US3953487A
Expired / Lapsed
US
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Process for preparing hydrophobic silicon dioxide
Assignee: Elektroschmelzwerk Kempten GmbH
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Filing: 1974-08-23
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Granted: 1976-04-27
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Expires: 1994-08-23
Abstract
Abstract Process for preparing hydrophobic SiO 2 by reacting solid SiO 2 of finest particle size with organosilicon compounds while subjecting the reaction mixture to a mechanical impact treatment which will at the same time result in a comminution of the SiO 2 particles as well as of their aggregates, said process comprising incorporation to the reaction mixture, in addition to the water adsorbed by the SiO 2 , an amount of 0.3 to 3% by weight of water calculated on the weight of the SiO 2 .
Inventors
- 👤 Gunther Kratel
- 👤 Gunter Stohr
- 👤 Georg Vogt
- 👤 Hans Kaiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:17
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/103; C; C08; C08K; C08K3/00; C08K3/34; C08K3/36; C09; C09C; C09C1/00; C09C1/28; C09C1/30; C09C1/309; C09C3/00; C09C3/04; C09C3/041; C09C3/12; C01; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
A process for preparing hydrophobic SiO 2 which comprises the steps of: a. reacting solid SiO 2 of finest particle size with an organosilicon compound having the general formula (R.sub.3 Si).sub.a Z wherein R represents the same or different monovalent hydrocarbon radicals, Z represents a member of the group consisting of halogen, hydrogen and a radical of the formula --OH, --OR', --NR'X, --ONR' 2 , --SR', --OOCR', --O--, --N(X)--, and --S--, wherein R' is alkyl with 1 to 4 carbon atoms, X is hydrogen or the same radicals as R, and a is an integer from 1 to 2, while subjecting the reaction mixture to a mechanical impact treatment which will at the same time result in a comminution of the SiO 2 particles as well as of aggregates of the same, whereby the SiO 2 contains organosilicon groups bonded to it after the reaction; b. while incorporating into the reaction mixture, in addition to the water adsorbed to the SiO 2 , an amount of from 0.3% to 3% by weight of water, calculated on the weight of the SiO 2 .
Claim 2
Dependent Claim
183 words
A process for preparing hydrophobic SiO 2 which comprises the steps of: a. reacting solid SiO 2 of finest particle size with an organosilicon compound having the general formula (R.sub.3 Si).sub.a Z wherein R represents the same or different monovalent hydrocarbon radicals, Z represents a member of the group consisting of halogen, hydrogen and a radical of the formula --OH, --OR', --NR'X, --ONR' 2 , --SR', --OOCR', --O--, --N(X)--, and --S--, wherein R' is alkyl with 1 to 4 carbon atoms, X is hydrogen or the same radicals as R, and a is an integer from 1 to 2, while subjecting the reaction mixture to a mechanical impact treatment which will at the same time result in a comminution of the SiO 2 particles as well as of aggregates of the same, whereby the SiO 2 contains organosilicon groups bonded to it after the reaction; b. while incorporating into the reaction mixture, in addition to the water adsorbed to the SiO 2 , an amount of from 0.3% to 3% by weight of water, calculated on the weight of the SiO 2 .
Claim 3
Dependent Claim
45 words
The process according to claim 1, wherein in case of an increase in bulk weight having occurred during the comminution of the SiO 2 particles, mechanical impact is brought to bear on the SiO 2 reacted with the organosilicon compound for decreasing said bulk weight.
Claim 4
Dependent Claim
15 words
The process according to claim 1, wherein condensation catalysts are present during the impact treatment.
Claim 5
Dependent Claim
13 words
The process according to claim 3, wherein HCl is used as condensation catalyst.
Claim 6
Dependent Claim
13 words
The process according to claim 3, wherein amines are used as condensation catalysts.
References Cited (Backward Citations)
US2802850A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |