Ethylene-based polymer, method of producing ethylene-based polymer, and film
Provided are an ethylene-based polymer capable of obtaining a film in which thickness unevenness is reduced, a method of producing the ethylene-based polymer, and a film containing the ethylene-based polymer. In the ethylene-based polymer according to the present invention, the following Expressions (1) and (2) are satisfied: 0.362≤η L 1,256% /ηL 10% ≤0.466 (1) 0.0282≤ I 5 2,506% /I 1 2,506% ≤0.0328 (2).
1. An ethylene-based polymer, wherein the following Expressions (1) and (2) are satisfied:
0.362≤η L 1,256% /ηL 10% ≤0.466 (1)
wherein,
ηL 10% represents a viscosity (Pa·sec) at the highest shear rate of the ethylene-based polymer at a strain of γ 0 =10% of the ethylene-based polymer measured by a large amplitude oscillatory shear (LAOS) method at 150° C. and 0.05 Hz, and
ηL 1,256% represents a viscosity (Pa·sec) at the highest shear rate of the ethylene-based polymer at a strain of γ 0 =1,256% of the ethylene-based polymer measured by the LAOS method at 150° C. and 0.05 Hz, and
0.0282≤ I 5 2,506% /I 1 2,506% ≤0.0328 (2)
wherein,
I1 2,506% represents an intensity of a first harmonic wave obtained by Fourier-transforming a response stress of the ethylene-based polymer at a strain of γ 0 =2,506% of the ethylene-based polymer measured by the LAOS method at 150° C. and 0.05 Hz, and
I5 2,506% represents an intensity of a first harmonic obtained by Fourier-transforming a response stress of the ethylene-based polymer at the strain of γ 0 =2,506% of the ethylene-based polymer measured by the LAOS method at 150° C. and 0.05 Hz.
2. The ethylene-based polymer according to claim 1 , wherein the following Expressions (1′) and (2′) are satisfied:
0.370≤η L 1,256% /ηL 10% ≤0.466 (1′), and
0.0282≤ I 5 2,506% /I 1 2,506% ≤0.0320 (2′).
3. The ethylene-based polymer according to claim 1 , wherein the following Expressions (1″) and (2″) are satisfied:
0.370≤η L 1,256% /ηL 10% ≤0.440 (1″), and
0.0300≤ I 5 2,506% /I 1 2,506% ≤0.0320 (2″)
4. The ethylene-based polymer according to claim 1 , wherein the ethylene-based polymer has a crosslinked structure.
5. The ethylene-based polymer according to claim 1 , wherein the ethylene-based polymer is a high-pressure low-density polyethylene.
6. The ethylene-based polymer according to claim 1 , wherein a melt flow rate of the ethylene-based polymer measured at a temperature of 190° C. and a load of 2.16 kg is 2 g/10 min or more and 6 g/10 min or less.
7. A method of producing the ethylene-based polymer according claim 1 , the method comprising:
a step (A) of melt-kneading a mixture containing an ethylene-based polymer and a radical initiator at a temperature T A (° C.);
a step (B) of melt-kneading a melt-kneaded product obtained in the step (A) at a temperature T B (° C.); and
a step (C) of melt-kneading a melt-kneaded product obtained in the step (B) at a temperature T C (° C.),
wherein the following Expression (11) is satisfied:
T A <T B <T C (11).
8. The method of producing the ethylene-based polymer according to claim 7 , wherein
the step (A) is a step of performing melt-kneading using a melt-kneading extruder (a),
the step (B) is a step of performing melt-kneading using a melt-kneading extruder (b),
the step (C) is a step of performing melt-kneading using a melt-kneading extruder (c), and
wherein the melt-kneading extruder (a), the melt-kneading extruder (b), and the melt-kneading extruder (c) are different from each other.
9. The method of producing the ethylene-based polymer according to claim 7 , wherein the step (A) is a step of melt-kneading a mixture containing an ethylene-based polymer and a radical initiator, and an ethylene-based polymer.
10. The method of producing the ethylene-based polymer according to claim 7 , wherein the radical initiator is peroxide.
11. A film comprising the ethylene-based polymer according to claim 1 .