Abstract: A method for applying a matting layer to a radiation-sensitive layer of a printing plate precursor is disclosed. The method comprises: (a) providing a matting composition comprising a polymer and a solvent, wherein the matting composition has a solid content of more than 10% and no more than 50% by weight based on the total composition; and (b) spraying the matting composition on the radiation-sensitive layer using an electrostatically aided rotary atomizer having a bell speed of more than 10,000 rpm, wherein the distance between the bell and the radiation-sensitive layer to be coated is less than 30 cm. The printing plate precursor may be in the form of a moving web. The method of the present invention can be used for matting any kind of radiation-sensitive layer of conventional positive and negative working lithographic printing plate precursors.

Abstract: Thermally imageable lithographic printing plate precursors and heat-sensitive compositions for use in these printing plate precursors are disclosed. The compositions contain an aqueous developer soluble polymer, such as a phenolic resin; a compound that reduces the aqueous developer solubility of the polymer; and optionally, and infrared absorber. Examples of compounds that reduce the aqueous developer solubility of the polymer are those that contain at least one quarternized nitrogen atom, such as quinolinium compounds, benzothiazolium compounds, pyridinium compounds, and imidazoline compounds. On thermal imaging, the irradiated areas become more soluble in the aqueous developer and can be removed to form a positive image.

Abstract: The present invention includes a radiation-imageable element for lithographic printing having a hydrophilic anodized aluminum base with a surface having pores and a image-forming layer having polymer particles coated on the aluminum base. The ratio of the average pore diameter to the average particle diameter is from 0.4:1 to 10:1. The present invention further includes a method of producing the imaged element. The method includes the steps of imagewise exposing the radiation-imageable element to radiation to produce exposed and unexposed regions and contacting the imagewise exposed radiation-imageable element and a developer to remove the exposed or the unexposed regions.

Abstract: An aqueous developer for imageable elements that contain a radiation-sensitive initiator system and at least one free radical polymerizable material is disclosed. The developer develops these plates quickly, with high throughput, but with no sludge formation in the developing process. The developer contains water, a buffer, and one or more filter dyes and/or one of more free radical inhibitors. The imageable elements are useful as printing plates.

Abstract: An infrared imaging composition contains two essential components, namely an infrared absorbing compound, and a phenolic resin that is either mixed or reacted with an o-diazonaphthoquinone derivative. These compositions are useful in positive-working elements such as lithographic printing plates that can be adapted to direct-to-plate imaging procedures. The weight ratio of infrared radiation absorbing compound to diazonaphthoquinone moiety is less than 1:14.

Abstract: Radiation-sensitive compositions comprise at least one novolak, at least one naphthoquinone diazide derivative and a copolymer; the copolymer consisting of the units A, B and C wherein unit A is present in an amount of 5 to a maximum of 50 mol % and R1 and R4 are selected such that the homopolymer of A is alkali-soluble, B is present in an amount of 20 to 70 mol % and R2, R6 and R7 are selected such that the homopolymer of B has a high glass transition temperature, and C is present in an amount of 10 to 50 mol % and R3 and R5 are selected such that the homopolymer of C is water-soluble and that unit A is different from unit C. Furthermore, the invention describes printing plates produced therefrom.

Abstract: Polymeric compounds for lithographic printing plates, especially plates for use in printing utilizing UV curable inks, may include a structural unit (I) wherein R1 represents an optionally-substituted cyclic or alkyl group, x represents 0 or 1 and A represents an optionally-substituted alkylene group. A range of compounds having different solubilities in selected solvents may be prepared by varying the identity or group R1. Such components may be prepared by reacting an amine of formula R1NH2 with the maleic anhydride derivative corresponding to moiety 1.

Abstract: The present invention includes a two-layer imageable element, including: a substrate, a top layer including a first thermally imageable composition including (a) a first thermally sensitive supramolecular polymer or (b) a thermally imageable composition free of the first thermally sensitive supramolecular polymer; and disposed between the substrate and the top layer, a bottom layer including a second thermally imageable composition, which includes a second thermally sensitive supramolecular polymer. The present invention also includes a method of producing the imaged element.

Abstract: A printing plate is prepared by the process including: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising a compound which comprises at least one nitrogen-containing heterocyclic moiety, providing a printing plate that is ready-to-use on a press without having to develop it. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: A printing plate is prepared by the method comprising: (a) providing a substrate; and (b) applying by ink jetting to the substrate a fluid composition comprising an acidic polymeric compound, in which the acid groups of the acidic polymeric compound are at least partially neutralized with base, providing a printing plate that is ready-to-use on a press without having to develop it. The printing plate of this invention is capable of extended press run length and advantageously avoids the need of chemical development.

Abstract: The present invention includes an imageable element, comprising a substrate and a thermally imageable composition which includes a graft copolymer having hydrophobic and hydrophilic segments. Upon imagewise exposure to thermal energy, the graft copolymer produces exposed regions that are less soluble in a developer than the unexposed regions. Also included is a method of producing an imaged element which includes a graft copolymer according to the present invention.

