JPWO2019082790A1 - Easy-to-open sealant film and its uses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an easily openable sealant film having excellent heat sealability and easy finger sticking property. SOLUTION: An ethylene-based polymer which is a long-chain branched ethylene / C4-10α-olefin satisfying a specific requirement and a high-pressure method low-density polyethylene are mixed in a weight ratio of an ethylene-based polymer: a high-pressure method low-density polyethylene. An easy-to-open sealant film containing an ethylene-based polymer composition contained in a ratio of 1:99 to 99: 1.

Description

The present invention relates to an ethylene polymer composition used for an easily open sealant film, its use, and the like. More specifically, the present invention relates to an ethylene-based polymer composition for an easily-openable sealant film, which is preferably used for containers and packaging materials for foods, beverages, medical treatments, etc., and its use.

Laminated films commonly used as packaging materials are polyethylene films produced by inflation molding or cast molding, and dry-laminated or extruded-laminated on paper, paperboard, polypropylene film, polyethylene terephthalate film, nylon film, metal foil, and metal. It is widely known that it is produced by adhering it to a base material such as a vapor-deposited film or a ceramic vapor-deposited film. Among these base materials, when a material having a strength relatively weaker than that of a plastic film such as aluminum foil or paper is used, it is often strongly desired that the packaging material can be easily opened. Currently, as seen in measures against food loss, which is a social problem worldwide, various products are individually packaged in smaller quantities so that they can be used when and in the required amount. Therefore, it can be said that easy opening of packaging materials is becoming more and more important performance as the chances of opening packaging materials are increasing, especially for relatively weak people such as children and the elderly. As for such performance, for example, it is easy to cut the packaging material by human power without a notch for opening, and it is easy to make a hole in the packaging material with a human finger. Examples include finger piercing property and easy piercing property in which a straw or the like can be easily pierced into the packaging material in order to take out the packaged liquid.

On the other hand, the laminated film used as a packaging material is required to be easy to open, but to ensure the tightness of the contents, so it is essential to balance both performances. In addition, the direction in which the easy-to-cut property appears (hereinafter, also referred to as the "easy-cut property direction") is simple because there are various directions in which each product displayed at a retail store such as a supermarket should be cut. It is strongly desired that not only the easy-cut property but also the easy-cut property can be adjusted in any direction.

Generally, as a method for improving the easy-opening property of a polyethylene material, it is possible to use a material having a small molecular weight and less molecular entanglement (weak strength). However, if the molecular weight of the material is reduced, the melt viscosity is also lowered, so that the stability of the molten resin at the time of inflation molding or cast molding deteriorates, and it becomes difficult to stably produce a film. The sex is significantly reduced. Further, it is generally performed to impart easy-cutting property by using high-pressure low-density polyethylene (hereinafter, also referred to as "LDPE") as a polyethylene resin having relatively weak strength, but the easy-cutting property is specified. It is easy to develop in the direction of. That is, when LDPE is used alone, it tends to be easily cut only in the lateral direction perpendicular to the resin flow direction during film production, and is a linear low-density polyethylene (hereinafter, also referred to as "LLDPE"). When and LDPE are blended, there is a tendency that the film is easily cut only in the vertical direction parallel to the flow direction of the resin during film production. However, when LLDPE is blended with LDPE, the easy finger sticking property deteriorates as the amount of LLDPE added increases, so that the film can be easily cut in any direction while maintaining the easy finger sticking property. It has been extremely difficult to produce a film having excellent heat-sealing properties.

In Patent Document 1, while using linear low-density polyethylene to ensure heat-sealing property, an inflation film having both heat-sealing property and easy tearing property is achieved by blending cyclic polyolefin in the intermediate layer of the three-layer film. Has been proposed. However, I Ching is not mentioned.

The laminate film described in Patent Document 2 uses a specific polyethylene containing a long-chain branch, is suitable for extrusion laminate molding, has excellent seal strength and easy-to-cut property, and is extruded laminate molding for the molding. Is particularly suitable. However, Patent Document 2 does not mention easy finger thrust.

Patent Document 3 proposes that an inflation film produced from an ethylene-based polymer having specific melting characteristics is excellent in easy-cutting property and inflation processability, and Patent Document 4 proposes ethylene having the specific melting characteristics. It has been proposed that the based polymer has an effect of modifying the inflation processability of LLDPE. However, heat sealability and easy finger sticking are not mentioned.

Japanese Unexamined Patent Publication No. 2004-284351 Japanese Unexamined Patent Publication No. 2014-074103 Japanese Unexamined Patent Publication No. 2008-031380 Japanese Unexamined Patent Publication No. 2008-031385

As described above, it is widely known that a film exhibiting easy-to-cut property is produced by inflation molding or cast molding of a polyethylene material. However, in the conventional technique, there is room for improvement in terms of processability when forming a film of a polyethylene material and various physical properties of the film.

For example, in a composition containing LLDPE and LDPE, easy-cutting property is likely to be exhibited in a specific direction as described above, and if the proportion of LLDPE is increased in order to change the direction of easy-cutting property, the easy-to-finger sticking property is inferior. Will end up.

In the technique described in Patent Document 1, since it is indispensable to use an expensive cyclic polyolefin, the cost of the packaging material becomes high, and there remains a problem in ensuring easy finger sticking.

Further, since the technique described in Patent Document 2 is a technique particularly suitable for an extruded laminated film, it is premised that a material having a low molecular weight is used, and sufficient workability is ensured for inflation molding and cast molding. The problem remains that it is difficult to do.

Further, the techniques described in Patent Documents 3 and 4 in which an ethylene polymer having a specific melting property is used alone or an ethylene polymer having a specific melting property is used in combination with LLDPE are easy to use. There remains the problem that it is difficult to develop easy-cutting property in any direction while ensuring finger-sticking property.

The present invention has been made to solve the above problems, and an object of the present invention is excellent processability (specifically, bubble stability when forming an inflation film), heat sealability and ease of use. To provide an ethylene-based polymer composition for an easily-openable sealant film capable of producing an easily-openable sealant film having excellent finger-stickability, and to provide an easy-to-open sealant film with excellent heat-sealing property and easy-to-finger sticking property. It is an object of the present invention to provide a method capable of realizing the property and adjusting the direction of the easy-to-cut property of the film in any direction.

As a result of diligent studies, the present inventors have excellent an easy-to-open sealant film that exhibits excellent heat-sealing property and easy finger-sticking property by a composition containing an ethylene-based polymer having specific properties and LDPE. The present invention has been completed by finding that it can be produced by processability and that the direction of easy-cutting property of the film can be adjusted in any direction by changing the ratio of these ethylene-based polymers to LDPE.

The gist of the present invention is as follows.

[1]
Ethylene-based polymer (A1) and high-pressure low-density polyethylene, ethylene-based polymer (A1): high-pressure low-density polyethylene = 1% by weight: 99% by weight to 99% by weight: 1% by weight (however, The total amount of the ethylene-based polymer (A1) and the high-pressure low-density polyethylene is 100% by weight), and the ethylene-based polymer (A1) contains ethylene and carbon satisfying the following requirements (I) to (V). An ethylene-based polymer composition (A2) for an easy-to-open sealant film, which is a copolymer with α-olefins of numbers 4 to 10.
(I) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is in the range of 0.1 to 10 g / 10 min.
(II) The density (d) is in the range of 875 to 970 kg / m ³ .
(III) ¹³ The sum of the number of methyl branches [A (/ 1000C)] per 1000 carbon atoms measured by C-NMR and the number of ethyl branches [B (/ 1000C)] [(A + B) (/ 1000C)] Is 1.80 or less.
(IV) The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is in the range of 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.50 .
(V) The ultimate 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) are the following relational expressions (V) Eq-1) is satisfied.

0.80 × 10 ^-4 × Mw ^0.776 ≦ [η] ≦ 1.65 × 10 ^-4 × Mw ^0.776
… (Eq-1)
[1a]
The ethylene-based polymer (A1) and the high-pressure method low-density polyethylene are mixed with the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 60% by weight: 40% by weight to 99% by weight: 1% by weight ( However, the ethylene-based polymer composition (A2) according to the above [1], which comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene in a total amount of 100% by weight).

[1b]
The ethylene-based polymer (A1) and the high-pressure method low-density polyethylene are mixed with the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 41% by weight: 59% by weight to 59% by weight: 41% by weight ( However, the ethylene-based polymer composition (A2) according to the above [1], which comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene in a total amount of 100% by weight).

[1c]
The ethylene-based polymer (A1) and the high-pressure method low-density polyethylene are mixed with the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 1% by weight: 99% by weight to 40% by weight: 60% by weight ( However, the ethylene-based polymer composition (A2) according to the above [1], which comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene in a total amount of 100% by weight).

[2]
An easy-to-open sealant film containing the ethylene-based polymer composition (A2) according to the above [1], [1a], [1b] or [1c].

[3]
The easy-to-open sealant film of the above [2] having a thickness of 15 to 300 μm.

[4]
The method for producing an easily-openable sealant film according to the above [2], which comprises a step of forming the ethylene-based polymer composition (A2) of the above [1], [1a], [1b] or [1c] into a film.

[5]
A laminated film having the easily openable sealant film of [2] or [3] and another film.

[6]
A bag having the easy-to-open sealant film of [2] or [3] or the laminated film of [5].

[7]
When producing an easily openable sealant film from the ethylene-based polymer composition (A2) of the above [1], [1a], [1b] or [1c], the ethylene polymer (A1) and the high-pressure method are used. Ethylene-based polymer (A1): high-pressure method Low-density polyethylene = 1% by weight: 99% by weight to 99% by weight: 1% by weight (however, ethylene-based polymer (A1) and high-pressure method A method of adjusting the direction in which the easy-to-cut property of an easily-openable sealant film is exhibited, which is changed in the range of 100% by weight of the total amount of low-density polyethylene.

According to the ethylene-based polymer composition for an easily-openable sealant film according to the present invention (hereinafter, also simply referred to as "ethylene-based polymer composition") (A2), it is excellent in heat sealability and easy finger sticking property. Easy-to-open sealant film can be produced. In addition, the bubble stability when molding an inflation film from the ethylene-based polymer composition (A2) according to the present invention is also excellent. Further, when producing an easy-to-open sealant film from the ethylene-based polymer composition (A2) according to the present invention, the ratio of the ethylene polymer (A1) and LDPE is changed within a predetermined range (that is, the present invention). The direction of the easy-to-cut property of the easy-to-open sealant film can be adjusted to any direction by the method according to the present invention (by the method of adjusting the direction in which the easy-to-cut property of the easy-to-open sealant film is exhibited).

Hereinafter, the ethylene-based polymer composition for an easily-openable sealant film according to the present invention, its use, and the like will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[Ethylene polymer composition]
The ethylene-based polymer composition (A2) according to the present invention comprises ethylene-based polymer (A1) and LDPE, and ethylene-based polymer (A1): LDPE = 1% by weight: 99% by weight to 99% by weight: 1. It is contained in a proportion of% by weight (however, the total amount of the ethylene polymer (A1) and LDPE is 100% by weight), and the ethylene polymer (A1) satisfies the following requirements (I) to (V). It is characterized by being a copolymer of ethylene and α-olefin having 4 to 10 carbon atoms. (I) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is in the range of 0.1 to 10 g / 10 min.
(II) The density (d) is in the range of 875 to 970 kg / m ³ .
(III) ¹³ The sum of the number of methyl branches [A (/ 1000C)] per 1000 carbon atoms measured by C-NMR and the number of ethyl branches [B (/ 1000C)] [(A + B) (/ 1000C)] Is 1.80 or less.
(IV) The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is in the range of 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.50 .
(V) The ultimate 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) are the following relational expressions (V) Eq-1) is satisfied.

0.80 × 10 ^-4 × Mw ^0.776 ≦ [η] ≦ 1.65 × 10 ^-4 × Mw ^0.776
… (Eq-1)
According to the present invention, by using a composition in which an ethylene-based polymer (A1) having specific characteristics and LDPE are combined, some action is exerted to change the orientation and crystal state of the resin. Generally, it is said that the direction in which the easy-to-cut property of the film is exhibited depends on the direction of the molecular orientation when the film is molded, and in the combination of LLDPE and LDPE, the molecular orientation occurs in the flow direction of the molecules during the film molding. Because of the ease, lamella crystals are also formed in a state of being oriented in the flow direction, and the resulting film tends to be easily cut in the flow direction and difficult to be cut in the direction perpendicular to the flow. On the other hand, a film produced in a state where molecular orientation is unlikely to occur due to film processing, such as using LLDPE having a narrow molecular weight distribution, tends to be difficult to cut in either direction. In addition, in the case of an inflation film using LDPE alone, it is presumed that molecular orientation occurs when the bubble is inflated, so it is easy to cut in the direction perpendicular to the resin flow, and conversely, in the molecular flow direction. It often has a performance that is hard to cut.

Therefore, in order to control the direction of easy cutting with a combination of well-known techniques, the amount of LDPE having a characteristic of being easily cut in the direction perpendicular to the flow direction is increased based on the combination of LLDPE and LDPE which are easy to cut in the flow direction. Is conceivable. However, although it seems that the entanglement between the LDPE molecule and the LLDPE molecule is extremely strong, as shown in Comparative Examples 1 to 4 of the present specification, orientation occurs in the flow direction unless the blending amount of LLDPE is extremely small. Since the easy performance cannot be suppressed, the blend range in which the direction of easy cutability can be controlled is extremely limited, and excellent heat sealability and easy finger sticking property cannot be achieved at the same time.

When the ethylene-based polymer (A1), which is the multi-branched polyethylene (hereinafter, also referred to as "E-PE") studied by the present inventors, is used alone for film molding, the introduction of the branch is introduced. It is presumed that the direction of molecular orientation changes depending on the state, but the behavior in the easy-cutting direction changes as compared with the case where LLDPE is used alone for film molding. Therefore, if the branching state can be changed depending on the catalyst for producing the ethylene polymer and the polymerization conditions, it is theoretically possible to freely change the direction of easy cutting, but in reality, it depends on the applicable packaging material. It is impossible to finely change the polymerization catalyst and polymerization conditions, and it is generally strongly required to control the directionality by combining available materials.

As described above, it is possible to control the direction of easy cutting by controlling the molecular orientation when molding the film, but it has been extremely difficult to control the direction with the existing known techniques. However, in the present invention, surprisingly, the E-PE type ethylene polymer (A1) (usually produced using a catalyst) and the E-PE type LDPE produced by radical polymerization are used. By combining the same E-PE type resin, while maintaining excellent heat-sealing property and easy finger sticking property, the direction of easy cutting property within a blend range that does not pose a practical problem. Can be controlled. The mechanism is not necessarily clear, but a mechanism is presumed in which the molecular orientation during molding is controlled by controlling the degree of entanglement between E-PE type molecules by blending.

According to the above estimation mechanism, according to the present invention, it is possible to sufficiently control the direction of the easy-cut property of the film even if high-speed molding is performed using a normal blender, and when the film is used alone or Even when processed into a laminated film, good cutability is exhibited in a desired direction.

Next, each component in the ethylene-based polymer composition (A2) will be specifically described.

[Ethylene polymer (A1)]
The ethylene-based polymer (A1) contains ethylene and an α-olefin having 4 to 10 carbon atoms, preferably ethylene and an α-olefin having 4 to 10 carbon atoms (however, when butene-1 is used as the copolymer). An α-olefin having 6 to 10 carbon atoms is also required), more preferably a copolymer of ethylene and an α-olefin having 6 to 10 carbon atoms. Examples of the α-olefin having 4 to 10 carbon atoms used for copolymerization with ethylene include 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene.

The ethylene-based polymer (A1) has the properties represented by the following requirements (I) to (V).

Requirement (I): Melt flow rate (MFR) is 0.1 to 10 g / 10 minutes, preferably 0.3 to 10 g / 10 minutes, more preferably 0.5 to 10 g / 10 minutes, particularly preferably 0.5. It is in the range of ~ 8.0 g / 10 minutes.

By specifying the melt flow rate (MFR), the molecular weight can be controlled, an elongation viscosity suitable for inflation processing or casting processing can be obtained, and a thick film can also be formed. When the melt flow rate (MFR) is 0.1 g / 10 minutes or more, the shear viscosity of the ethylene polymer is not too high, and the extrudability and workability of the thin film are good. When the melt flow rate (MFR) is 10 g / 10 minutes or less, particularly when it is 8.0 g / 10 or less, the heat seal strength of the film formed from the composition of the present invention is good, and bubbles during inflation processing are good. Excellent stability and neck-in during T-die molding.

Melt flow rate (MFR) is a numerical value related to heat seal strength and extrusion processing. Although MFR is a numerical value indicating the fluidity of the resin, it strongly depends on the molecular weight. The smaller the melt flow rate (MFR), the larger the molecular weight, and the larger the melt flow rate (MFR), the smaller the molecular weight. Further, it is known that the molecular weight of an ethylene-based polymer is determined by the composition ratio of hydrogen and ethylene (hydrogen / ethylene) in the polymerization system (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 the ethylene-based polymer by increasing or decreasing hydrogen / ethylene.

Melt flow rate (MFR) is measured according to JIS K7210 under the conditions of 190 ° C. and 2.16 kg load.

Requirement (II): The density (d) is in the range of 875 to 970 kg / m ³ , preferably 88 to 970 kg / m ³ , and more preferably 890 to 970 kg / m ³ .

When the density (d) is 875 kg / m ³ or more, the surface of the film formed from the ethylene polymer is less sticky, and when the density (d) is 970 kg / m ³ or less, the heat seal strength is good and the sealing property is good. Excellent, especially excellent low temperature sealing property.

The density is an index indicating the range that can be used as a film that is not sticky and can be sealed, and depends on the α-olefin content of the ethylene-based polymer. The smaller the α-olefin content, the higher the density, and the α- The higher the olefin content, the lower the density. Further, it is known that the α-olefin content in an ethylene-based polymer is determined by the composition ratio of α-olefin and ethylene in the polymerization system (for example, Walter Kaminsky, et al. Makromol.Chem. 193, p.606 (1992)). Therefore, by increasing or decreasing the α-olefin / ethylene, an ethylene-based polymer having a density in the above range can be produced.

The density (d) is measured according to the method of JIS K6922-1, the sample is heat-treated with boiling water for 30 minutes, slowly cooled to room temperature under cooling conditions over 1 hour, and then the density gradient tube is measured according to the method of JIS K7112. Is done by.

Requirement (III): ¹³ The sum of the number of methyl branches [A (/ 1000C)] per 1000 carbon atoms measured by C-NMR and the number of ethyl branches [B (/ 1000C)] [(A + B) (/ 1000C) )] Is 1.80 or less, preferably 1.30 or less, more preferably 0.80 or less, and even more preferably 0.50 or less.

When it is 1.80 or less, the film strength and the seal strength due to the deterioration of crystal packing are good.

If short-chain branches such as methyl branches and ethyl branches are present in the ethylene-based polymer, the short-chain branches are incorporated into the crystal and the interplanar spacing of the crystal is widened, which may reduce the mechanical strength of the resin. It is known (for example, supervised by Zenjiro Osawa et al., "Polymer Life Prediction and Life Extension Technology", NTS Co., Ltd., 2002, p.481). Therefore, when the sum (A + B) of the number of methyl branches and the number of ethyl branches is 1.80 or less, there are few short-chain branched structures that are easily incorporated into the crystal, so that the crystal packing is good and there are many tie molecules. , The mechanical strength of the ethylene-based polymer is good, and excellent heat-sealing strength is exhibited.

The number of methyl branches and the number of ethyl branches in the ethylene-based polymer strongly depend on the polymerization method of the ethylene-based polymer, and the sum thereof is a numerical value related to the packing of crystals and the strength of the film. The ethylene-based polymer obtained by high-pressure radical polymerization has a larger number of methyl branches and ethyl branches than the ethylene-based polymer obtained by coordination polymerization using a Ziegler-type catalyst system. In the case of coordinate polymerization, the number of methyl branches and the number of ethyl branches in the ethylene-based polymer strongly depend on the composition ratio of propylene, 1-butene and ethylene (propylene / ethylene, 1-butene / ethylene) in the polymerization system. To do. Therefore, by increasing or decreasing 1-butene / ethylene, it is possible to increase or decrease the sum (A + B) of the number of methyl branches and the number of ethyl branches of the ethylene polymer.

^{13 The} number of methyl branches and the number of ethyl branches measured by C-NMR are determined by the following method or an equivalent method.

The measurement is performed using an ECP500 type nuclear magnetic resonance device ( ¹ H: 500 MHz) manufactured by JEOL Ltd., and the number of integrations is 10,000 to 30,000. The peak of main chain methylene (29.97ppm) is used as a chemical shift reference. 250-400 mg of ethylene polymer sample and special grade o-dichlorobenzene manufactured by Wako Pure Chemical Industries, Ltd .: benzene manufactured by ISOTEC-d6 = 5: 1 (volume ratio) in a commercially available NMR measurement quartz glass tube with a diameter of 10 mm. ) Is added, and the mixture is heated at 120 ° C. and uniformly dispersed to measure the measurement. Attribution of each absorption in the NMR spectrum is performed according to the Chemical Region Special Edition 141 NMR-Review and Experimental Guide [I], pp. 132-133. The number of methyl branches per 1,000 carbons is calculated from the integral intensity ratio of the absorption of methyl groups derived from methyl branches (19.9 ppm) to the total integral of absorption appearing in the range of 5 to 45 ppm. The number of ethyl branches is calculated from the integrated intensity ratio of the absorption of ethyl groups derived from ethyl branches (10.8 ppm) to the total integrated absorption of absorption appearing in the range of 5 to 45 ppm.

Requirement (IV): The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.50 , preferably 1.0 × 10 ^4.30. It is in the range of ~ 1.0 × 10 ^4.48 , more preferably 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.45 .

When the molecular weight (peak top M) at the maximum weight fraction is within the above range, the heat seal strength is good, and the occurrence of take-back surging is suppressed during molding.

It is known that low molecular weight components have a strong influence on the mechanical strength of ethylene-based polymers. The presence of low molecular weight components is thought to reduce the mechanical strength due to the increase in molecular ends that are thought to be the starting point of fracture (edited by Kazuo Matsuura and Naotaka Mikami, "Polyethylene Technology Reader", Co., Ltd. Industrial Research Council, 2001, p.45). When the molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is 1.0 × 10 ^4.30 or more, the heat seal strength is low because there are few low molecular weight components that adversely affect the heat seal strength. Excellent for.

The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement indicates the strength of the film and is determined by the composition ratio of hydrogen and ethylene (hydrogen / ethylene) in the polymerization system. It is known (for example, Kazuo Soga et al., "Catalytic Olefin Polymerization", Kodansha Scientific, 1990, p.376). Therefore, by increasing or decreasing hydrogen / ethylene, it is possible to increase or decrease the molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve. Further, by using a preferable catalyst for olefin polymerization described later, it becomes easy to adjust the molecular weight (peak top M) at the maximum weight fraction within an appropriate range.

The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve is measured and calculated under the following conditions or similar conditions.

[Measurement condition]
Equipment used: Gel permeation chromatograph manufactured by Waters, alliance GPC2000 type (high temperature size exclusion chromatograph)
Analysis software; Chromatography data system Empower (Waters)
_{Column; TSKgel GMH 6 - HT × 2} + TSKgel GMH 6 -HTL × 2
(Inner diameter 7.5 mm x length 30 cm, Tosoh)
Mobile phase; o-dichlorobenzene (Wako Pure Chemicals Special Grade Reagent)
Detector; differential refractometer (built-in device)
Column temperature; 140 ° C
Flow rate; 1.0 mL / min Injection volume: 500 μL
Sampling time interval; 1 second Sample concentration: 0.15% (w / v)
Molecular weight calibration; monodisperse polystyrene (Tosoh) / molecular weight 495 ~ molecular weight 20.6 million
A molecular weight distribution curve is created in terms of polyethylene molecular weight according to the general calibration procedure described in Z. Crubisic, P. Rempp, H. Benoit, J. Polym. Sci., B5 , 753 (1967). From this molecular weight distribution curve, the molecular weight (peak top M) at the maximum weight fraction is calculated.

Requirement (V): The relationship between the ultimate 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) is as follows. The equation (Eq-1) is satisfied.

0.80 × 10 ^-4 × Mw ^0.776 ≦ [η] ≦ 1.65 × 10 ^-4 × Mw ^0.776
… (Eq-1)
That is, in the ethylene polymer (A1), the extreme viscosity [[η] (dl / g)] measured in decalin at 135 ° C. and the GPC-viscosity detector method (GPC-VISCO) were used. The ratio of the weight average molecular weight to the 0.776th power (Mw ^0.776 ) is the following formula (Eq-2).
0.80 × 10 ^-4 ≤ [η] / Mw ^0.776 ≤ 1.65 × 10 ^-4 … (Eq-2)
Meet. The lower limit is preferably 0.85 × 10 ^-4 , more preferably 0.90 × 10 ^-4 , and the upper limit is preferably 1.55 × 10 ^-4 , more preferably 1.45 × 10 ^-4 . is there.

It is known that when a long-chain branch is introduced into an ethylene-based polymer, the ultimate viscosity [η] (dl / g) becomes smaller for the molecular weight than a linear ethylene-based polymer without a long-chain branch. (For example, Walther Burchard, ADVANCES IN POLYMER SCIENCE, 143, Branched PolymerII, p.137 (1999)).

Based on the Mark-Houwink-Sakurada formula, polyethylene [η] is Mv to the 0.7th power, polypropylene [η] is Mw to the power of 0.80, and poly-4-methyl-1-pentene [η] is Mn 0.81. It has been reported to be proportional to the power (eg R. Chiang, J. Polym. Sci., 36, 91 (1959): P.94, R. Chiang, J. Polym. Sci., 28, 235 (1958). ): P.237, AS Hoffman, BA Fries and PC Condit, J. Polym. Sci. Part C, 4, 109 (1963): P.119 Fig. 4).

Then, it was decided to set Mw to the power of 0.776 as a typical index of the copolymer of ethylene and the α-olefin having 4 or more and 10 or less carbon atoms, and the molecular weight was relatively [η] as compared with the conventional ethylene-based polymer. ] Is small, which is the requirement (V).

Therefore, when [η] / Mw ^{0.776 of} the ethylene-based polymer (A1) is not more than the above upper limit value, particularly 1.65 × 10 ^-4 or less, it has a large number of long-chain branches, and the ethylene-based polymer composition. The product (A2) has excellent moldability and fluidity.

Since the long chain branching content is increased by adjusting the component ratio in the olefin polymerization catalyst as described later, an ethylene polymer (A1) having the ultimate viscosity [η] in the above range can be produced. ..

The weight average molecular weight (Mw) by the GPC-VISCO method is measured by the following method or an equivalent method.

A Waters GPC / V2000 is used as the measuring device. 1. A guard column using Shodex AT-G, two analytical columns AT-806, a column temperature of 145 ° C., o-dichlorobenzene for the mobile phase, and 0.3% by weight of BHT as an antioxidant. The sample is moved at 0 ml / min, the sample concentration is 0.1% by weight, and a differential refractometer and a 3-capillary viscometer are used as detectors. The standard polystyrene used is manufactured by Tosoh Corporation. In the molecular weight calculation, the measured viscosity is calculated from the viscometer and the refractometer, and the weight average molecular weight (Mw) is calculated from the measured universal calibration.

The ultimate viscosity [η] (dl / g) is measured as follows using a decalin solvent.

Dissolve about 20 mg of sample in 15 ml of decalin and measure the specific viscosity η _sp in an oil bath at 135 ° C. Add 5 ml of decalin solvent to this decalin solution to dilute it, and then measure the specific viscosity η _sp in the same manner. This dilution operation is repeated twice more, and the η _sp / C value when the concentration (C) is extrapolated to 0 is defined as the ultimate viscosity [η]. (See equation (Eq-3) below)
[Η] = lim (η _sp / C) (C → 0)… (Eq-3)
Next, a method for producing the ethylene-based polymer (A1) will be described.

The ethylene-based polymer (A1) comprises ethylene and an α-olefin having 4 to 10 carbon atoms in the presence of an olefin polymerization catalyst for producing the ethylene-based polymer (B1) described in JP-A-2017-25340. It can be efficiently produced by polymerizing by the method described in Open 2017-25340.

The preferred method for producing the ethylene-based polymer (A1) and the catalyst for production will be specifically described below, but the method for producing the ethylene-based polymer (A1) and the catalyst for production are not limited to the following.

(Preferable manufacturing method of ethylene polymer (A1))
-Preferable production catalyst of ethylene-based polymer (A1) The ethylene-based polymer (A1) contains ethylene and 4 or more carbon atoms in the presence of a catalyst containing a component (α), a component (β) and a component (γ). It can be efficiently produced by polymerizing with 10 or less α-olefins.

The catalyst may contain a solid support (S) and a component (G) in addition to the components (α), components (β) and components (γ) described below.

Each component used in the catalyst will be described.

・ Ingredient (α)
The component (α) is a crosslinked metallocene compound represented by the following general formula (I).

一般式（Ｉ）中、Ｍは周期表第４族遷移金属原子を示し、具体的には、チタン、ジルコニウムおよびハフニウムから選ばれる遷移金属原子であり、好ましくはジルコニウムである。

In the general formula (I), M represents a transition metal atom of Group 4 of the periodic table, and specifically, it is a transition metal atom selected from titanium, zirconium and hafnium, and is preferably zirconium.

R ^{1 to} R ⁸ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, halogen-containing groups, oxygen-containing groups, nitrogen-containing groups, boron-containing groups, sulfur-containing groups, phosphorus-containing groups, silicon-containing groups, and germanium-containing groups. Selected from groups and tin-containing groups, they may be the same or different from each other, but not all are hydrogen atoms at the same time. Further, among R ^{1 to} R ⁸ , adjacent groups may be bonded to each other to form an aliphatic ring (that is, a hydrocarbon ring having no aromaticity).

Aspects of R ^{1 to} R ⁸ are preferably hydrogen atoms or alkyl groups having 1 to 15 carbon atoms, and more preferably 6 or more of the substituents of R ^{1 to} R ⁸ are hydrogen atoms. The remaining two are alkyl groups having 3 to 15 carbon atoms, and particularly preferably, seven of the substituents of R ^{1 to} R ⁸ are hydrogen atoms, and the remaining one is an alkyl group having 3 to 15 carbon atoms. is there.

Q ¹ is a divalent group that binds two ligands, and contains a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group and an alkylidene group, a halogen-containing group, a silicon-containing group, and a germanium. It is a group selected from a group and a tin-containing group, and is particularly preferably a silicon-containing group.

X is an atom or group independently selected from a hydrogen atom, a halogen atom, a hydrocarbon group, a halogen-containing hydrocarbon group, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group and a phosphorus-containing group. , Preferably a halogen atom or a hydrocarbon group. Examples of the halogen atom include fluorine, chlorine, bromine and iodine, and chlorine is particularly preferable. As the hydrocarbon group, an alkyl group having 1 to 20 carbon atoms is particularly preferable.

・ Ingredient (β)
The component (β) is a crosslinked metallocene compound represented by the following general formula (II).

一般式（ＩＩ）中、Ｍは周期表第４族遷移金属原子を示し、具体的には、チタン、ジルコニウムおよびハフニウムから選ばれる遷移金属原子であり、好ましくはジルコニウムである。

In the general formula (II), M represents a transition metal atom of Group 4 of the periodic table, and specifically, it is a transition metal atom selected from titanium, zirconium and hafnium, and is preferably zirconium.

R ^{9 to} R ²⁰ are derived from hydrogen atoms, hydrocarbon groups, halogen-containing groups, oxygen-containing groups, nitrogen-containing groups, boron-containing groups, sulfur-containing groups, phosphorus-containing groups, silicon-containing groups, germanium-containing groups and tin-containing groups. It may be selected and may be the same or different from each other, and two adjacent groups of R ^{9 to} R ²⁰ may be connected to each other to form a ring. Preferred groups for R ^{9 to} R ²⁰ are hydrogen atoms and hydrocarbon groups, more preferably R ^{9 to} R ¹² are hydrogen atoms, and R ^{13 to} R ²⁰ are hydrogen atoms or alkyl groups having 1 to 20 carbon atoms. Is.

Q ² is a divalent group that binds two ligands, and is a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group and an alkylidene group, a halogen-containing group, a silicon-containing group, and germanium. It is a group selected from a containing group and a tin-containing group, preferably a group selected from a hydrocarbon group having 1 to 20 carbon atoms such as an alkylene group, a substituted alkylene group and an alkylidene group, and a silicon-containing group, and particularly preferably. It is a hydrocarbon group having 1 to 10 carbon atoms such as an alkylene group, a substituted alkylene group and an alkylidene group.

Examples of X include the same as X in the above formula (I).

・ Ingredient (γ)
The component (γ) is at least one compound selected from the group consisting of the following (γ-1) to (γ-3).

(Γ-1) An organometallic compound represented by the following general formula (III), (IV) or (V),
Rα _m Al (ORβ) _n H _p X _q・ ・ ・ (III)
[In general formula (III), Rα and Rβ represent hydrocarbon groups having 1 to 15 carbon atoms, which may be the same or different from each other, X represents a halogen atom, and m is 0 <m ≦ 3, n is a number of 0 ≦ n <3, p is a number of 0 ≦ p <3, q is a number of 0 ≦ q <3, and m + n + p + q = 3. ]
MαAlRα ₄ ... (IV)
[In the general formula (IV), Mα represents Li, Na or K, and Rα represents a hydrocarbon group having 1 to 15 carbon atoms. ]
Rα _r Mβ Rβ _s X _t・ ・ ・ (V)
[In the general formula (V), Rα and Rβ represent hydrocarbon groups having 1 to 15 carbon atoms, which may be the same or different from each other, Mβ represents Mg, Zn or Cd, and X represents a halogen atom. As shown, r is 0 <r ≦ 2, s is 0 ≦ s ≦ 1, t is 0 ≦ t ≦ 1, and r + s + t = 2. ]
(Γ-2) Organoaluminium oxy compound and
(Γ-3) A compound that reacts with component (α) and component (β) to form an ion pair,
At least one compound selected from.

Among the organic metal compounds (γ-1) represented by the general formulas (III), (IV) or (V), those represented by the general formula (III) are preferable, and specific examples thereof are trimethyl. Trialkylaluminum such as aluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, trihexylaluminum and trioctylaluminum; and dimethylaluminum hydride, diethylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride And alkylaluminum hydrides such as diisohexylaluminum hydride and the like. These may be used alone or in combination of two or more.

-Solid support (S)
In the present invention, the solid support (S) that can be used as needed is an inorganic or organic compound and is a solid in the form of granules or fine particles.

Among these, examples of the inorganic compound include porous oxides, inorganic chlorides, clays, clay minerals and ion-exchange layered compounds, and preferably porous oxides.

Porous oxides include SiO ₂ , Al ₂ O ₃ , MgO, ZrO, TiO ₂ , B ₂ O ₃ , CaO, ZnO, BaO, ThO _2, etc., or composites or mixtures containing these, specifically , Natural or synthetic zeolite, SiO _2- MgO, SiO _2- Al ₂ O ₃ , SiO _2- TiO ₂ , SiO _2- V ₂ O ₅ , SiO _2- Cr ₂ O ₃ and SiO _2- TiO _2- MgO, etc. Used. Of these, those containing SiO ₂ as the main component are preferable.

・ Ingredient (G)
Examples of the component (G) that can be used as needed include at least one compound selected from the group consisting of the following (g-1) to (g-6).

(G-1) Polyalkylene oxide block,
(G-2) Higher aliphatic amide,
(G-3) Polyalkylene oxide,
(G-4) Polyalkylene oxide alkyl ether,
(G-5) alkyl diethanolamine, and (g-6) polyoxyalkylene alkyl amine.

In the present invention, the component (G) may coexist in the catalyst for producing the ethylene-based polymer (A1) for the purpose of suppressing fouling in the reactor or improving the particle properties of the produced polymer. it can. Among the components (G), (g-1), (g-2), (g-3) and (g-4) are preferable, and (g-1) and (g-2) are particularly preferable. Here, examples of (g-2) include higher fatty acid diethanolamide and the like.

-Method for preparing a preferable production catalyst for an ethylene-based polymer (A1) A method for preparing a preferable production catalyst for an ethylene-based polymer (A1) will be described.

In the preferred production catalyst of the ethylene-based polymer (A1), the component (α), the component (β) and the component (γ) are added to the inert hydrocarbon or the polymerization system using the inert hydrocarbon. Can be prepared by.

When the solid carrier (S) is contained, at least one component of the component (α), the component (β) and the component (γ) is brought into contact with the solid carrier (S) in an inert hydrocarbon, and then The remaining components can be further contacted to prepare a solid catalyst component.

In the mechanism for producing the ethylene-based polymer (A1), the present inventors include a component (α) and a component (γ), and if necessary, a catalyst component for olefin polymerization including a solid carrier (S). Below, by polymerizing ethylene or ethylene with an α-olefin having 4 to 10 carbon atoms, preferably ethylene with an α-olefin having 4 to 10 carbon atoms, the terminal having a number average molecular weight of 4000 to 20000, preferably 4000 to 15000. Ethylene and carbon are produced by producing a "macromonomer" which is a polymer having vinyl, and then by a catalyst component for olefin polymerization including a component (β) and a component (γ) and, if necessary, a solid carrier (S). It is considered that a long-chain branch is generated in the ethylene-based polymer (A1) by competitively copolymerizing the macromonomer with the polymerization of α-olefins of numbers 4 to 10. The long-chain branching content in the ethylene-based polymer (A1) depends on the composition ratio of macromonomer and ethylene in the polymerization system ([macromonomer] / [ethylene]), and is [macromonomer] / [ethylene]. ] Is higher, the longer chain branching content in the ethylene polymer (A1) is higher. [Macromonomer] / [Ethylene] can be increased by increasing the ratio of the component (α) in the olefin polymerization catalyst ([Component (α)] / [Component (α) + Component (β)]). ..

As described above, the usage ratio of the component (α) and the component (β) can be arbitrarily determined from the amount of long-chain branching of the ethylene-based polymer (A1) to be produced, but the polymer produced from the component (α). The ratio of the polymer to the polymer produced from the component (β) [= the weight of the polymer produced from the component (α) / the weight of the polymer produced from the component (β)] is usually 40/60 to 95/5, preferably 50/50. It is in the range of ~ 95/5, more preferably 60/40 to 95/5.

The solid catalyst component can be used as it is for the production of the ethylene-based polymer (A1), but a solid catalyst component obtained by prepolymerizing an olefin to form a prepolymerization catalyst component can also be used.

In order to suppress variations in the physical property values of the obtained ethylene-based polymer (A1), the ethylene-based polymer particles obtained by the polymerization reaction and other components added as desired are melted, kneaded, or kneaded by an arbitrary method. Granulation or the like may be performed.

[High pressure method low density polyethylene]
The ethylene-based polymer composition (A2) contains high-pressure low-density polyethylene (LDPE).

The MFR of the LDPE (based on JIS K7210, 190 ° C., 2.16 kg load) is preferably 0.2 g / 10 minutes or more and 10 g / 10 minutes or less, and more preferably 0.2 g / 10 minutes or more and 6 g / 10 minutes or less. More preferably, it is in the range of 0.2 g / 10 minutes or more and 4 g / 10 minutes or less. LDPE having an MFR in the above range is preferable because it has good compatibility with the ethylene-based polymer (A1).

LDPE may be selected from common stocks available on the market.

