| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing an aqueous solution of polyvinyl alcohol with a high polymerization degree of a high concentration in a short time. SOLUTION: In the method for producing an aqueous polyvinyl alcohol solution of >=5 mass % solid concentration by use of polyvinyl alcohol powders of which at least one kind of the powders has an average polymerization degree of >=3,000, >=90 mass %, based on the total mass, of the polyvinyl alcohol powder is characterized by having a particle size distribution of 0.3-1.0μm. In another embodiment for the method for producing an aqueous polyvinyl alcohol solution by continuously mixing and dispersing a polyvinyl alcohol powder together with a solvent, the polyvinyl alcohol powder is characteristically fed onto a rotary disk and the solvent is fed from at least two positions. |
