Patent US4250881A successfully refreshed from Google Patents.
US4595578A
Expired / Lapsed
US
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Stabilized silica gel and process for making same
Assignee: SCM Glidco Organics Corp
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Filing: 1985-03-22
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Granted: 1986-06-17
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Expires: 2005-03-22
Abstract
Abstract There is provided an improved process for producing a silica gel having improved pore volume relative to conventional silica gels which comprises the steps of gelling an aqueous alkali metal silicate with an aqueous acid, washing the resulting gel to remove salt or salts and acid, and soaking the gel in an aqueous solution of a water soluble aluminum salt to impart from 0.1% to 0.7% by weight aluminum on the dry basis to said gel, drying and reducing the particle size of the dried gel to from 2.0 to 15 microns, said particles having a pore volume in the range of 1.25 to 2.25 cm 3 /gram. and a product produced by said process.
Inventors
- 👤 Howard J. Cohen
- 👤 Peter VAN DER Heem
- 👤 Steven J. Fitch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:36
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/152; C01B33/154
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
117 words
A process for producing a silica gel having improved pore volume relative to conventional silica gels which process comprises the steps of gelling an aqueous alkali metal silicate with an aqueous acid, washing the resulting gel to remove salt or salts and acid, aging said gel for 3 to 36 hours with aqueous ammonia solution and soaking the gel in an aqueous solution of a water soluble aluminum salt to impart from 0.1 to 0.7% by weight aluminum on the dry basis to said gel, drying and reducing the particle size of the dried gel to from 2.0 to 15 microns, said particles having a pore volume in the range of 1.25 to 2.25 cm 3 /gram.
Claim 2
Dependent Claim
117 words
A process for producing a silica gel having improved pore volume relative to conventional silica gels which process comprises the steps of gelling an aqueous alkali metal silicate with an aqueous acid, washing the resulting gel to remove salt or salts and acid, aging said gel for 3 to 36 hours with aqueous ammonia solution and soaking the gel in an aqueous solution of a water soluble aluminum salt to impart from 0.1 to 0.7% by weight aluminum on the dry basis to said gel, drying and reducing the particle size of the dried gel to from 2.0 to 15 microns, said particles having a pore volume in the range of 1.25 to 2.25 cm 3 /gram.
Claim 3
Dependent Claim
9 words
A product produced by the process of claim 1.
Claim 4
Dependent Claim
15 words
A process as defined in claim 1 wherein the alkali metal silicate is sodium silicate.
Claim 5
Dependent Claim
19 words
A process as defined in claim 1 wherein the aqueous acid is a water solution of a mineral acid.
Claim 6
Dependent Claim
14 words
A process as defined in claim 4 wherein the mineral acid is hydrochloric acid.
Claim 7
Dependent Claim
14 words
A process as defined in claim 4 wherein the mineral acid is sulphuric acid.
Claim 8
Dependent Claim
13 words
A process as defined in claim 6 wherein the acid is 35° Baume.
Claim 9
Dependent Claim
14 words
A process as defined in claim 1 wherein the aluminum salt is aluminum nitrate.
Claim 10
Dependent Claim
28 words
A process as defined in claim 1 wherein the gel is soaked in the aqueous solution of aluminum salt for a period of at least about 2 hours.
Claim 11
Dependent Claim
15 words
A process as defined in claim 9 wherein the aluminum salt is aluminum nitrate nonahydrate.
Claim 12
Dependent Claim
15 words
A process as defined in claim 10 wherein the aluminum salt is aluminum sulfate dodecahydrate.
Claim 13
Dependent Claim
15 words
A process as defined in claim 1 wherein the silica gel is a silica hydrogel.
Claim 14
Dependent Claim
15 words
A process as defined in claim 1 wherein the silica gel is a silica aerogel.
Claim 15
Dependent Claim
21 words
A process as defined in claim 1 wherein the temperature of drying the aluminum salt treated gel is from 200°-600° C.
Claim 16
Dependent Claim
21 words
A process as defined in claim 14 wherein the temperature of drying the aluminum salt treated gel is from 500°-600° C.
Claim 17
Dependent Claim
18 words
A process as defined in claim 1 wherein drying the milling occur simultaneously in a fluid energy mill.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |