Patent US4624800A successfully refreshed from Google Patents.
US4624800A
Expired / Lapsed
US
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Method for producing aqueous, low-alkali metal, low-alumina silica sols
Assignee: Mitsubishi Chemical Corp
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Filing: 1984-12-10
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Granted: 1986-11-25
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Expires: 2004-12-10
Abstract
Abstract A method for producing an aqueous silica sol is described, comprising admixing a fine silica powder having an ultimate particle size of 5 to 200 millimicrons with an aqueous medium at a pH not higher than 5 while applying ultrasonic vibrations having a frequency within the range of from 10 to 100 kilohertz to the aqueous medium to thereby disperse said silica powder in said aqueous medium and thus convert the mixture into an aqueous sol.
Inventors
- 👤 Yutaka Sasaki
- 👤 Toshio Nakamura
- 👤 Hiroshi Murata
- 👤 Yoshimi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:03
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/141; B; B01; B01J; B01J37/00; B01J37/34; B01J37/341; B01J37/343; B01J21/00; B01J21/06; B01J21/08; C01B33/1415
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
96 words
A method for producing an aqueous silica sol, comprising admixing a fine silica powder having an ultimate particle size of from 5 to 200 millimicrons, a content of sodium of not more than 500 ppm and a content of alumina of not more than 1000 ppm with an aqueous medium at a pH not higher than 5 while applying ultrasonic vibrations having a frequency within the range of from 10 to 100 kilohertz to the aqueous medium to thereby disperse said silica powder in said aqueous medium and thus convert the mixture into an aqueous sol.
Claim 2
Independent Claim
96 words
A method for producing an aqueous silica sol, comprising admixing a fine silica powder having an ultimate particle size of from 5 to 200 millimicrons, a content of sodium of not more than 500 ppm and a content of alumina of not more than 1000 ppm with an aqueous medium at a pH not higher than 5 while applying ultrasonic vibrations having a frequency within the range of from 10 to 100 kilohertz to the aqueous medium to thereby disperse said silica powder in said aqueous medium and thus convert the mixture into an aqueous sol.
Claim 3
Dependent Claim
22 words
A method as in claim 1, wherein the ultrasonic wave has a frequency within the range of from 15 to 50 kilohertz.
Claim 4
Dependent Claim
22 words
A method as in claim 2, wherein the concentration of silica in the silica sol formed is at least 15% by weight.
Claim 5
Dependent Claim
36 words
A method as in claim 2, wherein the content of sodium in the silica powder is not more than 1 ppm and the content of alumina in the silica powder is not more than 10 ppm.
Claim 6
Dependent Claim
22 words
A method as in claim 4, wherein the concentration of silica in the silica sol formed is at least 15% by weight.
Claim 7
Dependent Claim
44 words
A method as in claim 4, wherein following conversion of the silica powder to an aqueous sol, said silica sol is adjusted to a pH of not less than 7 by addition of aqueous ammonia or an organic amine to thereby stablize the sol.
Claim 8
Dependent Claim
44 words
A method as in claim 2, wherein following conversion of the silica powder to an aqueous sol, said silica sol is adjusted to a pH of not less than 7 by addition of aqueous ammonia or an organic amine to thereby stabilize the sol.
Claim 9
Dependent Claim
21 words
A method as in claim 1, wherein the content of sodium in the silica powder is not more than 1 ppm.
Claim 10
Dependent Claim
21 words
A method as in claim 8, wherein the content of alumina in the silica powder is not more than 10 ppm.
Claim 11
Dependent Claim
22 words
A method as in claim 9, wherein the concentration of silica in the silica sol formed is at least 15% by weight.
Claim 12
Dependent Claim
44 words
A method as in claim 9, wherein following conversion of the silica powder to an aqueous sol, said silica sol is adjusted to a pH of not less than 7 by addition of aqueous ammonia or an organic amine to thereby stabilize the sol.
Claim 13
Dependent Claim
21 words
A method as in claim 1, wherein the content of alumina in the silica powder is not more than 10 ppm.
Claim 14
Dependent Claim
22 words
A method as in claim 1, wherein the concentration of silica in the silica sol formed is at least 15% by weight.
Claim 15
Dependent Claim
44 words
A method as in claim 1, wherein following conversion of the silica powder to an aqueous sol, said silica sol is adjusted to a pH of not less than 7 by addition of aqueous ammonia or an organic amine to thereby stabilize the sol.
Claim 16
Dependent Claim
37 words
A method as in claim 1, wherein the ultimate particle size of silica particles occurring in the silica sol formed is substantially equal to the ultimate particle size of the silica powder used as the starting material.
Claim 17
Dependent Claim
45 words
A method as in claim 1, wherein the silica powder is a product of (a) oxidative decomposition of ethyl silicate, (b) hydrolysis of silicon tetrachloride, (c) co-combustion of silicon tetrachloride and a combustible gas, or (d) pyrolysis or oxidative degradation of an organic silicon compound.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-11-24 | 1990-05-26 | 1990-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-11-24 | 1994-05-26 | 1994-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-11-24 | 1998-05-26 | 1998-11-25 | $7700.00 | Window Closed / Lapsed |