US4031033A
Expired / Lapsed
US
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Method for producing powdered wetproofed material useful in making gas-diffusion electrodes
Assignee: Zlehit Pri Ban
•
Filing: 1975-05-30
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Granted: 1977-06-21
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Expires: 1995-05-30
Abstract
Abstract Powdered wetproofed materials, useful for the manufacture of gas-diffusion electrodes, are produced by forming a suspension of an electroconductive powder in a liquid which is water or an organic solvent in the presence of a wetproofing agent and recovering the wetproofed material.
Inventors
- 👤 Evgueni Bogdanov Budevski
- 👤 Iliya Dimitrov Iliev
- 👤 Anastasiya Rostislavova Kaisheva
- 👤 Sergei Sergeev Gamburtzev
- 👤 Elena Borisova Vakanova
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:25
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8817; H01M4/8821; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
126 words
A method for producing a powdered wetproofed material useful for the production of gas-diffusion electrodes, the method comprising the steps of ( 1) combining an aqueous suspension of a powder consisting of electrochemically inactive, electrically conductive micropore-free grains consisting of carbon black in an amount between 1 and 5 percent by total weight of said aqueous suspension, with an aqueous dispersion of a high molecular weight polyolefin wetproofing agent consisting of polytetrafluoroethylene, said aqueous dispersion of said polyolefin including a dispersion stabilizer, (2) mixing at ambient temperature until the resulting mixture is homogenized and (3) removing the liquid phase by filtration, drying and disintegrating the obtained solids, removing the stabilizer from the solids by heating, and again disintegrating said solids, thereby obtaining the powdered wetproofed material.
Claim 2
Independent Claim
126 words
A method for producing a powdered wetproofed material useful for the production of gas-diffusion electrodes, the method comprising the steps of ( 1) combining an aqueous suspension of a powder consisting of electrochemically inactive, electrically conductive micropore-free grains consisting of carbon black in an amount between 1 and 5 percent by total weight of said aqueous suspension, with an aqueous dispersion of a high molecular weight polyolefin wetproofing agent consisting of polytetrafluoroethylene, said aqueous dispersion of said polyolefin including a dispersion stabilizer, (2) mixing at ambient temperature until the resulting mixture is homogenized and (3) removing the liquid phase by filtration, drying and disintegrating the obtained solids, removing the stabilizer from the solids by heating, and again disintegrating said solids, thereby obtaining the powdered wetproofed material.
Claim 3
Dependent Claim
30 words
A method according to claim 1, wherein the amount of said wetproofing agent in said aqueous dispersion is between 1 and 60 percent by total weight of said aqueous dispersion.
Claim 4
Dependent Claim
28 words
A method according to claim 1, wherein said removal of stabilizers from the obtained solids is carried out by heating at a temperature from 250° to 350° C.
References Cited (Backward Citations)
US2782180A
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US3297484A
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US3272897A
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US3488225A
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US3649365A
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US3634569A
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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) | 1980-06-20 | 1980-12-20 | 1981-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-20 | 1984-12-20 | 1985-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-20 | 1988-12-20 | 1989-06-21 | $7700.00 | Window Closed / Lapsed |