Abstract: There is provided a process and apparatus which utilizes a purger capable of handling different solids having different particle sizes and operating at a purge gas velocity higher than the minimum fluidization velocity of solids without gas channeling or solids backmixing. The purger has tapered walls and a conically-shaped, gas-permeable, solids-impermeable constraint means.

Abstract: The invention relates to a method for purifying liquid polysiloxane containing impurities as a low-molecular-weight fraction, by evaporating the low-molecular-weight fraction, in which method a liquid stream of impure liquid material in the form of a bundle of a multiplicity of streams or jets is brought into contact with a flowing gas phase, after which the gas stream, which contains the impurities, is removed and purified liquid material is collected; a device for performing this method and also the use of purified liquid material.

Abstract: Saturated or superheated steam, or an inert gas, or a combination thereof is introduced into a gas phase above a molten acrylonitrile polymer in a vessel having a stirrer, while the polymer has a temperature of at least 120.degree. C. and a pressure at least equal to its autogenous pressure. Any unreacted acrylonitrile monomer, or both any such monomer and any acrylonitrile monomer or water used as a plasticizer are removed by evaporation from the vessel.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated compound in which a solid particulate material is suspended in a liquid diluent in which the polymer to be produced forms a suspension. The monomers are contracted in the liquid diluent containing the suspended solid particulate material with a catalyst composition which is based on a source of a Group VIII metal and a boron hydrocarbyl compound.

Abstract: A process for the copolymerization of carbon monoxide with an olefinically unsaturated compound in which the monomers are contacted in the presence of a liquid diluent and a protic compound with a catalyst composition which is based on a source of a Group VIII metal and a hydrocarbylborane. A stirring power is transmitted to the polymerization mixture of at least 0.25 kW/m.sup.3.

Abstract: Formulations including a high density polyester and a density reducing component. The formulations are useful for facilitating the separation of blood serum or plasma from the cellular portion of blood in blood collection applications.

Abstract: Process for direct production of shaped packaging material made of thermoplastic polyesters with no effect on the taste of foods packaged in them, where the diol component of the polyester consists of at least 70 wt % ethylene glycol, and the polyester is produced in the presence of the usual catalysts plus additional cobalt or cobalt and manganese compounds and phosphorus compounds. An inert gas is introduced into the polyester melt and distributed uniformly in the melt immediately after its discharge from the polycondensation reactor, 0.05 to 1.0 wt % of an amide compound with a low volatility is added to the polyester melt directly next to the gas inlet. Finally, the polyester melt is subjected to a vacuum degassing immediately before the shaping apparatus and the melt is sent directly to the shaping apparatus within a maximum of 30 minutes after its discharge from the reactor at a maximum temperature of 35.degree. C. above the crystallite melting point of the polyester.

Abstract: A medical implant made of polymeric material having an increased oxidation resistance is formed by a method including the steps of placing a resin powder in a sealed container. A substantial portion of the oxygen is removed from the sealed container by either a vacuum, an oxygen absorbent or by flushing with inert gas. The container is then repressurized with a gas such as nitrogen, argon, helium or neon so that long term storage may be possible. On use, the resin is transferred to a forming device which both melts and forms the resin in an oxygen reduced atmosphere to produce a polymeric raw material such as a rod or bar stock. The medical implant is then formed from this raw material annealed and sealed in an air-tight package in an oxygen reduced atmosphere. The implant is then radiation sterilized and thereafter annealed in the package for a predetermined time and temperature sufficient to form cross-links between any free radicals in neighboring polymeric chains.

Abstract: The present invention provides a melt process for the manufacture of thermoplastic solvent-free polycarbonates with the use of a continuously operated tubular reactor for monophenol vaporization.

Abstract: Disclosed is a process for increasing the molecular weight of condensation polymers involving the use of a high velocity rarefied inert gas sweep in the polymer finishing process.

Abstract: Disclosed is a process for removing acetaldehyde from polyester which comprises the steps ofa) transporting molten polyester to a vented, continuous screw conveyor having a polymer compression zone,b) rotating the screw of said conveyor so as to compress and convey through the extruder the molten polymer for a time of less than 15 minutes and at a temperature of less than 300.degree. C.,c) simultaneously with step b), flowing a purge agent into and out of said extruder to thereby remove volatile impurities and avoid appreciable build-up of acetaldehyde, andd) conveying the devolatized polymer melt to a mold wherein an article of manufacture is formed.

Abstract: Process for the preparation of elastomeric, non-agglomerated, powdery/crumbly polypropylene by polymerization of propylene, if appropriate together with other olefins as comonomers, in liquid propylene and subsequent precipitation of the polypropylenes formed with CO.sub.2 or a polar solvent of which the polar term "delta p" of the solubility parameter according to Hansen is greater than 5 and the total solubility parameter "delta" is less than 30.

Abstract: A one-step polymerization process for producing a bimodal resin having a distinct low molecular weight portion and a high molecular weight portion includes initiating an anionic polymerization of a monomer or monomers to produce living polymer chains, terminating a portion of the living polymer chains, and completing the polymerization of the remaining living polymer chains. The bimodal resin is useful, for example, in high gloss, low melt toner applications.

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: Process for thermal solid-state treatment of chips of saturated polyester, where the chips are crystallized immediately before the thermal treatment and the thermal treatment is carried out in a static bed at a chip temperature that is equal to TE (1 .mu.m) .+-.2.degree. C., where TE (1 .mu.m) is the temperature at which a measurement probe placed on a crystallized chip is lowered by 1 .mu.m under defined conditions in a thermomechanical analysis. The crystallization preferably takes place in a fluidized bed at three different specified temperatures.

Abstract: High melting point perfluorinated tetrafluoroethylene polymers dissolved in supercritical carbon dioxide at elevated temperatures and high pressures. The solutions are useful for making foams, spun-bonded or paper-like webs, or for purification of polymers.

Abstract: A method of making resin coated photographic paper which comprises providing a paper base, subjecting the paper base to a flame treatment and a corona discharge treatment, providing a polyolefin melt curtain, treating the polyolefin resin melt curtain with a mixture of ozone and air and bringing the paper base in contact with the polyolefin melt curtain to provide a uniform layer of polyolefin resin on the paper base.

Abstract: A method for reducing residual unsaturated monomer content of an aqueous dispersion of a saturated polymer. The method involves contacting the aqueous dispersion with ozone resulting in ozonolysis of unsaturated monomers. The method is simple, economical and can be used with existing production facilities.

Abstract: Polyarylene thioethers having recurring units of the formula[--(S--E--).sub.a --(--SO--E--).sub.b --(SO.sub.2 --E).sub.c --](I)in which E are, independently of one another, phenylene, naphthylene or biphenylene, a and c have, independently of one another, values from 0 to less than 1 and b has values from greater than zero to less than 1, with the proviso that the sum of a+b+c is equal to 1 and at least two of the indices are greater than zero, are obtained by oxidation of polyarylene sulfides in two stages, wherein in the first stage a polymer in solid form in a suspension medium is oxidized with ozone and the reaction product obtained is in the second stage reacted in acetic acid with hydrogen peroxide in the presence of catalytic amounts of concentrated sulfuric acid and/or with addition of equilibrium per-acids. The polyarylene thioethers are suitable for the production of molded parts having high temperature resistance and high resistance to chemicals.

Abstract: There is disclosed a process for decolorizing polysuccinimide by means of contacting the polysuccinimide in the solid state with an aqueous solution of a bleach. Typically, polysuccinimide is placed into a solution of hydrogen peroxide to form a slurry with solid particles whereby the color of the polysuccinimide is greatly reduced. Separation of the bleach solution is performed easily by means of solid liquid separation such as by filtration rendering the polysuccinimide acceptable for use directly into detergent formulations.

Abstract: The color of hydrocarbon resins having carbon-carbon double bonds and containing color bodies is lightened by a hydrotreating process comprising contacting a resin having a weight average molecular weight Mw of 250-10,000 with hydrogen in the presence of a catalyst that promotes the hydrogenation of the color bodies without substantially changing the content of carbon-carbon double bonds in the resin. The preferred catalysts are copper chromite and copper/zinc.

Abstract: A process for removing unpolymerized monomers from a solid olefin polymer containing the monomers by countercurrently feeding an inert purge gas through a bed of polymer in a cylindrical purge vessel having tapered walls wherein the vessel has a height to bottom diameter ratio of 0.5:1 to 10:1 and the walls have a tapered angle based on a vertical axis of 0.5 to 15 degrees. An apparatus for removing unpolymerized monomers from a solid olefin polymer containing the monomers which comprises, a cylindrical purge vessel having tapered walls wherein the vessel has a height to bottom diameter ratio of 0.5:1 to 10:1 and the walls have a tapered angle based on a vertical axis of 0.5 to 15 degrees; a solids inlet disposed in an upper portion of the vessel; a solids discharge disposed in a lower portion of the vessel; gas entry means disposed within or below a bed of solids, and gas discharge means disposed in the upper portion of the vessel.

Abstract: A process of preparing a polyester by reacting a diol with an acid or acid ester in the presence of a solid enzyme and in a supercritical fluid is described.

Abstract: This invention includes a process for preparing a solid state polymerized poly(ethylene naphthalate)or PEN polymer comprising: (1) preparing a molten PEN polymer with an intrinsic viscosity of from about 0.25 dl/g to about 0.55 dl/g, (2) dispersing an inert gas into the molten PEN polymer to form a foamed PEN polymer with a void fraction of from about 0.10 to about 0.50, (3) forming the foamed PEN polymer into granules, (4) devolatilizing the granular PEN polymer at a temperature of from about 80.degree. C. to about 140.degree. C., (5) crystallizing the devolatilized PEN polymer at a temperature of from about 150.degree. C. to about 260.degree. C., and (6) solid state polymerizing the crystallized PEN polymer at a temperature of from about 235.degree. C. to about 265.degree. C. to form a solid state polymerized PEN product.

Abstract: A medical implant made of polymeric material having an increased oxidation resistance is formed by a method including the steps of placing a resin powder in a sealed container. A substantial portion of the oxygen is removed from the sealed container by either a vacuum, an oxygen absorbent or by flushing with inert gas. The container is then repressurized with a gas such as nitrogen, argon, helium or neon so that long term storage may be possible. On use, the resin is transferred to a forming device which both melts and forms the resin in an oxygen reduced atmosphere to produce a polymeric raw material such as a rod or bar stock. The medical implant is then formed from this raw material annealed and sealed in an air-tight package in an oxygen reduced atmosphere. The implant is then radiation sterilized and thereafter annealed in the package for a predetermined time and temperature sufficient to form cross-links between any free radicals in neighboring polymeric chains.

Abstract: A thermoplastic resin such as a styrene/maleic anhydride copolymer is treated to remove volatile impurities such as unreacted styrene by admixing with a chemical blowing agent and extruding under a vacuum. The chemical blowing agent is converted into an inert gas such as carbon dioxide during extrusion; the gas evolved is removed, together with the volatile impurities, through one or more vents in the extruder. The use of a chemical blowing agent, rather than the inert gas itself, permits the facile distribution of the CO.sub.2 stripping agent throughout the molten thermoplastic resin using commonly available extruders without the need for elaborate gas injection means.

Abstract: A method for preparing a highly heat-resistant and burning-resistant poly(silyleneethynylene phenyleneethynylene) having a repeated unit represented by the following structural formula (1A): ##STR1## wherein the phenylene group may be in the o-, m- or p-form, R represents a halogen atom or an alkyl group, alkoxy group, phenoxy group, alkenyl group, alkynyl group, aromatic group, disubstituted amino group or silanyl group; n is an integer ranging from 0 to 4; and R' represents a hydrogen atom, an alkyl group, alkenyl group, alkynyl group or aromatic group, a product obtained by the method and a hardened product obtained by heat-treating, at a temperature ranging from 50.degree.to 700.degree. C., the poly(silyleneethynylene phenyleneethynylene).

Abstract: A method of treating an aramid monofilament by plasma in such a manner that the monofilament has a wettability by water satisfying the relationship WS.sub.SL .gtoreq.120, W.sub.SL being the reversible solid-liquid adhesion work expressed in mJ/m.sup.2. By way of example, the treatment is carried out by means of a plasma at reduced pressure, and the monofilament is subjected to a coating treatment after the surface treatment. The aramid monofilament is characterized by the following relationships:1.7.ltoreq.Ti.ltoreq.260;40.ltoreq.D.ltoreq.480;T.gtoreq.170-D/3;Mi.gtoreq.2,000; andW.sub.SL .gtoreq.120.In the above relationships, Ti represents linear density in tex, D represents diameter in .mu.m (micrometers), T represents tenacity in cN/tex, and Mi represents initial modulus in cN/tex. The aramid monofilament is particularly useful for reinforcing tires.

Abstract: This invention is a process for solid state polymerization of polyester using multiple reactors in series to achieve molecular weight increases, as measured by intrinsic viscosity, in excess of 0.25 dl/g with low levels of undesirable by-products.

