Barrier film, laminate using said barrier film, and packaged product using said laminate

Abstract

To provide a barrier film having a high barrier property and a laminate using the same.SOLUTION: A barrier film includes a base material and an aluminum oxide vapor deposition film laminated in this order. In the aluminum oxide vapor deposition film, intensities derived by an element bond Al2O3 and an element bond Al2O4H are detected when etched by a time-of-flight secondary ion mass spectrometry (TOF-SIMS) from a surface side of the vapor deposition film of the barrier film, an intensity ratio (Al2O4H / Al2O3) of the element bond Al2O4H is 0.30 or less against the element bond Al2O3 detected at a depth position by 1 / 3 in a film thickness direction from a surface of the vapor deposition film of the aluminum oxide vapor deposition film.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a barrier film, a laminate using the barrier film, and a packaging product using the laminate. [Background technology]

[0002] Conventionally, laminated films having a film formed on a substrate such as a long film or sheet of plastic are used in various applications. For example, a barrier laminated film has been developed in which a barrier layer made of a thin film of aluminum oxide or the like is provided on a plastic film to provide a barrier function against oxygen and water vapor.

[0003] As a method for producing a barrier film having an aluminum oxide thin film, for example, Patent Document 1 discloses that moisture contained in a reaction space where an oxidation reaction between oxygen gas and evaporated aluminum occurs is removed during vapor deposition, thereby suppressing the generation of aluminum hydroxide and improving hot water resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-203427 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a barrier film having an aluminum oxide vapor-deposited film and having even higher barrier properties, and a laminate using the barrier film. [Means for solving the problem]

[0006] As a result of extensive investigations into solving the above problems, the present inventors have found that by focusing on the distribution of aluminum oxide and aluminum hydroxide in an aluminum oxide vapor-deposited film, it is possible to obtain a barrier film with even higher barrier properties, and have thus completed the present invention.

[0007] Since aluminum hydroxide has a high affinity for water molecules, water molecules penetrate into the film made of aluminum hydroxide, reducing the barrier properties against water vapor. Here, the method of Patent Document 1 reduces the number of hydroxyl groups (hydrogen atoms) in the entire aluminum oxide film.

[0008] However, according to the findings of the present inventors, the growth of the aluminum oxide vapor-deposited film on the aluminum hydroxide surface proceeds in a two-dimensional manner, resulting in the formation of a denser aluminum oxide vapor-deposited film. In other words, the aluminum oxide film deposited on the aluminum hydroxide surface has the characteristic of exhibiting superior barrier properties against oxygen and water vapor compared to aluminum oxide deposited directly on the surface of a plastic film.

[0009] Therefore, in order to realize a barrier film with high barrier performance, an alumina hydroxide region is formed near the interface between the plastic film and the aluminum vapor deposition, and an aluminum oxide region is formed mainly on this alumina hydroxide region, thereby making it possible to provide even higher barrier properties.

[0010] Specifically, the present invention provides the following:

[0011] (1) A barrier film having a substrate and an aluminum oxide vapor-deposited film laminated in this order, When the aluminum oxide vapor-deposited film is etched from the vapor-deposited film surface side of the barrier film by time-of-flight secondary ion mass spectrometry (TOF-SIMS), intensities derived from elemental bond Al2O3 and elemental bond Al2O4H are detected; A barrier film, wherein the aluminum oxide vapor-deposited film has an intensity ratio (Al2O4H / Al2O3) of the elemental bond Al2O4H to the elemental bond Al2O3 of 0.30 or less, detected at a depth position of 1 / 3 from the surface of the vapor-deposited film in the film thickness direction.

[0012] (2) The barrier film according to (1), wherein the intensity derived from the element bond Al2O4H has a maximum peak, and the maximum peak is present at a depth of 55% to 95% from the surface of the vapor-deposited film.

[0013] (3) The aluminum oxide vapor-deposited film has, in an infrared absorption spectrum from the vapor-deposited film surface side of the barrier film, 940cm originating from Al-O bond -1 More than 960cm -1 The barrier film according to (1) or (2), which has an absorption peak at the following:

[0014] (4) 940 cm due to the Al-O bond -1 More than 960cm -1 The absorption intensity of the following peaks at 3350 cm originating from the OH bond -1 More than 3550cm -1 The barrier film according to (3), wherein the ratio of the absorption intensities of the following absorption peaks is 0.20 or less:

[0015] (5) A laminate comprising the barrier film according to any one of (1) to (4) above and a sealant layer.

[0016] (6) A packaging product comprising the laminate described in (5). [Effects of the Invention]

[0017] The barrier film of the present invention has even higher barrier properties. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view showing an example of a barrier film according to the present embodiment. [Figure 2] 1 is a diagram illustrating an example of a film forming apparatus according to an embodiment of the present invention. [Figure 3] FIG. 2 is a cross-sectional view showing an example of a plasma pretreatment mechanism of a film forming apparatus. [Figure 4] FIG. 2 is a plan view showing an example of an electrode unit and a magnetic field generating unit of a plasma pretreatment mechanism of a film forming apparatus. [Figure 5] 2 is a cross-sectional view showing an example of an electrode unit and a magnetic field generating unit of a plasma pretreatment mechanism of a film forming apparatus. FIG. [Figure 6] FIG. 2 is a cross-sectional view showing an example of a film formation mechanism of a film formation apparatus. [Figure 7] 1 is a cross-sectional view showing an example of a laminate including a barrier film according to an embodiment of the present invention. [Figure 8] FIG. 1 is a graph analysis diagram showing the measurement results of the barrier film of Example 1 by TOF-SIMS. [Figure 9] FIG. 1 is a graph analysis diagram showing the measurement results of the barrier film of Example 2 by TOF-SIMS. [Figure 10] FIG. 10 is a graph analysis diagram showing the measurement results of the barrier film of Example 3 by TOF-SIMS. [Figure 11] FIG. 10 is a graph analysis diagram showing the measurement results of the barrier film of Example 4 by TOF-SIMS. [Figure 12] FIG. 10 is a graph analysis diagram showing the measurement results of the barrier film of Example 5 by TOF-SIMS. [Figure 13] FIG. 1 is a graph analysis diagram showing the measurement results of the barrier film of Comparative Example 1 by TOF-SIMS. [Figure 14] FIG. 10 is a graph analysis diagram showing the measurement results of the barrier film of Comparative Example 2 by TOF-SIMS. [Figure 15] 1 is a graph showing the results of FT-IR measurement of the barrier films of Examples and Comparative Examples. [Figure 16] 1 is a graph showing the results of FT-IR measurement of the barrier films of Examples and Comparative Examples. [Figure 17] FIG. 1 is a plan view showing an example of a loop stiffness measuring device. [Figure 18] FIG. 17 is a cross-sectional view of the loop stiffness measuring device of FIG. 16 taken along line VV. [Figure 19] FIG. 10 is a diagram illustrating a process of attaching a test piece to a loop stiffness measuring instrument. [Figure 20] FIG. 10 is a diagram illustrating a step of forming a loop portion in a test piece. [Figure 21] FIG. 10 is a diagram illustrating a process of applying a load to a loop portion of a test piece. [Figure 22] FIG. 10 is a diagram illustrating a process of applying a load to a loop portion of a test piece. DETAILED DESCRIPTION OF THE INVENTION

[0019] Specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments and can be practiced with appropriate modifications within the scope of the object of the present invention. Furthermore, in this specification, the expression "X to Y" (X and Y are arbitrary numerical values) means "at least X and at most Y."

[0020] Fig. 1 is a cross-sectional view showing an example of a barrier film according to the present embodiment. A barrier film manufactured using the film formation apparatus according to the present embodiment includes a substrate 1 and a vapor-deposited film 2, such as barrier film A shown in Fig. 1. In the example shown in Fig. 1, the vapor-deposited film 2 is located on one surface of the substrate 1. In the example shown in Fig. 1, the vapor-deposited film 2 is located on the surface of the barrier film.

[0021] In this specification, "laminated in this order" means that the substrate and the aluminum oxide vapor-deposited film are laminated in this order, and a layer such as a primer may be laminated between these layers.

[0022] Each layer constituting the barrier film A will be described below.

[0023] [Base material] The substrate 1 is a layer mainly containing a resin. The resin is not particularly limited, and known resin films or sheets can be used. For example, resin films containing polyester resins such as polyethylene terephthalate resins, polybutylene terephthalate resins, and polyethylene naphthalate resins, polyamide resins, and polyolefin resins such as polymers and copolymers of α-olefins such as polyethylene and polypropylene can be used.

[0024] Among these resins, polyester resins are preferably used, and among polyester resins, polyethylene terephthalate resins and polybutylene terephthalate resins are preferably used. The polyester film used as the substrate 1 may be stretched in a predetermined direction. In this case, the polyester film may be a uniaxially stretched film stretched in one predetermined direction, or a biaxially stretched film stretched in two predetermined directions. For example, when a film made of polyethylene terephthalate is used as the substrate 1, a biaxially stretched polyethylene terephthalate film can be used.

[0025] The thickness of the polyester film used as the substrate 1 as described above is not particularly limited as long as it allows pretreatment and film formation treatment when forming the vapor-deposited film 2 using a film-forming apparatus described below, but from the viewpoint of flexibility and shape retention, a thickness in the range of 6 μm to 100 μm is preferred. When the polyester film has a thickness within this range, it is easy to bend and does not tear during transportation, and it is easy to handle in a film-forming apparatus used to produce a barrier film having a vapor-deposited film 2 with improved adhesion.

[0026] As the polyethylene terephthalate film (PET film), in addition to conventionally known PET films, biomass PET film, recycled PET film, and high-stiffness PET film (tough PET film) may be used as the substrate 1.

[0027] <Biomass PET film> Biomass PET film is a resin film containing biomass-derived polyester, whose diol unit is ethylene glycol derived from biomass and whose dicarboxylic acid unit is dicarboxylic acid derived from fossil fuels.

[0028] Because biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol, polyester films synthesized using biomass-derived ethylene glycol are comparable to conventional fossil fuel-derived polyester films in terms of physical properties such as mechanical properties. Therefore, substrates using biomass-derived polyester films have a layer made of a carbon-neutral material, and therefore can reduce the amount of fossil fuel used and the environmental impact compared to substrates produced from raw materials obtained from conventional fossil fuels.

[0029] Biomass-derived ethylene glycol is made from ethanol (biomass ethanol) produced from biomass such as sugarcane or corn. For example, biomass-derived ethylene glycol can be obtained by converting biomass ethanol into ethylene oxide by a conventionally known method to produce ethylene glycol. Alternatively, commercially available biomass ethylene glycol may be used; for example, biomass ethylene glycol commercially available from India Glycoal Limited can be suitably used.

[0030] The dicarboxylic acid unit of the polyester uses a dicarboxylic acid derived from a fossil fuel. As the dicarboxylic acid, an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid, and a derivative thereof can be used. Examples of the aromatic dicarboxylic acid include terephthalic acid and isophthalic acid, and examples of the derivatives of the aromatic dicarboxylic acid include lower alkyl esters of the aromatic dicarboxylic acid, specifically, methyl ester, ethyl ester, propyl ester, and butyl ester. Among these, terephthalic acid is preferred, and the aromatic dicarboxylic acid is preferred. As the derivative of phosphoric acid, dimethyl terephthalate is preferred.

[0031] The biomass-derived polyester can be obtained by a conventionally known method of polycondensing a diol unit and a dicarboxylic acid unit. Specifically, the biomass-derived polyester can be produced by a general melt polymerization method in which an esterification reaction and / or transesterification reaction between the dicarboxylic acid component and the diol component is followed by a polycondensation reaction under reduced pressure, or by a known solution heating dehydration condensation method using an organic solvent.

[0032] The resin composition constituting the resin film containing biomass-derived polyester may be composed solely of biomass-derived polyester, or may contain a fossil fuel-derived polyester in addition to the biomass-derived polyester. The fossil fuel-derived polyester is composed of diol units and dicarboxylic acid units, and is obtained by a polycondensation reaction using ethylene glycol, a fossil fuel-derived diol, as the diol unit and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit.

[0033] The resin in the resin composition constituting the resin film containing biomass-derived polyester may contain recycled polyester in addition to the biomass-derived polyester. The recycled polyester may be recycled from biomass-derived polyester or recycled from fossil fuel-derived polyester.

[0034] The resin composition constituting the resin film containing biomass-derived polyester can contain various additives. Examples of additives include plasticizers, UV stabilizers, color inhibitors, matting agents, deodorizers, flame retardants, weather resistance agents, antistatic agents, friction reducers, mold release agents, antioxidants, ion exchange agents, and color pigments. The additives are preferably contained in an amount of 5% by mass to 50% by mass, and more preferably 5% by mass to 20% by mass, of the entire resin composition containing PET.

[0035] A resin film containing a biomass-derived polyester can be formed, for example, by film formation using a T-die method. Specifically, after drying the above-mentioned PET, the resin composition is fed into a melt extruder heated to a temperature above the melting point of PET (Tm) to Tm + 70°C, where it is melted and extruded into a sheet form through a die such as a T-die. The extruded sheet is then rapidly cooled and solidified using a rotating cooling drum or the like to form a film. As the melt extruder, a single-screw extruder, twin-screw extruder, vent extruder, tandem extruder, or the like can be used depending on the purpose. Hereinafter, the melting point and the glass transition temperature may be referred to as Tm and Tg, respectively, as necessary.

[0036] Atmospheric carbon dioxide contains a certain proportion of 14C (105.5 pMC), and it is known that the 14C content in plants that grow by absorbing atmospheric carbon dioxide, such as corn, is also approximately 105.5 pMC. It is also known that fossil fuels contain almost no 14C. Therefore, the proportion of biomass-derived carbon can be calculated by measuring the proportion of 14C in the total carbon atoms in a polyester. In this specification, the "biomass ratio" refers to the mass ratio of biomass-derived components. Taking PET (polyethylene terephthalate) as an example, PET is a polymer formed by polymerizing ethylene glycol containing two carbon atoms and terephthalic acid containing eight carbon atoms in a 1:1 molar ratio. If only biomass-derived ethylene glycol is used, the mass ratio of biomass-derived components in PET is 31.25%, resulting in a biomass ratio of 31.25% (molecular weight derived from biomass-derived ethylene glycol / molecular weight of one polyester polymerization unit = 60 / 192). Furthermore, the mass ratio of biomass-derived components in the fossil fuel-derived polyester is 0%, and the biomass degree of the fossil fuel-derived polyester is 0%. In the present invention, the biomass degree in the resin film containing the biomass-derived polyester is preferably 5.0% or more, more preferably 10.0% or more, and preferably 30.0% or less.

[0037] The resin film containing the biomass-derived polyester is preferably biaxially stretched. Biaxial stretching can be performed by a conventionally known method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to form a longitudinally stretched film. This stretching is preferably performed by utilizing the difference in peripheral speed between two or more rolls. The longitudinal stretching is usually performed at a temperature range of 50 to 100°C. The longitudinal stretching ratio is preferably 2.5 to 4.2 times, although this depends on the required properties of the film application. If the stretching ratio is less than 2.5 times, the thickness unevenness of the polyester film becomes large, making it difficult to obtain a good film.

[0038] The longitudinally stretched film is then subjected to the sequential processes of transverse stretching, heat setting, and heat relaxation to become a biaxially stretched film. Transverse stretching is usually carried out at a temperature in the range of 50 to 100°C. The transverse stretching ratio is preferably 2.5 times or more and 5.0 times or less, depending on the required properties of the application. If the ratio is less than 2.5 times, the film thickness will become uneven, making it difficult to obtain a good film, and if the ratio is more than 5.0 times, breakage will occur easily during film formation.

[0039] After transverse stretching, heat setting is carried out. The preferred temperature range for heat setting is Tg+70 to Tm-10°C of the polyester. The heat setting time is preferably 1 to 60 seconds. For applications requiring a reduced thermal shrinkage rate, heat relaxation may be carried out as necessary.

[0040] The thickness of the resin film containing biomass-derived polyester is optional depending on the application, but is usually about 5 to 500 μm. The breaking strength of the resin film containing biomass-derived polyester is 5 to 40 kgf / mm in the MD direction. 2 , 5 to 35 kgf / mm in the TD direction 2 The elongation at break is 50 to 350% in the MD direction and 50 to 300% in the TD direction. The shrinkage rate when left in a temperature environment of 150°C for 30 minutes is 0.1 to 5%.

[0041] Resin films containing biomass-derived polyesters can be suitably used for packaging products such as bags, lids, and laminated tubes, various label materials, molded sheet products, etc. When a resin film containing recycled PET is used for packaging products, the thickness of the stretched film is preferably 5 to 30 μm.

[0042] <Recycled PET film> The recycled PET film is a resin film containing recycled PET, including PET recycled by mechanical recycling. Specifically, it includes PET recycled from PET bottles by mechanical recycling, and this PET contains ethylene glycol as the diol component and terephthalic acid and isophthalic acid as the dicarboxylic acid components.

[0043] Mechanical recycling is a method in which collected polyethylene terephthalate resin products such as PET bottles are generally crushed and washed with alkali to remove dirt and foreign matter from the surface of the PET resin products, and then dried at high temperature and reduced pressure for a certain period of time to diffuse and decontaminate contaminants remaining inside the PET resin, thereby removing dirt from the resin products made of PET resin and returning them to PET resin.

[0044] Hereinafter, polyethylene terephthalate recycled from PET bottles will be referred to as "recycled polyethylene terephthalate (hereinafter also referred to as recycled PET)," and polyethylene terephthalate that has not been recycled will be referred to as "virgin polyethylene terephthalate (hereinafter also referred to as virgin PET)."

[0045] The content of isophthalic acid in the PET substrate is preferably 0.5 mol % to 5 mol %, more preferably 1.0 mol % to 2.5 mol %, of the total dicarboxylic acid components constituting the PET. If the content of isophthalic acid is less than 0.5 mol %, flexibility may not be improved, while if it exceeds 5 mol %, the melting point of the PET may decrease, resulting in insufficient heat resistance.

[0046] In addition to the usual PET derived from fossil fuels, the PET may also be biomass-derived PET, which is PET that uses biomass-derived ethylene glycol as the diol component and fossil fuel-derived dicarboxylic acid as the dicarboxylic acid component.

[0047] The PET used in PET bottles can be obtained by a conventionally known method of polycondensing the diol component and the dicarboxylic acid component. Specifically, it can be produced by a common melt polymerization method in which the diol component and the dicarboxylic acid component are subjected to an esterification reaction and / or transesterification reaction, followed by a polycondensation reaction under reduced pressure, or by a known solution heating dehydration condensation method using an organic solvent. The amount of diol component used in producing the PET is essentially equimolar to 100 moles of dicarboxylic acid or its derivative. However, due to the distillation that occurs during the esterification and / or transesterification reaction and / or polycondensation reaction, an excess of 0.1 mol% to 20 mol% is generally used. Furthermore, the polycondensation reaction is preferably carried out in the presence of a polymerization catalyst. The timing of adding the polymerization catalyst is not particularly limited as long as it is before the polycondensation reaction. It may be added when the raw materials are charged or when the pressure reduction begins.

[0048] After the PET recycled from PET bottles has been polymerized and solidified as described above, it may be subjected to solid-state polymerization as necessary to further increase the degree of polymerization or to remove oligomers such as cyclic trimers. Specifically, the solid-state polymerization is carried out by cutting the PET into chips, drying it, heating it at a temperature of 100°C or higher and 180°C or lower for about 1 to 8 hours to pre-crystallize the PET, and then heating it at a temperature of 190°C or higher and 230°C or lower for 1 hour to several tens of hours in an inert gas atmosphere or under reduced pressure.

[0049] The intrinsic viscosity of the PET contained in the recycled PET is preferably 0.58 dL / g or more and 0.80 dL / g or less. If the intrinsic viscosity is less than 0.58 dL / g, the mechanical properties required for the PET film as a resin substrate may be insufficient. On the other hand, if the intrinsic viscosity exceeds 0.80 dL / g, productivity in the film production process may be impaired. The intrinsic viscosity is measured in an orthochlorophenol solution at 35°C.

[0050] The recycled PET preferably contains recycled PET in a proportion of 50% by mass or more and 95% by mass or less, and may contain virgin PET in addition to recycled PET. Virgin PET may be PET containing ethylene glycol as the diol component and terephthalic acid and isophthalic acid as the dicarboxylic acid component, or may be PET containing no isophthalic acid as the dicarboxylic acid component. For example, the dicarboxylic acid component may contain, in addition to aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, aliphatic dicarboxylic acids, etc.

[0051] Specific examples of aliphatic dicarboxylic acids include linear or alicyclic dicarboxylic acids typically having 2 to 40 carbon atoms, such as oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid. Examples of derivatives of aliphatic dicarboxylic acids include lower alkyl esters of the above aliphatic dicarboxylic acids, such as methyl esters, ethyl esters, propyl esters, and butyl esters, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids, such as succinic anhydride. Among these, preferred aliphatic dicarboxylic acids are adipic acid, succinic acid, dimer acid, or mixtures thereof, with those containing succinic acid as the main component being particularly preferred. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

[0052] The resin in the resin composition constituting the recycled PET-containing resin film may be composed solely of recycled PET, or may contain virgin PET in addition to recycled PET. The recycled PET film may be single-layer or multi-layer. When the recycled PET-containing resin film is a three-layer film consisting of an innermost layer, an intermediate layer, and an outermost layer, it is preferable that the intermediate layer be composed solely of recycled PET or a mixed layer of recycled PET and virgin PET, and the innermost and outermost layers on both sides be composed solely of virgin PET. By using only virgin PET in the innermost and outermost layers, it is possible to prevent the recycled PET from appearing on the front or back surface of the resin film. This ensures the hygienic properties of the laminate. When the recycled PET-containing resin film is a two-layer film, it is preferable that one layer be composed solely of recycled PET or a mixed layer of recycled PET and virgin PET, and the other layer be composed solely of virgin PET. When a single-layer resin film containing recycled PET is formed by blending recycled PET and virgin PET, the two layers may be fed separately to a molding machine, or they may be mixed by dry blending or the like and then fed. Among these, the method of mixing by dry blending is preferred from the viewpoint of ease of operation.

[0053] The resin composition constituting the resin film containing recycled polyethylene PET can contain various additives during or after its production process, provided that the additives do not impair its properties. Examples of additives include plasticizers, UV stabilizers, color inhibitors, matting agents, deodorizers, flame retardants, weather resistance agents, antistatic agents, friction reducers, mold release agents, antioxidants, ion exchange agents, and color pigments. The additives are preferably contained in an amount of 5% by mass to 50% by mass, and more preferably 5% by mass to 20% by mass, of the entire resin composition containing PET.

[0054] A resin film containing recycled PET can be formed, for example, by a T-die method. Specifically, after drying the PET, the resin composition is fed into a melt extruder heated to a temperature above the melting point of PET (Tm) to Tm + 70°C, melted, and extruded into a sheet from a die such as a T-die. The extruded sheet is rapidly cooled and solidified using a rotating cooling drum or the like to form a film. As the melt extruder, a single-screw extruder, twin-screw extruder, vent extruder, tandem extruder, or the like can be used depending on the purpose.

[0055] The resin film containing recycled PET is preferably biaxially stretched. Biaxial stretching can be performed by a conventional method. For example, the film extruded onto the cooling drum as described above is subsequently heated by roll heating, infrared heating, or the like, and stretched in the longitudinal direction to form a longitudinally stretched film. This stretching is preferably performed using the difference in peripheral speed between two or more rolls. Longitudinal stretching is typically performed at a temperature range of 50°C to 100°C. The longitudinal stretching ratio is preferably 2.5 to 4.2 times, depending on the required properties of the film's application. If the stretching ratio is less than 2.5 times, the thickness of the PET film becomes uneven, making it difficult to obtain a good film. The longitudinally stretched film is then sequentially subjected to the processes of transverse stretching, heat setting, and heat relaxation to form a biaxially stretched film. Transverse stretching is typically performed at a temperature range of 50°C to 100°C. The transverse stretching ratio is preferably 2.5 to 5.0 times, depending on the required properties of the application. If the stretching ratio is less than 2.5 times, the film thickness will be uneven, making it difficult to obtain a good film, and if it exceeds 5.0 times, breakage will be more likely to occur during film formation. After transverse stretching, heat setting is performed, and the preferred temperature range for heat setting is Tg+70 to Tm-10°C of PET. The heat setting time is preferably 1 second or more and 60 seconds or less. For applications requiring a lower thermal shrinkage rate, heat relaxation treatment may be performed as needed.

[0056] The thickness of the resin film containing recycled PET is optional depending on the application, but is usually about 5 to 500 μm. The breaking strength of the resin film containing recycled PET is 5 kgf / mm in the MD direction. 2 Over 40kgf / mm 2 Below 5kgf / mm in the TD direction 2 More than 35kgf / mm 2 The elongation at break is 50% to 350% in the MD direction and 50% to 300% in the TD direction. The shrinkage when left in a 150°C temperature environment for 30 minutes is 0.1% to 5%.

[0057] Virgin PET may be fossil fuel polyethylene terephthalate (hereinafter also referred to as fossil fuel PET) or biomass PET. Here, "fossil fuel PET" refers to PET containing a fossil fuel-derived diol as the diol component and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid component. Recycled PET may be obtained by recycling PET resin products made from fossil fuel PET, or may be obtained by recycling PET resin products made from biomass PET.

[0058] Resin films containing recycled PET can be suitably used for packaging products such as bags, lids, and laminated tubes, various label materials, molded sheet products, etc. When using a resin film containing recycled PET for packaging products, the thickness of the stretched film is preferably 5 to 30 μm.

[0059] <High-stiffness PET film (tough PET film)> The high-stiffness PET film contains polyester as a primary component and has a loop stiffness of 0.0017 N / 15 mm or more in at least one direction. For example, the high-stiffness film has a loop stiffness of 0.0017 N or more in at least one of the machine direction (MD) or the transverse direction (TD). For example, the high-stiffness film may have a loop stiffness of 0.0017 N or more in both the machine direction (MD) and the transverse direction (TD).

[0060] Loop stiffness is a parameter that represents the stiffness of a film. A method for measuring loop stiffness will be described below with reference to Figs. 17 to 22. The measurement method described below can be used not only for single-layer films such as stretched plastic films, but also for films including multiple layers, such as vapor-deposited films and laminated films. A vapor-deposited film is a film that includes a single-layer film such as a stretched plastic film and a vapor-deposited film formed on the single-layer film. A laminated film is a film that includes multiple laminated films.

[0061] FIG. 17 is a plan view showing the test piece 40 and the loop stiffness measuring device 45, and FIG. 18 is a cross-sectional view of the test piece 40 and the loop stiffness measuring device 45 taken along line IV-IV in FIG. 17. The test piece 40 is a rectangular film having long and short sides. In the present application, the length L1 of the long side of the test piece 40 is 150 mm, and the length L2 of the short side is 15 mm. As the loop stiffness measuring device 45, for example, No. 581 Loop Stiffness Tester (registered trademark) LOOP STIFFNESS TESTER DA type manufactured by Toyo Seiki Seisakusho, Ltd. can be used. The length L1 of the long side of the test piece 40 is adjustable as long as the test piece 40 can be gripped by a pair of chucks 46, which will be described later.

[0062] The loop stiffness measuring device 45 has a pair of chuck portions 46 for gripping a pair of ends in the long side direction of the test specimen 40, and a support member 47 for supporting the chuck portions 46. The chuck portions 46 include a first chuck 461 and a second chuck 462. In the state shown in FIGS. 17 and 18 , the test specimen 40 is placed on the pair of first chucks 461, and the second chuck 462 has not yet gripped the test specimen 40 between itself and the first chuck 461. As will be described later, during measurement, the test specimen 40 is gripped between the first chuck 461 and the second chuck 462 of the chuck portions 46. The second chuck 462 may be connected to the first chuck 461 via a hinge mechanism.

[0063] When the film to be measured, such as a stretched plastic film, a vapor-deposited film, or a laminated film, is available in a state before it is processed into a packaged product, the test piece 40 may be produced by cutting the film to be measured. Alternatively, the test piece 40 may be produced by cutting a packaged product made from a packaging material, such as a packaging bag, and removing the film to be measured.

[0064] A method for measuring the loop stiffness of the test piece 40 using the loop stiffness measuring device 45 will be described. First, as shown in FIGS. 17 and 18 , the test piece 40 is placed on the first chuck 461 of a pair of chucks 46 arranged with a gap L3 between them. In the present application, the gap L3 is set so that the length of a loop portion 41 (described later, also referred to as the loop length) is 60 mm. The test piece 40 includes an inner surface 40x located on the first chuck 461 side and an outer surface 40y located opposite the inner surface 40x. When the test piece 40 is made of a packaging material, the inner surface 40x and the outer surface 40y of the test piece 40 coincide with the inner surface and the outer surface of the packaging material. When a loop portion 41 (described later) is formed in the test piece 40, the inner surface 40x is located inside the loop portion 41, and the outer surface 40y is located outside the loop portion 41. Subsequently, as shown in FIG. 19, the second chuck 462 is placed on the test piece 40 so that the end of the test piece 40 in the long side direction is gripped between the second chuck 462 and the first chuck 461.

[0065] Next, as shown in FIG. 20 , at least one of the pair of chuck portions 46 is slid on the support member 47 in a direction that reduces the distance between the pair of chuck portions 46. This allows a loop portion 41 to be formed on the test piece 40. The test piece 40 shown in FIG. 20 has a loop portion 41, a pair of intermediate portions 42, and a pair of fixing portions 43. The pair of fixing portions 43 are portions of the test piece 40 that are gripped by the pair of chuck portions 46. The pair of intermediate portions 42 are portions of the test piece 40 that are located between the loop portion 41 and the pair of intermediate portions 42. As shown in FIG. 20 , the chuck portion 46 is slid on the support member 47 until the inner surfaces 40x of the pair of intermediate portions 42 come into contact with each other. This allows a loop portion 41 having a loop length of 60 mm to be formed. The loop length of the loop portion 41 is the length of the test piece 40 between position P1 where the surface of one second chuck 462 on the loop portion 41 side intersects with the test piece 40, and position P2 where the surface of the other second chuck 462 on the loop portion 41 side intersects with the test piece 40. If the thickness of the test piece 40 is ignored, the above-mentioned distance L3 is the value obtained by adding 2×t to the length of the loop portion 41, where t is the thickness of the second chuck 462 of the chuck portion 46.

[0066] Then, as shown in FIG. 21 , the posture of the chuck portion 46 is adjusted so that the protruding direction Y of the loop portion 41 relative to the chuck portion 46 is horizontal. For example, the posture of the chuck portion 46 supported by the support member 47 is adjusted by moving the support member 47 so that the normal direction of the support member 47 is horizontal. In the example shown in FIG. 21 , the protruding direction Y of the loop portion 41 coincides with the thickness direction of the chuck portion. Furthermore, a load cell 48 is prepared at a position a distance Z1 away from the second chuck 462 in the protruding direction Y of the loop portion 41. In this application, the distance Z1 is set to 50 mm. Next, the load cell 48 is moved toward the loop portion 41 of the test piece 40 at a speed V by a distance Z2 shown in FIG. 21 . The distance Z2 is set so that the load cell 48 contacts the loop portion 41 and then pushes the loop portion 41 toward the chuck portion 46, as shown in FIGS. 21 and 22 . In this application, the distance Z2 is set to 40 mm. In this case, the distance Z3 between the load cell 48 and the second chuck 462 of the chuck portion 46 when the load cell 48 is pressing the loop portion 41 toward the chuck portion 46 is 10 mm. The speed V at which the load cell 48 is moved was set to 3.3 mm / sec.

[0067] Next, as shown in Fig. 22, the load cell 48 is moved a distance Z2 toward the chuck portion 46, and in a state in which the load cell 48 is pressing into the loop portion 41 of the test piece 40, the value of the load applied to the load cell 48 from the loop portion 41 becomes stable, and then the value of the load is recorded. The value of the load thus obtained is used as the loop stiffness of the film constituting the test piece 40. In this application, unless otherwise specified, the environment during measurement of loop stiffness is a temperature of 23°C and a relative humidity of 50%.

[0068] By using a high-stiffness film having a loop stiffness of 0.0017 N or more in at least one direction as the stretched plastic film, the puncture strength of the stretched plastic film can be increased, thereby making it possible to increase the puncture strength of a laminated film including the high-stiffness film to, for example, 13 N or more, more preferably 14 N or more, and even more preferably 15 N or more or 16 N or more.

[0069] An example of a high-stiffness film is a high-stiffness PET film containing 51% by mass or more of PET. The PET content in the high-stiffness PET film may be 80% by mass or more, 90% by mass or more, or even 95% by mass or more. The thickness of the high-stiffness film is preferably 5 μm or more, more preferably 7 μm or more. The thickness of the high-stiffness film may be 10 μm or more, or may be 14 μm or more. The thickness of the high-stiffness film is preferably 30 μm or less, and may be 25 μm or less, or may be 20 μm or less.

[0070] Preferred mechanical properties of the high stiffness film are further described below. The puncture strength of the high stiffness film is preferably 10 N or more, more preferably 11 N or more. The tensile strength of the high stiffness film in at least one direction is preferably 250 MPa or more, more preferably 280 MPa or more. For example, the tensile strength of the high stiffness film in the machine direction is preferably 250 MPa or more, more preferably 280 MPa or more. The tensile strength of the high stiffness film in the perpendicular direction is preferably 250 MPa or more, more preferably 280 MPa or more. The tensile elongation of the high stiffness film in at least one direction is preferably 130% or less, more preferably 120% or less. For example, the tensile elongation of the high stiffness film in the machine direction is preferably 130% or less, more preferably 120% or less. The tensile elongation of the high stiffness film in the perpendicular direction is preferably 120% or less, more preferably 110% or less. Preferably, the tensile strength of the high stiffness film divided by the tensile elongation in at least one direction is 2.0 [MPa / %] or more. For example, the tensile strength of the high stiffness film divided by the tensile elongation in the transverse direction (TD) is preferably 2.0 [MPa / %] or more, more preferably 2.2 [MPa / %] or more. The tensile strength of the high stiffness film divided by the tensile elongation in the machine direction (MD) is preferably 1.8 [MPa / %] or more, more preferably 2.0 [MPa / %] or more.

[0071] The heat shrinkage of the high stiffness film in at least one direction is preferably 0.7% or less, more preferably 0.5% or less. For example, the heat shrinkage of the high stiffness film in the machine direction is preferably 0.7% or less, more preferably 0.5% or less. The heat shrinkage of the high stiffness film in the perpendicular direction is preferably 0.7% or less, more preferably 0.5% or less. The heating temperature for measuring the heat shrinkage is 100°C, and the heating time is 40 minutes.

[0072] The Young's modulus of the high stiffness film in at least one direction is preferably 4.0 GPa or more, more preferably 4.5 GPa or more. For example, the Young's modulus of the high stiffness film in the machine direction is preferably 4.0 GPa or more, more preferably 4.5 GPa or more. The Young's modulus of the high stiffness film in the perpendicular direction is preferably 4.0 GPa or more, more preferably 4.5 GPa or more.

[0073] Like tensile strength and tensile elongation, Young's modulus can be measured in accordance with JIS K7127. A tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used as a measuring instrument. A rectangular film cut from a high-stiffness film with a width of 15 mm and a length of 150 mm can be used as a test piece. The distance between the pair of chucks holding the test piece at the start of measurement is 100 mm, and the tensile speed is 300 mm / min. The length of the test piece can be adjusted as long as the test piece can be held by the pair of chucks. Unless otherwise specified in this application, the environment during measurement of Young's modulus is a temperature of 25°C and a relative humidity of 50%.

[0074] Even when a vapor-deposited film is provided, the high-stiffness film has mechanical properties equivalent to those of a single high-stiffness film. For example, a high-stiffness film provided with an aluminum oxide vapor-deposited film 3 has a loop stiffness of 0.0017 N or more in at least one direction. Furthermore, even when an organic coating layer is further provided on the vapor-deposited film, the high-stiffness film has mechanical properties equivalent to those of a single high-stiffness film. For example, a high-stiffness film provided with an aluminum oxide vapor-deposited film and an organic coating layer has a loop stiffness of 0.0017 N or more in at least one direction.

[0075] In the manufacturing process of a high-stiffness film, for example, a plastic film obtained by melting and molding polyester is first stretched 3 to 4.5 times in both the machine direction and the perpendicular direction at 90 to 145°C in a first stretching step. This is followed by a second stretching step in which the plastic film is stretched 1.1 to 3.0 times in both the machine direction and the perpendicular direction at 100 to 145°C in a second stretching step. This is followed by heat setting at 190 to 220°C. This is followed by a relaxation treatment (treatment to reduce the film width) of approximately 0.2 to 2.5% in both the machine direction and the perpendicular direction at 100 to 190°C. By adjusting the stretch ratio, stretching temperature, heat setting temperature, and relaxation treatment rate in these steps, a high-stiffness film having the above-mentioned mechanical properties can be obtained.

[0076] A specific example of a high-stiffness film is XP-55 manufactured by Toray Industries, Inc. This high-stiffness film is biaxially stretched, contains 90% or more by mass of PET, and is 16 μm thick. The measured loop stiffness of this high-stiffness PET film was 0.0021 N in both the machine direction and the perpendicular direction. The Young's modulus of the high-stiffness PET film in the machine direction was 4.8 GPa, and the Young's modulus of the high-stiffness PET film in the perpendicular direction was 4.7 GPa. The tensile strength of the high-stiffness PET film in the machine direction was 292 MPa, and the tensile strength of the high-stiffness PET film in the perpendicular direction was 257 MPa. The tensile elongation of the high-stiffness PET film in the machine direction was 107%, and the tensile elongation of the high-stiffness PET film in the perpendicular direction was 102%. In this case, the tensile strength of the high-stiffness PET film in the machine direction divided by the tensile elongation was 2.73 MPa / % and the tensile strength of the high-stiffness PET film in the perpendicular direction divided by the tensile elongation was 2.52 MPa / %. The heat shrinkage of the high-stiffness PET film in both the machine direction and perpendicular direction was 0.4%.

[0077] The substrate 1 may have a single layer or a multi-layer structure of two or more layers, and in the case of a multi-layer structure, the layers may have the same composition or different compositions. In the case of a multi-layer structure, the layers may be bonded to each other via an adhesive layer or the like.

[0078] [Aluminum oxide vapor deposition film] Next, the vapor-deposited film 2 will be described. The vapor-deposited film 2 contains aluminum oxide. The aluminum exists in the vapor-deposited film 2 in a state in which it forms elemental bonds, such as Al2O3. The vapor-deposited film 2 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, and zirconium oxide, or nitrides or carbides of these metals. The thickness of the vapor-deposited film 2 is preferably 3 nm or more and 100 nm or less, and more preferably 5 nm or more and 50 nm or less. Note that the term "aluminum oxide vapor-deposited film" in the present invention means a vapor-deposited film containing aluminum oxide, as described above, and may contain aluminum hydroxide Al2O4H in addition to aluminum oxide Al2O3.

[0079] (TOF-SIMS analysis) The composition of the barrier film according to this embodiment will be described in detail with reference to FIG. 9 of Example 2, which will be described later. FIG. 9 is an example of a graphical analysis diagram showing the intensities of elements and element bonds contained in the barrier film, measured by etching the barrier film A shown in FIG. 1 from the surface side of the vapor-deposited film 2 using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The unit of the vertical axis of the graph (intensity) is expressed as a common logarithm of the ion intensity. The unit of the horizontal axis of the graph (Et times) is the etching time.

[0080] TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) Secondary Ion Mass Spectrometry (SMS) is a method of mass analysis in which a primary ion beam from a primary ion gun is irradiated onto the surface of a solid sample to be analyzed, and the secondary ions sputtered and emitted from the sample surface are mass-separated using the difference in their flight times (flight time is proportional to the square root of mass).

[0081] Here, by detecting the secondary ion intensity while sputtering is progressing, the concentration distribution of the detected element in the depth direction on the sample surface can be determined by converting the transition time into depth data for the ion intensity of the secondary ions, i.e., the ions of the detected element or molecular ions bonded to the detected element.

[0082] Then, the depth of the depressions formed on the sample surface by irradiation with primary ions is measured in advance using a surface roughness meter, and the average sputtering rate is calculated from the depression depth and transition time. Under the assumption that the sputtering rate is constant, the depth (sputtering amount) can be calculated from the irradiation time (i.e., transition time) or the number of irradiation cycles.

[0083] Specifically, while repeatedly soft-etching the outermost surface of the vapor-deposited film 2 at a constant rate using a Cs (cesium) ion gun, a time-of-flight secondary ion mass spectrometer is used to measure the elements and element bonds at the interface between the vapor-deposited film 2 and the substrate 1, as well as the elements and element bonds of the vapor-deposited film 2, thereby obtaining graphs of the measured elements and element bonds. As a specific example, as shown in Fig. 9, at least the element bond AL2O3, the element bond AL2O4H, and the element bond C6 are detected from the barrier film according to this embodiment. The example shown in Fig. 9 shows an example in which the strengths of these three types of element bonds were measured.

[0084] In Figure 9, the position of Et time T1 where the intensity of the graph for element C6 is half of the maximum intensity is defined as the interface between the plastic substrate and aluminum oxide, and the area from the barrier film surface (T0) to the interface T1 is treated as an aluminum oxide vapor-deposited film (X in Figure 9), and 1 / 3 of the Et time from T0 to T1, i.e., the position of 1 / 3X, is defined as T2.

[0085] At this time, the strength of the element bond Al2O3 at T2 is I 21 Strength of elemental bond Al2O4H to I 22 The ratio (I 22 / I 21 ) is 0.30 or less, preferably 0.20 or less, and more preferably 0.10 or less. This allows the proportion of elemental bond Al2O4H to be low in the surface vicinity region of the vapor-deposited film, and a region in the state of mainly Al2O3 to exist, thereby improving the barrier performance.

[0086] In addition, in Figure 9, there is a maximum peak Tp of the element bond Al2O4H intensity in the aluminum oxide vapor-deposited film. When there are multiple maximum peaks, the first peak from the surface side of the vapor-deposited film is the maximum peak. The region from Tp to the interface T1 is called the transition region. In the present invention, it is preferable that the depth position of the maximum peak (Tp) with respect to X, which corresponds to the thickness of the vapor-deposited film, is 55% or more and 95% or less from the surface side (opposite to the substrate side) of the vapor-deposited film. Furthermore, the intensity I of the element bond Al2O3 at the position Tp P1 Strength of elemental bond Al2O4H to I P2 The ratio (I P2 / I P1 ) is preferably 0.10 or more and 4.00 or less.

[0087] The maximum peak derived from the element bond Al2O4H is between 55% and 95%, i.e., it is located closer to the substrate, so that the deposited film has a region mainly composed of Al2O4H on the substrate side, while the deposited film has a region mainly composed of Al2O3 near the surface, as described above. In other words, the deposited film has a structure of Al2O3 main region / Al2O4H main region / substrate, which enables high barrier properties.

[0088] In addition, the strength of the element bond Al2O3 at T2 is I 21 Strength of elemental bond Al2O4H to I 22 The ratio (I 22 / I 21 ) and the depth position of the maximum peak (Tp), and the intensity I of the element bond Al2O3 at the position Tp P1 Strength of elemental bond Al2O4H to I P2 The ratio (I P2 / I P1 ) can be adjusted by controlling the combination of the conditions of the pretreatment, particularly the oxygen plasma treatment, the conditions of the plasma-assisted treatment during deposition, and the oxygen concentration during deposition in forming the aluminum oxide vapor deposition film.

[0089] (FT-IR evaluation) The barrier film of the present invention has a wavelength of 940 cm in the infrared absorption spectrum from the surface side of the vapor-deposited film. -1 More than 960cm -1 Below 950cm, preferably -1 More than 960cm -1 There is an absorption peak at 940cm -1 More than 960cm -1 The following peaks are derived from Al-O bonds, and the presence of these peaks improves the film density of aluminum oxide.

[0090] In addition, the 940cm -1 More than 960cm -1 The absorption intensity of the following peaks at 3350 cm originating from the OH bond -1 More than 3550cm -1The ratio of the absorption intensities of the following absorption peaks is 0.20 or less, preferably 0.10 or less. Within this range, the composition becomes close to a complete oxide film of aluminum oxide, and the barrier properties are improved.

[0091] The FT-IR measurement conditions were as described in the examples.

[0092] (Film forming equipment) Next, an example of a film formation apparatus 10 used in the method for manufacturing a barrier film will be described. As shown in Fig. 2, the film formation apparatus 10 includes a substrate transport mechanism 11A for transporting the substrate 1, a plasma pretreatment mechanism 11B for performing plasma pretreatment on the surface of the substrate 1, and a film formation mechanism 11C for forming a vapor-deposited film 2. In the example shown in Fig. 5, the film formation apparatus 10 further includes a decompression chamber 12. The decompression chamber 12 has a decompression mechanism, such as a vacuum pump described below, that adjusts the atmosphere in at least a part of the space inside the decompression chamber 12 to atmospheric pressure or below.

[0093] 2, the decompression chamber 12 includes a substrate transfer chamber 12A in which the substrate transfer mechanism 11A is located, a plasma pretreatment chamber 12B in which the plasma pretreatment mechanism 11B is located, and a film formation chamber 12C in which the film formation mechanism 11C is located. The decompression chamber 12 is preferably configured to prevent the atmospheres inside each chamber from mixing with each other. For example, as shown in FIG. 2, the decompression chamber 12 may be located between the substrate transfer chamber 12A and the plasma pretreatment chamber 12B, between the plasma pretreatment chamber 12B and the film formation chamber 12C, and between the substrate transfer chamber 12A and the film formation chamber 12C, and may have partition walls 35a to 35c separating the chambers.

[0094] The substrate transfer chamber 12A, the plasma pre-treatment chamber 12B, and the film formation chamber 12C will now be described. The plasma pre-treatment chamber 12B and the film formation chamber 12C are each provided adjacent to the substrate transfer chamber 12A, and each has a portion connecting to the substrate transfer chamber 12A. This allows the substrate 1 to be transferred between the substrate transfer chamber 12A and the plasma pre-treatment chamber 12B, and between the substrate transfer chamber 12A and the film formation chamber 12C without being exposed to the atmosphere. For example, between the substrate transfer chamber 12A and the plasma pre-treatment chamber 12B, the substrate 1 can be transferred through an opening provided in the partition wall 35a. The same structure is also provided between the substrate transfer chamber 12A and the film formation chamber 12C, allowing the substrate 1 to be transferred between the substrate transfer chamber 12A and the film formation chamber 12C.

