| 摘要 |
PROBLEM TO BE SOLVED: To provide a polypropylene-based extrusion foamed article with a high expansion ratio and good surface appearance, which can be produced by using a conventional extrusion foaming apparatus, and to provide a production method therefor. SOLUTION: The polypropylene-based extrusion foamed article is obtained by melting and kneading a mixture of a polypropylene-based resin and a foam material within an extruder and then extrusion foaming the product from a die to a low pressure region, wherein the polypropylene-based resin satisfies the following A and B and when the resin is extrusion-foamed to the low pressure region, the apparent shear rate of a die wall at a site near the die outlet where a die clearance is minimum is 10 s<SP>-1</SP>or more and 1,000 s<SP>-1</SP>or less, and the expansion ratio is 3 or more times. (A) Pressure compensation value in Burgray correction is 4 or more MPa as determined by a capillary flow test under conditions of a measurement temperature of 210°C and a shear rate of 1,216 s<SP>-1</SP>. (B) A melt flow rate (MFR) is 0.5 g/10 minutes or more. COPYRIGHT: (C)2010,JPO&INPIT
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