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EP0052694A1
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Branched polycarbosilanes and their use in the production of silicon carbide
Assignee: Union Carbide Corp
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Filing: 1981-07-17
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Granted: —
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Expires: 2001-07-17
Abstract
Abstract Silicon carbide can be produced by the pyrolysis of branched polycarbosilanes which in turn are produced directly from selected monomer systems.
Inventors
- 👤 Curtis Louis Schilling, Jr.
- 👤 Thomas Charles Williams
- 👤 John Peter Wesson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 07:29
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/977; C08; C08G; C08G77/00; C08G77/60; C01P; C01P2004/00; C01P2004/10
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
86 words
A branched polycarbosilane comprising more than one unit of the formula wherein R is lower alkyl, a is 0 or 1, b is 0-3, c is 0-4, d is 0-4, and a + b + c + d totals 4, with the provisos that, in different units, a, b, c, d, and R may differ, but that, in at least one unit, a + d must total 1 or more and, in at least 1 unit, a + c + d must total 3 or more.
Claim 2
Dependent Claim
86 words
A branched polycarbosilane comprising more than one unit of the formula wherein R is lower alkyl, a is 0 or 1, b is 0-3, c is 0-4, d is 0-4, and a + b + c + d totals 4, with the provisos that, in different units, a, b, c, d, and R may differ, but that, in at least one unit, a + d must total 1 or more and, in at least 1 unit, a + c + d must total 3 or more.
Claim 3
Dependent Claim
18 words
A branched polycarbosilane as in claim 1 substantially composed of, in the ratio shown, units of the formulas
Claim 4
Dependent Claim
18 words
A branched polycarbosilane as in claim 1 substantially composed of, in the ratio shown, units of the formulas
Claim 5
Dependent Claim
18 words
A branched polycarbosilane as in claim 1 substantially composed of, in the ratio shown, units of the formulas
Claim 6
Dependent Claim
18 words
A branched polycarbosilane as in claim 1 substantially composed of, in the ratio shown, units of the formulas
Claim 7
Dependent Claim
28 words
A branched polycarbosilane as in claim 1 substantially composed of units of the formulas in a ratio selected from the group consisting of 0.6:1:1, 0.5:1:1, 0.6:0.6:1, and 0.5:1.4:1.
Claim 8
Dependent Claim
18 words
A branched polycarbosilane as in claim 1 substantially composed of, in the ratio shown, units of the formulas
Claim 9
Dependent Claim
26 words
A branched polycarbosilane as in claim 1 substantially composed of units of the formulas in a ratio selected from the group consisting of 1:1:1 and 0.9:1:1.
Claim 10
Dependent Claim
95 words
A process for producing branched polycarbosilanes which comprises reacting, with an active metal in an inert solvent at an elevated temperature, a compound system comprising one or more monomers of the formula (I) wherein R is lower alkyl', X is halo, a is 0 or 1, b is 0-3, c is 0-4, d is 0-4, a + b + c + d totals 4, and a + d totals at least 1, said compound system being selected such that its average molar functionality is at least 2.3 and the formation of silicon-carbon bonds is favored.
Claim 11
Dependent Claim
95 words
A process for producing branched polycarbosilanes which comprises reacting, with an active metal in an inert solvent at an elevated temperature, a compound system comprising one or more monomers of the formula (I) wherein R is lower alkyl', X is halo, a is 0 or 1, b is 0-3, c is 0-4, d is 0-4, a + b + c + d totals 4, and a + d totals at least 1, said compound system being selected such that its average molar functionality is at least 2.3 and the formation of silicon-carbon bonds is favored.
Claim 12
Dependent Claim
40 words
A process as in claim 9 wherein said monomer system contains at least two different monomers of formula (1), at least one of which is characterized by an a + b + c + d total of 3 or 4.
Claim 13
Dependent Claim
14 words
A process as in claim 10 wherein R is methyl and X is chloro.
Claim 14
Dependent Claim
28 words
A process as in claim 11 wherein the active metal is potassium, the solvent is tetrahydrofuran, and the elevated temperature is the ambient pressure reflux temperature of tetrahydrofuran.
Claim 15
Dependent Claim
16 words
The branched polycarbosilane product of the process of claim 9 or 10 or 11 or 12.
Claim 16
Dependent Claim
21 words
A branched polycarbosilane as claimed in claim 13 which, at room temperature, is normally solid and soluble in non-protic organic solvents.
Claim 17
Dependent Claim
21 words
A process for producing silicon carbide which comprises pyrolyzing in an inert atmosphere a branched polycarbosilane as claimed in claim 1.
Claim 18
Dependent Claim
28 words
A process for producing silicon carbide which comprises pyrolyzing in an inert atmosphere a branched polycarbosilane which has been produced in accordance with the process of claim 10.
Claim 19
Dependent Claim
30 words
A process for producing a silicon carbide product which comprises pyrolyzing in an inert atmosphere a branched polycarbosilane which has been produced in accordance with the process of claim 12.
Claim 20
Dependent Claim
30 words
A process for producing a silicon carbide product which comprises pyrolyzing in an inert atmosphere a branched polycarbosilane which has been produced in accordance with the process of claim 13.
Claim 21
Dependent Claim
17 words
The silicon carbide composition produced by the process of claim 15 or 16 or 17 or 18.
References Cited (Backward Citations)
US4134759A
Cited
JPS5465799A
Cited
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