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US3900540A
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Method for making a film of refractory material having bi-directional reinforcing properties
Assignee: Pfizer Inc
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Filing: 1974-03-06
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Granted: 1975-08-19
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Expires: 1994-03-06
Abstract
Abstract A thin film of substantially defect-free pyrolytic graphite, useful as a bi-directional reinforcing material, is formed by vapor deposition on an inert liquid substrate surface and separated therefrom. The substrate temperature is substantially below the melting point of the refractory material and the substrate surface is smooth and free of stress to enable formation of a substantially defect-free film. The films of other refractory materials can be made similarly by first forming a pyrolytic graphite film on the substrate, and then vapor depositing a film of refractory material on the pyrolytic graphite surface. The pyrolytic graphite and refractory material films are then separated from the substrate surface and then separated from each other. Various refractory film materials can be made including pyrolytic graphite; boron; silicon; and refractory carbides, borides and nitrides. For making pyrolytic graphite films, it is preferable to use tin as the substrate, at a temperature of about 1,600*-1,800*C., at atmospheric pressure, a source gas consisting of methane and argon, helium, or hydrogen, and a film residence time on the substrate surface of about 0.16-2 minutes.
Inventors
- 👤 William A Robba
- 👤 Robert W Froberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:30
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/01; C01; C01B; C01B21/00; C01B21/06; C01B21/064; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/977; C01B32/991; C01B33/00; C01B33/02; C01B35/00; C01B35/02; C01B35/023; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/522; C04B35/58; C04B35/583; C04B35/584; C01P; C01P2004/00; C01P2004/51; C01P2004/60; C01P2004/61; C01P2004/80; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
109 words
A METHOD OF MAKING A THIN FILM OF SUBSTANTIALLY DEFECTFREE PYROLYTIC GRAPHITE WHICH COMPRISES: MAINTAINING THE TEMPERATURE OF AN INERT LIQUID SUBSTRATE SELECTED FROM THE GROUP CONSISTING OF COPPER, GOLD, TIN, SILVER, PALLADIUM, LEAD, ANTIMONY, PLATINUM, AND GLASS BELOW THE MELTING POINT OF GRAPHITE, AND INTRODUCING A PERMIXED SOURCE GAS COMPRISING A MIXTURE OF A HYDROCARBON GAS AND A DILUENT GAS SELECTED FROM THE GROUP CONSISTING OF HELIUM, NEON, ARGON, KRYPTON, XENON, RANDON, HYDROGEN AND NITROGEN AT A DISTANCE ABOVE THE SURFACE OF SAID LIQUID SUBSTRATE, SAID SURFACE BEING SUBSTANTIALLY SMOOTH AND STRESS-FREE, WHEREBY SAID HYDROCARBON GAS DECOMPOSES UPON CONTACTING SAID SURFACE TO FROM A PYROLYTIC GRAPHITE FILM THEREON.
Claim 2
Independent Claim
109 words
A METHOD OF MAKING A THIN FILM OF SUBSTANTIALLY DEFECTFREE PYROLYTIC GRAPHITE WHICH COMPRISES: MAINTAINING THE TEMPERATURE OF AN INERT LIQUID SUBSTRATE SELECTED FROM THE GROUP CONSISTING OF COPPER, GOLD, TIN, SILVER, PALLADIUM, LEAD, ANTIMONY, PLATINUM, AND GLASS BELOW THE MELTING POINT OF GRAPHITE, AND INTRODUCING A PERMIXED SOURCE GAS COMPRISING A MIXTURE OF A HYDROCARBON GAS AND A DILUENT GAS SELECTED FROM THE GROUP CONSISTING OF HELIUM, NEON, ARGON, KRYPTON, XENON, RANDON, HYDROGEN AND NITROGEN AT A DISTANCE ABOVE THE SURFACE OF SAID LIQUID SUBSTRATE, SAID SURFACE BEING SUBSTANTIALLY SMOOTH AND STRESS-FREE, WHEREBY SAID HYDROCARBON GAS DECOMPOSES UPON CONTACTING SAID SURFACE TO FROM A PYROLYTIC GRAPHITE FILM THEREON.
Claim 3
Dependent Claim
55 words
The method of claim 1 wherein said film of pyrolytic graphite is separated from said liquid substrate surface as a continuous ribbon by means of two parallel carbon fibers moving under tension at a predetermined rate over said surface and to which said film continuously attaches itself as said film is deposited on said surface.
Claim 4
Dependent Claim
39 words
The method of claim 1 wherein the residence time of the graphite film on said substrate surface is from about 0.16 to 5 minutes, and the pressure during said vapor deposition is from about 5 to 850 mm Hg.
Claim 5
Dependent Claim
56 words
The method of claim 3 wherein said substrate is tin, said source-gas comprises a mixture of methane and a diluent gas selected from the group consisting of argon, helium, and hydrogen, said temperature is from about 1,600* to 1,800*C., said pressure is about 760 mm Hg, and said residence time is about 0.16 to 2 minutes.
Claim 6
Dependent Claim
22 words
The method of claim 2 wherein said separated pyrolytic graphite film is annealed at a temperature of about 2,600* to 3, 200*C.
Claim 7
Dependent Claim
64 words
A method of making a thin film of substantially defect-free non-oxygen-containing refractory material which comprises first making a thin film of substantially defect-free pyrolytic graphite by carrying out the method as claimed in claim 10, then forming by Vapor deposition a thin film of said refractory material on the surface of said graphite film, and finally separating said refractory film from said graphite film.
Claim 8
Dependent Claim
30 words
The method of claim 6 wherein said refractory material is a refractory carbide of a member selected from the group consisting of silicon, titanium, zirconium, hafnium, vanadium, chromium, and boron.
Claim 9
Dependent Claim
30 words
The method of claim 6 wherein said refractory material is a refractory boride of a member selected from the group consisting of silicon, titanium, zirconium, hafnium, vanadium, chromium, and aluminum.
Claim 10
Dependent Claim
29 words
The method of claim 6 wherein said refractory material is a refractory nitride of a member selected from the group consisting of silicon, titanium, hafnium, vanadium, boron, and aluminum.
Claim 11
Dependent Claim
19 words
The method of claim 6 wherein said refractory material is selected from the group consisting of boron and silicon.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |