| 摘要 |
<p>An extrusion-foamed polypropylene resin board which is thick and has a high percentage of closed cells, a small average cell diameter, and a low density. A resin blend obtained by blending (a) 50 to 95 parts by weight of a polypropylene resin having a melt tension at 230 °C of 0.05 N or higher with (b) 50 to 5 parts by weight of a polystyrene resin and (c) 0.5 to 15.0 parts by weight, per 100 parts by weight of the sum of the resins (a) and (b), of a hydrogenated styrene/isoprene/styrene block copolymer is mixed with a foaming agent with an extruder and then extruded into a low-pressure zone. Thus, an extrusion-foamed object having a density of 50 to 10 kg/m3 and a percentage of closed cells of 40 % or higher is obtained.</p> |
