US4737552A
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Ceramic materials from polycarbosilanes
Assignee: Dow Silicones Corp
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Filing: 1986-06-30
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Granted: 1988-04-12
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Expires: 2006-06-30
Abstract
Abstract A method is disclosed for the preparation of ceramic materials with reduced oxygen levels from polycarbosilanes by the pyrolysis of a mixture of a polycarbosilane, a hydrosilylation catalyst, and an unsaturated compound selected from the group consisting of reactive diolefins, reactive alkynes, polyolefins, vinylsilanes, and unaturated siloxanes where the mixture is rendered infusible prior to pyrolysis by heating to relatively low temperatures in an inert atmosphere. This invention is especially well suited for the production of ceramic fibers from polycarbosilanes.
Inventors
- 👤 Ronald H. Baney
- 👤 Gary T. Burns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:22
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/62227; C04B35/515; C04B35/56; C04B35/565; C04B35/571; C08; C08L; C08L83/00; C08L83/16; D; D01; D01F; D01F9/00; D01F9/08; D01F9/10
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
87 words
A method of rendering a preceramic polycarbosilane composition infusible prior to pyrolysis, which method comprises treating the preceramic polycarbosilane composition at a temperature of 150° to 400° C. under an inert atmosphere or vacuum for a time sufficient to render the preceramic composition infusible wherein the preceramic composition contains (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups, (2) a hydrosilylation catalyst, of the platinum metal group, and (3) an unsaturated compound selected from the group consisting of reactive alkynes, polyolefins, vinylsilanes, and unsaturated siloxanes.
Claim 2
Independent Claim
87 words
A method of rendering a preceramic polycarbosilane composition infusible prior to pyrolysis, which method comprises treating the preceramic polycarbosilane composition at a temperature of 150° to 400° C. under an inert atmosphere or vacuum for a time sufficient to render the preceramic composition infusible wherein the preceramic composition contains (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups, (2) a hydrosilylation catalyst, of the platinum metal group, and (3) an unsaturated compound selected from the group consisting of reactive alkynes, polyolefins, vinylsilanes, and unsaturated siloxanes.
Claim 3
Dependent Claim
37 words
A method as defined in claim 1 wherein the polycarbosilane contains from 0.2 to 5.0 weight percent Si-H groups and the preceramic polycarbosilane composition is rendered infusible by treatment at a temperature of 300° to 400° C.
Claim 4
Dependent Claim
55 words
A method as defined in claim 2 wherein the hydrosilylation catalyst is present at a metal level of one part per million to 0.5 weight percent based on the weight of the polycarbosilane and the unsaturated compound is present at a level of 2 to 5 weight percent based on the weight of the polycarbosilane.
Claim 5
Dependent Claim
21 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains platinum and the unsaturated compound is a reactive alkyne.
Claim 6
Dependent Claim
20 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains platinum and the unsaturated compound is a polyolefin.
Claim 7
Dependent Claim
20 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains platinum and the unsaturated compound is a vinylsilane.
Claim 8
Dependent Claim
21 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains platinum and the unsaturated compound is an unsaturated siloxane.
Claim 9
Dependent Claim
21 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains rhodium and the unsaturated compound is a reactive alkyne.
Claim 10
Dependent Claim
20 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains rhodium and the unsaturated compound is a polyolefin.
Claim 11
Dependent Claim
20 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains rhodium and the unsaturated compound is a vinylsilane.
Claim 12
Dependent Claim
21 words
A method as defined in claim 3 wherein the hydrosilylation catalyst contains rhodium and the unsaturated compound is an unsaturated siloxane.
Claim 13
Dependent Claim
28 words
A method as defined in claim 3 wherein the hydrosilylation catalyst is present at a level of ten parts per million to 0.1 weight percent as the metal.
Claim 14
Dependent Claim
98 words
A method as defined in claim 3 wherein the hydrosilylation catalyst is selected from the group consisting of (1) chloroplatinic acid and (2) the reaction product of chloroplatinic acid and at least one organosilicon compound of the formula ##STR3## where R is selected from the group consisting of monovalent hydrocarbon and monovalent halohydrocarbon radicals, at least one of the R groups containing terminal aliphatic unsaturation; X is a hydrolyzable group; n has an average value of 1.5 to 4; m has an average value of 1 to 20; and a has an average value of 0 to 2.5.
Claim 15
Dependent Claim
19 words
A method as defined in claim 3 wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 16
Dependent Claim
19 words
A method as defined in claim 12 wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 17
Dependent Claim
19 words
A method as defined in claim 13 wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 18
Independent Claim
73 words
A method of rendering a preceramic polycarbosilane composition infusible prior to pyrolysis, which method comprises treating the preceramic composition with a gas selected from the group consisting of reactive diolefins, reactive alkynes, and vinylsilanes at a temperature of 150° to 400° C. for a time sufficient to render the preceramic composition infusible wherein the preceramic composition contains (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups and (2) a hydrosilylation catalyst.
Claim 19
Independent Claim
73 words
A method of rendering a preceramic polycarbosilane composition infusible prior to pyrolysis, which method comprises treating the preceramic composition with a gas selected from the group consisting of reactive diolefins, reactive alkynes, and vinylsilanes at a temperature of 150° to 400° C. for a time sufficient to render the preceramic composition infusible wherein the preceramic composition contains (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups and (2) a hydrosilylation catalyst.
Claim 20
Dependent Claim
55 words
A method as defined in claim 17 wherein the hydrosilylation catalyst is present at a metal level of one part per million to 0.5 weight percent based on the weight of the polycarbosilane and the unsaturated compound is present at a level of 2 to 5 weight percent based on the weight of the polycarbosilane.
Claim 21
Dependent Claim
19 words
A method as defined in claim 18 wherein the polycarbosilane contains from 0.2 to 5.0 weight percent Si-H groups.
Claim 22
Dependent Claim
34 words
A method as defined in claim 19 wherein the hydrosilylation catalyst contains platinum and is present at a platinum level of ten parts per million to 0.1 weight percent based on the polycarbosilane weight.
Claim 23
Dependent Claim
34 words
A method as defined in claim 19 wherein the hydrosilylation catalyst contains rhodium and is present at a rhodium level of ten parts per million to 0.1 weight percent based on the polycarbosilane weight.
Claim 24
Dependent Claim
27 words
A method as defined in claim 19 wherein the gas is a reactive diolefin and wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 25
Dependent Claim
27 words
A method as defined in claim 19 wherein the gas is a reactive alkyne and wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 26
Dependent Claim
26 words
A method as defined in claim 19 wherein the gas is a vinylsilane and wherein the preceramic polycarbosilane composition is in the form of a fiber.
Claim 27
Dependent Claim
47 words
A preceramic polymer composition consisting essentially of (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups, (2) a hydrosilylation catalyst of the platinum metal group, and (3) an unsaturated compound selected from the group consisting of reactive diolefins, reactive alkynes, polyolefins, vinylsilanes, and unsaturated siloxanes.
Claim 28
Dependent Claim
47 words
A preceramic polymer composition consisting essentially of (1) a polycarbosilane containing at least 0.1 weight percent Si-H groups, (2) a hydrosilylation catalyst of the platinum metal group, and (3) an unsaturated compound selected from the group consisting of reactive diolefins, reactive alkynes, polyolefins, vinylsilanes, and unsaturated siloxanes.
Claim 29
Dependent Claim
36 words
A composition as defined in claim 25 wherein the hydrosilylation catalyst contains platinum and is present at a platinum level of ten parts per million to 0.1 weight percent based on the weight of the polycarbosilane.
Claim 30
Dependent Claim
98 words
A composition as defined in claim 26 wherein the hydrosilylation catalyst is selected from the group consisting of (1) chloroplatinic acid and (2) the reaction product of chloroplatinic acid and at least one organosilicon compound of the formula ##STR4## where R is selected from the group consisting of monovalent hydrocarbon and monovalent halohydrocarbon radicals, at least one of the R groups containing terminal aliphatic unsaturation; X is a hydrolyzable group; n has an average value of 1.5 to 4; m has an average value of 1 to 20; and a has an average value of 0 to 2.5.
Claim 31
Dependent Claim
36 words
A composition as defined in claim 25 wherein the hydrosilylation catalyst contains rhodium and is present at a rhodium level of ten parts per million to 0.1 weight percent based on the weight of the polycarbosilane.
Claim 32
Dependent Claim
14 words
A composition as defined in claim 25 wherein the unsaturated compound is a polyolefin.
Claim 33
Dependent Claim
15 words
A composition as defined in claim 25 wherein the unsaturated compound is a unsaturated siloxane.
Claim 34
Dependent Claim
54 words
A composition as defined in claim 25 wherein the hydrosilylation catalyst is present at a level of one part per million to 0.5 weight percent based on the weight of the polycarbosilane and the unsaturated compound is present at a level of 0.5 to 20 weight percent based on the weight of the polycarbosilane.
Claim 35
Dependent Claim
54 words
A composition as defined in claim 31 wherein the hydrosilylation catalyst is present at a level of ten parts per million to 0.1 weight percent based on the weight of the polycarbosilane and the unsaturated compound is present at a level of 2 to 5 weight percent based on the weight of the polycarbosilane.
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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) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |