Abstract: There is disclosed a process for preparing vinyl dispersion resins by conducting the polymerization reaction of the vinyl monomer or monomers in an aqueous medium using a low water solubility free radical yielding polymerization initiator or catalyst along with an inorganic or organic activator, using a fast reaction at the beginning of polymerization by employing a temperature below the desired temperature, then at the desired temperature and finally above the desired temperature, using an emulsifier system of an ammonium or an alkali metal salt of a high fatty acid containing from 8 to 20 carbon atoms, and/or a sulfate or sulfonate type soap, and at least one long straight chain alcohol containing from 12 to 24 carbon atoms, and conducting said polymerization in a reactor having a coating on the inner surfaces thereof comprising a polymerization inhibitor, the ingredients being thoroughly mixed prior to polymerization. Polymer buildup on the internal surfaces of the reactor is substantially reduced.

Abstract: This invention relates to the reduction of polymer buildup on the inner surfaces of a polymerization reactor by applying a polymer buildup resistant coating to the inner surfaces thereof, the method or process of applying said coating being the subject of this invention. An approximate monolayer coating on the inner surfaces of the reactor results from applying thereto an aqueous or organic solvent solution of the coating material by means of a hydrocarbon gas, such as propane, for example. The coating material is an organic compound or polymer which is capable of resisting polymer buildup thereon. As examples of such coating materials, there may be named the polyaromatic amines, self-condensed polyhydric phenols, tannic acid and tannates, various dyes, such as nigrosine, and the like, etc. When using hydrocarbon gas to apply the coating material, the same reaches the inner reactor surfaces in the form of a mist.

Abstract: This invention relates to the reduction of polymer buildup on the inner surfaces of a polymerization reactor by applying a polymer buildup resistant coating to the inner surfaces thereof, the method or process of applying said coating being the subject of this invention. An approximate monolayer coating on the inner surfaces of the reactor results from applying thereto an aqueous or organic solvent solution of the coating material by means of vinyl chloride in vapor form. The coating material is an organic compound or polymer which is capable of resisting polymer buildup thereon. As examples of such coating materials, there may be named the polyaromatic amines, self-condensed polyhydric phenols, tannic acid and tannates, various dyes, such as nigrosine, and the like, etc. When using vinyl chloride to apply the coating material, the same reaches the inner reactor surfaces in the form of a mist.

Abstract: An epoxy resin, useful for coating the internal surface(s) of a reactor such as one used for vinyl halide, particularly vinyl chloride, polymerisation in aqueous dispersion for the purpose of suppressing build-up, is made by cross-linking (I) the uncross-linked polyether intermediate of an epoxy resin, by admixture with (II) a product made from the reaction of (A) at least one aliphatic amine containing two or more primary aliphatic amino groups, (B) at least one aromatic amine containing two or more primary aromatic amino groups, and (C) at least one compound selected from oxo-group substituted aromatic compounds and quinone-type compounds, wherein the molar ratio (A):(B) is 4:1 to 1:3.Preferably, (I) is made from the reaction between 2,2-bis-(4-hydroxyphenyl) propane and epichlorohydrin and (II) is made from the reaction of (A) tetraethylenepentamine, (B) p-phenylene diamine, and (C) hydropquinone and pyrogallol.

Abstract: This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a coating on the internal surfaces of the polymerization reactor. The coating on said surfaces may be a singular layer or a dual layer coating. By inversion polymerization is meant conducting the initial stage of the polymerization reaction in a medium wherein the monomer or monomers being polymerized constitute the continuous phase and in the second or later stage of polymerization, water constitutes the continuous phase. The principal coating, or undercoating when a dual layer coating is employed, comprises a protein, such as egg albumen, and when a top coating is used it comprises a water-soluble suspending agent, such as an alkyl or alkyl hydroxyalkyl cellulose ether. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.

Abstract: This invention relates to the reduction of polymer buildup on the inner surfaces of a polymerization reaction vessel by applying a coating to the inner surfaces thereof. An approximate monolayer coating on the inner surfaces of the reactor results from applying thereto an aqueous solution of a hydrophilic polymer-inhibitor complex, for example, such as a complex of polyvinyl alcohol and the disodium salt of bisphenol A. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C< grouping, and mixtures thereof, in the presence of said coating, polymer buildup on the inner surfaces of the reaction vessel is substantially eliminated.

Abstract: Build-up during vinyl halide, particularly vinyl chloride, polymerization is prevented by employing a polymerization process using a reactor having an adherent internal coating of a coating product derived from the admixture of at least polyethyleneimine; one or more of hydroquinone, p-benzoquinone, catechol and o-benzoquinone; and at least one o-aldehyde-substituted phenol, particularly salicylaldehyde. The preferred system is prepared from polyethyleneimine, hydroquinone and salicylaldehyde.

Abstract: The present invention provides a process for the manufacture of vinyl chloride polymers by polymerization of the monomer or monomer mixture in aqueous dispersion in the presence of radical-forming catalysts and optionally suspension stabilizers, emulsifiers and further polymerization auxiliaries, which comprises carrying out the polymerization in a reactor the inner walls of which and other parts where polymer deposits may form are coated partially or entirely with a coating containing determined compounds of the formula ##STR1## In accordance with this invention, a substantial suppression of polymer deposit formation is achieved especially in the case of vinyl chloride copolymers.

Abstract: This invention relates to a process of coating the internal surface of a polymerization reactor in order to substantially eliminate the buildup of polymer on said surfaces during the polymerization process. There is applied to the surfaces a coating composition containing a straight chain or branched polyaromatic amine dissolved in an aqueous acid solution and thereafter the coated surfaces are flushed or rinsed with water without drying the same.

Abstract: In cooling polymeric hydrogel blocks of about 70.degree. to about 110.degree. C. to less than about 70.degree. C., said hydrogel blocks can efficiently be cooled in a short time by feeding them to a screw conveyor with a screw disposed in a horizontal or inclined trough, at least one end of which is blind and which has a discharge opening at the bottom or the side near the other end, and blowing the cooling air against the hydrogel blocks which are being pressed by the rotating screw against the blind end of the trough and lifted upward along the blind wall by the action of the rotary screw and are falling backward on the screw by gravity.

Abstract: This invention relates to a polymerization reaction vessel having a coating on the inner surfaces thereof resulting from applying thereto a coating composition containing the reaction product of (1) the self-condensation product of a polyhydric phenol, or (2) the condensation product of two or more polyhydric phenols, or (3) the self-condensation product of a polyhydric naphthol, with a bleaching material, such as, for example, sodium hypochlorite (NaOCl), dissolved in an aqueous alkaline solution. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C< group, and mixtures thereof, polymer buildup on the inner surfaces of the reaction vessel is substantially reduced. Further, 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(s) to the surrounding atmosphere.

Abstract: This invention relates to an improvement for reducing the amount of wall fouling in the suspension polymerization of vinyl chloride in stainless steel reactors. The improvement resides in wetting the reactor surface with a solution containing an alkali metal carbonate or alkali metal bicarbonate or both prior to charging the vinyl chloride recipe to the reactor. The alkaline material is included in a proportion which is effective for reducing wall fouling and typically this concentration is from about 1.25-25 percent for the carbonate and approximately 5-25 percent for the bicarbonate. Preferably, the surface of the reactor, after wetting, is heated to a temperature of about 40-100.degree. C. prior to charging the recipe.

Abstract: A process for polymerization of vinyl halide monomers in reactors with interior walls treated with a coating composition to prevent buildup said coating composition comprising a mixture of at least one compound chosen from the group consisting of monomeric aliphatic and aromatic amines, and at least one compound chosen from the group consisting of oxy-group substituted aromatic compounds and quinone type compounds. One embodiment is directed towards low temperature formation of the coating product in the presence of oxygen and on the reactor surface. Another embodiment concerns preforming the coating product and then applying it to the reactor surfaces.

