Abstract: A polytetrafluoroethylene porous material and a process for producing the same are disclosed, the material comprising a mixture of polytetrafluoroethylene having a number-average molecular weight of 2,000,000 or more and polytetrafluoroethylene having a number-average molecular weight of 1,000,000 or less, the material having been stretched at least uniaxially.

Abstract: In the preparation of expandable styrene polymers by polymerizing styrene, if desired together with up to 50% by weight of other monomers, in aqueous suspension with addition of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent and, if desired, conventional additives in effective amounts before, during or after the polymerization, foaming is reduced if the aqueous phase contains from 0.05 to 0.3% by weight of polyvinylpyrrolidone having a K value of from 100 to 150 as protective colloid.

Abstract: An expandable styrene polymer containinga) a styrene polymer,b) from 0.05 to 3% by weight, based on a), of water,c) from 0.001 to 1% by weight, based on a), of a finely divided organic polymer having a water absorption capacity of 10 g/g or more,d) from 0.5 to 8% by weight, based on a), of a C.sub.3 - to C.sub.6 -hydrocarbon, and, if desired,e) conventional additives in effective amounts, have good flow properties and low adhesion during prefoaming.

Abstract: A simple process for producing expandable thermoplastic resin particles is provided wherein a desired amount of a blowing agent is added to a particulate thermoplastic resin in a closed vessel and the mixture is allowed to age at ambient conditions for a sufficient period of time to allow the resin to become impregnated with the blowing agent.

Abstract: Solutions of segmented polyurethanes are coagulated to form shaped structures comprising a substantially continuous pore-free sheath surrounding a cellular core.

Abstract: Bead-like expandable molding materials having high heat distortion resistance contain from 80 to 99% by weight of a styrene polymer, from 1 to 20% by weight of poly-(2,6-dimethyl)-1,4-diphenylene ether and from 3 to 10% by weight of a C.sub.3 -C.sub.6 -hydrocarbon as a blowing agent and may contain conventional additives. They are obtained by suspension polymerization of a solution of the polyphenylene ether in styrene.

Abstract: Expandable thermoplastic resin microparticle compositions comprising low intrinsic viscosity polyphenylene ethers and a method for producing foam therefrom are disclosed.

Abstract: This invention relates to an expandable tape for use in making cables. The expandable tape comprises a carrier material carrying thermally expanding microcapsules therein or thereon. The invention also relates to the use of the tape in the manufacture of cables, and to the cables incorporating such tape.

Abstract: Thermoplastic compositions of internally plasticized polyvinyl alcohol material and a low molecular weight alcohol are provided that can be extruded into water soluble biodegradable foams. The compositions can be modified to provide foams that have varying degrees of water solubility and a broad range of physical characteristics.

Abstract: A process for producing styrene-containing polymers having a narrow particle size distribution, comprising the steps:(i) preparing a polymerization mixture, said mixture comprisinga) an organic phase comprising at least 50 wt %. styrene and a monomer-soluble polymerization initiator, andb) an aqueous phase comprising water, an organic protective colloid and a substantially water insoluble inorganic suspension stabilizer;(ii) adding to said polymerization mixture 50-500 ppm of a metal carbonate, bicarbonate or mixtures thereof based on said aqueous phase; and(iii) polymerizing said polymer mixture to produce said styrene-containing polymer particles.

Abstract: Exapandable beads of blends of poly (phenylene-ether) and a vinyl aromatic polymer are prepared by carrying out the polymerization of the vinyl aromatic monomer in presence of the poly(phenylene-ether) and of an expanding agent.

Abstract: A method for making low density (0.8-2 lb/cu.ft.) expanded polymeric products uses blowing agent in an amount of only from 2 to 4.4 weight percent, the process emitting blowing agent during processing in an amount of from only about 0.3 to about 2.5 weight percent. The process uses 2 to 5 expansion steps together with a polymer having a particular polydispersity, weight average molecular weight and M.sub.z :M.sub.n, this polymer having a greater expandability than conventional polymers. The process requires only about half of the amount of blowing agent currently being used in commerically viable processes for making expanded polystyrene products. The process can be used with or without a molding step.

Abstract: Organic materials, for example halocarbons, hydrocarbons or halogenated hydrocarbons are recovered from fluid streams, such as air or water, by passing these streams over post-cross-linked asdorptive porous resin beads. These beads have been prepared by(a) haloalkylating cross-linked copolymer beads of i) styrene or an alkylstyrene and ii) divinylbenzene and/or trivinylbenzene,(b) purifying the haloalkylated copolymer beads,(c) swelling the haloalkylated copolymer beads in an inert organic liquid and post-cross-linking the swollen beads in the presence of a Friedel-Crafts catalyst. The cross-linked copolymer beads which are used in the haloalkylation step are microporous copolymer beads of i) 99.8 to 98.2 weight percent of styrene or an alkylstyrene and ii) 0.2 to 1.8 weight percent of divinylbenzene and/or trivinylbenzene, based on the total weight of i) and ii).

Abstract: Novel foams having a density of from 0.01 to 0.1 g/cm.sup.3, based on a copolymer comprising ethylene, propylene and a C.sub.4 - to C.sub.8 -.alpha.-olefin, and having a torsion modulus of from 100 to 800 N/mm.sup.2 have high tensile, compressive and flexural strengths and at the same time high elongation at break.

Abstract: The use of tertiary ethers as blowing agent allows the preparation of lower density foams from many types of polymeric materials.

Abstract: A molded polypropylene foam tire core suitable for all types of wheels. The core may be inserted, in one or more sections, into a pneumatic-type tire casing and mounted on a wheel rim to provide puncture-proof and rupture-proof internal support for said tire casing.

Abstract: The polymerization in aqueous suspension of at least one vinylaromatic monomer is carried out in the presence, relative to the vinylaromatic monomer, of approximately 0.01% to 0.06% by weight of at least one polyethylene wax and of approximately 0.005% to 0.1% by weight of at least one nonionic surface-active agent which has an HLB value of between 7 and 16.Materials obtained from expandable beads prepared according to this polymerization process.

Abstract: A process for the production of expanded resin particles is disclosed, wherein an aqueous dispersion containing expandable particles of a polyolefin resin is discharged at a temperature higher than the softening point of the resin from a high pressure condition to a low pressure condition to expand the expandable particles and wherein the expandable particles contain fine particles of an inorganic material coated with an agent selected from isopropyltriisostearic titanate, tetraoctadecyl titanate, acetoalkoxyaluminum diisopropylates, stearic acid, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane and vinyltriethoxysilane.

Abstract: Expandable thermoplastic resin microparticle compositions comprising low intrinsic viscosity polyphenylene ethers and a method for producing foam therefrom are disclosed.

Abstract: Hollow, polymeric, acrylate, infusible, inherently tacky, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer. Preferred microspheres are those wherein a majority of the hollow microspheres contain at least one of interior void having a diameter of at least 10% of the diameter of the microsphere.These hollow microspheres are useful as repositionable pressure-sensitive adhesives. The invention also provides pressure-sensitive adhesives consisting essentially of such hollow microspheres. Aqueous suspensions of these microspheres, processes for their preparation, spray repositionable pressure-sensitive adhesive compositions, and microsphere-coated sheet materials are also provided. Surprisingly, hollow microspheres of the invention show reduced or even eliminated adhesive transfer, in comparison with prior art repositionable pressure-sensitive adhesives which are based on solid microspheres.

Abstract: Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units are disclosed. These materials when expanded have a volume expansion of at least 60 and maintain that volume expansion for a period of at least 30 minutes under expansion conditions after reaching the volume expansion of 60. Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units and an inhibitor for the monomer(s) and a crosslinker incorporated into the plastic material upon monomer polymerization are also disclosed. Also disclosed are expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units with blowing agents of 2,2-dimethylbutane, 2,3-dimethylbutane or mixtures of one or both with 1-chloro-1,1-difluoroethane or mixtures of at least 30 percent of one or both with other volatile blowing agents.

Abstract: Pre-foamed particles of an uncrosslinked, linear low-density polyethylene have a crystalline structure characterized in that two endothermic peaks appear on a DSC curve obtained by differential scanning calorimetry of the pre-foamed particles (said DSC curve having been obtained by heating 1-5 mg of the pre-foamed particles to 220.degree. C. at a rate of 10.degree. C./min by a differential scanning calorimeter) and the energy at the endothermic peak on the higher-temperature side is 5 J/g or more. A process for the production of the pre-foamed particles of the uncrosslinked, linear low-density polyethylene is also disclosed.

Abstract: Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units are disclosed. These materials when expanded have a volume expansion of at least 60 and maintain that volume expansion for a period of at least 30 minutes under expansion conditions after reaching the volume expansion of 60. Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units and an inhibitor for the monomer(s) and a crosslinker incorporated into the plastic material upon monomer polymerization are also disclosed. Also disclosed are expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units with blowing agents of 2,2-dimethylbutane, 2,3-dimethylbutane or mixtures of one or both with 1-chloro-1,1-difluoroethane or mixtures of at least 30 percent of one or both with other volatile blowing agents.

Abstract: Isotropic porous polymer beads having a high surface porosity and large pore diameters from about 0.002 to about 5 microns are produced from solutions of an acrylonitrile polymer or a copolymer by a thermally-induced phase separation process. The use of mixed solvent-non-solvent combinations as solvents for the polymers, produces high pore content, substantially spherical beads having a morphology ideally suited to the chromatography of large molecules, such as proteins, and for enzyme-binding.

Abstract: Hollow, polymeric, acrylate, infusible, inherently tacky, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer. Preferred microspheres are those wherein a majority of the hollow microspheres contain at least one of interior void having a diamter of at least 10% of the diameter of the microsphere.These hollow microspheres are useful as repositionable pressure-sensitive adhesives. The invention also provides pressure-sensitive adhesives consisting essentially of such hollow microspheres. Aqueous suspensions of these microspheres, processes for their preparation, spray repositionable pressure-sensitive adhesive compositions, and microsphere-coated sheet materials are also provided. Surprisingly, hollow microspheres of the invention show reduced or even eliminated adhesive transfer, in comparison with prior art repositionable pressure-sensitive adhesives which are based on solid microspheres.

Abstract: Foamed particles of a propylene resin are described which comprises, as a base resin, a random copolymer of propylene and 1-butene, said random copolymer having a 1-butene content of from 3 to 12% by weight.A foamed mold article is also described which is composed of a random copolymer of propylene and 1-butene, and having a density of from 0.015 to 0.09 g/cm.sup.3.A bumper core material for use in automobile bumpers is also described which is composed of a foamed mold article of a random copolymer of propylene and 1-butene, said random copolymer having a 1-butene content of from 3 to 12% by weight, said foamed mold article having a density of from 0.02 to 0.08 g/cm.sup.3, a compression stress at 50% compression as measured at 20.degree. C. of 2.5 to 10 kg/cm.sup.2, and an energy absorption efficiency as measured at 20.degree. C. of 60 to 90%, the ratio (E.sub.80 /E.sub.20) of the amount of the energy absorption of said foamed mold article as measured at 80.degree. C. (E.sub.

Abstract: Moldable shrunken foam beads comprising a foamable thermoplastic polymer, preferably a silane-crosslinked polyolefin foam, are produced by mixing a composition comprising a silane-modified polyolefin (such as a silane-grafted polyethylene) and a silanol condensation catalyst in an extruder to produce a melt, then projecting a blowing agent into the melt at a rate effective to produce a desired foam density in the extrudate; extruding and cutting the melt to form foam beads; allowing the beads to shrink; and exposing the foam beads to moisture to produce silane crosslinking of the polyolefin foam. In certain other embodiments the crosslinking of the thermoplastic polymer can be omitted, and/or shrinkage of the beads produced by vacuum treatment.

Abstract: The present invention provides polypropylene resin pre-expanded beads formed by shrinking polypropylene resin pre-expanded beads originally having a bulk density of not higher than 0.0930 g/cc to give them a bulk volume ratio of 10-75% at normal temperature and normal pressure, a manufacturing method thereof and an expansion-molding method with the aforementioned pre-expanded beads. According to this invention, it is possible to greatly reduce storing and transporting costs per unit weight of pre-expanded beads.

Abstract: A method of forming pre-foamed beads of a polyethylene-base resin are disclosed. The polyethylene-base resin has been obtained by crosslinking a starting polyethylene-base resin having a density greater than 0.940 g/cm.sup.3 and the pre-foamed beads have a crosslinking degree of 10-45% gel content. The pre-foamed beads can provide a molded articles having excellent rigidity and dimensional accuracy and showing superb dimensional stability under heat.

Abstract: Enhanced hiding power for opacifiers in paints, inks, and other coatings is provided by employing the opacifiers, such as TiO.sub.2, ZnO, talc, CaCo.sub.3, and the like, adhered to or embedded in the surface of thermoplastic microspheres. The composite opacifier-microsphere material is readily formed with a preselected specific gravity, so that there is little tendency for the material to separate. In addition, the composite behaves in the coating as a opacifier-air interface, having a very high difference in refractive indices, and exceptional hiding power. The high volume to weight ratio of the composite affords very attractive economic advantages, effectively reducing the weight proportion of opacifiers required in the formulations, and other related advantages.

Abstract: The polymerization in aqueous suspension of at least one vinylaromatic monomer is carried out in the presence, relative to the vinylaromatic monomer, of approximately 0.01% to 0.6% by weight of at least one polyethylene wax and of approximately 0.005% to 0.1% by weight of at least one nonionic surface-active agent which has an HLB value of between 7 and 16.Materials obtained from expandable beads prepared according to this polymerization process.

Abstract: Flame-resistant, expandable styrene polymers containing a styrene (co)polymer, from 0.4 to 6% by weight of hexabromocyclododecane having a mean particle size of from 1 to 50 .mu.m, the particles being provided with a firm coating which has a thickness of from 1/100 to 1/10 of the particle diameter and is insoluble in water and styrene, from 1 to 10% by weight of a C.sub.3 - to C.sub.6 -hydrocarbon as blowing agent, and, if desired, customary additives, are distinguished by a reduced internal water content and can be processed to form foams which have an improved foam structure and high UV stability.

Abstract: A stabilized powdered endothermic blowing agent which is a mixture of a polycarboxylic acid and an inorganic carbonate, and polycarboxylic acid and inorganic carbonate each having been surface treated with a component which prevents water from being absorbed thereby. The blowing agent is incorporated into a polymeric concentrate used for producing foamed products.

Abstract: A process for producing expandable thermoplastic resin beads which comprises suspending in an aqueous medium interpolymer beads comprising a polyphenylene ether resin and a polymerized vinyl aromatic monomer such as styrene, polymerizing the vinyl aromatic monomer in the presence of a polymerization catalyst to interpolymerize the vinyl aromatic monomer with the polyphenylene ether and, optionally, adding a cross-linking agent, to form interpolymerized thermoplastic resin beads, and introducing a blowing agent under pressure into the thermoplastic resin beads. The resulting resin beads have excellent foamability and molding fusability, and a foamed shaped article having superior thermal stability can be prepared from these beads.

Abstract: The clumping together of expandable vinylaromatic-acrylonitrile copolymer particles during expansion of such particles is substantially completely reduced by coating the unexpanded virgin particles with from 0.2 to 1.5 weight percent, based on weight of expandable copolymer particles, of particulate magnesium oxide.

Abstract: A repositionable pressure-sensitive adhesive comprising from about 70% to about 99% hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric microspheres comprising at least one alkyl acrylate or alkyl methacrylate ester, a majority of the microspheres having one or more interior voids having a diameter of at least about 10% of the diameter of the microsphere, and correspondingly, from about 30% to about 1% of a binder copolymer comprising an elastomeric polymeric backbone having pendant therefrom high Tg polymeric moieties.

Abstract: A method of introducing flame retardants into expandable vinyl aromatic polymer beads made in a one-step process is disclosed. Flame retardants with good solubility in blowing agents are introduced after monomer conversion is substantially complete, resulting in vinyl aromatic polymer beads with low residual monomer content.

Abstract: Certain organobromines are added to blends of polyphenylene ether and alkenyl aromatic polymer to reduce mold cool time of the composition. These organobromines also reduce residual blowing agent in the composition after expansion and especially following molding of the composition.

Abstract: Styrene polymer foam particles of from 10 to 30 kg/m.sup.3 in density are obtained by foaming styrene polymers which, per kg, contain from 0.7 to 3 moles of blowing agent mixture composed of from 60 to 90 mol % of water and from 10 to 40 mol % of the C.sub.4 - or C.sub.5 -hydrocarbon with the aid of microwaves.

Abstract: Expandable styrene polymers formed from 50 to 83% by weight of polystyrene and from 17 to 50% by weight of styrene-soluble styreneacrylonitrile copolymer having a total acrylonitrile content of not less than 5% by weight, containing from 3 to 10% by weight of a C.sub.3 -C.sub.6 -hydrocarbon with or without customary additives, are notable for high oil resistance and can be prepared by suspension polymerization of a solution of the styrene-acrylonitrile copolymer in styrene.

Abstract: Hollow, polymeric, acrylate, infusible, inherently tacky, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of the microspheres contain multiple interior voids, a majority of the voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the diameters of the voids being at least about 10% of the diameter of the microsphere.These hollow microspheres are useful as repositionable pressure-sensitive adhesives. The invention also provides pressure-sensitive adhesives consisting essentially of such acid-free hollow microspheres. Aqueous suspensions of these microspheres, processes for their preparation, spray repositionable pressure-sensitive adhesive compositions, and pressure-sensitive adhesive coated sheet materials are also provided.

Abstract: Porous organic microspheres for use in HPLC are formed by coacervating a colloidal silica sol in a uniform mixture of the sol and a polymerizable organic material. The silica particles which formed the sol are removed from the microspheres with ammonium bifluoride. The remaining organic microspheres are rigid, have uniform pore sizes and distribution, and do not swell or shrink in the presence of the solvents used in HPLC.

Abstract: Expandable styrene polymers of from 95 to 99.5% by weight of polystyrene and from 0.15 to 5% by weight of a styrene-soluble styrene/acrylonitrile copolymer having a total content of not less than 0.15% by weight of acrylonitrile, which contain from 3 to 10% by weight of a C.sub.3 -C.sub.6 -hydrocarbon and may contain conventional additives, give foams which do not shrink. The said styrene polymers can be prepared by suspension polymerization of a solution of the styrene/acrylonitrile copolymer in styrene.

Abstract: Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units are disclosed. These materials when expanded have a volume expansion of at least 60 and maintain that volume expansion for a period of at least 30 minutes under expansion conditions after reaching the volume expansion of 60. Expandable and expanded plastic materials having a majority of alkyl acrylate monomeric repeat units and an inhibitor for the monomer(s) and a crosslinker incorporated into the plastic material upon monomer polymerization are also disclosed. Also disclosed are expandable and expanded plastic materials having majority of alkyl acrylate monomeric repeat units with blowing agents of 2,2-dimethylbutane, 2,3-dimethylbutane or mixtures of one or both with 1-chloro-1,1-difluoroethane or mixtures of at least 30 percent of one or both with other volatile blowing agents.

Abstract: Fire-retardant expandable vinyl aromatic polymer beads are prepared by an aqueous suspension method whereby micronized hexabromocyclododecane and a volatile aliphatic hydrocarbon foaming agent are incorporated into particles of a thermoplastic such as polystyrene. The beads are useful in the preparation of molded foam articles having excellent resistance to flame.

Abstract: Bead-form expandable styrene polymers are obtained by suspension polymerization of styrene with addition of from 1 to 10% by weight of C.sub.3 - to C.sub.6 -hydrocarbons as blowing agents and, if desired, customary additives, where(a) the polymerization is initiated by rapidly heating the polymerization batch to form 80.degree. to 90.degree. C. within a maximum of 2 hours,(b) subsequently allowing the reaction temperature to increase to from 120.degree. C. to 130.degree. C. by from 8.degree. to 17.degree. C. per hour, and(c) the conversion is formed 30 to 60% when 100.degree. C. is reached, and(d) the conversion is 80% or more when the maximum temperature is reached, and(e) the batch is subsequently kept at from 100.degree. to 130.degree. C. until the residual monomer content in the polymer has dropped to less than 0.1%.

Abstract: A granular polymer composition having increased water absorption and desorption capability, resistance to photogradation and increased life span, comprising a water-insoluble but swellable cross-linked polymer material formed of at least one polymer and/or copolymer prepared from at least one unsaturated ethylene monomer having at least one carboxylic, amide, sulfuric, sulfonic, phosphoric, phosphonic, or hydroxyl functional group and at least one powdered mineral charge well dispersed in and intimately bonded to said polymer as a result of its introduction into the mixture of monomers of the same type or of a different type before their polymerization into said polymer or copolymer.

Abstract: High molecular weight polyester resins such as polyethylene terephthalate, are sometimes produced from low molecular weight polyester prepolymers having the same composition by solid state polymerization. The low molecular weight polyester prepolymers which are used in such solid state polymerizations are normally prepared by conventional melt polymerizations and are generally in the form of pellets or chips. Solid state polymerization rates can be greatly improved by utilizing polyester prepolymers which are in the form of porous pills. By utilizing polyester prepolymers that are in the form of porous pills, higher molecular weights can be achieved after shorter solid state polymerization times.This invention relates to an improved process for solid state polymerizing porous pills which are made by compacting fine fibers of the polyester prepolymer.

Abstract: Expandable styrene polymers which contain a C.sub.3 -C.sub.6 -hydrocarbon as a blowing agent, an organic bromine compound as a flameproofing agent and small amounts of ammonium salt and of an organic amine give, on expansion, foams which have a particularly homogenous foam structure and a good heat insulation effect.

Abstract: A process for producing expandable thermoplastic resin beads which comprises suspending in an aqueous medium interpolymer beads comprising a polyphenylene ether resin and a polymerized vinyl aromatic monomer such as styrene, polymerizing the vinyl aromatic monomer in the presence of a polymerization catalyst to interpolymerize the vinyl aromatic monomer with the polyphenylene ether and, optionally, adding a cross-linking agent, to form interpolymerized thermoplastic resin beads, and introducing a blowing agent under pressure into the thermoplastic resin beads. The resulting resin beads have excellent foamability and molding fusability, and a foamed shaped article having superior thermal stability can be prepared from these beads.