US5449507A
Expired / Lapsed
US
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Processes for producing graphite blocks from graphitizable organic polymers and process for carbonizing graphitizable polymer films
Assignee: Japan Science and Technology Agency
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Filing: 1993-08-18
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Granted: 1995-09-12
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Expires: 2013-08-18
Abstract
Abstract A process for producing a graphite block from a plurality of graphitizable polymer films or a plurality of carbonaceous films separately obtained from graphitizable polymer films is described. The method comprises superposing the plurality of the graphitizable polymer films or the plurality of the carbonaceous films, and thermally treating the plurality of the graphitizable polymer films or the plurality of the carbonaceous films in a substantially compression pressure-free condition when the treating temperature is in the thermal carbonization temperature range and the graphitization temperature range and under compression pressures in temperature ranges between the thermal carbonization temperature and the graphitization temperature ranges and over the graphitization temperature range. The compression pressure over the graphitization temperature range should be higher than that in the range between the thermal carbonization and graphitization temperature ranges. By this, a wrinkle-free graphite block with a good rocking characteristic is obtained.
Inventors
- 👤 Mutsuaki Murakami
- 👤 Toshiharu Hoshi
- 👤 Kazuhiro Watanabe
- 👤 Naomi Nishiki
- 👤 Katsuyuki Nakamura
- 👤 Hisashi Okada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 12:44
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/524
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
202 words
A process for producing a graphite block from a plurality of graphitizable polymer films or a plurality of carbonaceous films separately obtained from graphitizable polymer films, which process comprises: superposing the plurality of the graphitizable polymer films or the plurality of the carbonaceous films; and thermally treating the plurality of the graphitizable polymer films or the plurality of the carbonaceous films in first, second, third and fourth temperature ranges, the first temperature range being from the temperature at which carbonization of the films begins to a temperature at which any dimensional changes in the films resulting from carbonization are complete, the second temperature range being from the temperature at which any dimensional changes in the films resulting from carbonization are complete to approximately 2000° C., the third temperature range being from approximately 2000° C. to approximately 2600° C., and the fourth temperature range being over approximately 2600° C., wherein the thermal treatment is conducted under substantially compression pressure-free conditions in the first and third temperature ranges, and the thermal treatment is conducted under compression pressures in the second and fourth temperature ranges, and the compression pressure in the fourth temperature range being higher than the compression pressure in the second temperature range.
Claim 2
Dependent Claim
202 words
A process for producing a graphite block from a plurality of graphitizable polymer films or a plurality of carbonaceous films separately obtained from graphitizable polymer films, which process comprises: superposing the plurality of the graphitizable polymer films or the plurality of the carbonaceous films; and thermally treating the plurality of the graphitizable polymer films or the plurality of the carbonaceous films in first, second, third and fourth temperature ranges, the first temperature range being from the temperature at which carbonization of the films begins to a temperature at which any dimensional changes in the films resulting from carbonization are complete, the second temperature range being from the temperature at which any dimensional changes in the films resulting from carbonization are complete to approximately 2000° C., the third temperature range being from approximately 2000° C. to approximately 2600° C., and the fourth temperature range being over approximately 2600° C., wherein the thermal treatment is conducted under substantially compression pressure-free conditions in the first and third temperature ranges, and the thermal treatment is conducted under compression pressures in the second and fourth temperature ranges, and the compression pressure in the fourth temperature range being higher than the compression pressure in the second temperature range.
Claim 3
Dependent Claim
45 words
A process according to claim 1, wherein prior to the thermal treatment in the second temperature range, the plurality of the graphitizable polymer films or the plurality of the carbonaceous films are thermally treated up to the carbonization temperature in a substantially compression pressure-free condition.
Claim 4
Dependent Claim
27 words
A process according to claim 1, wherein the compression pressure in the second temperature range is in the range of from 2 to 50 kg/cm 2 .
