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US4645807A
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Method for forming new preceramic polymers for SiC and Si3 N4 /SiC systems
Assignee: Massachusetts Institute of Technology
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Filing: 1985-07-18
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Granted: 1987-02-24
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Expires: 2005-07-18
Abstract
Abstract A method of forming preceramic polymers using a organopolysilane of the formula [(RSiH) x (RSi) y ] n , where R is a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbons atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group and n is an integer greater than 1, and reacting it with alkali metal amides or silylamides in catalytic quantities is disclosed. Preferably, the alkali metal amide is a polymeric alkali metal silylamide of the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ] m where a+b+c=1; R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and n and m are integers greater than 1. Novel preceramic polymers formed by this method are also disclosed.
Inventors
- 👤 Dietmar Seyferth
- 👤 Timothy G. Wood
- 👤 Yuan-Fu Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:45
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/16; C08G; C08G77/00; C08G77/60
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
122 words
A method for preparing organosilicon polymers, wherein the method comprises: (a) mixing an organopolysilane of the formula [i (RSiH) x (RSi) y ] n , where x+y=1, R is a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkenyl group having 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbons atoms, and n is an integer greater than 1; with at least a catalytic amount of an alkali metal amide or a silylamide in an organic solvent; (b) allowing the mixture of step (a) to react at room temperature or above; and (c) quenching the reaction mixture with a reactive electrophile, thereby forming said organosilicon polymer.
Claim 2
Independent Claim
122 words
A method for preparing organosilicon polymers, wherein the method comprises: (a) mixing an organopolysilane of the formula [i (RSiH) x (RSi) y ] n , where x+y=1, R is a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkenyl group having 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbons atoms, and n is an integer greater than 1; with at least a catalytic amount of an alkali metal amide or a silylamide in an organic solvent; (b) allowing the mixture of step (a) to react at room temperature or above; and (c) quenching the reaction mixture with a reactive electrophile, thereby forming said organosilicon polymer.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein R is the lower alkyl group.
Claim 4
Dependent Claim
11 words
The method of claim 2, wherein R is CH 3 .
Claim 5
Dependent Claim
8 words
The method of claim 1, wherein x=1, y=0.
Claim 6
Dependent Claim
108 words
The method of claim 1, wherein the alkali metal amide is a polymeric alkali metal silylamide of the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ]m, where a+b+c=1, R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and m is an integer greater than 1.
Claim 7
Dependent Claim
109 words
The method of claim 2, wherein the alkali metal amide is a polymeric alkali metal silylamide of the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ] m where a+b+c=1, R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and m is an integer greater than 1.
Claim 8
Dependent Claim
110 words
The method of claim 3, wherein the alkali metal amide is a polymeric alkali metal silylamide of the formula [(R 1 SiHNH) a (R 1 SiN) b (R 1 SiHNM) c ] m , where a+b+c=1, R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; M is an alkali metal or one-half equivalent of an alkaline earth metal; and m is an integer greater than 1.
Claim 9
Dependent Claim
43 words
The method of claim 1, wherein the reaction mixture is quenched with an electrophile, E-X, wherein E is selected from the group consisting of lower alkyl groups and silyl groups and X is selected from the group consisting of halogen, sulfate and sulfonate.
Claim 10
Dependent Claim
53 words
The method of claim 5 wherein the polymeric metal silylamide is added in a sufficient quantity so that the excess carbon obtained on pyrolysis of the silylamide can react with excess silicon from the pyrolysis of the organopolysilane compound, thus producing a ceramic product which contains substantially no free silicon or free carbon.
Claim 11
Dependent Claim
25 words
The method of claim 5, wherein the polymeric metal silylamide is added in excess so that a ceramic product produced by pyrolysis contains free carbon.
Claim 12
Dependent Claim
28 words
The method of claim 5, wherein an excess of [(RSiH) x (RSi) y ] n is used so that a ceramic product produced by pyrolysis contains free silicon.
Claim 13
Dependent Claim
39 words
The method of claim 6 wherein the polymeric metal silylamide is added in a sufficient quantity so that the excess carbon obtained on pyrolysis of the silylamide can react with excess silicon from the pyrolysis of the organopolysilane compound.
Claim 14
Dependent Claim
21 words
The method of claim 12 wherein the polymeric alkali metal silylamide has the formula [(CH.sub.3 SiHNH).sub.a (CH.sub.3 SiN).sub.b (CH.sub.3 SiHNK).sub.c ].sub.m.
Claim 15
Dependent Claim
20 words
The method of claim 12 wherein the organopolysilane is [(CH 3 SiH) x (CH 3 Si) y ] n .
Claim 16
Dependent Claim
14 words
The method of claim 12 wherein R and R 1 are CH 3 .
Claim 17
Dependent Claim
14 words
The method of claim 10 wherein R and R 1 are CH 3 .
Claim 18
Dependent Claim
14 words
The method of claim 11 wherein R and R 1 are CH 3 .
Claim 19
Dependent Claim
17 words
The method of claim 13 wherein the mixture is allowed to react by stirring at room temperature.
Claim 20
Dependent Claim
12 words
The method of claim 18 wherein the mixture is heated at reflux.
Claim 21
Dependent Claim
19 words
The method of claim 18 wherein the reactive electrophile quenching the reaction is an organic halide or a halosilane.
Claim 22
Dependent Claim
14 words
The method of claim 18 wherein the organic halide is a lower alkyl halide.
Claim 23
Dependent Claim
14 words
The method of claim 21 wherein the lower alkyl halide is CH 3 I.
Claim 24
Dependent Claim
11 words
The method of claim 18 wherein the halosilane is a chlorosilane.
Claim 25
Dependent Claim
24 words
The method of claim 12 wherein the mole ratio of organopolysilane compound to polymeric alkali metal silylamide ranges from about 4:1 to about 1:4.
Claim 26
Dependent Claim
15 words
A preceramic polymer containing Si, C and N formed by the method of claim 1.
Claim 27
Dependent Claim
15 words
A preceramic polymer containing Si, C and N formed by the method of claim 5.
Claim 28
Dependent Claim
15 words
A preceramic polymer containing Si, C and N formed by the method of claim 6.
Claim 29
Dependent Claim
15 words
The method of claim 1 wherein the alkali metal amide is an alkali metal silylamide.
Claim 30
Dependent Claim
113 words
The method of claim 28 wherein the alkali metal silylamide is [R 2 R 3 R 4 Si] 2 NM wherein R 2 , R 3 and R 4 are each a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkoxy group having from 1 to about 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group, R 2 , R 3 and R 4 may be the same or different; and M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 31
Dependent Claim
39 words
The method of claim 28 wherein [R 2 R 3 R 4 Si] 2 NM is selected from the group consisting of [(CH 3 ) 2 (CH 2 ═CH)Si] 2 NM and [(CH 3 ) 3 Si] 2 NM.
Claim 32
Dependent Claim
120 words
The method of claim 28 wherein the alkali metal silylamide is partially deprotonated cyclo-[R 5 R 6 SiNH] m containing cyclo-[R 5 R 6 SiNM] units wherein R 5 and R 6 are each a lower alkyl group having from 1 to about 6 carbon atoms, a lower alkoxy group having from 1 to about 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group, R 5 and R 6 may be the same or different; M is an alkali metal or one-half equivalent of an alkaline earth metal and m is an integer greater than 1.
Claim 33
Dependent Claim
33 words
The method of claim 31 wherein cyclo-[R 5 R 6 SiNH] m is selected from the group consisting of [(CH 3 ) 2 SiNH] m and [(CH 3 )(CH 2 ═CH)SiN] m .
Claim 34
Dependent Claim
10 words
The method of claim 4 wherein the organopolysilane is poly(phenylsilane).
Claim 35
Dependent Claim
18 words
The method of claim 1 wherein the silylamide is a diorganocyclopolysilazane that is either partially or completely ring-opened.
Claim 36
Dependent Claim
96 words
The method of claim 34 where the diorganocyclopolysilazane comprises units having the formula [R 1 R 11 SiNH] m where R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted alkenyl group having from 2 to about 6 carbon atoms, a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, a tri(lower)alkyl- or di(lower)alkylsilyl group or a di(lower)alkylamino group; R 11 is defined as R 1 , and may be the same or different, and M is an integer greater than 1.
Claim 37
Dependent Claim
47 words
The method of claim 35 wherein the diorganocyclopolysilazane is reacted with a sufficient amount based on available NH groups of a base to produce polymeric silylamides containing [R 1 R 11 SiNM] units where M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 38
Dependent Claim
15 words
The method of claim 35 wherein R 11 is the same as R 1 .
Claim 39
Dependent Claim
15 words
The method of claim 37 wherein R 11 and R 1 are CH 3 .
Claim 40
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 4.
Claim 41
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 34.
Claim 42
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 35.
Claim 43
Independent Claim
65 words
A method for preparing an organosilicon preceramic polymer wherein the method comprises: (a) forming a methylpolysilane of the formula [(CH 3 SiH) x (CH 3L Si) y ] n , where x+y=1; and n is an integer greater than 1; by reacting CH 3 SiHCl 2 with an alkali metal; and (b) reacting the methylpolysilane with at least catalytic quantities of an alkali metal amide.
Claim 44
Independent Claim
65 words
A method for preparing an organosilicon preceramic polymer wherein the method comprises: (a) forming a methylpolysilane of the formula [(CH 3 SiH) x (CH 3L Si) y ] n , where x+y=1; and n is an integer greater than 1; by reacting CH 3 SiHCl 2 with an alkali metal; and (b) reacting the methylpolysilane with at least catalytic quantities of an alkali metal amide.
Claim 45
Dependent Claim
10 words
A preceramic polymer formed by the process of claim 42.
Claim 46
Dependent Claim
17 words
The method of claim 29 wherein the substituted vinyl group is a substituted or unsubstituted allyl group.
Claim 47
Dependent Claim
17 words
The method of claim 31 wherein the substituted vinyl group is a substituted or unsubstituted allyl group.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |