Jsp Corporation

Other

Kenji Haraguchi

Hajime Ohta

Jumpei Goto

Taketoshi Kajihara

The present invention relates to a styrene-based resin having a weight average molecular weight Mw' as determined by the GPC-MALS method of 1,000,000 or more and 5,000,000 or less, a degree of long-chain branching of 0.2 or more per 1,000 styrene units, and a tetrahydrofuran-insoluble matter of 0.1% by weight or less (including 0), the styrene-based resin being free from a component derived from a polyfunctional monomer in a molecular chain thereof. In a method for producing this styrene-based resin, in an impregnation step of adding a polymerization initiator and a styrene monomer in an aqueous medium, thereby impregnating the polymerization initiator and the styrene monomer in the seed particle at a temperature at which polymerization of the styrene monomer does not substantially proceed, the amount of the styrene monomer is 20 to 200 parts by weight based on 100 parts by weight of the seed particle; and in an additional impregnation polymerization step of graft polymerizing the styrene monomer on the styrene-based resin, the addition amount of the styrene monomer is 50 to 700 parts by weight based on 100 parts by weight of the seed particle, and the content of the styrene monomer in the seed particle is held at 10% by weight or less.

Styrene resin and method for producing styrene resin

Expandable polylactic acid resin particles including (a) a base resin containing a polylactic acid resin having at least 50 mol % of lactic acid monomer component units, (b) a polyolefin wax in an amount of 0.0001 to 1 part by weight per 100 parts by weight of the base resin, and (c) a blowing agent in an amount of 1 to 30% by weight based on the weight of the resin particles. The expandable resin particles can give expanded beads having an average cell diameter of 10 to 500 &#x3bc;m. The expanded beads can give in-mold foam moldings.

Expandable polylactic acid resin particles, expanded polylactic acid resin beads and molded article obtained from expanded polylactic acid resin beads

The present invention is to solve conventional problems, namely, that when an attempt is made to obtain a thick, in-mold foamed molded article with excellent fusibility between beads formed from an acrylic resin expanded beads, cooling takes an extremely long time and production efficiency is poor, and to provide acrylic resin expanded beads with which an in-mold foamed molded article with excellent fusibility between expanded beads can be manufactured in a short cooling time even with a thick foamed molded article such as a block foamed molded article, and the molding cycle can be improved. The acrylic resin expanded beads of the present invention are expanded beads in which an acrylic resin serves as a base resin, and the bead surfaces have continuous ridges in a mesh pattern.

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Yokkaichi, Japan

Kenji Haraguchi