Method of producing uniform, fine polymer beads by vibration jetting

Abstract

Speriodal polymer beads having a uniform size are prepared by polymerizing uniformly sized monomer droplets formed by dispersing a polymerizable monomer phase over double-walled cylindrical cross-flow membrane into an aqueous phase. A shear force is provided at a point of egression of the polymerizable monomer phase into the aqueous phase, the direction of shear substantially perpendicular to the direction of egression of the monomer phase. The polymer beads can be employed in applications where beads having uniform diameters of 10 to 200 μm are useful.

Description

technical field [0001] The present invention relates generally to the preparation of spherical polymeric beads, and more particularly, to spherical polymeric beads having a substantially uniform particle size. Such beads are useful in the manufacture of ion exchange resins. Background technique [0002] Spherical polymer beads in the size range of about 1 μm to 300 μm in diameter are useful for various applications. For example, such polymer beads have been used in various chromatographic applications as matrices for ion exchange resins, seeds for the preparation of larger sized polymer particles, calibration standards for hemocytometers, aerosol Instrumentation, pollution control equipment, and among other uses as spacers for photographic emulsions. [0003] Unfortunately, however, the preparation of uniformly sized polymer beads using known methods is generally not suitable for large-scale production. Typically, polymer beads can be prepared by suspension polymerization...

AI Technical Summary

Problems solved by technology

However, these conventional methods such as stirred batch polymerization often produce bead products exhibiting large particle size distributions, mainly due to problems with coalescence and / or breakdown of suspended monomer droplets

Current spraying methods also suffer from high cost and low output of products with a particle size below 300 μm

For example, the platejetting method has low overall productivity and is limited by large energy losses during the vibration generation step

In addition, methods that require injection into a gaseous medium require very sophisticated equipment and complex polymer formation methods

The use of cross-flow membranes for the generation of fine droplets using metal or glass sintered or electro-formed membranes is suitable for small-scale applications but difficult to implement in commercial operations

Furthermore, the low productivity per unit area of ​​cross-flow membranes requires complex and bulky equipment, which is unreliable and requires high capital and operating costs

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