Abstract: The invention relates to a process and system for the continuous polymerization of one or more ?-olefin monomers comprising the steps of: (a) withdrawing fluids from a reactor (b) cooling fluids comprising the withdrawn fluids with a cooling unit (c) introducing the cooled fluids to a separator to separate at least part of the liquid from these fluids to form a liquid phase and a gas/liquid phase (d) introducing the gas/liquid phase below to the reactor below a distribution plate (e) introducing the liquid phase to a settling tank to separate liquid from fines that settle down in the settling tank (f) introducing liquid from the settling tank up stream of the cooling unit.

Abstract: Disclosed is a method of preparing a vinyl based polymer and copolymer comprising a vinyl chloride based polymer and copolymer using suspension polymerization to prevent forming by elevating slowly reaction temperature such that pressure is maintained when pressure drops in the late stages of reaction. According to the method, the vinyl chloride based resin is prepared using suspension polymerizing vinyl chloride based monomers so as to reduce foaming and improve a protrusion, thermal stability and the like.

Abstract: Disclosed is a polyvinyl chloride resin latex which is prepared by polymerization using a decreased amount of polymerization water in an early polymerization stage and then additional polymerization water in a late polymerization stage, so that the polyvinyl chloride resin latex has an increased solid content and a decreased water content and thus finally remarkably reduces energy consumption in a spray drying process.

Abstract: The invention relates to polymers selected from among polypropylene (PP), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), polyvinylchloride (PVC) and polyethylene terephthalate (PET), nylon and polystyrene, having antibacterial properties, wherein the antibacterial effect is obtained by adding a zinc salt selected from among: zinc PCA, zinc oxide, zinc hydroxide, zinc pyrrolidone or zinc pyrithione during the process of polymerization of the monomers. The antibacterial polymers are used to prepare products intended to enter into contact with the skin.

Abstract: Provided are a vinyl chloride-based resin formed by polymerization of vinyl chloride-based small seed particles having an average particle diameter range of 0.15 ?m to 0.5 ?m prepared by emulsion polymerization and vinyl chloride-based large seed particles having an average particle diameter range of 0.51 ?m to 0.8 ?m prepared by micro-suspension polymerization, in which a content ratio (weight ratio) of the large seed particles to the small seed particles is in a range of 1 to 2, and a method of preparing the vinyl chloride-based resin. Excellent low viscosity characteristics of the vinyl chloride resin at high and low shear rates may be obtained by controlling the particle size of the small seed prepared by emulsion polymerization.

Abstract: Process for preparing a seed latex of a methyl methacrylate polymer (PMMA) by radical polymerization in aqueous emulsion of methyl methacrylate and optionally at least one comonomer. Process for preparing a chlorinated vinyl polymer latex by radical polymerization in aqueous emulsion of at least one chlorinated vinyl monomer, according to which the polymerization takes place in the presence of at most 3% by weight, expressed relative to the total weight of the monomers, of the PMMA seed latex.

Abstract: The invention relates to a process for the polymerization of vinyl-containing monomers such as, for example, monomeric vinyl halides, in a reaction mixture, in which process less waste is generated.

Abstract: Polymerization process comprising the steps of: (a) reacting an aqueous suspension comprising initiator, vinyl chloride, and optionally one or more co-monomers in a continuous stirred tank reactor; and (b) further reacting the resulting suspension in at least one second reactor; wherein the conversion level of vinyl chloride in the continuous stirred tank reactor of step (a) is from 10 to 60 wt %.

Abstract: Provided are a vinyl chloride-based resin formed by polymerization of vinyl chloride-based small seed particles having an average particle diameter range of 0.15 ?m to 0.5 ?m prepared by emulsion polymerization and vinyl chloride-based large seed particles having an average particle diameter range of 0.51 ?m to 0.8 ?m prepared by micro-suspension polymerization, in which a content ratio(weight ratio) of the large seed particles to the small seed particles is in a range of 1 to 2, and a method of preparing the vinyl chloride-based resin. Excellent low viscosity characteristics of the vinyl chloride resin at high and low shear rates may be obtained by controlling the particle size of the small seed prepared by emulsion polymerization.

Abstract: The present invention relates to a process for the production of polyvinyl chloride (PVC) having a median grain size of from 10 to 80 ?m by suspension polymerization of vinyl chloride, the process comprising the following process steps: (a) introduction of water, initiator(s), optionally one or more further adjuvants, and some of the vinyl chloride into a container as initial charge and mixing of the constituents; (b) dispersion, and addition of one or more suspension auxiliaries with continued dispersion; (c) heating of the mixture; (d) addition of the remaining vinyl chloride; and (e) working-up of the product.

