JP2024036304A - Laminated film and package - Google Patents

Abstract

To provide a laminated film with an excellent forming property and impact resistance, and a package using the same.SOLUTION: There is provided a laminated film comprising a functional layer and an oxygen barrier layer. The functional layer contains a propylene-based polymer and an ethylene-based polymer. In the functional layer, the ethylene-based polymer has a melt flow rate of 3 g/10 minutes or less. In the functional layer, a content ratio of the ethylene-based polymer to a total mass of the functional layer is 10 mass% or more and 40 mass% or less.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laminated film and a package.

A laminated film formed by laminating a plurality of resin layers is widely used as a material for packaging bodies. A typical laminated film includes at least a sealant layer provided for heat-sealing with the object to be sealed, and an outer layer provided on the side opposite to the sealant layer side.

On the other hand, such laminated films for packaging are produced and consumed in large quantities every day around the world due to their high convenience, and a large amount of waste is generated after use. The generation of waste has become an important issue to be solved from the perspective of improving the global environment, and in recent years, there has been a lot of research into ways to reduce the amount of waste generated and how to reuse (recycle) waste. is being considered.

For example, if the main constituent materials of multiple resin layers in a laminated film are the same, there is no need to separate and reuse each resin layer separately, and the entire laminated film can be easily reused. This makes it highly useful.
As such a laminated film, for example, a polyethylene laminate for packaging materials is disclosed, which includes at least a stretched polyethylene film, an adhesive layer, and a heat-sealable polyethylene layer, and the adhesive layer contains a solvent-free adhesive. (See Patent Document 1).

JP 2019-189333 Publication

However, when the main constituent material of the multiple resin layers in a laminated film is, for example, polypropylene, when the laminated film is heated during molding, the heated portion of the laminated film sag (draws) due to the fluidity of polypropylene. There was a problem that it was difficult to mold. There was also the problem that the impact resistance of the laminated film was not sufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminated film with excellent moldability and impact resistance, and a package using the laminated film.

In order to solve the above problems, the present invention employs the following configuration.
[1]. A laminated film comprising a functional layer and an oxygen barrier layer, wherein the functional layer contains a propylene polymer and an ethylene polymer, and in the functional layer, the ethylene polymer has a melt flow rate of 3 g/ 10 minutes or less, and in the functional layer, the ratio of the content of the ethylene polymer to the total mass of the functional layer is 10% by mass or more and 40% by mass or less.

[2]. The laminated film further includes an inner layer as one outermost layer, the inner layer contains a propylene polymer and an ethylene polymer, and the ethylene polymer has a melt flow rate of 3 g. /10 minutes or less, and in the inner layer, the content of the ethylene polymer is 10% by mass or more and 40% by mass or less with respect to the total mass of the inner layer.

[3]. The laminated film further includes an outer layer as the other outermost layer, the outer layer contains a propylene polymer and an ethylene polymer, and the ethylene polymer has a melt flow rate of 3 g. /10 minutes or less, and in the outer layer, the content of the ethylene polymer is 10% by mass or more and 40% by mass or less with respect to the total mass of the outer layer.

[4]. The laminated film according to [3], wherein the ratio of the total thickness of the functional layer, the inner layer, and the outer layer to the thickness of the laminated film is 85% or more.
[5]. The laminated film according to any one of [1] to [4], wherein in the laminated film, the content ratio of the polyolefin resin to the total mass of the laminated film is 80% by mass or more.
[6]. The laminated film according to any one of [1] to [5], wherein the oxygen barrier layer contains an ethylene-vinyl alcohol copolymer.

[7]. The laminated film according to any one of [1] to [6], wherein the laminated film includes two or more of the functional layers, and the oxygen barrier layer is provided between a pair of the functional layers. Laminated film.
[8]. The laminated film according to any one of [1] to [7], wherein the laminated film has a tensile impact strength of 225 kJ/m ² or more in directions parallel and perpendicular to the flow direction of the resin.
[9]. One or more selected from the group consisting of the propylene polymer contained in the functional layer, the propylene polymer contained in the inner layer, and the propylene polymer contained in the outer layer co-exist with a propylene block. The laminated film according to [3], which is a polymer.
[10]. The tensile impact strength of the laminated film in the direction parallel to the flow direction of the resin is 330 kJ/m ² or more, and the tensile impact strength of the laminated film in the direction perpendicular to the flow direction of the resin, The laminated film according to [9], which has a power of 330 kJ/m ² or more.
[11]. The laminated film according to any one of [1] to [10], wherein the laminated film has a drawdown length of 50 mm or less when the laminated film is heated at 400° C. for 120 seconds.

[12]. The surface roughness Ra of one outermost layer of the laminated film is 0.65 μm or less, and the surface roughness Ra of the other outermost layer of the laminated film is 0.65 μm or less, [1] to [8] ] The laminated film according to any one of the above.
[13]. The 60° glossiness of one outermost layer of the laminated film measured in accordance with JIS Z 8741 is 90 or more, and the other outermost layer of the laminated film measured in accordance with JIS Z 8741 The laminated film according to any one of [1] to [8], wherein the 60° glossiness of the laminated film is 90 or more.
[14]. A package constructed using the laminated film according to any one of [1] to [13].

According to the present invention, a laminated film with excellent moldability and impact resistance, and a package using the laminated film are provided.

It is a figure which shows typically an example of the measuring method of the drawdown length of a laminated film or a single layer film. 1 is a cross-sectional view schematically showing an example of a laminated film according to an embodiment of the present invention. It is a sectional view showing typically another example of the laminated film concerning one embodiment of the present invention. FIG. 1 is a cross-sectional view schematically showing an example of a package according to an embodiment of the present invention. 2 is a photograph showing cracking modes ((a) brittle fracture, (b) brittle to ductile fracture, (c) ductile fracture) during measurement of surface impact strength of a laminated film according to an embodiment of the present invention. It is a graph showing the relationship between elongation speed and elongation viscosity of pellets.

<<Laminated film>>
(Tensile impact strength)
The tensile impact strength of the laminated film in the directions parallel and perpendicular to the flow direction of the resin, measured in accordance with JIS K 7160A, is preferably 225 kJ/m ² or more, and preferably 225 kJ/m ² or more. It is more preferably 500 kJ/m ² or less, even more preferably 230 kJ/m ² or more and 490 kJ/m ² or less, and particularly preferably 240 kJ/m ² or more and 480 kJ/m ² or less, for example, 330 kJ/m 2 or more. m ² or more and 850 kJ/m ² or less, 340 kJ/m ² or more and 800 kJ/m ² or less, and 350 kJ/m ² or more and 750 kJ/m ² or less.
When the tensile impact strength is equal to or higher than the lower limit, the impact resistance of the laminated film can be further improved. When the tensile impact strength is less than or equal to the upper limit value, excessive tensile impact strength of the laminated film is further suppressed.

The tensile impact strength of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film to include a functional layer containing a propylene polymer and an ethylene polymer, the tensile impact strength of the laminated film can be easily improved.
For example, the tensile impact strength of the laminated film can be further improved by configuring the laminated film to include a functional layer, an inner layer, or an outer layer containing a propylene-based block copolymer and an ethylene-based polymer. For example, the tensile impact strength of the laminated film with improved tensile impact strength in the direction parallel to the flow direction of the resin is 330 kJ/m ^{2 or more, and the tensile impact strength of the laminated film is 330 kJ/m 2} or more, and It is preferable that the tensile impact strength in the direction perpendicular to the flow direction is 330 kJ/m ² or more, and the tensile impact strength in the direction parallel to the flow direction of the resin is 340 kJ/m ² or more, and It is further preferable that the tensile impact strength of the laminated film in a direction perpendicular to the flow direction of the resin is 350 kJ/m ² or more.
However, these are just examples, and the tensile impact strength of the laminated film can also be adjusted by adjusting other layers.

(Surface impact strength)
The surface impact strength (total penetration energy) of the laminated film measured in accordance with JIS K 7124-2 at a measurement temperature of 0°C and a measurement time of 15 minutes is 2.0 J or more and 4.0 J or less. It is preferably 2.1 J or more and 3.9 J or less, and even more preferably 2.2 J or more and 3.8 J or less.
When the surface impact strength is equal to or higher than the lower limit, the impact resistance of the laminated film can be further improved. When the surface impact strength is less than or equal to the upper limit value, excessive surface impact strength of the laminated film is further suppressed.

The surface impact strength of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film with a functional layer containing an ethylene polymer, the surface impact strength of the laminated film can be easily improved. However, this is just an example, and the surface impact strength of the laminated film can also be adjusted by adjusting other layers.

(Drawdown length)
When the laminated film is heated at 400° C. for 120 seconds, the drawdown length of the laminated film is preferably 50 mm or less, more preferably 3 mm or more and 45 mm or less, and 4 mm or more and 40 mm or less. is more preferable, and may be, for example, 5 mm or more and 50 mm or less, 6 mm or more and 48 mm or less, and 7 mm or more and 46 mm or less.
When the drawdown length is equal to or greater than the lower limit, the sheet will be in a uniformly melted state, and the formability of the laminated film can be improved. When the drawdown length is equal to or less than the upper limit value, it is possible to suppress wrinkles in the flange portion during molding of the laminated film.

The drawdown length of the laminated film can be measured, for example, by the following method. A test piece is cut out from the laminated film, and the upper surface of the test piece is indirectly heated at 400° C. for 120 seconds using a movable rod heater. After heating, the heater is removed and a laser displacement meter is used to measure the lowest point at which the sheet sag.
Specifically, as shown in Figure 1, the drawdown of the test piece is started from a point on the surface in the opposite direction to the drawdown direction of the test piece in an area where no drawdown of the test piece is observed. From the starting point to the ending point, with the farthest distance from the starting point in the direction of the drawdown among one point on the surface in the opposite direction to the direction of the drawdown in the area where down is observed. The distance D up to this point is the drawdown length of the laminated film.
The drawdown length of a single layer film can also be measured in the same manner as above.

The drawdown length of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film with a functional layer containing a propylene polymer and an ethylene polymer, the drawdown length of the laminated film can be easily reduced.
For example, by constructing a laminated film with a functional layer, inner layer, or outer layer containing a propylene-based block copolymer and an ethylene-based polymer, the elongational viscosity of the functional layer, inner layer, or outer layer is increased, and as a result, , the drawdown length of the laminated film can be further reduced. For example, when the laminated film whose drawdown length is further reduced in this way is heated at 400°C for 120 seconds, the drawdown length of the laminated film is preferably 50 mm or less, and 6 mm or more and 48 mm or less. It is more preferable that it is, and it is even more preferable that it is 7 mm or more and 46 mm or less.
However, these are just examples, and the drawdown length of the laminated film can also be adjusted by adjusting other layers.

(Surface roughness Ra of outermost layer)
The surface roughness Ra of one outermost layer of the laminated film measured in accordance with JIS B0601:2013 is 0.65 μm or less, and the surface roughness Ra of the other outermost layer of the laminated film is 0. It is preferable that it is .65 μm or less. That is, the surface roughness Ra of both outermost layers of the laminated film is preferably 0.65 μm or less, more preferably 0.01 μm or more and 0.65 μm or less, and 0.015 μm or more and 0.6 μm or less. It is further preferable that
When the surface roughness Ra of both outermost layers of the laminated film is equal to or greater than the lower limit, handling during sheet winding is improved (blocking is suppressed). When the surface roughness Ra of both outermost layers of the laminated film is equal to or less than the upper limit value, the glossiness of the sheet surface improves and the sheet appearance becomes good. Furthermore, the range of sealing strength of the laminated film becomes smaller, and there is less chance of it getting caught during peeling. As a result, the package obtained using the laminated film can be opened more smoothly.

The surface roughness Ra of the outermost layer of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in the manufacturing process or in any layer constituting the laminated film.
For example, by adjusting the surface roughness of a roll that presses the outermost layer of the laminated film, the surface roughness Ra of the outermost layer of the laminated film can be easily reduced. However, this is just an example, and the surface roughness Ra of the outermost layer of the laminated film can also be adjusted by adjusting any layer constituting the laminated film.

In this specification, "opening the package" means opening the package due to peeling of the lid material and the bottom material, unless otherwise specified.

(60° glossiness of the outermost layer)
The 60° glossiness of one outermost layer of the laminated film is 90 or more, and the 60° glossiness of the other outermost layer of the laminated film is 90 or more, as measured in accordance with JIS Z 8741. It is preferable. That is, the 60° glossiness of both outermost layers of the laminated film is preferably 90 or more, more preferably 91 or more and 110 or less, and even more preferably 92 or more and 109 or less.
When the 60° glossiness of both outermost layers of the laminated film is equal to or higher than the lower limit, the design of the package obtained using the laminated film can be further improved. When the 60° glossiness of both outermost layers of the laminated film is equal to or less than the upper limit value, the glossiness is sufficient for the design of the package.

The 60° glossiness of the outermost layer of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by adjusting the surface roughness of the roll against which the outermost layer of the laminated film is pressed, the 60° glossiness of the outermost layer of the laminated film can be easily improved. However, this is just an example, and the 60° glossiness of the outermost layer of the laminated film can also be adjusted by adjusting any layer constituting the laminated film.

(Haze)
The haze of the laminated film measured in accordance with JIS K 7136:2000 is preferably 5% or more, more preferably 5% or more and 60% or less, and 10% or more and 55% or less. is more preferable, and particularly preferably 15% or more and 50% or less, for example, it may be 5% or more and 96% or less, 10% or more and 95% or less, or 20% or more and 94% or less.
When the haze is equal to or higher than the lower limit value, visibility of the contents of the container can be sufficiently ensured, and the product can be easily manufactured. When the haze is below the upper limit value, the visibility of the contents becomes better in the package obtained using the laminated film.

The haze of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film to include a functional layer containing an ethylene polymer, the haze of the laminated film can be easily reduced. However, this is just an example, and the haze of the laminated film can also be adjusted by adjusting other layers.

(Seal strength)
The seal strength of the laminated film measured in accordance with JIS Z1707:2019 is preferably 5 N/15 mm or more and 25 N/15 mm or less, more preferably 7.5 N/15 mm or more and 22.5 N/15 mm or less. It is preferably 10 N/15 mm or more and 20 N/15 mm or less.
When the seal strength is equal to or higher than the lower limit value, the seal strength of the laminated film can be further improved, and the sealing properties of the contents can be maintained. When the sealing strength is equal to or less than the upper limit value, it is possible to achieve both sealing performance and removability of the contents. As a result, the package obtained using the laminated film can be opened more smoothly.

The seal strength of the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film with an inner layer containing a propylene polymer and an ethylene polymer, the seal strength of the laminated film can be easily improved. However, this is just an example, and the seal strength of the laminated film can also be adjusted by adjusting other layers.

(oxygen permeation amount)
The amount of oxygen permeated through the laminated film under the conditions of a temperature of 23°C and a relative humidity (RH) of 60%, measured in accordance with JIS K 7126-2:2006, is 5cc/( ^m2・24h・atm). ) or less, for example, 2.5cc/( ^m2・24h・atm) or less, 1cc/( ^m2・24h・atm) or less, 0.8cc/( ^m2・24h・atm) or less, It may be either 0.5 cc/(m ² ·24 h · atm) or less or 0.3 cc/(m ² ·24 h ·atm) or less.
On the other hand, the amount of oxygen permeation through the laminated film is 0 cc/(m ² ·24 h ·atm) or more.
That is, the amount of oxygen permeation through the laminated film is 0 to 5 cc/(m ² 24 h atm), 0 to 2.5 cc/(m ² 24 h atm), and 0 to 1 cc/(m ² 24 h atm) , 0~0.8c/( ^m2・24h・atm), 0~0.5cc/( ^m2・24h・atm), and 0~0.3cc/( ^m2・24h・atm). There may be.

The amount of oxygen permeation through the laminated film can be adjusted by adjusting the type, amount, thickness, etc. of the contained components in any of the layers constituting the laminated film.
For example, by configuring the laminated film with an oxygen barrier layer containing EVOH, the amount of oxygen permeation through the laminated film can be easily reduced. However, this is just an example, and the amount of oxygen permeation in the laminated film can also be adjusted by adjusting other layers.

(Other characteristics)
In the laminated film, the content ratio of the polyolefin resin to the total mass of the laminated film is preferably 80% by mass or more, more preferably 85% by mass or more and 100% by mass or less, and 90% by mass. % or more and 95% by mass or less is more preferable.
When the ratio is equal to or greater than the lower limit, the reusability of the laminated film becomes higher. When the ratio is equal to or less than the upper limit value, it becomes easy to impart other properties to the laminated film.

The overall thickness of the laminated film is not particularly limited, but is preferably 300 μm or more and 1500 μm or less, more preferably 315 μm or more and 1400 μm or less, and even more preferably 330 μm or more and 1300 μm or less.

In the laminated film, all the layers constituting it (for example, functional layer, oxygen barrier layer, inner layer, outer layer, adhesive layer) are preferably non-stretched layers (films). Such a non-stretched laminated film has particularly excellent moldability and is suitable for constructing a package, for example.
The type of package constructed using the laminated film can be arbitrarily selected depending on the purpose.

Hereinafter, the present invention will be described in detail with reference to the drawings. Note that in the drawings used in the following explanation, important parts may be shown enlarged for convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component are the same as in reality. Not necessarily.

FIG. 2 is a cross-sectional view schematically showing an example of the laminated film of this embodiment.
The laminated film 1 shown here has a first functional layer 111, a first adhesive layer 151, an oxygen barrier layer 12, a second adhesive layer 152, and a second functional layer 112 laminated in this order in the thickness direction, It is configured.
The first adhesive layer 151 and the second adhesive layer 152 have any configuration, and the laminated film 1 does not need to include these layers.

One surface 11b of the first functional layer 111 (the surface opposite to the first adhesive layer 151 side, sometimes referred to as "second surface" in this specification) is an exposed surface.
One surface 11a of the second functional layer 112 (the surface opposite to the second adhesive layer 152 side, sometimes referred to as the "first surface" in this specification) is an exposed surface.
In the laminated film 1, the first functional layer 111 functions as a sealant layer during manufacturing of the package.

FIG. 3 is a cross-sectional view schematically showing another example of the laminated film of this embodiment.
The laminated film 2 shown here includes an inner layer 13, a first functional layer 111, a first adhesive layer 151, an oxygen barrier layer 12, a second adhesive layer 152, a second functional layer 112, an outer layer 14, are laminated in this order in the thickness direction.
The inner layer 13, the first adhesive layer 151, the second adhesive layer 152, and the outer layer 14 have any configuration, and the laminated film 1 does not need to include these layers.

One surface 13b of the inner layer 13 (the surface opposite to the first functional layer 111 side, sometimes referred to as "second surface" in this specification) is an exposed surface.
One surface 14a of the outer layer 14 (the surface opposite to the second functional layer 112 side, sometimes referred to as the "first surface" in this specification) is an exposed surface.

Laminated film 2 is the same as laminated film 1 except that it further includes an inner layer as one outermost layer and an outer layer as the other outermost layer.
In the laminated film 2, the inner layer 13 functions as a sealant layer during manufacturing of the package.

A laminated film according to an embodiment of the present invention is a laminated film including a functional layer and an oxygen barrier layer, wherein the functional layer contains a propylene polymer and an ethylene polymer, and the functional layer includes the The melt flow rate of the ethylene polymer is 3 g/10 minutes or less, and in the functional layer, the content of the ethylene polymer is 10% by mass or more and 40% by mass with respect to the total mass of the functional layer. It is as follows.

<Functional layer>
The laminated film includes functional layers (a first functional layer 111 and a second functional layer 112 in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3). The functional layer provides the laminated film with excellent formability and impact resistance.

The functional layer contains a propylene polymer. The melting point of the propylene polymer contained in the functional layer is preferably 130°C or higher. Such a functional layer has high heat resistance.
As used herein, the term "propylene polymer" means a polymer (resin) having at least a structural unit derived from propylene, and a homopolypropylene (propylene homopolymer) having only a structural unit derived from propylene. , hPP), or a propylene-based copolymer having a structural unit derived from propylene and a structural unit derived from a monomer other than propylene.

Examples of the propylene-based copolymer contained in the functional layer include propylene-based random copolymers such as propylene-based random copolymers (also known as polypropylene random copolymers, rPP) and propylene-based block copolymers (also known as polypropylene block copolymers, bPP). Examples include copolymers.
Examples of the propylene block copolymer contained in the functional layer include propylene-ethylene block copolymer, propylene-1-butene block copolymer, propylene-ethylene-1-butene block copolymer, and propylene-1-butene block copolymer. Examples include hexene block copolymer, propylene-1-octene block copolymer, propylene-ethylene-1-hexene block copolymer, and the like.

The melting point of the propylene polymer contained in the functional layer is more preferably 140°C or higher, and may be either 145°C or higher or 150°C or higher. The higher the melting point of the propylene polymer, the more the heat resistance of the functional layer improves.
The upper limit of the melting point of the propylene polymer contained in the functional layer is not particularly limited. For example, the propylene polymer having a melting point of 170° C. or lower is easily available.

The functional layer preferably contains polypropylene (PP) as the propylene polymer, and preferably contains homopolypropylene or a propylene block copolymer.
When the functional layer contains homopolypropylene, it can be expected to improve heat resistance and transparency.
When the functional layer contains the propylene block copolymer, the tensile impact strength of the laminated film can be further improved.

The functional layer may contain only one type of propylene-based polymer, or may include two or more types, and in the case of two or more types, the combination and ratio thereof can be arbitrarily determined depending on the purpose. You can choose.

The functional layer preferably contains, as the propylene polymer, either one or both of homopolypropylene (propylene homopolymer, hPP) and a propylene copolymer, and has one of the above-mentioned melting points. It is more preferable to include one or both of homopolypropylene (propylene homopolymer, hPP) and a propylene copolymer having one of the melting points mentioned above. For example, homopolypropylene having a melting point of 130 to 170°C It may contain one or both of polypropylene (propylene homopolymer, hPP) and a propylene copolymer having a melting point of 130 to 170°C. The higher the melting point of the propylene polymer, the better the heat resistance of the functional layer.

The melt flow rate of the propylene polymer (herein, sometimes referred to as "MFR" not only in the case of propylene polymers) is 0.1 g/10 minutes or more and 2.0 g/10 minutes. It is preferably below, more preferably 0.2 g/10 minutes or more and 1.5 g/10 minutes or less, even more preferably 0.3 g/10 minutes or more and 1.0 g/10 minutes or less.
When the melt flow rate of the propylene polymer is equal to or higher than the lower limit value, film forming properties are improved and sheets can be easily produced. When the melt flow rate of the propylene polymer is equal to or lower than the above upper limit, the drawdown length of the laminated film can be further reduced, and as a result, the moldability of the laminated film can be further improved.

The melt flow rate of the propylene polymer can be adjusted by adjusting the melt tension, weight average molecular weight, etc. of the propylene polymer.
In this specification, unless otherwise specified, melt flow rate (also referred to as melt mass flow rate) refers to that measured in accordance with JIS K 7210-1:2014, not only in the case of propylene-based polymers. means.

The density of the propylene polymer is preferably 0.85 g/cm ³ or more and 0.95 g/cm ³ or less, more preferably 0.87 g/cm ³ or more and 0.92 g/cm ³ or less, and More preferably, it is .89 g/cm ³ or more and 0.91 g/cm ³ or less.

The functional layer further contains an ethylene polymer. A functional layer containing a propylene polymer and an ethylene polymer is suitable because it exhibits moldability and impact resistance.

As used herein, "ethylene polymer" means a polymer (resin) having at least a structural unit derived from ethylene, and a polyethylene (ethylene homopolymer) having only a structural unit derived from ethylene. ) or an ethylene copolymer having a structural unit derived from ethylene and a structural unit derived from a monomer other than ethylene and propylene.

Examples of the polyethylene included in the functional layer include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene catalyst linear low density polyethylene (mLLDPE), medium density polyethylene (MDPE), and high density polyethylene. (HDPE), etc.
Both linear low-density polyethylene (LLDPE) and metallocene-catalyzed linear low-density polyethylene (mLLDPE) are types of low-density polyethylene (LDPE).

In this specification, the density of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and metallocene-catalyzed linear low-density polyethylene (mLLDPE) is 0.910 g/cm ³ or more, 0.940 g/cm Less than ³ .
Further, the density of medium density polyethylene (MDPE) is 0.940 g/cm ³ or more and less than 0.950 g/cm ³ .
Further, the density of high-density polyethylene (HDPE) is 0.950 g/cm ³ or more.

Examples of the ethylene copolymer contained in the functional layer include ethylene-vinyl acetate copolymer (EVA), ethylene-methyl acrylate copolymer (EMA), ethylene-methyl methacrylate copolymer (EMMA), Ethylene-ethyl acrylate copolymer (EEA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-ethyl acrylate-maleic anhydride copolymer (E-EA) -MAH), ionomer resin (ION resin), etc.
The ionomer resin is, for example, a resin in which a copolymer of ethylene and a small amount of acrylic acid or methacrylic acid has an ionically cross-linked structure due to salt formation between the acid moiety and metal ions. can be mentioned.

The melting point of the ethylene polymer contained in the functional layer is preferably 100°C or higher, and may be, for example, 105°C or higher. When the melting point of the ethylene polymer is equal to or higher than the lower limit, the heat resistance of the functional layer is further improved.
The upper limit of the melting point of the ethylene polymer contained in the functional layer is not particularly limited. For example, the ethylene polymer having a melting point of 140° C. or lower is easily available.

The functional layer preferably contains polyethylene (PE) as the ethylene polymer, and more preferably contains low density polyethylene (LDPE).

The melt flow rate of the ethylene polymer is 3 g/10 minutes or less. The melt flow rate of the ethylene polymer is preferably 0.1 g/10 minutes or more and 2.5 g/10 minutes or less, more preferably 0.2 g/10 minutes or more and 1.5 g/10 minutes or less. Preferably, it is 0.3 g/10 minutes or more and 1.0 g/10 minutes or less, for example, 0.1 g/10 minutes or more and 3.0 g/10 minutes or less, 0.1 g/10 minutes or more and 1.0 g/10 minutes or more. /10 minutes or less, or 1.0 g/10 minutes or more and 3.0 g/10 minutes or less.
When the melt flow rate of the ethylene polymer is equal to or higher than the lower limit, the compatibility with the base polypropylene resin improves, and a clean sheet can be produced. When the melt flow rate of the ethylene polymer is equal to or lower than the upper limit value, the drawdown length of the laminated film can be reduced, and as a result, the moldability of the laminated film can be improved.

The melt flow rate of the ethylene polymer can be adjusted by adjusting the melt tension, weight average molecular weight, etc. of the ethylene polymer.

The density of the ethylene polymer is preferably 0.89 g/cm ³ or more and 0.97 g/cm ³ or less, more preferably 0.90 g/cm ³ or more and 0.95 g/cm ³ or less, and 0. More preferably, it is .91 g/cm ³ or more and 0.93 g/cm ³ or less.

The functional layer may contain only the propylene polymer and the ethylene polymer (that is, it may consist of the propylene polymer and the ethylene polymer), or it may contain only the propylene polymer and the ethylene polymer. The propylene polymer and the ethylene polymer may contain components other than these (herein sometimes referred to as "other components"). (It may also consist of a combination of the above-mentioned other components.)

The other components contained in the functional layer are not particularly limited and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component, which is a resin component, is a resin that does not fall under either the propylene polymer or the ethylene polymer.
The other component, which is a resin component, may be a homopolymer that is a polymer of one type of monomer, or a copolymer that is a polymer of two or more types of monomers.

Examples of the other non-resin components include additives known in the art.
Examples of the additives include pigments, antifogging agents, antiblocking agents, antioxidants, antistatic agents, crystal nucleating agents, inorganic particles, thinners, thickeners, thermal stabilizers, lubricants, and infrared absorbers. agents, ultraviolet absorbers, etc.

The functional layer may contain only one type of other components, or may include two or more types, and in the case of two or more types, the combination and ratio thereof may be arbitrarily selected depending on the purpose. can.

In the functional layer, the ratio of the total content (parts by mass) of the propylene polymer and the ethylene polymer to the total mass (parts by mass) of the functional layer (([of the propylene polymer in the functional layer] content (parts by mass)] + [content of ethylene polymer in the functional layer (parts by mass)])/[total mass of the functional layer (parts by mass)] x 100) should be 80% by mass or more. It is preferably 90% by mass or more, more preferably 95% by mass or more, and may be, for example, 85% by mass or more, 90% by mass or more, or 95% by mass or more. When the ratio is at least the lower limit, the moldability and impact resistance of the functional layer are further improved.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the total content (parts by mass) of the propylene-based polymer and the ethylene-based polymer with respect to the total content (parts by mass) of components that do not vaporize at room temperature in the functional layer forming composition described below. (parts by mass) (([Content of propylene polymer in functional layer forming composition (parts by mass)] + [Content of ethylene polymer in functional layer forming composition (parts by mass)])/ [Total content (parts by mass) of components that do not vaporize at room temperature of the composition for forming a functional layer] x 100).

As used herein, "normal temperature" means a temperature that is not particularly cooled or heated, that is, a normal temperature, and includes, for example, a temperature of 15 to 25°C.

In the functional layer, a content ratio of the ethylene polymer to the total mass of the functional layer is 10% by mass or more and 40% by mass or less. The proportion is preferably 15% by mass or more and 40% by mass or less, more preferably 17.5% by mass or more and 40% by mass or less, even more preferably 20% by mass or more and 40% by mass or less, For example, it may be 10% by mass or more and 30% by mass or less, 10% by mass or more and 25% by mass or less, and 10% by mass or more and 20% by mass or less.

As for the functional layer, for example, the ratio of the content of the propylene-based polymer to the total mass of the functional layer ([content of propylene-based polymer in the functional layer (parts by mass)]/[the content of the propylene-based polymer in the functional layer (parts by mass)] Total mass (parts by mass)]×100) is 60 to 90% by mass, and the ratio of the content of the ethylene polymer in the functional layer to the total mass of the functional layer ([Ethylene polymer in the functional layer The content (parts by mass)])/[total mass of the functional layer (parts by mass)]×100) is 10 to 40% by mass.
Among these, a preferable functional layer containing the propylene polymer and the ethylene polymer has a content ratio of the propylene polymer of 60 to 80% by mass relative to the total mass of the functional layer. and a functional layer in which the content of the ethylene polymer is 20 to 40% by mass with respect to the total mass of the functional layer. A functional layer that satisfies these conditions is superior in terms of moldability and impact resistance.
In addition, as a preferable functional layer containing the propylene-based polymer and the ethylene-based polymer, the ratio of the content of the propylene-based polymer to the total mass of the functional layer in the functional layer is 70 to 90% by mass. %, and the content of the ethylene polymer in the functional layer is 10 to 30% by mass relative to the total mass of the functional layer. A functional layer that satisfies these conditions is superior in terms of moldability and impact resistance.

The functional layer may be composed of one layer (single layer) or may be composed of two or more layers. When the functional layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.
Among these, it is preferable that the functional layer consists of one layer.

In this specification, not only functional layers but also single layers of the same type are arranged apart from each other in a laminated film without being directly laminated. It is not considered that the film is composed of layers (multiple layers), but rather that the layers composed of one layer are arranged at different positions in the laminated film.
Similarly, a layer consisting of two layers and a layer consisting of one layer are both of the same type, and a layer consisting of two layers and a layer consisting of one layer are separated from each other without being directly laminated in the laminated film. If the layers are arranged in such a way that they are not considered to consist of three layers, but the layer consisting of two layers and the layer consisting of one layer are disposed at different positions in the laminated film. It is assumed that there is.
The same applies to other combinations of the number of layers.

In this specification, not only in the case of functional layers, "the plurality of layers may be the same or different from each other" means "all the layers may be the same or all the layers may be different". ``Multiple layers may be the same, or only some of the layers may be the same,'' and ``the layers are different from each other'' means ``at least one of the constituent materials and thicknesses of each layer is different from each other.'' means.

The thickness of the functional layer is preferably 100 μm or more and 1000 μm or less, more preferably 125 μm or more and 950 μm or less, and even more preferably 150 μm or more and 900 μm or less. When the thickness of the functional layer is equal to or greater than the lower limit, the moldability and impact resistance of the laminated film can be further improved. When the thickness of the functional layer is equal to or less than the upper limit value, excessive thickness of the functional layer is further suppressed.
Here, "thickness of a functional layer" means the thickness of the entire functional layer. For example, the thickness of a functional layer consisting of multiple layers refers to the total thickness of all the layers that make up the functional layer. means.

The ratio of the thickness of the functional layer to the thickness of the laminated film is preferably 20% or more and 97% or less, more preferably 25% or more and 96% or less, and 30% or more and 95% or less. is even more preferable. When the ratio is greater than or equal to the lower limit, the moldability and impact resistance of the laminated film can be further improved. When the ratio is equal to or less than the upper limit value, excessive thickness of the functional layer is further suppressed.

<Oxygen barrier layer>
The laminated film according to this embodiment includes an oxygen barrier layer. The oxygen barrier layer (oxygen barrier layer 12 in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3) has strong oxygen barrier properties (in other words, the property of suppressing permeation of oxygen gas) in the laminated film. Give.

The oxygen barrier layer preferably contains ethylene-vinyl alcohol copolymer (EVOH, also known as saponified ethylene-vinyl acetate copolymer). When the oxygen barrier layer contains EVOH, the oxygen barrier properties of the laminated film can be further improved.

The oxygen barrier layer may contain polyvinylidene chloride (PVDC) in addition to EVOH (EVOH and PVDC are sometimes referred to as "oxygen barrier property-imparting resin" in this specification). By containing the oxygen barrier property-imparting resin in the oxygen barrier layer, the oxygen barrier property of the laminated film can be further improved.

The oxygen barrier layer may contain only the oxygen barrier property-imparting resin (that is, it may consist of the oxygen barrier property-imparting resin), or may contain the oxygen barrier property-imparting resin and other components (in this specification). (In other words, it may be composed of the oxygen barrier property-imparting resin and the other components).

The other components contained in the oxygen barrier layer are not particularly limited, and can be arbitrarily selected depending on the purpose, and may be, for example, either a resin component or a non-resin component.
The other component which is a resin component is a resin other than the oxygen barrier property imparting resin.
Examples of the other non-resin components include the same additives as mentioned above as other components included in the functional layer.

The oxygen barrier layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose. can.

In the oxygen barrier layer, the content ratio of the oxygen barrier property-imparting resin to the total mass of the oxygen barrier layer is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, and 70 to 100% by mass. It is more preferably 100% by mass, and may be, for example, 85 to 100% by mass. When the ratio is greater than or equal to the lower limit, the oxygen barrier properties of the laminated film become higher.
The above ratio is usually the same as the ratio of the content (parts by mass) of the oxygen barrier property-imparting resin to the total content (parts by mass) of components that do not vaporize at room temperature in the oxygen barrier layer forming composition described below. be.

In the oxygen barrier layer, the content of EVOH is preferably 85 to 100% by mass, more preferably 90 to 100% by mass, and 95 to 100% by mass with respect to the content of the oxygen barrier property-imparting resin. % is more preferable. When the ratio is greater than or equal to the lower limit, the oxygen barrier properties of the laminated film become higher.

The oxygen barrier layer may be composed of one layer (single layer) or may be composed of two or more layers. When the oxygen barrier layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the oxygen barrier layer is preferably 3 μm or more and 300 μm or less, more preferably 6 μm or more and 225 μm or less, even more preferably 9 μm or more and 150 μm or less, for example, 9 to 100 μm, 9 to 50 μm, and 9 to 25 μm. When the thickness of the oxygen barrier layer is equal to or greater than the lower limit value, layer breakage of the oxygen barrier layer can be further suppressed, and the oxygen barrier properties of the laminated film can be further improved. In addition, in this specification, "layer breakage of the oxygen barrier layer" means that a part of the oxygen barrier layer is not formed in the laminated film, and this is caused, for example, by the thickness of the oxygen barrier layer being too thin. arise.
When the thickness of the oxygen barrier layer is less than or equal to the upper limit value, the oxygen barrier layer is further prevented from becoming excessively thick.
Here, the "thickness of the oxygen barrier layer" means the thickness of the entire oxygen barrier layer. For example, the thickness of an oxygen barrier layer consisting of multiple layers is the total thickness of all the layers that make up the oxygen barrier layer. means the thickness of

The ratio of the thickness of the oxygen barrier layer to the thickness of the laminated film is preferably 1% or more and 20% or less, more preferably 2% or more and 15% or less, and 3% or more and 10% or less. It is even more preferable. When the ratio is equal to or higher than the lower limit, layer breakage of the oxygen barrier layer can be further suppressed, and the oxygen barrier properties of the laminated film can be further improved. When the ratio is equal to or less than the upper limit value, the oxygen barrier layer is prevented from becoming excessively thick.

The laminated film may include two or more of the functional layers, and the oxygen barrier layer may be provided between a pair of the functional layers. By providing the oxygen barrier layer between the pair of functional layers, it is possible to suppress the permeation of water vapor from the outside and sufficiently exhibit oxygen barrier performance. Additionally, sealing properties can be imparted.

<Inner layer>
The laminated film may include an inner layer (inner layer 13 in the laminated film 2 shown in FIG. 3). The inner layer provides moldability, impact resistance, and sealability to the laminated film.
The inner layer is one of the outermost layers of the laminated film, and is disposed at the outermost one in the lamination direction of each layer constituting the laminated film.

The inner layer may contain a propylene polymer.
Examples of the propylene-based polymer contained in the inner layer include the same propylene-based polymer contained in the functional layer described above.
The propylene polymer contained in the inner layer and the propylene polymer contained in the functional layer may be the same or different from each other.

The inner layer may further contain an ethylene polymer.
The ethylene polymer contained in the inner layer may be the same as the ethylene polymer contained in the functional layer described above.
The ethylene polymer contained in the inner layer and the ethylene polymer contained in the functional layer may be the same or different from each other.

The inner layer may contain only the propylene polymer, or the propylene polymer and the ethylene polymer (i.e., the propylene polymer, or the propylene polymer and the ethylene polymer). The propylene polymer, or the propylene polymer and ethylene polymer, and components other than these (herein referred to as "other components") (i.e., consisting of the propylene polymer and the other component, or the propylene polymer, the ethylene polymer, and the other component) ).

Examples of the other components contained in the inner layer include the same components as those contained in the functional layer described above.

Ratio of the total content (parts by mass) of the propylene polymer and the ethylene polymer to the total mass (parts by mass) of the inner layer in the inner layer (([Content of propylene polymer in the inner layer ( Parts by mass)]+[Content of ethylene polymer in inner layer (parts by mass)])/[Total mass of inner layer (parts by mass)]×100) is preferably 80% by mass or more, and 90% by mass. It is more preferably at least 95% by mass, even more preferably at least 95% by mass, and may be, for example, at least 90% by mass, at least 92.5% by mass, or at least 95% by mass. When the ratio is greater than or equal to the lower limit, the moldability, impact resistance, and sealing properties of the inner layer are further improved.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the total content (by mass) of the propylene polymer and the ethylene polymer relative to the total content (parts by mass) of components that do not vaporize at room temperature in the inner layer forming composition described below. (parts) (([Content of propylene polymer in inner layer forming composition (parts by mass)] + [Content of ethylene polymer in inner layer forming composition (parts by mass)]) / [Inner layer forming composition The total content (parts by mass) of components that do not vaporize at room temperature of the composition for use] x 100).

When the inner layer includes the ethylene polymer, it is preferable that the content of the ethylene polymer in the inner layer is 10% by mass or more and 40% by mass or less with respect to the total mass of the inner layer, It is more preferably 15% by mass or more and 40% by mass or less, even more preferably 20% by mass or more and 40% by mass or less, for example, 10% by mass or more and 30% by mass or less, 10% by mass or more and 25% by mass or less, And it may be 10% by mass or more and 20% by mass or less.

For the inner layer, for example, the ratio of the content of the propylene polymer to the total mass of the inner layer ([content of propylene polymer in the inner layer (parts by mass)]/[total mass of the inner layer (parts by mass)] )]×100) is 60 to 90% by mass, and the ratio of the content of the ethylene polymer in the inner layer to the total mass of the inner layer ([Content of ethylene polymer in the inner layer (parts by mass)] )/[Total mass of inner layer (parts by mass)]×100) is 10 to 40% by mass.
Among these, a preferable inner layer containing the propylene polymer and the ethylene polymer is such that the content of the propylene polymer in the inner layer is 60 to 80% by mass relative to the total mass of the inner layer; Examples include an inner layer in which the content of the ethylene polymer is 20 to 40% by mass relative to the total mass of the inner layer. An inner layer that satisfies these conditions is superior in its moldability, impact resistance, and sealability.
In addition, a preferable inner layer containing the propylene-based polymer and ethylene-based polymer has a content ratio of the propylene-based polymer in the inner layer of 70 to 100% by mass relative to the total mass of the inner layer. , an inner layer in which the content of the ethylene polymer is 0 to 30% by mass relative to the total mass of the inner layer. An inner layer that satisfies these conditions is superior in its moldability, impact resistance, and sealability.

When the inner layer does not contain the ethylene polymer, the content of the propylene polymer in the inner layer relative to the total mass of the inner layer is preferably 90% by mass or more and 100% by mass or less. , more preferably 95% by mass or more and 100% by mass or less, and still more preferably 97.5% by mass or more and 100% by mass or less.

The inner layer may be composed of one layer (single layer) or may be composed of two or more layers. When the inner layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.
Among these, it is preferable that the inner layer consists of one layer.

The thickness of the inner layer is preferably 15 μm or more and 750 μm or less, more preferably 18 μm or more and 735 μm or less, and even more preferably 21 μm or more and 720 μm or less. When the thickness of the inner layer is equal to or greater than the lower limit, the moldability, impact resistance, and sealing properties of the inner layer can be further improved. When the thickness of the inner layer is less than or equal to the upper limit value, excessive thickness of the inner layer is further suppressed.
Here, the "thickness of the inner layer" means the thickness of the entire inner layer, and for example, the thickness of the inner layer consisting of multiple layers means the total thickness of all the layers constituting the inner layer.

The ratio of the thickness of the inner layer to the thickness of the laminated film is preferably 5% or more and 50% or less, more preferably 6% or more and 49% or less, and preferably 7% or more and 48% or less. More preferred. When the ratio is at least the lower limit, the moldability, impact resistance, and sealing properties of the inner layer can be further improved. When the ratio is equal to or less than the upper limit value, excessive thickness of the inner layer is further suppressed.

The laminated film according to the present embodiment further includes an inner layer as one of the outermost layers, the inner layer contains a propylene polymer and an ethylene polymer, and the inner layer has a melt flow of the ethylene polymer. The rate may be 3 g/10 minutes or less, and in the inner layer, the content of the ethylene polymer may be 10% by mass or more and 40% by mass or less with respect to the total mass of the inner layer.

<Outer layer>
The laminated film may include an outer layer (outer layer 14 in the laminated film 2 shown in FIG. 3). The outer layer provides stiffness and heat resistance and improves sheet appearance. Further, the outer layer is a layer for protecting layers other than the outer layer that constitute the laminated film.
The outer layer is the other outermost layer of the laminated film, and is disposed at the other outermost layer in the lamination direction of each layer constituting the laminated film.

The outer layer may contain a propylene polymer.
Examples of the propylene-based polymer contained in the outer layer include the same propylene-based polymers as the propylene-based polymer contained in the functional layer described above.
The propylene polymer contained in the outer layer and the propylene polymer contained in the functional layer may be the same or different from each other.

The outer layer may further contain an ethylene polymer.
The ethylene polymer contained in the outer layer may be the same as the ethylene polymer contained in the functional layer described above.
The ethylene polymer contained in the outer layer and the ethylene polymer contained in the functional layer may be the same or different.

The outer layer may contain only the propylene polymer, or only the propylene polymer and the ethylene polymer (i.e., the propylene polymer, or the propylene polymer and the ethylene polymer). The propylene polymer, or the propylene polymer and ethylene polymer, and components other than these (herein referred to as "other components") (i.e., consisting of the propylene polymer and the other component, or the propylene polymer, the ethylene polymer, and the other component) ).

Examples of the other components contained in the outer layer include the same components as those contained in the functional layer described above.

Ratio of the total content (parts by mass) of the propylene polymer and the ethylene polymer to the total mass (parts by mass) of the outer layer in the outer layer (([Content of propylene polymer in the outer layer ( Parts by mass)]+[Content of ethylene polymer in outer layer (parts by mass)])/[Total mass of outer layer (parts by mass)]×100) is preferably 80% by mass or more, and 90% by mass. It is more preferably at least 95% by mass, even more preferably at least 95% by mass, and may be, for example, at least 90% by mass, at least 92.5% by mass, or at least 95% by mass. When the ratio is at least the lower limit, the sheet appearance, rigidity, and heat resistance of the outer layer can be further improved.
On the other hand, the ratio is 100% by mass or less.
The ratio is usually the total content (by mass) of the propylene polymer and the ethylene polymer relative to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an outer layer, which will be described later. (parts) (([Content of propylene polymer in outer layer forming composition (parts by mass)] + [Content of ethylene polymer in outer layer forming composition (parts by mass)])/[Outer layer forming composition The total content (parts by mass) of components that do not vaporize at room temperature of the composition for use] x 100).

When the outer layer includes the ethylene polymer, the content of the ethylene polymer in the outer layer relative to the total mass of the outer layer is preferably 10% by mass or more and 40% by mass or less. The proportion is more preferably 15% by mass or more and 40% by mass or less, even more preferably 20% by mass or more and 40% by mass or less, for example, 10% by mass or more and 30% by mass or less, 10% by mass or more and 25% by mass or less. It may be either 10% by mass or more and 20% by mass or less.

As for the outer layer, for example, the ratio of the content of the propylene polymer to the total mass of the outer layer ([content of propylene polymer in the outer layer (parts by mass)]/[total mass of the outer layer (parts by mass)] )]×100) is 60 to 90% by mass, and the ratio of the content of the ethylene polymer in the outer layer to the total mass of the outer layer ([Content of ethylene polymer in the outer layer (parts by mass)] )/[Total mass of outer layer (parts by mass)]×100) is 10 to 40% by mass.
Among these, a preferable outer layer containing the propylene polymer and the ethylene polymer has a content ratio of the propylene polymer in the outer layer of 60 to 80% by mass relative to the total mass of the outer layer, Examples include an outer layer in which the content of the ethylene polymer is 20 to 40% by mass relative to the total mass of the outer layer. An outer layer that satisfies these conditions is superior in terms of sheet appearance, rigidity, and heat resistance.
In addition, as a preferable outer layer containing the propylene polymer and the ethylene polymer, the content of the propylene polymer in the outer layer is 70 to 100% by mass relative to the total mass of the outer layer. Examples include a functional layer in which the content of the ethylene polymer is 0 to 30% by mass relative to the total mass of the functional layer. A functional layer that satisfies these conditions is superior in terms of its rigidity and heat resistance.

When the outer layer does not contain the ethylene polymer, the proportion of the propylene polymer in the outer layer relative to the total mass of the outer layer is preferably 90% by mass or more and 100% by mass or less. , more preferably 95% by mass or more and 100% by mass or less, and still more preferably 97.5% by mass or more and 100% by mass or less.

The outer layer may consist of one layer (single layer) or may consist of two or more layers. When the outer layer is composed of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.
Among these, the outer layer preferably consists of one layer.

The thickness of the outer layer is preferably 15 μm or more and 750 μm or less, more preferably 18 μm or more and 735 μm or less, and even more preferably 21 μm or more and 720 μm or less. When the thickness of the outer layer is equal to or greater than the lower limit, the sheet appearance, rigidity, and heat resistance of the outer layer can be further improved. When the thickness of the outer layer is equal to or less than the upper limit value, it is further suppressed that the outer layer becomes excessively thick.
Here, the "thickness of the outer layer" means the thickness of the entire outer layer, and for example, the thickness of the outer layer consisting of multiple layers means the total thickness of all the layers constituting the outer layer.

The ratio of the thickness of the outer layer to the thickness of the laminated film is preferably 5% or more and 50% or less, more preferably 6% or more and 49% or less, and preferably 7% or more and 48% or less. More preferred. When the ratio is at least the lower limit, the sheet appearance, rigidity, and heat resistance of the outer layer can be further improved. When the ratio is equal to or less than the upper limit value, excessive thickness of the outer layer is further suppressed.

The ratio of the total thickness of the functional layer, the inner layer, and the outer layer to the thickness of the laminated film is preferably 85% or more. The ratio is more preferably 86% or more and 99% or less, and even more preferably 87% or more and 98% or less.

The laminated film according to the present embodiment further includes an outer layer as the other outermost layer, the outer layer containing a propylene polymer and an ethylene polymer, and the melt flow of the ethylene polymer in the outer layer. The rate may be 3 g/10 minutes or less, and in the outer layer, the content of the ethylene polymer may be 10% by mass or more and 40% by mass or less with respect to the total mass of the outer layer.

<Adhesive layer>
The laminated film of this embodiment may include an adhesive layer that does not correspond to any of the functional layer, oxygen barrier layer, inner layer, and outer layer.
The adhesive layer is a layer for adhering two adjacent layers in a laminated film, and contains a component that exhibits adhesive properties.

The position of the adhesive layer in the laminated film is not particularly limited as long as it is not the outermost layer of the laminated film.
The adhesive layer may be placed at one location or at two or more locations in the laminated film. When the adhesive layers are arranged at two or more locations in the laminated film, the adhesive layers at these two or more locations may be the same or different from each other. Here, "the adhesive layers at two or more places may be the same or different from each other" means "all the adhesive layers may be the same, all the adhesive layers may be different, or the same "Only the adhesive layers of the adhesive layers may be the same" and "the adhesive layers are different from each other" means "at least one of the constituent materials and thicknesses of the adhesive layers are different from each other".

For example, the laminated film may include an adhesive layer (first adhesive layer 151 in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3) between the oxygen barrier layer and the first functional layer. Alternatively, an adhesive layer ("second adhesive layer 152" in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3) may be provided between the oxygen barrier layer and the second functional layer. .

It is preferable that the adhesive layer has transparency.
The adhesive layer has an arbitrary structure, and the laminated film does not need to have an adhesive layer, but the structure becomes more stable by including the adhesive layer.

The adhesive layer is preferably a resin layer containing an adhesive resin.

Examples of the adhesive resin include polyolefin resins.
The polyolefin resin is a resin having a structural unit derived from an olefin, and may be, for example, a modified polyolefin such as an acid-modified polyolefin having an acidic group.
Examples of polyolefin resins include ethylene copolymers, propylene copolymers, butene copolymers, modified products of these copolymers (in other words, modified copolymers), acid-modified polyethylene, acid-modified polypropylene, etc. can be mentioned.
The polyolefin resin may be a random copolymer, a graft copolymer, or a block copolymer in terms of improved adhesiveness.

Examples of the ethylene copolymer contained in the adhesive layer include the ethylene copolymer described above as being contained in the functional layer, modified products thereof (modified copolymers), and the like.
Examples of the propylene copolymer contained in the adhesive layer include copolymers of propylene and vinyl group-containing monomers, modified products thereof (modified copolymers), etc. Also included are the propylene copolymers described in . More specific examples of such propylene-based copolymers include maleic anhydride graft-modified linear low-density polypropylene, propylene-based thermoplastic elastomers, and the like.
Examples of the butene-based copolymers contained in the adhesive layer include copolymers of 1-butene and vinyl group-containing monomers, copolymers of 2-butene and vinyl group-containing monomers, and modified products of these copolymers. (modified copolymer), etc.

The adhesive layer may contain only one type of component that exhibits adhesiveness (for example, the adhesive resin), or may include two or more types, and if there are two or more types, a combination thereof. and the ratio can be arbitrarily selected depending on the purpose.

The adhesive layer may contain other components in addition to the component that exhibits adhesiveness (for example, the adhesive resin) within a range that does not impair its adhesiveness.
Examples of the other components contained in the adhesive layer include antioxidants and the like.

The adhesive layer may contain only one type of other components, or may include two or more types, and when there are two or more types, the combination and ratio thereof can be arbitrarily selected depending on the purpose. can.

In the adhesive layer, the ratio of the content of the component that exhibits adhesiveness to the total mass of the adhesive layer ([Content of the component that exhibits adhesiveness in the adhesive layer (parts by mass)]/[Total mass of the adhesive layer (mass)] [parts)]×100) is preferably 80% by mass or more, more preferably 90% by mass or more. When the ratio is equal to or higher than the lower limit, the adhesiveness of the adhesive layer becomes higher.
On the other hand, the ratio is 100% by mass or less.
The above ratio is usually the ratio of the content (parts by mass) of components that exhibit adhesiveness to the total content (parts by mass) of components that do not vaporize at room temperature in the composition for forming an adhesive layer (described later). The content of components that exhibit adhesiveness in the forming composition (parts by mass)]/[Total content of components that do not vaporize at room temperature in the composition for forming an adhesive layer (parts by mass)] x 100) be.

The adhesive layer per location may be composed of one layer (single layer) or may be composed of two or more layers. When the adhesive layer consists of multiple layers, these multiple layers may be the same or different from each other, and the combination of these multiple layers is not particularly limited as long as the effects of the present invention are not impaired.

The thickness of the adhesive layer per point is not particularly limited, but is preferably 3 μm or more and 150 μm or less, more preferably 4.5 μm or more and 135 μm or less, and even more preferably 6 μm or more and 120 μm or less. When the thickness of the adhesive layer is greater than or equal to the lower limit, the adhesive layer has better adhesive properties. By setting the thickness of the adhesive layer to be less than or equal to the upper limit value, it is possible to prevent the adhesive layer from becoming excessively thick. In addition, as the thickness of the adhesive layer becomes thinner, the transparency of the package (for example, the bottom material, which will be described later) improves. Visual recognition becomes easier.
Here, the "thickness of the adhesive layer" means the thickness of the entire adhesive layer. For example, the thickness of an adhesive layer consisting of multiple layers refers to the total thickness of all the layers that make up the adhesive layer. means.

The ratio of the thickness of the adhesive layer to the thickness of the laminated film is preferably 1% or more and 10% or less, more preferably 1.5% or more and 9% or less, and 2% or more and 8% or less. It is even more preferable that there be. When the ratio is equal to or greater than the lower limit, the adhesiveness of the adhesive layer can be further improved. When the ratio is equal to or less than the upper limit value, excessive thickness of the adhesive layer is further suppressed.

<Other layers>
The laminated film may include other layers that do not fall under any of the functional layer, oxygen barrier layer, inner layer, outer layer, and adhesive layer, as long as the effects of the present invention are not impaired. However, it is preferable that the other layer is not provided.
The other layer is a layer that does not contain a polyolefin resin, and by not including such another layer, the reusability of the laminated film becomes higher.

<<Manufacturing method of laminated film>>
The laminated film can be produced using, for example, a feed block method in which a resin or resin composition, etc. that is a forming material for each layer is melt-extruded using several extruders, a coextrusion T-die method such as a multi-manifold method, or an air-cooling method. Alternatively, it can be manufactured by a water-cooled coextrusion inflation method or the like.

When using the resin composition, for example, a blend of two or more components (dry blend, non-kneaded product) may be directly input into an extruder as a resin composition, or a blend of two or more components A pre-kneaded product obtained by kneading the components in advance may be fed into an extruder as a resin composition.
The pre-kneaded product can be obtained, for example, by melt-kneading two or more components using a device such as a twin-screw extruder or a Banbury mixer.

In addition, the laminated film can be obtained by separately preparing two or more films to constitute two or more of the layers, and then pasting them together by a thermal lamination method or the like without using an adhesive. It can also be manufactured by laminating layers and, if necessary, further layering layers other than these to form the desired arrangement.

The resin composition, which is a forming material for any layer in the laminated film, has the type and content of the components adjusted so that the layer to be formed contains the desired components in the desired amounts. You just have to manufacture it. For example, the content ratio of components that do not vaporize at room temperature in the resin composition is usually the same as the content ratio of the components in a layer formed from this resin composition.

A resin composition (main material) for forming the first functional layer and the second functional layer (the first functional layer 111 and the second functional layer 112 in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3). In the specification, examples of the composition (sometimes referred to as a "composition for forming a functional layer") include those containing the polyolefin resin and, if necessary, other components. The other components are the components described above.

A resin composition for forming an oxygen barrier layer (oxygen barrier layer 12 in the laminated film 1 shown in FIG. 2 and the laminated film 2 shown in FIG. 3) (herein referred to as "composition for forming an oxygen barrier layer"). Examples of the resin composition include an oxygen barrier property-imparting resin and, if necessary, the other components described above.

Examples of the resin composition (herein sometimes referred to as "inner layer forming composition") for forming the inner layer (inner layer 13 in the laminated film 2 shown in FIG. 3) include the polyolefins mentioned above. Examples include those containing a resin and, if necessary, other components. The other components are the components described above.

Examples of the resin composition (herein sometimes referred to as "outer layer forming composition") for forming the outer layer (the outer layer 14 in the laminated film 2 shown in FIG. 3) include the polyolefins mentioned above. Examples include those containing a resin and, if necessary, other components. The other components are the components described above.

A resin composition (herein referred to as "adhesive") for forming an adhesive layer (the first adhesive layer 151 or the second adhesive layer 152 in the laminated film 1 shown in FIG. Examples of the layer-forming composition (sometimes referred to as "layer-forming composition") include resin compositions containing the above-mentioned component that exhibits adhesiveness and, if necessary, the other components.

＜＜Package＞＞
The laminated film is suitable as a material for a package.
That is, as a preferable package, one constructed using the above-mentioned laminated film can be mentioned.
The package of this embodiment can be manufactured by packaging an object using the laminated film. When manufacturing a package, in the laminated film shown in FIG. 2, the first functional layer in the laminated film is placed on the side of the object to be packaged, and the second functional layer is placed on the side opposite to the side of the object to be packaged. It is preferable to package the object to be packaged, and in the laminated film shown in FIG. Preferably, the object to be packaged is packaged.

For example, the laminated film is suitable for forming the bottom material of a package. In particular, the laminated film with good moldability is suitable for forming a bottom material having a recessed portion for forming a storage section.

FIG. 4 is a cross-sectional view schematically showing an example of a package including the laminated film of this embodiment.
The package 101 shown here includes a lid material 8 (cover film) and a bottom material 10 (formed film). The bottom material 10 is constructed using the laminated film 1 shown in FIG. 2 or the laminated film 2 shown in FIG. 3.
In the bottom material 10 in FIG. 4, the distinction between each layer in the laminated film 1 or the laminated film 2 constituting the bottom material 10 is omitted.

A recess 100 is formed in the bottom material 10.
One surface 10b of the area of the bottom material 10 excluding the recess 100 (in this specification, sometimes referred to as the "second surface"), and one surface of the lid material 8 (in this specification, referred to as the "second surface"). The two surfaces 8b (sometimes referred to as "two surfaces") are sealing surfaces and are opposed to each other.
The package 101 is made up of a lid 8 and a bottom 10 sealed together. More specifically, the second surface 10b of the bottom material 10 in the region excluding the recess 100 and the second surface 8b of the lid material 8 are overlapped and sealed to each other in regions near their peripheral edges. As a result, in the area of the recess 100 of the bottom material 10, a storage portion 101a is formed between the second surface 10b of the bottom material 10 and the second surface 8b of the lid material 8. A stored object 9 is stored in this storage section 101a.

When the bottom material 10 is configured using the laminated film 1 shown in FIG. It is preferably the same as 11b. The other surface 10a of the bottom material 10 (herein sometimes referred to as "first surface") is preferably the same as the first surface 11a of the second functional layer 11 in the laminated film 1. .
When the bottom material 10 is configured using the laminated film 2 shown in FIG. It is preferable that The other surface 10a of the bottom material 10 (herein sometimes referred to as the "first surface") is preferably the same as the first surface 14a of the outer layer 14 in the laminated film 2.

Examples of the lid material 8 include a lid material containing an aluminum layer, a lid material containing a polyolefin layer such as polyethylene or polypropylene, and the like.

In FIG. 4, some gaps can be seen between the stored item 9 and the bottom material 10 and between the stored item 9 and the lid material 8 in the storage section 101a of the package 101. The presence of a gap is not essential in the package 101 in which the stored item 9 is stored.

The thickness of the bottom material 10 at its flat portion may be similar to the thickness of the laminated film 1 or the laminated film 2 described above.

<<Method for manufacturing the package>>
The package forms a storage section for storing the object to be packaged (in other words, a stored object) by, for example, the laminated films or the laminated film and another resin film other than the laminated film. It can be manufactured by storing the objects to be packaged while heating and sealing the area of the film other than the storage part.

Hereinafter, the present invention will be explained in more detail with reference to specific examples. However, the present invention is not limited to the examples shown below.

<<Evaluation of single layer film>>
<Manufacture of single layer film>
A single layer film was manufactured by the procedure shown below.
That is, the resins shown in Table 1 were prepared as resins constituting the single layer.

Monolayer films 1 and 6 (thickness: 400 μm) were obtained by extruding the homopolypropylene. All of these single layers are non-stretched layers.

A resin composition was prepared by mixing the homopolypropylene and the low density polyethylene in the proportions shown in Table 2. Single layer films 2 to 5 and 7 to 10 (thickness: 400 μm) were obtained by extruding these resin compositions. All of these single layers are non-stretched layers.

<Measurement of drawdown length of single layer film>
A test piece with a length of 300 mm and a width of 160 mm was cut out from the single-layer film obtained above, and a heater was installed on top of the test piece. The distance from the test piece to the heater is 100 mm.
Next, the heater was set at 500°C, the test piece was heated at 400°C for 120 seconds, and the drawdown length of the test piece was measured using the method described above. The results are shown in Table 2.

As is clear from the above results, when the amount of low-density polyethylene added was 30% by mass (single-layer films 5 and 10), and when the amount of low-density polyethylene added was 15% by mass (single-layer films 2 to 10), It was confirmed that the drawdown length was reduced compared to 4 and 7 to 9).
Furthermore, it was confirmed that the drawdown length was most reduced when hPP1 was used as the homopolypropylene and LDPE1 was used as the low density polypropylene.