[Ethylene polymer composition (A2)]
The ethylene-based polymer composition (A2) of the present invention comprises the ethylene-based polymer (A1) and the LDPE, and the ethylene-based polymer (A1): LDPE = 1% by weight: 99% by weight to 99% by weight: 1% by weight, preferably 5% by weight: 95% by weight to 95% by weight: 5% by weight, more preferably 10% by weight: 90% by weight to 90% by weight: 10% by weight (however, the ethylene polymer (A-1) and the total amount of the LDPE are 100% by weight). When the ratio of ethylene polymer (A1) or LDPE is less than 1% by weight of the whole, it becomes difficult for the resin blend to become uniform and the direction of easy cutting is not stable, so from the viewpoint of quality stability of the film product. Not preferred.

The ethylene-based polymer composition (A2) of the present invention may contain a resin component other than the ethylene-based polymer (A1) and LDPE as long as the effects of the present invention are not impaired. The content of the ethylene-based polymer composition (A2) is usually 10% by weight or less, preferably 5% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less.

In producing a film from the ethylene-based polymer composition (A2) of the present invention, the ratio of the ethylene-based polymer (A1) to the LDPE is changed within the above range, so that the film can be easily cut. Can be adjusted in any direction. Specifically, increasing the proportion of the ethylene-based polymer (A1) can exhibit easy-cutting property in the resin flow direction (MD), and increasing the proportion of LDPE is perpendicular to the resin flow. Easy-cutting property in the direction (TD) can be expressed, and when the ratio of both is about the same, easy-cutting property in all directions can be expressed.

That is, when it is desired to exhibit the easy-cut property in the flow direction (MD) direction of the resin at the time of molding, the ethylene-based polymer composition (A2) contains the ethylene-based polymer (A1) and the LDPE. , Ethylene-based polymer (A1): LDPE = 60% by weight: 40% by weight to 99% by weight: 1% by weight, preferably ethylene-based polymer (A1): LDPE = 61% by weight: 39% by weight. It is more preferably contained in a ratio of% to 99% by weight: 1% by weight, and further contained in a ratio of ethylene polymer (A1): LDPE = 70% by weight: 30% by weight to 99% by weight: 1% by weight. It is preferable (the total amount of the ethylene polymer (A1) and LDPE is 100% by weight). In these ratios, the upper limit of the amount of the ethylene polymer (A1) may be 95% by weight or 90% by weight (the lower limit of the amount of LDPE is 5% by weight, 10% by weight).

When it is desired to exhibit easy-cutting property in both the flow direction (MD) direction (MD) direction and the direction (TD) direction perpendicular to the flow direction (MD) of the resin during molding, the ethylene-based polymer composition (A2) has the ethylene-based weight. The coalescence (A1) and the LDPE are preferably contained in a ratio of ethylene-based polymer (A1): LDPE = 41% by weight: 59% by weight to 59% by weight: 41% by weight, and the ethylene-based polymer (A1). : LDPE = 45% by weight: 55% by weight to 55% by weight: more preferably 45% by weight (the total amount of the ethylene polymer (A1) and LDPE is 100% by weight).

When it is desired to exhibit easy-cutting property in the direction perpendicular to the flow of the resin during molding (TD), the ethylene-based polymer composition (A2) contains the ethylene-based polymer (A1) and the LDPE. Is preferably contained in a ratio of ethylene polymer (A1): LDPE = 1% by weight: 99% by weight to 40% by weight: 60% by weight, and ethylene polymer (A1): LDPE = 1% by weight: 99. It is more preferable to contain it in a ratio of% by weight to 39% by weight: 61% by weight, and it may be contained in a ratio of ethylene polymer (A1): LDPE = 1% by weight: 99% by weight to 30% by weight: 70% by weight. More preferably (the total amount of the ethylene polymer (A1) and LDPE is 100% by weight). In these ratios, the lower limit of the amount of the ethylene polymer (A1) may be 5% by weight and 10% by weight (the upper limit of the amount of LDPE is 95% by weight or 90% by weight).

The ethylene-based polymer composition (A2) of the present invention may or may not contain general additives such as antioxidants, slip agents, antiblocking agents, and antistatic agents.

The ethylene-based polymer composition of the present invention is particularly suitable for inflation molding or cast molding. Since these molding methods are performed at a relatively lower temperature than the extrusion laminating process, the obtained film has little effect on the taste and odor of the packaged contents, and good storage stability and aroma retention can be achieved. ..

[Use of ethylene polymer composition]
The film according to the present invention is characterized by being composed of the ethylene-based polymer composition (A2) according to the present invention, and is preferably used as an easy-to-open sealant film.

The film according to the present invention can be produced by molding the ethylene-based polymer composition (A2) according to the present invention into a film.

Further, the laminated film according to the present invention is characterized by having the film according to the present invention and another film. The laminated film according to the present invention is excellent in easy-to-cut property.

The laminated film according to the present invention can be produced, for example, by coextruding the ethylene-based polymer composition (A2) according to the present invention with another thermoplastic resin. A multilayer film having excellent moldability and easy cutability can be obtained. The coextrusion ratio (weight ratio) of the ethylene-based polymer composition according to the present invention to other thermoplastic resins is 99.9 / 0.1 to 0.1 / 99.9.

Other thermoplastic resins include crystalline thermoplastic resins such as polyolefins, polyamides, polyesters and polyacetals; non-crystalline thermals such as polystyrene, acrylonitrile-butadiene-styrene copolymers (ABS), polycarbonates, polyphenylene oxides, polyacrylates and the like. A plastic resin is used, and polyvinyl chloride is also preferably used.

Specifically, the polyolefins include ethylene copolymers, propylene-based polymers, butene-based polymers, 4-methyl-1-pentene-based polymers, 3-methyl-1-butene-based polymers, and hexene-based polymers. Examples thereof include polyolefins containing cyclic monomers. Of these, ethylene copolymers, propylene-based polymers, and 4-methyl-1-pentene-based polymers are preferable. The ethylene copolymer may be the ethylene-based polymer (A1), a conventional ethylene copolymer, or an ethylene / polar group-containing copolymer. As the conventional ethylene copolymer, high-pressure low-density polyethylene is preferable, and as the ethylene / polar group-containing copolymer, ethylene / vinyl acetate copolymer (EVA), ethylene / acrylic acid copolymer (EAA), etc. Acid copolymers such as ethylene / methacrylic acid copolymer (EMAA), ethylene / methacrylic acid ester copolymer, ethylene / acrylic acid ester copolymer, and ionomers in which their resins are pseudocrosslinked with metal ions are used. preferable.

Specific examples of the above-mentioned polyamide include aliphatic polyamides such as nylon-6, nylon-66, nylon-10, nylon-12, and nylon-46, and aromatic polyamides produced from aromatic dicarboxylic acids and aliphatic diamines. Can be mentioned.

Specific examples of the polyester include aromatic polyesters such as polyethylene terephthalate, polyethylene naphthalate and polybutylene terephthalate; polycaprolactone and polyhydroxybutyrate.

Specific examples of the polyacetal include polyformaldehyde (polyoxymethylene), polyacetaldehyde, polypropionaldehyde, and polybutylaldehyde. Of these, polyformaldehyde is particularly preferable.

The polystyrene may be a homopolymer of styrene, or may be a binary copolymer of styrene and acrylonitrile, methyl methacrylate, or α-methylstyrene.

The ABS contains a structural unit derived from acrylonitrile in an amount of 20 to 35 mol%, a structural unit derived from butadiene in an amount of 20 to 30 mol%, and a structural unit derived from styrene. ABS containing in an amount of 40 to 60 mol% is preferably used.

Examples of the above polycarbonate include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, and 2,2-bis (4-hydroxyphenyl). ) Examples thereof include polymers obtained from butane and the like. Of these, polycarbonate obtained from 2,2-bis (4-hydroxyphenyl) propane is particularly preferred.

As the polyphenylene oxide, it is preferable to use poly (2,6-dimethyl-1,4-phenylene oxide).

As the polyacrylate, it is preferable to use polymethyl methacrylate or polybutyl acrylate.

The above-mentioned thermoplastic resins may be used alone or in combination of two or more. A particularly preferable thermoplastic resin is a polyolefin, and an ethylene copolymer is particularly preferable.

Excellent moldability by extruding the ethylene-based polymer composition (A2) according to the present invention alone or by co-extruding the ethylene-based polymer composition (A2) with a different type of thermoplastic resin composition. Therefore, a film having excellent heat-sealing property and easy finger-sticking property, preferably an inflation film, can be obtained. At least one layer of this film is a layer made of the ethylene-based polymer composition of the present invention. The layer made of the ethylene-based polymer composition of the present invention may be at least one layer among the layers formed by multi-layer molding by coextrusion molding, or may be a layer formed by single-layer molding by single extrusion molding.

The thickness of the film made of the ethylene-based polymer composition (A2) according to the present invention is preferably 15 to 300 μm, more preferably 20 to 250 μm. A thickness of 15 μm or more is preferable from the viewpoint of heat seal strength, and a thickness of 300 μm or less is preferable from the viewpoint of easy finger sticking of the film.

For example, in inflation molding, the ethylene polymer composition (A2) is molded at 100 to 300 ° C., preferably 120 to 200 ° C. When the temperature is 100 ° C. or higher, the resin is sufficiently melted and the generation of unmelted gel can be suppressed, so that stable continuous production of the film becomes possible. Further, when the temperature is 300 ° C. or lower, it is possible to suppress the generation of lumps due to resin deterioration and the decomposition reaction of the resin. If the decomposition reaction can be suppressed, deterioration of the odor and taste of the film can be suppressed, especially when the film of the present invention is used for food packaging.

The film according to the present invention may be used for sandwich lamination by extrusion laminating processing, or may be adhered by usually applying an anchor coating agent (adhesive) to the film to be adhered as in dry laminating processing. In a laminated film having a film according to the present invention and a film to be adhered (base material), in order to maintain the easy-to-cut property of the film according to the present invention, a stretched plastic film (OPP) is used as the film to be adhered (base material). , OPET, ONy), paper, metal foil, etc., which are relatively easy to cut, are preferably used, and in order to impart easy finger sticking property, the film to be adhered (base material) Is particularly preferably containing paper and metal foil. As the base material, a resin-coated material or a printed material may be used as a protective layer. The thickness of the film to be adhered (base material) is preferably 1 to 500 μm, more preferably 5 to 300 μm. If the film to be adhered (base material) is too thin, the strength will be too weak to serve as a packaging material, and if it is too thick, the rigidity will be extremely high, making laminating difficult and resin performance. Is not properly exhibited.

