US4631260A
Expired / Lapsed
US
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Process for preparing ceramic materials
Assignee: Dow Silicones Corp
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Filing: 1986-05-23
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Granted: 1986-12-23
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Expires: 2006-05-23
Abstract
Abstract A method of preparing ceramic materials or articles by the pyrolysis of preceramic silazane polymers, wherein the preceramic silazane polymers are rendered infusible prior to pyrolysis by treatment with steam or a steam and oxygen mixture, is disclosed. This method is especially suited for the preparation of ceramic fibers.
Inventors
- 👤 Donald M. Bartos
- 👤 John H. Gaul, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:44
CPC Classifications
C; C08; C08L; C08L83/00; C08L83/16; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C08G; C08G77/00; C08G77/60; C08G77/62; D; D01; D01F; D01F9/00; D01F9/08; D01F9/10
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
99 words
A method of preparing a ceramic material, which method comprises (1) treating a preceramic silazane polymer with steam at a temperature in the range of 35° C. to 200° C. for a time sufficient to render the preceramic silazane polymer infusible wherein the treatment temperature is sufficiently low so that the preceramic silazene polymer remains unfused during the treatment step, and (2) heating the infusible preceramic silazane polymer of step (1) in an inert atmosphere, vacuum or ammonia-containing atmosphere to a temperature of at least 750° C. until said infusible preceramic silazane polymer is converted to a ceramic material.
Claim 2
Independent Claim
99 words
A method of preparing a ceramic material, which method comprises (1) treating a preceramic silazane polymer with steam at a temperature in the range of 35° C. to 200° C. for a time sufficient to render the preceramic silazane polymer infusible wherein the treatment temperature is sufficiently low so that the preceramic silazene polymer remains unfused during the treatment step, and (2) heating the infusible preceramic silazane polymer of step (1) in an inert atmosphere, vacuum or ammonia-containing atmosphere to a temperature of at least 750° C. until said infusible preceramic silazane polymer is converted to a ceramic material.
Claim 3
Dependent Claim
135 words
A method as defined in claim 1 wherein said preceramic silazane polymer is treated with steam at a temperature below the penetration temperature of said preceramic silazane polymer and wherein said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, an organochlorosilane or a mixture of organochlorosilanes of the general formula R'.sub.c SiCl.sub.(4-c) with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; and c has a value of 1 or 2.
Claim 4
Dependent Claim
150 words
A method as defined in claim 1 wherein said preceramic silazane polymer is treated with steam at a temperature below the penetration temperature of said preceramic silazane polymer and wherein said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, a chlorine-containing disilane or a mixture of chlorine-containing disilanes, of the general formula (Cl.sub.d R'.sub.e Si).sub.2 with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; d has a value of 0.5-3; e has a value of 0-2.5 and the sum of (d+e) is equal to three.
Claim 5
Dependent Claim
98 words
A method as defined in claim 1 wherein said preceramic silazane polymer is treated with steam at a temperature below the penetration temperature of said preceramic silazane polymer and wherein said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, trichlorosilane with a disilazane at a temperature in the range of 25° C. to 300° C. while removing byproduced volatile products, wherein said disilazane has the general formula (R.sub.3 Si).sub.2 NH where R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms.
Claim 6
Dependent Claim
176 words
A method as defined in claim 1 wherein said preceramic silazane polymer is treated with steam at a temperature below the penetration temperature of said preceramic silazane polymer and wherein said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, a mixture of (1) chlorine-containing disilane or a mixture of chlorine-containing disilanes, of the general formula (Cl.sub.d R'.sub.e Si).sub.2 and (2) an organochlorosilane or a mixture of organochlorosilanes of the general formula R'.sub.c SiCl.sub.(4-c) with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selectedf rom the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; d has a value of 0.5-3; e has a value of 0-2.5; the sum of (d+e) is equal to three; and c has a value of 1 or 2.
Claim 7
Dependent Claim
34 words
A method as defined in claim 1 wherein said perceramic polymer is treated with steam in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 8
Dependent Claim
34 words
A method as defined in claim 2 wherein said preceramic polymer is treated with steam in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 9
Dependent Claim
34 words
A method as defined in claim 3 wherein said preceramic polymer is treated with steam in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 10
Dependent Claim
34 words
A method as defined in claim 4 wherein said preceramic polymer is treated with steam in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 11
Dependent Claim
34 words
A method as defined in claim 5 wherein said preceramic polymer is treated with steam in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 12
Independent Claim
103 words
A method of preparing a ceramic material, which method comprises (1) treating a preceramic silazane polymer with a steam and oxygen mixture at a temperature in the range of 35° C. to 200° C. for a time sufficient to render the preceramic silazane polymer infusible wherein the treatment temperature is sufficiently low so that the preceramic silazane polymer remains unfused during the treatment step, and (2) heating the infusible preceramic silazane polymer of step (1) in an inert atmosphere, vacuum or ammonia-containing atmosphere to a temperature of at least 750° C. until said infusible preceramic silazane polymer is converted to a ceramic material.
Claim 13
Independent Claim
103 words
A method of preparing a ceramic material, which method comprises (1) treating a preceramic silazane polymer with a steam and oxygen mixture at a temperature in the range of 35° C. to 200° C. for a time sufficient to render the preceramic silazane polymer infusible wherein the treatment temperature is sufficiently low so that the preceramic silazane polymer remains unfused during the treatment step, and (2) heating the infusible preceramic silazane polymer of step (1) in an inert atmosphere, vacuum or ammonia-containing atmosphere to a temperature of at least 750° C. until said infusible preceramic silazane polymer is converted to a ceramic material.
Claim 14
Dependent Claim
138 words
A method as defined in claim 11 wherein said preceramic silazane polymer is treated with said steam and oxygen mixture at a temperature below the penetration temperature of said preceramic silazane polymer and said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, an organochlorosilane or a mixture of organochlorosilanes of the general formula R'.sub.c SiCl.sub.(4-c) with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; and c has a value of 1 or 2.
Claim 15
Dependent Claim
153 words
A method as defined in claim 11 wherein said preceramic silazane polymer is treated with said steam and oxygen mixture at a temperature below the penetration temperature of said preceramic silazane polymer and said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, a chlorine-containing disilane or a mixture of chlorine-containing disilanes, of the general formula (Cl.sub.d R'.sub.e Si).sub.2 with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; d has a value of 0.5-3; e has a value of 0-2.5 and the sum of (d+e) is equal to three.
Claim 16
Dependent Claim
101 words
A method as defined in claim 11 wherein said preceramic silazane polymer is treated with said steam and oxygen mixture at a temperature below the penetration temperature of said preceramic silazane polymer and said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, trichlorosilane with a disilazane at a temperature in the range of 25° C. to 300° C. while removing byproduced volatile products, wherein said disilazane has the general formula (R.sub.3 Si).sub.2 NH where R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms.
Claim 17
Dependent Claim
179 words
A method as defined in claim 11 wherein said preceramic silazane polymer is treated with said steam and oxygen mixture at a temperature below the penetration temperature of said preceramic silazane polymer and said preceramic silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous, atmosphere, a mixture of (1) chlorine-containing disilane or a mixture of chlorine-containing disilanes, of the general formula (Cl.sub.d R'.sub.e Si).sub.2 and (2) an organochlorosilane or a mixture of organochlorosilanes of the general formula R'.sub.c SiCl.sub.(4-c) with a disilazane having the general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling byproduced volatile products, wherein R' is selected from the group consisting of vinyl, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; R is selected from the group consisting of vinyl, hydrogen, phenyl, and alkyl radicals containing 1 to 3 carbon atoms; d has a value of 0.5-3; e has a value of 0-2.5; the sum of (d+e) is equal to three; and c has a value of 1 or 2.
Claim 18
Dependent Claim
22 words
A method as defined in claim 11 wherein said oxygen in said steam and oxygen mixture is in the form of air.
Claim 19
Dependent Claim
22 words
A method as defined in claim 12 wherein said oxygen in said steam and oxygen mixture is in the form of air.
Claim 20
Dependent Claim
22 words
A method as defined in claim 13 wherein said oxygen in said steam and oxygen mixture is in the form of air.
Claim 21
Dependent Claim
22 words
A method as defined in claim 14 wherein said oxygen in said steam and oxygen mixture is in the form of air.
Claim 22
Dependent Claim
22 words
A method as defined in claim 15 wherein said oxygen in said steam and oxygen mixture is in the form of air.
Claim 23
Dependent Claim
38 words
A method as defined in claim 16 wherein said preceramic polymer is treated with said steam and oxygen mixture in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 24
Dependent Claim
38 words
A method as defined in claim 17 wherein said preceramic polymer is treated with said steam and oxygen mixture in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 25
Dependent Claim
38 words
A method as defined in claim 18 wherein said preceramic polymer is treated with said steam and oxygen mixture in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 26
Dependent Claim
38 words
A method as defined in claim 19 wherein said preceramic polymer is treated with said steam and oxygen mixture in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 27
Dependent Claim
38 words
A method as defined in claim 20 wherein said preceramic polymer is treated with said steam and oxygen mixture in the temperature range of 35° C. to 10° C. below the penetration temperature of said preceramic silazane polymer.
Claim 28
Dependent Claim
25 words
A method as defined in claim 21 wherein the relative humidity of said steam and oxygen mixture at about room temperature is about 100 percent.
Claim 29
Dependent Claim
25 words
A method as defined in claim 22 wherein the relative humidity of said steam and oxygen mixture at about room temperature is about 100 percent.
Claim 30
Dependent Claim
25 words
A method as defined in claim 23 wherein the relative humidity of said steam and oxygen mixture at about room temperature is about 100 percent.
Claim 31
Dependent Claim
25 words
A method as defined in claim 24 wherein the relative humidity of said steam and oxygen mixture at about room temperature is about 100 percent.
Claim 32
Dependent Claim
25 words
A method as defined in claim 25 wherein the relative humidity of said steam and oxygen mixture at about room temperature is about 100 percent.
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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) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |