| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing a vinyl acetal resin using a vinyl ester-based resin as a raw material without taking out an intermediate by which the vinyl acetal resin with little discoloration and a high degree of acetalization can be obtained in a short time. <P>SOLUTION: The method for producing a vinyl acetal resin using a vinyl ester-based resin as a raw material without taking out an intermediate comprises a step 1 for dissolving the vinyl ester-based resin in a high temperature high pressure fluid including a carboxy group-containing compound at 100-400°C and 0.2-100 MPa by modifying ester side chains of the vinyl ester-based resin, a step 2 for putting an aldehyde in after a part or all of the ester side chains in the vinyl ester-based resin have been modified in step 1 and a step 3 for proceeding an acetalization reaction in the high temperature high pressure fluid. <P>COPYRIGHT: (C)2012,JPO&INPIT |
