| abstract |
Provided is a production method for modified vinyl alcohol polymer particles, wherein a mixed medium containing an unsaturated carboxylic acid, an acid catalyst, and water is mixed with vinyl alcohol polymer particles. In this production method, the mixed medium is mixed with the vinyl alcohol polymer particles to react the unsaturated carboxylic acid with the vinyl alcohol polymer particles, and thereby obtain modified vinyl alcohol polymer particles in which a vinyl ester unit represented by formula (2) is contained, the content of a vinyl alcohol unit with respect to all structural units is 60 mol% or more and less than 95 mol%, and the average particle size is 50-2000 μm. This production method is capable of controlling the particle shape, does not have the problem of residual sulfur content, and is also simple and economical. |