JP7758602B2 - Ethylene-based resin composition and molded article - Google Patents

Description

The present invention relates to an ethylene-based resin composition and a molded article, film, multilayer film, and laminate containing the composition.

Ethylene-based polymers are used in a variety of molding methods and applications, and different properties are required of them depending on the molding method and application. For example, in T-die molding, necking occurs, where the edges of the film shrink toward the center. When necking occurs, the film width decreases and the edges become thicker than the center. Therefore, if necking is large, problems such as reduced product yield and the inability to produce products of the desired width can occur. In blow molding, problems such as sagging and breakage of the molten film can occur, and in inflation molding, problems such as shaking and breakage of the molten film can occur. To prevent these problems, it is necessary to select an ethylene-based polymer with a high melt tension relative to its molecular weight.

Furthermore, in T-die molding, regular thickness fluctuations occur in the film's draw direction, known as draw surging (or draw resonance), which can lead to uneven thickness and resulting variations in mechanical strength from location to location. To consistently produce film with a uniform thickness, draw surging must be avoided, and this is thought to require resin properties such that the strain hardening of the elongational viscosity increases with increasing strain rate.

Ethylene polymers without long-chain branches obtained using metallocene catalysts have excellent mechanical strength, but have issues with moldability. For example, they can suffer from large neck-in and take-up surging during T-die molding. High-pressure low-density polyethylene has excellent moldability, such as high melt tension and small neck-in, and its elongational viscosity exhibits strain rate hardening, preventing take-up surging. However, high-pressure low-density polyethylene has a complex long-chain branching structure, which means it is inferior in mechanical strength, such as tensile strength, tear strength, and impact strength.

To solve these problems, various ethylene polymers with introduced long-chain branches have been disclosed. Patent Document 1 proposes a composition of an ethylene polymer obtained using a metallocene catalyst and high-pressure low-density polyethylene. However, if the content of high-pressure low-density polyethylene is high, it is expected that mechanical strength such as tensile strength, tear strength, and impact strength will be poor, and if the content of high-pressure low-density polyethylene is low, the improvement in melt tension will be insufficient, and poor moldability such as large neck-in will be expected.

Patent Document 2 discloses an ethylene polymer obtained by solution polymerization in the presence of a catalyst consisting of ethylenebis(indenyl)hafnium dichloride and methylalumoxane; Patent Document 3 discloses an ethylene polymer obtained by gas-phase polymerization in the presence of a catalyst consisting of ethylenebis(indenyl)zirconium dichloride and methylalumoxane supported on silica; Patent Document 4 discloses an ethylene polymer obtained by solution polymerization in the presence of a constrained geometry catalyst; and Patent Document 5 discloses an ethylene polymer obtained by gas-phase polymerization in the presence of a catalyst consisting of racemic and meso isomers of _Me2Si (2-Me-Ind) ₂ supported on silica and methylalumoxane. These ethylene polymers are described as having improved melt tension and excellent moldability compared to linear ethylene polymers without long chain branches. However, since neck-in is still large, it is expected that the improvement in moldability is insufficient. Furthermore, unlike high-pressure low-density polyethylene, these ethylene polymers do not exhibit strain-rate hardening in elongational viscosity, and therefore, it is expected that take-up surge will not be improved.

Patent Documents 6 and 7 disclose ethylene polymers in which the intrinsic viscosity and weight-average molecular weight satisfy a specific relationship, the melt tension and shear viscosity satisfy a specific relationship, and the zero-shear viscosity and weight-average molecular weight exhibit a specific relationship. These ethylene polymers have improved take-up surging and have improved neck-in compared to conventional ethylene polymers in which long-chain branches are introduced using a metallocene catalyst. However, although their mechanical strength is superior to that of high-pressure low-density polyethylene, further improvements in mechanical strength are desired.

Japanese Patent Application Publication No. 7-26079 Japanese Unexamined Patent Publication No. 2-276807 Japanese Patent Application Publication No. 4-213309 WO 93/08221 Japanese Patent Application Publication No. 8-311260 Japanese Patent Application Laid-Open No. 2006-233207 JP 2009-197225 A

The present invention aims to provide an ethylene-based resin composition that has excellent moldability and can form films with particularly excellent mechanical strength compared to conventionally known ethylene-based polymers, as well as films, laminates, etc. obtained from the ethylene-based resin composition.

The present invention relates to, for example, the following [1] to [13].
[1]
The present invention comprises an ethylene-α-olefin copolymer (A) which is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and satisfies the following requirements (1) to (6), and a high-pressure low-density polyethylene (B) which satisfies the following requirements (a) to (c),
The mass fraction (W _A ) of the ethylene-α-olefin copolymer (A) is 40% by mass or more and 90% by mass or less, and the mass fraction (W _B ) of the high-pressure low-density polyethylene (B) is 10% by mass or more and 60% by mass or less (wherein the sum of W _A and W _B is 100% by mass).
Ethylene-based resin composition (Z).
(1) The density is in the range of 890 kg/m ³ or more and 935 kg/m ³ or less.
(2) The melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 1.0 g/10 min or more and 15.0 g/10 min or less.
(3) The ratio [MT/η ^* (g/P)] of the melt tension [MT(g)] at 190°C to the shear viscosity [η ^* (P)] at 200°C and an angular velocity of 1.0 rad/sec is in the range of 1.40× ^10-4 or more and 2.90× ^10-4 or less.
(4) The zero shear viscosity [η ₀ (P)] at 200° C. and the weight average molecular weight (Mw) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1):
0.01×10 ^-13 ×Mw ^3.4 ≦ η ₀ ≦ 4.5×10 ^-13 ×Mw ^3.4 ... (Eq-1)
(5) The number average molecular weight (Mn), weight average molecular weight (Mw), and Z average molecular weight (Mz) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-2):
-2.0 ≦ Mz/Mw - Mw/Mn ≦ 15 ... (Eq-2)
(6) The total of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin per 1000 carbon atoms (units/1000C) measured by ¹ H-NMR is in the range of 0.1 to 1.0.
(a) The density is in the range of 915 kg/m ³ or more and 930 kg/m ³ or less.
(b) The melt flow rate (MFR) at 190°C under a load of 2.16 kg is in the range of 0.1 g/10 min or more and 20 g/10 min or less.
(c) The amount of components having a molecular weight of 1,000,000 or more in a molecular weight distribution curve obtained by GPC measurement is in the range of 1.0% to 20%.

[2]
The ethylene-α-olefin copolymer (A) further satisfies the following requirement (7):
(7) The intrinsic viscosity [η] (dl/g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-3):
0.7×10 ^-4 ×Mw ^0.776 ≦[η]≦ 1.65×10 ^-4 ×Mw ^0.776 ...(Eq-3)

[3]
The ethylene-based resin composition (Z) according to [1] or [2] above, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (8):
(8) The ratio Mz/Mw of the Z-average molecular weight (Mz) to the weight-average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) is in the range of 4.0 to 25.0.

[4]
The ethylene-based resin composition (Z) according to any one of [1] to [3], wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (9):
(9) There are multiple peaks in the melting curve obtained by differential scanning calorimetry (DSC).

[5]
The ethylene resin composition (Z) according to any one of [1] to [4], wherein the high-pressure low-density polyethylene (B) further satisfies the following requirement (d):
(d) The ratio [δ100/δ0.01] of the phase angle [δ100 (°)] at 200°C and an angular velocity of 100 rad/sec to the phase angle [δ0.01 (°)] at 200°C and an angular velocity of 0.01 rad/sec is in the range of 0.46 or more and 0.76 or less.

[6]
The ethylene-based resin composition (Z) according to any one of [1] to [5], further comprising a thermoplastic resin (excluding the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B)).

[7]
A molded article comprising the ethylene-based resin composition (Z) according to any one of [1] to [6].
[8]
A film comprising the ethylene resin composition (Z) according to any one of [1] to [6].

[9]
A multilayer film having a layer containing the ethylene resin composition (Z) according to any one of [1] to [6] above.
[10]
A laminate having a layer containing the ethylene resin composition (Z) according to any one of [1] to [6] above.

[11]
The laminate according to [10], further comprising a substrate layer.
[12]
The laminate according to [10] above, further comprising a barrier layer.

[13]
A method for producing a laminate, comprising extrusion laminating the ethylene-based resin composition (Z) according to any one of [1] to [6] above between a substrate layer and a barrier layer.

The ethylene-based resin composition (Z) of the present invention has excellent moldability (i.e., no take-up surging occurs during T-die molding and neck-in is small), and it is possible to suitably produce molded articles, particularly films, laminates, and containers made of such laminates, which have particularly excellent mechanical strength.

In addition, the ethylene-based resin composition (Z) of the present invention exhibits excellent adhesive strength when used in the adhesive layer of a laminate.

The ethylene-based resin composition (Z) according to the present invention will be specifically described below, along with its constituent components, the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B).

[Ethylene-based resin composition (Z)]
[Ethylene-α-olefin copolymer (A)]
The ethylene-α-olefin copolymer (A) is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms, preferably an α-olefin having 6 to 10 carbon atoms. Examples of the α-olefin having 4 to 10 carbon atoms that can be copolymerized with ethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene.

The ethylene/α-olefin copolymer (A) may contain structural units derived from at least one type of biomass-derived ethylene or α-olefin. The same type of monomer constituting the polymer may consist solely of biomass-derived monomers, solely of fossil fuel-derived monomers, or both biomass-derived and fossil fuel-derived monomers. Biomass-derived monomers are monomers derived from any renewable natural raw material, such as plant- or animal-derived, including fungi, yeast, algae, and bacteria, and their residues. They contain carbon-14C isotopes at a ratio of approximately 1× ^10-12 and have a biomass carbon concentration (pMC) of approximately 100 (pMC) as measured in accordance with ASTM D6866. Biomass-derived ethylene and α-olefins can be obtained, for example, by conventionally known methods.

It is preferable from the viewpoint of reducing the environmental load that the ethylene/α-olefin copolymer (A) contains a structural unit derived from a biomass-derived monomer.
The ethylene-α-olefin copolymer (A) has the following properties (1) to (6).

(1) The density is in the range of 890 kg/m ³ or more and 935 kg/m ³ or less, preferably 900 kg/m ³ or more and 925 kg/m ³ or less, and more preferably 905 kg/m ³ or more and 922 kg/m ³ or less.

When the density is equal to or higher than the lower limit, the surface of a film formed from the ethylene-based resin composition (Z) is less sticky, and when the density is equal to or lower than the upper limit, the impact strength of a film formed from the ethylene-based resin composition (Z) is good, and the mechanical strength, such as heat seal strength and the bag-breaking strength of bags made from the film, is good.

Density depends on the α-olefin content of the ethylene-α-olefin copolymer; the lower the α-olefin content, the higher the density, and the higher the α-olefin content, the lower the density. The α-olefin content of an ethylene-α-olefin copolymer is determined by the composition ratio of α-olefin to ethylene (α-olefin/ethylene) in the polymerization system (e.g., Walter Kaminsky, Makromol.Chem. 193, p.606(1992)). Therefore, by increasing or decreasing the α-olefin/ethylene ratio, ethylene-α-olefin polymers having densities within the above range can be produced.

The density is measured as follows.
The strand obtained when measuring MFR is heat treated at 100° C. for 30 minutes, and then allowed to stand at room temperature for 1 hour, after which the MFR is measured by the density gradient tube method.

(2) The melt flow rate (MFR) is in the range of 1.0 g/10 min or more and 15.0 g/10 min or less, preferably 1.0 g/10 min or more and 12.0 g/10 min or less, and more preferably 3.0 g/10 min or more and 12.0 g/10 min or less.

When the melt flow rate (MFR) is equal to or higher than the lower limit, the shear viscosity of the ethylene-based resin composition (Z) is not too high, and the extrusion load is good. When the melt flow rate (MFR) is equal to or lower than the upper limit, the mechanical strength of the ethylene-based resin composition (Z) is good.

The melt flow rate (MFR) is strongly dependent on molecular weight; the lower the MFR, the higher the molecular weight, and the higher the MFR, the lower the molecular weight. It is also known that the molecular weight of an ethylene-based polymer is determined by the composition ratio of hydrogen to ethylene (hydrogen/ethylene) in the polymerization system (see, for example, Kazuo Soga et al., Catalytic Olefin Polymerization, Kodansha Scientific, 1990, p. 376). Therefore, it is possible to increase or decrease the melt flow rate (MFR) of an ethylene-based polymer by increasing or decreasing the hydrogen/ethylene ratio. Melt flow rate (MFR) is measured in accordance with JIS K 7210 at 190°C under a load of 2.16 kg.

(3) The ratio [MT/η ^* (g/P)] of the melt tension [MT(g)] to the shear viscosity [η ^* (P)] (P is in Poise) at 200°C and an angular velocity of 1.0 rad/sec is in the range of 1.40× ^10-4 to 2.90× ^10-4 , preferably 1.50× ^10-4 to 2.70× ^10-4 , and more preferably 1.60× ^10-4 to 2.45× ^10-4 .

When MT/η ^* is equal to or greater than the lower limit, the ethylene-α-olefin copolymer (A) has a high melt tension relative to its molecular weight, and thus the ethylene-based resin composition (Z) has excellent moldability.When MT/η ^* is equal to or less than the upper limit, the ethylene-based resin composition (Z) has excellent mechanical strength.

The MT/η ^* depends on the long-chain branch content of the ethylene polymer, and the higher the long-chain branch content, the larger the MT/η ^* , and the lower the long-chain branch content, the smaller the MT/η ^* . Long-chain branches are defined as branch structures having a length equal to or greater than the entanglement molecular weight (Me) contained in the ethylene polymer, and it is known that the introduction of long-chain branches significantly changes the melt properties and moldability of the ethylene polymer (for example, Kazuo Matsuura et al., "Polyethylene Technology Reader," Kogyo Chosakai, 2001, pp. 32-36).

MT/η ^* can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when the same olefin polymerization catalyst (X) is used, MT/η* can be adjusted by the polymerization conditions or polymerization process; for example, MT/η ^* can be lowered by increasing the ethylene partial pressure. MT/η ^* near the lower limit can be obtained under the production conditions of Production Example 2 described below, and MT/η ^* near the upper limit can be obtained under the production conditions of Production Example 13 described below.

The melt tension [MT (g)] is measured as follows.
The melt tension (MT) (unit: g) is determined by measuring the stress when stretched at a constant speed. A capillary rheometer (for example, a Toyo Seiki Seisakusho Capillograph 1D capillary rheometer) was used for the measurement. The conditions were a resin temperature of 190°C, a melting time of 6 minutes, a barrel diameter of 9.55 mm, an extrusion speed of 15 mm/min, a take-up speed of 24 m/min (if the molten filament breaks, the take-up speed is reduced by 5 m/min), a nozzle diameter of 2.095 mm, and a nozzle length of 8 mm.

The shear viscosity [η ^* (P)] at 200°C and an angular velocity of 1.0 rad/sec is measured as follows. The shear viscosity (η ^* ) is measured by measuring the angular velocity [ω(rad/sec)] variance of the shear viscosity (η ^* ) at a measurement temperature of 200°C in the range of 0.01≦ω≦100. A viscoelasticity measuring device (for example, an Anton Paar Physica MCR301 viscoelasticity measuring device was used in the examples described below) is used, and a 25 mmφ parallel plate is used as the sample holder, with a sample thickness of approximately 2.0 mm. Five measurement points are set per ω digit. The strain amount is appropriately selected from the range of 3 to 10% so that the torque can be detected within the measurement range without exceeding the torque.

The samples used for shear viscosity measurement are prepared by press-molding the measurement sample to a thickness of 2 mm using a molding machine (for example, a press molding machine manufactured by Shinto Metal Industries was used in the examples described below) under the following conditions: preheating temperature 190°C, preheating time 5 minutes, heating temperature 190°C, heating time 2 minutes, heating pressure 100 kgf/ ^cm2 , cooling temperature 20°C, cooling time 5 minutes, and cooling pressure 100 kgf/ ^cm2 .

(4) The zero shear viscosity [η ₀ (P)] at 200° C. and the weight average molecular weight (Mw) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1).

0.01×10 ^-13 ×Mw ^3.4 ≦ η ₀ ≦ 4.5×10 ^-13 ×Mw ^3.4 ... (Eq-1)
Preferably, the following (Eq-1') is satisfied.
0.1×10 ^-13 ×Mw ^3.4 ≦ η ₀ ≦ 3.0×10 ^-13 ×Mw ^3.4 ...(Eq-1')
More preferably, the following (Eq-1") is satisfied.
0.2×10 ^-13 ×Mw ^3.4 ≦ η ₀ ≦ 2.0×10 ^-13 ×Mw ^3.4 ...(Eq-1")

When the zero-shear viscosity [η(P)] is plotted against the weight-average molecular weight (Mw) on a double logarithmic scale, it is known that resins whose extensional viscosity does not exhibit strain hardening, such as linear ethylene polymers without long chain branches, follow a power law with a slope of 3.4, whereas resins whose extensional viscosity exhibits strain rate hardening, such as high-pressure low-density polyethylene, show a zero-shear viscosity [ _η (P)] lower than the power law (C. Gabriel, H. Munstedt, J. Rheol., 47(3), 619(2003)). When the zero-shear viscosity [ _η (P)] at 200°C is not more than the upper limit, the extensional viscosity of the ethylene polymer exhibits strain rate hardening, and therefore, take-up surging does not occur when molding the ethylene resin composition (Z).

The relationship between the zero shear viscosity [η ₀ (P)] and the weight average molecular weight (Mw) is thought to depend on the content and length of long chain branches in the ethylene polymer, and it is thought that the greater the content of long chain branches and the shorter the length of the long chain branches, the smaller the zero shear viscosity [η ₀ (P)] will be, and the smaller the content of long chain branches and the longer the length of the long chain branches, the larger the zero shear viscosity [η ₀ (P)] will be.

The zero shear viscosity [η ₀ (P)] can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when the same olefin polymerization catalyst (X) is used, the zero shear viscosity [η _{0 (P)] can be adjusted by the polymerization conditions or polymerization process. For example, the zero shear viscosity [η 0} (P)] can be increased by increasing the ethylene partial pressure. The zero shear viscosity [η ₀ (P)] near the lower limit can be obtained under the production conditions of Production Examples 14 and 15 described below, and the zero shear viscosity [η ₀ (P)] near the upper limit can be obtained under the production conditions of Production Example 12 described below.

The zero shear viscosity [η ₀ (P)] at 200° C. is measured as follows.
At a measurement temperature of 200°C, the angular velocity ω (rad/sec) dispersion of shear viscosity (η ^* ) is measured in the range of 0.01≦ω≦100. A viscoelasticity measuring device is used for the measurement (for example, in the examples described below, an Anton Paar Physica MCR301 viscoelasticity measuring device is used), a 25 mmφ parallel plate is used as the sample holder, and the sample thickness is approximately 2.0 mm. Five measurement points are set per ω digit. The strain amount is appropriately selected from the range of 3 to 10% so that torque can be detected within the measurement range and torque over is not exceeded.

The samples used for shear viscosity measurement are prepared by press-molding the measurement sample to a thickness of 2 mm using a molding machine (for example, a press molding machine manufactured by Shinto Metal Industries was used in the examples described below) under the following conditions: preheating temperature 190°C, preheating time 5 minutes, heating temperature 190°C, heating time 2 minutes, heating pressure 100 kgf/ ^cm2 , cooling temperature 20°C, cooling time 5 minutes, and cooling pressure 100 kgf/ ^cm2 .

The zero shear viscosity (η ₀ ) is calculated by fitting the Carreau model of the following equation to an actually measured rheological curve [angular velocity (ω) variance of shear viscosity (η ^* )] by the nonlinear least squares method.

η ^* =η ₀ [1+(λω) ^a ] ^(n-1)/a
(λ is a parameter having a dimension of time, a is a fitting parameter, and n is the power law index of the material.)
The fitting by the nonlinear least squares method is performed so that d in the following formula is minimized.

(ηexp(ω) represents the measured shear viscosity, and ηcalc(ω) represents the shear viscosity calculated using the Carreau model.)
The weight average molecular weight (Mw) and the like are measured by gel permeation chromatography (GPC) as follows.

A differential refractometer and capillary viscometer were used as detectors, the column temperature was 145°C, o-dichlorobenzene was used as the mobile phase, the flow rate was 1.0 ml/min, the sample concentration was 0.1 wt%, and polystyrene was used as the standard polymer. In the examples described below, the Agilent PL-GPC220 GPC-viscometer (GPC-VISCO) was used as the measurement device, two Agilent PLgel Olexis analytical columns were used, and a Tosoh polystyrene standard was used. Molecular weight calculations were performed by calculating the actual viscosity using the viscometer and refractometer, and then using actual universal calibration to determine the number average molecular weight (Mn), weight average molecular weight (Mw), Z-average molecular weight (Mz), and molecular weight distribution (Mw/Mn, Mz/Mw).

(5) The number average molecular weight (Mn), weight average molecular weight (Mw), and Z average molecular weight (Mz) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relationship (Eq-2).

-2.0≦ Mz/Mw - Mw/Mn ≦15 ... (Eq-2)
Preferably, the following relational expression (Eq-2′) is satisfied.
-1.5≦ Mz/Mw - Mw/Mn ≦12 ... (Eq-2')
More preferably, the following relational expression (Eq-2″) is satisfied.
-1.0≦ Mz/Mw - Mw/Mn ≦10 ... (Eq-2")

When Mz/Mw - Mw/Mn is large, the molecular weight distribution is broadened to the high molecular weight side. When Mz/Mw - Mw/Mn is equal to or greater than the lower limit, the ethylene-based resin composition (Z) has excellent melt film stability, and when it is equal to or less than the upper limit, the ethylene-based resin composition (Z) has excellent thin film moldability.

Mz/Mw - Mw/Mn can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below, and can also be adjusted by the polymerization conditions or polymerization process, even when the same olefin polymerization catalyst (X) is used. It is possible to obtain an Mz/Mw - Mw/Mn near the lower limit under the production conditions of Production Example 5 described below, and an Mz/Mw - Mw/Mn near the upper limit under the polymerization conditions of Production Example 14 described below.

The number average molecular weight (Mn), weight average molecular weight (Mw), and Z average molecular weight (Mz) are measured using the methods described above.

(6) The numbers of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin measured by ¹ H-NMR satisfy the following relational expression (Eq-3).

0.1≦vinyl + vinylidene + disubstituted internal olefin + trisubstituted internal olefin≦1.0
...(Eq-3)
Preferably, the following relational expression (Eq-3′) is satisfied.
0.3≦vinyl + vinylidene + disubstituted internal olefin + trisubstituted internal olefin≦0.9
...(Eq-3')
More preferably, the following relational expression (Eq-3") is satisfied.
0.5≦vinyl + vinylidene + disubstituted internal olefin + trisubstituted internal olefin≦0.8
...(Eq-3")

The number of vinyl, vinylidene, disubstituted internal olefin, and trisubstituted internal olefin in a polymer is measured by ^1H -NMR and is the number per 1,000 carbon atoms contained in the polymer. It is known that the production ratio and number of vinyl, vinylidene, disubstituted internal olefin, and trisubstituted internal olefin increase or decrease depending on the transition metal compound used (H. SAIKI, S. MAKOTO, T. MASAO, S. MORIHIKO, Y. AKIHIRO, J. Polym. Sci., A: Polym. Chem., 38, 4641 (2000)). These can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below. Furthermore, even when the same olefin polymerization catalyst (X) is used, the amount can be adjusted by the polymerization conditions or polymerization process, for example, by increasing or decreasing the ethylene partial pressure.

When the number of units of vinyl + vinylidene + di-substituted internal olefin + tri-substituted internal olefin is equal to or greater than the above lower limit, long chain branching is likely to occur, and the ethylene-based resin composition (Z) has excellent moldability. When the number of units of vinyl + vinylidene + di-substituted internal olefin + tri-substituted internal olefin is equal to or less than the above upper limit, the ethylene-based resin composition (Z) has excellent heat-sealing properties, and the molded product has excellent transparency and mechanical strength, as the molten film is less susceptible to oxidation during molding.

The numbers of vinyl, vinylidene, di-substituted internal olefins, and tri-substituted internal olefins measured by ^1H -NMR (500 MHz) are measured using a nuclear magnetic resonance apparatus (for example, in the examples described later, a Bruker AVANCE III (Cryoprobe) nuclear magnetic resonance apparatus was used) as follows.

The measurement mode is single pulse, with a pulse width of 45°. The number of points is 32k, the observation range is 20 ppm (-6 to 14 ppm), the repetition time is 7 seconds, and the number of accumulations is 64. 20 mg of sample is dissolved in 0.6 ml of orthodichlorobenzene-d4 and measured at 120°C.

In the ^1H -NMR spectrum, the number of double bonds is calculated from the integrated values of signals derived from various double bonds (vinyl, vinylidene, internal olefin) in the range of 4.5 ppm to 5.8 ppm, and the relative value of the total number of carbon atoms is calculated from the total integrated value of all ^1H signals, and the number of various double bonds per 1,000 carbon atoms in the polymer is calculated.

The ethylene-α-olefin copolymer (A) preferably has the properties shown in (7) below.

(7) The intrinsic viscosity [η] (dl/g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relationship (Eq-3).

0.7×10 ^-4 ×Mw ^0.776 ≦[η]≦ 1.65×10 ^-4 ×Mw ^0.776 ...(Eq-3)
Preferably, the following (Eq-3') is satisfied.
0.7×10 ^-4 ×Mw ^0.776 ≦[η]≦ 1.40×10 ^-4 ×Mw ^0.776 ...(Eq-3')
More preferably, the following (Eq-3") is satisfied.
0.8×10 ^-4 ×Mw ^0.776 ≦[η]≦ 1.20×10 ^-4 ×Mw ^0.776 ...(Eq-3")

It is known that when long chain branches are introduced into an ethylene polymer, the intrinsic viscosity [η] (dl/g)] relative to the molecular weight becomes smaller than that of a linear ethylene polymer without long chain branches (for example, Walther Burchard, ADVANCES IN POLYMER SCIENCE, 143, Branched Polymer II, p. 137 (1999)). Therefore, when the intrinsic viscosity [η] (dl/g)] is 1.65 × 10 ⁻⁴ × Mw ^0.776 or less, the resulting ethylene polymer has many long chain branches and is excellent in moldability and flowability.

The intrinsic viscosity [η] (dl/g) can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below. Even when using the same olefin polymerization catalyst (X), the intrinsic viscosity [η] (dl/g) can be adjusted by the polymerization conditions or polymerization process. For example, the intrinsic viscosity [η] (dl/g) can be increased by increasing the ethylene partial pressure. The production conditions of Production Example 11 described below can be used to obtain an intrinsic viscosity [η] (dl/g) near the lower limit, while the production conditions of Production Example 12 described below can be used to obtain an intrinsic viscosity [η] (dl/g) near the upper limit.

The intrinsic viscosity [[η] (dl/g)] is measured as follows using decalin as a solvent.
Approximately 20 mg of the measurement sample is dissolved in 15 ml of decalin, and the specific viscosity ηsp is measured in an oil bath at 135°C. This decalin solution is diluted with 5 ml of decalin solvent, and the specific viscosity ηsp is measured in the same manner. This dilution procedure is repeated two more times, and the value of ηsp/C when the concentration (C) is extrapolated to 0 as shown in the following formula is calculated as the limiting viscosity [η] (unit: dl/g).

[η]=lim(ηsp/C) (C→0)
The weight average molecular weight (Mw) is measured as described above.
The ethylene-α-olefin copolymer (A) preferably has the properties shown in the following (8).

(8) The ratio (Mz/Mw) of the Z-average molecular weight (Mz) to the weight-average molecular weight (Mw), as measured by a GPC-viscosity detector (GPC-VISCO), is in the range of 4.0 to 25.0, preferably 7.0 to 20.0, and more preferably 10.0 to 18.0. The larger the Mz/Mw, the more high-molecular-weight components there are. When Mz/Mw is equal to or greater than the lower limit, the ethylene-based resin composition (Z) exhibits excellent neck-in properties, and when Mz/Mw is equal to or less than the upper limit, the ethylene-based resin composition (Z) exhibits excellent thin-film formability.

Mz/Mw can be adjusted by the type of component (A) or solid support (S) of the olefin polymerization catalyst (X) described below, and can also be adjusted by the polymerization conditions or polymerization process, even when the same olefin polymerization catalyst (X) is used. An Mz/Mw near the lower limit can be obtained under the production conditions of Production Example 5 described below, while an Mz/Mw near the upper limit can be obtained under the polymerization conditions of Examples 11 and 14 described below.

The ethylene-α-olefin copolymer (A) preferably has the properties shown in (9) below.

(9) There are multiple peaks in the melting curve obtained by differential scanning calorimetry (DSC).
If there are multiple peaks, there are many low-melting components and the heat sealability at low temperatures is excellent.
Differential scanning calorimetry (DSC) is carried out using a differential scanning calorimeter (for example, Diamond DSC manufactured by PerkinElmer was used in the examples described below) as follows.

Approximately 5 mg of sample is placed in an aluminum pan, heated to 200°C at 10°C/min, held at 200°C for 10 minutes, cooled to -30°C at 10°C/min, and then heated back up to 200°C at 10°C/min, obtaining an endothermic curve. If this endothermic curve has two or more peaks, it means that the melting curve obtained by differential scanning calorimetry (DSC) has multiple peaks.

When the ethylene-α-olefin copolymer (A) has the properties described in (9) above, the ethylene-based resin composition (Z) of the present invention exhibits excellent heat sealability when used in a heat seal layer of a laminate.

[High-pressure low-density polyethylene (B)]
The high-pressure low-density polyethylene (B) is produced by polymerizing ethylene by high-pressure radical polymerization, and has many branched long-chain branches.
The high-pressure low-density polyethylene (B) has the following properties (a) to (c).

(a) The density is in the range of 915 kg/m ³ or more and 930 kg/m ³ or less, preferably 915 kg/m ³ or more and 925 kg/m ³ or less, and more preferably 915 kg/m ³ or more and 920 kg/m ³ or less.

When the density is below the upper limit, the low-temperature heat sealability of a film formed from the ethylene-based resin composition (Z) is good. It is difficult to produce high-pressure low-density polyethylene with a density below the lower limit.

(b) The melt flow rate (MFR) is in the range of 0.1 g/10 min or more and 20 g/10 min or less, preferably 0.5 g/10 min or more and 10 g/10 min or less, and more preferably 0.8 g/10 min or more and 8.0 g/10 min or less.

When the melt flow rate (MFR) is at least the lower limit, the film formed from the ethylene-based resin composition (Z) has few fisheyes and a good appearance. When the melt flow rate (MFR) is at most the upper limit, the melt tension of the ethylene-based resin composition (Z) is high, resulting in good moldability, such as melt film stability.

(c) The amount of components with a molecular weight of 1,000,000 or more in the molecular weight distribution curve obtained by GPC measurement is in the range of 1.0% to 20%, preferably 2.0% to 15%, and more preferably 4.0% to 13%.

When the amount of components having a molecular weight of 1,000,000 or more in the molecular weight distribution curve obtained by GPC measurement is equal to or greater than the lower limit, the ethylene-based resin composition (Z) has excellent neck-in properties. When the amount of components having a molecular weight of 1,000,000 or more in the molecular weight distribution curve obtained by GPC measurement is equal to or less than the upper limit, the ethylene-based resin composition (Z) has excellent thin-film formability.

The amount of components with a molecular weight of 1 million or more in the molecular weight distribution curve obtained by GPC measurement is calculated by measuring under the following conditions using a gel permeation chromatograph. The following equipment was used in the examples described below.

[Equipment used]
Measuring device: HLC-8321 GPC/HT type (manufactured by Tosoh Corporation)
Data processing software: Empower 3 (Waters)
Column: 2x TSKgel GMH6-HT + 2x TSKgel GMH6-HTL
(Both 7.5 mm I.D. x 30 cm, manufactured by Tosoh Corporation)
Polystyrene: Monodisperse polystyrene (Tosoh Corporation); #3 std set

[Measurement conditions]
Column temperature: 140°C
Mobile phase: o-dichlorobenzene (containing 0.025% BHT)
Detector: differential refractometer Flow rate: 1.0 ml/min Sample concentration: 0.1% (w/v)
Injection volume: 400μL
Sampling time interval: 0.5 seconds Column calibration: Polystyrene Molecular weight conversion: PE conversion/general calibration method

From the molecular weight distribution curve obtained, the amount (%) of components having a molecular weight of 1,000,000 or more is calculated.
The high-pressure low-density polyethylene (B) preferably has the following properties (d).

(d) The ratio [δ100/δ0.01] of the phase angle [δ100 (°)] at 200°C and an angular velocity of 100 rad/sec to the phase angle [δ0.01 (°)] at 200°C and an angular velocity of 0.01 rad/sec is in the range of 0.46 to 0.76, preferably 0.46 to 0.72, and more preferably 0.47 to 0.64.

The angular velocity [ω (rad/sec)] dispersion of the phase angle (δ) is known to be strongly affected by the content, length, and structure of long-chain branches in an ethylene-based polymer (e.g., S. Trinkle, P. Walter, C. Friedrich, Rheol Acta, 41, 103 (2002)). When long-chain branches are introduced into an ethylene-based polymer, the δ100/δ0.01 ratio is larger than that of a linear ethylene-based polymer without long-chain branches. Furthermore, the longer the introduced long-chain branches are or the more complex the branching structure, the larger the δ100/δ0.01 ratio. When the δ100/δ0.01 ratio is equal to or greater than the lower limit, the ethylene-based resin composition (Z) exhibits excellent neck-in properties. When the δ100/δ0.01 ratio is equal to or less than the upper limit, the ethylene-based resin composition (Z) exhibits excellent mechanical strength.

The phase angle [δ100 (°)] at 200° C. and an angular velocity of 100 rad/sec and the phase angle [δ0.01 (°)] at 200° C. and an angular velocity of 0.01 rad/sec are measured as follows.
The dispersion of the angular velocity [ω (rad/sec)] of the phase angle (δ) at a measurement temperature of 200°C is measured in the range of 0.01≦ω≦100. A viscoelasticity measuring device is used for the measurement (for example, in the examples described below, an Anton Paar Physica MCR301 viscoelasticity measuring device is used), and a 25 mmφ parallel plate is used as the sample holder, with the sample thickness being approximately 2.0 mm. Five measurement points are set per ω digit. The strain amount is appropriately selected in the range of 3 to 10% so that the torque can be detected within the measurement range and does not exceed the torque.

The samples used for shear viscosity measurement are prepared by press-molding the measurement sample to a thickness of 2 mm using a molding machine (for example, a press molding machine manufactured by Shinto Metal Industries was used in the examples described below) under the following conditions: preheating temperature 190°C, preheating time 5 minutes, heating temperature 190°C, heating time 2 minutes, heating pressure 100 kgf/ ^cm2 , cooling temperature 20°C, cooling time 5 minutes, and cooling pressure 100 kgf/ ^cm2 .

<Ethylene-based resin composition (Z)>
The ethylene-based resin composition (Z) according to the present invention contains the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), and when the sum of the mass fraction ( _WA ) of the ethylene-α-olefin copolymer (A) and the mass fraction ( _WB ) of the ethylene-α-olefin copolymer (B) is 100 mass%, _WA is 40 to 90 mass% and _WB is 10 to 60 mass%. _WA is preferably 50 to 85 mass%, more preferably 60 to 75 mass%. Within these ranges, the ethylene-based resin composition (Z) has excellent moldability and mechanical strength.

The ethylene-based resin composition (Z) according to the present invention may consist essentially of the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), but is not limited thereto. In addition to the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), the ethylene-based resin composition (Z) may also contain a thermoplastic resin other than the ethylene-α-olefin copolymer (A) or the high-pressure low-density polyethylene (B) (hereinafter referred to as "another thermoplastic resin"). The ethylene-based resin composition (Z) obtained as a thermoplastic resin composition by blending the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) with the "other thermoplastic resin" has excellent moldability and mechanical strength.

The blend ratio of the total of the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) to the "other thermoplastic resin" (total mass of ethylene-α-olefin copolymer (A) and high-pressure low-density polyethylene (B) / mass of other thermoplastic resin) is typically 99.9/0.1 to 0.1/99.9, preferably 90/10 to 10/90, and more preferably 70/30 to 30/70.

(Other thermoplastic resins)
Other thermoplastic resins that can be used include crystalline thermoplastic resins such as polyolefin, polyamide, polyester, and polyacetal; and non-crystalline thermoplastic resins such as polystyrene, acrylonitrile-butadiene-styrene copolymer (ABS), polycarbonate, polyphenylene oxide, and polyacrylate. Polyvinyl chloride is also preferably used.

Specific examples of the polyolefin include ethylene polymers, propylene polymers, butene polymers, 4-methyl-1-pentene polymers, 3-methyl-1-butene polymers, and hexene polymers. Among these, ethylene polymers, propylene polymers, and 4-methyl-1-pentene polymers are preferred. In the case of ethylene polymers, they may be conventional ethylene polymers or ethylene-polar group-containing vinyl copolymers, with conventional ethylene polymers being more preferred. The ethylene polymers and propylene polymers may be ethylene polymers and propylene polymers, respectively, containing biomass-derived monomers.

The ethylene-based resin composition (Z) of the present invention may contain additives such as weather resistance stabilizers, heat resistance stabilizers, antistatic agents, antislip agents, antiblocking agents, antifogging agents, lubricants, pigments, dyes, nucleating agents, plasticizers, antioxidants, hydrochloric acid absorbers, and antioxidants, as needed, provided the purpose of the present invention is not impaired.

The total amount of additives is generally 10 parts by mass or less, preferably 1 part by mass or less, and more preferably 0.5 parts by mass or less, per 100 parts by mass of the total of the components of the ethylene-based resin composition (Z) other than the additives.

<Method for producing ethylene-α-olefin copolymer (A)>
Next, the method for producing the ethylene-α-olefin copolymer (A) will be described.
The ethylene-α-olefin copolymer (A) can be efficiently produced by polymerizing ethylene and an α-olefin having 4 to 10 carbon atoms in the presence of an olefin polymerization catalyst (X) comprising the following components:

[Olefin polymerization catalyst (X)]
The olefin polymerization catalyst (X) comprises the following component (A) and a solid support (S):

<Component (A)>
Component (A) is a transition metal compound represented by the following formula (1) (hereinafter also referred to as "transition metal compound (1)"). Olefin polymerization catalyst (X) contains at least one transition metal compound (1). That is, as component (A), one or more transition metal compounds (1) may be used.

In the formula (1), M is a zirconium atom or a hafnium atom, and is preferably a zirconium atom.
In the formula (1), n is an integer of 1 to 4, preferably 2, selected so that the transition metal compound (1) is electrically neutral.

In the formula (1), each X is independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, an oxygen-containing group, a nitrogen-containing group, or a conjugated diene derivative group, and is preferably a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

The halogen atom includes fluorine, chlorine, bromine and iodine, with chlorine being particularly preferred.
Examples of the hydrocarbon group having 1 to 20 carbon atoms include:
linear or branched alkyl groups such as methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, isopropyl, sec-butyl (butan-2-yl), tert-butyl (2-methylpropan-2-yl), isobutyl (2-methylpropyl), pentan-2-yl, 2-methylbutyl, isopentyl (3-methylbutyl), neopentyl (2,2-dimethylpropyl), cyamyl (1,2-dimethylpropyl), isohexyl (4-methylpentyl), 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, thexyl (2,3-dimethylbut-2-yl), and 4,4-dimethylpentyl;
linear or branched alkenyl groups or unsaturated double bond-containing groups such as a vinyl group, an allyl group, a propenyl group (prop-1-en-1-yl group), an iso-propenyl group (prop-1-en-2-yl group), an allenyl group (prop-1,2-dien-1-yl group), a but-3-en-1-yl group, a crotyl group (but-2-en-1-yl group), a but-3-en-2-yl group, a methallyl group (2-methylallyl group), a buta-1,3-dienyl group, a pent-4-en-1-yl group, a pent-3-en-1-yl group, a pent-2-en-1-yl group, an iso-pentenyl group (3-methylbut-3-en-1-yl group), a 2-methylbut-3-en-1-yl group, a pent-4-en-2-yl group, or a prenyl group (3-methylbut-2-en-1-yl group);
a straight-chain or branched alkynyl group or an unsaturated triple bond-containing group such as an ethynyl group, a prop-2-yn-1-yl group, or a propargyl group (prop-1-yn-1-yl group);
linear or branched alkyl groups and unsaturated double bond-containing groups containing aromatic groups, such as benzyl group, 2-methylbenzyl group, 4-methylbenzyl group, 2,4,6-trimethylbenzyl group, 3,5-dimethylbenzyl group, cuminyl group (4-isopropylbenzyl group), 2,4,6-tri-isopropylbenzyl group, 4-tert-butylbenzyl group, 3,5-di-tert-butylbenzyl group, 1-phenylethyl group, and benzhydryl group (diphenylmethyl group);
cyclic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloheptatrienyl group, a norbornyl group, a norbornenyl group, a 1-adamantyl group, and a 2-adamantyl group;
Examples of aromatic substituents include a phenyl group, a tolyl group (methylphenyl group), a xylyl group (dimethylphenyl group), a mesityl group (2,4,6-trimethylphenyl group), a cumenyl group (isopropylphenyl group), a duryl group (2,3,5,6-tetramethylphenyl group), a 2,6-di-isopropylphenyl group, a 2,4,6-tri-isopropylphenyl group, a 4-tert-butylphenyl group, a 3,5-di-tert-butylphenyl group, a naphthyl group, a biphenyl group, a ter-phenyl group, a binaphthyl group, an acenaphthalenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, and a ferrocenyl group, and preferred are a methyl group, an isobutyl group, a neopentyl group, a cyamyl group, a benzyl group, a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a cumenyl group.

The hydrocarbon group having 1 to 20 carbon atoms may be a halogen-substituted hydrocarbon group in which some or all of the hydrogen atoms of the hydrocarbon group having 1 to 20 carbon atoms have been substituted with halogen atoms. Examples of such a group include a fluoromethyl group, a trifluoromethyl group, a trichloromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a pentachloroethyl group, a pentafluorophenylmethyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a tetrafluorophenyl group, a pentafluorophenyl group, a trifluoromethylphenyl group, and a bistrifluoromethylphenyl group, with a pentafluorophenyl group being preferred.

Examples of the silicon-containing group include trimethylsilyl, triethylsilyl, tri-isopropylsilyl, diphenylmethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, triphenylsilyl, tris(trimethylsilyl)silyl, and trimethylsilylmethyl groups, with the trimethylsilylmethyl group being preferred.

Examples of the oxygen-containing group include methoxy, ethoxy, n-propoxy, iso-propoxy, allyloxy, n-butoxy, sec-butoxy, iso-butoxy, tert-butoxy, benzyloxy, methoxymethoxy, phenoxy, 2,6-dimethylphenoxy, 2,6-di-iso-propylphenoxy, 2,6-di-tert-butylphenoxy, 2,4,6-trimethylphenoxy, 2,4,6-tri-iso-propylphenoxy, acetoxy, pivaloyloxy, benzoyloxy, trifluoroacetoxy, perchlorate anion, and periodate anion, with methoxy, ethoxy, iso-propoxy, and tert-butoxy groups being preferred.

Examples of the nitrogen-containing group include amino, cyano, methylamino, dimethylamino, ethylamino, diethylamino, allylamino, diallylamino, benzylamino, dibenzylamino, pyrrolidinyl, piperidinyl, morpholyl, pyrrolyl, and bistriflylimide groups.

Examples of the conjugated diene derivative group include a 1,3-butadienyl group, an isoprenyl group (2-methyl-1,3-butadienyl group), a piperylenyl group (1,3-pentadienyl group), a 2,4-hexadienyl group, a 1,4-diphenyl-1,3-pentadienyl group, and a cyclopentadienyl group, with the 1,3-butadienyl group and the 1,3-pentadienyl group being preferred.

In the formula (1), Q is a carbon atom or a silicon atom, and is preferably a silicon atom.
In the formula (1), R ¹ to R ¹⁴ each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group having 1 to 20 carbon atoms, an oxygen-containing group having 1 to 20 carbon atoms, or a nitrogen-containing group having 1 to 20 carbon atoms, and are preferably a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or an oxygen-containing group having 1 to 20 carbon atoms.

Examples of the hydrocarbon group having 1 to 20 carbon atoms represented by R ¹ to R ¹⁴ include linear or branched alkyl groups such as methyl, ethyl, 1-propyl, 1-butyl, 1-pentyl, 1-hexyl, 1-heptyl, 1-octyl, isopropyl, sec-butyl (butan-2-yl), tert-butyl (2-methylpropan-2-yl), isobutyl (2-methylpropyl), pentan-2-yl, 2-methylbutyl, isopentyl (3-methylbutyl), neopentyl (2,2-dimethylpropyl), cyamyl (1,2-dimethylpropyl), isohexyl (4-methylpentyl), 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, thexyl (2,3-dimethylbut-2-yl), and 4,4-dimethylpentyl;
linear or branched alkenyl groups or unsaturated double bond-containing groups such as a vinyl group, an allyl group, a propenyl group (prop-1-en-1-yl group), an iso-propenyl group (prop-1-en-2-yl group), an allenyl group (prop-1,2-dien-1-yl group), a but-3-en-1-yl group, a crotyl group (but-2-en-1-yl group), a but-3-en-2-yl group, a methallyl group (2-methylallyl group), a buta-1,3-dienyl group, a pent-4-en-1-yl group, a pent-3-en-1-yl group, a pent-2-en-1-yl group, an iso-pentenyl group (3-methylbut-3-en-1-yl group), a 2-methylbut-3-en-1-yl group, a pent-4-en-2-yl group, or a prenyl group (3-methylbut-2-en-1-yl group);
a straight-chain or branched alkynyl group or an unsaturated triple bond-containing group such as an ethynyl group, a prop-2-yn-1-yl group, or a propargyl group (prop-1-yn-1-yl group);
linear or branched alkyl groups containing aromatic groups and unsaturated double bond-containing groups, such as benzyl group, 2-methylbenzyl group, 4-methylbenzyl group, 2,4,6-trimethylbenzyl group, 3,5-dimethylbenzyl group, cuminyl group (4-isopropylbenzyl group), 2,4,6-tri-isopropylbenzyl group, 4-tert-butylbenzyl group, 3,5-di-tert-butylbenzyl group, 1-phenylethyl group, benzhydryl group (diphenylmethyl group), and pentafluorophenylmethyl group;
cyclic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cycloheptatrienyl group, a norbornyl group, a norbornenyl group, a 1-adamantyl group, and a 2-adamantyl group;
aromatic substituents such as a phenyl group, a tolyl group (methylphenyl group), a xylyl group (dimethylphenyl group), a mesityl group (2,4,6-trimethylphenyl group), a cumenyl group (isopropylphenyl group), a duryl group (2,3,5,6-tetramethylphenyl group), a 2,6-di-isopropylphenyl group, a 2,4,6-tri-isopropylphenyl group, a 4-tert-butylphenyl group, a 3,5-di-tert-butylphenyl group, a naphthyl group, a biphenyl group, a ter-phenyl group, a binaphthyl group, an acenaphthalenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, and a ferrocenyl group;
halogen-substituted hydrocarbon groups in which some or all of the hydrogen atoms of the hydrocarbon groups having 1 to 20 carbon atoms have been substituted with halogen atoms, such as a fluoromethyl group, a trifluoromethyl group, a trichloromethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, a pentachloroethyl group, a pentafluorophenylmethyl group, a fluorophenyl group, a difluorophenyl group, a trifluorophenyl group, a tetrafluorophenyl group, a pentafluorophenyl group, a trifluoromethylphenyl group, and a bistrifluoromethylphenyl group;
and preferably a methyl group, an ethyl group, a 1-propyl group, a 1-butyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, an isopropyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, an allyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclooctenyl group, a norbornyl group, a bicyclo[2.2.2]octan-1-yl group, a 1-adamantyl group, a 2-adamantyl group, or a benzyl group. , benzhydryl group, cumyl group, 1,1-diphenylethyl group, trityl group, 2-phenylethyl group, 3-phenylpropyl group, cinnamyl group, phenyl group, tolyl group, xylyl group, mesityl group, cumenyl group, 2,6-di-iso-propylphenyl group, 2,4,6-tri-iso-propylphenyl group, 4-tert-butylphenyl group, 3,5-di-tert-butylphenyl group, 4-adamantylphenyl group, naphthyl group, biphenyl group, tert-phenyl group, binaphthyl group, phenanthryl group, anthracenyl group, ferrocenyl group, and pentafluorophenyl group.

Preferred examples of the silicon-containing group having 1 to 20 carbon atoms represented by R ¹ to R ¹⁴ include a trimethylsilyl group, a triethylsilyl group, a tri-isopropylsilyl group, a tert-butyldimethylsilyl group, a triphenylsilyl group, a cyclopentadienyldimethylsilyl group, a cyclopentadienyldiphenylsilyl group, an indenyldimethylsilyl group, a fluorenyldimethylsilyl group, a 4-trimethylsilylphenyl group, a 4-triethylsilylphenyl group, a 4-tri-isopropylsilylphenyl group, and a 3,5-bis(trimethylsilyl)phenyl group, and examples thereof include a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a 4-trimethylsilylphenyl group, a 4-triethylsilylphenyl group, a 4-tri-isopropylsilylphenyl group, and a 3,5-bis(trimethylsilyl)phenyl group.

The oxygen-containing group having 1 to 20 carbon atoms represented by R ¹ to R ¹⁴ includes a methoxy group, an ethoxy group, an iso-propoxy group, an allyloxy group, an n-butoxy group, a tert-butoxy group, a prenyloxy group, a benzyloxy group, a phenoxy group, a naphthoxy group, a toluyloxy group, an iso-propylphenoxy group, an allylphenoxy group, a tert-butylphenoxy group, a methoxyphenoxy group, a biphenyloxy group, a binaphthyloxy group, an allyloxymethyl group, a benzyloxymethyl group, a phenoxymethyl group, a methoxyethyl group, a methoxyallyl group, a benzyloxyallyl group, a phenoxyallyl group, a dimethoxymethyl group, a dioxolanyl group, a tetramethyldioxolanyl group, a dioxanyl group, a dimethyldioxanyl group, a methoxyphenyl group, an iso-propoxyphenyl group, an azobenzene group, a methylphenyl ... Examples of the alkyl group include an allyloxyphenyl group, a phenoxyphenyl group, a methylenedioxyphenyl group, a 3,5-dimethyl-4-methoxyphenyl group, a 3,5-di-tert-butyl-4-methoxyphenyl group, a furyl group, a methylfuryl group, a tetrahydropyranyl group, a furofuryl group, a benzofuryl group, and a dibenzofuryl group, and preferred are a methoxy group, an iso-propoxy group, a tert-butoxy group, an allyloxy group, a phenoxy group, a dimethoxymethyl group, a dioxolanyl group, a methoxyphenyl group, an iso-propoxyphenyl group, an allyloxyphenyl group, a phenoxyphenyl group, a 3,5-dimethyl-4-methoxyphenyl group, a 3,5-di-tert-butyl-4-methoxyphenyl group, a furyl group, a methylfuryl group, a benzofuryl group, and a dibenzofuryl group.

The nitrogen-containing group having 1 to 20 carbon atoms represented by R ¹ to R ¹⁴ includes an amino group, a dimethylamino group, a diethylamino group, an allylamino group, a benzylamino group, a dibenzylamino group, a pyrrolidinyl group, a piperidinyl group, a morpholyl group, a dimethylaminomethyl group, a benzylaminomethyl group, a pyrrolidinylmethyl group, a dimethylaminoethyl group, a pyrrolidinylethyl group, a dimethylaminopropyl group, a pyrrolidinylpropyl group, a dimethylaminoallyl group, a pyrrolidinylallyl group, an aminophenyl group, a dimethylaminophenyl group, a 3,5-dimethyl-4-dimethylaminophenyl group, a 3,5-di-iso-propyl-4-dimethylaminophenyl group, a julolidinyl group, a tetramethyljulolidinyl group, a pyrrolidinylphenyl group, a pyrrolylphenyl group, a carbazolylphenyl group, a di-tert-butylcarbazolyl group, a methyl ... Examples of the benzoxazolyl group include a benzoylphenyl group, a pyrrolyl group, a pyridyl group, a quinolyl group, a tetrahydroquinolyl group, an isoquinolyl group, a tetrahydro-isoquinolyl group, an indolyl group, an indolinyl group, a carbazolyl group, a di-tert-butylcarbazolyl group, an imidazolyl group, a dimethylimidazolidinyl group, a benzimidazolyl group, an oxazolyl group, an oxazolidinyl group, and a benzoxazolyl group. Preferred are an amino group, a dimethylamino group, a diethylamino group, a pyrrolidinyl group, a dimethylaminophenyl group, a 3,5-dimethyl-4-dimethylaminophenyl group, a 3,5-di-iso-propyl-4-dimethylaminophenyl group, a julolidinyl group, a tetramethyljulolidinyl group, a pyrrolidinylphenyl group, a pyrrolyl group, a pyridyl group, a carbazolyl group, and an imidazolyl group.

In formula (1), adjacent substituents among R ¹ to R ⁶ (e.g., R ¹ and R ² , R ² and R ³ , R ³ and R ⁴ , R ⁴ and R ⁵ , and R ⁵ and R ⁶ ) may be bonded to each other to form a ring which may have a substituent. In this case, the ring formed is preferably a 5- to 8-membered ring fused to the indenyl ring moiety and made of a saturated hydrocarbon (excluding the hydrocarbon of the indenyl ring moiety) or an unsaturated hydrocarbon which may have a substituent. When multiple rings are present, these may be the same or different. While not particularly limited as long as the effects of the present invention are achieved, the ring is more preferably a 5- or 6-membered ring. In this case, examples of the structure formed by combining the ring and the indenyl ring moiety of the mother nucleus include a benzoindenyl ring, a tetrahydroindacene ring, and a cyclopentatetrahydronaphthalene ring, with a benzoindenyl ring and a tetrahydroindacene ring being preferred. These rings may have a substituent.

In formula (1), adjacent substituents among ^R to ^R (e.g., R and ^R , R and R, ^R and ^R , ^R and ^R , R and ^R , R and ^R ) may be bonded to each other to form a ring which may have a substituent. In this case, the ring formed is preferably ^{a 5-} to ^{8 -} membered ring which is fused to the indenyl ring moiety and which is made of a saturated hydrocarbon (excluding the hydrocarbon of the indenyl ring moiety) or an unsaturated hydrocarbon which may have a substituent. When multiple rings are present, these may be the same or different. Although not particularly limited as long as the effects of the present invention are achieved, the ring is more preferably a 5- or 6-membered ring. In this case, examples of the structure formed by combining the ring and the indenyl ring moiety of the mother nucleus include a benzoindenyl ring, a tetrahydroindacene ring, a cyclopentatetrahydronaphthalene ring, a tetrahydrofluorene ring, and a fluorene ring, with a benzoindenyl ring and a tetrahydroindacene ring being preferred. These rings may have a substituent.

In the formula (1), R ¹³ and R ¹⁴ may be bonded to each other to form a ring containing Q, and these rings may have a substituent. In this case, the ring formed preferably forms a 3- to 8-membered saturated or unsaturated ring which may have a substituent. While not particularly limited as long as the effects of the present invention are achieved, a 4- to 6-membered ring is preferred. In this case, examples of the structure combined with Q include a cyclobutane ring, a cyclopentane ring, a fluorene ring, a silacyclobutane (siletane) ring, a silacyclopentane (silorane) ring, a silacyclohexane (silinane) ring, and a silafluorene ring, with a cyclopentane ring, a silacyclobutane ring, and a silacyclopentane ring being preferred. These rings may have a substituent.

Specific examples of the transition metal compound (1) are shown below, but the scope of the present invention is not particularly limited by these.
For convenience, the ligand structure of the transition metal compound (1) excluding the portion represented by MXn (metal portion) is divided into seven structures: a 2-indenyl ring portion, a 1-indenyl ring portion, ^R1 , ^R6 , and ^R8 substituents of the indenyl ring portion, ^R2 , ^R5 , ^R9, and ^R12 substituents of the indenyl ring portion, ^R3 , ^R4 , ^R10 , and ^R11 substituents of the indenyl ring portion, ^R7 substituent of the 1-indenyl ring portion, and a bridge portion. The abbreviation for the 2-indenyl ring moiety is α, the abbreviation for the 1-indenyl ring moiety is β, the abbreviation for the R ¹ , R ⁶ and R ⁸ substituents on the indenyl ring moiety is γ, the abbreviation for the R ² , R ⁵ , R ⁹ and R ¹² substituents on the indenyl ring moiety is δ, the abbreviation for the R ³ , R ⁴ , R ¹⁰ and R ¹¹ substituents on the indenyl ring moiety is ε, the abbreviation for the R ⁷ substituent on the 1-indenyl ring moiety is ζ, and the abbreviation for the structure of the bridged moiety is η. The abbreviations for the substituents are shown in Tables 1 to 7.

Note that the wavy lines in Tables 1 and 2 indicate the bond sites with the crosslinked moieties.

The R ¹ , R ⁶ and R ⁸ substituents in Table 3 may be the same or different from one another in combination.

The R ² , R ⁵ , R ⁹ and R ¹² substituents in Table 4 may be the same or different from one another in combination.

The R ³ , R ⁴ , R ¹⁰ and R ¹¹ substituents in Table 5 may be the same or different from one another in combination.

Specific examples of the metal moiety MXn include _ZrF2 , _ZrCl2 , _ZrBr2 , _ZrI2 , Zr(Me) ₂ , Zr(Bn)2, Zr(Allyl) ₂ , Zr( _CH2 -tBu) ₂ , Zr(1,3-butadienyl), _Zr (1,3-pentadienyl), Zr(2,4-hexadienyl), Zr(1,4-diphenyl-1,3-pentadienyl), Zr( _CH2 -Si(Me) ₃ ) ₂ , Zr(OMe) ₂ , Zr(OiPr) ₂ , Zr( _NMe2 ) ₂ , Zr(OMs) ₂ , Zr(OTs) ₂ , Zr(OTf) ₂ , and HfF. ₂ , HfCl ₂ , HfBr ₂ , HfI ₂ , Hf(Me) ₂ , Hf(Bn) ₂ , Hf(Allyl) ₂ , Hf(CH ₂ -tBu) ₂ , Hf(1,3-butadienyl), Hf(1,3-pentadienyl), Hf(2,4-hexadienyl), Hf(1,4-diphenyl-1,3-pentadienyl), Hf(CH ₂ -Si(Me) ₃ ) ₂ , Hf(OMe) ₂ , Hf(OiPr) ₂ , Hf(NMe ₂ ) ₂ , Hf(OMs) ₂ , Hf(OTs) ₂ , Hf(OTf) ₂ , and the like. Me is a methyl group, Bn is a benzyl group, tBu is a tert-butyl group, Si(Me) is a trimethylsilyl group, _OMe is a methoxy group, OiPr is an iso-propoxy group, _NMe is a dimethylamino group, OMs is a methanesulfonate group, OTs is a p-toluenesulfonate group, and OTf is a trifluoromethanesulfonate group.

According to the above notation, when the 2-indenyl ring moiety is α-1 in [Table 1], the 1-indenyl ring moiety is β-5 in [Table 2], the indenyl ring moiety R ¹ , R ⁶ and R ⁸ substituents are all γ-1 in [Table 3], the 2-indenyl ring moiety R ² and R ⁵ substituents are all δ-1 in [Table 4], the 2-indenyl ring moiety R ³ and R ⁴ substituents are all ε-1 in [Table 5], the 1-indenyl ring moiety R ⁷ substituent is ζ-30 in [Table 6], the 1-indenyl ring moiety R ⁹ substituent is δ-38 in [Table 4], the 1-indenyl ring moiety R ¹² substituent is δ-3 in [Table 4], and the bridging moiety is η-20 in [Table 7], and the metal moiety MXn is ZrCl ₂ , the compound represented by the following formula [6] is exemplified.

