moldability, excellent long-term characteristics, polyethylene resin composition and a bottle cap which is suitable for bottle cap

摘要

PROBLEM TO BE SOLVED: To provide a new polyethylene resin composition for a bottle cap, which has excellent rigidity and excellent high speed moldability without deteriorating the environmental stress crack resistance (stress crack resistance) capable of withstanding the internal pressure of a beverage bottle, and further has excellent required performance in opening torque or the like.;SOLUTION: The polyethylene resin composition satisfies the following requirements (a) to (d): (a) the MFR of a cord D measured under the conditions satisfying a temperature of 190°C and a load of 2.16 kg according to JIS K7210 is 3.5 to 10.0 g/10 min; (b) the density measured according to JIS K7112 is 963 to 967 Kg/m³; (c) the isothermal crystallization time of the peak in 124°C obtained by crystallization time measurement according to DSC is ≤10 min; and (d) f50 rupture time obtained by an environmental stress crack resistance (ESCR) test is ≥20 hr.;COPYRIGHT: (C)2013,JPO&INPIT