Pipe comprising ethylene base polymer
AssigneesIdemitsu Petrochemical Co., Ltd., Kurimoto, Ltd.
InventorsKatsutoshi Ohta, Shigeru Murakami, Ryouichi Nakano
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Abstract
The pipe of the present invention comprises an ethylene base polymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms, wherein (A) a maximum value of the residual stress is 0.13 MPa or less; (B) the crystallinity is 0.630 to 0.850; (C) a gradient of the crystallinity against a thickness of the pipe is 0.465 or less; and (D) the pipe has a thickness of 5 to 50 mm. It is excellent in a durability, a rigidity and an impact resistance and suited to uses for large diameter pipes receiving a high internal pressure.
Claims6
A pipe comprising an ethylene base polymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms, wherein (A) a maximum value of the residual stress is 0.13 MPa or less;
- (B) the crystallinity is 0.630 to 0.850;
- (C) a gradient of the crystallinity against a thickness of the pipe is 0.465 or less;
- and (D) the pipe has a thickness of 5 to 50 mm.
A pipe comprising an ethylene base polymer comprising ethylene and an α-olefin having 3 to 20 carbon atoms, wherein according to ISO 13479, the pipe is provided on a surface thereof with 4 notches (notch depth rate:
- 20%) and has a breaking time of 165 hours or longer which is measured at a temperature of 80° C. under a pressure of 0.92 MPa, and the pipe having a notch depth rate of 40% has a breaking time of 20 hours or longer.
Dependencies are inferred from the claim text.