JP2021070261A - Laminated film, method for producing the same and use of the same - Google Patents

Abstract

To provide a laminated film having excellent adhesive force between a barrier layer and an adhesion layer adjacent to the barrier layer.SOLUTION: There is provided a laminated film which has a barrier layer and an adhesion layer composed of an adhesion layer composition containing 50 to 95 pts.mass of an ethylene-based polymer (X) having a density of 890 to 950 kg/m3 and an MFR (at 190°C and a load of 2.16 kg) of 1 to 50 g/10 min and 5 to 50 pts.mass of an acid-modified ethylene-α-olefin copolymer (Y) having a density of 830 to 910 kg/m3, an MFR (at 190°C and a load of 2.16 kg) of 0.05 to 40 g/10 min and an acid modification degree of 0.45 to 20 mass% (provided that the total amount of (X) and (Y) is 100 pts.mass).SELECTED DRAWING: None

Description

The present invention relates to a laminated film, and more particularly to a laminated film that can be preferably used as a barrier film.

Packaging materials made of laminated plastic film are lightweight, airtight, strong, convenient to handle, and can be sealed by heat sealing, so they are used for packaging a wide variety of products such as foods and pharmaceuticals. .. The packaging material may be required to have a function of preventing quality deterioration of the contents, and depending on the contents, high oxygen gas barrier property, moisture resistance and the like are required.

Various laminated plastic films having these performances have been developed. For example, in Patent Document 1, low crystalline or amorphous ethylene / α-olefin copolymer% and unsaturated carboxylic acid are provided on an aluminum foil. Alternatively, a coextrusion laminating method is used in which an adhesive layer made of modified polyethylene graft-modified with a derivative thereof (such as a maleic anhydride-grafted ethylene-1-butene copolymer) and a tackifier and a resin layer selected from polyolefin or the like are coextruded. The laminated body laminated with the above is disclosed, and this laminated body is excellent in gas permeability resistance and interlayer adhesion.

Patent Document 2 discloses a laminated film in which a plastic film, a thin film layer of a gas barrier inorganic substance (aluminum oxide, etc.), a modified polyethylene composition layer, and a polyethylene film are laminated in this order, which makes it difficult for oxygen gas and water vapor to permeate. There is.

In Patent Document 3, a biaxially stretched polypropylene (OPP) film, an undercoat layer, a gas barrier layer, a coating layer made of aluminum oxide or the like, an adhesive layer made of modified polyolefin or the like, and a protective layer made of a polyolefin film are sequentially laminated. Therefore, a polyolefin film laminate that is difficult to permeate oxygen gas and water vapor is disclosed.

Patent Document 4 discloses a gas barrier laminated film containing an adhesive resin composition layer containing a modified ethylene / α-olefin copolymer and an unmodified ethylene / α-olefin copolymer, and a gas barrier resin layer. Has been done.

Patent Document 5 describes a support made of aluminum or the like and a layer of an adhesive composition provided on the support and made of an ethylene copolymer containing an unsaturated carboxylic acid ester type comonomer and a functional comonomer. The multilayer structure having is disclosed.

Further, Patent Document 6 discloses a laminate in which a barrier layer such as an aluminum foil, an adhesive layer containing an acid-modified olefin elastomer, and a sealant layer are laminated in this order, and the adhesive layer contains a small amount of polyolefin resin or the like. It is stated that it may be contained.

Japanese Unexamined Patent Publication No. 64-27922 Japanese Unexamined Patent Publication No. 2004-142390 Japanese Unexamined Patent Publication No. 2001-315250 JP-A-2018-171807 Japanese Patent Application Laid-Open No. 2008-524365 Japanese Unexamined Patent Publication No. 2012-71941

However, the conventional barrier laminated film has room for further improvement from the viewpoint of the adhesive force between the barrier layer made of aluminum foil or the like and the adjacent adhesive layer.

As a result of diligent research, the present inventors have found that the above problems can be solved by forming the adhesive layer from a composition containing an unmodified ethylene-based polymer and a predetermined acid-modified ethylene / α-olefin copolymer. The present invention has been completed.

The present invention relates to, for example, the following [1] to [7].
[1]
It has a barrier layer and an adhesive layer in contact with the barrier layer.
The adhesive layer is 50 ethylene-based polymer (X) having a density of 890 to 950 kg / m ³ and a melt flow rate (according to ASTM D1238, 190 ° C., 2.16 kg load) of 1 to 50 g / 10 minutes. ~ 95 parts by mass, density 830-910 kg / m ³ , melt flow rate (according to ASTM D1238, 190 ° C., 2.16 kg load) 0.05-40 g / 10 minutes, acid modification degree 0.45 ~ 20% by mass of the acid-modified ethylene / α-olefin copolymer (Y) in an amount of 5 to 50 parts by mass (however, the ethylene-based polymer (X) and the acid-modified ethylene / α-olefin copolymer (Y). A laminated film comprising an adhesive layer composition containing 100 parts by mass in total.
[2]
The laminated film of the above [1] in which the barrier layer is made of an inorganic substance.
[3]
The laminated film of the above [1] or [2], wherein the barrier layer comprises at least one selected from the group consisting of polyester, polyamide and ethylene / vinyl alcohol copolymer.
[4]
The laminated film according to any one of [1] to [3], further comprising a base material layer laminated in the order of a base material layer / the barrier layer / the adhesive layer.
[5]
The laminated film according to any one of [1] to [4], further comprising a heat-sealing layer laminated in the order of the barrier layer / the adhesive layer / the heat-sealing layer.
[6]
A package containing the laminated film according to any one of [1] to [5].
[7]
The method for producing a laminated film according to the above [1], wherein the barrier layer and the adhesive layer are laminated by an extrusion lamination method.

The laminated film of the present invention has excellent adhesive force between the barrier layer and the adhesive layer adjacent thereto.

Hereinafter, the present invention will be described in more detail.
The laminated film according to the present invention has a barrier layer and an adhesive layer.
The laminated film according to the present invention may further have a base material layer laminated in the order of a base material layer / the barrier layer / the adhesive layer, and may be a barrier layer / the adhesive layer / the heat seal layer. It may have a heat seal layer laminated in order.

(Base layer)
Since the base material layer is flexible and has high transparency, a polyester film such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and a polyamide film such as nylon 6 and nylon 66 are used. , Ethylene / vinyl alcohol copolymer film, polyolefin film such as polyethylene and polypropylene, polyimide film, etc. are preferable, and since they are excellent in physical properties such as transparency, heat resistance and mechanical strength, polyethylene terephthalate (PET) or polypropylene is used. A biaxially stretched film is more preferable, and a biaxially stretched polyethylene terephthalate film is further preferable.

The base material layer may contain additives that are usually contained in the base material layer of the barrier laminated film, as long as the effects of the present invention are not impaired.
The thickness of the base material layer is usually 3 to 100 μm, preferably 8 to 50 μm, and more preferably 10 to 30 μm.

(Barrier layer)
The barrier layer is arranged so as to be in contact with the adhesive layer.
The barrier layer prevents or suppresses the permeation of gases such as oxygen, water vapor, and odor. Further, the barrier layer also prevents light transmission by selecting an opaque material.

The barrier layer is made of an inorganic substance, for example, a metal or an inorganic oxide, or at least one resin selected from the group consisting of polyester, polyamide and ethylene / vinyl alcohol copolymer, and is made of at least one resin from the viewpoint of versatility. , Preferably composed of the above-mentioned inorganic substance.

Examples of the barrier layer made of an inorganic substance include a foil and a thin-film film formed on the surface of the base material layer.
Examples of the metal constituting the barrier layer include aluminum, copper, nickel, gold, silver, and stainless steel. From the viewpoint of versatility, aluminum is preferable, and aluminum foil is mainly used.

When the barrier layer is a vapor-deposited film, examples of the material thereof include metals such as aluminum and inorganic oxides such as aluminum oxide and silicon oxide, preferably aluminum, from the viewpoint of versatility.

The thickness of the metal foil is usually 1 to 30 μm, preferably 5 to 15 μm, and the thickness of the vapor-deposited layer is usually 10 to 2000 nm, preferably 20 to 100 nm.
When the barrier layer is a metal foil, for example, the matte surface of the metal foil (for example, aluminum foil) is directed toward the base material layer side, and if necessary, an adhesive (for example, a urethane-based adhesive) is used. The barrier layer can be manufactured by laminating the metal foil on the base material layer by the dry lamination method. When the barrier layer is manufactured by this method, the glossy surface of the metal foil comes into contact with the adhesive layer.

The vapor-deposited film can be formed by depositing a metal or other inorganic substance on the surface of the base material layer by a conventionally known method.
All or part of the surface of the barrier layer made of the metal may be oxidized.

When the barrier layer is made of the resin, examples of the polyester include polyethylene terephthalate.
Examples of the polyamide include nylon 6, nylon 66, nylon 6/10, nylon 12, nylon 11, MXD nylon, amorphous nylon, and terephthalic acid / adipic acid / hexamethylenediamine copolymers.

Examples of the ethylene / vinyl alcohol copolymer include copolymers in which the content of structural units derived from ethylene is preferably 15 to 70 mol%, more preferably 20 to 50 mol%.
The thickness of the barrier layer made of the resin is usually 1 to 30 μm, preferably 5 to 15 μm.

(Adhesive layer)
The adhesive layer is composed of an adhesive layer composition containing an ethylene-based polymer (X) and an acid-modified ethylene / α-olefin copolymer (Y).
The proportions of the ethylene-based polymer (X) and the acid-modified ethylene / α-olefin copolymer (Y) are 50 to 95 parts by mass and 5 to 50 parts by mass, respectively (however, the ethylene-based polymer (X)). And the total of the acid-modified ethylene / α-olefin copolymer (Y) is 100 parts by mass.), It is preferably 50 to 90 parts by mass and 10 to 50 parts by mass. Since the adhesive layer contains the acid-modified ethylene / α-olefin copolymer (Y) at a ratio of the lower limit value or more, the adhesive strength with the barrier layer is excellent. Since the adhesive layer has excellent adhesive strength with the barrier layer even if the proportion of the acid-modified ethylene / α-olefin copolymer (Y) is low, the production cost of the laminated film of the present invention can be suppressed. There are also advantages.

<Ethylene polymer (X)>
The density of the ethylene polymer (X) is 890 to 950 kg / m ³ , preferably 895 to 940 kg / m ³ , and more preferably 900 to 930 kg / m ³ .

The melt flow rate of the ethylene polymer (X) (according to ASTM D1238, 190 ° C., 2.16 kg load) is 1 to 50 g / 10 minutes, preferably 2 to 25 g / 10 minutes, more preferably 3 to 20 g / min. 10 minutes.

Examples of the ethylene-based polymer (X) include an ethylene homopolymer and a copolymer of ethylene and an α-olefin having 3 or more carbon atoms. The copolymer is usually a random copolymer.

The α-olefin has preferably 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms.
Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene.
The ethylene-based polymer (X) may be used alone or in combination of two or more.
The ethylene-based polymer (X) is not acid-modified, unlike the acid-modified propylene polymer (Y) described below.

<Acid-modified ethylene / α-olefin copolymer (Y)>
The acid-modified ethylene / α-olefin copolymer (Y) is unsaturated with an ethylene / α-olefin copolymer (may be a composition of two or more kinds of ethylene / α-olefin copolymers). It is modified with a carboxylic acid or a derivative thereof.

The density of the acid-modified ethylene / α-olefin copolymer (Y) is 830 to 910 kg / m ³ , preferably 860 to 905 kg / m ³ , and more preferably 860 to 900 kg / m ³ .

The melt flow rate of the acid-modified ethylene / α-olefin copolymer (Y) (according to ASTM D1238, 190 ° C., 2.16 kg load) is 0.05 to 40 g / 10 minutes, preferably 0.1 to 20 g. / 10 minutes, more preferably 0.1 to 15 g / 10 minutes.

The α-olefin has preferably 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms.
Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene, and 1-butene is preferable.

The α-olefin may be used alone or in combination of two or more.
Specific examples of the ethylene / α-olefin copolymer (before modification) include, for example, an ethylene / propylene copolymer, an ethylene / 1-butene copolymer, an ethylene / 1-hexene copolymer, and an ethylene / 1-octene copolymer. Examples thereof include ethylene and 1-butene copolymers, and among them, ethylene / 1-butene copolymers are preferable. The ethylene / α-olefin copolymer is usually a random copolymer.

The ethylene / α-olefin copolymer contains an ethylene-derived structural unit as a main component (50% by mass or more with respect to all the structural units).
From the viewpoint of molecular chain flexibility, the ethylene / α-olefin copolymer preferably does not contain a structural unit derived from an unsaturated carboxylic acid or an unsaturated carboxylic acid ester.

Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and itaconic acid.
Examples of the derivatives include maleic anhydride, endic acid anhydride (cis-5-norbornene-endo-2,3-dicarboxylic acid anhydride), itaconic anhydride, citraconic anhydride and other acid anhydrides;
Methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, monoethyl maleic acid ester, diethyl maleic acid, monomethyl fumarate, dimethyl fumarate, monomethyl itaconic acid ester, diethyl itaconic acid Etc .;
Acrylamide, methacrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-N, N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N, N-dibutylamide, Amides such as fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monobutylamide, fumaric acid-N, N-dibutylamide;
Imides such as maleimide, N-butyl maleimide, N-phenylmaleimide;
Examples thereof include metal salts such as sodium acrylate, sodium methacrylate, potassium acrylate, and potassium methacrylate.

Among these unsaturated carboxylic acids and their derivatives, maleic acid and maleic anhydride are preferable, and maleic anhydride is more preferable.
The acid-modified ethylene / α-olefin copolymer (Y) may be used alone or in combination of two or more.

The modification of the ethylene / α-olefin copolymer with an unsaturated carboxylic acid or a derivative thereof can be carried out by a conventionally known method. For example, an additive described later is added to the ethylene / α-olefin copolymer as necessary, and an unsaturated carboxylic acid or a derivative thereof (for example, maleic acid or an anhydride thereof) is grafted in the presence of a radical initiator. By polymerizing, the acid-modified ethylene / α-olefin copolymer (Y) can be obtained.

The amount of the unsaturated carboxylic acid or its derivative charged is usually 0.010 to 15 parts by mass, preferably 0.010 to 5.0 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin copolymer before modification. Is. The amount of the radical initiator used is usually 0.0010 to 1.0 parts by mass, preferably 0.0010 to 0.30 parts by mass with respect to 100 parts by mass of the ethylene / α-olefin copolymer before modification. ..

Radical initiators include, for example, organic peroxides, azo compounds and metal hydrides. The radical initiator may be used as it is by mixing it with an ethylene / α-olefin copolymer before modification, an unsaturated carboxylic acid or a derivative thereof, and other optional components as it is, or after being dissolved in a small amount of an organic solvent. You may use it. The organic solvent is not particularly limited as long as it is an organic solvent capable of dissolving the radical initiator.

The graft modification can be carried out by a conventionally known method, for example, an ethylene / α-olefin copolymer before modification is dissolved in an organic solvent, and an unsaturated carboxylic acid or a derivative thereof is added to the obtained solution. And a method of adding a radical initiator and the like and reacting at a temperature of 70 to 200 ° C., preferably 80 to 190 ° C. for 0.5 to 15 hours, preferably 1 to 10 hours can be mentioned.

Further, in an apparatus such as an extruder, an unsaturated carboxylic acid or a derivative thereof is reacted with an ethylene / α-olefin copolymer before modification in the presence of a radical initiator without using a solvent to obtain acid-modified ethylene. The α-olefin copolymer (Y) may be produced. This reaction is usually carried out at a temperature equal to or higher than the melting point of the ethylene / α-olefin copolymer before modification for 0.5 to 10 minutes.

The acid modification degree (hereinafter, also referred to as "graft amount") of the acid-modified ethylene / α-olefin copolymer (Y) defined by the following formula and measured by the method adopted in the examples described later is determined. It is 0.45 to 20% by mass, preferably 0.50 to 10% by mass, and more preferably 0.55 to 3% by mass.
Acid denaturation degree (graft amount) (mass%) = (mass of a structural unit having a structure derived from a monomer having an ethylenically unsaturated group and a polar functional group in one molecule) / (acid-modified ethylene / α- Mass of olefin copolymer (Y)) x 100

The adhesive layer composition may contain additives that are usually contained in the adhesive layer of the barrier laminated film, as long as the effects of the present invention are not impaired.
The adhesive layer composition is preferably a tackifier (that is, the ethylene-based weight) because it should suppress contamination of the die-slip portion due to the low molecular weight component and minimize the increase in raw material cost. It does not contain a solid amorphous polymer other than the coalescence (X) and the acid-modified ethylene / α-olefin copolymer (Y).

The thickness of the adhesive layer is usually 1 to 100 μm, preferably 5 to 80 μm, and more preferably 10 to 50 μm.
The adhesive layer contains an acid-modified ethylene / α-olefin copolymer (Y) having a relatively high degree of acid modification and a relatively small MFR, so that the surface of the barrier layer such as an aluminum foil is sufficiently wetted. Sufficient adhesive strength is exhibited by constructing a bond by a chemical reaction with the polar group on the surface of the barrier layer such as aluminum foil, and by making it difficult for the molecular chain connecting the bond and the adhesive layer made of resin to be pulled out. Guess.

(Heat seal layer)
The laminated film of the present invention may be provided with a heat seal layer in the order of any base material layer / barrier layer / adhesive layer / heat seal layer.
The heat-sealed layer is composed of an ethylene-based polymer such as high-density polyethylene, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and an ethylene / α-olefin (three or more carbon atoms) copolymer. , Single layer or multi-layer configuration may be used.

In the case of a single layer, an ethylene / α-olefin (three or more carbon atoms) copolymer is preferable as the material of the heat seal layer because heat sealing is easy, the strength is high, and the transparency is high. The ethylene / α-olefin is a random copolymer of ethylene and α-olefin, and the α-olefin is preferably an α-olefin having 3 to 12 carbon atoms, preferably 3 to 10 carbon atoms. Examples thereof include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene. Specific examples of the copolymer include ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene / 4-methyl-1-pentene copolymer, ethylene / 1-hexene copolymer, and ethylene / 1. -Ocene copolymers can be mentioned.

The density of the ethylene-based polymer used in the heat-sealing layer is preferably 885 to 960 kg / m ³ , and more preferably 890 to 950 kg / m ³ .
The melt flow rate of the ethylene polymer (according to ASTM D1238, 190 ° C., 2.16 kg load) is preferably 0.5 to 50 g / 10 minutes, more preferably 1 to 30 g / 10 minutes.

The heat-sealing layer may contain additives that are usually contained in the heat-sealing layer of the barrier laminated film, as long as the effects of the present invention are not impaired.
The thickness of the heat seal layer is usually 1 to 100 μm, preferably 5 to 50 μm, and more preferably 10 to 40 μm.

