US4255286A
Expired / Lapsed
US
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Process of preparing spherical microparticles
Assignee: Urad Predsednictva Slovenskej Akademie
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Filing: 1978-09-25
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Granted: 1981-03-10
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Expires: 1998-09-25
Abstract
Abstract A process of preparing spherical microparticles having size of from 0.5 to 1000 μm and designed as chromatographic column charge, catalyst vehicle and absorption filling, or the like, by polymerizing a monomeric or polymeric substance in a macromolecular dispersing medium, the polymer forming said medium being different from that arising in polymerization process.
Inventors
- 👤 Dusan Berek
- 👤 Ivan Novak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:55
CPC Classifications
C; C08; C08F; C08F291/00; Y; Y10; Y10S; Y10S516/00; Y10S516/922; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
51 words
A process for preparing spherical microparticles of silica gel having a size varying from 0.5 to 1000 μm in diameter, comprising dispersing a water glass solution into macromolecular polydimethylsiloxane, subjecting said water glass to controlled polymerization under static conditions to form said spherical microparticles and recovering said silica gel spherical microparticles.
Claim 2
Dependent Claim
51 words
A process for preparing spherical microparticles of silica gel having a size varying from 0.5 to 1000 μm in diameter, comprising dispersing a water glass solution into macromolecular polydimethylsiloxane, subjecting said water glass to controlled polymerization under static conditions to form said spherical microparticles and recovering said silica gel spherical microparticles.
Claim 3
Dependent Claim
16 words
The process according to claim 1 wherein said polydimethylsiloxane has an average molecular weight of 1000.
References Cited (Backward Citations)
US3489516A
Cited
US4104363A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |