US4395460A
Expired / Lapsed
US
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Preparation of polysilazane polymers and the polymers therefrom
Assignee: Dow Silicones Corp
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Filing: 1981-09-21
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Granted: 1983-07-26
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Expires: 2001-09-21
Abstract
Abstract What is disclosed is a process for preparing polysilazane polymers by contacting and reacting chlorine-containing disilanes with ammonia. The polysilazane polymers are useful as chemical intermediates to produce silicon-containing chemical compounds. They are also useful in the formation of silicon carbide-containing ceramic materials.
Inventors
- 👤 John H. Gaul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:25
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C08G77/62; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; Y; Y10; Y10T; Y10T428/00; Y10T428/30; Y10T428/31504; Y10T428/31652; Y10T428/31663
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
136 words
A process of preparing a polysilazane polymer which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 2
Dependent Claim
136 words
A process of preparing a polysilazane polymer which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 3
Dependent Claim
11 words
A process as claimed in claim 1 wherein B(i) is tetrachlorodimethyldisilane.
Claim 4
Dependent Claim
11 words
A process as claimed in claim 1 wherein B(i) is trichlorotrimethyldisilane.
Claim 5
Dependent Claim
36 words
A process as claimed in claim 1 wherein B(ii) is a mixture of (Cl 2 CH 3 Si) 2 , [Cl(CH 3 ) 2 Si] 2 and Cl(CH 3 ) 2 SiSiCH 3 Cl 2 .
Claim 6
Dependent Claim
39 words
A process as claimed in claim 4 wherein (Cl 2 CH 3 Si) 2 , [Cl(CH 3 ) 2 Si] 2 and Cl(CH 3 ) 2 SiSiCH 3 Cl 2 are present in a weight ratio of about 45:12:43.
Claim 7
Dependent Claim
27 words
A process as claimed in claim 1 wherein B(ii) is a mixture of (Cl 2 CH 3 Si) 2 and [Cl(CH 3 ) 2 Si] 2 .
Claim 8
Dependent Claim
29 words
A process as claimed in claim 6 wherein (Cl 2 CH 3 Si) 2 and [Cl(CH 3 ) 2 Si] 2 are present in a weight ratio of 50:50.
Claim 9
Dependent Claim
29 words
A process as claimed in claim 6 wherein (Cl 2 CH 3 Si) 2 and [Cl(CH 3 ) 2 Si] 2 are present in a weight ratio of 75:25.
Claim 10
Dependent Claim
29 words
A process as claimed in claim 1 wherein B(ii) is a mixture of (Cl 2 CH 3 Si) 2 and Cl(CH 3 ) 2 SiSiCH 3 Cl 2 .
Claim 11
Dependent Claim
31 words
A process as claimed in claim 9 wherein (Cl 2 CH 3 Si) 2 and Cl(CH 3 ) 2 SiSiCH 3 Cl 2 are present in a weight ratio of 65:35.
Claim 12
Dependent Claim
10 words
The polysilazane polymer produced by the process of claim 1.
Claim 13
Dependent Claim
10 words
The polysilazane polymer produced by the process of claim 2.
Claim 14
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 3.
Claim 15
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 4.
Claim 16
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 5.
Claim 17
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 6.
Claim 18
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 7.
Claim 19
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 8.
Claim 20
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 9.
Claim 21
Dependent Claim
10 words
A polysilazane polymer produced by the process of claim 10.
Claim 22
Independent Claim
180 words
A method of preparing a silicon carbide ceramic material which consists of heating a polysilazane polymer in an inert atmosphere or in a vacuum to at least a temperature of 750° C. until the polysilazane polymer is converted to silicon carbide ceramic material, which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 23
Independent Claim
180 words
A method of preparing a silicon carbide ceramic material which consists of heating a polysilazane polymer in an inert atmosphere or in a vacuum to at least a temperature of 750° C. until the polysilazane polymer is converted to silicon carbide ceramic material, which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 24
Dependent Claim
14 words
The silicon carbide ceramic material prepared by the method as claimed in claim 21.
Claim 25
Independent Claim
197 words
A method of preparing a silicon carbide containing ceramic article which consists of (A) forming an article of the desired shape from a polysilazane polymer; (B) heating the article formed in (A) in an inert atmosphere or in a vacuum to an elevated temperature of at least 750° C. until the polysilazane polymer is converted to silicon carbide containing ceramic, which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 26
Independent Claim
197 words
A method of preparing a silicon carbide containing ceramic article which consists of (A) forming an article of the desired shape from a polysilazane polymer; (B) heating the article formed in (A) in an inert atmosphere or in a vacuum to an elevated temperature of at least 750° C. until the polysilazane polymer is converted to silicon carbide containing ceramic, which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere, at a temperature in the range of 25° C. to 370° C. (A) ammonia and (B) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 27
Dependent Claim
9 words
The article prepared by the method of claim 23.
Claim 28
Dependent Claim
27 words
The method of claim 23 wherein at least one conventional ceramic filler is mixed with the polysilazane polymer prior to forming an article of the desired shape.
Claim 29
Dependent Claim
9 words
An article prepared by the method of claim 25.
Claim 30
Independent Claim
202 words
A method for preparing a substrate coated with a silicon carbide containing ceramic which consists of (A) coating a substrate with polysilazane polymer which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere at a temperature in the range of 25° C. to 370° C., (a) ammonia and (b) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, (B) heating the coated substrate in an inert atmosphere or in a vacuum to an elevated temperature of at least 750° C. until the coating is converted to a silicon carbide ceramic material, whereby a silicon carbide-containing ceramic coated substrate is obtained the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 31
Independent Claim
202 words
A method for preparing a substrate coated with a silicon carbide containing ceramic which consists of (A) coating a substrate with polysilazane polymer which polysilazane polymer is obtained by a process which consists of contacting and reacting in an inert, essentially anhydrous, atmosphere at a temperature in the range of 25° C. to 370° C., (a) ammonia and (b) chlorine-containing disilanes selected from the group consisting of (i) a chlorine-containing disilane having the general formula [Cl.sub.a R.sub.b Si].sub.2 and (ii) a mixture of chlorine-containing disilanes having the general formula [Cl.sub.c R.sub.d Si].sub.2 wherein a has a value of 1.5-2.0; b has a value of 1.0-1.5; the ratio of c to d is in the range of 1:1 to 2:1, (B) heating the coated substrate in an inert atmosphere or in a vacuum to an elevated temperature of at least 750° C. until the coating is converted to a silicon carbide ceramic material, whereby a silicon carbide-containing ceramic coated substrate is obtained the sum of a+b is equal to three; the sum of c+d is equal to three; and R in each case is selected from the group consisting of the vinyl group, alkyl radicals of 1-3 carbon atoms and the phenyl group.
Claim 32
Dependent Claim
25 words
The method of claim 27 wherein at least one conventional ceramic filler is mixed with the silazane polymer prior to the coating of the substrate.
Claim 33
Dependent Claim
10 words
The coated substrate prepared by the method of claim 28.
Claim 34
Dependent Claim
170 words
A process for preparing a polysilazane polymer which consists of contacting and reacting in an inert, essentially anhydrous atmosphere at a temperature in the range of 25° C. to 370° C., (A) ammonia and (B) a mixture of chlorine-containing disilanes and monosilanes selected from the group consisting essentially of (i) a mixture of a chlorine-containing disilane and a monosilane, (ii) a mixture of a chlorine-containing disilane and a mixture of monosilanes and (iii) a mixture of chlorine-containing disilanes mixed with a mixture of monosilanes, wherein the chlorine-containing disilanes have the general formula (Cl.sub.a R.sub.b Si).sub.2 and wherein the monosilanes in each case have the general formula R'.sub.n SiCl.sub.4-n, wherein R is a vinyl group, an alkyl radical of 1-3 carbon atoms or the phenyl group; R' is vinyl, hydrogen, an alkyl group of 1-3 carbon atoms or the phenyl group; a has a value of 1.5-2.0; b has a value of 1.0-1.5; the sum of a+b is equal to three and n has a value of 0, 1, or 3.
Claim 35
Dependent Claim
170 words
A process for preparing a polysilazane polymer which consists of contacting and reacting in an inert, essentially anhydrous atmosphere at a temperature in the range of 25° C. to 370° C., (A) ammonia and (B) a mixture of chlorine-containing disilanes and monosilanes selected from the group consisting essentially of (i) a mixture of a chlorine-containing disilane and a monosilane, (ii) a mixture of a chlorine-containing disilane and a mixture of monosilanes and (iii) a mixture of chlorine-containing disilanes mixed with a mixture of monosilanes, wherein the chlorine-containing disilanes have the general formula (Cl.sub.a R.sub.b Si).sub.2 and wherein the monosilanes in each case have the general formula R'.sub.n SiCl.sub.4-n, wherein R is a vinyl group, an alkyl radical of 1-3 carbon atoms or the phenyl group; R' is vinyl, hydrogen, an alkyl group of 1-3 carbon atoms or the phenyl group; a has a value of 1.5-2.0; b has a value of 1.0-1.5; the sum of a+b is equal to three and n has a value of 0, 1, or 3.
Claim 36
Dependent Claim
27 words
A process as claimed in claim 30 wherein in (B) (iii) there is present at least 50 weight percent disilanes, based on the total weight of silanes.
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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) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |