Abstract: A method for polymerizing vinyl chloride comprises polymerizing vinyl chloride in an aqueous medium or bulk-polymerizing vinyl chloride, wherein the inner wall of a polymerizer and parts of devices which come in contact with the monomer during the polymerization are coated, prior to the polymerization, with a reaction product having a molecular weight ranging from 500 to 100,000, obtained by condensing a polyhydric phenol and sulfur dichloride in the presence of a Lewis acid as a catalyst. The amount of the polymer adhered to the polymerizer during polymerization of vinyl chloride is substantially lowered and the adhered polymer can be easily washed away through simple water washing according to the foregoing method. Moreover, the method does not adversely affect the reaction time and the quality of the resulting product at all.

Abstract: Scale deposits during polymerization of monomers containing ethylene-type double bonds are prevented by coating the reactor walls and parts with cationic dyes oxidized with hydrogen peroxide.

Abstract: A method of treating the surface of an absorbent resin, which comprises mixing (A) 100 parts by weight of an absorbent resin powder possessing a carboxyl group (B) 0.01 to 30 parts by weight of a cross-linking agent, (C) 0 to 50 parts by weight of water, and (D) 0 to 60 parts by weight of a hydrophilic organic solvent in a high-speed stirring type mixer provided with an inner surface formed substantially of a substrate (I) possessing a contact angle of not less than about 60.degree. with respect to water and a heat distortion point of not lower than about 70.degree. C. and completing reaction of said absorbent resin powder (A) with said cross-linking agent (B).

Abstract: The present invention refers to a process for the preparation of a scale inhibiting solution that consists of: a) a low molecular weight compound belonging to the families of the polyhydroxybenzyls, polyhydroxyarylethers, its copolymers or blends b) an alkali and c) a strong electrolyte, which is used to coat the internal surfaces of polymerization reactors. This scale inhibiting solution reduces effectively the adherence of polymeric material to the inner parts of the reaction vessel when monomers such as vinylics, vinylidenes, acrylics, methacrylics, vinylaromatics, diolefins and their mixtures are polymerized via suspension, microsuspension, dispersion or emulsion.

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.

Abstract: A method for the production of an absorbent polymer by the polymerization of a liquid containing an aqeous hydrophilic monomer solution in a reaction vessel provided with at least one rotary stirring blade, which comprises polymerizing said hydrophilic monomer in a reaction vessel wherein, at least a portion of the inner wall surface of said reaction vessel repeatedly exposed to said aqueous solution or said absorbent polymer and a gas has the surface roughness, R.sub.max, thereof adjusted to not more than 3 .mu.m and at the same time said portion of the inner wall of surface is kept cooled constantly to a temperature of not more than 70.degree. C. from behind said portion with a cooling medium.

Abstract: A plastic light conduit of cross-linked polymer material having good light transmitting characteristics, without voids or noticeable bubbles, is disclosed. Also disclosed is a method of manufacture and an apparatus, involving progressive heating of reactive monomer mixture in a tube which is submerged in a progressive reactor utilizing cold oil to maintain a cold, non-reacting zone, and hot water to create a hot zone that causes reaction, while simultaneously carrying away the excess exothermic heat of reaction.

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 first coated with(A) a coating solution comprising a condensate of an aromatic compound and at least one member selected from the group consisting of metal compounds and inorganic colloids, and the coating thus formed has been then coated with(B) a coating solution comprising at least one member selected from the group consisting of anionic polymeric compounds, amphoteric polymeric compounds and hydroxyl group-containing polymeric compounds; and a polymerization vessel having a coating thus formed. According this method, polymer scale deposition on the inner wall, etc. of the polymerization vessel can be effectively prevented.

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 a coating comprising a reaction product of a tannin and an acid halide. Polymer scale deposition on the inner wall, etc. of the polymerization vessel can be effectively prevented. The preventive agent used has neither risk of produced polymer being colored nor toxicity.

Abstract: A process for treating a mixture of a polymer and a chlorinated organic solvent under heating, characterized by employing an apparatus in which a portion thereof to be brought into contact with the heated mixture is made of an acid resistant inorganic material selected from a group consisting of a metallic composition containing at least 85% of copper, nickel or a mixture thereof, and a ceramic material. Deterioration in color is improved in a process for recovering a polymer dissolved in the chlorinated organic solvent.

Abstract: Free radical polymerization of monomers in the presence of t-amylperoxy pivalate as the free radical initiator is described. Copolymers of maleic anhydride and a vinyl monomer, e.g. a C.sub.1 -C.sub.5 alkyl vinyl ether, and water soluble polyvinylpyrrolidone, are representative polymers prepared in accordance with the process of the invention.

Abstract: Polymerization of methacrylate and acrylate monomers on surfaces such as in vents is inhibited by coatings of water-base paint containing phenothiazine.

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 of which the inner wall has been previously coated with a coating solution comprising:(A) an aromatic amine-based condensate,(B) at least one member selected from the group consisting of alkali metal salts and ammonium salts of a sulfonation product prepared by sulfonation of an aromatic amine-based condensate, and(C) at least one member selected from the group consisting of metal compounds, inorganic colloids, dyes and pigments; a scale preventive agent comprising the components (A), (B) and (C); and a polymerization vessel having a coating comprising the scale preventive agent. According the method, polymer scale deposition on the inner wall, etc. of the polymerization vessel can be effectively prevented.

Abstract: The present invention relates to a process and compositions for delaying the gelling of vinyl monomers in an aqueous medium in the presence of a polymerization initiator, by employing a polymerization inhibitor consisting of an N-nitrosophenylamine salt in combination with an aminocarboxylic acid. The composition is used for plugging circulation losses when drilling at great depth.

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 a coating comprising a reaction product of a tannin and an aldehyde; a scale preventive agent comprising said reaction product; 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.

Abstract: A method of preventing polymer scale formation in a polymerization vessel during the polymerization of a monomer having an ethylenically double bond, wherein said polymerization is carried out in a polymerization vessel in which its inner wall surface has been previously coated with a coating solution containing (A) at least one member selected from the group consisting of particular anionic dyes, and alkali metal salts and ammonium salts of a sulfonated product obtained by sulfonation of a condensate of a particular aromatic amine compound with a particular aromatic nitro compound, and (B) a particular cationic dye and having a pH of more than 7, and then dried to form a coating. This method can effectively prevent scale formation in the polymerization of extensive monomers having an ethylenically double bond, so that 100 or more polymerization runs can be repeated without formation of polymer scale.

Abstract: A method of preventing polymer scale deposition in polymerization of a monomer having an ethylenically double bond, wherein said polymerization is carried out in a polymerization vessel in which its inner wall surface has been previously coated with a coating solution comprising:(A) a condensate of a phenolic hydroxy group-containing compound,(B) at least one member selected from the group consisting of metal compounds and inorganic colloids, and(C) at least one member selected from the group consisting of dyes and pigments. This method makes it possible to prevent polymer scale deposition regardless of polymerization conditions such as the kind of monomers, the type of polymerization vessel, etc.

Abstract: An improvement in the process for the continuous copolymerization of ethylene with certain polar comonomers having reactive double bonds, wherein a single phase is maintained in the reactor by means of methanol introduced concurrently with the reactants, whereby reactor fouling is significantly reduced or eliminated.

Abstract: A resin used for magnetic recording media, comprising a vinyl chloride copolymer containing vinyl monomers with hydroxyl groups and vinyl monomers with quaternary ammonium salt groups as component units. The resin is made by a method which comprises polymerizing an organic solvent solution containing vinyl chloride, vinyl monomers with hydroxyl groups and vinyl monomers with quaternary ammonium salt groups in a reacting apparatus to thereby precipitate a vinyl chloride copolymer, the interior surface of said reacting apparatus, which comes into contact with said organic solvent solution being coated with a fluororesin.