Abstract: Unstabilized vinylbenzyl chloride and substituted vinylbenzyl chlorides are essentially inert with respect to surfaces of aluminum or alloys containing at least 90 percent by weight of aluminum in sharp contrast to benzyl chloride and similar substituted benzyl halides. Aluminum and such alloys of aluminum are thus practical materials of construction for making containers, pipes, stills, still column packing and the like for handling vinylbenzyl chloride.

Abstract: This invention relates to a polymerization reaction vessel having a coating on the inner surfaces thereof resulting from applying thereto a coating composition containing, as a primary ingredient, the reaction product or oligomers of (1) an alkyl or halogen substituted phenol, such as p-chlorophenol and the like, (2) a condensing agent, such as formaldehyde, and the like, and (3) a polyhydric phenol, such as resorcinol, and the like, dissolved in water or an aqueous alkaline solution. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers, having at least one terminal ##STR1## and mixtures thereof, polymer buildup on the inner surfaces of the reaction vessel is substantially eliminated. Further, 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(s) to the surrounding atmosphere.

Abstract: Equipments for polymerization of vinyl chloride monomers characterized in that the inside wall of the polymerization vessel and/or the surface of attachments to the vessel which are brought into contact with said monomers are wholly or partially made of mirror-polished ferritic stainless steel containing 15 to 40% by weight of chromium, 0.5 to 5% by weight of molybdenum, not more than 0.5% by weight of nickel, not more than 0.05% by weight of carbon and not more than 0.05% by weight of nitrogen, or mirror-polished duplex-phase stainless steel comprising a ferrite phase and an austenitic phase.

Abstract: A process for producing a cationic polymer, which comprises polymerizing a vinyl monomer represented by the general formula, ##STR1## wherein R.sub.1 represents --H or --CH.sub.3, R.sub.2 represents --CH.sub.2 CH.sub.2 -- or ##STR2## R.sub.3 and R.sub.4 represent --CH.sub.3 or --CH.sub.2 CH.sub.3, R.sub.5 represents --C.sub.n H.sub.2n+1, in which n is an integer of 0 to 4, ##STR3## or --CH.sub.2 COOH, and X.sup.- represents Cl.sup.-, CH.sub.3 SO.sub.4.sup.-, CH.sub.3 SO.sub.3.sup.-, or 1/2 SO.sub.4.sup.--, either alone or in admixture with up to 25% by weight, based on the total weight of the monomers, of other copolymerizable vinyl monomers in the presence of 7 to 18% by weight, based on the weight of the polymerization system, of water and, if necessary, choline chloride by use of a polymerization initiator and elevating the temperature, in the final polymerization stage, to 110.degree. to 150.degree. C.

Abstract: Provided is a cross-linked polymer composition which can be in a transparent polymeric gel form having an equilibrium water content of at least 60 wt.% for use in soft contact lenses. The cross-linked polymer composition is prepared by polymerizing, using a bulk polymerization procedure, a monomer mixture comprising an alkyl methacrylate and an N-vinyllactam in the presence of a cross-linking agent comprising at least one compound selected from vinyl acrylate, vinyl methacrylate, triallyl isocyanurate and vinyl carboxylates expressed by the formula:R--COOCH.dbd.CH.sub.2).sub.nwhere R is a hydrocarbon radical having 1 to 10 carbon atoms and n is an integer of 2, 3 or 4.

Abstract: This invention relates to a process of producing vinyl polymers or resins by an inversion polymerization technique in the presence of a dual layer coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the polymerization reaction in two stages, in the first or initial stage of which the monomer or monomers being polymerized constitute the continuous phase, and in the second or latter stage of polymerization, water constitutes the continuous phase due to the addition of sufficient water to the reactor to form said phase.

Abstract: This invention relates to a process of producing vinyl polymers or resins by an inversion polymerization technique in the presence of a dual layer coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the polymerization reaction in two stages, in the first or initial stage of which the monomer or monomers being polymerized constitute the continuous phase, and in the second or latter stage of polymerization, water constitutes the continuous phase due to the addition of sufficient water to the reactor to form said phase. The dual layer coating comprises an undercoating or primary coating of a tannin or tannate such as tannic acid or ammonium tannate, said coating being applied from an aqueous solution thereof, and a top coating comprised of a water-soluble suspending agent, such as an alkyl or an alkyl hydroxyalkyl cellulose ether, said top coating being applied from an aqueous solution thereof.

Abstract: Build-up during vinyl halide, particularly vinyl chloride, polymerization is prevented by employing a reactor having an adherent internal coating of a product derived from the admixture of at least polyethyleneimine and one or more of hydroquinone, p-benzoquinone, catechol and o-benzoquinone. The preferred system excludes catechol, p-benzoquinone and o-benzoquinone and optionally includes a small quantity of pyrogallol. The chemical constitution of the resulting coating product is not properly understood but is thought to include aminoquinonoid structures, condensates and radical anions. One embodiment is directed towards low temperature formation of the coating product in the presence of oxygen and on the reactor surface. Another embodiment concerns preforming the coating product and then applying it to the reactor surfaces.

Abstract: A method for polymerizing vinyl chloride in an aqueous suspension wherein polymer scale is prevented from depositing on walls and other surfaces in contact with monomer in a polymerization reactor. According to the method, one or more compounds selected from iodine salts of alkali metals and alkaline earth metals are added to the polymerization mixture. The effect of this method can be enhanced synergistically by coating a polar organic compound or an organic dye over the surfaces in contact with the monomer.

Abstract: A novel and improved method for polymerizing a vinyl monomer in a polymerization reactor is provided. The inner walls of the polymerization reactor and other surfaces coming into contact with the monomer are coated with an aqueous liquid containing at least one alkali metal or ammonium salt of an anionic dye of the sulfonic carboxylic acid form and having a pH value adjusted not to exceed 7 by aid of a pH adjusting agent, and the thus coated surfaces are dried with heat before the polymerization is conducted. The method serves to greatly reduce the deposition of polymer scale on those surfaces and, consequently, improve the productivity as well as the quality of polymer product.

Abstract: A method for producing a water-soluble cationic polymer by polymerizing, in the presence of water, a high concentration of (a) at least one vinyl monomer represented by the following general formula (I)ch.sub.2 .dbd.cr.sub.1 coor.sub.2 n.sup..sym. r.sub.3 r.sub.4 r.sub.5 x.sup..crclbar. (i)wherein R.sub.1 is --H or --CH.sub.3 ; R.sub.2 is --CH.sub.2 CH.sub.2 -- or --CH.sub.2 CH(OH)CH.sub.2 --; R.sub.3 and R.sub.4, which may be the same or different, each is --CH.sub.3 or --CH.sub.2 CH.sub.3 ; R.sub.5 is --C.sub.n H.sub.2n+1 where n is 0 or an integer of 1 to 4, --CH.sub.2 C.sub.6 H.sub.5, or --CH.sub.2 COOH; and X is Cl.sup.-, Br.sup.-, 1/2SO.sub.4.sup.-- or CH.sub.3 SO.sub.4.sup.

Abstract: In a process for producing a water-soluble polymer in an easily grindable glassy state by subjecting to aqueous solution polymerization a mixture comprising a monomer composed mainly of a vinyl monomer represented by the general formula (I): ##STR1## and water in an amount of 7 to 18% by weight based on the total weight of the monomer and water, a water-soluble salt in a powdery form is added to and dispersed in the polymerization system and the polymerization is carried out in the state that the powdery salt is dispersed, whereby a water-soluble polymer excellent in flocculating action and dissolving workability is obtained.

