Laminate for packaging, packaging, and resin film for packaging

Abstract

To improve airtightness of a package formed of a laminate containing a resin film.SOLUTION: There is provided a laminate 20 comprising a resin film 10 and a gas barrier layer 11, wherein the resin film 10 contains a polyethylene terephthalate, in the spectrum measured with 1H-NMR, the ratio (IA / I0) of an integrated value (IA) obtained by integrating signals which are derived from isophthalic acid and have a chemical shift value of 7.11 ppm or more and 7.25 ppm or less to an integrated value (I0) obtained by integrating signals which are derived from a terephthalic acid component and have a chemical shift value of 7.40 ppm or more and 8.15 ppm or less is 1×10-3 or more 6×10-3 or less and the ratio (IB / I0) of an integrated value (IB) by integrating signals which are derived from a naphthalenedicarboxylic acid and have a chemical shift value of 8.34 ppm or more and 8.36 ppm or less to the integrated value (I0) is 1×10-4 or more and 5×10-4 or less.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a laminate for packaging, a packaging material, and a resin film for packaging. [Background technology]

[0002] Resin films containing polyethylene terephthalate are widely used as packaging materials for packaging contents such as food, medicines, and cosmetics. In general, these resin films have the property of slightly allowing gases such as oxygen and hydrogen to pass through. For this reason, a laminate of a resin film and a gas barrier layer including a metal film or a metal oxide film is used as a packaging material (see, for example, Patent Document 1). In addition, it is desirable for the resin film itself to be made of a material with high gas barrier properties, which means that the material of the resin film has the property of being difficult for gases to pass through. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-81607 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, during the distribution process of a product whose contents are packaged in a package made of a laminate of a resin film and a gas barrier layer, external forces that cause deformation such as friction and bending are repeatedly applied to the product. When external forces are repeatedly applied to the package in this way, cracks are formed in the gas barrier layer, and the airtightness of the package is lost. Therefore, the laminate is required to comprehensively improve the airtightness of the package by not only improving the gas barrier property but also increasing the resistance to deformation. [Means for solving the problem]

[0005] The laminate for packaging that solves the above problems includes a resin film and a gas barrier layer laminated on the resin film, the resin film including polyethylene terephthalate, 1 In the spectrum measured by H-NMR, the integral value (I0) of the signal derived from the terephthalic acid component having a chemical shift value of 7.40 ppm or more and 8.15 ppm or less, and the integral value (I A ) and the ratio (I A / I0) is 1×10 -3 More than 6×10 -3 The integral value (I0) is a value obtained by integrating the signal originating from the naphthalenedicarboxylic acid component having a chemical shift value of 8.34 ppm or more and 8.36 ppm or less. B ) and the ratio (I B / I0) is 1×10 -4 5×10 or more -4 The following is the result.

[0006] A package that solves the above problem is a package including a laminate, the laminate including a resin film and a gas barrier layer laminated on the resin film, the resin film including polyethylene terephthalate, 1 In the spectrum measured by H-NMR, the integral value (I0) of the signal derived from the terephthalic acid component having a chemical shift value of 7.40 ppm or more and 8.15 ppm or less, and the integral value (I A ) and the ratio (I A / I0) is 1×10 -3 More than 6×10 -3 The integral value (I0) is a value obtained by integrating the signal originating from the naphthalenedicarboxylic acid component having a chemical shift value of 8.34 ppm or more and 8.36 ppm or less. B ) and the ratio (I B / I0) is 1×10 -4 5×10 or more -4 The following is the result.

[0007] The resin film that solves the above problems is a resin film that constitutes a laminate for a packaging bag by laminating a gas barrier layer having gas barrier properties, the resin film containing polyethylene terephthalate, 1 In the spectrum measured by H-NMR, the integral value (I0) of the signal derived from the terephthalic acid component having a chemical shift value of 7.40 ppm or more and 8.15 ppm or less, and the integral value (I A ) and the ratio (I A / I0) is 1×10 -3 More than 6×10 -3 The integral value (I0) is a value obtained by integrating the signal originating from the naphthalenedicarboxylic acid component having a chemical shift value of 8.34 ppm or more and 8.36 ppm or less. B ) and the ratio (I B / I0) is 1×10 -4 5×10 or more -4 The following is the result.

[0008] According to each of the above configurations, the ratio of the integral value of the signal at 7.11 ppm or more and 7.25 ppm or less derived from the isophthalic acid component to the integral value of the signal at 7.40 ppm or more and 8.15 ppm or less derived from the terephthalic acid component (I A / I0) is 1×10 -3 More than 6×10 -3 Since the resin film has a flexibility of 8.34 ppm or less, the resin film has an increased flexibility. By increasing the flexibility of the resin film, the resin film can easily absorb the load applied to the laminate, so that the load applied to the gas barrier layer is reduced and the bending resistance is increased. In addition, the ratio of the integral value of the signal at 8.34 ppm or more and 8.36 ppm or less derived from the naphthalenedicarboxylic acid component (I B / I0) is 1×10 -4 5×10 or more -4 Since the plane orientation coefficient of the resin film is equal to or less than 100 nm, the plane orientation coefficient of the resin film can be increased. By increasing the plane orientation coefficient, the gas barrier property of the resin film itself can be improved. Therefore, the airtightness of the laminate in which the gas barrier layer is laminated can be comprehensively improved.

[0009] For the laminate for packaging, the integral value (I0) and the integral value (I A ) and the ratio (I A / I0) is 2×10 -3 More than 4×10 -3 and the integral value (I B ) and the ratio (I B / I0) is 2×10 -4 More than 3×10 -4 The following is the result. According to the above-mentioned configuration, it is possible to comprehensively improve the airtightness of the laminate resin film having the gas barrier layer laminated thereon. In the laminate for packaging, the gas barrier layer may contain at least one of aluminum oxide and silicon oxide. According to the above-mentioned configuration, a coating having transparency can be formed on the resin film. In addition, the gas barrier properties of the laminate can be improved by reducing the water vapor permeability and oxygen permeability of the gas barrier layer. In addition, the adhesion between the resin film and the first coating containing at least one of aluminum oxide and silicon oxide can be ensured.

[0010] In the laminate for packaging, the gas barrier layer is made of Si(OR 1 )4, or R 2 Si(OR 3 )3(OR 1 and OR 3 is a hydrolyzable group, R 2 is an organic functional group) or one or more types of hydrolyzates of silicon compounds, and a water-soluble polymer having a hydroxyl group.

[0011] According to the above-mentioned configuration, the water vapor permeability and oxygen permeability of the gas barrier layer are reduced, so that the gas barrier properties of the laminate can be further improved. Effect of the Invention

[0012] According to the present invention, it is possible to comprehensively improve the airtightness of a package comprising a laminate including a resin film. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing a cross-sectional structure of a resin film according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing a cross-sectional structure of a laminate according to an embodiment. [Diagram 3] FIG. 2 is a perspective view showing a packaging body according to an embodiment; [Figure 4] 1H-NMR spectrum of one embodiment. [Diagram 5] An enlarged view of a portion of the 1H-NMR spectrum in Figure 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of a laminate for a packaging body, a packaging body, and a resin film for a packaging body will be described with reference to the drawings. [Resin film] The structure of a resin film 10, which is a resin film for packaging, will be described with reference to FIG. 1. The resin film 10 is made of polyester and contains polyethylene terephthalate (PET). The PET resin is at least one of virgin PET newly synthesized from raw materials such as petroleum, and recycled PET, which is recycled PET resin. PET products that are subject to recycling include used PET bottles. The recycled PET constituting the resin film 10 is at least one of PET recycled by mechanical recycling and PET recycled by chemical recycling.

[0015] Mechanical recycling includes a process of crushing PET products into resin fragments, a process of washing the resin fragments to remove surface dirt and foreign matter, and a process of exposing the resin fragments to high temperatures to remove contaminants remaining inside the resin. Chemical recycling includes a process of crushing PET products into resin fragments, a process of washing the resin fragments to remove surface dirt and foreign matter, a process of returning the resin to an intermediate raw material by depolymerization, and a process of purifying the intermediate raw material and repolymerizing it. Mechanical recycling does not require large-scale equipment for chemical reactions compared to chemical recycling, so the cost required for manufacturing recycled PET can be reduced. In addition, it reduces carbon dioxide emissions, so the burden on the environment is small. In order to reduce costs and the burden on the environment, it is preferable that the recycled PET used as the raw material for the resin film 10 is PET regenerated by mechanical recycling.

[0016] When the resin film 10 contains virgin PET in addition to recycled PET, the proportion of recycled PET is preferably 60% by weight or more and 100% by weight or less of the resin film 10, from the viewpoint of reducing costs and environmental impact.

[0017] The polyester constituting the resin film 10 contains a terephthalic acid component, an isophthalic acid component, and a naphthalenedicarboxylic acid component as a dicarboxylic acid component, which is a repeating unit. The naphthalenedicarboxylic acid component is a polycarboxylic acid component having a naphthalene skeleton, and examples of the naphthalenedicarboxylic acid include 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid. Note that the polyester may contain 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 1,5-naphthalenedicarboxylic acid.

[0018] The isophthalic acid component and the naphthalenedicarboxylic acid component may be derived from recycled PET or from virgin PET. Or, they may be added at any step of the manufacturing process. Furthermore, a dicarboxylic acid component such as adipic acid, and a glycol component such as propylene glycol, 1,4-butanediol, tetramethylene glycol, neopentyl glycol, cyclohexanedimethanol, and diethylene glycol may be included. Generally, PET resin is produced by polymerizing terephthalic acid, which is a dicarboxylic acid, and ethylene glycol, which is a diol, but the PET resin used in the resin film 10 is a resin produced by copolymerizing terephthalic acid with isophthalic acid and naphthalenedicarboxylic acid, or a resin produced by copolymerizing terephthalic acid with isophthalic acid and mixing polyethylene naphthalate resin with polyethylene terephthalate resin. In other words, the isophthalic acid component and the naphthalenedicarboxylic acid component may be included as a copolymerization component with polyethylene terephthalate, or may be included as a polyester separate from polyethylene terephthalate.

[0019] The average molecular weight of the PET resin contained in the resin film 10 is not particularly limited, but is preferably, for example, about 1,000 to 1,000,000. The resin film 10 may contain resins other than PET and various additives such as plasticizers.

[0020] The resin film 10 is composed of a single layer or multiple layers. When the resin film 10 is composed of multiple layers, the materials constituting each layer may be the same or different. An example of a configuration in which the materials constituting each layer are different from each other is a laminate of a layer formed from recycled PET and a layer formed from virgin PET. Another example of a configuration in which the materials constituting each layer are different from each other is a laminate of a layer containing recycled PET in a first ratio to virgin PET and a layer containing recycled PET in a second ratio to virgin PET that is different from the first ratio.

[0021] The thickness of the resin film 10 is selected according to various properties required for the package, such as various environmental resistances such as heat and moisture, storage stability of the contents, filling stability of the contents, sealing processability, printing resistance including marking, etc. From the viewpoint of improving the processability of the resin film 10, for example, the thickness of the resin film 10 is preferably selected from the range of 3 μm to 100 μm, and more preferably selected from the range of 6 μm to 50 μm.

[0022] The method for forming the resin film 10 is a melt extrusion method or a melt coextrusion method. The flow direction of the resin film 10 is the direction in which the molding of the PET resin proceeds during the production of the resin film 10. The flow direction is also called the MD (Machine Direction) direction or the longitudinal direction. The direction perpendicular to the flow direction is also called the TD (Transverse Direction) direction or the lateral direction. When the resin film 10 is composed of multiple layers, the flow direction of each layer is the same.

[0023] The resin film 10 is a non-stretched film, a uniaxially stretched film stretched in the MD or TD at a predetermined ratio, or a biaxially stretched film stretched in the MD and TD at a predetermined ratio either sequentially or simultaneously. When the resin film 10 is composed of multiple layers, the stretching direction of each layer is the same.

[0024] [Laminate] A laminate 20, which is a laminate for packaging, will be described with reference to Fig. 2. The laminate 20 includes a resin film 10 and a gas barrier layer 11. The gas barrier layer 11 has a function of enhancing the gas barrier properties of the laminate 20. Note that the ratio of the thickness of the resin film 10 to the thickness of the gas barrier layer 11 is not limited to the ratio shown in Fig. 2.

[0025] The gas barrier layer 11 includes a vapor-deposited film formed by, for example, chemical vapor deposition or physical vapor deposition. The vapor-deposited film is an inorganic oxide film or a metal film. The inorganic substance contained in the inorganic oxide may be, for example, an oxide of silicon, aluminum, magnesium, calcium, potassium, tin, sodium, boron, titanium, lead, zirconium, yttrium, or the like. The metal may be, for example, aluminum, magnesium, tin, sodium, titanium, lead, zirconium, yttrium, gold, chromium, or the like.

[0026] The method for forming the vapor-phase deposition film may be, for example, a vacuum deposition method, a sputtering method, an ion plating method, or a plasma vapor deposition method (CVD). From the viewpoint of increasing the productivity of the laminate, the method for forming the vapor-phase deposition film is preferably a vacuum deposition method. In the vacuum deposition method, it is preferable to use any one of an electron beam heating method, a resistance heating method, and an induction heating method as a method for heating the deposition material. From the viewpoint of increasing the degree of freedom in the selection of the deposition material, it is preferable to use an electron beam heating method. From the viewpoint of increasing the adhesion between the vapor-phase deposition film and the resin film 10 and from the viewpoint of increasing the density of the vapor-phase deposition film, it is possible to use a plasma assist method and an ion beam assist method in the vacuum deposition method. From the viewpoint of increasing the transparency of the deposition layer, the gas barrier layer 11 may be formed by a reactive deposition method. In the reactive deposition method, a reactive gas such as oxygen gas is supplied to the film formation space.

[0027] The laminate 20 for forming a transparent package includes a vapor-phase deposited film formed from an inorganic oxide. In particular, vapor-phase deposited films formed from aluminum oxide and silicon oxide are preferred. The laminate 20 for forming a package having light-shielding properties includes a vapor-phase deposited film formed from a metal. In particular, a vapor-phase deposited film formed from aluminum is preferred.

[0028] The gas barrier layer 11 may be formed of a plurality of barrier layers. In this case, each barrier layer may be formed of the same material, or the plurality of barrier layers may include a barrier layer formed of a first material and a barrier layer formed of a second material different from the first material.

[0029] The thickness of the gas barrier layer 11 is not particularly limited, but in the case of a vapor-phase deposition film, it is, for example, 5 nm or more and 300 nm or less. When the thickness of the gas barrier layer 11 is 5 nm or more, the uniformity of the gas barrier layer 11 can be increased and the gas barrier layer 11 can have a sufficient thickness. Therefore, the gas barrier layer 11 can fully exhibit the gas barrier function. On the other hand, when the thickness is 300 nm or less, the gas barrier layer 11 can maintain flexibility. This suppresses cracks in the gas barrier layer 11 caused by external factors such as bending and pulling after film formation. The thickness of the gas barrier layer 11 is appropriately selected depending on the type of inorganic compound forming the gas barrier layer 11 and the configuration of the laminate 20. From the viewpoint of increasing the uniformity in the thickness of the gas barrier layer 11, it is more preferable that the thickness of the gas barrier layer 11 is included in the range of 10 nm or more and 150 nm or less.

[0030] The gas barrier layer 11 may include a coating film having gas barrier properties in addition to or instead of the above-mentioned vapor-phase deposited film. The coating film is made of a material containing a resin. The coating film protects the vapor-phase deposited film, and thus the gas barrier properties of the gas barrier layer can be improved.

[0031] The coating film is formed, for example, from a water-soluble polymer and an inorganic compound. The water-soluble polymer may be, for example, polyvinyl alcohol, polyvinylpyrrolidone, starch, methyl cellulose, carboxymethyl cellulose, sodium alginate, etc. From the viewpoint of improving the gas barrier properties of the gas barrier layer 11, it is preferable that the water-soluble polymer is polyvinyl alcohol (PVA).

[0032] The inorganic compound contained in the coating film is, for example, Si(OR 1 )4 or R 2 Si(OR 3 In addition, the silicon compound may be a silicon compound represented by the formula OR 1 and OR 3 is a hydrolyzable group, R 2 is an organic functional group. The inorganic compound may include one or more silicon compounds or hydrolysates of such silicon compounds.

[0033] Si(OR 1 For example, R may be tetraethoxysilane (Si(OC2H5)4) (TEOS). TEOS is preferred because it is relatively stable in aqueous solvents after hydrolysis. 2 Si(OR 3 )3 contains R 2 is preferably selected from the group consisting of a vinyl group, an epoxy group, a methacryloxy group, a ureido group, and an isocyanate group.

[0034] The coating film is formed by applying a mixed solution of a solvent, a water-soluble polymer, and a silicon compound or a hydrolyzate of a silicon compound onto a deposition layer, followed by heating and drying. The solvent may be water or a mixed solvent of water and alcohol. When forming the mixed solution, first, the water-soluble polymer is dissolved in a solvent, and then the silicon compound or a hydrolyzate of a silicon compound is mixed. The mixed solution may contain additives within a range in which the coating film formed using the mixed solution does not impair the gas barrier properties. The additives may be, for example, an isocyanate compound, a silane coupling agent, a dispersant, a stabilizer, a viscosity modifier, and a colorant.

[0035] When the water-soluble polymer is PVA, the ratio of the mass of PVA to the mass of the total solid content of the mixed solution is preferably 20% by mass or more and 50% by mass or less, and more preferably 25% by mass or more and 40% by mass or less. By including 20% ​​by mass or more of PVA, the flexibility of the coating film is maintained. Therefore, the coating film is easily formed. Furthermore, by including 50% by mass or less of PVA, the gas barrier layer 11 can have sufficient barrier properties.

[0036] The thickness of the coating film is, for example, 0.05 μm or more and 30 μm or less. When the gas barrier layer 11 includes a vapor-phase deposited film and a coating film, in the laminate 20, the vapor-phase deposited film may be located on the resin film 10, and the coating film may be located on the vapor-phase deposited film. Thereby, the coating film is in contact with the vapor-phase deposited film. Alternatively, the coating film may be located on the resin film 10.

[0037] From the viewpoint of strengthening the adhesion between the resin film 10 and the gas barrier layer 11, the surface of the resin film 10 on which the gas barrier layer 11 is to be formed may be subjected to a surface treatment such as a plasma treatment or a corona treatment. When the gas barrier layer 11 is formed from an inorganic oxide, an anchor coat layer may be located between the resin film 10 and the gas barrier layer 11. The surface treatment and the anchor coat layer improve the adhesion between the resin film 10 and the deposition layer after heat sterilization, and the barrier properties of the laminate 20.

[0038] The gas barrier layer 11 may include a layer formed of a metal foil and a metal nitride in addition to the above-mentioned vapor-phase deposited film and coating film, or instead of at least one of the above-mentioned vapor-phase deposited film and coating film. When the gas barrier layer 11 includes one or more layers other than the vapor-phase deposited film and coating film, another layer may be located between the vapor-phase deposited film and the coating film. Alternatively, another layer other than the coating film may be located between the vapor-phase deposited film and the resin film.

[0039] The laminate 20 may include a sealing layer, an adhesive layer, a decorative layer, and an information display layer in addition to the resin film 10 and the gas barrier layer 11. The sealing layer contains a thermoplastic resin. The sealing layer is melted by heat sealing when a package is formed using the laminate 20. As a result, in two laminates 20, an end of one laminate 20 is fused to an end of the other laminate 20. Alternatively, in one laminate 20, a first portion and a second portion of the laminate 20 are fused. The adhesive layer enhances adhesion between the gas barrier layer 11 and the upper layer of the gas barrier layer 11, or between the gas barrier layer 11 and the lower layer of the gas barrier layer 11. The decorative layer and the information display layer display decoration and information formed by printing.

[0040] The thickness of the laminate 20 may be selected according to various resistances required for a package formed using the laminate 20 and the processability required for the laminate 20. The thickness of the laminate 20 may be, for example, 30 μm or more and 300 μm or less.

[0041] The laminate 20 may be formed by the above-mentioned film forming method, various coating methods, a dry lamination method, an extrusion lamination method, or the like. [Packaging] The package will now be described with reference to FIG.

[0042] The packaging body 30 shown in FIG. 3 is formed from a laminate 20. The packaging body 30 defines a space capable of accommodating a packaged object inside the packaging body 30. In the example shown in FIG. 3, the packaging body 30 has a bag shape. The packaging body 30 is sealed by joining the ends over the entire circumference. In the packaging body 30, the gas barrier layer 11 is located on the inner side relative to the resin film 10. The shape and size of the packaging body 30 are not particularly limited. The shape and size of the packaging body 30 may be designed according to the shape and size of the packaged object. The packaged object may be, for example, food, medicine, cosmetics, etc.

[0043] The method of joining the ends of the laminate 20 is not particularly limited. For example, the ends of the laminate 20 may be joined using heat sealing as described above, or may be joined by other methods. In the example shown in Fig. 3, the packaging body 30 has a sealing portion 31 in which the ends of the first laminate and the second laminate are joined in two sheets of the laminate 20.

[0044] The packaging body 30 is not limited to the bag-like shape shown in Fig. 3. For example, the packaging body 30 may have a cylindrical shape or a bag-like shape with one cylindrical end sealed and the other cylindrical end open. Alternatively, the packaging body 30 may include the laminate 20 only in a portion thereof.

[0045] In addition, when the packaging body 30 using the laminate 20 is mass-produced, a roll-to-roll apparatus is used, and the laminate 20 is subjected to a process for forming the packaging body 30 while being transported by the roll-to-roll apparatus. The laminate 20 is transported by the roll-to-roll apparatus along the flow direction of the resin film 10. At this time, the laminate 20 is transported by the roll-to-roll apparatus in a state where it is pulled along the flow direction of the resin film 10. The resin film 10 is pulled along the flow direction with a stress that does not cause slack or bending in the laminate 20, in order to enable the transport of the laminate 20 and to prevent wrinkles from occurring in the packaging body 30 formed using the laminate 20.

[0046] [Physical properties of resin film] The physical properties of the resin film 10 will be described with reference to FIG. 4 and FIG. FIG. 4 and FIG. 5 are 1The spectrum of the resin film 10 measured by H-NMR is shown. When the standard substance is 1,4-bis-trimethylsilylbenzene-d4 and the chemical shift value of the signal of the standard substance is 0 ppm, three signals (peaks) originating from isophthalic acid components having an isophthalic acid skeleton appear at 7.11 ppm to 7.25 ppm, a signal originating from terephthalic acid components having a terephthalic acid skeleton appears at 7.40 ppm to 8.15 ppm, and a signal originating from naphthalenedicarboxylic acid components having a naphthalenedicarboxylic acid skeleton appears at 8.34 ppm to 8.36 ppm. Fig. 5 is an enlarged view of the spectrum. In this embodiment, the signal appearing at 7.11 ppm to 7.25 ppm is the signal indicated by "A" in Fig. 5, which is a signal derived from the hydrogen at the position "A" indicated by the arrow among the hydrogens bonded to the aromatic ring of the isophthalic acid skeleton represented by the following general formula (1). [ka] In this embodiment, the signal appearing at 7.40 ppm to 8.15 ppm is the signal indicated by "B" in FIG. 5, and is a signal derived from four hydrogen atoms bonded to an aromatic ring of a terephthalic acid skeleton represented by the following general formula (2). [ka] In this embodiment, the signals appearing at 8.34 ppm to 8.36 ppm are the signals indicated by "C" in FIG. 5, and are two peaks derived from the hydrogens at the position "C" indicated by the arrows among the hydrogens bonded to the aromatic rings of the aromatic rings of the naphthalenedicarboxylic acid skeleton represented by the following general formula (3). [ka]

[0047] In order to enhance the flexibility of the resin film 10 itself, the resin film 10 satisfies the following conditions 1 and 2. The integral value (I A) and the ratio of the integral value (I0), which is the area of ​​the signal derived from the terephthalic acid component at 7.40 ppm to 8.15 ppm (I A / I0) is 1×10 -3 More than 6×10 -3 The following is true (Condition 1).

[0048] · 1 The integral (I B ) and the ratio of the integral value (I0), which is the area of ​​the signal derived from the terephthalic acid component at 7.40 ppm to 8.15 ppm (I B / I0) is 1×10 -4 5×10 or more -4 The following is true (condition 2).

[0049] The integral value of the signal is the value obtained by integrating the relative intensity of the proton signal at each chemical shift when the chemical shift is changed by 0.01. In addition, in the range of 7.11 ppm to 7.25 ppm originating from the isophthalic acid component, the integral value I A is the sum of the integrals of the three signals.

[0050] By satisfying condition 1, the content of the isophthalic acid component in the resin film 10 falls within an appropriate range. As a result, the resin film 10 has flexibility suitable for use as a film in the package 30. As a result, even if an external force such as friction, piercing, bending, or impact is applied to the package 30, the resin film 10 absorbs the load by deforming in response to the external force, and cracks are less likely to form in the gas barrier layer 11 in contact with the resin film 10. A The ratio (I A / I0) is 1×10 -3If the integral value I is less than 100%, the content of the isophthalic acid component is insufficient, so that the resin film 10 cannot obtain high flexibility and the bending resistance is reduced. If the flexibility of the resin film 10 is low, cracks are likely to occur in the gas barrier layer 11, and the number of cracks increases, and the width and length of the cracks become large. As a result, it becomes difficult to maintain the quality of the contents of the package 30 in a good condition. On the other hand, if the integral value I A The ratio (I A / I0) is 6×10 -3 If the temperature exceeds this range, the heat resistance of the resin film 10 decreases, for example, the melting point and softening temperature of the resin film 10 decrease, and a uniform and dense vapor-phase deposited film of aluminum oxide or silicon oxide cannot be formed on the resin film 10. As a result, it becomes difficult to obtain a laminate 20 with high gas barrier properties. In order to adjust the content of the isophthalic acid component in the resin film 10 so as to satisfy the above condition 1, for example, the ratio of recycled PET to the total PET may be adjusted during the production of the resin film 10, or an isophthalic acid component may be added during polymerization of PET. Since PET bottles sometimes contain isophthalic acid components to improve processability, recycled PET tends to contain more isophthalic acid components than virgin PET. For this reason, when increasing the content of the isophthalic acid component in the resin film 10, it is considered to increase the ratio of recycled PET.

[0051] By satisfying condition 2, the content of the naphthalenedicarboxylic acid component falls within an appropriate range, and the planar orientation coefficient at the surface of the resin film 10 increases. The planar orientation coefficient is a measure of the orientation and crystallinity of the film, and can be expressed by the following formula (1). The refractive index in the direction in which the refractive index is maximum is n1, the refractive index in the direction perpendicular to the direction in which the refractive index is maximum is n2, and the refractive index in the thickness direction of the film is n3.

[0052] Plane orientation coefficient Fn = (n1 + n2) / 2 - n3 ... (1) By increasing the plane orientation coefficient of the resin film 10, the resin film 10 itself can maintain high gas barrier properties and also has good adhesion to the gas barrier layer 11.B The ratio (I B / I0) is 1×10 -4 If the integral value I is less than 100%, the gas barrier properties of the resin film 10 will be reduced, and cracks will be easily formed in the gas barrier layer 11 when the resin film 10 is used as the package 30 and a load such as bending is applied. If the adhesion between the resin film 10 and the gas barrier layer 11 is reduced, the number of cracks that occur in the gas barrier layer 11 will increase, and the width and length of the cracks will increase. If the number of cracks increases or the width and length increase, it will be difficult to maintain good quality of the contents of the package 30. B The ratio (I B / I0) is 5×10 -4 If the temperature exceeds this range, the adhesion to the gas barrier layer 11 may decrease to such an extent that the gas barrier layer 11 peels off from the resin film 10. In order to adjust the content of the naphthalene dicarboxylic acid component in the resin film 10 so as to satisfy the above condition 2, for example, the ratio of recycled PET to the total PET may be adjusted during the production of the resin film 10, or the naphthalene dicarboxylic acid component may be added during polymerization of PET. Recycled PET tends to contain more naphthalene dicarboxylic acid components than virgin PET. For this reason, when increasing the content of the naphthalene dicarboxylic acid component in the resin film 10, it is possible to increase the ratio of recycled PET. Then, when producing the packaging body 30, the content ratio of the isophthalic acid component and the content ratio of the naphthalene dicarboxylic acid component in the resin film 10 are measured in advance, and a resin film whose content ratios satisfy conditions 1 and 2, respectively, may be selected.

[0053] Integral value at 7.11 ppm to 7.25 ppm (I A ) ratio (I A / I0) and the integral value at 8.34 ppm to 8.36 ppm (I B ) ratio (I BBy producing the packaging body 30 using the resin film 10 having a ratio of 0.1 to 1.0, it is possible to improve the bending resistance of the packaging body 30 and to maintain good adhesion between the resin film 10 and the gas barrier layer 11. In addition, the integral value (I0) and the integral value (I A ) and the ratio (I A / I0) is 2×10 -3 More than 4×10 -3 The integral value (I0) and the integral value (I B ) and the ratio (I B / I0) is 2×10 -4 More than 3×10 -4 If it is equal to or less than this, the airtightness of the resin film 10 on which the gas barrier layer 11 is laminated can be further improved comprehensively.

[0054] As described above, according to one embodiment of the resin film for packaging, the laminate for packaging, and the packaging body, the following effects can be obtained. (1) The ratio of the integral value of the signal at 7.11 ppm to 7.25 ppm derived from isophthalic acid components to the integral value of the signal at 7.40 ppm to 8.15 ppm derived from terephthalic acid (I A / I0) is 1×10 -3 More than 6×10 -3 or less, the flexibility of the resin film 10 is enhanced. By increasing the flexibility of the resin film 10, the resin film 10 becomes more easily deformed in response to an external force, and the bending resistance of the laminate 20 for packaging and the packaging body 30 is improved. In addition, the ratio of the integral value of the signal at 8.34 ppm to 8.36 ppm derived from the naphthalene dicarboxylic acid component (I B / I0) is 1×10 -4 5×10 or more -4 Since the plane orientation coefficient of the resin film 10 is equal to or less than 100 nm, it is possible to suppress peeling between the resin film 10 and the gas barrier layer 11 while increasing the plane orientation coefficient of the resin film 10. By increasing the plane orientation coefficient, the gas barrier property of the resin film 10 itself is improved. Therefore, it is possible to comprehensively improve the airtightness of the resin film 10 laminated with the gas barrier layer 11.

[0055] (2) If the gas barrier layer 11 contains at least one of aluminum oxide and silicon oxide, a coating having transparency can be formed on the resin film 10. In addition, by reducing the water vapor permeability and oxygen permeability of the gas barrier layer 11, the gas barrier properties of the laminate can be improved. In addition, the ratio of the integrated values ​​of the signals derived from the naphthalenedicarboxylic acid component of the resin film 10 (I B / I0) is 5×10 -4 Since the thickness is equal to or less than 100 nm, adhesion to the first coating film containing at least one of aluminum oxide and silicon oxide can be ensured.

[0056] (3) The gas barrier layer 11 is made of Si(OR 1 )4, or R 2 Si(OR 3 By including one or more silicon compounds represented by Formula 3 or hydrolysates of silicon compounds and a water-soluble polymer having a hydroxyl group, the water vapor permeability and oxygen permeability of the gas barrier layer 11 are reduced, and the gas barrier property of the laminate 20 can be further improved.

[0057] [Example] Laminates provided with a resin film will be described below in accordance with Examples 1 to 4 and Comparative Example 1. Note that the present invention is not limited to these Examples.

[0058] [Example 1] A resin film having a thickness of 12 μm was prepared by laminating three resin layers by coextrusion. The PET constituting the resin layer was a mixture of recycled PET regenerated by mechanical recycling and virgin PET. The mass ratio of the recycled PET was 80% by weight of the resin film, and the mass ratio of the virgin PET was 20% by weight of the resin film. A part of this resin layer was cut, and the cut resin piece was dissolved in trifluoroacetic acid, which is a solvent, to prepare a sample for NMR measurement.

[0059] This sample, 1The NMR spectrum was obtained by measuring with a H-NMR (AVANCE NEO400, Bruker Japan). The measurement conditions were 256 scans, a flip angle of 30°, a capture time of 4.19 sec, and a waiting time of 2.00 sec. The integral value (I0) of the signal appearing near 7.80 ppm relative to the integral value (I A ) ratio (I A / I0) is 4×10 -3 In addition, the integral value (I0) at 8.35 ppm was B ) and the ratio (I B / I0) is 2×10 -4 It was.

[0060] A thin film of metallic aluminum was evaporated onto this resin film using a vacuum deposition apparatus using an electron beam heating method while introducing oxygen gas, forming a vapor-phase deposition film of aluminum oxide having a thickness of 15 nm.

[0061] Further, 72.1 g of hydrochloric acid (0.1N) was added to 17.9 g of tetraethoxysilane and 10 g of methanol, and the mixture was stirred for 30 minutes to hydrolyze the mixture, which was used as the first liquid. In addition, an aqueous solution of 5 mass% polyvinyl alcohol and 95 mass% water / methanol=95 / 5 (mass ratio) was used as the second liquid. Then, the first liquid and the second liquid were mixed in a ratio of 70:30 by weight of solid contents, and the solution was applied to the resin film on which the vapor-phase deposition film was formed by gravure coating, and dried to obtain a laminate.

[0062] [Example 2] Resin film 1 In the H-NMR spectrum, the integral value (I0) of the signal that appeared at around 7.80 ppm and the integral value (I A ) and the ratio (I A / I0) is 4×10 -3 In addition, the integral value (I0) and the integral value at 8.35 ppm (I B ) and the ratio (I B / I0) is 3 x 10 -4Other than that, a resin film and a laminate including a resin film were produced in the same manner as in Example 1.

[0063] [Example 3] Resin film 1 In the H-NMR spectrum, the integral value (I0) of the signal that appeared at around 7.80 ppm and the integral value (I A ) and the ratio (I A / I0) is 3 x 10 -3 In addition, the integral value (I0) and the integral value at 8.35 ppm (I B ) and the ratio (I B / I0) is 3 x 10 -4 Other than that, a resin film and a laminate including a resin film were produced in the same manner as in Example 1.

[0064] [Example 4] Resin film 1 In the H-NMR spectrum, the integral value (I0) of the signal that appeared at around 7.80 ppm and the integral value (I A ) and the ratio (I A / I0) is 2×10 -3 In addition, the integral value (I0) and the integral value at 8.35 ppm (I B ) and the ratio (I B / I0) is 2×10 -4 Other than that, a resin film and a laminate including a resin film were produced in the same manner as in Example 1.

[0065] [Comparative Example 1] A resin film was formed in the same manner as in Example 1, except that a PET (PET P60, manufactured by Toray Industries, Inc.) not containing an isophthalic acid component or a naphthalenedicarboxylic acid component was used. In other words, signals at 7.11 ppm to 7.25 ppm and signals at 8.34 to 8.36 ppm were not detected. A resin film and a laminate including the resin film were produced in the same manner as in Example 1, except that a resin film and a laminate including the resin film were produced.

[0066] [Evaluation method] [Face orientation coefficient] The plane orientation coefficient ΔP was measured by a phase difference measurement method using a phase difference measurement device (KOBRA-WR, manufactured by Oji Scientific Instruments Co., Ltd.). Specifically, a 40 mm × 40 mm area was set at the center in the TD direction of the resin film and at the end in the TD direction. The phase difference was measured at an incident angle of 0° to 50° (10° pitch) for this area.

[0067] [Gas barrier properties] Two test pieces were prepared from each of the laminates of Examples 1 to 4 and the laminate of Comparative Example 1, and the gas barrier properties were evaluated after the Gelbo flex test.

[0068] (Gelboflex test) A Gelbo Flex test was performed on each test piece using a flexibility evaluation device (Gelbo Flex Tester, manufactured by Tester Sangyo Co., Ltd.). At this time, each test piece was attached to the fixed head of the flexibility evaluation device so as to assume a cylindrical shape. In detail, both ends of each test piece were held by the fixed head, and the initial gripping distance was set to 175 mm. Then, the stroke was set to 87.5 mm, the twist was set to 440°, and each test piece was twisted and released from the twist reciprocating motion 100 times at a speed of 40 times / min.

[0069] (Oxygen permeability) The oxygen permeability of the laminates of Examples 1 to 4 and Comparative Example 1 was measured using an oxygen permeability measuring device (product name: OX-TRAN-2 / 20, manufactured by MOCON). The measurement conditions were a temperature of 30°C and a relative humidity of 70% RH. The method used was in accordance with JIS K 7126-2:2006 and ASTM D3985-81. The unit of the measured oxygen permeability is [cc / m 2 ·day·atm.

[0070] (Water vapor permeability) The laminates of Examples 1 to 4 and Comparative Example 1 were measured for water vapor permeability (g / (m) using a water vapor permeability measuring device (product name: PERMATRAN-W-3 / 31, manufactured by MOCON).2 The measurement conditions were a temperature of 40°C and a relative humidity of 90%. The measurement method used was in accordance with JIS K 7129-2:2019 and ASTM F1249-90.

[0071] [Evaluation Results] The planar orientation coefficient, oxygen permeability and water vapor permeability of the laminates of Examples 1 to 4 and the laminate of Comparative Example 1 were as shown in Table 1 below.

[0072] [Table 1] As shown in Table 1, the plane orientation coefficients of Examples 1 to 4 were larger in both the center and edge rows of the resin film than those of Comparative Example 1. The oxygen permeability of the resin films of Examples 1 to 4 after the Gelbo flex test was smaller than the oxygen permeability of the resin layer of Comparative Example 1. Similarly, the water vapor permeability of the resin films of Examples 1 to 4 after the Gelbo flex test was smaller than the water vapor permeability of the resin layer of Comparative Example 1. That is, it was suggested that the resin films of Examples 1 to 4 maintained high airtightness even after external force was applied compared to the resin film of Comparative Example 1. Therefore, by adopting a resin film that satisfies Condition 1 and Condition 2 described in the above embodiment as the resin film for the package, a package having excellent bending resistance and excellent adhesion to the gas barrier layer can be produced. [Explanation of symbols]

[0073] 10...Resin film 11...Gas barrier layer 20...Laminate 30...packaging

Claims

1. A laminate for packaging, comprising: A resin film; a gas barrier layer laminated on the resin film and having at least one of an inorganic oxide film and a metal film, The resin film is Contains polyethylene terephthalate having a molecular weight of 1,000 or more and 1,000,000 or less, The thickness is 6 μm or more and 50 μm or less, １ In the spectrum measured by H-NMR, the integral value (I ０ ) and the integral value (I Ａ ) and the ratio (I Ａ / I ０ ) is 2×10 −3 or more and 4×10 −3 or less, The integral value (I ０ ) and the integral value (I Ｂ ) and the ratio (I Ｂ / I ０ ) is 2×10 −4 or more and 3×10 −4 or less, The plane orientation coefficient on the surface of the resin film is 0.17 or more. Laminate for packaging.

2. The gas barrier layer is an inorganic oxide film, The inorganic oxide film is 2. The laminate for packaging according to claim 1, which is a vapor-phase deposited film containing at least one of aluminum oxide and silicon oxide and having a thickness of 5 nm to 300 nm.

3. The gas barrier layer is a vapor-phase deposited film having at least one of the inorganic oxide film and the metal film, and a coating film; the vapor-deposited film is located on the resin film; The coating film is Located on the vapor-deposited film, Si(OR １ ) ４ , or R ２ Si(OR ３ ) ３ (OR １ and OR ３ is a hydrolyzable group, R ２ is an organic functional group), or one or more types of hydrolyzates of the silicon compound, and a water-soluble polymer having a hydroxyl group, 3. The laminate for packaging according to claim 1 or 2, which has a thickness of 0.05 μm or more and 30 μm or less.

4. A laminate for packaging described in any one of claims 1 to 3, wherein the gas barrier layer is a metal film made of aluminum.

5. A package comprising a laminate, The laminate comprises: A resin film; a gas barrier layer laminated on the resin film and having at least one of an inorganic oxide film and a metal film, The resin film is Contains polyethylene terephthalate having a molecular weight of 1,000 or more and 1,000,000 or less, The thickness is 6 μm or more and 50 μm or less, １ In the spectrum measured by H-NMR, the integral value (I ０ ) and the integral value (I Ａ ) and the ratio (I Ａ / I ０ ) is 2×10 −3 or more and 4×10 −3 or less, The integral value (I ０ ) and the integral value (I Ｂ ) and the ratio (I Ｂ / I ０ ) is 2×10 −4 or more and 3×10 −4 or less, The plane orientation coefficient on the surface of the resin film is 0.17 or more. packaging.

6. A resin film for packaging that constitutes a laminate by laminating a gas barrier layer having at least one of an inorganic oxide film and a metal film, Contains polyethylene terephthalate having a molecular weight of 1,000 or more and 1,000,000 or less, The thickness is 6 μm or more and 50 μm or less, １ In the spectrum measured by H-NMR, the integral value (I ０ ) and the integral value (I Ａ ) and the ratio (I Ａ / I ０ ) is 2×10 −3 or more and 4×10 −3 or less, The integral value (I ０ ) and the integral value (I Ｂ ) and the ratio (I Ｂ / I ０ ) is 2×10 −4 or more and 3×10 −4 or less, The plane orientation coefficient on the surface of the resin film for packaging is 0.17 or more. Resin film for packaging.

Images