US4816497A
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Infusible preceramic silazane polymers via ultraviolet irradiation
Assignee: Dow Silicones Corp
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Filing: 1986-09-08
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Granted: 1989-03-28
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Expires: 2006-09-08
Abstract
Abstract A method is disclosed for the preparation of ceramic materials or articles by the pyrolysis of mixtures of vinyl- or allyl-containing preceramic silazane polymers, mercapto compounds, and photoinitiators wherein the mixtures are rendered infusible prior to pyrolysis by ultraviolet (UV) irradiation. This method is especially suited for the preparation of ceramic fibers.
Inventors
- 👤 Michael A. Lutz
- 👤 Ronald S. Reaoch
- 👤 Philip E. Reedy, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:43
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/28; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/589; C08L; C08L83/00; C08L83/16; C08J2383/00; C08J2383/16; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
81 words
A method of rendering a preceramic silazane polymer material infusible prior to pyrolysis, which method comprises treating the preceramic silazane polymer material with UV irradiation for a time sufficient to render the preceramic silazane polymer material infusible wherein the preceramic silazane polymer material contains (1) a vinyl- or allyl-containing preceramic silazane polymer with an average of at least 0.7 vinyl or allyl groups per molecule, (2) a mercapto compound with at least two SH groups per molecule, and (3) a photoinitiator.
Claim 2
Independent Claim
81 words
A method of rendering a preceramic silazane polymer material infusible prior to pyrolysis, which method comprises treating the preceramic silazane polymer material with UV irradiation for a time sufficient to render the preceramic silazane polymer material infusible wherein the preceramic silazane polymer material contains (1) a vinyl- or allyl-containing preceramic silazane polymer with an average of at least 0.7 vinyl or allyl groups per molecule, (2) a mercapto compound with at least two SH groups per molecule, and (3) a photoinitiator.
Claim 3
Dependent Claim
41 words
A method as defined in claim 1 wherein the preceramic silazane polymer material contains a vinyl-containing preceramic silazane polymer with an average of 0.7 vinyl groups per molecule and wherein the SH/(CH 2 ═CH) molar ratio is greater than one half.
Claim 4
Dependent Claim
19 words
A method as defined in claim 1 wherein the mercapto compound contains at least three SH groups per molecule.
Claim 5
Dependent Claim
19 words
A method as defined in claim 2 wherein the mercapto compound contains at least three SH groups per molecule.
Claim 6
Dependent Claim
16 words
A method as defined in claim 2 wherein the preceramic silazane polymer material is a fiber.
Claim 7
Dependent Claim
16 words
A method as defined in claim 3 wherein the preceramic silazane polymer material is a fiber.
Claim 8
Dependent Claim
16 words
A method as defined in claim 4 wherein the preceramic silazane polymer material is a fiber.
Claim 9
Dependent Claim
21 words
A method as defined in claim 4 wherein the SH/(CH 2 ═CH) molar ratio is in the 0.6 to 1.0 range.
Claim 10
Dependent Claim
41 words
A method as defined in claim 4 wherein the preceramic silazane polymer material contains 5 to 15 weight percent of the mercapto compound and 0.1 to 10 weight percent of the photoinitiator based on the weight of the preceramic silazane polymer.
Claim 11
Dependent Claim
30 words
A method as defined in claim 9 wherein the photoinitiator is present in the range of 2.0 to 5.0 weight percent based on the weight of the preceramic silazane polymer.
Claim 12
Dependent Claim
22 words
A method as defined in claim 7 wherein the photoinitiator is selected from the group consisting of benzophenone, 2-hydroxy-2-methyl-1-(p-isopropylphenyl)propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-diethoxyacetophenone.
Claim 13
Dependent Claim
22 words
A method as defined in claim 8 wherein the photoinitiator is selected from the group consisting of benzophenone, 2-hydroxy-2-methyl-1-(p-isopropylphenyl)propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-diethoxyacetophenone.
Claim 14
Dependent Claim
22 words
A method as defined in claim 9 wherein the photoinitiator is selected from the group consisting of benzophenone, 2-hydroxy-2-methyl-1-(p-isopropylphenyl)propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-diethoxyacetophenone.
Claim 15
Dependent Claim
43 words
A preceramic silazane polymer composition comprising (1) a vinyl- or allyl-containing preceramic silazane polymer with an average of at least 0.7 vinyl or allyl groups per molecule, (2) a mercapto compound with at least two SH groups per molecule, and (3) a photoinitiator.
Claim 16
Dependent Claim
43 words
A preceramic silazane polymer composition comprising (1) a vinyl- or allyl-containing preceramic silazane polymer with an average of at least 0.7 vinyl or allyl groups per molecule, (2) a mercapto compound with at least two SH groups per molecule, and (3) a photoinitiator.
Claim 17
Dependent Claim
17 words
A composition as defined in claim 14 wherein the mercapto compound contains at least three SH groups.
Claim 18
Dependent Claim
50 words
A composition as defined in claim 15 wherein the mercapto compound is present in the range of 5 to 15 weight percent and wherein the photoinitiator is present in the range of 0.1 to 10 weight percent where the percentages are based on the weight of the preceramic silazane polymer.
Claim 19
Dependent Claim
40 words
A composition as defined in claim 16 wherein the preceramic silazane polymer is a vinyl-containing preceramic silazane polymer with an average of 0.7 vinyl groups per molecule and wherein the SH/(CH 2 ═CH) molar ratio is greater than one half.
Claim 20
Dependent Claim
21 words
A composition as defined in claim 16 wherein the SH/(CH 2 ═CH) molar ratio is in the 0.6 to 1.0 range.
Claim 21
Dependent Claim
22 words
A composition as defined in claim 14 wherein the photoinitiator is selected from the group consisting of benzophenone, 2-hydroxy-2-methyl-1-(p-isopropylphenyl)propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-diethoxyacetophenone.
Claim 22
Dependent Claim
22 words
A composition as defined in claim 17 wherein the photoinitiator is selected from the group consisting of benzophenone, 2-hydroxy-2-methyl-1-(p-isopropylphenyl)propan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 2,2-diethoxyacetophenone.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |