| 摘要 |
Metallic, ash-producing residues which remain in poly(vinyl alcohol) polymer after its preparation from poly(vinyl acetate) are removed by a process which involves contacting a slurry of the poly(vinyl alcohol) polymer, after preparation and before polymer isolation, with ion-exchange resin particles, followed by removal of the ion-exchange resin particles from the poly(vinyl alcohol) polymer particles utilizing size or weight differences between them. The poly(vinyl alcohol) polymer remains in the solid state throughout, avoiding dissolution and the need for re-precipitation. |
