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EP0167306A2
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Silicon nitride-containing ceramics
Assignee: Dow Silicones Corp
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Filing: 1985-06-11
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Granted: —
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Expires: 2005-06-11
Abstract
Abstract What is disclosed is a process for preparing a silicon nitride-containing ceramic material from a R 3 SiNH- containing silazane polymer, which has been rendered infusible by treatment with certain reactive metal halides, by heating the infusible silazane polymerto an elevated temperature under an inert atmosphere. Suitable reactive metal halides are of the general formula MX " or R b SiX (4-b) where M is a metal atom of valence n, X is chlorine or bromine, R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms, and b has a value of 0, 1, or 2. Preferred reactive metal halides are SiCl 4 and HSiCl 3 .
Inventors
- 👤 John Patrick Cannady
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 01:59
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
175 words
A method of preparing a silicon nitride-containing ceramic material, which method comprises (1) treating a R 3 SiNH-containing silazane polymer with a reactive metal halide of general formula MX n or R b SiX (4-b) at a temperature below the softening point of the R 3 SiNH-containing silazane polymer for a time sufficient to render the silazane polymer infusible where R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; M is a metal atom of valence n; X is a halide atom selected from the group consisting of chlorine and bromine; and b has a value of 0, 1, or 2; where said reactive metal halide has fewer carbon atoms than the R 3 SiNH-endblocking group; and where said reactive metal halide has at least two halide atoms; and (2) heating the infusible silazane polymer of step (1) in an inert atmosphere or vacuum to a temperature of at least 750°C until said infusible silazane polymer is converted to a silicon nitride-containing ceramic material.
Claim 2
Independent Claim
175 words
A method of preparing a silicon nitride-containing ceramic material, which method comprises (1) treating a R 3 SiNH-containing silazane polymer with a reactive metal halide of general formula MX n or R b SiX (4-b) at a temperature below the softening point of the R 3 SiNH-containing silazane polymer for a time sufficient to render the silazane polymer infusible where R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; M is a metal atom of valence n; X is a halide atom selected from the group consisting of chlorine and bromine; and b has a value of 0, 1, or 2; where said reactive metal halide has fewer carbon atoms than the R 3 SiNH-endblocking group; and where said reactive metal halide has at least two halide atoms; and (2) heating the infusible silazane polymer of step (1) in an inert atmosphere or vacuum to a temperature of at least 750°C until said infusible silazane polymer is converted to a silicon nitride-containing ceramic material.
Claim 3
Dependent Claim
106 words
A method as defined in claim 1 wherein said. R 3 SiNH-containing silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, an organochlorosilane or a mixture of organochlorosilanes of general formula with a disilazane of general formula at a temperature in the range of 25°C to 300°C while removing byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; and c has a value of 1 or 2.
Claim 4
Dependent Claim
124 words
A method as defined in claim 1 wherein said R 3 SilTH-containing silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, a chlorine-containing disilane or a mixture of chlorine-containing disilazanes, of general formula with a disilazane of general formula at a temperature in the range of 25°C to 300°C while removing byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; d has a value of 0.5 to 3; e has a value of 0 to 2.5; and the sum of (d+e) is equal to 3.
Claim 5
Dependent Claim
73 words
A method as defined in claim 1 wherein said R 3 SiNH-containing silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, trichlorosilane with a disilazane at a temperature in the range of 25°C to 300°C while removing byproduced volatile products, wherein said disilazane has the general formula where R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms.
Claim 6
Dependent Claim
18 words
A method as defined in claim 1 wherein said reactive metal halide is of general formula MX .
Claim 7
Dependent Claim
19 words
A process as defined in claim 2 wherein said reactive metal halide is of general formula MX n .
Claim 8
Dependent Claim
19 words
A process as defined in claim 3 wherein said reactive metal halide is of general formula MX n .
Claim 9
Dependent Claim
17 words
A process as defined in claim 4 wherein said reactive metal halide is of general formula MXn.
Claim 10
Dependent Claim
38 words
A process as defined in claim 5 wherein said reactive metal halide is selected from the group consisting of BC1 3 , BBr 3 , PC1 3 , PBr 3 , ZrCl 4 , and SnCl 4 .
References Cited (Backward Citations)
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