US4757035A
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US
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Ceramic materials with increased crystallinity from silazane polymers
Assignee: Dow Silicones Corp
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Filing: 1986-05-23
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Granted: 1988-07-12
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Expires: 2006-05-23
Abstract
Abstract A method of preparing ceramic materials with increased levels of crystalline SiC and/or Si 3 N 4 is described. The method consists of firing a mixture of a R 3 SiNH-containing silazane polymer and an inorganic compound selected from the group consisting of iron compounds, cobalt compounds, nickel compounds, and copper compounds to an elevated temperature of at least 750° C. under an inert atmosphere or in a vacuum until a ceramic material with increased levels of crystalline SiC and/or Si 3 N 4 is obtained.
Inventors
- 👤 Ronald H. Baney
- 👤 Duane R. Bujalski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:56
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/45; C04B41/50; C04B41/5053; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C04B35/58; C04B35/584; C04B35/589; C08; C08K; C08K3/00; C08K3/10; C08K3/105
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
127 words
A method of preparing a ceramic material with increased crystallinity, said method comprising heating a modified R 3 SINH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 750° C. until said modified R 3 SiNH- containing silazane polymer is converted to a ceramic material with increased crystallinity relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions, wherein said modified R 3 SiNH-contianing silazane polymer is prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, crystallinity increasing, amount of an inorganic compound selected form the group consisting of iron III oxide, iron III octoate, iron II acetylacetonate, iron III chloride, cobalt II octoate, copper II octoate, nickel II octoate and noncarbonyldiiron.
Claim 2
Independent Claim
127 words
A method of preparing a ceramic material with increased crystallinity, said method comprising heating a modified R 3 SINH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 750° C. until said modified R 3 SiNH- containing silazane polymer is converted to a ceramic material with increased crystallinity relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions, wherein said modified R 3 SiNH-contianing silazane polymer is prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, crystallinity increasing, amount of an inorganic compound selected form the group consisting of iron III oxide, iron III octoate, iron II acetylacetonate, iron III chloride, cobalt II octoate, copper II octoate, nickel II octoate and noncarbonyldiiron.
Claim 3
Dependent Claim
125 words
A process as defined in claim 1 wherein said non-modified R 3 SiNH-containing 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 general formula (Cl.sub.b R.sub.c.sup.' Si).sub.2 with a disilazane of general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; b has a value of 0.5-3; c has a value of 0-2.5; and the sum of (b+c) is equal to three.
Claim 4
Dependent Claim
110 words
A process as defined in claim 1 wherein said non-modified R 3 SiNH-containing silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, an organochlorosilane or a mixture of organochlorosilanes of general formula R.sub.n.sup.' SiCl.sub.(4-n) with a disilazane of general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; and n has a value of 1 or 2.
Claim 5
Dependent Claim
25 words
A method as defined in claim 1 wherein said modified R 3 SiNH-containing silazane polymer is heated to a temperature of at least 1000° C.
Claim 6
Dependent Claim
25 words
A method as defined in claim 2 wherein said modified R 3 SiNH-containing silazane polymer is heated to a temperature of at least 1000° C.
Claim 7
Dependent Claim
25 words
A method as defined in claim 3 wherein said modified R 3 SiNH-containing silazane polymer is heated to a temperature of at least 1000° C.
Claim 8
Dependent Claim
33 words
A method as defined in claim 4 wherein said iron compound is selected from the group consisting of iron (III) octoate, iron (III) oxide, iron (II) acetylacetonate, iron (III) chloride, and nonocarbonyl diiron.
Claim 9
Dependent Claim
33 words
A method as defined in claim 5 wherein said iron compound is selected from the group consisting of iron (III) octoate, iron (III) oxide, iron (II) acetylacetonate, iron (III) chloride, and nonocarbonyl diiron.
Claim 10
Dependent Claim
33 words
A method as defined in claim 6 wherein said iron compound is selected from the group consisting of iron (III) octoate, iron (III) oxide, iron (II) acetylacetonate, iron (III) chloride, and nonocarbonyl diiron.
Claim 11
Dependent Claim
15 words
A method as defined in claim 4 wherein said cobalt compound is cobalt (II) octoate.
Claim 12
Dependent Claim
15 words
A method as defined in claim 5 wherein said cobalt compound is cobalt (II) octoate.
Claim 13
Dependent Claim
15 words
A method as defined in claim 6 wherein said cobalt compound is cobalt (II) octoate.
Claim 14
Dependent Claim
15 words
A method as defined in claim 4 wherein said nickel compound is nickel (II) octoate.
Claim 15
Dependent Claim
15 words
A method as defined in claim 5 wherein said nickel compound is nickel (II) octoate.
Claim 16
Dependent Claim
15 words
A method as defined in claim 6 wherein said nickel compound is nickel (II) octoate.
Claim 17
Dependent Claim
15 words
A method as defined in claim 4 wherein said copper compound is copper (II) octoate.
Claim 18
Dependent Claim
15 words
A method as defined in claim 5 wherein said copper compound is copper (II) octoate.
Claim 19
Dependent Claim
15 words
A method as defined in claim 6 wherein said copper compound is copper (II) octoate.
Claim 20
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 1.
Claim 21
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 2.
Claim 22
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 3.
Claim 23
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 4.
Claim 24
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 5.
Claim 25
Dependent Claim
11 words
A ceramic material as prepared by the method of claim 6.
Claim 26
Independent Claim
152 words
A method of preparing a ceramic material with increased crystallinity, said method comprising heating a modified R 3 SiNH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 1000 degrees C. until said modified R 3 SiNH-containing silazane polymer is converted to a ceramic material with increased crystallinity relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions wherein said increased crystallinity is in the form of increased levels of alpha-SiC, beta-SiC, alpha-Si 3 N 4 , or beta-Si 3 N 4 , wherein said modified R 3 SiNH-containing silazane polymer is prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, crystallinity increasing amount of an inorganic compound selected from the group consisting of iron III oxide, iron III octoate, iron II acetylacetonate, iron III chloride, cobalt II octoate, copper II octoate, nickel II octoate and noncarbonyldiiron.
Claim 27
Independent Claim
152 words
A method of preparing a ceramic material with increased crystallinity, said method comprising heating a modified R 3 SiNH-containing silazane polymer in an inert atmosphere or in a vacuum to a temperature of at least 1000 degrees C. until said modified R 3 SiNH-containing silazane polymer is converted to a ceramic material with increased crystallinity relative to a non-modified R 3 SiNH-containing silazane polymer heated under the same conditions wherein said increased crystallinity is in the form of increased levels of alpha-SiC, beta-SiC, alpha-Si 3 N 4 , or beta-Si 3 N 4 , wherein said modified R 3 SiNH-containing silazane polymer is prepared by mixing the non-modified R 3 SiNH-containing silazane polymer with an effective, crystallinity increasing amount of an inorganic compound selected from the group consisting of iron III oxide, iron III octoate, iron II acetylacetonate, iron III chloride, cobalt II octoate, copper II octoate, nickel II octoate and noncarbonyldiiron.
Claim 28
Dependent Claim
125 words
A method as defined in claim 25 wherein said non-modified R 3 SiNH-containing 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 general formula (Cl.sub.b R.sub.c.sup.' Si).sub.2 with a disilazane of general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; b has a value of 0.5-3; c has a value of 0-2.5; and the sum of (b+c) is equal to three.
Claim 29
Dependent Claim
110 words
A method as defined in claim 25 wherein said non-modified R 3 SiNH-containing silazane polymer is prepared by contacting and reacting in an inert, essentially anhydrous atmosphere, an organochlorosilane or a mixture of organochlorosilanes of general formula R.sub.n.sup.' SiCl.sub.(4-n) with a disilazane of general formula (R.sub.3 Si).sub.2 NH at a temperature in the range of 25° C. to 300° C. while distilling by-produced volatile products, wherein R' is a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; R is a hydrogen atom, a vinyl group, an alkyl group of 1-3 carbon atoms, or a phenyl group; and n has a value of 1 or 2.
References Cited (Backward Citations)
US4340619A
Cited
US4312970A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |