Modified vinyl alcohol polymer powder having reduced methanol content and production method therefor, and water-soluble film and packaging material

• Main Authors: Nii, Shinsuke, Horiguchi, Junpei, Tanida, Tatsuya, Kumaki, Yosuke, Fukuhara, Tadahito
• Format: Patent
• Language: English
• Published: 27.04.2021
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

A modified vinyl alcohol polymer powder having a structural unit derived from a derivative of an ethylenically unsaturated dicarboxylic acid, and containing a reduced amount of methanol, and a trace amount of a component that does not dissolve in water. The present invention relates to a modified vinyl alcohol polymer powder containing a structural unit derived from a derivative (A) of an ethylenically unsaturated dicarboxylic acid in a content (X) of 0.05 mol % or more and 10 mol % or less, and having a degree of saponification of 80.0 mol % or more and 99.9 mol % or less, the modified vinyl alcohol polymer powder has a methanol content of 0.01 weight % or more and less than 3.0 weight %, the modified vinyl alcohol polymer powder contains 0.1 ppm or more and less than 2,000 ppm of a component that is insoluble in a 90° C., 5 weight % aqueous solution.