Abstract: Infrared radiation-sensitive, positive-working lithographic printing plate precursors have improved scratch resistance in their outermost imageable layer because that layer comprises a unique combination of first and second alkali solution-soluble or -dispersible resins. The first alkali solution-soluble or -dispersible resin is an acid-functionalized novolak or acid-functionalized resole resin. The second alkali solution-soluble or -dispersible resin is a polyurethane or polyurethane urea comprising a polysiloxane unit segment in the polyurethane or polyurethane urea backbone or a side chain.

Abstract: Lithographic printing plate precursors can have an imageable layer that includes a polymeric binder having an acid number of at least 30 mg KOH/g of polymer to and including 150 mg KOH/g of polymer, at least 3 weight % of recurring units derived from one or more N-alkoxymethyl (alkyl)acrylamides or alkoxymethyl (alkyl)acrylates, at least 2 weight % of recurring units having pendant 1H-tetrazole groups, and at least 10 weight % of recurring units having pendant cyano groups. The use of such polymeric binders provides good bakeability and chemical solvent resistance, especially for positive-working precursors.

Abstract: Lithographic printing plate precursors can have an imageable layer that includes a polymeric binder having an acid number of at least 30 mg KOH/g of polymer to and including 150 mg KOH/g of polymer, at least 3 weight % of recurring units derived from one or more N-alkoxymethyl (alkyl)acrylamides or alkoxymethyl (alkyl)acrylates, at least 2 weight % of recurring units having pendant 1H-tetrazole groups, and at least 10 weight % of recurring units having pendant cyano groups. The use of such polymeric binders provides good bakeability and chemical solvent resistance, especially for positive-working precursors.

Abstract: An apparatus and method for improving the durability of an image on an imaging material, including increasing the press run length or a printing plate. The apparatus and method can involve the use of, as an example but not restricted to, an imaging device, a pre-bake oven, a processor, and a post-process treatment unit that employs infrared lamps adapted to irradiate the image.

Abstract: A lithographic processing solution has a pH of less than 12 and comprises at least 0.001 and up to and including 1 weight % of a water-soluble or water-dispersible, non-IR-sensitive compound that has a heterocyclic moiety with a quaternary nitrogen in the 1-position of the heterocyclic ring, and has one or more electron donating substituents attached to the heterocyclic ring, at least one of which electron donating substituents is attached in the 2-position. This processing solution can be used to develop both single-layer and multi-layer positive-working lithographic printing plate precursors that have been imaged using infrared radiation.

Abstract: Electrochemically grained and anodized aluminum supports are treated with a post-treatment coating solution containing a polymer derived at least in part from vinyl phosphonic acid and phosphoric acid. This post-treated support is useful as substrates in the preparation of lithographic printing plate precursors. The post-treatment substrate treatment enables wide latitude in manufacturing and compatibility with silicate-free developers to achieve negligible background staining and oxide attack.

Abstract: Single- and multi-layer positive-working imageable elements include an ink receptive outer layer that includes inorganic, non-metallic, inert discrete particles, such as nano-sized silica, aluminum oxide, or titanium dioxide particles. The presence of these particles in the outermost layer improves the abrasion and scratch resistance of the elements.

Abstract: A method and apparatus for producing an imaged lithographic printing plate are described, wherein the method comprises single-step processing and drying from at least the printing side of the plate, wherein the drying step is carried out immediately after squeezing the processed plate.

Abstract: On-press developable, negative-working, infrared radiation-sensitive lithographic printing plate precursors have an imageable layer on a substrate. The imageable layer includes a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to infrared radiation, a polymeric binder, a first infrared radiation absorbing compound that has a tetraaryl pentadiene chromophore, and a second infrared radiation absorbing compound that is different than the first infrared radiation absorbing compound. The first IR absorbing compound absorbs in both the IR and visible regions of the electromagnetic spectrum and provides coloration for visual inspection of the lithographic printing plates.

Abstract: Negative-working, infrared radiation-sensitive lithographic printing plate precursors have an imageable layer on a substrate. The imageable layer includes a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to infrared radiation, a polymeric binder, one or more infrared radiation absorbing compounds, and an inorganic phosphoric acid or inorganic phosphoric acid precursor. The lithographic printing plate precursors can be designed for either off-press or on-press development after IR imaging.

