| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyethylene for pipe and joint, which can be molded in a high cycle in both injection molding method and extrusion molding method, particularly in pipe and joint uses, due to short crystallization time and excellent moldability thereof, and has extremely high long-term durability in addition to excellent dimensional stability and scratch resistance, and a molded product thereof.SOLUTION: A polyethylene for pipe and joint satisfies the following features (i)-(v): (i) HLMFR is 7-15 g/10 min; (ii) density is 0.945-0.954 g/cm; (iii) rupture time in full-notch creep test (measured at 80°C, 5 Mpa) is 500 hours or more; (iv) peak top time in isothermal crystallization at 121.5°C, measured by a differential scanning calorimeter (DSC), is 180 seconds or less; and (v) flexural modulus (23°C) is 950 MPa or more. |