Abstract: An agent for preventing vinyl chloride polymer build-up, which contains as the effective ingredient a reaction product of ammonium salt or a metal salt of N-nitrosophenylhydroxylamine with an aldehyde.

Abstract: Polymer scale deposition on polymerization reactor inside surfaces in the polymerization of a monomer or monomers having an ethylenic double bond and/or a monomer or monomers having diolefinic double bonds is prevented, peelability or removability of polymer scales deposited on such surface, if any, is improved and the scale inhibitor adherence to the wall surface of glass-lined polymerization reactors is improved by coating the inside surfaces of the reactor in advance with a coating composition comprising a quinone-amine compound having a molecular weight of at least 3,000 as obtained by subjecting at least one aromatic diamine and at least one aromatic quinone to addition reaction in at least one solvent having a solubility parameter of 8.5 to 24.0 and/or a reduced form of said quinone-amine compound and at least one silica organosol or a mixture of at least one silica organosol and at least one alkyl silicate to thereby form a hydrophilic coat film on the surfaces.

Abstract: To reduce fouling on reactor surfaces, the surfaces are coated with a protective film of polymeric material of surface energy of less than 15 dynes/cm. The preferred coating materials are polymers of one or more monomer chosen from the 2-(N-alkylperfluorosulphonamido)) alkyl (meth)acrylates or the fluorochemical polymer known as Fluorad (Registered Trade Mark of the 3M company) FC-721.

Abstract: A method for the prevention of fouling of metallic surfaces exposed to reactive alpha-olefin gases during the production of polymeric resins which comprise coating such metallic surfaces with an amino silicone fluid and thereafter curing said coating by hydrolysis to form a continuous solid coating.

Abstract: The polymer buildup problem that may occur in the reactor where the inversion polymerization of vinylchloride is conducted can be effectively ameliorated by way of coating the internal surfaces of the reactor with a mixture comprising an expanding lattice clay, e.g., veegum, and a water-soluble suspending agent, e.g., polyacrylic acid.

Abstract: Polyvinyl chloride resins and copolymers thereof are produced containing little or no gel content, commonly referred to as "fisheyes", even after numerous charges to a reaction vessel without cleaning thereof between charges. A primary dispersant system such as a high hydrolyzed polyvinyl acetate and an optional modified cellulose ether is utilized in association with a low hydrolyzed secondary dispersant, for example, polyvinyl acetate, in the reaction vessel such as a polymerizer containing an aromatic inhibitor polymer build-up compound coated on the internal walls thereof. The resin particles produced tend to have a uniform particle size and a high porosity so that plasticizers can readily be incorporated therein. Since contamination buildup on the reaction vessel walls is reduced or prevented, the amount of gel is reduced and production rate is increased since, as noted above, cleaning of the vessels is not required.

Abstract: A method of preventing polymer scales from sticking in a polymerization vessel during the polymerization of a monomer having an ethylenically double bond, wherein said polymerization is carried out in a polymerization vessel of which the inner wall and other parts with which said monomer comes into contact during polymerization are previously first coated with (a) a coating solution comprising a cationic dye and the resulting coating is then coated with (b) a coating solution comprising at least one component selected from the group consisting of anionic polymeric compounds, amphoteric polymeric compounds and hydroxyl group-containing organic compounds. Polymer scale formation can be effectively prevented.

Abstract: Disclosed herein is a process for producing a medium- or high-molecular-weight polyarylene sulfide which comprises subjecting an alkali metal sulfide, a dihalo aromatic compound and optionally, small amount of tri- or higher polyhalo aromatic compound to dehalogenation and sulfidation reaction at a temperature of from 240.degree. to 270.degree. C. in the presence of a water in amount of from 0.5 to 5 mol per 1 kg of an aprotic organic polar solvent until the conversion of said dihalo aromatic compound reaches from 70 to 98 mol %, thereby forming a polyarylene sulfide prepolymer having a melt viscosity of from 5 to 300 poise (as measured at 310.degree. C. under a shear rate of 200 sec.sup.-1), adding water to the resultant reaction mixture containing the polyarylene sulfide prepolymer so that from 6 to 15 mol of water is present per 1 kg of said solvent, and then continuing the reaction at a temperature of from 240.degree.-290.degree. C.

Abstract: In the process of producing linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon in the presence of a catalyst composition formed from a palladium compound, a bidentate ligand of phosphorus and a non-hydrohalogenic acid having a pKa below 2, lessened reactor fouling is encountered when the amount of acid initially provided is limited with additional acid being provided when polymerization has reached a certain minimum level.

Abstract: This invention relates to a process for the preparation of polyarylene sulphides by melt condensation, in which the sulphide bridges of the polymer are formed by the splitting off of a compound which is volatile under the reaction conditions.

Abstract: This invention relates to a process for the preparation of polyarylene sulphides by melt condensation, in which the sulphide bridges of the polymer are formed by the splitting off of a compound which is volatile under the reaction conditions.

Abstract: In a process of polymerizing ethylenically unsaturated compounds by polymerization of ethylenically unsaturated monomers in the presence of a free radical-forming initiator system and customary protective colloids and/or emulsifiers and optional known additives in a reactor whose surfaces contact the reaction components, the improvement comprising providing the reactor surfaces with a coating that at least suppresses polymer deposit formation without effecting the color and quality of the polymer.

Abstract: A process for reducing sheeting during production of polyolefins by polymerization of alpha-olefins utilizing titanium based polymerization catalysts wherein the static electric charges in the reactor at the side of possible sheet formation are maintained below static voltage levels which would otherwise cause sheet formation.

Abstract: A process for preparing a vinyl chloride polymer by suspension polymerization with use of (A) a particular partially saponified polyvinyl alcohol having a high polymerization degree and a high saponification degree, (B) a particular hydoxypropyl methyl cellulose and (C) a particular partially saponified polyvinyl alcohol having a low polymerization degree and a low saponification degree as dispersion stabilizers, in a polymerization vessel coated with a scale preventive on its inner wall etc., wherein an (A)Agent/(B)agent ratio is 4/6 to 24/1 in weight ratio; Agent (C) is used in an amount of 0.001 to 0.1% by weight based on the charged monomers; Agent (C) is charged with or after the charging of Agent (A) and (B), and, the particle diameter of Agent (C) in the suspension mixture is controlled to not higher than 100 .mu.m. A vinyl chloride polymer having a high bulk density and high porosity can be produced without formation of polymer scale.

Abstract: A process for the gas phase polymerization of vinyl chloride, which comprises homopolymerizing monomeric vinyl chloride or copolymerizing monomeric vinyl chloride with a monomer copolymerizable therewith in the gas phase at a polymerization temperature of 55.degree. C. to 65.degree. C. under such conditions that the ratio Pr of the polymerization pressure to the saturated vapor pressure at the polymerization temperature is in the range of 1>Pr>0.5, wherein a mixture comprising diisopropylperoxy dicarbonate and di-2-ethoxyethylperoxy dicarbonate at a weight ratio of from 3/2 to 85/15 is used as the initiator.

Abstract: Disclosed herein is a process for producing a medium- or high-molecular-weight polyarylene sulfide which comprises subjecting an alkali metal sulfide, a dihalo aromatic compound and optionally, small amount of tri- or higher polyhalo aromatic compound to dehalogenation and sulfidation reaction at a temperature of from 235.degree. to 280.degree. C. in the presence of a water in amount of from 0.5 to 5 mol per 1 kg of an aprotic organic polar solvent until the conversion of said dihalo aromatic compound reaches from 70 to 98 mol %, thereby forming a polyarylene sulfide prepolymer having a melt viscosity of from 5 to 300 poise (as measured at 310.degree. C. under a shear rate of 200 sec.sup.-1), adding water to the resultant reaction mixture containing the polyarylene sulfide prepolymer so that from 6 to 15 mol of water is present per 1 kg of said solvent, and then continuing the reaction at a temperature of from 240.degree.-290.degree. C.

Abstract: A method for reducing sheeting during polymerization of alpha-olefins by feeding either a positive charge generating or negative charge generating chemical additive to the reactor responsive to particular static levels in the reactor. The chemical additive is added in amounts which neutralize the charges in the reactor.

Abstract: A polyarylenethioether primary melt formed article having a Hunter whiteness higher than 30% and a parallel light transmittance Tp higher than 60%, as measured for a sheet with a thickness of 0.3 mm, at the process for obtaining the article which comprises producing a polyarylenethioether according to the polymerization reaction comprising a dehalogenation/sulfidization reaction between an alkali metal sulfide and a dihaloaromatic compound in a polar organic solvent by carrying out the reaction with the addition of an effective amount of a halo-substituted organic compound to obtain a stabilized polyarylenethioether, and then subjecting the polyarylenethioether to melt extrusion. The melt formed article thus produced can be subjected to further melt processing to produce a secondary melt formed article or structure of polyarylenethioether.

Abstract: A process for preparing a scale deposition preventing agent of a quinone-amine compound suitable for use in a polymerization of acrylic or methacrylic acid ester monomers, which comprises (A) subjecting an aromatic quinone and an aromatic diamine to addition reaction in a solvent having a solubility parameter of 8.5 to 24.0 to give an addition product, and (B) converting the addition product into a high molecular weight compound within 24 hours after beginning the addition reaction (A) by adding an oxidizing agent to the addition reaction mixture or by subjecting the addition reaction mixture to anodic oxidation with an electrode to give a quinone-amine compound. According to the present invention, the preparation rate of the scale deposition preventing agent of the quinone-amine compound can be remarkably increased, the yield can be increased, and the obtained compound has excellent properties.

Abstract: A process for reducing sheeting during production of polyolefins by polymerization of alpha-olefins utilizing titanium based polymerization catalysts wherein the static electric charges in the reactor at the site of possible sheet formation are maintained below static voltage levels which would otherwise cause sheet formation.

Abstract: A process for production of a vinyl polymer by suspension polymerization or emulsion polymerization of at least one kind of vinyl monomer in an aqueous medium is disclosed.In this process, the polymerization is carried out in a polymerizer, the inner wall surface and portions of the auxiliary equipment thereof which may come into contact with the monomer during polymerization having a surface roughness of not greater than 5 .mu.m and being previously coated with a scaling preventive comprising at least one selected from dyes, pigments and aromatic or heterocyclic compounds having at least 5 conjugated .pi. bonds. According to this process, scaling on the inner wall surface of a polymerizer, etc. during polymerization can be prevented effectively and surely.

Abstract: This process is a process for production of a vinyl chloride polymer by suspension polymerization or emulsion polymerization of vinyl chloride monomer or a mixture of vinyl chloride monomer with a vinyl monomer copolymerizable with said vinyl chloride monomer in an aqueous medium, characterized in that the polymerization is carried out in a polymerizer, the inner wall surface and portions of the auxiliary equipment thereof which may come into contact with the monomer during polymerization being previously coated with a scaling preventive comprising at least one selected from dyes, pigments and aromatic or heterocyclic compounds having at least 5 conjugated .pi. bonds, while controlling the chloride ion concentration in the reaction mixture to not higher than 100 ppm. According to said process, scaling onto the inner wall surface of a polymerizer, etc. during polymerization can be prevented effectively and surely.

Abstract: An apparatus for producing a polyacetylene film by contacting acetylene gas with Ziegler-Natta catalyst to polymerize the acetylene gas in a vessel which comprises a catalyst introduction conduit to be introduced with the Ziegler-Natta catalyst provided at a cap provided at the top of the vessel and having an end opening disposed in the vicinity of the inner surface of the side wall of the vessel in such a manner that the conduit and the vessel are relatively moved in rotation, and a rotary transmission mechanism for driving to rotatably coat the catalyst flowed out from the end opening of the conduit on the inner surface of the bottom from the inner surface of the side wall of the vessel. Thus, the polyacetylene film can be produced in a uniform thickness and in a relatively large area by introducing the Ziegler-Natta catalyst of the suitable quantity, and the catalyst can be spread over the entire surface rapidly by the relative rotation between the conduit and the vessel.

Abstract: The invention relates to a process for producing a powder of a cationic polymer by spreading on a moveable carrier a layer of an aqueous solution of a vinyl monomer, carrying out continuous polymerization followed by peeling off hydrous polymer from the carrier in a hot state, and cutting said hydrous polymer in a hot state by a shearing stress.

Abstract: An aqueous coating solution is sprayed into the interior of the reactor. After the aqueous coating solution has been sprayed, steam is injected and condensed within the reactor. Upon polymerizing a vinyl chloride-base monomer composition in the reactor after having been treated, the formation of deposits of polymer on the internal surfaces of the reactor is substantially reduced and even suppressed.

Abstract: This invention relates to a polymerization reaction vessel having a coating on the inner surfaces thereof resulting from applying thereto an aqueous coating composition containing an unneutralized lightly crosslinked interpolymer of one or more carboxylic acid monomers with a polyunsaturated compound having a plurality of terminally unsaturated polymerizable groups whereby polymer buildup on said inner surfaces is substantially eliminated. Optionally, there is employed in the coating composition a water-soluble surfactant which contains polyether-type hydrophilic segments, such as, for example, polyoxyethylene (20) sorbitan monooleate. Multiple charges or batches of polymer can be made in said internally-coated reaction vessel without opening the same between charges, thus preventing the escape of unreacted monomer to the surrounding atmosphere.

Abstract: A process for the continuous preparation of aqueous plastic dispersions which comprises emulsifying one or more free-radically polymerizable monomers in an aqueous phase in the presence of an emulsifying agent, in an agitator vessel; initiating the free-radical polymerization of said monomer or monomers in said aqueous phase; and passing said aqueous emulsion of the free-radically polymerizing monomer or monomers through a tubular reactor whose internal surface comprises an (optionally fluorinated)saturated polyolefin.

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: Compositions of salts of water-soluble, carboxyl-containing polymers and surface active agents, deposited on polymerization reactor surfaces exposed to polymerization mixtures, substantially reduce or eliminate undesirable polymer build-up on reactor surfaces during aqueous polymerization of vinylidene monomers, even when the amount of carboxyl-containing polymers deposited on the reactor surfaces is very small.

Abstract: A method of preventing the scale from sticking wherein, upon the polymerization of vinyl type monomers in aqueous medium, reaction products of liquid polybutadiene with phenolic compounds or reaction products between thermoplastic resin gathered from the stumps of pine, phenolic compounds and, if desired, aldehyde compounds are coated beforehand onto the inside face of polymerization vessel, and a preventive agent of scale from sticking are disclosed.

Abstract: An apparatus for producing a polyacetylene film by contacting acetylene gas with Ziegler-Natta catalyst to polymerize the acetylene gas in a vessel which comprises a catalyst introduction conduit to be introduced with the Ziegler-Natta catalyst provided at a cap provided at the top of the vessel and having an end opening disposed in the vicinity of the inner surface of the side wall of the vessel in such a manner that the conduit and the vessel are relatively moved in rotation, and a rotary transmission mechanism for driving to rotatably coat the catalyst flowed out from the end opening of the conduit on the inner surface of the bottom from the inner surface of the side wall of the vessel. Thus, the polyacetylene film can be produced in a uniform thickness and in a relatively large area by introducing the Ziegler-Natta catalyst of the suitable quantity, and the catalyst can be spread over the entire surface rapidly by the relative rotation between the conduit and the vessel.