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Patent US5145719A successfully refreshed from Google Patents.
US5145719A
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Method for coating surface of fine particles with a layer of fine metal oxide powder
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1991-03-22
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Granted: 1992-09-08
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Expires: 2011-03-22
Abstract
Abstract Minute particles having the surface thereof coated with a dense layer of extremely fine particles of a metal oxide are produced by dispersing the fine particles having water adsorbed in advance on the surface thereof in a hydrophobic organic solvent having an alcohol and optionally an amine dissolved therein and adding to the resultant dispersion a hydrophobic organic solvent having a metal alkoxide dissolved therein, thereby inducing hydrolysis of the metal alkoxide on the surface of the fine particles and consequent deposition of a metal oxide on the surface of the fine particles.
Inventors
- 👤 Atsuya Towata
- 👤 Mutsuo Sando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:10
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; C04B35/62605; C04B35/62625; C04B35/6264; B; B01; B01J; B01J2/00; B01J2/006; C01; C01G; C01G19/00; C01G19/02; C01G23/00; C01G23/04; C01G23/047; C01G23/053; C01G9/00; C01G9/02; C04B35/628; C04B35/62802; C04B35/62805; C04B35/6281; C04B35/62818; C04B35/62821; C04B35/62823; C04B35/62886; C04B35/62892; C04B35/63; C04B35/632; C09; C09C; C09C1/00; C09C1/04; C09C1/043; C09C1/40; C09C1/407; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; C01P2006/00; C01P2006/12; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3217; C04B2235/3284; C04B2235/44; C04B2235/441; C04B2235/50; C04B2235/54; C04B2235/5409; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
96 words
A method for coating fine particles, which comprises: dispersing fine particles having water absorbed in advance on the surface thereof in a first hydrophobic organic solvent (a) which incorporates therein 2.5-10% by weight of an alcohol of 2-4 carbon atoms; and adding to the resultant dispersion of said fine particles a second hydrophobic organic solvent (b) having a metal alkoxide dissolved therein thereby forming on the surface of said fine particles a dense layer of extremely fine particles of a metal oxide as the metal alkoxide is hydrolyzed by the surface water on the fine particles.
Claim 2
Independent Claim
96 words
A method for coating fine particles, which comprises: dispersing fine particles having water absorbed in advance on the surface thereof in a first hydrophobic organic solvent (a) which incorporates therein 2.5-10% by weight of an alcohol of 2-4 carbon atoms; and adding to the resultant dispersion of said fine particles a second hydrophobic organic solvent (b) having a metal alkoxide dissolved therein thereby forming on the surface of said fine particles a dense layer of extremely fine particles of a metal oxide as the metal alkoxide is hydrolyzed by the surface water on the fine particles.
Claim 3
Dependent Claim
30 words
The method according to claim 1, wherein said hydrophobic organic solvents (a) and (b) are one member selected from the group consisting of benzene, toluene, xylene, kerosene, hexane and ligroin.
Claim 4
Dependent Claim
26 words
The method according to claim 1, wherein said hydrophobic organic solvents (a) and (b) are one member selected from the group consisting of hexane and ligroin.
Claim 5
Dependent Claim
25 words
The method according to claim 1, wherein said fine particles are formed of one member selected from the group consisting of alumina and zinc oxide.
Claim 6
Dependent Claim
47 words
The method according to claim 1, wherein said fine particles possess a BET specific surface area in the range of from 5 to 15 m 2 /g and adsorb water in an amount in the range of 0.1 to 30 mg per m 2 of surface area.
Claim 7
Dependent Claim
23 words
The method according to claim 1, wherein said alcohol is one member selected from the group consisting of ethanol, i-propanol, n-propanol, and n-butanol.
Claim 8
Dependent Claim
40 words
The method according to claim 1, wherein the amount of a metal alkoxide dissolved in said hydrophobic organic solvent (b) is in the range of 0.5 to 20 wt % based on the amount of said hydrophobic organic solvent (b).
Claim 9
Dependent Claim
45 words
The method according to claim 1, wherein the ratio of the amount of the hydrophobic organic solvent (a) having alcohol dissolved therein to the amount of the hydrophobic organic solvent (b) having the metal alkoxide dissolved therein is in the range of 20:1 to 1:1.
Claim 10
Dependent Claim
30 words
The method according to claim 1, wherein said second hydrophobic organic solvent has added thereto 0.005 to 0.05 mol of an amine per liter of said second hydrophobic organic solvent.
Claim 11
Dependent Claim
27 words
The method according to claim 9, wherein said amine is at least one member selected from the group consisting of n-hexyl amine, didecyl amine, and tri-n-octyl amine.
Claim 12
Dependent Claim
53 words
The method according to claim 7, wherein said metal alkoxide is a member selected from the group consisting of silicon methoxide and silicon ethoxide and is dissolved in said second hydrophobic organic solvent in an amount of from 5 to 20 wt. % based on the amount of said second hydrophobic organic solvent.
Claim 13
Dependent Claim
57 words
The method according to claim 7, wherein said metal alkoxide is a member selected from the group consisting of titanium ethoxide, titanium isopropoxide, titanium butoxide and zirconium propoxide and is dissolved in said second hydrophobic organic solvent in an amount ranging from 0.5 to 10 wt. % based on the amount of said second hydrophobic organic solvent.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1995-09-08 | 1996-03-09 | 1996-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-08 | 2000-03-09 | 2000-09-08 | $3760.00 | Window Closed / Lapsed |
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