RESIN PARTICLE AND PROCESS FOR PRODUCTION THEREOF

摘要

Disclosed is a process for producing a resin particle having both superior heat-resistant storage properties and superior melting properties to those of conventional resin particles.  Specifically disclosed is a process for producing a resin particle (X), which comprises the steps of: treating a resin particle (B) comprising a resin (A) with liquid or supercritical carbon dioxide (C); and removing the component (C) from the product.  In the process, the resin (A) is composed of a crystalline part (a) and a non-crystalline part (b), wherein the crystalline part (a) comprises, as the essential component, a polyester (p1) which is produced by the polycondensation of a polyol component and a polycarboxylic acid component and has no aromatic ring or a polyester (p2) which is produced by the polycondensation of a polyol component and a polycarboxylic acid component and has an aromatic ring.  The resin particle (X) has such a heat of fusion that meets the requirement represented by relational equation (1) as measured by differential scanning calorimetry (DSC). 0 = H2/H1 = 0.9     (1) [In relational equation (1), H1 represents a measurement value of a heat of fusion (J/g) generated upon the first temperature rising in the measurement by DSC; and H2 represents a measurement value of a heat of fusion (J/g) generated upon the second temperature rising in the measurement by DSC.]