US4861844A
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US
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Cationic catalysis process for the treatment of a polysilazane containing on average at least two .tbd.SiH groups per molecule
Assignee: Rhone Poulenc Specialites Chimiques
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Filing: 1988-02-22
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Granted: 1989-08-29
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Expires: 2008-02-22
Abstract
Abstract A process for the catalytic treatment of a polysilazane containing an average of at least two, preferably at least three, .tbd.SiH groups per molecule with a catalytically effective quantity of a strong inorganic or organic acid catalyst. The other organic radicals in the polysilazane that are bonded to the silicon or nitrogen atoms are hydrocarbon radicals free from alkene or alkyne unsaturations. The polysilazanes treated in this manner can be characterized by good thermal behavior and can be used, in particular, as precursors of ceramic products with a high yield of inorganic products.
Inventors
- 👤 Jean-Jacques Lebrun
- 👤 Hugues Porte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:34
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/16; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/58; C04B35/584; C04B35/589; C08G; C08G77/00; C08G77/60; C08G77/62
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
114 words
A process for the catalytic treatment of a polysilazane aminolysate, comprising the step of: catalytically treating at least one polysilazane aminolysate with a catalytically effective amount of a strong acid catalyst to polymerize, copolymerize or molecularly rear-range said aminolysate at the silicon atom, the polysilazane containing on average at least two .tbd.SiH groups per molecule and the other organic radicals in the polysilazane that are bonded to the silicon or nitrogen atoms being hydrocarbon radicals free from alkene or alkyne unsaturation, the acid being used in proportion of from 1 ppm to 10,000 ppm relative to the weight of the starting polysilazane aminolysate and the polymerization temperature being from 20° C. to 180° C.
Claim 2
Dependent Claim
114 words
A process for the catalytic treatment of a polysilazane aminolysate, comprising the step of: catalytically treating at least one polysilazane aminolysate with a catalytically effective amount of a strong acid catalyst to polymerize, copolymerize or molecularly rear-range said aminolysate at the silicon atom, the polysilazane containing on average at least two .tbd.SiH groups per molecule and the other organic radicals in the polysilazane that are bonded to the silicon or nitrogen atoms being hydrocarbon radicals free from alkene or alkyne unsaturation, the acid being used in proportion of from 1 ppm to 10,000 ppm relative to the weight of the starting polysilazane aminolysate and the polymerization temperature being from 20° C. to 180° C.
Claim 3
Dependent Claim
14 words
The process according to claim 1, wherein the treatment is carried out in bulk.
Claim 4
Dependent Claim
17 words
The process according to claim 1, wherein the treatment is carried out in an organic solvent solution.
Claim 5
Dependent Claim
18 words
The process according to claim 1, wherein the polymerization reaction time is from 30 minutes to 30 hours.
Claim 6
Dependent Claim
15 words
The process according to claim 1, wherein the treatment is carried out at atmospheric pressure.
Claim 7
Dependent Claim
19 words
The process according to claim 1, wherein the treatment is carried out at a pressure greater than atmospheric pressure.
Claim 8
Dependent Claim
15 words
The process according to claim 1, wherein the treatment is carried out under a vacuum.
Claim 9
Dependent Claim
16 words
The process according to claim 1, wherein the polymerization temperature is from 120° to 160° .
Claim 10
Dependent Claim
19 words
The process according to claim 1, wherein the acid catalyst has a pk a value of less than 5.
Claim 11
Dependent Claim
14 words
The process according to claim 1, wherein the acid catalyst is an organic acid.
Claim 12
Dependent Claim
14 words
The process according to claim 1, wherein the acid catalyst is an inorganic acid.
Claim 13
Dependent Claim
33 words
The process according to claim 1, wherein the strong acid catalyst is selected from the group consisting of trifluoromethane sulphonic, perchloric, trichloromethane sulphonic, hydrochloric, acetic, nitric, picric, pyrophosphonic, chromic, p-toluenesulphonic, and chloroplatinic acid.
Claim 14
Dependent Claim
47 words
The process according to claim 1, wherein the strong acid catalyst is selected from the group consisting of ion exchange resins containing strong acid anions, acid earths, montmorillonite washed with sulphuric acid, and porous inorganic substrates coated with a polymeric film carrying sulphuric or phosphonic acid groups.
Claim 15
Dependent Claim
23 words
The process according to claim 1, wherein the polysilazane has a viscosity from 10 mPa s to 5,000 mPa s at 25° C.
Claim 16
Dependent Claim
18 words
The process according to claim 14, wherein the viscosity is from 100 mPa s to 1,000 mPa s.
Claim 17
Dependent Claim
17 words
The process according to claim 1, wherein the polysilazane has at least three .tbd.SiH groups per molecule.
Claim 18
Dependent Claim
48 words
The process according to claim 1, wherein the strong acid catalyst is selected from the group consisting of CF 3 SO 3 CH 3 , CF 3 SO 3 H, CF 3 COOH, HClO 4 , CCl 3 COOH, H 2 SO 4 , and CH 3 COOH.
Claim 19
Dependent Claim
30 words
The process according to claim 1, wherein the strong acid catalyst is used in proportions of from 20 ppm to 4900 ppm relative to the weight of the starting polysilazane.
Claim 20
Dependent Claim
9 words
A polysilazane produced by the process of claim 1.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-08-28 | 1993-02-27 | 1993-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-28 | 1997-02-27 | 1997-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-28 | 2001-02-27 | 2001-08-29 | $7700.00 | Window Closed / Lapsed |