US4551220A
Expired / Lapsed
US
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Gas diffusion electrode material
Assignee: AGC Inc
•
Filing: 1983-07-28
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Granted: 1985-11-05
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Expires: 2003-07-28
Abstract
Abstract A gas diffusion electrode material which comprises a continuously micro-porous electrically insulating material and at least partially graphitized carbon black powder uniformly incorporated in the insulating material.
Inventors
- 👤 Yoshio Oda
- 👤 Takeshi Morimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:30
CPC Classifications
C; C25; C25B; C25B11/00; C25B11/04; C25B11/042; C25B11/043; C25B11/044; H; H01; H01M; H01M4/00; H01M4/86; H01M4/96; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A gas diffusion electrode material which comprises a continuously micro-porous electrically insulating material and partially graphitized carbon black powder uniformly incorporated in the insulating material, said continuously microporous electrically insulating material comprising numerous fine nodes of polytetrafluoroethylene and fine fibers of a polytetrafluoroethylene extending from the nodes and three dimensionally connecting the nodes to one another, the nodes being partially in contact or connected with one another, said partially graphitized carbon black powder being carbon black which has been graphitized to a graphitization ratio of from 10% to 90% by subjecting the carbon black to a treatment at a temperature of from 1,200° C. to 2,500° C. for 5 to 60 minutes.
Claim 2
Dependent Claim
112 words
A gas diffusion electrode material which comprises a continuously micro-porous electrically insulating material and partially graphitized carbon black powder uniformly incorporated in the insulating material, said continuously microporous electrically insulating material comprising numerous fine nodes of polytetrafluoroethylene and fine fibers of a polytetrafluoroethylene extending from the nodes and three dimensionally connecting the nodes to one another, the nodes being partially in contact or connected with one another, said partially graphitized carbon black powder being carbon black which has been graphitized to a graphitization ratio of from 10% to 90% by subjecting the carbon black to a treatment at a temperature of from 1,200° C. to 2,500° C. for 5 to 60 minutes.
Claim 3
Dependent Claim
23 words
The gas diffusion electrode material according to claim 1, wherein the graphitized carbon black powder is graphitized carbon black subjected to etching treatment.
Claim 4
Dependent Claim
22 words
The gas diffusion electrode material according to claim 2, wherein the etching treatment is conducted by oxidation treatment of graphitized carbon black.
Claim 5
Dependent Claim
37 words
The gas diffusion electrode material according to claim 3, wherein the oxidation treatment is conducted by heat treatment in an oxygen atmosphere or by treatment with an oxidizing agent comprising nitric acid, sulfuric acid or a permanganate.
Claim 6
Dependent Claim
19 words
The gas diffusion electrode material according to claim 1, wherein the continuously micro-porous electrically insulating material is a polytetrafluoroethylene.
Claim 7
Dependent Claim
24 words
The gas diffusion electrode material according to claim 1, wherein the graphitized carbon black powder has a particle size of at most 1 μm.
Claim 8
Dependent Claim
44 words
The gas diffusion electrode material according to claim 1, wherein the graphitized carbon black is incorporated in an amount of from 7 to 90% by weight based on the total weight of the continuously microporous electrically insulating material and the graphitized carbon black powder.
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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) | 1988-11-04 | 1989-05-06 | 1989-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-04 | 1993-05-06 | 1993-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-04 | 1997-05-06 | 1997-11-05 | $7700.00 | Window Closed / Lapsed |