Patent US4839150A successfully refreshed from Google Patents.
US4839150A
Expired / Lapsed
US
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Production of silicon carbide
Assignee: Advanced Industrial Materials
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Filing: 1987-05-15
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Granted: 1989-06-13
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Expires: 2007-05-15
Abstract
Abstract Silicon carbide is produced by a method which includes dipsersing silica in a residual oil, carbonizing the oil at elevated temperatures, and heating the carbonized dispersion to form silicon carbide. Preferably, the silica is an amorphous type. Preferred residual oils are produced by distilling away crude petroleum components at temperatures up to about 350° C. The silicon carbide product typically contains a mixture of powder and whisker configurations, and has many particles with a dimension less than about 1 micrometer.
Inventors
- 👤 Roy T. Coyle
- 👤 Phillman N. Ho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:41
CPC Classifications
C; C30; C30B; C30B25/00; C30B25/005; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/97; C30B29/00; C30B29/10; C30B29/36; C01P; C01P2002/00; C01P2002/80; C01P2002/88; C01P2004/00; C01P2004/10; C01P2004/50; C01P2004/60; C01P2004/62; C01P2006/00; C01P2006/12; Y; Y10; Y10S; Y10S977/00; Y10S977/70; Y10S977/773; Y10S977/775; Y10S977/776; Y10S977/84; Y10S977/90; Y10S977/902; Y10S977/932; Y10S977/949
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
65 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in a residual oil; (b) heating the silica-containing oil in a substantially nonoxidizing atmosphere at temperatures which carbonize the oil; (c) heating the carbonized oil in a substantially nonoxidizing atmosphere at temperatures which induce a reaction between silica and carbon to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 2
Independent Claim
65 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in a residual oil; (b) heating the silica-containing oil in a substantially nonoxidizing atmosphere at temperatures which carbonize the oil; (c) heating the carbonized oil in a substantially nonoxidizing atmosphere at temperatures which induce a reaction between silica and carbon to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 3
Dependent Claim
11 words
The method defined in claim 1, wherein the silica is amorphous.
Claim 4
Dependent Claim
26 words
The method defined in claim 1, wherein the silica is selected from the group consisting of fumed silica, hydrated silica, dried silica gel, and mixtures thereof.
Claim 5
Dependent Claim
27 words
The method defined in claim 1, wherein the residual oil is crude petroleum from which components boiling below about 80° C. at atmospheric pressure have been removed.
Claim 6
Dependent Claim
27 words
The method defined in claim 1, wherein the residual oil is crude petroleum from which components boiling below about 200° C. at atmospheric pressure have been removed.
Claim 7
Dependent Claim
27 words
The method defined in claim 1, wherein the residual oil is crude petroleum from which components boiling below about 350° C. at atmospheric pressure have been removed.
Claim 8
Dependent Claim
27 words
The method defined in claim 1, wherein the residual oil is crude petroleum from which components boiling below about 560° C. at atmospheric pressure have been removed.
Claim 9
Dependent Claim
33 words
The method defined in claim 1, wherein silica is dispersed in residual oil in amounts which yield a carbonized dispersion having molar ratios of carbon to silicon from about 1 to about 10.
Claim 10
Dependent Claim
33 words
The method defined in claim 1, wherein silica is dispersed in residual oil in amounts which yield a carbonized dispersion having molar ratios of carbon to silicon from about 2 to about 5.
Claim 11
Dependent Claim
23 words
The method defined in claim 1, wherein the heating of step (b) is at temperatures from about 350° C. to about 1200° C.
Claim 12
Dependent Claim
23 words
The method defined in claim 1, wherein the heating of step (b) is at temperatures from about 500° C. to about 750° C.
Claim 13
Dependent Claim
90 words
The method defined in claim 1, wherein the residual oil is crude petroleum from which components boiling below about 350° C. at atmospheric pressure have been removed, the silica particles are dispersed in the residual oil in amounts which yield a carbonized dispersion having molar ratios of carbon to silicon ranging from about 1 to about 10, the heating of step (b) is at temperatures between about 500° C. and about 750° C. and the heating of step (c) is at temperatures between about 1400° C. and about 2000° C.
Claim 14
Dependent Claim
26 words
The method defined by claim 1, wherein the carbonized oil formed in step (b) has a surface area greater than about 50 square meters per gram.
Claim 15
Dependent Claim
20 words
The method defined in claim 1, wherein the heating of step (c) is at temperatures at least about 1200° C.
Claim 16
Dependent Claim
23 words
The method defined in claim 14, wherein the heating of step (c) is at temperatures between about 1200° C. and about 2000° C.
Claim 17
Independent Claim
71 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in a residual oil; (b) heating the silica-containing oil in a substantially nonoxidizing atmosphere at temperatures from about 350° C. to about 1200° C. to carbonize the oil; (c) heating the carbonized oil in a substantially nonoxidizing atmosphere at temperatures of at least about 1200° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 18
Independent Claim
71 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in a residual oil; (b) heating the silica-containing oil in a substantially nonoxidizing atmosphere at temperatures from about 350° C. to about 1200° C. to carbonize the oil; (c) heating the carbonized oil in a substantially nonoxidizing atmosphere at temperatures of at least about 1200° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 19
Dependent Claim
30 words
The method defined in claim 16, wherein the silica particles are amorphous and are selected from the group consisting of fumed silica, hydrated silica, dried silica gel, and mixtures thereof.
Claim 20
Dependent Claim
26 words
The method defined in claim 16, wherein the residual oil is a residue from a distillation of crude petroleum at temperatures up to about 350° C.
Claim 21
Dependent Claim
27 words
The method defined in claim 16, wherein the residual oil is crude petroleum from which components boiling below about 350° C. at atmospheric pressure have been removed.
Claim 22
Dependent Claim
27 words
The method defined in claim 16, wherein the residual oil is crude petroleum from which components boiling below about 560° C. at atmospheric pressure have been removed.
Claim 23
Dependent Claim
33 words
The method defined in claim 16, wherein silica is dispersed in residual oil in amounts which yield a carbonized dispersion having molar ratios of carbon to silicon from about 1 to about 10.
Claim 24
Dependent Claim
33 words
The method defined in claim 16, wherein silica is dispersed in residual oil in amounts which yield a carbonized dispersion having molar ratios of carbon to silicon from about 2 to about 5.
Claim 25
Dependent Claim
23 words
The method defined in claim 16, wherein the heating of step (b) is at temperatures from about 350° C. to about 1200° C.
Claim 26
Dependent Claim
23 words
The method defined in claim 16, wherein the heating of step (b) is at temperatures from about 500° C. to about 750° C.
Claim 27
Dependent Claim
20 words
The method defined in claim 16, wherein the heating of step (c) is at temperatures at least about 1200° C.
Claim 28
Independent Claim
94 words
A method for producing silicon carbide comprising the steps of: (a) dispersing particles of amorphous silica in a residue from a distillation of crude petroleum at temperatures; (b) heating the silica-containing residue in a substantially nonoxidizing atmosphere at temperatures between about 350° C. and about 1200° C. to form a carbonized dispersion having molar ratios of carbon to silicon between about 1 and about 10; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures of at least about 1400° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 29
Independent Claim
94 words
A method for producing silicon carbide comprising the steps of: (a) dispersing particles of amorphous silica in a residue from a distillation of crude petroleum at temperatures; (b) heating the silica-containing residue in a substantially nonoxidizing atmosphere at temperatures between about 350° C. and about 1200° C. to form a carbonized dispersion having molar ratios of carbon to silicon between about 1 and about 10; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures of at least about 1400° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 30
Dependent Claim
27 words
The method defined in claim 26, wherein the amorphous silica is selected from the group consisting of fumed silica, hydrated silica, dried silica gel, and mixtures thereof.
Claim 31
Dependent Claim
22 words
The method defined in claim 26, wherein the distillation has removed crude petroleum components boiling below about 350° C. at atmospheric pressure.
Claim 32
Dependent Claim
23 words
The method defined in claim 26, wherein the carbonized dispersion has molar ratios of carbon to silicon between about 2 and about 5.
Claim 33
Dependent Claim
23 words
The method defined in claim 26, wherein the heating of step (b) is at temperatures from about 500° C. to about 750° C.
Claim 34
Dependent Claim
21 words
The method defined in claim 26, further comprising the step of separating silicon carbide whiskers from the product of step (d).
Claim 35
Independent Claim
131 words
A method for producing silicon carbide comprising the steps of: (a) dispersing particles of an amorphous silica selected from the group consisting of fumed silica, hydrated silica, dried silica gel, and mixtures thereof, having particle sizes less than about 10 micrometers, in a crude petroleum said crude petroleum having been treated by distillation to remove components boiling below about 350° C. at atmospheric pressure; (b) heating the silica-containing petroleum in a substantially nonoxidizing atmosphere at temperature between about 500° C. and about 750° C. to form a carbonized dispersion having molar ratios of carbon to silicon between about 2 and about 5; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures of at least about 1400° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 36
Independent Claim
131 words
A method for producing silicon carbide comprising the steps of: (a) dispersing particles of an amorphous silica selected from the group consisting of fumed silica, hydrated silica, dried silica gel, and mixtures thereof, having particle sizes less than about 10 micrometers, in a crude petroleum said crude petroleum having been treated by distillation to remove components boiling below about 350° C. at atmospheric pressure; (b) heating the silica-containing petroleum in a substantially nonoxidizing atmosphere at temperature between about 500° C. and about 750° C. to form a carbonized dispersion having molar ratios of carbon to silicon between about 2 and about 5; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures of at least about 1400° C. to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 37
Independent Claim
64 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in crude petroleum; (b) heating the silica-containing petroleum in a substantially nonoxidizing atmosphere at temperatures which carbonize the petroleum; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures which induce a reaction between silica and carbon to form silicon carbide; and (d) recovering a silicon carbide-containing product.
Claim 38
Independent Claim
64 words
A method for producing silicon carbide comprising the steps of: (a) dispersing silica particles in crude petroleum; (b) heating the silica-containing petroleum in a substantially nonoxidizing atmosphere at temperatures which carbonize the petroleum; (c) heating the carbonized dispersion in a substantially nonoxidizing atmosphere at temperatures which induce a reaction between silica and carbon to form silicon carbide; and (d) recovering a silicon carbide-containing product.
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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) | 1992-06-12 | 1992-12-12 | 1993-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-12 | 1996-12-12 | 1997-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-12 | 2000-12-12 | 2001-06-13 | $7700.00 | Window Closed / Lapsed |