Abstract: A resin particle aggregate is the resin particle aggregate formed by aggregating a plurality of resin particles including a polymer of a vinyl monomer, includes 100 parts by mass of the resin particles and 1 to 5 parts by mass of a surfactant. The resin particles are cross-linked by a cross-linkable monomer in an amount of 10 to 50% by mass relative to the total mass of the resin particles, the resin particle aggregate contains an inorganic component in an amount of 0.5% by mass or less, the resin particles have a volume average particle diameter D1, particles contained in a dispersion liquid of the resin particle aggregate in water have a volume average particle diameter D2, and the ratio of D2/D1 is 15 or less.

Abstract: The present invention provides porous resin particles made of a polymer of a monomer mixture, wherein the monomer mixture contains, as monomers, at least methyl methacrylate and a (meth)acrylic-based cross-linkable monomer, a content of the methyl methacrylate in the monomer mixture is 1 to 50% by weight, a content of the (meth)acrylic-based cross-linkable monomer in the monomer mixture is 50 to 99% by weight, the porous resin particles have a specific surface area of 130 to 180 m2/g, a pore volume of 0.3 to 0.7 ml/g, and an average pore size of 13 to 16 nm, an amount of unreacted methyl methacrylate remaining in the porous resin particles is 20 ppm or less, and the porous resin particles have a thermal decomposition starting temperature of 260° C. or more.

Abstract: A resin particle aggregate is the resin particle aggregate formed by aggregating a plurality of resin particles including a polymer of a vinyl monomer, includes 100 parts by mass of the resin particles and 1 to 5 parts by mass of a surfactant. The resin particles are cross-linked by a cross-linkable monomer in an amount of 10 to 50% by mass relative to the total mass of the resin particles, the resin particle aggregate contains an inorganic component in an amount of 0.5% by mass or less, the resin particles have a volume average particle diameter D1, particles contained in a dispersion liquid of the resin particle aggregate in water have a volume average particle diameter D2, and the ratio of D2/D1 is 15 or less.

Abstract: The present invention provides porous resin particles made of a polymer of a monomer mixture, wherein the monomer mixture contains, as monomers, at least methyl methacrylate and a (meth)acrylic-based cross-linkable monomer, a content of the methyl methacrylate in the monomer mixture is 1 to 50% by weight, a content of the (meth)acrylic-based cross-linkable monomer in the monomer mixture is 50 to 99% by weight, the porous resin particles have a specific surface area of 130 to 180 m2/g, a pore volume of 0.3 to 0.7 ml/g, and an average pore size of 13 to 16 nm, an amount of unreacted methyl methacrylate remaining in the porous resin particles is 20 ppm or less, and the porous resin particles have a thermal decomposition starting temperature of 260° C. or more.