US4619742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the simultaneous graining and chromium-plating of steel plates as supports for lithographic applications
Assignee: Hoechst AG
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Filing: 1985-07-03
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Granted: 1986-10-28
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Expires: 2005-07-03
Abstract
Abstract A process for producing chromium-plated, steel-based printing plate carriers comprises (A) simultaneously roughening and partially chromium-plating a substrate using alternating current in an electrolyte containing chromium, chloride, sulfate and, if appropriate, strontium ions and then, in the same electrolyte, (B) employing direct current to effect final chromium-plating. The printing plate supports produced in this manner have a uniform surface topography and peak-to-valley height values that are favorable for coating.
Inventors
- 👤 Engelbert Pliefke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:30
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/04; B; B41; B41N; B41N1/00; B41N1/04; B41N1/08; C25F; C25F3/00; C25F3/02; C25F3/06; Y; Y10; Y10S; Y10S205/00; Y10S205/921
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
64 words
A process for preparing a chromium-plated steel or steel-based substrate suitable for use as a lithographic printing plate support, comprising the steps of: (A) plating said substrate with alternating current in an acid electrolyte bath containing chromium ions, chloride ions and sulfate ions with alternating current; and (B) in the same electrolyte bath, carrying out an electrochemical treatment of said substrate with direct current.
Claim 2
Dependent Claim
64 words
A process for preparing a chromium-plated steel or steel-based substrate suitable for use as a lithographic printing plate support, comprising the steps of: (A) plating said substrate with alternating current in an acid electrolyte bath containing chromium ions, chloride ions and sulfate ions with alternating current; and (B) in the same electrolyte bath, carrying out an electrochemical treatment of said substrate with direct current.
Claim 3
Dependent Claim
24 words
A process as claimed in claim 1, wherein said electrolyte bath has a concentration of chromium ion between about 10 and about 300 g/l.
Claim 4
Dependent Claim
21 words
A process as claimed in claim 2, wherein said concentration of chromium ion is between about 30 and about 100 g/l.
Claim 5
Dependent Claim
15 words
A process as claimed in claim 1, wherein said electrolyte bath further contains strontium ions.
Claim 6
Dependent Claim
23 words
A process as claimed in claim 4, wherein said electrolyte bath has a concentration of strontium ion of about 100 g/l or less.
Claim 7
Dependent Claim
24 words
A process as claimed in claim 1, wherein said electrolyte bath has a concentration of sulfate ion between about 0.1 and about 10 g/l.
Claim 8
Dependent Claim
24 words
A process as claimed in claim 1, wherein said electrolyte bath has a concentration of chloride ion between about 1 and about 50 g/l.
Claim 9
Dependent Claim
23 words
A process as claimed in claim 1, wherein said alternating current has a density between about 10 and about 150 A/dm 2 .
Claim 10
Dependent Claim
20 words
A process as claimed in claim 8, wherein said density is between about 30 and about 100 A/dm 2 .
Claim 11
Dependent Claim
23 words
A process as claimed in claim 1, wherein said direct current has a density between about 10 and about 100 A/dm 2 .
Claim 12
Dependent Claim
20 words
A process as claimed in claim 10, wherein said density is between about 10 and about 70 A/dm 2 .
Claim 13
Dependent Claim
24 words
A process as claimed in claim 1, wherein said electrolyte bath during said process has a temperature between about 20° and about 60° C.
Claim 14
Dependent Claim
26 words
A process as claimed in claim 1, wherein said substrate has a residence time in said electrolyte bath of between about 10 and about 300 seconds.
Claim 15
Dependent Claim
26 words
A process as claimed in claim 1, wherein said electrolyte bath has a flow velocity over said substrate of between about 5 and about 100 cm/second.
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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) | 1989-10-27 | 1990-04-28 | 1990-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-27 | 1994-04-28 | 1994-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-27 | 1998-04-28 | 1998-10-28 | $7700.00 | Window Closed / Lapsed |