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AssigneeHoechst Aktiengesellschaft
InventorsDieter Mohr, Werner Frass
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The plate-, foil- or strip-shape support materials for offset printing plates are based on chemically, mechanically and/or electromechanically roughened aluminum, or on one of its alloys. Optionally, the aluminum may also have an aluminum oxide layer produced by anodic oxidation. One of the two surfaces the support material has a hydrophilic coating of at least one salt-type hydrophilic organic polymer which is a complex-type product obtained by reacting (a) a water-soluble organic polymer having acid functional groups containing phosphorus or sulfur (for example, polyvinylphosphonic or polyvinylsulfonic acid) with (b) a salt of an at least divalent metal cation. In a process for manufacturing this support material, the complex-type reaction product, dissolved in an aqueous acid, is applied to at least one surface of the support material and the support material thus modified is dried. It is also possible, however, to produce the complex-type reaction product of the components (a) and (b) on the support material. The support material is used in the preparation of offset printing plates having a light-sensitive layer.
A web-shaped support material for offset printing plates, comprising a base layer comprised of aluminum or an aluminum alloy and having a roughened surface, and a hydrophilic coating of at least one salt-type hydrophilic organic polymer on the roughened surface of the base layer, wherein the salt-type hydrophilic organic polymer consists essentially of a complex-type product obtained by reacting (a) a water soluble organic polymer having acid functional groups containing phosphorus or sulfur selected from the group consisting of polyvinylphosphonic acid, polyvinylmethylphosphinic acid, a phosphoric acid ester of polyvinyl alcohol, polyvinylsulfonic acid, polyvinylbenzenesulfonic acid, a sulfuric acid ester of polyvinyl alcohol, an acetal of polyvinyl alcohol formed with a sulfonated aliphatic aldehyde or a salt of these polymers with a monovalent cation, with (b) a salt of an at least divalent metal cation, and wherein the quantity of complex-type reaction product is less than about 0.1 mg per dm.sup.2 of support material surface.
A support material for offset printing plates as claimed in claim 1, wherein the base layer further includes an alumi oxide surface layer produced by anodic oxidation. , 7. A support material for offset printing plates as claimed in claim 1, wherein the base layer is electrochemically
Dependencies are inferred from the claim text.