[0095] The function of the decompression mechanism of the decompression chamber 12 will now be described. The decompression mechanism of the decompression chamber 12 is configured to be able to reduce the pressure of the atmosphere in the space in which at least the plasma pretreatment mechanism 11B or the film formation mechanism 11C of the film formation apparatus 10 is disposed to below atmospheric pressure. The decompression mechanism may be configured to be able to reduce the pressure of each of the substrate transfer chamber 12A, the plasma pretreatment chamber 12B, and the film formation chamber 12C, which are partitioned by partition walls 35a to 35c, to below atmospheric pressure.

[0096] The configuration of the decompression mechanism of the decompression chamber 12 will be described. The decompression chamber 12 may have, for example, a vacuum pump connected to the plasma pre-treatment chamber 12B. By adjusting the vacuum pump, the pressure inside the plasma pre-treatment chamber 12B can be appropriately controlled when performing the plasma pre-treatment described below. Furthermore, the method described below can prevent the plasma supplied into the plasma pre-treatment chamber 12B from diffusing to other chambers. The decompression mechanism of the decompression chamber 12 may have a vacuum pump connected to the film formation chamber 12C, similar to the vacuum pump connected to the plasma pre-treatment chamber 12B. The vacuum pump may be a dry pump, a turbomolecular pump, a cryopump, a rotary pump, a diffusion pump, or the like.

[0097] A substrate transport mechanism 11A for the substrate 1 of the film formation apparatus 10 according to this embodiment will be described together with the transport path of the substrate 1. The substrate transport mechanism 11A is a mechanism arranged in the substrate transport chamber 12A for transporting the substrate 1. In the example shown in FIG. 2, the substrate transport mechanism 11A has an unwinding roller 13 to which a roll of the substrate 1 is attached, a take-up roller 15 that winds up 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 (described later) arranged in the plasma pre-treatment chamber 12B and a film formation roller 25 (described later) arranged in the film formation chamber 12C.

[0098] Although not shown, the substrate conveying mechanism 11A may further include a tension pickup roller. By including the tension pickup roller in the substrate conveying mechanism 11A, the substrate 1 can be conveyed while adjusting the tension applied to the substrate 1.

[0099] (Plasma pretreatment mechanism) The plasma pretreatment mechanism 11B will now be described. The plasma pretreatment mechanism 11B is a mechanism for performing plasma pretreatment on the surface of the substrate 1. The plasma pretreatment mechanism 11B shown in FIG. 2 generates plasma P and performs plasma pretreatment on the surface of the substrate 1 using the generated plasma P. Plasma pretreatment activates the surface of the substrate 1, making it easier for nitrogen contained inside the substrate 1 to collect on the surface of the substrate 1 or for nitrogen contained in the environment surrounding the substrate 1 to be incorporated into the surface of the substrate 1. Therefore, when a vapor-deposited film 2 is formed on the surface of the substrate 1 that has been subjected to plasma pretreatment, a peak of elemental bond C—N can be formed at the interface between the substrate 1 and the vapor-deposited film 2. The plasma pretreatment mechanism 11B shown in FIG. 2 includes a pretreatment roller 20 arranged in a plasma pretreatment chamber 12B, an electrode unit 21 facing the pretreatment roller 20, and a magnetic field generating unit 23 that generates a magnetic field between the pretreatment roller 20 and the electrode unit 21.

[0100] The pretreatment roller 20 will now be described. FIG. 3 is an enlarged view of the area enclosed by the dashed line indicated by the symbol VI in FIG. 2. Note that FIG. 3 omits the power supply wiring 31 connecting the power source 32 shown in FIG. 2 to the electrode unit 21 (described later) and the plasma P generated by the plasma pretreatment mechanism 11B. The pretreatment roller 20 has a rotation axis X. The pretreatment roller 20 is disposed so that at least the rotation axis X is located within the plasma pretreatment chamber 12B defined by the partition walls 35a and 35b. A substrate 1 having a dimension in the direction of the rotation axis X is wrapped around the pretreatment roller 20. In the following description, the dimension of the substrate 1 in the direction of the rotation axis X is also referred to as the width of the substrate 1. The direction of the rotation axis X is also referred to as the width direction of the substrate 1.

[0101] As shown in FIG. 2, the pretreatment roller 20 may be provided so that a portion thereof is exposed on the substrate transfer chamber 12A side. In the example shown in FIG. 2, the plasma pretreatment chamber 12B and the substrate transfer chamber 12A are connected via an opening provided in the partition wall 35a, and a portion of the pretreatment roller 20 is exposed on the substrate transfer chamber 12A side through the opening. A gap is provided between the partition wall 35a between the substrate transfer chamber 12A and the plasma pretreatment chamber 12B and the pretreatment roller 20, and the substrate 1 can be transported from the substrate transfer chamber 12A to the plasma pretreatment chamber 12B through the gap. Although not shown, the pretreatment roller 20 may be provided so that its entirety is located within the plasma pretreatment chamber 12B.

[0102] Although not shown, the pretreatment roller 20 may have a temperature adjustment mechanism that adjusts the surface temperature of the pretreatment roller 20. For example, the pretreatment roller 20 may have a temperature adjustment mechanism inside the pretreatment roller 20 that includes piping for circulating a temperature adjustment medium such as a refrigerant or a heat medium. The temperature adjustment mechanism adjusts the surface temperature of the pretreatment roller 20 to a target temperature within a range of, for example, −20° C. or higher and 100° C. or lower.

[0103] By providing the pretreatment roller 20 with a temperature adjustment mechanism, shrinkage or damage to the substrate 1 due to heat during plasma pretreatment can be suppressed.

[0104] Pretreatment roller 20 is made of a material containing at least one of stainless steel, iron, copper, and chromium. The surface of pretreatment roller 20 may be treated with a hard chrome hard coat to prevent scratches. These materials are easy to process. Furthermore, using the above materials for pretreatment roller 20 increases the thermal conductivity of pretreatment roller 20 itself, making it easier to control the temperature of pretreatment roller 20.

[0105] The electrode unit 21 will now be described. In the example shown in FIGS. 2 and 3, the electrode unit 21 has a first surface 21c facing the pretreatment roller 20 and a second surface 21d located on the opposite side of the first surface 21c. In the example shown in FIGS. 2 and 3, the electrode unit 21 is a plate-shaped member, and both the first surface 21c and the second surface 21d are flat. The electrode unit 21 generates plasma between itself and the pretreatment roller 20 by applying an AC voltage between itself and the pretreatment roller 20. The electrode unit 21 preferably forms an electric field between itself and the pretreatment roller 20 such that the generated plasma moves perpendicularly to the surface of the substrate 1 toward the surface of the substrate 1. This enables efficient pretreatment of the substrate 1. Therefore, when a vapor-deposited film 2 is formed on the surface of the substrate 1 that has been subjected to plasma pretreatment, the peak intensity H1 of the peak of the element bond C—N formed at the interface between the substrate 1 and the vapor-deposited film 2 can be increased.

[0106] The number of electrode units 21 is preferably two or more. The two or more electrode units 21 are preferably arranged along the transport direction of the substrate 1. In the example shown in FIGS. 2 and 3, the film forming apparatus 10 has two electrode units 21. The number of electrode units 21 is, for example, 12 or less.

[0107] The effect of two or more electrode units 21 arranged along the transport direction of the substrate 1 will be described. As described above, plasma is generated between the electrode unit 21 and the pretreatment roller 20. The area in which plasma is generated expands as the dimension of the electrode unit 21 in the transport direction increases. On the other hand, if the electrode unit 21 is a flat, plate-shaped member, the larger the dimension of the electrode unit 21 in the transport direction, the greater the distance from the end of the first surface 21c of the electrode unit 21, which is the surface facing the pretreatment roller 20, to the pretreatment roller 20 in the transport direction, which reduces the processing ability of the plasma.

[0108] In the film forming apparatus 10, two or more electrode units 21 are arranged along the transport direction of the substrate 1. Therefore, even if the dimensions of the electrode units 21 in the transport direction of the substrate 1 are small, plasma can be generated over a wide range in the transport direction. Furthermore, by reducing the dimensions of the electrode units 21, the distance in the transport direction from the end of the first surface 21c of the electrode units 21 to the pretreatment roller 20 can be reduced, and plasma can be generated uniformly in the transport direction.

[0109] As shown in FIGS. 2 and 3 , the electrode unit 21 has a first end 21e and a second end 21f located on the first surface 21c of the electrode unit 21. The first end 21e is the upstream end in the transport direction of the substrate 1, and the second end 21f is the downstream end in the transport direction of the substrate 1. As described above, by reducing the dimension of the electrode unit 21 in the transport direction of the substrate 1, the distance from the first end 21e and the second end 21f of the electrode unit 21 to the pre-treatment roller 20 in the transport direction can be reduced. The dimension of the electrode unit 21 in the transport direction of the substrate 1 corresponds to the angle θ shown in FIG. 3 . The angle θ is the angle formed by a line passing through the first end 21e and the rotation axis X and a 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. By setting angle θ within the above range, plasma can be generated uniformly in the transport direction between electrode unit 21 and pretreatment roller 20 when first surface 21c of electrode unit 21 is flat.

[0110] There are no particular limitations on the material of the electrode portion 21 as long as it is conductive. Specifically, aluminum, copper, and stainless steel are preferably used as the material of the electrode portion 21.

[0111] The thickness L3 of electrode unit 21 when viewed in a direction perpendicular to first surface 21c of electrode unit 21 is not particularly limited, but is, for example, 15 mm or less. When electrode unit 21 has a thickness of the above value, magnetic field generating unit 23 can effectively generate a magnetic field between pretreatment roller 20 and electrode unit 21. Furthermore, thickness L3 of electrode unit 21 is, for example, 3 mm or more.

[0112] The magnetic field forming unit 23 will now be described. As shown in FIGS. 2 and 3, the magnetic field forming unit 23 is provided on the side of the electrode unit 21 opposite the side facing the pretreatment roller 20. The magnetic field forming unit 23 is a member that forms a magnetic field between the pretreatment roller 20 and the electrode unit 21. The magnetic field between the pretreatment roller 20 and the electrode unit 21 contributes to the generation of higher density plasma, for example, when plasma is generated using the plasma pretreatment mechanism 11B. The magnetic field forming unit 23 shown in FIGS. 2 and 3 has a first magnet 231 and a second magnet 232 provided on the second surface 21d of the electrode unit 21.

[0113] 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, each of the two or more magnetic field forming units 23 is preferably provided on the side of each of the two or more electrode units 21 opposite 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.

[0114] The structures of the first magnet 231 and the second magnet 232 in the normal direction to the second surface 21d of the electrode unit 21 will be described. As shown in FIGS. 2 and 3, the first magnet 231 and the second magnet 232 each have a north pole and a south pole. The symbol N shown in FIGS. 2 and 3 indicates the north pole of the first magnet 231 or the second magnet 232. The symbol S shown in FIGS. 2 and 3 indicates the south pole of the first magnet 231 or the second magnet 232. One of the north pole or south pole of the first magnet 231 is located closer to the substrate 1 than the other. The other of the north pole or south pole of the second magnet 232 is located closer to the substrate 1 than the other. In the example shown in FIGS. 2 and 3, the north pole of the first magnet 231 is located closer to the substrate 1 than the south pole of the first magnet 231, and the south pole of the second magnet 232 is located closer to the substrate 1 than the north pole of the second magnet. Although not shown, 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.

[0115] 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 unit 21 will be described. Fig. 4 is a plan view of the electrode unit 21 and the magnetic field generating unit 23 shown in Fig. 2, viewed from the magnetic field generating unit 23 side. Fig. 5 is a cross-sectional view showing a cross section taken along line VIII-VIII in Fig. 4. In Fig. 4, direction D1 is the direction in which the rotation axis X of the pre-treatment roller 20 extends.

[0116] 4 and 5, the first magnet 231 has a first axial portion 231c. As shown in Fig. 4, the first axial portion 231c extends along direction D1, i.e., along the rotation axis X of the pre-treatment roller 20. The first magnet 231 provided on one electrode unit 21 may have one first axial portion 231c, or may have two or more first axial portions 231c. In the example shown in Fig. 4, the first magnet 231 provided on one electrode unit 21 has one first axial portion 231c.

[0117] 4 and 5, the second magnet 232 has a second axial portion 232c. As shown in Fig. 4, the second axial portion 232c also extends along the direction D1, i.e., along the rotation axis X, similar to the first axial portion 231c.

[0118] Since both the first magnet 231 and the second magnet 232 include a portion extending along the rotation axis X, it is possible to increase the uniformity in the width direction of the substrate 1 of the strength of the magnetic field formed around the substrate 1. This makes it possible to increase the uniformity in the width direction of the substrate 1 of the distribution density of the plasma formed around the substrate 1.

[0119] The second magnet 232 provided on one electrode unit 21 may have one second axial portion 232c or two or more second axial portions 232c. In the example shown in Figures 4 and 5, the second magnet 232 provided on one electrode unit 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 direction D2, which is perpendicular to the rotation axis X in the planar direction of the second surface 21d of the electrode unit 21.

[0120] 5, the dimension L4 of the first axial portion 231c and the dimension L5 of the second axial portion 232c in the transport direction of the substrate 1 are not particularly limited. Furthermore, the ratio between the dimension L4 of the first axial portion 231c and the dimension L5 of the second axial portion 232c in the transport direction of the substrate 1 is not particularly limited. The dimension L4 of the first axial portion 231c and the dimension L5 of the second axial portion 232c may be equal, or the dimension L4 of the first axial portion 231c may be larger than the dimension L5 of the second axial portion 232c.

[0121] The distance L6 between the first axial portion 231c and the second axial portion 232c in the direction D2 is set so that a magnetic field generated by the first axial portion 231c and the second axial portion 232c is formed between the pre-treatment roller 20 and the electrode portion 21.

[0122] The second magnet 232 may surround the first magnet 231 when the magnetic field generating unit 23 is viewed along the normal direction of the second surface 21d of the electrode unit 21. For example, as shown in Fig. 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.

[0123] Examples of the types of magnets used as the magnetic field generating unit 23, such as the first magnet 231 and the second magnet 232, include permanent magnets such as ferrite magnets and rare earth magnets such as neodymium and samarium cobalt (samarium-cobalt). Alternatively, an electromagnet can be used as the magnetic field generating unit 23.

[0124] The magnetic flux density of the magnets of the magnetic field generating unit 23, such as the first magnet 231 and the second magnet 232, is, for example, 100 Gauss or more and 10,000 Gauss or less. If the magnetic flux density is 100 Gauss or more, a sufficiently strong magnetic field is formed between the pretreatment roller 20 and the electrode unit 21, thereby generating a sufficiently high-density plasma and forming a good pretreatment 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, an expensive magnet or magnetic field generating mechanism is required.

[0125] Although not shown, the plasma pretreatment mechanism 11B may have a plasma raw material gas supply unit. The plasma raw material gas supply unit supplies a plasma raw material gas 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 of the plasma pretreatment chamber 12B and include a hole for ejecting the plasma raw material gas. The plasma raw material gas supply unit may also have a nozzle for ejecting the plasma raw material gas at a position closer to the substrate 1 than the wall 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. The plasma raw material gas may be a single inert gas, a single active gas, or a mixture of two or more gases contained in the inert gas or active gas. A mixture of an inert gas such as argon and an active gas is preferably used as the plasma raw material gas. As an example, the plasma raw material gas supply unit supplies a mixed gas of argon (Ar) and oxygen (O2).

[0126] The plasma pretreatment mechanism 11B is configured to, for example, produce a plasma with a plasma density of 100 W·sec / m 2 More than 8000W sec / m 2 The following plasma is supplied between the pretreatment roller 20 and the electrode unit 21.

[0127] In the example shown in FIG. 2, the plasma pretreatment mechanism 11B includes a substrate transfer chamber 12A and a film formation chamber 11B. The plasma pre-treatment chamber 12B is separated from the plasma pre-treatment chamber 2C by a partition wall. By separating the pre-treatment chamber 12B from other areas such as the substrate transfer chamber 12A and the film formation chamber 12C, This makes it easier to independently adjust the atmosphere in the plasma pre-treatment chamber 12B. Control of plasma raw material gas concentration in the space where the pretreatment roller 20 and the electrode unit 21 face each other This facilitates the production of laminated films, thereby improving productivity.

[0128] In this embodiment, the voltage applied between pretreatment roller 20 and electrode unit 21 of plasma pretreatment mechanism 11B is an AC voltage. The application of the AC voltage generates plasma between pretreatment roller 20 and electrode unit 21. Preferably, the application of the AC voltage creates an electric field such that the generated plasma moves toward the surface of substrate 1 in a direction perpendicular to the surface of substrate 1.

[0129] The value of the AC voltage applied between pretreatment roller 20 and electrode unit 21 is preferably 250 V or more and 1000 V or less. When the AC voltage has the above value, plasma with sufficient plasma density can be generated between pretreatment roller 20 and electrode unit 21. Here, the value of the AC voltage refers to the effective value Ve. The effective value Ve of the AC voltage can be calculated by the following equation (2) when the maximum value of the AC voltage is Vm.

[0130]

number

[0131] The AC voltage applied between the pretreatment roller 20 and the electrode unit 21 has a frequency of, for example, 20 kHz or more and 500 kHz or less.

[0132] (Film forming mechanism) Next, the film formation mechanism 11C will be described. In the example shown in Fig. 2, the film formation mechanism 11C has a film formation roller 25 and an evaporation mechanism 24 disposed in a film formation chamber 12C.

[0133] The film-forming roller 25 will be described below. The film-forming roller 25 is a roller that wraps around and transports the substrate 1 with the treated surface of the substrate 1, which has been pretreated in the plasma pretreatment mechanism 11B, facing outward.

[0134] The material of the film-forming roller 25 will now be described. The film-forming roller 25 is preferably formed 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 chrome hard coat to prevent scratches. These materials are easy to process. Furthermore, by using the above materials for the film-forming roller 25, the thermal conductivity of the film-forming roller 25 itself is increased, resulting in excellent temperature controllability. 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.

[0135] Although not shown, the film-forming roller 25 may also have a temperature adjustment mechanism for adjusting the surface temperature of the film-forming roller 25. The temperature adjustment mechanism may have, for example, a circulation path for circulating a cooling medium or a heat source medium inside the film-forming roller 25. The cooling medium (refrigerant) may be, for example, an ethylene glycol aqueous solution, and the heat source medium (heat medium) may be, for example, silicone oil. The temperature adjustment mechanism may also have a heater installed in a position facing the film-forming roller 25. When the film-forming mechanism 11C forms a film by vapor deposition, the temperature adjustment mechanism preferably adjusts the surface temperature of the film-forming roller 25 to a target temperature within a range of −20°C to 200°C, in consideration of the heat resistance constraints of related mechanical components and versatility. By including a temperature adjustment mechanism in the film-forming roller 25, fluctuations in the temperature of the substrate 1 due to heat generated during film formation can be suppressed.

[0136] The evaporation mechanism 24 will now be described. FIG. 6 is an enlarged view of the area enclosed by the dashed line designated by the symbol IX in FIG. 2, showing a specific configuration of the evaporation mechanism 24 (omitted in FIG. 5) and a diagram showing the evaporation material supply unit 61 (omitted in FIG. 2) for supplying the evaporation material. Note that the decompression chamber 12 and partition walls 35b and 35c are omitted from FIG. 6. The evaporation mechanism 24 evaporates the evaporation material containing aluminum. The evaporated evaporation material adheres to the substrate 1, thereby forming an aluminum-containing evaporation film on the surface of the substrate 1. The evaporation mechanism 24 in this embodiment employs a resistance heating system. In the example shown in FIG. 6, the evaporation mechanism 24 includes a boat 24b. In this embodiment, the boat 24b includes a power supply (not shown) and a resistor (not shown) electrically connected to the power supply. A plurality of boats 24b may be arranged in the width direction of the substrate 1.

[0137] 6, the film forming mechanism 11C may have a vapor deposition material supply unit 61 that supplies a vapor deposition material to the evaporation mechanism 24. In FIG. 6, an example is shown in which the vapor deposition material supply unit 61 continuously feeds out an aluminum metal wire.

[0138] Although not shown, the film formation mechanism 11C has a gas supply mechanism. The gas supply mechanism is a mechanism that supplies gas between the evaporation mechanism 24 and the film formation roller 25. The gas supply mechanism supplies at least oxygen gas. The oxygen gas reacts with or bonds with an evaporation material such as aluminum that evaporates from the evaporation mechanism 24 and heads toward the substrate 1 on the film formation roller 25. This allows a vapor deposition film containing aluminum oxide to be formed on the surface of the substrate 1.

[0139] The film formation mechanism 11C also includes 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 FIGS. 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 hollow portion that is partially open. The hollow cathode 51 can generate plasma within the hollow portion. In the example shown in FIG. 6, the hollow cathode 51 is disposed so that the opening of the hollow portion of the hollow cathode 51 is positioned diagonally above the boat 24b. Although not shown, the plasma supply mechanism 50 according to this embodiment also includes an anode facing the opening, which extracts plasma from the opening of the hollow cathode 51. The plasma supply mechanism 50 according to this embodiment generates plasma within the hollow portion of the hollow cathode 51 and extracts the plasma between the surface of the substrate 1 and the evaporation mechanism 24 using the opposing anode, thereby generating a strong plasma between the surface of the substrate 1 and the evaporation mechanism 24. The position of the opposing anodes is not particularly limited as long as the opposing anodes can extract 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 opposing anodes are disposed on both sides of the boat 24b in the width direction of the substrate 1. In this case, the film formation mechanism 11C may have multiple boats 24b and multiple opposing anodes, and the multiple boats 24b and the multiple 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 a plasma raw material gas at least into the cavity of the hollow cathode 51. The plasma raw material gas supplied by the raw material supply device may be the same as 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.

[0140] By using the plasma supply mechanism 50 to supply plasma between the surface of the substrate 1 and the evaporation mechanism 24, plasma assist during deposition can be performed, activating the aluminum and oxygen gas evaporated in the evaporation mechanism 24 and promoting the reaction or bonding between the aluminum and oxygen gas. This can increase the proportion of aluminum present as aluminum oxide in the evaporated film 2 formed on the surface of the substrate 1, and stabilize the properties of the evaporated film 2.

[0141] Although not shown, the film formation apparatus 10 may include a substrate charge removal unit in the substrate transport chamber 12A, located downstream of the film formation chamber 12C in the transport direction of the substrate 1. The substrate charge removal unit performs post-processing to remove charge generated on the substrate 1 due to film formation by the film formation mechanism 11C. The substrate charge removal unit may be provided to remove charge from one side of the substrate 1, or may be provided to remove charge from both sides of the substrate 1.

[0142] The device used as the substrate charge removal section for post-treating the substrate 1 is not particularly limited, but examples that can be used include a plasma discharge device, an electron beam irradiation device, an ultraviolet irradiation device, a static elimination bar, a glow discharge device, and a corona treatment device.

[0143] When post-treatment is performed by generating a discharge using a plasma treatment device or a glow discharge device, a discharge gas such as argon, oxygen, nitrogen, or helium, or a mixture of these gases, is supplied near the substrate 1, and post-treatment can be performed 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-treatment using a plasma discharge device.

[0144] The substrate charge removal unit is installed in a portion of the substrate transport chamber 12A that is located downstream of the film-forming chamber 12C in the transport direction of the substrate 1, and by removing the charge from the substrate 1, the substrate 1 can be transported by quickly separating it from the film-forming roller 25 at a predetermined position. This enables stable substrate transport, prevents damage to the substrate 1 or deterioration in quality due to charging, and improves post-processing suitability by improving the wettability of the front and back surfaces of the substrate.

[0145] (power supply) In the example shown in FIG. 2, the film forming apparatus 10 further includes a power supply 32 electrically connected to the pretreatment roller 20 and the electrode unit 21. In the example shown in FIG. 5, the power supply 32 is electrically connected to the pretreatment roller 20 and the electrode unit 21 via 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, the power supply 32 can apply an AC voltage having a frequency of, for example, 20 kHz to 500 kHz between the pretreatment roller 20 and the electrode unit 21. The input power that can be applied by the power supply 32 (the power that can be applied per meter of width of the electrode unit 21 in the width direction of the substrate 1) is not particularly limited, but is, for example, 0.5 kW / m to 20 kW / m. The pretreatment roller 20 may be installed at an electrically earth level or at an electrically floating level.

[0146] (Barrier film manufacturing method) Next, a method for producing the barrier film shown in FIG. 1 using the above-described film formation apparatus 10 will be described. First, a film formation method for forming a vapor-deposited film 2 on the surface of a substrate 1 will be described. In film formation using the film formation apparatus 10, a plasma pretreatment step is performed in which plasma pretreatment is performed on the surface of the substrate 1 using a plasma pretreatment mechanism 11B, and a film formation step is performed in which a vapor-deposited film is formed on the surface of the substrate 1 using a film formation mechanism 11C, while the substrate 1 is transported along the above-described transport path of the substrate 1. 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.

[0147] (Plasma pretreatment process) The plasma pretreatment step is performed, for example, by the following method. First, a 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 unit 21. When applying the AC voltage, input power control or impedance control may be performed.

[0148] The plasma raw material gas supplied in the pretreatment is oxygen alone or a mixture of oxygen gas and an inert gas, which is supplied from a gas reservoir through a flow controller while the flow rate is measured. The inert gas may be one or a mixture of two or more gases selected from the group consisting of argon, helium, and nitrogen.

[0149] In the plasma treatment, the mixing ratio of oxygen gas to the inert gas, that is, oxygen gas / inert gas, is preferably 6 / 1 to 1 / 1, and more preferably 5 / 2 to 3 / 2.5.

[0150] By setting the mixing ratio to 6 / 1 to 1 / 1, the energy required to form the evaporated aluminum film on the resin substrate increases, and by setting it to 5 / 2 to 3 / 2, the degree of oxidation of the evaporated aluminum oxide film is increased, ensuring adhesion between the evaporated aluminum oxide film and the substrate.

[0151] Application of AC voltage generates plasma simultaneously with glow discharge, and plasma P becomes denser between pretreatment roller 20 and magnetic field forming unit 23. In this way, plasma P can be supplied between pretreatment roller 20 and magnetic field forming unit 23. This plasma P can be used to perform plasma (ion) pretreatment on the surface of substrate 1.

[0152] Plasma intensity per unit area in plasma processing: 50 W·sec / m 2 More than 8000W sec / m 2 less than 50 W·sec / m 2 Below this, the effect of plasma pretreatment is not observed, and 2Above this level, the resin substrate tends to deteriorate due to the plasma, such as wear, damage, discoloration, and burning. In particular, the plasma intensity for plasma pretreatment to form an aluminum oxide layer should be 100 W·sec / m 2 More than 1000W sec / m 2 The following is preferred:

[0153] The pressure inside plasma pretreatment chamber 12B when an AC voltage is applied between pretreatment roller 20 and electrode unit 21 is reduced to below atmospheric pressure by decompression chamber 12. In this case, the pressure inside plasma pretreatment chamber 12B is adjusted, for example, so that glow discharge can be generated between pretreatment roller 20 and electrode unit 21 by applying an AC voltage. The degree of vacuum inside plasma pretreatment chamber 12B when an AC voltage is applied between pretreatment roller 20 and electrode unit 21 can be set and maintained at approximately 0.1 Pa or more and 100 Pa or less, and particularly preferably 1 Pa or more and 20 Pa or less.

[0154] The function of the magnetic field generating unit 23 in the plasma pretreatment step will now be described. The magnetic field generating unit 23 generates a magnetic field between the pretreatment roller 20 and the electrode unit 21. The magnetic field can act to capture and accelerate electrons present between the pretreatment roller 20 and the electrode unit 21. This increases the frequency of collisions between the electrons and the plasma raw material gas in the region where the magnetic field is generated, thereby increasing and localizing the plasma density, thereby improving the efficiency of the plasma pretreatment.

[0155] (Film forming process) In the film formation step, a film is formed using film formation mechanism 11C on the surface of substrate 1. As an example of the film formation step, a case will be described in which an aluminum oxide vapor deposition film is formed using film formation mechanism 11C having evaporation mechanism 24 shown in FIG.

[0156] First, a vapor deposition material containing aluminum is supplied into the boat 24b of the evaporation mechanism 24 so as to face the deposition roller 25. An aluminum metal wire can be used as the vapor deposition material. In the example shown in FIG. 6, the vapor deposition material is supplied to the boat 24b by continuously feeding the aluminum metal wire into the boat 24b using a vapor deposition material supply unit 61.

[0157] The aluminum is evaporated in the boat 24b by heating. For convenience, FIG. 6 shows the evaporated aluminum vapor 63. The oxygen gas that oxidizes the aluminum can be supplied either as a single gas or as a mixture with an inert gas such as argon. By controlling the amount of oxygen, both barrier properties and transparency can be achieved. The degree of vacuum at this time is preferably 0.05 Pa or more and 8.00 Pa or less.

[0158] Next, 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. In this embodiment, plasma is generated within 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 opposing anode, and the plasma within the cavity of the hollow cathode 51 is drawn between the surface of the substrate 1 and the evaporation mechanism 24.

[0159] In this embodiment, the discharge generated between hollow cathode 51 and the opposing anode is an arc discharge. The arc discharge means a discharge with a current value of 10 A or more, for example.

[0160] By evaporating aluminum while supplying plasma between the surface of the substrate 1 and the evaporation mechanism 24, the 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 deposition film on the surface of the substrate 1, and the barrier film shown in FIG. 1 can be produced.

[0161] The plasma raw material gas supplied by the plasma supply mechanism 50 is preferably oxygen alone or a mixed gas of oxygen gas and an inert gas.

[0162] In this embodiment, a plasma pretreatment step is performed before the film formation step, in which plasma is supplied to the surface of the substrate 1. In the plasma pretreatment step, an AC voltage is applied between the electrode unit 21 and the pretreatment roller 20. A magnetic field is generated in the space between the electrode unit 21 and the pretreatment roller 20 using the magnetic field generating unit 23 located on the surface of the electrode unit 21 opposite the surface facing the pretreatment roller 20. This allows plasma to be efficiently generated in the space between the electrode unit 21 and the pretreatment roller 20, and the plasma can be made to perpendicularly enter the surface of the substrate 1 wrapped around the pretreatment roller 20. This improves adhesion between the film formed in the film formation step and the substrate 1.

[0163] (Laminate) An example of a laminate formed using the barrier film according to this embodiment will be described. FIG. 7 is a diagram showing an example of a laminate 40 formed using the barrier film according to this embodiment. The laminate 40 comprises the barrier film shown in FIG. 1 and a sealant layer 7. Specifically, the laminate 40 further comprises, on the vapor-deposited film of the barrier film shown in FIG. 1, an adhesive layer 4, a second substrate 5 made of polyamide or the like, an adhesive layer 6, and a sealant layer 7, in this order. The laminate of the present invention is formed by laminating at least one heat-sealable layer on a barrier film, and a heat-sealable thermoplastic resin is laminated as the innermost layer, with or without an adhesive layer interposed therebetween, to impart sealability such as heat sealing.

[0164] Examples of thermoplastic resins constituting the sealant layer 7 include films containing one or more of low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, polymethylpentene, polystyrene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, elastomer, etc. The thickness of the sealant layer 7 is preferably 3 to 100 μm, and more preferably 15 to 70 μm.

[0165] (packaging material) The above laminate is useful when used as a packaging material for producing a packaging bag for containing contents such as food. In particular, a barrier film that maintains high adhesion even when subjected to heat treatment is suitable for use as a material for packaging bags. When a packaging product is produced using the barrier film as a material, the above barrier film can suppress peeling of the layers that make up the barrier film in the packaging product. For example, when a packaging bag produced using the barrier film as a material is subjected to a heat sterilization treatment using hot water, such as a retort treatment or a boiling treatment, peeling of the layers that make up the barrier film, particularly peeling of the vapor-deposited film 2 from the substrate 1, can be suppressed.

[0166] Retort processing is a process in which the contents are filled into a packaging bag, the packaging bag is sealed, and then the packaging bag is heated under pressure using steam or heated hot water. The temperature for retort processing is, for example, 120°C or higher. Boiling processing is a process in which the contents are filled into a packaging bag, the packaging bag is sealed, and then the packaging bag is heated in a water bath under atmospheric pressure. The temperature for boiling processing is, for example, 90°C or higher and 100°C or lower. [Example]

[0167] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these descriptions in any way. First, barrier films according to Examples 1 to 3 and Comparative Examples 1 to 3 were produced using the film formation apparatus and film formation method described in this embodiment. Pretreatment conditions, deposition conditions, etc. are summarized in Table 1. In Table 1, "Good" in the "with or without plasma pretreatment" category indicates that plasma pretreatment was performed, and "Poor" indicates that plasma pretreatment was not performed. In addition, in the "with or without plasma assistance during deposition" category, "Good" indicates that plasma assistance was performed during deposition, and "Poor" indicates that plasma assistance was not performed during deposition.

[0168] Example 1 A biaxially stretched polyethylene terephthalate film (PET film) having a thickness of 12 μm was used as the substrate 1, and a plasma pretreatment step and a film formation step were carried out using the film formation apparatus 10 shown in FIG.

[0169] In the pretreatment step, 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, a mixed gas of oxygen (O2) and argon (Ar) (O2:Ar = 2.5:1) was supplied to the plasma pretreatment chamber 12B using the plasma raw material gas supply unit, while the pressure inside the plasma pretreatment chamber 12B was adjusted using the decompression 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 pressure inside the plasma pretreatment chamber 12B was 6.2 Pa, and a 1000 gauss permanent magnet was used as the magnetic field generating unit 23. The plasma density was 417 W·sec / m 2 It was.

[0170] In the film formation process, an evaporation mechanism 24 as shown in FIG. 6 is used to evaporate an acid by vacuum evaporation. Specifically, the degree of vacuum in the film formation chamber 12C was adjusted to 1.5 Pa, and then aluminum metal wires were supplied as the deposition material into the boat 24b. The deposition material in the boat 24b was heated using the resistance heating evaporation mechanism 24, and the aluminum was evaporated so as to reach the surface of the substrate 1. At the same time, oxygen was supplied at 12,500 sccm, and the deposition film 2 was formed on the surface of the substrate 1.

[0171] In addition, the plasma supply mechanism 50 used had a hollow cathode 51 shown in FIG. 6 and anodes (not shown) arranged on both sides of the substrate 1 in the width direction as viewed from the boat 24b, facing the opening of the hollow cathode 51. A plasma raw material gas (O2:Ar=35:1) was supplied to the hollow cathode 51, and discharge was caused to excite plasma. This plasma was then extracted by the opposing anodes to between the surface of the substrate 1 and the evaporation mechanism 24, thereby providing plasma assistance during deposition.

[0172] By the above method, a barrier film having the substrate 1 and the vapor-deposited film 2 shown in Fig. 1 was produced at a conveying speed of 600 m / min. The thickness of the vapor-deposited film 2 of the produced barrier film was 8 nm.

[0173] Example 2 A barrier film of Example 2 was produced in the same manner as in Example 1, except that the conveying speed was 480 m / min and the thickness of the vapor-deposited film 2 was 13 nm.

[0174] Example 3 A barrier film of Example 3 was produced in the same manner as in Example 2, except that the plasma pretreatment in Example 2 was not carried out.

[0175] Example 4 A barrier film of Example 4, which was not subjected to plasma pretreatment, was produced in the same manner as in Example 3, except that a film-forming apparatus different from those used in Examples 1 to 3 was used and the production conditions were changed to those in Table 1.

[0176] Example 5 A barrier film of Example 5, which had been subjected to plasma pretreatment, was produced in the same manner as in Example 1, except that a film-forming apparatus different from that used in Examples 1 to 3 was used and the production conditions were changed to those in Table 1.

[0177] (Comparative Example 1) As shown in Table 1, the barrier film of Comparative Example 1 was produced in the same manner as in Example 1, except that no plasma pretreatment was performed, an EB (electron beam) type evaporation mechanism (not shown) was used instead of the resistance heating type evaporation mechanism 24, no plasma-assisted treatment was performed during deposition, the oxygen supply amount was set to 8500 sccm, and the degree of vacuum during deposition was set to 0.15 Pa.

[0178] (Comparative Example 2) As shown in Table 1, the barrier film of Comparative Example 2 was produced in the same manner as in Example 1, except that the degree of vacuum in the plasma pretreatment chamber 12B was set to 3.5 Pa, plasma-assisted treatment was not performed during deposition, the oxygen supply amount was 10,000 sccm, and the degree of vacuum during deposition was 0.02 Pa.

[0179] (Comparative Example 3) As shown in Table 1, the barrier film of Comparative Example 3 was produced in the same manner as in Comparative Example 2, except that the conveying speed was 480 m / min and the thickness of the vapor-deposited film 2 was 13 nm.

[0180] [Table 1]

[0181] [TOF-SIMS analysis] For the barrier films of Examples 1 to 5 and Comparative Examples 1 and 2, mass analysis was performed using a time-of-flight secondary ion mass spectrometer (TOF.SIMS5, manufactured by ION TOF) under the following measurement conditions: soft etching was performed repeatedly at a constant rate from the vapor-deposited surface side of the barrier film using a Cs (cesium) ion gun. Mass analysis was performed on C6 (mass number 72.00) derived from the resin substrate, Al2O3 (mass number 101.94) derived from the vapor-deposited aluminum oxide film, and Al2O4H (mass number 118.93) derived from the vapor-deposited aluminum oxide film. Graphical analyses of the measurement results are shown in Figures 8 to 14. Figure 8 shows the measurement results for Example 1, Figure 9 shows the measurement results for Example 2, Figure 10 shows the measurement results for Example 3, Figure 11 shows the measurement results for Example 4, Figure 12 shows the measurement results for Example 5, Figure 13 shows the measurement results for Comparative Example 1, and Figure 14 shows the measurement results for Comparative Example 2. In the figure, the unit of the vertical axis (intensity) is the common logarithm of the ion intensity, and the unit of the horizontal axis (Et times (s)) is the number of seconds during which etching was performed.

[0182] TOF-SIMS measurement conditions Primary ion type: Bi 3++ (0.2pA, 100μs) ·Measurement area: 150×150μm 2 Etching gun type: Cs (1 keV, 60 nA) Etching area: 600 x 600 μm 2 Etching rate: 10sec / cycle

[0183] The position where the strength of C6, a constituent material of the plastic substrate, is half of its maximum strength (C6 half-life 1 / 2C6 (shown as C6 half-life (X) in the table)) was defined as the interface between the film substrate and the aluminum oxide vapor-deposited film. The aluminum oxide vapor-deposited film spanned from the vapor-deposited film surface (position before etching) to this interface, and the position 1 / 3 of the way down from the vapor-deposited film surface in the total vapor-deposited film thickness was determined. The ratio of the strength of the elemental bond Al2O4H to the strength of the elemental bond Al2O3 (Al2O4H / Al2O3) at this position 1 / 3 of the way down from the vapor-deposited film surface was then calculated.

[0184] The position representing the intensity peak of the measured elemental bond Al2O4H (mass number 118.93) was determined in terms of etching seconds (peak position Y), and the depth position from the surface of the deposited film at that position (peak position Y / X, unit: %) and the ratio of the elemental bond Al2O4H intensity to the elemental bond Al2O3 intensity at that position (Al2O4H / Al2O3) were calculated. These results are summarized in Table 2.

[0185] [Table 2]

[0186] [FT-IR analysis] The barrier films of Examples 1 to 3 and Comparative Example 1 were measured by reflection ATR from the vapor-deposited film surface side of the barrier film using an FT-IR (FT-610, manufactured by JASCO Corporation) under the following measurement conditions, and the difference spectrum with the FT-IR of the substrate alone was obtained. The measurement results are shown in Figures 13 and 14 and Table 3.

[0187] FT-IR measurement conditions Supply gas: Nitrogen purge with nitrogen gas ATR crystal: Germanium (Ge) (wavenumber range 5500-600 cm -1 , penetration depth 0.7μm) ·Resolution: 4cm -1 ·Incidence angle: 45 degrees ·Measurement temperature: room temperature Number of times accumulated: 128 Measurement method for PET substrate for difference calculation (measurement on the back side in the stretching direction, 1410 cm -1 (Measure the difference so that the peak of

[0188] [Table 3]

[0189] (Barrier property evaluation) The water vapor permeability and oxygen permeability of each of the barrier films of Examples 1 to 5 and Comparative Examples 1 to 3 produced by the above-mentioned method were measured.

[0190] The water vapor transmission rate was measured using a water vapor transmission rate measuring device (manufactured by Mocon, product name "Permatran") at 40°C and 100% RH in accordance with JIS K 7129 Method B. The oxygen transmission rate was measured using an oxygen transmission rate measuring device (manufactured by Mocon, product name "OXTRAN") at 23°C and 90% RH in accordance with JIS K 7126-2. The results are shown in Table 4.

[0191] (Evaluation of Adhesion) Vapor-deposited barrier films of Examples 1 to 5 and Comparative Examples 1 to 3 produced by the above method A two-component curing polyurethane laminating adhesive was applied to the surface of the laminate (2) to a thickness of 4.0 g / m using the gravure roll coating method. 2 (in a dry state) to form an adhesive layer 4, and then a 15 μm-thick biaxially oriented nylon 6 film was placed facing the surface of adhesive layer 4 as a second substrate 5 and dry-laminated to form a laminate. Next, an adhesive layer 6 for lamination was formed on the surface of second substrate 5 in the same manner as for adhesive layer 4, and then a 70 μm-thick unstretched polypropylene film was dry-laminated to form a sealant layer 7 on the surface of adhesive layer 6 to produce a laminate having the layer structure shown in FIG.

[0192] Next, the laminates with this layer structure were placed so that the sealant layers faced each other and heat-sealed to form pouches. The pouches were filled with water and then retorted at 135°C for 40 minutes. The water peel strength of each laminate after retort treatment was measured. The results are summarized in Table 4.

[0193] The water peel strength was measured using the following method. First, each laminate after retort treatment was cut into strips to obtain rectangular test pieces with a width of 15 mm. Next, the vapor-deposited film of each test piece was partially peeled away from the substrate in the longitudinal direction of the test piece (the direction perpendicular to the width direction of the test piece). The vapor-deposited film and the substrate were peeled away so that they remained partially bonded. Next, using a Tensilon universal testing machine in accordance with JIS Z6854-2, the peel strength of the interface between the vapor-deposited film and the substrate was measured at a peel angle of 180° and a peel rate of 50 mm / min. In measuring the water peel strength, water was dropped with a dropper onto the boundary between the part where the vapor-deposited film and the substrate remained bonded and the part where the vapor-deposited film and the substrate were peeled away along the longitudinal direction of the test piece. The tensile force required to cause the peel to proceed over a 30 mm distance was measured, and the average tensile force was calculated. For each of Examples 1 to 5 and Comparative Examples 1 to 3, the average tensile strength was calculated for each of the five test pieces, and the average value was defined as the water-wet peel strength (adhesion) for each of Examples 1 to 5 and Comparative Examples 1 to 3. The results are shown in Table 4.

[0194] [Table 4]

[0195] As can be seen from Tables 2 and 4, in Examples 1 to 3 where the ratio of the elemental bond Al2O4H intensity to the elemental bond Al2O3 intensity (Al2O4H / Al2O3) measured by TOF-SIMS at a position one-third of the way from the surface of the deposited film is within the range of the present invention, the film has higher barrier properties than Comparative Examples 1 to 3.

[0196] Furthermore, as can be seen from Tables 2 and 4, Examples 1 to 5, which have a maximum peak in intensity derived from the element bond Al2O4H at a depth of 55% to 95% from the surface of the vapor-deposited film as measured by TOF-SIMS, have higher barrier properties than Comparative Examples 1 to 3.

[0197] In addition, from Tables 3 and 4, the 940 cm peak due to the Al-O bond was observed by FT-IR. -1 More than 960cm -1 There is an absorption peak at 940 cm due to the Al-O bond. -1 More than 960cm -1 The absorption intensity of the following peaks at 3350 cm originating from the OH bond -1 More than 3550cm -1 In Examples 1 to 3, in which the ratio of the absorption intensities of the following absorption peaks is within the range of the present invention, higher barrier properties are obtained compared to Comparative Example 1. [Explanation of symbols]

[0198] 1 Base material 2. Vapor-deposited film 4 Adhesive layer 5 Second base material 6 Adhesive layer 7 Sealant Layer 10 Film deposition equipment P plasma X rotation axis 11A Substrate transport mechanism 11B Plasma pretreatment mechanism 11C Film formation mechanism 12 Decompression Chamber 12A Substrate transport chamber 12B Plasma pretreatment chamber 12C Deposition chamber 13 Unwinding roller 14a~d Guide roll 15 Winding roller 20 Pre-treatment roller 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 Coating roller 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 comprising a substrate and an aluminum oxide vapor-deposited film laminated in this order, The aluminum oxide vapor deposition film was etched from the vapor deposition film surface side of the barrier film by time-of-flight secondary ion mass spectrometry (TOF-SIMS). ２ O ３ and element bond Al ２ O ４ Intensity derived from H was detected, The element bond Al detected at a depth position of 1 / 3 from the surface of the aluminum oxide vapor-deposited film in the film thickness direction ２ O ３ Elemental bonding to Al ２ O ４ H intensity ratio (Al ２ O ４ H / Al ２ O ３ ) is 0.30 or less, The element bond Al ２ O ４ A barrier film, wherein the intensity derived from H has a maximum peak, and the maximum peak is present at a depth position of 55% to 95% from the surface of the vapor-deposited film.

2. The aluminum oxide vapor-deposited film has an infrared absorption spectrum from the vapor-deposited film surface side of the barrier film, 940 cm due to Al-O bond －１ 960cm or more －１ 2. The barrier film of claim 1, having an absorption peak at:

3. The 940 cm attributed to the Al—O bond －１ 960cm or more －１ The absorption intensity of the following absorption peaks at 3350 cm originating from OH bonds －１ More than 3550cm －１ 3. The barrier film of claim 2, wherein the ratio of the absorption intensities of the following absorption peaks is 0.20 or less:

4. A laminate comprising the barrier film according to claim 1 and a sealant layer.

5. A packaging product comprising the laminate of claim 4.

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