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US4935481A
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Polysilazanes, process for the preparation thereof, silicon nitride-containing ceramic materials which can be prepared therefrom, and the prepaation thereof
Assignee: Hoechst AG
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Filing: 1988-11-03
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Granted: 1990-06-19
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Expires: 2008-11-03
Abstract
Abstract The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RsiCl 2 -Nr'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.
Inventors
- 👤 Tilo Vaahs
- 👤 Hans-Jerg Kleiner
- 👤 Marcellus Peuckert
- 👤 Martin Bruck
- 👤 Fritz Aldinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:49
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
63 words
A process for the preparation of polymeric silazanes, which comprises reacting one or more dialkylaminoorganyldichlorosilanes of the formula RSiCl 2 --NR'R', in which R is C 1 -C 4 -alkyl, vinyl or phenyl, and R' is C 1 -C 4 -alkyl, with at least 3.35 moles of ammonia per mole of silane in a solvent at temperatures from -80° C. to +70° C.
Claim 2
Dependent Claim
63 words
A process for the preparation of polymeric silazanes, which comprises reacting one or more dialkylaminoorganyldichlorosilanes of the formula RSiCl 2 --NR'R', in which R is C 1 -C 4 -alkyl, vinyl or phenyl, and R' is C 1 -C 4 -alkyl, with at least 3.35 moles of ammonia per mole of silane in a solvent at temperatures from -80° C. to +70° C.
Claim 3
Dependent Claim
19 words
The process as claimed in claim 1, wherein R is methyl, ethyl, vinyl or phenyl, and R' is methyl.
Claim 4
Dependent Claim
15 words
The process as claimed in claim 1, wherein R is ethyl and R' is methyl.
Claim 5
Dependent Claim
20 words
The process as claimed in claim 1, wherein at least 3.5 moles of ammonia are used per mole of dialkylaminoorganyldichlorosilane.
Claim 6
Dependent Claim
74 words
A polymeric silazane of the formula ##STR5## in which R and R* may be identical or different and R and R* are C 1 -C 4 -alkyl, vinyl or phenyl, R' is C 1 -C 4 -alkyl, and x and y denote the molar fractions of the two structural units, where x+y=1 and x=0.7-0.95 and wherein each (NH) 1/2 denotes a single NH group linked to the Si atom and a second Si atom.
Claim 7
Dependent Claim
74 words
A polymeric silazane of the formula ##STR5## in which R and R* may be identical or different and R and R* are C 1 -C 4 -alkyl, vinyl or phenyl, R' is C 1 -C 4 -alkyl, and x and y denote the molar fractions of the two structural units, where x+y=1 and x=0.7-0.95 and wherein each (NH) 1/2 denotes a single NH group linked to the Si atom and a second Si atom.
Claim 8
Dependent Claim
26 words
A polymeric silazane as claimed in claim 5, wherein, independently of one another, R and R* are methyl, ethyl, vinyl or phenyl, and R' is methyl.
Claim 9
Dependent Claim
18 words
A polymeric silazane as claimed in claim 5, wherein R and R* are ethyl and R' is methyl.
Claim 10
Dependent Claim
10 words
A polymeric silazane as claimed in claim 5, wherein x=0.85-0.95.
Claim 11
Dependent Claim
14 words
A polymeric silazane, which is obtained by the process as claimed in claim 1.
References Cited (Backward Citations)
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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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |