Patent US4283376A successfully refreshed from Google Patents.
US4283376A
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Method of producing silicon carbide fibers
Assignee: Research Institute for Special Inorganic Materials
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Filing: 1979-06-12
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Granted: 1981-08-11
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Expires: 1999-06-12
Abstract
Abstract A process for producing polycarbosilane partly containing siloxane bonds, which comprises adding 0.01 to 15% by weight of polyborosiloxane having phenyl groups in at least a part of the side chains of Si with its skeletal structure being composed of B, Si and O to a polysilane having the structure ##STR1## wherein n is at least 3, and R 1 and R 2 , independently from each other, represent methyl, ethyl, phenyl or hydrogen; and heating the polymer mixture in an atmosphere inert to the reaction thereby to polymerize it. The polycarbosilane is converted into silicon carbide fibers by first preparing a spinning dope; subjecting the dope to a treatment of rendering it infusible under tension or under no tension and firing the treated dope in a vacuum or in an inert atmosphere.
Inventors
- 👤 Seishi Yajima
- 👤 Kiyohito Okamura
- 👤 Yoshio Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:57
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/04; C08G77/32; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/977; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C08L; C08L83/00; C08L83/14; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2002/80; C01P2002/82; C01P2002/85; C01P2002/88; C01P2004/00; C01P2004/10; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/22; C01P2006/90
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
156 words
A process for producing continuous silicon carbide fibers composed mainly of SiC, which comprises (1) preparing polycarbosilane partly containing siloxane bonds by adding 0.01 to 15% by weight of polyborosiloxane having phenyl groups in at least a part of the side chains of Si with its skeletal structure being composed of B, Si and O to a polysilane having the structure ##STR27## wherein n is at least 3, and R 1 and R 2 , independently from each other, represent methyl, ethyl, phenyl of hydrogen; and heating the polymer mixture in an atmosphere inert to the reaction thereby to polymerize said polymer mixture, (2) preparing a spinning dope of the polycarbosilane and spinning the dope, (3) subjecting the result fibers to a treatment of rendering them infusible under tension or under no tension, and (4) firing the treated fibers at a temperature of from 800° to 1800° C. in vacuum or in an inert gaseous atmosphere.
Claim 2
Dependent Claim
156 words
A process for producing continuous silicon carbide fibers composed mainly of SiC, which comprises (1) preparing polycarbosilane partly containing siloxane bonds by adding 0.01 to 15% by weight of polyborosiloxane having phenyl groups in at least a part of the side chains of Si with its skeletal structure being composed of B, Si and O to a polysilane having the structure ##STR27## wherein n is at least 3, and R 1 and R 2 , independently from each other, represent methyl, ethyl, phenyl of hydrogen; and heating the polymer mixture in an atmosphere inert to the reaction thereby to polymerize said polymer mixture, (2) preparing a spinning dope of the polycarbosilane and spinning the dope, (3) subjecting the result fibers to a treatment of rendering them infusible under tension or under no tension, and (4) firing the treated fibers at a temperature of from 800° to 1800° C. in vacuum or in an inert gaseous atmosphere.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the spinning dope in step (2) is prepared by heat-melting the polycarbosilane obtained in step (1).
Claim 4
Dependent Claim
25 words
The process of claim 1 wherein the spinning dope in step (2) is prepared by dissolving the polycarbosilane obtained in step (1) in a solvent.
Claim 5
Dependent Claim
34 words
The process of claim 1 wherein the treatment of step (3) is performed by heating the spun fibers obtained in step (2) to a temperature of 50° to 400° C. in an oxidizing atmosphere.
Claim 6
Dependent Claim
38 words
The process of claim 1 wherein the treatment of step (3) is performed by subjecting the spun fibers obtained in step (2) to the irradiation of γ-rays or electron beams in an oxidizing atmosphere or a non-oxidizing atmosphere.
Claim 7
Dependent Claim
21 words
The process of claim 1 wherein after step (4), the fired fibers are subjected to a step of removing impurities therefrom.
Claim 8
Dependent Claim
23 words
The process of claim 6 wherein the removal of the impurities is carried out by dipping the fired fibers in an impurity-removing agent.
Claim 9
Dependent Claim
43 words
The process of claim 6 wherein the removal of the impurities is carried out by heating the fired fibers to a temperature of 800° to 1600° C. in an atmosphere of a gas selected from oxygen, air, ozone, hydrogen, steam and carbon monoxide.
Claim 10
Dependent Claim
94 words
Continuous silicon carbide fibers composed of ultrafine particles of amorphous SiC and/or β-type SiC crystals, said fibers having superior thermal stability, oxidation resistance and acid resistance and having the composition, by weight, of Si:50-70 C: 30-40, O: 0.01-10, H: not more than 0.01, and B: not more than 500 ppm, a specific gravity of 2.3 to 3.1, a tensile strength of 200 to 500 kg/mm 2 and a modulus of elasticity of 15 to 40 tons/mm 2 prepared according to the process of claim 7 at a firing temperature of 1,000° to 1,500° C.
References Cited (Backward Citations)
US4100233A
Cited
US4117565A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |