Abstract: A method for producing cross-linked polyethylene resin expanded beads, including dispersing polyethylene resin particles containing a halogen-containing flame retardant in a dispersing medium in an autoclave, impregnating the dispersed resin particles with an organic peroxide and cross-linking the polyethylene resin therewith at a specific temperature range determined by the melting point of the polyethylene resin and by melting point or glass transition temperature of the flame retardant, impregnating the dispersed resin particles with a blowing agent, and then foaming and expanding the resulting cross-linked polyethylene-based resin particles.

Abstract: A process produces a polyolefin-based resin expanded beads molded article that is excellent in bending deflection characteristics, high in porosity, low in bulk density and light in weight, and has interconnected void spaces. The process comprises filling, in a mold cavity, multi-layered polyolefin-based resin expanded beads each of which has a cylindrical, polyolefin-based resin expanded core layer and a polyolefin-based resin outer layer covering the expanded core layer and which satisfy specific requirements, introducing steam in the mold cavity to heat the multi-layered expanded beads filled in the mold cavity to fuse bond and mold the multi-layered expanded beads in the mold cavity.

Abstract: A polypropylene resin foamed bead from which a foamed bead molded article excelling in appearance, heat resistance and mechanical properties can be obtained at the molding temperature lower than that for conventional polypropylene resin foamed beads; and a foamed bead molded article obtained by molding the same. The polypropylene resin foamed bead is characterized by having such a crystal structure that in the first DSC curve obtained when the temperature of the foamed bead sample is raised from ordinary temperature to 200° C. at a temperature rising rate of 2° C./min by a differential scanning calorimetry, there appear a main endothermic peak of 100° to 140° C. endothermic peak apex temperature exhibiting 70 to 95% endothermic peak calorific value based on the total endothermic peak calorific value and two or more endothermic peaks exhibited on the high temperature side with respect to the main endothermic peak.

Abstract: A process produces a polylolefin-based resin expanded beads molded article that is excellent in bending deflection characteristics, high in porosity, low in bulk density and light in weight, and has interconnected void spaces. The process comprises filling, in a mold cavity, multi-layered polylolefin-based resin expanded beads each of which has a cylindrical, polylolefin-based resin expanded core layer and a polylolefin-based resin outer layer covering the expanded core layer and which satisfy specific requirements, introducing steam in the mold cavity to heat the multi-layered expanded beads filled in the mold cavity to fuse bond and mold the multi-layered expanded beads in the mold cavity.

Abstract: Foamed polyolefin resin beads having antistatic properties obtained by a process, which includes dispersing polyolefin resin beads into an aqueous medium, injecting a blowing agent, stirring and allowing the polyolefin resin beads to foam and expand. The polyolefin resin beads are composite resin beads comprising a core layer of a core layer polyolefin resin and a covering layer of a covering layer polyolefin resin.

Abstract: Foamed polyolefin resin beads having antistatic properties obtained by a process, which includes dispersing polyolefin resin beads into an aqueous medium, injecting a blowing agent, stirring and allowing the polyolefin resin beads to foam and expand. The polyolefin resin beads are composite resin beads comprising a core layer of a core layer polyolefin resin and a covering layer of a covering layer polyolefin resin.

Abstract: A polypropylene resin foamed bead from which a foamed bead molded article excelling in appearance, heat resistance and mechanical properties can be obtained at the molding temperature lower than that for conventional polypropylene resin foamed beads; and a foamed bead molded article obtained by molding the same. The polypropylene resin foamed bead is characterized by having such a crystal structure that in the first DSC curve obtained when the temperature of the foamed bead sample is raised from ordinary temperature to 200° C. at a temperature rising rate of 2° C/min by a differential scanning calorimetry, there appear a main endothermic peak of 100° to 140° C. endothermic peak apex temperature exhibiting 70 to 95% endothermic peak calorific value based on the total endothermic peak calorific value and two or more endothermic peaks exhibited on the high temperature side with respect to the main endothermic peak.

Abstract: The present invention relates to foamed polyolefin resin beads. Further, the present invention provides foamed resin beads obtained by foaming and expanding composite resin beads which include a core layer constituted by a polyolefin resin and a covering layer which covers the core layer constituted by a polyolefin resin, wherein (a) the polyolefin resin constituting the core layer is a crystalline polyolefin resin, (b) the polyolefin resin constituting the covering layer is a crystalline polyolefin resin which has a lower melting point (B) than a melting point (A) of the polyolefin resin constituting the core layer, wherein a temperature difference [(A)?(B)] between the melting point (B) and the melting point (A) is more than 0° C. and 80° C.

Abstract: Expanded polypropylene resin beads having a melting point of not less than 120° C. but less than 140° C., the melting point being determined from a DSC curve obtained by heat flux differential scanning calorimetry in accordance with JIS K7121-1987 in which a sample of 1 to 3 mg of the expanded polypropylene resin beads is heated to 200° C. at a heating rate of 10° C./minute, then cooled to 30° C. at a rate of 10° C./minute, and again heated from 30° C. to 200° C. at a heating rate of 10° C./minute to obtain the DSC curve. The expanded polypropylene resin beads has an apparent density ?1 before heating and an apparent density ?2 after being heated for 10 seconds with steam at a temperature higher by 5° C. than the melting point thereof, wherein a ratio of ?1 to ?2 is not greater than 1.5.