Abstract:
A laser sensitive lithographic printing plate comprises an electrochemically grained, anodized, hydrophilically treated aluminum substrate with a reflection optical density of 0.30 or higher; a free radical polymerizable photosensitive layer; and a water soluble or dispersible overcoat. The photosensitive layer comprises a polymeric binder, a free radical polymerizable monomer, a free radical initiator, and a sensitizing dye. Such dark aluminum substrate in combination with the hydrophilic treatment allows both clean background and good printing durability. Such plate can be exposed with a suitable laser at lower dosage to cause hardening in the exposed areas. The exposed plate can be developed with a regular liquid developer or with ink and/or fountain solution.
Abstract:
Negative thermosensitive lithographic printing plates comprise on a hydrophilic substrate an oleophilic thermosensitive layer comprising a polymeric binder, urethane (meth)acrylate monomer having at least 6 (meth)acrylate groups, a non-urethane (meth)acrylate monomer having at least 4 (meth)acrylate groups, a free-radical initiator, and an infrared absorbing dye; wherein the weight ratio of said urethane (meth)acrylate monomer to said non-urethane (meth)acrylate monomer is from 0.10 to 3.0, and said thermosensitive layer is capable of hardening upon exposure to an infrared radiation. Lithographic plates with such compositions have excellent press durability.
Abstract:
High speed violet or ultraviolet laser sensitive lithographic printing plate comprising on a hydrophilic substrate a specific photosensitive composition is described. The photosensitive layer comprises a polymeric binder, a multifunctional (meth)acrylate monomer, a free-radical initiator, and a sensitizing dye, with specific weight ratio of the monomer to the polymer. Combination of multifunctional urethane (meth)acrylate monomer and multifunctional non-urethane (meth)acrylate monomer can be advantageously used. The plate is imagewise exposed with a violet or ultraviolet laser at a dosage of less than 300 μJ/cm2, and then developed with an aqueous developer or with ink and/or fountain solution.
Abstract translation:描述了在亲水基底上包含特定光敏组合物的高速紫色或紫外线激光平版印刷版。 感光层包括聚合物粘合剂,多官能(甲基)丙烯酸酯单体,自由基引发剂和敏化染料,其单体与聚合物的比例为重量比。 可以有利地使用多官能氨基甲酸酯(甲基)丙烯酸酯单体和多官能非氨基甲酸酯(甲基)丙烯酸酯单体的组合。 用紫外线或紫外线激光以小于300μJ/ cm 2的剂量成像曝光,然后用含水显影剂或油墨和/或润版液显影。
Abstract:
A method of developing a laser sensitive lithographic printing plate with ink and/or fountain solution is described. The printing member comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser. The plate is exposed with a laser and deactivated under a safe light or in the dark, and then on-press developed with ink and/or fountain solution preferably under white light. Alternatively, the plate is developed with ink and/or fountain solution or the likes off press, and then mounted on press for lithographic printing.
Abstract:
A method of treating an on-press developable lithographic printing plate with a treating solution after imagewise exposure and before on-press development is described. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is imagewise exposed with a radiation, overall treated with a treating solution to cause at least one chemical or physical change in the photosensitive layer or on the substrate surface, and then on-press developed with ink and/or fountain solution. Such a treatment allows improvement on the performance of the imagewise exposed plate by, for example, improving the white light stability, forming visible imaging, increasing the hydrophilicity of the substrate, or increasing the developability of the photosensitive layer.
Abstract:
A lithographic printing press having a plate cylinder in a substantially light-tight compartment suitable for on-press imaging and developing a laser sensitive plate is described. The plate cylinder as well as certain other press parts is covered by non-transparent and/or safe-light-passing-only covers so that no or only limited amount of unsafe light passes onto the plate mounted on the plate cylinder during on-press imaging and development. The plate comprises on a substrate a photosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to a laser having a wavelength selected from 200 to 1200 nm. The plate is on-press exposed with the laser, developed with ink and/or fountain solution, and then directly prints inked images to the receiving sheets.
Abstract:
A laser sensitive lithographic printing plate comprises an electrochemically grained, anodized, hydrophilically treated aluminum substrate with a reflection optical density of 0.30 or higher; a free radical polymerizable photosensitive layer; and a water soluble or dispersible overcoat. The photosensitive layer comprises a polymeric binder, a free radical polymerizable monomer, a free radical initiator, and a sensitizing dye. Such dark aluminum substrate in combination with the hydrophilic treatment allows both clean background and good printing durability. Such plate can be exposed with a suitable laser at lower dosage to cause hardening in the exposed areas. The exposed plate can be developed with a regular liquid developer or with ink and/or fountain solution.
Abstract:
New methods and compositions are provided that enable application and processing of photoresist as thick coating layers, e.g. at dried layer (post soft-bake) thicknesses of in excess of 2 microns. Resists can be imaged at short wavelengths in accordance with the invention, including 248 nm.
Abstract:
A method of deactivating and on-press developing an exposed lithographic printing plate is disclosed. The plate comprises on a substrate a photosensitive layer developable with ink and/or fountain solution and capable of hardening upon exposure to a radiation. The plate is exposed with the radiation, deactivated, and then on-press developed with ink and/or fountain solution. The deactivation of the exposed plate allows the handling of the plate under regular office light or any other light without causing the hardening of the non-exposed areas of the photosensitive layer.
Abstract:
High speed violet or ultraviolet laser sensitive lithographic printing plate comprising on a hydrophilic substrate a specific photosensitive composition is described. The photosensitive layer comprises a polymeric binder, a multifunctional (meth)acrylate monomer, a free-radical initiator, and a sensitizing dye, with specific weight ratio of the monomer to the polymer. Combination of multifunctional urethane (meth)acrylate monomer and multifunctional non-urethane (meth)acrylate monomer can be advantageously used. The plate is imagewise exposed with a violet or ultraviolet laser at a dosage of less than 300 μJ/cm2, and then developed with an aqueous developer or with ink and/or fountain solution.
Abstract translation:描述了在亲水基底上包含特定光敏组合物的高速紫色或紫外线激光平版印刷版。 感光层包括聚合物粘合剂,多官能(甲基)丙烯酸酯单体,自由基引发剂和敏化染料,其单体与聚合物的比例为重量比。 可以有利地使用多官能氨基甲酸酯(甲基)丙烯酸酯单体和多官能非氨基甲酸酯(甲基)丙烯酸酯单体的组合。 用紫外线或紫外线激光以小于300μJ/ cm 2的剂量成像曝光,然后用含水显影剂或油墨和/或润版液显影。