Ethylene-α-olefin copolymer, method of producing ethylene-α-olefin copolymer, ethylene-based resin composition, and film
An ethylene-α-olefin copolymer capable of implementing formation of a film having excellent slipperiness and suppressed fish eyes, a method of producing the ethylene-α-olefin copolymer, an ethylene-based resin composition containing the ethylene-α-olefin copolymer, and a film containing the ethylene-α-olefin copolymer or the ethylene-based resin composition. An ethylene-α-olefin copolymer according to the present invention has: a monomer unit (1) based on ethylene; and a monomer unit (2) based on an α-olefin having 3 to 20 carbon atoms, wherein a branching parameter is 0.70 to 0.90, and a light scattering area ratio is 1.60 to 3.60.
1. An ethylene-α-olefin copolymer comprising:
a monomer unit (1) based on ethylene; and
a monomer unit (2) based on an α-olefin having 3 to 20 carbon atoms,
wherein a branching parameter represented by the following Equation (i) is 0.70 to 0.90, and
a light scattering area ratio represented by the following Equation (ii) is 1.60 to 3.60,
[
Math
.
1
]
Branching
parameter
=
∑
M
=
10
4.3
10
5.5
W
M
×
g
M
′
∑
M
=
10
4.3
10
5.5
W
M
(
i
)
wherein M represents an absolute molecular weight of the ethylene-α-olefin copolymer, W M represents a weight fraction of the ethylene-α-olefin copolymer in the absolute molecular weight M, and g′ M represents an intrinsic viscosity ratio of the ethylene-α-olefin copolymer in the absolute molecular weight M, and
[
Math
.
2
]
Light
scattering
area
ratio
=
LS
LS
′
(
ii
)
wherein LS represents a light scattering area of a solution obtained by dissolving the ethylene-α-olefin copolymer in ortho-dichlorobenzene at a concentration of 2 mg/mL, and LS′ represents a light scattering area of a solution obtained by dissolving NIST Standard Reference Material Linear polyethylene 1475a in ortho-dichlorobenzene at a concentration of 2 mg/mL.
2. The ethylene-α-olefin copolymer according to claim 1 , wherein the branching parameter is 0.70 to 0.80.
3. The ethylene-α-olefin copolymer according to claim 1 , wherein the light scattering area ratio is 2.70 to 3.00.
4. The ethylene-α-olefin copolymer according to claim 1 , wherein when a total mass of the ethylene-α-olefin copolymer is 100% by mass, a content of the monomer unit (1) is 90% by mass or more, and a content of the monomer unit (2) is 10% by mass or less.
5. The ethylene-α-olefin copolymer according to claim 1 , wherein the monomer unit (2) is a monomer unit based on an α-olefin having 4 to 8 carbon atoms.
6. The ethylene-α-olefin copolymer according to claim 1 , wherein a melt flow rate measured under conditions of a temperature of 190° C. and a load of 21.18 N is 0.010 g/10 min to 0.2 g/10 min.
7. The ethylene-α-olefin copolymer according to claim 1 , wherein a density is 910 kg/m 3 to 940 kg/m 3 .
8. An ethylene-based resin composition comprising:
the ethylene-α-olefin copolymer according to claim 1 ; and
an ethylene-based polymer having a monomer unit based on ethylene (different from the ethylene-α-olefin copolymer).
9. The ethylene-based resin composition according to claim 8 , wherein a melt flow rate of the ethylene-based polymer measured under conditions of a temperature of 190° C. and a load of 21.18 N is 0.01 g/10 min to 5 g/10 min, and a density of the ethylene-based polymer is 910 kg/m 3 to 940 kg/m 3 .
10. The ethylene-based resin composition according to claim 8 , wherein a content of the ethylene-α-olefin copolymer is 1% by mass to 30% by mass with respect to a total content of 100% by mass of the ethylene-α-olefin copolymer and the ethylene-based polymer.
11. A film comprising the ethylene-α-olefin copolymer according to claim 1 .
12. A film comprising the ethylene-α-olefin copolymer according to claim 8 .