US3661742A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrolytic method of marine fouling control
Assignee: Dow Chemical Co
•
Filing: 1970-06-22
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Granted: 1972-05-09
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Expires: 1990-06-22
Abstract
Abstract An improved method of inhibiting the sustained attachment of marine organisms to metallic surfaces while preventing corrosion of the metallic surface by cathodic protection. Inhibition of marine organism attachment takes place when toxic ions are forced into solution by reversing and increasing the current density in the cathodic protection system at periodic intervals for a short period of time.
Inventors
- 👤 Oliver Osborn
- 👤 Bernard L Prows
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:20
CPC Classifications
C; C23; C23F; C23F13/00; C23F13/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
25 words
The improved method of claim 1 wherein the toxic metal covering is selected from the group consisting of copper, mercury, silver, tin, arsenic and cadmium.
Claim 2
Dependent Claim
34 words
The improved method of claim 1 wherein the current is reversed each hour for between about 1.0 minute to about 1.5 minutes at a density of between about 50 ma/ft2 to about 200 ma/ft2.
Claim 3
Dependent Claim
34 words
The improved method of claim 1 wherein the current is reversed each day for between about 1.0 minute to about 1.5 minutes at a density of between about 1,200 ma/ft2 to about 2,000 ma/ft2.
Claim 4
Dependent Claim
103 words
In an electrolytic method for the cathodic protection of a metallic surface in contact with seawater wherein said surface is covered with a metal whose ions are toxic to marine organisms and wherein a current is applied between said surface as the cathode and an anode, the improvement comprising reversing said current once each hour for between about 0.5 minute to about 2 minutes at a density of between about 10 ma/ft2 to about 1,000 ma/ft2, thereby forcing said toxic ions into solution which inhibit the formation of said marine organisms on said metallic surfaces without causing an appreciable amount of corrosion thereto.
Claim 5
Dependent Claim
25 words
The improved method of claim 5 wherein the toxic metal covering is selected from the group consisting of copper, mercury, silver, tin, arsenic and cadmium.
Claim 6
Dependent Claim
34 words
The improved method of claim 5 wherein the current is reversed each hour for between about 1.0 minute to about 1.5 minutes at a density of between about 50 ma/ft2 to about 200 ma.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |