Polymer scale preventive agent, polymerization vessel wherein polymer scale is prevented from depositing, and process of producing polymer using the same

U.S. Patent Number: 5352748

Abstract: A polymer scale preventive agent used for polymerizing a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing (A) an anthraquinone dye and (B) a reducing agent. Where the monomer is polymerized in a polymerization vessel having, on the inner wall surface, a coating film formed by applying and drying said preventive agent, polymer scale can effectively be prevented from being deposited not only on the liquid phase part in the polymerization vessel but also near the interface between the gas phase part and the liquid phase part, so that the thus obtained polymer can provide a molded item having few fish eyes, when the polymer is molded into a sheet or the like.

Inventors: Shimizu; Toshihide (Urayasu, JP), Watanabe; Mikio (Kamisu, JP)

Assignee: Shin-Etsu Chemical Co., Ltd. (Tokyo, JP)

Application Number: 08/020,978

Issued: 1994-10-04

Expired: 2006-10-04

Classes: 526/62 ; 422/131; 526/208

Field of search: 526/62,208 422/131

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