| 摘要 |
PURPOSE:To shorten a feeding time and a heating time necessary for the start of polymerization and to form a vinyl chloride resin of high quality, by feeding water in two divided portions under specified conditions in performing the titled suspension polymerization. CONSTITUTION:An autoclave is charged with 30-90%, based on the total water used, water (30-80 deg.C), a vinyl chloride monomer, a polymerization initiator and a suspending agent, and the mixture is agitated, wherein the temperature of the feed is controlled so that the temperature of the polymerization system after starting agitation may be about 50 deg.C or below and further below the cloud point (or gelation temperature) of the suspending agent. The balance of the water is added at a temperature >= the polymerization temperature, and the reaction mixture is suspension-polymerized at a predetermined temperature to produce a polyvinyl chloride polymer. The obtained vinyl chloride resin has a low fish eye content and a good particle diameter distribution.
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