Electrolytically grained aluminum support for making a lithographic plate and presensitized lithographic printing plate
AssigneesFuji Photo Film Co., Ltd., Nippon Light Metal Company, Ltd.
InventorsHirokazu Sakaki, Akira Shirai, Azusa Ohashi
Life of this patent
Estimating the term…
Abstract
A support for a lithographic plate comprising an aluminum plate or an aluminum-alloy plate the surface of which has been grained such that the grain structure comprises pits and; (i) the distribution of pit diameter is such that the pits corresponding to 5% and 95% on a cumulative frequency curve for pit diameter are about 3.mu. or more and about 10.+-.1.mu. in diameter, respectively; and (ii) the center line average roughness (Ra) of said surface is on the range from about 0.6 to 1.0.mu.. A light-sensitive material for preparing a lithographic plate is also disclosed.
Claims16
A support for a lithographic plate comprising an aluminum plate or an aluminum-alloy plate the surface of which has been grained such that the grain structure comprises pits and:
- (i) the distribution of pit diameter is such that the pits corresponding to 5% and 95% on a cumulative frequency curve for pit diameter are 3.mu. or more and 10.+-.1.mu. in diameter, respectively;
- and
- (ii) the center line average roughness (Ra) of said surface is in the range from 0.6 to 1.0.mu..
In a light-sensitive material for the preparation of a lithographic printing plate comprising an aluminum or aluminum-alloy support having provided thereon a photosensitive layer, the improvement which comprises:
- said support having a grain structure comprising pits wherein:
- (i) the distribution of pit diameter is such that the pits corresponding to 5% and 95% on a cumulative frequency curve for pit diameter is about 3 microns or more and about 10.+-.1 micron in diameter, respectively;
- and
- (ii) The center line average roughness (Ra) of said surface is in the range of from about 0.6 to 1.0 micron.
Dependencies are inferred from the claim text.