An expanded particle producing apparatus includes a vessel and a blade stirrer that is located inside the vessel. The blade stirrer comprises a stirrer base and an impeller blade that is attached to the stirrer base. A distance from the bottom of the vessel to the center of the stirrer base (L1) and a depth of the vessel (L2) have a ratio (L1/L2) of 0.01 to 0.2. L1 is measured in a depth direction parallel to L2, and a central axis of the blade stirrer coincides with a central axis of the vessel. The apparatus is configured to produce expanded particles.

An expanded particle producing apparatus includes a vessel and a blade stirrer that is located inside the vessel. The blade stirrer comprises a stirrer base and an impeller blade that is attached to the stirrer base. A distance from the bottom of the vessel to the center of the stirrer base (L1) and a depth of the vessel (L2) have a ratio (L1/L2) of 0.01 to 0.2. L1 is measured in a depth direction parallel to L2, and a central axis of the blade stirrer coincides with a central axis of the vessel. The apparatus is configured to produce expanded particles.

A method of forming a particle includes, in a disperse phase within an aqueous suspension, polymerizing a plurality of mer units of a hydrophilic monomer having a hydrophobic protection group, thereby forming a polymeric particle including a plurality of the hydrophobic protection groups. The method further includes converting the polymeric particle to a hydrophilic particle.

A method of forming a particle includes, in a disperse phase within an aqueous suspension, polymerizing a plurality of mer units of a hydrophilic monomer having a hydrophobic protection group, thereby forming a polymeric particle including a plurality of the hydrophobic protection groups. The method further includes converting the polymeric particle to a hydrophilic particle.

A composite material according to the present invention includes a solid portion including inorganic particles and a resin. The composite material has a porous structure including a plurality of voids surrounded by the solid portion. The composite material satisfies (i) and/or (ii). (i) P.sub.2 is 500 or more. (ii) The composite material has a heat conductivity of 0.5 W/(m.Math.K) or more and a thickness of 0.5 mm to 2.5 mm, the void have an average diameter of 50 μm to 1500 μm, and P.sub.3 is 70% to 90%. P.sub.2=the heat conductivity [W/(m.Math.K)] of the composite material×P.sub.3×100/an amount [volume %] of the inorganic particles P.sub.3 [%]=(F.sub.0−F.sub.1)×100/F.sub.0

The present invention provides a thermally expandable microcapsule that has excellent heat resistance and compression resistance and that enables the production of a foam molded article that is less likely to undergo deterioration or appearance defects over a long period of time, as well as a foamable masterbatch and a foam molded article each produced using the thermally expandable microcapsule. Provided is a thermally expandable microcapsule including a shell and a volatile expansion agent as a core agent encapsulated by the shell, the shell containing a black material and a polymer compound.

The present invention provides a thermally expandable microcapsule that has excellent heat resistance and compression resistance and that enables the production of a foam molded article that is less likely to undergo deterioration or appearance defects over a long period of time, as well as a foamable masterbatch and a foam molded article each produced using the thermally expandable microcapsule. Provided is a thermally expandable microcapsule including a shell and a volatile expansion agent as a core agent encapsulated by the shell, the shell containing a black material and a polymer compound.

Heat-expandable microspheres which have a blowing agent encapsulated efficiently therein so as to prevent the blowing agent from escaping out of the microspheres during storage at high temperature, a process for producing the same, and applications thereof. The process for producing heat-expandable microspheres containing a thermoplastic resin shell and a thermally vaporizable blowing agent encapsulated therein includes preparing an aqueous suspension in which oil droplets of an oily mixture containing the blowing agent and a polymerizable component are dispersed in an aqueous dispersion medium and fine particles of an inorganic compound and a monomer (A) and/or a monomer (B) described below are contained in the aqueous dispersion medium; and polymerizing the polymerizable component, wherein Monomer (A): Polymerizable unsaturated monomer having a total sulfuric acid value ranging from more than 0% to 35%; and Monomer (B): Polymerizable unsaturated monomer with a total phosphoric acid ranging from more than 0% to 50%.

Heat-expandable microspheres which have a blowing agent encapsulated efficiently therein so as to prevent the blowing agent from escaping out of the microspheres during storage at high temperature, a process for producing the same, and applications thereof. The process for producing heat-expandable microspheres containing a thermoplastic resin shell and a thermally vaporizable blowing agent encapsulated therein includes preparing an aqueous suspension in which oil droplets of an oily mixture containing the blowing agent and a polymerizable component are dispersed in an aqueous dispersion medium and fine particles of an inorganic compound and a monomer (A) and/or a monomer (B) described below are contained in the aqueous dispersion medium; and polymerizing the polymerizable component, wherein Monomer (A): Polymerizable unsaturated monomer having a total sulfuric acid value ranging from more than 0% to 35%; and Monomer (B): Polymerizable unsaturated monomer with a total phosphoric acid ranging from more than 0% to 50%.

The present disclosure relates to thermoplastic polymeric microspheres comprising a thermoplastic polymer shell surrounding a hollow core, in which the thermoplastic polymer shell comprises a homopolymer or copolymer of a monomer of Formula 1

##STR00001## wherein: each of A1 to A11 are independently selected from H and C1 to C4 alkyl, in which each C1-4 alkyl group can optionally be substituted with one or more substituents selected from halogen, hydroxy and C1-4 alkoxy; X is a linking group selected from —O—, —NR″—, —S—, —OC(O)—, —NR″C(O)—, —SC(O)—, —C(O)O—, —C(O)NR″—, and —C(O)S—; and R″ is H or C1-2 alkyl optionally substituted with one or more substituents selected from halogen and hydroxy.