Based on the above results, in the following examples, hPP1 was used as the homopolypropylene, LDPE1 was used as the low density polypropylene, and the amount of LDPE1 added was increased to more than 15% by mass.

[Example 1]
<<Manufacture of laminated film>>
A laminated film having the configuration shown in FIG. 2 was manufactured by the procedure shown below.
That is, the hPP1 and the LDPE1 were prepared as resins constituting the first functional layer and the second functional layer.
Modified polypropylene (modified PP) ("ADMER (registered trademark) QF551" (product number) manufactured by Mitsui Chemicals, Inc.) was prepared as a resin constituting the first adhesive layer and the second adhesive layer.
As a resin constituting the oxygen barrier layer, an ethylene-vinyl alcohol copolymer (EVOH) ("EVAL (registered trademark) F101A" (product number) manufactured by Kuraray Co., Ltd., ethylene copolymerization ratio of 32 mol %) was prepared.

A resin composition (1) was prepared by mixing the hPP1 (80% by mass) and the LDPE1 (20% by mass).

By coextruding the resin composition (1), the modified PP, the EVOH, the modified PP, and the resin composition (1) in this order, a first functional layer (thickness: 364 μm ), a first adhesive layer (thickness: 20 μm), an oxygen barrier layer (thickness: 32 μm), a second adhesive layer (thickness: 20 μm), and a second functional layer (thickness: 364 μm), in this order: A laminated film (thickness: 800 μm) was obtained by laminating these in the thickness direction.
The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all non-stretched layers.

<<Evaluation of laminated film>>
<Measurement of tensile impact strength of laminated film>
The tensile impact strength of the laminated film obtained above in the direction (TD) perpendicular to the flow direction of the resin was measured in accordance with JIS K 7160A. The results are shown in Table 3.

<Measurement of surface impact strength of laminated film>
The surface impact strength and cracking mode of the laminated film obtained above were measured in accordance with JIS K 7124-2 at a measurement temperature of 0° C. and a measurement time of 15 minutes. The results of surface impact strength and cracking mode are shown in Table 3, and a photograph of the cracking mode is shown in FIG.

<Measurement of drawdown length of laminated film>
A test piece with a length of 300 mm and a width of 160 mm was cut out from the laminated film obtained above, and a heater was installed on top of the test piece. The distance from the test piece to the heater is 100 mm.
Next, the heater was set at 500° C., the test piece was heated at 400° C. for 120 seconds, and the drawdown length of the test piece was measured by the method described above. The results are shown in Table 3.

<Measurement of surface roughness Ra of laminated film>
Regarding the laminated film obtained above, the surface roughness Ra (μm) of the outermost layer on the first functional layer side and the surface roughness of the outermost layer of the second functional layer are determined according to JIS B0601:2013. Ra (μm) was measured. The results are shown in Table 3.

<Measurement of 60° glossiness of laminated film>
Regarding the laminated film obtained above, the 60° glossiness of the outermost layer on the first functional layer side and the 60° glossiness of the outermost layer on the second functional layer side were measured in accordance with JIS Z 8741. did. The results are shown in Table 3.

<Measurement of haze of laminated film>
The haze of the laminated film obtained above was measured in accordance with JIS K 7136:2000. The results are shown in Table 3.

<Measurement of seal strength of laminated film>
The laminated films obtained above were placed facing each other so that the outermost layers on the first functional layer side faced each other, and the sealing temperature was 180°C, the sealing pressure was 0.2 MPa, the sealing time was 2.0 seconds, and the sealing width was A test piece was prepared by heat sealing under the condition of 15 mm.
Regarding this test piece, the laminated films were peeled off from each other at a peeling speed of 200 mm/min in accordance with JIS Z 0238:1998, and the measured value of the peel strength at this time was determined as the seal strength of the laminated film (N/15 mm). It was adopted as The results are shown in Table 3.

<Measurement of oxygen permeation amount of laminated film>
Regarding the laminated film obtained above, the amount of oxygen permeation was measured under conditions of a temperature of 23° C. and a relative humidity of 60% in accordance with JIS K 7126-2:2006. The results are shown in Table 3.

<<Manufacture and evaluation of laminated film>>
[Example 2]
A laminated film having the configuration shown in FIG. 3 was manufactured by the procedure shown below.
That is, the hPP1 and LDPE1 were prepared as resins constituting the inner layer, the outer layer, the first functional layer, and the second functional layer.

A resin composition (2) was prepared by mixing the hPP1 (70% by mass) and the LDPE1 (30% by mass).

The resin composition (1), the resin composition (2), the modified PP, the EVOH, the modified PP, the resin composition (2), and the resin composition (1). By coextruding in this order, the inner layer (80 μm thick), the first functional layer (284 μm thick), the first adhesive layer (20 μm thick), the oxygen barrier layer (32 μm thick), and the first functional layer (284 μm thick) are formed. A laminated film (thickness: 800 μm) was obtained.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Example 3]
A laminated film having the configuration shown in FIG. 3 was manufactured by the procedure shown below.
That is, the hPP1 ("Novatec PP (registered trademark) EA9 (product number)" manufactured by Nippon Polypropylene Co., Ltd., density 0.900 g/cm ³ , MFR 0.5 g/10 min) was prepared as the resin constituting the inner layer and the outer layer.

By coextruding the hPP1, the resin composition (1), the modified PP, the EVOH, the modified PP, the resin composition (1), and the hPP1 in this order, An inner layer (thickness: 80 μm), a first functional layer (thickness: 284 μm), a first adhesive layer (thickness: 20 μm), an oxygen barrier layer (thickness: 32 μm), a second adhesive layer (thickness: 20 μm), A laminated film (thickness: 800 μm) was obtained in which a second functional layer (thickness: 284 μm) and an outer layer (thickness: 80 μm) were laminated in this order in the thickness direction.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Comparative example 1]
A laminated film having the configuration shown in FIG. 2 was manufactured by the procedure shown below.
That is, by coextruding the hPP1, the modified PP, the EVOH, the modified PP, and the hPP1 in this order, a first functional layer (thickness: 364 μm) and a first adhesive layer ( A layer (thickness: 20 μm), an oxygen barrier layer (thickness: 32 μm), a second adhesive layer (thickness: 20 μm), and a second functional layer (thickness: 364 μm) are stacked in this order in the thickness direction. A laminated film (thickness: 800 μm) was obtained.
The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 1. The results are shown in Table 3.

As is clear from the above results, the tensile impact strength of the laminated films of Examples 1 to 3 was higher than that of the laminated film of Comparative Example 1, and it was confirmed that the impact resistance was better.

The surface impact strength of the laminated films of Examples 1 to 3 was higher than that of the laminated film of Comparative Example 1. Here, the laminated films of Examples 1 and 3 and Comparative Example 1 were brittlely fractured as shown in FIG. 5(a), whereas the laminated films of Example 2 were fractured as shown in FIG. 5(b). It was confirmed that the cracking mode, that is, the impact resistance, was better.

It was confirmed that the drawdown lengths of the laminated films of Examples 1 to 3 were shorter than the drawdown length of the laminated film of Comparative Example 1, and that the moldability was better.

The surface roughness Ra of the outermost layer of the laminated films of Examples 1 to 3 was small on both the first functional layer side and the second functional layer side, whereas the surface roughness Ra of the outermost layer of the laminated film of Comparative Example 1 was small. The value of Ra was small only on the second functional layer side. That is, the packages obtained using the laminated films of Examples 1 to 3 are easier to open than the packages obtained using the laminated film of Comparative Example 1 (the range of seal strength is smaller). It was confirmed that there was less catching during peeling.

The 60° glossiness of the outermost layer of the laminated films of Examples 1 to 3 was large on both the first functional layer side and the second functional layer side, whereas the 60° glossiness of the outermost layer of the laminated film of Comparative Example 1 was large. The glossiness was high only on the first functional layer side. That is, it was confirmed that the packages constructed using the laminated films of Examples 1 to 3 had better design than the packages constructed using the laminated film of Comparative Example 1.

It was confirmed that the haze of the laminated films of Examples 1 to 3 was smaller than that of the laminated film of Comparative Example 1.
It was confirmed that the seal strength of the laminated films of Examples 1 to 3 was equivalent to that of the laminated film of Comparative Example 1.
It was confirmed that the oxygen permeation amount of the laminated films of Examples 1 to 3 was equivalent to the oxygen permeation amount of the laminated film of Comparative Example 1.

<<Evaluation of single layer film>>
<Manufacture of single layer film>
A single layer film was manufactured by the procedure shown below.
That is, the resins shown in Table 4 were prepared as resins constituting the single layer.

A monolayer film 11 (thickness: 400 μm) was obtained by extruding the propylene block copolymer (bPP). This single layer is a non-stretched layer.

The bPP and the low density polyethylene (LDPE4) were kneaded in a twin screw extruder at the ratio shown in Table 5 to obtain pellets 1 to 4 (particle size 5 mm).

<Measurement of elongational viscosity of single layer film>
Regarding pellets 1 to 4 obtained above, the elongational viscosity of the pellets to be measured at 240° C. was measured by the Cogswell method using a capillary rheometer “RHEOGRAPH 20”. The results are shown in FIG.

As is clear from the above results, the amount of LDPE4 added was 0% by mass (single layer film 11), 8% by mass (single layer film 12), 14% by mass (single layer film 13), and 18% by mass (monolayer film 13). It was confirmed that the extensional viscosity tends to increase as the layer film 14) increases.

It can be inferred that as the elongational viscosity increases, the drawdown length decreases, so in the following examples, using the bpp and the LDPE4, in the laminated film, the content of the LDPE4 with respect to the total mass of the laminated film The proportion was changed to 0% by mass, 8% by mass, 14% by mass, and 18% by mass.

[Example 4]
<<Manufacture of laminated film>>
A laminated film having the configuration shown in FIG. 3 was manufactured by the procedure shown below.
That is, the bPP and the LDPE4 were prepared as resins constituting the inner layer, the outer layer, the first functional layer, and the second functional layer.
Modified polypropylene (modified PP) ("ADMER (registered trademark) QF551" (product number) manufactured by Mitsui Chemicals, Inc.) was prepared as a resin constituting the first adhesive layer and the second adhesive layer.
As a resin constituting the oxygen barrier layer, an ethylene-vinyl alcohol copolymer (EVOH) ("EVAL (registered trademark) F101A" (product number) manufactured by Kuraray Co., Ltd., ethylene copolymerization ratio of 32 mol %) was prepared.
A cream pigment masterbatch ("PP-M-SSCD 16N9913 Cream" manufactured by Dainichiseika Chemical Industry Co., Ltd.) was prepared as a pigment (PG) to be added to the first functional layer and the second functional layer.