As the anchor coating agent (adhesive), at least one of commercially available urethane-based, titanate-based, imine-based, butadiene-based, and olefin-based may be applied.

The film using the film using the ethylene-based polymer composition (A2) of the present invention alone, or the laminated film obtained by laminating the film according to the present invention is a water packaging bag or a liquid soup packaging bag. , Liquid paper container, Lami raw fabric, special shape liquid packaging bag (standing pouch, etc.), standard bag, heavy bag, wrap film, sugar bag, oil packaging bag, various packaging films for food packaging, protective film, infusion It is suitable as a material for bags, agricultural materials, back-in boxes, semiconductor materials, pharmaceuticals, clean films used for packaging foods, and the like. In these uses, the laminated film may be in the form of laminating a layer made of an ethylene polymer composition (A2) on a base material made of nylon, polyester, polyolefin film or the like.

The bag body using the easily openable sealant film according to the present invention is produced from a film containing at least one layer made of the ethylene-based polymer composition of the present invention. The film used for the bag body (the bag body also includes a container) according to the present invention has at least one stretched film, paper, and metal foil in addition to the film layer according to the present invention from the viewpoint of appearance and feel. It may be a laminated film containing a substrate such as. Further, if necessary, the outermost layer of the film may be coated with a resin as a protective layer thereof.

For the bag body according to the present invention, the laminated film according to the present invention is used, and the surfaces of the sealing layer, that is, the layer made of the easily openable sealant film of the present invention are overlapped with each other facing each other, and then the peripheral ends thereof are overlapped. It can also be manufactured by heat-sealing to form a sealed portion. As a manufacturing method thereof, for example, the peripheral ends of the laminated film are bent or overlapped so that the surfaces of the inner layers face each other, and the peripheral ends thereof are, for example, a side seal type, a two-way seal type, and a three-way seal type. , Four-sided seal type, envelope sticker type, gassho sticker type (pillow seal type), fold seal type, flat bottom seal type, square bottom seal type, gusset type, etc. Be done. The bag body can take various forms depending on the contents, the usage environment, and the usage pattern. In addition, for example, a self-supporting packaging bag (standing pouch) or the like is also possible. As a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, or an ultrasonic seal can be used.

The bag may be filled with the contents through the opening, and then the opening may be heat-sealed.

For the bag body having such a structure, for example, a film prepared from the ethylene-based polymer composition (A2) according to the present invention is used as a sealant, and the film is in contact with each other or the surface protective layer of the substrate and the seal layer. By superimposing the films so that they overlap each other and heat-sealing the predetermined locations, and adhering the layers of the ethylene copolymer composition (A2) facing each other at the predetermined locations so as to obtain a bag with an open side. Can be manufactured.

As described above, by using the ethylene-based polymer composition (A2) according to the present invention, it is possible to adjust the balance of molecular orientation during film processing, which cannot be achieved within the range of known techniques, and ethylene. By changing the ratio of the system polymer (A1) and LDPE, the direction of easy-cutting property can be adjusted while exhibiting excellent heat-sealing property and easy finger-sticking property. By using the film of the present invention as a packaging material, it is possible to achieve both properties that are practically easy to open while having sufficient heat-sealing properties (sealing properties).

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

<Analysis or evaluation of ethylene-based polymers>
The analysis method and evaluation method of the ethylene polymer (A1) are as described in the above description, and the methods not described in the above description are as follows. The same applies to the method for analyzing or evaluating an ethylene polymer other than the ethylene polymer (A1).

[Zero shear viscosity (η ₀ )]
The zero shear viscosity [η ₀ (P)] at 200 ° C. was determined as follows.

The angular velocity [ω (rad / sec)] dispersion of the shear viscosity (η ^* ) at a measurement temperature of 200 ° C. was measured in the range of 0.02512 ≦ ω ≦ 100. A dynamic stress rheometer SR-5000 manufactured by Leometrics was used for the measurement. A parallel plate having a diameter of 25 mm was used as the sample holder, and the sample thickness was about 2.0 mm. The measurement points were 5 points per ω digit. The amount of strain was appropriately selected in the range of 3 to 10% so that the torque in the measurement range could be detected and the torque was not exceeded. The sample used for the shear viscosity measurement was a press molding machine manufactured by Shinto Metal Industry Co., Ltd., preheating temperature 190 ° C., preheating time 5 minutes, heating temperature 190 ° C., heating time 2 minutes, heating pressure 100 kg weight / cm ² , cooling temperature. It was prepared by press-molding the measurement sample to a thickness of 2 mm under the conditions of 20 ° C., a cooling time of 5 minutes, and a cooling pressure of 100 kg weight / cm ² .

Zero shear viscosity η ₀ was calculated by fitting the Carreau model of the following equation (Eq-4) to the measured rheology curve [angular velocity (ω) variance of shear viscosity (η ^* )] by the nonlinear least squares method.

ここで、λは時間の次元を持つパラメーター、ｎは材料の冪法則係数（power law index）を表す。なお、非線形最小二乗法によるフィッティングは下記数式（Eq-5）におけるｄが最小となるよう行われる。

Here, λ is a parameter having a dimension of time, and n is a power law index of the material. The fitting by the nonlinear least squares method is performed so that d in the following mathematical formula (Eq-5) is minimized.

ここで、η_exp（ω）は実測のせん断粘度、η_calc（ω）はCarreauモデルより算出したせん断粘度を表す。

Here, η _exp (ω) represents the measured shear viscosity, and η _calc (ω) represents the shear viscosity calculated from the Carreau model.

[Melting tension]
The melt tension (MT) was determined by measuring the stress when the molten ethylene polymer was stretched at a constant rate. An MT measuring machine manufactured by Toyo Seiki Seisakusho was used for the measurement. The measurement conditions are resin temperature 190 ° C., melting time 6 minutes, barrel diameter 9.55 mmφ, extrusion speed 15 mm / min, winding speed 24 m / min (if the molten filament breaks, the winding speed is 5 m / min. The nozzle diameter was 2.095 mmφ and the nozzle length was 8 mm.

<Analysis or evaluation of film>
An inflation film was prepared by the following method and analyzed or evaluated.

[Inflation film molding]
The resin (ethylene-based polymer composition, ethylene-based polymer, LDPE or LLDPE; the same applies hereinafter) obtained in Examples and the like is subjected to a single-layer inflation manufactured by Modern Co., Ltd. having a 50 mmφ extruder and a round die having a die diameter of 100 mmφ. An inflation film was processed under the following conditions using a molding machine.

Frost line: 300mm
Resin temperature: 180-200 ° C
Pick-up speed: 20 m / min Film size: 320 mm width x 40 μm thickness [Bubble stability]
Bubble sway was confirmed during the molding of the inflation film and evaluated according to the following criteria (determined as a sensory test).

○: No shaking △: Less shaking ×: Easy to shake [Heat seal test]
The inflation film produced by the above method was cut into a width of 15 mm to obtain a test piece.

The two test pieces were superposed, heat-sealed according to the following conditions, and the heat-seal strength was measured. Table 2 shows the average value of the five measurements.

・ Uses single-sided heating bar sealer Heat seal pressure: 2 kg / cm ²
Heat seal time: 0.5 seconds Heat seal temperature: 130 ° C
Seal bar width: 10 mm
Specimen width: 15 mm
Peeling angle: 180 degrees Peeling speed: 300 mm / min The peeling state of the heat seal was evaluated by visually confirming the peeling surface at n = 5 and using the following criteria (sensory test).

〇: In all 5 times, the two test pieces were completely fused and the film was broken.

X: Peeling occurred at the heat-sealed interface in one or more of the five measurements.

[Finger thrust test]
With the inflation film stretched appropriately, a human thumb was pierced into the film, and the ease of piercing was sensually evaluated according to the following criteria.

◯: Easy piercing property equivalent to LDPE film ×: Difficult piercing property equivalent to LLDPE film △: Puncture property in between these [Elmendorf tear strength, easy cut property direction]
The measurement was performed under the following conditions in accordance with ASTM D1922.

Using a light load tear tester (manufactured by Toyo Seiki Seisakusho: a capacitance weight B: 79 g is attached to the left end of the pendulum), the length is 63.5 mm (long side) in the tear direction (MD direction and TD direction) from the inflation film. A rectangular test piece with a width of 50 mm (short side) was cut out in the direction perpendicular to the tearing direction (TD direction and MD direction), and a notch of 12.7 mm from the end was made in the center of the short side to prepare a plurality of test pieces. ..

One test piece was placed in the machine and a tear test was performed to determine the tear strength (N) in the TD direction. The measurement range (R) of the testing machine was set to 200.

Another test piece was placed in the machine and a tear test was performed to determine the tear strength (N) in the MD direction. The measurement range (R) of the testing machine was set to 200.

The value of the tear strength in the MD direction / the tear strength in the TD direction was calculated, and the direction of easy cutability was evaluated based on this.

[Manufacturing of prepolymerization catalyst component]
Prepolymerization catalyst component (XP-1), (XP-2) according to the description of [Catalyst Preparation Example XP-1], [Catalyst Preparation Example XP-2] and [Catalyst Preparation Example XP-3] of JP-A-2017-25340. ) And (XP-3) were produced respectively. The specific manufacturing method will be described below.

[Catalyst Preparation Example XP-1]
(Preparation of solid carrier (X-1))
Silica gel (manufactured by Fuji Silysia Chemical Ltd .: average particle size 70 μm, specific surface area 340 m ² / g, pore volume 1.3 cm ³ / g, 250 ° C. for 10 hours) in a reactor with an internal volume of 270 liters and a nitrogen atmosphere. Dry) 10 kg was suspended in 77 liters of toluene and then cooled to 0-5 ° C. To this suspension, 19.4 liters of a toluene solution of methylaluminoxane (3.5 mmol / mL in terms of Al atoms) was added dropwise over 30 minutes. At this time, the temperature inside the system was kept at 0 to 5 ° C. After the contact was continued at 0 to 5 ° C. for 30 minutes, the temperature inside the system was raised to 95 ° C. over about 1.5 hours, and the contact was continued at 95 ° C. for 4 hours. Then, the temperature was lowered to room temperature, the supernatant was removed by decantation, and the residue was washed twice with toluene to prepare a total amount of 115 liters of toluene slurry. When a part of the obtained slurry component was collected and the concentration was examined, the slurry concentration was 122.6 g / L and the Al concentration was 0.62 mol / L.

(Preparation of solid catalyst components)
A reactor with a stirrer having an internal volume of 200 ml was charged with 300 ml of toluene and 400 ml of the solid support obtained above (0.25 mol in terms of Al atoms) under a nitrogen atmosphere. Next, as a transition metal complex (component (β)), a toluene solution of isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride was added in terms of Zr atoms. After dropping 12 mmol and contacting the mixture at an in-system temperature of 20 to 25 ° C. for 1 hour, the temperature inside the system was raised to 95 ° C. and the contact was carried out for another 2 hours. After lowering the temperature to 30 ° C., a toluene solution of dimethylsilylene (3-n-butylcyclopentadienyl) (cyclopentadienyl) zirconium dichloride as a transition metal complex (component (α)) is 0.12 mmol in terms of Zr atom. The drops were added dropwise, and these were brought into contact with each other at an in-system temperature of 20 to 30 ° C. for 1 hour. The supernatant was removed by decantation, washed twice with hexane, and then hexane was added to bring the total volume to 1 liter to prepare a slurry of solid catalyst components.

(Preparation of prepolymerization catalyst component (XP-1))
After cooling the solid catalyst component slurry obtained by the above method to 10 ° C., 120 mmol of diisobutylaluminum hydride (DiBAl—H) was added. Further, ethylene was continuously supplied into the system for several minutes under normal pressure. During this time, the temperature in the system was maintained at 10-15 ° C., then 18 ml of 1-hexene was added. After the addition of 1-hexene, the temperature inside the system was raised to 35 ° C., and 3 equal amounts of ethylene were polymerized with respect to the solid catalyst component in terms of weight. Then, the supernatant was removed by decantation, washed 4 times with hexane, and then hexane was added to bring the total volume to 1 liter. Next, after raising the temperature in the system to 35 ° C., 1.0 g of Emargen (registered trademark) 108 (manufactured by Kao Corporation) was added as a component (G), and the mixture was contacted for 2 hours. Then, the supernatant was removed by decantation and washed 4 times with hexane. Next, the hexane slurry was transferred to a glass glass filter having an internal volume of 1 liter, the hexane was filtered off, and then dried under reduced pressure to obtain 196 g of a prepolymerization catalyst component (XP-1). When the composition of the obtained prepolymerization catalyst was examined, 0.54 mg of Zr atoms were contained in 1 g of the prepolymerization catalyst component.

[Catalyst Preparation Example XP-2]
(Preparation of solid catalyst components)
Using the solid support (X-1), isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride of Catalyst Preparation Example 1 and dimethylsilylene (3-n) -Butylcyclopentadienyl) (cyclopentadienyl) Under the same conditions as in Catalyst Preparation Example XP-1, except that the amount of zirconium dichloride added was changed to 1.59 mmol and 0.18 mmol in terms of Zr atoms, respectively. A slurry of solid catalyst components was prepared.

(Preparation of prepolymerization catalyst component (XP-2))
Prepared under the same conditions as in Catalyst Preparation Example 1 except that the component (G) of Catalyst Preparation Example 1 was changed to 2 g of Chemistat (registered trademark) 2500 (manufactured by Sanyo Chemical Industries, Ltd.). XP-2) 186 g was obtained. When the composition of the obtained prepolymerization catalyst was examined, 0.84 mg of Zr atoms were contained in 1 g of the prepolymerization catalyst component.

[Catalyst Preparation Example XP-3]
(Preparation of solid catalyst components)
A reactor with a stirrer having an internal volume of 200 ml was charged with 300 ml of toluene and 400 ml of the solid support obtained in Catalyst Preparation Example 1 (0.25 mol in terms of Al atoms) under a nitrogen atmosphere. Next, a toluene solution of isopropylidene (cyclopentadienyl) (2,7-di-t-butyl-9-fluorenyl) zirconium dichloride was added dropwise at 1.07 mmol in terms of Zr atom, and dimethylsilylene (3-n-) was added. A toluene solution of butylcyclopentadienyl) (cyclopentadienyl) zirconium dichloride was added dropwise at 0.17 mmol in terms of Zr atoms, and these were contacted at an in-system temperature of 20 to 25 ° C. for 1 hour, and then the in-system temperature was adjusted. The temperature was raised to 75 ° C., and the mixture was contacted for another 2 hours. After the temperature was lowered to 30 ° C., the supernatant was removed by decantation, and the mixture was washed twice with hexane, and then hexane was added to make a total volume of 1 liter to prepare a slurry of solid catalyst components.

(Preparation of prepolymerization catalyst component (XP-3))
The hexane slurry of the solid catalyst component obtained by the above method was heated to 38 to 40 ° C., and then 120 mmol of diisobutylaluminum hydride (DiBAl—H) was added. While maintaining the temperature inside the system at 38 to 40 ° C., ethylene supply was started under normal pressure, and 3 equal amounts of ethylene were polymerized with respect to the solid catalyst component in terms of weight. Then, the supernatant was removed by decantation, washed 4 times with hexane, and then hexane was added to bring the total volume to 1 liter. Next, after raising the temperature in the system to 35 ° C., 1.0 g of Emargen (registered trademark) 108 (manufactured by Kao Corporation) was added as a component (G), and the mixture was contacted for 2 hours. Then, the supernatant was removed by decantation and washed 4 times with hexane. Next, the hexane slurry was transferred to a glass glass filter having an internal volume of 1 liter, the hexane was filtered off, and then dried under reduced pressure to obtain 195 g of a prepolymerization catalyst component (XP-3). When the composition of the obtained prepolymerization catalyst was examined, 0.54 mg of Zr atoms were contained in 1 g of the prepolymerization catalyst component.

[Manufacturing Example 1]
An ethylene / 1-hexene copolymer was produced using a prepolymerization catalyst component (XP-1) in a fluidized bed type gas phase polymerization reactor having an internal volume of 1.7 m ³ .

The raw material gas and the like were supplied so that the gas composition in the reactor had the values shown in Table 1. The prepolymerization catalyst component (XP-1) was also continuously supplied in the amounts shown in Table 1. Further, the manufacturing conditions were set as shown in Table 1.

The polymerization reaction product was continuously withdrawn from the reactor and dried in a drying apparatus to obtain an ethylene polymer (A1-1) powder.

Sumitomo GP (manufactured by Sumitomo Chemical Co., Ltd., registered trademark) 850 ppm was added to the ethylene polymer (A1-1) powder as a heat-resistant stabilizer, and the temperature was 200 ° C. Pellets of an ethylene polymer (A1-1) were obtained by melt-kneading under the conditions of a screw rotation speed of 300 rpm and a feeder rotation speed of 30 rpm. Table 1 shows the physical properties of the obtained ethylene polymer (A-1).

[Manufacturing Examples 2 and 3]
Ethylene-based polymers (A1-2) and (A1-3) were produced in the same manner as in Production Example 1 except that the conditions were changed as shown in Table 1. Table 1 shows the physical properties of the obtained ethylene-based polymers (A1-2) and (A1-3).

[Manufacturing Example 4]
An ethylene polymer was produced according to Example 1 of Patent Document 2 (Japanese Unexamined Patent Publication No. 2014-074103). Table 1 shows the physical properties of the obtained ethylene polymer (C1).

[Manufacturing Example 5]
An ethylene polymer was produced according to Production Example 18 of Patent Document 3 (Japanese Unexamined Patent Publication No. 2008-031380). Table 1 shows the physical properties of the obtained ethylene polymer (C2).

The specific production method in Production Example 5 will be described below.

(Preparation of solid component (S-1))
In a reactor with an internal volume of 260 liters, 10 kg of silica (SiO ₂ : average particle size 12 μm) dried at 250 ° C. for 10 hours under a nitrogen atmosphere was suspended in 90.5 liters of toluene, and then 0 to 5 ° C. Cooled down to. To this suspension, 45.5 liters of a toluene solution of methylarmoxane (3.0 mmol / ml in terms of Al atom) was added dropwise over 30 minutes. At this time, the temperature in the system was kept at 0 to 5 ° C. After the reaction was continued at 0 to 5 ° C. for 30 minutes, the temperature was raised to 95 to 100 ° C. over about 1.5 hours, and the reaction was continued at 95 to 100 ° C. for 4 hours. Then, the temperature was lowered to room temperature, and the supernatant was removed by decantation. The solid component thus obtained was washed twice with toluene, and then toluene was added to bring the total volume to 129 liters to prepare a toluene slurry of the solid component (S-1). A part of the obtained solid component was collected and the concentration was examined. As a result, the slurry concentration was 137.5 g / L and the Al concentration was 1.1 mol / L.

(Preparation of solid catalyst component (X-5))
50 ml of toluene was placed in a 200 ml glass flask substituted with nitrogen, and the toluene slurry (2.0 g in terms of solid part) of the solid component (S-1) prepared above was charged under stirring. Next, a toluene solution (0.002 mmol / ml in terms of Zr atom) of a premixed dimethylsilylenebis (cyclopentadienyl) zirconium dichloride (hereinafter, also referred to as “metallocene compound (A-1)”) 32. Mixing 5 ml and 7.23 ml of a toluene solution (0.001 mmol / ml in terms of Zr atom) of isopropylidene (cyclopentadienyl) (fluorenyl) zirconium dichloride (hereinafter, also referred to as “metallocene compound (B-1)”). The liquid was added dropwise and reacted at room temperature for 1 hour. Then, the supernatant was removed by decantation and washed twice with a decane to prepare a decane slurry of the solid catalyst component (X-5). The mixed molar ratio of the metallocene compound (A-1) and the metallocene compound (B-1) at the time of preparing the solid catalyst component (X-5) was (A-1) / (B-1) = 90/10. .. Moreover, when a part of the decan slurry of the obtained solid catalyst component (X-5) was collected and the concentration was examined, it was found that the Zr concentration was 0.065 mg / ml and the Al concentration was 3.77 mg / ml.

