JP2021138007A - Resin film and packaging container - Google Patents

Abstract

To provide a resin film which can reduce the carbon dioxide emission and has excellent pinhole resistance.SOLUTION: The resin film at least comprises a first layer and a second layer directly laminated to the first layer. The second layer is thicker than the first layer. The resin film contains 90 mass% or more, based on the entire resin film, of linear low-density polyethylene formed by polymerization of ethylene and α-olefin monomers. The resin film contains 51 mass% or more, based on the entire resin film, of linear low-density polyethylene formed by polymerization of ethylene and α-olefin monomers having 6 or more carbon atoms. The resin film contains biomass linear low-density polyethylene.SELECTED DRAWING: Figure 1

Description

The present invention relates to a resin film and a packaging container containing the same.

Packaging containers such as bag-in-boxes are widely used for storing and transporting liquid products (beverages, car oils, detergents, chemicals, etc.) in various fields such as the food industry, car industry, pharmaceutical industry, and toiletry industry. .. The bag-in-box is composed of an inner bag for storing the contents such as a liquid product and an outer body for storing the inner bag and holding the outer shape.

By the way, in recent years, with the increasing demand for the construction of a sound material-cycle society, it is desired to break away from fossil fuels in the material field as well as energy, and the use of biomass is drawing attention. Biomass is an organic compound photosynthesized from carbon dioxide and water, and by utilizing it, it becomes carbon dioxide and water again, so-called carbon-neutral renewable energy. In recent years, the practical use of biomass plastics made from these biomass raw materials is rapidly advancing, and attempts are being made to produce various resins from the biomass raw materials.

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

Japanese Unexamined Patent Publication No. 2019-51968

The present inventors have attempted to manufacture a bag-in-box using the above-mentioned inner bag. However, in such a bag-in-box, pinholes may occur in the inner bag when the inner bag is manufactured or the back-in box is transported, and the contents may be affected by the outside air or the contents may leak out. A new problem of sexuality 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 capable of reducing carbon dioxide emissions and having 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 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 linear low-density polyethylene formed by polymerizing ethylene and an α-olefin monomer 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 includes a third layer which is directly laminated on 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.

Keep the resin film of the present invention, the density of the resin film, may be 0.900 g / cm ³ or more 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, fossil fuel linear low-density polyethylene is a fossil fuel obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel using a metallocene catalyst. The fuel may contain linear low density polyethylene.

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.

In the resin film of the present invention, the biomass degree may be 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 outer body.
At least one of the outer layer film and the inner layer film contains the above resin film.

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

According to the present invention, it is possible to provide a resin film capable of reducing carbon dioxide emissions and having excellent pinhole resistance.
Further, according to the present invention, it is possible to provide a packaging container containing this resin film.

It is sectional drawing which shows an example of the resin film of this invention. 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. It is a top view which shows an example of the inner bag provided in the packaging container of this invention. It is sectional drawing which shows an example of the inner bag provided in the packaging container of this invention (the sectional view taken along line AA of FIG. 4). It is a top view which shows another example of the inner bag provided in the packaging container of this invention. It is sectional drawing which shows an example of the outer layer film of the inner bag provided in the packaging container of this invention. It is sectional drawing which shows an example of the outer layer film of the inner bag provided in the packaging container of this invention. It is sectional drawing which shows an example of the outer layer film of the inner bag provided in the packaging container of this invention. It is sectional drawing which shows an example of the outer layer film of the inner bag provided in the packaging container of this invention. It is a top view which shows the test piece for evaluating the impact strength. It is a figure which shows an example of the measuring method of the impact strength.

An embodiment of the present invention will be described with reference to FIGS. 1 to 12. In the drawings attached to the present specification, the scale, aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

In addition, as used in the present specification, the terms such as "parallel", "orthogonal", and "identical" and the values of length and angle that specify the shape and geometric conditions and their degrees are strictly used. Without being bound by meaning, we will interpret it including the range in which similar functions can be expected.

[Resin film]
As shown in FIG. 1, 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, and the first layer 11 is a resin film 10. It is located on the inner surface 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, as shown in FIG. 2, the resin film 10 is directly laminated on the first layer 11, the second layer 12 directly laminated on the first layer 11, and the second layer 12. The first layer is located on the inner surface side of the resin film 10, including the three layers 13.

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

Here, linear low density polyethylene (LLDPE) will be described. The linear low-density polyethylene is a copolymer of ethylene and α-olefin polymerized using a multisite catalyst represented by a Ziegler-Natta catalyst or a single-site catalyst represented by a metallocene catalyst, and has a density. Refers to those with a value of 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 the α-olefin that serves as a comonomer of linear low-density polyethylene include α-olefins having 3 or more carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, and 4 -Methylpentene, 3,3-dimethylbutene and the like, and mixtures thereof. The density of polyethylene is a value measured according to the method specified in the method A of JIS K7112-1980 after performing the annealing described in JIS K6760-1980.

The above-mentioned single-site catalyst is a catalyst capable of forming a uniform active species, and is usually prepared by contacting a metallocene-based transition metal compound or a non-metallocene-based transition metal compound with an activation co-catalyst. NS. Compared with the multisite catalyst, the single-site catalyst is preferable because it has a uniform active site structure and can polymerize a polymer having a high molecular weight and a high uniformity 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 organic metal compound if necessary, and each catalyst component of the carrier. Is.

In the transition metal compound of Group IV of the Periodic Table containing the ligand having the cyclopentadienyl skeleton, the cyclopentadienyl skeleton is a cyclopentadienyl group, a substituted cyclopentadienyl group or the like. .. The substituted cyclopentadienyl group includes a hydrocarbon group having 1 to 30 carbon atoms, a silyl group, a silyl substituted alkyl group, a silyl substituted aryl group, a cyano group, a cyanoalkyl group, a cyanoaryl group, a halogen group, a haloalkyl group, and a halosilyl. 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 to form an indenyl ring, a fluorenyl ring, an azulenyl ring, a hydrogenated product thereof, or the like. It may be formed. Rings formed by bonding substituents to each other may further have substituents to 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 and hafnium, and zirconium and hafnium are particularly preferable. The transition metal compound usually has two ligands having a cyclopentadienyl skeleton, and the ligands having each cyclopentadienyl skeleton are preferably bonded to each other by a bridging group. Examples of the cross-linking group include a substituted silylene group such as an alkylene group having 1 to 4 carbon atoms, a silylene group, a dialkyl silylene group and a diaryl silylene group, and a substituted gel millene group such as a dialkyl gel millene group and a diaryl gel millene group. It is preferably a substituted silylene group.

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

The transition metal compound of Group IV of the Periodic Table containing a ligand having a cyclopentadienyl skeleton can contain one kind or a mixture of two or more kinds as a catalyst component.

The co-catalyst is one in which the transition metal compound of Group IV of the periodic table can be effectively used as a polymerization catalyst, or the ionic charge in a catalytically activated state can be equalized. As co-catalysts, benzene-soluble aluminoxane of organic aluminum oxy compounds, benzene-insoluble organic aluminum oxy compounds, ion-exchangeable layered silicates, boron compounds, active hydrogen group-containing or non-active hydrogen group-containing or non-coordinating anions are used. Examples thereof include ionic compounds, lanthanoid 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, which contains a ligand having a cyclopentadienyl skeleton, may be used by supporting it on a carrier of an inorganic or organic compound. The carrier is preferably an inorganic or organic compound porous oxide, and specifically, ion-exchangeable layered silicate such as montmorillonite, SiO ₂ , Al ₂ O ₃ , MgO, ZrO ₂ , TiO ₂ , B ₂ O. ₃ , CaO, ZnO, BaO, ThO _2, etc. or a mixture thereof can be mentioned.

Further, examples of the organometallic compound used as necessary include organoaluminum compounds, organomagnesium compounds, organozinc compounds and the like. Of these, organoaluminum is preferably used.

The resin film of the present invention contains 51% by mass or more of linear low-density polyethylene formed by polymerizing ethylene and an α-olefin monomer having 6 or more carbon atoms with respect to the entire resin film. As a result, a resin film having excellent pinhole resistance can be obtained. The resin film of the present invention may contain 51% by mass or more and 95% by mass or less of linear low-density polyethylene formed by polymerizing ethylene and α-olefin monomers having 6 or more carbon atoms with respect to the entire resin film. It is more preferable to contain 60% by mass or more and 90% by mass or less, and further preferably 70% by mass or more and 90% by mass or less.

The resin film of the present invention contains biomass linear low-density polyethylene. As a result, it is possible to reduce the amount of carbon dioxide emissions and obtain a resin film having excellent environmental load reduction properties.

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 a conventionally known method. Hereinafter, an example of a method for producing ethylene-derived ethylene will be described.

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

Biomass-derived fermented ethanol refers to ethanol that has been purified after being 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. Conventionally known methods such as distillation, membrane separation, and extraction can be applied to the purification of ethanol from the culture broth. For example, a method of adding benzene, cyclohexane or the like and azeotropically boiling the mixture, or removing water by membrane separation or the like can be mentioned.

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

A catalyst is usually used when ethylene is obtained by a dehydration reaction of ethanol, but the catalyst is not particularly limited, and a conventionally known catalyst can be used. Advantageous in the process is a fixed bed flow reaction in which the catalyst and the product can be easily separated, and for example, γ-alumina and the like are preferable.

Since this dehydration reaction is an endothermic reaction, it is usually carried out under heating conditions. As long as the reaction proceeds at a commercially useful reaction rate, the heating temperature is not limited, but a temperature of 100 ° C. or higher, more preferably 250 ° C. or higher, still more preferably 300 ° C. or higher is suitable. The upper limit is not particularly limited, but is preferably 500 ° C. or lower, more preferably 400 ° C. or lower, 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 the ethanol supplied as a raw material. Generally, when a dehydration reaction is carried out, it is preferable that there is no water in consideration of the efficiency of removing water. However, in the case of the dehydration reaction of ethanol using a solid catalyst, it was found that the amount of other olefins, especially butene, tends to increase in the absence of water. It is presumed that it is not possible to suppress ethylene dimerization after dehydration without the presence of a small amount of water. The lower limit of the allowable water content is 0.1% by mass or more, preferably 0.5% by mass or more. The upper limit is not particularly limited, but from the viewpoint of mass balance and heat balance, it is preferably 50% by mass or less, more preferably 30% by mass or less, and further preferably 20% by mass or less.

By performing the ethanol dehydration reaction in this way, a mixed portion of ethylene, water and a small amount of unreacted ethanol can be obtained. However, since ethylene is a gas at about 5 MPa or less at room temperature, it is separated from these mixed portions by gas-liquid separation. Ethylene can be obtained except for 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, and the like are not particularly limited except that the operating pressure at this time is normal pressure or higher.

When the raw material is ethanol derived from ammonia, the obtained ethylene contains carbonyl compounds such as ketones, aldehydes, and esters, which are impurities mixed in the ethanol fermentation process, carbon dioxide gas, which is a decomposition product thereof, and decomposition products of enzymes. It contains a very small amount of nitrogen-containing compounds such as amines and amino acids, which are impurities, and ammonia, which is a decomposition product thereof. Depending on the use of ethylene, these trace amounts of impurities may cause a problem, and may be removed by purification. The purification method is not particularly limited, and can be performed by a conventionally known method. As a suitable purification operation, for example, an adsorption purification method can be mentioned. The adsorbent used is not particularly limited, and conventionally known adsorbents can be used. For example, a material having 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 ethanol derived from biomass.

In addition, caustic water treatment may be used in combination as a method for purifying impurities in ethylene. When treating with caustic water, it is desirable to perform it before adsorption purification. In that case, it is necessary to perform a water removal treatment after the caustic treatment and before the adsorption purification.

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

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

The resin film of the present invention preferably has a biomass degree of 40% or less. As a result, 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 C14 at a constant ratio (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, for example, corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, the proportion of biomass-derived carbon can be calculated by measuring the proportion of C14 contained in all carbon atoms. In the present invention, the "biomass degree" indicates the weight ratio of the biomass-derived component. For example, 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 and therefore is derived from biomass as ethylene glycol. When only one is used, the weight ratio of the biomass-derived component in the polyester is 31.25%, so that the theoretical value of the biomass degree 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. Further, the weight ratio of the biomass-derived component in the fossil fuel polyester produced by using the fossil fuel-derived ethylene glycol and the fossil fuel-derived dicarboxylic acid is 0%, and the fossil fuel polyester has a biomass degree of 0%. Become. Hereinafter, unless otherwise specified, the "biomass degree" shall indicate the weight ratio of the biomass-derived components.

In the present invention, theoretically, if only a biomass-derived raw material is used as the raw material for polyethylene, the ethylene concentration derived from biomass is 100%, and the biomass degree of biomass polyethylene is 100%. Further, the biomass-derived ethylene concentration in the fossil fuel polyethylene produced only from the fossil fuel-derived raw material is 0%, and the biomass degree of the 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, and the sealing properties such as the sealing strength of the resin film and the low temperature sealing property. Further, the fossil fuel linear low-density polyethylene preferably contains fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel. It is more preferable to contain fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel using a metallocene catalyst. Thereby, the pinhole resistance and the sealing property of the resin film can be further improved.

The density of the resin film is preferably not more than 0.900 g / cm ³ or more 0.930 g / cm ^3. 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 the sealing property of the resin film can be improved. The density of the resin film is more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, more preferably not more than 0.910 g / cm ³ or more 0.920 g / cm ^3.

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 sealing property 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, and 0. It is more preferably 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 the molding process can be reduced. By setting the MFR to 10 g / 10 minutes or less, the mechanical strength of the resin film can be increased.

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 further preferably 1.00 J or more. The 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 more, more preferably 40 MPa or more in at least one direction. For example, the tensile strength of the film in the flow direction (MD) is preferably 35 MPa or more, more preferably 40 MPa or more. The tensile strength of the resin film in the vertical (TD) direction is preferably 35 MPa or more, more preferably 40 MPa or more.

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

The resin film of the present invention may contain one or more high-density polyethylene (HDPE), medium-density polyethylene (MDPE), and low-density polyethylene (LDPE) as long as the object of the present invention is not impaired. The high-density polyethylene ^{means polyethylene having a density of 0.942 g / cm 3} or more, and the 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. The low-density polyethylene means the above-mentioned high-pressure method 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, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

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

<First layer>
The first layer is a layer located on the inner surface side of the 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 sealing property 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, the environmental load reduction property can be improved, and the pinhole resistance and the sealing property of the resin film can be improved.

The content of the fossil fuel linear low-density polyethylene in the first layer is preferably 50% by mass or more. Thereby, the pinhole resistance, impact strength and sealing property of the resin film can be further improved. The content of the fossil fuel linear low-density polyethylene in the first layer is more preferably 75% by mass or more, further preferably 95% by mass or more. Further, the first layer may be composed of fossil fuel linear low-density polyethylene.

The first layer fossil fuel linear low-density polyethylene contains fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel. Is preferable. Thereby, the pinhole resistance, impact strength and sealing property of the resin film can be further improved.

The content of the biomass linear low-density polyethylene in the first layer is preferably 50% by mass or less. As a result, the environmental load reduction property can be improved, and the pinhole resistance, impact strength and sealing property of the resin film can be further improved. The content of the biomass linear low-density polyethylene in the first layer is more preferably 1% by mass or more and 50% by mass or less, and further 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, the environmental load reduction property can be improved, and the pinhole resistance, impact strength and sealing property of the resin film can be further improved. 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.

Density of the first layer is preferably less 0.900 g / cm ³ or more 0.930 g / cm ^3. 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 the sealing property of the resin film can be improved. Density of the first layer, more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, more preferably not more than 0.910 g / cm ³ or more 0.920 g / cm ^3.

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 sealing property 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 further 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 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, and is 0. It is more preferably .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 the molding process can be reduced. By setting the MFR to 10 g / 10 minutes or less, the mechanical strength of the resin film can be increased.

The first layer may contain one or more 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 object of the present invention is not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

The first layer may be a single layer or a multi-layer having two or more layers.

<2nd layer>
The second layer is a layer directly laminated on the first layer. Further, in the resin film of the present invention, the thickness of the second layer is thicker than the thickness of the first layer. As a result, a resin film having excellent pinhole resistance can be obtained. The thickness ratio of the first layer: the second layer is preferably 1: 4 to 1.1, and more preferably 1: 3 to 1.5.

When the resin film of the present invention contains a 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 ratio of the thickness of the second layer: the third layer is preferably 4 to 1.1: 1, and 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, the environmental load reduction property can be improved, and the pinhole resistance and impact strength of the resin film can be improved.
The content of the 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. It is more preferably mass% or less.
The content of the 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 preferably 60% by mass or less.

In one embodiment, the second layer contains more biomass linear low density polyethylene than the first layer. Also, in one embodiment, the second layer contains more biomass linear low density polyethylene than the third layer. As a result, the environmental load reduction property can be further improved, and the pinhole resistance and impact strength of the resin film can be further improved.

The fossil fuel linear low-density polyethylene contained in the second layer is a fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel. It is preferably contained, and more preferably it contains Mars fuel linear low density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel using a metallocene catalyst. .. Thereby, the pinhole resistance and the 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, the environmental load reduction property can be improved, and the pinhole resistance and impact strength of the resin film can be further improved. 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.

Density of the second layer is preferably less 0.900 g / cm ³ or more 0.930 g / cm ^3. 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 the sealing property of the resin film can be improved. Density of the second layer, more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, more preferably not more than 0.910 g / cm ³ or more 0.920 g / cm ^3.

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 further 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 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, and is 0. It is more preferably .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 the molding process can be reduced. By setting the MFR to 10 g / 10 minutes or less, the mechanical strength of the resin film can be increased.

The second layer may contain one or more 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 object of the present invention is not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

The second layer may be a single layer or a multilayer 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, sealing property and laminating 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, the environmental load reduction property can be improved, and the pinhole resistance, impact strength, sealing property, and lamination strength of the resin film can be improved.

The content of the fossil fuel linear low-density polyethylene in the third layer is preferably 50% or more by mass. Thereby, the pinhole resistance, the sealing property and the laminating strength of the resin film can be further improved. The content of the fossil fuel linear low-density polyethylene in the third layer is more preferably 75% by mass or more, further preferably 95% by mass or more. Further, the third layer may be composed of fossil fuel linear low-density polyethylene.

The third layer fossil fuel linear low-density polyethylene contains fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 or more carbon atoms derived from fossil fuel. Is preferable. Thereby, the pinhole resistance and the sealing strength of the resin film can be further improved.

The content of the biomass linear low-density polyethylene in the third layer is preferably 50% by mass or less. As a result, the environmental load reduction property can be improved, and the pinhole resistance, impact strength, sealing property, and lamination strength of the resin film can be further improved. The content of the biomass linear low-density polyethylene in the third layer is more preferably 1% by mass or more and 50% by mass or less, and further 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, the environmental load reduction property can be improved, and the pinhole resistance, impact strength, sealing property, and lamination strength of the resin film can be further improved. The biomass degree of the second layer is more preferably 1% or more and 50% or less, and further preferably 1% or more and 25% or less.

Density of the third layer is preferably less 0.900 g / cm ³ or more 0.930 g / cm ^3. 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, sealing property, and laminating strength of the resin film can be improved. Density of the third layer, more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, more preferably not more than 0.910 g / cm ³ or more 0.920 g / cm ^3.

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, sealing property, and laminating 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 further 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 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, and is 0. It is more preferably .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 the molding process can be reduced. By setting the MFR to 10 g / 10 minutes or less, the mechanical strength of the resin film can be increased.

The third layer may contain one or more 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, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

The third layer may be a single layer or a multi-layer having two or more layers.

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

In the T-die method, the resin constituting the first layer and the resin constituting the second layer are dried, and then melt extrusion heated to a temperature (Tm) to Tm + 70 ° C., which is equal to or higher than the melting point of each of the resins. It is possible to form a resin film by supplying it to a machine, melting them, co-extruding them into a sheet from a T-die die, and quenching and solidifying the co-extruded sheet 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 and 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 by heating to a temperature (Tm) to Tm + 70 ° C. above the melting point of each of these. It is supplied to an extruder, melted, and co-extruded into a cylindrical shape by a die of 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 from below to the outside of the cylinder. This expanded cylindrical body is called a bubble. Subsequently, the bubble is folded into a film by a guide plate and a pinch roll, and wound up at the winding portion. The folded film may be wound in a tubular shape, or both ends of the cylinder may be removed with a slitter or the like, separated into two films, and then each may be wound. As a result, the resin film can be molded.
As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder and 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 by using the resins constituting each layer.

[Packaging container]
In the present invention, the packaging container includes an inner bag containing an outer layer film and an inner layer film, and an outer body. Further, in the present invention, in the packaging container, at least one of the outer layer film and the inner layer film contains the resin film of the present invention. As a result, an inner bag having excellent pinhole properties can be obtained.
In one embodiment, the packaging container of the present invention includes a spout joined to an 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 outer body 30 and an inner bag 40 housed in the outer body 30. Further, as shown in FIG. 3, the packaging container 20 may be provided with 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 include a spout and two or more openings for exposing the spout to the outside of the exterior (not shown).

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

The material constituting the exterior body can be appropriately selected according to the conditions such as the capacity of the contents, the type of the contents, the packaging purpose, the packaging form, the distribution form, the sales form, and the like. For example, corrugated cardboard. , Metal, resin and the like.

<Inner bag>
The inner bag of the packaging container of the present invention is housed in an outer body and has a space inside which the contents can be stored. The capacity of the inner bag can be appropriately selected according to the conditions such as the type of contents, packaging purpose, packaging form, distribution form, sales form, etc. For example, a small bag of 20 L or less or a large bag of 200 L or more. 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. The flat bag type inner bag 40 as shown in FIG. 4 includes a top portion 43, a bottom portion 44 facing the top portion 43, and a pair of side portions 45a and 45b extending from the top portion 43 to the bottom portion 44. 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 a sealing portion for joining the film-shaped members. The seal portion has a top seal portion 46 located at the top 43, a bottom seal portion 47 located at the bottom 44, and a side seal portion 48 located at the pair of side portions 45a and 45b. The method for forming the seal portion is not particularly limited, but for example, a part of the film-like member is melted by heating or the like, and the film-like members are welded to each other to form the seal portion. May be good. At this time, as a heat sealing method, for example, a known method such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, or an ultrasonic seal can be used.

Further, a spout 50 for injecting the contents into the inner bag 40 and pouring out the contained contents is attached to the front surface 41 of the inner bag 40. The spout 50 projects outward from the front surface 41. A cap may be attached to the spout by, for example, a plug.

As shown in FIG. 5, such an inner bag 40 is composed of an outer layer film 411 forming the front surface 41 and an outer layer film 421 forming the rear surface 42. Further, the inner layer film 412 is provided inside the outer layer film 411, and the 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 from the inner bag 40. Further, in this case, the above-mentioned spout 50 is attached to the outer layer film 411 and the inner layer film 412, and is configured to communicate the inside and the outside of the inner bag 40.

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. The gusset-shaped inner bag 70 as shown in FIG. 6 includes a front surface 71, a rear surface 72, and a pair of side surfaces 73. The pair of side surfaces 73 are sandwiched between the front surface 71 and the rear surface 72. The pair of side surfaces 73 have a folded-back portion 74, which is a gusset, protruding inside the inner bag. The front surface 71, the rear surface 72, and the side surface 73 shown in FIG. 6 have a rectangular shape.

On the four sides of the front surface 71 and the rear surface 72, the front surface 71 and the rear surface 72 facing each other and the pair of side surfaces 73 are adhered by a seal. The 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 a side seal portion 77, respectively. Each sealing portion can be formed by the heat sealing method described above.

Further, on the front surface 71 of the inner bag 70, two injection ports 50 for injecting the contents into the inner bag 71 and pouring out the contained contents are attached. The spout 50 projects outward from the front surface 71. A cap may be attached to the spout by, for example, a plug.

In the inner bag 70 shown in FIG. 6, the front surface 71, the rear surface 72, and the side surface 73 are made of an outer layer film (not shown). Further, 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.

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

(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. 7 to 10.

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. Further, the sealant layer 91 is located on the inner surface side of the outer layer film 90. "Inner surface 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 thin film film 94, and a gas barrier resin layer 93, as shown in FIG. Further, the sealant layer 91 is located 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 vapor deposition film 94, a gas barrier resin layer 93, and a surface resin layer 95, as shown in FIG. Further, the sealant layer 91 is located 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. Further, the sealant layer 91 is located on the inner surface side of the outer layer film 90.

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

[Sealant layer]
The sealant layer contains a resin material that exhibits fusion properties by heat, and includes, for example, polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene, and polypropylene (copolymer, block polymer, random). Polymer), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methacrylate copolymer (EMAA), ethylene- Methyl methacrylate copolymer (EMMA), ionomer resin, heat-sealing ethylene / vinyl alcohol resin, or copolymerized resin Methylpentene-based resin, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene, polypropylene And acid-modified 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 (Meta) Acrylic resin and the like can be mentioned. Among these, polyethylene is preferable from the viewpoint of sealing property, and linear low-density polyethylene is preferable from the viewpoint of sealing property 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 object of the present invention is not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

The density of the sealant layer is preferably not more than 0.900 g / cm ³ or more 0.930 g / cm ^3, more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, 0.910 g It is more preferably / 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 further preferably 30 μm or more and 100 μm or less. Further, the sealant layer may be a single layer or a multilayer 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, and 0. It is more preferably 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, the T-die method and the inflation method.
Further, as the sealant layer, a film composed of the above resin material can be laminated on another layer such as a gas barrier resin layer via the adhesive resin layer described below by using a melt extrusion lamination method.

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 located on the inner surface side of the inner bag.

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

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

[Gas barrier resin layer]
The gas barrier resin layer contains a gas barrier resin, and includes, for example, ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, nylon 6, nylon 6,6 and polymethoxylylen adipamide (MXD6). Examples thereof 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 kinds of gas barrier resins.

As the gas barrier resin layer, a film made of the resin material as described above may be used. From the viewpoint of strength and the like, the gas barrier resin layer preferably uses a film stretched in the uniaxial or biaxial direction.

The gas barrier resin layer may contain a resin other than the gas barrier resin or may contain an additive as long as the object of the present invention is not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment 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, and 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 property and the water vapor barrier property of the outer layer film can be further improved. Further, the gas barrier resin layer may be a single layer or a multilayer of two or more layers.

As the gas barrier resin layer, a film composed of the above gas barrier resin can be laminated via an adhesive resin layer.

[Embedded film]
The outer layer film may include a thin-film deposition film. Thereby, the gas barrier property of the outer layer film can be improved.
The vapor deposition film is, for example, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti). , Lead (Pb), zirconium (Zr), yttrium (Y) and the like, and can be a vapor-deposited film of one or more kinds of inorganic substances or inorganic oxides. Further, the thin-film deposition film may be composed of two or more layers, and may be composed of the same material or different materials.

The film thickness of the thin-film deposition film is 100 Å to 2000 Å, preferably 200 Å to 1000 Å.

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

In one embodiment, the outer layer film may include a gas barrier coating film adjacent to the vapor deposition film. Thereby, the gas barrier property of the outer layer film can be further improved.

The gas barrier coating film is of the general formula R ¹ _n M (OR ² ) _m (where R ¹ and R ² represent organic groups having 1 to 8 carbon atoms, M represents a metal atom, and n. Represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M). It is obtained by a gas barrier composition containing a resin and / or an ethylene / vinyl alcohol copolymer and further polycondensing by the solgel method in the presence of a solgel method catalyst, acid, water and an organic solvent.

As the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m , at least one or more of a partial hydrolyzate of the alkoxide and a condensate of the hydrolysis of the alkoxide can be used. Further, the partial hydrolyzate of the alkoxide may be one in which all of the alkoxy groups are hydrolyzed, one or more in which one or more are hydrolyzed, and a mixture thereof. As the condensate of hydrolysis of the alkoxide, one having a dimer or more of the partially hydrolyzed alkoxide, specifically, one having a dimer of 2 to 6 is used.

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

Further, in the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m ^{, specific examples of the organic group represented by R 1} include, for example, a methyl group, an ethyl group, an n-propyl group, and i. Alkyl groups such as −propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-hexyl group, n-octyl group and others can be mentioned. Further, in the alkoxide represented by the above general formula R ¹ _n M (OR ² ) _m ^{, specific examples of the organic group represented by R 2} include, for example, a methyl group, an ethyl group, an n-propyl group, and i. -Propyl group, n-butyl group, sec-butyl group, etc. can be mentioned. In addition, these alkyl groups may be the same or different in the same molecule.

When preparing the above gas barrier composition, for example, a silane coupling agent or the like may be added. As the above-mentioned silane coupling agent, a known organic reactive group-containing organoalkoxysilane can be used. In this embodiment, an organoalkoxysilane having an epoxy group is particularly preferably used, and specifically, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, or , Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane and the like can be used. The above-mentioned silane coupling agent may be used alone or in combination of two or more.

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

The metal constituting the metal foil is not particularly limited, and a metal foil composed 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, and 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 property of the outer layer film can be further improved.

The metal leaf can be laminated on any layer via the adhesive resin layer.

[Surface resin layer]
The surface resin layer is a layer provided on the opposite side of the outer layer film from the sealant layer. As the resin constituting the surface resin 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.

The thickness of the surface resin layer can be appropriately changed, but is preferably 3 μm or more and 30 μm or less, and more preferably 5 μm or more and 20 μm or less. Further, the surface resin layer may be a single layer or a multilayer of two or more layers.

As an example of the layer structure when the outer layer film is a laminated body, for example, the following structure can be mentioned.
ONY / contact PE / PEF
ONY / Al thin film / contact PE / PEF
ONY / SiOn vapor deposition film / contact PE / PEF
Table PE / ONY / SiOn vapor deposition film / contact PE / PEF
ONY / contact PE / Al foil / contact PE / PEF
In one example of the above layer structure, the left side means the outside of the inner bag. The "/" symbol indicates the boundary between each layer. In an example of the above layer structure, the resin film of the present invention can be used as "PEF". The names of the other abbreviations are as follows.
ONY: Stretched nylon contact PE: Polyethylene as adhesive resin layer Table PE: Polyethylene as surface resin layer Al vapor deposition film: Vapor deposition film made of aluminum SiOn vapor deposition film: Vaporized 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 located 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 capacity of the contents, the type of the contents, the purpose of packaging, the packaging form, the distribution form, the sales form, and the like. The above may be done. By making the inner layer film double or more in the inner bag, leakage of the contents from the inner bag can be further suppressed. When the inner layer film is made of two or more layers, each inner layer film may be made of the same material or different materials.

The inner layer film contains a resin material that exhibits fusion properties by heat, and includes, for example, polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene (copolymer, 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 Acrylic ethylene / vinyl alcohol resin or copolymerized resin Methylpentene-based resin, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene, polypropylene, cyclic olefin copolymer and other polyolefin-based resin, polyolefin-based resin Examples thereof include acid-modified polyolefin resins modified with unsaturated carboxylic acids such as acids, methacrylates, maleic acids, maleic anhydrides, fumaric acids and itaconic acids, vinyl resins, and (meth) acrylic resins. Among these, polyethylene is preferable from the viewpoint of sealing property, and linear low-density polyethylene is preferable from the viewpoint of sealing property and pinhole resistance. The inner layer film may contain two or more kinds of the above resin materials.

The inner layer film may contain additives as long as the object of the present invention is not impaired. Additives include, for example, plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, thread friction reducing agents, slip agents, anti-blocking agents, oxidation. One or more kinds of inhibitor, ion exchanger, coloring pigment and the like can be added.

Density of the inner layer film is preferably not more than 0.900 g / cm ³ or more 0.930 g / cm ^3, more preferably at most 0.904 g / cm ³ or more 0.926 g / cm ^3, 0.910 g It is more preferably / 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 further preferably 30 μm or more and 100 μm or less. Further, the inner layer film may be a single layer or a multilayer film having two or more layers.

The melt flow rate (MFR) of the inner layer 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, and 0. It is more preferably 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 the resin film 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 the 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 located on the inner surface side of the inner bag.

<Outlet>
The spout is joined to the inner bag and is exposed to the outside of the exterior body through the opening of the exterior body.
In one embodiment, the packaging container of the present invention may include two or more spouts.

The shape of the spout can be appropriately selected according to the conditions such as the capacity of the contents, the type of the contents, the packaging purpose, the packaging form, the distribution form, the sales form, and the like. There are types and so on.

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

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 following Examples as long as the gist of the present invention is not exceeded.

[Example 1A]
Fossil fuel linear low-density polyethylene ((( Made by Prime Polymer Co., Ltd., trade name: UZ1520L, density: 0.914 ^{g / cm 3} , MFR: 2.3 g / 10 minutes, biomass degree: 0%) (hereinafter, also referred to as "petrified C6LLDPE_A"). This was melted.
Next, as the resin constituting the second layer, fossil fuel linear low-density polyethylene obtained by polymerizing ethylene derived from fossil fuel and α-olefin monomer having 6 carbon atoms derived from fossil fuel using a metallocene catalyst. Made by Ube Maruzen Polyethylene Co., Ltd., trade name: UM0520F, density: 0.904 g / cm ³ , MFR: 2.0 g / 10 minutes, degree of polymerization: 0%) (hereinafter, also referred to as "petrified C6LLDPE_B") 76.5 Biomass linear low-density polyethylene (manufactured by Brasschem, trade name: SLL-118, density: 0. These were melted using 23.5 parts by mass of 916 g / cm ³ , MFR: 1.0 g / 10 min, biomass degree 87%) (hereinafter, also referred to as “Bio-C4LLDPE”).
Next, petrified C6LLDPE_A was used as the resin constituting the third layer, and this was melted.

A resin film was coextruded from these melts by inflation molding so that the layer thickness ratios of the first layer, the second layer, and the third layer were 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 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 petrified C6LLDPE_B and 53.0 parts by mass of bio-C4LLDPE were used as the resin 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 petrified C6LLDPE_B and 70.5 parts by mass of bio-C4LLDPE were used as the resin 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 petrified C6LLDPE_A and 5.0 parts by mass of bio-C4LLDPE were used as the resin 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 petrified C6LLDPE_A and 23.0 parts by mass of bio-C4LLDPE were used as the resins constituting the first layer, the second layer and the third layer. A resin film was obtained. 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 resin constituting the second layer and the third layer, respectively. 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 50.0 parts by mass of petrified C6LLDPE_A and 50.0 parts by mass of bio-C4LLDPE were used as the resin constituting the third layer. , A resin film was obtained 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 petrified C6LLDPE_A was used as the resin constituting the first layer, the second layer, and the third layer, respectively. 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 resin films produced in the above Examples and Comparative Examples were bent 2000 times with a gelboflex tester under low temperature (5 ° C.) conditions, and then the number of pinholes was measured. This was repeated 3 times to calculate the average number of pinholes. In the resin films having the same composition, the total number of pinholes at each layer thickness was evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4.
(Evaluation criteria)
A: The total number of pinholes is less than 3 B: The total number of pinholes is 3 or more and less than 5 C: The total number of pinholes is 5 or more

<Evaluation of pinhole resistance (normal temperature)>
The resin films produced in the above Examples and Comparative Examples were bent 5000 times with a gelboflex tester under normal temperature (23 to 30 ° C.) conditions, and then the number of pinholes was measured. This was repeated 3 times to calculate the average number of pinholes. In the resin films having the same composition, the total number of pinholes at each layer thickness was evaluated according to the following criteria. The evaluation results are shown in Tables 3 and 4.
A: The total number of pinholes is less than 6 B: The total number of pinholes is 6 or more and less than 10 C: The total 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 by the following method using a film impact tester FT-M manufactured by Toyo Seiki Seisakusho Co., Ltd.
First, the resin film 10 produced in the above Examples and Comparative Examples was cut into a size of 10 cm × 10 cm to prepare a test piece 100. As shown in FIG. 11, the test piece 100 was sandwiched between ring-shaped jigs 101 and 102 and fixed. Subsequently, as shown in FIG. 12, a fixed test piece 100 is installed, 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 the 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 at the time of measurement was a temperature of 23 ° C. and a relative humidity of 50%. The measurement results are shown in Tables 3 and 4.

<Evaluation of tensile strength>
The tensile strengths of the resin films produced in the above Examples and Comparative Examples in the flow direction (MD) and the vertical direction (TD) were 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 Co., Ltd. was used. As the test piece, a resin film cut out into a rectangular film having a width of 10 mm and a length of 120 mm can be used. The distance at the start of measurement between the pair of chucks holding the test piece is 80 mm, and the tensile speed is 500 mm / min. The temperature at the time of measurement was 23 ° C. The measurement results are shown in Tables 3 and 4.

As shown in Tables 3 and 4, it can be seen that the resin film of the present invention has excellent pinhole resistance after bending under low temperature conditions and normal temperature conditions.

Using the resin film of the above example, a flat bag type inner bag 40 having a capacity of 10 L as shown in FIG. 3 was produced. In the inner bag, the inner layer film and the outer layer film are each single layer. The inner layer film is made of the resin film of the above embodiment. 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 embodiment as a sealant layer. The inner bag produced by using the resin film of the above example has excellent pinhole resistance.

Using the resin film of the above example, a gusset-type inner bag 70 having 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 made of the resin film of the above embodiment. 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 embodiment as a sealant layer. The inner bag produced by using the resin film of the above example has excellent 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 portion 46 : Top seal part 47: Bottom seal part 48: Side seal part 50: Outlet 60: Opening 70: Inner bag 71: Front 72: Rear surface 73: Side surface 74: Folded part 75: Top seal part 76: Bottom seal part 77 : Side seal part 90: Outer layer film 91: Sealant layer 92: 97: Adhesive resin layer 93: Gas barrier resin layer 94: Vapor deposition film 95: Surface resin layer 96: Metal foil 100: Test pieces 101, 102: Jig 103 : Supporting point 104: Arm 105: Indenter 411,421: Outer layer film 421,422: Inner layer film

Claims (13)

A resin film containing at least a first layer and a second layer directly laminated on the first layer.
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 linear low-density polyethylene formed by polymerizing ethylene and an α-olefin monomer having 6 or more carbon atoms with respect to the entire resin film.
A resin film in which the resin film contains biomass linear low-density polyethylene. It further comprises a third layer that is 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 density of the resin film is 0.900 g / cm ³ or more 0.930 g / cm ³ or less, the resin film according to any one of claims 1-4. The resin film according to any one of claims 1 to 5, wherein the resin film contains fossil fuel linear low-density polyethylene. The resin according to claim 6, wherein the fossil fuel linear low-density polyethylene contains a linear low-density polyethylene obtained by polymerizing ethylene and an α-olefin monomer having 6 or more carbon atoms using a metallocene catalyst. the film. The resin film according to any one of claims 1 to 7, wherein the second layer contains 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 degree 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 including an inner bag containing an outer layer film and an inner layer film and an outer body.
A packaging container in which at least one of the outer layer film and the inner layer film contains the resin film according to any one of claims 1 to 11. The packaging container according to claim 12, which comprises a spout joined to the inner bag.

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