Process for the preparation of bead polymers of uniform particle size by polymerization of microencapsulated monomer
First Claim
1. A process for the preparation of bead polymers of improved uniform particle size and uniform quality, comprising(a) in known manner producing droplets of uniform size from the monomer or polymerisation mixture to be polymerised by spraying these materials into a liquid which is continuously fed in and which is essentially immiscible with the monomer or polymerisation mixture;
- (b) by means of coacervation, complex coacervation or by a phase interface reaction continuously encapsulating these droplets of uniform size in the said liquid according to processes of micro-encapsulation which are in themselves known either directly with shells which are stable under the polymerisation conditions to be used, or first with shells which are stable to shearing forces, and, in a second step, continuously or discontinuously hardening these shells which are stable to shearing forces to give shells which are stable under the polymerisation conditions to be used;
(c) polymerising the monomer droplets or droplets of polymerisation mixture encapsulated with shells which are stable under the polymerisation conditions to be used, with the provisions(α
) that the monomer or the polymerisation mixture is sprayed into the continuously fed-in continuous phase, co-current with this phase;
(β
) that the production of the droplets and the encapsulation thereof are undertaken in different regions of a single reaction vessel;
(γ
) that the process steps (a) and (b) are carried out in such a manner that no forces which alter the integrity of the droplets act on the droplets from their production until their encapsulation.
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Abstract
Process for the production of bead polymers of improved uniform particle size and uniform quality comprising (a) producing droplets which have a uniform particle size from the monomer or polymerization mixture to be polymerized by spraying the monomer or polymerization mixture into a liquid (continuous phase) which is essentially immiscible with the monomer or polymerization mixture, (b) encapsulating these droplets of uniform size are by shells which are stable under the polymerization conditions to be used and (c) then polymerizing the encapsulated droplets, and with the provision to maintain in the process steps of droplet production and encapsulation of the droplets certain special conditions.
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Citations
9 Claims
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1. A process for the preparation of bead polymers of improved uniform particle size and uniform quality, comprising
(a) in known manner producing droplets of uniform size from the monomer or polymerisation mixture to be polymerised by spraying these materials into a liquid which is continuously fed in and which is essentially immiscible with the monomer or polymerisation mixture; -
(b) by means of coacervation, complex coacervation or by a phase interface reaction continuously encapsulating these droplets of uniform size in the said liquid according to processes of micro-encapsulation which are in themselves known either directly with shells which are stable under the polymerisation conditions to be used, or first with shells which are stable to shearing forces, and, in a second step, continuously or discontinuously hardening these shells which are stable to shearing forces to give shells which are stable under the polymerisation conditions to be used; (c) polymerising the monomer droplets or droplets of polymerisation mixture encapsulated with shells which are stable under the polymerisation conditions to be used, with the provisions (α
) that the monomer or the polymerisation mixture is sprayed into the continuously fed-in continuous phase, co-current with this phase;(β
) that the production of the droplets and the encapsulation thereof are undertaken in different regions of a single reaction vessel;(γ
) that the process steps (a) and (b) are carried out in such a manner that no forces which alter the integrity of the droplets act on the droplets from their production until their encapsulation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification
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- Resources
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Current AssigneeBayer AG
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Original AssigneeBayer AG
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InventorsLange, Peter M., Struver, Werner
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Primary Examiner(s)Schofer, Joseph L.
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Assistant Examiner(s)Kulkosky, Peter F.
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Application NumberUS06/290,982Time in Patent Office900 DaysField of Search521/38US Class Current521/38CPC Class CodesC08F 2/00 Processes of polymerisation
