Claims
- 1. A process for producing an aluminum support for a lithographic printing plate, which comprises etching a surface of an aluminum plate containing at least 0.3% by weight of manganese with an alkali etching solution such that from 0.01 to 1.0 g/m.sup.2 of aluminum is removed, chemically etching the alkali-etched aluminum plate in an aqueous solution containing sulfuric acid in an amount of from 1 to 40% by weight to remove from 0.001 to 5.0 g/m.sup.2 of aluminum, and subsequently subjecting the aluminum plate to electrolytic graining in an acidic electrolytic solution, wherein said alkali etching is carried out at an alkali agent concentration of from 0.001 to 5 % by weight, at a temperature of from 20.degree. to 90.degree. C., for a period of from 1 second to 5 minutes.
- 2. A process as in claim 1, wherein said aluminum plate contains from 0.3% to 3% by weight of manganese.
- 3. A process as in claim 1, wherein said temperature is within a range of from 20.degree. to 80.degree. C.
- 4. A process in claim 1, wherein said acidic electrolytic solution is an aqueous solution containing nitric acid in an amount of from 0.1 to 10% by weight.
- 5. A process as in claim 1, wherein said etching in an aqueous solution containing sulfuric acid is carried out at a temperature of from 20.degree. to 80.degree. C.
- 6. A process as in claim 1, wherein said electrolytic graining provides a primary surface roughness having a pit depth of from 0.1 to 10 .mu.m and a pit diameter of from 0.2 to 20 .mu.m.
- 7. A process as in claim 6, further comprising electrolytically graining the electrolytically grained aluminum plate having a primary surface roughness in an acidic solution to provide a secondary surface roughness having a pit depth of from 0.1 to 1 .mu.m and a pit diameter of from 0.1 to 5 .mu.m.
Priority Claims (3)
Number |
Date |
Country |
Kind |
62-284317 |
Nov 1987 |
JPX |
|
62-295135 |
Nov 1987 |
JPX |
|
63-185425 |
Jul 1988 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/270,584 filed Nov. 14, 1988, now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (1)
Number |
Date |
Country |
57-16918 |
Apr 1982 |
JPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
270584 |
Nov 1988 |
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