Patent US4027673A successfully refreshed from Google Patents.
US4100233A
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Silicon carbide fibers having a high strength and a method for producing said fibers
Assignee: Research Institute for Iron Steel and Other Metals of Tohoku University
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Filing: 1976-04-19
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Granted: 1978-07-11
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Expires: 1996-04-19
Abstract
Abstract Silicon carbide fibers having a high tensile strength are produced by (1) dissolving at least one of organosilicon high molecular weight compounds having a softening point of higher than 50° C, in which silicon and carbon are the main skeleton components, in a solvent for the organosilicon high molecular weight compounds or heating and melting said organosilicon high molecular weight compounds to prepare a spinning solution and spinning said spinning solution into filaments, (2) preliminarily heating the spun filaments at a temperature of 350°-800° C under vacuum to volatilize low molecular weight compounds contained in the high molecular weight compounds, and (3) baking the thus treated filaments at a temperature of 800°-2,000° C under vacuum or at least one non-oxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas, to form silicon carbide fibers.
Inventors
- 👤 Seishi Yajima
- 👤 Josaburo Hayashi
- 👤 Mamoru Omori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:12
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/10; C; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; B; B82; B82Y; B82Y30/00; C01B32/963; C01B32/977; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C01P; C01P2002/00; C01P2002/70; C01P2002/72; C01P2002/80; C01P2002/85; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/10; C01P2004/60; C01P2004/61; C01P2004/64; C01P2006/00; C01P2006/90
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
255 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting at least one organosilicon compound selected from (1) a compound having only Si-C bond, (2) a compound having Si-H bond other than Si-C bond, (3) a compound having Si-Hal bond, (4) a compound having Si-N bond, (5) a compound having Si-OR bond (R═alkyl or aryl), (6) a compound having Si-OH bond, (7) a compound having Si-Si bond, (8) a compound having Si-O-Si bond (9) an ester of organosilicon compound and (10 ) an oxide of organosilicon compound, to polycondensation to produce organosilicon high molecular weight compounds, in which silicon and carbon are the main skeleton components, (2) reducing the content of low molecular weight compounds mixed together with said high molecular weight compound by treating the mixture to produce the organosilicon high molecular weight compound having a softening point of higher than 50° C, (3) preparing a spinning solution from the thus treated organosilicon high molecular weight compound and spinning said spinning solution into fibers, (4 ) heating the spun fibers at a temperature of 50°-400° C under an oxidizing atmosphere to form an oxide layer on the filament surface, (5) preliminarily heating the spun fibers at a temperature of 350°-800° C under a non-oxidizing atmosphere to volatilize the remaining low molecular weight compounds, and (6) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one non-oxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas.
Claim 2
Independent Claim
255 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting at least one organosilicon compound selected from (1) a compound having only Si-C bond, (2) a compound having Si-H bond other than Si-C bond, (3) a compound having Si-Hal bond, (4) a compound having Si-N bond, (5) a compound having Si-OR bond (R═alkyl or aryl), (6) a compound having Si-OH bond, (7) a compound having Si-Si bond, (8) a compound having Si-O-Si bond (9) an ester of organosilicon compound and (10 ) an oxide of organosilicon compound, to polycondensation to produce organosilicon high molecular weight compounds, in which silicon and carbon are the main skeleton components, (2) reducing the content of low molecular weight compounds mixed together with said high molecular weight compound by treating the mixture to produce the organosilicon high molecular weight compound having a softening point of higher than 50° C, (3) preparing a spinning solution from the thus treated organosilicon high molecular weight compound and spinning said spinning solution into fibers, (4 ) heating the spun fibers at a temperature of 50°-400° C under an oxidizing atmosphere to form an oxide layer on the filament surface, (5) preliminarily heating the spun fibers at a temperature of 350°-800° C under a non-oxidizing atmosphere to volatilize the remaining low molecular weight compounds, and (6) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one non-oxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said mixture of low molecular weight compounds and high molecular weight compound is treated with a solvent that will preferentially dissolve the low molecular weight compounds.
Claim 4
Dependent Claim
25 words
The method as claimed in claim 2, wherein said solvent for reducing the content of the low molecular weight compound is an alcohol or acetone.
Claim 5
Dependent Claim
42 words
The method of claim 1 wherein the polycondensation is achieved by the addition of a catalyst selected from the group consisting of Na, KOH, H 2 SO 4 , H 2 PtCl 6 , benzoyl peroxide, di-tert.butyl peroxy-oxalate, di-tert.-butyl peroxide and azoisobutyronitrile.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the polycondensation is achieved by irradiation.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the polycondensation is achieved by heating.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein said mixture of low molecular weight compounds and high molecular weight compound is aged at a temperature of 50°-700° C.
Claim 9
Dependent Claim
26 words
The method of claim 1 wherein said mixture of low molecular weight compounds and high molecular weight compound is distilled at a temperature of 100°-500° C.
Claim 10
Dependent Claim
64 words
The method of claim 1 wherein said spinning solution is prepared by dissolving said organosilicon high molecular weight compound in a solvent selected from the group consisting of benzene, toluene, xylene, ethylbenzene, styrene, cumene, pentane, hexane, octane, cyclopentadiene, cyclohexane, cyclohexene, methylene chloride, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, methylchloroform, 1,1,2-trichloroethane, hexachloroethane, chlorobenzene, dichlorobenzene, ethyl ether, dioxane, tetrahydrofuran, methyl acetate, ethyl acetate, acetonitrile and carbon disulfide.
Claim 11
Dependent Claim
21 words
The method of claim 1 wherein said spinning solution is prepared by heating and melting said organosilicon high molecular weight compound.
Claim 12
Dependent Claim
23 words
The method as claimed in claim 1 wherein said preliminarily heating (step 5) is effected under a tension of 0.001-20 Kg/mm 2 .
Claim 13
Dependent Claim
33 words
The method as claimed in claim 1 wherein said baking (step 6) is effected under a tension of 0.001-100 Kg/mm 2 or ultrasonic wave having a frequency of 10 KHz - 20 MHz.
Claim 14
Dependent Claim
28 words
The method as claimed in claim 1 wherein said baking (step 6) is effected under exposure to an ultrasonic wave having a frequency of 10KHz - 20 MHz.
Claim 15
Dependent Claim
31 words
The method as claimed in claim 1, wherein said heating for forming the oxide layer on the fibers surface (step 4) is effected under a tension of 0.001-5 Kg/mm 2 .
Claim 16
Dependent Claim
24 words
The method as claimed in claim 1, wherein said oxidizing atmosphere in the step (4) is air, ozone, oxygen, chloride gas or bromine gas.
Claim 17
Dependent Claim
35 words
The method as claimed in claim 1, wherein said oxidizing atmosphere in the step (4) is an aqueous solution of KMnO 4 , K 2 Cr 2 O 7 or H 2 O 2 .
Claim 18
Independent Claim
228 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting at least one organosilicon compound selected from (1) a compound having only Si-C bond, (2) a compound having Si-H bond other than Si-C bond, (3) a compound having Si-Hal bond, (4) a compound having Si-N bond, (5) a compound having Si-OR bond (R═alkyl or aryl), (69 a compound having Si-OH bond, (7) a compound having Si-Si bond, (8) a compound having Si-O-Si bond, (9) an ester of organosilicon compound and (10) an oxide of organosilicon compound, to polycondensation to produce organosilicon high molecular weight compounds, in which silicon and carbon are the main skeleton components, (2) reducing the content of low molecular weight compounds mixed together with said high molecular weight compound by treating the mixture to produce the desired organosilicon high molecular weight compound having a softening point of higher than 50° C, (3) preparing a spinning solution from the thus treated organosilicon high molecular weight compound and spinning said spinning solution into fibers, (4) preliminarily heating the spun fibers at a temperature of 350°-800° C under vacuum to volatilize the remaining low molecular weight compounds, and (5) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one nonoxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas.
Claim 19
Independent Claim
228 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting at least one organosilicon compound selected from (1) a compound having only Si-C bond, (2) a compound having Si-H bond other than Si-C bond, (3) a compound having Si-Hal bond, (4) a compound having Si-N bond, (5) a compound having Si-OR bond (R═alkyl or aryl), (69 a compound having Si-OH bond, (7) a compound having Si-Si bond, (8) a compound having Si-O-Si bond, (9) an ester of organosilicon compound and (10) an oxide of organosilicon compound, to polycondensation to produce organosilicon high molecular weight compounds, in which silicon and carbon are the main skeleton components, (2) reducing the content of low molecular weight compounds mixed together with said high molecular weight compound by treating the mixture to produce the desired organosilicon high molecular weight compound having a softening point of higher than 50° C, (3) preparing a spinning solution from the thus treated organosilicon high molecular weight compound and spinning said spinning solution into fibers, (4) preliminarily heating the spun fibers at a temperature of 350°-800° C under vacuum to volatilize the remaining low molecular weight compounds, and (5) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one nonoxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas.
Claim 20
Dependent Claim
26 words
The method of claim 17 wherein said mixture of low molecular weight compounds and high molecular weight compound is aged at a temperature of 50°-700° C.
Claim 21
Dependent Claim
31 words
The method as claimed in claim 18, wherein said aging for reducing the content of the low molecular weight compound is effected under an atmosphere of air, oxygen or ammonia gas.
Claim 22
Dependent Claim
42 words
The method of claim 17 wherein the polycondensation is achieved by the addition of a catalyst selected from the group consisting of Na, KOH, H 2 SO 4 , H 2 PtCl 6 , benzoyl peroxide, di-tert.-butyl peroxy-oxalate, di-tert.-butyl peroxide and azoisobutyronitrile.
Claim 23
Dependent Claim
12 words
The method of claim 17 wherein the polycondensation is achieved by irradiation.
Claim 24
Dependent Claim
12 words
The method of claim 17 wherein the polycondensation is achieved by heating.
Claim 25
Dependent Claim
32 words
The method of claim 17 wherein said mixture of low molecular weight compounds and high molecular weight compound is treated with a solvent that will preferentially dissolve the low molecular weight compounds.
Claim 26
Dependent Claim
26 words
The method of claim 17 wherein said mixture of low molecular weight compounds and high molecular weight compound is distilled at a temperature of 100°-500° C.
Claim 27
Dependent Claim
70 words
The method of claim 17 wherein said spinning solution is prepared by dissolving said organosilicon high molecular weight compound in a solvent selected from the group consisting of benzene, toluene, xylene, ethylbenzene, styrene, cumene, pentane, hexane, octane, cyclopentadiene, cyclohexane, cyclohexene, methylene chloride, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, methylchloroform, 1,1,2-trichloroethane, hexachloroethane, chlorobenzene, dichlorobenzene, ethyl ether, dioxane, tetrahydrofuran, methyl acetate, ethyl ether, dioxane, tetrahydrofuran, methyl acetate, ethyl acetate, acetonitrile and carbon disulfide.
Claim 28
Dependent Claim
21 words
The method of claim 17 wherein said spinning solution is prepared by heating and melting said organosilicon high molecular weight compound.
Claim 29
Dependent Claim
23 words
The method as claimed in claim 17, wherein said preliminary heating (step 4) is effected under a tension of 0.011-20 Kg/mm 2 .
Claim 30
Dependent Claim
22 words
The method as claimed in claim 17, wherein said baking (step 5) is effected under s tension of 0.001-100 Kg/mm 2 .
Claim 31
Dependent Claim
27 words
The method as claimed in claim 17 wherein said baking (step 3) is effected under exposure to an ultrasonic wave having a frequency of 10KHz - 20MHz.
Claim 32
Dependent Claim
40 words
The method as claimed in claim 17 wherein after the baking in step (5) the fibers are heated at a temperature of 600°-1,700° C under an oxidizing atmosphere to remove free carbon contained in the filaments as CO 2 .
Claim 33
Dependent Claim
25 words
The method as claimed in claim 17, wherein said solvent for reducing the content of the low molecular weight compound is an alcohol or acetone.
Claim 34
Independent Claim
117 words
A method for producing silicon carbide fibers having a high tensile strength which comprises (1) preparing a spinning solution from at least one organosilicon high molecular weight compound having a softening point of higher than 50° C, in which silicon and carbon are the main skeleton components, and spinning said spinning solution into fibers, (2) preliminarily heating the spun fibers at a temperature of 350°-800° C under vacuum to volatilize low molecular weight compounds contained therein, and (3) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one nonoxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas, to form said silicon carbide fibers.
Claim 35
Independent Claim
117 words
A method for producing silicon carbide fibers having a high tensile strength which comprises (1) preparing a spinning solution from at least one organosilicon high molecular weight compound having a softening point of higher than 50° C, in which silicon and carbon are the main skeleton components, and spinning said spinning solution into fibers, (2) preliminarily heating the spun fibers at a temperature of 350°-800° C under vacuum to volatilize low molecular weight compounds contained therein, and (3) baking the thus treated fibers at a temperature of 800°-2,000° C under vacuum or at least one nonoxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas, to form said silicon carbide fibers.
Claim 36
Dependent Claim
64 words
The method of claim 20 wherein said spinning solution is prepared by dissolving said organosilicon high molecular weight compound in a solvent selected from the group consisting of benzene, toluene, xylene, ethylbenzene, styrene, cumene, pentane, hexane, octane, cyclopentadiene, cyclohexane, cyclohexene, methylene chloride, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane, methylchloroform, 1,1,2-trichloroethane, hexachloroethane, chlorobenzene, dichlorobenzene, ethyl ether, dioxane, tetrahydrofuran, methyl acetate, ethyl acetate, acetonitrile and carbon disulfide.
