US4639501A
Expired / Lapsed
US
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Method for forming new preceramic polymers containing silicon
Assignee: Massachusetts Institute of Technology
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Filing: 1985-09-04
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Granted: 1987-01-27
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Expires: 2005-09-04
Abstract
Abstract A method of forming preceramic polymers by mixing (A) a methylpolysilane of the formula [(RSiH) x (RSi) y ] n , (where R is a lower alkyl group having from 1 to about 6 carbon atoms, a cycloalkyl group having from 3 about to 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 x+y=1, (x and y are each >0 and also x=l, y=o), and n is an integer greater than 1 with (B) an organic or organisilicon compound having at least two alkenyl groups and allowing the mixture to react is disclosed. Preferably, the alkenyl group is a vinyl group. The reaction is preferably initiated by the generation of reactive free radicals. Novel preceramic polymers formed by this method are also disclosed.
Inventors
- 👤 Dietmar Seyferth
- 👤 Yuan-Fu Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:54
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08L; C08L83/00; C08L83/16; G; G03; G03F; G03F7/00; G03F7/004; G03F7/075; G03F7/0757
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
131 words
A method for preparing preceramic organosilicon polymers, wherein the method comprises: (a) mixing an organopolysilane of the formula [(RSiH) x (RSi) y ] n with a sufficient quantity to undergo a hydrosilylation reaction of an organosilicon compound containing at least two alkenyl groups or a cyclic organic compound containing at least three alkenyl groups where x+6= 1, 0<x<1, 0<y<1, R is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to 10 carbon atoms, and n is an integer greater than 1, and (b) allowing the mixture of step (a) to react, neat or in an organic solvent, thereby forming said preceramic organosilicon polymer.
Claim 2
Independent Claim
131 words
A method for preparing preceramic organosilicon polymers, wherein the method comprises: (a) mixing an organopolysilane of the formula [(RSiH) x (RSi) y ] n with a sufficient quantity to undergo a hydrosilylation reaction of an organosilicon compound containing at least two alkenyl groups or a cyclic organic compound containing at least three alkenyl groups where x+6= 1, 0<x<1, 0<y<1, R is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to 10 carbon atoms, and n is an integer greater than 1, and (b) allowing the mixture of step (a) to react, neat or in an organic solvent, thereby forming said preceramic organosilicon polymer.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the reaction of step (b) is initiated by the generation of reactive free radicals.
Claim 4
Dependent Claim
27 words
The method of claim 2 which further comprises adding a catalyst to the mixture of step (a) which on appropriate input of energy provides reactive free radicals.
Claim 5
Dependent Claim
15 words
The method of claim 3 wherein an energy source for free radical generation is heat.
Claim 6
Dependent Claim
25 words
The method of claim 2 wherein an energy source for free radical generation is ultraviolet irradiation in the presence or the absence of a catalyst.
Claim 7
Dependent Claim
21 words
The method of claim 2 wherein the free radical catalyst is selected from the group consisting of peroxides and azo compounds.
Claim 8
Dependent Claim
11 words
The method of claim 6 wherein the azo compound is azobisisobutyronitrile.
Claim 9
Dependent Claim
12 words
The method of claim 6 wherein the peroxide is an organic peroxide.
Claim 10
Dependent Claim
12 words
The method of claim 8 wherein the organic peroxide is benzoyl peroxide.
Claim 11
Dependent Claim
25 words
The method of claim 2 which further comprises adding a transition metal catalyst which is effective in hydrosilylation reactions to the mixture of step (a).
Claim 12
Dependent Claim
18 words
The method of claim 10 wherein the transition metal catalyst is H 2 PtCl 6 .6H 2 O.
Claim 13
Dependent Claim
47 words
The method of claim 1 wherein the organopolysilane and the alkenyl-containing organic or organosilicon compound and the compounds are added in an amount so that the mole ratio of SiH in the organopolysilane to the alkenyl group in the organic or organosilicon compound is larger than 3.
Claim 14
Dependent Claim
14 words
The method of claim 12 wherein the mole ratio is about 6 or larger.
Claim 15
Dependent Claim
13 words
The method of claim 3 wherein the mixture is heated to 70°-90° C.
Claim 16
Dependent Claim
13 words
The method of claim 4 wherein the mixture is heated to 70°-90° C.
Claim 17
Dependent Claim
20 words
The method of claim 2 wherein the alkenyl group is a lower alkenyl group having 2 to 6 carbon atoms.
Claim 18
Dependent Claim
13 words
The method of claim 16 wherein the alkenyl group is CH 2 ═CH.
Claim 19
Dependent Claim
12 words
The method of claim 1, wherein R is the lower alkyl group.
Claim 20
Dependent Claim
12 words
The method of claim 16, wherein R is a lower alkyl group.
Claim 21
Dependent Claim
11 words
The method of claim 18, wherein R is CH 3 .
Claim 22
Dependent Claim
7 words
The method of claim 1 where X=1.
Claim 23
Dependent Claim
32 words
The method of claim 1, wherein the polymer product is pyrolyzed in a nitrogen or inert gas atmosphere for a sufficient time and at a sufficient temperature to form a ceramic product.
Claim 24
Dependent Claim
32 words
The method of claim 18 wherein the polymer is pyrolyzed in a nitrogen or an inert gas atmosphere for a sufficient time and at a sufficient temperature to form a ceramic product.
Claim 25
Dependent Claim
197 words
The method of claim 19 wherein the organic or organosilicon compound is selected from the group consisting of [R 1 2 (A)Si] 2 Y, [R 1 (A) 2 Si] 2 Y, [(A) 3 Si] 2 Y, R 1 n (A) 3-n Si--Si(A) 3-q R 1 q , (A) 4 Si, cyclo-[R 1 (A)SiY 1 ] m , and cyclo[(A) 2 SiY 1 ] m where Y=O, S, NH, NR 2 , CH 2 , CH 2 CH 2 , or ##STR2## and other organic bridges; n and q are 0, 1 or 2, n may be the same or different than q; Y 1 =O, S, NH, NR 2 , CH 2 , m is 2 or greater when Y 1 is NH, NR 2 , S and CH 2 , m is 3 or greater when Y 1 is 0, R 1 is a substituted or unsubstituted lower alkyl group having 1-6 carbon atoms, or a substituted or unsubstituted lower aryl group having 6-10 carbon atoms, R 2 is defined as R 1 and can be the same or different; and A is a substituted or unsubstituted vinyl group or a substituted or unsubstituted allyl group.
Claim 26
Dependent Claim
9 words
The method of claim 24 wherein A is vinyl.
Claim 27
Dependent Claim
83 words
The method of claim 20 wherein the alkenyl-containing organosilicon compound is selected from the group consisting of cyclo-[(CH 3 )(CH 2 ═CH)SiO] 4 , cyclo-[(CH 3 )(CH 2 ═CH)SiO] 5 , cyclo-[(CH 3 )(CH 2 ═CH)SiO] 6 , combinations of cyclo-[(CH 3 )(CH 2 ═CH)SiO] n , n=4, and larger cyclo-[(CH 3 )(CH 2 ═CH)SiS] 3 , cyclo-[(CH 3 )(CH 2 ═CH)SiNH] 3 cyclo-[(CH 3 )(CH 2 ═CH)SiNH] 4 , and combination of cyclo-[(CH 3 )(CH 2 ═CH)SiNH] n , n=3 and larger.
Claim 28
Dependent Claim
58 words
The method of claim 24 wherein the organic or organosilicon compound is added in a sufficient quantity so that the excess carbon obtained on pyrolysis of the incorporated organic or organosilicon compound can react with excess silicon from the pyrolysis of the organopolysilane compound, thus producing a ceramic product which contains virtually no free silicon or free carbon.
Claim 29
Dependent Claim
35 words
The method of claim 24, wherein the organic or organosilicon compound is added in an amount so that a ceramic product produced by pyrolysis contains free carbon which has not reacted with silicon on pyrolysis.
Claim 30
Dependent Claim
36 words
The method of claim 24, wherein [(RSiH) x (RSi) y ] n is added in an amount so that a ceramic product produced by pyrolysis contains free silicon which has not reacted with carbon on pyrolysis.
Claim 31
Dependent Claim
40 words
The method of claim 25 wherein the organosilicon compound is added in a sufficient quantity so that the excess carbon obtained on pyrolysis of the incorporated organisilicon compound can react with excess silicon from the pyrolysis of the methylpolysilane compound.
Claim 32
Dependent Claim
16 words
The method of claim 30 wherein the R 1 and R 2 are CH 3 .
Claim 33
Dependent Claim
15 words
The method of claim 28 wherein R 1 and R 2 are CH 3 .
Claim 34
Dependent Claim
15 words
The method of claim 29 wherein R 1 and R 2 are CH 3 .
Claim 35
Dependent Claim
28 words
The method of claim 31 wherein the organopolysilane is [(CH 3 SiH) x (CH 3 Si) y ] n , x, y and n are as defined above.
Claim 36
Dependent Claim
13 words
The method of claim 34 wherein the mixture is heated to 70°-90° C.
Claim 37
Dependent Claim
22 words
The method of claim 35 wherein the polymer is pyrolyzed under an inert gas stream to about 1000° C. to 1300° C.
Claim 38
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 1.
Claim 39
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 12.
Claim 40
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 13.
Claim 41
Dependent Claim
10 words
A preceramic polymer formed by the method of claim 21.
Claim 42
Dependent Claim
11 words
The method of claim 24 wherein m is 3 or greater.
Claim 43
Dependent Claim
28 words
The method of claim 28 wherein the organopolysilane is [(CH 3 SiH) x (CH 3 Si) y ] n , x, y and n are as defined above.
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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) | 1990-01-26 | 1990-07-28 | 1991-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-26 | 1994-07-28 | 1995-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-26 | 1998-07-28 | 1999-01-27 | $7700.00 | Window Closed / Lapsed |