Abstract: A process, particularly a gas phase fluidised bed process, for the production of polymers avoids formation of sheets or chunks within the reactor, without the need to use antistatic agents, which can reduce the activity of the catalyst or alter the characteristics of the yielded product. According to the invention, a device generates a corona discharge in the polymerisation reactor during the polymerisation process; an AC voltage difference is applied between the elements which constitute the discharging pair of the device.

Abstract: At least one single-stage or multistage stirrer which produces not only a tangential flow component but also an axial flow field is used in a stirred-vessel reactor in connection with the preparation of polymers by liquid phase polymerization.

Abstract: A continuous process for preparing polymers is disclosed. The continuous process includes the steps of continuously feeding a reaction mixture containing a monomer into a non-cylindrical channel, continuously controlling the temperature of the non-cylindrical channel by exposing the surface of the non-cylindrical channel not exposed to the monomer to a temperature control medium, polymerizing the monomer in the non-cylindrical channel, and continuously removing the polymer from the non-cylindrical channel. The continuous process is suitable for the preparation of polymers containing ethylenically unsaturated monomers as polymerized units by emulsion polymerization, solution polymerization, and suspension polymerization.

Abstract: The present invention relates to an improved catalyst delivery method for introducing a supported bulky ligand metallocene-type catalyst system to a reactor for polymerizing one or more olefin(s). In particular, the invention provides for a method of introducing a supported metallocene-type catalyst system into a polymerization reactor by and in the presence of a carrier solution of an antistatic agent and a liquid diluent. Also, the invention is directed toward a catalyst feeder for use in a polymerization process.

Abstract: A method for making a syndiotactic vinylaromatic polymer. The method includes mixing a first amount of a vinylaromatic monomer with a catalyst in a first back-mixed reaction zone under polymerization conditions such that the vinylaromatic monomer polymerizes to a conversion of from 60 to 85 percent to form a polymer-containing mixture. The polymer-containing mixture is passed to at least one other back-mixed reaction zone where it contacts a second amount of the vinylaromatic monomer under polymerization conditions such that the syndiotactic vinylaromatic polymer is formed.

Abstract: Particles of a copolymer of a vinyl arene and a copolymerizable compound containing a polar moiety and a vinyl moiety containing water may be prepared by forming a mixture of monomers and small amounts of water and polymerizing under agitation to 20 to 70% conversion and then suspending the mass in water and finishing the polymerization. The resulting polymer beads contain finely dispersed water which is useful as an environmentally acceptable blowing agent.

Abstract: A continuous process for the manufacture of olefin polymers in a continuous gas phase polymerization reaction wherein monomer, after passage through the fluidized bed, is cooled to a temperature below its dew point to produce a mixture of cold gas and liquid. All or part of the cold gas is introduced into the bottom of the reactor to serve as the fluidizing gas stream for the fluidized bed. Cold liquid separated from the mixture is warmed to form a heated fluid by passing in indirect heat exchange relation with the fluidized bed and the heated fluid is then injected directly into the bed; combined with the fluidizing gas stream; sprayed on top of the bed or combined with gaseous monomer removed from the fluidized bed for cooling.

Abstract: There is provided a process for the gas phase production of an ethylene-propylene or ethylene-propylene-diene rubber in the presence of a single site or single-site like catalyst (e.g., metallocene) catalyst system and an inert particulate material comprising pretreating the inert particulate material with trialkylaluminum (e.g., tri-isobutylaluminum) before commencing polymerization.

Abstract: A continuous gas fluidized bed process for the polymerization of olefins, especially ethylene, propylene, or mixtures thereof with other alpha-olefins by cooling the recycle gas stream to condense some liquid (e.g., a comonomer), separating at least part of the liquid and spraying it under pressure through a nozzle (1) directly into the fluidized bed by pressurizing the liquid and feeding it to a spray nozzle (1) having a mechanical device (6) for atomizing the liquid, under conditions such that the spray is formed within a spray-forming zone (5) of the nozzle outlet. The spray-forming zone (5) is preferably shielded from the fluidized bed particles by a wall or walls which can be, for example, a tube or a plate. Also described is a nozzle having two or more series of outlets, each series being fed and controlled independently to enable improved turn-up/turn-down of the liquid supply to the bed.

Abstract: The invention concerns a process for producing polymethacrylate moulding compounds, which have high thermal dimensional stability and high stability with respect to thermal decomposition, by the radical polymerization of methylmethacrylate monomers and optionally comonomers in at least two reactors operated successively, ensuring a high degree of blending. The process is characterized in that: a) a first reactor is operated at a temperature of less than 120° C.; and b) a second reactor or further successive reactors is/are operated in a temperature range of more than 130° C. and at most 200° C.

Abstract: Devolatilization of molten polymer is carried out using a vertical static mixer which opens directly into a flash tank. Expansion of a stripping agent injected at an inlet of the static mixer occurs in the static mixer and the continued shearing causes disengagement of the vapor from the polymer, so that expansion is complete before the polymer enters the flash tank and stripper and volatiles are removed by a pump and condenser arrangement which holds the flash tank at a reduced pressure. Polymer outlets are in the floor of the flash tank and have metering pumps at their bottom end.

Abstract: The present invention teaches the use of particular soluble metallocene catalysts to produce stereoregular polymers in gas phase polymerizations wherein the catalysts are fed into a particular lean zone in the reactor. The metallocene catalysts are bridged bis(substituted indenyl) compounds.

Abstract: A method for producing a cross-linked polymer manifesting a high absorption capacity and having a small content of soluble component by a convenient and expeditious process with high productivity is provided. An absorbent resin such that disposable diapers and other products incorporating the absorbent resin manifest outstanding qualities and a method for the production of the absorbent resin are proposed.

Abstract: The novel process for preparing ethylene copolymers by polymerizing ethylene with, as comonomer, up to 10% by weight, based on the total amount of the monomers, of a 1-olefin of the formula R—CH═CH2, where R is a straight-chain or branched alkyl radical having from 1 to 4 carbon atoms, is carried out in a polymerization reactor and in suspension with a dispersion medium at a temperature of from 20 to 100° C. and a pressure of from 2 to 20 bar, in the presence of a catalyst. The dispersion medium is then separated from the polymer. After carrying out the polymerization, but before removing the dispersion medium from the polymer, the suspension stream is partly evaporated, with the result that some of the wax formed in the polymerization is adsorbed onto the polymer and the resultant vapor stream is fed directly into the reactors after condensation or back into the process after distillative removal of the comonomer.

Abstract: A process for polymerization of olefin monomers by forming a fluid stream containing catalyst, continuously feeding the fluid stream into an elongated polymerization reactor having at least two successive chambers separated by dividing plates having a diameter slightly smaller than that of the polymerization rector, feeding monomers, and an optional catalyst and donor into the polymerization reactor under temperature conditions to polymerize the olefin while maintaining a mixed flow in the chambers to polymerize the monomers and optional comonomer in the fluid, and removing the resultant polymer slurry from the polymerization reactor.

Abstract: A hydrogel polymer obtained by polymerizing a monomer component including acrylic acid (salt) is post-neutralized so that each of polymer particles derived from a polymer produced by neutralizing the hydrogel polymer has an allowable neutralization ratio. The polymer as obtained by neutralizing the hydrogel polymer is reacted with a crosslinking agent reactive to a functional group of the polymer.

Abstract: A continuous gas fluidized bed process for the polymerization of olefin monomer(s) wherein the recycled gaseous stream withdrawn from the reactor is divided into two streams (A and B) and that (a) a first stream (A) having been cooled to a temperature at which liquid condenses out is then reintroduced directly into the fluidized bed in the reactor in such a way that, at any time, the condensed liquid is continuously introduced into the bed at a minimum rate of 10 liters of liquid per cubic meter of fluidized bed material per hour, and (b) a second stream (B), which by-passes the above cooling/condensing step, is passed through an exchanger and is then reintroduced into the reactor. The continuous introduction of a liquid into the reactor reduces or even eliminates fouling problems which can be encountered in conventional gas phase olefin polymerization processes.

