Patent US4333804A successfully refreshed from Google Patents.
US4333804A
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US
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Method of preventing deterioration of palladium oxide anode
Assignee: AGC Inc
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Filing: 1981-01-21
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Granted: 1982-06-08
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Expires: 2001-01-21
Abstract
Abstract The deterioration of a palladium oxide type anode caused by stopping the operation of a diaphragm type electrolytic cell in the electrolysis of an alkali metal chloride is prevented by increasing the concentration of hypochlorite ions in the anolyte to give a predominant anode potential in short circuit state higher than the reduction potential of palladium oxide.
Inventors
- 👤 Kohji Saito
- 👤 Hidenori Shibata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:47
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C25B15/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
The method of preventing deterioration of a palladium oxide type anode in the anolyte of a diaphragm type electrolytic cell for electrolysis of an alkali metal chloride comprising adding to said anolyte a compound generating hypochlorite ion during shortcircuit state, the concentration of said hypochlorite ion being higher than 1.0 g./l., whereby the concentration of hypochlorite ion in the anolyte yields an anode potential higher than the reduction potential of palladium oxide.
Claim 2
Independent Claim
72 words
The method of preventing deterioration of a palladium oxide type anode in the anolyte of a diaphragm type electrolytic cell for electrolysis of an alkali metal chloride comprising adding to said anolyte a compound generating hypochlorite ion during shortcircuit state, the concentration of said hypochlorite ion being higher than 1.0 g./l., whereby the concentration of hypochlorite ion in the anolyte yields an anode potential higher than the reduction potential of palladium oxide.
Claim 3
Dependent Claim
35 words
The method according to claim 1 wherein said compound generating hypochlorite ion compound is hypochlorous acid, an alkali metal hypochlorite, an alkaline earth metal hypochlorite, an alkali metal hydroxide or an alkaline earth metal hydroxide.
Claim 4
Dependent Claim
28 words
The method according to claim 1 wherein said palladium oxide type anode is an electrode having a valve metal substrate coated with a surface layer comprising palladium oxide.
Claim 5
Dependent Claim
22 words
The method according to claim 3 wherein the content of palladium oxide in said surface layer is more than 5 mol %.
Claim 6
Dependent Claim
31 words
The method according to claim 3 or 4 wherein said surface layer comprises 5 to 99 mol % of palladium oxide and 1 to 95 mol % of platinum group metal.
Claim 7
Dependent Claim
13 words
The method according to claim 5 wherein said platinum group metal is platinum.
Claim 8
Dependent Claim
28 words
The method according to claim 1 wherein said diaphragm type electrolytic cell for electrolysis of an alkali metal chloride is a diaphragm electrolytic cell using a porous diaphragm.
Claim 9
Dependent Claim
31 words
The method according to claim 1 wherein said diaphragm type electrolytic cell for electrolysis of an alkali metal chloride is an ion exchange membrane electrolytic cell using a cation exchange membrane.
Claim 10
Dependent Claim
17 words
The method according to claim 1 wherein said alkali metal chloride is sodium chloride or potassium chloride.
References Cited (Backward Citations)
US4233340A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-07 | 1985-12-07 | 1986-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-07 | 1989-12-07 | 1990-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-07 | 1993-12-07 | 1994-06-08 | $7700.00 | Window Closed / Lapsed |