EP0360217A2
Expired / Lapsed
EP
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Process for producing graphite blocks
Assignee: Panasonic Holdings Corp
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Filing: 1989-09-19
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Granted: —
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Expires: 2009-09-19
Abstract
Abstract Graphite blocks are produced by a process wherein one or plural polymer films having a thickness of from 1 to 400 µm and selected from aromatic polyimides, aromatic polyamides and polyoxadiazoles are heat treated to obtain carbonaceous films. A plurality of the carbonaceous films are hot pressed under certain conditions to obtain thick graphite blocks. The blocks have a remarkably improved rocking characteristic and are useful as radiation optical elements such as X-ray or neutron ray monochromators or filters. The blocks may be curved to obtain bent-type graphite articles.
Inventors
- 👤 Matsuaki Murakami
- 👤 Susumu Yoshimura
- 👤 Naomi Nishiki
- 👤 Katsuyuki Nakamura
- 👤 Kazuhiro Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:02
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/524; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T156/1043; Y10T156/1044; Y10T156/1048
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
110 words
A process for producing a graphite block which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization, thereby forming a graphite block.
Claim 2
Dependent Claim
110 words
A process for producing a graphite block which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization, thereby forming a graphite block.
Claim 3
Dependent Claim
20 words
A process according to Claim 1, wherein the heat treatment is effected at a temperature ranging from 450 to 2000°C.
Claim 4
Dependent Claim
20 words
A process according to Claim 1, wherein the heat treatment and hot pressing are, respectively, effected in an inert gas.
Claim 5
Dependent Claim
123 words
A process for producing a graphite block which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing at temperature of not lower than 800°C in such a way that the pressure is increased from zero to a level not higher than 200 kg/cm² and decreased to zero or a level lower than the first-mentioned level, and the pressure increasing and decreasing procedure is repeated several to several tens times whereby the resultant graphite block is wrinkle-free.
Claim 6
Dependent Claim
123 words
A process for producing a graphite block which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing at temperature of not lower than 800°C in such a way that the pressure is increased from zero to a level not higher than 200 kg/cm² and decreased to zero or a level lower than the first-mentioned level, and the pressure increasing and decreasing procedure is repeated several to several tens times whereby the resultant graphite block is wrinkle-free.
Claim 7
Dependent Claim
135 words
A process according to Claim 4, wherein the hot pressing is effected at a temperature of 2000°C or below in such a way that the pressure up to 20 kg/cm² is applied to the carbonaceous films at which the films are kept for a given time and then the pressure is returned to zero or a given low level, and this pressure application process is repeated several to several tens times, and then at a temperature higher than 2000°C in such a way that a pressure higher than 20 kg/cm² is applied to the films at which the films are kept for a given time and then the pressure is returned to a level not higher than 20 kg/cm², and the above procedure is repeated several to several tens times, thereby obtaining a graphite block.
Claim 8
Dependent Claim
101 words
A process for producing a graphite block which comprises heat treating a plurality of 1 to 400 µm thick films of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to carbonaceous films, and hot pressing the plurality of the carbonaceous films at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization, thereby forming a graphite block.
Claim 9
Dependent Claim
101 words
A process for producing a graphite block which comprises heat treating a plurality of 1 to 400 µm thick films of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to carbonaceous films, and hot pressing the plurality of the carbonaceous films at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization, thereby forming a graphite block.
Claim 10
Dependent Claim
22 words
A process according to Claim 6, wherein the heat treatment is effected at a temperature of from 400 to 1000°C under pressure.
Claim 11
Dependent Claim
34 words
A process according to Claim 6, wherein the heat treatment is effected at a temperature of from 400 to 1000°C while inhibiting expansion of the films in the direction vertical to the film face.
Claim 12
Dependent Claim
43 words
A process according to Claim 6, wherein the plurality of the superposed carbonaceous films are subjected to hot pressing at temperature of not lower than 800°C in such a way that the pressure is applied intermittently, whereby the resultant graphite block is wrinkle-free.
Claim 13
Dependent Claim
135 words
A process according to Claim 9, wherein the hot pressing is effected at a temperature of 2000°C or below in such a way that the pressure up to 20 kg/cm² is applied to the carbonaceous films at which the films are kept for a given time and then the pressure is returned to zero or a given low level, and this pressure application process is repeated several to several tens times, and then at a temperature higher than 2000°C in such a way that the pressure higher than 20 kg/cm² is applied to the films at which the films are kept for a given time and then the pressure is returned to a level not higher than 20 kg/cm², and the above procedure is repeated several to several tens times, thereby obtained a graphite block.
Claim 14
Dependent Claim
110 words
A process for producing a curved graphite article which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing along a curved surface at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization.
Claim 15
Dependent Claim
110 words
A process for producing a curved graphite article which comprises heat treating a 1 to 400 µm thick film of a polymer selected from the group consisting of aromatic polyimides, aromatic polyamides and polyoxadiazoles at a temperature sufficient to convert the film to a carbonaceous film, superposing a plurality of the carbonaceous films, and subjecting the plurality of the superposed carbonaceous films to hot pressing along a curved surface at a pressure of not higher than 20 kg/cm² in a temperature range of not higher than 2800°C and then at a pressure higher than 20 kg/cm² in a temperature range of higher than 2800°C for a time sufficient for graphitization.
Claim 16
Dependent Claim
37 words
A process according to Claim 11, wherein the heat treatment is effected at a temperature which is higher than the decomposition temperature of the polymer film and which is in the range of from 400 to 2000°C.
Claim 17
Dependent Claim
18 words
A process according to Claim 12, wherein the temperature of the heat treatment is not lower than 1000°C.
Claim 18
Dependent Claim
19 words
A process according to Claim 10, wherein the thickness is in the range of from 1 to 200 µm.
Claim 19
Dependent Claim
41 words
A process according to Claim 10, wherein the polymer film is in a dome-shaped form and heat treated, and a plurality of the resultant dome-shaped carbonaceous films are hot pressed along a dome-shaped surface, thereby obtaining a double bent-type graphite article.
Claim 20
Dependent Claim
42 words
A process according to Claim 15, wherein the dome-shaped film is obtained by applying a solution of the polymer in a solvent on a substrate, evaporating part of the solvent, and subjecting the resultant film to vacuum molding in a dome-shaped mold.
References Cited (Backward Citations)
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