US5319121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydridosiloxanes as precursors to ceramic products
Assignee: SRI International Inc
•
Filing: 1992-07-02
•
Granted: 1994-06-07
•
Expires: 2012-07-02
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
2026-10-23 13:47
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; 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; C04B41/45; C04B41/4505; C04B41/455; C04B41/4554; 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: 11
Claim 1
Independent Claim
106 words
A ceramic precursor prepared by the process 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 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, or wherein R' is hydrogen, in an inert atmosphere 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to activate Si--H bonds, to give a ceramic precursor in which hydrogen atoms in the hydridosiloxane polymer have been replaced by OR' moieties.
Claim 2
Dependent Claim
106 words
A ceramic precursor prepared by the process 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 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, or wherein R' is hydrogen, in an inert atmosphere 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 OR' moieties.
Claim 3
Dependent Claim
160 words
The ceramic precursor of claim 1, wherein said hydridosiloxane polymer contains recurring mer units having the formula ##STR24## wherein x is 1 or 2, and R is selected from the group consisting of: (i) hydroxyl; (ii) C 1 -C 10 alkyl, which is either unsubstituted or substituted with hydroxyl, lower alkyl, lower alkoxy, halogens, silyl or NR" 2 groups, wherein R" is hydrogen or lower alkyl; (iii) C 1 -C 10 alkoxy, optionally substituted as in (ii); (iv) aryl of 1-2 rings, optionally substituted as in (ii); (v) NR" 2 ; (vi) silyl; and (vii) ML a , OML a , and NR"ML a , wherein M is a metal atom selected from the group consisting of lithium, sodium, potassium, magnesium, calcium, boron, aluminum, phosphorus, transition metals, lanthanides and actinides and L is a ligand associated therewith which is selected from the group consisting of carbonyl, cyano, cyclopentadienyl, phenyl, halide, alkoxy, and αC.tbd.Cα wherein α is lower alkyl or phenyl.
Claim 4
Dependent Claim
15 words
The ceramic precursor of claim 1, wherein R' is unsubstituted C 1 -C 10 alkyl.
Claim 5
Dependent Claim
16 words
The ceramic precursor of claim 1, wherein R' is unsubstituted aryl of 1 to 2 rings.
Claim 6
Dependent Claim
10 words
The ceramic precursor of claim 1, wherein R' is hydrogen.
Claim 7
Dependent Claim
54 words
The ceramic precursor of claim 1, further comprising reacting the ceramic precursor with a coupling agent H--Z--H wherein Z is selected from the group consisting of oxygen, sulfur, phosphoro, primary amino, lower alkyl substituted secondary amino, lower alkyl substituted tertiary amino, --O--Y--O--, --NX--NX--, or --NX--Y--NX--, where X and Y are lower alkyl or silyl.
Claim 8
Dependent Claim
14 words
The ceramic precursor of claim 2, wherein R is C 1 -C 10 alkyl.
Claim 9
Dependent Claim
14 words
The ceramic precursor of claim 2, wherein R is C 1 -C 10 alkoxy.
Claim 10
Dependent Claim
13 words
The ceramic precursor of claim 2, wherein R is aryl of 1-2 rings.
Claim 11
Dependent Claim
24 words
The ceramic precursor of claim 2, wherein the hydridosiloxane polymer is prepared by polymerization of a monomeric halogenated silane in the presence of water.
References Cited (Backward Citations)
US4985578A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |