METHOD OF PRODUCING POLYMER BEADS OF UNIFORM SIZE Russian patent published in 2013 - IPC C08F2/01 C08F2/16 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of producing beads having a uniform particle size distribution. Described is a method of producing monodisperse cross-linked polymer beads, comprising the following steps: (a) introducing droplets having a harmonic mean size from 50 to 1500 mcm and comprising at least one monomer, at least one cross-linking agent and a free-radical polymerisation initiator into an aqueous medium through openings in a moulding column to produce an aqueous suspension of droplets having a volume fraction of droplets from 35 to 64%; wherein the droplets are not encapsulated; wherein the monomers are selected from a group comprising monoethylene unsaturated compounds and polyethylene unsaturated compounds, monoethylene unsaturated monomers are selected from a group comprising (meth)acrylic acids and esters thereof, methyl-substituted styrenes, vinyl pyridines and vinyl esters, ethers and ketones; (b) forcing the aqueous suspension of droplets to move down a pipe such that: (I) the ratio of droplet harmonic mean size to inside pipe diameter is from 0.001 to 0.035; (II) mean linear flow velocity in the pipe is from 0.5 to 2.5 ft/s (0.15 to 0.75 m/s); and (III) temperature in the pipe is maintained at least 20°C below the temperature at which the polymerisation initiator has a half-life of 1 hour; wherein the droplets are forced up the moulding column, and the redirected down into the pipe, with subsequent redirection up into a reactor; and (c) polymerising the droplets in the reactor.

EFFECT: obtaining polymer beads of a uniform size by forcing a jet down into a reactor and without partial polymerisation or encapsulation.

10 cl, 3 ex