| 摘要 |
PURPOSE:To prevent the scale deposition on the wall surface and obtain the titled polymer, by applying a dye or pigment to part to be in contact with a monomer of the inner surface of a polymerizer and ancillary equipment thereof, and polymerizing vinyl chloride etc. while controlling the Cl<-> concentration at a specific value or below during polymerization. CONSTITUTION:Vinyl chloride monomer or a mixture thereof with a vinyl based monomer copolymerizable therewith, e.g. vinyl acetate, is suspension or emulsion polymerized in an aqueous medium. In the process, a dye or pigment, e.g., azo based dye or pigment or anthraquinone dye or pigment, as a scale deposition inhibitor, preferably together with a fixing agent, e.g. shellac resin, is applied to parts to be in contact with the monomer of the inner surface of a polymerizer and acillary equipment thereof, and the polymerization is carried out while controlling the Cl<-> concentration in the reaction mixture at <=100ppm during polymerization. Preferably, an inorganic compound, e.g. colloidal silica, is added to the above-mentioned dye or pigment. |