(Manufacturing method of laminated film)
In the laminated film according to the present invention, any of the base material layer, the barrier layer, the adhesive layer, and any of the heat seal layers are arranged in this order so that the barrier layer is in contact with the adhesive layer. Other than that, it can be produced by adopting a conventionally known method. For example, it can be manufactured by extruding the adhesive layer onto the barrier layer using an extruded laminator.

(Use of laminated film)
The laminated film according to the present invention can be preferably used as a packaging material, particularly as a packaging material for contents such as foods and pharmaceuticals, which are required to have high oxygen gas barrier properties and moisture resistance.

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to the Examples.
[Measurement or evaluation method]
The physical properties of the raw materials and the like and the evaluation of the laminated film were carried out by the following methods.

(Melt flow rate)
According to ASTM D1238, the melt flow rate (MFR) was measured at 190 ° C. with a load of 2.16 kgf.

(density)
Density was measured according to ASTM D1505.

(Melting point (measurement by reheating method))
The sample was held at 200 ° C. for 10 minutes in a DSC measuring device, cooled to -20 ° C. at a temperature lowering rate of 10 ° C./min, held at -20 ° C. for 1 minute, and then heated at a temperature rise rate of 10 ° C./min. The DSC curve obtained when measured below was created. The temperature at which the melting peak is given in this DSC curve is defined as the melting point.

(Acid denaturation (graft amount))
A polymer modified with maleic anhydride was heat-pressed at 250 ° C. to prepare a film, and this film was subjected to FT-IR measurement to have ^{a peak intensity of 1780 cm-1} wave number assigned to a carbonyl group, and separately prepared. The graft amount (mass%) defined by the following formula was obtained based on the calibration curve.
Acid denaturation (graft amount) (% by mass) = (mass of a structural unit having a structure derived from a monomer having an ethylenically unsaturated group and a polar functional group in one molecule) / (modified with maleic anhydride) Mass of polymer produced) x 100

(Adhesive strength of laminated film)
The laminated film produced in the examples or comparative examples was cut out as a strip test piece having a width of 15 mm one week after the production, a cut was made between the adhesive layer and the aluminum foil, and the film was separated using a tensile tester. The gas barrier layer and the adhesive layer at each location were grasped with a chuck, and a T-type peeling test was performed at a tensile speed of 50 mm / min. The average value of the locations where a stable peeling load was shown at a peeling distance of 10 mm or more when both layers were peeled off was taken as the adhesive force.

(Manufacturing cost)
The manufacturing cost was evaluated. The meaning of each symbol in Table 3 is as follows.
◎: Cheapest 〇: Higher cost than ◎ △: Higher cost than 〇

(Odor during film formation)
The strength of the odor was judged by a relative evaluation of the three panelists who performed the film forming work. When the resin was extruded from the die and laminated to the aluminum foil, each level of odor was confirmed by standing within a radius of 1 m around the die. In addition, the standing position of the panelists for each level was fixed.
The meaning of each symbol in Table 3 is as follows.
◎: Weakest odor 〇: Stronger odor than ◎ △: Stronger odor than 〇

[Manufacturing Example 1]
(Manufacturing of base material layer with barrier layer)
Aluminum foil made by Toyo Aluminum K.K. (for food packaging) on Embret (registered trademark) PET-12 (biaxially stretched PET film, thickness 12 μm) manufactured by Unitika Ltd. via a urethane adhesive. Laminated normal brand (7 μm in thickness) was laminated on the matte surface side of the aluminum foil toward the biaxially stretched PET film by the dry lamination method to produce a base material layer with a barrier layer.

[Manufacturing Example 2]
(Production of acid-modified ethylene / α-olefin copolymer (Y), etc.)
The polymers shown in Table 1 were prepared as targets for acid denaturation.

