Photosensitive lithographic printing plate with hydrophilic sublayer
AssigneeOji Paper Co., Ltd.
InventorsHideaki Shinohara, Masaru Kato, Yoshiaki Takamatsu
Life of this patent
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Abstract
A photosensitive lithographic printing plate having an excellent printing durability, which comprises a supporting layer, a hydrophilic layer formed on the supporting layer, a photosensitive layer formed on the hydrophilic layer surface and, optionally, a water-proof layer located between the supporting layer and the hydrophilic layer, the photosensitive layer being composed of a photosensitive diazo resin modified by a phenol compound and a water-soluble acrylic polymer compound, and the hydrophilic layer being composed of a resinous component comprising 5 to 40% by weight of a urea compound resin and 60 to 95% by weight of a polyamide resin, and a pigment component.
Claims11
A photosensitive lithographic printing plate comprising:
- a supporting layer comprising a substrate and having a hydrophilic surface, and;
- a photosensitive layer which is formed on said hydrophilic surface of said supporting layer and which comprises a mixture of:
- (A) a photosensitive diazo resin modified with a phenol compound, which resin has been prepared by pre-condensation polymerizing an aromatic diazonium compound and an aldehyde compound in the presence of an acid catalyst, by blending salt pre-condensation product with a phenol compound, and by completely condensation polymerizing said blend, and;
- (B) a water-soluble acrylic polymer compound containing, as a polymarization component, at least one member selected from the group consisting of acrylic acid and .alpha.- and .beta.-substituted acrylic acid derivatives,
- which printing plate is characterized in that said hydrophilic surface is formed by a surface of a hydrophilic layer located between said substrate and said photosensitive layer, said hydrophilic layer comprising (I) a resinous component consisting of (a) from 5 to 40% by weight of at least one urea compound resin selected from the group consisting of non-modified urea-formaldehyde resins, cation-modified urea-formaldehyde resins modified with 5 to 20% based on the weight of the urea, of at least one multifunctional basic compound having two or more basic groups, nonion-modified urea-formaldehyde resins modified with 5 to 15%, based on the weight of the urea, of at least one polyol compound and anion-modified urea-formaldehyde resins modified with 5 to 15%, based on the weight of the urea, of at least one acid salt of sulfurous acid, and (b) from 60 to 95% by weight of at least one polyamide resin selected from the group consisting of nylon 6, nylon 66, nylon 610, modified polyamide resins which have been prepared by modifying at least one member selected from the group consisting of nylon 6, nylon 66 and nylon 610, with a modifying agent consisting of a member selected from the group consisting of mixtures of formaldehyde and aliphatic alcohols and epoxy compounds, and mixtures of epichlorohydrin and polyamine compounds, and (II) a pigment component mixed into said resinous component.
Dependencies are inferred from the claim text.