Claim 37
Dependent Claim
21 words
The method of claim 32 wherein said spinning solution is prepared by heating and melting said organosilicon high molecular weight compound.
Claim 38
Dependent Claim
23 words
The method as claimed in claim 32, wherein said preliminary heating (step 2) is effected under a tension of 0.001-20 Kg/mm 2 .
Claim 39
Dependent Claim
21 words
The method as claimed in claim 32, wherein said baking (step 3) is effected under a tension of 0.001-100Kg/mm 2 .
Claim 40
Dependent Claim
26 words
The method as claimed in claim 32 wherein said baking (step 3) is effected under exposure to an ultrasonic wave having a frequency of 10KHz-20 MHz.
Claim 41
Dependent Claim
40 words
The method as claimed in claim 32, wherein after the baking in step (3), the fibers are heated at a temperature of 600°-1,700° C under an oxidizing atmosphere to remove free carbon contained in the filaments as CO 2 .
Claim 42
Independent Claim
179 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting polysilanes having Si-Si bond which have no halogen atoms to polycondensation reaction by at least one process of addition of a polycondensation catalyst, irradiation and heating to produce polycarbosilanes containing no halogen atoms, (2) reducing a content of low molecular weight compounds contained in said polycarbosilanes by treating the above described polycarbosilanes with at least one treatment of a solvent, aging said polycarbosilanes at a temperature of 50°-700° C and distilling said polycarbosilanes at a temperature of 100°- 500° C, to produce the polycarbosilanes having a softening point of higher than 50° C, (3) dissolving the thus treated polycarbosilanes in a solvent or melting said polycarbosilanes to prepare spinning solution or spinning melt, and spinning said spinning solution or spinning melt into filaments, (4) baking the thus treated filaments at a temperature of 800°- 2,000° C, under vacuum or at least one non-oxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas to form silicon carbide fibers.
Claim 43
Independent Claim
179 words
A method for producing silicon carbide fibers having a high tensile strength which comprises: (1) subjecting polysilanes having Si-Si bond which have no halogen atoms to polycondensation reaction by at least one process of addition of a polycondensation catalyst, irradiation and heating to produce polycarbosilanes containing no halogen atoms, (2) reducing a content of low molecular weight compounds contained in said polycarbosilanes by treating the above described polycarbosilanes with at least one treatment of a solvent, aging said polycarbosilanes at a temperature of 50°-700° C and distilling said polycarbosilanes at a temperature of 100°- 500° C, to produce the polycarbosilanes having a softening point of higher than 50° C, (3) dissolving the thus treated polycarbosilanes in a solvent or melting said polycarbosilanes to prepare spinning solution or spinning melt, and spinning said spinning solution or spinning melt into filaments, (4) baking the thus treated filaments at a temperature of 800°- 2,000° C, under vacuum or at least one non-oxidizing atmosphere selected from the group consisting of an inert gas, CO gas and hydrogen gas to form silicon carbide fibers.
Claim 44
Dependent Claim
32 words
The method as claimed in claim 39, wherein the spun filaments are treated under an oxidizing condition to form an oxide layer on the filament surface prior to the baking step (4).
Claim 45
Dependent Claim
19 words
The method as claimed in claim 39, wherein said polysilanes having Si-Si bond in the step (1) are polydimethylsilanes.
Claim 46
Dependent Claim
20 words
The method as claimed in claim 39, wherein said polycondensation reaction in the step (1) is effected in an autoclave.
Claim 47
Dependent Claim
21 words
The method as claimed in claim 39, wherein said baking in step (4) is effected at a temperature of 1,000°-1,500° C.
Claim 48
Dependent Claim
62 words
Continuous silicon carbide fibers having tensile strength of 200-800 Kg/mm 2 , Young's modulus of 10-40 ton/mm 2 and resistant to corrosion and oxidation and showing no decrease in the tensile strength and Young's modulus at a high temperature of higher than 800° C, which are composed of ultra-fine grain silicon carbide having an average grain size of less than 0.1 μ.
Claim 49
Dependent Claim
62 words
Continuous silicon carbide fibers having tensile strength of 200-800 Kg/mm 2 , Young's modulus of 10-40 ton/mm 2 and resistant to corrosion and oxidation and showing no decrease in the tensile strength and Young's modulus at a high temperature of higher than 800° C, which are composed of ultra-fine grain silicon carbide having an average grain size of less than 0.1 μ.
References Cited (Backward Citations)
US3246950A
Cited
US3386840A
Cited
US3632715A
Cited
US3433725A
Cited
US3403008A
Cited
US3529044A
Cited
US3652711A
Cited
US3640693A
Cited
DE2236078A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |