Particulate, multiphase polymers which have a core (A) and an overlying shell (B) wherein the core (A) is an organic, resinous polymer comprising polymerized olefinically unsaturated monomer units having softening point temperatures of at least 30.degree. C. and wherein the shell (B) is an organopolysiloxane are obtained by producing in a first stage an organic resinous polymer in latex form by emulsion polymerization and, in a second stage, the latex particles of the first stage are surrounded with a shell (B) organopolysiloxane by polymerizing low molecular weight organosiloxanes in the presence of the latex particles of the first stage.