Patent US2145463A successfully refreshed from Google Patents.
US4150101A
Expired / Lapsed
US
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Process for the production of silica with an aerogel type structure
Assignee: Evonik Operations GmbH
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Filing: 1975-03-14
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Granted: 1979-04-17
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Expires: 1995-03-14
Abstract
Abstract Aerogel like silica is prepared having: A BET surface area between 80-450 m 2 /g; A bulk density between 10-60 g/l; A DBP number between 2.4-3.8; An average particle size range of 0.1-7 μm; A most frequent particle size range of 1-2 μm; A pH value in a 4% aqueous suspension of 6-8. The aerogel is produced by homogeneously distributing 5-50 weight % of water in air dispersed pyrogenic silica and drying the powdery mixture obtained. The products are especially useful as delustering agents.
Inventors
- 👤 Felix Schmidt
- 👤 Kurt Spitznagel
- 👤 Adolf Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:01
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/309; C09C3/00; C09C3/04; C09C3/041; C09C3/043; C09C3/06; C09C3/08; C09D; C09D7/00; C09D7/40; C09D7/42; C01; C01P; C01P2006/00; C01P2006/12; C01P2006/19
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
32 words
A process for the production of an aerogel-like structured silica comprising uniformly working 5 to 50 weight % of water into an air dispersed pyrogenic silica and drying the powdery mixture produced.
Claim 2
Dependent Claim
32 words
A process for the production of an aerogel-like structured silica comprising uniformly working 5 to 50 weight % of water into an air dispersed pyrogenic silica and drying the powdery mixture produced.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein there is employed silica having a bulk density of 10-60 g/l.
Claim 4
Dependent Claim
12 words
The process of claim 2 wherein the bulk density is 15-30 g/l.
Claim 5
Dependent Claim
13 words
The process of claim 3 wherein the bulk density is about 20 g/l.
Claim 6
Dependent Claim
21 words
The process of claim 2 wherein the silica employed has a BET surface area between 100 and 480 m 2 /g.
Claim 7
Dependent Claim
28 words
The process of claim 5 wherein the silica employed has a BET surface area between 250 and 300 m 2 /g and a bulk density of 15-30 g/l.
Claim 8
Dependent Claim
17 words
The process of claim 6 wherein there is worked in 7 to 15 weight % of water.
Claim 9
Dependent Claim
17 words
The process of claim 2 wherein there is worked in 5 to 20 weight % of water.
Claim 10
Dependent Claim
12 words
The process of claim 2 wherein the water contains a basic compound.
Claim 11
Dependent Claim
21 words
The process of claim 9 wherein the basic compound is ammonia, sodium hydroxide, potassium hydroxide, a water soluble amine or waterglass.
Claim 12
Dependent Claim
13 words
The process of claim 9 wherein the water has a pH of 7-14.
Claim 13
Dependent Claim
13 words
The process of claim 11 wherein the water has a pH of 8-12.
Claim 14
Dependent Claim
13 words
The process of claim 12 wherein the water has a pH of 10-11.
Claim 15
Dependent Claim
31 words
The process of claim 2 comprising obtaining uniform distribution of the water in the silica by injecting the water into agitated silica at a silica temperature of 20° to 100° C.
Claim 16
Dependent Claim
13 words
The process of claim 14 wherein the temperature is 40° to 70° C.
Claim 17
Dependent Claim
11 words
The process of claim 15 wherein the temperature is 50°-60° C.
Claim 18
Dependent Claim
17 words
The process of claim 14 comprising spraying the water into a fluidized flowing mass of the silica.
Claim 19
Dependent Claim
20 words
The process of claim 2 wherein the water which is worked in has a temperature between 20° and 100° C.
Claim 20
Dependent Claim
18 words
The process of claim 18 wherein the water which is worked in has a temperature of 50°-100° C.
Claim 21
Dependent Claim
18 words
The process of claim 18 wherein the water which is worked in has a temperature of 9°-100° C.
Claim 22
Dependent Claim
33 words
The process of claim 18 wherein the water laden silica is steamed before drying in a closed vessel for 5 to 60 minutes at a temperature up to the boiling point of water.
Claim 23
Dependent Claim
15 words
The process of claim 21 wherein the steaming is at a temperature of 50°-80° C.
Claim 24
Dependent Claim
14 words
The process of claim 22 wherein the steaming is carried out for 10-30 minutes.
Claim 25
Dependent Claim
19 words
The process of claim 23 wherein the steaming is carried out at about 60° C. for about 20 minutes.
Claim 26
Dependent Claim
12 words
The process of claim 2 wherein the water laden silica is ground.
Claim 27
Dependent Claim
15 words
The process of claim 25 comprising after the grinding step drying the water laden silica.
Claim 28
Dependent Claim
14 words
The process of claim 25 comprising simultaneously grinding and drying the water laden silica.
Claim 29
Dependent Claim
32 words
The process of claim 2 wherein there is added free silica produced by acidification or ion exchange of alkali silicate solution or the hydrolytic splitting of tetramethyl silicate or sodium methyl siliconate.
References Cited (Backward Citations)
CA790489A
Cited
DE1075573B
Cited
US3103495A
Cited
US2249767A
Cited
GB684016A
Cited
US3580844A
Cited
US2731326A
Cited
US2856268A
Cited
US2990249A
Cited
GB1058618A
Cited
US3379546A
Cited
US3393155A
Cited
US3455717A
Cited
US3472459A
Cited
GB1152051A
Cited
GB1184094A
Cited
US3484368A
Cited
US3652215A
Cited
US3632352A
Cited
FR2134510B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-16 | 1982-10-16 | 1983-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-16 | 1986-10-16 | 1987-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-16 | 1990-10-16 | 1991-04-17 | $7700.00 | Window Closed / Lapsed |