Lithographic printing plates
AssigneeVickers, Incorporated
InventorPhilip A. Atkinson
Life of this patent
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Abstract
Aluminium sheets for lithographic printing plate production are anodized firstly in a phosphoric acid electrolyte and secondly in an electrolyte containing a major amount of phosphoric acid and a minor amount of sulphuric acid.
Claims7
A method of treating aluminium or an alloy thereof for use as a substrate in lithographic printing plate production which comprises firstly anodising it in phosphoric acid electrolyte and secondly anodising it in an electrolyte comprising a mixture containing a major amount of phosphoric acid and a minor amount of sulphuric acid.
A method of manufacturing a radiation sensitive plate for lithographic printing plate production which comprises
- (i) anodising aluminium or aluminium alloy using an electrolyte consisting essentially of aqueous phosphoric acid solution,
- (ii) anodising the aluminium or aluminium alloy using an electrolyte consisting essentially of a major amount of phosphoric acid, a minor amount of sulphuric acid, and water, and
- (iii) coating the anodised aluminium or aluminium alloy with a radiation sensitive composition to obtain the desired radiation sensitive plate.
Dependencies are inferred from the claim text.