Polymer scale preventive agent

U.S. Patent Number: 5378774

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) at least one member selected from the group consisting of (A-1) an aromatic compound having at least 2 amino groups and (A-2) an aromatic dibasic acid dihydrazide compound, (B) an inorganic colloid, and (C) a water-soluble polymer compound. This agent is low in toxicity and high in safety. The agent is used for forming a coating on the inner wall surfaces of a polymerization vessel. Such a vessel is effective in preventing polymer scale deposition during polymerization not only on the areas in the liquid phase but also at and in the vicinity of the interface between the gas and liquid phases therein, and is useful in producing a polymer product that shows very few fish eyes and good whiteness when formed into sheets or the like.

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

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

Application Number: 08/159,250

Issued: 1995-01-03

Expired: 2007-01-03

Classes: 526/62 ; 526/74

Field of search: 526/62,74 524/192

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