US4675424A
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Method for making polysilazanes
Assignee: General Electric Co
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Filing: 1986-03-19
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Granted: 1987-06-23
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Expires: 2006-03-19
Abstract
Abstract A method of preparing silazane polymers, with 3 or more repeating units, of the general formula -((CH3)2N)eSi(R)a(R'HN)fHc(NR')g- and a (CH3)2NH byproduct group where R is hydrogen, an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, a=0, or 1, b=2-4, C=0-2, d=0 or 1, e=0-2, f=0-2, g=1-3 and a+c+e+f+g=4 for the polymer units; and R' is hydrogen or methyl, whereby the silazane polymer is substantially free of halide impurities, and wherein this method comprises: transaminating an aminosilane of the general formula (R)a((CH3)2N)bHcS; where R is defined as above and a+b+c=4 with an amine of the general formula (CH3)dNH3-d whereby d is defined as above and the amine has a molecular weight lower than 45 all in the presence of an acid catalyst or the ammonium salt of the acid and thereafter condensing to form the polymer.
Inventors
- 👤 Roswell E. King, III
- 👤 Bernard Kanner
- 👤 Steven P. Hopper
- 👤 Curtis L. Schilling, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:40
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/10
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
170 words
A method of preparing silazane polymers, with 3 or more repeating units, of the general formula --((CH 3 ) 2 e Si(R) a (R'HN) f H c (NR') g --and a (CH 3 ) 2 NH byproduct where R is hydrogen, an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, a=0, or 1, b =2-4, C=0-2, d=0 or 1, e=0-2, f=0-2, g=1-3 and a+c+e+f+g=4 for the polymer units; and R' is hydrogen or methyl, whereby said silazane polymer is substantially free of halide impuriites, which method comprises: transaminating an aminosilane of the general formula (R) a ((CH 3 ) 2 N) b H c S; where R is defined as above and a+b+c=4 with an amine of the general formula (CH 3 ) d NH 3-d whereby d is defined as above and said amine has a molecular weight lower than 45 all in the presence of an acid catalyst or the ammonium salt of said acid and thereafter condensing to form the polymer.
Claim 2
Independent Claim
170 words
A method of preparing silazane polymers, with 3 or more repeating units, of the general formula --((CH 3 ) 2 e Si(R) a (R'HN) f H c (NR') g --and a (CH 3 ) 2 NH byproduct where R is hydrogen, an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, a=0, or 1, b =2-4, C=0-2, d=0 or 1, e=0-2, f=0-2, g=1-3 and a+c+e+f+g=4 for the polymer units; and R' is hydrogen or methyl, whereby said silazane polymer is substantially free of halide impuriites, which method comprises: transaminating an aminosilane of the general formula (R) a ((CH 3 ) 2 N) b H c S; where R is defined as above and a+b+c=4 with an amine of the general formula (CH 3 ) d NH 3-d whereby d is defined as above and said amine has a molecular weight lower than 45 all in the presence of an acid catalyst or the ammonium salt of said acid and thereafter condensing to form the polymer.
Claim 3
Dependent Claim
9 words
The method of claim 1 wherein c=1 or 2.
Claim 4
Dependent Claim
11 words
The method of claim 1 wherein a=o, b=3, c=1, and d=o.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein a=o, b=3, c=1, and d=1.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein R equals CH═CH 2 , a=1, b=3, c=o, and d=o.
Claim 7
Dependent Claim
16 words
The method of claim 1 wherein R equals CH═CH 2 , a=1, b=3, c=o and d=1.
Claim 8
Dependent Claim
16 words
The method of claim 1 wherein R equals methyl or ethyl, a=1, b=3, c=o, and d=o.
Claim 9
Dependent Claim
16 words
The method of claim 1 wherein R equals methyl or ethyl, a=1, b=3, c=o, and d=1.
Claim 10
Dependent Claim
29 words
The method of claim 1 wherein the catalyst is a strong organic or inorganic acid having a pKa of less than 2.2 or the ammonium salt of said catalyst.
Claim 11
Dependent Claim
35 words
The method of claim 9 wherein said strong organic or inorganic acid is selected from the group consisting of trifluoromethylsulfonic acid, para-toluene sulfonic acid, methylsulfonic acid, sulfuric acid, nitric acid, phosphoric acid, and trifluoroacetic acid.
Claim 12
Dependent Claim
14 words
The method of claim 2 wherein the catalyst is a source of carbon dioxide.
