Process for preparing uniformly sized polymer particles by suspension polymerization of vibratorily excited monomers in a gaseous or liquid stream
AssigneeThe Dow Chemical Company
InventorsEdward E. Timm, Douglas E. Leng
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Abstract
Spheroidal polymer beads having a uniform size are prepared by polymerizing uniformly sized monomer droplets formed by vibratory excitation of a laminar jet of monomeric material flowing in a gas phase. For example, a laminar jet of a monomer mixture comprising styrene, divinylbenzene and a polymerization initiator can be subjected to vibratory excitation and the resulting monomer droplets polymerized to yield copolymer beads having a narrow particle size range distribution. The copolymer beads can be employed in applications where beads having diameters of 5 .mu.m to 100 .mu.m are useful.
Claims14
A method for preparing small spheroidal polymer beads having a volume average particle diameter of about 5 .mu.m to about 100 .mu.m, said method comprising forming a monomer jet having laminar flow characteristics by flowing a vibratorily excited liquid monomer phase comprising a polymerizable monomer through an opening into a continuous gas phase under conditions sufficient to form a plurality of monomer droplets comprising the polymerizable monomer;
- said monomer droplets ranging in size from about 5 .mu.m to about 100 .mu.m, subsequently polymerizing said monomer droplets under conditions which do not cause significant coalescence or additional dispersion thereof by (a) polymerizing said droplets which are dispersed in said gas phase, or (b) dispersing said droplets into a continuous phase comprising a liquid immiscible with the polymerizable monomer phase and containing a stabilizing amount of suspending agent and subsequently polymerizing said droplets in suspension under conditions which do not cause significant coalescence or additional dispersion thereof.
Dependencies are inferred from the claim text.