EP0055076A1
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EP
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Continuous inorganic fibers containing Si, Zr and C, and their preparation
Assignee: Ube Corp
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Filing: 1981-12-16
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Granted: —
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Expires: 2001-12-16
Abstract
Abstract Continuous inorganic fibers consisting substantially of Si, Zr and C, and optionally of 0, are composed of (1) an amorphous material consisting substantially of Si, Zr and C and optionally of 0, or (2) an aggregate consisting substantially of ultrafine crystalline particles of β-SiC, ZrC, a solid solution of β-SiC, and ZrC and ZrC 1-x wherein 0<x< and having a particle diameter of not more than 500 A, in which amorphous Si0 2 and Zr0 2 can exist in the neighborhood of the ultrafine crystalline particles, or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles. The fibers can be produced by: a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula (-Si-CH2-), each silicon atom of said carbosilane units having bonded thereto a side-chain atom or group selected from hydrogen, lower alkyl and phenyl, and zirconoxane units of the formula (-Zr-0-); a second step of preparing a spinning dope of said semi-inorganic block copolymer and spinning the dope: a third step of subjecting the resulting fibers to a treatment of rendering them infusible; and a fourth step of firing the infusible fibers at a temperature of 800 to 1800°C in vacuum or in an atmosphere of an inert gas or a reducing gas.
Inventors
- 👤 Seishi Tohoku Daigaku Shukusha 4-2 Yajima
- 👤 Kiyohito Tohoku Daigaku Shukusha 2-2 Okamura
- 👤 Yoshio Hasegawa
- 👤 Takemi Yamamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 23:38
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/62272; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C08; C08G; C08G77/00; C08G77/60; Y; Y10; Y10S; Y10S264/00; Y10S264/19; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/294
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
Continuous inorganic fibers consisting substantially of Si, Zr and C and optionally of 0, characterised in that the fibers are composed of:- (1) an amorphous material consisting substantially of Si, Zr and C and optionally of 0; or (2) an aggregate consisting substantially of ultrafine crystalline particles of β-SiC, ZrC, a solid solution of β-SiC and ZrC and ZrC 1-x wherein 0 < x < 1 and having a particle diameter of not more than 500 Å (5 x 10 -8 m), in which amorphous Si0 2 and ZrO 2 can exist in the neighborhood of the ultrafine crystalline particles; or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles.
Claim 2
Dependent Claim
117 words
Continuous inorganic fibers consisting substantially of Si, Zr and C and optionally of 0, characterised in that the fibers are composed of:- (1) an amorphous material consisting substantially of Si, Zr and C and optionally of 0; or (2) an aggregate consisting substantially of ultrafine crystalline particles of β-SiC, ZrC, a solid solution of β-SiC and ZrC and ZrC 1-x wherein 0 < x < 1 and having a particle diameter of not more than 500 Å (5 x 10 -8 m), in which amorphous Si0 2 and ZrO 2 can exist in the neighborhood of the ultrafine crystalline particles; or (3) a mixture of said amorphous material (1) and said aggregate (2) of ultrafine crystalline particles.
Claim 3
Dependent Claim
137 words
A process for producing continuous inorganic fibers as claimed in claim 1, which comprises a first step of preparing a semi-inorganic block copolymer comprising polycarbosilane blocks having a main chain skeleton composed mainly of carbosilane units of the formula (-Si-CH 2 -), each silicon atom of said carbosilane units having bonded thereto a side-chain group selected from hydrogen, lower alkyl and phenyl, and zirconoxane units of the formula (-Zr-0-); a second step of preparing a spinning dope of said semi-inorganic block copolymer and spinning the dope; a third step of subjecting the resulting fibers to a treatment of rendering them infusible under tension or under no tension; and a fourth step of firing the infusible fibers at a temperature of 800 to 1800°C in vacuum or in an atmosphere of an inert gas or a reducing gas.
Claim 4
Dependent Claim
274 words
A process according to claim 2 wherein said semi-inorganic block copolymer is an organometallic copolymer having a number average molecular weight of 1000 to 50000 and composed of crosslinked polycarbosilane blocks and polyzirconosiloxane blocks, which is obtained by mixing (1) polycarbosilane with a number average molecular weight of 500 to 10000 having a main chain skeleton composed mainly of'carbosilane units of the formula (-Si-CH 2 -), each silicon atom of the carbosilane units having bonded thereto a side-chain atom or group selected from hydrogen, lower alkyl and phenyl, with (2) polyzirconosiloxane with a number average molecular weight of 500 to 10000 having a main chain skeleton composed mainly of zirconoxane units of the formula (-Zr-0-) and siloxane units of the formula (Si-0§, most of the zirconium atoms of said zirconoxane units having bonded thereto a side-chain group selected from lower alkoxy, phenoxy and acetylacetoxy, most of the silicon atoms of said siloxane units having bonded thereto a side-chain group selected from lower alkyl and phenyl, and the ratio of the total number of said zirconoxane units to that of said siloxane units being from 30:1 to 1:30, in such mixing proportions that the ratio of the total number of said carbosilane units to the sum of the total number of said zirconoxane units and the total number of said siloxane units is from 100:1 to 1:100; and heating the resulting mixture in an organic solvent in an atmosphere inert to the reaction to bond at least some of the silicon atoms of said polycarbosilane (1) with at least some of the zirconium atoms and/or silicon atoms of said polyzirconosiloxane (2) through an oxygen atom.
Claim 5
Dependent Claim
28 words
A process according to claim 3 wherein at least some of the side-chain atoms or groups bonded to the silicon atoms of the carbosilane units are hydrogen atoms.
Claim 6
Dependent Claim
171 words
A process according to claim 2 wherein said semi-inorganic block polymer is a polyzirconocarbosilane having a number average molecular weight of 700 to 100,000 obtained by mixing a polycarbosilane having a number average molecular weight of 200 to 10000 and a main chain skeleton composed mainly of units of the formula wherein R represents a hydrogen atom, a lower alkyl group or a phenyl group, with an organozirconium compound of the general formula wherein X represents an alkoxy group having 1 to 20 carbon atoms, a phenoxy group or an acetylacetoxy group, in such proportions that the ratio of the total number of structural units of the formula (-Si-CH 2 -) of the polycarbosilane to the total number of structural units of the formula (-Zr-0-) of the zirconium compound is from 2:1 to 200:1; and heating the resulting mixture in an atmosphere inert to the reaction, thereby to bond at least some of the silicon atoms of the polycarbosilane to the zirconium atoms of the zirconium compound through an oxygen atom.
Claim 7
Dependent Claim
23 words
A process according to claim 5 wherein at least some of the side-chain atoms or groups R of the polycarbosilane are hydrogen atoms.
Claim 8
Dependent Claim
31 words
A process according to any one of claims 2 to 6 wherein the spinning dope used in the second step is obtained by heat-melting the copolymer obtained in the first step.
Claim 9
Dependent Claim
34 words
A process according to any one of claims 2 to 6 wherein the spinning dope used in the second step is prepared by dissolving the copolymer obtained in the first step in a solvent.
Claim 10
Dependent Claim
35 words
A process according to any one of claims 2 to 8 wherein the third step is carried out by heating the spun fibers obtained in the second step, at low temperatures in an oxidizing atmosphere..
Claim 11
Dependent Claim
42 words
A process according to any one of claims 2 to 8 wherein the third step is carried out by exposing the fibers obtained in the second step to irradiation by y-rays or electron beams in an oxidizing atmosphere or a non-oxidizing atmosphere.
Claim 12
Dependent Claim
47 words
A process according to any one of claims 2 to 10 wherein after the first step but before the second step, low-molecular-weight compounds in the copolymer obtained in the first step are extracted by a solvent thereby to reduce the content of low-molecular-weight compounds in the copolymer.
Claim 13
Dependent Claim
61 words
A process according to any one of claims 2 to 10 wherein after the first step but before the second step, the copolymer formed in the first step is heated under reduced pressure or in an inert gaseous atmosphere to remove a part of the low-molecular-weight compounds in the copolymer thereby to reduce the content of low-molecular-weight compounds in the copolymer.
Claim 14
Dependent Claim
47 words
A process according to any one of claims 2 to 12 wherein after the fourth step, the fired fibers are treated with an acid or alkali, and/or heated at a temperature of 800 to 1600°C in an oxidizing atmosphere, thereby to remove impurities in the fired fibers.
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