A method of microcellular foam molding an article includes feeding plastic granules to a hopper; supplying a supercritical fluid (SCF) to the hopper to effuse through the plastic granules; conveying the effused plastic granules to a buffer tank; and conveying the effused plastic granules in the buffer tank to a mold of an injection molding machine to perform foam molding on the effused plastic granules to produce a foamed article. In a second embodiment, the injection molding machine is replaced by an extrusion press.

Poly(3-hydroxyalkanoate) foam particles are obtained by: introducing a blowing agent into an aqueous dispersion in a pressure-resistant vessel, the aqueous dispersion containing a crosslinking agent and resin particles containing a poly(3-hydroxyalkanoate); heating the contents of the pressure-resistant vessel to a given temperature in a range of 130 to 150° C.; holding the contents of the pressure-resistant vessel at the given temperature for 5 to 55 minutes; and opening one end of the pressure-resistant vessel to discharge the contents of the pressure-resistant vessel into a low-pressure atmosphere and foam the resin particles. The poly(3-hydroxyalkanoate) is a mixture containing a poly(3-hydroxyalkanoate) copolymer and a poly(3-hydroxybutyrate) homopolymer at a weight ratio of 99:1 to 80:20, and the crosslinking agent is an organic peroxide which is a percarbonate.

Poly(3-hydroxyalkanoate) foam particles are obtained by: introducing a blowing agent into an aqueous dispersion in a pressure-resistant vessel, the aqueous dispersion containing a crosslinking agent and resin particles containing a poly(3-hydroxyalkanoate); heating the contents of the pressure-resistant vessel to a given temperature in a range of 130 to 150° C.; holding the contents of the pressure-resistant vessel at the given temperature for 5 to 55 minutes; and opening one end of the pressure-resistant vessel to discharge the contents of the pressure-resistant vessel into a low-pressure atmosphere and foam the resin particles. The poly(3-hydroxyalkanoate) is a mixture containing a poly(3-hydroxyalkanoate) copolymer and a poly(3-hydroxybutyrate) homopolymer at a weight ratio of 99:1 to 80:20, and the crosslinking agent is an organic peroxide which is a percarbonate.

A process can be used for producing (rigid) particle foams from polymer compositions containing at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. with an underwater pelletization system.

A process can be used for producing (rigid) particle foams from polymer compositions containing at least one polymer having a glass transition temperature according to ISO 11357-2 of at least 180° C. with an underwater pelletization system.

The present invention relates to bead foams made of thermoplastic polyurethane and polystyrene produced moldings, to processes for the production of the bead foams and moldings, and also to the use of the moldings for shoe intermediate soles, shoe insoles, shoe combisoles, or cushioning elements for shoes.

The present invention relates to bead foams made of thermoplastic polyurethane and polystyrene produced moldings, to processes for the production of the bead foams and moldings, and also to the use of the moldings for shoe intermediate soles, shoe insoles, shoe combisoles, or cushioning elements for shoes.

A thermoplastic resin foam including a thermoplastic resin, wherein: the thermoplastic resin includes a polyester resin and a polyimide resin, and the thermoplastic resin foam shows a single glass transition temperature Tg. The glass transition temperature of the thermoplastic resin is preferably 80 to 130° C. An absolute value of difference between heat absorption and heat generation, each determined by heat flux differential scanning calorimetry at a heating rate of 10° C./min, is preferably 3 to 35 J/g.

The present invention provides a polymer composition for manufacturing a foam, the polymer composition comprising a vinyl aromatic based copolymer and a processing aid, wherein the amount of the processing aid in the total weight of the polymer composition is equal to or more than 5 wt % and equal to or less than 75 wt %; and the polymer composition does not comprise ethylene-vinyl acetate copolymer, ethylene-butyl acrylate copolymer, ethylene-α-olefin copolymer, homopolymer and copolymer of polyethylene, homopolymer and copolymer of polypropylene, homopolymer and copolymer of polybutene and olefin-based ionic polymer. The present invention also provides the foam and the method for forming the same.

A spacer used in an electrical device that sends and receives radio waves comprises a foam that contains a resin composition containing a thermoplastic or thermosetting resin as a base resin. When the foam is not a bead foam, a ratio (B/A) of an average diameter B of central section cells relative to an average diameter A of surface layer cells is not less than 0.3 and less than 3.0. When the foam is a bead foam, a ratio (B′/A′) of an average diameter B′ of center cells relative to an average diameter A′ of outermost layer cells is not less than 0.3 and less than 3.0. Water absorption of the resin composition in a high-temperature and high-humidity environment is 2.2 mass % or less, and (εr).sup.1/2×tan δ (εr: relative permittivity, tan δ: a dielectric dissipation factor) is 0.0120 or less at 28 GHz.