JP2017193372A - Film for packaging hood stretching - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film for packaging hood stretching which enables high-speed packaging, in particular, a film for hood stretching which quickly stabilizes a sealed portion without lowering a binding force of the film.SOLUTION: A film F for packaging hood stretching has a layer formed from an ethylenic resin composition (A) blended with an ethylene/α-olefin block copolymer (a1). The ethylene/α-olefin block copolymer (a1) has such a structure that hard blocks polymerized with a monomer unit based on ethylene and soft blocks polymerized with a monomer unit based on α-olefin are alternately connected to each other, and the hard blocks contribute to high heat resistance and the soft blocks contribute to flexibility and low temperature characteristics.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a “stretch hood packaging” in which a hood-like (cylindrical one end sealed) stretch film is covered on a pallet cargo for the purpose of preventing cargo collapse of palletized cargo (hereinafter abbreviated as pallet cargo). It is related with the film used for.

Pallet cargo is often subjected to “pallet stretch wrapping” in which stretch film is wound so as not to collapse during transportation. However, the operation of winding the film is complicated and takes time. In pallet stretch packaging, the top surface of the pallet cargo is not protected by the stretch film, so there is a risk of dust adhering to the top surface or water intrusion from the top surface. In addition, there were problems of dust adhesion and water intrusion. As a packaging form that can solve these problems, in recent years, “stretch hood packaging” that covers a hood-like stretch film has been performed. Stretch food packaging can be completed in a few tens of seconds, can prevent collapse of goods with a small amount of packaging material, and can also cover the top surface of pallet cargo with a film.
FIG. 1 is a schematic view for explaining stretch food packaging. In stretch hood packaging, a cylindrical stretch film is first fed over a pallet cargo. Next, the cylindrical film is sealed Fs at one end, further cut, and processed into a hood-like film F. Finally, the hood-like film F is stretched and placed on the pallet cargo to complete the packaging.

Films used for stretch food packaging are required to have a sufficient binding force when restored from a fully stretched state to a state in which pallet cargo can be bound.
In Patent Documents 1 and 2, the core layer containing the ethylene-α-olefin copolymer (B) and the ethylene-vinyl acetate copolymer (C) satisfying specific requirements, and the specific requirements are satisfied. A tubular ethylene resin multilayer film having two surface layers containing an ethylene-α-olefin copolymer (A) is disclosed, and a stretch hood film comprising the film is proposed.

Patent Document 3 discloses a multilayer film having a core layer (inner layer) containing at least 50% by weight of a polyethylene copolymer having a heat of fusion of more than 115 ° C. and less than 5 joules / gram, and having an elastic recovery rate of at least 40%. Further, a stretch hood film formed from the film has been proposed.
In Patent Document 4, a core layer (core layer) containing ultra-low density polyethylene (ULDPE), low-density polyethylene (LDPE), and ethylene-vinyl acetate copolymer (EVA), ultra-low density polyethylene (ULDPE), A stretch food packaging film composed of a surface layer (skin layer) containing low density polyethylene (LDPE) has been proposed.

JP2013-49264A JP 2013-60006 A Special table 2013-532077 gazette Special table 2013-535355 gazette

In recent years, speeding up of stretch food packaging has been studied. However, when the packaging speed was increased, the problem of poor sealing occurred. This is thought to be due to the increase in speed, which shortened the time from when the cylindrical film was sealed and cut into a hood-like film and then stretched. Since the seal portion is stretched before it is sufficiently stabilized (hardened), the seal portion is opened.
For the purpose of improving the sealing property, the present inventors added a high-density linear low-density polyethylene to a conventional stretch hood film, but the sealing property was improved, but the film cohesive strength was reduced. It was.

  An object of the present invention is to provide a food stretch packaging film capable of high-speed packaging. Specifically, an object of the present invention is to provide a stretch hood film that quickly stabilizes the sealing portion without reducing the film binding force.

According to the present invention, as a means for solving the above-mentioned problems, a stretch hood comprising a layer comprising an ethylene resin composition (A) in which an ethylene / α-olefin block copolymer (a1) is blended is provided. A packaging film is provided.
The stretch food packaging film is characterized in that the ethylene / α-olefin block copolymer (a1) has a density of 900 kg / m ³ or less and a melting point of 100 ° C. or more.
The stretch food packaging film is characterized in that the ethylene resin composition (A) further contains an ethylene resin (a2) other than the ethylene / α-olefin block copolymer.
The stretch food packaging film is characterized in that the ethylene resin (a2) other than the ethylene / α-olefin block copolymer is a linear low density polyethylene having a density of 910 kg / m ³ or more. The

There is also provided a stretch hood packaging film having at least a seal layer and a core layer, wherein the seal layer is composed of the ethylene resin composition (A).
In addition, the stretch food packaging film is characterized in that the core layer is mainly composed of linear low density polyethylene having a density of 910 kg / m ³ or less.

  The present invention pays attention to an ethylene / α-olefin block copolymer having a lower density and a higher melting point than general linear low-density polyethylene, and without using the resin, the sealing force is reduced without reducing the cohesive strength of the film. It provides a stretch hood film that quickly stabilizes the portion.

  The stretch hood film of the present invention exhibits a high binding force even after being stretched, and the heat seal portion is quickly stabilized. Therefore, when used for stretch food packaging, high-speed packaging is possible.

It is the schematic for demonstrating stretch food packaging. It is drawing for demonstrating the measuring method of binding force. It is drawing for demonstrating the sealing strength (hot tack strength) measuring method.

[Ethylene resin composition (A)]
The film for stretch hoods of the present invention includes a layer made of an ethylene resin composition (A) in which an ethylene / α-olefin block copolymer (a1) is blended.

<Ethylene / α-olefin block copolymer (a1)>
The ethylene / α-olefin block copolymer (a1) has a structure in which hard blocks in which monomer units based on ethylene are polymerized and soft blocks in which monomer units based on α-olefin are polymerized are alternately connected. It is known that hard blocks contribute to high heat resistance, and soft blocks contribute to flexibility and low temperature characteristics. The ethylene / α-olefin copolymer (a1) has a melting point of 100 ° C. or higher even when the density is 900 kg / m ³ or lower. Specific examples of such an ethylene / α-olefin block copolymer (a1) include “Infuse (registered trademark)” manufactured by Dow Chemical Co., Ltd.
Examples of the α-olefin that forms the soft block include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, and 1-dodecene. In consideration of flexibility and ease of processing, 1-octene is preferable.

When the ethylene / α-olefin block copolymer (a1) is employed in a stretch hood packaging film, a film capable of stable and high-speed packaging that has not been conventionally available can be obtained. This seems to be because the hard block contributes to the quick stabilization of the seal part and the soft block contributes to the improvement of the binding force. In the present invention, among the ethylene / α-olefin block copolymers (a1), those having a density of 900 kg / m ³ or less and a melting point of 100 ° C. or more can be suitably used, and in particular, the density is 890 kg / m. Those having a melting point of ³ or less and 118 ° C. or more can be suitably employed. If the density is too high, the binding force of the stretch hood packaging film is reduced, and if the melting point is too low, the stability of the seal portion may be reduced. The melting point can be obtained by differential scanning calorimetry, but when there are a plurality of endothermic peaks at the time of temperature rise, in the present invention, all temperatures at which the peaks appear are called melting points.

<Ethylene resin (a2) other than ethylene / α-olefin block copolymer>
The ethylene resin composition (A) can contain other ethylene resin (a2) in addition to the ethylene / α-olefin block copolymer (a1).
The ethylene-based resin (a2) used in the ethylene-based resin composition (A) forming the stretch hood film is a polymer having a monomer unit based on ethylene as a main unit, and a monomer unit based on ethylene Is a polymer having a content of 50% by weight or more based on the total weight (100% by weight) of the ethylene-based resin (a2).
As the ethylene resin (a2), an ethylene resin conventionally used for a stretch food packaging film can be used without any particular limitation. For example, low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer in which a monomer unit based on ethylene and a monomer unit based on vinyl acetate are copolymerized can be used.

Further, in consideration of film binding properties and raw material prices, a linear low density in which a monomer unit based on ethylene and a monomer unit based on α-olefin are randomly copolymerized as the ethylene resin (a2). It is desirable to use polyethylene. Examples of the α-olefin in the linear low density polyethylene include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene and the like. However, 1-hexene and 1-octene are desirable from the viewpoint of film forming stability.
The linear low-density polyethylene is polymerized using a multi-site catalyst or a single-site catalyst, but those having a density of 900 kg / m ³ or less are usually polymerized by a single-site catalyst, and the melting point is Below 100 ° C.

Since the hood-like film used for stretch packaging is difficult to cover the pallet cargo when the inner surface is blocked, it is preferable that the hood-like film is not easily blocked and has a good opening property. In order to improve the opening of the hood-like film, it is preferable to use a linear low density polyethylene having a relatively high density as the ethylene-based resin (a2). Specifically, ethylene-based resin (a2) as density 910 kg / ^{m 3} or more, preferably it is preferable to use a 915 kg / ^{m 3} or more linear low density polyethylene.

  The blending ratio of the ethylene / α-olefin block copolymer (a1) and the ethylene resin (a2) is not particularly limited, but the ethylene / α-olefin block copolymer (a1): ethylene resin (a2 ) = 10 to 90% by weight: 90 to 10% by weight is desirable. When both the ethylene / α-olefin block copolymer (a1) and the ethylene-based resin (a2) are less than 10% by weight, it is difficult to exhibit the characteristics of each resin. Since the ethylene / α-olefin block copolymer (a1) is more expensive than the general ethylene resin (a2), the ethylene / α-olefin block copolymer (a1): ethylene resin (a2) ) = 10-50 wt%: 90-50 wt% is desirable, and 10-40 wt%: 90-60 wt% is particularly preferable. If the ethylene / α-olefin block copolymer (a1) is less than 10% by weight, the cohesive strength of the film and the stability of the seal part cannot be improved. Can be achieved generally.

<Other ingredients>
In addition to the ethylene / α-olefin block copolymer (a1) and the ethylene resin (a2) described above, the ethylene resin composition (A) includes other resins as long as the properties of these resins are not impaired. Ingredients can be blended. If necessary, known fillers, pigments, nucleating agents, antioxidants, heat stabilizers, anti-aging agents, weathering stabilizers, antistatic agents, flame retardants, dispersants, metal soaps, waxes and other lubricants, Additives such as anti-blocking agents and anti-fogging agents can be added.

[Multilayer film]
The stretch food packaging film of the present invention may be a single-layer film composed only of the above-described ethylene-based resin composition (A), but a multilayer film comprising a layer composed of the ethylene-based resin composition (A). It is preferable that
In the case of a multilayer film, it is preferably a film of two or more layers having at least a seal layer and a core layer, and particularly preferably a film of three or more layers having a surface layer in addition to the seal layer and the core layer. Hereinafter, although the case where the film for stretch food packaging is a three-layer film of seal layer / core layer / surface layer will be described in detail, the film for stretch food packaging of the present invention is not limited thereto. In addition, other layers can be provided between the respective layers as long as the object of the present invention can be achieved.

<Sealing layer>
A sealing layer is a layer located in the innermost part of a cylindrical film, and becomes a sealing surface when the film is processed into a hood. The sealing layer is the layer most involved in the sealing performance of the film, and is preferably made of the above-described ethylene-based resin composition (A). Since the ethylene-based resin composition (A) contains the ethylene / α-olefin block copolymer (a1), the seal portion can be stabilized quickly.

<Core layer>
The core layer is a layer that is not a seal layer when the stretch food packaging film has a two-layer structure, and is a layer that is neither a seal layer nor a surface layer when the film has three or more layers. In order to increase the cohesive strength of the stretch food packaging film, the core layer is composed mainly of a linear low density polyethylene having a relatively low density (the component having the largest weight ratio among the resins forming the core layer). It is preferable. Specifically, density 910 kg / ^{m 3} or less, preferably it is preferable that a main component 905 kg / ^{m 3} or less linear low density polyethylene. Also, the above-mentioned ethylene / α-olefin block copolymer (a1) can be blended in the core layer. By blending the ethylene / α-olefin block copolymer, the binding force of the stretch food packaging film is further improved.

<Surface layer>
The surface layer is a layer located on the surface when the film is processed into a hood-like film. Usually, a stretch hood packaging film is formed into a cylindrical shape by an inflation molding method, which will be described later, and wound and stored in a roll shape. It is preferable that the surface layer is made of a resin composition that is difficult to block so that when the film is put on a pallet cargo after storage, the film is smoothly fed out. Specifically, density 910 kg / m ³ or more, preferably to (of the resin forming the surface layer, the largest component of the weight) and 915 kg / m ³ or more linear low density polyethylene main component and Is preferred. The layer can also be blended with an ethylene / α-olefin block copolymer for the purpose of improving the cohesive strength of the film.

  The blending ratio of the ethylene / α-olefin block copolymer in the seal layer is Ws wt%, the blending ratio of the ethylene / α-olefin block copolymer in the core layer is Wc wt%, and the ethylene / α-olefin in the surface layer. When the blending ratio of the block copolymer is Wf wt%, it is desirable that both Ws and Wf are larger than Wc. Even if the amount of the ethylene / α-olefin block copolymer in the whole stretch hood packaging film is the same, the layer located on the surface of the film, that is, the seal layer or the surface layer has a large amount of ethylene / α-olefin block copolymer. When the amount is blended, the film has a higher binding force than when it is blended more in the core layer.

  In addition to the linear low-density polyethylene and the ethylene / α-olefin block copolymer, other resin components and various additives should be added to the above-described layers as long as the properties of these resins are not impaired. Can do. When about 5 to 10% by weight of low density polyethylene by the high pressure method is blended, film formation stability of the film can be achieved.

The thickness of the stretch hood packaging film of the present invention is preferably 10 to 250 μm, and particularly preferably 20 to 150 μm, considering the tear strength, the binding force, and the like. If the film thickness becomes too thick, the binding force becomes too strong, and depending on the palletized cargo, there is a possibility of being damaged. Moreover, it becomes easy to tear when it becomes too thin.
When the stretch food packaging film of the present invention is a three-layer film of seal layer / core layer / surface layer, the thickness constitution ratio of each layer is preferably about 1: 1: 1 to 1: 10: 1. In order to achieve the effects of the present invention while keeping the blending amount of the ethylene / α-olefin block copolymer low, it is desirable that the seal layer and the surface layer are thin, but if the thickness is smaller than the above range, production stability and Production efficiency is degraded.

[Production method]
The stretch food packaging film of the present invention can be produced by, for example, a conventionally known film forming method such as the inflation extrusion method or the T-die cast extrusion method. In addition, when the stretch food packaging film is a multilayer film, after each layer is formed separately, a lamination method in which the layers are bonded together by heat, etc., or after forming the surface layer and the seal layer separately, between these layers For example, an extrusion laminating method in which a resin for forming the core layer is poured in a molten state can be used. However, in consideration of processing into a hood-like film as will be described later, it is desirable to employ an inflation (co) extrusion method.

[Method for producing hood-like film]
When stretch food packaging is performed using a stretch food packaging film, it is necessary to first process the film into a hood shape. In the case of processing a film by a T-die cast (co) extrusion method into a hood shape, the film is first processed into a cylindrical shape, and then sealed and cut every predetermined length. If an inflation (co) extrusion method is employed, a cylindrical film can be obtained, and therefore the step of processing the film into a cylindrical shape can be omitted.
When a cylindrical film is sealed, cut and processed into a hood-like film, it is preferable to provide gussets on both sides of the film. A hooded film containing a gusset is easy to cover pallet cargo with a shape close to a square.

  Hereinafter, the film for stretch hoods of the present invention will be described based on examples. The binding force of each film was evaluated by the following method.

[Bundling power]
1) Each film is cut into a rectangle having a length of 150 mm and a width of 10 mm to prepare a test piece. When measuring the binding force in the MD direction (length direction) of the film, when measuring the binding force in the TD direction (width direction) of the film so that the longitudinal direction of the test piece becomes the MD direction of the film. Cut out the test piece so that the vertical direction of the test piece is the TD direction of the film.
2) Set the test piece between the chucks of the autograph, and set the gap between the chucks to 40 mm (FIG. 2A). At this time, the test piece 1 is sandwiched by 45 mm between the chucks 2 and 2 ′ so that it is 60 mm between the chucks. Using a jig 3 having a triangular columnar holding tool 31 at the tip, which is a substantially isosceles triangle having a base of 20 mm and a height of 10 mm and having a cross-sectional shape of a substantially isosceles triangle whose one top is a curve of R = 6.5 mm, The top part of the pressing tool 31 is applied to the test piece 1 so that the test piece 1 is stretched between the chucks 2 and 2 'without stress.
3) The distance between chucks is increased to 100 mm, the test piece is stretched by about 100% (about twice the original length), the load at this time is measured (FIG. 2 (B)), and the measured value is taken as the film thickness ( divided by 100 μm) and converted to a value per 100 μm. The obtained value is defined as “100% tensile load”.
4) The distance between the chucks was reduced to 70 mm, the test piece was stretched by about 50% (about 1.5 times the original length), the load at this time was measured (FIG. 2 (C)), and the measured value was The value converted into a value per thickness of 100 μm is defined as “50% load immediately after”.
5) After 15 minutes have elapsed in the state shown in FIG. 2C, the load according to the autograph is measured, and the measured value converted to a value per 100 μm thickness is referred to as “50% 15 minute load”.

  Table 1 shows the results of 100% tensile load value, 50% load immediately after, and 50% load for 15 minutes. The load immediately after 50% is a value indicating the binding force immediately after the hood-like film is placed on the pallet cargo, and the larger the value, the better the effect of preventing the load collapse immediately after the hood-like film is placed. The 50% load for 15 minutes is a value indicating the binding force after lapse of time after the hood-like film is placed on the pallet, and a film having a large value has a high binding force during stretch hood packaging.

The raw materials used in each example and comparative example are as follows.
LL1 linear low density polyethylene MFR: 1.0 g / 10 min Density: 916 kg / m ³
LL2 linear low density polyethylene MFR: 1.0 g / 10 min Density: 902 kg / m ³
LL3 linear low density polyethylene MFR: 0.8 g / 10 min Density: 905 kg / m ³
LD High pressure method low density polyethylene MFR: 2.0 / 10 min Density: 921 kg / m ³
EBC ethylene / α-olefin block copolymer MFR: 0.5 / 10 min Density: 870 kg / m ³
MFR is a value measured according to JIS K7210.

[Examples 1 to 3 Comparative Example 1]
Using the resin composition shown in Table 1, a three-layer stretch food packaging film comprising a seal layer / core layer / surface layer was obtained by an inflation coextrusion method. The film thickness of the stretch food packaging film was 50 μm, and the thickness ratio of each layer was 1: 5: 1. In addition, 3 parts by weight of an antiblocking agent was added to 100 parts by weight of the resin shown in Table 1 in the resin composition forming the seal layer and the surface layer. Table 1 shows the binding force of the obtained film.

Stretch food packaging films (Examples 1 to 3) composed of a composition blended with an ethylene / α-olefin block copolymer have a higher minimum cohesive force than films without blending (Comparative Example 1). I understand that. The higher the minimum value of the cohesive force, the less likely to collapse. When stretch hood wrapping is performed using the film of Comparative Example 1, since the binding force in the TD direction of the film immediately after covering the hood-like film is low, the pallet cargo is likely to collapse when moved immediately after packaging.
Further, the film of Example 1 in which the outer layer (seal layer and surface layer) is blended with the ethylene / α-olefin block copolymer has the core layer blended with the ethylene / α-olefin block copolymer. Although the amount of the ethylene / α-olefin block copolymer blended in the entire film was smaller than that of the film of Example 2, the binding force was large.

[Examples 4 and 5 and Comparative Examples 2 to 4]
Using the resin composition shown in Table 2, a three-layer stretch food packaging film comprising a seal layer / core layer / surface layer was obtained by an inflation coextrusion method. The film thickness of the stretch food packaging film was 100 μm, and the thickness ratio of each layer was 1: 5: 1. In addition, 3 parts by weight of an antiblocking agent was added to 100 parts by weight of the resin shown in Table 2 in the resin compositions forming the seal layers and the surface layers of Examples 4 and 5 and Comparative Examples 2 and 3. Also, 3 parts by weight of an antiblocking agent was added to 100 parts by weight of the resin in the resin composition forming Comparative Example 4. Table 1 shows the binding force of the obtained film.

