Method of manufacturing a support for a lithographic printing plate

Abstract

Disclosed is a method of manufacturing a support for a lithographic printing plate, which method includes: a casting step in which an aluminum alloy melt is fed between a pair of cooling rollers by a melt feed nozzle and is rolled as it is being solidified by the pair of cooling rollers, forming an aluminum alloy plate, and a graining treatment step in which a surface of the aluminum alloy plate is subjected to graining treatment which includes at least alkali etching treatment and subsequent electrochemical graining treatment, thereby giving a support for a lithographic printing plate; wherein the surface of the aluminum alloy plate on the side which is subjected to the graining treatment undergoes an amount of aluminum dissolution X per square meter (g / m2) during the alkali etching treatment and has a total amount of electricity Y per square decimeter (C / dm2) applied thereto during an anode reaction in the electrochemical graining treatment such as to satisfy formula (1) below: 1,000>Y≧10X (1). By using this method, a support for a lithographic printing plate which is free of surface mottling is provided.

Description

[0001] The entire contents of literatures cited in this specification are incorporated by reference. BACKGROUND OF THE INVENTION [0002] The present invention relates to a method of manufacturing a support for a lithographic printing plate using an aluminum alloy plate. [0003] Aluminum alloy plate is generally produced by casting a slab from an aluminum alloy melt by a semi-continuous casting process, subjecting the slab to homogenizing heat treatment, then hot rolling, cold rolling and, if necessary, annealing. To produce aluminum alloy plate continuously in a simpler operation, various continuous casting processes have been proposed which use a moving mold to cast an aluminum alloy melt directly as a plate. [0004] Continuous casting processes which use such a moving mold include processes that employ a moving mold in the form of a pair of belts, such as the Hazelett process and processes which employ a moving mold in the form of a pair of rolls, such as the Hunter process and the 3...

AI Technical Summary

Benefits of technology

[0007] Accordingly, the object of the present invention is to provide a method of manufacturing lithographic printing plate supports which are free of surface mottling.

[0009] The inventors have also found that, even in such a case, the surface mottling that has arisen can be reduced by increasing the total amount of electricity during the anode reaction in subsequent electrochemical graining treatment. The inventors have learned as well that a total amount of electricity during the anode reaction in the electrochemical graining treatment which is too large diminishes the surface mottling reducing effect.

Problems solved by technology

However, when supports for lithographic printing plates are manufactured using an aluminum alloy plate obtained by these methods, surface mottling arises.

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