POLYURETHANE PARTICLES AND METHOD FOR PRODUCING POLYURETHANE PARTICLE CLUSTER

摘要

Provided are polyurethane particles that can absorb oil such that the particles themselves are unlikely to fuse or aggregate together during production, handling, storage or transportation, as well as a method for producing these polyurethane particles.  The polyurethane particles are formed from a polyurethane particle body and a hydrophilic silica micropowder cluster that coats the surface of the particle body.  The polyurethane particle body is obtained by subjecting an isocyanate-terminal urethane prepolymer obtained by reacting a polyisocyanate component and a polyol component containing polytetramethylene glycol to three-dimensional polymerization in the presence of a polyfunctional amine having three or more functional groups.  The polyurethane particle cluster is obtained by using a spray dryer to spray dry an aqueous mixed dispersion in which a hydrophilic silica micropowder cluster and a polyurethane spherical body cluster obtained by the above-mentioned three-dimensional polymerization are dispersed in water.