Abstract: Arylene sulfide polymers containing ash-forming impurities or materials are purified by contacting an aqueous mixture of such polymer with molecular oxygen under conditions sufficient to reduce the ash-forming impurities and concurrently at least partially cure the polymer.

Abstract: A process for the continuous production of high molecular weight polyethylene terephthalate wherein the crystallized prepolymer having an intrinsic viscosity of at least 0.3 is dried, preheated and polymerized in a single moving bed reaction zone. The method is characterized by an inert gas atmosphere and a reaction zone with a temperature gradiant ranging from about 170.degree. C. at the uppermost portion and a higher temperature of about 225.degree. C. at the lowermost portion.

Abstract: Arylene sulfide polymers containing ash-forming impurities or materials are purified by contacting an aqueous mixture of such polymer with molecular oxygen and a chemical treating agent under conditions sufficient to reduce the ash-forming impurities and concurrently at least partially cure the polymer. In another embodiment, at least partially cured arylene sulfide polymers are treated with a chemical treating agent in the absence of molecular oxygen to stabilize the melt flow of the resin.

Abstract: A degassing or purging process is disclosed for the removal of unpolymerized gaseous monomers from solid olefin polymers. The disclosed process comprises conveying the solid polymer, e.g. in granular form, to the top of a purge vessel by means of an inert gas stream, feeding an inert gas stream to the bottom of the purge vessel and countercurrently contacting the solid polymer with the inert gas purge stream to strip away the gaseous monomers evolved from the solid polymer, and recycling a portion of the resulting stream to the purge vessel. In one embodiment, the recycle serves as the conveying gas and in another embodiment as the purge stream. The process is especially useful in purging gaseous unpolymerized hydrocarbon monomers from low pressure-polymerized, low density ethylene-hydrocarbon copolymers.

Abstract: .epsilon.-Caprolactam is melt polymerized in the presence of water and from about 0.01 mole percent to less than about 0.6 mole percent of an amine boiling at a temperature greater than 245.degree. C. An amine may be a primary or secondary amine wherein the NH has attached thereto, for example alkyl radicals, cycloalkyl radicals, and the like. The resultant polymer has a methanol extractable content of 3 weight percent or less.

Abstract: A process for the regeneration and further condensation of a linear polyalkylene terephthalate, which is inactive due to recondensation treatment in the solid phase, and which has a viscosity number of at least 60 cc/g, the process being conducted in two stages, at an elevated temperature, in the presence of an alkanediol, comprises, in a first stage, treating the inactive polyalkylene terephthalate at a reaction temperature of 30.degree.-80.degree. C. below its melting point, with 0.3-3.5% by weight, based on the weight of the polyalkylene terephthalate, of an alkanediol whose boiling point under normal pressure is 20.degree.-70.degree. C. above the reaction temperature, in an inert gas stream, wherein the amount of inert gas passed through per hour, measured under standard conditions, corresponds to 0.3-2 times the gross reactor volume; and, in a second stage, condensing the polyalkylene terephthalate at a temperature of 5.degree.-25.degree. C.

Abstract: An improved process for polymerizing olefins in the presence of a catalyst employing hydrogen for molecular weight control is disclosed wherein the improvement resides in adding additional hydrogen to the polymer slurry produced in the reactor system so as to eliminate or reduce the formation of gels in articles fabricated from the resultant polymer.

Abstract: This invention provides a method for enhancing wettability of high density polyethylene film, that comprises subjecting said film to plasma surface treatment using oxygen or argon gas atmosphere.

Abstract: In a gas phase olefin polymerization using a transition metal compound/aluminum alkyl catalyst system, polymerization can be terminated rapidly by injecting an amount of carbon oxide and then restarting efficiently by addition of an amount of aluminum alkyl.

Abstract: Halogenated aromatic polyesters having the recurring structural formula ##STR1## wherein X is chlorine or bromine and Y is hydrogen, chlorine or bromine, with the provision that when X is chlorine, Y is hydrogen or chlorine and when X is bromine, Y is hydrogen or bromine, R and R' may be the same or different and represent lower alkyl groups, hydrogen, or together constitute a cyclic hydrocarbon group, and n is an integer which is at least about 10, are prepared by(a) reacting in solution in the presence of an excess amount of a tertiary amine(1) a bisphenol having the structural formula ##STR2## wherein X, Y, R and R' have the same meanings as given above; with (2) an aromatic acid halide selected from the group consisting of terephthaloyl halide, isophthaloyl halide, and mixtures thereof to form a reaction mixture comprising solvent, tertiary amine hydrochloride, unreacted tertiary amine, and the halogenated aromatic polyester,(b) adding to the reaction mixture an amount of gaseous, substantially anhydrous,

Abstract: Polyolefin polymer powder containing active catalyst residues is deactivated by (1) purging with an inert gas containing water vapor and (2) then contacting such powder with a gas mixture containing an inert gas, water vapor, and a third component selected from the group consisting of oxygen, carbon monoxide, carbon dioxide, C.sub.1 -C.sub.4 alcohols and C.sub.2 -C.sub.4 alkeneoxides.

