Abstract: A vibration damping, resinous, open cell cellular body is disclosed. The body has a base material thereof which consists essentially of a mixture of a tri-block copolymer as a combination of polystyrene and vinyl-polyisoprene and an ethylene series resin. In a method of manufacture, the mixture is blended and kneaded with a foaming agent and a crosslinking agent to form a foamable and crosslinkable composition. The composition is heated in a non-airtight mold to foam, thereby forming a cellular body with cells therein. The cellular body is then mechanically deformed to cause cells therein to be interconnected, thereby producing the open cell cellular body.

Abstract: A crosslinked ethylene-olefin copolymer foam and a method for the production thereof are disclosed. The foam having a gel content of 70 to 99%, an apparent density of 0.2 to 0.02 g/cm3, 25% compression set at 40° C. of 0.1 to 20.0%, 25% compression hardness of 0.1 to 1.0 kgf/cm2, and Asker C type surface hardness of 3 to 40 is foamed from a copolymer of ethylene and &agr;-olefin having 3 to 18 carbon atoms, the copolymer having a melt flow rate (MFR) of 0.1 to 100 g/10 minutes, a critical shear rate (CSR) satisfying the equation: log[CSR]≦2.48+0.500×log[MFR], a density of 0.860 to 0.935 g/cm3, a Q value determined by the size exclusion chromatography (SEC) of 1.5 to 4, and an extrapolated end temperature of melting (Tem) of 65° C. to 130° C.

Abstract: An open-cell foam of a cross-linked polyolefin possessing uniform physical properties, a high degree of expansion, and a high open-cell ratio can be produced with high operational efficiency and high material utilization by a method which includes thermally shaping under pressure a foamable and cross-linkable polyolefin composition capable of being heated with a microwave, then heating the composition by irradiation with a microwave thereby inducing partial decomposition of a cross-linking agent and a foaming agent contained in the composition, subsequently externally heating under normal pressure the resultant intermediate partially foamed product thereby effecting decomposition of the remainders of the cross-linking agent and foaming agent, and thereafter subjecting the resultant foam to mechanical deformation thereby establishing intercommunication among the cells.

Abstract: An open-cell cross-linked polyolefin foam possessing extremely high non-flammability is produced by dispersing a thermally expansible graphite in an adhesive agent and applying the resultant adhesive agent mixture to at least part of the surface of a flame-retardant open-cell cross-linked polyolefin foam. As the flame-retardant open-cell cross-linked polyolefin foam, an open-cell cross-linked polyolefin foam which possesses a polymer of a phosphorus type flame-retarding agent in the interior and the surface of the open-cell foam or an open-cell cross-linked polyolefin foam which contains a halogen type flame-retarding agent in the cell membranes thereof and possesses a polymer of a phosphorus type flame-retarding agent in the interior and the surface of the open-cell foam is preferably used.

Abstract: An electroconductive cross-linked polyolefin foam having electric resistance of not more than 100 M.OMEGA. and comprising uniform minute cells and proving useful for the production of IC cases, etc. is provided by a method which comprises kneading 100 parts by weight of a polyolefin, 10 to 30 parts by weight of carbon particles, and suitable amounts of a foaming agent and a cross-linking agent and heating the resultant cross-linkable and foamable composition under atmospheric pressure thereby allowing the composition to be cross-linked and foamed without being abruptly foamed or expanded or by a method which comprises heating the aforementioned cross-linkable and foamable composition in a metal mold under pressure to a temperature at which the foaming agent is not substantially decomposed thereby cross-linking the composition and then heating the resultant cross-linked foamable composition under atmospheric pressure thereby allowing the composition to be foamed without being abruptly foamed or expanded.

Abstract: An open-cell foamed article of a cross-linked polyolefin having a high open-cell ratio and a high degree of expansion is produced by a method which comprises the steps of preparing a foamable and cross-linkable polyolefin composition, forming the composition into a desired shape maintaining its gel percent at zero, decomposing the cross-linking agent and blowing agent concurrently by heating the composition under atmospheric pressure in such conditions that the peak of the ratio of the degree of cross-linking to the degree of decomposition of the blowing agent is not more than 20 and exerting a mechanical deformation to the resulting polyolefin foam to rupture the cell membranes.