| 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> |
