POLYVINYL ALCOHOL, METHOD FOR PRODUCING THE SAME, AND USE OF THE SAME

• Main Author: FUKUHARA TADAHITO
• Format: Patent
• Language: English; Japanese
• Published: 17.12.2020
• Subjects: CHEMISTRY; COMPOSITIONS BASED THEREON; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP

To provide PVA which can suppress formation of coarse particles in a vinyl-based resin obtained when used as a dispersion stabilizer for suspension polymerization of a vinyl compound and can obtain particles having uniform diameters, and can suppress occurrence of fish eyes, and to provide PVA capable of simply obtaining a crosslinked body having excellent water resistance.SOLUTION: Polyvinyl alcohol has a degree of saponification of 70 mol% or more and less than 99.9 mol%, has a degree of viscosity average polymerization of 400 or more and less than 1,800, contains 0.05 mol% or more and less than 0.5 mol% of an aldehyde group at its terminal, and has an absorbance at 280 nm of 0.1 mass% aqueous solution of 0.17 or more and less than 0.55.SELECTED DRAWING: None 【課題】ビニル化合物の懸濁重合用分散安定剤として用いたときに、得られるビニル系樹脂において粗大粒子の形成を抑制することができるとともに径が均一な粒子を得ることができ、なおかつフィッシュアイの発生を抑制することができるＰＶＡを提供する。また、耐水性に優れた架橋体を簡便に得ることのできるＰＶＡを提供する。【解決手段】けん化度が７０モル％以上９９．９モル％未満、粘度平均重合度が４００以上１８００未満であり、末端にアルデヒド基を０．０５モル％以上０．５モル％未満含有し、かつ０．１質量％水溶液の２８０ｎｍにおける吸光度が０．１７以上０．５５未満であるポリビニルアルコール。【選択図】なし