dihydropyridine derivative of the formula (I)

Abstract: A method of preparing negative-working, single-layer imageable elements improves their storage stability in a humid environment. The method includes enclosing the coated imageable elements in a water-impermeable sheet material that substantially inhibits the transfer of moisture to and from the imageable element. Such imageable elements include a radiation-sensitive composition that includes a radically polymerizable component, an initiator composition to provide radicals upon exposure to imaging radiation, a radiation absorbing compound, and a polymeric binder having poly(alkylene glycol) side chains.

Abstract: The present invention provides an imageable element including a lithographic substrate and an imageable layer disposed on the substrate. The imageable layer includes a radically polymerizable component, an initiator system capable of generating radicals sufficient to initiate a polymerization reaction upon exposure to imaging radiation, and a polymeric binder having a hydrophobic backbone and including both constitutional units having a pendant cyano group attached directly to the hydrophobic backbone, and constitutional units having a pendant group including a hydrophilic poly(alkylene oxide) segment. The invention also provides a method for preparing a suitable polymeric binder. The method comprises contacting a combination of co-monomers in a solvent mixture consisting essentially of a (C1–C6) alkanol and water.

Abstract: A positive-working imageable element comprises inner and outer layers and a radiation absorbing compound such as an IR absorbing dye. The inner layer includes a polymeric material that is removable using an alkaline developer. An ink receptive outer layer is not removable using an alkaline developer before its exposure to imaging radiation. The outer layer includes a polymer binder having pendant epoxy groups that are substantially unreacted during exposure.

Abstract: The present invention relates to negative-working imageable elements that can be used for the manufacture of printing plates. These imageable elements can be developed on on-press by the action of a lithographic printing ink used in combination with either water or a fountain solution. The imageable elements comprise an imageable layer that is not removable in water or fountain solution alone. The imageable layer includes a free radically polymerizable compound, a free radical initiator composition, an infrared radiation absorbing compound, and a polymeric binder comprising poly(alkylene oxide) pendant groups, and preferably additionally pendant cyano groups.

Abstract: The present invention provides methods of imagewise exposing a thermally sensitive composition formed from a nanopaste comprising inorganic nanoparticles, a carrier, and preferably certain polymeric binders. The composition has been applied to a substrate and treated to improve adhesion. Exposure affects the solubility of exposed portions of the applied and treated layer relative to unexposed portions of the applied layer. The imaged layer is then developed on-press with a fountain solution, lithographic ink, or both, to remove the exposed portions or unexposed portions of the layer to form an image in a printing plate.

Abstract: Imageable elements that contain silicate-coated polymer particles in the imageable layer, stacks of these elements, and methods for forming images using these elements are disclosed. The elements do not stick to each other when stacked without interleaving paper, and only one imageable element is lifted at a time when the imageable elements are handled by automatic processing equipment. Blanket piling is not observed when silicate-coated particles are present in the imageable layer.

Abstract: A method for eliminating unwanted ink-receptive sections in positive working printing plates resulting from shading of the surface layer during exposure by the clamps holding the plate on the exposure apparatus following development of an imagewise exposed precursor. Accordingly the areas that are shaded are identified prior to development and the surface layer is scored in those areas to a depth and density sufficient to result in the scored layer being removed during development but not deep enough to damage the underlying hydrophilic layer.

Abstract: Imageable elements, useful as on press developable lithographic printing plate precursors, are disclosed. The elements comprise an imageable layer over a substrate and an one or more adhesion promoting ingredients. The imageable layer comprises a polymerizable compound and a polymeric binder. The adhesion promoting ingredients are titanium chelate and/or co-polymers of a monomer having a polethylene oxide side chain with a monomer having either an acidic group or an anhydride group that has been ring opened to form an acidic group or groups.

Abstract: Initiator system comprising: (a) at least one substance capable of absorbing IR radiation, (b) at least one compound capable of forming free radicals, and (c) at least one 1,4-dihydropyridine derivative of the formula (I) wherein R1 is selected from a hydrogen atom, —C(O)OR7, an optionally substituted alkyl group, an optionally substituted aryl group and an optionally substituted aralkyl group, R2 and R3 are independently selected from optionally substituted alkyl groups, optionally substituted aryl groups, CN and a hydrogen atom, R4 and R5 are independently selected from —C(O)OR7, —C(O)R7, —C(O)NR8R9 and CN, or R2 and R4 together form an optionally substituted phenyl ring or a 5- to 7-membered carbocyclic or heterocyclic ring, wherein the unit is present in the carbocyclic or heterocyclic ring adjacent to position 5 of the dihydropyridine ring and wherein the carbocyclic or heterocyclic ring optionally comprises additional substituents, or both R2 and R4 as well as R3 and R5 form either optiona

Abstract: The present invention provides an imageable composition including an acid curable composition, an acid generator, an infrared absorber having a counter anion derived from a non-volatile acid, and a strong acid such as a sulfonic acid. The imageable composition may include components such as a crosslinkable binder or a colorant. In one embodiment, the imageable composition further includes a colorant having a counter anion derived from a non-volatile acid. The present invention further provides an imageable element, which includes a substrate and an imageable coating on a surface of the substrate. Also provided is method of producing an imaged element according to the invention.

Abstract: A method for forming images useful as lithographic printing plate precursors is disclosed. An imageable element in which the imageable layer comprises an acid generator, a crosslinking agent, and a binder is imaged with ultraviolet radiation and developed with a solvent based developer. The acid generator is an iodonium, sulfonium, or diazonium salt in which the anion is an organic sulfate or thiosulfate anion. The binder comprises a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, in which the reactive pendent group is hydroxyl, carboxylic acid, sulfonamide, alkoxymethyl, or a mixture thereof. The method is especially suited for use with direct digital ultraviolet imaging devices. The resulting image is useful as a lithographic printing plate.

Abstract: An apparatus and method for providing substantially intimate rolling contact between a portion of a donor sheet and a portion of an acceptor element in a laser-induced thermal transfer printer comprises a rotatably mounted cylindrical drum, an acceptor element affixed to and supported by the cylindrical drum, a rotatably mounted dispensing roller for dispensing a donor sheet, and a rotatably mounted receiving roller for receiving the donor sheet, so that the donor sheet is extended between the dispensing roller and the receiving roller. A plurality of rotatably mounted contact rollers configured to bring a portion of the donor sheet extended between the dispensing roller and the receiving roller into contact with a portion of the acceptor element is also included.

Abstract: Imageable elements, useful as on press developable lithographic printing plate precursors, are disclosed. The elements comprise an imageable layer over a substrate and an one or more adhesion promoting ingredients. The imageable layer comprises a polymerizable compound and a polymeric binder. The adhesion promoting ingredients are titanium chelate and/or co-polymers of a monomer having a polethylene oxide side chain with a monomer having either an acidic group or an anhydride group that has been ring opened to form an acidic group or groups.