Patent US4455489A successfully refreshed from Google Patents.
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EP0251322A2
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EP
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Method for refining non-oxide ceramic powders
Assignee: JFE Engineering Corp
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Filing: 1987-07-02
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Granted: —
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Expires: 2007-07-02
Abstract
Abstract A method for refining powders comprising the steps of: (a) adding fluororesin powders to non-oxide ceramic powders to form a mixture by mixing; and (b) heating the mixture in non-oxidizing atmosphere to allow oxides existing on the surface of the non-oxide ceramic powders to convert into gaseous fluorides, the gaseous fluorides being removed. The fluororesin is polytetrafluoroethylene resins. The heating temperature in the non-oxidizing atmosphere is 500°C to 1300°C.
Inventors
- 👤 Hiroaki c/o Patent &Licence and Nishio
- 👤 Michitaka c/o Patent & Licence and Sato
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:05
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/64; C04B35/65; C01; C01B; C01B21/00; C01B21/06; C01B21/0615; C01B21/062; C01B21/064; C01B21/068; C01B21/0687; C01B21/072; C01B21/0728; C01B21/076; C01B21/0768; C01B32/00; C01B32/90; C01B32/914; C01B32/921; C01B32/956; C01B35/00; C01B35/02; C01B35/04; C04B35/515; C04B35/56; C04B35/5607; C04B35/5611; C04B35/563; C04B35/565; C04B35/58; C04B35/58007; C04B35/58014; C04B35/5805; C04B35/58064; C04B35/58071; C04B35/58078; C04B35/583; C04B35/584; C01P; C01P2006/00; C01P2006/60; C01P2006/80
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
59 words
A method for refining non-oxide ceramic powders, characterized by of comprising the steps of; adding powders of polytetrafluoroethylene resins to non-oxide ceramic powders to form a mixture by mixing; and heating the mixture in non-oxidizing atmosphere to allow oxides existing on the surface of the non-oxide ceramic powders to convert into gaseous fluorides, thereby the gaseous fluorides being removed.
Claim 2
Independent Claim
59 words
A method for refining non-oxide ceramic powders, characterized by of comprising the steps of; adding powders of polytetrafluoroethylene resins to non-oxide ceramic powders to form a mixture by mixing; and heating the mixture in non-oxidizing atmosphere to allow oxides existing on the surface of the non-oxide ceramic powders to convert into gaseous fluorides, thereby the gaseous fluorides being removed.
Claim 3
Dependent Claim
34 words
A method according to claim 1, characterized in that said powders of polytetrafluoroethylene resins include being at least one selected from the group consisting of tetrafluoroethylene resin, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkylvinylether copolymer, and tetrafluoroethylene-ethylene copolymer.
Claim 4
Dependent Claim
32 words
A method according to claim 1 or 2, characterized in that said step of adding the powders of polytetrafluoroethylene resins includes adding the powders of polytetrafluoroethylene resins by 1 to 10 wt.%.
Claim 5
Dependent Claim
30 words
A method according to claim 3, characterized in that said step of adding the powders of polytetrafluoroethylene resins includes adding the powders of polytetrafluoroethylene resins by 1 to 5 wt.%.
Claim 6
Independent Claim
33 words
A method according to any one of claims 1 to 4, characterized in that said non-oxide ceramic powders include being at least one selected from the group consisting of nitride, carbide and boride.
Claim 7
Dependent Claim
33 words
A method according to claim 5, characterized in that said nitride includes being at least one selected from the group consisting of silicon nitride, aluminium nitride, boron nitride, chromium nitride and titanium nitride.
Claim 8
Dependent Claim
29 words
A method according to claim 5, characterized in that said carbide includes being at least one selected from the group consisting of silicon carbide, boron carbide and titanium carbide.
Claim 9
Dependent Claim
27 words
A method according to claim 5. characterized in that said boride includes being at least one selected from the group consisting of titanium boride and zirconium boride.
Claim 10
Independent Claim
20 words
A method according to any one of claims 1 to 8, characterized in that said non-oxidizing atmosphere includes being vacuum.
Claim 11
Independent Claim
27 words
A method according to any one of claims 1 to 9, characteized in that said step of heating includes heating at the temperature of 500° to 1300°C.
Claim 12
Dependent Claim
20 words
A method according to claim 10, characterized in that said heating includes heating at the temperature of 600°C to 1000°C.
Claim 13
Independent Claim
67 words
A method for refining non-oxide ceramic powders which comprises the steps of: adding powders of polytetrafluoroethylene resins to non-oxide ceramic powders to form a mixture by mixing; compacting the mixture into a green compact; and heating the green compact at the temperature of 500°-1300°C to allow oxides existing on the surface of the non-oxide ceramic powders to convert into gaseous fluorides, thereby the gaseous fluorides being removed.
Claim 14
Independent Claim
67 words
A method for refining non-oxide ceramic powders which comprises the steps of: adding powders of polytetrafluoroethylene resins to non-oxide ceramic powders to form a mixture by mixing; compacting the mixture into a green compact; and heating the green compact at the temperature of 500°-1300°C to allow oxides existing on the surface of the non-oxide ceramic powders to convert into gaseous fluorides, thereby the gaseous fluorides being removed.
Claim 15
Dependent Claim
24 words
A method according to claim 12, characterized in that said step of compacting the mixture includes applying cold isostatistic press treatment to the mixture.
Claim 16
Dependent Claim
28 words
A method according to claim 12 or 13, characterized by further comprising the additional step of sintering the green compact from which the gaseous fluorides have been removed.
Claim 17
Dependent Claim
37 words
A method according to claim 12, 13 or 14, characterized in that said step of adding powders of polytetrafluoroethylene resins includes adding the powders of polytetrafluoroethylene resins of 0.5 to 2.5 wt.% to the non-oxide ceramic powders.
References Cited (Backward Citations)
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