The sealing strength (hot tack strength) of the film was measured by the following method.
[Seal strength]
1) Cut out two rectangular test pieces of 300 mm length and 50 mm width from each film. At this time, the longitudinal direction of the test piece is set to be the MD direction of the stretch hood packaging film.
2) One end 4a of one test piece 4 is fixed to the jig 6 and one end 5a of the other test piece 5 is fixed to a digital force gauge 7 (ZP-500N manufactured by IMADA) (FIG. 3A).
3) The other end 4b of one test piece and the other end 5b of the other test piece are overlapped and heat-sealed with a heat sealing machine (TP-701-B heat seal tester manufactured by Tester Sangyo Co., Ltd.) It is formed (FIG. 3B). The upper seal bar having a width of 3 mm was used, and heat sealing was performed with a fluororesin-impregnated glass cloth adhesive tape. The lower seal bar used was a silicone rubber (rubber hardness 50), and the test was conducted by applying a fluororesin-impregnated glass cloth adhesive tape in the same manner as the upper seal bar. The sealing pressure was 1.8 MPa, the sealing time was 1.0 second, the temperature of the upper seal bar was 120 ° C., and the temperature of the lower seal bar was 23 ° C.
4) Immediately after heat sealing, the digital force gauge is lowered vertically, and a load is applied to the seal portion 8 until the seal portion 8 is peeled off (FIG. 3C). And
5) Change the temperature of the upper seal bar from 120 ° C to 210 ° C in increments of 10 ° C and measure the seal strength at each temperature.

According to this measuring method, the strength of the seal part immediately after heat sealing can be confirmed. In the region where the temperature of the upper seal bar is high (region exceeding 180 ° C.), a film showing high seal strength is loaded immediately after sealing for processing into a hood, even if the seal portion is hot. You can hang it. Therefore, high-speed packaging can be performed. On the other hand, a film showing a low sealing strength in a region where the temperature of the upper seal bar is high cannot apply a load to the seal portion until the temperature of the seal portion is lowered to some extent after sealing. Therefore, the packaging speed becomes slow.
The stability of the seal portions of Examples 4 and 5 and Comparative Examples 2 to 4 was measured, and the measurement results are shown in Table 3. If the seal strength is 4 N / 50 mm or more, a hood-like film can be spread and a load can be applied to the seal portion. Of the temperatures at which the seal strength is 4 N / 50 mm or more, the highest temperature is shown in Table 2 as the stable seal temperature.

Stretch food packaging films (Examples 4 and 5) composed of a composition blended with an ethylene / α-olefin block copolymer have a larger minimum cohesive force than films without blending (Comparative Example 2). I understand that. Therefore, it is hard to collapse.
In the stretch food packaging films of Comparative Examples 3 and 4 in which low density linear low density polyethylene (LL2, LL3) was blended in the seal layer and the surface layer, the minimum value of the binding force was relatively large. The aptitude was inferior. This seems to be because the resin density of the whole film is low, the heat resistance is lowered, and it takes time to cool and solidify. In order to use these films for stretch hood packaging, it is necessary to wait for the seal portion processed into a hood shape to become a low temperature and cover the pallet cargo with the film. Therefore, it is not suitable for high-speed packaging. Further, when stretch hood packaging was performed using the film of Comparative Example 4 in which the sealing layer was composed only of low-density linear low-density polyethylene, the film was blocked and the hood-like film could not be opened.

F Hood-like film Fs Seal 1 Test piece 2, 2 ′ Chuck 3 Jig 4 Test piece 5 Test piece 6 Jig 7 Digital force gauge 8 Seal part

Claims (6)

A stretch food packaging film comprising a layer made of an ethylene resin composition (A) in which an ethylene / α-olefin block copolymer (a1) is blended. The stretch food packaging film according to claim 1, wherein the ethylene / α-olefin block copolymer (a1) has a density of 900 kg / m ³ or less and a melting point of 100 ° C or higher. The stretch according to any one of claims 1 and 2, wherein the ethylene resin composition (A) further contains an ethylene resin (a2) other than the ethylene / α-olefin block copolymer. Food packaging film. The stretch food packaging film according to claim 3, wherein the ethylene resin (a2) other than the ethylene / α-olefin block copolymer is a linear low-density polyethylene having a density of 910 kg / m ³ or more. . A stretch hood packaging film having at least a seal layer and a core layer, wherein the seal layer comprises the ethylene-based resin composition (A) according to any one of claims 1 to 4. Packaging film. The stretch food packaging film according to claim 5, wherein the core layer is mainly composed of linear low-density polyethylene having a density of 910 kg / m ³ or less.

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