INJECTION FOAM MOLDED PRODUCT OF ETHYLENIC RESIN

摘要

PROBLEM TO BE SOLVED: To provide a thermally stable injection foam molded product of an ethylenic resin which is composed of an ethylenic polymer having excellent injection moldability, high foamability and high melt tension, excellent in the mechanical characteristics, especially the balance of rigidity and low temperature impact strength and also excellent in thermal stability. SOLUTION: The injection foam molded product of an ethylenic resin with a foaming rate of at least 2 times to at most 15 times is obtained by filling a resin composition composed of a foaming agent and an ethylenic polymer constituted of a repeating unit derived from ethylene or a repeating unit derived from ethylene and a repeating unit derived from a 3-8C α-olefin and satisfying following conditions (A) and (B) in a metal cavity with expandable and contractable volume of a metal mold, and then expanding the metal cavity to foam mold. (A) The density (d) measured by density gradient tube method according to JIS K6760 is at least 930 Kg/m3and at most 960 kg/m3. (B) The relationship between the melt stress (MS160(mN)) measured at 160°C and the melt flow rate (MFR) measured at 190°C with the load of 2.16 kg satisfies formula (1): (1) MS160>150-100×log (MFR). COPYRIGHT: (C)2011,JPO&INPIT