Abstract: The invention provides a novel method for modifying surface properties, e.g. liability to surface bleeding of plasticizers and other additives and affinity with water, of shaped articles of polymeric materials such as vinyl chloride-based resins and silicone rubbers by the treatment with low temperature plasma of a gas. The plasma treatment in the inventive method is carried out in two steps with the first step carried out in an atmosphere of oxygen and the second step carried out in a non-oxidizing gas such as argon and carbon monoxide. Different from the conventional methods of plasma treatment which suffer from poor reproducibility and low effectiveness, the inventive method can give good reproducibility and high effectiveness presumably owing to the removal of the surface stain in the first step plasma treatment.

Abstract: In aqueous dispersions on the basis of polyvinyl chloride the content of residual monomers is reduced by the countercurrent method by contacting the rapidly moved surface of the dispersion with secluded intensely mixed gas atmospheres in several successive chambers. To carry out the process a device is used which permits to obtain under mild conditions residual monomer contents of 10 ppm and therebelow.

Abstract: The improvement of passing an inert, preferably vaporizable and condensible, liquid material through or over a polyester molten mass in a polymer reactor to further increase surface area-to-volume ratio and/or lower the partial pressure of vaporous products of condensation so that viscosity of the polymer is increased at a substantially greater rate in the same residence time is taught for the prior art condensation process in a film-forming reactor at temperatures of 275.degree. C. to 300.degree. C., pressures of 0.1 to 760 Torr, and residence times of 0.1 to 6 hours. A polymer having an intrinsic viscosity above 0.65, preferably over 0.7, is produced.

Abstract: In an improved process for preparing discrete particles from solution polymers in which water and neutralizing agent are added to the polymer to form a suspension, the organic solvent is removed therefrom, and the particles are collected by filtration, washing and drying, the suspension is formed by co-feeding the flowable polymer and the aqueous phase containing neutralizing agent into a reactor vessel under specified conditions; stirring the reactants; and discharging the resultant suspension from the reactor vessel, with all steps being carried out in a continuous manner. In one embodiment of the process, additional neutralizing agent, which is preferably sodium hydroxide, is added to the suspension during removal of the solvent therefrom.

Abstract: A novel process for preparing foundry cores or molds and binder materials used therefor are provided. The binder materials comprise (a) an alcohol-soluble phenolic resin, (b) a polyvalent metal hydroxide and/or oxide, (c) water, (d) an organic solvent, and (e) an alkali metal hydroxide. They are admixed with refractory particles, such as sand, and cured with carbon dioxide to form shaped foundry cores or molds. The process and materials of the invention bring about such advantages that curing may be performed with safe carbon dioxide, that shaped foundry cores or molds may be taken out from pattern immediately after curing, and that the products have a superior collapsibility after pouring a molten metal.

Abstract: An improved method for reducing the halogen content of a particulate polyolefin formed by catalytic polymerization of an olefin in the presence of a Ziegler-Natta catalyst is taught which comprises the steps of causing the polyolefin in the dry state to flow into a gas phase fluidized bed, contacting the polyolefin in the fluidized bed with a gas comprising 0.05% to 0.2% alkylene oxide, 5% to 30% water, and the balance inert gas such that the alkylene oxide reacts with halogens present in the polyolefin to form an alkylene halohydrin, removing the alkylene halohydrin from the fluidized bed and thus reducing the halogen content of the polyolefin. The improvement comprises regenerating the alkylene oxide by contacting the inert gas containing alkylene halohydrin with a caustic solution in alcohol or water and recovering therefrom alkylene oxide formed by the reaction of the alkylene halohydrin and the caustic solution.

Abstract: Certain wet strength resins based on the epichlorohydrin/polyamine reaction which are characterized by extremely long gel times can be purified from epichlorohydrin residuals by azeotropic distillation.

