| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foam which can solve drawbacks of conventional propylene-based resin extruded foams using a noncrosslinked propylene-based resin as a substrate resin and, has excellent properties in forms ranging from a low expansion ratio to a high expansion ratio, and to provide a method which has a wide suitable foaming temp. range and can easily obtain a propylene-based resin extruded foam having excellent properties. SOLUTION: This propylene-based resin extruded foam is a plate extruded foam, having a density of 0.18 to 0.018 g/cm<3> and a thickness of 10 to 100 mm, comprising as a substrate a noncrosslinked propylene resin having a melt tension of not less than 7 gf at 230 deg.C and a semicrystallization time of not less than 800 sec at a temp. of crystallization temp. +15 deg.C. The propylene resin extruded foam is obtd. by melt-kneading the substrate resin within an extruder 1 at high temp. and high pressure conditions, extruding the melt-kneaded product into an accomulator 2 kept at temp. and pressure which do not create foaming, and then extrusion-foaming the melt-kneaded product under a lower pressure than the pressure of the accumulator 2. |
