Barrier films, laminates, and packaging bags

Abstract

This invention provides a barrier film comprising a vapor-deposited film formed on an OPP film substrate and, if necessary, a coating layer, which enables both a reduction in barrier properties after heat sterilization and resistance to gelboflex. A barrier film in which a polypropylene substrate, a base layer, and an aluminum oxide vapor-deposited film are laminated in this order, The aluminum oxide vapor-deposited film is a barrier film in which the intensity ratio P1, defined below, is 0.090 or more and 0.170 or less when X-ray absorption microstructure analysis is performed from the surface side of the barrier film opposite to the polypropylene substrate side. P1 = (Average intensity from 1561.0 eV to 1563.6 eV) / (Average intensity from 1566.5 eV to 1571.6 eV)

Description

[Technical Field]

[0001] This invention relates to barrier films, laminates, and packaging bags. [Background technology]

[0002] Conventionally, laminated films, which have a film formed on a substrate such as a long film or sheet of plastic, have been used in a variety of applications. For example, barrier films have been developed that have a barrier layer made of a thin film of aluminum oxide or the like on a plastic film, providing barrier properties against oxygen and water vapor.

[0003] As a method for manufacturing a barrier film comprising an aluminum oxide thin film, for example, Patent Document 1 discloses a method for manufacturing a barrier film in which a PET film surface is subjected to plasma treatment and then aluminum oxide is deposited.

[0004] On the other hand, in recent years, from an environmental perspective, monomaterial packaging materials have been considered with the aim of improving the recyclability of packaging materials. For example, instead of the conventionally used polyester film (PET film), a polyolefin film such as biaxially oriented polypropylene film (OPP film) is applied as the base material, and a laminate using a polyolefin film such as unoriented polypropylene film (CPP film) as the sealant layer laminated with it is being considered as a monomaterial packaging material (see Patent Document 2). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 7355957 [Patent Document 2] Patent No. 6902231 [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 2 discloses a barrier laminate comprising an OPP film substrate, a vapor-deposited film, and a barrier coating layer provided on the vapor-deposited film, wherein by controlling the coating film constituting the barrier coating layer, a barrier film with excellent transparency and barrier properties after boiling or retorting can be manufactured even when using an OPP film substrate.

[0007] However, in addition to this, resistance to bending tests (Gelboflex tests) was also required, necessitating further improvements. [Means for solving the problem]

[0008] The inventors of the present invention conducted diligent research to solve the above problems and, as a result, discovered a barrier film that, while using an OPP film substrate, exhibits excellent barrier properties after boiling and retorting treatments, as well as superior resistance to the Gelboflex test, thus completing the present invention. Specifically, the present invention provides the following:

[0009] (1) A barrier film in which a polypropylene substrate, a base layer, and an aluminum oxide vapor-deposited film are laminated in this order, The aluminum oxide vapor-deposited film is a barrier film in which the intensity ratio P1, defined below, is 0.090 or more and 0.170 or less when X-ray absorption microstructure analysis is performed from the surface side of the barrier film opposite to the polypropylene substrate side. P1 = (Average intensity from 1561.0 eV to 1563.6 eV) / (Average intensity from 1566.5 eV to 1571.6 eV)

[0010] (2) The barrier film according to (1), wherein the aluminum oxide vapor-deposited film has an intensity ratio P2 defined below of 0.990 or more and 1.040 or less when X-ray absorption microstructure analysis is performed from the surface side of the barrier film opposite to the polypropylene substrate side. P2 = (Average intensity from 1570.5 eV to 1571.6 eV) / (Average intensity from 1566.5 eV to 1567.6 eV)

[0011] (3) The barrier film according to (1), wherein a coating layer is laminated on the aluminum oxide vapor deposition film.

[0012] (4) The barrier film according to (1), wherein the ratio of silicon atoms to carbon atoms (Si / C) measured by X-ray photoelectron spectroscopy (XPS) of the coating layer is 1.30 or more and 1.70 or less.

[0013] (5) The barrier film according to (1), wherein the base layer is a surface resin layer formed on the polypropylene base material.

[0014] (6) The base material layer includes at least a first layer and a second layer, the first layer is formed on the side of the base layer, the first layer contains modified polypropylene, (5) The barrier film according to (5), wherein the surface resin layer contains a polyamide resin.

[0015] (7) The barrier film according to (6), wherein the polyamide resin contains 25% by mass or more and 100% by mass or less of an amorphous polyamide resin.

[0016] (8) A laminate comprising the barrier film according to any one of (1) to (7) and a sealant layer.

[0017] (9) A laminate comprising a second polypropylene base material, the barrier film according to any one of (1) to (7), and a sealant layer.

[0018] (10) A packaging bag comprising the laminate according to (8).

Advantages of the Invention

[0019] The barrier film of the present invention, while using an OPP film base material, is excellent not only in barrier properties after heat sterilization treatment such as boiling treatment or retort treatment but also in resistance to gelbo flex test.

Brief Description of the Drawings

[0020] [Figure 1] This is a cross-sectional view showing an example of a barrier film according to this embodiment. [Figure 2] This figure shows an example of a film deposition apparatus according to an embodiment of the present invention. [Figure 3] This is a cross-sectional view showing an example of a plasma pretreatment mechanism for a film deposition apparatus. [Figure 4] This is a plan view showing an example of the electrode section and magnetic field formation section of the plasma pretreatment mechanism of a film deposition apparatus. [Figure 5] This is a cross-sectional view showing an example of the electrode section and magnetic field forming section of the plasma pretreatment mechanism of a film deposition apparatus. [Figure 6] This is a cross-sectional view showing an example of the film deposition mechanism of a film deposition apparatus. [Figure 7] This is a cross-sectional view showing an example of a laminate using the barrier film of the present invention. [Figure 8] This is a cross-sectional view showing another example of a laminate using the barrier film of the present invention. [Figure 9] This figure shows the normalized XAFS spectra of the examples and comparative examples superimposed on each other. [Figure 10] This figure shows the normalized XAFS spectrum of the barrier film of Example 1. [Figure 11] This figure shows the normalized XAFS spectrum of the barrier film of Example 2. [Figure 12] This figure shows the normalized XAFS spectrum of the barrier film of Example 3. [Figure 13] This figure shows the normalized XAFS spectrum of the barrier film of Comparative Example 1. [Figure 14] This figure shows the normalized XAFS spectrum of the barrier film of Comparative Example 2. [Figure 15] This figure shows the normalized XAFS spectrum of the barrier film of Comparative Example 3. [Figure 16] This figure shows the normalized XAFS spectrum of the barrier film of Comparative Example 4. [Figure 17] This figure shows the normalized XAFS spectrum of the barrier film of Comparative Example 5. [Modes for carrying out the invention]

[0021] The following describes specific embodiments of the present invention in detail. However, the present invention is not limited to the following embodiments and can be implemented with appropriate modifications within the scope of the object of the present invention. In this specification, the notation "X~Y" (where X and Y are arbitrary numerical values) means "X or greater and Y or less".

[0022] Figure 1 is a cross-sectional view showing an example of a barrier film according to this embodiment. A barrier film manufactured using the film-forming apparatus according to this embodiment comprises, for example, a substrate 100 corresponding to the biaxial polypropylene substrate of the present invention, a base layer 115, a vapor-deposited film 120, and a coating layer 130 as needed, as shown in the barrier film 100A in Figure 1. In the example shown in Figure 1, the base layer 115 is located on one surface of the substrate 100. Also in the example shown in Figure 1, the barrier film 100A is laminated in the order of substrate 100, base layer 115, vapor-deposited film 120, and coating layer 130, with the coating layer 130 located on the surface of the barrier film. The vapor-deposited film 120 and the coating layer 130 constitute the barrier layer.

[0023] In this specification, "laminated in this order" means that the polypropylene substrate, the underlayer, the aluminum oxide vapor-deposited film, and the barrier coating layer are laminated in this order, and further layers such as the anchor coat layer described later may be laminated between these layers.

[0024] The following describes each layer that makes up barrier film 100A.

[0025] [Polypropylene base material] Polypropylene substrate 100 is a polypropylene substrate that has been biaxially stretched. Hereafter, unless the stretching process is specifically mentioned, the term "polypropylene substrate" refers to a polypropylene substrate that has been biaxially stretched.

[0026] The polypropylene substrate is composed of at least polypropylene. The polypropylene may be propylene homopolymer, propylene random copolymer, or propylene block copolymer, or a mixture of two or more selected from these.

[0027] A propylene homopolymer is a polymer consisting solely of propylene. A propylene random copolymer is a random copolymer of propylene and α-olefins other than propylene. A propylene block copolymer is a copolymer having polymer blocks made of propylene and polymer blocks made of at least α-olefins other than propylene. The latter polymer blocks may be polymer blocks made of propylene and α-olefins other than propylene.

[0028] Examples of α-olefins include α-olefins having 2 to 20 carbon atoms, specifically ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, 3-methyl-1-butene, 4-methyl-1-pentene, and 6-methyl-1-heptene.

[0029] Among polypropylenes, random copolymers are preferable from the viewpoint of transparency. When rigidity and heat resistance of the laminate are important, homopolymers are preferable. When impact resistance of the laminate is important, block copolymers are preferable.

[0030] The melt flow rate (MFR) of polypropylene may, in one embodiment, be 0.1 g / 10 min to 50 g / 10 min or 0.3 g / 10 min to 30 g / 10 min, from the viewpoint of film-forming properties and processability. The lower limit of the melt flow rate (MFR) of polypropylene may be 0.1 g / 10 min or more or 0.3 g / 10 min or more, in one embodiment. The upper limit of the melt flow rate (MFR) of polypropylene may be 50 g / 10 min or less or 30 g / 10 min or less, in one embodiment. The MFR of polypropylene is measured in accordance with ASTM D1238 under conditions of a temperature of 230°C and a load of 2.16 kg.

[0031] As for the polypropylene, biomass-derived polypropylene or mechanically or chemically recycled polypropylene may be used.

[0032] The polypropylene content in the polypropylene substrate is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0033] The polypropylene substrate may contain resin materials other than polypropylene. Examples of resin materials include polyolefins such as polyethylene, (meth)acrylic resins, vinyl resins, cellulose resins, polyamides, polyesters, and ionomer resins.

[0034] Polypropylene substrates may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0035] The polypropylene substrate is a substrate that has undergone biaxial stretching. This improves, for example, the heat resistance, impact resistance, water resistance, and dimensional stability of the barrier substrate. Laminates comprising such a barrier substrate are suitable as packaging materials that undergo boiling or retorting treatments, for example.

[0036] When stretching in the longitudinal direction (the flow direction of the substrate, MD direction), the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less. When stretching in the longitudinal direction (the flow direction of the substrate, MD direction), the lower limit of the stretching ratio is preferably 2 times or more, more preferably 5 times or more. When stretching in the longitudinal direction (the flow direction of the substrate, MD direction), the upper limit of the stretching ratio is preferably 15 times or less, more preferably 13 times or less. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the stretching ratio is preferably 2 times or more and 15 times or less, more preferably 5 times or more and 13 times or less. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the lower limit of the stretching ratio is preferably 2 times or more, more preferably 5 times or more. When stretching in the transverse direction (the direction perpendicular to the MD direction, TD direction), the upper limit of the stretching ratio is preferably 15 times or less, more preferably 13 times or less. By increasing the stretching ratio to 2 times or more, the strength and heat resistance of the polypropylene substrate can be further improved, and when the polypropylene substrate is used as the outermost layer, the printability of the polypropylene substrate can be improved. From the viewpoint of the breaking limit of the polypropylene substrate, a stretching ratio of 15 times or less is preferable.

[0037] The thickness of the polypropylene substrate is preferably 10 μm or more and 100 μm or less, more preferably 10 μm or more and 50 μm or less, and even more preferably 15 μm or more and 25 μm or less. The lower limit of the thickness of the polypropylene substrate is preferably 10 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more. The upper limit of the thickness of the polypropylene substrate is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 25 μm or less. If the thickness is above the lower limit, for example, the strength and heat resistance of the barrier substrate can be further improved. If the thickness is below the upper limit, for example, the processability of the barrier substrate can be further improved.

[0038] The polypropylene substrate may be a co-extruded stretched film. It can be manufactured by first forming a film using a conventionally known method such as the T-die method or the inflation method to obtain a laminated film, and then stretching the laminated film. When forming the film using the inflation method, the stretching of the laminated film may be performed simultaneously.

[0039] The polypropylene substrate may be surface-treated. This can improve, for example, the adhesion between the polypropylene substrate and other layers. Examples of surface treatment methods include physical treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using one or more gases selected from oxygen gas, argon gas, nitrogen gas, etc., and glow discharge treatment; as well as chemical treatments such as oxidation treatment using chemicals. In addition, an easy-adhesion layer may be provided on the surface of the polypropylene substrate.

[0040] When a polypropylene substrate is used as the outermost layer of the laminate, a printed layer may be provided on the second layer. The image formed on the printed layer is not particularly limited and may include letters, patterns, symbols, and combinations thereof. The printed layer can also be formed using biomass-derived ink. This further reduces the environmental impact.

[0041] Conventional printing methods such as gravure printing, offset printing, and flexographic printing can be used to form the printed layer. Among these, flexographic printing is preferred from the viewpoint of reducing environmental impact.

[0042] The polypropylene substrate is preferably transparent. Specifically, it is preferable that it has a high total light transmittance as measured according to JIS K 7361-1:1997. Specifically, it is preferable that the total light transmittance is 70% or higher, more preferably 80% or higher, and particularly preferable 90% or higher.

[0043] Preferably, the base material 100 of the winding body is humidity-controlled by a base layer formation process or a humidity control process after base layer formation. This improves barrier properties. It also prevents the base material from breaking due to sticking during unwinding in the vapor deposition process described later. As an example of humidity control conditions, storage at a temperature of 22-30°C and a relative humidity of 40-65%RH for 1-7 days is recommended. It is also effective to rewind the winding body before storage for humidity control. In this case, it is preferable to perform the rewinding process under the above humidity control conditions.

[0044] The polypropylene substrate may be a multilayer film comprising at least a first layer and a second layer. The first layer is the layer on one side of the polypropylene substrate (the side on which a barrier layer such as a vapor-deposited film is formed), and the second layer is the layer on the other side of the polypropylene substrate.

[0045] The first and second layers may each be propylene random copolymers, which are random copolymers of propylene and other α-olefins. The random copolymerization of the first and second layers improves adhesion to other layers in contact with them. Examples of α-olefins include ethylene, 1-butene, and 1-hexene.

[0046] The first layer may be a modified polypropylene, such as an acid-modified polypropylene having polar groups such as maleic acid, as exemplified by Admer®. When the underlying layer described later is a polyamide resin, adhesion with the polyamide resin is improved.

[0047] The polypropylene substrate may include a third layer as an intermediate layer between the first and second layers. The intermediate layer preferably contains a polypropylene homopolymer. The intermediate layer may have a single-layer structure or a multilayer structure.

[0048] As a specific example of a three-layer structure, the layers are arranged in the order of propylene random copolymer / propylene homopolymer / propylene random copolymer from the side where the vapor-deposited film is formed, starting from the first layer / third layer / second layer. In this case, the first layer being a propylene random copolymer improves adhesion to the anchor coat layer when the underlying layer described later is an anchor coat layer. Furthermore, the second layer being a propylene random copolymer improves adhesion to the first adhesive layer 161 for laminating the sealant layer 150 when forming the laminate shown in Figure 7, described later.

[0049] Another specific example of a three-layer configuration is a first layer / third layer / second layer, in the order of modified polypropylene / propylene homopolymer / propylene random copolymer, starting from the side where the vapor-deposited film is formed. In this case, the first layer being modified polypropylene improves adhesion to the polyamide resin when the underlying layer, described later, is a polyamide resin. Furthermore, the third layer being a propylene random copolymer improves adhesion to the first adhesive layer 161 for laminating the sealant layer 150 when forming the laminate shown in Figure 7, described later.

[0050] [Base layer] A base layer 150 is formed on the surface of the substrate 100 on which the vapor-deposited film 120 is formed. When the base layer is a high-heat-resistant surface resin layer made of a high-melting-point resin material or a material with a high glass transition point, as described later, vapor deposition resistance is improved, promoting the migration of the vapor-deposited material, and a vapor-deposited film consisting of a dense, gapless, and highly flexible continuous layer is obtained. In addition, because the base layer is made of a high-heat-resistant material, resistance to heat sterilization treatment is also improved. When the base layer is an anchor coat layer made by a coating, as described later, the surface of the substrate can be made smoother, promoting the migration of the vapor-deposited material, increasing the adhesion strength between the polypropylene substrate and the vapor-deposited film, and a vapor-deposited film consisting of a dense, gapless, and highly flexible continuous layer is obtained. As a result, high gas barrier properties are obtained, and the rupture of the vapor-deposited film and coating layer due to deformation and bending of the film, as well as the decrease in gas barrier properties caused by this, can be suppressed. Furthermore, a barrier film with excellent heat resistance that can withstand heat sterilization treatment can be obtained.

[0051] (Surface resin layer) The base layer is preferably the surface resin layer. By providing a highly heat-resistant surface resin layer containing a resin material having a melting point of preferably 180°C or higher (hereinafter also referred to as a high melting point resin material) or a material having a high glass transition temperature (hereinafter also referred to as a high Tg material) on a polypropylene substrate, a dense vapor deposition film with few gaps can be formed on the surface resin layer, and the gas barrier property can be improved.

[0052] The melting point of the high melting point resin material is more preferably 100°C or higher, further preferably 180°C or higher, and particularly preferably 200°C or higher. By setting the melting point of the high melting point material to 100°C or higher, when the first layer has a copolymer of propylene and other monomers or modified polypropylene, the first layer can be protected from the vapor deposition material. By setting the melting point of the high melting point resin material to 180°C or higher, the density of the vapor deposition film can be improved, and the gas barrier property can be further improved. Also, the resistance of the laminate to heat sterilization treatment can be further improved. From the viewpoint of film-forming properties, the melting point of the high melting point resin material is preferably 265°C or lower, more preferably 260°C or lower, and further preferably 250°C or lower. In this specification, the melting point can be measured in accordance with JIS K7121:2012 (Method for Measuring Transition Temperature of Plastics). Specifically, using a differential scanning calorimetry (DSC) apparatus, a DSC curve can be measured at a heating rate of 10°C / min, and the melting point can be determined.

[0053] The glass transition temperature of high-Tg materials is preferably 90°C or higher, more preferably 100°C or higher, and even more preferably 120°C or higher. By setting the melting point of the high-Tg material to 90°C or higher, the first layer can be protected from the vapor-deposited material when the first layer has a copolymer of propylene and other monomers or modified polypropylene. By setting the glass transition temperature of the high-Tg material to 120°C or higher, the density of the vapor-deposited film can be improved, and the gas barrier properties can be further improved. In addition, the resistance of the laminate to heat sterilization treatment can be further improved. From the viewpoint of film-forming properties, the glass transition temperature of high-Tg materials is preferably 200°C or lower, more preferably 180°C or lower, and even more preferably 160°C or lower.

[0054] The difference between the melting point of the high-melting-point resin material contained in the surface resin layer and the melting point of the polypropylene contained in the biaxially oriented polypropylene substrate is preferably 20 to 100°C, and more preferably 20 to 70°C. The lower limit of the difference between the melting point of the high-melting-point resin material contained in the surface resin layer and the melting point of the polypropylene contained in the biaxially oriented polypropylene substrate is preferably 20°C or higher. The upper limit of the difference between the melting point of the high-melting-point resin material contained in the surface resin layer and the melting point of the polypropylene contained in the biaxially oriented polypropylene substrate is preferably 100°C or lower, and more preferably 70°C or lower. A melting point difference of 20°C or higher can further improve the density of the vapor-deposited film and improve its gas barrier properties. It can also further improve the resistance of the laminate to heat sterilization treatment. A melting point difference of 100°C or lower can further improve film-forming properties.

[0055] High heat-resistant materials preferably have polar groups. In the present invention, a polar group refers to a group containing one or more heteroatoms, and examples include ester groups, epoxy groups, hydroxyl groups, amino groups, amide groups, carboxyl groups, carbonyl groups, carboxylic acid anhydride groups, sulfone groups, thiol groups, and halogen groups. Among these, from the viewpoint of the lamination strength of packaging containers, hydroxyl groups, ester groups, amino groups, amide groups, carboxyl groups, and carbonyl groups are preferred, with hydroxyl groups being more preferred.

[0056] High heat-resistant materials can be used without particular limitations as long as they have a melting point of 180°C or higher or a glass transition temperature of 90°C or higher. Examples of high heat-resistant materials include vinyl resins, polyamides, polyimides, polyesters, (meth)acrylic resins, cellulose resins, polyolefin resins, and ionomer resins.

[0057] In the present invention, the high heat-resistant material is a resin material having a melting point of 180°C or higher or a glass transition point of 90°C or higher, and having polar groups. Ethylene-vinyl alcohol copolymers, polyvinyl alcohol, polyesters, and polyamides are preferred, and polyamides such as nylon 6 (hereinafter, "nylon" is a registered trademark), nylon 6,6, aromatic-containing nylon, and amorphous nylon (amorphous polyamide) are more preferred. By using such a resin material, the gas barrier properties of the vapor-deposited film formed on the surface resin layer can be effectively improved.

[0058] Furthermore, by using polyamide as a highly heat-resistant material, the decrease in gas barrier properties can be suppressed even when the barrier laminate is heated. Polyamides containing benzene rings (aromatic rings) are preferred as highly heat-resistant materials from the viewpoint of mechanical strength and gas barrier properties. Polyamides containing benzene rings can be co-extruded in combination with other materials. Examples of polyamides containing benzene rings include nylon MXD6 manufactured by Mitsubishi Gas Chemical.

[0059] A polyamide containing a benzene ring is a polyamide in which a benzene ring is contained in either or both of the constituent units derived from a diamine or a dicarboxylic acid. It may also be a copolymer of one or more diamines and one or more dicarboxylic acids. Alternatively, it may be a mixture of two or more copolymers. Examples of copolymers include copolymers of a diamine containing a benzene ring and an aliphatic dicarboxylic acid, copolymers of an aliphatic diamine and a dicarboxylic acid containing a benzene ring, copolymers of a diamine containing a benzene ring and a dicarboxylic acid containing a benzene ring and an aliphatic dicarboxylic acid, and copolymers of an aliphatic diamine and a diamine containing a benzene ring and a dicarboxylic acid containing a benzene ring.

[0060] The surface resin layer may contain polyamide that does not contain benzene rings. Additionally, polyester, acrylic resin, ionomer resin, etc., may be added to the extent that they do not affect processability and physical properties.

[0061] Diamines containing a benzene ring include metaxylenediamine, paraxylenediamine, metaphenylenediamine, and paraphenylenediamine. One or more of these should be used.

[0062] Dicarboxylic acids containing a benzene ring include aromatic dicarboxylic acids such as terephthalic acid (TPA) and isophthalic acid (IPA), and naphthalenedicarboxylic acids such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. One or more of these should be used.

[0063] Aliphatic diamines include linear aliphatic diamines such as 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine (hexamethylenediamine), 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine (NDA), 1,10-decanediamine (DDA), 1,11-undecanediamine, and 1,12-dodecanediamine, as well as 2-methyl-1,8-octanediamine (MODA) and 4- These include branched aliphatic diamines such as methyl-1,8-octanediamine, 5-methyl-1,9-nonanediamine, 2,2,4- / 2,4,4-trimethyl-1,6-hexanediamine, 2-methyl-1,5-pentanediamine, 2-methyl-1,6-hexanediamine, and 2-methyl-1,7-heptanediamine, as well as alicyclic diamines such as isophoronediamine, norbornanedimethylamine, and tricyclodecanedimethylamine. One or more of these are used.

[0064] Aliphatic dicarboxylic acids are aliphatic dicarboxylic acids having 2 to 20 carbon atoms. Considering polymerization suitability and processability, adipic acid is the most preferred, but other dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedionic acid, dodecadionic acid, hexadecadionic acid, eicosanedionic acid, eicosadienedionic acid, and 2,2,4-trimethyladipic acid. One or more of these are used.

[0065] Polyamides that do not contain a benzene ring include polyamides 6, 7, 10, 11, 12, 410, 56, 66, 69, 610, 611, 612, 1010, etc. The surface resin layer may contain one or more of these.

[0066] The surface resin layer preferably contains 20% by mass or more of polyamide containing a benzene ring, more preferably 40% by mass or more, even more preferably 60% by mass or more, and even more preferably 80% by mass or more. By containing 20% ​​by mass or more of polyamide containing a benzene ring, moist heat swelling can be suppressed, thereby improving adhesion with the vapor-deposited film and reducing the deterioration of the barrier performance of the vapor-deposited film during heat sterilization by boiling or retorting. If the amount is less than 20% by mass, poor adhesion with the vapor-deposited film and a decrease in barrier performance during heat sterilization may occur.

[0067] The surface resin layer preferably contains 20% by mass or more of crystalline polyamide, more preferably 30% by mass or more, and even more preferably 40% by mass or more. Including 20% ​​by mass or more of crystalline polyamide enhances gas barrier properties and suppresses swelling due to moist heat. Examples of crystalline polyamides include copolymers of metaxylenediamine and adipic acid, copolymers of hexamethylenediamine and terephthalic acid, and polyamide 6.

[0068] The surface resin layer may contain 90% by mass or less of crystalline polyamide, more preferably 80% by mass or less, and even more preferably 70% by mass or less. This allows for the mixing of amorphous polyamide, which will be described later.

[0069] The surface resin layer preferably contains 25% by mass or more of amorphous polyamide, more preferably 30% by mass or more, and even more preferably 40% by mass or more. Including 25% by mass or more of amorphous polyamide improves extrusion and stretchability, making it easier to manufacture the base film 10.

[0070] The surface resin layer preferably contains 100% by mass or less of amorphous polyamide, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. This allows for the mixing of crystalline polyamide.

[0071] In this disclosure, amorphous polyamide means a polyamide that does not have a distinct melting point, and specifically refers to a polyamide whose enthalpy of melting ΔHm is 5 J / g or less. The enthalpy of melting is preferably 3 J / g or less, and more preferably 1 J / g or less. In this disclosure, crystalline polyamide means a polyamide with a distinct melting point, specifically a polyamide whose crystalline melting enthalpy ΔHm is greater than 5 J / g. The enthalpy of crystalline fusion is obtained by differential scanning calorimetry (DSC) in accordance with JIS K 7121:2012 and JIS K 7122:2012.

[0072] The amorphous polyamide may be an amorphous aromatic polyamide, an amorphous alicyclic polyamide, or an amorphous aliphatic polyamide.

[0073] Examples of amorphous aromatic polyamides include copolymers of 1,6-hexanediamine and isophthalic acid, copolymers of metaxylenediamine and isophthalic acid, copolymers of 1,6-hexanediamine and isophthalic acid and terephthalic acid, copolymers of metaxylenediamine and adipic acid and isophthalic acid, copolymers of 2-methyl-1,5-pentanediamine and isophthalic acid and terephthalic acid, and copolymers of 2,2,4-trimethylhexamethylenediamine and terephthalic acid. Copolymers of 1,6-hexanediamine with isophthalic acid and terephthalic acid include copolymers of 1,6-hexanediamine with a dicarboxylic acid having a molar ratio of 7 / 3 of isophthalic acid / terephthalic acid, and copolymers of 1,6-hexanediamine with a dicarboxylic acid having a molar ratio of 1 / 1 of isophthalic acid / terephthalic acid. Copolymers of metaxylenediamine with adipic acid and isophthalic acid include copolymers of metaxylenediamine with a dicarboxylic acid having a molar ratio of 1 / 1 of adipic acid / isophthalic acid. Copolymers of 2-methyl-1,5-pentanediamine with isophthalic acid and terephthalic acid include copolymers of 2-methyl-1,5-pentanediamine with a dicarboxylic acid having a molar ratio of 7 / 3 of isophthalic acid / terephthalic acid.

[0074] Examples of crystalline aromatic polyamides include copolymers of metaxylenediamine and adipic acid, and copolymers of metaxylenediamine, adipic acid, and isophthalic acid. Copolymers of metaxyldiamine with adipic acid and isophthalic acid include copolymers of metaxyldiamine with a dicarboxylic acid having a molar ratio of adipic acid / isophthalic acid of 93 / 7, and copolymers of metaxyldiamine with a dicarboxylic acid having a molar ratio of adipic acid / isophthalic acid of 8 / 2.

[0075] Examples of amorphous alicyclic polyamides include copolymers of 4,4'-methylenebis(2-methylcyclohexylamine) and dodecanediic acid (PA MACM12), copolymers of 4,4'-methylenebis(2-methylcyclohexylamine), 4,4'-methylenebis(cyclohexylamine), and dodecanediic acid (PA MACM12 / PACM12), copolymers of 4,4'-methylenebis(2-methylcyclohexylamine), isophthalic acid, and dodecanediic acid (PA MACMI / 12), copolymers of 4,4'-methylenebis(2-methylcyclohexylamine), isophthalic acid, terephthalic acid, and dodecanediic acid (PA MACMI / MACMT / 12), and copolymers of 4,4'-methylenebis(2-methylcyclohexylamine) and tetradecanedioic acid (PA MACM14).

[0076] Of the above, it is also preferable to use amorphous aromatic polyamide and crystalline aliphatic polyamide in combination. In this case, the amorphous aromatic polyamide can be 50-95% by mass and the crystalline aliphatic polyamide 5-50% by mass, preferably 70-90% by mass of amorphous aromatic polyamide and 10-30% by mass of crystalline aliphatic polyamide. This provides the effect of improved film formation and reduced material costs without impairing heat resistance and gas barrier properties.

[0077] Of the above, it is also preferable to use amorphous alicyclic polyamide and crystalline aliphatic polyamide in combination. In this case, the amorphous alicyclic polyamide can be 50-95% by mass and the crystalline aliphatic polyamide 5-50% by mass, preferably 70-92% by mass of amorphous alicyclic polyamide and 8-30% by mass of crystalline aliphatic polyamide. This provides the effect of improving film formation and reducing material costs without impairing heat resistance and gas barrier properties.

[0078] As for the crystalline aliphatic polyamide used in combination, PA6, PA11, PA12, PA66, PA610, PA612, PA6 / 66, and PA6 / 66 / 12 are preferred from the viewpoint of improving physical properties such as abrasion resistance, cold resistance, impact resistance, and oil resistance.

[0079] The melting point of crystalline aliphatic polyamide is preferably 170°C or higher, more preferably 180°C or higher. The melting point of crystalline aliphatic polyamide is preferably 300°C or lower, more preferably 250°C or lower, even more preferably 230°C or lower, even more preferably 220°C or lower, and particularly preferably 215°C or lower or 210°C or lower. In this disclosure, the melting point is obtained by differential scanning calorimetry (DSC). When the above melting point is low, for example, when co-extruding polypropylene and crystalline aliphatic polyamide to form a co-extruded resin film, the difference in melting points between polypropylene and crystalline aliphatic polyamide becomes small, which can improve moldability. For example, the melting point of a crystalline aliphatic polyamide is preferably 170°C to 300°C, more preferably 170°C to 250°C, even more preferably 170°C to 230°C, even more preferably 170°C to 220°C, and particularly preferably 180°C to 215°C, or 180°C to 210°C.

[0080] The thickness of the surface resin layer is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.2 μm or more and 2 μm or less. The lower limit of the thickness of the surface resin layer is preferably 0.1 μm or more, and more preferably 0.2 μm or more. The upper limit of the thickness of the surface resin layer is preferably 5 μm or less, and more preferably 2 μm or less. By setting the thickness of the surface resin layer to 0.1 μm or more, the density of the vapor-deposited film can be further improved, and the gas barrier properties can be further improved. By setting the thickness to 5 μm or less, the film-forming properties and processability can be further improved.

[0081] The surface resin layer can be formed by melt extrusion. It may also be formed by extruding onto a biaxially oriented polypropylene film to form the polypropylene substrate of the present invention, or by co-extruding it with polypropylene in multiple layers and then stretching it to form the polypropylene substrate of the present invention.

[0082] The base layer may be an anchor coat layer. The anchor coat layer can be formed by coating using a resin material having polar groups. Preferred resin materials having polar groups include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyester, polyethyleneimine, hydroxyl group-containing (meth)acrylic resin, nylon 6, nylon 6,6, aromatic-containing nylon, amorphous nylon, and polyurethane, with hydroxyl group-containing (meth)acrylic resin, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol being more preferred. Of the resin materials having polar groups, (meth)acrylic resins containing urethane groups and hydroxyl groups are particularly preferred from the viewpoint of smoothness and gas barrier properties after heat sterilization treatment due to high cohesive energy.

[0083] It is preferable to add a silane coupling agent to the anchor coat layer from the viewpoint of adhesion with the vapor-deposited film. The silane coupling agent described later can be used.

[0084] In the present invention, the anchor coat layer can be formed using an aqueous emulsion or a solvent-based emulsion. Specific examples of aqueous emulsions include polyamide-based emulsions, polyethylene-based emulsions, and polyurethane-based emulsions, while specific examples of solvent-based emulsions include polyester-based emulsions.

[0085] As the polyurethane emulsion, for example, a mixture of a polyurethane emulsion and an emulsion of an oxazoline group-containing polymer is preferably used. Furthermore, the polyurethane emulsion may contain a silane coupling agent.

[0086] The thickness of the anchor coat layer is preferably 0.02 μm or more and 5 μm or less, more preferably 0.05 μm or more and 2 μm or less, even more preferably 0.1 μm or more and 1 μm or less, and even more preferably 0.2 μm or more and 0.5 μm or less. The lower limit of the thickness of the anchor coat layer is preferably 0.02 μm or more, more preferably 0.05 μm or more, even more preferably 0.1 μm or more, and even more preferably 0.2 μm or more. The upper limit of the thickness of the anchor coat layer is preferably 5 μm or less, more preferably 2 μm or less, even more preferably 1 μm or less, and even more preferably 0.5 μm or less. By setting the thickness of the anchor coat layer to 0.02 μm or more, the smoothness can be further improved and the gas barrier properties after deposition can be further improved. By setting the thickness of the anchor coat layer to 5 μm or less, the processability and productivity can be further improved.

[0087] The anchor coat layer may be formed by coating (applying, coating) on ​​a biaxially oriented polypropylene substrate, or it may be formed by coating on a polypropylene film and then biaxially oriented.

[0088] [Vaporized film] Next, the vapor-deposited film 120 will be described. The vapor-deposited film contains the inorganic oxide aluminum oxide. In the vapor-deposited film, at least a portion of the aluminum oxide exists in the form of Al2O3. The vapor-deposited film may further contain metal oxides such as silicon oxide, silicon nitride, silicon oxynitride, silicon carbide, magnesium oxide, titanium oxide, tin oxide, indium oxide, zinc oxide, zirconium oxide, or metal nitrides and carbides thereof.

[0089] The lower limit of the thickness of the deposited film is preferably 3 nm or more, and more preferably 5 nm or more. The upper limit is preferably 100 nm or less, more preferably 50 nm or less, and particularly preferably 15 nm or less.

[0090] In this invention, "aluminum oxide vapor-deposited film" means "a vapor-deposited film containing aluminum oxide" as described above, and may contain aluminum hydroxide oxide (AlO(OH)) and aluminum hydroxide (Al(OH)3) in addition to aluminum oxide (Al2O3). A detailed explanation follows below.

[0091] (XAFS spectral analysis) XAFS analysis is an X-ray absorption fine structure (XAFS) spectrum analysis that involves irradiating the surface of the barrier film's vapor-deposited surface (or the coating layer side, if present) with X-rays and measuring the amount of absorption. Detailed measurement and analysis conditions are described in the examples.

[0092] In particular, XAFS spectral analysis using soft X-rays from synchrotron radiation provides information about the entire bulk of the deposited film, not just a portion of the surface, and allows for information about the size of hydroxyl groups in aluminum oxide deposited films. Furthermore, even if a coating layer exists on the surface of the deposited film, information about the deposited film can be obtained with the coating layer present by irradiating the film through the coating layer from the surface side.

[0093] Figure 9 shows the normalized results of XAFS measurements for the barrier films of Examples 1-3 and Comparative Examples 1-5, which will be described later. In Figure 9, the vertical axis represents absorption intensity (au), and the horizontal axis represents energy (eV).

[0094] The barrier film of the present invention is a barrier film in which the strength ratio P1, as defined below, is 0.090 or more and 0.170 or less. The barrier film of the present invention is a barrier film in which the lower limit of the strength ratio P1, as defined below, is 0.090 or more. The barrier film of the present invention is a barrier film in which the upper limit of the strength ratio P1, as defined below, is 0.170 or less. P1 = (Average intensity from 1561.0 eV to 1563.6 eV) / (Average intensity from 1566.5 eV to 1571.6 eV)

[0095] Here, the numerator (average intensity from 1561.0 eV to 1563.6 eV) represents the intensity derived from metallic aluminum, while the denominator (average intensity from 1566.5 eV to 1571.6 eV) represents the intensity derived from aluminum oxide + aluminum hydroxide. Therefore, the intensity ratio P1 reflects the amount of metallic aluminum present.

[0096] The intensity ratio P1 is preferably 0.090 or more and 0.170 or less, more preferably 0.095 or more and 0.160 or less, and even more preferably 0.100 or more and 0.150 or less. The lower limit of the intensity ratio P1 is preferably 0.090 or more, more preferably 0.095 or more, and even more preferably 0.100 or more. The upper limit of the intensity ratio P1 is preferably 0.170 or less, more preferably 0.160 or less, and even more preferably 0.150 or less.

[0097] A strength ratio P1 of less than 0.090 is undesirable because it reduces Gelboflex resistance, and a P1 of more than 0.170 is also undesirable because it can reduce barrier properties depending on the humidity when measuring oxygen permeability, and also reduces resistance to heat sterilization.

[0098] The strength ratio P1 in the barrier film can be adjusted by controlling the humidity control of the polypropylene substrate including the underlayer, plasma pretreatment, the use of plasma assist treatment and cold traps during deposition, and the combination of aging treatment after the film formation process and aging treatment after the coating layer formation process. In particular, by controlling the light transmittance at a wavelength of 366 nm by adjusting the amount of oxygen supplied during the film formation process, a barrier film with excellent barrier properties after heat sterilization treatment as well as resistance to the Gelboflex test can be obtained. These results will be described in detail in the manufacturing method description and examples below.

[0099] In the barrier film of the present invention, it is preferable that the strength ratio P2, as defined below, is 1.000 or more and 1.040 or less. In the barrier film of the present invention, it is preferable that the lower limit of the strength ratio P2, as defined below, is 1.000 or more. In the barrier film of the present invention, it is preferable that the upper limit of the strength ratio P2, as defined below, is 1.040 or less. P2 = (Average intensity from 1570.5 eV to 1571.6 eV) / (Average intensity from 1566.5 eV to 1567.6 eV)

[0100] Here, the numerator (average intensity from 1570.5 eV to 1571.6 eV) represents the intensity derived from aluminum hydroxide, and the denominator (average intensity from 1566.5 eV to 1567.6 eV) represents the intensity derived from aluminum oxide. Therefore, the intensity ratio P2 reflects the amount of aluminum hydroxide present.

[0101] The intensity ratio P2 is preferably 0.990 or more and 1.040 or less, and more preferably 1.000 or more and 1.030 or less. The lower limit of the intensity ratio P2 is preferably 0.990 or more, and more preferably 1.000 or more. The upper limit of the intensity ratio P2 is preferably 1.040 or less, and more preferably 1.030 or less.

[0102] A strength ratio P1 of less than 0.990 is undesirable because it reduces Gelboflex resistance, and a strength ratio greater than 1.040 is undesirable because it reduces the barrier properties of the barrier film itself.

[0103] Aluminum oxide films are considered to have better flexibility when amorphous than crystalline, and therefore, amorphous is preferable when used as a barrier film. However, determining whether a film is crystalline or amorphous has been difficult with conventional X-ray analysis (XRD), except in cases where a clear crystalline peak can be observed.

[0104] The XAFS spectrum of this invention shows an absorption shoulder from 1566.0 eV to 1567.0 eV, confirming that the aluminum oxide film is amorphous. Furthermore, the intensity ratio P2 provides information about the amount of hydroxyl groups in the aluminum oxide film.

[0105] Furthermore, the adjustment of the intensity ratio P2 in the barrier film can be performed in the same way as the adjustment of the intensity ratio P1.

[0106] [Coating layer] The coating layer 130, which is formed on the vapor-deposited film 120 as needed, is a coating layer (barrier coat layer) that mechanically and chemically protects the vapor-deposited film and improves its barrier performance.

[0107] The coating layer is formed by applying a barrier coating agent onto a vapor-deposited film and allowing it to solidify. For example, a cured resin composition containing an alkoxysilane and a hydroxyl group-containing water-soluble resin (water-soluble polymer), with the addition of a silane coupling agent, a sol-gel catalyst, an acid, etc., as needed, can be used. Other barrier coating agents can be formed using a two-component curable urethane resin consisting of a main component such as an acrylic polyol and a curing agent, an aqueous emulsion, or a solvent-based emulsion.

[0108] Examples of aqueous emulsions include polyamide emulsions, polyethylene emulsions, and polyurethane emulsions, while examples of solvent-based emulsions include polyester emulsions.

[0109] As the polyurethane emulsion, for example, a mixture of a polyurethane emulsion and an emulsion of an oxazoline group-containing polymer is preferably used. Furthermore, the polyurethane emulsion may contain a silane coupling agent.

[0110] As for metal alkoxides, the general formula is R1 n M(OR 2 ) m (In the formula, R1 and R2 represent organic groups having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n+m represents the valence of M.) Examples of the metal atom represented by M in the metal alkoxide include silicon, zirconium, titanium, aluminum, and others, and it is preferable to use an alkoxysilane in which M is Si.

[0111] The above alkoxysilane is, for example, one represented by the general formula Si(ORa)4 (wherein Ra represents a lower alkyl group). In the above, Ra can be a methyl group, an ethyl group, an n-propyl group, an n-butyl group, or the like. Specific examples of the above alkoxysilane include, for example, tetramethoxysilane Si(OCH3)4, tetraethoxysilane Si(OC2H5)4, tetrapropoxysilane Si(OC3H7)4, tetrabutoxysilane Si(OC4H9)4, and the like. Two or more of the above alkoxides may be used in combination.

[0112] As silane coupling agents, those having reactive groups such as vinyl groups, epoxy groups, methacrylic groups, and amino groups can be used. Organoalkoxysilanes having epoxy groups are particularly preferred, and examples include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyldimethylethoxysilane, or β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The above silane coupling agents may be used individually or in combination of two or more.

[0113] In particular, the crosslinking density of the cured film of a coating layer using bifunctional materials such as γ-glycidoxypropylmethyldimethoxysilane and γ-glycidoxypropylmethyldiethoxysilane is lower than that of systems using trialkoxysilane. Therefore, while it is an excellent film in terms of gas barrier properties and resistance to hot water treatment, it is also a flexible cured film with excellent bending resistance, so the gas barrier properties do not deteriorate easily.

[0114] The water-soluble polymer can be a polyvinyl alcohol-based resin or an ethylene-vinyl alcohol copolymer, either individually or in combination. In the coating layer according to this embodiment, a polyvinyl alcohol-based resin is preferred.

[0115] As the polyvinyl alcohol resin, generally, one obtained by saponifying polyvinyl acetate can be used. The polyvinyl alcohol resin may be a partially saponified polyvinyl alcohol resin in which several tens of percent of acetate groups remain, a fully saponified polyvinyl alcohol in which no acetate groups remain, or a modified polyvinyl alcohol resin in which the OH groups are modified. As for the degree of saponification of the polyvinyl alcohol resin, it is necessary to use one that undergoes crystallization to improve the film hardness of the gas barrier coating, preferably with a degree of saponification of 70% or more. Furthermore, the degree of polymerization can be any within the range used in conventional sol-gel methods (approximately 100 to 5000). Examples of such polyvinyl alcohol resins include "RS-110 (degree of saponification = 99%, degree of polymerization = 1,000)" manufactured by Kuraray Co., Ltd., and "Gosenor NM-14 (degree of saponification = 99%, degree of polymerization = 1,400)" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.

[0116] As the ethylene-vinyl alcohol copolymer, a saponified copolymer of ethylene and vinyl acetate, i.e., one obtained by saponifying an ethylene-vinyl acetate random copolymer, can be used. For example, it includes, but is not particularly limited to, partially saponified copolymers in which several tens of mole percent of acetate groups remain, and fully saponified copolymers in which only a few mole percent of acetate groups remain or none remain. However, from the viewpoint of barrier properties, the lower limit of the preferred degree of saponification is 80% or more, more preferably 90% or more, and even more preferably 95% or more. The upper limit is 100% or less.

[0117] Acid or amine compounds are preferred as catalysts for the sol-gel process.

[0118] Examples of acids that can be used include mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, as well as organic acids such as acetic acid and tartaric acid.

[0119] The acid content is preferably 0.001 to 0.05 mol%, and more preferably 0.01 to 0.03 mol%, relative to the total molar amount of alkoxy groups in the metal alkoxide. The lower limit of the acid content is preferably 0.001 mol% or more, and more preferably 0.01 mol% or more, relative to the total molar amount of alkoxy groups in the metal alkoxide. The upper limit of the acid content is preferably 0.05 mol% or less, and more preferably 0.03 mol% or less, relative to the total molar amount of alkoxy groups in the metal alkoxide. If the acid content is less than 0.001 mol%, the catalytic effect is too weak, and if it is more than 0.05 mol%, the catalytic effect is too strong, the reaction rate becomes too fast, and the reaction tends to become heterogeneous.

[0120] As the amine compound, a tertiary amine that is substantially insoluble in water and soluble in organic solvents is preferred. Specifically, for example, N,N-dimethylbenzylamine, tripropylamine, tributylamine, tripentylamine, etc. can be used. N,N-dimethylbenzylamine is particularly preferred.

[0121] The amine compound content is preferably, for example, 0.01 to 1.0 parts by mass, and more preferably 0.03 to 0.3 parts by mass, per 100 parts by mass of metal alkoxide. The lower limit of the amine compound content is preferably, for example, 0.01 parts by mass or more, and more preferably 0.03 parts by mass or more, per 100 parts by mass of metal alkoxide. The upper limit of the amine compound content is preferably, for example, 1.0 part by mass or less, and more preferably 0.3 parts by mass or less, per 100 parts by mass of metal alkoxide. If the content is less than 0.01 parts by mass, the catalytic effect will be too weak, and if it is more than 1.0 part by mass, the catalytic effect will be too strong, the reaction rate will be too fast, and the reaction will tend to become non-uniform.

[0122] As a solvent, it is preferable to use water or alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropanol, or n-butanol.

[0123] The barrier coating layer formed as described above has a thickness of 100 to 500 nm, preferably 200 to 400 nm. The barrier coating layer formed as described above has a lower limit of thickness of 100 nm or more, preferably 200 nm or more. The barrier coating layer formed as described above has an upper limit of thickness of 500 nm or less, preferably 400 nm or less. Within this range, the coating film does not crack and sufficiently covers the surface of the deposited film, which is preferable.

[0124] When a barrier coating agent contains a silane coupling agent, the composition can be adjusted to include 5 to 10 parts by mass of a water-soluble polymer such as a polyvinyl alcohol resin and 1 to 10 parts by mass of the silane coupling agent per 100 parts by mass of alkoxysilane. This maintains the flexibility of the film. However, using more than 20 parts by mass of the silane coupling agent is undesirable because it increases the rigidity and brittleness of the formed barrier coating film.

[0125] Furthermore, if a silane coupling agent is not included, the ratio of metal alkoxides can be reduced and barrier properties enhanced by using 10 to 20 parts by mass of a water-soluble polymer such as polyvinyl alcohol resin per 100 parts by mass of alkoxysilane.

[0126] In the coating layer, the lower limit of the ratio of the mass of a metal alkoxide such as tetraethoxysilane (on an SiO2 basis) to the mass of a water-soluble resin such as polyvinyl alcohol is preferably 1.6 or higher, and more preferably 1.9 or higher. The upper limit is preferably 4.5 or lower, and more preferably 3.5 or lower. A ratio greater than 4.5 is undesirable because the barrier properties may decrease in subsequent processes, and a ratio less than 1.6 is undesirable because the barrier properties after retort processing decrease.

[0127] The silicon atom-to-carbon atom ratio (Si / C) of the coating layer is preferably 0.85 to 1.70, more preferably 0.90 to 1.70, even more preferably 1.30 to 1.70, and particularly preferably 1.30 to 1.55. The lower limit of the silicon atom-to-carbon atom ratio (Si / C) of the coating layer is preferably 0.85 or higher, more preferably 0.90 or higher, and even more preferably 1.30 or higher. The upper limit of the silicon atom-to-carbon atom ratio (Si / C) of the coating layer is preferably 1.70 or lower, and more preferably 1.55 or lower. A ratio greater than 1.70 is undesirable because the barrier properties may decrease in subsequent processes, and a ratio less than 0.85 is undesirable because the barrier properties after heat sterilization treatment decrease. The silicon atom-to-carbon atom ratio of the coating layer can be measured by X-ray photoelectron spectroscopy (XPS), specifically under the conditions described in the examples.

[0128] (Film forming equipment) Next, an example of a film deposition apparatus 10 used in a barrier film manufacturing method will be described. As shown in Figure 2, the film deposition apparatus 10 includes a substrate transport mechanism 11A for transporting the substrate 1, a plasma pretreatment mechanism 11B for applying plasma pretreatment to the surface of the substrate 1, and a film deposition mechanism 11C for depositing a vapor-deposited film 2. In the example shown in Figure 2, the film deposition apparatus 10 further includes a vacuum chamber 12. The vacuum chamber 12 has a vacuum mechanism, such as a vacuum pump described later, that adjusts the atmosphere of at least a part of the space inside the vacuum chamber 12 to below atmospheric pressure.

[0129] In the example shown in Figure 2, the reduced pressure chamber 12 includes a substrate transport chamber 12A where the substrate transport mechanism 11A is located, a plasma pretreatment chamber 12B where the plasma pretreatment mechanism 11B is located, and a film deposition chamber 12C where the film deposition mechanism 11C is located. Preferably, the reduced pressure chamber 12 is configured to suppress the mixing of the atmospheres inside each chamber. For example, as shown in Figure 2, the reduced pressure chamber 12 may have partition walls 35a to 35c located between the substrate transport chamber 12A and the plasma pretreatment chamber 12B, between the plasma pretreatment chamber 12B and the film deposition chamber 12C, and between the substrate transport chamber 12A and the film deposition chamber 12C, separating each chamber.

[0130] The substrate transport chamber 12A, the plasma pretreatment chamber 12B, and the film deposition chamber 12C will now be described. The plasma pretreatment chamber 12B and the film deposition chamber 12C are each provided in contact with the substrate transport chamber 12A and each has a portion that connects to the substrate transport chamber 12A. This allows the substrate 1 to be transported between the substrate transport chamber 12A and the plasma pretreatment chamber 12B, and between the substrate transport chamber 12A and the film deposition chamber 12C, without being exposed to the atmosphere. For example, between the substrate transport chamber 12A and the plasma pretreatment chamber 12B, the substrate 1 can be transported through an opening provided in the partition wall 35a. The substrate transport chamber 12A and the film deposition chamber 12C have a similar structure, and the substrate 1 can be transported between the substrate transport chamber 12A and the film deposition chamber 12C.

[0131] The function of the depressurization mechanism of the depressurization chamber 12 will now be described. The depressurization mechanism of the depressurization chamber 12 is configured to reduce the atmosphere in the space where at least the plasma pretreatment mechanism 11B or the film deposition mechanism 11C of the film deposition apparatus 10 is located to below atmospheric pressure. The depressurization mechanism may be configured to reduce the pressure in each of the substrate transport chamber 12A, the plasma pretreatment chamber 12B, and the film deposition chamber 12C, which are partitioned by partition walls 35a to 35c, to below atmospheric pressure.

[0132] The configuration of the depressurization mechanism of the depressurization chamber 12 will now be described. The depressurization chamber 12 may have, for example, a vacuum pump connected to the plasma pretreatment chamber 12B. By adjusting the vacuum pump, the pressure inside the plasma pretreatment chamber 12B can be appropriately controlled when performing the plasma pretreatment described later. Furthermore, the diffusion of the plasma supplied to the plasma pretreatment chamber 12B into other chambers can be suppressed by the method described later. The depressurization mechanism of the depressurization chamber 12 may have a vacuum pump connected to the film deposition chamber 12C, similar to the vacuum pump connected to the plasma pretreatment chamber 12B. As the vacuum pump, dry pumps, turbomolecular pumps, cryopumps, rotary pumps, diffusion pumps, etc., can be used.

[0133] The substrate transport mechanism 11A of the film deposition apparatus 10 according to this embodiment will be described along with the transport path of the substrate 1. The substrate transport mechanism 11A is a mechanism for transporting the substrate 1 located in the substrate transport chamber 12A. In the example shown in Figure 2, the substrate transport mechanism 11A has an unwinding roller 13 to which a roll of the substrate 1 is attached, a winding roller 15 for winding the substrate 1, and guide rolls 14a to 14d. The substrate 1 sent out from the substrate transport mechanism 11A is then transported by a pre-treatment roller 20 located in the plasma pre-treatment chamber 12B, which will be described later, and a film deposition roller 25 located in the film deposition chamber 12C, which will be described later.

[0134] Although not shown in the diagram, the substrate transport mechanism 11A may further include a tension pickup roller. By having a tension pickup roller in the substrate transport mechanism 11A, the substrate 1 can be transported while adjusting the tension applied to the substrate 1.

[0135] (Plasma pretreatment mechanism) The plasma pretreatment mechanism 11B will now be described. The plasma pretreatment mechanism 11B is a mechanism for applying plasma pretreatment to the surface of the substrate 1. The plasma pretreatment mechanism 11B shown in Figure 2 generates plasma P and uses the generated plasma P to apply plasma pretreatment to the surface of the substrate 1. When the surface of the substrate 1 is activated by plasma pretreatment, for example, hydrogen is released from the substrate resin component, and carbon radicals are generated. Subsequently, by combining with oxygen and hydrogen in the atmosphere, functional groups such as hydroxyl groups, carboxyl groups, and ketone groups are generated. It is believed that the adhesion between the substrate 1 and the deposited film 2 is improved by the generation of such functional groups. The plasma pretreatment mechanism 11B shown in Figure 2 has a pretreatment roller 20 located in the plasma pretreatment chamber 12B, an electrode section 21 facing the pretreatment roller 20, and a magnetic field forming section 23 that forms a magnetic field between the pretreatment roller 20 and the electrode section 21.

[0136] The pre-treatment roller 20 will now be described. Figure 3 is an enlarged view of the area enclosed by the dashed line labeled VI in Figure 2. Note that in Figure 3, the power supply wiring 31 connecting the power supply 32 shown in Figure 2 and the electrode section 21, which will be described later, and the plasma P generated by the plasma pre-treatment mechanism 11B are omitted. The pre-treatment roller 20 has a rotation axis X. The pre-treatment roller 20 is installed such that at least the rotation axis X is located within the plasma pre-treatment chamber 12B, which is partitioned by partition walls 35a and 35b. A substrate 1 having dimensions in the direction of the rotation axis X is wound around the pre-treatment roller 20. In the following description, the dimensions of the substrate 1 in the direction of the rotation axis X will also be referred to as the width of the substrate 1. The direction of the rotation axis X will also be referred to as the width direction of the substrate 1.

[0137] As shown in Figure 2, the pre-treatment roller 20 may be provided such that a portion of it is exposed to the substrate transport chamber 12A. In the example shown in Figure 2, the plasma pre-treatment chamber 12B and the substrate transport chamber 12A are connected via an opening in the partition wall 35a, and a portion of the pre-treatment roller 20 is exposed to the substrate transport chamber 12A through this opening. There is a gap between the partition wall 35a between the substrate transport chamber 12A and the plasma pre-treatment chamber 12B and the pre-treatment roller 20, and the substrate 1 can be transported from the substrate transport chamber 12A to the plasma pre-treatment chamber 12B through this gap. Although not shown, the pre-treatment roller 20 may be provided such that its entirety is located inside the plasma pre-treatment chamber 12B.

[0138] Although not shown in the diagram, the pre-treatment roller 20 may have a temperature control mechanism for adjusting the surface temperature of the pre-treatment roller 20. For example, the pre-treatment roller 20 may have a temperature control mechanism inside the pre-treatment roller 20 that includes piping for circulating a temperature control medium such as a refrigerant or a heat transfer medium. The temperature control mechanism adjusts the surface temperature of the pre-treatment roller 20 to a target temperature within a range of, for example, -20°C to 100°C.

[0139] The pre-treatment roller 20 has a temperature control mechanism, which helps to suppress shrinkage and damage of the substrate 1 due to heat during plasma pre-treatment.

[0140] The pre-treatment roller 20 is made of a material containing at least one of stainless steel, iron, copper, and chromium. The surface of the pre-treatment roller 20 may be treated with a hard chromium hard coat or the like to prevent scratching. These materials are easy to process. Furthermore, by using the above materials as the material for the pre-treatment roller 20, the thermal conductivity of the pre-treatment roller 20 itself is increased, making it easier to control the temperature of the pre-treatment roller 20.

[0141] The electrode portion 21 will now be described. In the example shown in Figures 2 and 3, the electrode portion 21 has a first surface 21c facing the pre-treatment roller 20 and a second surface 21d located on the opposite side of the first surface 21c. In the example shown in Figures 2 and 3, the electrode portion 21 is a plate-shaped member, and both the first surface 21c and the second surface 21d are planar. The electrode portion 21 generates plasma between itself and the pre-treatment roller 20 by applying an AC voltage to it. Preferably, the electrode portion 21 forms an electric field between itself and the pre-treatment roller 20 such that the generated plasma moves perpendicular to the surface of the substrate 1 so that it is directed toward the surface of the substrate 1. This allows the substrate 1 to be pre-treated efficiently.

[0142] The number of electrode sections 21 is preferably two or more. Preferably, the two or more electrode sections 21 are arranged along the transport direction of the substrate 1. In the examples shown in Figures 2 and 3, an example is shown where the film deposition apparatus 10 has two electrode sections 21. Also, the number of electrode sections 21 is, for example, 12 or less.

[0143] The effect of having two or more electrode sections 21 arranged along the transport direction of the substrate 1 will be explained. As described above, plasma is generated between the electrode section 21 and the pre-treatment roller 20. The area where plasma is generated expands as the dimensions of the electrode section 21 in the transport direction increase. On the other hand, if the electrode section 21 is a flat plate-shaped member, as the dimensions of the electrode section 21 in the transport direction increase, the distance from the edge of the first surface 21c of the electrode section 21, which is the surface facing the pre-treatment roller 20, to the pre-treatment roller 20 increases, and the processing capacity by plasma decreases.

[0144] In the film deposition apparatus 10, two or more electrode sections 21 are arranged along the transport direction of the substrate 1. Therefore, even if the dimensions of the electrode sections 21 in the transport direction of the substrate 1 are small, plasma can be generated over a wide area in the transport direction. Furthermore, by reducing the dimensions of the electrode sections 21, the distance from the edge of the first surface 21c of the electrode section 21 to the pre-treatment roller 20 in the transport direction can be reduced, and plasma can be generated uniformly in the transport direction.

[0145] As shown in Figures 2 and 3, the electrode portion 21 has a first end 21e and a second end 21f located on the first surface 21c of the electrode portion 21. The first end 21e is the upstream end in the conveying direction of the substrate 1, and the second end 21f is the downstream end in the conveying direction of the substrate 1. As described above, by reducing the dimensions of the electrode portion 21 in the conveying direction of the substrate 1, the distance from the first end 21e and the second end 21f of the electrode portion 21 to the pre-processing roller 20 in the conveying direction can be reduced. The dimensions of the electrode portion 21 in the conveying direction of the substrate 1 correspond to the angle θ shown in Figure 3. The angle θ is the angle between the line passing through the first end 21e and the rotation axis X and the line passing through the second end 21f and the rotation axis X. The angle θ is preferably 20° or more and 90° or less, more preferably 60° or less, and even more preferably 45° or less. When the angle θ falls within the above range, and the first surface 21c of the electrode portion 21 is flat, plasma can be generated uniformly in the transport direction between the electrode portion 21 and the pre-processing roller 20.

[0146] The material of the electrode portion 21 is not particularly limited as long as it is electrically conductive. Specifically, aluminum, copper, and stainless steel are preferably used as the material for the electrode portion 21.

[0147] The thickness L3 of the electrode portion 21, when viewed in a direction perpendicular to the first surface 21c of the electrode portion 21, is not particularly limited, but is, for example, 15 mm or less. The thickness of the electrode portion 21 being this value allows the magnetic field forming unit 23 to effectively form a magnetic field between the pre-treatment roller 20 and the electrode portion 21. Alternatively, the thickness L3 of the electrode portion 21 may be, for example, 3 mm or more.

[0148] The magnetic field forming section 23 will now be described. As shown in Figures 2 and 3, the magnetic field forming section 23 is provided on the side of the electrode section 21 opposite to the side facing the pre-treatment roller 20. The magnetic field forming section 23 is a component that forms a magnetic field between the pre-treatment roller 20 and the electrode section 21. The magnetic field between the pre-treatment roller 20 and the electrode section 21 contributes to the generation of a higher density plasma, for example, when generating plasma using the plasma pre-treatment mechanism 11B. The magnetic field forming section 23 shown in Figures 2 and 3 has a first magnet 231 and a second magnet 232 provided on the second surface 21d of the electrode section 21.

[0149] The number of magnetic field forming units 23 is preferably two or more. When the plasma pretreatment mechanism 11B has two or more electrode units 21 and two or more magnetic field forming units 23, it is preferable that each of the two or more magnetic field forming units 23 is provided on the side of each of the two or more electrode units 21 that is opposite to the side facing the pretreatment roller 20. In the example shown in Figures 2 and 3, each of the two magnetic field forming units 23 is provided on the second surface 21d of each of the two electrode units 21.

[0150] The structures of the first magnet 231 and the second magnet 232 in the direction normal to the second surface 21d of the electrode portion 21 will now be described. As shown in Figures 2 and 3, the first magnet 231 and the second magnet 232 each have a north pole and a south pole. The symbol N in Figures 2 and 3 indicates the north pole of the first magnet 231 or the second magnet 232. The symbol S in Figures 2 and 3 indicates the south pole of the first magnet 231 or the second magnet 232. One of the north poles or south poles of the first magnet 231 is located closer to the base material 1 than the other. The other of the north poles or south poles of the second magnet 232 is located closer to the base material 1 than the other. In the example shown in Figures 2 and 3, the north pole of the first magnet 231 is located closer to the base material 1 than the south pole of the first magnet 231, and the south pole of the second magnet 232 is located closer to the base material 1 than the north pole of the second magnet. Although not shown in the diagram, the south pole of the first magnet 231 may be located closer to the substrate 1 than the north pole of the first magnet 231, and the north pole of the second magnet 232 may be located closer to the substrate 1 than the south pole of the second magnet 232.

[0151] Next, the structure of the first magnet 231 and the second magnet 232 in the planar direction of the second surface 21d of the electrode section 21 will be described. Figure 4 is a plan view of the electrode section 21 and magnetic field forming section 23 shown in Figure 2, as seen from the magnetic field forming section 23 side. Figure 5 is a cross-sectional view showing a cross section along the line VIII-VIII in Figure 4. Also, in Figure 4, direction D1 is the direction in which the rotation axis X of the pre-processing roller 20 extends.

[0152] As shown in Figures 4 and 5, the first magnet 231 has a first axial portion 231c. As shown in Figure 4, the first axial portion 231c extends along direction D1, i.e., along the rotation axis X of the pre-processing roller 20. A first magnet 231 provided on one electrode portion 21 may have one first axial portion 231c, or it may have two or more first axial portions 231c. In the example shown in Figure 4, a first magnet 231 provided on one electrode portion 21 has one first axial portion 231c.

[0153] Furthermore, as shown in Figures 4 and 5, the second magnet 232 has a second axial portion 232c. As shown in Figure 4, the second axial portion 232c, like the first axial portion 231c, extends along direction D1, i.e., along the axis of rotation X.

[0154] Since both the first magnet 231 and the second magnet 232 include portions that extend along the rotation axis X, the uniformity of the magnetic field strength formed around the substrate 1 in the width direction of the substrate 1 can be increased. This makes it possible to increase the uniformity of the plasma distribution density formed around the substrate 1 in the width direction of the substrate 1.

[0155] A second magnet 232 provided on one electrode portion 21 may have one second axial portion 232c, or it may have two or more second axial portions 232c. In the example shown in Figures 4 and 5, a second magnet 232 provided on one electrode portion 21 has two second axial portions 232c. The two second axial portions 232c may be positioned so as to sandwich the first axial portion 231c in the direction D2 perpendicular to the rotation axis X in the planar direction of the second surface 21d of the electrode portion 21.

[0156] As shown in Figure 5, the dimensions L4 of the first axial portion 231c and L5 of the second axial portion 232c of the base material 1 in the transport direction are not particularly limited. Furthermore, the ratio of the dimensions L4 of the first axial portion 231c and L5 of the second axial portion 232c in the transport direction of the base material 1 is not particularly limited. The dimensions L4 of the first axial portion 231c and L5 of the second axial portion 232c may be equal, or the dimensions L4 of the first axial portion 231c may be larger than the dimensions L5 of the second axial portion 232c.

[0157] The distance L6 between the first axial portion 231c and the second axial portion 232c in direction D2 is set so that the magnetic field generated by the first axial portion 231c and the second axial portion 232c is formed between the pre-processing roller 20 and the electrode portion 21.

[0158] The second magnet 232 may surround the first magnet 231 when the magnetic field forming section 23 is viewed along the direction normal to the second surface 21d of the electrode section 21. For example, as shown in Figure 4, the second magnet 232 may have two second axial portions 232c and two connecting portions 232d provided to connect the two second axial portions 232c.

[0159] Examples of magnets used as the magnetic field forming section 23, such as the first magnet 231 and the second magnet 232, include permanent magnets such as ferrite magnets, neodymium magnets, and rare earth magnets such as samarium cobalt (samarium-cobalt). Electromagnets can also be used as the magnetic field forming section 23.

[0160] The magnetic flux density of the magnets in the magnetic field forming section 23, such as the first magnet 231 and the second magnet 232, is, for example, between 100 gauss and 10,000 gauss. The lower limit of the magnetic flux density of the magnets in the magnetic field forming section 23, such as the first magnet 231 and the second magnet 232, is, for example, 100 gauss or more. The upper limit of the magnetic flux density of the magnets in the magnetic field forming section 23, such as the first magnet 231 and the second magnet 232, is, for example, 10,000 gauss or less. If the magnetic flux density is 100 gauss or more, a sufficiently strong magnetic field can be formed between the pre-treatment roller 20 and the electrode section 21, thereby generating a sufficiently high-density plasma and enabling the formation of a good pre-treatment surface at high speed. On the other hand, to increase the magnetic flux density on the surface of the substrate 1 to more than 10,000 gauss, expensive magnets or a magnetic field generating mechanism are required.

[0161] Although not shown in the figures, the plasma pretreatment mechanism 11B may have a plasma raw material gas supply unit. The plasma raw material gas supply unit supplies the gas that will be used as the raw material for the plasma into the plasma pretreatment chamber 12B. The configuration of the plasma raw material gas supply unit is not particularly limited. For example, the plasma raw material gas supply unit may be provided on the wall surface of the plasma pretreatment chamber 12B and may include holes for ejecting the gas that will be used as the raw material for the plasma. The plasma raw material gas supply unit may also have a nozzle that discharges the plasma raw material gas at a position closer to the substrate 1 than the wall surface of the plasma pretreatment chamber 12B. The plasma raw material gas supplied by the plasma raw material gas supply unit may be, for example, an inert gas such as argon, an active gas such as oxygen, nitrogen, carbon dioxide, or ethylene, or a mixture of these gases. As the plasma raw material gas, one type of inert gas may be used alone, one type of active gas may be used alone, or a mixture of two or more gases contained in the inert gas or active gas may be used. It is preferable to use a mixture of an inert gas such as argon and an active gas as the plasma raw material gas. For example, the plasma raw material gas supply unit supplies a mixed gas of argon (Ar) and oxygen (O2).

[0162] The plasma pretreatment mechanism 11B, for example, has a plasma density of 100 W·sec / m³. 2 More than 8000W sec / m 2 The following plasma is supplied between the pre-treatment roller 20 and the electrode section 21.

[0163] In the example shown in Figure 2, the plasma pretreatment mechanism 11B is located in a plasma pretreatment chamber 12B, which is separated from the substrate transport chamber 12A and the film deposition chamber 12C by a partition wall. By separating the plasma pretreatment chamber 12B from other areas such as the substrate transport chamber 12A and the film deposition chamber 12C, it becomes easier to independently adjust the atmosphere of the plasma pretreatment chamber 12B. This makes it easier to control the plasma raw material gas concentration in the space where the pretreatment roller 20 and the electrode section 21 face each other, thereby improving the productivity of laminated films.

[0164] (Film forming mechanism) Next, the film deposition mechanism 11C will be described. In the example shown in Figure 2, the film deposition mechanism 11C includes a film deposition roller 25 located in the film deposition chamber 12C and an evaporation mechanism 24.

[0165] The film deposition roller 25 will now be described. The film deposition roller 25 is a roller that wraps around and transports the substrate 1, which has been pre-treated in the plasma pre-treatment mechanism 11B, with the treated surface facing outwards.

[0166] The material of the film-forming roller 25 will now be described. Preferably, the film-forming roller 25 is made from a material containing at least one of stainless steel, iron, copper, and chromium. The surface of the film-forming roller 25 may be treated with a hard chromium hard coat to prevent scratching. These materials are easy to process. Furthermore, by using the above materials as the material for the film-forming roller 25, the thermal conductivity of the film-forming roller 25 itself is increased, resulting in excellent temperature control when temperature control is performed. The average surface roughness Ra of the surface of the film-forming roller 25 is, for example, 0.1 μm or more and 10 μm or less.

[0167] Although not shown in the figures, the film-forming roller 25 may also have a temperature control mechanism for adjusting the surface temperature of the film-forming roller 25. The temperature control mechanism may have, for example, a circulation path inside the film-forming roller 25 for circulating a cooling medium or a heat source medium. The cooling medium (refrigerant) may be, for example, an aqueous solution of ethylene glycol, and the heat source medium (heat transfer medium) may be, for example, silicone oil. The temperature control mechanism may also have a heater installed at a position opposite the film-forming roller 25. When the film-forming mechanism 11C forms a film by vapor deposition, due to constraints on the heat resistance of the related mechanical parts and in terms of versatility, the temperature control mechanism preferably adjusts the surface temperature of the film-forming roller 25 to a target temperature within the range of -20°C to 200°C. By having a temperature control mechanism in the film-forming roller 25, fluctuations in the temperature of the substrate 1 caused by the heat generated during film formation can be suppressed.

[0168] The evaporation mechanism 24 will now be described. Figure 6 is an enlarged view of the area enclosed by the dashed line labeled IX in Figure 2, showing the specific form of the evaporation mechanism 24 which was omitted in Figure 5, and also showing the deposition material supply unit 61 which supplies the deposition material, which was omitted in Figure 2. Note that the vacuum chamber 12 and partitions 35b and 35c are not shown in Figure 6. The evaporation mechanism 24 is a mechanism for evaporating the deposition material containing aluminum. The evaporated deposition material adheres to the substrate 1, forming a deposition film containing aluminum on the surface of the substrate 1. The evaporation mechanism 24 in this embodiment employs a resistance heating method. In the example shown in Figure 6, the evaporation mechanism 24 has a boat 24b. In this embodiment, the boat 24b has a power supply (not shown) and a resistor (not shown) electrically connected to the power supply. Multiple boats 24b may be arranged in the width direction of the substrate 1.

[0169] As shown in Figure 6, the film formation mechanism 11C may have a deposition material supply unit 61 that supplies deposition material to the evaporation mechanism 24. In Figure 6, an example is shown in which the deposition material supply unit 61 continuously feeds out aluminum metal wire.

[0170] Although not shown in the diagram, the film deposition mechanism 11C includes a gas supply mechanism. The gas supply mechanism supplies gas between the evaporation mechanism 24 and the film deposition roller 25. The gas supply mechanism supplies at least oxygen gas. The oxygen gas reacts with or combines with evaporation materials such as aluminum that evaporate from the evaporation mechanism 24 and move toward the substrate 1 on the film deposition roller 25. This allows a vapor-deposited film containing aluminum oxide to be formed on the surface of the substrate 1.

[0171] Furthermore, although not essential in the present invention, the film deposition mechanism 11C may also include a plasma supply mechanism 50 that supplies plasma between the surface of the substrate 1 and the evaporation mechanism 24. In the examples shown in Figures 2 and 6, the plasma supply mechanism 50 has a hollow cathode 51. In this embodiment, the hollow cathode 51 is a cathode having a cavity that is partially open. The hollow cathode 51 can generate plasma within its cavity. In the example shown in Figure 6, the hollow cathode 51 is provided such that the opening of the cavity of the hollow cathode 51 is located diagonally above the boat 24b. Although not shown, the plasma supply mechanism 50 according to this embodiment also has an anode facing the opening that draws plasma from the opening of the cavity of the hollow cathode 51. The plasma supply mechanism 50 according to this embodiment can generate a powerful plasma between the surface of the substrate 1 and the evaporation mechanism 24 by generating plasma within the cavity of the hollow cathode 51 and drawing that plasma between the surface of the substrate 1 and the evaporation mechanism 24 using the opposing anode. The positions of the opposing anodes are not particularly limited, as long as the opposing anodes can draw plasma from the opening of the cavity of the hollow cathode 51 and supply plasma between the surface of the substrate 1 and the evaporation mechanism 24. In this embodiment, the case in which the opposing anodes are arranged on both sides of the boat 24b in the width direction of the substrate 1 will be described. In this case, the film deposition mechanism 11C has a plurality of boats 24b and a plurality of opposing anodes, and the plurality of boats 24b and the plurality of opposing anodes may be arranged alternately in the width direction of the substrate 1. Although not shown, the plasma supply mechanism 50 may have a raw material supply device that supplies plasma raw material gas into at least the cavity of the hollow cathode 51. As the plasma raw material gas supplied by the raw material supply device, for example, a gas similar to the gas that can be used as the plasma raw material gas supplied by the plasma raw material gas supply unit of the plasma pretreatment mechanism 11B can be used.

[0172] By supplying plasma between the surface of the substrate 1 and the evaporation mechanism 24 using the plasma supply mechanism 50, plasma assistance is provided during deposition. This activates the aluminum and oxygen gas evaporated in the evaporation mechanism 24, promoting the reaction or bonding between aluminum and oxygen gas. As a result, the proportion of aluminum present as aluminum oxide in the deposited film 2 formed on the surface of the substrate 1 can be increased, stabilizing the properties of the deposited film 2.

[0173] Although not shown in the figures, the film deposition apparatus 10 may be equipped with a substrate charge removal unit in the portion of the substrate transport chamber 12A located downstream of the film deposition chamber 12C in the transport direction of the substrate 1. This unit performs post-processing to remove static charge generated on the substrate 1 due to film deposition by the film deposition mechanism 11C. The substrate charge removal unit may be provided to remove static charge from one side of the substrate 1, or it may be provided to remove static charge from both sides of the substrate 1.

[0174] The apparatus used as a substrate static charge removal unit for post-treatment of the substrate 1 is not particularly limited, but for example, a plasma discharge apparatus, an electron beam irradiation apparatus, an ultraviolet irradiation apparatus, a static discharge bar, a glow discharge apparatus, a corona treatment apparatus, etc., can be used.

[0175] When post-processing is performed by forming a discharge using a plasma processing apparatus or glow discharge apparatus, it is possible to supply a discharge gas such as argon, oxygen, nitrogen, or helium, or a mixture thereof, to the vicinity of the substrate 1 and perform post-processing using any discharge method, such as alternating current (AC) plasma, direct current (DC) plasma, arc discharge, microwave, or surface wave plasma. In a reduced pressure environment, it is most preferable to perform post-processing using a plasma discharge apparatus.

[0176] The substrate charge removal unit is installed in the substrate transport chamber 12A, in a portion located downstream of the film deposition chamber 12C in the transport direction of the substrate 1. By removing the charge from the substrate 1, the substrate 1 can be quickly separated from the film deposition roller 25 at a predetermined position and transported. This enables stable substrate transport, prevents damage to the substrate 1 and deterioration of quality caused by static charge, and improves the suitability for post-processing by improving the wettability of the front and back surfaces of the substrate.

[0177] (power supply) In the example shown in Figure 2, the film deposition apparatus 10 further includes a power supply 32 electrically connected to the pre-treatment roller 20 and the electrode section 21. In the example shown in Figure 5, the power supply 32 is electrically connected to the pre-treatment roller 20 and the electrode section 21 via a power supply wiring 31. The power supply 32 is, for example, an AC power supply. When the power supply 32 is an AC power supply, it is possible to apply an AC voltage having a frequency of, for example, 20 kHz or more and 500 kHz or less between the pre-treatment roller 20 and the electrode section 21. The input power that can be applied by the power supply 32 (power that can be applied per 1 m width of the electrode section 21 in the width direction of the substrate 1) is not particularly limited, but for example, it is 0.5 kW / m or more and 20 kW / m or less. The pre-treatment roller 20 may be electrically installed at ground level or electrically installed at floating level.

[0178] (Method of manufacturing barrier film) Next, a method for manufacturing the barrier film shown in Figure 1 using the above-described film deposition apparatus 10 will be explained. First, a film deposition method for depositing a vapor-deposited film 2 on the surface of a substrate 1 will be explained. In film deposition using the film deposition apparatus 10, while transporting the substrate 1 along the transport path of the substrate 1 described above, a plasma pretreatment step is performed in which plasma pretreatment is applied to the surface of the substrate 1 using the plasma pretreatment mechanism 11B, and a film deposition step is performed in which a vapor-deposited film is deposited on the surface of the substrate 1 using the film deposition mechanism 11C. The transport speed of the substrate 1 is preferably 200 m / min or more, and more preferably 400 m / min or more and 1000 m / min or less. The lower limit of the transport speed of the substrate 1 is preferably 200 m / min or more, and more preferably 400 m / min or more. The upper limit of the transport speed of the substrate 1 is more preferably 1000 m / min or less.

[0179] (Plasma pretreatment process) The plasma pretreatment process is carried out, for example, by the following method. First, plasma raw material gas is supplied into the plasma pretreatment chamber 12B. Next, the above-mentioned AC voltage is applied between the pretreatment roller 20 and the electrode section 21. When applying the AC voltage, input power control or impedance control may be performed.

[0180] In the pretreatment process, the plasma raw material gas supplied is either oxygen alone or a mixture of oxygen and an inert gas, supplied from the gas storage unit via a flow controller while measuring the gas flow rate. The inert gas can be one or more gases selected from the group consisting of argon, helium, and nitrogen.

[0181] For plasma treatment, the mixing ratio of oxygen gas to the inert gas, oxygen gas / inert gas, is preferably 6 / 1 to 1 / 1, and more preferably 5 / 2 to 3 / 2.5.

[0182] By setting the mixing ratio to 6 / 1 to 1 / 1, the film formation energy of the vapor-deposited aluminum on the resin substrate increases. Furthermore, by setting it to 5 / 2 to 3 / 2, the degree of oxidation of the vapor-deposited aluminum oxide film can be increased, ensuring adhesion between the vapor-deposited aluminum oxide film and the substrate.

[0183] By applying an alternating voltage, plasma is generated simultaneously with glow discharge, and the plasma P becomes denser between the pretreatment roller 20 and the magnetic field forming section 23. In this way, the plasma P can be supplied between the pretreatment roller 20 and the magnetic field forming section 23. By means of this plasma P, plasma pretreatment can be performed on the surface of the base material 1.

[0184] The plasma intensity per unit area in plasma treatment is 50 W·sec / m 2 or more and 8000 W·sec / m 2 or less. The lower limit value of the plasma intensity per unit area in plasma treatment is 50 W·sec / m 2 or more. The upper limit value of the plasma intensity per unit area in plasma treatment is 8000 W·sec / m 2 or less. If it is 50 W·sec / m 2 or less, the effect of plasma pretreatment cannot be seen, and if it is 8000 W·sec / m 2 or more, deterioration of the resin base material due to plasma such as consumption, breakage, coloring, and firing of the resin base material tends to occur. In particular, for the plasma intensity of plasma pretreatment for forming an aluminum oxide layer, 100 W·sec / m 2 or more and 1000 W·sec / m 2 or less is preferable. In particular, as the lower limit value of the plasma intensity of plasma pretreatment for forming an aluminum oxide layer, 100 W·sec / m 2 or more is preferable. In particular, as the upper limit value of the plasma intensity of plasma pretreatment for forming an aluminum oxide layer, 1000 W·sec / m 2 or less is preferable.

[0185] When an AC voltage is applied between the pre-treatment roller 20 and the electrode section 21, the atmospheric pressure inside the plasma pre-treatment chamber 12B is reduced to below atmospheric pressure by the depressurization chamber 12. In this case, the atmospheric pressure inside the plasma pre-treatment chamber 12B is adjusted so that, for example, a glow discharge can be generated between the pre-treatment roller 20 and the electrode section 21 by applying an AC voltage. The pressure inside the plasma pre-treatment chamber 12B when an AC voltage is applied between the pre-treatment roller 20 and the electrode section 21 can be set and maintained to approximately 0.1 Pa or more and 100 Pa or less, with 1 Pa or more and 20 Pa or less being particularly preferred.

[0186] The operation of the magnetic field generating unit 23 in the plasma pretreatment process will now be explained. The magnetic field generating unit 23 forms a magnetic field between the pretreatment roller 20 and the electrode unit 21. The magnetic field can act to trap and accelerate electrons present between the pretreatment roller 20 and the electrode unit 21. Therefore, in the region where the magnetic field is formed, the frequency of collisions between electrons and plasma raw material gas can be increased, the plasma density can be increased and localized, and thus the efficiency of plasma pretreatment can be improved.

[0187] (Film forming process) In the film formation process, a film is formed on the surface of the substrate 1 using the film formation mechanism 11C. As an example of the film formation process, we will describe the case in which an aluminum oxide vapor-deposited film is formed using the film formation mechanism 11C having the evaporation mechanism 24 shown in Figure 6.

[0188] First, a deposition material containing aluminum is supplied into the boat 24b of the evaporation mechanism 24, facing the film-forming roller 25. Aluminum metal wire can be used as the deposition material. In the example shown in Figure 6, the deposition material is supplied to the boat 24b by continuously feeding aluminum metal wire into the boat 24b using the deposition material supply unit 61. The thickness of the deposited film can be controlled by the speed at which the substrate is transported and the amount of aluminum metal wire supplied (thickness of the metal wire, feeding speed).

[0189] By heating, the aluminum is evaporated inside the boat 24b. For convenience, Figure 6 shows the evaporated aluminum vapor 63. By controlling the amount of oxygen gas that oxidizes the aluminum, both barrier properties and transparency can be achieved, and furthermore, the resistance to gelboflex can be improved. The pressure at this time is preferably between 0.01 Pa and 3 Pa. The lower limit of the pressure at this time is preferably 0.01 Pa or higher. The upper limit of the pressure at this time is preferably 3 Pa or lower.

[0190] Furthermore, a method for supplying plasma between the surface of the substrate 1 and the evaporation mechanism 24 by the plasma supply mechanism 50, i.e., plasma assistance during deposition, will be described as needed. In this embodiment, plasma is generated in the cavity of the hollow cathode 51 of the plasma supply mechanism 50. Next, a discharge is generated between the hollow cathode 51 and the anode facing it, and the plasma in the cavity of the hollow cathode 51 is drawn out between the surface of the substrate 1 and the evaporation mechanism 24.

[0191] In this embodiment, the discharge generated between the hollow cathode 51 and the anode facing it is an arc discharge. An arc discharge refers to a discharge in which the current value is, for example, 10A or more.

[0192] By supplying plasma between the surface of the substrate 1 and the evaporation mechanism 24, and evaporating aluminum, plasma is supplied to the aluminum vapor 63. The supply of plasma can promote the reaction or bonding between the aluminum vapor 63 and oxygen gas. This allows the aluminum vapor 63 to be oxidized before it reaches the surface of the substrate 1. The evaporated and oxidized aluminum adheres to the substrate 1, forming an aluminum oxide vapor-deposited film on the surface of the substrate 1, thereby producing the barrier film shown in Figure 1.

[0193] The plasma raw material gas supplied by the plasma supply mechanism 50 is preferably argon gas.

[0194] In this embodiment, a plasma pretreatment step is performed before the film deposition step by supplying plasma to the surface of the substrate 1. In the plasma pretreatment step, an AC voltage is applied between the electrode section 21 and the pretreatment roller 20. Furthermore, a magnetic field generating section 23, located on the side of the electrode section 21 opposite to the side facing the pretreatment roller 20, is used to generate a magnetic field in the space between the electrode section 21 and the pretreatment roller 20. This allows for efficient plasma generation in the space between the electrode section 21 and the pretreatment roller 20, and enables the plasma to be incident perpendicularly on the surface of the substrate 1 wrapped around the pretreatment roller 20. Consequently, the adhesion between the film deposited in the film deposition step and the substrate 1 can be improved.

[0195] (Aging process after film formation) The rolled barrier film that has undergone the above film formation process is subjected to an aging treatment (heating treatment) for a predetermined period. This promotes the introduction of hydroxyl groups into the aluminum oxide vapor-deposited film, resulting in a vapor-deposited film with excellent oxygen permeability and water vapor permeability.

[0196] The aging temperature is preferably 50°C to 60°C. The lower limit of the aging temperature is preferably 50°C or higher. The upper limit of the aging temperature is preferably 60°C or lower. The lower limit of the aging time is 24 hours (1 day) or more, more preferably 48 hours (2 days) or more. The upper limit is 144 hours (6 days) or less, more preferably 96 hours (4 days) or less. The aging humidity is not particularly limited, but it does not need to be high humidity; a normal relative humidity of 40% to 70% is sufficient.

[0197] (Coating layer formation process) The coating layer 3 can be manufactured by the following method. First, the above metal alkoxide, water-soluble polymer, a silane coupling agent added as needed, a sol-gel catalyst, an acid, and an organic solvent such as water, methyl alcohol, ethyl alcohol, or isopropanol are mixed to prepare a barrier coating agent. Next, the above barrier coating agent is applied to the aluminum oxide vapor-deposited film by a conventional method and dried. This drying process further promotes the polycondensation of silanols generated from the above metal alkoxide and silane coupling agent, forming a coating film. The above drying conditions are a temperature of 20 to 200°C and below the melting point of the plastic substrate, preferably in the range of 50 to 180°C, and heated for 3 seconds to 10 minutes. This allows the coating layer 3 of the above barrier coating agent to be formed on the aluminum oxide vapor-deposited film. In addition, the above coating operation may be repeated on the first coating film to form multiple coating films consisting of two or more layers.

[0198] The rolled barrier film that has undergone the above coating layer formation process is subjected to an aging treatment (heating treatment) for a predetermined period. This allows for appropriate condensation of the coating layer, resulting in a barrier film whose barrier properties do not deteriorate easily after retort testing.

[0199] The lower limit of the aging temperature after the coating layer formation process is preferably 40°C or higher, more preferably 50°C or higher. The upper limit is preferably 100°C or lower, more preferably 70°C or lower. The lower limit of the aging time is 24 hours (1 day) or more, more preferably 48 hours (2 days) or more. The upper limit is 144 hours (6 days) or lower, more preferably 96 hours (4 days) or lower. The aging humidity is not particularly limited, but it does not need to be high humidity; a normal relative humidity of 40% to 70% is sufficient.

[0200] (Film formation process 2) An aluminum oxide vapor-deposited film may be further deposited on top of the coating layer. This can be done under the same conditions as the above-described film deposition process and aging treatment.

[0201] (Coating layer formation step 2) A coating layer may be further formed on the aluminum oxide vapor-deposited film obtained through the film formation process 2. This can be done under the same conditions as the coating layer formation process described above.

[0202] (Laminated structure) Figure 7 is a cross-sectional view showing an example of a laminate using a barrier film according to this embodiment. This laminate 100 is a laminate using the barrier film 100A shown in Figure 1. Specifically, the barrier film 100A is composed of a first polypropylene substrate 110, a base layer 115, a vapor-deposited film 120, and a barrier coating layer 130. One surface of the barrier film on the side facing the first polypropylene substrate 110 is laminated with a sealant layer 150 via a first adhesive layer 161, and the other surface of the barrier film, the surface facing the coating layer 130, is laminated with a second polypropylene substrate 140 via an adhesive layer 162. Specifically, it is a three-layer film structure with the barrier film as an intermediate layer: second polypropylene substrate 140 / second adhesive layer 162 / barrier film / first adhesive layer 161 / sealant layer 150. The components other than barrier film A will be described below.

[0203] [Adhesive layer] The surface of the barrier film facing the first polypropylene substrate 110 is laminated with the sealant layer 150 via a first adhesive layer 161, and the surface of the barrier film facing the coating layer 130 is laminated with the second polypropylene substrate 140 via an adhesive layer 162. This improves the adhesion between the barrier film and the sealant layer, and the adhesion between the first polypropylene substrate and the second substrate, thereby suppressing the decrease in barrier properties during heat sterilization processes such as retorting and boiling.

[0204] The first adhesive layer 161 and the second adhesive layer 162 may be a one-component curing adhesive, a two-component curing adhesive, or a non-curing adhesive. The adhesive may be a solvent-free adhesive or a solvent-based adhesive suitable for dry lamination.

[0205] Examples of solvent-free adhesives, i.e., non-solvent laminating adhesives, include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing type urethane-based adhesives are more preferred.

[0206] Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, olefin-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and urethane-based adhesives. Among these, urethane-based adhesives are preferred, and two-component curing type urethane-based adhesives are more preferred.

[0207] The thickness of the adhesive layer is, for example, 0.1 μm or more and 10 μm or less, preferably 0.2 μm or more and 8 μm or less, and more preferably 0.5 μm or more and 6 μm or less. The lower limit of the thickness of the adhesive layer is, for example, 0.1 μm or more, preferably 0.2 μm or more, and more preferably 0.5 μm or more. The upper limit of the thickness of the adhesive layer is, for example, 10 μm or less, preferably 8 μm or less, and more preferably 6 μm or less.

[0208] [Second polypropylene substrate] The second polypropylene substrate 140 is laminated to the side of the barrier film facing the coating layer 30 via the second adhesive layer 162. Here, the second polypropylene substrate can be the same as the first polypropylene substrate 110, so its description is omitted.

[0209] In the case of a three-layer structure as shown in Figure 7, the printed layer (not shown) may be formed on the outermost surface of the second polypropylene substrate 140, or on the surface of the second polypropylene substrate 140 on the side of the second adhesive layer 162.

[0210] [Sealant layer] The sealant layer 150 contains a resin material that can fuse with each other by heat. Examples of resin materials that can fuse with each other by heat include polyolefins, specifically polyethylene such as low-density polyethylene, linear low-density polyethylene and medium-density polyethylene, polypropylene, polybutene, methylpentene polymer, and cyclic olefin copolymer.

[0211] The sealant layer is preferably made of polypropylene. This ensures that the three-layer film is entirely composed of polypropylene, thus enabling the packaging material to be monomaterial. After collecting used packaging materials, there is no need to separate the base material and the sealant layer, improving the recyclability of the packaging material. By using polypropylene for the sealant layer, oil resistance can also be improved, resulting in a sealant layer that can withstand heat sterilization.

[0212] The polypropylene content in the sealant layer is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more. This can improve, for example, the recyclability of the packaging material.

[0213] When the sealant layer is made of polypropylene, the proportion of polypropylene to the total amount of resin material contained in the laminate is preferably 80% by mass or more, more preferably 85% by mass or more, even more preferably 88% by mass or more, and particularly preferably 90% by mass or more. This makes it possible to produce, for example, a monomaterial packaging material using the laminate, and improve the recyclability of the packaging material.

[0214] Examples of polypropylene include propylene homopolymers, propylene random copolymers such as propylene-α-olefin random copolymers, and propylene block copolymers such as propylene-α-olefin block copolymers. Details of α-olefins are as described above. From the viewpoint of heat sealability, the density of polypropylene is, for example, 0.88 g / cm³. 3 More than 0.92g / cm 3 The following applies: The lower limit of the density of polypropylene is, for example, 0.88 g / cm³. 3 That concludes the explanation. The upper limit for the density of polypropylene is, for example, 0.92 g / cm³. 3 The following applies: Density is measured in accordance with JIS K7112, particularly Method D (density gradient tube method, 23°C). From the perspective of reducing environmental impact, biomass-derived polypropylene and / or recycled polypropylene may be used.

[0215] The sealant layer may contain additives. Examples of additives include crosslinking agents, antioxidants, antiblocking agents, lubricants, UV absorbers, light stabilizers, fillers, reinforcing agents, lubricants, antistatic agents, pigments, and modifying resins. For example, the sealant layer may contain an antistatic agent. This can suppress the generation of static electricity on the surface of the laminate, and for example, can suppress adhesion between laminates.

[0216] The sealant layer may have a single-layer structure or a multi-layer structure. The thickness of the sealant layer is preferably 10 μm to 200 μm, more preferably 20 μm to 150 μm. The lower limit of the sealant layer thickness is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 30 μm or more. The upper limit of the sealant layer thickness is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or more. If the thickness is above the lower limit, for example, the lamination strength of the packaging material comprising the laminate can be further improved. If the thickness is below the upper limit, for example, the processability of the laminate can be further improved. When making pouches (especially retort pouches) from the laminate, the thickness of the sealant layer is more preferably 30 μm to 100 μm.

[0217] The sealant layer is preferably an unstretched resin film, and more preferably an unstretched polypropylene film, from the viewpoint of heat sealability. The resin film can be manufactured, for example, by a casting method, a T-die method, or an inflation method. The sealant layer may be laminated via an adhesive layer as in this embodiment, or it may be formed by melt-extruding a resin material that can fuse with each other by heat onto a barrier film.

[0218] [Other examples of lamination] Figure 8 shows an example in which the coating layer 130 of barrier film A is laminated with the sealant layer 150 via the first adhesive layer 161. Thus, in the present invention, the laminate is not limited to a three-layer film structure, but may also have a two-layer structure.

[0219] [Packaging products] The above laminate can be used as a packaging product, such as a packaging bag for containing contents like food, by forming it into a bag shape with the sealant layer facing inward. Furthermore, the laminate of the present invention is a heat-sterilized laminate used in packaging bags for retort foods and boiled foods.

[0220] Heat sterilization includes not only retort processing but also boiling. Boiling, for example, means heat sterilization at 60-100°C for 10-60 minutes.

[0221] Retort processing refers to heat and pressure sterilization at 100-140°C. A preferred F value, which is a concept representing the integral value of the load of heating, is 4 or higher, more specifically, 121°C for 3 minutes or more, or 120°C for 4 minutes or more as stipulated in the Food Sanitation Act. More specifically, 120-130°C for 15-60 minutes is common, but processing conditions of 105-120°C for 15-60 minutes or 130-140°C for 15-60 minutes are also acceptable.

[0222] [Composite modulus of elasticity and indentation hardness of the coating layer] In the present invention, the composite modulus and indentation hardness after lamination and the above-mentioned heat sterilization treatment are measured from the cross-section of the coating layer of the laminate by nanoindentation, where the composite modulus is 5.0 GPa or more and 8.5 GPa or less, and the indentation hardness is 0.9 GPa or more and 1.7 GPa or less. Within this range, a decrease in barrier properties can be suppressed not only after boiling the laminate but also after retort treatment.

[0223] Furthermore, it is even more preferable that the composite modulus is 6.0 GPa or more and 8.5 GPa or less, and the indentation hardness is 1.0 GPa or more and 1.5 GPa or less, as this suppresses a decrease in barrier properties even after high-retort treatment of the laminate.

[0224] The indentation hardness of the coating layer is calculated using the following formula (1). Furthermore, the composite modulus of the coating layer is calculated using the following formula (2). Indentation stiffness = Pmax / A···(1)

number

[0225] Here, Pmax: Maximum load (unit: μN) A: Contact projected area at maximum depth (unit: μm) 2 ) S: Contact stiffness That is the case.

[0226] The composite modulus of elasticity and indentation hardness of the coating layer in a laminate after heat sterilization are measured by pre-treating the laminate after heat sterilization by embedding it in epoxy resin or the like, and then processing it with a microtome to expose the cross-section of the coating layer. This allows measurement from the "cross-section" of the coating layer of the laminate using the nanoindentation method. This method allows measurement of the composite modulus of elasticity and indentation hardness of the coating layer without peeling the laminate to expose the coating layer. The above cross-section is obtained by cutting in the thickness direction perpendicular to the main surface of the film. Cross-section preparation was carried out by creating a block by embedding the film in embedding resin, and cutting the block using a commercially available rotary microtome at room temperature (23°C). Finishing was performed with a diamond knife.

[0227] The indentation hardness and composite modulus of the cross-section of a coating layer are measured using the nanoindentation method. First, an indenter is placed on the cross-section of the coating layer and pressed down to a load of 15 μN from the cross-section over 10 seconds, and held in that position for 5 seconds. The indenter is pressed into the area near the center in the thickness direction of the coating layer, where the cross-section of the coating layer is exposed. Then, the load is removed over 10 seconds. This yields the maximum load Pmax, the contact projected area A at the maximum depth, and the load-displacement curve. Unless otherwise specified, measurements are performed in an environment of 50% relative humidity and 23°C. Measurements are performed at five or more locations on the same cross-section, and the indentation hardness and composite modulus are recorded as the arithmetic mean of the five values ​​measured with good reproducibility. Further detailed measurement conditions are described in the examples.

[0228] When a laminate is subjected to heat sterilization, the coating layer needs to be rigid enough to suppress the destruction of the vapor-deposited film due to thermal shrinkage of the OPP substrate during heat sterilization. On the other hand, during the lamination of packaging materials, the OPP substrate is stretched by tension, which also causes a decrease in barrier properties due to the destruction of the vapor-deposited film. However, this decrease in barrier properties can be suppressed by giving the coating layer appropriate flexibility.

[0229] The inventors have identified a range of elastic modulus and indentation hardness suitable for heat sterilization applications such as retort processing for the coating layer constituting a monomaterial packaging material which is a laminate of polypropylene films, and have found a laminate that can suppress the deterioration of barrier properties even "after lamination" and "after heat sterilization processing".

[0230] As a result, the oxygen permeability of the laminate after heat sterilization treatment at 23°C and 90%RH, in accordance with JIS K 7126-2, is 10.0 cc / (m³). 2 (day·atm) or less, preferably 5.0 cc / (m 2 (day·atm) or less, particularly preferably 2.0 cc / (m 2 (day·atm) or less, most preferably 1.0cc / (m 2 We have succeeded in achieving a value of less than or equal to (day·atm). Furthermore, the water vapor transmission rate at 40°C and 100%RH after heat sterilization treatment, in accordance with JIS K 7129 B method, is preferably 3.0 g / (m³). 2 Less than 2.0 g / (m²) 2 The duration is less than or equal to (day). In this way, a laminate with high gas barrier properties can be obtained even after retort processing.

[0231] The composite modulus and indentation hardness of the coating layer can be adjusted, for example, by the composition of the coating layer or the drying temperature during coating layer formation. [Examples]

[0232] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way to these descriptions. First, barrier films according to Examples 1 to 18 and Comparative Examples 1 to 6 were manufactured using the film deposition apparatus 10, film deposition method, and coating layer formation process described in this embodiment. The pretreatment conditions, deposition conditions, etc., are summarized in Tables 1 and 2.

[0233] (Example 1) A substrate film with a thickness of 20 μm was produced, comprising a substrate layer consisting of a 50% by mass mixture of a copolymer of metaxylenediamine and adipic acid, and a 50% by mass mixture of a dicarboxylic acid with an isophthalic acid / terephthalic acid molar ratio of 2 / 1 and a copolymer of hexamethylenediamine (indicated as PA1 in Table 1). The substrate consisted of an acid-modified polypropylene random copolymer as the first layer, homopolypropylene as the third layer, and a copolymer of propylene, ethylene, and 1-butene as the second layer. After co-extrusion of the substrate layer / first layer / third layer / second layer, the film was sequentially stretched five times in the longitudinal direction (MD direction) and ten times in the transverse direction (TD direction) using a biaxial stretching apparatus, resulting in a substrate film with a thickness of 20 μm, comprising a substrate layer (0.7 μm), a first layer (1.5 μm), a third layer (17.1 μm), and a second layer (0.7 μm).

[0234] Next, as part of the humidity control process, the rolled raw material was rewound in a 25°C, 50%RH atmosphere, and then stored for 3 days at 25°C, 50%RH to control humidity.

[0235] The following pretreatment steps were first performed using the film deposition apparatus. <Pre-treatment process> Plasma pretreatment was performed on the surface of the substrate 1 using the plasma pretreatment mechanism 11B shown in Figures 2 and 3. Specifically, first, plasma forming gas was supplied to the plasma pretreatment chamber 12B using the plasma raw material gas supply unit, while the air pressure inside the plasma pretreatment chamber 12B was adjusted using the depressurization chamber 12. Next, a voltage was applied between the pretreatment roller 20 and the electrode unit 21 to generate plasma, and plasma pretreatment was performed on the surface of the substrate 1. The plasma pretreatment was performed under the following conditions. <Pretreatment conditions> Material transport speed: 420 m / min High-frequency power output: 4kW High-frequency power supply frequency: 40kHz Plasma intensity: 550 W·sec / m 2 Plasma-forming gases: Oxygen 100 (sccm), Argon 1000 (sccm) Magnetic forming means: 1000 gauss permanent magnet Voltage applied between pre-treatment drum and plasma supply nozzle: 420V Pressure in the pretreatment section: 2.0 × 10 -1 Pa

[0236] Next, the film deposition process was carried out in the film deposition apparatus. In the film deposition process, a vapor-deposited film containing aluminum oxide was deposited by vacuum deposition using a resistance heating evaporation mechanism 24 as shown in Figure 6. Specifically, while supplying aluminum metal wire as the deposition material into the boat 24b, the evaporation material in the boat 24b was heated using the resistance heating evaporation mechanism 24, and the aluminum was evaporated so that it reached the surface of the underlying layer of the substrate film. At the same time, oxygen was supplied, and a vapor-deposited film was deposited on the surface of the substrate film. Note that the cold trap was not in operation.

[0237] A vapor-deposited film was laminated onto the substrate film using the method described above. The transport speed at this time was 420 m / min, and the thickness of the vapor-deposited film was 10.0 nm. At this time, the light transmittance at a wavelength of 366 nm, measured in-line after deposition, was set to a baseline of 100% based on the transmittance of the substrate film before pretreatment and deposition. Then, deposition was started, and the oxygen supply was feedback-controlled so that the light transmittance was 72.0%. The pressure during deposition was 0.2 Pa.

[0238] The barrier film rolls that had undergone the above film formation process were subjected to an aging treatment at 55°C and 50RH for 3 days.

[0239] Furthermore, a coating layer was laminated onto the vapor-deposited film in the coating layer formation process. As a water-soluble polymer, polyvinyl alcohol with a saponification value of 99% or higher and a degree of polymerization of 2400 was mixed with a solution of water and isopropyl alcohol in a ratio of 95 / 5 to obtain solution A, which was adjusted to have a solid content of 4%. Water, isopropyl alcohol, and 1N hydrochloric acid were mixed in a ratio of 65 / 34 / 1 to obtain solution B. Tetraethoxysilane was prepared as a metal alkoxide as solution C. Solution D was obtained by adjusting the ratio of solution B and solution C and mixing them, and the barrier coating agent was obtained by adjusting the ratio of solution A and solution D and mixing them. The barrier coating agent had a solid content of 7% after mixing, and the ratio of solution B to solution C and the ratio of solution A to solution D were adjusted so that the mass of tetraethoxysilane in terms of SiO2 was 2.5 relative to the solid content of PVA. This barrier coating agent was designated as solution X.

[0240] The barrier coating agent prepared above was applied to the above-mentioned vapor-deposited film by direct gravure coating. Then, it was dried at 100°C for 10 seconds to form a coating layer with a dry thickness of 300 nm. Subsequently, the coating layer was aged at 55°C and 50% RH for 7 days to further solidify the coating layer, thereby producing the barrier film of Example 1.

[0241] (Example 2) The barrier film of Example 2 was manufactured in the same manner as in Example 1, except that the oxygen supply amount was adjusted during the film formation process and feedback-controlled so that the light transmittance was 76.0%.

[0242] (Example 3) The barrier film of Example 3 was manufactured in the same manner as in Example 1, except that the oxygen supply amount was adjusted during the film formation process and feedback-controlled so that the light transmittance was 80.0%.

[0243] (Example 4) The barrier film of Example 4 was manufactured in the same manner as in Example 3, except that the humidity control process involved rewinding the roll of raw material in a 30°C, 60%RH atmosphere, followed by storage at 30°C, 60%RH for 3 days to control humidity.

[0244] (Example 5) A barrier film of Example 5 was produced in the same manner as in Example 2, except that a mixture of 70% by mass of a copolymer of metaxylenediamine and adipic acid and 30% by mass of a copolymer of a dicarboxylic acid having a molar ratio of isophthalic acid / terephthalic acid of 2 / 1 and hexamethylenediamine (described as PA2 in Table 1) was used as the base layer.

[0245] (Example 6) A barrier film of Example 6 was produced in the same manner as in Example 2, except that a mixture of 20% by mass of a copolymer of metaxylenediamine and adipic acid and 80% by mass of a copolymer of a dicarboxylic acid having a molar ratio of isophthalic acid / terephthalic acid of 2 / 1 and hexamethylenediamine (described as PA3 in Table 1) was used as the base layer.

[0246] (Example 7) A barrier film of Example 7 was produced in the same manner as in Example 2, except that a mixture of 10% by mass of a copolymer of metaxylenediamine and adipic acid and 90% by mass of a copolymer of a dicarboxylic acid having a molar ratio of isophthalic acid / terephthalic acid of 2 / 1 and hexamethylenediamine (described as PA4 in Table 1) was used as the base layer. and a barrier film of Example 7 was produced.

[0247] (Example 8) A barrier film of Example 8 was produced in the same manner as in Example 2, except that a mixture of 0% by mass of a copolymer of metaxylenediamine and adipic acid and 100% by mass of a copolymer of a dicarboxylic acid having a molar ratio of isophthalic acid / terephthalic acid of 2 / 1 and hexamethylenediamine (described as PA5 in Table 1) was used as the base layer.

[0248] (Example 9) A barrier film of Example 9 was produced in the same manner as in Example 2, except that in the step of forming the coating layer, the ratios of Solution B and Solution C and the ratios of Solution A and Solution D were adjusted so that the mass of SiO2 in terms of tetraethoxysilane became 2.0 with respect to the solid content of PVA.

[0249] (Example 10) In the coating layer forming step, except that the ratios of Solution B to Solution C and Solution A to Solution D were adjusted so that the mass of tetraethoxysilane in terms of SiO₂ was 3.0 with respect to the solid content of PVA, the barrier film of Example 10 was produced in the same manner as in Example 2.

[0250] (Example 11) In the coating layer forming step, except that the ratios of Solution B to Solution C and Solution A to Solution D were adjusted so that the mass of tetraethoxysilane in terms of SiO₂ was 3.5 with respect to the solid content of PVA, the barrier film of Example 11 was produced in the same manner as in Example 2.

[0251] (Example 12) When mixing Solution B and Solution C, 8% of 1,3,5-tris(3-trialkoxysilylpropyl)isocyanurate was added with respect to the weight of tetraethoxysilane, and as the coating layer, a barrier coating agent obtained by adjusting and mixing the ratios of Solution B to Solution C and Solution A to Solution D so that the solid content was 7% and the mass of tetraethoxysilane in terms of SiO₂ was 4.0 with respect to the solid content of PVA was designated as Solution Z. The barrier film of Example 12 was produced in the same manner as in Example 2, except that Solution Z was used instead of Solution X in the coating layer forming step.

[0252] (Example 13) A solution of acrylic polyol was prepared as the main agent. The solvent of the main agent was a mixed solvent of 10 wt% ethyl acetate, 20 wt% propyl acetate, 20 wt% isopropyl alcohol, and 50 wt% propylene glycol monomethyl ether. A solution of ethyl acetate of a mixture of a trimethylolpropane (TMP) adduct of xylene diisocyanate (XDI) and hexamethylene diisocyanate (HDI) (molar ratio 3:1) was prepared as the curing agent. Next, the above main agent and the above curing agent were blended so that NCO / OH was 1.5 to obtain a coating liquid (Solution P) for forming a coating layer. The barrier film of Example 13 was produced in the same manner as in Example 2, except that after coating Solution P by the direct gravure method, it was dried at 100 °C for 10 seconds to form a coating layer with a thickness of 800 nm.

[0253] (Example 14) The barrier film of Example 14 was produced in the same manner as in Example 2, except that the base layer consisted of a mixture of 86% by mass of amorphous aromatic polyamide (a copolymer of 1,6-hexanediamine and a dicarboxylic acid with a molar ratio of isophthalic acid / terephthalic acid of 7 / 3) and 14% by mass of aliphatic polyamide (a homopolymer of 6-aminohexanoic acid units, synthesized by ring-opening polymerization of ε-caprolactam) (indicated as PA6 in Table 1).

[0254] (Example 15) The barrier film of Example 15 was produced in the same manner as in Example 2, except that the base layer consisted of a mixture of 90% by mass of amorphous aromatic polyamide (a copolymer of 1,6-hexanediamine and a dicarboxylic acid with a molar ratio of isophthalic acid / terephthalic acid of 7 / 3) and 10% by mass of aliphatic polyamide (a homopolymer of 6-aminohexanoic acid units, synthesized by ring-opening polymerization of ε-caprolactam) (indicated as PA7 in Table 1).

[0255] (Example 16) The barrier film of Example 16 was prepared in the same manner as in Example 2, except that the base layer consisted of a mixture of 78.1% by mass of amorphous alicyclic polyamide (a copolymer of 4,4'-methylenebis(2-methylcyclohexylamine) and dodecanedioic acid) and 21.9% by mass of crystalline aliphatic chain polyamide (polylauryl lactam) (indicated as PA8 in Table 1).

[0256] (Example 17) The barrier film of Example 17 was manufactured in the same manner as in Example 2, except that the base layer was a mixture of 84.3% by mass of amorphous alicyclic polyamide (a copolymer of 4,4'-methylenebis(2-methylcyclohexylamine) and dodecanedioic acid) and 15.7% by mass of crystalline aliphatic chain polyamide (polylauryl lactam) (indicated as PA9 in Table 1).

[0257] (Example 18) The barrier film of Example 18 was manufactured in the same manner as in Example 2, except that the base layer consisted of a mixture of 90.6% by mass of amorphous alicyclic polyamide (a copolymer of 4,4'-methylenebis(2-methylcyclohexylamine) and dodecanedioic acid) and 9.4% by mass of crystalline aliphatic chain polyamide (polylauryl lactam) (indicated as PA10 in Table 1).

[0258] (Comparative Example 1) A barrier film of Comparative Example 1 was manufactured in the same manner as in Example 1, except that the oxygen supply amount was adjusted during the film formation process and feedback-controlled so that the light transmittance was 88.0%.

[0259] (Comparative Example 2) A barrier film of Comparative Example 2 was manufactured in the same manner as in Example 1, except that the oxygen supply amount was adjusted during the film formation process and feedback-controlled so that the light transmittance was 93.0%.

[0260] (Comparative Example 3) As the polypropylene substrate for Substrate 1, a biaxially oriented polypropylene film with a thickness of 20 μm was used (the first layer, which is the surface on the vapor deposition side, is a 1.0 μm thick layer made of a copolymer of propylene, ethylene, and 1-butene; the second layer, which is the surface opposite the vapor deposition side, is a 1.0 μm thick layer made of a copolymer of propylene, ethylene, and 1-butene; and the third layer (intermediate layer) is a homopolypropylene with a thickness of 18 μm, with corona treatment applied to the surface of the first layer).

[0261] Next, an anchor coat layer-forming coating solution, consisting of a mixture of hydroxyl group-containing (meth)acrylic resin and tolylene diisocyanate, was applied as a base layer to the first layer of substrate 1 using the direct gravure method, and then dried to form an anchor coat layer with a thickness of 0.2 μm.

[0262] After forming the anchor coat layer, the rolled raw material was rewound in a 25°C, 50%RH atmosphere as a humidity control process, and then stored at 25°C, 50%RH for 3 days to control humidity before use.

[0263] In the film forming process, a vapor deposition film containing aluminum oxide was formed by the vacuum vapor deposition method using the resistance heating type evaporation mechanism 24 as shown in FIG. 6. Specifically, while supplying a metal wire of aluminum as a vapor deposition material into the boat 24b, using the resistance heating type evaporation mechanism 24, the vapor deposition material in the boat 24b was heated, and aluminum was evaporated so as to reach the surface of the substrate 1. At the same time, while supplying oxygen, a vapor deposition film was formed on the surface of the substrate 1.

[0264] Further, as the plasma supply mechanism 50, a form having a hollow cathode 51 shown in FIG. 6 and an anode (not shown) disposed on both sides in the width direction of the substrate 1 as viewed from the boat 24b and facing the opening of the hollow portion of the hollow cathode 51 was used. A plasma raw material gas (argon gas) was supplied to the hollow portion of the hollow cathode 51, discharged to excite the plasma, and this plasma was drawn out between the surface of the substrate 1 and the evaporation mechanism 24 by the opposing anode to perform plasma assist during vapor deposition. The conditions for plasma assist were such that the supply amount of argon gas to the hollow cathode was 80 sccm, the anode current was 154 A, and the anode voltage was 18 V. Note that the cold trap was operated, and the plasma post-treatment process after the plasma assist process during vapor deposition was not performed.

[0265] A vapor deposition film was laminated on the substrate 1 by the above method. The conveyance speed at this time was 600 m / min, and the thickness of the vapor deposition film was 8.9 nm. At this time, the light transmittance of light with a wavelength of 366 nm measured in-line after vapor deposition was set with respect to the substrate 1 with the transmittance in the state before pretreatment and without vapor deposition as a reference of 100%. Then, vapor deposition was started, and the oxygen supply amount was feedback-controlled so that the light transmittance became 99.7%. The pressure during vapor deposition was 1.1 Pa.

[0266] The reel of the barrier film that had undergone the above film forming process was subjected to an aging treatment at 55 °C and 50% RH for 3 days.

[0267] After the coating layer forming process, a coating layer was formed in the same manner as in Example 1, and a barrier film of Comparative Example 3 was manufactured.

[0268] (Comparative Example 4) In the film formation process, the barrier film of Comparative Example 4 was produced in the same manner as in Comparative Example 3, except that the conditions of plasma assist were set such that the anode current was 140 A and the anode voltage was 16 V.

[0269] (Comparative Example 5) In the film formation process, the barrier film of Comparative Example 5 was produced in the same manner as in Comparative Example 3, except that the cold trap was not operated, plasma assist was not performed, the conveyance speed was 670 m / min, the thickness of the vapor deposition film was 8.0 nm, the light transmittance was 94.0%, and the pressure was 0.3 Pa.

[0270] (Comparative Example 6) In the film formation process, after setting the supply amount of the aluminum metal wire so that the thickness of the vapor deposition film became 12 nm, vapor deposition was performed without supplying oxygen, and as a result, the light transmittance was 34.0% at a pressure of 0.1 Pa. Then, the barrier film of Comparative Example 6 was produced in the same manner as in Example 1, except that the coating layer was not formed.

[0271]

Table 1

[0272]

Table 2

[0273] [Obtaining and Analyzing XAFS Spectra] For the barrier films of Examples 1 to 12 and Comparative Examples 1 to 6, XAFS spectra were obtained from the surface side of the barrier film (from the surface side of the vapor deposition film or the surface side of the coating layer) under the following measurement conditions. Among these, the results of Examples 1 to 3 are shown in FIGS. 10 to 12, and the results of Comparative Examples 1 to 5 are shown in FIGS. 13 to 17. The vertical axis in the figures is the intensity of the generated fluorescent X-ray (described as absorption intensity (a.u) in the figures), and the horizontal axis is the light (or X-ray) energy (eV).

[0274] <XAFS Spectrum Obtaining> · Utilized line: BL1N2 of the Aichi Synchrotron Light Center · Acceleration energy: 1.2 GeV · Beam size: 1.0 mm horizontally × 1.0 mm vertically · Incident angle to the sample: 22.5° (assuming the vertical direction with respect to the sample is 0°) · Entrance slit: 30 μm · Exit slit: 30 μm · Measurement method: Partial fluorescence yield method · Energy range (Al K-edge): 1500 - 1700 eV · Energy step: 1500 - 1550 eV: 2.0 eV / step 1550 - 1555 eV: 1.0 eV / step 1555 - 1575 eV: 0.2 eV / step 1575 - 1600 eV: 0.5 eV / step 1600 - 1680 eV: 1.0 eV / step 1680 - 1700 eV: 2.0 eV / step (Integration time: all 10 s / point) · Energy calibration: Energy calibration using Au 4f 7 / 2 of the Au plate (calibrated with the value obtained by subtracting the theoretical value of 1500 eV from the measured value)

[0275] <XAFS Spectrum Analysis> To compare each data, the regions before the absorption edge (Pre-edge) and after the absorption edge (Post-edge) were normalized. The normalization was performed using Athena, the measurement data analysis software included in the XAFS analysis program Demeter. Specifically, the Pre-edge range was set to 1530 eV - 1555 eV, the Normalization range was set to 1600 eV - 1670 eV, and the Normalization order was set to 3.

[0276] From the normalized data, the following P1 and P2 were calculated. P1 = (Average value of intensity from 1561.0 eV to 1563.6 eV) / (Average value of intensity from 1566.5 eV to 1571.6 eV) P2 = (Average value of intensity from 1570.5 eV to 1571.6 eV) / (Average value of intensity from 1566.5 eV to 1567.6 eV)

[0277] The calculated intensity ratios P1 and P2 are shown in Table 3.

[0278] [Elemental analysis of the coating layer] For the coating layer surfaces of the barrier films in the examples and comparative examples, narrow spectra of each element were measured using an X-ray photoelectron spectrometer (XPS). After that, etching of the measured surface was performed under the conditions described later to expose a new measurement surface. For the exposed measurement surface, narrow spectra of each element were measured under the same conditions. For each narrow spectrum of C1s and Si2p, background was subtracted using Shirley's method with analytical software to obtain the integrated intensity (area) of the peak of each element. Using the obtained integrated intensity (area), the ratio of each element (element %) was calculated. The Si / C ratio was calculated from the ratio of each element after etching for 60 seconds × 2 times and is shown in Table 3. <X-ray photoelectron spectroscopy measurement conditions> Apparatus: ESCA3400 manufactured by Shimadzu Corporation X-ray source: MgKα Emission current: 20 mA Acceleration voltage: 10 kV Resolution: Low Measurement area: Approximately 6 mmφ <Etching conditions> Ion species: Ar + Pressure of Ar gas introduction: 2.0×10 -2 Pa Emission current: 30 mA Acceleration voltage: 0.3 kV Etching time: 60 seconds × 2 times

[0279]

Table 3

[0280] <Creating a laminate> For the barrier films of the examples and comparative examples, the side facing the coating layer 130 or the side facing the vapor-deposited film 120 was bonded to a second biaxially oriented polypropylene film 140 (thickness 20 μm) using a polyurethane-based two-component curing solvent-based adhesive via a second adhesive layer 162 by dry lamination. Furthermore, the side of the barrier film opposite to the coating layer 130 was bonded to a sealant layer (unoriented polypropylene film 60 μm) using a two-component curing solvent-based adhesive via a first adhesive layer 161 by dry lamination to produce the laminates of the examples and comparative examples.

[0281] <Retort processing> The laminates of the examples and comparative examples were subjected to retort treatment at 121°C for 30 minutes.

[0282] <Measurement of barrier properties of barrier films and laminates> The water vapor permeability and oxygen permeability values ​​were measured for the barrier films of the examples and comparative examples, and for laminates using the same. The results are shown in Table 4.

[0283] Oxygen permeability (cc / (m) 2 The values ​​for day and atm (indicated as "OTR" in the table) were measured using an oxygen permeability analyzer (MOCON Corporation, product name "OX-TRAN 2 / 20") at 23°C and 90% RH, in accordance with JIS K 7126-2.

[0284] Water vapor transmission rate (g / m³) 2 The water vapor transmission rate (indicated as "WVTR" in the table) was measured using a water vapor transmission rate measuring device (manufactured by Mokon, product name "PERMATORAN-W 3 / 31") at 40°C and 100%RH, in accordance with JIS K 7129 B method.

[0285] <Measurement of barrier properties of barrier films and laminates> For Example 1 and the Comparative Example, the water vapor and oxygen permeability values ​​were measured after a gel-flex test under the following conditions for the barrier film and the laminate using the same. The results are shown in Table 4.

[0286] <Gelboflex test after retort processing> For the laminates using the barrier films of the examples and comparative examples, after retort treatment at 121°C for 30 minutes, a Gelboflex test was performed under the following conditions in accordance with ASTM F392, and the water vapor and oxygen permeability values ​​after the test were measured. The results are shown in Table 4. Gelboflex test conditions • Testing equipment: BE-1005 Gelboflex Tester, manufactured by Tester Industries Co., Ltd. • Sample: A laminate of A4 size (210mm x 297mm) is set into a cylindrical shape in the testing machine. • Rotation amount: 400° rotation • Stroke: 80mm • Number of times: 10

[0287] [Table 4]

[0288] Table 4 shows that the laminate using the barrier film made of the polypropylene substrate according to this embodiment, in which the intensity ratio P1 obtained from the XAFS spectrum is 0.090 or more and 0.170 or less, exhibits high barrier properties after retort treatment and excellent resistance to gelboflex. [Explanation of symbols]

[0289] 110 (First) Polypropylene Substrate 115 Base layer 120 Deposited film 130 Covering layer 140 Second polypropylene substrate 150 sealant layer 161 First adhesive layer 162 Second adhesive layer 100, 200 laminated 100A Barrier Film 10 Film deposition equipment P Plasma X rotation axis 11A Substrate transport mechanism 11B Plasma pretreatment mechanism 11C Film formation mechanism 12. Reduced pressure chamber 12A Substrate transport chamber 12B Plasma Pretreatment Room 12C Deposition chamber 13. Unwinding roller 14a~d Guide Roll 15. Winding roller 20 Pre-treatment rollers 21 Electrode part 23 Magnetic field forming part 23a 1st page 23b 2nd side 231 First Magnet 231c 1st axis direction part 232 Second Magnet 232c 2nd axis direction part 232d Connection part 24 Evaporation Mechanism 24b Boat 25 Film-forming rollers 31 Power supply wiring 32 Power supply 35a~35c Bulkhead 50 Plasma supply mechanism 51 Hollow cathode 61 Vapor deposition material supply section 63 Aluminum vapor

Claims

1. A barrier film in which a polypropylene substrate, a base layer, and an aluminum oxide vapor-deposited film are laminated in this order, The aluminum oxide vapor-deposited film is a barrier film in which the intensity ratio P1, as defined below, is 0.090 or more and 0.170 or less when X-ray absorption microstructure analysis is performed from the surface side of the barrier film opposite to the polypropylene substrate side. P1 = (Average intensity from 1561.0 eV to 1563.6 eV) / (Average intensity from 1566.5 eV to 1571.6 eV)

2. The barrier film according to claim 1, wherein the aluminum oxide vapor-deposited film has an intensity ratio P2 defined below of 0.990 or more and 1.040 or less when X-ray absorption microstructure analysis is performed on the surface side of the barrier film opposite to the polypropylene substrate side. P2 = (Average intensity from 1570.5 eV to 1571.6 eV) / (Average intensity from 1566.5 eV to 1567.6 eV)

3. The barrier film according to claim 1, wherein a coating layer is laminated on the aluminum oxide vapor-deposited film.

4. The barrier film according to claim 3, wherein the coating layer has a silicon atom to carbon atom ratio (Si / C) measured by X-ray photoelectron spectroscopy (XPS) of 1.30 or more and 1.70 or less.

5. The barrier film according to claim 1, wherein the underlayer is a surface resin layer formed on the polypropylene substrate.

6. The polypropylene substrate comprises at least a first layer and a second layer, wherein the first layer is formed on the underlayment side. The first layer contains modified polypropylene, The barrier film according to claim 5, wherein the surface resin layer contains a polyamide resin.

7. The barrier film according to claim 6, wherein the polyamide resin contains 25% by mass or more and 100% by mass or less of amorphous polyamide resin.

8. A laminate comprising a barrier film according to any one of claims 1 to 7 and a sealant layer.

9. A laminate comprising a second polypropylene substrate, a barrier film according to any one of claims 1 to 7, and a sealant layer.

10. A packaging bag comprising the laminate described in claim 8.

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