Abstract: The invention provides an economical and efficient process for preparing a dimeric cyclic ester of an .alpha.-hydroxycarboxylic acid by depolymerizing a corresponding .alpha.-hydroxycarboxylic acid oligomer, which comprises the steps of (1) heating a mixture containing the .alpha.-hydroxycarboxylic acid oligomer and at least one high-boiling polar organic solvent having a boiling point within a range of 230.degree.-450.degree. C. to a temperature, at which the depolymerization of the oligomer takes place, under atmospheric pressure or reduced pressure, (2) dissolving the oligomer in the solvent until a residual rate of a melt phase of the oligomer reaches 0.5 or lower, (3) further continuing the heating at the temperature, at which the depolymerization of the oligomer takes place, to depolymerize the oligomer, (4) distilling out the dimeric cyclic ester formed together with the high-boiling polar organic solvent, and (5) recovering the dimeric cyclic ester from the distillate.

Abstract: The present invention provides a process for the isolation of partially crystalline polycarbonate powder or oligocarbonate powder from solutions thereof, in which process the organic solvent of a polycarbonate solution is vaporized in a heat exchanger, optionally with incorporation of steam, or in a holding tube with incorporation of steam and the pasty mixture of concentrated solution, solvent vapor and optionally water is separated in a separator. In this process, the solvent vapor is condensed in a heat exchanger downstream from the separator. The solvent is vaporized in the heat exchanger by indirect input of heat through the heat exchanger walls and vaporization may be promoted by preheating the polycarbonate or oligocarbonate solution in an upstream heat exchanger or by introducing steam or both.

Abstract: A process for removing contaminating solvents from solutions containing solid solutes comprising contacting a co-solvent that forms an azeotrope with the contaminating solvent forming a mixture thereby and spray drying the contaminating solvent co-solvent mixture in the presence of the co-solvent at a temperature equal to or above the temperature where the azeotrope distills whereby the contaminating solvent has been azeotropically distilled away from the solute. The process is particularly useful for polymeric solutes, especially silicones.

Abstract: The present invention provides a novel halogen-free solvent system which can produce a good isobutylene polymer and can be easily reused. A novel process for the production of an isobutylene polymer is provided which comprises using a hydrocarbon solvent having a boiling point of not lower than 105.degree. C. and a melting point of not higher than -90.degree. C. Heretofore, a solvent system containing a halogenated hydrocarbon such as methylene chloride has been used for the production of an isobutylene polymer. However, such a solvent system has a great adverse effect on the environment. Therefore, a non-halogenated solvent is desirable. The present invention is characterized by the use of a hydrocarbon solvent as a reaction solvent. The resulting polymer has good properties. Further, compounds which are produced as by-products during the reaction can be easily removed, enabling the recycling of the solvent used. Thus, the production cost can be reduced.

Abstract: A method for product recovery method of polyolefins, particularly high-molecular-weight amorphous poly alpha-olefins, wherein the use of water during the method is significantly decreased and wherein the intermediate stage of storing and drying the chunk form of the polyolefin is eliminated. Polyolefins produced in a reactor are heated in a kneader to remove any unreacted monomer(s). The polyolefin material in a liquid form is then transferred directly to an extruder to further remove any unreacted monomer(s) and catalyst(s). Finally, the polyolefin material is pelletized using a pelletizer.

Abstract: A process for continuously preparing a high quality methacrylic polymer with a high productivity is provided. The process comprises continuously polymerizing methyl methacrylate alone or a monomer mixture of methyl methacrylate and an alkyl acrylate by a solution polymerization using methanol as a solvent, directly feeding the resulting polymerization reaction product to an extruder having a plurality of vents, and extruding the polymer, while volatiles are removed through the vents.

Abstract: A method for removing residual vinyl chloride monomers from an aqueous slurry is disclosed. The method preferably utilizes a tower having a plurality of vertically spaced plates, which define a plurality of chambers, each chamber defined between adjacent plates. The tower features a plate in one of the chambers having a diameter of 1.05 to 5 times larger than the diameter of the plates in chambers above and below the chamber having the large plate. The method is based upon introducing the slurry to a particular location in the tower depending upon the porosity of the polyvinyl chloride in the slurry.

Abstract: Polyester particles in suspension in a liquid can be agglomerated below their melting points and the agglomerated particles are more easily filtered.

Abstract: Toughened vinyl aromatic compounds, in particular high impact polystyrene, are prepared by a continuous process in which the vinyl aromatic compound and the impact modifier, an elastomeric block copolymer, are each prepared separately in a reaction zone by anionic polymerization, with or without heat exchange with the environment and, if required, with the addition of a solvent, and are polymerized until complete conversion is achieved, and the living chain ends are terminated in a manner known per se, and a thermoplastic, toughened molding material is based on a vinyl aromatic compound having a residual content of less than 50 ppm of monomers and less than 100 ppm of oligomers.

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 invention is directed to purification of phenolic resins and to a process for preparing an organic photoresist coating composition. The process comprises reacting one or more phenols to form a crude phenolic resin. The crude phenolic resin formed is then separated from its reaction mixture and dissolved in an aqueous insoluble organic solvent in an organic solvent that is a solvent for the photoresist coating composition. The solution so formed is then mixed with an aqueous phase to extract water soluble impurities from the resin solution into the aqueous phase. Finally, the purified resin solution is further diluted with additional photoresist solvent.

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: A polyester mixture is prepared composed of a diol, a dicarboxylic acid and optionally a monofunctional compound as a chain stopper, in which there is less than 3 wt. % of compounds having a molecular weight of up to 800. The process preferably involves stripping off volatile components from the mixture, for example by molecular distillation. The mixture may be used for forming shaped plastic objects for use in car interiors.

Abstract: A method of producing a polycarbonate excellent in the hue, the thermal stability, and the electrolysis stability by supplying a polycarbonate obtained by a transesterification method to an extruder having vent(s), melting the polycarbonate, and adding an acidic compound to the molten polycarbonate followed by kneading to continuously devolatilize low molecular weight compounds remaining in the polycarbonate. Better result is obtained by adding water to the kneaded mixture of the polycarbonate and the acidic compound before devolatilizing the low molecular weight compounds.

Abstract: Volatile components are eliminated from polyacrylate melts by distilling off the volatile components by a process in which the volatile components are distilled off under reduced pressure, entraining agents are added to the melts at above 100.degree. C. and the melts are simultaneously circulated.

Abstract: A process for preparing a styrenic resin is herein disclosed which comprises the step of volatilizing-extruding a styrenic polymer (SPS) powder having a syndiotactic configuration in the presence of water, an alcohol or an antioxidant by the use of an extruder to obtain pellets. According to this process, the operation of volatilization-extrusion is done in the presence of water, the alcohol or the antioxidant to stably and efficiently prepare the SPS pellets in which yellowing is inhibited, and the operation of the volatilization-extrusion is carried out in the presence of water to stably and efficiently prepare the SPS pellets containing a less amount of a remaining volatile component such as an unreacted monomer.

Abstract: A method of improving the oxidative thermal stability of ethylene polymers is disclosed. The method comprises removing residual unreacted monomer(s), solvent and thermally unstable species from the molten polymer. The resulting polymer is characterized by having an oxidative exotherm of not more than about 50 percent of the original polymer, as measured by differential scanning calorimetry.

Abstract: A styrenic resin is prepared by a method which comprises extruding a styrenic polymer powder having a syndiotactic configuration at a molding temperature of from the melting point of the polymer to 400.degree. C. at an extrusion rate meeting the equation Q/(D.times.H.times.V)=2.0.times.10.sup.4 to 6.0.times.10.sup.5, by the use of an extruder provided with one or more vents having an internal pressure of 0 to 760 Torr, wherein Q is an extrusion rate (kg/hr), D is a screw diameter (m), H is a screw groove depth (m), and V is a screw peripheral speed (m/sec); a residual volatile component, such as a monomer in the styrenic polymer powder having the syndiotactic configuration, can economically and efficiently be decreased at the time of extrusion, whereby a molding material having a good shape and containing a reduced amount of the residual volatile component can efficiently be prepared to prevent the emission of an objectionable odor at the time of the extrusion or molding.