Furthermore, when the 2-indenyl ring moiety is α-1 in [Table 1], the 1-indenyl ring moiety is β-2 in [Table 2], the indenyl ring moiety R ¹ , R ⁶ and R ⁸ substituents are all γ-1 in [Table 3], the 2-indenyl ring moiety R ² and R ⁵ substituents are all δ-2 in [Table 4], the 2-indenyl ring moiety R ³ and R ⁴ substituents are all ε-1 in [Table 5], the 1-indenyl ring moiety R ⁷ substituent is ζ-1 in [Table 6], the bridging moiety is composed of a combination of η-4 in [Table 7], and the metal moiety MXn is Zr(NMe ₂ ) ₂ , the compound represented by the following formula [7] is exemplified.

Furthermore, when the 2-indenyl ring moiety is α-3 in [Table 1], the 1-indenyl ring moiety is β-1 in [Table 2], the ^R1 and ^R6 substituents of the 2-indenyl ring moiety are both γ-2 in [Table 3], the ^R2 , ^R5 and ^R12 substituents of the indenyl ring moiety are all δ-1 in [Table 4], the ^R7 substituent of the 1-indenyl ring moiety is ζ-12 in [Table 6], the ^R8 substituent of the 1-indenyl ring moiety is γ- ¹ in [Table 3], the R9 substituent of the 1-indenyl ring moiety is δ-42 in [Table 4], the ^R10 substituent of the 1-indenyl ring moiety is ε-3 in [Table 5], the ^R11 substituent of the 1-indenyl ring moiety is ε-12 in [Table 5], and the bridging moiety is η-31 in [Table 7], and the metal moiety MXn is _HfMe2 , a compound represented by the following formula [8] is exemplified.

In addition, the α-1,1-indenyl ring moiety in [Table 1] is the β-1,2-indenyl ring moiety ^R1 and ^R6 in [Table 2], the R2 substituent in [Table 3] is the γ-1,2-indenyl ring moiety ^R2 in [Table 4], the ^R3 , ^R4 , ^R10 and ^R11 substituents in [Table 5] are the ε-1,2-indenyl ring moiety ^R5 in [Table 5], the ^R7 substituent in [Table 4] is the δ-2,1-indenyl ring moiety R8 in [Table 6], and the R9 and ^R11 substituents in [Table 3] are the γ-9,1-indenyl ring moiety ^R9 and R10 in [Table 3]. In the case where all ¹² substituents are composed of a combination of δ-1 in [Table 4], the bridging portion is composed of a combination of η-29 in [Table 7], and the metal portion MXn is Zr(1,3-pentadienyl), the compound represented by the following formula [9] is exemplified.

The transition metal compound (1) can be produced by any conventionally known method, and the production method is not particularly limited.
The substituted indene compound as a starting material can be produced by a known method, and the production method is not particularly limited. Known production methods include, for example, "Organometallics 1994, 13, 954.", "Organometallics 2006, 25, 1217.", JP-A-2006-509059, "Bioorg. Med. Chem. 2008, 16, 7399.", WO2009/080216, "Organometallics 2011, 30, 5744.", JP-A-2011-500800, "Organometallics 2012, 31, 4962.", and "Chem. Eur. J. 2012,18,4174.", JP 2012-012307 A, JP 2012-121882 A, JP 2014-196319 A, JP 2014-513735 A, JP 2015-063495 A, JP 2016-501952 A, JP 2019-059933 A, and the like.

Known methods for producing transition metal compound (1) and precursor compounds (ligands) are described, for example, in "Macromolecules 2001, 34, 2072," "Macromolecules 2003, 36, 9325," "Organometallics 2004, 23, 5332," "Eur. J. Inorg. Chem. 2005, 1003," and "Eur. J. Inorg. Chem. 2009, 1759."

Furthermore, the transition metal compound (1) has two faces (front and back) of the indenyl ring moiety that bond to the central metal across the bridge. Therefore, when the 2-indenyl ring moiety does not have a plane of symmetry, two structural isomers exist, as shown, for example, in the following general formula [10a] or [10b].

Similarly, when the substituents R ¹³ and R ¹⁴ in the bridging moiety are not the same, there exist two structural isomers, for example, represented by the following general formula [11a] or [11b].

Purification and separation of these structural isomer mixtures, or selective production of structural isomers, can be achieved by known methods, and the production method is not particularly limited. Known production methods include those listed as the production method for transition metal compound (1) above, as well as those disclosed in JP-A-10-109996, "Organometallics 1999, 18, 5347," "Organometallics 2012, 31, 4340," and JP-A-2011-502192.

Within the scope of the transition metal compound (1), the transition metal compound may be used alone or in combination of two or more types, or a structural isomer mixture may be used, or a structural isomer may be used alone or in combination of two or more types. As described above, according to the present invention, an ethylene polymer having many long-chain branches introduced therein can be produced with high catalytic activity by using only the transition metal compound (1) as the transition metal compound constituting the olefin polymerization catalyst. However, as long as this effect is not impaired, one or more transition metal compounds other than the transition metal compound (1) may be used in combination as the transition metal compound. In this case, the transition metal compound (1) may be in any of the above-mentioned forms.

<Solid Carrier (S)>
The solid support (S) contained in the olefin polymerization catalyst (X) is an inorganic or organic compound, and is a granular or fine particle solid.

Inorganic compounds used as the solid support (S) include porous oxides, solid aluminoxane compounds, inorganic chlorides, clays, clay minerals, and ion-exchange layered compounds.

The porous oxides that can be used include _{SiO2 , Al2O3} , MgO, ZrO _, TiO2, _B2O3 , CaO, ZnO, BaO, and _ThO2 , as well _as composites or mixtures containing these, specifically natural or synthetic zeolites, SiO2 _- MgO, _SiO2 - _Al2O3 , SiO2 _{- TiO2 , SiO2} - _V2O5 , _SiO2 - _Cr2O3 , and _SiO2 - _{TiO2 - MgO} . Of these, those containing _SiO2 as the main component are preferred.

The porous oxide may contain small amounts of _carbonates , sulfates _, nitrates _, and oxides such as _Na2CO3 , _K2CO3 , _CaCO3 , _MgCO3 , _Na2SO4 , _Al2 ( _SO4 ) ₃ , _BaSO4 , _KNO3 , Mg( _NO3 ) ₂ , Al( _NO3 ) ₃ , _Na2O , _K2O , and _Li2O .

Although the properties of such porous oxides vary depending on the type and production method, the solid support (S) preferably has a particle size of usually 0.2 to 300 μm, preferably 1 to 200 μm, a specific surface area of usually 50 to 1200 ^m /g, preferably 100 to 1000 ^m /g, and a pore volume of usually 0.3 to 30 ^cm /g. If necessary, such a support may be calcined, for example, at 100 to 1000° C., preferably 150 to 700° C., before use.

Examples of the solid aluminoxane compound include aluminoxanes having a structure represented by the following general formula (S-a), aluminoxanes having a structure represented by the following general formula (S-b), and aluminoxanes having a structure comprising a repeating unit represented by the following general formula (S-c) and a repeating unit represented by the following general formula (S-d).

In the above formulas (S-a) to (S-d), R ^e each independently represents a hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. Specific examples include hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, isopropenyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, tridecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclohexyl, cyclooctyl, phenyl, tolyl, and ethylphenyl. Methyl, ethyl, and isobutyl groups are preferred, with methyl being particularly preferred. Furthermore, R ^e may be partially substituted with halogen atoms such as chlorine or bromine, and the halogen content may be 40% by weight or less based on R ^e . In the above formulas (S-c) and (S-d), a line not connected to an atom on one side represents a bond to another atom not shown.

In the formulas (S-a) and (S-b), r represents an integer of 2 to 500, preferably 6 to 300, and particularly preferably 10 to 100. In the formulas (S-c) and (S-d), s and t each represent an integer of 1 or greater. r, s, and t are selected so that the aluminoxane can remain substantially in a solid state in the reaction environment in which it is used.

The solid aluminoxane compound differs from conventionally known olefin polymerization catalyst supports in that it does not contain inorganic solid components such as silica or alumina, or organic polymer components such as polyethylene or polystyrene, but is a solidified product made primarily from an alkylaluminum compound. "Solid" means that the aluminoxane component remains substantially solid in the reaction environment in which it is used. More specifically, the aluminoxane component remains substantially solid when component (A) is contacted with the aluminoxane component to prepare an olefin polymerization catalyst (e.g., an ethylene polymerization catalyst), as described below, and when the prepared olefin polymerization catalyst is used to polymerize an olefin (e.g., ethylene) (e.g., suspension polymerization).

While visual inspection is the simplest method for determining whether the aluminoxane component is in a solid state, visual inspection is often difficult, for example, during polymerization. In such cases, it is possible to determine this from the properties of the polymer powder obtained after polymerization and the state of adhesion to the reactor. Conversely, if the polymer powder has good properties and adhesion to the reactor is minimal, the gist of this invention does not deviate from the spirit of the present invention even if some of the aluminoxane component leaches out in the polymerization environment. Indicators for determining the properties of the polymer powder include bulk density, particle shape, surface shape, and the presence of amorphous polymers, but polymer bulk density is preferred from the perspective of quantitative accuracy. The bulk density is typically 0.01 to 0.9, preferably 0.05 to 0.6, and more preferably 0.1 to 0.5.

The solubility of the solid aluminoxane compound in n-hexane maintained at 25°C is typically in the range of 0 to 40 mol%, preferably 0 to 20 mol%, and particularly preferably 0 to 10 mol%.

The dissolution rate is determined by adding 2 g of the solid aluminoxane compound carrier to 50 ml of n-hexane maintained at 25°C, stirring for 2 hours, separating the solution using a G-4 glass filter, and measuring the aluminum concentration in the filtrate. Therefore, the dissolution rate is determined as the ratio of aluminum atoms present in the filtrate to the amount of aluminum atoms equivalent to 2 g of aluminoxane used.

The solid aluminoxane compound can be any known solid aluminoxane without limitation, and can include, for example, the solid polyaluminoxane composition described in WO 2014/123212. Known production methods include those described in JP-B-7-42301, JP-A-6-220126, JP-A-6-220128, JP-A-11-140113, JP-A-11-310607, JP-A-2000-38410, JP-A-2000-95810, and WO 2010/55652.

The average particle diameter of the solid aluminoxane compound is generally in the range of 0.01 to 50,000 μm, preferably 0.1 to 1,000 μm, and particularly preferably 1 to 200 μm. The average particle diameter of the solid aluminoxane compound is determined by observing the particles with a scanning electron microscope, measuring the particle diameters of 100 or more particles, and averaging the weight values. First, the particle diameter d of each particle is determined by measuring the length of the particle image between two parallel lines in the horizontal and vertical directions, and then using the following formula:

Particle size d = ((horizontal length) ² + (vertical length) ² ) ^0.5
Next, the weight average particle size of the solid aluminoxane compound is calculated by the following formula using the particle size d calculated above and the number of particles n.
Average particle size = Σnd ⁴ /Σnd ³
The solid aluminoxane compound preferably has a specific surface area of 50 to 1000 m ² /g, more preferably 100 to 800 m ² /g, and a pore volume of 0.1 to 2.5 cm ³ /g.

Examples of the inorganic halide include _MgCl2 , _MgBr2 , _MnCl2 , and _MnBr2 . The inorganic halide may be used as is, or may be used after being pulverized using a ball mill or a vibration mill. Alternatively, the inorganic halide may be dissolved in a solvent such as alcohol and then precipitated into fine particles using a precipitating agent.

Clay is usually composed primarily of clay minerals. Ion-exchangeable layered compounds are compounds with a crystalline structure in which planes formed by ionic bonds or other factors are stacked parallel to one another with weak bonding forces, and the ions they contain are exchangeable. Most clay minerals are ion-exchangeable layered compounds. These clays, clay minerals, and ion-exchangeable layered compounds are not limited to naturally occurring substances; synthetic compounds can also be used.

Examples of clays, clay minerals, or ion-exchangeable layered compounds include clays, clay minerals, and ionic crystalline compounds having layered crystal structures such as hexagonal close packing type, antimony type, CdCl ₂ type, and CdI ₂ type.

Examples of such clays and clay minerals include kaolin, bentonite, kibushi clay, gairome clay, allophane, hisingerite, pyrophyllite, ummo group, montmorillonite group, vermiculite, ryokudeite group, palygorskite, kaolinite, nacrite, dickite, halloysite, and the like. Examples of ion-exchange layered compounds include α-Zr(HAsO ₄ ) ₂ ·H ₂ O, α-Zr(HPO ₄ ) ₂ , α-Zr(KPO ₄ ) ₂ ·3H ₂ O, α-Ti(HPO ₄ ) ₂ , α-Ti(HAsO ₄ ) ₂ ·H ₂ O, α-Sn(HPO ₄ ) ₂ ·H ₂ O, γ-Zr(HPO ₄ ) ₂ , γ-Ti(HPO ₄ ) ₂ and crystalline acid salts of polyvalent metals such as γ-Ti(NH ₄ PO ₄ ) ₂ ·H ₂ O.

Such clays, clay minerals, or ion-exchange layered compounds preferably have a pore volume of 0.1 cc/g or more, particularly 0.3 to 5 cc/g, having a radius of 20 Å or more as measured by mercury intrusion porosimetry. Here, the pore volume is measured by mercury intrusion porosimetry using a mercury porosimeter over a pore radius range of 20 to 3×10 ⁴ Å. When a carrier having a pore volume of less than 0.1 cc/g having a radius of 20 Å or more is used, it tends to be difficult to obtain high polymerization activity.

It is also preferable to chemically treat clay and clay minerals. Chemical treatments include surface treatments that remove impurities from the surface and treatments that affect the crystalline structure of the clay. Specific examples of chemical treatments include acid treatment, alkali treatment, salt treatment, and organic treatment. Acid treatment not only removes surface impurities, but also increases the surface area by eluting cations such as Al, Fe, and Mg from the crystalline structure. Alkali treatment destroys the crystalline structure of the clay, resulting in structural changes. Salt treatment and organic treatment also form ionic complexes, molecular complexes, organic derivatives, and the like, which can change the surface area and interlayer distance.

The ion-exchangeable layered compound may be a layered compound in which the interlayer spacing is expanded by utilizing the ion exchange property and exchanging the exchangeable ions between the layers with other large, bulky ions. Such bulky ions act as supports supporting the layered structure and are commonly called pillars. The introduction of another substance between the layers of a layered compound is called intercalation. Examples of guest compounds to be intercalated include cationic inorganic compounds such as _TiCl4 and _ZrCl4 , metal alkoxides such as Ti(OR) ₄ , Zr(OR) ₄ , PO(OR _{) 3} , and B(OR) ₃ (where R is a hydrocarbon group, etc.), and metal hydroxide ions such as [ _Al13O4 (OH) ₂₄ ] ⁷⁺ , [ _Zr4 (OH) ₁₄ ] ²⁺ , and [ _Fe3O ( _OCOCH3 ) ₆ ] ⁺ . These compounds may be used alone or in combination of two or more. Furthermore, when these compounds are intercalated, polymers obtained by hydrolysis of metal alkoxides (R is a hydrocarbon group or the like) such as Si(OR) ₄ , Al(OR) ₃ , and Ge(OR) ₄ , and colloidal inorganic compounds such as SiO ₂ can also be present. Examples of pillars include oxides produced by intercalating the above metal hydroxide ions between layers and then dehydrating them with heat.

The clays, clay minerals, and ion-exchange layered compounds may be used as is, or after treatment such as ball milling or sieving. They may also be used after adding and adsorbing new water or after heat dehydration treatment. Furthermore, they may be used alone or in combination of two or more types.

Examples of the organic compound used as the solid carrier (S) include granular or particulate solids having a particle size in the range of 10 to 300 μm. Specific examples of the organic compound include polymers produced mainly from olefins having 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, polymers and reactants produced mainly from vinylcyclohexane, styrene, and divinylbenzene, and granular or particulate solids made of modified products thereof.
The solid support (S) is preferably a porous oxide from the viewpoint of preventing foreign matter from being formed during molding.

<Component (C)>
The olefin polymerization catalyst (X) may preferably further contain a component (C), and the component (C) is at least one compound selected from the group consisting of organometallic compounds (c-1) represented by the following general formulas (3) to (5), organoaluminum oxy compounds (c-2), and compounds (c-3) that react with the component (A) to form an ion pair:

R ^a _m Al (OR ^b ) _n H _p X _q ...(3)
In formula (3), R ^a and R ^b each independently represent a hydrocarbon group having 1 to 15 carbon atoms, X represents a halogen atom, m is a number that satisfies 0<m≦3, n is a number that satisfies 0≦n<3, p is a number that satisfies 0≦p<3, and q is a number that satisfies 0≦q<3, and m+n+p+q=3.

M ^a AlR ^a ₄ ...(4)
In formula (4), M ^a represents Li, Na or K, and R ^a represents a hydrocarbon group having 1 to 15 carbon atoms.

R ^a _r M ^b R ^b _s X _t ...(5)
In formula (5), R ^a and R ^b each independently represent a hydrocarbon group having 1 to 15 carbon atoms, M ^b is selected from Mg, Zn, and Cd, X represents a halogen atom, r is 0<r≦2, s is 0≦s≦1, t is 0≦t≦1, and r+s+t=2.

Among the organometallic compounds (c-1), those represented by the formula (3) are preferred, specifically, trialkylaluminums such as trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum, and tri-2-ethylhexylaluminum;
dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, diisopropylaluminum chloride, diisobutylaluminum chloride, and dimethylaluminum bromide;
alkylaluminum sesquihalides such as methylaluminum sesquichloride, ethylaluminum sesquichloride, isopropylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide;
alkylaluminum dihalides such as methylaluminum dichloride, ethylaluminum dichloride, isopropylaluminum dichloride, and ethylaluminum dibromide;
alkylaluminum hydrides such as dimethylaluminum hydride, diethylaluminum hydride, dihydrophenylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride, diisohexylaluminum hydride, diphenylaluminum hydride, dicyclohexylaluminum hydride, di-sec-heptylaluminum hydride, and di-sec-nonylaluminum hydride;
Examples include dialkylaluminum alkoxides such as dimethylaluminum ethoxide, diethylaluminum ethoxide, diisopropylaluminum methoxide, and diisobutylaluminum ethoxide.

An example of the compound represented by formula (4) is lithium aluminum hydride, and an example of the compound represented by formula (5) is a dialkylzinc compound described in JP-A-2003-171412, which can also be used in combination with a phenol compound.

The organoaluminum oxy compound (c-2) is preferably an organoaluminum oxy compound prepared from trialkylaluminum or tricycloalkylaluminum, and particularly preferably an aluminoxane prepared from trimethylaluminum or triisobutylaluminum, such as methylaluminoxane. Such organoaluminum oxy compounds may be used alone or in combination of two or more.

Examples of the compound (c-3) that reacts with component (A) to form an ion pair include Lewis acids, ionic compounds, borane compounds, and carborane compounds, as well as heteropoly and isopoly compounds, as described in, for example, JP-T-1-501950, JP-T-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, and US Pat. No. 5,321,106.

When an organoaluminum oxy compound such as methylaluminoxane is used in combination as a cocatalyst component in olefin polymerization catalyst (X), not only does it exhibit extremely high polymerization activity for olefin compounds, but it also reacts with active hydrogen in the solid support to easily prepare a solid support component containing the cocatalyst component. Therefore, it is preferable that component (C) contain at least an organoaluminum oxy compound (c-2).

<Usage and addition order of each ingredient>
The olefin polymerization catalyst (X) can be prepared by mixing and contacting the components (A) and (S), and optionally the component (C), in an inert hydrocarbon.

As a method for contacting each component, when paying attention to the order of contact, for example,
(i) a method of contacting component (S) with component (A); (ii) a method of contacting component (S) with component (C) and then with component (A); (iii) a method of contacting component (A) with component (C) and then with component (S); (iv) a method of contacting component (S) with component (C) and then with a mixture of component (A) and component (C);
(v) A method in which component (S) is contacted with component (C), then with component (C), and then with a mixture of component (A) and component (C). When multiple types of component (C) are used, the components (C) may be the same or different. Of the above methods, (i), (ii), and (iii) are preferred.

In each of the methods showing the contact order form described above, in the step involving contact of component (S) with component (C) and the step involving contact of component (S) with component (A), the coexistence of component (G) suppresses fouling during the polymerization reaction and improves the particle properties of the resulting polymer. Component (G) can be a compound having a polar functional group, preferably a nonionic surfactant, and more preferably a polyalkylene oxide block, higher aliphatic amide, polyalkylene oxide, polyalkylene oxide alkyl ether, alkyldiethanolamine, polyoxyalkylene alkylamine, glycerin fatty acid ester, or N-acylamino acid. These may be used alone or in combination of two or more.

Solvents used in preparing the olefin polymerization catalyst (X) include inert hydrocarbon solvents, such as aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane; and mixtures thereof.

When components (C) and (S) contact each other, reactive sites in component (C) react with reactive sites in component (S) to chemically bond them, forming a contact product of components (C) and (S). The contact time between components (C) and (S) is typically 1 minute to 20 hours, preferably 30 minutes to 10 hours, and the contact temperature is typically -50 to 200°C, preferably -20 to 120°C. If the initial contact between components (C) and (S) is rapid, the heat generated by the reaction and the reaction energy can cause component (S) to disintegrate, deteriorating the morphology of the resulting solid catalyst component. When used in polymerization, this can often result in poor polymer morphology and make continuous operation difficult. Therefore, it is preferable to initially contact components (C) and (S) at a lower temperature to suppress the heat generated by the reaction, or to control the heat generated by the reaction and react at a rate that maintains the initial contact temperature. This also applies when components (C) and (S) are first contacted and then component (C) is subsequently contacted. The contact weight ratio between component (C) and component (S) (weight of component (C)/weight of component (S)) can be selected arbitrarily, but a higher contact weight ratio allows more component (A) to be contacted, improving the catalytic activity per weight of the solid catalyst component.

The contact weight ratio of component (C) to component (S) [=weight of component (C)/weight of component (S)] is preferably 0.05 to 3.0, particularly preferably 0.1 to 2.0.
When the contact product of component (C) and component (S) is contacted with component (A), the contact time is usually 1 minute to 20 hours, and preferably 1 minute to 10 hours, and the contact temperature is usually within the range of −50 to 200° C., and preferably −50 to 100° C.

Component (C-1) is used in an amount such that the molar ratio of component (C-1) to the total transition metal atoms (M) in component (A) [(C-1)/M] is typically 0.01 to 100,000, preferably 0.05 to 50,000.

Component (C-2) is used in an amount such that the molar ratio of component (C-2) (in terms of aluminum atoms) to the total transition metal atoms (M) in component (A) [(C-2)/M] is typically 10 to 500,000, preferably 20 to 100,000.

Component (C-3) is used in an amount such that the molar ratio of component (C-3) to the total transition metal atoms (M) in component (A) [(C-3)/M] is generally 1 to 10, preferably 1 to 5.
The ratio of component (C) to the total transition metal atoms (M) in component (A) can be determined by inductively coupled plasma atomic emission spectrometry (ICP analysis). For ethylene polymerization, the olefin polymerization catalyst (X) can be used as is, but it can also be used after prepolymerizing an olefin on this olefin polymerization catalyst to form a prepolymerization catalyst (XP).

The prepolymerization catalyst (XP) can be prepared by prepolymerizing ethylene or the like, typically in an inert hydrocarbon solvent, in the presence of the olefin polymerization catalyst (X). This can be carried out batchwise, semi-continuously, or continuously, and can be carried out under reduced pressure, atmospheric pressure, or elevated pressure. Furthermore, it is desirable to produce the prepolymerization catalyst (XP) in an amount of 0.01 to 1,000 g, preferably 0.1 to 800 g, and more preferably 0.2 to 500 g, per 1 g of the solid catalyst component through prepolymerization.

The prepolymerized catalyst (XP) produced in the inert hydrocarbon solvent may be separated from the suspension and then resuspended in the inert hydrocarbon, and ethylene may be introduced into the resulting suspension. Alternatively, ethylene may be introduced into the suspension after drying.

The prepolymerization temperature is -20 to 80°C, preferably 0 to 60°C, and the prepolymerization time is 0.5 to 100 hours, preferably 1 to 50 hours. An olefin containing ethylene as the main component is preferably used for the prepolymerization.

The form of the solid catalyst component used in the prepolymerization can be any of those already mentioned, without any restrictions. Component (C) is also used if necessary, and organometallic compound (c-1) represented by formula (3) is preferably used. When component (C) is used, component (C) is used in an amount such that the molar ratio (Al/M) of aluminum atoms (Al) in component (C) to transition metal atoms (M) in component (A) is 0.1 to 10,000, preferably 0.5 to 5,000.

The concentration of the olefin polymerization catalyst (X) in the prepolymerization system is typically 1 to 1,000 grams/liter, preferably 10 to 500 grams/liter, in terms of the olefin polymerization catalyst/polymerization volume ratio. During prepolymerization, the aforementioned component (G) may be present to suppress fouling or improve particle properties.

Furthermore, for the purpose of improving the fluidity of the prepolymerized catalyst (XP) and suppressing the occurrence of heat spots, sheeting, and polymer lumps during polymerization, component (G) may be brought into contact with the prepolymerized catalyst (XP) once produced by prepolymerization.

The temperature when contacting component (G) is usually −50 to 50° C., preferably −20 to 50° C., and the contact time is usually 1 minute to 20 hours, preferably 5 minutes to 10 hours.
When the olefin polymerization catalyst (X) is contacted with the component (G), the component (G) is used in an amount of 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight, more preferably 0.4 to 5 parts by weight, per 100 parts by weight of the olefin polymerization catalyst (X).

The olefin polymerization catalyst (X) and component (G) can be mixed and contacted in an inert hydrocarbon solvent, and examples of the inert hydrocarbon solvent include those similar to those mentioned above.
In the method for producing an ethylene polymer according to the present invention, a dried prepolymerized catalyst (XP) (hereinafter also referred to as a "dried prepolymerized catalyst") can be used as the olefin polymerization catalyst (X). Drying of the prepolymerized catalyst (XP) is usually carried out after removing the hydrocarbon dispersant from the obtained suspension of the prepolymerized catalyst by filtration or the like.

The prepolymerized catalyst (XP) is dried by maintaining the prepolymerized catalyst (XP) at a temperature of 70°C or less, preferably in the range of 20 to 50°C, under a flow of inert gas. The volatile component content of the resulting dried prepolymerized catalyst is desirably 2.0% by weight or less, preferably 1.0% by weight or less. The lower the volatile component content of the dried prepolymerized catalyst, the better; there is no particular lower limit, but in practice it is 0.001% by weight. The drying time is usually 1 to 48 hours, depending on the drying temperature.

The dried prepolymerized catalyst has excellent fluidity, allowing it to be stably supplied to the polymerization reactor. Furthermore, using the dried prepolymerized catalyst eliminates the need to entrain the solvent used for suspension in the gas-phase polymerization system, allowing for stable polymerization.

[Method of producing ethylene polymer]
Next, the method for producing an ethylene polymer according to the present invention will be described. An ethylene polymer is obtained by polymerizing (homopolymerizing or copolymerizing) ethylene in the presence of the above-mentioned olefin polymerization catalyst (X). By using the olefin polymerization catalyst (X), it is possible to efficiently produce a low-density ethylene copolymer having numerous long-chain branches, which has high polymerization activity, excellent moldability and mechanical strength. The ethylene polymer of the present invention refers to a polymer having an ethylene content of 10 mol % or more.

In the present invention, polymerization can be carried out using either a liquid phase polymerization method such as solution polymerization or suspension polymerization, or a gas phase polymerization method. However, in suspension polymerization and gas phase polymerization methods, it is preferable to use the prepolymerization catalyst (XP).

Specific examples of inert hydrocarbon media used in liquid-phase polymerization methods include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane, and mixtures thereof. Furthermore, in liquid-phase polymerization methods, the olefin itself can also be used as the solvent.

When ethylene is polymerized using the above-mentioned olefin polymerization catalyst, component (A) is used in an amount of usually 1× ¹⁰ to 1× ¹⁰ mol, preferably 1× ¹⁰ to 1× ¹⁰ mol, per liter of reaction volume. Component (C) is also used, and the organoaluminum compound represented by formula (3) in (c-1) is particularly preferably used.

The polymerization temperature of ethylene using the prepolymerized catalyst (XP) is usually in the range of -50 to +200°C, preferably 0 to 170°C, and particularly preferably 60 to 170°C. The polymerization pressure is usually normal pressure to 100 kgf/ ^cm2 , preferably normal pressure to 50 kgf/ ^cm2 , and the polymerization reaction can be carried out by any of a batch system, a semi-continuous system, and a continuous system. Furthermore, the polymerization can be carried out in two or more stages with different reaction conditions.

The molecular weight of the resulting polymer can be adjusted by adding hydrogen to the polymerization system or by changing the polymerization temperature. Generally, the greater the amount of low-molecular-weight components, the greater the amount of adhesion to the polymerization reactor walls and agitator blades, which can increase the burden on cleaning processes and lead to reduced productivity. Component (G) can be present during polymerization to suppress fouling or improve particle properties.

In the present invention, the monomer supplied together with ethylene to the copolymerization reaction is one or more monomers selected from α-olefins having 4 to 10 carbon atoms, preferably α-olefins having 6 to 10 carbon atoms. Specific examples of α-olefins having 4 to 10 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, and 1-decene. Furthermore, monomers other than ethylene and α-olefins having 4 to 10 carbon atoms may or may not be supplied, provided that the effects of the present invention are not impaired.

<Method for producing high-pressure low-density polyethylene (B)>
The high-pressure low-density polyethylene (B) used in the present invention is produced by polymerizing ethylene by high-pressure radical polymerization. For example, it can be produced in an autoclave or tubular reactor by radical polymerization of ethylene monomer at a pressure in the range of 500 to 3500 kgf/cm ² G, a polymerization temperature in the range of 100 to 400°C, and using oxygen or an organic peroxide as a polymerization initiator. Commercially available high-pressure low-density polyethylene can be used as the high-pressure low-density polyethylene (B). Specific examples include Suntec (registered trademark) LD manufactured by Asahi Kasei Corporation, Mirason (registered trademark) manufactured by Mitsui Dow Polychemicals Co., Ltd., and Novatec (registered trademark) LD manufactured by Japan Polyethylene Corporation, which satisfy requirements (a) to (c) and, optionally, requirement (d).

The high-pressure low-density polyethylene (B) may contain structural units derived from biomass-derived ethylene. The ethylene constituting the polymer may be solely biomass-derived ethylene, solely fossil fuel-derived ethylene, or both biomass-derived ethylene and fossil fuel-derived ethylene. Biomass-derived ethylene is a monomer obtained from any renewable natural raw material, such as a plant-derived or animal-derived raw material, including fungi, yeast, algae, and bacteria, and its residues. It contains about 1×10 ^C isotope as carbon and has a biomass carbon concentration (pMC) of about 100 (pMC) measured in accordance with ASTM D6866. Biomass-derived ethylene can be obtained, for example, by a conventionally known method.
It is preferable from the viewpoint of reducing the environmental load that the high-pressure low-density polyethylene (B) contains a structural unit derived from a biomass-derived monomer.

<Method for producing ethylene-based resin composition (Z)>
The ethylene-based resin composition (Z) can be produced by melt-kneading the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), or by dry-blending pellets of the ethylene-α-olefin copolymer (A) with pellets of the high-pressure low-density polyethylene (B). When produced by melt-kneading, a continuous extruder or an internal kneader can be used. Examples of suitable devices include a single-screw extruder, a twin-screw extruder, a mixing roll, a Banbury mixer, and a kneader. Among these, a single-screw extruder and/or a twin-screw extruder is preferred from the viewpoints of economy, processing efficiency, and the like.

When the melt-kneading and dry-blending are carried out, the "other thermoplastic resin" may be blended in addition to the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B). Furthermore, the "additive" may be further blended in addition to or instead of the "other thermoplastic resin."

The order in which the "other thermoplastic resin" and the "additive" are added is not particularly limited. For example, the "other thermoplastic resin" and the "additive" may be blended simultaneously with one or both of the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B), or may be added after the ethylene-α-olefin copolymer (A) and the high-pressure low-density polyethylene (B) have been kneaded.

[Molded body, film, laminate]
By processing the ethylene resin composition (Z) of the present invention, a molded article having excellent moldability and mechanical strength, preferably a film, and more preferably a laminate containing the film, can be obtained.

The ethylene-based resin composition (Z) of the present invention can be processed by general film molding, sheet molding, blow molding, injection molding, extrusion molding, and other methods. Examples of film molding include extrusion lamination, T-die film molding, and inflation molding (air cooling, water cooling, multi-stage cooling, high-speed processing). The resulting film can be used as a single layer, but by forming it into a multilayer, it can be given a variety of additional functions. Examples of molding methods used in this case include coextrusion. On the other hand, lamination molding methods such as extrusion lamination and dry lamination enable lamination with paper or barrier films (aluminum foil, vapor-deposited film, coating film, etc.) that are difficult to coextrude. The production of high-performance multilayer products by coextrusion is possible by blow molding, injection molding, and extrusion molding, just as it is by film molding.

Examples of molded articles obtained by processing the ethylene-based resin composition (Z) of the present invention include films, sheets, blown infusion bags, blown bottles, gasoline tanks, extrusion-molded tubes, pipes, wire coatings, tear-off caps, injection-molded articles such as miscellaneous daily necessities, fibers, and large-scale rotational moldings.

Furthermore, films obtained by processing the ethylene-based resin composition (Z) of the present invention are suitable for various packaging films such as packaging bags for liquids, liquid soup pouches, liquid paper containers, laminated raw material, specially shaped liquid packaging bags (standing pouches, etc.), standard bags, heavy-duty bags, cling film, sugar bags, oily food packaging bags, food packaging films, protective films, infusion bags, agricultural materials, bag-in-boxes, and clean films used for packaging semiconductor materials, pharmaceuticals, food, etc. The above films can also be used as multilayer films by laminating them with substrates such as nylon, polyester, and polyolefin films.

The laminate containing the ethylene resin composition (Z) of the present invention in at least one layer will be described in more detail below.
Examples of layers other than the above-mentioned layers that make up the laminate include a substrate layer and a barrier layer.

Examples of substrates used as the substrate layer include films of polyamide, polyester, polypropylene, polyethylene, ethylene-vinyl alcohol copolymer, etc. Preferably, the film is a stretched film. Other examples include paper substrates, such as paper and paper coated with polyethylene. These substrates may be printed or coated as needed. They may also be pretreated as needed, such as by corona treatment, flame treatment, plasma treatment, ultraviolet treatment, or anchor coating.

Specific examples of substrates include paper such as fine paper, kraft paper, tissue paper, and Kent paper; cellophane; woven fabric; nonwoven fabric; nylon substrates such as oriented nylon, unoriented nylon, special nylon (MXD6, etc.), and K-nylon (polyvinylidene fluoride coated); polypropylene substrates such as oriented PET (polyethylene terephthalate), unoriented PET (polyethylene terephthalate), K-PET (polyethylene terephthalate), oriented polypropylene (OPP), unoriented polypropylene (CPP), K-PP, and co-extruded PP film; LDPE film, LLDPE film, EVA film, oriented LDPE film, and oriented HDPE film.

Barrier substrates used as barrier layers include metal foils, thermoplastic resin films vapor-deposited with metals or inorganic materials, and thermoplastic resin films with barrier coatings. Thermoplastic resin films include oriented nylon, oriented PET (polyethylene terephthalate), oriented polypropylene (OPP), and unoriented polypropylene (CPP).

A part of the raw materials of the laminate, such as the substrate and the barrier substrate, may contain an ethylene-based polymer or a propylene-based polymer containing a biomass-derived monomer.
In the present invention, metal foil refers to metal foil such as aluminum, gold, silver, iron, copper, nickel, or an alloy containing any of these as a main component. Metal-vapor-deposited thermoplastic resin film refers to a film in which a metal such as aluminum or silicon is vapor-deposited on the surface of a film such as polyester or polyamide. Inorganic-vapor-deposited thermoplastic resin film refers to a thermoplastic resin film in which silica or alumina is vapor-deposited. Barrier coating refers to coating a film surface with a barrier resin such as polyvinyl alcohol or polyvinylidene chloride.

The substrate layer is used, for example, as a printing substrate, whereas the barrier substrate is not typically used as a printing substrate.
Specific examples of the laminate structure of the present invention are shown below, but the present invention is not limited to these.

In the following structures, "PE laminate" refers to an ethylene-based resin laminated by extrusion lamination. The ethylene-based resin used in at least one PE laminate in each structure is the ethylene-based resin composition (Z) of the present invention.

When a PE laminate using the ethylene-based resin composition (Z) of the present invention is used as an adhesive layer adjacent to the aluminum vapor-deposited layer or aluminum foil of an aluminum vapor-deposited film, the PE laminate exhibits excellent adhesive strength with the aluminum vapor-deposited layer or aluminum foil.

Coextrusion lamination (acid copolymer/PE laminate) refers to the lamination of two layers of an acid copolymer and an ethylene-based resin by coextrusion lamination, with the acid copolymer adjacent to the aluminum foil. Examples of acid copolymers include ethylene-acrylic copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), and ethylene-acrylic acid ester copolymer (EEA, EMA, EMMA, etc.). The film used in the innermost layer (opposite the stretched substrate film) is a thermoplastic resin film, and a propylene-based resin film or an ethylene-based resin film is preferably used.

Stretched nylon / adhesive / PE laminate (1) / PE laminate (2),
Paper/PE laminate,
Stretched polypropylene / adhesive / PE laminate (1) / aluminum foil / adhesive / film or PE laminate (2),
Stretched polypropylene / adhesive / PE laminate (1) / aluminum vapor deposition film (the aluminum vapor deposition layer is adjacent to the PE laminate (1) layer),
Oriented polypropylene/adhesive/PE lami (1)/aluminum vapor-deposited film/adhesive/film or PE lami (2) (the aluminum vapor-deposited layer is adjacent to the PE lami (1) layer),
Stretched polypropylene / adhesive / extrusion lamination (1) / inorganic vapor deposition film,
Oriented polypropylene / adhesive / PE laminate (1) / inorganic vapor deposition film / adhesive / film or PE laminate (2),
Stretched polyethylene terephthalate / adhesive / extrusion lamination (1) / aluminum foil / adhesive / film or PE lamination (2),
Stretched polyethylene terephthalate / adhesive / extrusion laminate (1) / aluminum vapor deposition film / adhesive / film or PE laminate (2) (the aluminum vapor deposition layer is adjacent to the PE laminate (1) layer),
Stretched polyethylene terephthalate / adhesive / PE laminate (1) / inorganic vapor deposition film,
Stretched polyethylene terephthalate / adhesive / PE laminate (1) / inorganic vapor deposition film / adhesive / film or PE laminate (2),
PE laminate (1) / paper / PE laminate (2) / aluminum foil / co-extrusion laminate (acid copolymer / PE laminate (3)),
PE laminate (1) / paper / PE laminate (2) / aluminum foil / adhesive / polyethylene terephthalate / adhesive / film or PE laminate (3),
PE laminate (1) / paper / PE laminate (2) / aluminum vapor deposition film / adhesive / film or PE laminate (3),
PE laminate (1) / paper / PE laminate (2) / inorganic vapor deposition film / adhesive / film or PE laminate (3)

The present invention will be explained in more detail below using examples. However, the present invention is not limited to the following examples.

[Measurement or evaluation method]
In the following examples, various physical properties of ethylene-α-olefin copolymers and the like were measured by the methods described in [Mode for Carrying Out the Invention], and the following methods were used as evaluation methods not described in [Mode for Carrying Out the Invention].

Extrusion Laminate Evaluation :
[Neck-in]
The ethylene resin composition was extrusion laminated onto a substrate of 50 g/m ² kraft paper under the following conditions using a laminator manufactured by Sumitomo Heavy Industries, Ltd., equipped with a 65 mmφ extruder and a 500 mm wide T-die.

Air gap: 130 mm
Resin temperature below the die: 320°C
・Taking speed: 80 m/min ・Film thickness: 20 μm
When the width of the T-die is L ₀ and the width of the film laminated on the kraft paper at each take-up speed is L, the neck-in was calculated by L ₀ -L.

[Receipt surging]
The ethylene-based resin composition was extrusion laminated onto a 50 g/ ^m2 kraft paper substrate using a laminator manufactured by Sumitomo Heavy Industries, Ltd., equipped with a 65 mmφ extruder and a 500 mm T-die, under conditions of an air gap of 130 mm and a resin temperature below the die of 320°C. The extrusion rate was set so that the film thickness would be 20 μm at a take-up speed of 80 m/min. The take-up speed was increased, and neck-in was measured five times at a take-up speed of 150 m/min. Take-up surging was deemed to have occurred when two or more measurements showed a difference of ±1.5 mm or more from the average neck-in value.

[Aluminum adhesive strength ratio]
The ethylene-based resin composition was extrusion laminated between the substrate and the aluminum vapor-deposited film to a thickness of 15 μm using a laminator manufactured by Sumitomo Heavy Industries, Ltd., equipped with a 65 mmφ extruder and a 500 mm T-die, under conditions of a resin temperature below the die of 320°C and a take-up speed of 150 m/min. The substrate used was a 12 μm thick stretched polyethylene terephthalate film (trade name: Emblet (registered trademark), manufactured by Unitika Ltd.) coated on one side (the ethylene-based resin composition layer side) with a two-component curing urethane anchor coating agent. The aluminum vapor-deposited film used was a 12 μm thick ML PET (manufactured by Mitsui Chemicals Tocello Co., Ltd.). The extrusion-laminated ethylene-based resin composition was in contact with the aluminum surface. The resulting extrusion-laminated film was cut into 15 mm wide strips, and the adhesive strength between the resulting ethylene-based resin composition layer and the aluminum vapor-deposited film layer was determined by T-peel at a peel speed of 300 mm/min. The ratio of the determined peel strength to a peel strength (LDPE) determined in the same manner using high-pressure LDPE (high-pressure low-density polyethylene, Suntec (registered trademark)-LD "L1850A" manufactured by Asahi Kasei Corporation) instead of the ethylene-based resin composition was defined as the AL adhesive strength ratio.
AL adhesive strength ratio = peel strength / peel strength (LDPE)

[Trouser tear strength]
The ethylene-based resin composition was extrusion laminated onto a substrate of 50 g/m kraft paper using a laminator manufactured by Sumitomo Heavy Industries, Ltd., equipped with a 65 mmφ extruder and a 500 mm wide T-die, to a film thickness of 20 μm under the conditions of an air gap of 130 mm, a resin temperature below the die of 320°C, and a take-up speed of 80 m/min. In accordance with JIS K7128-1, the obtained laminate was cut into a piece 50 mm wide and 150 mm long, a 75 mm notch was made in the center of the width, and the tear strength was measured at a speed of 200 mm/min.

[Raw materials used]
The transition metal compounds and component (G) used in the production examples are as follows:
Transition metal compound (A-1): dimethylsilylene(2-indenyl)(4-(3,5-di-tert-butyl-4-methoxyphenyl)-7-methoxy-1-indenyl)zirconium dichloride [synthesized by the method described in JP 2019-059933 A.]
Transition metal compound (B-1): dimethylsilylene(3-n-propylcyclopentadienyl)(cyclopentadienyl)zirconium dichloride [synthesized based on the method described in Japanese Patent No. 5,455,354.]
Transition metal compound (B-2): isopropylidene(cyclopentadienyl)(2,7-di-tert-butylfluorenyl)zirconium dichloride [synthesized based on the method described in JP-A-4-69394]
Component (G-1): Lauryldiethanolamine (Kao Corporation)
Ingredient (G-2): Emulgen (registered trademark) 108 (Kao Corporation)

<Synthesis of prepolymerization catalyst (XP-1)>
In a 270 L reactor equipped with a stirrer, 10 kg of silica (average particle size 70 μm, specific surface area 340 m ² /g, pore volume 1.3 cm ³ /g, calcined at 250°C) manufactured by Fuji Silysia Ltd. as a solid support (S) was suspended in 77 L of toluene under a nitrogen atmosphere and then cooled to 0 to 5°C. To this suspension, 20.4 L of a toluene solution of methylaluminoxane (3.5 mol/L in terms of Al atoms) as component (C) was added dropwise over 30 minutes. During this process, the temperature in the system was maintained at 0 to 5°C. After the reaction was continued for 30 minutes at 0 to 5°C, the temperature was raised to 95 to 100°C over approximately 1.5 hours, and the reaction was continued for 4 hours at 95 to 100°C. The temperature was then lowered to room temperature, the supernatant liquid was removed by decantation, and the mixture was washed twice with toluene, to prepare a toluene slurry with a total volume of 58.0 L. A portion of the resulting slurry component was sampled and the concentration was examined, which was found to be 248.0 g/L and Al concentration 1.21 mol/L.

Next, 6.1 L of the toluene slurry obtained above and 21.9 L of toluene were charged into a 114 L reactor equipped with a stirrer and thoroughly purged with nitrogen. 5.4 L of an 8 mM toluene solution of transition metal compound (A-1) was added, and the mixture was allowed to contact for 1 hour at a system temperature of 20-25°C. The supernatant was removed by decantation, and the mixture was washed twice with hexane to prepare a total volume of 30.9 L of slurry. While adjusting the temperature of the resulting slurry to 10-15°C, 3.1 L of a 0.92 M hexane solution of diisobutylaluminum hydride was added, and ethylene gas was started at a flow rate of 0.74 kg/hr. 34.3 mL of 1-hexene was added, followed by a temperature increase. While adjusting the system temperature to 32-38°C, 34.3 mL of 1-hexene was added every hour for a total of five times. Six hours after the start of ethylene supply, the ethylene supply was stopped when the ethylene supply reached 4.5 kg. The system was then thoroughly purged with nitrogen, the supernatant was removed by decantation, and the mixture was washed four times with hexane to prepare a slurry with a total volume of 21.9 L. While maintaining the obtained slurry at 35 to 40°C, 6.1 L of a 10 g/L hexane solution of component (G-1) was added and the mixture was allowed to come into contact for 2 hours. The entire amount of the obtained slurry was placed in an evaporative dryer equipped with a stirrer and having an internal volume of 43 L under a nitrogen atmosphere, and the pressure inside the dryer was reduced to -68 kPaG over approximately 60 minutes. Once the pressure reached -68 kPaG, the mixture was vacuum dried for approximately 4.3 hours to remove hexane and volatiles from the prepolymerized catalyst components. The pressure was further reduced to -100 kPaG, and once the pressure reached -100 kPaG, the mixture was vacuum dried for 8 hours to obtain 6.2 kg of prepolymerized catalyst (XP-1). A portion of the resulting prepolymerized catalyst (XP-1) was sampled and its composition was examined, revealing that it contained 0.56 mg of Zr atoms per 1 g of prepolymerized catalyst component.

<Synthesis of prepolymerization catalyst (XP-2)>
In a 270 L reactor equipped with a stirrer, 10 kg of silica (average particle size 70 μm, specific surface area 340 m ² /g, pore volume 1.3 cm ³ /g, calcined at 250°C) manufactured by Fuji Silysia Ltd. as a solid support (S) was suspended in 77 L of toluene under a nitrogen atmosphere and then cooled to 0 to 5°C. To this suspension, 20.4 L of a toluene solution of methylaluminoxane (3.5 mol/L in terms of Al atoms) as component (C) was added dropwise over 30 minutes. During this process, the temperature in the system was maintained at 0 to 5°C. After the reaction was continued for 30 minutes at 0 to 5°C, the temperature was raised to 95 to 100°C over approximately 1.5 hours, and the reaction was continued for 4 hours at 95 to 100°C. The temperature was then lowered to room temperature, the supernatant liquid was removed by decantation, and the mixture was washed twice with toluene, to prepare a toluene slurry with a total volume of 58.0 L. A portion of the resulting slurry component was sampled and the concentration was examined, which was found to be 248.0 g/L and Al concentration 1.21 mol/L.

Next, 6.1 L of the toluene slurry obtained above and 22.7 L of toluene were charged into a 114 L reactor equipped with a stirrer and thoroughly purged with nitrogen. 1.5 L of an 8 mM toluene solution of transition metal compound (B-1) and 3.1 L of an 8 mM toluene solution of transition metal compound (B-2) were added, and the mixture was allowed to contact for 1 hour at a system temperature of 70-75°C. The supernatant was then removed by decantation, and the mixture was washed twice with hexane to prepare a total volume of 29.8 L of slurry. While adjusting the temperature of the resulting slurry to 35-40°C, 4.0 L of a 0.92 M hexane solution of diisobutylaluminum hydride was added, and ethylene gas was started to be fed at a flow rate of 795.4 L/hr. Five hours after the start of ethylene feed, the ethylene feed was stopped when the ethylene feed reached 3,980 L. The system was then thoroughly purged with nitrogen, the supernatant was removed by decantation, and the mixture was washed four times with hexane to prepare a slurry with a total volume of 21.7 L. While maintaining the obtained slurry at 35 to 40°C, 3.8 L of a 10 mg/mL hexane solution of component (G-2) was added and the mixture was allowed to come into contact for 2 hours. The entire amount of the obtained slurry was placed in an evaporative dryer equipped with a stirrer and having an internal volume of 43 L under a nitrogen atmosphere, and the pressure inside the dryer was reduced to -68 kPaG over approximately 60 minutes. Once the pressure reached -68 kPaG, the mixture was vacuum dried for approximately 4.3 hours to remove hexane and volatiles from the prepolymerized catalyst components. The pressure was further reduced to -100 kPaG, and once the pressure reached -100 kPaG, the mixture was vacuum dried for 8 hours to obtain 6.1 kg of prepolymerized catalyst (XP-2). A portion of the resulting prepolymerized catalyst (XP-2) was sampled and its composition was examined, revealing that it contained 0.52 mg of Zr atoms per 1 g of prepolymerized catalyst component.

<Production of ethylene-α-olefin copolymer>
[Production Example 2]
(Production of ethylene-α-olefin copolymer (A-2))
An ethylene polymer was produced by a gas-phase polymerization process using a fluidized-bed gas-phase polymerization reactor. 24 kg of spherical ethylene polymer particles having an average particle size of 900 μm was introduced into the reactor in advance, and nitrogen was supplied to form a fluidized bed. Ethylene, hydrogen, 1-hexene, a prepolymerization catalyst, and Electrostripper (registered trademark) EA (Kao Corporation) were then continuously supplied to achieve a steady state under the polymerization conditions shown in Table 8. The polymerization product was continuously withdrawn from the reactor and dried in a dryer to obtain a powder of ethylene-α-olefin copolymer (A-2).

[Production Examples 3, 4, 6, 7, 11 to 16]
(Production of ethylene-α-olefin copolymers (A-3), (A-4), (A-6), (A-7), and (A-11) to (A-16))
Ethylene-α-olefin copolymer powder was obtained in the same manner as in Production Example 2, except that the polymerization conditions were changed as shown in Table 8. Table 8 lists Chemistat (registered trademark) 2500 (manufactured by Sanyo Chemical Industries, Ltd.) as a component that was not used in Production Example 2.

[Production Example 1]
(Production of Ethylene-α-Olefin Copolymer (A-1))
An ethylene polymer was produced in a two-stage polymerization process using the fluidized-bed gas-phase polymerization reactor used in Production Example 2 as the primary reactor and a fluidized-bed gas-phase polymerization reactor with an internal volume of 0.6 m as the secondary reactor. Two-stage polymerization refers to the continuous withdrawal of the polymerization product obtained in the primary reactor into the secondary reactor, with the polymerization reaction continuing in the primary reactor as in the secondary reactor. 24 kg of spherical ethylene polymer particles with an average particle size of 900 μm were previously introduced into the primary reactor. Nitrogen was supplied to form a fluidized bed. Ethylene, hydrogen, 1-hexene, a prepolymerization catalyst, and an electrostripper EA were continuously supplied to both the primary and secondary reactors so that a steady state was reached under the polymerization conditions shown in Table 8. However, the prepolymerization catalyst and electrostripper EA were supplied only to the primary reactor. The polymerization product obtained by the two-stage polymerization in the latter-stage polymerization reactor was continuously withdrawn from the latter-stage polymerization reactor and dried in a dryer to obtain an ethylene-α-olefin copolymer powder.

[Production Examples 5, 8 to 10]
(Production of ethylene-α-olefin copolymers (A-5), (A-8) to (A-10))
An ethylene-α-olefin copolymer powder was obtained in the same manner as in Production Example 1, except that the polymerization conditions were changed as shown in Table 8.

<Measurement of polymer properties>
[Ethylene-α-olefin copolymer (A-1)]
The powder of ethylene-α-olefin copolymer (A-1) obtained in Production Example 1 was melt-kneaded using a 46 mmφ twin-screw co-rotating extruder manufactured by Ikegai Corporation at a set temperature of 200°C and a screw rotation speed of 300 rpm, and then extruded into a strand shape and cut to obtain pellets. The obtained pellets were used as measurement samples and their physical properties were measured. The measurement results are shown in Table 9.

[Ethylene-α-olefin copolymers (A-2) to (a-16)]
Pellets were prepared and the physical properties were measured in the same manner as in the measurement of the physical properties of the ethylene-α-olefin copolymer (A-1), except that the ethylene-α-olefin copolymer (A-1) was changed to any of the ethylene-α-olefin copolymers (A-2) to (A-16) obtained in Production Examples 2 to 16. The measurement results are shown in Table 9.

[Ethylene-α-olefin copolymer (a-17)]
The physical properties of Ultzex 15150J manufactured by Prime Polymer Co., Ltd. were measured. The measurement results are shown in Table 9.

[High-pressure low-density polyethylene (B-1)]
The physical properties of Suntech-LD "L1850A" manufactured by Asahi Kasei Corporation were measured. The measurement results are shown in Table 10.

[High-pressure low-density polyethylene (b-2)]
The physical properties of Suntech-LD "M1920" manufactured by Asahi Kasei Corporation were measured. The measurement results are shown in Table 10.

<Production of ethylene-based resin composition>
[Example 1]
75% by mass of the resulting ethylene-α-olefin copolymer (A-1) pellets and 25% by mass of the high-pressure low-density polyethylene (B-1) pellets were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Example 2]
50% by mass of the resulting ethylene-α-olefin copolymer (A-1) pellets and 50% by mass of the high-pressure low-density polyethylene (B-1) pellets were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Example 3]
75% by mass of the resulting ethylene-α-olefin copolymer (A-2) pellets and 25% by mass of the high-pressure low-density polyethylene (B-1) pellets were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Example 4]
50% by mass of the resulting ethylene-α-olefin copolymer (A-2) pellets and 50% by mass of the high-pressure low-density polyethylene (B-1) pellets were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Example 5]
50% by mass of the resulting ethylene-α-olefin copolymer (A-3) pellets and 50% by mass of the high-pressure low-density polyethylene (B-1) pellets were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Comparative Example 1]
75% by mass of pellets of ethylene-α-olefin copolymer (a-17) and 25% by mass of pellets of high-pressure low-density polyethylene (B-1) were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Comparative Example 2]
75% by mass of pellets of ethylene-α-olefin copolymer (a-17) and 25% by mass of pellets of high-pressure low-density polyethylene (b-2) were dry-blended, and extrusion lamination evaluation was performed. The evaluation results are shown in Table 11.

[Comparative Example 3]
Using high-pressure low-density polyethylene (B-1), extrusion lamination evaluation was carried out. The evaluation results are shown in Table 11.

[Comparative Example 4]
The pellets of the ethylene-α-olefin copolymer (a-16) thus obtained were used to perform extrusion lamination evaluation. The evaluation results are shown in Table 11.

Claims (13)

The present invention comprises an ethylene-α-olefin copolymer (A) which is a copolymer of ethylene and an α-olefin having 4 to 10 carbon atoms and satisfies the following requirements (1) to (6), and a high-pressure low-density polyethylene (B) which satisfies the following requirements (a) to (c),
The mass fraction (W _A ) of the ethylene-α-olefin copolymer (A) is 40% by mass or more and 90% by mass or less, and the mass fraction (W _B ) of the high-pressure low-density polyethylene (B) is 10% by mass or more and 60% by mass or less (wherein the sum of W _A and W _B is 100% by mass).
Ethylene-based resin composition (Z).
(1) The density is in the range of 890 kg/m ³ or more and 935 kg/m ³ or less.
(2) The melt flow rate (MFR) at 190° C. under a load of 2.16 kg is in the range of 1.0 g/10 min or more and 15.0 g/10 min or less.
(3) The ratio [MT/η ^* (g/P)] of the melt tension [MT(g)] at 190°C to the shear viscosity [η ^* (P)] at 200°C and an angular velocity of 1.0 rad/sec is in the range of 1.40× ^10-4 or more and 2.90× ^10-4 or less.
(4) The zero shear viscosity [η ₀ (P)] at 200° C. and the weight average molecular weight (Mw) measured by the GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-1):
0.01×10 ^-13 ×Mw ^3.4 ≦ η ₀ ≦ 4.5×10 ^-13 ×Mw ^3.4 ... (Eq-1)
(5) The number average molecular weight (Mn), weight average molecular weight (Mw), and Z average molecular weight (Mz) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-2):
-2.0 ≦ Mz/Mw - Mw/Mn ≦ 15 ... (Eq-2)
(6) The total of vinyl, vinylidene, di-substituted internal olefin, and tri-substituted internal olefin per 1000 carbon atoms (units/1000C) measured by ¹ H-NMR is in the range of 0.1 to 1.0.
(a) The density is in the range of 915 kg/m ³ or more and 930 kg/m ³ or less.
(b) The melt flow rate (MFR) at 190°C under a load of 2.16 kg is in the range of 0.1 g/10 min or more and 20 g/10 min or less.
(c) The amount of components having a molecular weight of 1,000,000 or more in a molecular weight distribution curve obtained by GPC measurement is in the range of 1.0% to 20%. The ethylene-based resin composition (Z) according to claim 1, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (7):
(7) The intrinsic viscosity [η] (dl/g) measured in decalin at 135°C and the weight average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) satisfy the following relational expression (Eq-3):
0.7×10 ^-4 ×Mw ^0.776 ≦[η]≦ 1.65×10 ^-4 ×Mw ^0.776 ...(Eq-3) The ethylene-based resin composition (Z) according to claim 1 or 2, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (8):
(8) The ratio Mz/Mw of the Z-average molecular weight (Mz) to the weight-average molecular weight (Mw) measured by a GPC-viscosity detector method (GPC-VISCO) is in the range of 4.0 to 25.0. The ethylene-based resin composition (Z) according to any one of claims 1 to 3, wherein the ethylene-α-olefin copolymer (A) further satisfies the following requirement (9):
(9) There are multiple peaks in the melting curve obtained by differential scanning calorimetry (DSC). The ethylene-based resin composition (Z) according to any one of claims 1 to 4, wherein the high-pressure low-density polyethylene (B) further satisfies the following requirement (d):
(d) The ratio [δ100/δ0.01] of the phase angle [δ100 (°)] at 200°C and an angular velocity of 100 rad/sec to the phase angle [δ0.01 (°)] at 200°C and an angular velocity of 0.01 rad/sec is in the range of 0.46 or more and 0.76 or less. The ethylene-based resin composition (Z) according to any one of claims 1 to 5, further comprising a thermoplastic resin (excluding the ethylene-α-olefin copolymer (A) and high-pressure low-density polyethylene (B)). A molded article comprising the ethylene-based resin composition (Z) according to any one of claims 1 to 6. A film comprising the ethylene-based resin composition (Z) described in any one of claims 1 to 6. A multilayer film having a layer containing the ethylene-based resin composition (Z) described in any one of claims 1 to 6. A laminate having a layer containing the ethylene-based resin composition (Z) described in any one of claims 1 to 6. The laminate according to claim 10, further comprising a substrate layer. The laminate according to claim 10, further comprising a barrier layer. A method for producing a laminate, comprising extrusion laminating the ethylene-based resin composition (Z) described in any one of claims 1 to 6 between a substrate layer and a barrier layer.