US4482669A
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Preceramic organosilazane polymers
Assignee: Massachusetts Institute of Technology
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Filing: 1984-01-19
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Granted: 1984-11-13
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Expires: 2004-01-19
Abstract
Abstract A preceramic polymer which is a polysilazane is described. It is made by reacting an organodihalosilane with ammonia to form an ammonolysis product, and treating the ammonolysis product with a basic catalyst capable of deprotonating an NH group that is adjacent to an SiH group to form said polymer. The polymer is preferrably further treated with an electrophilic reagent. These polymers are useful for making various ceramic products.
Inventors
- 👤 Dietmar Seyferth
- 👤 Gary H. Wiseman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:59
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: 40
Claim 1
Independent Claim
108 words
A polysilazane comprising: a plurality of precursor residues having repeating units of the formula: ##STR11## said residues being linked together by Si 2 N 2 bridges having the formula ##STR12## wherein: R is hydrogen, 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 unstubstituted vinyl group, a substituted or unsubstituted allyl 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; and n is an integer greater than 1; said residue being cyclic or linear.
Claim 2
Dependent Claim
108 words
A polysilazane comprising: a plurality of precursor residues having repeating units of the formula: ##STR11## said residues being linked together by Si 2 N 2 bridges having the formula ##STR12## wherein: R is hydrogen, 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 unstubstituted vinyl group, a substituted or unsubstituted allyl 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; and n is an integer greater than 1; said residue being cyclic or linear.
Claim 3
Dependent Claim
25 words
The polysilazane of claim 1 wherein R is selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, vinyl, allyl, benzyl, phenyl and tolyl.
Claim 4
Dependent Claim
16 words
The polysilazane of claim 1 wherein n is in the range of 3 to about 12.
Claim 5
Dependent Claim
22 words
The polysilazane of claim 1 wherein the number of residues per polymer chain is in the range of 3 to about 10.
Claim 6
Dependent Claim
20 words
The polysilazane of claim 1 wherein the average number of residues per polymer chain is from 3 to about 5.
Claim 7
Dependent Claim
21 words
The polysilazane of claim 1 wherein the average number of residues per polymer chain is from about 7 to about 9.
Claim 8
Dependent Claim
116 words
The polysilazane polymer comprising cyclic precursor residues, said polymer having the structural formula: ##STR13## R is a hydrogen, 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 allyl 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; and x and y are each independently 0 or a positive integer; m is an integer greater than 1; and x and y can be the same or different from each cyclic precursor residue in the polymer chain.
Claim 9
Dependent Claim
116 words
The polysilazane polymer comprising cyclic precursor residues, said polymer having the structural formula: ##STR13## R is a hydrogen, 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 allyl 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; and x and y are each independently 0 or a positive integer; m is an integer greater than 1; and x and y can be the same or different from each cyclic precursor residue in the polymer chain.
Claim 10
Dependent Claim
23 words
The polymer of claim 7 wherein R is selected from the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl, benzyl, phenyl and tolyl.
Claim 11
Dependent Claim
23 words
The polymer of claim 7 wherein the sum of x and y for each cyclic precursor residue is from 3 to about 10.
Claim 12
Dependent Claim
16 words
The polymer of claim 7 wherein m is in the range of 3 to about 12.
Claim 13
Dependent Claim
17 words
The polymer of claim 7 wherein m is in the range of about 3 to about 5.
Claim 14
Dependent Claim
17 words
The polymer of claim 7 wherein m is in the range of about 7 to about 9.
Claim 15
Dependent Claim
9 words
The polymer of claim 7 wherein R is methyl.
Claim 16
Independent Claim
102 words
A method for preparing an organosilazane polymer, said method comprising: reacting in solution anhydrous ammonia with RSiHX 2 where R is hydrogen, a lower alkyl group having from 1 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, thereby forming a mixture of cyclic and/or linear precursors and reacting said precursors in the presence of a basic catalyst capable of deprotonating the hydrogen from a nitrogen atom adjacent to a silicon atom to form an Si 2 N 2 bridge, thereby forming said organosilazane polymer.
Claim 17
Independent Claim
102 words
A method for preparing an organosilazane polymer, said method comprising: reacting in solution anhydrous ammonia with RSiHX 2 where R is hydrogen, a lower alkyl group having from 1 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, thereby forming a mixture of cyclic and/or linear precursors and reacting said precursors in the presence of a basic catalyst capable of deprotonating the hydrogen from a nitrogen atom adjacent to a silicon atom to form an Si 2 N 2 bridge, thereby forming said organosilazane polymer.