Abstract: The present invention provides a production process, in which hydrophilic crosslinked polymers can be dried uniformly with good efficiency, and the deterioration during the drying is little. The production process of a hydrophilic crosslinked polymer comprises the steps of polymerizing an aqueous solution including a hydrophilic monomer and a crosslinking agent to obtain a hydrogel crosslinked polymer, and drying the hydrogel crosslinked polymer, thus obtaining the hydrophilic crosslinked polymer, and is characterized in that: the hydrogel crosslinked polymer is dried in a static state until it becomes possible to disintegrate an aggregate of the hydrogel crosslinked polymer; the dried hydrogel crosslinked polymer is disintegrated into a particle size of 20 mm or less; and the disintegrated hydrogel crosslinked polymer is dried in a stirred state and/or a fluidized state.

Abstract: In a continuous gas-phase polymerization process for preparing ethylene and propene homopolymers and copolymers, in which ethylene, propene or a mixture of ethylene or propene and C3-C8-&agr;-monoolefins is polymerized in the polymerization zone of a gas-phase polymerization reactor at from 30 to 125° C. and a pressure of from 1 to 100 bar in the gas phase in a bed of finely divided polymer in the presence of a catalyst, where the reactor gas is circulated to remove the heat of polymerization, polymer deposits in the circulating gas line are prevented by metering a catalyst poison having a boiling point above the maximum temperature within the circulating gas line into this circulating gas line in at most such an amount that it does not significantly impair the productivity of the catalyst in the reactor.

Abstract: A particulate polymer P having an average particle diameter d50 of from 0.1 to 50 &mgr;m is prepared by a process in which an emulsion E is prepared from one or more monomers M, which are polymerizable by free radical polymerization to give the polymer P, water, and at least one protective colloid PC by the action of high shear forces, and the emulsion E is subjected to polymerization in a reactor with the use of a free radical polymerization initiator RI wherein, based on the emulsion E, not more than 75% by weight of the emulsion E (initially taken portion of E) are initially taken in the reactor at the beginning of the polymerization and at least 25% by weight of the emulsion E (feed portion of E) are not fed to the reactor until after the beginning of the polymerization.

Abstract: A method for producing optical rod-shaped graded-index polymer preform by making the composition of the preform near the core differ from the composition of the shell of the preform by polymerization with rotation of a mixture containing the starting substances, whereby a mixture comprising various monomers is rotated and that after achieving a distribution of the monomers, the polymerization is carried out with rotation of the mixture, or that a monomer and thermoplastic polymer-containing mixture, whereby said monomer is different from the monomer from which said polymer has been prepared, is rotated and that, after achieving a distribution of said monomer and polymer, the monomer present in said mixture is subsequently polymerized with rotation, in which both cases the rotation is carried out with a diameter dependent rotation velocity, represented by the following general equation: rpm>10,000 d.sup.-0.5 wherein: rpm=rotation velocity, revolutions per minute d=diameter of the preform (cm).

Abstract: A method for tailoring the viscosity of a conjugated polymer precursor, the method comprising synthesizing the precursor by a polymerization reaction and, during the polymerization reaction, applying a shear to the reactants of the polymerization reaction so as to define the viscosity of the precursor at a desired value.

Abstract: The present invention relates to a process for the preparation of hydrophilic hydrogels of high swelling capacity by (co)polymerization of hydrophilic monomers in a fluidized bed apparatus.

Abstract: Liquid catalyst composition is fed to a fluidized bed olefin polymerization reactor through an ultrasonic nozzle, enabling improved control over average catalyst composition droplet size and size distribution, which provides better control over resin particle size. The spray may be surrounded by a shroud of gas which creates a particle lean zone, thus reducing the likelihood of contact by the catalyst composition with existing product particles already suspended in the fluid bed.

