Abstract: The invention provides an efficient method for preventing polymer scale deposition on the reactor walls in the suspension or emulsion polymerization of an ethylenically unsaturated monomer, e.g. vinyl chloride and styrene, by coating the reactor walls, prior to introduction of the polymerization mixture, with an aqueous coating solution containing (a) a silicic acid compound, e.g. colloidal silicic acid, and (b) a phosphorous compound, e.g. phytic acid and polyphosphoric acid, in a specified weight proportion followed by drying.

Abstract: The invention provides a novel method for preventing deposition of polymer scale on the walls of a polymerization reactor in the course of polymerization of various ethylenically unsaturated monomers such as the suspension polymerization of vinyl chloride in an aqueous medium. The method comprises coating the reactor walls with a coating solution containing (a) a polymeric compound having hydroxyl groups such as a polyvinyl alcohol and (b) a silicic acid compound such as water glass followed by drying of the coated surface and washing thereof with water.

Abstract: 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.

Abstract: The invention provides an improved method for preventing polymer scale deposition on the reactor walls, for example, in the suspension polymerization of vinyl chloride by coating the walls prior to introduction of the polymerization mixture with a specific coating composition of which the essential ingredient is a combination of (a) a condensation product of an aromatic amine compound, e.g. aniline or a derivative thereof, and an aromatic nitro compound, e.g. nitrobenzene or a derivative thereof, and (b) a sulfonation product of a condensation product of an aromatic amine compound and an aromatic nitro compound in the form of a salt with an alkali metal or ammonium as dissolved in a solvent.

Abstract: The invention provides a method for preventing deposition of polymer scale on the reactor walls in the polymerization of an ethylenically unsaturated monomer, in particular, by emulsion polymerization. The method comprises coating the reactor walls with a coating composition containing, as the essential components, (A) an organic compound having at least 5 conjugated .pi. bonds in a molecule, (B) a chelating agent and (C) a metal compound capable of producing metal ions having a coordination number of at least 2 which presumably forms a metallic chelate compound with the chelating agent contributing to the formation of a strongly adsorbed layer on the reactor walls. The coating composition may be further admixed with a silicic acid compound such as a colloidal silica.