Abstract: A monomer having an ethylenic double bond is polymerized in a polymerization vessel provided on its inner wall surfaces with a coating of a polymer scale preventive agent which comprises a condensation product of an aromatic amine compound with an aromatic hydroxyl compound condensate. This process makes it possible to prevent effectively the deposition of polymer scale and to produce a polymer which shows few fish eyes and good whiteness when formed into sheets or the like.

Abstract: A polymer scale deposition 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) a diphenyl compound having at least two amino groups and (B) a quinone compound. When the aforementioned monomer is polymerized in a polymerization vessel having a coating formed by applying the aforementioned preventive agent to inner wall surfaces followed by drying, polymer scale can be effectively prevented from being deposited not only on the areas located in the liquid-phase region but also on the areas around the interface between the gas and liquid phases in the polymerization vessel. When an obtained polymer is formed into a sheet or the like, it is possible to obtain a formed product having few fish eyes and good initial coloration.

Abstract: A polycarbonate is produced by transesterification from a dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane and a diester of carbonic acid such as bisphenyl carbonate in the presence of a substance containing iron in an amount of 50% by weight or less to contact the reactants. Also, a polycarbonate is produced by transesterification from a dihydroxy compound and a diester of carbonic acid in a reactor made of stainless steel and treated by electropolishing or acid pickling or buffed on a surface part thereof to contact the reactants. As the transesterification catalyst, (a) a nitrogen-containing, electron-donating compound and (b) a nitrogen-containing, electron-donating compound and an alkali metal compound or an alkaline earth metal compound are preferably used.

Abstract: A process to prevent scale adhesion on rector surfaces when polymerizing vinyl esters, vinyl esthers, carboxylic acids, styrene or diene monomers. Coating of internal reactor surfaces with a combination of an amino containing aromatic compound, and an alkali metal or ammonium salt of polyvinylsulfuric acid results in the scale prevention. This combination is applied to reactor surfaces via its mixture with a solvent and is subsequently dried to form the coating.

Abstract: A process to prevent scale adhesion on reactor surfaces when polymerizing vinyl monomers. Coating of internal reactor surfaces with a combination of an amino containing aromatic compound, and an alkali metal or ammonium salt of polyvinylsulfuric acid results in the scale prevention. This combination is applied to reactor surfaces via its mixture with a solvent and is subsequently dried to form the coating.

Abstract: A process to prevent scale adhesion to reactor surfaces using an alkaline solution of the condensation product of an aromatic diamino compound and a quinone. The aromatic amino compound has the general formula (1): ##STR1## wherein R.sup.1 is at least one group selected from the group consisting of --OH, --COOH and --SO.sub.3 H, R.sup.2 is a hydrogen atom or a substituent group, X is a single bond or a divalent group of the formula --CH.dbd.CH--, and m and n are each an integer from 0 to 4, provided m and n are not simultaneously zero, when a plurality of R.sup.1 groups are present they may be identical or different, and when a plurality of R.sup.2 groups are present they may be identical or different, with (A-2) a quinone compound, and a process for producing a polymer using the agent are disclosed.

Abstract: A polymer scale preventive agent for coating internal reactor surfaces. The coating is a condensation product of an aromatic amine and a quinone in an alkaline solvent, used in conjunction with colloidal silica and/or alkali metal silicates.

Abstract: A process to prevent the adhesion of polymer scale during the polymerization of vinyl monomers which involves coating the internal reactor surfaces with the condensation product of a diamino heterocyclic and an amine compound. The coating is applied as an alkaline solution followed by drying. The coating is effective in preventing scale adhesion on the portions of the reactor exposed to the liquid phase reaction medium as well as the gas-liquid interface. The polymer resulting from use of the coating exhibits few fish eyes and little discoloration.

Abstract: A process to inhibit scale adhesion to the interior of a polymerization vessel using a two part coating composition. The coating is a hydroxyanthraquinone compound used in conjunction with a water soluble salt of chitosan, applied as a solution and dried on the vessel interior. Advantages of the coating are its effective scale prevention, unaltered color of the polymer product and low toxicity.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising (A) a pyrogallol-acetone resin, and (B) a water-soluble polymeric compound. When a coating comprising the polymer scale preventive agent is formed on inner wall surfaces of a polymerization vessel and the polymerization is carried out by use of the vessel, deposition of polymer scale can be effectively prevented not only in the areas in the liquid phase inside the vessel but also in the vicinity of the interface between the gas phase and the liquid phase in the vessel. The polymeric product thus obtained can then be processed into sheets or other formed products which have few fish eyes and low initial coloration.

Abstract: A polymer scale preventive liquid for use in polymerization of a monomer having an ethylenic double bond, comprising (A) a protein and (B) an anionic polysaccharide, and having a pH 7 or less; and a method of preventing polymer scale deposition in a polymerization vessel, which comprises carrying out the polymerization of said monomer in a polymerization vessel having a coating on its inner wall surfaces by applying said liquid and then drying. Deposition of polymer scale can be effectively prevented; in addition, polymers with a high whiteness can be prepared. Moreover, this polymer scale preventive liquid has no poisonousness and is highly safe.

Abstract: A polymer scale preventive agent for use in polymerization of a monomer having an ethylenically unsaturated double bond, comprising:(A) at least one compound selected from the group consisting of diaminobenzenes and diaminonaphthalenes,(B) a hydroxynaphthoquinone, and(C) an acid. The polymerization vessel having a coating comprising the polymer scale preventive agent on its inner wall, etc. is effective in preventing deposition of polymer scale, and the polymeric product has a high whiteness and is of high quality.

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 dibasic acid dihydrazide 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 and useful in producing a polymer that shows very few fish eyes and good whiteness when formed into sheets or the like.

Abstract: A process and coated vessel for use in the prevention of scale adhesion during the polymerization of a monomer having an ethylenic double bond, the two part coating comprising an N-substituted leucophenothiazine dye having the general formula (I): 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., used in conjunction with a vinyl pyrrolidone polymer. The two part coating is used 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 condensation product of:(A) an aromatic amine compound, and(B) an aromatic hydroxyl compound condensate.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 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 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 for use in polymerization of a haloethylene or a monomer mixture containing the same, comprising:(A) an aromatic compound having at least one group selected from the class consisting of primary, secondary and tertiary amino groups, quaternary ammonium groups and the azo group and/or a dye having at least one group selected from said class, and(B) an alkali metal or ammonium salt of a polyvinylsulfonic acid, and(C) a naphthoquinone natural dye; a polymerization vessel having a coating comprising said scale preventive agnet. A process of preparing a haloethylene polymer using the vessel can produce a polymer of high quality without polymer scale deposition.

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 polycarbonate having desirable color tone or transparency, as well as desirable heat resistance and water resistance, in which the amounts of residual metals in the polycarbonate are 10 ppm or less in total of Fe, Cr and Mo and 50 ppm or less in total of Ni and Cr. The polycarbonate is obtained by transesterification of (A) a dihydroxy compound and (B) a carbonic diester in a reactor made of a metallic material containing at least one metal selected from the group consisting of Fe, Cr, Mo, Ni and Cu, and controlling the water content in the reactor to 500 ppm or less.

Abstract: A process and plant are disclosed for the manufacture of particulate or liquid elastomeric polymers suitable for the manufacture of a wide variety of commercial elastomers, substantially in the absence of water for purifying and particulating the elastomer.

Abstract: Disclosed are a deposit suppressant composition for the internal surfaces of a polymerization reactor for polymerizing a vinyl monomer, comprising a naphthol sulfide compound having an average molecular weight of about 500 to 5000, as well as a method of polymerizing a vinyl monomer wherein prior to the polymerization, the deposit suppressant composition is applied to the internal surfaces of a polymerization reactor or added to the reaction system.

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: Polyvinyl chloride reactor wall scale is reduced by conducting the polymerization in the presence of a phenothiazine dimer or higher oligomer made by reacting an aldehyde such as acetaldehyde or benzaldehyde with phenothiazine, or by reacting 2-acetylphenothiazine with formaldehyde.

Abstract: A process for producing a vinyl chloride polymer by polymerizing a monomer comprising vinyl chloride by suspension polymerization in a polymerization vessel on the inner wall surface of which a coating of a polymer scale preventive agent is formed, comprising the steps of applying a high-speed shearing force to a mixture comprising water, the monomer, a polymerization initiator, and (A) a dispersant comprising a partially saponified polyvinyl alcohol having a specified average degree of polymerization and a specified degree of saponification plus (B) a dispersant comprising a hydroxypropylmethylcellulose which has a specified methoxyl substitution degree, a specified hydroxypropoxyl substitution degree, and a specified viscosity and subjecting the mixture to said suspension polymerization. A vinyl chloride polymer having an average particle diameter of 200 to 600 .mu.m and a narrow particle size distribution and excellent in plasticizer take-up, etc. is provided.

Abstract: A method of preventing polymer scale deposition in a polymerization vessel in polymerization of a particular monomer having an ethylenic double bond having a high dissolving power against the conventional scale preventive coatings, wherein said polymerization is carried out in a polymerization vessel of which the inner wall has been previously coated with a first coating liquid comprising:(A) a water-soluble anionic dye, and(B) a metal salt, to form a first coating, and the first coating thus formed has been then coated with a second coating liquid comprising:(C) an alkaline earth metal compound, and at least one member selected from the group consisting of:(D) a water-soluble anionic dye and(E) an inorganic colloid,to form a second coating. Polymer scale deposition can be effectively prevented.

Abstract: A process for preparation of a vinyl chloride polymer comprising the steps of subjecting an aqueous medium containing vinyl chloride monomer or a mixture of vinyl chloride monomer with other vinyl monomer, a polymerization initiator and a dispersant to high-speed shear agitation at a shear rate of 10.sup.4 sec.sup.-1 or above to prepare a suspended dispersion containing fine particles of the monomer(s) dispersed therein, then subjecting the suspended dispersion to low-speed shear agitation at a shear rate of from 10 to 100 sec.sup.-1, and thereafter starting suspension polymerization. Even with a decreased amount of dispersant, the process inhibits the coarsening of the polymer particles, to yield the polymer with a narrow particle diameter distribution. Deposition of scale and formation of fish-eyes are also prevented effectively.

Abstract: Disclosed is a method of polymerizing a vinyl monomer wherein prior to the polymerization, a deposit suppressant composition comprising an 8-hydroxyquinoline sulfide compound is applied to the internal surfaces of a polymerization reactor.

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: Polymer scale deposition from a polymerization medium in which a monomer having an ethylenic double bond is polymerized, is prevented by conducting the polymerization in a polymerization vessel having a coating by applying a liquid comprising (A) an organic compound containing at least one member selected from the group consisting of a sulfonic acid group and a carboxylic acid group and having a molecular weight of 1000 or less and (B) a water-insoluble compound having an absorption band in the visible light range of 540 to 750 nm, the compounds (A) and (B) having been dissolved or dispersed in (C) an ester-based organic solvent, and having a pH of 3 or less; to the inner wall surfaces of said polymerization vessel. Polymer scale can be effectively prevented and polymeric products are barely colored.

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 in a polymerization vessel in polymerization of a particular monomer having an ethylenic double bond having a high dissolving power against the conventional scale preventive coatings, wherein said polymerization is carried out in a polymerization vessel of which the inner wall has been previously coated with a first coating solution comprising:(A) a water-soluble anionic dye, and(B) at least one member selected from the group consisting of inorganic colloids and cationic dyes, to form a first coating, and the first coating thus formed has been then coated with a second coating solution comprising:(C) an alkaline earth metal compound, and at least one member selected from the group consisting of:(D) a water-soluble anionic dye and(E) an inorganic colloid, to form a second coating. The polymerization vessel having the double coating as prepared above is also disclosed. Polymer scale deposition can be effectively prevented.

Abstract: A microsuspension polymerization process for polymerizing vinyl chloride and optional comonomers to polyvinyl chloride and optional copolymers is disclosed which comprises conducting the polymerization in a tubular reaction zone without agitation in the presence of a compound having the formula ##STR1##

Abstract: The present invention relates to a coating solution for preventing adhesion of polymer scale and a method for preventing scale adhesion during preparation of polymers which can provide polymers having high quality without coloring thereof while preventing adhesion of polymer scale to a polymerizer when a monomer having an ethylenically unsaturated double bond is polymerized. A coating solution for preventing adhesion of polymer scale which comprises anaphthoquinone natural dyestuffs, anthraquinone natural dyestuffs, tannin natural dyestuffs, xanthone natural dyestuffs, flavonoid natural dyestuffs, or/and benzoquinone natural dyestuffs and a polyvinyl alcohol having a degree of saponification of not less than 70 mole % was applied on at least a part of a polymerizer which comes in contact with a monomer having an ethylenically unsaturated double bond and was dried to give a coating film during polymerization thereof.

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: The present invention relates to a process for substantially inhibiting polymer build-up on reactor surfaces during polymerization. The method generally comprises the application of a polyaniline coating composition to the reactor surfaces in contact with the reaction medium prior to charging the reactor and the carrying out of the polymerization reaction. The polyaniline coating composition broadly consists of about 0.01 to about 20% by weight of deprotonated polyaniline, such as polyaniline in the pernigraniline oxidation state, dissolved in an organic solvent carrier, such as dimethyl sulfoxide (DMSO), 1-methyl-2-pyrrolidinone (NMP), acetic acid, sulfuric acid, formic acid and tetrahydrofuran (THF).

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: An improvement is proposed in the process of suspension polymerizatiopn of vinyl chloride monomer in an aqueous polymerization medium, by which a resin product of high quality relative to the contents of foamy resin and fish-eyes can be produced in a high efficiency with little deposition of polymer scale on the reactor walls. The improvment comprises heating and keeping the surfaces of the polymerization reactor and accessory equipment coming into contact with the gaseous phase above the polymerization mixture at a temperature of 55.degree. C. or higher during a period starting from a moment when the temperature of the polymerization mixture under temperature elevation up to the polymerization temperature is still 45.degree. C. or lower to a moment when conversion of the monomer into polymer is at least 10% so that foaming on the polymerization mixture can be greatly reduced.

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: The present invention refers to a process for inhibiting the formation of polymer buildup on the inner surfaces of a vinyl polymerization reactor by coating such surfaces with an alkaline solution of a linear or branched low molecular weight compound belonging to the poly(hydroxybenzyl) and poly(hydroxybenzylether) families and including their copolymers or blends. This process effectively reduces the adherence of polymeric material to the inner parts of the reaction vessel wherein substituted ethylene monomers are polymerized.

Abstract: A process for preparing high molecular weight water soluble polymer gels having relatively narrow molecular weight distributions is disclosed. An aqueous reaction mixture comprising a solution of a water soluble vinyl monomer and a suitable catalyst system is polymerized in a reactor comprising a tube or bag of an oxygen-impermeable film in the substantial absence of oxygen.

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 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.