Abstract: The present invention relates to a process for continuous gas-phase polymerisation of olefin(s) in a fluidized-bed reactor, comprising drawing off the polymer from the vertical side wall of the reactor into a lock hopper via a draw-off conduit so that all flow of the polymer in the draw-off conduit is produced according to a downward direction forming with a horizontal plane an inclination with an angle A at least equal to the angle of repose .beta. of the polymer and not exceeding 90.degree.. The present invention improves the degree of filling of the lock hopper and reduces the amount of gas drawn off with the polymer.

Abstract: The present invention provides a continuous gas fluidised bed process for the polymerisation of olefin monomer selected from (a) ethylene, (b) propylene, (c) mixtures of ethylene and propylene, and (d) one or more other alpha-olefins mixed with (a), (b) or (c), to produce a polymer in a fluidised bed reactor which process comprises:(a) continuously withdrawing from the reactor a gaseous stream comprising unreacted olefin monomer and having entrained therein catalyst and/or polymer particles;(b) continuously recycling said gaseous stream comprising unreacted olefin monomer through a fluidised bed in said reactor in the presence of a polymerisation catalyst under reactive conditions;(c) cooling by means of heat exchanger(s) at least part of said gaseous stream withdrawn from said reactor to a temperature at which liquid condenses out;(d) separating at least part of the condensed liquid from the gaseous stream; and(e) introducing at least part of the separated liquid directly into the fluidised bed, characterise

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: A process for the production of elastomeric polypropylene is disclosed. The process entails contacting the propylene monomer neat or in an unreactive hydrocarbon solvent, with a catalyst in a recirculated, stirred reactor at a temperature of about 60.degree. to 80.degree. C. thereby producing elastomeric polypropylene. The reactor contents are in the slurry/solution phase and are essentially free of catalyst poisons. The reactor is capable of recirculating contents that are very viscous such that the reactor contents are well mixed while a portion of the contents of the reactor containing propylene, any solvent, and elastomeric polypropylene are continually removed by the use of a high viscosity pump to recover the elastomeric polypropylene.

Abstract: Process for the polymerization in aqueous suspension of acrylic monomers in the presence of a polymeric suspending agent, homopolymer or copolymer of a compound of formula: ##STR1## wherein: R.sub.1 is H or CH.sub.3 ; R.sub.2 and R.sub.3, equal or different, are H or alkyls C.sub.1 -C.sub.8, optionally branched when possible; M is an alkaline or alkaline-earth metal or ammonium and A is NH, O or NCH.sub.3, characterized in that the polymerization aqueous phase is wholly or partly formed by the mother waters obtained after the separation of the acrylic polymer, so as to have a polymerizable suspension containing at least 0,01% by weight and up to about 1% of said suspending agent and at least from 0.05% to 5% by weight of the other products above mentioned obtained during the polymerization.

Abstract: An improved process for the copolymerization of ethylene and .alpha.-olefins utilizing highly dilute .alpha.-olefin feedstreams to effect high conversions and catalyst productivities. The instant invention is particularly adaptable to copolymerizing the .alpha.-olefin content of commercially available refinery feedstreams such as Raffinate-2.

Abstract: A process for rejecting reactor byproduct from the polymerization reactor in an olefins polymerization process wherein reactor waste gas stream(s) comprising unreacted monomers, reactor byproduct and light components are treated in an absorption process to additionally recover the monomers. The absorption process comprises contacting the reactor waste gas stream(s) with an absorption solvent in an absorption zone to produce a gas stream comprising the light components, and a liquid stream comprising the absorption solvent, absorbed reactor byproduct and absorbed monomers. The liquid stream is fractionated in a distillation column to produce a distillation column bottoms stream that is the absorption solvent which is conveyed to the absorption zone, and an overhead stream comprising the monomers and reactor byproduct which is further fractionated in a splitter column to reject the reactor byproduct as a bottoms stream. The recovered monomers from the splitter overhead can be conveyed to the reactor.

Abstract: A process for the preparation of polyolefin which comprises polymerizing or copolymerizing olefin in the presence of a catalyst for olefin polymerization comprising (A) a metallocene compound of a transition metal selected from the Group IVB of the periodic table, and (B) an organoaluminum oxy-compound; wherein the organoaluminum oxy-compound (B) is added to the polymerization system in the form of a slurry in an aliphatic hydrocarbon or alicyclic hydrocarbon, and the polymerization is carried out in the presence of the aliphatic hydrocarbon diluent or an alicyclic hydrocarbon diluent having a boiling point below 100.degree. C.

Abstract: A process for the production of amorphous polyolefins is disclosed. The process entails contacting the olefin monomer, in an unreactive hydrocarbon solvent, with a catalyst in a recirculated, stirred reactor thereby producing amorphous polyolefin. The reactor is capable of recirculating contents that are very viscous.

Abstract: A process for gas phase polymerization of olefins wherein reactor vent gas stream(s) comprising unreacted monomers and light components are treated in an absorption process to recover the monomers. The absorption process comprises contacting the reactor vent gas stream(s) with an absorption solvent in an absorption zone to produce a gas stream comprising the light components, and a liquid stream comprising the absorption solvent and absorbed monomers. The liquid stream is fractionated in a distillation column to produce a distillation column bottoms stream that is the absorption solvent which is conveyed to the absorption zone, and an overhead stream comprising the monomers which can be conveyed to the reactor. In a preferred embodiment, the absorption solvent consists essentially of components derived from the reactor vent gas stream(s) so that no external solvent is required.

Abstract: The invention is directed toward polymerizing or copolymerizing alpha-olefins either alone or in combination with one or more other alpha-olefins in the presence of a metallocene catalyst in a gas phase reactor having a fluidized bed and a fluidizing medium such that the fluidizing medium entering the reactor comprises a gas and a liquid phase.

Abstract: A polymerization process, comprises a polymerization vessel, a reflux condenser installed outside the polymerization vessel and a pipe connected between the reflux condenser and a wall of the polymerization vessel with an end thereof opening into a gaseous phase region inside the polymerization vessel, for returning the liquid condensate to the polymerization vessel, wherein said end projects from an inner surface of the wall of the polymerization vessel into the gaseous phase region. In polymerizing a monomer having an ethylenically unsaturated double bond using the polymerization apparatus, the quantity of heat removed by the reflux condenser is increased stepwise or continuously with progress of the polymerization, such that not less than 20% of the total reaction heat generated during the whole course of the polymerization is removed by the reflux condenser. With 100 or more repeated polymerization runs, polymer scale deposition inside the vessel is minimal even below the pipe end.

Abstract: The invention is directed toward polymerizing or copolymerizing alpha-olefins either alone or in combination with one or more other alpha-olefins in a gas phase reactor having a fluidized bed and a fluidizing medium such that the fluidizing medium entering the reactor comprises a gas and a liquid phase.

Abstract: The invention is directed toward polymerizing alpha-olefins either alone or in combination with one or more other alpha-olefins utilizing a bulky ligand transition metal catalyst in a gas phase fluidized bed polymerization reactor operating in condensed mode.

Abstract: A process for regulating the reaction in the preparation of polyisobutylene by polymerizing isobutylene at from -130.degree. to 0.degree. C. in the presence of from 0.01 to 1.0% by weight of a Friedel-Crafts catalyst, from 0.0001 to 0.1% by weight of a molecular weight regulator, and a low boiling point solvent that is inert under the reaction conditions, the percentages by weight being based in each case on isobutylene, in which the solvent that has evaporated in the polymerization is continuously removed, liquefied and recycled in the liquid state to the polymerization zone, wherein vinyl ethers are used as molecular weight regulators. The vinyl ether used in this process acts both as an accelerator and an inhibitor of the cationic polymerization.

Abstract: The invention is directed toward polymerizing or copolymerizing alpha-olefins either alone or in combination with one or more other alpha-olefins in a gas phase reactor having a fluidized bed and a fluidizing medium such that the fluidizing medium entering the reactor comprises a gas and a liquid phase.

Abstract: A process for the preparation of a random copolymer of at least one conjugated diene and at least one vinyl aromatic compound comprising reacting the monomers with the aid of an initiator based on lithium in the presence of an essentially inert solvent wherein said solvent consists of at least 60 per cent by weight of cyclopentane and the heat of reaction is withdrawn by means of reflux cooling.

