| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject polymer particles useful for paints, coatings for metals, paper and films, adhesives, binders for magnetic tapes, etc., by dispersing vinyl chloride-based polymer particles in pure water having a specific pH. SOLUTION: The vinyl chloride-based polymer particles having (preferably vinyl chloride-vinyl acetate copolymer particles) excellent dehydrochlorination resistance are characterized in that the pH of water is 6-8, after the vinyl chloride-based polymer particles are thermally treated at 80 deg.C for 4 hr in a state dispersed in pure water in an amount of 5-10 wt.% based on the pure water. The vinyl chloride-based polymer particles are preferably dispersed in water containing a carbonate and/or a phosphate and having a pH of 5-9 at 60-100 deg.C. The vinyl chloride-based polymer particles preferably have a particles diameter of 10-1000μm. The polymerization degree of the vinyl chloride-based polymer preferably has a number-average mol.wt. of >=400 expressed in terms of polystyrene particles and measured by SEC(size-excluded chromatography).
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