PURPOSE: To prevent the viscosity increase of a liq. polymn. system during polymn.
CONSTITUTION: A high-solid water-base emulsion mainly comprising an ethylene- vinyl ester copolymer contg. 5-40wt.% ethylene units is produced in two steps: the first step wherein 40-90wt.% of a vinyl ester to be copolymerized, an emulsifier in an amt. of 2.5-5.0 pts.wt. based on 100 pts.wt. the total vinyl ester to be copolymerized, and water are mixed by stirring to give an emulsion wherein the max. diameter of dispersed particles is 50μm or lower and at least 90% (in number) of particles having diameters of 0.1μm or higher have diameters of 5μm or lower; and the second step wherein the emulsion formed at the former step is polymerized together with the rest, 10-60wt.%, of the total of the total of the vinyl ester used in the polyinesization in the presence of a redox catalyst at 30-80°C under an ethylene pressure of 10-100kg/cm2.
YOSHII YUJI
ICHINOSE TAKAHIRO
TOMIZAWA CHOJI
KANEJIMA YASUO
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