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AssigneeShin-Etsu Chemical Co., Ltd.
InventorsToshihide Shimizu, Ichiro Kaneko, Yoshiteru Shimakura
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The invention provides an efficient method for removing polymer scale deposited on the walls of the polymerization reactor after completion of a polymerization run of an ethylenically unsaturated monomer, e.g. vinyl chloride, in an aqueous medium. The polymer scale adhering to the walls is soaked with a scale-remover solution containing a soluble cellulose derivative, such as ethyl cellulose, hydroxypropyl methyl cellulose and the like, applied thereto and, after standing as wet for a while, washed down easily with water. Certain additives to the solution, e.g. acids, alkalis, paraffins and emulsifying agents, may further enhance the effectiveness of the remover solution.
A method for removing polymer scale from the reactor walls after completion of a run of polymerization of an ethylenically unsaturated polymerizable monomer or a monomer mixture in an aqueous medium which comprises applying a scale remover solution containing a soluble cellulose derivative selected from the group consisting of methyl cellulose, ethyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, nitrocellulose and cellulose acetate, dissolved therein to the polymer scale deposited on the reactor walls and washing down the polymer scale with a washing liquid.
A scale remover solution for removing polymer scale from the reactor walls after completion of a run of polymerization of an ethylenically unsaturated monomer or a monomer mixture in an aqueous medium which comprises
Dependencies are inferred from the claim text.