[Manufacturing Example 2-1]
100 parts by mass of Toughmer A-20090S, 0.8 parts by mass of maleic acid anhydride, and radical initiator (2,5-dimethyl-2,5-di- (t-butylperoxy) -3-hexine (trade name). Perhexa 25B))) is mixed at a ratio of 0.15 parts by mass and extruded using a twin-screw extruder at a resin temperature of 200 ° C., a screw rotation speed of 250 rpm, and a discharge rate of 300 kg / hour to obtain acid-modified ethylene / α. An acid-modified ethylene / 1-butene copolymer (hereinafter referred to as "acid-modified EBR-1") as an olefin copolymer (Y) was obtained. The physical characteristics are shown in Table 3.

[Manufacturing Example 2-2-2-13]
The polymer to be modified was changed from Tuffmer A-20090S to the polymer shown in Table 2, and the amount of maleic acid anhydride was set to the amount shown in Table 2 in the same manner as in Production Example 2-1. Acid-modified EBR-2 to 13 and acid-modified LLDPE, which are acid-modified polymers, were produced, respectively. The physical characteristics of each acid-modified polymer are shown in Table 3.

[Example 1]
A laminated film was manufactured using a coextrusion laminator consisting of two extruders. Specifically, LDPE (Mirason 16P) is extruded from one extruder for forming the outermost layer so as to have a thickness of 30 μm, and another layer for forming a layer in contact with the barrier layer (aluminum foil) is formed. From one extruder, 80 parts by mass of LDPE (high pressure method low density polyethylene, trade name: Mirason (registered trademark) 16P, manufactured by Mitsui Dow Polychemical, MFR (190 ° C., 2.), Which is a raw material for forming an adhesive layer. 16 kgf): 3.7 g / 10 minutes, density: 923 kg / m ³ , melting point: 111 ° C.), and 20 parts by mass of the acid-modified EBR-1 produced in Production Example 2-1 after being kneaded in an extruder. On the barrier layer (aluminum foil) of the base material layer with a barrier layer obtained in Production Example 1, the thickness is 20 μm under the conditions of an extrusion temperature of 305 ° C. and a film forming speed of 7.5 m / min ( The co-extruded resin was extruded (so that the total thickness was 50 μm) to form a laminated film. The evaluation results of the laminated film are shown in Table 3.

[Examples 2 to 15, Comparative Examples 1 to 3]
A laminated film was produced in the same manner as in Example 1 except that the raw material for forming the adhesive layer was changed as shown in Table 3. The evaluation results of the laminated film are shown in Table 3.

Claims (7)

It has a barrier layer and an adhesive layer in contact with the barrier layer.
The adhesive layer is 50 ethylene-based polymer (X) having a density of 890 to 950 kg / m ³ and a melt flow rate (according to ASTM D1238, 190 ° C., 2.16 kg load) of 1 to 50 g / 10 minutes. ~ 95 parts by mass, density 830-910 kg / m ³ , melt flow rate (according to ASTM D1238, 190 ° C., 2.16 kg load) 0.05-40 g / 10 minutes, acid modification degree 0.45 ~ 20% by mass of the acid-modified ethylene / α-olefin copolymer (Y) in an amount of 5 to 50 parts by mass (however, the ethylene-based polymer (X) and the acid-modified ethylene / α-olefin copolymer (Y). A laminated film comprising an adhesive layer composition containing 100 parts by mass in total. The laminated film according to claim 1, wherein the barrier layer is made of an inorganic substance. The laminated film according to claim 1, wherein the barrier layer is made of at least one resin selected from the group consisting of polyester, polyamide and ethylene / vinyl alcohol copolymer. The laminated film according to any one of claims 1 to 3, further comprising a base material layer laminated in the order of a base material layer / the barrier layer / the adhesive layer. The laminated film according to any one of claims 1 to 4, further comprising a heat-sealing layer laminated in the order of the barrier layer / the adhesive layer / the heat-sealing layer. A package containing the laminated film according to any one of claims 1 to 5. The method for producing a laminated film according to claim 1, wherein the barrier layer and the adhesive layer are laminated by an extrusion lamination method.