Abstract: This invention is directed to processes of making polymer in the presence of a hydrofluorocarbon or perfluorocarbon and recovering the polymer. The processes provided enable polymerization processes to be practiced with minimal fouling in the reaction system, and to the recovery of the hydrofluorocarbon and other hydrocarbons such as hydrocarbons for reuse in the process or hydrocarbon by-products from the polymerization process. The invention is particularly beneficial in the production of ethylene based polymers using bulky ligand metallocene-type catalyst systems.

Abstract: A method for the continuous production of polydienes, the method comprising the steps of (a) charging a mixture of one or more monomer, catalyst system, and less than 50% weight percent organic solvent based on the total weight of the monomer, catalyst and solvent, into first vessel, (b) polymerizing the monomer to a conversion of up to 20% by weight of the monomer to form a mixture of reactive polymer and monomer, (c) removing the mixture of reactive polymer and monomer from the vessel, and (d) terminating the reactive polymer prior to a total monomer conversion of 25% by weight.

Abstract: A method for controlling the flowability of polymer particles flowing downward in a densified form inside a polymerization reactor, in which one or more monomers are gas-phase polymerized in the presence of a polymerization catalyst, the density of solid (Kg of polymer per m3 of reactor occupied by the polymer) being higher than 80% of the “poured bulk density” of the polymer, the method being characterized in that a liquid stream is continuously fed into the polymerization reactor at a mass flow rate per unity of reactor surface higher than 30 Kg/h m2.

Abstract: The present invention relates to a process for improving the start up of polymerization or copolymerization of ethylene in a gas phase reactor, preferably a fluidized bed gas phase reactor.

Abstract: Zero VOC compositions are described and may include: one of vinyl ester solids, unsaturated polyester solids (e.g., isophthalic polyester, orthophthalic polyester, terephthalic polyester, and mixtures thereof), and mixtures thereof; polymerizable solids (e.g., a monomer, an oligomer, and mixtures thereof); and/or at least one photochemical catalyst. Zero VOC compositions may be produced by: heating polymerizable solids to a range of about 300° F. to about 500° F.; and adding one of vinyl ester solids, unsaturated polyester solids, and mixtures thereof. Additional steps may include reducing the heat to about 70° F. to about 100° F. and adding at least one photochemical catalyst and/or at least one additive. Zero VOC compositions may be curable without requiring evaporation of a VOC there from upon exposure to ultraviolet light and/or mixing with at least one thermal catalyst.

Abstract: A process and apparatus for gas phase polymerization of olefins in a fluidized bed reactor are disclosed. The process and apparatus employ a vertically oriented fines ejector in order to reduce fouling and reactor downtime.

Abstract: Provided is a method of preparing styrene polymers, the method comprising: homogeneously mixing a styrene monomer; a cocatalyst mixture of Group 13 metal-containing organic metal compound cocatalyst and an inert organic solvent; and a catalyst mixture of a metallocene catalyst and the inert organic solvent using a high speed homogenizing mixer to obtain a homogenized mixture; and providing the homogenized mixture to a reactor to initiate polymerization. In this method, catalyst is quickly dispersed among monomers using a high speed homogenizing mixer so that formation of gel, which occurs when a syndiotactic styrene polymer is produced, can be fundamentally prevented. In addition, a styrene polymer prepared using the method has high activity, good stereoregularity, and uniform molecular distribution.

Abstract: The invention relates to an improvement in apparatus and process for the formation of a complex of Lewis acidic or Lewis basic gases in a reactive liquid of opposite character and for the breaking (fragmentation) of said complex associated with the recovery of the Lewis gas therefrom. The improvement resides in forming finely divided droplets of reactive liquid and controlling the temperature, pressure and concentration of said Lewis gas of opposite character to provide for (a) the formation of said complex between said gas and reactive liquid or (b) the breaking of said complex and the recovery of the atomized droplets of reactive liquid.

Abstract: A method of preparing a latex that includes pigments copolymerized with a crystalline polymer includes: dispersing a pigment and a dispersing agent in water having an ultra-high purity to obtain a pigment dispersion; dissolving a crystalline monomer in a basic monomer mixture to obtain an organic phase; dissolving while heating the dispersing agent in water having an ultra-high purity, and then mixing the solution with the pigment dispersion to obtain an aqueous phase; mixing and agitating the organic phase and the aqueous phase to obtain a homogenized solution; agitating and heating the homogenized solution; adding a polymerization initiator to the homogenized solution to be reacted; and cooling the reaction solution to room temperature.

Abstract: The invention relates to a process for the preparation of polyether polyols, which process involves: (a) contacting a phosphorus containing compound having at least one hydroxyl group with alkylene oxide to obtain alkoxylated initiator, (b) contacting the alkoxylated initiator with further alkylene oxide in the presence of a double metal cyanide complex catalyst.

Abstract: A water-soluble polymer dispersion, process for producing the same and a method of use therefor. In particular, the water-soluble polymer dispersion is one comprising water-soluble polymer fine particles of 100 ?m or less diameter having at least one ionic property selected from among cationic, amphoteric, nonionic and anionic properties together with a polyalkyleneimine and/or a product of polyalkyleneimine modification wherein according to necessity an appropriate amount of water-soluble inorganic salt is incorporated. The provided process enables easily performing the production in dispersed form by means of production facilities of low cost. The obtained water-soluble polymer dispersion is excellent in storage stability and exhibits satisfactory fluidity and solubility so as to enable use in papermaking raw material pretreatments added to papermaking raw materials prior to machine operation and also for enhancement of freeness, increase of sizing degree and enhancement of yield.

Abstract: A method of preventing or inhibiting fouling in an olefin polymerization fluidized-bed reactor is provided. The method involves varying the fluidization velocity inside the reactor over time about a set point.

Abstract: A method for polymerizing olefins in a fluidized-bed reactor is provided. The method involves introducing a fluid into the fluidized-bed reactor at an angle and amount sufficient to induce one or more swirls in the fluidized bed in the reactor.

Abstract: A polymerization method in which a first liquid and a second liquid are mixed in a gas phase and polymerized in the form of droplets is disclosed, wherein a polymerizable monomer and a polymerization initiator are each contained in at least one of the first liquid and the second liquid, and at least one of the first liquid and the second liquid is injected in a spatially expanding film shape. By employing the polymerization method of this invention, high-quality polymer can be efficiently produced in large quantity by the droplet polymerization even using a polymerizable monomer with a rapid reaction rate.

Abstract: Production of vinyl polymers by the polymerization of vinyl monomers in a planetary gear extruder.

Abstract: A process including: heating to a first polymerization temperature a first mixture including a free radical polymerizable monomer, a free radical initiator, and a stable free radical compound to polymerize only a portion of the monomer, resulting in a prepolymer composition; shearing a second mixture including the prepolymer composition, a continuous phase liquid, and a stabilizing compound to create a miniemulsion; and flowing the miniemulsion within a polymerization reactor and heating the miniemulsion at a second polymerization temperature to form polymeric particles wherein the formation of the polymeric particles occurs while the miniemulsion flows within the reactor.

Abstract: There is disclosed a process to uniformly and rapidly carry out the mixing of a monomer liquid and a polymerization initiator and thus for the resulting polymer not to adhere to the inner surface of the piping or the inside of the apparatus in an art of producing a water-absorbent resin by continuously mixing the monomer liquid and the polymerization initiator together and thereby carrying out polymerization. This process comprises the steps of: (a) continuously supplying a monomer liquid 20 to such as a supply pipe 10 to continuously stir the monomer liquid 20 in the supply pipe 10 with such as a stirring apparatus 12; (b) causing a polymerization initiator 30 to join into a flow of the monomer liquid 20 being in a stirred state, thereby obtaining a mixed liquid 40 of the monomer liquid 20 and the polymerization initiator 30; and (c) continuously supplying the mixed liquid 40 from the supply pipe line 10 to a polymerization apparatus to cause the mixed liquid 40 to run a polymerization reaction.

Abstract: A method for preventing or inhibiting fouling in a gas-phase polyolefin polymerization process. The method includes maintaining the inside surface temperature of the process equipment below the dew point temperature of the gas mixture passing through the equipment.

Abstract: Melt-fabricable, tough copolymer of tetrafluoroethylene and fluorinated vinyl ether is produced in a suspension polymerization process by copolymerizing tetrafluoroethylene and fluorinated vinyl ether in a pressurized, agitated reaction vessel which contains aqueous medium, free radical initiator, and a telogen, the aqueous medium being essentially free of fluorine containing organic solvent. The contents of the reaction vessel are agitated during polymerization sufficiently to coagulate copolymer of tetrafluoroethylene and fluorinated vinyl ether. The melt-fabricable, tough copolymer having a melt viscosity of less than about 1×106 Pa·S is isolated directly from the reaction vessel.

Abstract: A polymerization process and a catalyst delivery system are provided. For example, a polymerization process is described, including providing a conduit having a catalyst inlet, a first propylene stream inlet located downstream of the catalyst inlet, and a second propylene stream inlet located downstream of the first propylene stream inlet, the conduit being operably connected to a polymerization vessel, introducing a catalyst to the conduit through the catalyst inlet, and passing the catalyst through the conduit to the polymerization vessel. The process may further include introducing a first propylene stream to the conduit to provide a mixed catalyst stream downstream of the catalyst inlet. The process may additionally include stopping the flow of the catalyst passing through the conduit, introducing a second propylene stream to the conduit through the second propylene stream inlet, removing a section of the conduit, and replacing the removed section of the conduit with a different conduit section.

Abstract: A polymerization process is provided. For example, a polymerization process is described, including providing a catalyst slurry having a metallocene catalyst and a first oil, providing a transport medium including a second oil and combining the transport medium and the catalyst slurry to form a catalyst mixture. The process may further include introducing the catalyst mixture to a polymerization reactor and contacting olefin monomers with the catalyst mixture to polymerize the olefin monomers and form polyolefins.

Abstract: A continuous polymerization process for producing reactive polymers comprises continuously charging into a first reaction zone at least one functional monomer and polymerizing the monomers to produce a first polymeric product having at least one functional group. This first polymeric product is then continuously directly charged into a second reaction zone together with at least one modifier reactant having a functional group that is complementary to the functional group of the first polymeric product. At least a portion of the modifier reactant reacts with at least one of the functional groups of the first polymeric product to produce a second polymeric product which incorporates at least a portion of the modifier reactant, such that the second polymeric product is a reactive polymer.

Abstract: The process comprises the following phases: formation of a pre-emulsion of monomers in water; transfer into the polymerisation reactor with stirring, of (1) reaction stock consisting of a water solution of a surfactant, in an amount by weight relative to the weight of final polymer dispersion of 1–15%; (2) a portion of the pre-emulsion prepared in the previous phase, in an amount of 1%–10% by weight of the initial pre-emulsion; phase C.1: initiation of the polymerisation ; phase C.2: polymerisation of the monomer mixture at 30–90° C., by gradually adding into the reactor, separately, the initiator solution and the remaining portion of the pre-emulsion with an added salt, which is soluble in water at 25° C. to at least 1% by weight, in an amount so as to have a salt concentration in the added pre-emulsion of 0.02–0.25% by weight; phase C.3: scrubbing of the residual monomers.

Abstract: Process for the polymerization of olefins CH2?CHR, in which R is hydrogen or a hydrocarbon radical with 1–12 carbon atoms, carried out in the presence of a catalyst component (A) comprising Mg, Ti and halogen as essential elements and of a catalyst component (B) capable to produce, under the same polymerization conditions, a polymer with an average particle size lower than that obtainable with the said catalyst component A. The said process provides polymers with increased bulk density.

Abstract: A novel polymer support for solid phase peptide synthesis comprising polystyrene backbone and propoxylate function of hexanedioldiacrylate crosslinks having optimum hydrophilic/hydrophobic balance and a process of preparation thereof.

Abstract: A process for continuously producing a polymer drag reducing agent (DRA) is described. The process concerns mixing a monomer and a catalyst in at least one continuously stirred tank reactor (CSTR) to form a mixture. The mixture is continuously injected into a volume continuously formed by a thermoplastic material, such as polyethylene. The thermoplastic material is periodically sealed off to form a temporary container or bag. The monomer is permitted to polymerize in the temporary container to form polymer. In one non-limiting embodiment, the polymerization in the bag takes place within an inert, circulating fluid that accelerates heat transfer. The polymer and the temporary container are then ground together, preferably at non-cryogenic temperatures, to produce a particulate polymer drag reducing agent. In one preferred, non-limiting embodiment, the grinding or pulverizing occurs in the presence of at least one solid organic grinding aid.

Abstract: A latex having a reduced amount of 4-phenylcyclohexene is obtainable by reacting A) 30–90% by weight of at least one ethylenically unsaturated monomer; B) 70–10% by weight of a diene; C) 1–10% by weight of ?,?-unsaturated carboxylic acids, carboxylic acid nitriles, carboxylic acid amides, or mixtures thereof; and D) an auxiliary, an additive or mixtures thereof. The reaction follows a gradient regime for components A and B.

Abstract: This invention provides a process for manufacturing a methyl methacrylate polymer comprising the steps of feeding a monomer containing at least 80 wt % of methyl methacrylate and a radical polymerization initiator represented formula (III) to a reactor; polymerizing the material at a polymerization temperature of 110 to 160° C. under the conditions satisfying particular equations between an initiator concentration and a polymerization temperature; feeding a reaction mixture taken out from the reactor to a devolatilization step (feeding step); and separating and removing volatiles from the reaction mixture (devolatilization step).

Abstract: A method of polymerizing olefins comprising combining in one embodiment ethylene and optionally one or more ?-olefins with a catalyst composition in a continuous polymerization reactor at a pressure of less than 10,000 kPa; wherein the catalyst composition comprises a hafnocene; and isolating a polyethylene having a density in the range of from 0.930 to 0.975 g/cm3. Also provided is a method of transitioning a continuous polymerization reactor from production of a low density polyethylene to a medium or high density polyethylene. Also provided is a medium to high density polyethylene suitable for injection or rotomolding applications. Also provided is a single catalyst composition suitable for such needs.

Abstract: A method for continuously separating polymer from a high pressure fluid stream comprises subjecting the high pressure fluid stream comprising polymer particles to a filter, wherein the filter segregates the high pressure fluid stream from the polymer particles; subjecting the polymer particles to a rotating device which transports the polymer particles away from the filter, wherein the polymer particles are exposed to thermal conditions sufficient to melt the polymer particles and form a seal surrounding at least a portion of the rotating device; and separating the molten polymer from the rotating device. The method is carried out such that the separation of polymer from the high pressure fluid stream occurs under steady-state.

Abstract: A process for making a relatively low molecular weight, mid-range vinylidene content PIB polymer product comprising a liquid phase polymerization process conducted in a loop reactor at a temperature of at least 60° F. using a BF3/methanol catalyst complex and a contact time of no more than 4 minutes. At least about 90% of the PIB molecules present in the product comprise alpha or beta position isomers. The vinylidene (alpha) isomer content of the product may range from 20% to 70% thereof, and the content of tetra-substituted internal double bonds is very low, advantageously no more than about 10%, preferably less than about 5% and ideally less than about 1–2%.

Abstract: A method of conducting polymerisation reactions on a rotating surface reactor which allows substantially increased conversions (up to around 99%) to be achieved without a corresponding increase in polydispersity as would be expected as a result of the Trommsdorff-Norrish effect. The rotating surface reactor serves to disentangle and/or stretch growing polymer chains so as to result in better control over polymerisation kinetics.

Abstract: A slurry polymerization process removes a portion of the fluid slurry without using a settling leg or a continuous take-off. The process uses a reactor take-off valve that is periodically fully closed and fully opened such that the withdrawn slurry is removed from the reactor in a discontinuous manner. The regular, periodic full closing and full opening of the take-off valve reduces instances of polymer plugging the take-off valve. In another aspect of the invention, a take-off valve is throttled in a repetitive pattern to reduce plugging of the take-off valve.

Abstract: Apparatus for olefin polymerization includes one or more shell and tube olefin polymerization reactors, each of which has an olefin polymerization reaction mixture inlet connection and a crude polyolefin product outlet connection. Each reactor is equipped with a recirculation system including a pump arranged to circulate a reaction mixture through the tube side of the reactor independently of the introduction of olefin polymerization reaction mixture into the reactor. The apparatus may also include an inlet reaction mixture distribution manifold and an outlet polymerization reaction mixture collection manifold interconnecting the reactors for operation in parallel. The apparatus also includes catalyst composition and catalyst modifier inlets for each reactor arranged such that a catalyst modifier to may be introduced into each reactor at a rate which is independent of the introduction of catalyst composition.

Abstract: A method for producing an aqueous polymer dispersion by radical emulsion polymerization of an aqueous monomer emulsion, wherein the monomer emulsion is produced continually according to consumption by mixing the components thereof using a mixing device.

Abstract: The present invention provides a process to create without mechanical agitation a zone of low shear, low turbulence flow pattern within a continuous liquid phase contained in a vessel and comprising a dispersed phase consisting of particles or immiscible liquid droplets which have a density different from and should be distributed within the continuous phase without excessive agglomeration or breakups in order to largely preserve the initial particle size distribution, by a continuous or periodic re-circulation of at least a part of the continuous phase which is preferably free of dispersed particles or droplets.

Abstract: A method for carrying out the continuous polymerization of a monomer in a carbon dioxide reaction medium comprises the steps of: (a) providing an apparatus including a continuous reaction vessel and a separator; (b) carrying out a polymerization reaction in the reaction vessel by combining a monomer and a carbon dioxide reaction medium therein (and preferably by also combining an initiator therein), wherein the reaction medium is a liquid or supercritical fluid, and wherein the reaction produces a solid polymer product in the reaction vessel; then (c) withdrawing a continuous effluent stream from the reaction vessel during the polymerization reaction, wherein the effluent stream is maintained as a liquid or supercritical fluid; then (d) passing the continuous effluent stream through the separator and separating the solid polymer therefrom while maintaining at least a portion of the effluent stream as a liquid or supercritical fluid; and then (e) returning at least a portion of the continuous effluent stream t

Abstract: Temperature control and efficient heat transfer are important to producing high quality polymer drag reducing agents from alpha-olefin and/or other monomers. Many polymerization reactions are exothermic, and controlling or minimizing the exotherm combined with low reaction temperatures yields high molecular weight and, for poly(alpha-olefins), high quality drag reducing agent polymers. It has been found that a shell and tube heat exchanger-type reactor, with the inner tubes hosting the reaction mixture and a coolant circulating through the shell side gives good temperature control. The use of appropriate release agents helps to keep the inner reaction chambers from building up any polymer residue. These reactors can be operated in a continuous filling and harvesting mode to facilitate the continuous production of polymer drag reducing agent and related formulations.

Abstract: A gas-phase olefin polymerization process in a plug flow reactor uses a catalyst system containing a magnesium halide supported titanium-containing component, an organoaluminum component, and at least one external electron donor component; in the process a first external donor component is added to the reactor at an injection point axially near an injection point for the supported transition metal containing component, and at least a second external donor component is added to the reactor axially downstream from the injection point for the first external donor component.

Abstract: A continuous process for producing conjugated diene polymers comprising the steps of contacting, within an hydrocarbon solvent and within a continuous reactor, conjugated diene monomer and a catalyst composition prepared by combining: (a) a lanthanide compound, (b) an alkylating agent, and (c) a halogen-containing compound, and maintaining a non-ideal flow pattern within the continuous reactor so that 10% of the reagents entering the reactor at a reference time t0 are still present within the continuous reactor at a time t0+xtrt, where trt is the residence time corresponding to ideal flow within the continuous reactor and x is a numeral greater than 1.5.

Abstract: A novel liquid phase polymerization process for preparing a polyolefin product having preselected properties is disclosed. The process includes the steps of providing a liquid feedstock which contains an olefinic component and a catalyst composition consisting of a stable complex of BF3 and a complexing agent therefor. The feedstock may comprise any one or more of a number of olefins including branched olefins such as isobutylene, C3 to C15 linear alpha olefins and C4 to C15 reactive non-alpha olefins. The feedstock and the catalyst composition are introduced into a residual reaction mixture recirculating in a loop reactor reaction zone provided in the tube side of a shell and tube heat exchanger at a recirculation rate sufficient to cause intimate intermixing of the residual reaction mixture, the added feedstock and the added catalyst composition.

Abstract: The present invention provides such a production process that a low-cost water-absorbent resin having excellent quality can be obtained by reasonable steps in aqueous solution polymerization. The production process for a water-absorbent resin comprises a polymerization setup that includes the steps of: supplying an aqueous solution of a water-soluble unsaturated monomer component including a major proportion of acrylic acid and/or its salt into a polymerization vessel causing shearing action; and then carrying out polymerization, involving crosslinking, of the water-soluble unsaturated monomer and at the same time carrying out fine division of the resultant hydrogel; with the production process being characterized in that the aqueous solution of the water-soluble unsaturated monomer component as supplied into the polymerization vessel has a temperature of not lower than 40° C.

Abstract: This invention relates to processes for transitioning among polymerization catalyst systems, preferably catalyst systems, which are incompatible with each other. Particularly, the invention relates to processes for transitioning among olefin polymerization reactions utilizing Ziegler-Natta catalyst systems, metallocene catalyst systems and chromium-based catalyst systems.

Abstract: A continuous vapor-phase fluidized-bed process for the preparation of ethylene homopolymers and copolymers having a density of from 0.87 to 0.97 g/cm3 in which ethylene or mixtures of ethylene and C3-C8 a-monoolefins are (co)polymerized in the presence of a supported chromium catalyst in the polymerization zone of a vapor-phase fluidized-bed reactor under pressures ranging from 1 to 100 bar and at temperatures ranging from 30° to 125° C. in the vapor phase in an agitated bed of bulk material comprising particulate polymer, the resultant heat of polymerization is removed by cooling the recirculated reactor gas and the resulting (co)polymer is removed from the vapor-phase fluidized-bed reactor, wherein, for the preparation of a (co)polymer of a specific density d, the (co)polymerization is carried out at a temperature which is in a range restricted by an upper envelope defined by equation I T H = 171 + 6 ? ? ? d ? 0.

Abstract: Apparatus for olefin polymerization includes a plurality of shell and tube olefin polymerization reactors, each of which has an olefin polymerization reaction mixture inlet connection and a crude polyolefin product outlet connection. Each reactor is equipped with a recirculation system including a pump arranged to circulate a reaction mixture through the tube side of the reactor independently of the introduction of olefin polymerization reaction mixture into the reactor. The apparatus also includes an inlet reaction mixture distribution manifold and an outlet polymerization reaction mixture collection manifold interconnecting the reactors for operation in parallel. The apparatus also includes catalyst composition and catalyst modifier inlets for each reactor arranged such that a catalyst modifier to may be introduced into each reactor at a rate which is independent of the introduction of catalyst composition.

