US5246738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydridosiloxanes as precursors to ceramic products
Assignee: SRI International Inc
•
Filing: 1992-04-17
•
Granted: 1993-09-21
•
Expires: 2012-04-17
Abstract
Abstract A method is provided for preparing preceramic polymers and and silicious ceramic materials which derive therefrom. The preceramic polymers are polysiloxanes which are synthesized by catalytically activating Si-H bonds in a hydridosiloxane starting material and replacing the activated hydrogen atoms with non-hydrogen substituents. These preceramic polysiloxanes are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, and metal silicates.
Inventors
- 👤 Yigal Blum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:49
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/185; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/58; C04B35/584; C04B35/589; C04B35/597; C04B35/622; C04B35/62227; C04B35/626; C04B35/63; C04B35/6303; C04B35/6316; C04B41/00; C04B41/45; C04B41/4505; C04B41/455; C04B41/4554; C04B41/80; C04B41/81; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/10; C07F7/21; 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: 36
Claim 1
Independent Claim
144 words
A method of preparing a coating of a silicious ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si-H bonds per mer unit; (b) reacting said hydridosiloxane polymer with a hydroxyl-containing compound of the formula R'--OH, wherein R' is hydrogen, C 1 -C 10 alkyl, or aryl of 1-2 rings, and may be substituted with hydroxyl, lower alkyl, lower alkoxy, halogeno, silyl, or amino groups, or combinations thereof, in an inert atmosphere in the presence of a catalyst effective to activate Si--H bonds, to provide a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced by OR' moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious ceramic material.
Claim 2
Independent Claim
144 words
A method of preparing a coating of a silicious ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si-H bonds per mer unit; (b) reacting said hydridosiloxane polymer with a hydroxyl-containing compound of the formula R'--OH, wherein R' is hydrogen, C 1 -C 10 alkyl, or aryl of 1-2 rings, and may be substituted with hydroxyl, lower alkyl, lower alkoxy, halogeno, silyl, or amino groups, or combinations thereof, in an inert atmosphere in the presence of a catalyst effective to activate Si--H bonds, to provide a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced by OR' moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious ceramic material.
Claim 3
Independent Claim
112 words
A method of preparing a coating of a silicious ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) introducing carbon-containing moieties into said polymer by reaction with a compound containing an unsaturated carbon-carbon bond, in the presence of a catalyst effective to activate Si--H bonds, to give a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced by carbon-containing moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious ceramic material.
Claim 4
Independent Claim
112 words
A method of preparing a coating of a silicious ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) introducing carbon-containing moieties into said polymer by reaction with a compound containing an unsaturated carbon-carbon bond, in the presence of a catalyst effective to activate Si--H bonds, to give a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced by carbon-containing moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious ceramic material.
Claim 5
Independent Claim
127 words
A method of preparing a coating of a silicious, nitrogen-containing ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) introducing nitrogen-containing moieties into said polymer by reaction with a compound NHR" 2 wherein the R" are independently selected from hydrogen, lower alkyl, sily, and aryl of 1-2 rings, in the presence of a catalyst effective to activate Si--H bonds, to give a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced with nitrogen-containing moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious, nitrogen-containing ceramic material.
Claim 6
Independent Claim
127 words
A method of preparing a coating of a silicious, nitrogen-containing ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) introducing nitrogen-containing moieties into said polymer by reaction with a compound NHR" 2 wherein the R" are independently selected from hydrogen, lower alkyl, sily, and aryl of 1-2 rings, in the presence of a catalyst effective to activate Si--H bonds, to give a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced with nitrogen-containing moieties; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious, nitrogen-containing ceramic material.
Claim 7
Independent Claim
136 words
A method of preparing a coating of a silicious, metal-containing ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) reacting said hydridosiloxane polymer with a compound selected from the group consisting of ML a and M--OH, wherein M is a metal atom, L is an organic ligand associated therewith, and a represents the molar ratio L--M in said complex, in the presence of a catalyst effective to activate Si--H bonds, to provide a ceramic precursor in which said activated Si--H bonds have been replaced by Si--M bonds; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious, metal-containing ceramic material.
