US3580519A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for hindering the agglomeration or reagglomeration of ground finely divided powdered substances
Assignee: Evonik Operations GmbH
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Filing: 1968-03-25
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Granted: 1971-05-25
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Expires: 1988-03-25
Abstract
Abstract Process for protecting ground finely divided powdered substances against agglomeration or reagglomeration wherein the substance to be protected is finely ground together with a finely divided hydrophobic silica or wherein a mixture of finely divided hydrophobic silica and finely divided hydrophilic silica is added to the substance to be protected already in finely ground state and intensively mixed therewith in a mill having a grinding action.
Inventors
- 👤 Kurt Klein
- 👤 Gerd Lumbeck
- 👤 Joachim Maluzi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:23
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/26; A; A23; A23K; A23K20/00; A23K20/20; A23K20/28; A23P; A23P10/00; A23P10/40; A23P10/43; A61; A61K; A61K47/00; A61K47/02; B; B01; B01J; B01J2/00; B01J2/30; C01B17/00; C01B17/02; C01B17/10; C01F; C01F5/00; C01F5/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
42 words
The method of claim 1 in which said hydrophobized silica is a silica which has been hydrophobized by treatment with an organic halogen silane and has a carbon content of 0.9 to 2.8 percent, a BET surface area of about 100-150 m.2/g.
Claim 2
Dependent Claim
66 words
The method of claim 1 in which the finely divided powdered substance to be protected is magnesium oxide and such magnesium oxide is admixed in finely divided powdered state with about 8-10 wt. percent of a mixture of 5-9 wt. parts of the hydrophobized silica and 5-1 wt. parts of the hydrophilic silica and such admixture is intimately mixed in a mill having a grinding action.
References Cited (Backward Citations)
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Cited
US3133792A
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US1909557A
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US2591988A
Cited
US2728732A
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US2882254A
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US3333776A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |