US4952715A
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US
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Polysilazanes and related compositions, processes and uses
Assignee: SRI International Inc
•
Filing: 1988-04-04
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Granted: 1990-08-28
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Expires: 2008-04-04
Abstract
Abstract Silazanes and related compounds are prepared by providing a precursor containing one or more cyclic silazane units, causing polymerization to occur in the presence of a transition metal catalyst to form a polysilazane product. Further products may result from additional reaction. The novel compounds may be pyrolyzed to yield ceramic materials such as silicon nitride, silicon carbide and mixtures thereof. In a preferred embodiment, substantially pure silicon nitride and articles prepared therefrom are provided. Fibers, coatings, binders and the like may be prepared from the novel materials.
Inventors
- 👤 Yigal D. Blum
- 👤 Edward J. Crawford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:35
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/21; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/185; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B41/00; C04B41/45; C04B41/4505; C04B41/455; C04B41/4554; C07F7/08; C07F7/10; C08; C08G; C08G77/00; C08G77/04; C08G77/38; C08G77/382; C08G77/398; C08G77/48; C08G77/54; C08G77/60; C08G77/62; C08G79/00
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
174 words
A method of making a polysilazane having n recurring units of the structures (I) or (II) or both ##STR14## where m is O or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'-- or --NR'--Y--NR'-- where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R' and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl, wherein the method comprises (a) providing a silazane precursor having one or more units of the formula ##STR15## wherein the precursor contains either (i) at least one N--H bond and at least one Si--H bond, or (ii) at least two Si--H bonds, or both; and (b) reacting the precursor in the presence of a transition metal catalyst.
Claim 2
Independent Claim
174 words
A method of making a polysilazane having n recurring units of the structures (I) or (II) or both ##STR14## where m is O or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'-- or --NR'--Y--NR'-- where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R' and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl, wherein the method comprises (a) providing a silazane precursor having one or more units of the formula ##STR15## wherein the precursor contains either (i) at least one N--H bond and at least one Si--H bond, or (ii) at least two Si--H bonds, or both; and (b) reacting the precursor in the presence of a transition metal catalyst.
Claim 3
Dependent Claim
18 words
The method of claim 1, wherein said reacting is carried out in a solvent for the silazane precursor.
Claim 4
Dependent Claim
17 words
The method of claim 1, wherein said reacting is carried out in the presence of gaseous ammonia.
Claim 5
Dependent Claim
57 words
The method of claim 1, wherein said reacting is carried out in the presence of a co-reactant given by the structure NH 2 where is hydrogen, lower alkyl, silyl optionally substituted with one or more alkyl groups, or --(CH 2 ) x NH 2 where x is an integer in the range of 0 to 20 inclusive.
Claim 6
Independent Claim
27 words
The method of claim -, wherein the reaction of the precursor is carried out at a temperature in the range of about 0° C. to 150° C.
Claim 7
Dependent Claim
27 words
The method of claim 5, wherein the reaction of the precursor is carried out at a temperature in the range of about 20° C. to 90° C.
Claim 8
Dependent Claim
23 words
The method of claim 1, wherein the transition metal catalyst is a homogeneous catalyst, a heterogeneous catalyst, or a mixture or mixtures thereof.
Claim 9
Dependent Claim
14 words
The method of claim 6, wherein the transition metal catalyst is a ruthenium catalyst.
Claim 10
Dependent Claim
32 words
The method of claim 1, wherein said reacting is carried out in the presence of a co-reactant given by the structure R'" 2 SiH 2 and R'" is hydrogen or lower alkyl.
Claim 11
Dependent Claim
20 words
The method of claim 1, wherein the precursor includes one or more silazane bridge groups given by the structure ##STR16##
Claim 12
Dependent Claim
17 words
The method of claim 1, wherein the precursor includes cyclomers bridged by one or more amine groups.
Claim 13
Dependent Claim
17 words
The method of claim 1, wherein the precursor includes cyclomers bridged by one or more silyl groups.
Claim 14
Dependent Claim
23 words
The method of claim 1, wherein the precursor is CMS, and the reaction is carried out in ammonia gas using a ruthenium catalyst.
Claim 15
Dependent Claim
23 words
The method of claim 1, wherein the precursor is CMS, and the reaction is carried out in monomethylamine gas using a ruthenium catalyst
Claim 16
Dependent Claim
114 words
Polysilazanes consisting essentially of n recurring units of the structures (I) or (II) or both ##STR17## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'-- or --NR'--Y--NR'-- where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R' and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 17
Dependent Claim
114 words
Polysilazanes consisting essentially of n recurring units of the structures (I) or (II) or both ##STR17## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'-- or --NR'--Y--NR'-- where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R' and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 18
Dependent Claim
107 words
Polysilazanes consisting essentially of n recurring units of the structure (I) ##STR18## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'--or --NR'--Y--NR'--where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R'and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 19
Dependent Claim
107 words
Polysilazanes consisting essentially of n recurring units of the structure (I) ##STR18## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, X is --NR'--or --NR'--Y--NR'--where Y is an optional linking group which, if present, is lower alkyl or silyl, and the R'and R" may be the same or different and are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 20
Dependent Claim
82 words
Polysilazanes consisting essentially of n recurring units of the structure (II) ##STR19## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, and the R, substituents are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 21
Dependent Claim
82 words
Polysilazanes consisting essentially of n recurring units of the structure (II) ##STR19## wherein m is 0 or an integer, n is an integer greater than 1, the R substituents may be the same or different and are selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl, aryl, and amino, unsubstituted or substituted with 1 or 2 lower alkyl groups, and the R, substituents are independently selected from the group consisting of hydrogen, lower alkyl, lower alkenyl, silyl and aryl.
Claim 22
Dependent Claim
9 words
Ceramic fibers spun from the polysilazanes of claim 15.
Claim 23
Dependent Claim
9 words
Ceramic fibers spun from the polysilazanes of claim 16.
Claim 24
Dependent Claim
9 words
Ceramic fibers spun from the polysilazanes of claim 17.
References Cited (Backward Citations)
US2579418A
Cited
US3230242A
Cited
US3140288A
Cited
US3228895A
Cited
US3481964A
Cited
US3291760A
Cited
US3655615A
Cited
US4482669A
Cited
US4595775A
Cited
US4612383A
Cited
WO1986006377A1
Cited
US4788309A
Cited
US4659850A
Cited
WO1987005298A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-27 | 1994-02-26 | 1994-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-27 | 1998-02-26 | 1998-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-27 | 2002-02-26 | 2002-08-28 | $7700.00 | Window Closed / Lapsed |