Abstract: A method for making a lithographic printing plate precursor is disclosed comprising the steps of a. providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, a photopolymerizable coating comprising a photopolymerizable composition, and an overcoat layer comprising a water soluble low molecular weight acid, wherein said overcoat layer has a surface pH-value ranging between 1 to 6; b. image-wise exposing the precursor; c. optionally heating the exposed precursor; d. processing the obtained precursor by applying a gum solution and optionally brushing the precursor, and/or by mounting the precursor on a plate cylinder of a lithographic printing press and rotating the plate cylinder while feeding dampening liquid and/or ink to the coating.

Abstract: A method of making a lithographic printing plate includes the steps of a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a preheating unit, and d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the coating from the support, wherein the coating further includes a compound capable of interacting with the support, the compound being present in the photopolymerizable layer and/or in the intermediate layer.

Abstract: A method of making a lithographic printing plate includes the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound and a polymerization initiator, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a pre-heating unit, d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the photopolymerizable layer from the support, wherein the photopolymerizable layer further includes a polymer containing an acid group and a basic nitrogen-containing compound capable of neutralizing the acid group, or wherein the photopolymerizable layer furt

Abstract: A method of making a lithographic printing plate includes the steps of a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound, a polymerization initiator, and a reactive binder; b) image-wise exposing the coating in a plate setter; c) optionally, heating the precursor in a pre-heating unit; d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the photopolymerizable layer from the support, wherein the reactive binder is a polymer containing a monomeric unit which includes a group having an ethylenically unsaturated bond.

Abstract: The method of preparing a lithographic printing plate precursor according to the present invention comprises the steps of: providing an aluminum support; graining and anodizing the aluminum support; without applying a hydrophilic layer on the anodized aluminum support, coating a composition which is photopolymerizable upon absorption of light having a wavelength in the range of from 350 nm to 450 nm and comprising a polymerizable monomer or oligomer, a binder and a photo-initiator on the grained and anodized aluminum support to form a photopolymerizable layer; coating an overcoat on the photopolymerizable layer; characterized in that the ratio of the total solid amount of polymerizable monomer and oligomer to the total solid amount of binder is from 1.0 to 2.0.

Abstract: A method of making a lithographic printing plate comprising the steps of: a) providing a lithographic printing plate precursor comprising (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a photopolymerizable coating on said support, b) image-wise exposing said coating in a plate setter, c) developing the precursor, thereby removing the non-exposed areas of the coating from the support, whereby the developing step is carried out off-press in a gumming unit by treating the coating of the precursor with a gum solution.

Abstract: A gum solution is provided which comprises a film-forming hydrophilic polymer or surfactant, and a salt formed by reaction of an acid, selected from phosphoric acid and phosphorous acid, with a di- or tri-alkanolamine. The gum solution is suitable for developing and gumming a lithographic photopolymer printing plate precursor. Also provided is a method for preparing a lithographic printing plate wherein this gum solution is used, and whereby printing plates are obtained which exhibit an improved clean-out performance.

Abstract: A method for making a lithographic printing plate precursor is disclosed comprising the steps of a. providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, a photopolymerizable coating comprising a photopolymerizable composition, and an overcoat layer comprising a water soluble low molecular weight acid, wherein said overcoat layer has a surface pH-value ranging between 1 to 6; b. image-wise exposing the precursor; c. optionally heating the exposed precursor; d. processing the obtained precursor by applying a gum solution and optionally brushing the precursor, and/or by mounting the precursor on a plate cylinder of a lithographic printing press and rotating the plate cylinder while feeding dampening liquid and/or ink to the coating.

Abstract: A method of making a lithographic printing plate includes the steps of a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound, a polymerization initiator, and a reactive binder; b) image-wise exposing the coating in a plate setter; c) optionally, heating the precursor in a pre-heating unit; d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the photopolymerizable layer from the support, wherein the reactive binder is a polymer containing a monomeric unit which includes a group having an ethylenically unsaturated bond.

Abstract: A method of making a lithographic printing plate includes the steps of: a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, wherein the photopolymerizable layer includes a polymerizable compound and a polymerization initiator, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a pre-heating unit, d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the photopolymerizable layer from the support, wherein the photopolymerizable layer further includes a polymer containing an acid group and a basic nitrogen-containing compound capable of neutralizing the acid group, or wherein the photopolymerizable layer furt

Abstract: A method of making a lithographic printing plate includes the steps of a) providing a lithographic printing plate precursor including (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a coating on the support including a photopolymerizable layer, and, optionally, an intermediate layer between the photopolymerizable layer and the support, b) image-wise exposing the coating in a plate setter, c) optionally, heating the precursor in a preheating unit, and d) developing the precursor off-press in a gumming unit by treating the coating of the precursor with a gum solution, thereby removing the non-exposed areas of the coating from the support, wherein the coating further includes a compound capable of interacting with the support, the compound being present in the photopolymerizable layer and/or in the intermediate layer.

Abstract: A photopolymer printing plate precursor is disclosed comprising in this order a photosensitive coating and a protective coating on a support, wherein said photosensitive coating comprises a composition that is photopolymerizable upon absorption of light, said composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, and wherein said protective coating comprises one or more types of polyvinylalcohol, characterized in that said photoinitiator is a hexaaryl-bisimidazole compound and the mean saponification degree of all the polyvinylalcohols which are used in the protective coating is less than 93 mol-%. Said printing plate precursor has high speed and a good pre-heat latitude.

Abstract: The present invention relates to a radiation-sensitive mixture which contains an acrylate or methacrylate monomer and/or oligomer capable of free radical polymerization and having at least two acrylate and/or methacrylate groups and at least one photooxidizable group, a photoinitiator, an organic polymeric binder and a heptamethinecyanine dye acting as an IR-absorbing dye. It furthermore relates to a recording material comprising a substrate and a photopolymerizable layer and a process for the production of a printing plate from this recording material. The recording material is distinguished by suitable photosensitivity.

Abstract: The invention relates to an alkaline developer for irradiated radiation sensitive compositions, which developer is based on water and at least one inorganic salt having an alkaline reaction, wherein the developer has a pH of at least 11 and comprises at least three structurally different surfactants of formulae (A), (B) and (C), characterised in that the surfactant of formula (A) has one anionic group, the surfactant of formula (B) has two anionic groups, the surfactant of formula (C) is non-ionic and has at least one non-ionic hydrophilic group, and the concentration of each of the surfactants of formulae (A), (B) and (C) in the developer is at least 0.05 weight-% based on the total weight of the developer. The developer leads to less depositions and has a superior stability when used.

Abstract: The invention relates to an alkaline developer for irradiated radiation sensitive compositions, which developer is based on water, comprises at least one alkaline reacting silicate and has a pH of at least 11, characterized in that the developer comprises at least a non-ionic surfactant, wherein the hydrophobic part is an aryl group having in addition to the hydrophilic part at least two substituents different to hydrogen, and the hydrophilic part is a polyethyleneoxy group with at least 6 ethyleneoxy units. The developer leads to less depositions in the developing apparatus and on the processed printing plates and has an increased sedimentation stability.

Abstract: The invention relates to a method of making a lithographic printing plate comprising the steps of providing a photopolymer printing plate precursor that is photopolymerizable upon absorption of light in the wavelength range from 300 to 700 nm, exposing said printing plate precursor with light in the range from 300 to 700 nm and processing said exposed precursor with an aqueous alkaline developer, characterized in that the alkaline developer comprises a polyethyleneoxide/polypropyleneoxide surfactant having a specific composition. The method leads to less depositions in the developing apparatus and on the processed printing plates and the developer used has an increased sedimentation stability.

Abstract: A method of making a lithographic printing plate comprising the steps of: a) providing a lithographic printing plate precursor comprising (i) a support having a hydrophilic surface or which is provided with a hydrophilic layer, (ii) a photopolymerizable coating on said support, b) image-wise exposing said coating in a plate setter, c) developing the precursor, thereby removing the non-exposed areas of the coating from the support, whereby the developing step is carried out off-press in a gumming unit by treating the coating of the precursor with a gum solution.

Abstract: The invention relates to an alkaline developer for irradiated radiation sensitive compositions, which developer is based on water and at least one inorganic salt having an alkaline reaction, wherein the developer has a pH of at least 11 and comprises at least three structurally different surfactants of formulae (A), (B) and (C), characterised in that the surfactant of formula (A) has one anionic group, the surfactant of formula (B) has two anionic groups, the surfactant of formula (C) is non-ionic and has at least one non-ionic hydrophilic group, and the concentration of each of the surfactants of formulae (A), (B) and (C) in the developer is at least 0.05 weight-% based on the total weight of the developer. The developer leads to less depositions and has a superior stability when used.

Abstract: The present invention relates to a radiation-sensitive mixture which contains an acrylate or methacrylate monomer and/or oligomer capable of free radical polymerization and having at least two acrylate and/or methacrylate groups and at least one photooxidizable group, a photoinitiator, an organic polymeric binder and a heptamethinecyanine dye acting as an IR-absorbing dye. It furthermore relates to a recording material comprising a substrate and a photopolymerizable layer and a process for the production of a printing plate from this recording material. The recording material is distinguished by suitable photosensitivity.

Abstract: A composition is disclosed which is photopolymerizable upon absorption of light in the wavelength range between 300 and 450 nm, the composition comprising a binder, a polymerizable compound, a sensitizer and a photoinitiator, characterized in that the sensitizer is an optical brightening agent. A high speed is obtained, enabling the preparation of a lithographic photopolymer plates with low-cost blue or violet laser diodes.