Aluminum alloy support for lithographic printing plate and process for producing substrate for support
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Jan 8, 2002
Grant Date -
N/A
app pub date -
Jul 28, 1999
filing date -
Jul 30, 1998
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
The present invention provides a support for a lithographic printing plate prepared by cold rolling a sheet while intermediate annealing is omitted to save energy and the number of the cold rolling steps are decreased to simplify the sheet production steps and to give a desired strength of the sheet, and by inhibiting precipitation of Si particles in the substrate to give extremely excellent resistance to ink staining in the nonimage areas during printing, and a process for producing a substrate therefore. The production process comprises homogenization heat-treating an aluminum alloy slab comprising 0.10 to 0.40 wt % of Fe, 0.03 to 0.15 wt % of Si, 0.004 to 0.03 wt % of Cu, and the balance of Al and unavoidable impurities, hot rolling the heat-treated slab, and cold-rolling the hot-rolled strip without intermediate annealing, the cold rolling including a final pass after which the sheet temperature becomes at least the recovery temperature of the sheet and the following rapid cooling, whereby an aluminum alloy substrate for a lithographic printing plate having a content of precipitated Si of up to 30 ppm and a tensile strength of from 145 to 180 MPa is produced. When the aluminum alloy is electrolytically grained and anodically oxidized, the resultant anodic oxide film can contain up to 200/mm.sup.2 of precipitated Si particles having an average particle size of at least 0.5 .mu.m.
First Claim
Other Claims data not available