US4840713A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the electrochemical roughening of aluminum for use in printing plate supports
Assignee: Agfa Gevaert NV
•
Filing: 1988-05-25
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Granted: 1989-06-20
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Expires: 2008-05-25
Abstract
Abstract A process is disclosed for the electrochemical roughening of aluminum for use in printing plate supports, which is carried out by means of an electrolyte containing sulfate ions and aluminum chloride; preference is given to sulfuric acid and aluminum chloride. Printing plate supports roughened by the process according to the present invention show a particularly uniform, pit-free and overall roughening structure.
Inventors
- 👤 Engelbert Pliefke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:10
CPC Classifications
B; B41; B41N; B41N3/00; B41N3/03; B41N3/034; C; C25; C25F; C25F3/00; C25F3/02; C25F3/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
59 words
A process for electrochemical roughening of supports of aluminum and aluminum alloys for use in printing plates, comprising the steps of: immersing the support in an electrolytic, acidic, unsaturated solution of aluminum chloride comprising from 5 to 100 g/l sulfate ions and from 1 to 100 g/l chloride ions; and applying an alternating current to electrochemically roughen the support.
Claim 2
Dependent Claim
59 words
A process for electrochemical roughening of supports of aluminum and aluminum alloys for use in printing plates, comprising the steps of: immersing the support in an electrolytic, acidic, unsaturated solution of aluminum chloride comprising from 5 to 100 g/l sulfate ions and from 1 to 100 g/l chloride ions; and applying an alternating current to electrochemically roughen the support.
Claim 3
Dependent Claim
13 words
A process as claimed in claim 1, wherein the electrolyte comprises sulfuric acid.
Claim 4
Dependent Claim
19 words
A process as claimed in claim 1, wherein the concentration of sulfate ions ranges between 20 an 50 g/l.
Claim 5
Dependent Claim
23 words
A process as claimed in claim 1, wherein the concentration of the chloride ions is in the range of 10 to 70 g/l.
Claim 6
Dependent Claim
24 words
A process as claimed in claim 1, wherein the concentration of the aluminum chloride is from 20 to 250 g/l, relative to the electrolyte.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 1, wherein the current density used is greater than 40 A/dm 2 .
Claim 8
Dependent Claim
21 words
A process as claimed in claim 1, wherein roughening is carried out for a duration of from 3 to 30 seconds.
Claim 9
Dependent Claim
17 words
A process as claimed in claim 1, wherein further acids or salts are added to the electrolyte.
Claim 10
Dependent Claim
10 words
A process as claimed in claim 1, additionally comprising anodization.
Claim 11
Dependent Claim
17 words
A process as claimed in claim 1, wherein the pH of the electrolyte is less than 2.
Claim 12
Dependent Claim
21 words
A process as claimed in claim 9, additionally comprising a chemical treatment step between said electrochemical roughening step and said anodization.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |