| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a foam having a high expansion ratio and excellent surface smoothness. <P>SOLUTION: A method of producing the foam includes a molding step of extrusion-foaming a thermoplastic resin with an expansion ratio of≥10 and a cooling step of cooling the extrusion-foamed foam 3. In the cooling step, a foam having an apparent density of≤0.1 g/cm<SP POS="POST">3</SP>and an average surface roughness of≤5μm is prepared by cooling the foam 3 in the vicinity of a mold 2. In the foam 3, the ratioϕ1/ϕ2 of the average cell diameterϕ1 of cells positioned in the surface part to the average cell diameterϕ2 of cells crossing the center line in the thickness direction may be about 1/2-1/100. The foam is suitable as a protective material for covering hard convex and/or corner parts of a to-be-protected material. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
