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: A process for continuously producing copolymer comprising moieties derived from ethylene and an .alpha.-olefin in the presence of a metallocene catalyst system, said process comprising continuously supplying into a liquid-phase reaction zone a feed of ethylene, a feed of liquefied .alpha.-olefin, a feed of diluent, a feed of metallocene catalyst system, and continuously drawing out a reactor effluent produced thereby; and in accordance with a procedure comprising (a) setting the rate of metallocene system feed to a fixed molar rate; (b) introducing said ethylene feed at a fixed rate as required to produce the desired molar quantity of copolymer product per unit time; (c) setting the total rate of all feeds and the volume of said liquid-phase reaction zone to a fixed residence time, said residence no less than the minimum required to substantially eliminate molecular ethylene from said effluent; (d) performing an isokathic adjustment of the ethylene/.alpha.

Abstract: A process for adhering hydrophilic surfaces and thermoset resin surfaces comprising coating the hydrophilic surface with an aqueous solution containing methylacrylato-chromium complex and poly(vinyl alcohol) is disclosed.

Abstract: A process to control the heat transfer coefficient in slurry olefin polymerization processes comprising shocking the polymerization reactor is provided. This shock comprises quickly decreasing and then restoring to normal operating conditions, the higher alpha-olefin comonomer to ethylene monomer weight feed ratio.

Abstract: The names of a plurality of polyolefine resins are previously registered as index data in a name data base. An optimal operational pattern is stored in an operational pattern table for each combination of the name of a current resin under production and the name of a target resin to be produced. The optimal operation pattern is selected based on the name of the current resin under production and the name of the next target resin to be produced. Based on the selected optimal operational pattern, resin-type change control is executed.

Abstract: The method and apparatus for startup control of a polyolefine polymerization reactor of the present invention determines an olefine feed rate based on a reaction amount set by the heat balance within the polyolefine polymerization reactor, a reaction balance amount calculated from its unreacted amount and dynamic compensation amount, and the olefine concentration within the polyolefine polymerization reactor. Due to this, model errors are reduced, and the practical application of feed-forward control is possible.

Abstract: A method for controlling reaction temperature for a reaction vessel having a flow channel for a heat transfer medium for heating or cooling or both when vinyl chloride-based monomer is polymerized in an aqueous medium, which entails employing two or more independent flow channels and feeding two or more coolants having different temperatures to the independent flow channels to thereby cool the reaction vessel.

Abstract: The present invention provides a method for producing an oxymethylene copolymer, which comprises:copolymerizing trioxane and a cyclic ether and/or a cyclic formal in the presence of at least one selected from the group consisting of boron trifluoride, boron trifluoride hydrate, and a coordination compound of an organic compound having an oxygen or a sulphur atom with boron trifluoride,volatilizing the residual polymerization catalyst to decrease its amount, by heating the obtained oxymethylene copolymer in an atmosphere of inert gas at or below its melting point, and/or reducing the pressure, without conducting any operation of deactivating the residual polymerization catalyst before volatilizing the residual polymerization catalyst, andstabilizing terminal moities of the oxymethylene copolymer after deactivating residual catalyst or stabilizing terminal moieties of the oxymethylene copolymer directly.

Abstract: Control of a gas phase polymerization reactor is performed with the product melt index, the reaction temperature, and the partial pressure of the controlling reactant.

Abstract: This invention relates to a method for the measurement and control of polyamides and polyamide precursor mixtures by means of near-infrared spectroscopy.

Abstract: A system for the solid phase polymerization of polymers comprising a crystallizer, and wherein cold amorphous polymer is introduced to the crystallizer. A source of infrared radiation is associated with the crystallizer, and the polymer is heated by applying infrared radiation thereto. The degree of heating is controlled so that the polymer reaches the crystallization or polymerization temperature without exceeding the polymer melting point.

Abstract: In withdrawing a reaction slurry from a polymerization reactor wherein solid particles in the slurry must be maintained in solution to prevent solidification, a redundant effluent line is provided to remove the slurry in the event the primary line becomes plugged. In use the primary and redundant lines are controlled in different manners such that a v-notch ball valve in the primary line is manipulated continuously to remove effluent while maintaining stable reactor conditions, and a control valve in the redundant line is manipulated intermittently as a backup for the primary control valve.

Abstract: An improved condenser system for condensing the by-product of resin cooking processes to minimize contamination of the condenser system by entrained liquid resin particles and to increase the efficiency of resin processing systems, including means for efficiently extracting particles from the vapor produced during processing and cool-down of the liquid and returning said particles to the processing container without fouling the condenser system or losing product. The system also includes design improvements and operation improvements for increasing the efficiency, safety and reliability of the condenser system used in the process of cooling and controlling the processing container.

Abstract: A process for preparing halogenated polycarbonate wherein the total amount of base the end pH of the aqueous phaser and the amount of coupling catalyst employed in the reaction are controlled to selected levels.

Abstract: There is disclosed a process for continuously and efficiently producing a styrenic polymer having a high degree of syndiotactic configuration which comprises effecting polymerization reaction by continuously introducing a styrenic monomer and a polymerization catalyst into a polymerization reactor, the inside of which has been brought into fluidized state by particles previously fed therein, which process is characterized in that the polymerization reactor temperature is controlled by vaporizing a part of the styrenic monomer which has been introduced into the polymerization reactor, while the inside of the reactor is maintained under reduced pressure. According to the above process, such problems as difficulty in polymerization reactor scale-up, adhesion of polymer to the reactor inside and polymer particle agglomerate are simultaneously solved, and thereby the industrial significance of the process is remarkably enhanced.

Abstract: The invention relates to a regulation method for regulating the temperature in a reactor utilized in the polymerization of olefines. A circulating gas is led to the reactor along a circulating gas flow line, and the circulating gas is cooled by leading part of the circulating gas flowing along a circulating gas flow line along a by-pass flow line through a cooler. A regulating device for the circulating gas inlet-flow temperature controls the amount of the circulating gas by-pass flow along a circulating gas by-pass flow line through the cooler such that the sum of the openings of a valve in the circulating gas flow line and a valve in the circulating gas by-pass flow line is maintained substantially constant in the range from about 90 to about 120%.

Abstract: Disclosed herein is a process for the production of cycloolefin random copolymers comprising flash drying a solution of a cylcoolefin random copolymer in a hydrocarbon, said solution being obtained by copolymerization of ethylene and a specific cycloolefin in said hydocarbon in the presence of a catalyst. Further proposed herein is a process for the production of cycloolefin random copolymers by copolymerization of ethylene with a specific cycloolefin of the in a hydrocarbon in the presence of a catalyst wherein said copolymerization is carried out in a polymerization reactor where a gas phase is not substantially present.

Abstract: The present invention provides a process for producing a polyacetylene.In the present process for producing a polyacetylene, acetylene is polymerized with a Ziegler-Natta catalyst consisting of a trialkylaluminum and an alkyl titanate, wherein there is used, as the trialkylaluminum, a trialkylaluminum having an alkyl group of 6 or more carbon atoms, or, as the alkyl titanate, an alkyl titanate having an alkyl group of 6 or more carbon atoms.The polyacetylene obtained according to the present invention is superior in mechanical properties, particularly stretchability.

Abstract: A process for preparing halogenated polycarbonate wherein the total amount of base, the end pH of the aqueous phase, and the amount of coupling catalyst employed in the reaction are controlled to selected levels.

Abstract: A process for producing a highly water absorptive polymer by polymerizing a water-soluble, ethylenically unsaturated monomer in a water-in-oil type of dispersion consisting of the dispersion phase of an aqueous monomer solution comprising the water-soluble, ethylenically unsaturated monomer, water, a water-soluble polymerization initiator and an optional water-soluble crosslinking agent and the continuous phase of an organic solvent containing a dispersant, characterized in that the aqueous monomer solution is added to the organic solvent at such a temperature as to form an oil-in-water type of dispersion, and the oil-in-water type of dispersion is then heated at least to a phase reversal temperature at which it is transformed into the water-in-oil type of dispersion.

Abstract: Formation of polyimide film with a preselected coefficient of thermal expansion is disclosed employing relationships between cure temperature and heating rates.

Abstract: The invention relates to a process for preparing polymers, with a polydispersity optionally approaching the theoretical polydispersity and substituted by functional groups in .alpha.,.omega.-positions, via radical polymerization of radically polymerizable monomers and using one or more initiators. In compliance with this process the degree of polymerization is maintained at the desired value by continuous elevation of the temperature.In case of a given heat program, the process of the invention renders possible to increase the conversion in producing polymers without the deterioration of the polydispersity.

Abstract: A self-regulating porous heater regulates the temperature of fluid passing through it. This device includes at least one layer of a porous material which has a magnetic permeability inversely related to temperature over a given range. Due to conductor skin effects, changes in permeability cause changes in the depth of penetration of alternating current passing through the magnetic layer. Changes in the depth of penetration, in turn, result in changes in resistance--the less the depth the greater the resistance--and in I.sup.2 R Joule heat. The combined result of these effects is to provide more heat where the temperature of the fluid and the layer through which the fluid flows is below a specified temperature which is related to the Curie temperature of the layer. Significantly, by properly defining pore dimensions, the heater device can filter contaminants from a fluid as it flows therethrough. In a preferred mode, a porous heater device is included in a chemical reaction chamber.

Abstract: A non-fouling economical liquid cooled cryogenic polymerization process is disclosed for essentially olefinic monomers. The heat of cooling and polymerization is removed by evaporation of the liquid nitrogen and the nitrogen vapors eliminate the need for moisture traps and drying agents to block the in flow of said moisture.

Abstract: There is provided an improvement in a method for terminating a gas phase olefin polymerization reaction with a kill gas such as carbon monoxide or carbon dioxide. The improvement involves the use of a carrier gas to increase the rate of penetration of kill gas into the reaction medium. The improved method is particularly adaptable to a fluid bed reactor system.

Abstract: The time taken for a run of suspension polymerization of vinyl chloride monomer can be remarkably decreased without affecting the quality of the resin product when the temperature of the polymerization mixture under polymerization is increased continuously or step-wise during the period in which the conversion of the monomer to polymer is 10% or larger in such a manner that the average degree of polymerization of the polymer taken at an intermediate stage by sampling is always in the range from 90% to 110% of that of the finally obtained polyvinyl chloride resin product.

Abstract: A method is provided for determining the stoichiometric end point of phosgenation reactions which produce polycarbonates and chloroformates, respectively, by monitoring the rate of heat generated by the reaction mixture per unit of phosgene utilized.

Abstract: A reflux condenser attracts attention from the standpoints of improvement in productivity by increase in cooling capacity as well as saving in energy, and recently, it is frequently employed in particularly large-sized polymerization reactors. But, the well-known cooling method has a problem that the overall heat transfer coefficient of condensers lowers with the progress of polymerization to result in the reduction of heat-removing capacity and reduction of the stability of polymerization temperature control. In order to solve the above problems, in the present invention the temperature is controlled with the heat amount removed by the condenser as a control variable, coupled with intermittent purge of a part of the unreacted monomer from the reflux condenser.

Abstract: Disclosed herein is a method for controlling the polymerization temperature in a polymerization apparatus equipped with a cooling system in which steam, which has occurred in the presence of a volatile liquid medium in a reaction system, is condensed in a reflux condenser and the resulting noncondensable gas and condensate are then returned to the reaction system, thereby removing the polymerization heat. A portion of the noncondensable gas is recirculated to the cooling system. The flow rate of the noncondensable gas to be recirculated and the flow rate of a cooling medium to be introduced into the reflux condenser are controlled in accordance with the temperature of the reaction system.

Abstract: A method is provided for determining the stoichiometric end point of phosgenation reactions which produce polycarbonates and chloroformates, respectively, by monitoring the rate of heat generated by the reaction mixture per unit of phosgene utilized.

Abstract: The danger of explosion due to decomposition of high-pressure industrial process gases, such as ethylene, is reduced by beginning to cool the decomposition gases with a delay of no more than 25 milliseconds from the onset of flow of the gases out of a high-pressure vessel. The process may be implemented by using apparatus comprising: (1) means containing an inert gas at a pressure P between about 5 and 50 bars and an inert liquid of high heat of vaporization; and (2) a valve located upstream of an inert-liquid dispersing means, of which the opening is operated by a means detecting the opening of a safety means of the high-pressure vessel and operating the working of the dispersing means.

Abstract: The method is particularly adapted for controlling the molecular weight of a product output from a polybutene reactor. The method includes the steps of: deriving from the operating parameter of a polybutene reactor system a formula which correlates molecular weight as determined by product viscosity or other parameters of the product output with operating variables such as temperature of the reactor and concentration of isobutylene in the reactor, which concentration can be controlled by the amount of catalyst, e.g.

Abstract: A method for determining the optimum component ratios in an exothermic process for producing polyurethane foam is described which consists of continuously measuring the temperature differential with respect to time and then determining the optimum component ratios by comparing the maximum value of each of the sequential temperature differential peaks and the times at which they occur.

Abstract: A method of forming a polyester resin from dicarboxylic acid anhydrides and monoepoxides in a specially designed mixing apparatus. The mixing apparatus is a vessel having a centrally disposed vertical draft tube and a centrifugal impeller at the lower end of the draft tube. A plurality of vertical heat exchange tubes surround the draft tube. The reactants are admitted into the vessel and drawn down through the draft tube by the impeller which mixes the reactants and forces the reactants up through the heat exchange tubes. The heat exchange tube portion of the vessel acts as a plug flow reactor, and the upper and lower portions of the vessel act as a back mix reactor. As reactants are admitted into the vessel, product is drawn off from the vessel.

Abstract: A method for determining the concentration of additives in a compounding process by measuring the capacitance and dissipation factor (tan.delta.) of the mixture and converting such values to the concentrations of the additives. This method may also be utilized to determine the concentration of the polymers in the mixture. This method is preferably applied to a compounding process of blending polyphenylene oxide and polystyrene thermoplastic resins and is preferably applied to a continuous compounding process of these resins to determine therein the concentration of an aryl phosphate ester flame retardant.

Abstract: The invention relates to a method and a device for producing a reaction mixture from flowable foam-forming or solid-forming components (preferably polyurethane forming components) which are conveyed continuously and are mixed together or are circulated. The quantity to be conveyed is preselected. The injection pressure is preselected and the circulatory pressure is measured for each component. The predetermined quantity and pressure to be conveyed as well as the measured value are preferably fed into a control computer during the circulation and the mixing process and are compared with actual values. Cavities are filled out with the reaction mixture produced and, in particular, molded articles are produced in molds.

Abstract: A method for determining the concentration of ingredients and other process variables in a polymerization process by measuring the capacitance and dissipation factor of the mixture and determining its dielectric constant at various stages of the process. By the use of an automatic capacitance bridge and a computer, the process variables can be determined and controlled in a matter of seconds.

Abstract: The disclosure is directed to an improvement in the gas phase polymerization of propylene using a Ziegler-Natta catalyst in the presence of hydrogen wherein the gaseous propylene is withdrawn from the reactor, cooled and condensed and returned as a liquid to the reactor in order to regulate the polymerization temperature. The amount of the gaseous phase in the condenser-cooler-accumulator system is kept constant by regulating the amount of gaseous phase returned to the reactor.

Abstract: Process which accelerates the activated and non-activated polymerization of 2-pyrrolidone. A prepared polymerization charge containing monomer and components of the initiation system is first allowed to polymerize at a temperature above the monomer melting temperature, then is cooled below the melting point of the mixture, and then the crystalline reaction mixture is heated to a polymerization temperature of 25.degree. to 60.degree. C.

Abstract: A process for the preparation of propylene homopolymers or copolymers by polymerizing the monomer or monomers in the gas phase in a centric stirred bed of finely divided polymer, with removal of the heat of polymerization by evaporative cooling, the temperature in the polymerization zone being regulated by measuring the temperature continuously and causing any change therein to trigger a change in the amount of liquid monomer, evaporating in the reaction zone, which is introduced per unit time, in which process(1) the radius and height of the centric stirred bed are in a particular ratio to one another, (2) the finely divided polymer in the centric stirred bed is caused to move upward in the peripheral zone of the bed and downward in the central zone of the bed, (3) the temperature in the polymerization zone is regulated by simultaneously measuring it at (3.1) one or more points of the inner part of the stirred bed and (3.

Abstract: A gas-phase olefin polymerization system is provided with means for sensing a potentially dangerous condition and means for introducing carbon dioxide into the system to at least reduce the rate of polymerization. The system may be a stirred-bed system provided with means for automatically introducing carbon dioxide into the system in response to failure of the stirrer motor.

Abstract: In a continuous process for producing olefin polymers by contacting olefin monomers with an initiator or catalyst in a polymerization zone, the improvement comprising contacting fast poisons in the feed with a scavenging agent in a scavenging zone under conditions such that no significant amount of polymerization occurs until said feed is contacted with the initiator or catalyst in a polymerization zone.