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: A water insoluble, aqueous alkali soluble novolak resin, process for producing such a novolak resin, a photoresist containing such a novolak resin, and a method for producing a semiconductor device, wherein the resin is isolated by sub surface forced steam distillation.

Abstract: A method and apparatus for continuously separating polymer from a plastic, and the resulting separated polymer. The plastic is made flowable into a stream through melting or solubilizing. A critical fluid, such as supercritical carbon dioxide, is added to the plastic stream to promote mechanical or thermodynamic separation of the polymer from contaminants and other components of the plastic.

Abstract: A process for producing a water insoluble, aqueous alkali soluble, film forming novolak resin having low metal ions, made by the fractionation of a phenol formaldehyde condensation product, a process for producing a resin a photoresist composition of superior quality containing such novolak resin, and a method for producing a semiconductor device using such photoresist composition.

Abstract: This invention relates to benzylic ether phenolic resole resins prepared in a sealed reaction vessel. The benzylic ether phenolic resole resins are prepared by heating phenol and an aldehyde in a sealed reaction vessel in the presence of a divalent metal catalyst without removing water generated by the reaction until an appropriate endpoint for the resin is reached. The benzylic ether phenolic resole resins produced by the process are preferably free or essentially free of unreacted formaldehyde and can be used in the resin component of phenolic-urethane foundry binders to make foundry cores and/or molds by the cold-box and no-bake processes. The cores and/or molds are used for making metal castings.

Abstract: Polymerization process to obtain elastomeric copolymers or terpolymers based on ethylene for cold flow improver (CFI) having a viscosimetric average molecular weight ranging between 600 and 16,000.a) The process includes polymerizing monomers in suspension in the presence of an alpha-olefin liquid under reaction conditions, in the presence of an amount of solvent from about 5 to 30% by volume of the reactor volume in the presence of a polymerization catalyst able to give the X.sub.2 and/or X.sub.4 parameters, lower less than or equal to 0.02, X.sub.2 and X.sub.4 representing the fraction of uninterrupted methylenic sequences of 2 and 4 methylenic groups between two successive methyl or methylene groups respectively in the polymeric chain, as compared with the uninterrupted total sequences of methylene groups determined by .sup.

Abstract: A process for producing polymer particles from an organic solvent solution of a polymer, which includes: (a) initially introducing polymer particles into a particle producing zone, (b) introducing an organic solvent solution containing an organic solvent and having a polymer concentration of 3 to 70% by weight, onto the polymer particles which are maintained in the particle producing zone, the particle producing zone not substantially containing steam, the organic solvent solution being added in an amount of not more than 250% by weight per hour based on the amount of the polymer particles which are initially held in the particle producing zone, and stirring the polymer particles under conditions in which the organic solvent would be vaporized, (c) separately introducing a poor solvent for the polymer into the particle producing zone, the poor solvent being selected from the group consisting of benzene, toluene, xylene, pentane, hexane, octane, acetone and methyl ethyl ketone, the poor solvent being in an amo

Abstract: A high-temperature high-pressure process for producing an ethylene/.alpha.-olefin copolymer is provided in which a saturated hydrocarbon of 4 or less carbons is injected to an unreacted monomer mixture fed to a separator in a high-pressure recycling system. This process enables stable running of the production apparatus for a long term without clogging of the tubing in the high-pressure recycling system.

Abstract: A process for purifying a polymer by separating and removing volatile components from a polymer composition containing the volatile components, which comprises: (a) heating the polymer composition containing a methanol solvent to a temperature of 120.degree. to 240.degree. C. by a heater, wherein an internal pressure the heater is maintained at 8 to 35 kg/cm.sup.2 G; (b) discharging the heated polymer composition into a tank in which pressure is maintained at -0.7 to 1.0 kg/cm.sup.2 G, and then separating and collecting most of the volatile components to lower the concentration of the solvent in the remaining volatile components in the polymer composition to 0.5% by weight or less; and (c) feeding the resultant polymer composition to a vent extruder maintained such that a barrel temperature at an inner side thereof is 160.degree. to 280.degree. C.

Abstract: A styrenic polymer having a highly syndiotactic configuration (SPS) is herein disclosed in which the weight-average molecular weight of the styrenic polymer is in the range of 1.times.10.sup.4 to 2.times.10.sup.6 and in which the weight fraction of an extract extracted with methylene chloride from a gel obtained by dissolving the styrenic polymer in 1,2,4-trichlorobenzene and then cooling the solution is 10% by weight or less, and a molded article comprising the SPS is also disclosed.

Abstract: A resin tablet for sealing a semiconductor formed by solidifying a molten thermosetting resin composition by cooling, wherein the content of volatile matters in the tablet is 0.05% by weight or less, and the content of gelled particles in the tablet is 0 for the particles of 60 mesh on and is 10 ppm or less for the particles of 100 mesh on.

Abstract: Aqueous dispersions of cationic water-soluble polymers are provided, as well as processes for making and methods of using the same.

Abstract: A process for producing a water insoluble, aqueous alkali soluble, film forming novolak resin fraction having a low metal ion content, made by the fractionation of a phenol formaldehyde condensation product, a process for producing a photoresist compositions containing such a novolak resin, and a method for producing a semiconductor device using such a photoresist composition.

Abstract: The invention is a purification process of an aliphatic polyester prepared in the presence of a catalyst from a hydroxycarboxylic acid or a cyclic ester of a hydroxycarboxylic acid, or a combination of an aliphatic polyhydric alcohol with an aliphatic polybasic acid, or a mixture of these compounds, comprising deactivating the catalyst while maintaining the aliphatic polyester in a molten or dissolved state, or insolubilizing and separating the catalyst and successively removing low molecular compounds; and can provide aliphatic polyester which has a low content of unreacted monomers and low molecular weight compounds and is excellent in heat resistance and weatherability.

Abstract: In a process for producing an amorphous thermoplastic resin composition comprising melt-kneading at least one amorphous thermoplastic resin, an improvement comprising melt-kneading the amorphous thermoplastic resin in the presence of not less than 1% by weight, based on the amorphous thermoplastic resin, of an organic solvent in a kneader having a vent hole(s) while maintaining at least one vent hole of the kneader under reduced pressure by means of an evacuator to remove the organic solvent so as to reduce the organic solvent content in the final composition to less than 1% by weight. Thermal deterioration of the resin during melt-kneading can be inhibited to provide a resin composition having well-balanced impact resistance and heat resistance and excellent hue.

Abstract: The invention relates to a novel process for depolymerizing polyesters by subjecting the polyesters to catalysts and organic solvents which are substantially free of oxygen and water in order to produce macrocyclic polyester oligomers substantially free of hydroxybutyl terminated linear impurities.

Abstract: A true solution of up to about 15 weight % of polyphenylene ether (PPO) in a styrenic polymer may be prepared by dissolving the PPO in one or more of the monomers polymerized to form the styrenic polymer and polymerizing the resulting solution in the presence of a free radical initiator. The resulting polymer has a higher Tg than crystal polystyrene and is suitable for use in hot drink containers.

Abstract: A method are provided for separating diluents from solid polymers in an effluent extracted from a polymerization reactor. The separation utilizes a two-stage flash involving a first intermediate pressure flash and a second lower pressure flash, with the first intermediate pressure flash occurring in a cyclone vessel having an extended solids reservoir.

Abstract: The use of falling-film evaporation and a concentration means such as centrifugal separation to dehydrate and concentrate a water-in-oil polymer emulsion or suspension is disclosed. In a preferred embodiment, a water-in-oil polymer composition containing less than about 25% active polymer solids is dehydrated in falling-film evaporator to produce an evaporator concentrate containing less than about 5.0% water. The evaporator concentrate then flows to a separation device such as a centrifuge, wherein oil is removed to produce a composition that is substantially a polymer and emulsifying surfactant-in-oil composition containing in excess of about 60 weight % polymer solids. The centrifuge raffinate may optionally be treated in a second separation means to capture additional polymer solids, with optional recycle of the oil-rich raffinate. The concentrated polymer composition is preferably stabilized with a steric stabilizer to produce a free flowing liquid product.

Abstract: An efficient method of obtaining polymer particles by evaporating an organic solvent while maintaining a solution of a polymer in the organic solvent in contact with polymer particles, using a simple apparatus and a simple procedure. The polymer particles (powder) produced by the method have a small particle diameter, a high bulk density, a small amount of residual solvent, and are thus excellent in quality. The method includes introducing the organic solvent solution of the polymer into a particle producing zone which does not substantially contain steam, wherein an atmosphere is maintained in which the organic solvent is vaporizable and the particles are stirred. The organic solvent is evaporated, while maintaining the solution in contact with the polymer particles. Additionally a breaker is used in combination with a mixer; a poor solvent is employed; polymer particles are recycled; or a horizontal particle producing vessel is utilized.

Abstract: The invention provides an apparatus and method of its use, for recovering either devulcanized rubber or purified carbon and volatiles from a crumb rubber feed material. The apparatus comprises a chamber; a vacuum pump for providing reduced pressure within the chamber; an inlet for feeding crumb rubber into the chamber; an auger for providing continuous movement of the crumb rubber though the chamber; a battery of microtrons for providing substantially precise energy input into the crumb rubber as it is continuously moved through the chamber by the auger; at least one condenser for recovering volatiles from the crumb rubber after it has been sufficiently heated by said the microtrons; and an outlet for withdrawing either a devulcanized rubber or a purified carbon product residue from the chamber.

Abstract: An insulating material characterized by that said insulating material is made by curing a mixture composed of a bisphenol A type epoxy resin having purity which is equal to or more than 90% and an organic filler, the thermal conductivity thereof is in a range of 5.0.times.10.sup.-3 to 18.0.times.10.sup.-3 (cal/.degree.C..multidot.cm.multidot.sec) and the glass transition temperature thereof is in a range of 164.degree. to 240.degree. C.

Abstract: The production of diene rubbers polymerized by means of Nd catalysts and having reduced cold flow and low intrinsic odor is effected by the polymerization of diolefines adiabatically at temperatures of -20.degree. to 150.degree. C. in the presence of inert organic solvents and in the presence of metallo-organic mixed catalysts based on neodymium carboxylate, by subsequently depressurizing the reaction mixture obtained in this manner by reducing the pressure, and by treating the reaction mixture thereafter with disulphur dichloride, sulphur dichloride and/or thionyl chloride.

Abstract: A process for working up residues which contain dihydroxy compounds and are obtained in the preparation of polyesters by reacting dicarboxylic acids or their esters or ester-forming derivatives with dihydroxy compounds,a) in a first stage a diester of a dicarboxylic acid with an alkanol being subjected to transesterification with a molar excess of a dihydroxy compound,b) the vapors which are obtained in the reaction according to a) and contain predominantly the alkanol formed in the transesterification, excess dihydroxy compounds and oligomeric and polymeric reaction products being transferred to a column in which the alkanol is separated off via the top and the other products are separated off as a bottom product, andc) the bottom product being then subjected to a further treatment to recover the dihydroxy compound,wherein a liquid residue containing dihydroxy compounds is added in stage b) of the process, and the bottom product is discharged in substantially liquid form from the column and then subjected to

Abstract: The present invention provides a new and improved method of producing coating materials comprising the steps of providing a first organic material which is solid at room temperature, providing a second organic material which is solid at room temperature and which is substantially different in chemical composition from the first organic material, providing a source of supercritical fluid, providing a first container having a mechanical agitator, providing a second container, introducing the first and second organic materials and the supercritical fluid into the first container and mechanically agitating such materials and the supercritical fluid, and discharging the contents of the first container into the second container so as to collect substantially all of the first and second organic materials in the second vessel, the second container being maintained at a lower pressure than the first container.

Abstract: Poly(lactic acid) with a high molecular weight is produced by the polycondensation reaction of the free monomer carried out in the presence of a catalytically effective quantity of iron ions. High molecular weight poly(lactic acid) and lactide are obtained as the principal products.

Abstract: This invention concerns a process for increasing the molecular weight and viscosity of polyamides and other condensation polymers, by first injecting an inert gas into the polymer melt at elevated pressure, then stripping the volatiles from the polymer through the application of reduced pressure, followed by holding the polymer at elevated temperatures long enough for the reaction to occur. Activators may be added to the polymer. Port areas used in the stripping zone, may be kept hot for continuous operation.

Abstract: The subject invention relates to method for processing crude polyoxymethylene in which the isolation of unstable components from crude polyoxymethylene, such as residual monomers which are at least partly in the form of cyclic formaldehyde derivatives, is effected by treatment of the crude polyoxymethylene with an inert gaseous medium. The method of the invention is characterized in that the gaseous medium contains at least 10 volume % of water vapor, and less than 0.1 volume % of a volatile base, and/or less than 1 volume % of a volatile solvent. In an alternative variant method, the gaseous medium contains at least 10 volume % of water vapor and the treatment occurs at a temperature between 114.degree. C and the softening temperature of the crude polyoxymethylene and at a pressure of less 1.2 .multidot.10.sup.5 Pa.

Abstract: A method for thermally processing polyester pellets by crystallization and polymerization in the solid state which comprises providing a confined processing unit. The pellets are introduced to said unit along with a liquid medium. The combination of pellets and liquid medium is agitated to achieve mixing and the temperature of the agitated mixture is controlled to achieve treating of the polyester pellets in the agitated heating liquid medium at a temperature slightly below the sticking temperature of the polyester. The treatment is continued for a period sufficient to substantially increase the crystallinity and molecular weight of the polyester.

Abstract: The invention provides a method of manufacturing polyesters which comprises an esterifying step wherein a dicarboxylic acid and a dihydroxyl compound are esterified and the next liquid phase polycondensation step wherein the resulting ester is subjected to liquid phase polycondensation in the presence of a polycondensation catalyst while a distillate which contains an reacted dihydroxyl compound and the polycondensation catalyst is distilled, wherein the distillate is subjected to a purification treatment comprising:(a) a distilling step;(b) a filtering step; and(c) a decoloring stepand then the thus purified distillate is recovered and supplied to the esterifying step. A further method comprises a purification treatment comprising:(a) a distilling step;(b) a depolymerizing step; and(c) a decoloring step.

Abstract: A process for preparing a polybutene amine composition comprises the steps of reacting a chlorinated polybutene with an excess of at least one mole of at least one type of an amine compound per mole of the chlorinated polybutene at a reaction temperature of at least about 100.degree. C.; neutralizing the reaction mixture with a base selected from the group of alkali metal and alkaline earth metal alkoxides and amides with formulation of one of an alcohol or ammonia, respectively; neutralizing any excess base with an acid that will produce essentially no water as a by-product; and recovering the polybutene amine composition, the process including the steps of removing the alcohol or ammonia in a timely fashion; and removing excess of the amine compound.

Abstract: The present invention is directed to a process of preparing multicyanate esters by: a) reacting an adduct of a tertiary amine and a phenol-formaldehyde oligomer or derivative thereof with cyanogen halide in a solvent reaction medium under conditions to form a reaction product stream containing at least one of the following compounds selected from the group consisting of tertiary amine-hydrohalide salt, solvent, and impurities, and, based upon the total weight of the reaction product stream excluding the weight of said tertiary amine-hydrohalide salt, from about 10 percent to about 40 percent of a multicyanate ester; b) recycling a portion of said reaction product stream into the mixture of step a; and c) separating and recovering said solvent and tertiary amine from said reaction product stream.The multicyanate ester products produced according to the present invention are useful as bonding agents in friction materials, molding materials, coatings, and adhesives.