Claim 5
Dependent Claim
23 words
A process according to claim 1, wherein the compression pressure in the fourth temperature range is not lower than 50 kg/cm 2 .
Claim 6
Dependent Claim
99 words
A process according to claim 1, wherein the superposed films are thermally treated (a) at a compression pressure of from 2 to 50 kg/cm 2 in the second temperature range, (b) in a substantially pressure-free condition in the third temperature range of from 2000° to 2600° C., (c) at a compression pressure of not lower than 50 kg/cm 2 in the fourth temperature range wherein the temperature is from 2600° to 3000° C., and (d) at a compression pressure of from 2 to 50 kg/cm 2 in the fourth temperature range wherein the temperature is greater than 3000° C.
Claim 7
Dependent Claim
84 words
A process according to claim 1, wherein when a compression pressure of not lower than 10 kg/cm 2 is applied in the second temperature range, the thermal treatment is maintained at a substantially constant temperature during the application of the compression pressure, and when a compression pressure of not lower than 50 kg/cm 2 is applied in the fourth temperature range of not lower than 2600° C., the thermal treatment is maintained at a substantially constant temperature during the application of the compression pressure.
Claim 8
Dependent Claim
92 words
A process according to claim 6, wherein the thermal treatment is effected in such a way that when the compression pressure in the second temperature range is applied in a range of not lower than 10 kg/cm 2 , the thermal treatment is maintained at a substantially constant temperature in the second temperature range, and when the compression pressure in the fourth temperature range is applied in a range of not lower than 50 kg/cm 2 , the thermal treatment is maintained at a substantially constant temperature in the fourth temperature range.
Claim 9
Dependent Claim
23 words
A process according to claim 7, wherein the compression pressure in the second temperature range is not lower than 20 kg/cm 2 .
Claim 10
Dependent Claim
22 words
A process according to claim 7, wherein the compression pressure in the fourth temperature range is 100 to 500 kg/cm 2 .
Claim 11
Dependent Claim
42 words
A process according to claim 1, further comprising at least once lowering the resultant block to a temperature in a range of not higher than 1600° C. and then heating to a temperature in a range of not lower than 2600° C.
Claim 12
Dependent Claim
29 words
A process according to claim 10, wherein after the reheating to a temperature in the range of not lower than 2600° C., the films are compressed at least once.
Claim 13
Dependent Claim
49 words
A process according to claim 10, wherein when reheated, the films are compressed at a pressure of not higher than 20 kg/cm 2 to a temperature of not higher than 2600° C. and at a pressure of not lower than 20 kg/cm 2 over a temperature of 2600° C.
Claim 14
Dependent Claim
38 words
A process according to claim 10, wherein during the lowering to a temperature in a range of not higher than 1600° C., the pressure applied prior to the lowering is maintained down to a temperature of 2000° C.
Claim 15
Dependent Claim
39 words
A process according to claim 1, wherein the graphitizable polymer film is a film of a polymer selected from the group consisting of polyphenyleneoxadiazoles, polybenzothiazole, polybenzobisthiazole, polybenzooxazole, polybenzobisoxazole, aromatic polyimides, aromatic polyamides, polyphenylenebenzoimidazole, polyphenylenebenzobismidazole, polythiazole, poly-p-phenylenevinylene and mixtures thereof.
Claim 16
Dependent Claim
29 words
A process according to claim 5, wherein in at least one of steps (a), (c) and (d), the temperature is maintained substantially constant during application of the compression pressure.
Claim 17
Dependent Claim
28 words
A process according to claim 5, wherein in each of the steps (a), (c) and (d), the temperature is maintained substantially constant during application of the compression pressure.
Claim 18
Dependent Claim
19 words
A process according to claim 1, wherein the first temperature range is from approximately 400° C. to 1000° C.
Claim 19
Dependent Claim
17 words
A process according to claim 1, wherein each film has a thickness not larger than 400 μm.
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