PROCESS FOR PRODUCING POLYVINYL ACETAL RESIN, POLYVINYL BUTYRAL RESIN, AND PROCESS FOR PRODUCING ESTERIFIED POLYVINYL ALCOHOL RESIN

摘要

It is an object of the present invention to provide a method of producing a polyvinyl acetal resin by which a polyvinyl acetal resin having a high acetalization degree can be produced even in a solid catalyst system, a polyvinyl butyral resin produced by the above-mentioned production method of a polyvinyl acetal resin, and a method of producing an esterified polyvinyl alcohol resin by which the esterification can be performed at high efficiency even in a solid catalyst system. The present invention is a method of producing a polyvinyl acetal resin, wherein a solution or a suspension containing a polyvinyl alcohol resin and a carbonyl compound is pressurized in the presence of a solid catalyst.