Abstract: The application relates to polyethylene and/or polypropylene foam moldings for packaging which consist of more than 50% of recycled material, and to a process for the production thereof.

Abstract: A vibration-absorbing element comprised of a foamed thermoplastic polymer selected from the group consisting of polyamide elastomers, EPDM polymers and SEBS polymers containing conventional additives, the foam structure having a pore size which decreases from the inside towards the outer surface and terminating in a smooth closed surface.

Abstract: Disclosed is a normally solid, high molecular weight, gel-free, amorphous to predominantly crystalline, propylene polymer characterized by high melt strength due to strain hardening which is believed to be caused by free-end long chain branches of the molecular chains forming the polymer.Also disclosed is a process for making the polymer by high energy radiation of a normally solid, high molecular weight, linear, propylene polymer in a reduced active oxygen environment, maintaining the irradiated material in such environment for a specific period of time, and then deactivating free radicals in the material.Further disclosed is the use of the strain hardening polymer in extensional flow operations such as, for example, extrusion coating, film production, and thermoforming.

Abstract: Foamed gaskets comprising at least one homogeneously branched ethylene polymer and at least one blowing agent are disclosed. The gaskets are particularly useful for sealing food and liquid containers and do not contribute to taste and/or odor of the packaged product, which is especially useful in food-stuff applications.

Abstract: A flexible closed cell polymeric foam contains expandable graphite as fire retardant. The foam is prepared by mixing a polymer, a curing agent, at least one blowing agent and an expandable graphite at a temperature of at least 100.degree. C. but below a temperature causing activation of the blowing agent to foam a foamable mixture and thereafter heating the foamable mixture to activate the blowing agent and cause foaming. The method of preparation may additionally include a curing step in which the foamable mixture is heated under pressure to activate simultaneously each of a curing agent, which is preferably a free radical curing agent, and a foaming agent. The foams are capable of meeting the U.S. Federal Aviation Authority Standards, especially the oil burner test of FAR 25 Appendix F, part II.

Abstract: This invention relates to a polymer foam prepared by dispersing an organophilic multi-layered material into a melt comprising an olefinic or styrenic polymer having polar functionality so that at least a portion of the polymer intercalates between layers of the particles; and expanding the polymer with a blowing agent under such condition to form the polymer foam. The organophilic multi-layered material can also be dispersed into an olefinic or styrenic monomer, which can then be polymerized to form a polymer melt prior to, or along with the foaming step.

Abstract: A foam cell nucleating agent that is a combination of sulfonic or phosphonic acid or salt thereof and inorganic salt containing a polyatomic anion yields improved foaming of thermoplastic resins such as polyolefins and melt-fabricable fluoropolymers.

Abstract: A resin composition for low expansion moldings which comprises (A) 20 to 80 parts by weight of a vinyl chloride resin having an average degree of polymerization of from 500 to 1700 and (B) correspondingly from 80 to 20 parts by weight of a copolymer made of 60 to 90 parts by weight a polymerizable monomer mixture consisting of 20 to 40 wt % of acrylonitrile, 20 to 60 wt % of .alpha.-methylstyrene and 20 to 40 wt % of styrene and, correspondingly, 40 to 10 parts by weight of a crosslinked acrylic rubber. The resin composition further comprises (C) 0.5 to 30 parts by weight of an acrylic resin having a reduced viscosity of not less than 3.0 dl/g when measured by use of a chloroform solution of the acrylic resin at a concentration of 0.1 g/100 ml, (D) 0.1 to 10 parts by weight of a thermally decomposable rosining agent, and (E) from 1 to 10 parts by weight of a stabilizer, each based on 100 parts by weight of a mixture of the components (A) and (B).

Abstract: Disclosed is a closed-cell polymer foam comprising a quantity of titanium dioxidce particulates sufficient to reduce the thermal conductivity of the foam to less than that of a corresponding foam without the titanium dioxide particulates. The titanium dioxide particulates have a wetting aggent applied to a substantial portion of their surfaces. Further disclosed are processes for making the foams.

