US4561944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing supports for lithographic printing plates
Assignee: Fujifilm Holdings Corp
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Filing: 1984-06-11
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Granted: 1985-12-31
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Expires: 2004-06-11
Abstract
Abstract A method for producing a support for a lithographic printing plate is described, which comprises mechanically graining the surface of an aluminum sheet, and then electrolytically graining the surface of the aluminum sheet in a solution containing hydrochloric acid, nitric acid, or a mixture thereof by applying thereto an alternating current in such manner that the ratio the quantity of electricity during the cathodic period to the quantity of electricity anodic period is in the range of from 1.0/1 to 2.5/1.
Inventors
- 👤 Hirokazu Sasaki
- 👤 Akira Morita
- 👤 Takemasa Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:28
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; Y; Y10; Y10S; Y10S204/00; Y10S204/09; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
98 words
A method for producing a support for a lithographic printing plate which comprises mechanically graining the surface of an aluminum sheet, and then electrolytically graining the surface of the aluminum sheet in a solution containing hydrochloric acid, nitric acid, or a mixture thereof by applying thereto an unsymmetrical alternating current in such manner that the ratio of the quantity of electricity during the cathodic period to the quantity of electricity during the anodic period is in the range of from 1.0/1 to 2.5/1 and the quantity of electricity during the anodic period is 300 coulombs/dm 2 or less.
Claim 2
Independent Claim
98 words
A method for producing a support for a lithographic printing plate which comprises mechanically graining the surface of an aluminum sheet, and then electrolytically graining the surface of the aluminum sheet in a solution containing hydrochloric acid, nitric acid, or a mixture thereof by applying thereto an unsymmetrical alternating current in such manner that the ratio of the quantity of electricity during the cathodic period to the quantity of electricity during the anodic period is in the range of from 1.0/1 to 2.5/1 and the quantity of electricity during the anodic period is 300 coulombs/dm 2 or less.
Claim 3
Dependent Claim
35 words
A method for producing a support for a lithographic printing plate as in claim 1, wherein after the mechanical graining but prior to the electrolytic graining, the surface of the aluminum sheet is chemically etched.
Claim 4
Dependent Claim
53 words
A method for producing a support for a lithographic printing plate as in claim 2, wherein the chemical etching is carried out by immersing the aluminum sheet in an aqueous solution of an acid selected from the group consisting of sulfuric acid, persulfuric acid, hydrofluoric acid, phosphoric acid, nitric acid, and hydrochloric acid.
Claim 5
Dependent Claim
54 words
A method for producing a support for a lithographic printing plate as in claim 2, wherein the chemical etching is carried out by immersing the aluminum sheet in an aqueous solution of a base selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium tertiary phosphate, sodium aluminate, sodium metasilicate, and sodium carbonate.
Claim 6
Dependent Claim
28 words
A method for producing a support for a lithographic printing plate as in claim 1, comprising the step of further anodizing th aluminum sheet after said electrolytic graining.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-30 | 1989-07-01 | 1989-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-30 | 1993-07-01 | 1993-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-30 | 1997-07-01 | 1997-12-31 | $7700.00 | Window Closed / Lapsed |