Abstract: The necessity of opening a large polymerization reactor, in order to introduce a polymerization catalyst between charges in the batch suspension of polymerization of vinyl chloride on a commercial scale, is eliminated, thereby avoiding vinyl chloride emissions into the atmosphere, by isolating a segment of a charging conduit for a polymerization reactor containing vinyl chloride under pressure proximate the reactor; partially filling the isolated segment with water; charging the isolated segment above the water therein with a water-insoluble polymerization catalyst; and displacing into the reactor from the catalyst-charged segment first the water therein and then the catalyst therein with vinyl chloride under pressure.

Abstract: Acrylamide polymers or copolymers are partially hydrolyzed by mixing the particles of hydrous gel of the polymer in an apparatus which has a mixing mechanism comprising of blades having a blank space and the face of the apparatus where the polymer is contacted with is made of or coated with synthetic resin.

Abstract: Polymer buildup in polymerization reactions during vinyl chloride polymerizations is greatly reduced by applying a water dispersion of alumina and oxalyl bis(benzylidenehydrazide) (OABH) to the reactor surfaces exposed to the polymerization medium prior to carrying out the polymerization. Long term effects of the buildup preventor can be obtained by applying a caustic wash to the reactor walls, prior to applying the oxalyl bis(benzylidenehydrazide) and alumina dispersion. The effect of the OABH/alumina and caustic is synergistic since the preventative effect is greater than either material used alone.

Abstract: This invention relates to a polymerization reaction vessel having an approximate monolayer coating on the inner surfaces thereof which is obtained by applying thereto an aqueous coating solution containing a tannin, such as, for example, tannic acid. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 =C< grouping, in such a coated reaction vessel, polymer build-up on the inner surfaces thereof is substantially eliminated. Multiple charges of polymer can be made in said coated vessel without opening the same between charges thus preventing the escape of unreacted monomer to the atmosphere.

Abstract: There is provided a process for the manufacture of vinyl chloride homopolymers, copolymers or graft polymers by carrying out the polymerization in a reactor the inner parts and inserts of which are coated with a coating consisting of defined hydrazine derivatives and, preferably, a film-forming material as carrier substance.

Abstract: This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a two layer coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the initial stage of the polymerization reaction wherein the monomer or monomers being polymerized constitute the continuous phase and in the latter stage of polymerization, water constitutes the continuous phase. The coatings comprise an undercoating of an alkali soluble dye dissolved in an aqueous alkali metal hydroxide solution or an ammonium hydroxide solution. The top coating is comprised of a water soluble suspending agent, such as an alkyl or alkylhydroxy alkyl cellulose ether. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.

Abstract: In the polymerization under pressure of liquid olefin to polyolefin using a Ziegler type catalyst in which the reaction mass, comprising a mixture of catalyst and polyolefin dissolved in liquid monomer, is mixed in a mixer with water to kill the catalyst and reaction after which the highly corrosive aqueous solution of Ziegler catalyst is separated from the monomer and dissolved polymer in a settling tank; lining the inner wall of the mixer and/or settling tank and/or any other part of the equipment coming into contact with the aqueous Ziegler catalyst solution with an acid resistant brick lining having an intermediate membrane lining between it and such inner wall and in which the mortar of the brick lining is a carbon-filled furan polymer, in which the membrane is a fiber glass reinforced furan polymer and in which the brick lining is cemented to the membrane and the membrane is cemented to the inner wall by a carbon-filled furan polymer adhesive.

Abstract: This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the initial stage of the polymerization reaction wherein the monomer or monomers being polymerized constitute the continuous phase and in the latter stage of polymerization, water constitutes the continuous phase. The coating is comprised of a water-soluble suspending agent, such as an alkyl or alkyl hydroxyalkyl cellulose ether. By means of the present inventive process, polymer buildup on the internal surfaces of the reactor are reduced.

