POLYMER PARTICLES, PROCESS FOR PRODUCING SAME, AND USE THEREOF

摘要

Polymer particles which have a surfactant content higher than 0 ppm but less than 50 ppm; and a process for producing the polymer particles which includes a solid-liquid separation step in which a crude reaction product (P) obtained by polymerizing a vinyl monomer in a polymerization medium in the presence of a surfactant is introduced into a filter (1) and the polymerization medium contained in the crude reaction product (P) is passed through the filter medium (3) of the filter (1) and a cleaning step in which a cleaning fluid is introduced into the filter (1) to clean the polymer particles present on the filter medium (3). When the area of the interface between the filter medium (3) and the mixture to be filtered is expressed by A (m2), the amount X (kg/min) of the polymerization medium which has passed through the filter medium (3) per unit time period in the solid-liquid separation step satisfies X≤5.50×A, while the amount Y of the cleaning fluid which has passed through the filter medium (3) per unit time period in the cleaning step satisfies Y≤8.50×A. The weight amount of the cleaning fluid to be used in the cleaning step is at least 10 times that of the polymer particles held on the filter medium (3).