JP2007314774A5 - - Google Patents

Description

That is, the present invention
(1) Expanded acrylic resin particles having an acrylic resin as a base resin, the surface of the particles having continuous ridges in a mesh pattern,
(2) The acrylic resin expanded particles according to (1), wherein the average size of the mesh surrounded by the ridges is 4 to 40 μm / piece,
(3) The acrylic resin expanded particles according to (1) or (2), wherein the base resin is a copolymer of a methacrylic acid ester and an aromatic vinyl compound,
(4) Expandable acrylic resin particles containing a foaming agent for producing the acrylic resin foam particles according to any one of (1) to (3) above, in the cross section of the resin particles, At least some of the bubbles exist between the surface and a position 5 μm inside from the surface, and each bubble is a closed cell having a maximum dimension between 1 to 10 μm between the inner walls forming the bubble, or an open cell having an opening on the surface. Expandable acrylic resin particles , characterized in that
(5) Expandable acrylic resin particles containing a foaming agent for producing the acrylic resin foam particles according to any one of (1) to (3 ) above, in the raw material monomer before polymerization, The foamable acrylic as described in (4) above, wherein liquid paraffin and / or higher fatty acid ester and / or olefin is added in an amount of 0.1 to 3 parts by weight with respect to 100 parts by weight of the total monomers. Resin particles,
( 6 ) Expandable acrylic resin particles according to the above (4) or (5), which contains an organic physical foaming agent having a boiling point of 80 ° C. or less as a foaming agent,
( 7 ) The foamable acrylic resin particles according to the above ( 6 ), wherein the foaming agent is pentane,
( 8 ) The acrylic resin foamed particles according to any one of (1) to (3) above are filled in a mold, the foamed particles in the mold are heated, fused to each other, and taken out from the mold after cooling. A method for producing an acrylic resin expanded particle molded article,
( 9 ) The method for producing an acrylic resin expanded particle molded body according to ( 8 ) above, wherein the minimum dimension of the in-mold space at the time of in-mold molding is at least 15 cm,
Is the gist.

The addition amount of the network former is preferably 0.1 to 3 parts by weight, particularly preferably 0.3 to 2% by weight, per 100 parts by weight of the base resin of the expanded particles. Within this range, continuous protrusions in a mesh pattern can be easily formed on the surface of the obtained expanded particles. When the addition ratio of the network former to the base resin is too small, there is a possibility that the mesh-shaped ridges may not be formed, and the foaming efficiency is also lowered. Moreover, when the addition ratio of the network former to the base resin is too large, the strength and heat resistance of the obtained foamed molded product may be lowered, and the production cost may be increased. Liquid paraffin and / or a higher fatty acid esters and / or olefins prior to polymerization of A acrylic resin, it is preferable to add in advance the raw material monomer in. The addition amount of network-forming agent to the base resin, if added in obtaining a suspension of A acrylic-based resin is the addition amount relative to the total monomer amount 100 parts by weight per used in the polymerization.

Claims (9)

A foamed acrylic resin particle having an acrylic resin as a base resin and having continuous protrusions in a mesh pattern on the particle surface. The acrylic resin expanded particles according to claim 1, wherein the average size of the mesh surrounded by the ridges is 4 to 40 µm / piece. The acrylic resin expanded particles according to claim 1 or 2, wherein the base resin is a copolymer of a methacrylic acid ester monomer and an aromatic vinyl compound. It is an expandable acrylic resin particle containing the foaming agent for manufacturing the acrylic resin foam particle in any one of Claims 1-3, Comprising: In the cross section of a resin particle, the position inside 5 micrometers from the surface And at least a part of the bubbles, and each bubble is a closed cell whose maximum dimension between the inner walls forming the bubble is 1 to 10 μm, or an open cell having an opening on the surface. Expandable acrylic resin particles. It is an expandable acrylic resin particle containing the foaming agent for manufacturing the acrylic resin expanded particle in any one of Claims 1-3, Comprising: In a raw material monomer before superposition | polymerization, a liquid paraffin and / or high grade The foamable acrylic resin particles according to claim 4, wherein the fatty acid ester and / or olefin is added in an amount of 0.1 to 3 parts by weight with respect to 100 parts by weight of the total amount of monomers. The expandable acrylic resin particle according to claim 4 or 5, which contains an organic physical foaming agent having a boiling point of 80 ° C or lower as a foaming agent. The foamable acrylic resin particle according to claim 6, wherein the foaming agent is pentane. The acrylic resin foam particles according to claim 1 are filled in a mold, the foam particles in the mold are heated, fused to each other, and taken out from the mold after cooling. For producing a resin-based foamed resin molded body. The method for producing an acrylic resin foamed particle molded body according to claim 8 , wherein the minimum dimension of the space in the mold at the time of molding in the mold is at least 15 cm.