Process for the preparation of cross-linked polymer particles

Abstract

A process for the preparation of highly crosslinked polymer particles from polymerizable vinyl monomers comprising 15% by weight or more of a crosslinking vinyl monomer. The process comprises: providing an organic solvent, a mixture of organic solvents, or a mixture of at least one organic solvent and water which can dissolve the polymerizable vinyl monomers but cannot dissolve the polymer which is produced by the polymerization of the polymerizable vinyl monomers, the solubility in water of the polymerizable vinyl monomer being not more than 30% by weight, dispersing the polymerizable vinyl monomers into the organic solvent, the mixture of organic solvents, or the mixture of the at least one organic solvent and water, and polymerizing the polymerizable vinyl monomers in the presence of a dispersion stabilizer and a radical polymerization initiator. The crosslinked polymer particles have a comparatively uniform particle size within the particle size range of 0.1-10 .mu.m. They are useful as a slip property improver for plastic films, a spacer for liquid crystal display devices, a carrier for chromatography, and a standard sample for microscopic examination.