Claim 13
Dependent Claim
22 words
The method of claim 11 wherein the catalyst is selected from the group consisting of carbon dioxide, ammonium carbamate salts, and carbamatosilane.
Claim 14
Dependent Claim
17 words
The method of claim 1 wherein the transaminating reaction is run at a temperature of 20°-200° C.
Claim 15
Dependent Claim
32 words
The method of claim 13 wherein the temperature at which the transaminating reaction is run and the transamination catalyst vary depending on the overall morphology desired on the final silicone nitride product.
Claim 16
Dependent Claim
33 words
The method of claim 14 wherein, in the production of high purity silicone nitride, the transaminating reaction is run at a temperature of 100°-200° C. in the presence of a strongly acid catalyst.
Claim 17
Dependent Claim
16 words
The method of claim 15 wherein the strongly acidic catalyst is H 2 SO 4 .
Claim 18
Dependent Claim
41 words
The method of claim 14 wherein, in the production of silazane polymers to be used as impregnants in porous preformed ceramic parts, the transaminating reaction is run at a temperature of 20°-80° C. in the presence of a mildly acidic catalyst.
Claim 19
Dependent Claim
14 words
The method of claim 17 wherein the mildly acidic catalyst is para-toluene sulfonic acid.
Claim 20
Dependent Claim
22 words
The method of claim 1 wherein the transaminating reaction is run in a solvent which is largely unreactive under the reaction conditions.
Claim 21
Dependent Claim
29 words
The method of claim 19 wherein said solvent is selected from the group consisting of alkanes and alkylated benzenes having 6-20 carbon atoms wherein the reaction products are insoluble.
Claim 22
Dependent Claim
29 words
The method of claim 19 wherein the solvent is selected from the group consisting of alkanes and alkylated benzenes having 6-10 carbon atoms wherein the reaction products are soluble.
Claim 23
Dependent Claim
12 words
The method of claim 19 wherein the solvent is toluene or xylene.
Claim 24
Dependent Claim
25 words
The method of claim 1 wherein the starting aminosilane reactant comprises a mixture of polymers as defined by the aminosilane general formula transaminated with amine.
Claim 25
Dependent Claim
21 words
The method of claim 23 wherein the starting aminosilane reactants are mixtures of tris(dimethylamino)silane and vinyltris(dimethyamino) silane transaminated with NH 3
Claim 26
Dependent Claim
23 words
The method of claim 23 wherein the starting aminosilane reactants are mixtures of tris(dimethylamino)silane and vinyl-tris(dimethylamino)silane transmitted with CH 3 NH 2 .
Claim 27
Dependent Claim
10 words
The silazane polymers produced by the method of claim 1.
Claim 28
Dependent Claim
14 words
The silazane polymers produced by the method of claim 1 wherein c=1 or 2.
Claim 29
Dependent Claim
10 words
The silazane polymers produced by the method of claim 14.
Claim 30
Dependent Claim
29 words
The silazane polymers produced by the method of claim 1 wherein the starting reactant comprises a mixture of polymers as defined by the aminosilane general formula transaminated with amine.
Claim 31
Dependent Claim
26 words
The silazane polymers produced by the method of claim 1 wherein the starting aminosilane reactants are mixtures of tris(dimethylamino)silane and vinyl-tri(dimethylamino)silane transaminated with NH 3 .
Claim 32
Dependent Claim
28 words
The silazane polymers produced by the method of claim 1 wherein the starting aminosilane reactants are mixtures of tris-(dimethylamino)silane and vinyl-tris(dimethylamino)silane transaminated with CH 3 NH 2 .
Claim 33
Dependent Claim
12 words
The silicon nitride-containing ceramics prepared from the silazane polymers of claim 26.
Claim 34
Dependent Claim
12 words
The silicon nitride-containing ceramics prepared from the silazane polymers of claim 27.
Claim 35
Dependent Claim
12 words
The silicone nitride-containing ceramics prepared from the silazane polymers of claim 28.
Claim 36
Dependent Claim
12 words
The silicon nitride-containing ceramics prepared from the silazane polymers of claim 29.
Claim 37
Dependent Claim
12 words
The silicon nitride-containing ceramics prepared from the silazane polymers of claim 30.
Claim 38
Dependent Claim
12 words
The silicon nitride-containing ceramics prepared from the silazane polymers of claim 31.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-22 | 1990-12-22 | 1991-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-22 | 1994-12-22 | 1995-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-22 | 1998-12-22 | 1999-06-23 | $7700.00 | Window Closed / Lapsed |