Abstract: A cored multi-shell emulsion particle consisting of a core particle, a void layer existing in the exterior of the core particle and a shell layer, each of which has a diameter of .phi., d and D, respectively, and the ratio of .phi., d and D is in the following range..phi./D=0.1-0.6d/D=0.2-0.8 (d>.phi.)The particle exhibits excellent hiding power, brightness, gloss and thermal insulation property as an organic pigment without impairing drying ability and strength of coated layer.

Abstract: A synthetic resin emulsion whose polymer particles are solid core-shell particles in which form pores spontaneously upon drying is produced by the steps of preparing as core particles from 2 to 60 parts by weight of polymer (A) by emulsion polymerization of from 10 to 80 parts by weight of acrylate ester (a.sub.1) having an alkyl group of from 1 to 3 carbon atoms and from 90 to 20 parts by weight another of vinyl-type monomer (a.sub.2) copolymerizable therewith, forming a shell of a polymer (B) on the surface of the core particles of polymer (A) by emulsion polymerization in the presence thereof of from 98 to 40 parts by weight of vinyl-type monomer (b), different from polymer (a.sub.1) and successively hydrolyzing the core portion of the particles with an alkaline material. Organic pigments prepared from the synthetic resin emulsion can improve the hiding power, brightness, gloss and other properties of articles coated therewith.

Abstract: A thermosensitive recording paper is disclosed useful for thermosensitive recording which comprises a substrate, a thermosensitive recording layer and an undercoat layer interposed therebetween which contains 10 to 40 parts of a binder and 60 to 90 parts by weight of crosslinked polymer microparticles having a particle diameter of 0.2 to 5.0 .mu.m and a ratio of weight average diameter to number average diameter of 2.0 or less.