Abstract: An imaged and developed element, such as a lithographic printing plate, is provided by infrared radiation imaging of a positive-working imagable element having inner and outer imagable layers. One or both layers contain a polymeric binder having pendant 1H-tetrazole groups. The imaged element is developed with a single processing solution having a pH of from about 5 to about 11 to remove predominantly only the exposed regions and to provide a protective layer over the imaged surface.

Abstract: Negative-working imageable elements are prepared with radiation-sensitive imageable layers that contain surface-modified silica particles such as fumed silica particles and sol-gel silica particles, that are present in an amount of from about 1 to about 40 weight %, have an average particle size of from about 1 to about 500 nm, have surface hydroxy groups, and have a carbon content of from about 0.5 to about 15 weight % that is derived from surface hydrophobic groups having 1 to 30 carbon atoms. The presence of the surface-modified silica particles provides improved abrasion resistance, reduced tackiness, and various other desired properties.

Abstract: A lithographic processing solution having a pH of less than 12 and comprising at least 0.001 and up to and including 1 weight % of a water-soluble or water-dispersible, non-IR-sensitive compound that has a heterocyclic moiety with a quaternary nitrogen in the 1-position of the heterocyclic ring, and having one or more electron donating substituents attached to the heterocyclic ring, at least one of which electron donating substituents is attached in the 2-position. The processing solution can be used to develop both single-layer and multi-layer positive-working lithographic printing plate precursors that have been imaged using infrared radiation.

Abstract: The process for improving the scratch-resistance of a lithographic printing plate, comprising: applying an aqueous composition comprising inorganic, non-metallic, inert particles composed of silica, alumina or titanium dioxide and having an average particle size of from 1 nm to 0.5 ?m, to an exposed and optionally developed lithographic printing plate precursor.

Abstract: Lithographic printing plate precursors can have an imageable layer that includes a polymeric binder having an acid number of 40 meq/g KOH or more, at least 3 weight % of recurring units derived from one or more N-alkoxymethyl (alkyl)acrylamides or alkoxymethyl(alkyl)acrylates, at least 2 weight % of recurring units having pendant 1H-tetrazole groups, and at least 10 weight % of recurring units having pendant cyano groups. The use of such polymeric binders provides good bakeability and chemical solvent resistance, especially for positive-working precursors.

Abstract: Radiation-sensitive negative working element comprising (a) a substrate with a hydrophilic surface and (b) a layer on the hydrophilic surface of the substrate, wherein said layer comprises a modified polymer obtainable by reacting (i) a polymer with —COOH, —SO3H, —P03H2 and/or —PO4H2 in the side chains, wherein the polymer is soluble in aqueous alkaline solutions and the solubility is not changed by IR radiation, and (ii) a salt with an inorganic or organic cation, wherein the modified polymer is soluble in aqueous alkaline solutions and the solubility is not changed by IR radiation, said layer being soluble in aqueous alkaline developer, but is rendered insoluble in aqueous alkaline developer by IR radiation.

Abstract: Radiation-sensitive compositions and imageable elements include a polymeric or non-polymeric component in an imageable layer, which component includes 1H-tetrazole groups. The non-polymeric components can be radically polymerizable compounds. The polymeric components can have 1H-tetrazole groups that are pendant to the backbone. The use of such components in negative- or positive-working imageable elements provides high photospeed and improved developability for providing imaged and developed elements, such as lithographic printing plates that show improved chemical resistance and run length.

Abstract: Thermally imagable elements are described comprising on a substrate with hydrophilic surface (a) a first layer comprising a first polymer soluble or swellable in aqueous alkaline developer and insoluble in organic solvents with low polarity and (b) a second layer comprising a second polymer soluble or swellable in aqueous alkaline developer, wherein the first polymer is different from the second polymer and the second polymer comprises vinyl acetal repeating units and pendant acidic groups selected from COOH, —SO3H, —PO3H2, —PO4H2, aromatic OH and groups having acidic amide or imide groups.

Abstract: An apparatus and method for improving the durability of an image on an imaging material, including increasing the press run length or a printing plate. The apparatus and method can involve the use of, as an example but not restricted to, an imaging device, a pre-bake oven, a processor, and a post-process treatment unit that employs infrared lamps adapted to irradiate the image.

Abstract: An imaged and developed element, such as a lithographic printing plate, is provided by infrared radiation imaging of a positive-working imagable element having inner and outer imagable layers. One or both layers contain a polymeric binder having pendant 1H-tetrazole groups. The imaged element is developed with a single processing solution having a pH of from about 5 to about 11 to remove predominantly only the exposed regions and to provide a protective layer over the imaged surface.