Patent US5314923A successfully refreshed from Google Patents.
US5314923A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous polymer beads and process
Assignee: Cytec Technology Corp
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Filing: 1991-08-29
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Granted: 1994-05-24
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Expires: 2011-08-29
Abstract
Abstract Isotropic porous polymer beads having a high surface porosity and large pore diameters from about 0.002 to about 5 microns are produced from solutions of a polymer or a copolymer by a thermally-induced phase separation process. The use of mixed solvent-non-solvent combinations as solvents for the polymers, produces high pore content, substantially spherical beads having a morphology ideally suited to the chromatography of large molecules, such as proteins, and for enzyme-binding.
Inventors
- 👤 Michael T. Cooke
- 👤 Laura J. Hiscock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:36
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01J20/26; C; C08; C08J; C08J3/00; C08J3/12; C08J9/00; C08J9/28; C08J2201/00; C08J2201/04; C08J2201/052; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/31
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
145 words
A process for the preparation of isotropic polymer beads, said process comprising: (i) heating and mixing a polymer or copolymer selected from the group consisting of vinyl addition polymers, condensation polymers and oxidation polymers which are soluble in a liquid medium and form rigid structures at the temperatures at which said beads will be used with a mixture comprising an organic or inorganic liquid solvent capable of dissolving said polymer or copolymer without permanent chemical transformation and a liquid non-solvent which is immiscible with said polymer or copolymer to form a homogeneous solution: (ii) breaking said homogenous solution into droplets; (iii) cooling said droplets, optionally in the presence of an inert liquid, to bring about phase separation and solidification of the polyerm or copolymer in the droplets; and (iv) separating the droplets from any inert liquid and the solvent-non-solvent mixture to produce isotropic porous beads.
Claim 2
Dependent Claim
145 words
A process for the preparation of isotropic polymer beads, said process comprising: (i) heating and mixing a polymer or copolymer selected from the group consisting of vinyl addition polymers, condensation polymers and oxidation polymers which are soluble in a liquid medium and form rigid structures at the temperatures at which said beads will be used with a mixture comprising an organic or inorganic liquid solvent capable of dissolving said polymer or copolymer without permanent chemical transformation and a liquid non-solvent which is immiscible with said polymer or copolymer to form a homogeneous solution: (ii) breaking said homogenous solution into droplets; (iii) cooling said droplets, optionally in the presence of an inert liquid, to bring about phase separation and solidification of the polyerm or copolymer in the droplets; and (iv) separating the droplets from any inert liquid and the solvent-non-solvent mixture to produce isotropic porous beads.
Claim 3
Dependent Claim
41 words
A process as defined in claim 1 wherein said solvent is dimethyl sulfone, the non-solvent is urea, water, propylene glycol, ethylene glycol or a mixture thereof and step (i) is carried out at a temperature of at least about 130° C.
Claim 4
Dependent Claim
19 words
A process as defined in claim 1 wherein the inert liquid is mineral oil, heptane or a mixture thereof.
Claim 5
Dependent Claim
24 words
A process as defined in claim 2 wherein the beads are extracted with acetone, methanol, water or a mixture of any of the foregoing.
Claim 6
Dependent Claim
16 words
A process as defined in claim 1 wherein said polymer is polymerized methyl methacrylate or polysulfone.
Claim 7
Dependent Claim
22 words
A process as defined in claim 1 wherein said homogeneous solution contains less then about 10 weight percent of polymer or copolymer.
Claim 8
Dependent Claim
14 words
A process as defined in claim 1 or 6 wherein the polymer is polyacrylonitrile.
Claim 9
Dependent Claim
15 words
A process as defined in claim 1 wherein said isotropic porous polymer beads are skinless.
Claim 10
Dependent Claim
34 words
A process as defined in claim 1 wherein the homogeneous solution of step (i) contains less than about 10 weight percent total polymer or copolymer solids and the isotropic porous polymer beads are skinless.
Claim 11
Dependent Claim
8 words
The product of the process of claim 1.
Claim 12
Dependent Claim
8 words
The product of the process of claim 6.
Claim 13
Dependent Claim
8 words
The product of the process of claim 7.
Claim 14
Dependent Claim
8 words
The product of the process of claim 8.
Claim 15
Dependent Claim
8 words
The product of the process of claim 9.
References Cited (Backward Citations)
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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) | 1997-05-23 | 1997-11-22 | 1998-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-23 | 2001-11-22 | 2002-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-23 | 2005-11-22 | 2006-05-24 | $7700.00 | Window Closed / Lapsed |