Abstract: A bulk-density measuring device includes a first vessel in which contracted pre-expanded particles are swollen and recovered from contraction in a pressure-reduced state where a vessel internal pressure is lower than atmospheric pressure; a second vessel filled with the pre-expanded particles after being swollen in the first vessel in the pressure-reduced state where a vessel internal pressure is lower than the atmospheric pressure, and into which the pre-expanded particles of a constant volume are collected fractionally; a pressure-reducing unit that adjusts the vessel internal pressures of the first vessel and the second vessel to be lower than the atmospheric pressure; and a scale that measures a weight of the pre-expanded particles filled in the second vessel.

Abstract: A bulk-density measuring device includes a first vessel in which contracted pre-expanded particles are swollen and recovered from contraction in a pressure-reduced state where a vessel internal pressure is lower than atmospheric pressure; a second vessel filled with the pre-expanded particles after being swollen in the first vessel in the pressure-reduced state where a vessel internal pressure is lower than the atmospheric pressure, and into which the pre-expanded particles of a constant volume are collected fractionally; a pressure-reducing unit that adjusts the vessel internal pressures of the first vessel and the second vessel to be lower than the atmospheric pressure; and a scale that measures a weight of the pre-expanded particles filled in the second vessel.

Abstract: An object of the present invention is to provide a modifier for styrene resins that has excellent powder characteristics and that can provide a styrene resin composition for a styrene resin having high impact resistance and formability when the modifier is contained in a small amount. A modifier (C) for styrene resins that has improved powder characteristics can be obtained by mixing, in advance or in advance in latex form, 1 to 400 parts by weight of a styrene copolymer (B) with 100 parts by weight of a polyorganosiloxane-containing graft copolymer (A) having a polyorganosiloxane backbone produced by polymerizing an organosiloxane and a grafting agent, and then granulating the resulting mixture. Thus, the above-described object can be achieved.

Abstract: Pre-expanded particles of polyolefin resin having less fluctuation in expansion ratio, uniform particle size and low expansion ratio are provided without using any volatile foaming agent. The low expansion ratio means 2 to 10 times, preferably 3 to 8 times. Resin particles to be released are uniformly contacted with saturated vapor at the time of pre-expanding polyolefin resin particles by dispersing the resin particles into an aqueous dispersion medium in a closed vessel, heating the resin particles to temperature of at least the softening point of the polyolefin resin and releasing the particles from the closed vessel into an atmosphere of lower pressure than the inner pressure of the closed vessel.

Abstract: Pre-expanded particles of polyolefin resin having less fluctuation in expansion ratio, uniform particle size and low expansion ratio are provided without using any volatile foaming agent. The low expansion ratio means 2 to 10 times, preferably 3 to 8 times. Resin particles to be released are uniformly contacted with saturated vapor at the time of pre-expanding polyolefin resin particles by dispersing the resin particles into an aqueous dispersion medium in a closed vessel, heating the resin particles to temperature of at least the softening point of the polyolefin resin and releasing the particles from the closed vessel into an atmosphere of lower pressure than the inner pressure of the closed vessel.

Abstract: A rubber latex with its particles grown through cohesion by adding 100 weight parts of (B) a rubber latex (solid), 0.1-15 weight parts (solid) of (A) an acid group-containing latex having an average particle size of 50-500 nm prepared by polymerizing a monomer mixture comprising (a), (b), (c) and (d) [wherein (a)+(b)+(c)+(d)=100 weight %]: (a) 5-25 weight % of at least one of unsaturated acids selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid and crotonic acid, (b) 20-95 weight % of at least one of alkyl methacrylates with its alkyl group 1-12 in carbon number, (c) 0-30 weight % of at least one of alkyl acrylates with its alkyl group 1-12 in carbon number, (d) 0-40 weight % of at least one selected from the group consisting of aromatic vinyls, compounds having at least two polymerizable functional groups in a molecule and vinyl cyanides, copolymerizable with the aforementioned (a), (b) and (c) is provided.

Abstract: Post-treatment method of polyolefin resin pre-expanded particles comprising: introducing the polyolefin resin pre-expanded particles foamed by using an inflammable blowing agent into an extraction vessel filled with steam previously; feeding an additional steam into the extraction vessel; extracting the inflammable blowing agent gas from the polyolefin resin pre-expanded particles; discharging the resulting steam which contains the extracted inflammable blowing agent gas from the extraction vessel continuously or intermittently; and liquefying the steam to separate and recover the inflammable blowing agent gas. According to the post-treatment method of polyolefin resin pre-expanded particles, the inflammable blowing agent can be extracted from the pre-expanded particles in a short period of time and the extracted inflammable blowing agent can be re-used.