Abstract: In a polymerizing apparatus which comprises a polymerization vessel and a circulating line comprising a heat exchanger installed outside said polymerization vessel and a circulating pipeline extending from said polymerization vessel and returning to said polymerization vessel through said heat exchanger, the improvement comprising a strainer installed in the course of said circulating pipeline. Since polymer scale and a polymer in the form of blocks formed in the circulating line can be trapped, the circulating pipeline and tubes of the heat exchanger can be prevented from being blocked up. Further, since they can be prevented from mixing with a reaction mixture in the polymerization vessel, when the obtained polymer is worked into a molded item such as a sheet, fish eyes can be prevented from increasing. Therefore, a polymer can be produced efficiently with high productivity.

Abstract: The present invention relates to a process and a device for polymerizing alpha-olefins such as ethylene or propylene in a gas phase. The device comprises a gas phase polymerization reactor (5) into which a suspension of prepolymer particles in liquid saturated hydrocarbon(s) is continuously introduced. The prepolymer suspension is prepared in one or more prepolymerization vessels (14) and is continuously passed to a post-treatment unit comprising a degassing means (10) wherein most of the dissolved unreacted olefinic monomer(s) is separated. Preferably, the post-treatment unit may comprise a particle separation means (11) for removing the finest and/or coarsest prepolymer particles from the suspension and/or a concentration means (11a) for concentrating the suspension.High activity catalyst can be used in the process with reduced amounts of prepolymer agglomerates. Prepolymer can be obtained with a constant quality and a desired size.

Abstract: A process for preparing polyamides from amide monomers in a reaction vessel where a portion of the monomers remain unreacted or form oligomers as an extractable fraction includes extracting from the polyamide unreacted amide monomers and oligomers to yield an extracted proportion by weight based on total reaction charge; reducing the oligomer concentration of the extracted proportion relative to the total extract concentration; and returning the extract to the reaction vessel as substantially the same proportion as extracted by weight based on the total reaction charge, so that, after a single extraction, throughout the process the extractable fraction remains below its equilibrium concentration.

Abstract: The present invention relates to an improvement of the known Ziegler catalyst which comprises a combination of a titanium-containing component and an organoaluminum component, and the present invention is characterized by a specific titanium-containing component. Namely, this titanium-containing component is obtained by contacting a known titanium-containing component of the Ziegler type catalyst which comprises Ti, Mg and a halogen, with an alkoxyalkylsilane compound which is characterized in that at least one of the alkyl groups has a branched structure. This catalyst does not require a so-called external electron donor, and no reduction of the polymerization velocity caused by the use of the electron donor is entailed. When this catalyst is used, a propylene/ethylene block copolymer in which the molecular weight of the propylene/ethylene copolymer portion and/or the polyethylene portion is increased, that is, the rigidity and impact strength are increased, can be prepared.

Abstract: A process control method for controlling a polyolefin polymerization process, such as a solution polyethylene process, which includes five steps. The first step is to flow a stream of a solvent into a polyolefin reactor, such as flowing a stream of heptane solvent into the reactor at essentially a constant rate. The second step is to add a principal monomer to the stream of solvent, such as by adding ethylene at a controllable rate to the stream of solvent. The third step is to add a co-monomer to the stream of solvent, such as by adding 1-octene at a controllable rate to the stream of solvent.

Abstract: The preparation of novolaks from phenols or mixtures of different phenols, and oxo compounds or mixtures of oxo compounds by condensation of the reactants in a medium having a low water content in homogeneous phase at temperature of .gtoreq.110.degree. C., preferably between 115.degree. and 200.degree. C. and preferably at normal pressure, in the presence of water-immiscible and/or only partially water-miscible inert organic solvents and of acids as catalysts with removal of water by distillation, the medium having a low water content being prepared or maintained by distilling off water from the reaction mixture, preferably by azeotropic distillation. Particular advantages are obtained when readily volatile oxo compounds, in particular aqueous formaldehyde solutions, are used.

