Abstract: A composite foamed polypropylene resin molding including a plurality of sections which are fuse-bonded to each other, at least two of which differ from each other in color, apparent density, composition and/or mechanical strengths, each of which is formed from expanded polypropylene resin beads, and each of which shows a high temperature endothermic peak in a DSC curve thereof. At least one of the sections satisfies conditions (d) to (f) at the same time: (d) to be formed from specific expanded polypropylene resin beads of a base resin having a tensile modulus of at least 1,200 MPa, (e) to have an apparent density D2 of 10-500 g/L, and (f) to have such a high temperature endothermic peak with a calorific of E2 J/g, wherein D2 and E2 have the relationship 20?0.020×D2?E2. ?65?0.100×D2.

Abstract: A method for producing expanded polypropylene resin particles wherein polypropylene resin particles impregnated with a physical blowing agent are heated along with an aqueous medium and a dispersant and are released and expanded at reduced pressure from the interior of a pressure-tight vessel, wherein the aforementioned aqueous medium has an electrical conductivity of from not less than 0.00 ms/m to not more than 20.00 mS/m. The resulting particles obtained are without inconsistencies caused by differences in the amount of dispersant adhering to the particles or the amount of dispersant added to prevent the particles from fusing together during the heat treatment step of the method.

Abstract: A process of producing a foamed molding, wherein expanded, substantially non-crosslinked polypropylene-based resin beads are heated in a mold to fuse-bond the beads together into a unitary body. Each of the expanded beads has been surface-modified with an organic peroxide.

Abstract: A process for the production of expanded beads, including kneading a base resin containing a polypropylene resin and having a tensile modulus of at least 1,200 MPa together with a mixture of a coloring agent and a thermoplastic polymer having a tensile modulus lower than that of the base resin to form a kneaded mixture including a matrix of the base resin and a multiplicity of domains dispersed in the matrix and each containing the thermoplastic polymer and the coloring agent. The kneaded mixture is formed into resin particles, then treated with an organic peroxide to modify surfaces of the resin particles therewith. Foaming and expanding of the surface-modified resin particles gives expanded beads having an inside region surrounded by a surface region. The heat of fusion of a high temperature peak of the surface region is lower than that of the inside region.

Abstract: An expansion-molded article (foamed body) produced by using foamed and expanded beads, and having open voids has sound absorbing qualities, and can be used as a sound absorbing material. A sound absorbing material which is able to attain a high sound absorption coefficient in a wide acoustic frequency range is provided by a molded article produced by using resin particles, having through hole(s) and a porosity of 45 to 80% in a most densely packed state. The void content of the molded article is 10 to 60%, and the bulk density thereof is 0.01 to 0.6 g/cm3.

Abstract: Expanded, substantially non-crosslinked polypropylene resin beads capable of producing a high rigidity foamed molding at a relatively low temperature. The beads are produced by a process including a step of dispersing substantially non-crosslinked polypropylene resin particles in a dispersing medium containing an organic peroxide to obtain a dispersion, a step of heating the dispersion to decompose the organic peroxide and to modify the surface of the surface-modified polypropylene resin particles, and a step of expanding the non-crosslinked, surface-modified polypropylene resin particles using a blowing agent.

Abstract: Expanded, substantially non-crosslinked polypropylene resin beads capable of producing a high rididity foamed molding at a relatively low temperature. The beads are produced by a process including a step of dispersing substantially non-crosslinked polypropylene resin particles in a dispersing medium containing an organic peroxide to obtain a dispersion, a step of heating the dispersion to decompose the organic peroxide and to modify the surface of the surface-modified polypropylene resin particles, and a step of expanding the non-crosslinked, surface-modified polypropylene resin particles using a blowing agent.

Abstract: A method for producing expanded polypropylene resin particles wherein polypropylene resin particles impregnated with a physical blowing agent are heated along with an aqueous medium and a dispersant and are released and expanded at reduced pressure from the interior of a pressure-tight vessel, wherein the aforementioned aqueous medium has an electrical conductivity of from not less than 0.00 ms/m to not more than 20.00 mS/m. The resulting particles obtained are without inconsistencies caused by differences in the amount of dispersant adhering to the particles or the amount of dispersant added to prevent the particles from fusing together during the heat treatment step of the method.

Abstract: An expansion-molded article (foamed body) produced by using foamed and expanded beads, and having open voids has sound absorbing qualities, and can be used as a sound absorbing material. However, a sound absorbing material comprising such an expansion-molded article has been unable to attain a high sound absorption coefficient in a wide acoustic frequency range.

Abstract: An expansion-molded article (foamed body) produced by using foamed and expanded beads, and having open voids has sound absorbing qualities, and can be used as a sound absorbing material. However, a sound absorbing material comprising such an expansion-molded article has been unable to attain a high sound absorption coefficient in a wide acoustic frequency range.

Abstract: A polycarbonate resin foamed molding having a density D of 0.6 g/cm3 or less and at least 30 (kg·cm/cm3)/(g/cm3) of a value E80/D obtained by dividing an amount of energy absorbed through 50% compression of the molding at 80° C. (E80 kg·cm/cm3) by the density of the molding. A shock absorber for a vehicle includes a core of the above molding, and a skin covering a surface of the core.

Abstract: Disclosed herein is an molded article of foamed and expanded beads of a propylene resin, which is obtained by heating and molding the foamed beads of the propylene resin, wherein the apparent density of the molded article is 0.11 to 0.45 g/cm.sup.3, a value obtained by dividing its maximum bending strength (kgf/cm.sup.2) determined in accordance with JIS K 7221 by the apparent density (g/cm.sup.3) is at least 160 (kgf/cm.sup.2)/(g/cm.sup.3), and the average number of cells at its section is within a range of 5 to 100 cells/mm.sup.2.