Polymer non-spherical particles and a method of manufacturing the same

摘要

PURPOSE: To obtain polymer particles having a narrow particle size distribution and suitable for a toner etc.. by treating a liq. dispersion of particles of a polymer having ionically dissociatable groups (e.g. acrylic acid groups) with an electrolyte, a solvent, and a nonionic surfactant to form agglomerates and thermally fusing the particles in the agglomerates. CONSTITUTION: Nonspherical polymer particles are formed by treating a liq. dispersion of particles of a polymer (A) having ionically dissociatable groups with an electrolyte (B) in a concn. higher than the critical agglomeration concn. of the dispersion, an org. solvent (C) infinitely sol. in water and a nonionic surfactant (D) to form agglomerates and thermally fusing the particles in the agglomerates. Component A is obtd. e.g. by copolymerizing a monomer having a carboxyl, sulfo, or amino group, etc., pref. by emulsion polymn.. and may be compounded with a pigment, a dye, etc., if required. Component B is pref. a salt of a monovalent metal. Component C is pref. methanol, etc. Using component D in a concn. higher than one-half the critical micelle concn. prevents excess agglomeration. The nonspherical polymer particles, having a narrow particle size distribution, is suitably used for an electrophtographic toner and a carrier for a physiologically active substance.