Patent US2813798A successfully refreshed from Google Patents.
Patent US4244934A successfully refreshed from Google Patents.
US4244934A
Expired / Lapsed
US
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Process for producing flexible graphite product
Assignee: Individual
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Filing: 1979-04-26
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Granted: 1981-01-13
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Expires: 1999-04-26
Abstract
Abstract Wet graphite particles obtained by subjecting graphite particles to oxidizing treatment with nitric acid of comparatively low concentration and a permanganic acid salt and impregnating the treated graphite particles with a specific antioxidant comprising a metal salt of a boric acid ester of a saccharide, are heated to form expanded graphite masses, which are then compressed together to obtain a flexible graphite product. The thus obtained flexible graphite product is not only excellent in heat resistance and chemical inertness but also free of contamination with sulfur and chlorine, and is very useful in various applications.
Inventors
- 👤 Teruhisa Kondo
- 👤 Jiro Ishiguro
- 👤 Nobuatsu Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:55
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/536
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
143 words
A process for producing a flexible graphite product which comprises the steps of: (1) subjecting graphite particles to oxidizing treatment with nitric acid having a concentration of about 60 to about 95% by weight and a permanganic acid salt; (2) washing the treated graphite particles with water; (3) contacting the washed graphite particles with an antioxidant comprising at least one metal salt of a boric acid ester of a member selected from the group consisting of a reduction product of a monosaccharide, a dimer of a monosaccharide and combinations thereof for a sufficient time for said antioxidant to permeate said washed graphite particles, said metal being a member selected from metals of the group II of the periodic table; (4) heating the resulting graphite particles to obtain expanded graphite masses; and (5) compressing the expanded graphite masses to form a flexible graphite product.
Claim 2
Dependent Claim
143 words
A process for producing a flexible graphite product which comprises the steps of: (1) subjecting graphite particles to oxidizing treatment with nitric acid having a concentration of about 60 to about 95% by weight and a permanganic acid salt; (2) washing the treated graphite particles with water; (3) contacting the washed graphite particles with an antioxidant comprising at least one metal salt of a boric acid ester of a member selected from the group consisting of a reduction product of a monosaccharide, a dimer of a monosaccharide and combinations thereof for a sufficient time for said antioxidant to permeate said washed graphite particles, said metal being a member selected from metals of the group II of the periodic table; (4) heating the resulting graphite particles to obtain expanded graphite masses; and (5) compressing the expanded graphite masses to form a flexible graphite product.
Claim 3
Dependent Claim
65 words
A process according to claim 1, wherein said reduction product of a monosaccharide is a member selected from the group consisting of sorbitol, mannitol and combinations thereof and said dimer of a monosaccharide is a member selected from the group consisting of sucrose, maltose, lactose and combinations thereof, and said metal is a member selected from the group consisting of magnesium, calcium, zinc and barium.
Claim 4
Dependent Claim
20 words
A process according to claim 1, wherein said antioxidant is an aqueous solution of said at least one metal salt.
Claim 5
Dependent Claim
158 words
A process for producing a flexible graphite product which comprises the steps of: (1) dispersing graphite particles in nitric acid having a concentration of about 60 to about 95% by weight to form a slurry of the graphite particles; (2) adding a permanganic acid salt to said slurry to effect oxidation of said graphite; (3) washing the oxidized graphite particles with water; (4) contacting the washed graphite particles with an antioxidant comprising at least one metal salt of a boric acid ester of a member selected from the group consisting of a reduction product of a monosaccharide, a dimer of a monosaccharide and combinations thereof for a sufficient time for said antioxidant to permeate said washed graphite particles, said metal being a member slected from metals of the group II of the periodic table; (5) heating the resulting graphite particles to obtain expanded graphite masses; and (6) compressing the expanded graphite masses to form a flexible graphite product.
Claim 6
Dependent Claim
158 words
A process for producing a flexible graphite product which comprises the steps of: (1) dispersing graphite particles in nitric acid having a concentration of about 60 to about 95% by weight to form a slurry of the graphite particles; (2) adding a permanganic acid salt to said slurry to effect oxidation of said graphite; (3) washing the oxidized graphite particles with water; (4) contacting the washed graphite particles with an antioxidant comprising at least one metal salt of a boric acid ester of a member selected from the group consisting of a reduction product of a monosaccharide, a dimer of a monosaccharide and combinations thereof for a sufficient time for said antioxidant to permeate said washed graphite particles, said metal being a member slected from metals of the group II of the periodic table; (5) heating the resulting graphite particles to obtain expanded graphite masses; and (6) compressing the expanded graphite masses to form a flexible graphite product.
Claim 7
Dependent Claim
29 words
A process according to claim 4, wherein the permanganic acid salt is employed in an amount of about 4 to about 20% by weight based on the graphite particles.
Claim 8
Dependent Claim
11 words
A flexible graphite product produced by a process of claim 1.
Claim 9
Dependent Claim
11 words
A flexible graphite product produced by a process of claim 2.
Claim 10
Dependent Claim
11 words
A flexible graphite product produced by a process of claim 3.
Claim 11
Dependent Claim
11 words
A flexible graphite product produced by a process of claim 4.
Claim 12
Dependent Claim
11 words
A flexible graphite product produced by a process of claim 5.
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) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |