US4937304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
New polysilazane and process for production of the same
Assignee: JNC Corp
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Filing: 1988-06-10
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Granted: 1990-06-26
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Expires: 2008-06-10
Abstract
Abstract There is provided a new polysilazane product from a specific precursor. Desired molecular weight of the polysilazane can be obtained by selecting proper amount of a silazane or silylamine compound ##STR1## as an additive. The polysilazane is stable during storage without gelation. The polymerization of the precursor can be carried out without gelation even at a high temperature and hence can be completed in a short time. The polysilazane can be made into ceramics fiber by spinning from a solution and subsequent firing.
Inventors
- 👤 Koichi Ayama
- 👤 Kaneo Noake
- 👤 Tamio Serita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:52
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/58; C04B35/584; C04B35/589
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
125 words
A polysilazane having the skeleton composed of the repeating units of the formula: ##STR20## in which polysilazane, precursor residues, each composed of the unit of the formula: ##STR21## and the unit of the formula: ##STR22## are connected to each other through a structural unit of the formula: ##STR23## wherein R 1 , R 2 , R 3 and R 4 each represents a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted allyl group, a substituted or unsubstituted lower aryl group having 6 to 10 carbon atoms, tri(lower)alkyl- or di(lower)alkyl-silyl group, or di(lower)alkylamino group, with R 1 , R 2 , R 3 , and R 4 being the same or different from one another.
Claim 2
Dependent Claim
125 words
A polysilazane having the skeleton composed of the repeating units of the formula: ##STR20## in which polysilazane, precursor residues, each composed of the unit of the formula: ##STR21## and the unit of the formula: ##STR22## are connected to each other through a structural unit of the formula: ##STR23## wherein R 1 , R 2 , R 3 and R 4 each represents a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted vinyl group, a substituted or unsubstituted allyl group, a substituted or unsubstituted lower aryl group having 6 to 10 carbon atoms, tri(lower)alkyl- or di(lower)alkyl-silyl group, or di(lower)alkylamino group, with R 1 , R 2 , R 3 , and R 4 being the same or different from one another.
Claim 3
Dependent Claim
21 words
A polysilazane as claimed in claim 1, wherein the content of the unit (B) in said polysilazane is 1-60 mol %.
Claim 4
Dependent Claim
31 words
A polysilazane as claimed in claim 1, wherein R 1 , R 2 , and R 3 in said each formula are all methyl group, and R 4 is dimethylsilyl group.
Claim 5
Dependent Claim
153 words
A process for producing a polysilazane which comprises: (a) reacting anhydrous ammonia with an organo-dihalosilane, R 1 SiHX 2 , in a solvent, thereby forming a cyclic or linear silazane precursor; (b) reacting said silazane precursor coexistent with a silazane or silylamine compound represented by the formula: ##STR24## in the presence of a basic catalyst capable of deprotonating hydrogen from a nitrogen atom adjacent to a silicon atom, thereby performing polymerization through dehydrogenation, cyclization, and crosslinking, wherein R 1 , R 2 , R 3 and R 4 each represents a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubtituted vinyl group, a substituted or unsubstituted allyl group, a substituted or unsubstituted lower aryl group having 6 to 10 carbon atoms, tri(lower)alkyl- or di(lower)alkyl-silyl group, or di(lower)alkylamino group, with R 1 , R 2 , R 3 , and R 4 being the same or different from one another.
Claim 6
Dependent Claim
153 words
A process for producing a polysilazane which comprises: (a) reacting anhydrous ammonia with an organo-dihalosilane, R 1 SiHX 2 , in a solvent, thereby forming a cyclic or linear silazane precursor; (b) reacting said silazane precursor coexistent with a silazane or silylamine compound represented by the formula: ##STR24## in the presence of a basic catalyst capable of deprotonating hydrogen from a nitrogen atom adjacent to a silicon atom, thereby performing polymerization through dehydrogenation, cyclization, and crosslinking, wherein R 1 , R 2 , R 3 and R 4 each represents a lower alkyl group having 1 to 6 carbon atoms, a substituted or unsubtituted vinyl group, a substituted or unsubstituted allyl group, a substituted or unsubstituted lower aryl group having 6 to 10 carbon atoms, tri(lower)alkyl- or di(lower)alkyl-silyl group, or di(lower)alkylamino group, with R 1 , R 2 , R 3 , and R 4 being the same or different from one another.
Claim 7
Dependent Claim
37 words
A process for producing a polysilazane as claimed in claim 4, wherein the silazane or silylamine compound is used in an amount of 1 to 60 mol % calculated on the basis of a unit formula: ##STR25##
Claim 8
Dependent Claim
35 words
A process for producing a polysilazane as claimed in claim 4, wherein R 1 , R 2 , and R 3 in said each formula are all methyl group, and R 4 is dimethylsilyl group.
Claim 9
Dependent Claim
19 words
A process for producing a polysilazane as claimed in claim 4 wherein said silazane or silylamine compound comprises tetramethyldisilazane.
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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) | 1993-06-25 | 1993-12-25 | 1994-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-25 | 1997-12-25 | 1998-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-25 | 2001-12-25 | 2002-06-26 | $7700.00 | Window Closed / Lapsed |