Polymeric microbeads and method of preparation
First Claim
1. Porous crosslinked polymeric microbeads having cavities joined by interconnecting pores wherein at least some of the cavities at the interior of each microbead communicate with the surface of the microbead and wherein approximately 10% of the microbeads are substantially spherical or substantially ellipsoidal or a combination thereof.
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Abstract
The present invention relates to porous crosslinked polymeric microbeads having cavities joined by interconnecting pores wherein at least some of the cavities at the interior of each microbead communicate with the surface of the microbead. The present invention also relates to a process for producing a porous, crosslinked polymeric microbead as well as the product of this process. This process involves combining an oil phase with an aqueous discontinuous phase to form an emulsion, adding the emulsion to an aqueous suspension medium to form an oil-in-water suspension of dispersed emulsion droplets, and polymerizing the emulsion droplets to form microbeads. At least 10% of the microbeads produced in accordance with the present invention are substantially spherical or substantially ellipsoidal or a combination of the two.
119 Citations
71 Claims
- 1. Porous crosslinked polymeric microbeads having cavities joined by interconnecting pores wherein at least some of the cavities at the interior of each microbead communicate with the surface of the microbead and wherein approximately 10% of the microbeads are substantially spherical or substantially ellipsoidal or a combination thereof.
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4. A process for producing a porous, crosslinked polymeric microbead comprising
(a) combining (i) an oil phase comprising (1) a substantially water-insoluble, monofunctional monomer; -
(2) a substantially water-insoluble, polyfunctional crosslinking agent; (3) an emulsifier that is suitable for forming a stable water-in-oil emulsion; and (4) a stabilizer, wherein said stabilizer is a film-forming compound that is soluble in an organic solvent, and said stabilizer is present in the oil phase at a concentration in the range of about 0.01 to about 15 weight percent; and (ii) an aqueous discontinuous phase to form an emulsion, wherein the emulsion comprises at least about 70% aqueous discontinuous phase; (b) adding the emulsion to an aqueous suspension medium to form an oil-in-water suspension of dispersed emulsion droplets; and (c) polymerizing the emulsion droplets. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71)
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24. A process for producing a porous crosslinked polymeric microbead comprising
(a) combining (i) an oil phase comprising (1) styrene; -
(2) divinylbenzene; (3) lauroyl peroxide; (4) trichloroethane; (5) sorbitan monooleate; and (6) ethylcellulose; and (ii) an aqueous discontinuous phase that does not contain a polymerization initiator to form an emulsion; (b) adding the emulsion to an aqueous suspension medium to form an oil-in-water suspension of dispersed emulsion droplets, wherein said suspension medium comprises acacia gum and does not contain a polymerization initiator; and (c) polymerizing the emulsion droplets.
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25. A porous crosslinked polymeric microbead produced by the process comprising
(a) combining (i) an oil phase comprising (1) styrene; -
(2) divinylbenzene; (3) lauroyl peroxide; (4) trichloroethane; (5) sorbitan monooleate; and (6) ethylcellulose; and (ii) an aqueous discontinuous phase that does not contain a polymerization initiator to form an emulsion; (b) adding the emulsion to an aqueous suspension medium to form an oil-in-water suspension of dispersed emulsion droplets, wherein said suspension medium comprises acacia gum and does not contain a polymerization initiator; and (c) polymerizing the emulsion droplets.
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Specification