| 摘要 |
PROBLEM TO BE SOLVED: To obtain a foamed article excellent in balance between remaining compressive stress rate which is an indicator of a shape retaining property, and BIT which is an indicator of kneading property. SOLUTION: The foamed articles are obtained by using an ethylene-alpha-olefin-non-conjugated diene copolymer rubber satisfying following requirements (1) to (4): (1) a ratio of a Z-average molecular chain length (Az) measured according to a gel permeation chromatography to a number average molecular chain length (An), Az/An, of the ethylene-alpha-olefin-non-conjugated diene copolymer rubber is from 20 to 30, (2) a ratio of a weight average molecular chain length (Aw) to the number average molecular chain length (An), Aw/An, which is an index of a molecular weight distribution, of the ethylene-alpha-olefin-non-conjugated diene copolymer rubber is more than 5, (3) a unimodal or bimodal molecular weight distribution structure, which is present in a maximum amount in a range of 3.8<Log Aw<4.5, exists in the ethylene-alpha-olefin-non-conjugated diene copolymer rubber, and (4) a viscosity (ML<SB>1+4</SB>, 121°C.) of the ethylene-alpha-olefin-non-conjugated diene copolymer rubber measured with an ML viscometer is more than 60 and less than 160. COPYRIGHT: (C)2004,JPO&NCIPI
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