Abstract: This invention relates to a process of producing vinyl polymers by an inversion polymerization technique in the presence of a two layer coating on the internal surfaces of the polymerization reactor. By inversion polymerization is meant conducting the initial stage of the polymerization reaction wherein the monomer or monomers being polymerized constitute the continuous phase and in the latter stage of polymerization, water constitutes the continuous phase. The coatings comprise an undercoating of a polyaromatic amine, or like material, and the top coating is comprised of a water-soluble suspending agent, such as an alkyl or alkyl hydroxyalkyl cellulose ether. By means of the present inventive process, polymer buildup on the internal surfaces of the reactor are substantially reduced.

Abstract: In the polymerization of at least one ethylenically unsaturated monomer other than vinyl chloride, deposition of polymer scale on the inner walls of a polymerization reactor and other surfaces coming into contact with the monomer is effectively prevented (regardless of the type of polymerization used, so long as it takes place in a heterogeneous phase) by coating the surfaces of the reactor with at least one compound selected from organic electron donor compounds and organic electron-acceptor compounds prior to polymerization; the compound or compounds having been or being brought into contact with an oxidizing agent, a reducing agent, an acid or a base, or having been or being irradiated with ultraviolet light.

Abstract: This invention relates to a polymerization reaction vessel having an approximate monolayer coating on the inner surfaces thereof which is obtained by applying thereto an aqueous coating solution containing a tannin, such as, for example, tannic acid. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C< grouping, in such a coated reaction vessel, polymer buildup on the inner surfaces thereof is substantially eliminated. Multiple charges of polymer can be made in said coated vessel without opening the same between charges thus preventing the escape of unreacted monomer to the atmosphere.

Abstract: Vinyl chloride monomer or a monomeric mixture composed mainly of vinyl chloride is polymerized in a polymerization vessel having its inner walls and the surfaces of an agitator and other equipment attached thereto coming into contact with the monomer or monomers coated with a metal complex of a polar organic compound and/or an organic dye. This method of polymerization serves to greatly reduce the deposition of polymer scale on those surfaces and produce high quality polymer.

Abstract: A process for retarding undesirable buildup of polymeric material on the internal surfaces of reactors used in the polymerization of substantially water-insoluble ethylenically unsaturated monomer, particularly vinyl chloride monomer, and for significantly reducing the tendency of reactor contents to foam during deoxygenation of such contents prior to subsequent polymerization reactions, such process comprising introducing sulfur trioxide into the reactor in an amount sufficient to provide at least about 0.045 grams of sulfur trioxide per gallon of reactor volume.

Abstract: A method for preventing polymer buildup in the polymerization reactor during the suspension polymerization of vinyl chloride monomer to form polyvinyl chloride polymer and copolymers, the method comprising coating reactor surfaces in contact with the reaction medium with a material selected from the group consisting of alumina, dithiooxamide, and mixtures of these prior to carrying out this polymerization.

Abstract: A concentrated solution of a water-soluble vinyl monomer is mixed at or below room temperature with an effective amount of a peroxygen catalyst and the resulting solution is freed of inhibitory oxygen and thereafter atomized into a reaction vessel containing an atmosphere of gaseous sulfur dioxide to produce a polymer product by redox catalysis.

Abstract: Vinyl chloride monomers or a monomeric mixture composed mainly of vinyl chloride is bulk-polymerized in a polymerization vessel. The inner walls and other surfaces of said vessel, coming into contact with the monomer or monomers, are coated with one or more specifically selected inorganic or organic compounds having a solubility greater than 0.5 g in 100 g of water at 25.degree. C and a boiling point higher than 60.degree. C. This bulk polymerization method serves to greatly reduce the deposition of polymer scale on the vessel walls and other surfaces. In addition the polymer scale deposited can be readily separated and removed by merely washing with water or gas under pressure. The present method provides high quality polymers.

Abstract: Vinyl chloride is polymerized in aqueous dispersion, preferably in aqueous dispersion, preferably in aqueous suspension, in a reactor with walls coated with a layer of a cross-linked polymeric material containing polar groups formed from a reaction mixture having an aldehyde, preferably formaldehyde, as one component thereof.

Abstract: In the emulsion polymerization of a dienic monomer or a mixture containing a dienic monomer and at least one other copolymerizable monomer in an aqueous medium, the deposition of polymer scale on the inner walls of the polymerization reactor and other surfaces in contact with the monomer or monomeric mixture can be remarkably reduced or prevented by providing coating layers of an organopolysiloxane on those surfaces, prior to the polymerization, by applying the organopolysiloxane directly to the surfaces or by applying one or a mixture of hydrolyzable organosilanes to the surfaces, followed by hydrolysis-condensation of the silanes, to form the organopolysiloxane in situ.

Abstract: .alpha.-Ethylenically unsaturated monomers are polymerized in aqueous media in a vessel with electrically conductive inner surface, in which partial areas of the inner surface covered by liquid are electrically insulated from the remaining surface areas and conductively connected therewith by an external source of current. In this manner the formation of deposits on the wall of vessel is hindered or suppressed.

Abstract: This invention relates to a polymerization reactionvessel having an approximate monolayer coating on the inner surface thereof resulting from applying thereto an aqueous alkali metal hydroxide coating solution containing a straight chain or branched polyaromatic amine and a dispersant operable in aqueous media, such as, for example, polyvinyl alcohol. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C< grouping, and mixtures thereof, in the presence of said coating, polymer build-up on the inner surfaces of the reaction vessel is substantially eliminated. Further, 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 atmosphere.

Abstract: This invention relates to a polymerization reaction vessel having a coating on the inner surfaces thereof resulting from applying thereto a coating composition containing, as a primary ingredient, (1) the self-condensation product of a polyhydric phenol, or (2) the condensation product of two or more polyhydric phenols, or (3) the self-condensation product of a polyhydric naphthol, dissolved in an aqueous alkali metal hydroxide solution. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 .dbd.C< group, and mixtures thereof, in the presence of said coating, polymer build-up on the inner surfaces of the reaction vessel is substantially eliminated. Further, 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: In the suspension polymerization in an aqueous medium of vinyl chloride alone or of a monomer mixture comprising vinyl chloride as a major component and other monomers copolymerizable therewith as a minor component, depositin of polymer scales on the inside surfaces of the polymerization vessel is surprisingly prevented by coating the interior surface of the vessel and auxiliary equipment prior to the polymerization with at least one compound selected from the group consisting of hydroxyhydroquinone and pyrogallol.

Abstract: This invention relates to a polymerization reaction vessel having a coating on the inner surfaces thereof resulting from applying thereto a coating composition containing, as a primary ingredient, an alkali soluble dye dissolved in an aqueous alkali metal hydroxide solution or an ammonium hydroxide solution. When polymerizing olefinic monomers, such as vinyl halides, vinylidene halides, and vinylidene monomers having at least one terminal CH.sub.2 =C< grouping, and mixtures thereof, in the presence of said coating, polymer build-up on the inner surfaces of the reaction vessel is substantially eliminated. Further, 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 atmosphere.

Abstract: A method for preventing polymer buildup in the polymerization reactor during the suspension polymerization of vinyl chloride monomer to form polyvinyl chloride polymer and copolymers, the method comprising coating reactor surfaces in contact with the reaction medium with a material selected from the group consisting of alumina, dithiooxamide, and mixtures of these prior to carrying out this polymerization.

Abstract: A reactor for vinyl chloride polymerization in aqueous dispersion and inside said reactor at least one polished surface provided by a layer constructed from a Cr/Ni stainless steel of Cr content 13-30 wt % and Ni content 20-35 wt %.Preferably the layer provides at least part of the interior surface of the body of the reactor.A process for the production of a vinyl chloride polymer in such a reactor is also disclosed.