Abstract: The invention provides a process for preparing vinyl chloride-vinyl acetate copolymers in the form of their solid resins by means of free-radically initiated suspension polymerization in aqueous medium of 70% to 90% by weight of vinyl chloride, 10% to 30% by weight of vinyl acetate and, if desired, further comonomers copolymerizable therewith, characterized in that 0.1% to 5% by weight of a vinyl acetate-vinyl chloride copolymer soluble in ethyl acetate is introduced as an initial charge, the amounts in % by weight being based in each case on the total weight of the comonomers.

Abstract: The present invention relates to a method of preparing a polymer resin based on a halogenated vinyl polymer and a copolymer bearing associative groups, comprising the steps that consist in forming a latex of each of these polymers, blending said latices, then isolating and drying the polymers contained in said latices in order to form a pulverulent resin. The present invention also relates to said resin, to a pulverulent composition containing said resin, and also to the use of this composition for manufacturing rigid or plasticized materials.

Abstract: The invention pertains to a process to polymerize one or more monomers wherein one or more initiators and optionally one or more surfactants are added to a polymerization mixture when the pressure in the polymerization reactor is dropping. This process allows a shorter polymerization time due to a higher pressure drop rate at the end of the polymerization reaction. Moreover, the cooling capacity of the polymerization reactor is used more efficiently.

Abstract: A copolymer of (i) an alkyl acrylate or alkyl methacrylate and (ii) a hydroxyalkyl acrylate or hydroxyalkyl methacrylate is used as a secondary protective colloid in the suspension polymerization of vinyl chloride monomer. The alkyl group of the alkyl acrylate or alkyl methacrylate is preferably a 2-ethylhexyl group. The hydroxyalkyl group of the hydroxyalkyl acrylate or hydroxyalkyl methacrylate is preferably a hydroxyethyl group.

Abstract: A method is disclosed for producing polyvinyl chloride which includes mixing a vinyl chloride solution with an initiator solution in at least one high shear mixing device comprising at least one rotor/stator set producing a rotor tip speed of at least 5.1 m/sec (1000 ft/min), to form a polymerization mixture; and allowing the mixture to polymerize by free radical polymerization to form polyvinyl chloride. The polymerization mixture may be subjected to free radical polymerization conditions comprising a temperature in the range of about 20° C. to about 230° C. In some embodiments, the high shear mixing device produces a shear rate of at least 20,000 s?1. A system for carrying out the method is also disclosed.

Abstract: The present invention provides a method for producing a polymer by conducting polymerization in a polymerization reactor having an inner wall covered with an anti-fouling agent comprising an aqueous solution containing a polyvinyl alcohol obtained through saponification of a polyvinyl ester that contains monomer units having a silyl group. In the present invention, the polyvinyl alcohol satisfies the following formulae (I) and (II): 370<P×S<9000 ??(I) where P indicates the viscosity-average degree of polymerization of the polyvinyl alcohol, and S indicates the content (mole %) of the monomer units having a silyl group of formula (1) in the polyvinyl alcohol; 0.2/100?(A?B)/(B)?75/100 ??(II) where A indicates the content (ppm) of silicon atoms in the polyvinyl alcohol, and B indicates the content (ppm) of silicon atoms in the polyvinyl alcohol that was washed with sodium hydroxide-containing methanol and then washed with methanol by Soxhlet extraction.

Abstract: The invention provides a process for preparing vinyl chloride-vinyl acetate copolymers in the form of their solid resins by means of free-radically initiated suspension polymerization in aqueous medium of 70% to 90% by weight of vinyl chloride, 10% to 30% by weight of vinyl acetate and, if desired, further comonomers copolymerizable therewith, characterized in that 0.1% to 5% by weight of a vinyl acetate-vinyl chloride copolymer soluble in ethyl acetate is introduced as an initial charge, the amounts in % by weight being based in each case on the total weight of the comonomers.

Abstract: There is provided a process for producing a vinyl chloride-based polymer, in which a suspension polymerization of either vinyl chloride monomer, or a mixture of vinyl chloride monomer and another copolymerizable monomer, is conducted in a polymerization vessel fitted with a reflux condenser, the process including the steps of: (A) adding to the reaction mixture a high-activity, oil-soluble polymerization initiator, with a 10-hour half life temperature of no more than 40° C. at a concentration of 0.1 mol/L in benzene, for a specified time within a period from the commencement of heat removal using the reflux condenser through to completion of the polymerization, and (B) adding an antioxidant either continuously or intermittently to the reaction mixture at least during the period from the commencement of addition of the high-activity, oil-soluble polymerization initiator through to completion of that addition.

Abstract: The invention relates to a polymerization process wherein at least one peroxide, with a half life in between 1 hour and 0.001 hour at the polymerization temperature at the moment of dosing, is dosed to the reaction mixture at the polymerization temperature and wherein at least during part of the period in which the peroxide is dosed i) the cooling means of the reactor are kept at essentially maximum cooling capacity and ii) the amount of initiator that is dosed is actively controlled such that the desired polymerization temperature is achieved and maintained within 0.3° C. of said polymerization temperature.

Abstract: There is provided a process for producing a vinyl chloride-based polymer, in which a suspension polymerization of either vinyl chloride monomer, or a mixture of vinyl chloride monomer and another copolymerizable monomer, is conducted in a polymerization vessel fitted with a reflux condenser, the process including the steps of: (A) adding to the reaction mixture a high-activity, oil-soluble polymerization initiator, with a 10-hour half life temperature of no more than 40° C. at a concentration of 0.

Abstract: The invention pertains to a process wherein initiators and protective colloids are both metered to a polymerization mixture. This manner of metering allows for improved control of the polymerization rate and an improved reactor space-time yield, and the process will render a polymer with a relatively high porosity.

Abstract: Process for the preparation of latices by batchwise radical polymerization of one or more monomers, comprising the participation, in the polymerization, of: (a) one or more fine dispersions of one or more finely dispersed monomers and (b) one or more seed latices of one or more seeding polymers.

Abstract: A process for producing organic peroxide initiators useful in the polymerization of ethylenically unsaturated monomers. The process for making the organic peroxides includes forming an aqueous emulsion of the organic peroxide. The organic peroxide is dispersed as small droplets of from 1 to 10 microns in size in the aqueous emulsion. The organic peroxide may be added to a polymerization reactor containing an ethylenically unsaturated monomer. The organic peroxide functions as a free radical initiator to polymerize the monomer. The organic peroxide may be substantially free of organic solvents and plasticizers. The resulting polymers are of high quality.

Abstract: A process is provided for producing a vinyl chloride-based polymer by polymerization of vinyl chloride or a monomer mixture containing it in a reaction vessel. Heat generated during polymerization is removed using a reflux condenser. When the polymerization rate is within a range from 30% to 50%, a copolymeric polyether, with a weight average molecular weight of 1,500,000 to 2,000,000, and an ethylene oxide to propylene oxide molar ratio within a range from 78/22 to 82/18, is added to the reaction mass. Foaming of the polymer slurry due to the use of the reflux condenser beyond the point where the polymerization rate reaches 60% is suppressed, and the polymer can be produced with no deleterious effects on the quality of the product polymer.

Abstract: There is provided a process for producing a vinyl chloride-based polymer by conducting a suspension polymerization in an aqueous medium using an oil soluble polymerization initiator, wherein the oil soluble polymerization initiator utilizes a combination of (A) t-amyl peroxyneodecanoate and (B) a peroxide-based polymerization initiator with a 10 hour half-life temperature in a solution with a concentration of 0.1 mol/liter in trichloroethylene within a range of at least 30° C. but less than 55° C., and when a predetermined polymerization conversion rate is reached, the polymerization reaction temperature is raised by a predetermined amount, followed by addition of an antioxidant to said polymerization mixture to halt the polymerization reaction. According to this process, a vinyl chloride-based polymer with good anti-initial discoloration can be produced in high yield and with good productivity.

Abstract: The present invention pertains to a process for controlled free radical polymerization or copolymerization of vinyl chloride at a temperature between 40° C. and 95° C., at a pressure between 5 and 30 bar in the presence of a stable free nitroxyl radical.

Abstract: A method of producing a vinyl chloride-based polymer by suspension polymerization is provided, by which heat removal performed by a reflux condenser can be increased, but total heat removal performed by the jacket can be reduced, without affecting the quality of the product polymer. The method includes commencing heat removal when or after a polymerization conversion rate reaches 15%, and controlling said reflux condenser so as to remove a fixed quantity of heat per unit of time depending on the polymerization conversion rate as the polymerization process proceeds.

