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US4046720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crosslinked, porous, polyacrylate beads
Assignee: California Institute of Technology
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Filing: 1975-05-30
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Granted: 1977-09-06
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Expires: 1995-05-30
Abstract
Abstract Uniformly-shaped, porous, round beads are prepared by the co-polymerization of an acrylic monomer and a cross-linking agent in the presence of 0.05 to 5% by weight of an aqueous soluble polymer such as polyethylene oxide. Cross-linking proceeds at high temperature above about 50 DEG C or at a lower temperature with irradiation. Beads of even shape and even size distribution of less than 2 micron diameter are formed. The beads will find use as adsorbents in chromatography and as markers for studies of cell surface receptors.
Inventors
- 👤 Alan Rembaum
- 👤 Shiao-Ping S. Yen
- 👤 William J. Dreyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:36
CPC Classifications
C; C08; C08J; C08J9/00; C08F; C08F20/00; C08F20/62; G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/53; G01N33/543; G01N33/54313; C08J2333/00; C08J2333/04; C08J2333/06; Y; Y10; Y10S; Y10S521/00; Y10S521/905
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
43 words
A composition consisting essentially of uniformly shaped, hydrophilic, swellable, porous, round beads, at least 80% having a diameter less than 2 microns and being the cross-linked polymer of acrylamide and 0.1 to 30 weight percent of a liquid diene or triene cross-linking agent.
Claim 2
Dependent Claim
43 words
A composition consisting essentially of uniformly shaped, hydrophilic, swellable, porous, round beads, at least 80% having a diameter less than 2 microns and being the cross-linked polymer of acrylamide and 0.1 to 30 weight percent of a liquid diene or triene cross-linking agent.
Claim 3
Dependent Claim
23 words
A composition according to claim 1 in which at least 90% of the beads have a uniform diameter between 0.001 and 2 microns.
Claim 4
Dependent Claim
13 words
A composition according to claim 1 in which the cross-linking agent is N,N'-methylene-bis-acrylamide.
Claim 5
Dependent Claim
34 words
A composition according to claim 1 in which the beads contain 1-35 weight percent based on acrylamide of a comonomer selected from a lower alkyl methacrylate, acrylic acid, methacrylic acid, styrene or vinyl toluene.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-05 | 1981-03-07 | 1981-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-05 | 1985-03-07 | 1985-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-05 | 1989-03-07 | 1989-09-06 | $7700.00 | Window Closed / Lapsed |