JP7774992B2 - Laminate, packaging bag, and bag-in-box - Google Patents

Description

The present invention relates to films, laminates, packaging bags, and bag-in-boxes.

Due to their versatility, films are used for packaging a variety of products, including food, medicines, cosmetics, and chemicals.
Patent Document 1 discloses a sealant film that has both low-temperature sealing properties and boilability up to 100°C.

Japanese Patent Application Publication No. 11-320786

However, conventional films have the problem of blocking occurring during storage when stored in roll form at room temperature after production, particularly in temperatures around 40°C in the summer.

In recent years, bag-in-box containers have been used as containers for transporting liquids, etc. Bag-in-box containers are containers in which a double-layered interior packaging film (interior bag) with a spout is housed in an exterior cardboard box or the like.
The film is required to have flexibility that can withstand the bending movement during transportation in a bag-in-box or the like.

The present invention aims to provide a film, a laminate, a packaging bag made from the laminate, and a bag-in-box equipped with the packaging bag that are highly flexible and exhibit reduced blocking even when stored at room temperature.

According to one aspect of the present invention, a film is provided that contains a polyethylene resin composition containing a linear ethylene copolymer (A) and a low-density polyethylene (B), and a modifier.

The film according to one embodiment of the present invention may further contain polyethylene having a density of 930 kg/m ³ or less.

In a film according to one embodiment of the present invention, the content of the polyethylene resin composition may be 5% by mass or more and less than 100% by mass.

In a film according to one embodiment of the present invention, the content of the modifier may be 2% by mass or more and 60% by mass or less.

In the film according to one embodiment of the present invention, the modifier may be an ethylene-α-olefin copolymer.

The film according to one embodiment of the present invention may further contain 0.01% by mass or more of an antiblocking agent.

The film according to one embodiment of the present invention may contain multiple types of the polyethylene resin composition.

The film according to one embodiment of the present invention may contain a plant-derived resin.

The film according to one embodiment of the present invention may be a single-layer film.

According to one aspect of the present invention, there is provided a laminate having multiple layers, at least one of which is a film according to one aspect of the present invention.

In one aspect of the laminate of the present invention, the content of the polyethylene resin composition in the laminate may be 5% by mass or more and less than 100% by mass.

In one aspect of the laminate of the present invention, the content of the modifier in the laminate may be 0.5% by mass or more and 60% by mass or less.

A laminate according to one aspect of the present invention may have a first outermost layer and a second outermost layer, and at least one of the first outermost layer and the second outermost layer may be the film.

A laminate according to one embodiment of the present invention may have an intermediate layer between the first outermost layer and the second outermost layer, and the first outermost layer, the second outermost layer, and the intermediate layer may be the film.

In one aspect of the laminate of the present invention, the modifier in the first outermost layer and the intermediate layer may be an ethylene-α-olefin copolymer, and the modifier in the second outermost layer may be a styrene-based elastomer.

In one aspect of the laminate of the present invention, the thermal adhesion strength between the first outermost layer and the second outermost layer may be 0 or more and 1.2 kgf/50 mm or less.

A laminate according to one embodiment of the present invention may have a pinhole count of 1.0 pinholes/A4 or less when measured at -20°C and 1,500 times using a Gelbo flex tester.

The laminate according to one aspect of the present invention may have a loop stiffness of 10 N/15 mm or less.

The laminate according to one embodiment of the present invention may contain a plant-derived resin.

According to one aspect of the present invention, there is provided a packaging bag made from a laminate according to one aspect of the present invention.

According to one aspect of the present invention, a bag-in-box is provided that includes a packaging bag according to one aspect of the present invention.

One aspect of the present invention provides a film, a laminate, a packaging bag made of the laminate, and a bag-in-box equipped with the packaging bag that are highly flexible and exhibit reduced blocking even during storage at room temperature.

1 is a cross-sectional schematic view of a film according to one embodiment of the present invention. 1 is a cross-sectional schematic view of a laminate according to one embodiment of the present invention. 1 is a schematic diagram of a packaging bag according to one embodiment of the present invention.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that in this specification and drawings, components that have substantially the same functional configuration will be assigned the same reference numerals, and redundant explanations will be omitted.

First Embodiment
In the first embodiment, a film according to one aspect of the present invention and a laminate according to one aspect of the present invention having the film will be described.

(film)
1 is a schematic cross-sectional view of a film 1 according to this embodiment. The film 1 according to this embodiment may be used as a single layer film, or may be used as at least one layer of a laminate having multiple layers, such as a laminate 50 (FIG. 2) described below.
The film 1 contains a polyethylene resin composition and a modifier.

Polyethylene Resin Composition The polyethylene resin composition contains a linear ethylene copolymer (A) and a low-density polyethylene.
The content of the linear ethylene copolymer (A) in the polyethylene resin composition is preferably 70% by mass or more and 95% by mass or less, and more preferably 75% by mass or more and 90% by mass or less. The content of the low-density polyethylene (B) in the polyethylene resin composition is preferably 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less. By setting the contents of the linear ethylene copolymer (A) and the low-density polyethylene (B) in the polyethylene resin composition within these ranges, blocking of the film 1 according to this embodiment and blocking of the laminate 50 can be further suppressed.

Linear ethylene copolymer (A)
The linear ethylene copolymer (A) is a copolymer of ethylene and at least one α-olefin (hereinafter, sometimes referred to as "ethylene-α-olefin copolymer (a)").
The number of carbon atoms of the α-olefin in the linear ethylene copolymer (A) is preferably 4 to 10, and more preferably 6 to 10. Examples of α-olefins having 4 to 10 carbon atoms include 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, and 1-decene.
The linear ethylene copolymer (A) is preferably an ethylene-1-hexene copolymer.

The linear ethylene copolymer (A) preferably has a density of 894 kg/ ^m3 or more and 914 kg/ ^m3 or less, more preferably 895 kg/ ^m3 or more and 912 kg/ ^m3 or less, and even more preferably 896 kg/ ^m3 or more and 910 kg/ ^m3 or less. When the density of the linear ethylene copolymer (A) is 894 kg/ ^m3 or more, the self-adhesiveness of the film 1 does not increase and the blocking phenomenon can be suppressed. When the density of the linear ethylene copolymer (A) is 914 kg/ ^m3 or less, the melting point of the linear ethylene copolymer (A) does not become too high and the low-temperature heat sealability of the film 1 becomes good.
The density in this specification can be measured in accordance with JIS K7112 1999.

The linear ethylene copolymer (A) preferably has an MFR (Melt Flow Rate) of 0.1 g/10 min or more and 250 g/10 min or less, more preferably 1 g/10 min or more and 150 g/10 min or less, even more preferably 2 g/10 min or more and 20 g/10 min or less, and particularly preferably 3 g/10 min or more and 10 g/10 min or less. When the MFR is within the above range, the processability of the film 1 becomes good.
Unless otherwise specified, the MFR in this specification can be measured in accordance with ASTM D1238-89 at a measurement temperature of 190° C. and a load of 2.16 kg.

The linear ethylene copolymer (A) may contain a plurality of ethylene-α-olefin copolymers (a). In this case, the plurality of ethylene-α-olefin copolymers (a) may have different α-olefin units, different densities, or different MFRs, for example.
When the linear ethylene copolymer (A) contains a plurality of ethylene-α-olefin copolymers (a) having different densities and/or MFRs, the density and/or MFR of each ethylene-α-olefin copolymer (a) may be appropriately adjusted so that the density and/or MFR of the linear ethylene copolymer (A) falls within the above-mentioned range.

The linear ethylene copolymer (A) can be produced by a gas phase polymerization reaction using a metallocene catalyst.
When the linear ethylene copolymer (A) contains multiple types of ethylene-α-olefin copolymers (a), the linear ethylene copolymer (A) may be produced by homopolymerizing each ethylene-α-olefin copolymer (a) and then mixing or melt-kneading them by a conventionally known method, or multiple types of ethylene-α-olefin copolymers (a) may be subjected to multistage polymerization, or multiple types of ethylene-α-olefin copolymers (a) may be polymerized in the same polymerization vessel in the presence of multiple metallocene catalysts to produce the linear ethylene copolymer (A).

Low-density polyethylene (B)
The low-density polyethylene (B) is not particularly limited as long as it is a low-density polyethylene (LDPE), but it preferably satisfies the following requirements and is preferably a low-density polyethylene polymerized by a high-pressure method.

Requirements: The intrinsic viscosity [η] (dl/g) measured in decalin at 135°C and the weight average molecular weight (GMw) measured by gel permeation chromatography-viscosity detector (GPC-VISCO) preferably satisfy the following relational formula (R-1), and more preferably satisfy the following relational formula (R-2):
Relational Formula (R-1):
0.55×10 ^-4 ≦[η]/[(GMw)×0.776]≦2.0×10 ^-4
Relational formula (R-2):
0.70×10 ^-4 ≦[η]/[(GMw)×0.776]≦1.8×10 ^-4

It is known that when long-chain branches are introduced into low-density polyethylene, the intrinsic viscosity [η] (dl/g) becomes smaller than that of linear low-density polyethylene of a similar molecular weight but without long-chain branches (for example, Walther Burchard, ADVANCES IN POLYMER SCIENCE, 143, Branched Polymer II, p. 137 (1999)). Therefore, low-density polyethylene (B) that meets the above requirements has numerous long-chain branches and therefore excellent moldability and flowability.

The value of [η]/[(GMw)×0.776] can be increased or decreased, for example, by increasing or decreasing the amount of long chain branches introduced into the low-density polyethylene (B) by a conventionally known method.
The low-density polyethylene (B) may be a homopolymer of ethylene, or an ethylene copolymer containing units derived from ethylene and a small amount of units derived from other polymerizable monomers (for example, containing 20% by mass or less of units derived from vinyl acetate, acrylic esters, etc.). When the low-density polyethylene (B) is an ethylene copolymer, it can be confirmed whether the low-density polyethylene (B) is an ethylene copolymer by, for example, confirming the difference in peak shape and melting point by DSC, confirming and structurally analyzing the infrared absorption spectrum by FT-IR, or by NMR or the like.

The low-density polyethylene (B) preferably has a density of 935 kg/m ^or less, preferably 930 kg/m ^or less, more preferably 920 kg/m ^or less, and even more preferably 910 kg/m ^or less. The lower limit is not particularly limited, but is usually 870 kg/m ^{or less} .

The polyethylene resin composition may contain, as necessary, various additives that are usually added to polyolefins, such as weather stabilizers, heat stabilizers, antistatic agents, anti-fogging agents, anti-blocking agents, slip agents, lubricants, pigments, and anti-dripping agents.
It is also preferred that the polyethylene resin composition consists of only the linear ethylene copolymer (A) and the low-density polyethylene (B).

The density of the polyethylene resin composition is preferably 896 kg/m ^{or more} and 912 kg/m ^or less. The density of the polyethylene resin composition is more preferably 898 kg/m ^{or more} and 910 kg/m ^or less, and even more preferably 900 kg/m or ^more and 908 kg/m ^or less.

The polyethylene resin composition preferably has an MFR of 1 g/10 min or more and 20 g/10 min or less. It is more preferable that the polyethylene resin composition have an MFR of 2 g/10 min or more and 15 g/10 min or less.

When film 1 is used as a single layer, the content of the polyethylene resin composition in the single layer film 1 is preferably 5% by mass or more and less than 100% by mass, more preferably 15% by mass or more and less than 100% by mass, even more preferably 30% by mass or more and less than 100% by mass, and even more preferably 40% by mass or more and less than 100% by mass.
When the content of the polyethylene resin composition in the single-layer film 1 is 5% by mass or more, the film has excellent blocking resistance. When the content of the polyethylene resin composition in the single-layer film 1 is 100% by mass, the desired physical properties cannot be obtained, which is not preferable.

Film 1 may contain only one type of polyethylene-based resin composition, or may contain multiple types of polyethylene-based resin compositions.

Modifiers The modifiers are not particularly limited, but examples thereof include α-olefin copolymers such as ethylene-α-olefin copolymers, and styrene-based elastomers, with ethylene-α-olefin copolymers being preferred.
Examples of the ethylene-α-olefin copolymer include an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-octene copolymer. An ethylene-1-butene copolymer or an ethylene-1-octene copolymer is preferred, and an ethylene-1-octene copolymer is more preferred.
As the styrene-based elastomer, a hydrogenated styrene block copolymer is preferred.

When the modifier is an ethylene-α-olefin copolymer, the density of the modifier is preferably 800 kg/m ³ or more and 900 kg/m ³ or less, and more preferably 810 kg/m ³ or more and 890 kg/m ³ or less.
When the modifier is a styrene-based elastomer, the density of the modifier is preferably 800 kg/m ³ or more and 950 kg/m ³ or less, and more preferably 850 kg/m ³ or more and 920 kg/m ³ or less.

The MFR of the modifier is preferably 0.5 g/10 min or more and 20.0 g/10 min or less, and more preferably 0.7 g/10 min or more and 15.0 g/10 min or less. When the MFR is within the above range, moldability is good. In the case of styrene-based elastomers, the MFR can be measured in accordance with ASTM D1238-89 at a measurement temperature of 230°C and a load of 2.16 kg.
When the modifier is an ethylene-α-olefin copolymer, the MFR of the modifier is preferably 0.5 g/10 min or more and 10.0 g/10 min or less. When the MFR is within the above range, the moldability is good.

When an ethylene-α-olefin copolymer is used as the modifier, the melting point of the modifier is preferably 100°C or lower, more preferably 90°C or lower, and even more preferably 80°C or lower. When an ethylene-α-olefin copolymer is used as the modifier, the lower limit of the melting point of the modifier is not particularly limited, but is, for example, 20°C.

When film 1 is used as a single layer, the content of the modifier in the single layer film 1 is preferably 2% by mass or more and 60% by mass or less, more preferably 4% by mass or more and 50% by mass or less, even more preferably 5% by mass or more and 40% by mass or less, particularly preferably 6% by mass or more and 30% by mass or less, and most preferably 7% by mass or more and 20% by mass or less.
When the content of the modifier in the single-layer film 1 is 2% by mass or more, the physical properties such as loop rigidity and Gelbo property can be set within the preferred ranges described below. When the content of the modifier in the film 1 is more than 60% by mass, the blocking resistance decreases.

In addition to the polyethylene resin composition and modifier, the film 1 may further contain polyethylene having a density of 930 kg/ ^m3 or less. In this case, the polyethylene may be an ethylene homopolymer or a copolymer of ethylene and another α-olefin monomer, and is preferably an ethylene homopolymer.
The density of the polyethylene is preferably 920 kg/m ³ or less, more preferably 910 kg/m ³ or less. There is no particular limitation on the lower limit of the density of the polyethylene, but it is, for example, 870 kg/m ³ .
The content of polyethylene having a density of 930 kg/ ^m3 or less in the film 1 is more than 0 mass% and 70 mass% or less, preferably 10 mass% or more and 60 mass% or less, and more preferably 20 mass% or more and 50 mass% or less.

The film 1 may also contain additives such as an anti-blocking agent, ultra-high molecular weight polyethylene, and acrylic beads.
The film 1 preferably contains an antiblocking agent. The antiblocking agent is not particularly limited, but it is preferable to use various antiblocking agents containing silicon dioxide. The content of the antiblocking agent in the film 1 is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.1% by mass or more and 15% by mass or less, and even more preferably 0.3% by mass or more and 12% by mass or less.
In the film 1, even if the content of the antiblocking agent is small, the antiblocking effect can be obtained.

The film 1 may also contain a plant-derived resin. In this case, at least a portion of the above components may be a plant-derived resin. The plant-derived resin may be, for example, one or more selected from biopolyethylene, biopolypropylene, biopolyethylene terephthalate, etc., and biopolyethylene is more preferably used.
The film 1 contains a plant-derived resin, which reduces the environmental impact.

When film 1 is used as a single layer, the thermal adhesion strength between the front surface of film 1 and the back surface of film 1 is preferably 0 or more and 1.2 kgf/50 mm or less, more preferably 1.0 kgf/50 mm or less, and even more preferably 0.8 kgf/50 mm or less.
If the thermal adhesion strength between the front and back surfaces is within the above range, blocking can be prevented when the film 1 is stored in the form of a roll.
In this specification, the thermal adhesion strength of the film 1 is a value measured within 30 minutes after the production of the film 1. The thermal adhesion strength can be measured in accordance with the examples described later.

When film 1 is used as a single layer, it is preferable that the number of pinholes generated in film 1 measured at -20°C and 1,500 times (condition 1) using a Gelbo flex tester is 1.0 pinholes or less per A4 size (1.0 pinholes or less per A4 size). If the number of pinholes generated in film 1 measured under the above condition 1 is within the above range, film 1 has excellent flex resistance.
Furthermore, when film 1 is used as a single layer, it is more preferable that the number of pinholes generated in film 1 measured at -20°C and 5,000 times (condition 2) using a Gelbo flex tester is 10 or less per A4 size (10 or less per A4 size). If the number of pinholes generated in film 1 measured under the above condition 2 is within the above range, film 1 has better flex resistance.
In this specification, the number of pinholes generated in Film 1 under both Condition 1 and Condition 2 is a value measured within 20 days after the production of Film 1.

When film 1 is used as a single layer, the number of pinholes generated in film 1 measured under the above condition 1 is preferably 1.0 pinholes/A4 or less, more preferably 0.5 pinholes/A4 or less, and even more preferably 0 pinholes/A4.
When film 1 is used as a single layer, the number of pinholes occurring in film 1 measured under the above condition 2 is preferably 6 or less per A4 sheet, more preferably 3 or less per A4 sheet, even more preferably 1 or less per A4 sheet, and even more preferably 0 or less per A4 sheet.

When film 1 is used as a single layer, the loop stiffness in at least one of MD (machine direction) and TD (transverse direction) is preferably 10 N/15 mm or less, more preferably 6 N/15 mm or less, more preferably 4 N/15 mm or less, and more preferably 3 N/15 mm or less. Furthermore, the loop stiffness in both MD and TD of film 1 is also preferably 10 N/15 mm or less, more preferably 6 N/15 mm or less, more preferably 4 N/15 mm or less, and more preferably 3 N/15 mm or less.
If the loop stiffness is within the above range, the film 1 has excellent flexibility.
In this specification, the loop stiffness of film 1 is a value measured within 20 days after the production of film 1.

The thickness of film 1 is not particularly limited. The thickness of film 1 is set appropriately depending on the application. The thickness of film 1 is, for example, 1 μm or more and 1000 μm or less, more preferably 5 μm or more and 500 μm or less, even more preferably 12 μm or more and 300 μm or less, even more preferably 20 μm or more and 150 μm or less, and particularly preferably 30 μm or more and 100 μm or less.

The surface roughness Ra of at least one of the front and back surfaces of the film 1 is usually 0.1 μm or more. If the surface roughness Ra is 0.1 μm or more, the surface becomes smooth, which can suppress thermal adhesion. On the other hand, if the surface roughness Ra is 0.8 μm or less, for example, the transmittance of the film 1 does not decrease, making it suitable for use when transparency is important. Therefore, the surface roughness Ra is preferably 0.2 μm or more and 0.8 μm or less, more preferably 0.2 μm or more and 0.5 μm or less.
The surface roughness Ra in this specification is measured using a Handysurf. Specifically, it can be measured by the method described in the examples.

The method for producing the film 1 is not particularly limited.
Examples of methods for producing the film 1 include a method of preparing a composition (resin composition for film) containing a polyethylene resin composition and a modifier, and, if desired, a resin or resin composition other than the polyethylene resin composition described above, and additives, and then subjecting this composition to inflation molding or extrusion molding, and a method of dissolving or dispersing the composition in a suitable solvent to prepare a coating liquid and coating this coating liquid onto a support (for example, an intermediate layer described below).

(Laminate)
FIG. 2 shows a schematic cross-sectional view of a laminate 50 according to this embodiment.
The laminate 50 is a laminate having three layers: a first outermost layer 10 , an intermediate layer 20 , and a second outermost layer 30 .

In the laminate 50, it is preferable that at least one of the first outermost layer 10, intermediate layer 20, and second outermost layer 30 be the film 1 according to this embodiment, it is more preferable that at least one of the first outermost layer 10 and the second outermost layer 30 be the film 1 according to this embodiment, and it is even more preferable that both the first outermost layer 10 and the second outermost layer 30 be the film 1 according to this embodiment.

In the laminate 50, it is also preferable that the first outermost layer 10, the intermediate layer 20, and the second outermost layer 30 are all the film 1 according to this embodiment.
In this case, the modifier in each layer may be any of the modifiers described above.

In the laminate 50, when at least one of the first outermost layer 10 and the second outermost layer 30 is the film 1 according to this embodiment, the content of the modifier in the first outermost layer 10 and/or the second outermost layer 30 is preferably 2% by mass or more and 60% by mass or less, more preferably 4% by mass or more and 50% by mass or less, even more preferably 5% by mass or more and 40% by mass or less, particularly preferably 6% by mass or more and 30% by mass or less, and most preferably 7% by mass or more and 20% by mass or less.
In the laminate 50, when both the first outermost layer 10 and the second outermost layer 30 are the film 1 of this embodiment, it is preferable that the content of the modifier in at least one of the first outermost layer 10 and the second outermost layer 30 satisfies the above range.

Furthermore, in the laminate 50, when at least the intermediate layer 20 is the film 1 according to this embodiment, the content of the modifier in the intermediate layer 20 is preferably 2% by mass or more and 60% by mass or less, more preferably 4% by mass or more and 55% by mass or less, even more preferably 5% by mass or more and 50% by mass or less, particularly preferably 6% by mass or more and 46% by mass or less, and most preferably 7% by mass or more and 35% by mass or less.

In the laminate 50, the content (total amount) of the polyethylene resin composition in all layers constituting the laminate 50 is preferably 5% by mass or more and less than 100% by mass, more preferably 15% by mass or more and less than 100% by mass, even more preferably 30% by mass or more and less than 100% by mass, and even more preferably 40% by mass or more and less than 100% by mass.

In the laminate 50, the content (total amount) of the modifier in all the layers constituting the laminate 50 is preferably 0.5% by mass or more and 60% by mass or less, more preferably 4% by mass or more and 54% by mass or less, even more preferably 5% by mass or more and 47% by mass or less, particularly preferably 6% by mass or more and 41% by mass or less, and most preferably 8% by mass or more and 35% by mass or less.
In this case, the compounding ratio of the modifier may not be uniform among the layers, but may vary.
When the laminate 50 is a laminate including a plurality of films 1 according to this embodiment, it is preferable that the modifier be contained in a larger amount in the intermediate layer 20 than in the other layers.

When multiple films 1 according to this embodiment are included in the laminate 50, the polyethylene resin compositions in each film 1 may be the same or different.

Of the multiple layers constituting the laminate 50, the material of the layers other than the film 1 according to this embodiment is not particularly limited.
For example, when the first outermost layer 10 is the film 1 according to the present embodiment, and the intermediate layer 20 and the second outermost layer 30 are layers other than the film 1 according to the present embodiment, the intermediate layer 20 and the second outermost layer 30 are preferably made of resin. In this case, the intermediate layer 20 and the second outermost layer 30 may contain various additives.

When the intermediate layer 20 and the second outermost layer 30 are made of resin, examples of the resin include polyolefin resin, nylon resin, and polyester resin.
Examples of polyolefin resins include polyethylene resins, polypropylene resins, and ethylene-α-olefin copolymers.
Examples of polypropylene resins include homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene (BPP).
Examples of polyethylene resins include high density polyethylene (HDPE) and (linear) low density polyethylene (LDPE).
Examples of nylon resins include nylon 6, nylon 8, nylon 11, nylon 12, nylon 6,6, nylon 6,10, and nylon 6,12.
Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate.

When the intermediate layer 20 and the second outermost layer 30 are made of resin, the resin is preferably a polyethylene resin or an ethylene-α-olefin copolymer. Examples of α-olefins in this case include 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, and 1-decene. When the intermediate layer 20 and the second outermost layer 30 are made of resin, the resin is more preferably a polyethylene resin or an ethylene-1-hexene copolymer, and even more preferably a polyethylene resin.

When the intermediate layer 20 and the second outermost layer 30 are made of resin, the resin intermediate layer 20 and the resin second outermost layer 30 preferably contain a modifier. In this case, the content (total amount) of the modifier in all layers constituting the laminate 50 is preferably 0.5% by mass or more and 60% by mass or less, more preferably 4% by mass or more and 54% by mass or less, even more preferably 5% by mass or more and 47% by mass or less, particularly preferably 6% by mass or more and 41% by mass or less, and most preferably 8% by mass or more and 35% by mass or less. The blending ratio of the modifier may not be uniform in each layer and may vary, but it is preferable that the intermediate layer 20 contains more modifier than the other layers.

Furthermore, if the second outermost layer 30 is made of resin, it preferably contains an anti-blocking agent.

The laminate 50 may contain a plant-derived resin. In this case, the layer that is the film 1 according to this embodiment may contain a plant-derived resin as described above, or a layer that is not the film 1 according to this embodiment may contain a plant-derived resin, or both layers may contain a plant-derived resin. Suitable plant-derived resins include, for example, one or more selected from biopolyethylene, biopolypropylene, and biopolyethylene terephthalate, with biopolyethylene being more suitable.

In the laminate 50, the thermal adhesion strength between the first outermost layer 10 and the second outermost layer 30 is preferably 0 or more and 1.2 kgf/50 mm or less, more preferably 1.0 kgf/50 mm or less, and even more preferably 0.8 kgf/50 mm or less.
If the thermal adhesion strength between the first outermost layer 10 and the second outermost layer 30 is within the above range, blocking can be prevented when the laminate 50 is stored in the form of a roll.
In this specification, the thermal adhesion strength of the laminate 50 is a value measured within 30 minutes after the production of the laminate 50. The thermal adhesion strength can be measured in the same manner as in the examples described later.

The laminate 50 preferably has a pinhole count of 1.0 pinholes/A4 or less, measured using a Gelbo flex tester under the above-mentioned condition 1. If the pinhole count of the laminate 50 measured under the above-mentioned condition 1 is within the above range, the laminate 50 has superior flex resistance.
Furthermore, it is more preferable that the number of pinholes occurring in the laminate 50, measured using a Gelbo flex tester under the above-mentioned condition 2, is 10 or less per A4 size (10 or less per A4 size). If the number of pinholes occurring in the laminate 50, measured under the above-mentioned condition 2, is within the above range, the laminate 50 has superior flex resistance.
In this specification, the number of pinholes generated in the laminate 50 under both Condition 1 and Condition 2 is a value measured within 20 days after the laminate 50 was produced.

The number of pinholes generated in the laminate 50 measured under the above condition 1 is preferably 1.0 pinholes/A4 or less, more preferably 0.5 pinholes/A4 or less, and even more preferably 0 pinholes/A4.
The number of pinholes occurring in the laminate 50 measured under the above condition 2 is preferably 6 or less per A4 sheet, more preferably 3 or less per A4 sheet, even more preferably 1 or less per A4 sheet, and even more preferably 0 or less per A4 sheet.

The loop stiffness of the laminate 50 in at least one of the MD and the TD is preferably 10 N/15 mm or less, more preferably 6 N/15 mm or less, more preferably 4 N/15 mm or less, and more preferably 3 N/15 mm or less. The loop stiffness of the laminate 50 in both the MD and the TD is also preferably 10 N/15 mm or less, more preferably 6 N/15 mm or less, more preferably 4 N/15 mm or less, and more preferably 3 N/15 mm or less.
If the loop stiffness is within the above range, the laminate 50 has excellent flexibility.
In this specification, the loop stiffness of the laminate 50 is a value measured within 20 days after the laminate 50 is produced.

The overall thickness of the laminate 50 is not particularly limited. The overall thickness of the laminate 50 is set appropriately depending on the application. The overall thickness (total thickness) of the laminate 50 is, for example, 1 μm or more and 1000 μm or less, more preferably 10 μm or more and 500 μm or less, even more preferably 20 μm or more and 200 μm or less, and particularly preferably 30 μm or more and 100 μm or less.

The surface roughness Ra of at least one of the surfaces of the first outermost layer 10 of the laminate 50 (the surface opposite to the surface in contact with the intermediate layer 20) and the second outermost layer 30 (the surface opposite to the surface in contact with the intermediate layer 20) is typically 0.1 μm or greater. A surface roughness Ra of 0.1 μm or greater will result in a smooth surface, which can suppress thermal adhesion. On the other hand, a surface roughness Ra of 0.8 μm or less will not reduce the transmittance of the laminate 50, making it suitable for use in situations where transparency is important. Therefore, the surface roughness Ra is preferably 0.2 μm or greater and 0.8 μm or less, and more preferably 0.2 μm or greater and 0.5 μm or less.

The method for manufacturing the laminate 50 is not particularly limited.
Examples of methods for manufacturing the laminate 50 include a method of inflation molding or co-extrusion of the material for the first outermost layer 10, the material for the intermediate layer 20, and the material for the second outermost layer 30; a method of extruding and laminating the first outermost layer 10 onto one side of a pre-manufactured intermediate layer 20, and extruding and laminating the material for the second outermost layer 30 onto the other side of the intermediate layer 20; a method of laminating a film corresponding to the first outermost layer 10, a film corresponding to the intermediate layer 20, and a film corresponding to the second outermost layer 30 by bonding them together; and a method of coating one side of a pre-manufactured intermediate layer 20 with a coating liquid containing the material for the first outermost layer 10, and coating the other side of the intermediate layer 20 with a coating liquid containing the material for the second outermost layer 30.

(packaging bag)
Next, a packaging bag having a laminate according to one embodiment of the present invention will be described.
FIG. 3 shows a schematic diagram of a packaging bag 100 according to this embodiment.
The packaging bag 100 includes a bag body 110 having a first surface 111 and a second surface 112 that face each other.
The bag body 110 is formed using the laminate 50 according to this embodiment. In this embodiment, two laminates 50 are joined to each other by heat sealing or the like at the side seal portions 121, 122 and the bottom seal portion 130, thereby forming the bag body 110 having the first surface 111 and the second surface 112.
The film on the inner surface (contents side) of the bag body 110 of the packaging bag 100 is preferably the film 1 according to this embodiment.

The packaging bag 100 may be, for example, a packaging bag with zipper tape by forming a zipper tape at the opening 140.
In addition, the packaging bag 100 may be formed by attaching a spout to one of the laminates 50 forming the first surface 111 and the laminates 50 forming the second surface 112, and then joining the peripheries of these laminates 50 together by heat sealing or the like.

Examples of items that can be packaged in the packaging bag 100 include food products, seasonings, food ingredients, beverages, pharmaceuticals, blood, cosmetics, detergents, nutrients, chemicals, adhesives, pressure sensitive adhesives, paints, pesticides, and fertilizers.
The packaging bag 100 has excellent flexibility and can therefore be preferably used as a packaging bag for a bag-in-box. A bag-in-box equipped with the packaging bag 100 as an inner bag can withstand bending movements during transportation of packaged items due to the excellent flexibility of the packaging bag.

(Effects of this embodiment)
The film 1 and laminate 50 according to this embodiment are highly flexible and do not block even when stored at room temperature. Furthermore, the packaging bag and bag-in-box according to this embodiment are made of such a film and laminate, and therefore can withstand bending movements during transportation.

[Modification]
The present invention is not limited to the above embodiment.
For example, in the above first embodiment, a laminate 50 is exemplified in which at least one, preferably both, of the first outermost layer 10 and the second outermost layer 30 is the film 1 according to the first embodiment, but the first outermost layer 10, the intermediate layer 20, and the second outermost layer 30 may all be the film 1 according to the first embodiment.

For example, in the first embodiment described above, a laminate 50 having a three-layer structure consisting of a first outermost layer 10, an intermediate layer 20, and a second outermost layer 30 is exemplified, but a laminate having a multi-layer structure of two layers or four or more layers may also be used.

For example, in the first embodiment described above, a packaging bag 100 formed using a laminate 50 was illustrated, but the packaging bag may also be formed using a film 1.

The following describes examples of the present invention. The present invention is not limited to these examples.

<Forming of film-like laminate>
A three-layer laminate having a first outermost layer, an intermediate layer, and a second outermost layer was formed into a film by multilayer coextrusion T-die casting.
The raw materials for each layer in each of the Examples , Comparative Examples , and Reference Examples were as follows.
The total thickness of the laminate in each of the Examples , Comparative Examples , and Reference Examples was 80 μm, and the layer thickness ratios were as shown in Tables 1 and 2.

[ Reference example A ]
The components of each layer were as follows, and the blending amounts were as shown in Table 1.
(1) First Outermost Layer Raw Material A-1: Polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A / manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material A-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
Raw material A-3: Anti-blocking agent (silicon dioxide, 10 μm diameter)
(2) Intermediate layer Raw material B-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material B-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
(3) Second outermost layer Raw material C-1: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A, manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material C-3: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S/manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
Raw material C-4: Antiblocking agent (silicon dioxide, 10 μm diameter)

[ Reference example B ]
Except for the components of the second outermost layer described below, the components were the same as those in Reference Example A. The blending amounts of the components of each layer were as shown in Table 1.
(1) Second Outermost Layer Raw Material C-1: Polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A / manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material C-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
Raw material C-3: Antiblocking agent (silicon dioxide, 10 μm diameter)

[ Reference example C ]
The components other than those of the first outermost layer and the second outermost layer described below were the same as those of Reference Example A. The blending amounts of the components of each layer were as shown in Table 1.
(1) First Outermost Layer Raw Material A-1: Polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A / manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material A-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4085S, manufactured by Mitsui Chemicals, Inc., density: 885 kg/m ³ , MFR: 3.6 g/10 min)
Raw material A-3: Anti-blocking agent (silicon dioxide, 10 μm diameter)
(2) Second outermost layer Raw material C-1: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4085S/manufactured by Mitsui Chemicals, Inc., density: 885 kg/m ³ , MFR: 3.6 g/10 min),
Raw material C-3: Antiblocking agent (silicon dioxide, 10 μm diameter)

[ Reference example D ]
Except for changing the surface roughness of the first outermost layer, the same procedures were carried out as in Reference Example C. The surface roughness of the first outermost layer in Reference Examples C and D was measured as follows.

[Measurement of surface roughness (arithmetic mean roughness) Ra]
The arithmetic mean roughness Ra of the surface of the first outermost layer of the obtained laminate (the surface opposite to the surface in contact with the intermediate layer) was measured using the following measuring device and under the following conditions. The results are shown in Table 3.
Measuring device: Handysurf E-35A/B (manufactured by ACCRETECH Co., Ltd., 18-6-8589)
Measurement conditions: Cutoff value: 0.8 μm

[ Reference example E ]
The components of each layer were as follows, and the blending amounts were as shown in Table 1.
(1) First Outermost Layer Raw Material A-1: Polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A / manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material A-2: Modifier (ethylene-1-octene copolymer) (trade name: Affinity (registered trademark) EG8100G, manufactured by Dow Chemical Company, density: 870 kg/m ³ , MFR: 1.0 g/10 min)
Raw material A-3: Anti-blocking agent (silicon dioxide, 10 μm diameter)
(2) Intermediate layer Raw material B-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material B-2: Modifier (ethylene-1-octene copolymer) (trade name: Affinity (registered trademark) EG8100G, manufactured by Dow Chemical Company, density: 870 kg/m ³ , MFR: 1.0 g/10 min)
(3) Second outermost layer Raw material C-1: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A, manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material C-3: Modifier (ethylene-1-octene copolymer) (trade name: Affinity (registered trademark) EG8100G, manufactured by Dow Chemical Company, density: 870 kg/m ³ , MFR: 1.0 g/10 min)

[Example 6]
Except for the components of the second outermost layer described below, the components were the same as those in Reference Example E. The blending amounts of the components of each layer were as shown in Table 1.
(1) Second outermost layer Raw material C-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510 / manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A, manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material C-3: Modifier (styrene-ethylene/butylene-styrene copolymer) (trade name: Kraton G-1657VS, manufactured by Kraton Polymer Japan Co., Ltd., density: 900 kg/m ³ )

[Example 7]
Except for the components of the second outermost layer described below, the components were the same as those in Reference Example E. The blending amounts of the components of each layer were as shown in Table 1.
(1) Second outermost layer Raw material C-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510 / manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: polyethylene resin composition (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0523A, manufactured by Prime Polymer Co., Ltd., density: 908 kg/m ³ , MFR: 2.0 g/10 min)
Raw material C-3: Modifier (styrene-ethylene/butylene-styrene copolymer) (product name: TUFTEC (registered trademark) H1052/manufactured by Asahi Kasei Corporation, density: 890 kg/m ³ , MFR: 13.0 g/10 min)

[Example 8]
The components other than the components of the intermediate layer described below were the same as those in Example 7. The blending amounts of the components of each layer were as shown in Table 1.
(1) Intermediate layer: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material B-2: modifier (styrene-ethylene/butylene-styrene copolymer) (product name: TUFTEC (registered trademark) H1052/manufactured by Asahi Kasei Corporation, density: 890 kg/m ³ , MFR: 13.0 g/10 min)

[Example 9]
The intermediate layer was the same as in Example 8 except for the amounts of raw materials B-1 and B-2 blended.

[Example 10]
The intermediate layer was the same as in Example 8 except for the amounts of raw materials B-1 and B-2 blended.

[Comparative Example 1]
The components of each layer were as follows, and the blending amounts were as shown in Table 2.
(1) First outermost layer Raw material A-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP1510/manufactured by Prime Polymer Co., Ltd., density: 915 kg/m ³ , MFR: 1.0 g/10 min)
Raw material A-2: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510, manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material A-3: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-1085S, manufactured by Mitsui Chemicals, Inc., density: 885 kg/m ³ , MFR: 1.2 g/10 min)
Raw material A-4: Antiblocking agent (silicon dioxide, 10 μm diameter)
(2) Intermediate layer Raw material B-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material B-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-1085S, manufactured by Mitsui Chemicals, Inc., density: 885 kg/m ³ , MFR: 1.2 g/10 min)
(3) Second outermost layer Raw material C-1: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP1510/manufactured by Prime Polymer Co., Ltd., density: 915 kg/m ³ , MFR: 1.0 g/10 min)
Raw material C-2: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510, manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-3: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-1085S, manufactured by Mitsui Chemicals, Inc., density: 885 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-4: Antiblocking agent (silicon dioxide, 10 μm diameter)

[Comparative Example 2]
The components of each layer were as follows, and the blending amounts were as shown in Table 2.
(1) First outermost layer Raw material A-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material A-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
Raw material A-3: Anti-blocking agent (silicon dioxide, 10 μm diameter)
(2) Intermediate layer Raw material B-1: Linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material B-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
(3) Second outermost layer Raw material C-1: linear low-density polyethylene (comonomer: ethylene-1-hexene copolymer) (trade name: Evolue (registered trademark) SP0510/manufactured by Prime Polymer Co., Ltd., density: 904 kg/m ³ , MFR: 1.2 g/10 min)
Raw material C-2: modifier (ethylene-1-butene copolymer) (trade name: Tafmer (registered trademark) A-4070S, manufactured by Mitsui Chemicals, Inc., density: 870 kg/m ³ , MFR: 3.6 g/10 min)
Raw material C-3: Antiblocking agent (silicon dioxide, 10 μm diameter)

[Comparative Example 3]
The same procedures as in Comparative Example 2 were followed except for the amounts of raw materials A-1 and A-2 in the first outermost layer and the amounts of raw materials C-1, C-2, and C-3 in the second outermost layer.

[Comparative Example 4]
The amounts of raw materials A-1 and A-2 in the first outermost layer, raw materials B-1 and B-2 in the intermediate layer, and raw materials C-1 and C-2 in the second outermost layer were the same as in Comparative Example 2.

<Various evaluations>
The laminates prepared in each of the Examples , Comparative Examples , and Reference Examples were evaluated as follows. The evaluation results for the Examples and Reference Examples are shown in Table 1, and the evaluation results for the Comparative Examples are shown in Table 2.

(Thermal adhesion strength)
The laminate was cut into a size of 10 cm x 5 cm to prepare a rectangular test film. Two test films were used, and the first outermost layer side of one test film was placed in contact with the second outermost layer side of the other test film. The two test films were then sandwiched from above and below with a heat seal tester (TP-701-B manufactured by Tester Sangyo Co., Ltd.) using a seal bar heated to 38 ° C. A pressure load of 1.5 kgf was applied for 900 seconds to adhere the two test films together. The adhered films were then released from the seal bar and allowed to stand at room temperature for 15 minutes to stabilize. Using a universal material testing machine (Tensilon), the peeled piece was pulled at a rate of 300 mm/min, and shear peeling was performed and measurements were taken. Measurements were taken within 30 minutes after the test film was prepared.

(Bending resistance)
The laminate was cut into a rectangular test film measuring 21.0 cm (14.3 inches) x 29.7 cm (11.7 inches). This test film was then wound into a cylindrical shape measuring 21.0 cm (14.3 inches). One end of the cylindrical film was fixed to the outer periphery of the disk-shaped fixed head of a Gelbo Flex Tester (manufactured by Rigaku Kogyo Co., Ltd.), and the other end of the cylindrical film was fixed to the outer periphery of the disk-shaped movable head of the tester, which faced the fixed head at a distance of 17.8 cm (7.0 inches). The movable head was then rotated 440° toward the fixed head along the axes of the opposing parallel heads, moving 8.8 cm (3.5 inches) toward the fixed head. It was then moved straight forward 6.4 cm (2.5 inches) without rotating, and these movements were then repeated in the reverse direction to return the movable head to its initial position. This complete bending test cycle was continuously repeated at a rate of 40 cycles per minute. The bending tests were carried out within 20 days after the preparation of the test films, and evaluations were carried out for two items: a total of 5,000 cycles ( Reference Examples A to D and Comparative Examples 1 to 4) and a total of 1,500 cycles (Examples 6 to 10 , Comparative Examples 1 to 4 , and Reference Examples A to E ), each at -20°C. After that, the number of pinholes (A4 size: number of pinholes per 528.7 ^cm2 (81.9 square inches)) that occurred within a 17.8 cm (7.0 inches) x 29.7 cm (11.7 inches) area of the tested film, excluding the portions fixed to the outer periphery of the fixed head and movable head, was counted.

(loop stiffness)
The laminate was cut into a rectangular test film measuring 1.5 cm x 18 cm. This test film was looped, and the loop stiffness was measured by measuring the stress when the apex of the loop was pressed a certain distance with an indenter using a loop stiffness tester (manufactured by Toyo Seiki Seisaku-sho, Ltd., A222401101) according to the loop stiffness test method (film stiffness test method).

As is clear from Tables 1 and 2, the laminates of Examples 6 to 10 were excellent in flexibility and no blocking occurred.

The above describes in detail preferred embodiments of the present invention with reference to the accompanying drawings, but the present invention is not limited to these examples. It is clear that a person skilled in the art of the technology to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

1...film, 10...first outermost layer, 20...intermediate layer, 30...second outermost layer, 50...laminated body, 100...packaging bag, 110...bag body, 111...first surface, 112...second surface, 121, 122...side seal portion, 130...bottom seal portion, 140...opening.

Claims (15)

A laminate,
a first outermost layer, a second outermost layer, and an intermediate layer between the first outermost layer and the second outermost layer;
at least one layer of the first outermost layer, the intermediate layer, and the second outermost layer is a film containing a polyethylene-based resin composition containing a linear ethylene-based copolymer (A) and a low-density polyethylene (B), and a modifier;
the linear ethylene copolymer (A) has a density of 894 kg/m ^or more and 914 kg/m or ^less ;
The density of the low-density polyethylene (B) is 935 kg/ ^m3 or less,
The laminate, wherein the modifier is a styrene -based elastomer. the content of the polyethylene resin composition in the laminate is 5% by mass or more and less than 100% by mass;
The laminate according to claim 1 . The content of the modifier in the laminate is 0.5% by mass or more and 60% by mass or less.
The laminate according to claim 2 . the second outermost layer is the film;
The laminate according to any one of claims 1 to 3. The linear ethylene copolymer (A) has a density of 896 kg/m ^or more and 910 kg/m or ^less .
The laminate according to any one of claims 1 to 4. The density of the low-density polyethylene (B) is 870 kg/m ³ or more and 910 kg/m ³ or less.
The laminate according to any one of claims 1 to 5. a thermal adhesion strength between the first outermost layer and the second outermost layer is 0 to 1.2 kgf/50 mm;
The laminate according to any one of claims 1 to 6. The number of pinholes generated in the laminate, measured using a Gelbo flex tester at −20° C. and 1,500 cycles, is 1.0 pinholes/A4 or less.
The laminate according to any one of claims 1 to 7. The loop rigidity of the laminate is 10 N/15 mm or less.
The laminate according to any one of claims 1 to 8. Contains plant-derived resin,
The laminate according to any one of claims 1 to 9. the second outermost layer and the intermediate layer are the films;
The laminate according to any one of claims 1 to 10. the first outermost layer, the second outermost layer, and the intermediate layer are the films;
The laminate according to any one of claims 1 to 11. the first outermost layer comprises an antiblocking agent;
The laminate according to any one of claims 1 to 12 . A packaging bag comprising the laminate according to any one of claims 1 to 13 . A bag-in-box comprising the packaging bag according to claim 14 .