Photosensitive resin composition, printing plate precursor and flexographic printing plate

Abstract

Disclosed is a photosensitive resin composition that is superior in water developability, drying characteristics, and image reproducibility. The photosensitive resin composition comprises a water dispersible latex (A), a rubber (B), a surfactant (C), a photopolymerizable monomer (D), and a photoinitiator (E). The mass percent of the aforementioned (C) component is within the range of 0.1-20% of the combined mass of the aforementioned (A) component, the aforementioned (B) component, and the aforementioned (C) component. The mass percent of the aforementioned (A) component is within the range of 20-90% of the combined mass of the aforementioned (A) component and the aforementioned (B) component. The size in the dispersal phase, in which the aforementioned (B) component is the principal component, is less or equal to 10 [mu]m.

Description

technical field [0001] The invention relates to a photosensitive resin composition, a printing plate precursor, and a flexographic printing plate. Background technique [0002] Conventionally, letterpress printing, gravure printing, or lithographic printing have been performed on objects to be printed such as packaging materials, labels, magazines, and the like using printing plates. Among them, letterpress printing is performed using a letterpress. In the letterpress, a flexographic printing plate can be used for various objects to be printed, including objects to be printed made of soft materials. [0003] The original plate of the flexographic printing plate includes a photosensitive layer made of a photosensitive resin composition on a substrate of PET resin or the like. In the flexographic printing plate, the photosensitive layer is irradiated with ultraviolet light through the negative film that is in contact with the photosensitive layer, and the uncured part is rem...

AI Technical Summary

Problems solved by technology

[0008] However, the photosensitive resin composition of Patent Document 1 has a problem that the developing process takes a long time because there are many components with low water solubility and / or water permeability.

The long development time is not only a problem of workability, but also the surface of the original printing plate is rubbed by the brush for a long time in order to remove the unhardened part during development, so the image reproducibility is low due to the loss of fine dots, etc.

[0009] In addition, Patent Document 2 contains a surfactant in the photosensitive resin composition in order to shorten the developing time, although this is effective for shortening the developing time, however, since the main component of the photosensitive resin composition is water-soluble or water-swellable polymer matter, so the drying time after water development is too long, so the practicality is low

[0010] Furthermore, if the surfactant of the composition disclosed in Patent Document 2 is simply added to the water-dispersible latex, the photopolymerizable monomer, the rubber, and the photopolymerization initiator of the composition disclosed in Patent Document 1, fine grains on the negative film can be reproduced. Image reproducibility of screen dots may decrease

[0011] Therefore, conventional photosensitive resin compositions do not satisfy water developability, dryness, and image reproducibility at the same time.

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