Abstract: A process for polymerizing vinyl chloride or a monomer mixture containing vinyl chloride in an aqueous medium in a polymerization vessel fitted with a reflux condenser, characterized by starting to add (A) an anti-foam agent, and (B) a partially saponified polyvinyl alcohol with an average degree of polymerization of 100 to 500 and a saponification degree of 75 to 85 mole %, to a reaction mixture during the operation of said reflux condenser, and continuing the addition of (A) and (B) until recovery of unreacted monomers from said polymerization vessel is completed, thereby preventing the polymer slurry from foaming, rising, or scattering during polymerization or recovery of unreacted monomers.

Abstract: The invention pertains to a process wherein peroxides are dosed to a polymerization mixture, with essentially all of the organic peroxide that is used in the polymerization process having a half-life from 0.05 hour to 1.0 hour at the polymerization temperature. The dosing of such peroxide allows for accurate control of the polymerization rate, and the process will render a polymer with a low residual peroxide level.

Abstract: A dispersion stabilizer for suspension polymerization of a vinyl compound containing a vinyl alcohol polymer (A) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 60 mol % or more and a degree of polymerization of 600 or more and a vinyl alcohol polymer (B) selected from the group consisting of a vinyl alcohol polymer (B1) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 20 to 80 mol % and a degree of polymerization of 100 to 600, a vinyl alcohol polymer (B2) having a degree of saponification of 20 to 60 mol % and a degree of polymerization of 100 to 600 and a vinyl alcohol polymer (B3) having a content of an ethylene unit of 0.5 to 10 mol %, a degree of saponification of 90 mol % or more and a degree of polymerization of 1,000 or more.

Abstract: A production method of a vinyl resin, which comprises subjecting a vinyl compound to suspension polymerization in a polymerization tank equipped with a reflux condenser in the presence of a dispersion stabilizer, wherein a polyvinyl alcohol resin (A) having a degree of hydrolysis of not less than 65 mol %, a polymerization degree of not less than 700 and satisfying the following formula (1) 0.0300≦(3−Y)/X<0.0330  (1) wherein X is a degree of hydrolysis (mol %) and Y is a degree of iodine absorption, is added at a polymerization conversion rate of the vinyl compound of not less than 30%. The production method of a vinyl resin of the present invention affords a vinyl resin having a high bulk density, which shows a superior antifoaming effect to suppress dry foams generated during the middle and the latter periods of polymerization.

Abstract: The present invention relates to a process for seeded microsuspension polymerization of vinyl chloride in aqueous medium under the action of at least one organosoluble initiator, at least one reducing agent and at least one water-soluble metal salt in the presence of at least one fatty acid alkali metal or ammonium salt. It also relates to the polymers obtained in this way which are suitable for giving plastisols having specific properties.

Abstract: This invention involves several ways for improving a coalescing process for purifying a crude polyether. In one aspect, particulate zirconium dioxide is selected as a coalescing medium. In a second aspect, alkali metal catalyst is recovered and recycled to make additional polyether product. In a third aspect, a polyether stream obtained from the coalescing step is purified by stripping water in at least two phases, the first of which involves moderate conditions so that water but not allyl alcohol or higher molecular weight impurities are removed from the polyether, and the second of which involves more stringent stripping conditions. In a fourth aspect, crude polyether that is subjected to a holding period before undergoing a coalescing step is mixed with water to minimize the formation of impurities that are believed to compatibilize the aqueous and polyether phases. In a fifth aspect, the coalescing process is conducted under a non-oxidizing atmosphere.

Abstract: As a method of vacuum recovery of residual monomers from PVC paste resin latex by heating the latex, the present invention is capable of breaking foam derived from foamable PVC paste resin latex after polymerization by utilizing the methods: using a residual monomer vacuum recovery apparatus having a foam separator and transferring the foam which overflows from the vacuum recovery vessel to the foam separator so that the foam makes direct contact with steam causing a breakdown of the foam. This is done without reducing operability, without lowering stable operation, without degrading product quality, and without reducing the solid concentration of the latex.

Abstract: There is provided a process for producing a vinyl chloride polymer wherein in a polymerization vessel, vinyl chloride monomer or a vinyl monomer mixture comprised mainly of vinyl chloride monomer is polymerized by the aid of a polymerization initiator in an aqueous medium, comprising previously forming a coating film comprised of a polymer scale deposition preventive agent prior to the polymerization on the inner wall surface of the polymerization vessel and the other areas, to which said monomer contacts during the polymerization, by coating thereon a coating solution containing the polymer scale deposition preventive agent by the aid of steam as a carrier; and carrying out said polymerization in the presence of a chelating agent capable of forming a Fe(II) or Fe(III) complex in said aqueous medium.

Abstract: A method for continuously stripping an unreacted monomer from a vinyl chloride paste resin latex, comprising the steps of continuously supplying the latex to a vacuum recovery vessel, wherein the latex is boiling with generation of foam, under the condition that the temperature of the latex to be supplied is higher than that of the latex in the recovery vessel, withdrawing a monomer gas generated in the recovery vessel through an exhaust line provided with a foam separator, contacting the foam entrained into the exhaust line with steam introduced to the exhaust line and/or the foam separator, thereby destroying the foam, and returning the resulting latex in the separator to the recovery vessel. The unreacted monomer can be efficiently recovered from the latex by a continuous operation, and defoaming can be achieved without deteriorating the quality and without lowering the productivity.

Abstract: A vinyl chloride polymer is prepared by charging a reactor with a vinyl chloride monomer, effecting polymerization, removing a slurry of the polymer from the reactor, and washing the reactor interior with water, and repeating the series of steps. The reactor has an internal volume of at least 40 m3. A cylinder-guided lift type washer assembly having a nozzle is secured to the reactor at its top in a sealed manner such that the nozzle can be moved downward and upward in the reactor. Water is fed to the nozzle through the assembly for injecting water from the nozzle into the reactor for cleaning. The large size reactor can be effectively washed with water in the closed state, and vinyl chloride polymers of quality with least fisheyes are produced batchwise, leading to an improved productivity.

Abstract: Vinyl monomers are polymerized in the aqueous phase in the presence of at least one N-oxyl compound of a secondary amine, having no hydrogen atoms bonded to the &agr; carbon atoms. This process substantially eliminates deposits on reactor surfaces.

Abstract: A process for preparing homo- and copolymers of vinyl chloride by batch polymerization in aqueous emulsion in the presence of an emulsifier combination comprising at least two emulsifiers selected from the class consisting of anionic and nonionic emulsifiers, metered in during the polymerization, which comprises metering-in in the first phase of the polymerization, at least one emulsifier of the emulsifier combination having at least 10 carbon atoms, and not starting to meter in the remaining emulsifiers of the emulsifier combination until a polymerization conversion of at least 10% has been reached.

Abstract: A process for producing a vinyl chloride polymer is provided which includes the steps of: (A) suspension polymerizing vinyl chloride or a monomer mixture containing vinyl chloride, in an aqueous medium to obtain a polymer slurry; (B) stripping unreacted monomers remaining in the polymer slurry; and (C) subjecting the polymer slurry having passed through the step (B), to dehydration at a temperature of from 80° C. to 95° C., preferably within 60 minutes after the stripping. According to this process, the polymer cake obtained after the polymer slurry Is dehydrated can be made to have a greatly low water content. Hence the drying time in the drying step can be shortened to bring about an improvement in productivity and also to achieve a reduction of energy consumption in the drying step and consequently a reduction of production cost. Vinyl chloride polymer dried products having good anti-initial discoloration properties can be obtained.

Abstract: A process for polymerizing a vinyl chloride monomer wherein the vinyl chloride monomer is subjected to homopolymerization or (co)polymerization with a monomer copolymerizable with the vinyl chloride monomer in an aqueous solvent, comprising applying in advance a coating liquid containing a cocondensation product obtained by reacting either a phenothiazine derivative and an aldehyde or a phenothiazine derivative, a naphthol derivative and an aldehyde to give an initial condensation product and then reacting the initial product with a polyphenol, to an inner wall of a polymerization tank and parts of an apparatus in contact with the monomers during the polymerization process. The process makes it possible to apply the cocondensation product as an aqueous solution to, e.g., an inner wall of a polymerization tank; to quite effectively prevent polymer adhesion in, e.g.

Abstract: Disclosed is a method of eliminating the odor from a malodorous gas, where the odor is due to the presence of a C10 to C18 fatty acid in the gas. An aqueous solution containing at least a stoichiometric amount of a base that reacts with said C10 to C18 fatty acid to produce a salt is sprayed into the gas.