Aluminum alloy sheet for lithographic printing plate and method of producing the same

Abstract

An aluminum alloy sheet for a lithographic printing plate which allows pits to be more uniformly formed by an electrochemical surface-roughening treatment and exhibits more excellent adhesion to a photosensitive film and water retention properties, and a method of producing the same are disclosed. The aluminum alloy sheet includes 0.1 to 1.5% of Mg, more than 0.05% and 0.5% or less of Zn, 0.1 to 0.6% of Fe, 0.03 to 0.15% of Si, 0.0001 to 0.10% of Cu, and 0.0001 to 0.05% of Ti, with the balance being aluminum and impurities, the Mg content and the Zn content satisfying a relationship “4×Zn %−1.4%≦Mg %≦4×Zn %+0.6%”, and the amount of aluminum powder on the surface of the aluminum alloy sheet being 0.1 to 3.0 mg/m². It is more effective when precipitates with a diameter (circle equivalent diameter) of 0.1 to 1.0 μm are dispersed on the surface of the sheet in a number of 10,000 to 100,000 per square millimeter (mm²).

Description

TECHNICAL FIELD[0001]The present invention relates to an aluminum alloy sheet for a lithographic printing plate. More particularly, the present invention relates to an aluminum alloy sheet for a lithographic printing plate which can be surface-roughened uniformly by an electrochemical etching treatment and exhibits excellent strength and thermal softening resistance, and a method of producing the same.BACKGROUND ART[0002]An aluminum alloy sheet is generally used as a support for a lithographic printing plate (including an offset printing plate). Such a support is surface-roughened from the viewpoint of improving adhesion to a photosensitive film and improving the water retention properties in a non-image area. As the surface roughening method, a mechanical surface roughening method such as ball graining, brush graining, or wire graining has been employed. In recent years, a method of roughening the surface of a support aluminum alloy sheet by an electrochemical etching treatment has...

AI Technical Summary

Benefits of technology

[0008]The present invention has been achieved as a result of further experiments and studies based on the above findings. An object of the present invention is to provide an aluminum alloy sheet for a lithographic printing plate which allows pits to be more uni

Problems solved by technology

If the strength of the support is insufficient, the secured portion of the suppor

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