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Magnetizable composite microspheres of hydrophobic crosslinked polymer, process for preparing them and their application in biology
Assignee: Rhodia Chimie SAS
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Filing: 1993-06-01
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Granted: 1994-10-18
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Expires: 2013-06-01
Abstract
Abstract Magnetizable composite microspheres approximately from 0.05 to 10 mu m in diameter, comprising a core of magnetizable particles and a shell of a hydrophobic crosslinked copolymer formed from a vinylaromatic monomer and a crosslinking emulsifying polymer. The microspheres are obtained by the pre-emulsification in water of a magnetic fluid composed of magnetizable particles dispersed in a vinylaromatic monomer and in a crosslinking emulsifying polymer, polymerization, separation of the magnetizable microspheres and optional redispersion in water. The microspheres are useful in biological applications.
Inventors
- 👤 Dominique Charmot
- 👤 Christine Vidil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:52
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; G01N33/54326; G01N33/5434; C; C08; C08F; C08F292/00; C08K; C08K9/00; C08K9/10; G01N2446/00; G01N2446/20; G01N2446/30; G01N2446/60; G01N2446/64; G01N2446/66; G01N2446/80; G01N2446/84; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
102 words
Magnetizable composite microspheres of hydrophobic crosslinked vinylaromatic polymer which are approximately from 0.05 to 10 μm in diameter, and which comprise: (1) a core comprising magnetizable particles less than 300×10 -4 μm in diameter coated with an approximately mono molecular layer of a non-water-soluble dispersing agent; and (2) a shell consisting essentially of a hydrophobic crosslinked copolymer formed from at least one hydrophobic vinylaromatic monomer and at least one polyethylenically unsaturated emulsifying polymer which is soluble in said vinylaromatic monomer(s) and capable of crosslinking with said vinylaromatic monomer(s), wherein said shell is substantially free from said magnetic particles relative to said core.
Claim 2
Dependent Claim
102 words
Magnetizable composite microspheres of hydrophobic crosslinked vinylaromatic polymer which are approximately from 0.05 to 10 μm in diameter, and which comprise: (1) a core comprising magnetizable particles less than 300×10 -4 μm in diameter coated with an approximately mono molecular layer of a non-water-soluble dispersing agent; and (2) a shell consisting essentially of a hydrophobic crosslinked copolymer formed from at least one hydrophobic vinylaromatic monomer and at least one polyethylenically unsaturated emulsifying polymer which is soluble in said vinylaromatic monomer(s) and capable of crosslinking with said vinylaromatic monomer(s), wherein said shell is substantially free from said magnetic particles relative to said core.
Claim 3
Dependent Claim
28 words
The microspheres of claim 1, wherein the weight of magnetizable particles forming the core represents approximately from 0.5 to 70% of the weight of said magnetizable composite microspheres.
Claim 4
Dependent Claim
15 words
The microspheres of claim 1, wherein said magnetizable particles are of magnetite or of haematite.
Claim 5
Dependent Claim
37 words
The microspheres of claim 1, wherein said crosslinking emulsifying polymer is a polyester of alkylene glycol and unsaturated aliphatic diacid, aromatic diacid or a mixture thereof having a weight average molecular mass approximately from 500 to 10,000.
Claim 6
Dependent Claim
23 words
The microspheres of claim 1, wherein said crosslinking emulsifying polymer represents approximately from 3 to 15% of the weight of hydrophobic vinylaromatic monomer.
Claim 7
Dependent Claim
9 words
An aqueous dispersion comprising the microspheres of claim 1.
Claim 8
Dependent Claim
27 words
The aqueous dispersion of claim 6, wherein the weight of dispersed magnetizable microspheres corresponds to approximately from 10 to 70% of the total weight of said dispersion.
Claim 9
Dependent Claim
17 words
The microspheres of claim 1, wherein said microspheres are approximately from 0.10 to 5 μm in diameter.
Claim 10
Dependent Claim
20 words
The microspheres of claim 1, wherein the magnetizable particles are approximately from 50×10 -4 to 200×10 -4 μm in diameter.
References Cited (Backward Citations)
US3228881A
Cited
US3714102A
Cited
US3843540A
Cited
US4339337A
Cited
US4358388A
Cited
US4421660A
Cited
US4454234A
Cited
US4695392A
Cited
US4680200A
Cited
US4948739A
Cited
JPS63305149A
Cited
US5034145A
Cited
US4985166A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-17 | 1998-04-18 | 1998-10-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-17 | 2002-04-18 | 2002-10-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-17 | 2006-04-18 | 2006-10-18 | $7700.00 | Window Closed / Lapsed |