Abstract: A process for discharging a granular organic polymer, which is sensitive to molecular oxygen at elevated temperatures, from a treatment zone in which it has been continuously treated, at above 70.degree. C., with an inert gas which is free from molecular oxygen, and has subsequently been cooled, which process comprises withdrawing the polymer at .ltoreq.50.degree. C. through a narrow elongate tubular discharge zone, the said zone always being filled with granular polymer.

Abstract: A continuous process for simultaneously drying, thickening and increasing the flowability and processibility of polycarbonate powders is disclosed. The powders are fed to a tubular drier equipped with a mechanical stirrer in which they are fluidized with the aid of a stream of heated inert gas or vapor flowing counter-currently to the powders.

Abstract: In the inventive method, shaped articles of a plasticized polyvinyl chloride resin are subjected to the surface treatment by with low temperature plasma so that the undesirable phenomenon of bleeding of the plasticizer on the surface can be effectively prevented when the plasticizer for plasticizing the resin is a compound having at least one aromatic nucleus in a molecule or a combination of two or more of plasticizers including 10% by weight or more of a plasticizer which is a compound having at least one aromatic nucleus in a molecule.

Abstract: Process for the polymerization of vinyl chloride in aqueous suspension in the presence of dialkyl peroxydicarbonates in which the polymer is treated with a monobasic hydroxide at the end of polymerization and before the unreacted vinyl chloride is removed. The alkaline treatment is advantageously applied to polymers that are subsequently subjected to steam stripping.The treatment improves the initial heat stability of vinyl chloride polymers.

Abstract: A process for the separation of polyolefins manufactured at low pressure with the aid of catalysts. Carbon monoxide is added to the reaction mixture resulting from the polymerization. The process makes it possible to obtain perfectly homogeneous polyolefins which can be used for the manufacture of films and fibers.

Abstract: Apparatus for crystallizing an amorphous material which is in granular form involves admitting the granular synthetic resin into a vertical crystallization zone and permitting the granular resin to descend through this zone under the influence of gravity. A counterflow of hot gas is passed through the descending granular resin and heats the latter to a temperature at which it transforms from an amorphous to a crystalline state. Once the granular resin has passed through the crystallization zone, it is subjected to abrasion for the purpose of separating crystalline particles which adhere to one another. An apparatus for carrying out the method includes a vertical vessel which extends outwardly and downwardly and which may be of rectangular or circular cross-section. An inlet for granular material and an outlet for spent gas are provided at the top of the vessel. An outlet for the crystallized material and an inlet for hot gas are provided at the bottom of the vessel.

Abstract: The invention relates to the removal of acetaldehyde from crystalline polyethylene terephthalate granules by passing a dry inert gas through a bed of resin at a temperature of 170.degree. C. to 250.degree. C. for a time sufficient to remove the aldehydes.

Abstract: Vinyl chloride is removed from polyvinyl chloride dispersions, latexes, and slurries by sparging them with an inorganic gas, such as air or ammonia, while they are maintained at subatmospheric pressure.

Abstract: Vinyl chloride is removed from polyvinyl chloride dispersions and latexes by adding to them from 2% to 8% by weight of a polar water-soluble organic compound that has a boiling point between about 50.degree. C. and 150.degree. C. and sparging the resulting mixtures with a gas, such as nitrogen, while they are maintained at subatmospheric pressure.

Abstract: A thermotropic wholly aromatic polyester is provided which is capable of forming an anisotropic melt phase. This novel polyester displays surprising tractability and may be used as a molding resin or may be melt spun into fibers. The aromatic polyester of the present invention consists essentially of the recurring units (a) 2,6-dioxyanthraquinone moiety, (b) 4-oxybenzoyl moiety, and (c) aromatic diacid moiety. The resulting polyester exhibits a melting point below approximately 375.degree. C., and preferably below approximately 350.degree. C. Fibers which are melt spun from the polyester exhibit unexpectedly good thermal stability. The desirable tractability properties of the polyester are attributed to its anisotropic melt phase, which is due to the inclusion of the 2,6-dioxyanthraquinone moiety in the polymer.

Abstract: The discoloration of polyvinyl chloride that usually occurs when a slurry containing this polymer is heated at a temperature above 70.degree. C. to reduce its monomer content to less than 10 ppm is minimized or prevented by carrying out the heating step in the presence of an oxidizing agent.

Abstract: An improved method of degassing polymers and copolymers prepared by mass polymerizing a monomeric composition, based on vinyl chloride. The polymer is kept under agitation, the monomeric composition to be eliminated is brought from polymerization pressure to a pressure below 120 mm of mercury, the polymer is brought to or kept at a temperature of at least 70.degree. C. and below the temperature at which degradation of the polymer or copolymer commences, and these conditions of pressure and temperature are maintained substantially until the degassing process stops, the polymer being put into contact with a quantity of water representing 0.01 to 0.8% and preferably 0.05 to 0.5% of its weight, after the residual monomeric vinyl chloride content of the polymer or copolymer has been reduced below 2000 ppm. The polymers and copolymers obtained, before being placed in open air, have a residual monomeric vinyl chloride content which is less than 50 ppm, generally less than 20 ppm and may be as little as 1 ppm.

Abstract: Process and device for cooling a mixture of polymer and monomer from a reactor in which ethylene is polymerized or copolymerized at a pressure greater than 1,000 bars between a pressure-reduction valve located downstream of the reactor and a medium pressure separator. The cooling is achieved by injecting monomer at a pressure below that of the separator using a device with a nozzle cross-section S.sub.1 through which the mixture from the reactor passes, a convergent mixing zone in which the mixture is mixed with the monomer injected, which is supplied at a flow rate q, and a diffuser of throat cross-section S.sub.3, which makes it possible to bring the mixture to the pressure of the separator. The dimensions of the device are such that the ratio Q/S.sub.1 is between 0.20 and 1.35 t/hr.mm2 and the ratio (q+Q/S.sub.3 is between 0.1 and 0.3 t/hr.mm2.

Abstract: The preparation of elastomeric materials in the form of free flowing particles in which the latex formed by the polymerization of the monomers in aqueous medium is coagulated to produce particles of a size within the range of 0.5 to 5 millimeters and in which the particles are ultimatedly dried and then cooled while in a fluidized state and which includes the addition of partitioning agents to obstruct agglomeration.

Abstract: Polybutylene terephthalates having a narrow molecular weight distribution, a low carboxyl group content and an intrinsic viscosity of from 0.2 to 1.4 dl/g can be continuously produced by transporting a molten reaction mixture of terephthalic acid mono- and/or bis-(hydroxybutyl) ester or low viscosity polybutylene terephthalate at 160.degree. to 300.degree. C.

Abstract: Catalyst residues of a transition metal compound and an organometalliccompound contained in a polymer slurry are deactivated by contact with anhydrous carbon dioxide. Preferably the contacting is carried out in a transfer line connecting the reaction zone with a zone of sufficiently lower pressure that flashing of diluent occurs in the transfer line to assure mixing of the carbon dioxide and the catalyst residues.

Abstract: In the preparation of polyester having, as the main recurring unit, alkylene aromatic dicarboxylate, the vapor of alkylene glycol is continuously blown into the polycondensation vessel to make clean the inside thereof.

Abstract: Reduction of yellowing and improvement of impact strength are obtained during the processing of nitrile polymers when said polymers are heated to a plastic state in the presence of an inert gas, thereby excluding oxygen.

Abstract: Process for removing the residual vinyl chloride monomer present after polymerisation in vinyl chloride polymers in the form of an aqueous dispersion which is heated to a temperature at least equal to the glass transition temperature of the polymer and subjected to stripping by an inert fluid while being maintained at a temperature at least equal to the glass transition temperature of the polymer.

Abstract: In order to remove monomer residues from an acrylonitrile polymer which has been produced in the form of particles, for the purpose of reducing the residual monomer content to virtually negligible values, the particles are subjected to a removal process which includes raising the temperature of the particles to a value between the glass transition temperature and the melting point of the polymer.

Abstract: A process for purifying propylene homopolymers or copolymers which comprises:(i) polymerizing or copolymerizing propylene with other unsaturated hydrocarbon monomers in liquid propylene in the presence of a catalyst system consisting essentially of (a) an activated titanium trichloride obtained by reducing titanium tetrachloride with an organo-aluminum compound followed by activation and (b) an organo-aluminum compound;(ii) introducing the resulting polymer slurry into an upper portion of a counter-current washing tower to counter-currently contact the polymer slurry with a C.sub.3 -C.sub.8 alcohol and liquid propylene, whereby said catalyst is deactivated and at the same time the propylene homopolymers or copolymers dissolved in the polymer slurry and the catalyst are removed by washing, wherein said alcohol is used in an amount 0.

Abstract: This invention is directed to an improved method for the work-up of the reaction product from stereospecific polymerization of propylene with Ziegler Type catalysts in a liquid phase polymerization process employing a C.sub.3 reaction medium. The product work-up comprises treatment of the reactor effluent slurry with a small amount of a C.sub.3 or C.sub.4 alkanol and with oxygen or an effective peroxide, followed by washing of the polymer with a C.sub.3 hydrocarbon medium containing a small amount of a C.sub.3 or C.sub.4 alkanol.

Abstract: In a two step process for preparing polymeric material wherein said polymeric material is formed by polymerizing alpha-monoolefins in the presence of a halogen-containing polymerization catalyst that leaves corrosive halogen-containing catalyst residues in said polymeric material, the improvement which comprises contacting said polymeric material containing corrosive catalyst residues with steam, air and nitrogen at a temperature where the polymeric material is in a fluid or liquid state and thereafter treating said steam-air-nitrogen treated molten polymer with alumina. The polymeric material treated with the two step catalyst deactivation process had good color, low chlorides and low volatiles.

Abstract: Process for obtaining hydroxycarboxylic polymers of reduced molecular weight from corresponding polymers of higher molecular weight, comprising heating the polymer of higher molecular weight in a gaseous medium to a temperature of between 60.degree. and 240.degree. C.

Abstract: The rheological properties of paste-formable, powdered polymerizates produced by polymerizing vinyl chloride or a mixture of vinyl chloride and a copolymerizable monomer in an aqueous emulsion in the presence of a water-soluble catalyst and an alkali metal salt of a fatty acid as the polymerization emulsifier and spray drying the resultant polymerizate, are improved by treating the powdered polymerizate with a gas which forms an acid in an aqueous solution.

Abstract: Powders of physiologically-tolerable copolymers of vinyl and vinylidene monomers, said copolymers being useful as fast-dissolving resin binders for the preparation of pharmaceutical coatings, having a residual monomer content of less than 0.05 percent by weight, and having a primary particle size less than one micron; a method of preparing such powders by spray drying an aqueous dispersion of a copolymer under non-sintering temperature conditions; a method for preparing solutions for coating orally-ingestible dosage unit forms with said copolymers; and such dosage unit forms coated with said copolymers.

Abstract: A method for reducing the vinyl halide content of polyvinyl halide, in particle form, containing vinyl halide, to a preselected level is disclosed. Briefly, the method comprises: (a) determining the threshold temperature corresponding to said preselected level of vinyl halide, and (b) purging the polyvinyl halide containing vinyl halide with an inert gas heated to a temperature of at least the determined threshold temperature until the vinyl halide content of the polyvinyl halide reaches said preselected level.

Abstract: Polyurethane products having improved flex crack resistance can be obtained by curing a mixture of (a) a polyurethane prepolymer having terminal isocyanate group and (b) at least one curative selected from polyamine and polyol to prepare a polyurethane product, and heat treating the polyurethane product at a temperature of 60.degree.-180.degree. C for 1-30,000 minutes under an atmosphere having an absolute humidity of at least 2%.

Abstract: An improved process for preparing prepolymers or precopolymers of diallyl phthalate in a solid state from a prepolymer or precopolymer phase separated by the liquid phase extraction in a liquid state of fluidity and containing 10-30% by weight of the extractant, which comprises forming the prepolymer or precopolymer phase in a liquid state of fluidity and containing the extractant into a sheetlike form prior to solidifying it by cooling, heating prepolymer or precopolymer phase under foaming conditions accompanied by the evaporation of the extractant, and thereafter solidifying the prepolymer or precopolymer.

Abstract: A process for at least partly removing residual chlorinated hydrocarbon solvent from a chlorinated polymer obtained by precipitation from the said solvent, which comprises treatment of the chlorinated polymer with the vapor of an aliphatic halo-hydrocarbon having a boiling point below that of the chlorinated hydrocarbon to be removed, at a temperature 10.degree. above the boiling point of the halo-hydrocarbon employed in the treatment.

Abstract: Organic compounds having at least one replaceable hydrogen atom are fluorinated in the liquid or solid state by treatment with fluoroxyperfluoroalkanes or fluoroxypentafluorosulfur under the influence of a free radical initiator.

Abstract: In a process for preparing a polyolefin without separation of catalyst residues by polymerizing an olefin in the pres ence of a Ziegler catalyst having high catalytic activity, in an inert gas sealing system; an improvement comprises separating the polyolefin containing the catalyst residue from the polymerization mixture, and contacting the polyolefin containing the catalyst residue with a weak reactive gas of oxygen and/or steam diluted with an inert gas.