| 摘要 |
PURPOSE:To obtain a stabilizer excellent in emulsifying and dispersing stability, by saponifying multi-branched polvinyl ester by a solvent mixture containing methanol and having dielectric constant of 18-27 (C.G.S.e.s.u). CONSTITUTION:A polyvinyl ester type polymer of which the branching degree (the polymerization degree of polyvinyl ester/that of perfectly saponified polyvinyl alcohol obtained by perfectly saponifying polyvinyl ester-1) is 1 or more, such as vinyl formate, vinyl acetate or vinyl propionate is saponified in a solvent mixture, which is prepared by mixing methanol and a solvent (benzene, toluene, xylene) in a wt ratio of 40/60-90/10 at 10-70 deg.C. NaOH, KOH or LiOH is used as a saponification catalyst.
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