Abstract: There is described a process for the homopolymerization or copolymerization in the bulk of alkenylaromatic compounds in a continuous flow agitation vessel. The feed of the monomer(s) is preheated and a controlled larger or smaller part of the preheated monomer feed is cooled, depending on the deviation of the temperature of the contents of the reaction vessel from the determined value. The inventive process ensures an improved constancy of the reaction temperature, and, consequently, of the molecular weight of the polymer obtained.

Abstract: The invention relates to a process for rapidly letting-down the pressure in continuous high pressure polymerization systems for the polymerization of ethylene. In this process, the let-down hot reaction mixture is passed into an expansion vessel in such a way that the jet of let-down hot reaction mixture issuing from the let-down line is led into the partially water-filled expansion vessel at an angle of from 0.degree. to 45.degree. to the water surface, so that the jet does not enter below the surface but must touch or strike it. The method described makes it possible to let the mixture down partially and thus to slow down the decomposition in the case of explosive decomposition reactions occurring in the polymerization system.

Abstract: Polymerization of a mono-.alpha.-olefine monomer is effected by contacting the gaseous monomer with a solid phase comprising polymer and catalyst at a pressure and temperature which are such that the temperature is in the range from tp + 0.1.degree. C up to tp + 5.0.degree. C, where tp is the temperature at which the monomer condenses at a pressure which is equal to the monomer partial pressure within the polymerization vessel.

Abstract: A process for cooling a polymerization reaction of compounds in a dispersion and/or solution involves evaporation of one or more liquids contained in the dispersion and/or solution, condensation of the vapors in a reflux condenser, and recycling of the thus-condensed vapors into the reactor, together with the use of a controllable flow of coolant which is introduced into the reflux condenser jacket. In this process the amount of heat given off during condensation serves as the control variable for a controller for controlling the input of cooling medium for the reflux condenser.

Abstract: In apparatus for polymerizing high-pressure ethylene to produce polyethylene, a tubular reactor is connected to a source of solution to the tubular reactor. This solution includes one or more catalysts which promote the polymerization reaction. Within the tubular reactor, a peak temperature occurs in proximity of the point at which the catalysts are introduced. If the catalysts are introduced at more than one point, peak temperatures will result downstream of each of such points. For various reasons, the peak temperatures are displaced along the tubular reactor and a plurality of thermocouples are distributed at spaced positions in the tubular reactor to measure the temperatures at the positions at which the peak temperature might occur. These thermocouples generate signals which are fed into a gating arrangement which selects the peak signal which is compared in a comparator circuit with an adjustable or selectable signal representative of the peak temperature which is desired.

Abstract: The method of this invention is particularly useful for removing heat from an exothermic reaction of a liquid medium. An example of such a reaction is an emulsion polymerization of styrene and butadiene to obtain a latex product. In this reaction the butadiene will boil at the temperature and pressure conditions in the reactor. Attached to the reactor is a condenser unit, which is basically a modified shell and tube heat exchanger. During the reaction the butadiene vapors are directed from the reactor into the tube bundle of the condenser unit through the top of the unit. In the condenser the butadiene vapors are condensed to a liquid, which flows downwardly into the reactor to cool the reaction mass.

Abstract: An adduct of a fulvene and unsaturated silane produced in a Diels-Alder reaction and the interpolymerization of the adduct with ethylene, with or without propylene, with or without a polyene, in the preparation of ethylene interpolymers.

Abstract: An improved method of removing heat from polymerization reactions of normally gaseous monomers in the gas phase comprising feeding the monomer in liquid form to a polymerization zone, immediately after entering said zone, removing a portion of said gaseous monomer from the polymerization zone, liquefying said portion of monomer by cooling it at the same pressure as that prevailing in the polymerization zone, recycling the liquefied monomer to the polymerization zone together with fresh monomer in liquid form and causing said liquid monomer to change to the gaseous form immediately after entering said zone. The improvement consists in not only condensing the monomer outside the polymerization zone but also storing the same, in keeping the temperature in the polymerization zone constant by regulating the rate at which liquid monomer is fed to the zone, and in keeping the temperature and pressure in the polymerization zone within limits conducive to the gaseous state of the monomer.