Claim 18
Dependent Claim
19 words
The method of claim 14 further comprising the additional step of treating said organosilazane polymer with an electrophilic compound.
Claim 19
Dependent Claim
12 words
The method of claim 15 wherein said electrophilic compound is methyl iodide.
Claim 20
Dependent Claim
25 words
The method of claim 14 wherein R is selected from the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl, vinyl, allyl, benzyl, phenyl and tolyl.
Claim 21
Dependent Claim
9 words
The method of claim 14 wherein R is methyl.
Claim 22
Dependent Claim
43 words
The method of claim 14 wherein said basic catalyst is selected from the group consisting of alkali and alkaline earth metal hydrides, complex metal hydrides, alkali metal alkoxides, anhydrous alkali metal hydroxides, alkali metal amides, alkali and alkaline earth silylamides and alkali metals.
Claim 23
Dependent Claim
34 words
A polymethylsilazane comprising a plurality of residues of cyclic monomers having the formula ##STR14## wherein n is an integer greater than 1 and each residue in said polymethylsilazane can be the same or different.
Claim 24
Dependent Claim
34 words
A polymethylsilazane comprising a plurality of residues of cyclic monomers having the formula ##STR14## wherein n is an integer greater than 1 and each residue in said polymethylsilazane can be the same or different.
Claim 25
Dependent Claim
13 words
The polymethylsilazane of claim 20 wherein n is from 3 to about 10.
Claim 26
Dependent Claim
17 words
The polymethylsilazane of claim 20 wherein the number of cyclic residues is from 3 to about 12.
Claim 27
Dependent Claim
93 words
An organosilazane polymer comprising structural units of RSiHNH, RSiHNCH 3 , and RSiN and represented by the formula (RSiHNH) a (RSiHNCH 3 ) b (RSiN) c , where 1+b+c=1 and R is hydrogen, 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 allyl 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.
Claim 28
Dependent Claim
93 words
An organosilazane polymer comprising structural units of RSiHNH, RSiHNCH 3 , and RSiN and represented by the formula (RSiHNH) a (RSiHNCH 3 ) b (RSiN) c , where 1+b+c=1 and R is hydrogen, 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 allyl 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.
Claim 29
Dependent Claim
25 words
The polymer of claim 23 where R is selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, vinyl, allyl, benzyl, phenyl and tolyl.
Claim 30
Dependent Claim
9 words
The polymer of claim 23 where R in methyl.
Claim 31
Dependent Claim
102 words
An organosilazane polyemr comprising structural units of RSiHNH, RSiHNM, and RSiN, and represented by the formula, (RSiHNH) 1 (RSiHNM) b (RSiN) c , where a+b+c=1; R is hydrogen, 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 allyl 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; and M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 32
Dependent Claim
102 words
An organosilazane polyemr comprising structural units of RSiHNH, RSiHNM, and RSiN, and represented by the formula, (RSiHNH) 1 (RSiHNM) b (RSiN) c , where a+b+c=1; R is hydrogen, 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 allyl 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; and M is an alkali metal or one-half equivalent of an alkaline earth metal.
Claim 33
Dependent Claim
25 words
The polymer from claim 26 where R is selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, vinyl, allyl, benzyl, phenyl and tolyl.
Claim 34
Dependent Claim
9 words
The polymer of claim 26 where R is methyl.
Claim 35
Dependent Claim
12 words
The polymer of claim 26 where M is potassium, sodium or lithium.
Claim 36
Dependent Claim
15 words
The polysilazane of claim 1 in admixture with a ceramic powder or a ceramic fiber.
Claim 37
Dependent Claim
42 words
A polysilazane made by reacting an organodihalosilane with ammonia to form an ammonolysis product, and treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group to form said polysilazane.
Claim 38
Dependent Claim
42 words
A polysilazane made by reacting an organodihalosilane with ammonia to form an ammonolysis product, and treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group to form said polysilazane.
Claim 39
Dependent Claim
20 words
The polysilazane of claim 31 which is further treated with an electrophilic reagent capable of reacting with RSiHNM functional groups.
Claim 40
Dependent Claim
25 words
The polysilazane of claim 32 wherein said electrophilic reagent is selected from the group consisting of lower alkyl halides, allyl halides, benzyl halides and halosilanes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-13 | 1988-05-14 | 1988-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-13 | 1992-05-14 | 1992-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-13 | 1996-05-14 | 1996-11-13 | $7700.00 | Window Closed / Lapsed |