US4720532A
Expired / Lapsed
US
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Organopolysilazane precursors to silicon nitride-rich mixed SiC/Si3 N4
Assignee: Massachusetts Institute of Technology
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Filing: 1986-08-22
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Granted: 1988-01-19
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Expires: 2006-08-22
Abstract
Abstract A method for preparing preceramic polymers is disclosed. This method includes the steps of (1) reacting in solution anhydrous ammonia with a mixture of R 1 SiHX 2 (where R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and X is a halogen) and RSiX 3 (where R is H, a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms), thereby forming a mixture of precursor polymers; and reacting the precursor polymers in the presence of a basic catalyst capable of deprotonating the NH functions in the precursor polymers to form the preceramic polymer. Preferably, this preceramic polymer is treated with an electrophile compound. Pyrolyzing the polymer in an inert gas stream or ammonia atmosphere to form a ceramic material is also disclosed.
Inventors
- 👤 Dietmar Seyferth
- 👤 Joanne M. Schwark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:37
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
191 words
A method for preparing preceramic organosilicon polymers, wherein the method comprises: (a) reacting in solution anhydrous ammonia with a mixture of R 1 SiHX 2 , wherein R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and X is a halogen, and RSiX 3 wherein R is H. a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, or a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, thereby forming a mixture of precursor polymers; and (b) reacting said precursor polymers in the presence of a basic catalyst capable of deprotonating the NH functions in said precursors to form said preceramic polymer.
Claim 2
Independent Claim
191 words
A method for preparing preceramic organosilicon polymers, wherein the method comprises: (a) reacting in solution anhydrous ammonia with a mixture of R 1 SiHX 2 , wherein R 1 is a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, and X is a halogen, and RSiX 3 wherein R is H. a lower alkyl group having from 1 to about 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having from 3 to about 6 carbon atoms, or a substituted or unsubstituted lower alkenyl group having from 2 to about 6 carbon atoms, or a substituted or unsubstituted lower aryl group having from 6 to about 10 carbon atoms, thereby forming a mixture of precursor polymers; and (b) reacting said precursor polymers in the presence of a basic catalyst capable of deprotonating the NH functions in said precursors to form said preceramic polymer.
Claim 3
Dependent Claim
19 words
The method of claim 1 further comprising the additional step of treating said preceramic polymer with an electrophile compound.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein X is Cl, R 1 is a lower alkyl group and R is H or a lower alkyl group.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein R 1 is CH 3 .
Claim 6
Dependent Claim
13 words
The method of claim 4 wherein R is H or CH 3 .
Claim 7
Dependent Claim
10 words
The preceramic polymer formed by the method of claim 2.
Claim 8
Dependent Claim
10 words
The preceramic polymer formed by the method of claim 4.
Claim 9
Dependent Claim
10 words
The preceramic polymer formed by the method of claim 5.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein the mole ratio of R 1 SiHX 2 :RSiX 3 is from about 8:1 to about 1:6.
Claim 11
Dependent Claim
15 words
The method of claim 9 wherein the mole ratio is about 8:1 to about 1:2.
Claim 12
Dependent Claim
23 words
The method of claim 3 wherein the mole ratio of R 1 SiHX 2 :RSiX 3 is from about 8:1 to about 1:6.
Claim 13
Dependent Claim
15 words
The method of claim 11 wherein the mole ratio is about 6:1 to about 1:2.
Claim 14
Dependent Claim
23 words
The method of claim 4 wherein the mole ratio of R 1 SiHX 2 :RSiX 3 is from about 6:1 to about 1:6.
Claim 15
Dependent Claim
15 words
The method of claim 13 wherein the mole ratio is about 6:1 to about 1:2.
Claim 16
Dependent Claim
15 words
The method of claim 14 wherein the mole ratio is about 6:1 to about 3:1.
Claim 17
Dependent Claim
15 words
The method of claim 14 wherein the mole ratio is about 2:1 to about 1:2.
Claim 18
Dependent Claim
23 words
The method of claim 5 wherein the mole ratio of R 1 SiHX 2 :RSiX 3 is from about 6:1 to about 1:2.
Claim 19
Dependent Claim
15 words
The method of claim 17 wherein the mole ratio is about 6:1 to about 3:1.
Claim 20
Dependent Claim
15 words
The method of claim 14 wherein the mole ratio is about 2:1 to about 1:2.
Claim 21
Dependent Claim
48 words
The method of claim 1 wherein said basic catalyst is selected from the group consisting of alkali metals, alkali and alkaline earth metal hydrides, complex metal hydrides, alkali metal alkoxides, alkali metal and alkaline earth metal amides, alkali and alkaline earth metal silylamides and alkali metal organic compounds.
Claim 22
Dependent Claim
27 words
The method of claim 2 wherein the electrophile has the formula E--X 1 an organic or silyl group. and X 1 is a halide, sulfate or sulfonate.
Claim 23
Dependent Claim
15 words
The method of claim 21 wherein E is a lower alkyl group or silyl group.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1991-01-18 | 1991-07-20 | 1992-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-18 | 1995-07-20 | 1996-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-18 | 1999-07-20 | 2000-01-19 | $7700.00 | Window Closed / Lapsed |