A resin composition (3) was prepared by mixing the bPP (73% by mass), the LDPE4 (18% by mass), and the PG (9% by mass).

By coextruding the bPP, the resin composition (3), the modified PP, the EVOH, the modified PP, the resin composition (3), and the bPP in this order, An inner layer (thickness 180 μm), a first functional layer (thickness 184 μm), a first adhesive layer (thickness 20 μm), an oxygen barrier layer (thickness 32 μm), a second adhesive layer (thickness 20 μm), A laminated film (thickness: 800 μm) was obtained in which a second functional layer (thickness: 184 μm) and an outer layer (thickness: 180 μm) were laminated in this order in the thickness direction.
In the laminated film, the content ratio of the LDPE4 to the total mass of the laminated film was 8% by mass.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.

<<Evaluation of laminated film>>
<Measurement of tensile impact strength of laminated film>
Regarding the laminated film obtained above, the tensile impact strength in the direction parallel (MD) and perpendicular direction (TD) to the flow direction of the resin was measured in accordance with JIS K 7160A. The results are shown in Table 6.

<Measurement of surface impact strength of laminated film>
The surface impact strength and cracking mode of the laminated film obtained above were measured in accordance with JIS K 7124-2 at a measurement temperature of 0° C. and a measurement time of 15 minutes. Table 6 shows the results of surface impact strength and cracking mode.

<Measurement of drawdown length of laminated film>
A test piece with a length of 300 mm and a width of 160 mm was cut out from the laminated film obtained above, and a heater was installed on top of the test piece. The distance from the test piece to the heater is 100 mm.
Next, the heater was set at 500°C, the test piece was heated at 400°C for 120 seconds, and the drawdown length of the test piece was measured using the method described above. The results are shown in Table 6.

<Measurement of haze of laminated film>
The haze of the laminated film obtained above was measured in accordance with JIS K 7136:2000. The results are shown in Table 6.

<Measurement of seal strength of laminated film>
The laminated films obtained above were placed facing each other so that the outermost layers on the first functional layer side faced each other, and the sealing temperature was 180°C, the sealing pressure was 0.2 MPa, the sealing time was 2.0 seconds, and the sealing width was A test piece was prepared by heat sealing under the condition of 15 mm.
Regarding this test piece, the laminated films were peeled off from each other at a peeling speed of 200 mm/min in accordance with JIS Z 0238:1998, and the measured value of the peel strength at this time was determined as the seal strength of the laminated film (N/15 mm). It was adopted as The results are shown in Table 6.

<Measurement of oxygen permeation amount of laminated film>
Regarding the laminated film obtained above, the amount of oxygen permeation was measured under conditions of a temperature of 23° C. and a relative humidity of 60% in accordance with JIS K 7126-2:2006. The results are shown in Table 6.

<<Manufacture and evaluation of laminated film>>
[Example 5]
A resin composition (4) was prepared by mixing the bPP (80% by mass) and the LDPE4 (20% by mass).

A laminated film was produced in the same manner as in Example 4, except that the resin composition (4) was used instead of the bPP as the resin constituting the inner layer and the outer layer.
In the laminated film, the content ratio of the LDPE4 to the total mass of the laminated film was 17% by mass.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 6.

[Example 6]
A resin composition (5) was prepared by mixing the bPP (76% by mass), the LDPE4 (19% by mass), and the PG (5% by mass).
The thickness of the inner layer and the outer layer is changed to 80 μm, the thickness of the first functional layer and the second functional layer is changed to 284 μm, and the resin composition part (3) is used as the resin constituting the first functional layer and the second functional layer. A laminated film was produced in the same manner as in Example 4, except that the resin composition (5) was used instead.
In the laminated film, the content ratio of the LDPE4 to the total mass of the laminated film was 14% by mass.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 6.

[Example 7]
A laminated film was produced in the same manner as in Example 6, except that the resin composition (4) was used instead of the bPP as the resin constituting the inner layer and the outer layer.
In the laminated film, the content ratio of the LDPE4 to the total mass of the laminated film was 18% by mass.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 6.

[Example 8]
A resin composition (6) was prepared by mixing the bPP (85% by mass), the LDPE4 (10% by mass), and the PG (5% by mass).
In the same manner as in Example 6, except that the resin composition (6) was used instead of the resin composition part (5) as the resin constituting the first functional layer and the second functional layer, A laminated film was produced.
In the laminated film, the content of LDPE4 was 7% by mass with respect to the total mass of the laminated film.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 7.

[Comparative example 2]
A resin composition (7) was prepared by mixing the bPP (95% by mass) and the PG (5% by mass).

In the same manner as in Example 6, except that the resin composition (7) was used instead of the resin composition (5) as the resin constituting the first functional layer and the second functional layer, A laminated film was produced.
The inner layer, the first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, the second functional layer, and the outer layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 7.

[Comparative example 3]
A laminated film having the configuration shown in FIG. 2 was manufactured by the procedure shown below.
That is, a resin composition (8) was prepared by mixing the bPP (96.5% by mass) and the PG (3.5% by mass).
By coextruding the resin composition (8), the modified PP, the EVOH, the modified PP, and the resin composition (8) in this order, a first functional layer (thickness: 364 μm ), a first adhesive layer (thickness: 20 μm), an oxygen barrier layer (thickness: 32 μm), a second adhesive layer (thickness: 20 μm), and a second functional layer (thickness: 364 μm), in this order: A laminated film (thickness: 800 μm) was obtained by laminating these in the thickness direction.
The first functional layer, the first adhesive layer, the oxygen barrier layer, the second adhesive layer, and the second functional layer are all non-stretched layers.
This laminated film was evaluated in the same manner as in Example 4. The results are shown in Table 7.

As is clear from the above results, the tensile impact strength of the laminated films of Examples 4 to 8 is greater than that of the laminated films of Comparative Examples 2 and 3, confirming that they have better impact resistance. Ta.

The surface impact strengths of the laminated films of Examples 4 to 8 were approximately the same as those of Comparative Examples 2 and 3. Here, the laminated films of Examples 4 to 8 and Comparative Examples 2 and 3 were ductilely fractured as shown in FIG. 5(c), and it was confirmed that the cracking mode, that is, the impact resistance was better. Ta.

Further, the drawdown lengths of the laminated films of Examples 4 to 8 were shorter than those of the laminated films of Comparative Examples 2 and 3, and it was confirmed that the moldability was better.

It was confirmed that the haze of the laminated films of Examples 4 to 8 was equivalent to that of the laminated films of Comparative Examples 2 and 3.
It was confirmed that the sealing strength of the laminated films of Examples 4 to 8 was almost the same as that of the laminated films of Comparative Examples 2 and 3.
It was confirmed that the oxygen permeation amounts of the laminated films of Examples 4 to 8 were equivalent to the oxygen permeation amounts of the laminated films of Comparative Examples 2 and 3.

INDUSTRIAL APPLICATION This invention can be utilized for the manufacture of the laminated film excellent in moldability and impact resistance, and the package using the said laminated film.

DESCRIPTION OF SYMBOLS 1... Laminated film 2... Laminated film 11... Functional layer 111... First functional layer 112... Second functional layer 12... Oxygen barrier layer 13... Inner layer 14... Outer layer 15... Adhesive layer 151... First adhesive layer 152... Second adhesive layer 8... Lid material 9... Storage item 10... Bottom material 101... Packaging body

Claims (14)

A laminated film comprising a functional layer and an oxygen barrier layer,
The functional layer contains a propylene polymer and an ethylene polymer,
In the functional layer, the ethylene polymer has a melt flow rate of 3 g/10 minutes or less,
A laminated film, wherein in the functional layer, a content ratio of the ethylene polymer to the total mass of the functional layer is 10% by mass or more and 40% by mass or less. The laminated film further includes an inner layer as one outermost layer,
The inner layer contains a propylene polymer and an ethylene polymer,
In the inner layer, the ethylene polymer has a melt flow rate of 3 g/10 minutes or less,
The laminated film according to claim 1, wherein in the inner layer, a content ratio of the ethylene polymer to the total mass of the inner layer is 10% by mass or more and 40% by mass or less. The laminated film further includes an outer layer as the other outermost layer,
The outer layer contains a propylene polymer and an ethylene polymer,
In the outer layer, the ethylene polymer has a melt flow rate of 3 g/10 minutes or less,
The laminated film according to claim 2, wherein in the outer layer, a content ratio of the ethylene polymer to the total mass of the outer layer is 10% by mass or more and 40% by mass or less. The laminated film according to claim 3, wherein the ratio of the total thickness of the functional layer, the inner layer, and the outer layer to the thickness of the laminated film is 85% or more. The laminated film according to any one of claims 1 to 3, wherein in the laminated film, the content ratio of the polyolefin resin to the total mass of the laminated film is 80% by mass or more. The laminated film according to any one of claims 1 to 3, wherein the oxygen barrier layer contains an ethylene-vinyl alcohol copolymer. The laminated film includes two or more of the functional layers,
The laminated film according to any one of claims 1 to 3, wherein the oxygen barrier layer is provided between a pair of the functional layers. The laminated film according to any one of claims 1 to 3, wherein the laminated film has a tensile impact strength of 225 kJ/m ² or more in directions parallel and perpendicular to the flow direction of the resin. One or more selected from the group consisting of the propylene-based polymer contained in the functional layer, the propylene-based polymer contained in the inner layer, and the propylene-based polymer contained in the outer layer co-exist with a propylene-based block. The laminated film according to claim 3, which is a polymer. The tensile impact strength of the laminated film in a direction parallel to the flow direction of the resin is 330 kJ/m ² or more, and the tensile impact strength of the laminated film in the direction perpendicular to the flow direction of the resin is The laminated film according to claim 9, which has a power of 330 kJ/m2 or ^more . The laminated film according to any one of claims 1 to 3, wherein the laminated film has a drawdown length of 50 mm or less when the laminated film is heated at 400° C. for 120 seconds. The surface roughness Ra of one outermost layer of the laminated film is 0.65 μm or less,
The laminated film according to any one of claims 1 to 3, wherein the other outermost layer of the laminated film has a surface roughness Ra of 0.65 μm or less. The 60° glossiness of one of the outermost layers of the laminated film is 90 or more, as measured in accordance with JIS Z 8741,
The laminated film according to any one of claims 1 to 3, wherein the other outermost layer of the laminated film has a 60° glossiness of 90 or more, as measured in accordance with JIS Z 8741. A package constructed using the laminated film according to any one of claims 1 to 3.

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