[polymerization]
500 ml of purified heptane was placed in a fully nitrogen-substituted SUS autoclave having an internal volume of 1 liter, ethylene was circulated, and the liquid and gas phases were saturated with ethylene. Next, after replacing the inside of the system with a hydrogen-ethylene mixed gas (hydrogen concentration: 0.064 vol%), a solid catalyst containing 30 ml of 1-hexene, 0.375 mmol of triisobutylaluminum, and 0.0026 mmol in terms of zirconium. The component (X-5) was charged in this order. The temperature was raised to 70 ° C., and polymerization was carried out at 0.78 MPa-G for 90 minutes. The obtained polymer was vacuum dried for 10 hours to obtain 92.9 g of an ethylene polymer.

［実施例１〜３］
製造例３で製造されたエチレン系重合体（Ａ１−３）のペレットと、ＬＤＰＥとして旭化成株式会社より市販されている高圧ラジカル重合法によるポリエチレン（商品名：サンテックＬＤ Ｍ１９２０）の製品ペレット（その物性を表１に示す。）とを、表１に記載されたブレンド比率でドライブレンドを行い、得られた混合物を用いてインフレーションフィルムの成形を行った。物性評価の結果を表２に示す。

[Examples 1 to 3]
Pellets of ethylene-based polymer (A1-3) produced in Production Example 3 and product pellets of polyethylene (trade name: Suntech LD M1920) commercially available from Asahi Kasei Corporation as LDPE by the high-pressure radical polymerization method (physical properties thereof). Is shown in Table 1.) Was dry-blended at the blend ratios shown in Table 1, and an inflation film was formed using the obtained mixture. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 1]
Inflation using product pellets (the physical properties of which are shown in Table 1) of ethylene / 1-hexene copolymer (trade name: Evolu SP1510), which is a linear low-density polyethylene commercially available from Prime Polymer Co., Ltd. The film was molded. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 2]
Product pellets of ethylene / 1-hexene copolymer (trade name: Evolu SP1510), which is a linear low-density polyethylene marketed by Prime Polymer Co., Ltd., and polyethylene by the high-pressure radical polymerization method marketed by Asahi Kasei Co., Ltd. The product pellet of (trade name: Suntech LD M1920) was dry-blended at a ratio of 80% by weight: 20% by weight, and an inflation film was formed from the obtained mixture. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 3]
Product pellets of ethylene / 1-hexene copolymer (trade name: Evolu SP1510), which is a linear low-density polyethylene marketed by Prime Polymer Co., Ltd., and polyethylene by the high-pressure radical polymerization method marketed by Asahi Kasei Co., Ltd. Product pellets of (trade name: Suntech LD M1920) were dry-blended at a ratio of 20% by weight: 80% by weight, and an inflation film was formed from the obtained mixture. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 4]
An inflation film was formed using the product pellets of polyethylene (trade name: Suntech LD M1920) commercially available from Asahi Kasei Corporation by the high-pressure radical polymerization method. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 5]
Product pellets of ethylene / 1-hexene copolymer (trade name: Evolu SP1510), which is a linear low-density polyethylene commercially available from Prime Polymer Co., Ltd., and the ethylene-based polymer (A1-3) produced in Production Example 3. ) And 80% by weight: 20% by weight, and an inflation film was formed from the obtained mixture. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 6]
An inflation film was formed only from the ethylene polymer (A1-3) used in Example 1. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 7]
An inflation film was formed only from the ethylene polymer (C1) produced in Production Example 4. The results of the physical property evaluation are shown in Table 2.

[Comparative Example 8]
An inflation film was formed only from the ethylene polymer (C2) produced in Production Example 5. The results of the physical property evaluation are shown in Table 2.

比較例１〜４のフィルムは、バブルの安定性、指突き性およびヒートシール性のいずれかが実施例のフィルムよりも劣っていた。

The films of Comparative Examples 1 to 4 were inferior to the films of Examples in any of bubble stability, finger sticking property and heat sealing property.

According to Comparative Examples 1 to 4, in the system containing LDPE and LLDPE, the blending range in which the direction of easy cutting can be controlled is considered to be an extremely limited range in which the blending amount of LLDPE is extremely small. Be done.

The film of Comparative Example 5 was inferior to the film of Example in finger stickability.

The film of Comparative Example 6 had a heat seal strength inferior to that of the film of Example.

According to Comparative Examples 1, 5 and 6, in a film composed of an ethylene-based polymer composition containing an ethylene-based polymer (A1) and LLDPE, the expression of easy-cutting property is exhibited only in a specific direction (MD direction). It is thought that it will be limited to. It is considered that the cause is that the molecular orientation cannot be balanced when the ethylene polymer (A1) is combined with LLDPE instead of LDPE.

Since the film of Comparative Example 7 was made from an ethylene-based polymer (C1) that does not meet the above-mentioned requirement (I), and the film of Comparative Example 8 is an ethylene-based polymer (C2) that does not meet the above-mentioned requirement (IV). Since they were produced from, the heat seal strength was weaker than that of the film of Comparative Example 6 produced from the ethylene polymer (A-3). Therefore, when a film is prepared by blending an ethylene-based polymer (C1) or an ethylene-based polymer (C2) in place of the ethylene-based polymer (A-3) in Examples 1 to 3, heat sealing of those films is performed. The strength is considered to be weaker than that of the film of the example.

Claims (9)

Ethylene-based polymer (A1) and high-pressure low-density polyethylene, ethylene-based polymer (A1): high-pressure low-density polyethylene = 1% by weight: 99% by weight to 99% by weight: 1% by weight (however, The total amount of the ethylene-based polymer (A1) and the high-pressure low-density polyethylene is 100% by weight), and the ethylene-based polymer (A1) contains ethylene and carbon satisfying the following requirements (I) to (V). An easy-to-open sealant film containing an ethylene-based polymer composition (A2) which is a copolymer with α-olefins of numbers 4 to 10.
(I) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is in the range of 0.1 to 10 g / 10 min.
(II) The density (d) is in the range of 875 to 970 kg / m ³ .
(III) ¹³ The sum of the number of methyl branches [A (/ 1000C)] per 1000 carbon atoms measured by C-NMR and the number of ethyl branches [B (/ 1000C)] [(A + B) (/ 1000C)] Is 1.80 or less.
(IV) The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is in the range of 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.50 .
(V) The ultimate 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) are the following relational expressions (V) Eq-1) is satisfied.
0.80 × 10 ^-4 × Mw ^0.776 ≦ [η] ≦ 1.65 × 10 ^-4 × Mw ^0.776
… (Eq-1) The ethylene-based polymer composition (A2) comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene, and the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 60% by weight: 40% by weight. The easy-to-open property according to claim 1, which comprises a ratio of% to 99% by weight: 1% by weight (however, the total amount of the ethylene polymer (A1) and the high-pressure low-density polyethylene is 100% by weight). Sealant film. The ethylene-based polymer composition (A2) comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene, and the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 41% by weight: 59% by weight. The easy-to-open property according to claim 1, which comprises a ratio of% to 59% by weight: 41% by weight (however, the total amount of the ethylene polymer (A1) and the high-pressure low-density polyethylene is 100% by weight). Sealant film. The ethylene-based polymer composition (A2) comprises the ethylene-based polymer (A1) and the high-pressure method low-density polyethylene, and the ethylene-based polymer (A1): high-pressure method low-density polyethylene = 1% by weight: 99% by weight. The easy-to-open property according to claim 1, which comprises a ratio of% to 40% by weight: 60% by weight (however, the total amount of the ethylene polymer (A1) and the high-pressure low-density polyethylene is 100% by weight). Sealant film. The easy-to-open sealant film according to any one of claims 1 to 4, which has a thickness of 15 to 300 μm. The method for producing an easily-openable sealant film according to any one of claims 1 to 5, which comprises a step of molding the ethylene-based polymer composition (A2) into a film. A laminated film comprising the easily-openable sealant film according to any one of claims 1 to 5 and another film. A bag having the easily-openable sealant film according to any one of claims 1 to 5 or the laminated film according to claim 7. Ethylene-based polymer (A1) and high-pressure low-density polyethylene, ethylene-based polymer (A1): high-pressure low-density polyethylene = 1% by weight: 99% by weight to 99% by weight: 1% by weight (however, The total amount of the ethylene-based polymer (A1) and the high-pressure low-density polyethylene is 100% by weight), and the ethylene-based polymer (A1) contains ethylene and carbon satisfying the following requirements (I) to (V). When producing an easily openable sealant film from an ethylene-based polymer composition (A2) which is a copolymer of α-olefins of numbers 4 to 10, the ethylene polymer (A1) and the high-pressure low-density polyethylene are used. Ethylene-based polymer (A1): high-pressure method low-density polyethylene = 1% by weight: 99% by weight to 99% by weight: 1% by weight (however, ethylene-based polymer (A1) and high-pressure method low-density A method of adjusting the direction in which the easy-to-cut property of an easily-openable sealant film is exhibited, which is changed within the range of (the total amount of polyethylene is 100% by weight).
(I) The melt flow rate (MFR) at 190 ° C. under a 2.16 kg load is in the range of 0.1 to 10 g / 10 min.
(II) The density (d) is in the range of 875 to 970 kg / m ³ .
(III) ¹³ The sum of the number of methyl branches [A (/ 1000C)] per 1000 carbon atoms measured by C-NMR and the number of ethyl branches [B (/ 1000C)] [(A + B) (/ 1000C)] Is 1.80 or less.
(IV) The molecular weight (peak top M) at the maximum weight fraction in the molecular weight distribution curve obtained by GPC measurement is in the range of 1.0 × 10 ^{4.30 to} 1.0 × 10 ^4.50 .
(V) The ultimate 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) are the following relational expressions (V) Eq-1) is satisfied.
0.80 × 10 ^-4 × Mw ^0.776 ≦ [η] ≦ 1.65 × 10 ^-4 × Mw ^0.776
… (Eq-1)