| 摘要 |
<p>The present invention provides a method for producing a chlorinated vinyl chloride-based resin which has excellent thermal stability (initial coloring performance, heat-resistant stability) and from which a translucent molded article is obtained. The method for producing a chlorinated vinyl chloride-based resin comprises, in the process of running a vinyl chloride-based resin through a thermal chlorination reaction in a water suspension state in a sealable reaction vessel, running a first thermal chlorination reaction while also heating a water suspension of vinyl chloride-based resin powder to a predetermined temperature in the temperature range of 85°C to less than 95°C, and thereafter running a second thermal chlorination reaction at the predetermined temperature; wherein chlorine gas is introduced to the reaction vessel at a water suspension temperature of 55-70°C to start a thermal chlorination reaction, and the temperature inside the reaction vessel is raised to the predetermined temperature while staying at a temperature not greater than the glass transition temperature of the chlorinated vinyl chloride-based resin inside the reaction vessel, to run the first thermal chlorination reaction so that the chlorine content of the chlorinated vinyl chloride-based resin inside the reaction vessel is 58 wt% to less than 60 wt%, and thereafter the second thermal chlorination reaction is run at the predetermined temperature.</p> |
