Patent US4925538A successfully refreshed from Google Patents.
US4925538A
Expired / Lapsed
US
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Method of electrolytic treatment of metals
Assignee: De Nora Permelec Ltd
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Filing: 1989-09-05
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Granted: 1990-05-15
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Expires: 2009-09-05
Abstract
Abstract A method of electrolytically treating metals with an a.c. current or alternating pulsive current using an electrode comprising a metal substrate having a coating that comprises an oxide of ruthenium, iridium or rhodium as a counter electrode.
Inventors
- 👤 Yukiei Matsumoto
- 👤 Yoshinori Nishiki
- 👤 Kazuhiro Hirao
- 👤 Takayuki Shimamune
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:58
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/04; C25F7/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
56 words
A method of electrolytically etching aluminum or stainless steel, the method consisting of passing an a.c. current or alternating pulsive current through an electrolytic cell containing said metal to be etched as an electrode and an electrode comprising a metal substrate having a coating comprising an oxide of ruthenium, iridium or rhodium as a counter electrode.
Claim 2
Independent Claim
56 words
A method of electrolytically etching aluminum or stainless steel, the method consisting of passing an a.c. current or alternating pulsive current through an electrolytic cell containing said metal to be etched as an electrode and an electrode comprising a metal substrate having a coating comprising an oxide of ruthenium, iridium or rhodium as a counter electrode.
Claim 3
Dependent Claim
22 words
A method according to claim 1 wherein the a.c. current or alternating pulsive current has a frequency of at least 20 Hz.
Claim 4
Dependent Claim
27 words
A method according to claim 1 wherein the a.c. current or alternating pulsive current is applied at a current density of 10 to 200 A/dm 2 .
Claim 5
Dependent Claim
23 words
A method according to claim 1 wherein the metal substrate of said counter electrode is made of titanium, tungsten or an alloy thereof.
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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) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |