JP2022163558A - Resin film and packaging container - Google Patents

Abstract

To provide a resin film which can reduce an emission amount of carbon dioxide, and is excellent in pinhole resistance.SOLUTION: A resin film of the present invention includes at least a first layer, and a second layer laminated directly on the first layer, wherein the thickness of the resin film is 15 μm or more and 150 μm or less, the thickness of the second layer is thicker than the thickness of the first layer, the resin film contains 90 mass% or more of linear low-density polyethylene obtained by polymerization of ethylene and a monomer of α-olefin with the entire resin film, the resin film contains 51 mass% or more of linear low-density polyethylene obtained by polymerization of ethylene and a monomer of α-olefin containing a compound having 6 or more carbon atom with the entire resin film, and the resin film contains biomass linear low-density polyethylene.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a resin film and a packaging container including the same.

Packaging containers such as bag-in-box are widely used to store and transport liquid products (drinks, car oils, detergents, medicines, etc.) in various fields such as the food industry, automobile industry, pharmaceutical industry, and toiletry industry. . A bag-in-box is composed of an inner bag for containing contents such as a liquid product, and an exterior body for containing the inner bag and retaining its outer shape.

By the way, in recent years, along with the growing demand for building a recycling-based society, there is a desire to break away from fossil fuels in the material field as well as energy, and the use of biomass is attracting attention. Biomass is an organic compound that is photosynthesised from carbon dioxide and water, and is a so-called carbon-neutral renewable energy that is regenerated into carbon dioxide and water by using it. In recent years, biomass plastics using biomass as raw materials have been rapidly put to practical use, and attempts have been made to produce various resins from biomass raw materials.

For example, Cited Document 1 proposes a bag-in-box in which a biomass-derived polyolefin resin is used for the inner bag for the purpose of reducing the amount of petroleum resources used.

Japanese Patent Application Laid-Open No. 2019-51968

The present inventors attempted to manufacture a bag-in-box using the inner bag described above. However, with such a bag-in-box, pinholes may occur in the inner bag during the manufacture of the inner bag and the transportation of the bag-in-box, and the contents may be affected by the outside air or the contents may leak. A new problem arose.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a resin film that can reduce carbon dioxide emissions and has excellent pinhole resistance.
Another object of the present invention is to provide a packaging container containing this resin film.

The resin film of the present invention includes at least a first layer and a second layer directly laminated on the first layer,
The thickness of the resin film is 15 μm or more and 150 μm or less,
The thickness of the second layer is thicker than the thickness of the first layer,
The resin film contains 90% by mass or more of linear low-density polyethylene obtained by polymerizing ethylene and α-olefin monomers with respect to the entire resin film,
The resin film contains 51% by mass or more of a linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms with respect to the entire resin film,
The resin film contains biomass linear low density polyethylene.

In the resin film of the present invention, the resin film further comprises a third layer directly laminated to the second layer,
The thickness of the second layer may be thicker than the thickness of the third layer.

In the resin film of the present invention, the second layer may contain more biomass linear low-density polyethylene than the first and third layers.

In the resin film of the present invention, the third layer may contain more biomass linear low-density polyethylene than the first layer.

The resin film of the present invention may have a density of 0.900 g/cm ³ or more and 0.930 g/cm ³ or less.

In the resin film of the present invention, the resin film may contain fossil fuel linear low density polyethylene.

In the resin film of the present invention, a fossil fuel linear low density polyethylene is polymerized with a metallocene catalyst to polymerize a fossil fuel-derived ethylene and an α-olefin monomer containing a fossil fuel-derived compound having 6 or more carbon atoms. It may also contain a fossil fuel linear low density polyethylene consisting of:

In the resin film of the present invention, the second layer may contain biomass linear low density polyethylene and fossil fuel linear low density polyethylene.

The resin film of the present invention may have a biomass degree of 40% or less.

In the resin film of the present invention, the biomass degree of the first layer may be 25% or less.

In the resin film of the present invention, the resin film may be used for the inner bag of the packaging container.

The packaging container of the present invention includes an inner bag containing an outer layer film and an inner layer film, and an exterior body,
At least one of the outer layer film and the inner layer film contains the resin film.

In the packaging container of the present invention, the packaging container may include a spout joined to the inner bag.

ADVANTAGE OF THE INVENTION According to this invention, the resin film which can reduce the discharge|emission amount of a carbon dioxide and was excellent in pinhole resistance can be provided.
Moreover, according to this invention, the packaging container containing this resin film can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the resin film of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the resin film of this invention. It is a perspective view which shows an example of the packaging container of this invention. FIG. 2 is a plan view showing an example of an inner bag included in the packaging container of the present invention; FIG. 4 is a cross-sectional view (cross-sectional view taken along line AA in FIG. 4) showing an example of an inner bag included in the packaging container of the present invention; FIG. 4 is a plan view showing another example of an inner bag included in the packaging container of the present invention; FIG. 3 is a cross-sectional view showing an example of an outer layer film of an inner bag provided in the packaging container of the present invention; FIG. 3 is a cross-sectional view showing an example of an outer layer film of an inner bag provided in the packaging container of the present invention; FIG. 3 is a cross-sectional view showing an example of an outer layer film of an inner bag provided in the packaging container of the present invention; FIG. 3 is a cross-sectional view showing an example of an outer layer film of an inner bag provided in the packaging container of the present invention; FIG. 4 is a plan view showing a test piece for evaluating impact strength; It is a figure which shows an example of the measuring method of impact strength.

An embodiment of the present invention will be described with reference to FIGS. 1 to 12. FIG. In addition, in the drawings attached to this specification, for the convenience of illustration and easy understanding, the scale, length-to-width ratio, etc. are appropriately changed and exaggerated from those of the real thing.

In addition, the terms such as "parallel", "perpendicular", "same" and the like, length and angle values, etc. that specify shapes and geometric conditions and their degrees used in this specification are strictly It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.

In this specification, when two or more upper limit candidates and two or more lower limit candidates are given for a parameter, the numerical range of the parameter includes any one upper limit candidate and any It may be configured by combining one lower limit value candidate. For example, consider a case where it is described that "parameter B is, for example, greater than or equal to A1 and may be greater than or equal to A2. Parameter B is, for example, less than or equal to A3 and may be less than or equal to A4." In this case, the numerical range of parameter B may be A1 or more and A3 or less, A1 or more and A4 or less, A2 or more and A3 or less, or A2 or more and A4 or less.

[Resin film]
The resin film 10 of the present invention includes at least a first layer 11 and a second layer 12 directly laminated on the first layer 11, as shown in FIG. located on the inner side of The "inner surface side" means the content side when the resin film is used for the inner bag of the packaging container.

In one embodiment, the resin film 10 includes a first layer 11, a second layer 12 directly laminated to the first layer 11, and a second layer 12 directly laminated to the second layer 12, as shown in FIG. 3 layers 13 , the first layer being located on the inner surface side of the resin film 10 .

The resin film of the present invention contains 90% by mass or more of linear low-density polyethylene obtained by polymerizing ethylene and α-olefin monomers with respect to the entire resin film. Thereby, a resin film having excellent pinhole resistance can be obtained. The resin film preferably contains 95% by mass or more, more preferably 98% by mass or more, of linear low-density polyethylene relative to the entire resin film.

Linear low density polyethylene (LLDPE) will now be described. Linear low-density polyethylene is a copolymer of ethylene and α-olefin polymerized using a multi-site catalyst typified by a Ziegler-Natta catalyst or a single-site catalyst typified by a metallocene catalyst. is less than 0.930 g/cm ³ . Therefore, it is a high-pressure ethylene homopolymer and is distinguished from low-density polyethylene (hereinafter also referred to as high-pressure low-density polyethylene) that can be obtained by a conventionally known high-pressure radical polymerization method. Examples of α-olefins that are comonomers for linear low-density polyethylene include α-olefins that are compounds having 3 or more carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1- nonene, 4-methylpentene, 3,3-dimethylbutene, etc., and mixtures thereof. The density of polyethylene is a value measured according to method A of JIS K7112-1980 after annealing according to JIS K6760-1995.

The above-mentioned single-site catalyst is a catalyst capable of forming uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound or non-metallocene-based transition metal compound with an activating co-catalyst. be. A single-site catalyst has a more uniform active site structure than a multi-site catalyst, and is therefore preferable because it can polymerize a polymer having a high molecular weight and a highly uniform structure. As the single-site catalyst, it is particularly preferable to use a metallocene-based catalyst. The metallocene-based catalyst is a catalyst containing a transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, a cocatalyst, an organometallic compound if necessary, and each catalyst component of a carrier. is.

In the transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group, or the like. . Substituted cyclopentadienyl groups include hydrocarbon groups having 1 to 30 carbon atoms, silyl groups, silyl-substituted alkyl groups, silyl-substituted aryl groups, cyano groups, cyanoalkyl groups, cyanoaryl groups, halogen groups, haloalkyl groups and halosilyl groups. It has at least one substituent selected from groups and the like. The substituted cyclopentadienyl group may have two or more substituents, and the substituents are bonded to each other to form a ring such as an indenyl ring, a fluorenyl ring, an azulenyl ring, hydrogenated forms thereof, and the like. may be formed. A ring formed by combining substituents with each other may further have a substituent with each other.

In the transition metal compound of group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton, examples of the transition metal include zirconium, titanium, hafnium and the like, with zirconium and hafnium being particularly preferred. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and each ligand having a cyclopentadienyl skeleton is preferably bonded to each other by a bridging group. The bridging group includes an alkylene group having 1 to 4 carbon atoms, a silylene group, a dialkylsilylene group, a substituted silylene group such as a diarylsilylene group, and a substituted germylene group such as a dialkylgermylene group and a diarylgermylene group. A substituted silylene group is preferred.

In the transition metal compounds of Group IV of the periodic table, typical examples of ligands other than ligands having a cyclopentadienyl skeleton include hydrogen, hydrocarbon groups having 1 to 20 carbon atoms (alkyl groups , an alkenyl group, an aryl group, an alkylaryl group, an aralkyl group, a polyenyl group, etc.), a halogen, a metaalkyl group, a metaaryl group, and the like.

One or a mixture of two or more of the transition metal compounds of Group IV of the periodic table containing the ligand having a cyclopentadienyl skeleton can be used as a catalyst component.

The co-catalyst is one that can make the above Group IV transition metal compound of the periodic table effective as a polymerization catalyst, or one that can balance the ionic charges in a catalytically activated state. Examples of co-catalysts include benzene-soluble aluminoxanes of organoaluminumoxy compounds, benzene-insoluble organoaluminumoxy compounds, ion-exchange layered silicates, boron compounds, cations containing or not containing active hydrogen groups, and non-coordinating anions. ionic compounds, lanthanide salts such as lanthanum oxide, tin oxide, and phenoxy compounds containing a fluoro group.

The transition metal compound of Group IV of the periodic table containing a ligand having a cyclopentadienyl skeleton may be supported on an inorganic or organic compound carrier before use. As the carrier, porous oxides of inorganic or organic compounds are preferable, and specifically, ion-exchange layered silicates such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ and B ₂ O. ₃ , CaO, ZnO, BaO, _ThO2 , etc. or mixtures thereof.

Examples of organometallic compounds that may be used if necessary include organoaluminum compounds, organomagnesium compounds, and organozinc compounds. Of these, organic aluminum is preferably used.

The resin film of the present invention contains 51% by mass or more of linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms with respect to the entire resin film. Thereby, a resin film having excellent pinhole resistance can be obtained. The ratio of linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms to the entire resin film may be 60% by mass or more, or 70% by mass or more. There may be. The ratio of linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms to the entire resin film may be 95% by mass or less, or 90% by mass or less. There may be.

The “α-olefin containing compounds having 6 or more carbon atoms” may be a single compound. For example, "α-olefin containing a compound having 6 or more carbon atoms" may be an α-olefin that is a compound having 6 carbon atoms or an α-olefin that is a compound having 8 carbon atoms.

The "α-olefin containing compounds having 6 or more carbon atoms" may be a mixture of two or more compounds. For example, "α-olefin containing a compound with 6 or more carbon atoms" may be a mixture of an α-olefin that is a compound with 4 carbon atoms and an α-olefin that is a compound with 6 carbon atoms. In this case, the linear low-density polyethylene is a terpolymer obtained by polymerizing ethylene, an α-olefin having 4 carbon atoms and an α-olefin having 6 carbon atoms.

The resin film of the present invention contains biomass linear low-density polyethylene. As a result, the amount of carbon dioxide emitted can be reduced, and a resin film having excellent environmental load reduction properties can be obtained.

The method for producing biomass-derived ethylene and α-polyolefin, which are raw materials for biomass linear low-density polyethylene, is not particularly limited, and can be obtained by conventionally known methods. An example of a method for producing biomass-derived ethylene will be described below.

Biomass-derived ethylene can be produced using biomass-derived ethanol as a raw material. In particular, it is preferable to use biomass-derived fermented ethanol obtained from plant raw materials. Plant raw materials are not particularly limited, and conventionally known plants can be used. For example, corn, sugar cane, beets, and manioc can be mentioned.

Biomass-derived fermented ethanol refers to ethanol produced by contacting a culture solution containing a carbon source obtained from a plant material with a microorganism that produces ethanol or a product derived from a crushed product thereof, and then refining the ethanol. Conventionally known methods such as distillation, membrane separation, and extraction can be applied to purify ethanol from the culture medium. For example, a method of adding benzene, cyclohexane or the like to cause azeotropy, or removing water by membrane separation or the like can be mentioned.

In order to obtain the above-mentioned ethylene, at this stage, advanced purification such as reducing the total amount of impurities in ethanol to 1 ppm or less may be further performed.

A catalyst is usually used to obtain ethylene by the dehydration reaction of ethanol, but the catalyst is not particularly limited, and conventionally known catalysts can be used. Advantageous in terms of process is a fixed bed flow reaction in which the catalyst and product can be easily separated, and for example, γ-alumina is preferred.

Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. Although the heating temperature is not limited as long as the reaction proceeds at a commercially useful reaction rate, a temperature of preferably 100° C. or higher, more preferably 250° C. or higher, and even more preferably 300° C. or higher is suitable. Although the upper limit is not particularly limited, it is preferably 500° C. or less, more preferably 400° C. or less from the viewpoint of energy balance and equipment.

In the dehydration reaction of ethanol, the yield of the reaction depends on the amount of water contained in ethanol supplied as a raw material. In general, when a dehydration reaction is performed, it is preferable that there is no water in consideration of water removal efficiency. However, it has been found that in the case of ethanol dehydration using a solid catalyst, the amount of other olefins, especially butene, tends to increase in the absence of water. It is presumed that this is probably because ethylene dimerization after dehydration cannot be suppressed unless a small amount of water exists. The lower limit of the allowable water content is 0.1% by mass or more, preferably 0.5% by mass or more. Although the upper limit is not particularly limited, it is preferably 50% by mass or less, more preferably 30% by mass or less, and still more preferably 20% by mass or less from the viewpoint of material balance and heat balance.

By carrying out the dehydration reaction of ethanol in this way, a mixed portion of ethylene, water and a small amount of unreacted ethanol is obtained. Ethylene can be obtained by removing water and ethanol. This may be done by a known method.

Ethylene obtained by gas-liquid separation is further distilled, and the distillation method, operating temperature, residence time, etc. are not particularly limited except that the operating pressure at this time is normal pressure or higher.

When the raw material is biomass-derived ethanol, the resulting ethylene contains carbonyl compounds such as ketones, aldehydes, and esters, which are impurities mixed in the ethanol fermentation process, and carbon dioxide, which is their decomposition products, and enzyme decomposition products. Nitrogen-containing compounds such as amines and amino acids, which are contaminants, and ammonia, which are decomposition products thereof, are contained in extremely small amounts. Depending on the use of ethylene, these trace amounts of impurities may pose a problem, so they may be removed by refining. The purification method is not particularly limited, and a conventionally known method can be used. A suitable purification operation is, for example, an adsorption purification method. The adsorbent to be used is not particularly limited, and conventionally known adsorbents can be used. For example, a material with a high surface area is preferable, and the type of adsorbent is selected according to the type and amount of impurities in ethylene obtained by the dehydration reaction of biomass-derived ethanol.

As a method for purifying impurities in ethylene, caustic water treatment may be used in combination. If caustic water is to be treated, it is desirable to do so before adsorption purification. In that case, after the caustic treatment, it is necessary to apply moisture removal treatment before adsorption purification.

The biomass linear low-density polyethylene may be obtained by polymerizing a monomer containing biomass-derived ethylene and/or biomass-derived α-polyolefin. When biomass-derived ethylene is used as the monomer, it is preferable to use one obtained by the above-described production method. Since biomass-derived ethylene and/or biomass-derived α-polyolefin are used as raw material monomers, the polymerized polyethylene is derived from biomass. The raw material monomer for polyethylene does not have to contain 100% by mass of biomass-derived monomers.

The monomer, which is the raw material for biomass linear low-density polyethylene, may further contain fossil fuel-derived ethylene and/or fossil fuel-derived α-olefin.

The α-polyolefin used to produce the biomass linear low-density polyethylene may be an α-olefin containing compounds with 6 or more carbon atoms. For example, α-polyolefin used for producing biomass linear low-density polyethylene is a mixture of α-olefin which is a compound having 4 carbon atoms and α-olefin which is a compound having 6 carbon atoms. good. The α-olefin which is a compound having 4 carbon atoms and/or the α-olefin which is a compound having 6 carbon atoms may be derived from fossil fuel or biomass.

The resin film of the present invention preferably has a biomass degree of 40% or less. Thereby, the pinhole resistance of the resin film can be further improved, and the impact strength of the resin film can be improved. The biomass degree of the resin film is more preferably 5% or more and 40% or less, and further preferably 10% or more and 30% or less.

Since carbon dioxide in the atmosphere contains a certain amount of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in all carbon atoms, the ratio of biomass-derived carbon can be calculated. In the present invention, the term “biomass degree” indicates the weight ratio of biomass-derived components. Taking polyethylene terephthalate as an example, polyethylene terephthalate is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1. In the case of using only this material, the weight ratio of the biomass-derived component in the polyester is 31.25%, so the theoretical value of the degree of biomass is 31.25%. Specifically, the mass of polyethylene terephthalate is 192, of which the mass derived from biomass-derived ethylene glycol is 60, so 60÷192×100=31.25. In addition, the weight ratio of the biomass-derived component in the fossil fuel polyester produced using fossil fuel-derived ethylene glycol and fossil fuel-derived dicarboxylic acid is 0%, and the biomass degree of the fossil fuel polyester is 0%. Become. Hereinafter, unless otherwise specified, the “biomass degree” indicates the weight ratio of biomass-derived components.

In the present invention, theoretically, if only biomass-derived raw materials are used as raw materials for polyethylene, the concentration of biomass-derived ethylene is 100%, and the biomass degree of biomass polyethylene is 100%. Further, the concentration of biomass-derived ethylene in fossil fuel polyethylene produced only from fossil fuel-derived raw materials is 0%, and the biomass degree of fossil fuel polyethylene is 0%.

The resin film of the present invention may contain fossil fuel linear low density polyethylene. This makes it possible to improve the pinhole resistance of the resin film, the impact strength of the resin film, the seal strength of the resin film, and the sealability such as the low-temperature sealability. In addition, the fossil fuel linear low density polyethylene includes fossil fuel linear low density polyethylene obtained by polymerizing α-olefin monomers containing fossil fuel-derived ethylene and fossil fuel-derived compounds having 6 or more carbon atoms. Preferably, using a metallocene catalyst, fossil fuel-derived ethylene and α-olefin monomers containing fossil fuel-derived compounds having 6 or more carbon atoms are polymerized. more preferred. Thereby, the pinhole resistance and sealability of the resin film can be further improved.

The α-olefin containing a fossil fuel-derived compound having 6 or more carbon atoms, which is used to produce the fossil fuel linear low density polyethylene, may be a single compound. For example, the α-olefin containing a fossil fuel-derived compound having 6 or more carbon atoms, which is used to produce a fossil fuel linear low-density polyethylene, may be a fossil fuel-derived C6 α-olefin. Alternatively, it may be an α-olefin having 8 carbon atoms derived from a fossil fuel.

The α-olefin containing a fossil fuel-derived compound having 6 or more carbon atoms used for producing the fossil fuel linear low-density polyethylene may be a mixture of two or more fossil fuel-derived compounds. For example, the α-olefin containing a fossil fuel-derived compound having 6 or more carbon atoms, which is used for producing fossil fuel linear low-density polyethylene, is composed of a fossil fuel-derived α-olefin having 4 carbon atoms and a fossil fuel It may be a mixture with the derived C 6 α-olefin.

The density of the resin film is preferably 0.900 g/cm ³ or more and 0.930 g/cm ³ or less. By setting the density of the resin film to 0.900 g/cm ³ or more, the mechanical strength of the resin film can be increased. By setting the density of the resin film to 0.930 g/cm ³ or less, the pinhole resistance and sealability of the resin film can be improved. The density of the resin film is more preferably 0.904 g/cm ³ or more and 0.926 g/cm ³ or less, and further preferably 0.910 g/cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the resin film is preferably 15 μm or more and 150 μm or less. By setting the thickness of the resin film to 15 μm or more, the impact strength and sealability of the resin film can be improved. By setting the thickness of the resin film to 150 μm or less, the flexibility of the resin film can be improved. The thickness of the resin film is more preferably 20 μm or more and 120 μm or less, and further preferably 30 μm or more and 100 μm or less.

The melt flow rate (MFR) of the resin film is preferably 0.1 g/10 minutes or more and 10 g/10 minutes or less, more preferably 0.2 g/10 minutes or more and 5 g/10 minutes or less. More preferably, it is 5 g/10 minutes or more and 3 g/10 minutes or less. By setting the MFR to 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. By setting the MFR to 10 g/10 minutes or less, the mechanical strength of the resin film can be enhanced.

The impact strength of the resin film of the present invention is preferably 0.60 J or more, more preferably 0.8 J or more, and still more preferably 1.00 J or more. A method for measuring the impact strength will be described in Examples described later.

The tensile strength of the resin film of the present invention is preferably 35 MPa or higher, more preferably 40 MPa or higher, in at least one direction. For example, the tensile strength of the film in the machine direction (MD) is preferably 35 MPa or higher, more preferably 40 MPa or higher. Also, the tensile strength of the resin film in the vertical (TD) direction is preferably 35 MPa or more, more preferably 40 MPa or more.

Tensile strength can be measured according to JIS Z1702. As a measuring instrument, a tensile tester RTC-1210 manufactured by Orientec Co., Ltd. can be used. As the test piece, a dumbbell-shaped film having a width of 10 mm and a length of 120 mm cut out from the resin film can be used. The distance between the pair of chucks holding the specimen at the start of the measurement is 80 mm, and the pulling speed is 500 mm/min. Note that the length of the test piece can be adjusted as long as the test piece can be gripped by the pair of chucks. In the present application, unless otherwise specified, the temperature during the measurement of tensile strength and tensile elongation is 23°C.

The resin film of the present invention may contain one or more of high-density polyethylene (HDPE), medium-density polyethylene (MDPE), and low-density polyethylene (LDPE) as long as the objects of the present invention are not impaired. High-density polyethylene means polyethylene having a density of 0.942 g/cm ³ or more, and medium-density polyethylene means polyethylene having a density of 0.930 g/cm ^{3 or more and less than 0.942 g/cm 3 .} means. Low-density polyethylene means the above-described high-pressure low-density polyethylene, and means polyethylene having a density of less than 0.930 g/cm ³ .

The resin film of the present invention may contain additives as long as the object of the present invention is not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

Since the resin film of the present invention is excellent in pinhole resistance, it can be suitably used for the inner bag of a packaging container such as a bag-in-box.

<First layer>
A 1st layer is a layer located in the inner surface side of a resin film. In one embodiment, the first layer comprises linear low density polyethylene. Thereby, the pinhole resistance of the resin film can be improved.

In one embodiment, the first layer comprises fossil fuel linear low density polyethylene. Thereby, the pinhole resistance, impact strength, and sealability of the resin film can be improved.
Also, in one embodiment, the first layer comprises biomass linear low density polyethylene. Thereby, the environmental load reduction property can be improved.
Also, in one embodiment, the first layer comprises fossil fuel linear low density polyethylene and biomass linear low density polyethylene. As a result, it is possible to improve the ability to reduce the environmental load, and to improve the pinhole resistance and sealability of the resin film.

The content of the fossil fuel linear low-density polyethylene in the first layer is preferably 50% by mass or more. This can further improve the pinhole resistance, impact strength, and sealability of the resin film. The content of the fossil-fuel linear low-density polyethylene in the first layer is more preferably 75% by mass or more, and even more preferably 95% by mass or more. Also, the first layer may be composed of fossil fuel linear low-density polyethylene.

The fossil fuel linear low density polyethylene of the first layer is a fossil fuel linear low density polyethylene obtained by polymerizing α-olefin monomers containing fossil fuel-derived ethylene and fossil fuel-derived compounds having 6 or more carbon atoms. It is preferred to include This can further improve the pinhole resistance, impact strength, and sealability of the resin film.

The content of biomass linear low-density polyethylene in the first layer is preferably 50% by mass or less. As a result, it is possible to improve the ability to reduce the environmental load, and to further improve the pinhole resistance, impact strength, and sealability of the resin film. The content of biomass linear low-density polyethylene in the first layer is more preferably 1% by mass or more and 50% by mass or less, and even more preferably 1% by mass or more and 25% by mass or less.

The first layer preferably has a biomass degree of 50% or less. As a result, it is possible to improve the ability to reduce the environmental load, and to further improve the pinhole resistance, impact strength, and sealability of the resin film. The biomass degree of the first layer is more preferably 1% or more and 50% or less, and further preferably 1% or more and 25% or less.

The density of the first layer is preferably 0.900 g/cm ³ or more and 0.930 g/cm ³ or less. By setting the density of the first layer to 0.900 g/cm ³ or more, the mechanical strength of the resin film can be increased. By setting the density of the first layer to 0.930 g/cm ³ or less, the pinhole resistance and sealability of the resin film can be improved. The density of the first layer is more preferably 0.904 g/cm ³ or more and 0.926 g/cm ³ or less, and further preferably 0.910 g/cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the first layer is preferably 5 μm or more and 50 μm or less. By setting the thickness of the first layer to 5 μm or more, the impact strength and sealability of the resin film can be improved. By setting the thickness of the first layer to 50 μm or less, the flexibility of the resin film can be improved. The thickness of the first layer is more preferably 10 μm or more and 40 μm or less, and even more preferably 10 μm or more and 30 μm or less.

The melt flow rate (MFR) of the first layer is preferably 0.1 g/10 min or more and 10 g/10 min or less, more preferably 0.2 g/10 min or more and 5 g/10 min or less. 5 g/10 minutes or more and 3 g/10 minutes or less is more preferable. By setting the MFR to 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. By setting the MFR to 10 g/10 minutes or less, the mechanical strength of the resin film can be enhanced.

The first layer may contain one or more of high-density polyethylene, medium-density polyethylene, and low-density polyethylene as long as the object of the present invention is not impaired.

The first layer may contain additives as long as the objects of the present invention are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The first layer may be a single layer or multiple layers of two or more layers.

<Second layer>
A second layer is a layer that is directly laminated to the first layer. Moreover, in the resin film of the present invention, the thickness of the second layer is thicker than the thickness of the first layer. Thereby, a resin film having excellent pinhole resistance can be obtained. The thickness ratio of the first layer to the second layer is preferably 1:4 to 1.1, more preferably 1:3 to 1.5.

When the resin film of the present invention includes the third layer, the thickness of the second layer is preferably thicker than the thickness of the third layer. Thereby, the pinhole resistance of the resin film can be improved. The thickness ratio of the second layer to the third layer is preferably 4 to 1.1:1, more preferably 3 to 1.5:1.

In one embodiment, the second layer comprises biomass linear low density polyethylene and fossil fuel linear low density polyethylene. As a result, it is possible to improve the ability to reduce the environmental load, and to improve the pinhole resistance and impact strength of the resin film.
The content of fossil fuel linear low-density polyethylene in the second layer is preferably 20% by mass or more and 95% or less, more preferably 30% by mass or more and 90% by mass or less, and 40% by mass or more and 80% by mass. % by mass or less is more preferable.
In addition, the content of biomass linear low-density polyethylene in the second layer is preferably 5% by mass or more and 80% by mass or less, more preferably 10% by mass or more and 70% by mass or less, and 20% by mass. It is more preferable that the content is 60% by mass or more.

In one embodiment, the second layer comprises more biomass linear low density polyethylene than the first layer. Also, in one embodiment, the second layer comprises more biomass linear low density polyethylene than the third layer. As a result, it is possible to further improve the ability to reduce the environmental load, and to further improve the pinhole resistance and impact strength of the resin film.

The fossil fuel linear low-density polyethylene contained in the second layer is a fossil fuel linear low-density polyethylene obtained by polymerizing α-olefin monomers containing fossil fuel-derived ethylene and fossil fuel-derived compounds having 6 or more carbon atoms. Linear low-density polyethylene for Mars fuel, preferably containing density polyethylene, obtained by polymerizing fossil fuel-derived ethylene and α-olefin monomers containing fossil fuel-derived compounds having 6 or more carbon atoms using a metallocene catalyst. It is more preferable to include Thereby, the pinhole resistance and impact strength of the resin film can be further improved.

The second layer preferably has a biomass degree of 70% or less. As a result, it is possible to improve the ability to reduce the environmental load, and to further improve the pinhole resistance and impact strength of the resin film. The biomass degree of the second layer is more preferably 10% or more and 60% or less, and further preferably 15% or more and 50% or less.

The density of the second layer is preferably 0.900 g/cm ³ or more and 0.930 g/cm ³ or less. By setting the density of the second layer to 0.900 g/cm ³ or more, the mechanical strength of the resin film can be increased. By setting the density of the second layer to 0.930 g/cm ³ or less, the pinhole resistance and sealability of the resin film can be improved. The density of the second layer is more preferably 0.904 g/cm ³ or more and 0.926 g/cm ³ or less, and further preferably 0.910 g/cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the second layer is preferably 10 μm or more and 100 μm or less. By setting the thickness of the second layer to 10 μm or more, the impact strength of the resin film can be improved. By setting the thickness of the second layer to 100 μm or less, the flexibility of the resin film can be improved. The thickness of the second layer is more preferably 20 μm or more and 80 μm or less, and even more preferably 20 μm or more and 60 μm or less.

The melt flow rate (MFR) of the second layer is preferably 0.1 g/10 min or more and 10 g/10 min or less, more preferably 0.2 g/10 min or more and 5 g/10 min or less. 5 g/10 minutes or more and 3 g/10 minutes or less is more preferable. By setting the MFR to 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. By setting the MFR to 10 g/10 minutes or less, the mechanical strength of the resin film can be enhanced.

The second layer may contain one or more of high-density polyethylene, medium-density polyethylene, and low-density polyethylene as long as the object of the present invention is not impaired.

The second layer may contain additives as long as the objects of the present invention are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The second layer may be a single layer or multiple layers of two or more layers.

<Third layer>
In one embodiment, the resin film further comprises a third layer. Thereby, the sealing property of the resin film and the lamination strength with other layers can be improved. Also, in one embodiment, the third layer comprises linear low density polyethylene. Thereby, the pinhole resistance of the resin film can be improved.

In one embodiment, the third layer comprises fossil fuel linear low density polyethylene. Thereby, the pinhole resistance, impact strength, sealability and lamination strength of the resin film can be improved.
Also, in one embodiment, the third layer comprises biomass linear low density polyethylene. Thereby, the environmental load reduction property can be improved.
Also, in one embodiment, the third layer comprises fossil fuel linear low density polyethylene and biomass linear low density polyethylene. As a result, it is possible to improve the ability to reduce the environmental load, and to improve the pinhole resistance, impact strength, sealability, and lamination strength of the resin film.

The content of the fossil fuel linear low-density polyethylene in the third layer is preferably 50% by mass or more. This can further improve the pinhole resistance, sealability and lamination strength of the resin film. The content of fossil fuel linear low-density polyethylene in the third layer is more preferably 75% by mass or more, and even more preferably 95% by mass or more. Also, the third layer may be composed of fossil fuel linear low-density polyethylene.

The fossil fuel linear low density polyethylene of the third layer is a fossil fuel linear low density polyethylene obtained by polymerizing α-olefin monomers containing fossil fuel-derived ethylene and fossil fuel-derived compounds having 6 or more carbon atoms. It is preferred to include Thereby, the pinhole resistance of the resin film and the sealing lamination strength can be further improved.

The content of biomass linear low-density polyethylene in the third layer is preferably 50% by mass or less. As a result, it is possible to improve the ability to reduce the environmental load, and to further improve the pinhole resistance, impact strength, sealability, and lamination strength of the resin film. The content of biomass linear low-density polyethylene in the third layer is more preferably 1% by mass or more and 50% by mass or less, and even more preferably 1% by mass or more and 25% by mass or less.

The third layer preferably has a biomass degree of 50% or less. As a result, it is possible to improve the ability to reduce the environmental load, and to further improve the pinhole resistance, impact strength, sealability, and lamination strength of the resin film. The biomass degree of the second layer is more preferably 1% or more and 50% or less, and even more preferably 1% or more and 25% or less.

The density of the third layer is preferably 0.900 g/cm ³ or more and 0.930 g/cm ³ or less. By setting the density of the third layer to 0.900 g/cm ³ or more, the mechanical strength of the resin film can be increased. By setting the density of the third layer to 0.930 g/cm ³ or less, the pinhole resistance, sealability and laminate strength of the resin film can be improved. The density of the third layer is more preferably 0.904 g/cm ³ or more and 0.926 g/cm ³ or less, and even more preferably 0.910 g/cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the third layer is preferably 10 μm or more and 100 μm or less. By setting the thickness of the third layer to 10 μm or more, the impact strength, sealability and lamination strength of the resin film can be improved. By setting the thickness of the third layer to 100 μm or less, the flexibility of the resin film can be improved. The thickness of the third layer is more preferably 20 μm or more and 80 μm or less, and even more preferably 20 μm or more and 60 μm or less.

The melt flow rate (MFR) of the third layer is preferably 0.1 g/10 min or more and 10 g/10 min or less, more preferably 0.2 g/10 min or more and 5 g/10 min or less. 5 g/10 minutes or more and 3 g/10 minutes or less is more preferable. By setting the MFR to 0.1 g/10 minutes or more, the extrusion load during molding can be reduced. By setting the MFR to 10 g/10 minutes or less, the mechanical strength of the resin film can be enhanced.

The third layer may contain one or more of high-density polyethylene, medium-density polyethylene, and low-density polyethylene as long as the object of the present invention is not impaired.

The third layer may contain additives as long as the object of the present invention is not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The third layer may be a single layer or multiple layers of two or more layers.

[Method for producing resin film]
The method for producing the resin film of the present invention is not particularly limited, and it can be produced by a conventionally known method. The resin film is preferably co-extruded, and more preferably co-extruded by a T-die method or an inflation method. An example of a method for producing a resin film by a T-die method or an inflation method will be described below.

In the T-die method, after drying the resin constituting the first layer and the resin constituting the second layer, respectively, the melt extrusion heated to a temperature above the melting point (Tm) to Tm + 70 ° C. It is possible to form a resin film by supplying the materials to a machine, melting them, coextrusion into a sheet form from a die of a T die, and rapidly solidifying the coextruded sheet material with a rotating cooling drum or the like. can.
As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

In the inflation method, first, the resin constituting the first layer and the resin constituting the second layer are dried, and then melted at a temperature above the melting point (Tm) to Tm + 70 ° C. They are fed to an extruder, melted, and co-extruded into a cylindrical shape through an annular die. At this time, air is sent from below into the cylindrical molten resin to expand the diameter of the cylinder to a predetermined size, and cooling air is sent outside the cylinder from below. This expanded cylindrical body is called a bubble. Subsequently, the bubble is folded into a film by means of guide plates and pinch rolls and wound up in a winding section. The folded film may be wound as it is in a cylindrical shape, or both ends of the cylinder may be removed by a slitter or the like, cut into two films, and then each film may be wound. Thereby, a resin film can be molded.
As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose.

In the case of a resin film having a first layer, a second layer, and a third layer, it can be produced in the same manner as described above, using resins constituting each layer.

[Packaging container]
In the present invention, the packaging container includes an inner bag including an outer layer film and an inner layer film, and an exterior body. Moreover, in the present invention, at least one of the outer layer film and the inner layer film of the packaging container contains the resin film of the present invention. As a result, the inner bag can have excellent pinhole resistance.
In one embodiment, the packaging container of the present invention includes a spout joined to the inner bag.

FIG. 3 is a perspective view showing an example of the packaging container 20 of the present invention. The packaging container 20 includes an exterior body 30 and an inner bag 40 housed in the exterior body 30 . Moreover, as shown in FIG. 3, the packaging container 20 may have a spout 50 for pouring out the contents. In this case, the exterior body 30 may be formed with an opening 60 for exposing the spout 50 to the outside of the exterior body 30 .
In one embodiment, the packaging container may have two or more spouts and openings for exposing the spouts to the outside of the exterior body (not shown).

<Exterior body>
The exterior body of the packaging container of the present invention is used to protect the inner bag housed in the exterior body. In one embodiment, the exterior body is configured in a substantially rectangular parallelepiped shape or a substantially columnar shape.

The material constituting the outer package can be appropriately selected according to the conditions such as the capacity of the contents, the type of contents, the purpose of packaging, the form of packaging, the form of distribution, the form of sales, and others. , metals, resins, and the like.

<inner bag>
The inner bag of the packaging container of the present invention is accommodated in the exterior body and has a space inside which can accommodate contents. The capacity of the inner bag can be appropriately selected according to conditions such as the type of contents, packaging purpose, packaging form, distribution form, sales form, and other conditions. There are various things such as bags.

FIG. 4 is a plan view showing an example of an inner bag included in the packaging container of the present invention. A flat bag-type inner bag 40 as shown in FIG. In the example shown in FIG. 4, the inner bag 40 has a rectangular outer shape.

In the inner bag 40, the front surface 41 and the rear surface 42 are adhered to each other at the sealing portion that joins the film-like members. The seal portion has a top seal portion 46 located on the top portion 43, a bottom seal portion 47 located on the bottom portion 44, and side seal portions 48 located on a pair of side portions 45a and 45b. The method for forming the seal portion is not particularly limited, but for example, the seal portion is formed by melting a part of the film-like member by heating or the like and welding the film-like members together. good too. At this time, as a method of heat sealing, for example, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing can be used.

A spout 50 is attached to the front surface 41 of the inner bag 40 to inject the content into the inner bag 40 and to pour out the contained content. This spout 50 protrudes outward from the front face 41 . The spout may be capped, for example, by tapping.

Such an inner bag 40 is composed of an outer layer film 411 forming a front surface 41 and an outer layer film 421 forming a rear surface 42, as shown in FIG. An inner layer film 412 is provided inside the outer layer film 411 , and an inner layer film 422 is provided inside the outer layer film 421 . In this case, the contents are accommodated between the inner layer film 412 and the inner layer film 422 . As a result, even if the outer layer film 411 or the outer layer film 421 is broken, it is possible to prevent the contents from leaking out of the inner bag 40 . Moreover, in this case, the outlet 50 described above is attached to the outer layer film 411 and the inner layer film 412, and is configured to allow the inside and the outside of the inner bag 40 to communicate with each other.

In one embodiment, the packaging container of the present invention may include an inner bag 70 shown in FIG. 6 as an inner bag.

FIG. 6 is a plan view showing another example of the inner bag included in the packaging container of the present invention. A gusseted bladder 70 as shown in FIG. 6 includes a front surface 71 , a rear surface 72 and a pair of side surfaces 73 . A pair of side surfaces 73 are sandwiched between the front surface 71 and the rear surface 72 . A pair of side surfaces 73 has folded-back portions 74, which are gussets, protruding inside the inner bag. A front surface 71, a rear surface 72 and a side surface 73 shown in FIG. 6 have a rectangular shape.

The front surface 71 and the rear surface 72 facing each other and the pair of side surfaces 73 are adhered by seals in four directions of the front surface 71 and the rear surface 72 . Four contact portions of the front surface 71 and the rear surface 72 are sealed to form a top seal portion 75 , a bottom seal portion 76 and side seal portions 77 . Each sealed portion can be formed by the heat sealing method described above.

In addition, two spouts 50 are attached to the front surface 71 of the inner bag 70 for injecting the content into the inner bag 70 and for pouring out the accommodated content. This spout 50 protrudes outward from the front surface 71 . The spout may be capped, for example, by tapping.

The inner bag 70 shown in FIG. 6 has a front surface 71, a rear surface 72 and side surfaces 73 made of an outer layer film (not shown). An inner layer film is provided inside these outer layer films (not shown). In this case, the contents are accommodated between the inner layer films.

Contents accommodated in the inner bag include foods, chemicals, industrial liquids, pharmaceuticals, and the like. Examples of foods include milk, dairy products, oils and fats, soup stock, liquid seasonings, beverages, alcoholic beverages, water, and the like. An inert gas such as nitrogen may be contained when the contents are contained in the inner bag.

(Outer layer film)
The outer layer film is a layer used to improve the strength of the inner bag, and includes at least a sealant layer. In one embodiment, the outer layer film may be composed of a sealant layer, or may be composed of a laminate of a sealant layer and other layers as shown in FIGS.

In one embodiment, the outer layer film 90 includes a sealant layer 91, an adhesive resin layer 92, and a gas barrier resin layer 93, as shown in FIG. Also, the sealant layer 91 is positioned on the inner surface side of the outer layer film 90 . "Inner side" means the content side of the inner bag.

In one embodiment, the outer layer film 90 includes a sealant layer 91, an adhesive resin layer 92, a deposited film 94, and a gas barrier resin layer 93, as shown in FIG. Also, the sealant layer 91 is positioned on the inner surface side of the outer layer film 90 .

In one embodiment, the outer layer film 90 includes a sealant layer 91, an adhesive resin layer 92, a deposited film 94, a gas barrier resin layer 93, and a surface resin layer 95, as shown in FIG. Also, the sealant layer 91 is positioned on the inner surface side of the outer layer film 90 .

In one embodiment, the outer layer film 90 includes a sealant layer 91, an adhesive resin layer 92, a metal foil 96, an adhesive resin layer 97, and a gas barrier resin layer 93, as shown in FIG. Also, the sealant layer 91 is positioned on the inner surface side of the outer layer film 90 .

It is also possible to appropriately combine a plurality of layer structures of the outer layer films shown in FIGS. 7 to 10 described above.

[Sealant layer]
The sealant layer contains a resin material that exerts heat-bonding properties, for example, polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene (homopolymer, block polymer, random polymer), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene- Methyl methacrylate copolymer (EMMA), ionomer resin, heat-sealable ethylene-vinyl alcohol resin or copolymerized resin Methylpentene resin, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene, polypropylene And polyolefin resins such as cyclic olefin copolymers, acid-modified polyolefin resins obtained by modifying polyolefin resins with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and itaconic acid, vinyl resins, and (Meth) acrylic resins and the like. Among these, polyethylene is preferable from the viewpoint of sealability, and linear low-density polyethylene is preferable from the viewpoint of sealability and pinhole resistance. The sealant layer may contain two or more of the above resin materials.

The sealant layer may contain additives as long as the objects of the present invention are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The density of the sealant layer is preferably 0.900 g/cm 3 or more and 0.930 g/cm ³ or less, more preferably 0.904 g/cm ³ or more and 0.926 g/cm ³ or less, and 0.910 g/cm ³ or more. /cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the sealant layer is preferably 15 μm or more and 150 μm or less, more preferably 20 μm or more and 120 μm or less, and even more preferably 30 μm or more and 100 μm or less. Further, the sealant layer may be a single layer or multiple layers of two or more layers.

The melt flow rate (MFR) of the sealant layer is preferably 0.1 g/10 minutes or more and 10 g/10 minutes or less, more preferably 0.2 g/10 minutes or more and 5 g/10 minutes or less. More preferably, it is 5 g/10 minutes or more and 3 g/10 minutes or less.

The sealant layer can be formed as a film from the above resin material by, for example, a T-die method and an inflation method.
The sealant layer can be formed by laminating a film made of the above resin material onto other layers such as a gas barrier resin layer using a melt extrusion lamination method via an adhesive resin layer described below.

In one embodiment, the sealant layer may use the resin film of the present invention. When the resin film of the present invention is used as the sealant layer, the first layer of the resin film of the present invention is positioned on the inner surface side of the inner bag.

[Adhesive resin layer]
The adhesive resin layer is provided between the sealant layer and the gas-barrier resin layer or between the sealant layer and the deposited film, and is a layer formed by a melt extrusion lamination method using a thermoplastic resin. be. Examples of thermoplastic resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer. coalescence, ethylene-methyl methacrylate copolymer, ethylene-maleic acid copolymer, ionomer resin, graft polymerization of unsaturated carboxylic acid, unsaturated carboxylic acid, unsaturated carboxylic acid anhydride, ester monomer to polyolefin resin, Alternatively, a copolymerized resin, a resin obtained by graft-modifying maleic anhydride to a polyolefin resin, or the like can be used. The adhesive resin layer may contain two or more thermoplastic resins.

The thickness of the adhesive resin layer is preferably 0.1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less. Further, the adhesive resin layer may be a single layer or multiple layers of two or more layers.

[Gas barrier resin layer]
The gas barrier resin layer contains a gas barrier resin such as ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6 and polymetaxylylene adipamide (MXD6). Examples include polyamide, polyester, polyurethane, and (meth)acrylic resin. Among these, polyamide is preferable from the viewpoint of gas barrier properties such as oxygen barrier properties and water vapor barrier properties. The gas barrier resin layer may contain two or more gas barrier resins.

The gas-barrier resin layer may use a film made of a resin material such as those described above. From the viewpoint of strength and the like, the gas barrier resin layer preferably uses a film stretched uniaxially or biaxially.

The gas-barrier resin layer may contain a resin other than the gas-barrier resin and may contain additives as long as the object of the present invention is not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The thickness of the gas barrier resin layer is preferably 3 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. By setting the thickness of the gas barrier resin layer to 7 μm or more, the oxygen barrier properties and water vapor barrier properties of the outer layer film can be further improved. Further, the gas barrier resin layer may be a single layer or multiple layers of two or more layers.

The gas-barrier resin layer can be formed by laminating a film composed of the above-described gas-barrier resin with an adhesive resin layer interposed therebetween.

[Deposition film]
The outer layer film may comprise a vapor deposited film. Thereby, the gas barrier property of the outer layer film can be improved.
Vapor-deposited films include, for example, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), and titanium (Ti). , lead (Pb), zirconium (Zr), yttrium (Y), etc., or two or more inorganic substances or inorganic oxides. Also, the deposited film may have a structure of two or more layers, and may be made of the same material or different materials.

The film thickness of the deposited film is 100 Å to 2000 Å, preferably 200 Å to 1000 Å.

The method for forming the deposited film is not particularly limited, and for example, a physical vapor deposition method (Physical Vapor Deposition method, PVD method) such as a vacuum deposition method, a sputtering method, and an ion plating method, or a plasma chemical vapor deposition method. A chemical vapor deposition method (Chemical Vapor Deposition method, CVD method) such as a phase growth method, a thermal chemical vapor deposition method, and a photochemical vapor deposition method can be used.

In one embodiment, the outer layer film may be provided with a gas barrier coating so as to be adjacent to the deposited film. Thereby, the gas barrier property of the outer layer film can be further improved.

The gas barrier coating film has the general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) and at least one or more alkoxides represented by the above polyvinyl alcohol-based A gas barrier composition containing a resin and/or an ethylene-vinyl alcohol copolymer and further polycondensed by a sol-gel method in the presence of a sol-gel catalyst, acid, water and an organic solvent.

As the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , at least one of partial hydrolyzate of alkoxide and condensate of hydrolysis of alkoxide can be used. The partial hydrolyzate of the above alkoxide does not need to have all of the alkoxy groups hydrolyzed, and may be one or more hydrolyzed, or a mixture thereof. As the condensate obtained by hydrolysis of alkoxide, a partially hydrolyzed alkoxide dimer or higher, specifically a dimer to hexamer, is used.

In the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , the metal atom represented by M can be silicon, zirconium, titanium, aluminum, or the like. In this embodiment, preferred metals include, for example, silicon and titanium. In the present invention, alkoxides can be used singly or as a mixture of alkoxides of two or more different metal atoms in the same solution.

Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group, and other alkyl groups. Further, in the alkoxide represented by the general formula R ¹ _n M(OR ² ) _m , specific examples of the organic group represented by R ² include a methyl group, an ethyl group, an n-propyl group, i -propyl group, n-butyl group, sec-butyl group, and the like. These alkyl groups may be the same or different in the same molecule.

For example, a silane coupling agent or the like may be added when preparing the gas barrier composition. Known organic reactive group-containing organoalkoxysilanes can be used as the silane coupling agent. In this embodiment, an organoalkoxysilane having an epoxy group is particularly preferably used. Specifically, examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or , β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like can be used. The above silane coupling agents may be used singly or in combination of two or more.

[Metal foil]
In one embodiment, the outer layer film comprises a metal foil. Thereby, gas barrier property can be improved more.

The metal that constitutes the metal foil is not particularly limited, and a metal foil made of aluminum, magnesium, or the like can be used.

The thickness of the metal foil is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 10 μm or less. By setting the thickness of the metal foil to 3 μm or more, the gas barrier properties of the outer layer film can be further improved.

The metal foil can be laminated on any layer via an adhesive resin layer.

[Surface resin layer]
The surface resin layer is a layer provided on the opposite side of the outer layer film to the sealant layer. Polyolefins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene (homopolymer, block polymer, random polymer) can be used as the resin constituting the surface resin layer.

Although the thickness of the surface resin layer can be changed as appropriate, it is preferably 3 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less. Moreover, the surface resin layer may be a single layer or a multilayer of two or more layers.

An example of the layer configuration when the outer layer film is a laminate includes the following configuration.
ONY/contact PE/PEF
ONY/Al deposition film/contact PE/PEF
ONY/SiOn deposited film/contact PE/PEF
Front PE/ONY/SiOn deposition film/contact PE/PEF
ONY/bonded PE/Al foil/bonded PE/PEF
In one example of the above layer configuration, the left side means the outside of the inner bag. The "/" symbol indicates the boundary of each layer. In one example of the above layer structure, the resin film of the present invention can be used for "PEF". Other abbreviations are as follows.
ONY: stretched nylon bonded PE: polyethylene as adhesive resin layer Front PE: polyethylene as surface resin layer Al vapor-deposited film: vapor-deposited film made of aluminum SiOn vapor-deposited film: vapor-deposited film made of silicon oxide Al foil: aluminum foil

(inner layer film)
In the inner bag of the packaging container of the present invention, the inner layer film is positioned inside the outer layer film. The inner layer film serves as a sealant layer.

In one embodiment, the inner bag of the packaging container of the present invention is double-layered with an inner layer film according to conditions such as the volume of contents, the type of contents, the purpose of packaging, the form of packaging, the form of distribution, the form of sales, and others. You can do more than that. By making the inner layer film double or more, the inner bag can further suppress the leakage of the contents from the inner bag. When the inner layer film is double or more, each inner layer film may be composed of the same material or different materials.

The inner layer film contains a resin material that exerts heat-bonding properties, for example, polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene (homopolymer, block polymer, random polymer), ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ionomer resin, heat seal Polyethylene-vinyl alcohol resin, or copolymerized resin Methylpentene resin, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyolefin resin such as polyethylene, polypropylene and cyclic olefin copolymer, acrylic polyolefin resin Examples include acid-modified polyolefin resins modified with unsaturated carboxylic acids such as acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid and itaconic acid, vinyl resins, and (meth)acrylic resins. Among these, polyethylene is preferable from the viewpoint of sealability, and linear low-density polyethylene is preferable from the viewpoint of sealability and pinhole resistance. The inner layer film may contain two or more of the above resin materials.

The inner layer film may contain additives as long as the objects of the present invention are not impaired. Additives include, for example, plasticizers, ultraviolet stabilizers, anti-coloring agents, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, antiblocking agents, oxidation One or two or more of inhibitors, ion exchange agents, color pigments, and the like can be added.

The density of the inner layer film is preferably 0.900 g/cm ³ or more and 0.930 g/cm ^{3 or less, more preferably 0.904 g/cm 3 or} more and 0.926 g/cm ³ or less, and 0.910 g /cm ³ or more and 0.920 g/cm ³ or less.

The thickness of the inner layer film is preferably 15 μm or more and 150 μm or less, more preferably 20 μm or more and 120 μm or less, and even more preferably 30 μm or more and 100 μm or less. Also, the inner layer film may be a single layer or a multilayer of two or more layers.

The melt flow rate (MFR) of the inner layer film is preferably 0.1 g/10 min or more and 10 g/10 min or less, more preferably 0.2 g/10 min or more and 5 g/10 min or less. More preferably, it is 5 g/10 minutes or more and 3 g/10 minutes or less.

The method for producing the resin film of the present invention is not particularly limited, and it can be produced by a conventionally known method such as a T-die method or an inflation method.

In one embodiment, the resin film of the present invention may be used as an inner layer film. When the resin film of the present invention is used as the inner layer film, the first layer of the resin film of the present invention is positioned on the inner surface side of the inner bag.

<Spout>
The spout is joined to the inner bag and exposed to the outside of the outer package through the opening of the outer package.
In one embodiment, the packaging container of the present invention may have two or more spouts.

The shape of the spout can be appropriately selected according to conditions such as the capacity of the contents, the type of contents, the purpose of packaging, the form of packaging, the form of distribution, the form of sales, and others. types, etc.

The spout can be formed by an injection molding method using a resin such as polyolefin.

EXAMPLES Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the description of the Examples below as long as the gist of the present invention is not exceeded.

[Example 1A]
As the resin constituting the first layer, using a Ziegler-Natta catalyst, fossil fuel linear low-density polyethylene (( Prime Polymer Co., Ltd., trade name: UZ1520L, density: 0.914 g/cm ³ , MFR: 2.3 g/10 min, biomass degree: 0%) (hereinafter also referred to as “petrochemical C6LLDPE_A”), It was melted.
Next, as the resin constituting the second layer, a fossil fuel linear low-density polyethylene ( Ube Maruzen Polyethylene Co., Ltd., trade name: UM0520F, density: 0.904 g/cm ³ , MFR: 2.0 g/10 min, biomass degree: 0%) (hereinafter also referred to as “petrochemical C6LLDPE_B”) 76.5 Part by mass, biomass linear low-density polyethylene (manufactured by Braskem, trade name: SLL-118, density: 0. 916 g/cm ³ , MFR: 1.0 g/10 min, biomass content of 87%) (hereinafter also referred to as “bio C4LLDPE”) and 23.5 parts by mass of these were melted.
Then, petrochemical C6LLDPE_A was used as the resin constituting the third layer and melted.

These melts were co-extruded into a resin film by inflation molding such that the layer thickness ratio of the first, second and third layers was 1:2:1. The thickness of the resin film was 40 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example. In addition, in Table 1, all "%" are based on mass.

[Example 1B]
A resin film was obtained in the same manner as in Example 1A, except that the thickness of the resin film was 50 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 1C]
A resin film was obtained in the same manner as in Example 1A, except that the thickness of the resin film was 70 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 2A]
A resin film was obtained in the same manner as in Example 1A, except that 47.0 parts by mass of petrochemical C6LLDPE_B and 53.0 parts by mass of bio-C4LLDPE were used as the resins constituting the second layer. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 2B]
A resin film was obtained in the same manner as in Example 2A, except that the thickness of the resin film was 50 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 2C]
A resin film was obtained in the same manner as in Example 2A, except that the thickness of the resin film was 70 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 3A]
A resin film was obtained in the same manner as in Example 1A, except that 29.5 parts by mass of petrochemical C6LLDPE_B and 70.5 parts by mass of bio-C4LLDPE were used as the resins constituting the second layer. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 3B]
A resin film was obtained in the same manner as in Example 3A, except that the thickness of the resin film was 50 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 3C]
A resin film was obtained in the same manner as in Example 3A, except that the thickness of the resin film was 70 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 4A]
A resin film was obtained in the same manner as in Example 1A, except that 95.0 parts by mass of petrochemical C6LLDPE_A and 5.0 parts by mass of bio-C4LLDPE were used as the resins constituting the first layer. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 4B]
A resin film was obtained in the same manner as in Example 4A, except that the thickness of the resin film was 50 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 4C]
A resin film was obtained in the same manner as in Example 4A, except that the thickness of the resin film was 70 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 5A]
Same as Example 1A, except that 77.0 parts by mass of petrochemical C6LLDPE_A and 23.0 parts by mass of bio-C4LLDPE were used as the resins constituting the first, second, and third layers. to obtain a resin film. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 5B]
A resin film was obtained in the same manner as in Example 5A, except that the thickness of the resin film was 50 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Example 5C]
A resin film was obtained in the same manner as in Example 5A, except that the thickness of the resin film was 70 μm. Table 1 shows the average density, biomass degree, and C6LLDPE content of the resin film of this example.

[Comparative Example 1A]
A resin film was obtained in the same manner as in Example 1A, except that Bio-C4LLDPE was used as the resin constituting the second layer. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 1B]
A resin film was obtained in the same manner as in Comparative Example 1A, except that the thickness of the resin film was 50 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 1C]
A resin film was obtained in the same manner as in Comparative Example 1A, except that the thickness of the resin film was 70 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 2A]
A resin film was obtained in the same manner as in Example 1A, except that Bio-C4LLDPE was used as the resins constituting the second layer and the third layer. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 2B]
A resin film was obtained in the same manner as in Comparative Example 2A, except that the thickness of the resin film was 50 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 2C]
A resin film was obtained in the same manner as in Comparative Example 2A, except that the thickness of the resin film was 70 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 3A]
Except that bio-C4LLDPE was used as the resin constituting the second layer, and that 50.0 parts by mass of petrochemical C6LLDPE_A and 50.0 parts by mass of bio-C4LLDPE were used as the resins constituting the third layer. , to obtain a resin film in the same manner as in Example 1A. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 3B]
A resin film was obtained in the same manner as in Comparative Example 3A, except that the thickness of the resin film was 50 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 3C]
A resin film was obtained in the same manner as in Comparative Example 3A, except that the thickness of the resin film was 70 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 4A]
A resin film was obtained in the same manner as in Example 1A, except that Bio-C4LLDPE was used as the resins constituting the first layer, the second layer, and the third layer. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 4B]
A resin film was obtained in the same manner as in Comparative Example 4A, except that the thickness of the resin film was 50 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

[Comparative Example 4C]
A resin film was obtained in the same manner as in Comparative Example 4A, except that the thickness of the resin film was 70 μm. Table 2 shows the average density, biomass degree, and C6LLDPE content of the resin film of this comparative example.

<Evaluation of pinhole resistance (low temperature)>
The number of pinholes was measured after bending the resin films prepared in the above examples and comparative examples 2000 times with a gelbo flex tester under low temperature (5° C.) conditions. This was repeated three times, and the average number of pinholes was calculated. In resin films of the same composition, the total number of average pinholes at each layer thickness was evaluated according to the following criteria. Evaluation results are shown in Tables 3 and 4.
(Evaluation criteria)
A: The total average number of pinholes is less than 3 B: The total average number of pinholes is 3 or more and less than 5 C: The total average number of pinholes is 5 or more

<Evaluation of pinhole resistance (room temperature)>
The resin films prepared in the above examples and comparative examples were bent 5000 times with a gelbo flex tester under normal temperature (23 to 30° C.) conditions, and then the number of pinholes was measured. This was repeated three times, and the average number of pinholes was calculated. In resin films of the same composition, the total number of average pinholes at each layer thickness was evaluated according to the following criteria. Evaluation results are shown in Tables 3 and 4.
A: The total average number of pinholes is less than 6 B: The total average number of pinholes is 6 or more and less than 10 C: The total average number of pinholes is 10 or more

<Evaluation of Impact Strength>
The impact strength of the resin films produced in the above examples and comparative examples was evaluated. The impact strength was evaluated using a film impact tester FT-M manufactured by Toyo Seiki Seisakusho Co., Ltd. by the following method.
First, a test piece 100 was produced by cutting the resin film 10 produced in the above Examples and Comparative Examples into a size of 10 cm×10 cm. As shown in FIG. 11, a test piece 100 was sandwiched between ring-shaped jigs 101 and 102 and fixed. Subsequently, as shown in FIG. 12, the fixed test piece 100 is placed, the arm portion 104 is swung down around the fulcrum portion 103, and the test piece 100 is pierced by the conical indenter 105 at the tip of the arm portion 104. rice field. The strength at the time of breaking through was defined as impact strength (J). The diameter of the indenter 105 was 1 inch (25.4 mm), the load was 30 kg·cm, and the lifting angle of the arm was 90°. The environment during the measurement was a temperature of 23° C. and a relative humidity of 50%. Tables 3 and 4 show the measurement results.

<Evaluation of tensile strength>
The tensile strength in the machine direction (MD) and perpendicular direction (TD) of the resin films produced in the above examples and comparative examples was evaluated. The tensile strength of the resin film was measured according to JIS Z1702. As a measuring instrument, a tensile tester RTC-1210 manufactured by Orientec was used. A rectangular film having a width of 10 mm and a length of 120 mm cut from a resin film can be used as the test piece. The distance between the pair of chucks holding the specimen at the start of the measurement is 80 mm, and the pulling speed is 500 mm/min. The temperature at the time of measurement was 23°C. Tables 3 and 4 show the measurement results.

As shown in Tables 3 and 4, the resin films of the present invention are excellent in pinhole resistance after bending under low temperature conditions and normal temperature conditions.

A flat bag type inner bag 40 having a capacity of 10 L as shown in FIG. 3 was produced using the resin film of the above example. In the inner bag, the inner layer film and the outer layer film are each single layer. The inner layer film is composed of the resin film of the above example. The outer layer film is composed of a nylon film as a gas barrier layer, polyethylene as an adhesive resin layer, and the resin film of the above example as a sealant layer. The inner bag produced using the resin film of the above example is excellent in pinhole resistance.

Using the resin film of the above example, a gusset-type inner bag 70 with a capacity of 1000 L as shown in FIG. 6 was produced. In the inner bag, the inner layer film is double and the outer layer film is single. The inner layer film is composed of the resin film of the above example. The outer layer film is composed of a nylon film as a gas barrier layer, polyethylene as an adhesive resin layer, and the resin film of the above example as a sealant layer. The inner bag produced using the resin film of the above example is excellent in pinhole resistance.

10: Resin film 11: First layer 12: Second layer 13: Third layer 20: Packaging container 30: Exterior body 40: Inner bag 41: Front surface 42: Rear surface 43: Top 44: Bottom 45a, 45b: Side 46 : Top seal portion 47 : Bottom seal portion 48 : Side seal portion 50 : Spout 60 : Opening 70 : Inner bag 71 : Front surface 72 : Rear surface 73 : Side surface 74 : Folding portion 75 : Top seal portion 76 : Bottom seal portion 77 : Side sealing portion 90: Outer layer film 91: Sealant layer 92: 97: Adhesive resin layer 93: Gas barrier resin layer 94: Deposited film 95: Surface resin layer 96: Metal foil 100: Test piece 101, 102: Jig 103 : fulcrum portion 104: arm portion 105: indenters 411, 421: outer layer films 412, 422: inner layer film

Claims (13)

A resin film including at least a first layer and a second layer directly laminated on the first layer,
The thickness of the resin film is 15 μm or more and 150 μm or less,
The thickness of the second layer is thicker than the thickness of the first layer,
The resin film contains 90% by mass or more of linear low-density polyethylene obtained by polymerizing ethylene and α-olefin monomers with respect to the entire resin film,
The resin film contains 51% by mass or more of a linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms with respect to the entire resin film,
The resin film, wherein the resin film contains biomass linear low-density polyethylene. further comprising a third layer directly laminated to the second layer;
The resin film according to claim 1, wherein the thickness of the second layer is thicker than the thickness of the third layer. The resin film according to claim 2, wherein the second layer contains more biomass linear low-density polyethylene than the first layer and the third layer. The resin film according to claim 2 or 3, wherein the third layer contains more biomass linear low-density polyethylene than the first layer. The resin film according to any one of claims 1 to 4, wherein the resin film has a density of 0.900 g/cm ³ or more and 0.930 g/cm ³ or less. The resin film according to any one of claims 1 to 5, wherein the resin film contains fossil fuel linear low-density polyethylene. Claim 6, wherein the fossil-fuel linear low-density polyethylene comprises a linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer containing a compound having 6 or more carbon atoms using a metallocene catalyst. The described resin film. The resin film according to any one of claims 1 to 7, wherein the second layer comprises biomass linear low density polyethylene and fossil fuel linear low density polyethylene. The resin film according to any one of claims 1 to 8, which has a biomass degree of 40% or less. The resin film according to any one of claims 1 to 9, wherein the first layer has a biomass content of 25% or less. The resin film according to any one of claims 1 to 10, which is used for an inner bag of a packaging container. A packaging container comprising an inner bag containing an outer layer film and an inner layer film and an exterior body,
A packaging container, wherein at least one of the outer layer film and the inner layer film comprises the resin film according to any one of claims 1 to 11. 13. The packaging container of claim 12, including a spout joined to the inner bag.

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