Abstract: An imaging member is composed of a hydrophilic imaging layer having a hydrophilic heat-sensitive polymer containing heat-activatable thiosulfate groups, and optionally a photothermal conversion material. Upon application of energy that generates heat, such as from IR irradiation, the polymer is crosslinked and rendered more hydrophobic. The imaging layer is disposed on an interlayer on a support, which interlayer comprises a Group IVB element (such as titanium, hafnium or zirconium) compound for improved mechanical and imaging properties. The exposed imaging member can be contacted with a lithographic printing ink and used for printing with or without post-imaging wet processing. This imaging member is particularly useful for direct write imaging using IR lasers or thermal printing heads.

Abstract: A novel fluorinated aromatic acetal polymer comprises at least one unit of A and at least one unit of B or C, or at least one unit of each of A, B and C and optionally further comprises at least one unit of either D or E or at least one unit of each of D and E, wherein the units A and B and/or C, and optionally D and/or E are linked together by single covalent C-C bonds and have the formulae: 1

Abstract: The present invention includes an imageable element, which includes a sheet substrate, an imaging layer and a silicone layer, which comprises a crosslinked silicone polymer. The crosslinked silicone polymer is the curing product of a vinyl functional polysiloxane copolymer and a hydrosiloxane compound. The curing is catalyzed by a platinum carbonyl complex. Upon imagewise exposure and development, an imaged element is obtained, which is mounted on a dry printing press containing lithographic ink and used to produce printed stock.

Abstract: The photosensitive printing plate of the present invention comprises a substrate, a photosensitive layer formed on the substrate, and mat particles formed on the photosensitive layer, wherein the mat particles contain a copolymer which contains at least one (meth)acrylamides as a unit. The method of producing the photosensitive printing plate of the present invention is a method which comprises the steps of forming a photosensitive layer on a substrate, and coating the photosensitive layer with a solution prepared by dissolving a copolymer containing at least one (meth)acrylamides as a unit in a solvent to form mat particles. The photosensitive printing plate of the present invention has excellent vacuum contact properties and resistance to friction and pressure and is free from tack on the surface when used, avoids problems in developing properties during long storage times, and is superior in terms of solubility in an exhausted developer.

Abstract: Phenolic resin compositions formulated for use in lithographic exposure processes are given a heat treatment at 40-90° C. for at least 4 hours shortly after their coating onto lithographic substrates, to produce lithographic printing forms. It is found that such a heat treatment improves later exposure processes, in particular by rendering the sensitivity of the compositions less variable, over time.

Abstract: A lithographic printing form precursor comprises an imagable coating on a roughened and anodized aluminum support. The precursor is prepared by a process comprising: (a) anodising an aluminum sheet; and (b) without having effected a chemical treatment step after the anodising step, applying a composition comprising a polymeric substance to the anodised surface of the aluminum sheet and drying the composition to form the imagable coating thereon, wherein the coating contains a pigment and does not contain a dye. Undesired staining of the lithographic printing form during development is avoided by using the precursor in the lithographic printing process.

Abstract: A system and method for correction and reconstruction of digital color images make use of one or more of a set of algorithms for color calibration and correction, and reconstruction. An algorithm for optimized bit depth reduction also can be used to match the response curve of the scanner to that of the scanned media, thereby improving signal-to-noise ratio and decreasing artifacts such as pixelization, which can result from sampling the tone curve too coarsely. In a photographic film application, in particular, a color calibration and correction algorithm enables correction of the image for variations in hue from film type to film type, over-exposure or under-exposure, exposure-induced hue shifts, hue shifts caused by lighting effects, processing related hue shifts, and other variables in film processing, while preserving overall hue of the subject matter in the originally photographed image.

Abstract: A novel fluorinated aromatic acetal polymer comprises at least one unit of A and at least one unit of B or C, or at least one unit of each of A, B and C and optionally further comprises at least one unit of either D or E or at least one unit of each of D and E, wherein the units A and B and/or C, and optionally D and/or E are linked together by single covalent C—C bonds and have the formulae: wherein RA is H or C1-C11 alky, or an aryl group that does not contain fluorine, and RB and RC are an aryl groups that contain fluorine. The polymer is prepared by reacting a hydrolyzed polyvinyl acetate polymer or copolymer with at least one non-fluorinated aldehyde component, and at least one fluorinated aromatic component. The polymer is useful is preparing a photosensitive composition which comprises at least one diazo resin and at least one such fluorinated aromatic acetal polymer.

Abstract: A radiation-sensitive composition comprises: (i) at least one component capable of absorbing IR radiation; and (ii) a diazonium polycondensation product soluble in an organic solvent; with the proviso that the composition does not contain components capable of reacting with decomposition products produced from IR radiation exposure of the diazonium polycondensation product. The composition may additionally comprise a polymeric binder of the type useful for conventional negative-working printing plates. The composition is suitable for preparing thermally imageable printing plate precursors and printing plates and may also be used in a method for providing an image on such plate precursors and printing plates.