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Patent US4870035A successfully refreshed from Google Patents.
US4870035A
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Process for manufacturing organic silazane polymers and process for manufacturing ceramics from the polymers
Assignee: Shin-Etsu Chemical Co Ltd
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Filing: 1988-06-28
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Granted: 1989-09-26
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Expires: 2008-06-28
Abstract
Abstract A process for manufacturing an organic silazane polymer which comprises reacting ammonia with a mixture of methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane to obtain an ammonolysis product. The ammonolysis product is polymerized in the presence of a basic catalyst capable of deprotonation to obtain an organic silazane polymer. The silazane polymer may be further melted, shaped and infusibilized. The thus infusibilized product is finally sintered to obtain a ceramic material.
Inventors
- 👤 Minoru Takamizawa
- 👤 Mitsuo Umemura
- 👤 Masato Kanari
- 👤 Yoshihumi Takeda
- 👤 Akira Hayashida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:29
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C08; C08G; C08G77/00; C08G77/60; C08G77/62
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
61 words
A process for manufacturing a ceramic material which comprises reacting ammonia with a mixture of methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane to obtain anammonolysis product, and polymerizing the ammonolysis product in the presence of a basic catalyst capable of deprotonation to obtain an organic silazane polymer, melting, molding and infusibilizing the silazane polymer, and sintering the resulting polymer to obtain a ceramic material.
Claim 2
Dependent Claim
61 words
A process for manufacturing a ceramic material which comprises reacting ammonia with a mixture of methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane to obtain anammonolysis product, and polymerizing the ammonolysis product in the presence of a basic catalyst capable of deprotonation to obtain an organic silazane polymer, melting, molding and infusibilizing the silazane polymer, and sintering the resulting polymer to obtain a ceramic material.
Claim 3
Dependent Claim
35 words
A process according to claim 1, wherein mixing ratios of methyldichlorosilane, methyltrichlorosilane and dimethyldichlorosilane are in ranges of 55 to 80 mole %, 10 to 30 mole % and 5 to 25 mole %, respectively.
Claim 4
Dependent Claim
35 words
A process according to claim 1, wherein said organic silazane polymer has a melting point of 60° to 200° C. and an intrinsic viscosity of 0.06 to 0.09 as determined in benzene at 20° C.
Claim 5
Dependent Claim
24 words
A process according to claim 1, wherein said organic silizane polymer is infusibilized in air at a temperature of from 50° to 150° C.
Claim 6
Dependent Claim
36 words
A process according to claim 1, wherein said organic silazane polymer is infusibilized in vacuum or in N 2 gas by irradiation of an electron beam at an exposed dose of from 50 to 200 Mrad.
Claim 7
Dependent Claim
19 words
A process according to claim 1, wherein said organic silazane polymer is melted and spun to obtain ceramic fibers.
Claim 8
Dependent Claim
20 words
A process according to claim 1, wherein the sintering is effected at a temperature of from 700° to 2000° C.
Claim 9
Dependent Claim
39 words
A process according to claim 7, wherein the sintering is effected in vacuum or in an atmosphere of at least one gas selected from the group consisting of inert gases, N 2 , H 2 and NH 3 gases.
Claim 10
Dependent Claim
19 words
The process of claim 1 wherein said basic catalyst is KH, NaH, NaNH 2 , or KNH 2 .
Claim 11
Dependent Claim
15 words
The process of claim 1 wherein the ammonolysis reaction is effected in an inert solvent.
Claim 12
Dependent Claim
24 words
The process of claim 1 wherein the polymerization reaction is effected in an inert solvent at a temperature of from 0° to 200° C.
Claim 13
Dependent Claim
24 words
The process of claim 1 further comprising adding an electrophilic compound after completion of the polymerization reaction whereby the remaining basic catalyst is decomposed.
Claim 14
Dependent Claim
31 words
The process of claim 1 wherein the basic catalyst is selected from the group consisting of alkali metal hydrides, alkaline earth metal hydrides, alkali metal amides and alkaline earth metal amides.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-25 | 1993-03-27 | 1993-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-25 | 1997-03-27 | 1997-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-25 | 2001-03-27 | 2001-09-26 | $7700.00 | Window Closed / Lapsed |