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: The present invention relates to a process for obtaining polyarylene sulfide from polyarylene sulfide-containing material. For this purpose, the polyarylene sulfide-containing material is treated with a solvent in which it dissolves, and is subsequently reprecipitated. The invention also relates to the purification of polyarylene sulfide-containing material by separating off extraneous substances, to polyphenylene sulfide particles having a specific surface area of at least 80 m.sup.2 /g and to their use as filter material.

Abstract: The present invention provides a method for substantially continuously polymerizing olefins comprising: introducing into a first reaction zone a fresh olefin polymerization catalyst; contacting said fresh olefin polymerization catalyst in said first reaction zone with a first vent mixture at a first feed rate and under conditions sufficient to form and avoid melting a polyolefin, wherein first vent mixture comprises unreacted olefins and a diluent vented from a second reaction zone; withdrawing a vent product of unreacted olefins and diluent from said first reaction zone; withdrawing from said first reaction zone a first product mixture comprising said catalyst and said polyolefin; passing said first product mixture to said second reaction zone; contacting said first product mixture in said second reaction zone with a second vent mixture at a second feed rate and under conditions sufficient to form and avoid melting said polyolefin, wherein said second vent mixture comprises a material selected from the group

Abstract: The present invention teaches a process for controlling a continuous gas phase (exothermic) process operating in condensing mode (e.g. polymerization) with a selected temperature for the reactor bed or outlet and with a temperature differential between the reactor inlet and the reactor bed or outlet by controlling the heat transfer provided by the heat exchanger in the recycle line to maintain the selected reactor bed temperature or outlet temperature while simultaneously controlling a condensable liquid feed rate to maintain the temperature differential.

Abstract: A method is disclosed of producing a copolymer of polyethylene terephthalate and polyethylene naphthalate. The method comprises esterifying a combination of a diester of naphthalene, terephthalic acid, and ethylene glycol to produce an esterification reaction mixture that includes the alcohol byproduct of the naphthalene diester, distilling the reaction mixture to remove at least a portion of the esterification byproducts from the reaction mixture in the form of a vapor stream of which the majority component is water vapor and which includes the alcohol byproduct of the naphthalate ester in the vapor state, and combusting at least a portion of the vapor stream under conditions sufficient to decompose at least a portion of the alcohol byproduct present in the vapor stream.

Abstract: A process for preparing high density polyethylene in the gas phase comprising contacting a mixture comprising ethylene and one or more alpha-olefins with the supported reaction product of a bis-hydrocarbylsilyl chromate and a hydrocarbylaluminum compound or a hydrocarbyl boron compound in a fluidized bed reactor having a recycle gas line, under particularly defined polymerization conditions, including, but not limited to, the following provisos:(i) oxygen and/or another catalyst poison is introduced into the reactor in the range of about 0.005 to about 0.5 part by volume of catalyst poison per million parts by volume of ethylene; and(ii) a relatively low boiling inert hydrocarbon is introduced into the recycle gas line in an amount sufficient to raise the dew point of the recycle gas, which is comprised of alpha-olefins and other reactor gases, and the recycle gas is partially condensed and recycled to the reactor where it promotes cooling by evaporation.

Abstract: The invention relates to continuous gas fluidised bed polymerisation of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer-containing recycle gas employed to fluidise the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and is fed directly to the bed to produce cooling by latent heat of evaporation. The liquid feeding to the bed can be through gas-induced atomiser nozzles (FIG. 2), or through liquid-only nozzles. The process provides substantially improved productivity of gas fluidised bed polymerisation of olefins.

Abstract: The present invention relates to a process for obtaining polyarylene sulfide from polyarylene sulfide-containing material. For this purpose, the polyarylene sulfide-containing material is treated with a solvent in which it dissolves, and is subsequently reprecipitated. The invention also relates to the purification of polyarylene sulfide-containing material by separating off extraneous substances, to polyphenylene sulfide particles having a specific surface area of at least 80 m.sup.2 /g and to their use as filter material.

Abstract: A high quality copolymer of styrene and methyl methacrylate is economically produced by polymerizing styrene and methyl methacrylate in a homogeneous solution of raw materials comprising methyl methacrylate, styrene, and an antioxidant, while the solution of raw materials is continuously supplied to a polymerization reactor including at least one complete-mixing type reaction tank, continuously removing the polymerization product from the polymerization reactor, supplying the polymerization product removed from the polymerization reactor directly to an extruder having a plurality of vents, and extruding a copolymer from the extruder, while volatile matter are removed through the plurality of vents.

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 solution polymerization system for polymerizing a olefin monomer by reacting the monomer with catalyst and solvent has been invented. The system in one aspect including a flow loop with a product polymer outlet, the flow loop forming a recycling reactor, a catalyst inlet on the flow loop through which catalyst and solvent flow into the flow loop, a monomer inlet on the flow loop through which monomer and solvent flow into the flow loop and, with the catalyst, form a reactant materials stream, a first heat exchanger on the flow loop for receiving the reactant materials stream and any formed polymer and for removing heat of reaction or polymerization from the flow loop, and pump apparatus for pumping the reactant materials stream and formed polymer in the flow loop and from the first heat exchanger to the product polymer outlet.

Abstract: Disclosed is a method for controlling or reducing the amount of powder fines present in a polyethylene fluidized bed reactor. The method uses hydrocarbons that are inert with respect to the polymerization reaction, as well as using reactive olefins. The reduction of powder fines provides significant operating benefits in the fluid bed process, including reduced formation of powder agglomerates in the reactor and reduced fouling of equipment in the recycle gas stream.

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 method for producing a methyl methacrylate polymer, wherein monomers containing methyl methacrylate as a main component are bulk-polymerized or solution-polymerized in the presence of a polymerization initiator and mercaptan compound as a chain transfer agent to form a liquid polymer composition containing unreacted monomers and then a volatile content is separated from the liquid polymer composition, the method comprising the steps of: distilling the volatile content to recover unreacted monomers, (1) subjecting the residue to a contact treatment with hydrazine compound or (2) subjecting the residue to an azeotropic distillation with water to remove impurities, distilling the resultant to recover the mercaptan compound and reusing the mercaptan compound as the chain transfer agent of raw materials.

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: Disclosed is a process for the continuous preparation of a polyester-based polymer having excellent quality which is useful as materials for medical care, coatings, and wrapping. In the process for the continuous preparation, a column-type continuous reactor is essentially employed.

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 in said reaction zone at a temperature within the range of about 0.degree. C. to about 100.degree. C.

Abstract: A process for continuously producing a propylene-based block copolymer having an excellent impact resistance of the present invention, comprises:a first polymerization step comprising polymerizing .alpha.-olefin comprising propylene in the presence of hydrogen and a stereoregular polymerization catalyst comprising a solid catalyst component containing magnesium, titanium, halogen atom and an electron-donor compound, an organoaluminum compound and, if required, an electron-donar compound in a single polymerization reactor; anda second polymerization step comprising transporting .alpha.-olefin polymer obtained in the first polymerization step to a copolymerization reactor and copolymerizing propylene with .alpha.-olefin other than propylene in a gas phase substantially in the presence of said stereoregular polymerization catalyst used in the first polymerization step.

Abstract: A process for producing a polyester of uniform quality, in which a slurry of powdery aromatic dicarboxylic acid in a liquid diol is prepared and the resulting slurry is processed through an esterification step and a polycondensation step in the presence of a catalyst, is provided by performing the reactions in the esterification and the polycondensation in a stabilized condition, which process comprisesrecycling a liquid containing the unreacted diol and the catalyst separated from the reaction mixture in the polycondensation step back to the esterification step as recycling liquor,detecting the concentrations of diol, diol condensation product, catalyst and water in the recycling liquor in the course of being recycled back to the esterification step by a near infrared spectrophotometer of a noise level of at the highest 50.times.10.sup.-6 Abs with a wave length repeatability of 0.

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 invention relates to continuous gas fluidized bed polymerization of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer-containing recycle gas employed to fluidize the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and is fed directly to the bed to produce cooling by latent heat of evaporation. The liquid feeding to the bed can be through gas-induced atomizer nozzles (FIG. 2), or through liquid-only nozzles. The process provides substantially improved productivity of gas fluidized bed polymerization of olefins.

Abstract: A process for working up dihydroxy compound residues from the preparation of polyesters bya) a first step of (trans)esterifying a dicarboxylic acid or its esters or ester-forming derivatives with a molar excess of a dihydroxy compound,b) at least one second step of polycondensing the esterification product of a), andc) subjecting the vapors from the reaction of a) and b) to a treatment for recovering the starting materials, comprises1) combining the vapors of step a) and some of the vapors of step b) of the process in at least one column A) and removing the low boiling constituents of the vapors overhead and recycling the bottom product, which predominantly contains the excess dihydroxy compounds and also oligomeric and polymeric reaction products, into step a), and2) transferring the other part of the vapors of step b) of the process into at least one column B) and removing the low boiling constituents of the vapors overhead and discharging the bottom product from the column and subsequently subjecting it to

Abstract: The present invention relates to a process for continuously manufacturing ethylene (co-)polymer in a gaseous phase in a polymerization zone through which passes an essentially gaseous reaction mixture comprising the (co-)monomers(s). In addition the process comprises transferring a mixture (A) formed by the gaseous reaction mixture and the solid (co-)polymer in a depressurization zone, and separating the mixture (A) into a solid phase (B) and a gaseous phase (C) returned into the polymerization zone. The solid phase (B) is subjected to (1) at least one non-deactivating flushing with respect to the active catalytic residues, and subsequently (2) a deactivating flushing with a gaseous mixture of nitrogen, water and oxygen. The (co-)polymer thus obtained has very low contents of unreacted (co-)monomer(s) and volatile organic compounds, and exhibits a high whiteness index and a long thermal stability with time.

Abstract: A continuous process for preparing polyester prepolymer comprising the steps of esterifying a diacid with a diol, reacting the esterified product with additional diol, and passing the product downward through a countercurrent column reactor while inert gas flows upward through the column reactor. The resulting prepolymer product has fewer acid end groups than the esterified material.

Abstract: The present invention relates to a continuous process for the polymerization of olefin(s) utilizing a metallocene catalyst or catalyst system in a continuous slurry or gas phase polymerization process for polymerizing monomer(s). The invention is more particularly drawn to a gas phase polymerization process for polymerizing one or more olefin(s), alone or in combination, in the presence of a metallocene catalyst system in a fluidized bed reactor, preferably operating in a condensed mode.

Abstract: The present invention provides a method capable of continuously efficiently producing a 2-hydroxycarboxylic acid oligomer while effectively removing the water contained in a raw material and the water produced by dehydration reaction. In production of a 2-hydroxycarboxylic acid oligomer by supplying a 2-hydroxycarboxylic acid to a reaction system, a dehydration system is provided between a raw material supply system and a polymerization reaction system so as to remove the water contained in the raw material and the water produced in the polymerization reaction system. As a result, the raw material in the dehydration system is concentrated and then supplied to the polymerization reaction system.

Abstract: In a process for the continuous preparation of polymers from reaction components, in particular of copolymers of styrene and acrylonitrile, by mass or solution polymerization, the reaction components are passed through a circulation reactor which has at least one tube reactor in which is arranged at least one static mixing element through which a liquid heat-transfer medium flows. The static mixing element has multiply curved pipelines.

Abstract: Disclosed is a method for producing an aromatic polycarbonate, which comprises: reacting a feedstock dialkyl carbonate with a feedstock phenol in the presence of a catalyst to produce diphenyl carbonate, wherein a phenol mixture comprising component phenols which are different in supply source is used as the feedstock phenol, and polymerizing the produced diphenyl carbonate with an aromatic dihydroxy compound to produce an aromatic polycarbonate while producing phenol as a by-product, wherein the by-product phenol obtained in the production of the aromatic polycarbonate is used as a component phenol of the feedstock phenol mixture for producing diphenyl carbonate, and wherein the content of the by-product phenol in the feedstock phenol mixture is controlled to a level in the range of from 70 to 99% by weight. According to the method of the present invention, an aromatic polycarbonate having excellent melt stability at high temperatures can be stably produced.

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: In a process and an apparatus for the continuous preparation of polymers from reaction components, in particular of copolymers of styrene and acrylonitrile, by bulk or solution polymerization, the reaction components are passed through a recycle reactor which has at least one tube bundle reactor whose tubes are in thermal contact with a liquid heat-transfer medium and which is connected to at least one static mixing element.

Abstract: A method for inhibiting polymer build-up in a recycle line and a heat exchanger during a polymerization process of one or more alpha olefins, particularly sticky polymers, or of one or more diolefins such as butadiene, isoprene, styrene, or styrene and butadiene which method comprises introducing as an antifouling agent an alcohol having 1 to 20 carbon atoms, an alkyl or cycloalkyl ether having 2 to 20 carbon atoms, ammonia, an ester of an inorganic acid, a compound of a group IV element of the periodic table, alkyl and aryl amines, a sulfur-containing compound, or a mixture thereof at one or more locations in the recycle gas line in an amount sufficient to inhibit polymer buildup.

Abstract: A process for the continuous preparation of polymers from reaction components, in particular of copolymers of styrene and acrylonitrile, by bulk or solution polymerization, where the reaction components are passed through the tubes of a recycle reactor, the recycle reactor has at least one tube bundle reactor with straight tubes around which a liquid heat-transfer medium flows, and each tube bundle reactor consists of at least two shell and tube heat exchangers which are connected together by at least one intermediate mixing section. Moreover the volume of the shell and tube heat exchangers is at least 50% of the total volume of the arrangement. The intermediate mixing sections consist of tubes with static mixing elements, around which tubes a heat-transfer medium flows.

Abstract: The present invention relates to a continuous process for the polymerization of olefin(s) utilizing a metallocene catalyst or catalyst system in a continuous slurry or gas phase polymerization process. The invention is more particularly drawn to a gas phase polymerization process for polymerizing one or more olefin(s) in the presence of a metallocene catalyst system in a fluidized bed reactor in the absence of or with a low mount of a scavenger.

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: The invention relates to continuous gas fluidised bed polymerisation of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer-containing recycle gas employed to fluidise the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and is fed directly to the bed to produce cooling by latent heat of evaporation. The liquid feeding to the bed can be through gas-induced atomiser nozzles (FIG. 2), or through liquid-only nozzles. The process provides substantially improved productivity of gas fluidised bed polymerisation of olefins.

Abstract: A process comprising contacting ethylene and at least one alpha-olefin comonomer having 3 to 8 carbon atoms with a transition metal based catalyst system in two fluidized bed reactors connected in series, in the gas phase, under polymerization conditions, with the provisos that:(a) the first reactor is operated at a temperature at or above the dew point of the mixture of monomers, but no higher than about 5 degrees C. above said dew point;(b) the mixture of ethylene copolymer matrix and active catalyst formed in the first reactor in the series is transferred to the second reactor in the series;(c) other than the active catalyst referred to in proviso (b), no additional catalyst is introduced into the second reactor;(d) in the reactor in which a low melt index copolymer is made:(1) the alpha-olefin is present in a ratio of about 0.01 to about 0.4 mol of alpha-olefin per mol of ethylene; and(2) optionally, hydrogen is present in a ratio of about 0.001 to about 0.

Abstract: The invention relates to a fluidized-bed reactor for polymerization of olefins, said reactor comprising an upper section of the reactor acting as a polymerization space in which olefin monomers are polymerized in a fluidized bed formed by polymerizing particles and a lower section of the reactor acting as a mixing space through which circulating gas removed from the top of the polymerization space is passed to the fluidized bed contained in the lower part of the polymerization space through a horizontal gas distributor plate in order to maintain the fluidized state of the bed, in which arrangement the circulating gas is passed to the lower section of the reactor via one or more inlet nozzles and the bottom section of the reactor is additionally provided with means for directing the circulating gas.

Abstract: The process for carrying out a polymerization in a tube reactor (1) comprises the following steps: Freshly introduced monomer (M) is mixed with a returned monomer-polymer mixture. The mixture is cooled to a prescribed initial temperature (heat exchanger 4). A polymerization starter (S) which is inactivatable upon heating above a decomposition temperature is admixed. A partial polymerization takes place in the tube reactor. The mixture leaving the tube reactor is heated up to at least the said decomposition temperature (heat exchanger 2). Finally, a portion of the mixture is returned (pump 3) and the other portion removed as product (P).

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: This process uses such a polymerization apparatus that the inner volume of the polymerization vessel is 100 m.sup.3 or more, the ratio L/D of the length L of the straight barrel to the inner diameter D is 1.5 or more, and the uppermost stirring impeller is arranged in the range of 150 to 300 cm downwardly from the upper end position of the straight barrel of the polymerization vessel in terms of the height of the center line of the vertical width of the blade, and is characterized in that after the liquid contents of the polymerization vessel are heated to a temperature near the polymerization temperature, noncondensable gases coming into the reflux condenser are evacuated under such conditions that the flow rate of the evacuation is 10 to 100 Nm.sup.3 /hour and the evacuation time is a period equal to 20% or more of the total polymerization time, and simultaneously with or after the start of the evacuation of the noncondensable gases, the cooling by the reflux condenser is started.

Abstract: This invention relates to a method for preparing compositions comprising terminally unsaturated polymers of low molecular weight, referred to as oligomers or macromonomers. In particular, a first oligomer composition is obtained by free radical polymerization of a reaction mixture comprising monomers. Terminally unsaturated oligomers in the first oligomer composition, or a selected portion of the composition, are reinitiated into free radicals in order to continue their oligomerization to a desired endpoint. The process is useful for preparing an oligomer composition having a controlled degree of polymerization. The process is also useful for preparing block copolymers. Such oligomer compositions or block polymers are useful for preparing engineered or structured polymers used in making various end products, including plastics, coatings, films, and dispersants.

Abstract: The invention relates to continuous gas fluidized bed polymerization of olefins, especially ethylene, propylene, or mixtures of these with other alpha olefins, wherein the monomer-containing recycle gas employed to fluidize the bed is cooled to condense out at least some liquid hydrocarbon. The condensed liquid, which can be a monomer or an inert liquid, is separated from the recycle gas and is fed directly to the bed to produce cooling by latent heat of evaporation. The liquid feeding to the bed can be through gas-induced atomizer nozzles (FIG. 2), or through liquid-only nozzles. The process provides substantially improved productivity of gas fluidized bed polymerization of olefins.

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: 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 mixture which is suitable as a defoamer, especially for ABS latices, comprising (A) a C.sub.10 -C.sub.20 alcohol, (B) a mineral oil, (C) an ester from a thiodicarboxylic acid with 4 to 8 carbon atoms and a C.sub.10 -C.sub.20 alcohol and (D) a non-ionic emulsifier and a process for removing residual monomers from ABS latices using these defoaming mixtures.

Abstract: A method for the rapid esterification of dicarboxylic acids or the transesterification of lower alkyl carboxylic acid diesters with diols is disclosed. The method includes recycling of evaporated unreacted starting materials and can be carried out at elevated pressures. The resulting esterification or transesterification products can then be polymerized into polyesters, for example by a thin film polymerization method.

Abstract: An ethylene stream which contains ethane as an impurity or a propylene stream which contains propane as an impurity is contacted with a polymerization catalyst thereby producing a polymer product containing unreacted ethylene or propylene and the corresponding alkane. A gas mixture containing ethylene or propylene and the corresponding alkane is separated from the polymer product and subjected to adsorption at a temperature of 50.degree. to 200.degree. C. in a bed of adsorbent which selectively adsorbs alkenes, thereby adsorbing substantially all of the propylene or ethylene from the gas mixture. The ethylene or propylene is desorbed from the adsorbent and recycled to the polymerization zone. The process is operated on a low per pass conversion with recycle of unreacted monomer. In the system of the invention the adsorption unit may be upstream or downstream of the polymerization reactor.

Abstract: Process for multi-stage generation of a vacuum and condensation and recycling of the vapors of polycondensation in the production of polyester, where the last stage includes a liquid ring pump compressing to atmospheric pressure, a cooler and a degasifier tank. The process also includes at least two preceding stages each using a glycol vapor jet that is operated with superheated glycol vapor at a pressure in the range of 0.8 to 1.0 bar abs. and a downstream glycol spray condenser whose operating conditions are regulated to condense a maximum quantity of glycol and at the same time causing the low-boiling reaction by-products including water to remain in the gas phase.

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.