Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing a condensation product of (A) an aromatic compound having at least two amino groups and (B) an aromatic bis-ester anhydride. This agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Such a vessel is effective in preventing polymer scale deposition and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising a condensation product of (A) hydrazine and (B) a quinone compound. Where the monomer is polymerized in a polymerization vessel having, on its inner wall surface, a coating comprising the condensation product, deposition of polymer scale can be effectively prevented 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 and low in initial coloration, when the polymer is molded into a sheet or the like.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing a condensation product of (A) an aromatic diaminodicarboxylic acid compound, and (B) an organic compound containing two --COX groups, wherein X is halogen. This agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Such a vessel is effective in preventing polymer scale deposition, not only on the areas in the liquid phase but also near the interface between the liquid phase and the gas phase in the vessel, and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.

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.

Abstract: Aqueous polymerization of vinyl monomer is conducted in a vessel with an internal coating. This coating is composed of the condensation reaction of an aliphatic diamine and a quinone, with the addition of a reaction stopper when reaction is 70-99% complete. Reaction stopper is an inorganic compound of sodium or sulfur.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) a N-substituted leucophenothiazine having the general formula (I): ##STR1## wherein Z is a carbonyl group or a sulfonyl group, R.sup.1, R.sup.2 and R.sup.3 are a hydrogen atom, alkyl group, an amino group, etc., and (B) a water-soluble basic polysaccharide. The agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be effectively prevented, and polymeric product with high whiteness is obtained.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) a nitrogen-containing organic compound having at least five continuous conjugated .pi. bonds, (B) an anionic organic compound having at least one group selected from the group consisting of the sulfonic acid group and the carboxyl group and having at least five continuous conjugated .pi. bonds, and (C) a water-soluble basic polysaccharide. The agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be effectively prevented not only in the liquid phase area but also in the vicinity of the interface between the gas and liquid phases. Products formed from polymer obtained have very few fish eyes.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising an alkaline solution containing a condensation product of (A) an aliphatic diamine compound and (B) an aromatic tetracarboxylic acid anhydride. This agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Such a vessel is effective in preventing polymer scale deposition, not only on the areas in the liquid phase but also near the interface between the liquid phase and the gas phase in the vessel, and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.

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.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenic double bond, comprising (A) a nitrogen-containing organic compound having at least five continuous conjugated .pi. bonds, (B) an anionic organic compound having at least one group selected from the group consisting of the sulfonic acid group and the carboxylic group and having at least five continuous conjugated .pi. bonds, and (C) a vinylpyrrolidone-based polymer. The agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be effectively prevented not only in the liquid phase area but also in the vicinity of the interface between the gas and liquid phases. Products formed from polymer obtained have very few fish eyes.

Abstract: This process is a method of preventing polymer scale formation in a polymerization vessel during the polymerization of a monomer having an ethylenically unsaturated double bond. The inner wall surface of a polymerization vessel is coated with a water-based coating solution containing (a) a water-soluble anionic dye and (b) at least water-insoluble cationic dye or water-insoluble nitrogen-containing organic compound, where the water-based coating solution has a pH of 7 or less. The coating solution is applied and then dried to form a coating.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising a pyrogallol-acetone resin. The agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be effectively prevented, and polymeric product with high whiteness is obtained.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenic double bond, comprising at least one compound selected from the group consisting of agars and agaroses. A process of producing a polymer by polymerizing the monomer in a polymerization vessel having on its inner wall surfaces a coating comprising the scale preventive agent. Polymer scale deposition inside the polymerization can be effectively prevented, and polymers with high whiteness can be prepared. Moreover, the scale preventive agent no poisonousness and is highly safe.

Abstract: A method of preventing polymer scale deposition during polymerization of a monomer having an ethylenically double bond in a polymerization vessel, comprising the step of carrying out said polymerization in a polymerization vessel of which the inner wall surface has a coating comprising:(A) a polyvinyl alcohol, and(B) a water-soluble polymeric compound having a carboxyl group which may be in the form of a salt, and a polymer scale preventive agent comprising said (A) and (B). Deposition of polymer scale can be effectively prevented. Since the components (A) and (B) have no poisonousness, safety of operators are ensured.

Abstract: A method of preventing polymer scale deposition during polymerization of a monomer having an ethylenically double bond in a polymerization vessel, comprising the step of carrying out said polymerization in a polymerization vessel of which the inner wall surface has a coating comprising:(A) a water-soluble nitrogen-containing cationic polymeric compound, and(B) a water-soluble anionic polymeric compound; and a polymer scale preventive agent comprising said (A) and (B). Polymer scale deposition is effectively prevented, and polymers with high whiteness can be prepared.

Abstract: A method of preventing polymer scale deposition during polymerization of a monomer having an ethylenically double bond in a polymerization vessel, comprising the step of carrying out said polymerization in a polymerization vessel of which the inner wall surface has a coating comprising:(A) a lignin, and(B) a cellulose derivative; and a polymer scale preventive agent comprising said components (A) and (B).Deposition of polymer scale can be effectively prevented; polymers with high whiteness can be prepared; the scale preventive agent used has no poisonousness and are highly safe, therefore this method can be performed with high safe.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) a water-soluble basic polysaccharide and (B) an organic acid compound. The agent is used for forming a coating on the inner wall, etc. of a polymerization vessel. Deposition of polymer scale can be effectively prevented, and polymeric product with high whiteness is obtained.

Abstract: This process is a method of preventing polymer scale formation in a polymerization vessel during the polymerization of a monomer having an ethylenically unsaturated double bond. The inner wall surface of a polymerization vessel is coated with a water-based coating solution containing (A) a water-soluble anionic dye and (B) at least one water-insoluble cationic dye or water-insoluble nitrogen-containing organic compound, where the water-based coating solution has a pH of 7 or less. The coating solution is applied and then dried to form a coating.

Abstract: A method of preventing polymer scale deposition during polymerization of a monomer having an ethylenically double bond in a polymerization vessel, comprising the step of carrying out said polymerization in a polymerization vessel of which the inner wall surface has a coating comprising a water-soluble polysaccharide; and a polymer scale preventive agent comprising polysaccharide. By use of the method or agent, deposition of polymer scale can be effectively prevented; in addition, polymers with a high whiteness can be prepared. Moreover, the scale preventive agent used has no poisonousness or the like and is highly safe.

Abstract: A method of preventing polymer scale deposition in a polymerization vessel during polymerization of a monomer having an ethylenically double bond, wherein said polymerization is carried out in a polymerization vessel of which the inner wall has been previously coated with a coating solution containing(A) a tannin, and(B) a water-soluble polymeric compound, followed by drying to form a coating; a scale preventive agent comprising the components (A) and (B); and a polymerization vessel having said coating on the inner wall thereof. Polymer scale deposition on the inner wall, etc. of the polymerization vessel can be effectively prevented.