Abstract: Disclosed is an improvement in a process for producing linear polyesters wherein a precursor polyester is first formed and subsequently the precursor polyester is formed into particles and further polymerized in the solid state, wherein the improvement comprises contacting the particles while at a temperature of about 140.degree. to about 2.degree. C. below the melting point of the polyester with the vapor of water or an organic compound having at least one OH group.

Abstract: Disclosed is an improvement in a process for producing branched polyesters wherein a precursor polyester is first formed and subsequently the precursor polyester is formed into particles and further polymerized in the solid state, wherein the improvement comprises contacting the particles while at a temperature of about 140.degree. to about 2.degree. C. below the melting point of the polyester with the vapor of water or an organic compound having at least one OH group.

Abstract: Polytetrafluoroethylene coagulate obtained from aqueous dispersion polymerization of tetrafluoroethylene in the presence of volatile initiator, surfactant, and possibly wax, is purified of these contaminants by exposing the coagulate to heated air with the coagulate being formed as a shallow bed on a fabric of polymer filament, the heated air passing through the bed from top to bottom to volatilize the contaminants including the water content of the coagulate and thereby cause them to leave the bed through openings in the fabric.

Abstract: A process for the production of polycarbonates is disclosed. Accordingly, oligocarbonate in the melt is passed through a heated tube and inert gas is simultaneously introduced by injecting to the melt.

Abstract: Continuous agglomeration of an absorbent resin powder is accomplished by a method which comprises introducing the absorbent resin powder into a cylindrical member having an open lower end by means of a current of air through a dispersing member disposed in the upper part of the cylindrical member and, at the same time, spraying minute droplets of an aqueous liquid downwardly through a nozzle disposed inside the dispersing member thereby establishing mutual parallel flow contact between the absorbent resin powder descending toward the lower part of the cylindrical member as dispersed with the current of air and the liquid droplets descending toward the lower part of the cylindrical member as diffused in the radial direction, and removing the produced agglomerate having a plurality of particles of the absorbent resin powder cohesively united through the medium of the liquid droplets via the lower part of the cylindrical member. An apparatus for working the method is also disclosed.

Abstract: A process is disclosed for removing palladium from a contaminated polyketone containing palladium which comprises contacting the contaminated polyketone with an olefin in the substantial absence of carbon monoxide at a temperature above the temperature at which the polyketone was formed and in a solvent in which the contaminated polyketone is insoluble. The process is preferably carried out in the presence of an acid. The temperature at which the process is carried out is preferably at least 20.degree. C. greater than the polymerization temperature.

Abstract: The present invention relates to polyesters which are particularly suitable in coating compositions which are sprayed with compressed fluids which act as viscosity reducing diluents.

Abstract: In accordance with the present invention, there is provided a bubble-containing ethylene/.alpha.-olefin rubber excellent in kneadability, characterized in that the ethylene/.alpha.-olefin rubber prepared by copolymerization of 50-95 mol % of ethylene, 5-50 mol % of .alpha.-olefin having at least 3 carbon atoms and 0-10 mol % of non-conjugated polyene contains 5-1000 parts by volume, based on 100 parts by volume of said rubber, of bubbles and has a water absorption volume as measured in accordance with ASTM D 1506 of less than 20% by volume of the total bubble volume.

Abstract: A copolymer of maleic anhydride and an alkyl vinyl ether is stabilized by contacting same with a non-reactive substantially moisture free gas at a temperature of from about 30.degree.-100.degree. C. for from about 0.5-24 hours. The copolymer is preferably prepared by reacting together maleic anhydride and an alkyl vinyl ether in the presence of a free radical initiator.

Abstract: A process for the solid state upgrading of a polyester resin by polyaddition reaction in which the resin is upgraded in the presence of an upgrading additive which is a compound different from a dianhydride of an aromatic tetracarboxylic acid, containing two groups capable of addition reactions with the terminal groups of the polyester, selected for example in the group of the dianhydrides of aliphatic and cycloaliphatic tetracarboxylic acids.

Abstract: A process for the solid state polyaddition of a polyester resin in which the resin, blended in a molten state with a dianhydride of an aromatic tetracarboxylic acid is granulated, crystallized and then upgraded, characterized in that the crystallization and upgrading temperature is comprised in the range between the TG and 170.degree. C., preferably between 130.degree. and 170.degree. C.

Abstract: Polyolefins are produced by a process which includes the steps of: polymerizing an olefin in a reaction zone; removing unreacted olefin from the polymer in a flash chamber and recycling the unreacted olefin to the reaction zone; stripping unreacted olefin from the polymer by passing a stripping gas through the polymer in a stripping zone; passing the unreacted olefin from the stripping zone at superatmospheric pressure through an adsorbent which selectively adsorbs olefins; depressurizing the adsorbent to produce a substantially pure olefin and recycling the substantially pure olefin to the reaction zone; purging the adsorbent bed with a nonadsorbable gas to remove residual unreacted olefin from the adsorbent; and passing the purge gas-unreacted olefin to the stripping zone to be used as stripping gas.

Abstract: A process for isolating high bulk density polymer resins from polymer resin solutions is provided herein. More particularly, a polymer resin having a glass transition temperature of greater than about ambient temperature is isolated from a polymer resin solution by subjecting the polymer resin solution a gaseous component under moderate pressure and ambient temperature.

Abstract: A process for removing unpolymerized gaseous monomers from a solid olefin polymer containing said gaseous monomers by feeding an inert purge gas through a vessel containing constraint means which defines the upper limit of an expandable bed in the vessel and countercurrently contacting the solid polymer under expanded bed conditions.

Abstract: Solutions of polymers of aspartic acid or its amine copolymers prepared by thermal condensation are reacted with a decolorizing agent selected from the group consisting of hypochlorfte, chlorine, chlorine dioxide, hydrogen peroxide, a peroxycarboxylate or ozone, sufficient in strength to effect the desired decolorization.

Abstract: A method of crystallizing plastic such as polyethylene terephthlate in the form of small particles comprises the steps of placing the particles in a liquid bath such as water, agitating the bath using jets of hot gas such as steam while simultaneously raising the temperature of the particles to a level at which the plastic crystallizes to a predetermined level of crystallinity. The particles are thereafter separated from the bath and dried.

Abstract: Recently, vinylphenol polymers have received special attention as materials for photoresists, since these materials have excellent transmittance of deep ultraviolet light in the neighborhood of 248 nm. Although particularly useful in this regard, vinylphenol polymers usually contain metal impurities, while photoresists must have high transmittance and extremely low metal content. As a result, vinylphenol polymers satisfying these requirements have not been available on industrial scale. In the present invention, a process for producing such purified vinylphenol polymers, both economically and easily, is realized. In the process of this invention, the vinylphenol polymer solution is hydrogenated and the hydrogenated solution is contacted with a strongly acidic cation exchange resin. In this way, substantially metal-free vinylphenol polymers are obtained.

Abstract: The viscosity stability of a copolymer of ethylene with at least one comonomer which is an ethylenically unsaturated carboxylic acid is improved by exposing the isolated copolymer to moisture for a sufficient period to cause the copolymer to retain at least 20 weight percent more water than it would retain if it were purged with air or nitrogen heated to a temperature at least 5.degree. C. above ambient, which air or nitrogen has not been humidified after it has been heated to such temperature.

Abstract: Very low molecular weight polymers are sometimes used in toners which are designed for high speed printers and copiers. It is extremely difficult to prepare polymers having the ultra-low molecular weights required in such applications by standard emulsion polymerization techniques. By utilizing the techniques of this invention, the molecular weight of polymers made by conventional emulsion polymerization can be reduced to a very low level.

Abstract: A supercritical separation process is proposed for polymers, utilizing mixed solvents. Such a process can be used to remove light end, or heavy end, or generate bulk fractions of low polydispersity. Three modes of operation are proposed: increasing solvent capacity, decreasing solvent capacity, and single-vessel multistage separation.

Abstract: According to the invention, a special process for isolating polycarbonate from methylene chloride at temperatures of 30.degree. to 80.degree. C. in the form of a powder with residual solvent contents below 5% by weight is started up as a continuous process by starting up in a two-component nozzle, in which CO.sub.2 -containing fluid and the polymer solution are continuously combined, with a large excess of CO.sub.2 and then allowing the polycarbonate/methylene chloride/CO.sub.2 fluid system to pass through the gel-forming range of the polycarbonate/methylene chloride/CO.sub.2 phase diagram with continuous reduction of the CO.sub.2 throughput to a ratio of CO.sub.2 to organic solution of 4:1 to 2:1. The process started up in this way has a particularly long useful life.