Polymerization process characterized by a two layer coating against scale formation deposited using a steam carrier
申请人:SHIN-ETSU CHEMICAL CO., LTD.
公开号:EP0934955A1
公开(公告)日:1999-08-11
An improved process for producing a polymer by polymerizing a monomer having an ethylenic double bond in a polymerization vessel having a polymer scale preventive coating film on its inner wall surfaces, etc. is provided. The coating film is formed by coating a first coating liquid containing a compound selected from the group consisting of an aromatic compound having 5 or more conjugated π bonds and a heterocyclic compound having 5 or more conjugated π bonds, and then coating a second coating liquid on the first layer. The first and second coating liquids are applied by means of steam as a carrier. The second layer has a surface having a contact angle to water of less than 60° after its surface has been brought into contact with a solution of mixture of water and a vinyl chloride monomer in a weight ratio of 1:1, at 50°C for 1 hour. This process can shorten the time for forming the coating film to improve productivity, can improve the effect of preventing adhesion of polymer scale, can make colored particles less mix into polymer products obtained by this process, can lessen fish eyes and initial discoloring of formed products and can improve the quality of polymeric products and their formed or molded products.
本发明提供了一种通过在聚合容器中聚合具有乙烯双键的单体来生产聚合物的改进工艺,该聚合容器的内壁表面等处具有聚合物防垢涂膜。该涂膜是通过涂覆第一涂覆液形成的,第一涂覆液含有选自具有 5 个或更多共轭 π 键的芳香族化合物和具有 5 个或更多共轭 π 键的杂环化合物的一组化合物,然后在第一层上涂覆第二涂覆液。第一种和第二种涂覆液通过蒸汽作为载体进行涂覆。第二层表面与水和氯乙烯单体重量比为 1:1 的混合物溶液在 50°C 下接触 1 小时后,其表面与水的接触角小于 60°。这种工艺可以缩短涂膜的形成时间,从而提高生产率;可以提高防止聚合物鳞片附着的效果;可以使有色颗粒较少地混入通过这种工艺获得的聚合物产品中;可以减少成型产品的鱼眼和初期褪色现象;可以提高聚合物产品及其成型或模塑产品的质量。