Process for the preparation of multi-shell emulsion particles

摘要

A multi-shell emulsion particle comprising a dry state structure having one or more of penetrating pore connecting the surface layer of the particle with the interior of the particle and having a particle diameter of from 0.1 to 5.0 mu preferably from 0.1 to 1.2 mu can be prepared by carrying out emulsion polymerization of a vinyl monomer (a) containing from 5 to 80% by weight of an unsaturated carboxylic acid, forming a polymer (B) in the presence of a particle consisting of the resultant polymer (A) while adding a vinyl monomer (b) in an amount of 10 times by weight or less and at a rate of 3 times by weight per hour or more for the weight of the polymer (A), and treating the resultant multi-shell emulsion polymer with an alkaline material to neutralize and swell the polymer (A); or, after the neutralization treatment, further forming a polymer (C) by adding and emulsion-polymerizing a vinyl monomer (c) in an amount of 20 times by weight or less for the total weight of the polymer (A) and polymer (B). The particle is useful as a component of resin composition for paints, paper-coating and heat-sensitive recording materials.