Abstract: A process for preparing polyamides of substantially constant cyclic dimer concentration from amide monomers includes extracting unreacted amide monomers and oligomers, reducing the oligomer concentration relative to the concentration of total extractants and then returning the extract to the reaction vessel in substantially the same total proportion as extracted.

Abstract: A free-radical initiated process for preparing fluorinated polymers wherein at least one gaseous fluoroolefin is polymerized in a stirred polymerizer, the improvement comprising preparing a non-volatile polymeric seed in a reaction zone separate from the polymerizer by decomposing initiator in the presence of fluoromonomer to form oligomeric free radicals and condensing said radicals onto previously prepared polymer; and conveying said non-volatile seed to the polymerizer.

Abstract: In the process for the production of a linear alternating polymer of carbon monoxide and at least one ethylenically unsaturated hydrocarbon, the liquid portion of the product mixture is suitable for recycle as the catalyst composition mixture in subsequent polymerizations when the linear alternating polymer produced has a limiting viscosity number, measured in m-cresol at 60.degree. C., of from about 0.5 dl/g to about 2.5 dl/g and a melting point of at least 225.degree. C.

Abstract: Odoriferous by-product compounds, e.g. 2,4,6-trimethylanisole, are reduced in a process for the production of polyphenylene ether resin in liquid aromatic hydrocarbon solution by continuously distilling and recycling the aromatic hydrocarbon solvent.

Abstract: In the process of producing hydroxylated polybutadiene from a diene monomer in the presence of hydrogen peroxide and a solvent, wherein the solvent is recovered by distillation for reuse; after separation of the hydroxylated polybutadiene from mixture containing such solvent and reaction impurities, the improvement comprising subjecting said mixture to the action of an alkali metal hydroxide or a hydrazine prior to distillation.

Abstract: By a process for suspension polymerization, which comprises steps of:supplying a slurry comprising droplets of a monomer liquid having a substantially uniform size dispersed in an aqueous dispersion medium to a tower type reactor in which said medium forms a downflow, andsuspension polymerizing the monomer with avoiding merging or splitting of the droplets in a fluidized bed which is formed by the downflow of said medium and buoyancy of the monomer liquid droplets, whereinthe specific gravity of said medium is made larger than that of a polymer particle to be produced by the addition of a water soluble inorganic salt to said medium, anda polycarboxylic acid type anionic polymeric surfactant is used as a suspension stabilizer for the monomer liquid droplets,polymer particles having a substantially uniform size are produced with high polymerization conversion.

Abstract: This invention relates to a process for removing a solute from a solution. The process comprises maintaining the solution at reflux conditions to produce a vapor which evolves from the reaction solution. At least a portion of the vapor is removed from the zone and is contacted, outside of the reaction zone, with a solid removal agent which is specific for capturing to itself that portion of the vapor which was the solute to be removed and originally present in the reaction solution. After such capture, the remaining vapor is condensed and returned to the reaction zone. In another embodiment, the solute is removed from the solution by first maintaining the solution at reflux conditions in a zone to produce a vapor which evolves from the solution. At least a portion of that vapor is removed from the zone and condensed. The resultant condensate is contacted, outside of the reaction zone, with a solid removal agent which is specific for capturing unto itself the solute from the condensate.

Abstract: Aluminum alkyls are deactivated in a spent hydrocarbon carrier for an olefin polymerization system by the addition of effective amounts of triglycerides.

Abstract: A process for purifying a solvent suitable for use in the polymerization of an olefin in the presence of a Ziegler-Natta catalyst, which comprises feeding the polymerization solvent to a stage lower than a chimney tray of a multi-stage distillation column, said chimney tray being provided at a height between the top and bottom of the column, feeding an organoaluminum compound to a stage higher than the chimney tray, drawing out a condensate from the chimney tray, heating the condensate to produce heated vapor, introducing the heated vapor to the chimney tray or to a stage higher than the chimney tray but lower than the stage to which the organoaluminum compound has been fed, and drawing the solvent in a purified state from the top.

Abstract: A fluidized bed olefin polymerization process incorporates a recycle of a vent gas, containing unreacted monomers, from the product purge bin vessel to the polymerization reactor. The recycle of the vent gas minimizes the loss of the unpolymerized reactants, thereby decreasing overall process and product costs.

Abstract: A continuous gas fluidized bed process is disclosed for the production of polymer from monomer wherein a gaseous stream comprising monomer is passed through a fluidized bed in a reaction zone in the presence of catalyst under reactive conditions, withdrawing from the reaction zone polymeric product and a stream comprising unreacted gases and solid particles, cooling the stream and recycling the cooled stream to the reaction zone together with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product, and wherein at least a part of the recycle stream is cooled to condense a portion thereof and form a liquid-containing mixture wherein the weight ratio of liquid to solid particles is not less than about two to one, and introducing the mixture into the reaction zone wherein the liquid in the mixture is vaporized.

Abstract: Ethylene is copolymerized with one or more 1-olefins under conditions of high temperature and pressure in the presence of an inert gaseous ratio modifier. As a result, liquid condensation which contributes to equipment damage and unsafe operation is avoided, and copolymer product density is readily controllable.

Abstract: Isobutylene polymers are prepared continuously, in aliphatic C.sub.3 -C.sub.6 -hydrocarbons in the presence of soluble cationic polymerization initiators and coinitiators at from -40.degree. to 40.degree. C. and under from 0.01 to 10 bar, and the solvents and monomers vaporized during the polymerization are recycled, by a process in which the liquid stream of the monomer solution, containing 40-95, in particular 50-85, percent by weight of the monomers, the liquid streams of the recycle and of the coinitiator solution and the separate stream of the initiator solution are combined in a first zone containing the polymerization zone, and the resulting polymer solution is taken off continuously through a second zone vertically below the first zone. The liquid streams of the monomer solution, the coinitiator solution and the recycle can furthermore be fed into the first zone separately from one another.

Abstract: Process for the production of polyphenylene oxide by means of the oxidative polymerization of 2,6-xylenol, with either oxygen or a gas containing molecular oxygen, in the presence of a catalyst, by continuously operating in a circulation system, and with the precipitation of the polymer in the liquid reaction medium.

Abstract: A process is described for increasing the space time yield of polymer production in a fluidized bed reactor employing an exothermic polymerization reaction by cooling the recycle stream to below its dew point and returning the resultant two-phase fluid stream to the reactor to maintain the fluidized bed at a desired temperature above the dew point of the recycle stream.

Abstract: A process for the manufacture of vinyl chloride polymers or copolymers by microsuspension polymerization of vinyl chloride or vinyl chloride and up to 30% by weight, based on the total monomer content, of .alpha.-olefinically unsaturated monomers copolymerizable with vinyl chloride comprising the steps of:(1) dispersing the monomer or the monomer mixture in water in the presence of from 0.1 to 3% by weight, based on the total weight of the monomer content, of microsuspension dispersion auxiliaries and from 0.001 to 3% by weight, based on the total weight of the monomer content, of microsuspension monomer - soluble radical - initiators;(2) homogenizing said dispersion so that monomer droplets mostly having a mean diameter of from 0.1 to 3 .mu.

Abstract: A process for producing an ethylene copolymer which comprises polymerizing a predominant amount of ethylene and a minor amount of an alpha-olefin having 4 to 10 carbon atoms in the gaseous phase in the presence of a catalyst composed of (A) a transition metal catalyst component and (B) an organometallic compound of a metal of Groups I to III of the periodic table; characterized in that the copolymerization is carried out under the following conditions (i) and (ii),(i) at least 1 mole, per mole of ethylene, of a gaseous saturated hydrocarbon having 3 to 6 carbon atoms is caused to be present in the gaseous phase copolymerization system, and(ii) the gaseous mixture containing the unreacted olefin which has been discharged from the gaseous phase copolymerization system is cooled to a temperature at which the mixture is not liquefied, and the cooled gaseous mixture is recycled to the gaseous phase copolymerization system.

Abstract: It is possible to remove quantities of heat from exothermically running polymerization reactions of vinyl monomers in heterogeneous phase, in a sophisticated manner by adding liquids to the reaction medium for the removal of heat and to regulate the reaction temperature, which liquids do not dissolve the polymer under the reaction conditions and the boiling temperatures of which are lower than or are identical to the technically predetermined reaction temperatures under the polymerization conditions which are applied, and the heat which is released in the reaction system is removed by evaporating these liquids.

Abstract: An improved method for the production of polyphenylene ethers is disclosed. The method comprises oxidatively coupling monohydric phenols in the presence of a complex catalyst and in a liquid medium which is a solvent for the monomer and catalyst and a non-solvent for the polyphenylene ether. The polyphenylene ether precipitates to form a slurry of particulate solids which is then washed with an aqueous solution of a chelating agent to remove catalyst residue.

Abstract: A process for producing aromatic polyester polycarbonate particles from a methylene chloride solution of an aromatic polyester polycarbonate comprises continuously supplying the methylene chloride solution of an aromatic polyester polycarbonate to a particle-forming tank, heating it while maintaining it in a suspended state in water to evaporate methylene chloride and to form aromatic polyester polycarbonate particles, subjecting at least a part of the resulting aqueous slurry withdrawn from the particle-forming tank and containing the aromatic polyester polycarbonate particles to wet pulverization treatment and recycling the treated slurry to the particle-forming tank.

Abstract: A method for processing a polymer solution by changing the thermodynamic state of the solution to produce a dilute phase and a concentrated phase such that the thermodynamic state is sufficiently changed that the two phases are formed by spinodal decomposition.

Abstract: A process for the preparation of polyisobutylene by polymerizing isobutylene in a polymerization zone which is at from 0.degree. to -130.degree. C., by means of from 0.01 to 1.0 percent by weight of boron trifluoride catalyst, in the presence of a primary or secondary alcohol as polymerization accelerator and in the presence of from 30 to 90% by weight of a low-boiling solvent which is inert under the reaction conditions, wherein the solvent vaporized during the polymerization is continuously drawn off, liquefied and recycled, in the liquid state, to the polymerization zone, and wherein the boron trifluoride catalyst used contains less than 0.3, in particular less than 0.01, percent by volume of silicon tetrafluoride and the solvent, which is preferably ethylene, is recycled not less than twice but not more than 36 times during the continuous polymerization.

Abstract: The efficiency of a rectifying zone for the recovery of diamine vapor from water vapor being separated from a reaction zone in which a polyamide-forming salt is being heated to form a prepolymer is improved by adding a dicarboxylic acid to the reflux water at the top of the rectifying zone.

Abstract: There is disclosed a process of preparing vinyl dispersion resins by conducting the polymerization reaction of the vinyl monomer or monomers in an aqueous medium in the presence of a polymerization initiator or catalyst and an emulsifier or emulsifier system to form a vinyl resin latex, which is then subjected to an ultrafiltration step by forcing the same through a semipermeable membrane leaving behind the polymer particles and reusing the permeate, which contains dissolved monomer(s) and emulsifier, in the further production of vinyl resin latices. Unexpectedly, further use of the permeate substantially reduces polymer buildup in the reactor and since the ultrafiltration step increases the polymer particle concentration in the latex, considerable heat energy is saved in the spray-drying step.

Abstract: Active polymerization catalyst is deactivated using a high molecular weight epoxide.

Abstract: Methods of preparing polyimides and polyimide precursors from liquid resins containing tetracarboxylic acid esters and primary diamines which involve spray drying the resin.

Abstract: A process for the continuous manufacture of ethylene polymers by catalytic polymerization of the monomer at an elevated temperature and elevated partial pressures of ethylene in a hydrocarbon which is a solvent for the monomer but a non-solvent for the polymer formed, the polymer being isolated by (a) discharging a mixture of polymer, hydrocarbon and monomer from the polymerization chamber, (b) bringing the mixture from stage (a) to a pressure and temperature such that a gaseous phase consisting of the monomer and hydrocarbon and a solid phase consisting of the polymer, with adhering hydrocarbon, is formed, and (c) flushing the solid phase from stage (b) with an inert gas, so as to form a solid phase consisting of polymer and a gaseous phase consisting of hydrocarbon and inert gas, wherein, as additional measures (d), the gaseous phase from stage (c) is brought to a pressure and temperature such that a gaseous phase consisting of inert gas and a liquid phase consisting of hydrocarbon are formed and (e) the li