| 摘要 |
PURPOSE:To produce PVC having a low residual monomer content and excellent moldability and improved in fish eye formation, by using a specified alpha-olefin as a comonomer in the presence of a specified combination of dispersants in the suspension polymerization of a vinyl chloride monomer in an aqueous medium. CONSTITUTION:In the production of PVC by suspension-polymerizing a vinyl chloride monomer in an aqueous medium, a combination, as a dispersant, of partially saponified PVAc of a degree of saponification >=60mol% with a water- soluble cellulose ether (e.g., methylhydroxypropylcellulose) and 0.1-5wt%, based on the vinyl chloride monomer, 6-20C alpha-olefin (e.g., hexene-1 or octadecene-1) are added to the reaction system. PVC having a low residual vinyl chloride monomer content and improved in fish eye formation can be obtained without decreasing the bulk density of PVC and, especially, a molding improved in production rate during processing and excellent in appearance, for example, transparency of a calendered film, can be obtained.
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