US4476006A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Supports for lithographic printing plates and process for producing the same
Assignee: Fujifilm Holdings Corp
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Filing: 1982-09-07
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Granted: 1984-10-09
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Expires: 2002-09-07
Abstract
Abstract A support for a lithographic plate and process for producing a support for such a plate are described, which process comprises: mechanically roughening the surface of an aluminum plate, chemically etching about 5 to 20 g/m 2 of aluminum from the surface of the plate, and applying an alternating wave-form electric current to the plate in an acidic aqueous solution such that the quantity of electricity generated with the plate as the anode is equal to or greater than the quantity of electricity generated with the plate as the cathode, electrolysis being carried out such that the current density when the plate is the anode is not less than about 20 A/dm 2 and the quantity of electricity generated with the plate as the anode is about 200 coulombs/dm 2 or less.
Inventors
- 👤 Hisao Ohba
- 👤 Kazutaka Oda
- 👤 Hirokazu Sakaki
- 👤 Akira Shirai
- 👤 Azusa Ohashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:07
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; H; H05; H05K; H05K3/00; H05K3/38; H05K3/382; H05K3/44; Y; Y10; Y10S; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
124 words
A process for producing a support for a lithographic printing plate which comprises: mechanically roughening the surface of an aluminum plate, chemically etching about 5 to 20 g/m 2 of aluminum from the surface of the plate, and applying an alternating wave-form electric current to the plate in an acidic aqueous solution such that the quantity of electricity generated with the plate as the anode is equal to or greater than the quantity of electricity generated with the plate as the cathode, electrolysis being carried out such that the current density when the plate is the anode is not less than about 20 A/dm 2 and the quantity of electricity generated with the plate as the anode is about 200 coulombs/dm 2 or less.
Claim 2
Dependent Claim
124 words
A process for producing a support for a lithographic printing plate which comprises: mechanically roughening the surface of an aluminum plate, chemically etching about 5 to 20 g/m 2 of aluminum from the surface of the plate, and applying an alternating wave-form electric current to the plate in an acidic aqueous solution such that the quantity of electricity generated with the plate as the anode is equal to or greater than the quantity of electricity generated with the plate as the cathode, electrolysis being carried out such that the current density when the plate is the anode is not less than about 20 A/dm 2 and the quantity of electricity generated with the plate as the anode is about 200 coulombs/dm 2 or less.
Claim 3
Dependent Claim
27 words
The process as in claim 1, wherein the quantity of electricity generated while the aluminum plate is an anode is about 70 to 200 coulombs/dm 2 .
Claim 4
Dependent Claim
27 words
The process as in claim 1, wherein the density of the current when the aluminum plate is an anode is about 25 to 70 A/dm 2 .
Claim 5
Dependent Claim
34 words
The process as in claim 1, wherein the ratio of the electricity generated with said plate as the cathode to the electricity generated with said plate as the anode is about 0.5/1 to 1.0/1.
Claim 6
Dependent Claim
19 words
The process as in claim 1, wherein said acidic aqueous solution has a concentration of about 0.1 to 4%.
Claim 7
Dependent Claim
27 words
The process as in claim 1, wherein said electrolytic treatment is carried out with anode and cathode voltages in the range of about 1 to 50 V.
Claim 8
Dependent Claim
14 words
The process as in claim 1, wherein said electrolytic treatment is followed by desmutting.
Claim 9
Dependent Claim
29 words
The process as in claim 7, wherein the desmutting is carried out by contacting the surface of the electrolytically treated plate with an aqueous solution of acid or alkali.
Claim 10
Dependent Claim
20 words
The process as in claim 8, wherein the acid is phosphoric acid, sulfuric acid, chromic acid, or a mixture thereof.
Claim 11
Dependent Claim
15 words
The process as in claim 1, wherein said electrolytic treatment is followed by anodic oxidation.
Claim 12
Dependent Claim
26 words
The process as claimed in claim 1, wherein said acid aqueous solution is selected from the group consisting of hydrochloric acid, nitric acid, and mixtures thereof.
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) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |