Abstract: A pre-expanded polypropylene resin particle can be produced in the following manner: a polypropylene resin particle produced by an under water cut method, water, a dispersing agent, and a foaming agent are charged in a pressure-resistant container, the resulting mixture is heated to a temperature equal to or higher than the softening temperature of the polypropylene resin particle to allow the polypropylene resin particle to be impregnated with the foaming agent under pressure, and the resulting product is released into the atmosphere having a pressure lower than the pressure of the inside of the pressure-resistant container. As the polypropylene resin composition, a composition is used which comprises 100 parts by weight of a polypropylene resin and 1 to 20 parts by weight of a polyethylene resin having a melt viscosity of 10 to 2000 mPa·s at 140° C.

Abstract: A pre-expanded polypropylene resin particle can be produced in the following manner: a polypropylene resin particle produced by an under water cut method, water, a dispersing agent, and a foaming agent are charged in a pressure-resistant container, the resulting mixture is heated to a temperature equal to or higher than the softening temperature of the polypropylene resin particle to allow the polypropylene resin particle to be impregnated with the foaming agent under pressure, and the resulting product is released into the atmosphere having a pressure lower than the pressure of the inside of the pressure-resistant container. As the polypropylene resin composition, a composition is used which comprises 100 parts by weight of a polypropylene resin and 1 to 20 parts by weight of a polyethylene resin having a melt viscosity of 10 to 2000 mPa·s at 140° C.

Abstract: An expandable thermoplastic resin and a foamed article thereof excellent in balance between crack resistance and compression strength, which is suitable for light-weighted plastic parts, a heat insulating parts for architecture, and buffer packing materials which is used under the condition where the materials are repeatedly dropped. And expandable thermoplastic resin particles for obtaining a foamed article having crack resistance and compression strength suitable for an automobile interior and having a low combustion rate. And foamed parts for an automobile having both of high crack resistance and high compression strength. Concretely, they relates to expandable thermoplastic resin particles obtained by containing a blowing agent into a thermoplastic resin obtained by polymerizing monomer mixture, in which a macromonomer is contained in the monomer mixture and the gel content of a foamed article obtained from the expandable thermoplastic resin particle is 1 to 40% by weight.

Abstract: The present invention relates to expandable styrene resin particles used for obtaining molded foams by pre-expansion and molding. To prevent the content stored in a molded foam such as food container from permeating to the container wall and through the container wall to the exterior, and to prevent mold staining, expandable styrene resin particles containing expandable styrene resin particles containing 3 to 5.5 wt % of an highly volatile blowing agent containing 15 to 60 wt % of isopentane and having a styrene monomer content of not more than 1000 ppm, wherein the expandable styrene resin particles are coated with, based on 100 parts by weight of the resin particles, 0.2 to 0.5 parts by weight of zinc stearate containing not more than 0.1 wt % of a fatty acid sodium salt are provided.

Abstract: Foamable modified polystyrene resin particles which are foamable modified polystyrene resin particles (d) comprising modified polystyrene resin particles (c) containing a blowing agent (e); the modified polystyrene resin particles (c) comprising a polystyrene resin and rubber polymer particles (b) being dispersed in the resin, wherein the rubber polymer particles (b) are dispersed uniformly throughout a continuous phase of the polystyrene resin or in a state of a density of the particles (b) being higher in a center portion of the resin particle than in a surface layer portion thereof, and the modified polystyrene resin particles (c) are modified polystyrene resin particles prepared by impregnating a monomer mixture consisting essentially of a styrene monomer and a conjugated diene monomer and comprising the styrene monomer in a larger amount than the conjugated diene monomer, into polystyrene resin particles (a) and carrying out copolymerization.

Abstract: Foamable modified polystyrene resin particles which are foamable modified polystyrene resin particles (d) comprising modified polystyrene resin particles (c) containing a blowing agent (e); the modified polystyrene resin particles (c) comprising a polystyrene resin and rubber polymer particles (b) being dispersed in the resin, wherein the rubber polymer particles (b) are dispersed uniformly throughout a continuous phase of the polystyrene resin or in a state of a density of the particles (b) being higher in a center portion of the resin particle than in a surface layer portion thereof, and the modified polystyrene resin particles (c) are modified polystyrene resin particles prepared by impregnating a monomer mixture consisting essentially of a styrene monomer and a conjugated diene monomer and comprising the styrene monomer in a larger amount than the conjugated diene monomer, into polystyrene resin particles (a) and carrying out copolymerization.

Abstract: Foamable modified polystyrene resin particles (E) comprising a particle of a modified polystyrene resin (C) containing a blowing agent (D), wherein the modified polystyrene resin (C) comprises conjugated diene polymer rubber particles (B) dispersed uniformly throughout a polystyrene resin (A) and when the foamable modified polystyrene resin particle (E) is expanded, there is substantially no deformation of the rubber particles (B) before and after the expansion. A foamed article of a modified polystyrene resin which has a cell membrane of the modified polystyrene resin comprising a polystyrene resin and conjugated diene polymer rubber particles dispersed uniformly throughout the polystyrene resin and has a fusion rate of not less than 50%, wherein the rubber particles maintain substantially spherical form in the cell membrane.