Claim 8
Independent Claim
136 words
A method of preparing a coating of a silicious, metal-containing ceramic material on a substrate, which comprises: (a) providing a hydridosiloxane polymer containing one or more Si--H bonds per mer unit; (b) reacting said hydridosiloxane polymer with a compound selected from the group consisting of ML a and M--OH, wherein M is a metal atom, L is an organic ligand associated therewith, and a represents the molar ratio L--M in said complex, in the presence of a catalyst effective to activate Si--H bonds, to provide a ceramic precursor in which said activated Si--H bonds have been replaced by Si--M bonds; (c) coating a substrate with said ceramic precursor; and (d) pyrolyzing said ceramic precursor on said substrate at a temperature of at least about 500° C. to provide a coating of said silicious, metal-containing ceramic material.
Claim 9
Dependent Claim
21 words
The method of claim 1, wherein said substrate is selected from the group consisting of metallic, glass, ceramic and graphite materials.
Claim 10
Dependent Claim
10 words
The method of claim 5, wherein said substrate is metallic.
Claim 11
Dependent Claim
10 words
The method of claim 5, wherein said substrate is glass.
Claim 12
Dependent Claim
10 words
The method of claim 5, wherein said substrate is ceramic.
Claim 13
Dependent Claim
10 words
The method of claim 5, wherein said substrate is graphite.
Claim 14
Dependent Claim
23 words
The method of claim 5, wherein said pyrolyzing is conducted at a heating rate between about 0.1° C. and 10.0° C. per minute.
Claim 15
Dependent Claim
14 words
The method of claim 5, wherein step (c) is carried out using flash pyrolysis.
Claim 16
Dependent Claim
21 words
The method of claim 2, wherein said substrate is selected from the group consisting of metallic, glass, ceramic and graphite materials.
Claim 17
Dependent Claim
10 words
The method of claim 12, wherein said substrate is metallic.
Claim 18
Dependent Claim
10 words
The method of claim 12, wherein said substrate is glass.
Claim 19
Dependent Claim
10 words
The method of claim 12, wherein said substrate is ceramic.
Claim 20
Dependent Claim
10 words
The method of claim 12, wherein said substrate is graphite.
Claim 21
Dependent Claim
23 words
The method of claim 12, wherein said pyrolyzing is conducted at a heating rate between about 0.120 C. and 10.0° C. per minute.
Claim 22
Dependent Claim
14 words
The method of claim 12, wherein step (c) is carried out using flash pyrolysis.
Claim 23
Dependent Claim
21 words
The method of claim 3, wherein said substrate is selected from the group consisting of metallic, glass, ceramic and graphite materials.
Claim 24
Dependent Claim
10 words
The method of claim 19, wherein said substrate is metallic.
Claim 25
Dependent Claim
10 words
The method of claim 19, wherein said substrate is glass.
Claim 26
Dependent Claim
10 words
The method of claim 19, wherein said substrate is ceramic.
Claim 27
Dependent Claim
10 words
The method of claim 19, wherein said substrate is graphite.
Claim 28
Dependent Claim
23 words
The method of claim 19, wherein said pyrolyzing is conducted at a heating rate between about 0.1° C. and 10.0° C. per minute.
Claim 29
Dependent Claim
14 words
The method of claim 19, wherein step (c) is carried out using flash pyrolysis.
Claim 30
Dependent Claim
21 words
The method of claim 4, wherein said substrate is selected from the group consisting of metallic, glass, ceramic and graphite materials.
Claim 31
Dependent Claim
10 words
The method of claim 26, wherein said substrate is metallic.
Claim 32
Dependent Claim
10 words
The method of claim 26, wherein said substrate is glass.
Claim 33
Dependent Claim
10 words
The method of claim 26, wherein said substrate is ceramic.
Claim 34
Dependent Claim
10 words
The method of claim 26, wherein said substrate is graphite.
Claim 35
Dependent Claim
23 words
The method of claim 26, wherein said pyrolyzing is conducted at a heating rate between about 0.1° C. and 10.0° C. per minute.
Claim 36
Dependent Claim
14 words
The method of claim 26, wherein step (c) is carried out using flash pyrolysis.
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) | 1996-09-20 | 1997-03-22 | 1997-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-20 | 2001-03-22 | 2001-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-20 | 2005-03-22 | 2005-09-21 | $7700.00 | Window Closed / Lapsed |