Abstract: A receptacle (10), such as an attache case or brief case, has a cover panel (22), back panel (24), front panel (26), top panel (30), bottom panel (32) opposing tabs (34) and opposing side panels (36). The case is made from a unitary sheet of expanded polyethylene. The expanded polyethylene sheet material is produced by encapsulating a thermoplastic blowing agent (azodicarbonamide) within an ethylene vinyl acetate carrier resin to form a pelletized compound which is combined with high-density polyethylene resin and extruded. The melt temperature of the pelletized blowing agent is lower than that of the polyethylene resin, and controls the expansion of the polyethylene resin.

Abstract: A thermal insulator of the present invention includes a foam containing solidified CO.sub.2 gas. A method for producing the thermal insulator includes the steps of: mixing a metal compound selected from the group consisting of a metal oxide and a metal hydroxide, water, a polyol component, and an isocyanate component to generate a mixture; foaming the mixture in a container to generate closed-cells made of a water-foamed polyurethane; and allowing CO.sub.2 gas generated during the foaming step to react with the selected metal compound to solidify the CO.sub.2 gas, thereby depressurizing the closed-cells in the closed-celled foam.

Abstract: Biaxially oriented films from high molecular weight polyethylene are characterized by a gas permeable structure formed from random-arranged microfibrils. The films have coefficients of static friction and kinetic friction of not more than 1.0. The biaxially oriented films are further characterized by service smoothness as well as tensile (tangent) modulus and tensile strength. The films may be used for lamination, filter, or for packaging for moisture absorbers. The biaxially oriented films may be obtained by extracting a hydrocarbon plasticizer from a sheet formed from the high molecular weight polyethylene and a hydrocarbon plasticizer, stretching the resulting sheet to obtain an oriented film having a specific surface area of at least 70 m.sup.2 /g and a fibril structure, and heating the oriented film under a standard length constraint to reduce the oriented film in specific area by at least 20 m.sup.2 /g.

Abstract: The present invention provides a process for producing thermoplastic foam, including:(a) melting a thermoplastic polymer to produce a polymer melt;(b) introducing a carbon dioxide blowing agent into the polymer melt;(c) adding to the polymer melt one or more additives selected from the group consisting of(1) polysiloxane, and(2) mineral oil; and(d) extruding and foaming the melted polymer melt, blowing agent, and one or more additives to produce thermoplastic foam.The resultant thermoplastic foam can be thermoformed into various foamed articles, such as foam packaging trays. The quality of foams made from a carbon dioxide blowing agent, and particularly 100% carbon dioxide, has been found to be substantially improved by adding one or more of the foregoing additives, i.e., polysiloxane, mineral oil and, optionally, polyolefin to the polymer melt during the extrusion and foaming process.

Abstract: A crosslinked foamed body obtained by subjecting a rubber compounded product comprising (A) a chlorinated ethylene/.alpha.-olefin copolymer rubber, (B) a triazinethiol as a vulcanization agent, (C) an alkyl ammonium halide as a vulcanization promotor, and (D) a hydrazide-type blowing agent to two step vulcanization and foaming at a vulcanization temperature of 120.degree. to 140.degree. C. for a vulcanization time of 5 to 10 minutes in a first step and at a vulcanization temperature of 125.degree. to 160.degree. C. for a vulcanization time of 5 to 20 minutes in a second step, the second step vulcanization temperature being higher than the first step by at least 5.degree. C., so that the expansion factor will be 3 to 10 times. This crosslinked foamed body can be colored brilliantly, exhibit excellent weatherability, suppleness and shape retention as well as good outer appearance. This product is well usable, for example, as wet suits.

Abstract: An expandable thermoplastic composition is disclosed for extrusion foaming wherein the composition comprises a polyethylene resin and a blowing agent comprising ethane present in an amount of at least about 40 percent or more by weight based upon the total weight of the blowing agent and a different alkane selected from the group consisting of C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, and C.sub.6 alkanes and mixtures thereof, wherein the minimum percentage of ethane increases above 40 percent as the arithmetic mean carbon number of the different alkane increases from 3 to 5. A process for extrusion foaming of the composition is also disclosed.

Abstract: A silicone sponge rubber having a great tensile strength even when it has a low foam density can be obtained from a foamable silicone rubber composition including:(A) a polyolefin dispersion obtained by polymerizing monomers having polymerizable aliphatic unsaturated double bonds, dispersed in a dispersion medium of an organopolysiloxane having a viscosity of from 50 cSt to 1,000,000 cSt at 25.degree. C. whose molecular chain both terminals are terminated with silanol groups, to form a polyolefin in the silanol group-containing organopolysiloxane;(B) an organohydrogenpolysiloxane having at least two hydrogen atoms in one molecule;(C) at least one selected from the group consisting of water, an alcohol, a silanol group-containing organosilane, and a silanol group-containing siloxane having a viscosity of less than 50 cSt at 25.degree. C.; and(D) a platinum family metal catalyst.

Abstract: Shaped microcellular structures having substantially non-cellular skins are produced from reactive liquid polymer systems incorporating thermoplastic microspheres containing volatile materials such as low boiling point halogenated or non-halogenated organic materials. Use of thermoplastic microspheres encapsulating such volatile materials facilitates the removal of the shaped foamed structure from molds, eliminating the need for release agents. Various products based on this process, such as bathroom fixtures, bicycle and wheel chair tires, shoe soles, and automotive parts, are provided.

Abstract: A process for producing an automotive molded roof material is provided which comprises sheeting a foamable sheet forming composition comprising a specified propylene resin, a glass fiber, a radical initiator, a crosslinking auxiliary and a foaming agent in specific proportions into a foamable sheet, lining one side of the foamable sheet with a backing sheet so as to integrate these and irradiating the foamable sheet with ionizing radiation to thereby crosslink the propylene resin, followed by heating the foamable sheet so as to cause the foamable sheet to foam, placing a cover sheet on the other side of the foamed sheet before the sheet cools to solidify and press molding the cover sheet on the foamed sheet to cover. There is also provided an automotive molded roof material produced by the above process. An automotive molded roof material is obtained which can be recycled, is lightweight and has high rigidity.

Abstract: A flexible closed cell polymeric foam contains expandable graphite as fire retardant. The foam is prepared by mixing a polymer, a curing agent, at least one blowing agent and an expandable graphite at a temperature of at least 100.degree. C. but below a temperature causing activation of the blowing agent to foam a foamable mixture and thereafter heating the foamable mixture to activate the blowing agent and cause foaming. The method of preparation may additionally include a curing step in which the foamable mixture is heated under pressure to activate simultaneously each of a curing agent, which is preferably a free radical curing agent, and a foaming agent. The foams are capable of meeting the US Federal Aviation Authority Standards, especially the oil burner test of FAR 25 Appendix F, part II.

Abstract: Biaxially oriented films from high molecular weight polyethylene are characterized by a gas permeable structure formed from random-arranged microfibrils. The films have coefficients of static friction and kinetic friction of not more than 1.0. The biaxially oriented films are further characterized by service smoothness as well as tensile (tangent) modulus and tensile strength. The films may be used for lamination, filter, or for packaging for moisture absorbers. The biaxially oriented films may be obtained by extracting a hydrocarbon plasticizer from a sheet formed from the high molecular weight polyethylene and a hydrocarbon plasticizer, stretching the resulting sheet to obtain an oriented film having a specific surface area of at least 70 m.sup.2 /g and a fibril structure, and heating the oriented film under a standard length constraint to reduce the oriented film in specific area by at least 20 m.sup.2 /g.

Abstract: Disclosed is an extruded propylene polymer resin foam comprising a propylene polymer resin exhibiting a biaxial extensional viscosity of at least 3.0.times.10.sup.6 poise at a biaxial extensional strain of 0.2, and a biaxial strain hardening rate .alpha. of at least 0.25, the biaxial strain hardening rate .alpha. being defined by the following formula:.alpha.=0.77.times.(log .eta..sub.2 -log .eta..sub.1)wherein .eta..sub.1 represents the biaxial extensional viscosity at a biaxial extensional strain of 0.01, and .eta..sub.2 represents the biaxial extensional viscosity at a biaxial extensional strain of 0.2,said foam containing a vast plurality of cells, and having a thickness of at least 20 mm, a density of from 0.005 to 0.03 g/cm.sup.3, an average cell diameter of from 0.4 to 2.0 mm, and a closed cell ratio of at least 80%.

Abstract: A molded structure 1 produced by extrusion, such as an expanded plastic foam, a sheet, a profile or the like, contains at least 10% by volume of open cells 2, 4 which have a polyhedron-like shape and are adjacent to one another. A higher temperature during the extrusion in comparison with the extrusion of thermoplastic molded structures having a closed-cell structure results in deformation-free opening of the cells. Webs 3 of cell walls 5, 6 remain intact in shape whether they have orifices 7 or no passages, so that the mechanical strength of the cell skeleton or of the space matrix is retained.

Abstract: An improved foam nucleation system based on selected boron nitride provides smaller foam cell size for melt-fabricable fluoropolymers.

Abstract: Disclosed herein are surface activated, organic polymers useful for biopolymer synthesis. Most preferably, aminated polypropylene is used for the synthesis of oligonucleotides thereto, and these devices are most preferably utilized for genetic analysis of patient samples.

Abstract: A foamable organic composition comprising a compound foamable to 50% or more comprising an organic polymer and a chemical foaming agent, and, as a physical foaming agent, at least one member selected from the group consisting of rare gases and carbon dioxide; and a method for producing a foamed article having a high expansion ratio by using said composition. According to the present invention, a foamed article having a uniform and fine foam structure and a high expansion ratio of not less than 75% (which is as high as when freon gas is used) can be obtained without causing environmental problems such as depletion of the ozon layer. When applied, in particular, to a foamed layer for an insulated conductor, such as foam-insulated electric wire which is required to have high performance insulation and is occasionally installed under severe conditions, the composition of the present invention advantageously provides an insulated conductor with no potential buckling.

Abstract: Disclosed is a compatibilized carbon black useful in melt processing of plastic material. The carbon black is coated with a compatibilizing agent which enhances the dispersibility of the carbon black in a melt of the plastic material. Further disclosed are processes for making plastic foam structures with the compatibilized carbon black.

Abstract: Disclosed is a low density, dimensionally-stable, extruded propylene polymer foam comprising primarily of an expanded propylene polymer material wherein the foam has a blowing agent comprising at least 15 percent by weight of one or more inorganic blowing agents. The propylene polymer material comprises at least about 15 weight percent of propylene monomeric units. The foam has a density of from about 10 to about 150 kilograms per cubic meter. The foam having an average cell wall thickness of less than about 35 micrometers.

Abstract: A process for the manufacture of a closed cell, rigid, polymer foam from polymer foam-forming ingredients containing a filler which comprises:(a) dispersing the filler in at least a portion of the foam-forming ingredients to form a filled dispersion, a fluorochemical surfactant being incorporated in the foam-forming ingredients either before, during or after the dispersing operation to form a dispersion containing a filler and a fluorochemical surfactant,(b) mixing the dispersion formed in step (a) with any remaining foam-forming ingredient or ingredients, and(c) foaming and curing the resultant foam-forming composition.The fluorochemical surfactant improves the stability, flowability and mixing of the dispersion during the foam production.

Abstract: A process for the preparation of expandable thermoplastic polymers by post-impregnation with a blowing agent in aqueous suspension in the presence of a mixture of magnesium pyrophosphate and a sulfonate group-containing extender as suspension stabilizer, in a reactor comprisesa) preparing the magnesium pyrophosphate in the same reactor at below 50.degree. C. by adding a solid magnesium salt in an amount corresponding to an at least 3% stoichiometric excess, based on pyrophosphate, to an aqueous solution of the pyrophosphate,b) heating the suspension medium to from 70.degree. to 140.degree. C. andc) adding the blowing agent in this temperature range.

Abstract: Catalyst support containing an .alpha.-olefin polymer which is in the form of particles of mean size from 5 to 350 .mu.m in which the pore volume generated by the pores of radius from 1,000 to 75,000 .ANG. is at least 0.2 cm.sup.3 /g.Catalyst usable for the polymerization of .alpha.-olefins, including a compound containing at least one transition metal belonging to groups IIIb, IVb, IVb and VIb of the Periodic Table, bound in or on this support.

Abstract: An uncrosslinked, closed cell, low density ethylenic polymer foam having a density of less than 150 kg/m.sup.3 is prepared from, for example, uncrosslinked low density polyethylene using inorganic blowing agents, such as carbon dioxide, argon, or mixtures thereof. A process for preparing such uncrosslinked, closed cell, low density ethylenic polymer foam comprising extruding a ethylenic polymer of suitable melt tension using a 100 percent inorganic blowing agent, such as carbon dioxide, argon, or mixtures thereof, and the foams produced with this process are also disclosed.

Abstract: The production of approximately spherical polyolefin foam particles having a coarse cell structure and a narrow cell size distribution by dispersion foaming is achieved by a process in which the reactor contents, which essentially comprise polyolefin particles, a liquid dispersion medium and, if desired, a volatile blowing agent, are first treated at a first temperature above the crystallite melting point T.sub.m of the polyolefin, and subsequently passed through a cooling device, in which the dispersion is brought to a second, lower temperature, and the polymer particles are then foamed at this temperature. The foamed particles can be converted into moldings by known methods.

Abstract: Novel porous copolymers are disclosed which can be used to prepare ion-exchange resins and polymeric adsorbents. The copolymers comprise a copolymer of at least one monovinylidene monomer and a crosslinking monomer and have a unique cellular pore structure. The cellular structure comprises a macroporous void phase which is dispersed within a continuous copolymer phase. The porous void phase comprises a plurality of cellular void spaces which are at least partially enclosed by walls of the continuous copolymer phase. Also disclosed are processes which can be used to prepare the porous copolymers, as well as ion-exchange resins and polymeric adsorbents using the porous copolymers.

Abstract: An ultra-low density, microcellular open-celled polymer foam and a method for making such foam. A polymer is dissolved in a heated solution consisting essentially of at least one solvent for the dissolution of the polymer in the heated solution and the phase inversion of the dissolved polymer to a liquid gel upon sufficient cooling of the heated solution. The heated solution is contained in a containment means provided with a nucleating promoting means having a relatively rough surface formed of fixed nucleating sites. The heated solution is cooled for a period of time sufficient to form a liquid gel of the polymer by phase inversion. From the gel, a porous foam having a density of less than about 12.0 mg/cm.sup.3 and open porosity provided by well interconnected strut morphology is formed.

Abstract: The present invention relates to uncrosslinked polyethylene particles for the production of expanded particles that can easily and securely produce expanded particles which can be molded without applying a special internal pressure, are excellent in moldability, such as secondary expansion, fusion and dimensional accuracy, and have a high expansion rate and to uncrosslinked polyethylene expanded particles made of said uncrosslinked polyethylene particles. The present uncrosslinked polyethylene particles for the production of expanded particles are resin particles whose base resin is an uncrosslinked polyethylene having a density of over 0.920 g/cm.sup.3 and up to and including 0.940 g/cm.sup.3 and wherein, in the DSC curve that is obtained by using a differential scanning calorimeter in such a manner that after 1 to 10 mg of the resin particles is heated to 200.degree. C. at 10.degree. C./min and then is cooled to room temperature at 10.degree. C./min, heating is again carried out to 200.degree. C. at 10.

Abstract: Foams are prepared under reduced pressure and are subsequently encased in a material which will prevent ambient air from entering the cell voids. In the most preferred embodiment of the invention a polyurethane or polyisocyanurate foam is formed by mixing the polyol and isocyanate components under reduced pressure, allowing the gas within the foam to reach equilibrium at a lesser pressure then in prior systems. The need for blowing agents is substantially reduced and the K-factor of such foams is highly desirable. The foams are particularly well suited for use in refrigeration applications where the foams can be encased to prevent air from entering the cells after curing of the foam.

Abstract: A process for producing thin microporous polymeric films for a variety of uses. The process utilizes a dense gas (liquified gas or supercritical fluid) selected to combine with a solvent-containing polymeric film so that the solvent is dissolved in the dense gas, the polymer is substantially insoluble in the dense gas, and two phases are formed. A microporous film is obtained by removal of a dense gas-solvent phase.

Abstract: An uncrosslinked, closed cell, low density ethylenic polymer foam having a density of less than 150 kg/m.sup.3 is prepared from, for example, uncrosslinked low density polyethylene using inorganic blowing agents, such as carbon dioxide, argon, or mixtures thereof. A process for preparing such uncrosslinked, closed cell, low density ethylenic polymer foam comprising extruding a ethylenic polymer of suitable melt tension using a 100 percent inorganic blowing agent, such as carbon dioxide, argon, or mixtures thereof, and the foams produced with this process are also disclosed.

Abstract: Disclosed is an extruded, unitary, closed-cell olefin polymer foam structure in plank form. The foam structure has a cross-section of 2 or more inches in one dimension and 18 or more inches in the other dimension. The olefin polymer material has a melt index of about 3.5 grams/10 minutes or less. The foam structure contains a blowing agent of about 75 mole percent or more 1,1-difluoroethane based upon the total moles of blowing agent. Further disclosed is a process for making the foam structure at a shear rate of about 400/second or more. It was found surprising that 1,1-difluoroethane which has relatively low solubility in olefin polymers, could be used to make olefin polymer foam structures of large cross-section.

Abstract: Disclosed is a cross-linked ethylenic polymer foam structure of an ethylenic polymer material of a cross-linked, substantially linear ethylenic polymer. The substantially linear ethylenic polymer having in an uncross-linked state has: a) a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation: M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylenic polymer having about the same I.sub.2 and M.sub.w /M.sub.n. Further disclosed is a process for making the above foam structure.

Abstract: Disclosed is an ethylene polymer foam structure having enhanced processing and physical properties. The foam structure comprises an ethylenic polymer material and a blowing agent of isobutane and 1,1-difluoroethane. Further disclosed is a process for making the foam structure.

Abstract: Disclosed is an ethylene polymer foam structure having enhanced processing and physical properties. The foam structure comprises an ethylenic polymer material and a blowing agent. The blowing agent has a primary blowing agent of isobutane and a secondary blowing agent of 1,1,1-trifluoroethane, 1,1,1,2-tetrafluoroethane, or a blend of them. Further disclosed is a process for making the foam structure.

Abstract: Disclosed is a compatibilized carbon black useful in melt processing of plastic material. The carbon black is coated with a compatibilizing agent which enhances the dispersibility of the carbon black in a melt of the plastic material. Further disclosed are processes for making plastic foam structures with the compatibilized carbon black.