Abstract: A process comprising contacting one or more monomers with a catalyst, in the gas phase, under polymerization conditions, in a fluidized bed reactor, with the proviso that the reactor is at least partially cooled internally by the vaporization of a liquid cryogen directly into the reactor.

Abstract: A method of suspension polymerization of a monomeric composition to produce a polymer or a polymer composition is disclosed which method comprises the steps of retaining a disperse phase component composed of the monomeric composition and a continuous phase component composed of a medium in independent vessels, supplying the disperse phase component and the continuous phase component from their respective vessels into a disperser simultaneously and continuously through associated independent passageways, applying shear force in the disperser to form a dispersion having droplets of a desired size, subsequently introducing the dispersion into a polymerization vessel, and completing a polymerizating reaction to produce a polymer or a polymer composition.

Abstract: This invention provides a method of producing polyester and charging apparatus therefor capable of producing a high quality polyethylene naphthalate usable for photographic purpose from recovered polyethylene naphthalate which comprises subjecting an ester-forming derivative consisting essentially of naphthalene dicarboxylic acid or its lower alkyl ester and a diol compound consisting essentially of ethylene glycol to ester exchange reaction or esterification to produce polyethylene naphthalate, wherein recovered polyethylene naphthalate resin is charged before beginning of effusion of alcohol or water which is a by-product of the ester exchange reaction or esterification, and a charging apparatus comprising a slidable inner pipe capable of penetrating through a supply valve.

Abstract: Polymers of vinylaromatic compounds are prepared at from -80 to 150.degree. C. in the presence of metallocene catalyst systems by a process in which polymerization is carried out in one stage with the use of a closely intermeshing twin-screw extruder having corotating screws.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: The present invention relates to a gas phase process for the polymerization of monomer(s) utilizing a metallocene catalyst system to produce easy processing polyolefin polymers.

Abstract: A process for the homo- or copolymerization of C.sub.2 -C.sub.8 -alk-1-enes by means of a Ziegler-Natta or a metallocene catalyst system in a stirred bed of finely divided polymer from the gas phase, the transition metal-containing catalyst solid of the Ziegler-Natta or metallocene catalyst system being fed to the reactor by C.sub.2 -C.sub.8 -alk-1-ene metered into the reactor, wherein the transition metal-containing catalyst solid, together with at least some of the C.sub.2 -C.sub.8 -alk-1-ene, is fed to the reactor through one or more pipes which project perpendicularly or virtually perpendicularly from above into the gas space and end above the pulverulent stirred reactor bed.

Abstract: The invention teaches a novel design for a fluidized bed polymerization reactor which utilizes a primary fluidization grid to provide mixing and fluidization of the polymer and at least one secondary distribution plate located above the first distribution plate to promote segregation of polymer particles by size, the larger particles falling into the lower fluidization zone and the smaller particles being entrained up from the primary fluidization grid and through the secondary distribution grid into an upper reaction zone.

Abstract: Disclosed is a polymerization process comprising feeding a monomer as a raw material, a polymerization catalyst, and optionally, an inert medium to a tubular reactor in a pressurized state; permitting a part of the raw material monomer and the inert medium fed to the reactor to form a gas phase and the remainder to form a liquid phase, so that both of the gas phase comprising the raw material monomer and/or the inert medium and the liquid phase comprising the raw material monomer and/or the inert medium are present in the reactor, wherein said liquid phase may contain a resulting polymer as a solid, and so that a gas-liquid separated flow or a gas-liquid-solid separated flow has the gas phase that is continuous in the direction of flow is formed in the reactor; and polymerizing the raw material monomer while carrying the liquid phase by the gas phase flow, wherein the ratio of a volume flow rate of the liquid phase to a volume flow rate of the gas phase at the outlet of the reactor is 0.00001 to 100,000.

Abstract: Disclosed herein is a fluid bed polymerization process including an improved method for cooling the fluid bed. The recycled fluid stream is cooled by a method comprisinga) cooling said gas sufficiently to condense a portion of said gas to a liquid,b) thereafter separating said liquid from said cooled gas,c) compressing said cooled gas,d) thereafter recooling said cooled gas sufficiently to condense a portion thereof to a liquid,e) reintroducing said liquid portions and said recooled gas into said reactor sufficiently to maintain reactive conditions.

Abstract: Process for preparing pigment preparations by mixing a colored composition with monomers and simultaneously polymerizing the monomers in an extruder at elevated temperatures, whereby the following steps are carried out:(A) introducing continuously into an extruder(a) from 40 to 90% by weight of a pigment,(b) from 60 to 10% by weight of at least a monomer, selected from the group consisting of an acrylate and a methacrylate, whereby the amounts of pigment and monomer sum up to 100%, and, if desired,(c) from 0 to 10% by weight, based on the amount of component (b), of an initiator, and(B) mixing the components (a), (b), and, if desired, (c) therein, and(C) withdrawing continuously the obtained reaction mixture from the extruder, and a high molecular organic material pigmented with the pigment preparation.

Abstract: A process for producing polymer in a gas phase reactor by introducing a stream of monomer and gas into a polymerization zone while providing at least one liquid component in the polymerization zone.

Abstract: The present invention provides a Ziegler-Natta catalyst based on titanium and vanadium useful in solution processes for the polymerization of olefins having a low amount of aluminum and magnesium. The catalysts of the present invention have a molar ratio of magnesium to the first aluminum component from 4.0:1 to 8.0:1 and molar ratio of magnesium to titanium and vanadium from 4.0:1 to 8.0:1. The invention provides a novel catalyst preparation method to substantially increase the polymer molecular weight in the high temperature ethylene polymerization process.

Abstract: There is a need for polymers which are utilized in automotive interiors which offer increased heat and ultraviolet light resistance. It is particularly critical for polymers which are utilized in making skin compounds for automotive instrument and door panels to display excellent heat and ultraviolet light resistance. This invention discloses a continuous process for preparing a rubbery polymer which can be blended with polyvinyl chloride to make leathery compositions having good heat and ultraviolet light resistance. This technique involves utilizing a multiple continuous reactor system wherein a first phase monomer solution containing butyl acrylate, an acrylic monomer, acrylonitrile and a crosslinking agent is continuously charged into at least three initial reactors. To attain a small particle size, it is necessary to limit the solids content in each of these initial reactors.

Abstract: The present invention provides a process and apparatus for feeding powders such as fine, cohesive, or powdery particulate materials from a low pressure system to a high pressure system. In a preferred embodiment a process and apparatus of pressurizing and feeding carbon black fluff to a polymerization reactor is provided particularly a gas phase fluidized polymerization reactor to provide for a close-coupling of a carbon black reactor to a polymerization reactor.

Abstract: The use of perpendicular spray nozzles to deliver liquid catalyst to a gas-phase polymerization reactor is taught. Moreover, a method of reducing the amount of gas needed to deliver catalyst is also taught.

Abstract: By utilizing the vapor phase polymerization techniques of the present invention, numerous distinct and highly beneficial advantages are realized. For instance, cis-1,4-polyisoprene rubber and high cis-1,4-polybutadiene rubber having a consistent and controllable molecular weight can be easily and practically prepared without utilizing a solvent. The subject invention more specifically discloses a method for vapor phase polymerizing isoprene into cis-1,4-polyisoprene in a process comprising the steps of:(1) charging into a reaction zone said isoprene and a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrachloride, preferably in the presence of at least one ether; wherein the isoprene is maintained in the vapor phase in said reaction zone by a suitable combination of temperature and pressure;(2) allowing said isoprene to polymerize into cis-1,4-polyisoprene at a temperature within the range of about 35.degree. C. to about 70.degree. C.

Abstract: A process for the (co)polymerization of a monomer material, which includes at least an acrylonitrile monomer as an essential component, at a temperature of 80.degree. C. or higher by bulk or solution polymerization while allowing said monomer material to evaporate. The (co)polymerization is conducted while providing a vapor phase over a polymerization mixture in a reaction tank. During the (co)polymerization, the temperature of the vapor phase is maintained in a range of from 30.degree. C. to 65.degree. C. so that the polymerization is conducted without substantially releasing vapor, which is evaporated from the polymerization mixture, to outside of the reaction tank. By cooling the vapor phase of the reaction tank and maintaining its temperature in the above specific range in accordance with the present invention, it is possible to avoid mixing of a gelled polymer in a product and also to effectively remove reaction heat at the time of the (co)polymerization.

Abstract: A process for the radical polymerization of ethylenically unsaturated monomers in an aqueous medium has (a) the starting solution used for the polymerization and the educts required for polymerization such as monomers, germ latex, buffering agents, emulsifiers and/or protective colloids are introduced into a pre-mixing device and thoroughly mixed, heated before being transferred to the polymerization vessel to the polymerization temperature, no initiator being used if a thermal radical initiator is used and only individual initiator components being used where a redox initiator system is used; (b) once the mixture has reached polymerization temperature, it is transferred to a polymerization vessel, the wall of which during the transfer and polymerization is maintained by cooling at a temperature below the polymerization temperature; polymerization is started by adding the thermal initiator or additional initiator components of the redox initiator system, the other educts being added at the start of and/or dur

Abstract: An improved method of bed temperature control is provided by the coordinated manipulation of the water flow rate in one or more heat exchangers and cycle gas flow rate to the reactor.

Abstract: The present invention provides a method for the polymerization of free-radically polymerizable vinyl monomers in a batch reactor under essential adiabatic conditions.

Abstract: The invention relates to a process and an apparatus for the microsuspension polymerization of vinyl chloride in vessels whose contents are agitated predominantly by natural convection where, in a reactor having a ratio of height H to diameter D of H/D 2, which is equipped externally or internally with a heat exchanger provided with water and connected to a pumped circulation system provided with water, the introduction of the cooling water takes place in the upper third of the heat exchanger and the cooling water is conducted downward and is conducted away in the lower third of the heat exchanger.

Abstract: A polymerization process is provided comprising contacting under polymerization conditions a catalyst, a taming agent, ethylene and optionally a comonomer, wherein the catalyst comprises chromium oxide, titanium oxide and an inorganic refractory oxide, wherein the taming agent is selected from the group consisting of water, alcohols, aldehydes, ketones, esters, and organic acids and mixtures thereof. The process is especially suited for polymerizing ethylene resins suitable for blow molding use.

Abstract: The present invention provides a polymerizable monomer composition particle and a resin particle, both of which display a narrow particle diameter distribution. A process for producing a resin particle comprises the steps of: passing two liquids through a static type in-line mixer having a liquid-dividing mechanism standing in a static state, wherein the two liquids are formable into two phases including one of the two liquids as a dispersing phase component and the other as a continuous phase component; then passing the two liquids through a high speed shearing type dispersing machine having a liquid-shearing mechanism which revolves at a high speed, thus dispersing a fine liquid drop of the dispersing phase component into the continuous phase component; and forming a resin particle from the resultant liquid drop.

Abstract: An improved process for the production of polyolefins in an autoclave reactor having several reaction zones operated at a pressure of 100 to 300 MPa and a temperature of 100 to 300.degree. C. is disclosed. Dunng operation, temperatures are measured continuously inside the autoclave reactor at specific points distributed along the reactor length, each of said measured temperatures is compared with a corresponding preset temperature and the detected deviation between each pair of preset and measured temperatures is used in regulating the amount of monomer and initiator fed into the autoclave through several feed inlets distributed along the reactor length, in order to minimize the temperature deviations and thus obtain an improved control of the polymerization process.

Abstract: The present invention teaches the use of an effervescent nozzle to deliver liquid catalyst to a gas phase polymerization system.