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EP0175382A2
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Ceramic materials from silazane polymers
Assignee: Dow Silicones Corp
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Filing: 1985-09-20
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Granted: —
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Expires: 2005-09-20
Abstract
Abstract A method is disclosed for increasing the ceramic yield of a ceramic material obtained by firing a R3SiNH-containing silazane polymer to an elevated temperature in an inert atmosphere or in a vacuum. The method involves adding certain boron compounds to the R3SiNH-containing silazane polymer prior to firing. Suitable boron compounds include, among others, metaboric acid, orthoboric acid, and organoboron compounds of the general formula BR@ where R sec is selected from the group consisting of alkyl radicals containing 1 to 5 carbon atoms, phenyl radicals, and -OR''' radicals where R''' is an alkyl radical containing 1 to 4 carbon atoms.
Inventors
- 👤 Duane Ray Mujalski
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 16:37
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C04B35/56; C04B35/565; C04B35/571; C08; C08K; C08K3/00; C08K3/38
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
A method of preparing a ceramic material, said method comprising heating a modified R 3 SiNH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 750°C until said modified R 3 SiNH- containing silazane polymer is converted to a ceramic material with increased ceramic yield relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions, wherein said method is characterized by the modified R 3 SiNH-containing silazane polymer being prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, ceramic yield increasing, amount of a boron compound.
Claim 2
Independent Claim
101 words
A method of preparing a ceramic material, said method comprising heating a modified R 3 SiNH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 750°C until said modified R 3 SiNH- containing silazane polymer is converted to a ceramic material with increased ceramic yield relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions, wherein said method is characterized by the modified R 3 SiNH-containing silazane polymer being prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, ceramic yield increasing, amount of a boron compound.
Claim 3
Dependent Claim
125 words
A process as defined in claim 1 wherein said non-modified R 3 SiNH-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 disilanes of general formula with a disilazane of general formula at a temperature in the range of 25°C to 300°C while distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1 - 3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1 - 3 carbon atoms, or a phenyl group; b has a value of 0.5 - 3; c has a value of 0 - 2.5; and the sum of (b+c) is equal to three.
Claim 4
Dependent Claim
107 words
A process as defined in claim 1 wherein said non-modified 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 distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1 - 3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1 - 3 carbon atoms, or a phenyl group; and n has a value of 1 or 2.
Claim 5
Dependent Claim
75 words
A process as defined in claim 1 wherein said non-modified 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 distilling by-produced volatile products, wherein said disilazane has the general formula where R is a hydrogen atom, a vinyl group, an alkyl group containing 1 - 3 carbon atoms, or a phenyl group.
Claim 6
Dependent Claim
29 words
A method as defined in claim 1 wherein said boron compound is selected from the group consisting of metaboric acid, orthoboric acid, tetraboric acid, boron oxide, and boron silicide.
Claim 7
Dependent Claim
29 words
A method as defined in claim 2 wherein said boron compound is selected from the group consisting of metaboric acid, orthoboric acid, tetraboric acid, boron oxide, and boron silicide.
Claim 8
Dependent Claim
29 words
A method as defined in claim 3 wherein said boron compound is selected from the group consisting of metaboric acid, orthoboric acid, tetraboric acid, boron oxide, and boron silicide.
Claim 9
Dependent Claim
29 words
A method as defined in claim 4 wherein said boron compound is selected from the group consisting of metaboric acid, orthoboric acid, tetraboric acid, boron oxide, and boron silicide.
References Cited (Backward Citations)
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