Mitsubishi Chemical Basf Company Limited

Mitsubishi Yuka Badische Company, Ltd.

Yuka Badische Co., Ltd.

Takanori Suzuki

Hiroshi Endo

Masayuki Tanaka

Kenji Haraguchi

Toshio Yagi

Yonezo Ueda

Masahiro Tanaka

Hiroki Shinozaki

Hiroshi Matsui

Yoshinari Itoh

Hiromi Yamanaka

Mitsuo Furuichi

Expandable ABS resin beads containing a volatile blowing agent are disclosed which have an internal-water content of 5% by weight or lower and, when expanded in an expansion ratio of 30, give expanded beads each having a non-expanded surface layer having a thickness of not more than 50 .mu.m. A process for producing the expandable ABS resin beads is also disclosed which comprises dispersing ABS resin beads into an aqueous medium in a closed vessel and impregnating a volatile blowing agent into the ABS resin beads, said aqueous medium containing an electrolyte at least during the impregnation of the volatile blowing agent, with the concentration of the electrolyte in the aqueous medium being from 0.01 to 2 mol/l. The expandable resin beads are capable of giving an expanded molded article excellent in chemical resistance and toughness and especially in surface appearance and heat resistance.

Expandable ABS resin beads and process for producing the same

An expandable styrene resin bead containing voids therein, wherein the number of the voids present in the area from the surface of the bead to a depth of 0.1 mm along the radial direction is not more than 100 per mm.sup.2 as counted on a cross section passing through approximately the center of the bead. A process for producing expandable styrene resin beads by suspension polymerization is also disclosed in which a styrene monomer is suspended in an aqueous medium in the presence of an initiator and a suspending agent, and a blowing agent is incorporated into polymer beads produced, wherein an alkali metal salt or ammonium salt of persulfuric acid is added to the reaction system in an amount of 0.5 to 30 ppm based on the aqueous medium while the degree of conversion of said monomer is in the range of from 0 to 30%, and an electrolyte is added to the reaction system in a concentration of 0.02 to 5.0 mol/l based on the aqueous medium when the degree of conversion is 30% or higher. The expandable styrene resin bead does not require aging and, when pre-expanded, show little variation in the state of the cells, i.e., expandable styrene resin beads which hardly undergo influences of storage conditions.

Expandable styrene resin beads and process for producing the same

Expandable rubber-modified styrene resin beads, expanded rubber-modified styrene resin beads, and expanded molded rubber-modified styrene resin articles are described. The expandable beads comprise a rubber-modified styrene resin comprising a styrene resin having dispersed therein 8 to 15% by weight of conjugated diene rubber particles having a 1,4-cis structure in a proportion of not less than 70% and an average particle size of 1.5 to 3.0 .mu.m, the rubber-modified styrene resin having a mineral oil content of not more than 3.0% by weight, and the expandable rubber-modified styrene resin beads containing 1 to 15% by weight of a volatile blowing agent. The expanded molded article has excellent appearance, impact resistance and softness.

Expandable rubber-modified styrene resin beads, expanded beads thereof,

A process for producing propylene random copolymer resin foamed particles is disclosed. The process comprises dispersing propylene-ethylene random copolymer resin particles having an ethylene content of from 1 to 12% by weight in water in a closed vessel, feeding an inorganic gas into the closed vessel to raise the pressure within the closed vessel to at least 5 Kg/cm.sup.2 G, heating the dispersion to a temperature above the melting point of said copolymer resin particles but not higher than that by 25.degree. C. or more, opening a discharge port provided in the closed vessel below the water surface, and releasing the copolymer resin particles together with water as a dispersing medium into an atmosphere having a lower pressure than in the closed vessel. A foamed product produced by molding the foamed particles has firm bondage among the particles and excellent mechanical strength.

Process for producing foamed particles of propylene copolymer resin

A process for producing foamed particles of a polyolefin resin which comprises dispersing polyolefin resin particles in water in a closed vessel, feeding a volatile blowing agent into the closed vessel, heating the dispersion to a temperature above the softening point of the polyolefin resin particles but below their melting point, opening a discharge port provided within the closed vessel below the water surface and releasing the aqueous dispersion containing the polyolefin resin particles impregnated with the blowing agent into an atmosphere kept at a lower pressure than the pressure within the closed vessel; wherein

Process for producing foamed particles of polyolefin resin

Growing community of inventors

Mie, Japan

Takanori Suzuki