Abstract: Disclosed is a cross-linked ethylenic polymer foam structure of an ethylenic polymer material of a cross-linked, substantially linear ethylenic polymer. The substantially linear ethylenic polymer having in an uncross-linked state has: a) a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation: M.sub.w /M.sub.n <(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylenic polymer having about the same I.sub.2 and M.sub.w /M.sub.n. Further disclosed is a process for making the above foam structure.

Abstract: Disclosed is an ethylenic polymer foam structure comprising an ethylenic polymer material. The ethylenic polymer material contains a substantially linear ethylenic polymer having: a) a melt flow ratio, I.sub.10 /I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation M.sub.w /M.sub.n .gtoreq.(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures. The foam structures have foam quality similar to those made with conventional LDPE but with enhanced toughness and elasticity. Further disclosed is a process for making the above foam structure and making it in a foam bead form.

Abstract: Controlled foams of crystalline amorphous polymers include a second phase polymeric material having a transition temperature below that of the matrix polymeric material. The second phase material provides nucleating sites for the growth of gas formed cells which are limited in size by the particle size of the second phase polymeric material.

Abstract: Disclosed is a process for making a low density, dimensionally-stable, open-cell, extruded propylene polymer foam comprising primarily an expanded propylene polymer material wherein the foam has a blowing agent comprising greater than 85 percent by weight of one or more organic blowing agents based upon the total weight of the blowing agent. The propylene polymer material comprises more than 50 weight percent or more of propylene monomeric units based upon the total weight of the propylene polymer material. The foam has a density about 96 kilograms or less per cubic meter. The foam is greater than 20 percent open cell.

Abstract: An expandable thermoplastic composition is disclosed for extrusion foaming wherein the composition comprises a polyethylene resin; a blowing agent comprising a blend of about 50% by weight of carbon dioxide and about 50% by weight of either normal butane, isobutane, propane, or a mixture of any two or all three hydrocarbons in admixture with the resin in a ratio of about one part blowing agent to about 10 parts resin; zinc oxide nucleation agent in an amount of from about 0.05 to 0.5 kg per 100 kg of the resin; and glycerol monostearate aging modifier in an amount of from about 0.5 to 5 kg per 100 kg of the resin. A process for extrusion foaming of the composition is also disclosed.

Abstract: A method for preparing an .alpha.-olefin polymer in which an .alpha.-olefin is polymerized in the presence of a catalyst, characterized in that the catalyst is a solid obtained by making the following components (ii) and (iii) be supported in the component (i):Component (i): an organic porous polymer having an average particle diameter of 5 to 1,000 .mu.m, in which the total pore volume of all pores whose diameter is 0.006 to 10 .mu.m is 0.3 cc/g or more, and the total pore volume of all pores whose diameter is 0.05 to 2 .mu.m is 50% or more of the total pore volume of all pores whose diameter is 0.006 to 10 .mu.m;Component (ii) a compound having the structure ##STR1## in which R is a hydrocarbon group having 1 to 10 carbon atoms; and Component (iii) a compound of a transition metal which belongs to one of the Groups IVB to VIB in the Periodic Table, having at least one conjugated 5-membered cyclic ligand.

Abstract: Disclosed is an ethylenic polymer foam structure comprising an ethylenic polymer material. The ethylenic polymer material contains a substantially linear ethylenic polymer having: a) a melt flow ratio, I.sub.10 I.sub.2, .gtoreq.5.63; b) a molecular weight distribution, M.sub.w /M.sub.n, defined by the equation M.sub.w /M.sub.n .ltoreq.(I.sub.10 /I.sub.2)-4.63; and c) a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear olefin polymer having about the same I.sub.2 and M.sub.w /M.sub.n. The foam structures have toughness and elasticity similar to those formed from conventional LLDPE without the poor dimensional stability and foam quality associated with those structures. The foam structures have foam quality similar to those made with conventional LDPE but with enhanced toughness and elasticity. Further disclosed is a process for making the above foam structure and making it in a foam bead form.