US4983369A
Expired / Lapsed
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Process for forming highly uniform silica spheres
Assignee: Honeywell International Inc
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Filing: 1989-11-22
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Granted: 1991-01-08
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Expires: 2009-11-22
Abstract
Abstract A process for producing highly uniform microspheres of silica having an average diameter of 0.1-10 μm from the hydrolysis of a silica precursor, such as tetraalkoxysilanes, which is characterized by employing precursor solutions and feed rates which initially yield a two-phase reaction mixture.
Inventors
- 👤 Timothy J. Barder
- 👤 Philip D. DuBois
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:59
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01P; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/30; C01P2004/32; C01P2004/51; C01P2004/52; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/10; C01P2006/12
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
80 words
A process for producing microspheres of silica having a uniform size between 0.1 and 10 μm diameter comprising: (a) combining a hydrolyzable silica precursor, an alcohol, ammonia, and water in proportions such that two liquid phases would form and wherein the combined composition is 20-50 wt.% hydrolyzable silica precursor, 5-30 wt.% alkanol, 40-70 wt.% water and 5-10 wt.% ammonia, (b) forming microspheres by hydrolysis of said silica precursor in the mixture of (a), (c) recovering the microspheres formed in (b).
Claim 2
Dependent Claim
80 words
A process for producing microspheres of silica having a uniform size between 0.1 and 10 μm diameter comprising: (a) combining a hydrolyzable silica precursor, an alcohol, ammonia, and water in proportions such that two liquid phases would form and wherein the combined composition is 20-50 wt.% hydrolyzable silica precursor, 5-30 wt.% alkanol, 40-70 wt.% water and 5-10 wt.% ammonia, (b) forming microspheres by hydrolysis of said silica precursor in the mixture of (a), (c) recovering the microspheres formed in (b).
Claim 3
Dependent Claim
34 words
The process of claim 1 wherein said hydrolyzable silica precursor, optionally combined with an alcohol forms a first precursor solution and said ammonia and water, optionally containing an alcohol forms a second precursor solution.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein the hydrolyzable silica precursor is at least one member of the group consisting of tetralkoxysilanes and alkylalkoxysilanes.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein the hydrolyzable silica precursor is tetraalkoxysilane.
Claim 6
Dependent Claim
10 words
The process of claim 4 wherein the tetralkoxysilane is tetraethoxysilane.
Claim 7
Dependent Claim
24 words
The process of claim 1 wherein said alcohol is at least one member of the group consisting of methanol, ethanol, propanols, butanols, and pentanols.
Claim 8
Dependent Claim
10 words
The process of claim 6 wherein said alcohol is ethanol.
Claim 9
Dependent Claim
26 words
The process of claim 1 wherein said hydrolyzable silica precursor is tetralkoxysilane and said alkanol is the same as that produced by hydrolysis of said tetraalkoxysilane.
Claim 10
Dependent Claim
15 words
The process of claim 8 wherein said tetraalkoxysilane is tetraethoxysilane and said alkanol is ethanol.
Claim 11
Dependent Claim
19 words
The process of claim 1 wherein the process is carried out at a temperature of about 10°C. to 50°C.
Claim 12
Dependent Claim
98 words
The process for producing microspheres of silica having a uniform size between 0.1 and 10 μm diameter comprising: (a) preparing a dispersion of silica spheres in water, optionally containing ammonia and/or an alkanol, (b) adding to said dispersion of (a) a hydrolyzable silica precursor, an alcohol, ammonia, and water in proportions such that two liquid phases form and wherein the combined composition is 20-50 wt.% hydrolyzable silica precursor, 5-30 wt.% alkanol, 40-70 wt.% water and 5-10 wt.% ammonia, (c) growing the silica spheres of (a) by hydrolysis of said silica precursor, (d) recovering the microspheres grown in (c).
Claim 13
Dependent Claim
98 words
The process for producing microspheres of silica having a uniform size between 0.1 and 10 μm diameter comprising: (a) preparing a dispersion of silica spheres in water, optionally containing ammonia and/or an alkanol, (b) adding to said dispersion of (a) a hydrolyzable silica precursor, an alcohol, ammonia, and water in proportions such that two liquid phases form and wherein the combined composition is 20-50 wt.% hydrolyzable silica precursor, 5-30 wt.% alkanol, 40-70 wt.% water and 5-10 wt.% ammonia, (c) growing the silica spheres of (a) by hydrolysis of said silica precursor, (d) recovering the microspheres grown in (c).
Claim 14
Dependent Claim
34 words
The process of claim 11 wherein said hydrolyzable silica precursor, optionally combined with an alcohol forms a first precursor solution and said ammonia and water, optionally containing an alcohol forms a second precursor solution.
Claim 15
Dependent Claim
23 words
The process of claim 11 wherein the hydrolyzable silica precursor is at least one member of the group consisting of tetralkoxysilanes and alkylalkoxysilanes.
Claim 16
Dependent Claim
12 words
The process of claim 13 wherein the hydrolyzable silica precursor is tetraalkoxysilane.
Claim 17
Dependent Claim
10 words
The process of claim 14 wherein the tetralkoxysilane is tetraethoxysilane.
Claim 18
Dependent Claim
24 words
The process of claim 11 wherein said alcohol is at least one member of the group consisting of methanol, ethanol, propanols, butanols, and pentanols.
Claim 19
Dependent Claim
10 words
The process of claim 16 wherein said alcohol is ethanol.
Claim 20
Dependent Claim
26 words
The process of claim 11 wherein said hydrolyzable silica precursor is tetraalkoxysilane and said alkanol is the same as that produced by hydrolysis of said tetraalkoxysilane.
Claim 21
Dependent Claim
15 words
The process of claim 19 wherein said tetraalkoxysilane is tetraethoxysilane and said alkanol is ethanol.
Claim 22
Dependent Claim
21 words
The process of claim 11 wherein the process is carried out at a temperature of about 10° C. to 50° C.
Claim 23
Dependent Claim
29 words
The process of claim 1 wherein the combined composition of (a) is 25-35 wt. % hydrolyzable silica precursor 5-10 wt.% alkanol 50-60 wt. % water and 5-10 wt.% ammonia.
Claim 24
Dependent Claim
27 words
The process of claim 11 wherein the combined composition of (b) is 25-35 wt.% hydrolyzable silica precursor 5-10 wt.% alkanol 50-60 wt.% water and 5-10 wt.% ammonia.
References Cited (Backward Citations)
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-01-07 | 1994-07-09 | 1995-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-01-07 | 1998-07-09 | 1999-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-01-07 | 2002-07-09 | 2003-01-08 | $7700.00 | Window Closed / Lapsed |