Abstract: Apparatus for olefin polymerization includes a plurality of shell and tube olefin polymerization reactors, each of which has an olefin polymerization reaction mixture inlet connection and a crude polyolefin product outlet connection. Each reactor is equipped with a recirculation system including a pump arranged to circulate a reaction mixture through the tube side of the reactor independently of the introduction of olefin polymerization reaction mixture into the reactor. The apparatus also includes an inlet reaction mixture distribution manifold and an outlet polymerization reaction mixture collection manifold interconnecting the reactors for operation in parallel. The apparatus also includes catalyst composition and catalyst modifier inlets for each reactor arranged such that a catalyst modifier to may be introduced into each reactor at a rate which is independent of the introduction of catalyst composition.

Abstract: An improved process for the polymerisation of olefin monomer selected from (a) ethylene, (b) propylene, (c) mixtures of ethylene and propylene and (d) mixtures of (a), (b) or (c) with one or more alpha-olefins in a fluidised bed gas phase reactor, said process comprising passing a gaseous mixture of said olefin monomers(s) through the fluidised bed under effective polmerisation conditions to provide a polymer product containing unreacted monomer(s) and a gaseous effluent stream comprising unreacted monomer(s), removing the polymer product to a degassing vessel, recycling a first portion of the gaseous effluent stream to the fluidised bed and passing a second portion of the gaseous effluent stream to counter currently contact the polymer product in said degassing vessel to produce a polymer product having a reduced amount of unreacted monomer(s), characterised in that the improvements to the process comprise: (i) removing heavy hydrocarbons from the second portion of the effluent stream and returning said hydr

Abstract: Continuous gas-phase polymerization process for preparing ethylene and propene homopolymers and copolymers, in which ethylene, propene or mixtures comprising ethylene or propene and C3-C8-&agr;-monoolefins are polymerized in the polymerization zone of a gas-phase polymerization reactor at from 30 to 125° C. and pressures of from 1 to 100 bar in the gas phase in a bed comprising finely divided polymer in the presence of a catalyst. To remove the heat of polymerization, the reactor gas is circulated and firstly passes through a cyclone after leaving the reactor. To prevent polymer deposits in the circulating gas system, a catalyst poison having a boiling point above the maximum temperature within the circulating gas system is fed into this circulating gas system at a position between the reactor and the cyclone.

Abstract: There is provided a process for producing a modified polymer rubber, which comprises the steps of: (1) reacting one part by mol of an organoalkali metal compound with n±0.7 (n is an integer of 3 or more) parts by mol of a specific diphenyl compound to produce a reaction mixture, (2) polymerizing in the presence of the produced reaction mixture an aromatic vinyl monomer and a conjugated diene monomer in a hydrocarbon solvent, and after completion of the polymerizing, stirring for at least 30 minutes, to produce a polymerization reaction mixture, and (3) repeating such an operation n−2 times that (i) an aromatic vinyl monomer and a conjugated diene monomer are added to the produced polymerization reaction mixture, and polymerized, and (ii) after completion of the polymerizing, stirring is carried out for at least 30 minutes, and thereby producing a modified polymer rubber, whose both ends and n−2 positions in its chain are modified by the compound represented by the formula (1).

Abstract: Apparatus for olefin polymerization includes a plurality of shell and tube olefin polymerization reactors, each of which has an olefin polymerization reaction mixture inlet connection and a crude polyolefin product outlet connection. Each reactor is equipped with a recirculation system including a pump arranged to circulate a reaction mixture through the tube side of the reactor independently of the introduction of olefin polymerization reaction mixture into the reactor. The apparatus also includes an inlet reaction mixture distribution manifold and an outlet polymerization reaction mixture collection manifold interconnecting the reactors for operation in parallel. The apparatus also includes catalyst composition and catalyst modifier inlets for each reactor arranged such that a catalyst modifier to may be introduced into each reactor at a rate which is independent of the introduction of catalyst composition.