US4631179A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of silicon carbide by the pyrolysis of a polycarbosilane polymer
Assignee: Ethyl Corp
•
Filing: 1985-05-28
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Granted: 1986-12-23
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Expires: 2005-05-28
Abstract
Abstract Silicon carbide production by pyrolysis of polycarbosilane polymers formed by prior art methods is fraught with defects. These can be obviated by utilizing as the polycarbosilane polymer, a poly(silmethylene) formed by polymerizing 1,3-disilacyclobutane with a ring-opening catalyst of a Group VIII element of atomic number 44 or above, preferably a Pt-containing catalyst, in an inert liquid medium and under an inert atmosphere. At pyrolysis temperatures of at least about 900° C., silicon carbride in a crystalline state is formed. The poly(silmethylene) may be molded or shaped into various forms such as fibers before being subjected to the pyrolysis.
Inventors
- 👤 Troy L. Smith, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:27
CPC Classifications
C; C08; C08G; C08G77/00; C08G77/60; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/977; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/622; C04B35/62227; C08L; C08L83/00; C08L83/04; C08L83/08; C01P; C01P2002/00; C01P2002/80; C01P2002/82
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
56 words
In a process of producing silicon carbide by pyrolysis of a polycarbosilane polymer, the improvement which comprises utilizing as the polycarbosilane polymer a moldable or shapeable poly(silmethylene) formed by polymerizing 1,3-disilacyclobutane with a ring-opening catalyst of a Group VIII element of atomic number 44 or above, in an inert liquid medium and under an inert atmosphere.
Claim 2
Dependent Claim
56 words
In a process of producing silicon carbide by pyrolysis of a polycarbosilane polymer, the improvement which comprises utilizing as the polycarbosilane polymer a moldable or shapeable poly(silmethylene) formed by polymerizing 1,3-disilacyclobutane with a ring-opening catalyst of a Group VIII element of atomic number 44 or above, in an inert liquid medium and under an inert atmosphere.
Claim 3
Dependent Claim
17 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum.
Claim 4
Dependent Claim
23 words
A process of claim 1 in which the ring-opening catalyst as charged to the system is H 2 PtCl 6 .6H 2 O.
Claim 5
Dependent Claim
21 words
A process of claim 1 in which the ring-opening catalyst as charged to the system is a diene platinum (II) dichloride.
Claim 6
Dependent Claim
19 words
A process of claim 1 in which the ring-opening catalyst as charged to the system is (1,5-cyclooctadiene)platinum (II) dichloride.
Claim 7
Dependent Claim
30 words
A process of claim 1 in which the pyrolysis is conducted at a temperature of at least about 900° C. so that silicon carbide in a crystalline state is formed.
Claim 8
Dependent Claim
28 words
A process of claim 1 in which the poly(silmethylene) is molded or shaped prior to the pyrolysis and the pyrolysis is performed on the molded or shaped poly(silmethylene).
Claim 9
Dependent Claim
29 words
A process of claim 1 in which the poly(silmethylene) is spun or drawn into a fiber prior to the pyrolysis and the pyrolysis is performed on the poly(silmethylene) fiber.
Claim 10
Dependent Claim
43 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum and in which the pyrolysis is conducted at a temperature of at least about 900° C. so that silicon carbide in a crystalline state is formed.
Claim 11
Dependent Claim
41 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum and in which the poly(silmethylene) is molded or shaped prior to the pyrolysis and the pyrolysis is performed on the molded or shaped poly(silmethylene).
Claim 12
Dependent Claim
42 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum and in which the poly(silmethylene) is spun or drawn into a fiber prior to the pyrolysis and the pyrolysis is performed on the poly(silmethylene) fiber.
Claim 13
Dependent Claim
72 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum, in which the poly(silmethylene) is molded or shaped prior to the pyrolysis and the pyrolysis is performed on the molded or shaped poly(silmethylene), and in which the pyrolysis of the molded or shaped poly(silmethylene) is conducted at a temperature of at least about 900° C. so that silicon carbide in a crystalline state is formed.
Claim 14
Dependent Claim
24 words
A process of claim 12 in which the ring-opening catalyst as charged to the system is a hydrate of H 2 PtCl 6 .
Claim 15
Dependent Claim
21 words
A process of claim 12 in which the ring-opening catalyst as charged to the system is a diene platinum (II) dichloride.
Claim 16
Dependent Claim
71 words
A process of claim 1 in which the Group VIII element in the ring-opening catalyst is platinum, in which the poly(silmethylene) is spun or drawn into a fiber prior to the pyrolysis and the pyrolysis is performed on the poly(silmethylene) fiber, and in which the pyrolysis of the poly(silmethylene) fiber is conducted at a temperature of at least about 900° C. so that silicon carbide in a crystalline state is formed.
Claim 17
Dependent Claim
24 words
A process of claim 14 in which the ring-opening catalyst as charged to the system is a hydrate of H 2 PtCl 6 .
Claim 18
Dependent Claim
21 words
A process of claim 14 in which the ring-opening catalyst as charged to the system is a diene platinum (II) dichloride.
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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) | 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 |