HIGHLY CLEAN POROUS POLYVINYL ACETAL RESIN, METHOD FOR PREPARING THE SAME, AND METHOD FOR STORING THE SAME

摘要

A porous poly(vinyl acetal) resin body is made to have COD of 5 ppm or smaller, a conductivity of 5 mu S/cm or lower, and the number of particles having a size of 2.5 mu m or larger of 50,000/cc or smaller, as measures for the cleanliness. Using the porous poly(vinyl acetal) resin body having such a high degree of cleanliness in a cleaning process in a clean room or the like, one can reduce or eliminate a conventionally required pretreatment such as a thorough cleaning of the body to prevent elution of contaminants.