| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a polyvinyl alcohol resin which is superior in handling and less prone to generate dissolution residue when dissolved in water, and a method for producing the same. <P>SOLUTION: A polyvinyl alcohol resin slurry obtained through a polymerization step (step S1) and a saponification step (step S2) is heated to 100 to 170°C to reduce volatile components contained therein to 1 mass% or lower (step S3). Thereafter, the resin from which the volatile components have been removed is extrusion-molded into a strand shape using a die provided with a hole having a diameter of 3 to 8 mmμm, and the extrusion-molded resin is air-cooled or wind-cooled until the temperature reaches 45°C or lower (step S4). Then, the cooled resin is pulverized into rod-shaped particles having a length of 1 to 10 mm and a maximum diameter of 0.5 to 3.0 mm (step S5). <P>COPYRIGHT: (C)2012,JPO&INPIT |
