Abstract: A process for producing a porous body of tourmaline includes the step of sintering a mixture of fine powder of tourmaline and fine powder of polyethylene or fine powder of polypropylene.

Abstract: Catalyst for the polymerization of olefins, process for its preparation, and its use.The present invention relates to a supported catalyst for the polymerization of olefins, which can be prepared by reacting the reaction product formed from an aluminoxane and at least one metallocene with a microporous, polymeric support.

Abstract: New cross-linked polymeric foam compositions, and methods for making the same, are provided. The new compositions utilize novel cross-linked polyolefin copolymers and show improvements in strength, toughness, flexibility, heat resistance and heat-sealing temperature ranges as compared to conventional low density polyethylene compositions. The new compositions also show processing improvements over linear low density polyethylene. The novel polyolefins, which are essentially linear, comprise ethylene polymerized with at least one alpha-unsaturated C3 to C20 olefinic comonomer, and optionally at least one C3 to C20 polyene, and exhibit, in an uncross-linked sense, a resin density in the range of about 0.86 g/cm3 to about 0.96 g/cm3, a melt index in the range of about 0.5 dg/min to about 100 dg/min, a molecular weight distribution in the range of from about 1.5 to about 3.5, and a composition distribution breadth index greater than about 45 percent.

Abstract: Novel molding compositions consisting essentially of a mixture of a skin-forming component and a foam core-foaming component physically dry-blended together. The skin-forming component comprises two distinct phases blended together, a high zero-shear viscosity material and a low zero-shear viscosity material. The foam core-forming component preferably comprises a foamable polymeric material including a suitable blowing agent. In a preferred embodiment, the three materials are selected from suitable homopolymers and copolymers of ethylene.

Abstract: Fine-celled polyolefin foams of high dimensional stability at elevated temperatures and high stiffness, with foam densities ranging from 10 to 600 kg/m.sup.3, consisting of mixtures of polypropylenes and polyolefins, which were reacted with bifunctional, unsaturated monomers and/or hydrolyzable, ethylenically unsaturated organosilane compounds in the presence of thermally decomposing free radical-forming agents in two reactive process steps and subsequently foamed. The fine-celled polyolefin foams are suitable for use in the packaging sector, preferably for packaging foods, for external and internal parts of motor vehicles and for components of electric and electronic equipment.

Abstract: Improved compositions useful for the production of rotomolded articles having a foamed interior and non-foamed exterior skin are provided. The compositions of the invention are comprised of a first thermoplastic resin component which is an ethylene polymer in pellet form containing a chemical foaming agent, an organic peroxide and, optionally, a metal-containing activator compound and a second resin component which is a powder and can be a thermoplastic ethylene polymer or ethylene copolymer having less than 30% crystallinity. An improved one-step process for producing foamed rotomolded articles having foamed interiors and non-foamed exterior skins is also provided.

Abstract: An improved closed cell polymer foam and foaming agent involving the use of a hydrogen-containing halocarbon blowing agent (e.g., HCFC-22) in combination with an effective amount of a hydrogen bond forming blocking agent (e.g., organic ether, ester or ketone). The presence of the blocking agent is shown to significantly reduce the escape of blowing agent from and entry of air into the foam resulting in low thermal conductivity over a longer period of time and improved thermal insulation value. A closed cell thermoplastic foam such as polyethylene, polypropylene, polystyrene, among others, is disclosed produced by means of an environmentally friendly nonflammable blowing agent substantially free of halogen substituents other than fluorine and comprising HFC-134 (1,1,2,2-tetrafluoroethane).

Abstract: Members either of the polyglycol family of substances, more generally, or of the polyglycol ether subset of polyether compounds, more particularly, both for their gas absorption properties and for their plasticizing effect in a polyethylenic extrudate, are combined with physical atmospheric blowing agents, such as, nitrogen, argon, carbon dioxide, water, and blends thereof, to produce uncrosslinked polyethylenic foams having densities as low as 10 kg/m.sup.3.

Abstract: A rubber-modified styrenic resin composition comprising 100 parts by weight of a rubber-modified styrenic resin (A) having 10 to 40% by weight of the content of a soft component particle and a mean particle diameter of the said particle of 0.1 to 1.2 .mu.m, and 1 to 30 parts by weight of fine particles having a mean particle diameter of 0.1 to 5 .mu.m and not having a glass transition temperature between -130 to 90.degree. C.A rubber-modified styrenic resin composition having superior plane impact strength, rigidity and gloss, and its molded article are provided.

Abstract: Highly uniform microporous foam suitable for medical applications and methods for preparing these foams. The highly uniform microporous foams are of controlled pore size that may be utilized in a variety of applications. In preparing the foams, an organic crystalline polymer is melted and combined with a selected solid crystalline fugitive compound to produce a substantially isotropic solution. The solution is cooled under controlled conditions, which foster solid-solid phase separation by the simultaneous crystallization of the fugitive compound and the polymer, to produce a foam precursor containing the solidified fugitive compound dispersed through a matrix of the organic polymer. Crystals of fugitive compound are then removed by solvent extraction and/or sublimation, or like process to produce microcellular foams having a continuous, open-cell structure.

Abstract: In the process and an extrusion device for producing a foamed polymer, a polymer is melted and a foaming agent is added to the polymer melt. After the polymer melt and the foaming agent have been mixed, a throttle generates a pressure drop for nucleation for gas bubbles or cells. The mixture is then shaped, foamed and cooled. In order to produce high-grade foamed polymer with a microcellular or sub-microcellular structure continuously without any shaping limitations, the throttle controlling the flow rate has a passage control so that the flow rate can be adjusted independently of the pressure drop.

Abstract: The object of the present invention is to provide a thermoexpandable microcapsule which can be expanded at a lower temperature without decrease of various properties such as chemical resistance and heat resistance; said thermoexpandable microcapsule contains at least two kinds of volatile expanding agents having different boiling points lower than softening temperature of a polymeric material forming a shell, production thereof; and a method of expanding the microcapsule in which it is subjected to first heating below the starting temperature of expanding and then to the second heating.

Abstract: Open cell foamed articles including silane-grafted single-site inititiated polyolefin resins are described. The single-site initiated olefin polymer resin can be a polyethylene, a copolymer of ethylene, a C3-C20 alpha-olefin, or a copolymer of ethylene, a C3-C20 alpha-olefin and a C4-C20 diene. The open cell foamed articles have good cushioning properties and can be non-allergenic.

Abstract: A method for altering a macroporous cross-linked hydrophobic copolymeric lattice produced by precipitation polymerization in a solvent of at least one monounsaturated ester monomer and at least one polyunsaturated ester monomer soluble therein, in order to render the hydrophobic copolymeric lattice hydrophilic. The method involves saponifying the hydrophobic copolymeric lattice by reacting the surface of the hydrophobic copolymeric lattice with an aqueous alkali. The surface can also be rendered hydrophilic by polymerizing an acrylate monomer onto the lattice in order to form a surface containing carboxylic acid sites. The carboxylic acid sites formed on the surface of the lattice are converted to carboxylate anions.

Abstract: Highly uniform microporous foam suitable for medical applications and methods for preparing these foams. The highly uniform microporous foams are of controlled pore size that may be utilized in a variety of applications. In preparing the foams, an organic crystalline polymer is melted and combined with a selected solid crystalline fugitive compound to produce a substantially isotropic solution. The solution is cooled under controlled conditions, which foster solid--solid phase separation by the simultaneous crystallization of the fugitive compound and the polymer, to produce a foam precursor containing the solidified fugitive compound dispersed through a matrix of the organic polymer. Crystals of fugitive compound are then removed by solvent extraction and/or sublimation, or like process to produce microcellular foams having a continuous, open-cell structure.

Abstract: The invention relates to physically-blown low density polyethylene (LDPE) foams that are blends of an LDPE resin and a silane-grafted single-site initiated polyolefin resin. The LDPE resin generally has a density between about 0.91 and about 0.93 g/cm.sup.3 and a melt index greater than 1, and the silane-grafted single-site initiated polyolefin resin generally is a copolymer of ethylene and a C.sub.3 -C.sub.20 alpha-olefin that has a density between about 0.86 and about 0.96 g/cm.sup.3 and a molecular weight distribution between about 1.5 and about 3.5.

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 disclosed invention is a crystalline microporous polymer and process for preparing a low density microporous polymer comprising, providing a mixture of a polymer and a polymer solvent, the mixture capable of achieving a supercritical condition; applying pressure, at a temperature sufficient for the mixture to attain a super critical condition; cooling the supercritical solution that results and precipitating a microporous crystalline polymer product.

Abstract: The present invention relates to a plastic article formed from several foamed thermoplastic elastomers, such as a thermoplastic polyolefin elastomer based on polypropylene and a vulcanized elastomer at least one of an elastomeric styrene/ethylene/butylene/styrene block copolymer, an elastomeric styrene/butadiene/styrene block copolymer, a thermoplastic elastomer based on polypropylene and an elastomeric styrene/ethylene/butylene/styrene block copolymer and a thermoplastic elastomer based on polypropylene and an elastomeric styrene/butadiene/styrene block copolymer. The present invention further provides plastic articles based on a blend of thermoplastic elastomers and thermoplastic elastomer olefins. The invention further provides a process for making these articles.

Abstract: A propylene homopolymer or copolymer, or a blend thereof, possessing both sufficient strain hardening, viscoelastic behavior, and melt ductility is heated, melted, and mixed in an extruder with an organic or inorganic physical blowing agent, or a mixture of organic and inorganic physical blowing agents, and with optional compatibilizing agents, nucleating agents, stabilizers and miscellaneous additives. This mixture is pressurized and, subsequently, is cooled to an appropriate temperature at an elevated pressure, and is extruded through a die at rates in excess of 1000 kg/hr to produce an expanded and dimensionally-stable, predominately closed cell propylene polymer foam with a density of between 10 kg/m.sup.3 and 150 kg/m.sup.3, and with a thickness in excess of 1.3 cm. The resultant foamed structure is characterized by a Foamability Index of greater than 1.9 and an Ebullition Time of less than 2.0.times.10.sup.-4 seconds.

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 foamed rubber composition for tire comprises a particular amount of particles having specified hardness and average particle size and containing aluminum-bonded hydroxy group and/or silicon-bonded hydroxy group at its surface, and a particular amount of at least one specified silane coupling agent, and develops excellent performances on ice. Further, pneumatic tires contain the foamed rubber composition as a tread rubber.

Abstract: A method of producing a microporous polyolefin membrane having a relatively large pore size and a high permeability, the membrane being suitable for use in water treatment, microfiltration, etc. The method comprises dissolving a polyolefin composition in a solvent to prepare a solution, extruding the solution through a die lip into a form of gel-like sheet, rapidly cooling the gel-like sheet, removing a residual solvent in the cooled sheet by a washing solvent, and drying the resultant sheet to remove the washing solvent. The polyolefin composition is a mixture of (A) an ultra high molecular weight polyolefin having a weight average molecular weight of 5.times.10.sup.5 or more and (B) a polyolefin having a weight average molecular weight less than 5.times.10.sup.5, and a weight ratio of (B)/(A) is 0.2 to 20.

Abstract: Improved compositions useful for the production of foamed rotomolded articles are provided. The compositions of the invention are comprised of a first thermoplastic resin component which is an ethylene polymer in pellet form containing a foaming agent and a second thermoplastic resin component which is a powder consisting of a mixture of different particle size and melt index ethylene polymers. An improved process for producing foamed rotomolded articles having uniformly foamed interiors and smooth exterior skins which are substantially free of surface defects is also provided.

Abstract: A structure of synthetic resin foam has a core layer of thermoplastic resin foam and skin layers of non-foamed thermoplastic resin merged with the core layer, and the skin layers gives rise to increase the mechanical strength of the structure.

Abstract: A foamed rubber composition for pneumatic tires comprises at least one diene polymer as a rubber ingredient and includes closed cells in a matrix rubber, each of these cells being covered with a coat layer made from a given amount of a resin or resin composite having a JIS-C hardness of not less than 75, a particle size of 10-200 .mu.m and a reacted conjugate diene unit content of not less than 10% by weight. In the production of the foamed rubber composition, the melting point or glass transition point of the resin or resin composite is restricted to at least 5.degree. C. lower than the vulcanizing temperature.

Abstract: A process for the production of at least one foamed layer of polyolefins comprising: polymerizing a polyolefin elastomer (POE) or polyolefin plastomer (POP) and optionally one or more additional polyolefins with a metallocene catalyst to form a polymerized polyolefin; mixing said polymerized polyolefin, up to 100 parts by weight of a mineral filling material and from 1-10 parts by weight of a chemical propellant based on 100 parts by weight of said polymerized polyolefins to form a sheet layer mixture; rolling said sheet layer mixture on a multiroller calender to produce a sheet layer; heating at least one sheet layer at a temperature above the decomposition point of the chemical propellant so as to foam the sheet layer and form at least one foamed layer. The present invention is also concerned with new coverings which are produced according to this process.

Abstract: A fluoroelastomer polymer foam having a compression set value in the range of from about 8.3% to about 43% and closed cell microvoids having diameters of from about 0.002 mm to about 0.048 mm or less, and a method for foaming a fluoroelastomer polymer comprising the steps of dispersing in a fluoroelastomer polymer to be foamed a phenol-based blowing agent to produce a foaming formulation and curing the formulation at a temperature of from about 250.degree. F. (121.degree. C.) to about 450.degree. F. (232.degree. C.) and a pressure of from about ambient to about 3.0 atm.

Abstract: A stability control agent composition for foamable polyolefin compositions comprising at least one compound that is a partial ester of fatty acid with polyol, and at least one compound selected from the group consisting of higher alkyl amines, fatty acid amides and/or complete esters of higher fatty acids.

Abstract: The molded articles of foamed particles, which are produced by using foamed particles composed of a polypropylene-based polymer, have had excellent cushioning characteristics and impact resilience, but have been not always satisfactory in stiffness such as compressive strength.The invention is directed to foamed particles comprising a polypropylene homopolymer as a base resin and having a tensile modulus of 15,000-25,000 kg/cm.sup.2 and a crystal structure that an inherent peak and a high-temperature peak appear as endothermic peaks on a DSC curve obtained by differential scanning calorimetry of the foamed particles. A quantity of heat at the high-temperature peak is 30-60 J/g.A molded article of foamed particles according to the invention is obtained by using the foamed particles as described above and molding them, and has a density of 0.01-0.3 g/cm.sup.3 and a tensile modulus of 15,000-25,000 kg/cm.sup.2.

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: A styrene resin composition is disclosed which constitutes 45 to 92% by weight of a styrene resin (A), 5 to 45% by weight of an olefin resin other than an ethylene-unsaturated carboxylic acid ester copolymer(B), and 3 to 25% by weight of an ethylene-unsaturated carboxylic acid ester copolymer (C). The styrene resin composition of the present invention may be used to make a variety of shaped articles which exhibit excellent mechanical properties, such as an impact strength, elongation at break and resistance against chemicals such as Freon and oil.

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 composition for use in sculpturing, a sculpturing piece comprising the composition and a method for obtaining the piece, wherein the composition comprises 90 to 99% of a particulate material consisting of particles having a size from 0.05 to 2 mm, and a plastic binder from 1 to 10% by weight based on the total weight of the composition, each particle of the particulate material being encapsulated by a film layer of the plastic binder.

Abstract: The present invention relates to powdery, water-swellable, cross-linked polymers having a high absorption capacity for aqueous liquids, in particular body fluids, under load, which polymers are formed of:a) 55-99.9%-wt. acid-groups-containing monomers which are neutralized to the extent of at least 50 mole-%,b) 0-40%-wt. of monomers which are copolymerizable with a),c) 0.1-5.0%-wt. of at least one cross-linking agent,d) 0-30%-wt. of a water-soluble polymer.The cations of the salts according to a) are Li.sup.+, Na.sup.+, preferably K.sup.+, Cs.sup.+, Rb.sup.+, as well as primary, secondary, and tertiary methyl ammonium ions, either alone or in combination. The polymers are manufactured in that a blowing agent based on carbon dioxide is added to the monomers, followed by polymerization, that the polymer is dried and then heated to a temperature of 100.degree.-300.degree. C. with one or several compounds which are reactive for surface cross-linkage.

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 method of manufacturing an adhesive foamed product for use in a hollow component of a motorcar, includes the steps of mixing an adhesive resin, a foaming agent, a crosslinking agent, a foaming accelerator and a polymerizable monomer to thereby formulate a highly foamable composition, arranging the foamable composition thus formulated in the interior of a hollow component of a motorcar, and heating the foamable composition until it is foamed to have a shape corresponding substantially to the shape of the hollow component.

Abstract: The present invention describes a method for preparing an asymmetric porous membrane by a dry-wet phase inversion method, which comprises contacting a cast or spun polymer solution with water or organic vapor prior to immersing into the non-solvent precipitation medium, whereby said water or organic vapor is adsorbed onto the cast or spun polymer solution. Higher permeability and excellent rejection ability can be obtained, due to the high porosity and uniform pore size of said membranes according to the present invention.

Abstract: A low density, high temperature resistant insulation material that is very thermally efficient, is easily moldable and is unaffected by water. The insulation material is especially suitable for use in aviation, aerospace and automotive applications. The insulation material contains inorganic fiber; inorganic binder; hydrophilic particulate inorganic material; hydrophobic particulate inorganic material; polymer; and preferably a setting agent and an opacifier.

Abstract: A crosslinked PVP-I.sub.2 foam product, useful as an iodophor, contains about 0.1-2% crosslinker and about 16-18% total inorganic iodine.

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 foaming resin composition consisting essentially of (A) an organic compound having a carbon-carbon double bond, (B) a compound having an SiH group, and (C) a compound having an OH group is foamed and cured at room temperature or under heat at relatively low temperatures, to obtain hard, semi-hard or soft plastic foam having good weather resistance and good compatibility with coating compositions and adhesives.

Abstract: A plastic foam material composed of a blended resin composition which includes at least two thermoplastic resins and a silane-modified based resin. The blended resin composition consists essentially of 100 parts by weight of at least two thermoplastic resins, from about 1 to about 50 parts by weight of a silane-modified, cross-linked, thermoplastic resin; from about 0.001 to about 2.5 parts by weight of a cross-linking catalyst for use in a silane compound and from about 1 to about 20 parts by weight of a foaming agent. According to one embodiment of the present invention, the thermoplastic resins include at least two substantially incompatible and substantially uncross-linked thermoplastic resins, while in another embodiment the two thermoplastic resins need not be substantially incompatible. The blended resin composition may further include reinforcers such as glass fibers and filler. The thermodecomposition foaming agent decomposes at sufficiently high temperatures to yield a plastic foam material.

Abstract: A method of manufacturing a rigid foamed product includes the steps of mixing a metal adhesive resin, a foaming agent, a foaming accelerator, a crosslinking agent, a monomer, and a fibrous material to formulate a foamable composition, arranging the foamable composition thus formulated in a cavity of a formed metal component, and heating the metal component with the foamable composition.

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 foamed plastic manufactured by foaming a mixture of a resin and a volatile polymerizable foaming agent, wherein the pressure in the foams of the foamed plastic is less than atmospheric pressure, is disclosed. Further, a foamed plastic manufactured by hermetically sealing with an airtight film and foaming a mixture of a resin and a volatile polymerizable foaming agent, wherein the pressure in a gap region between the airtight film and the foamed plastic and the pressure in the foams of the foamed plastic are less than atmospheric pressure is disclosed. Further, a method of manufacturing foamed plastic comprising foaming a mixture of a volatile polymerizable foaming agent and a resin, and irradiating the foamed plastic with an energy beam.

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.