Positive-image PS-version and CTcP lithographic plate printing plate material

Abstract

The invention provides a positive-image PS-version and CTcP lithographic plate printing plate material. The plate material comprises a hydrophilic support body, a bottom layer and a top layer, wherein the bottom layer and the top layer cover the hydrophilic support body and are capable of being dissolved by alkali after exposure. A bottom layer photosensitive composition comprises chemical resistant functional resin, a photosensitive compound and background coloring dye, wherein a branch chain carbon atom of the chemical resistant function resin is provided with benzylsulfonyl amino and N-aromatic maleimide circulating units. The molecular weight is between 1000 and 100000. A top layer photosensitive composition consists of film-forming resin, a photosensitive compound, a photoacid generator and background coloring dye. The bottom layer and the top layer are sensitive to visible light and ultraviolet light, after being exposed by the visible light and / or ultraviolet light, the bottom layer and the top layer are developed in an alkaline solution. An exposure area is eliminated after being dissolved, and the non-exposure area is insoluble or subjected to slight corrosion and remains. The positive-image PS-version and CTcP lithographic plate printing plate material has excellent solvent resistance, high sensitivity, high resolution and good developing tolerance level and is applicable to the UV ink printing.

Description

technical field [0001] The invention belongs to the field of printing plate making, and in particular relates to a positive PS plate and a CTcP planographic printing plate material used in lithographic printing. Background technique [0002] Since the German Kalle company invented the diazonaphthoquinone positive PS plate in the 1930s, it has a history of more than 80 years. This system has always been the basic system of the commercial positive PS plate. Diazonaphthoquinone sulfonate As the photosensitive compound, the novolac resin is used as the film-forming resin, the photosensitive compound and the film-forming resin are mixed in a certain proportion, a certain amount of background coloring dye is added, and a positive PS plate photosensitive liquid is formulated with a solvent such as ethylene glycol monoalkyl ether. It is coated on an aluminum plate base with a hydrophilic grainy structure, and dried to obtain a pre-coated photosensitive plate PS plate. The photosens...

AI Technical Summary

Problems solved by technology

[0004] However, starting from the photosensitive imaging principle of the traditional PS plate, the sensitivity and alkali water resistance, that is, after a short-time exposure of the photosensitive coating, the exposed part can be completely dissolved in the developer, and the non-exposed part has as little loss as possible.

The resolution of this balance is limited by

Moreover, whether it is a conventional PS plate or a CTcP plate, there is a problem of poor chemical resistance. The poor resistance to solvents is manifested in low printing force, poor resistance to chemical cleaning agents, and UV ink resistance. If you want to improve the above properties Generally, the baking operation is adopted. The baking operation has problems such as high temperature baking, inability to modify the plate, and poor precision. As the country's environmental protection requirements become more and more stringent, the VOC emissions of printing plants are also gradually strictly controlled, and at the same time, there is no VOC. The continuous development of emitted UV curable inks, in addition to the advantages of no VOC emissions, also has the advantages of bright color, good adaptability, and is also suitable for heat-sensitive substrates. Therefore, it is more and more important to improve the solvent resistance of the plate.

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