JP2022189878A - packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package which allows rust of a metal product packaged in a packaging bag to be prevented without adopting a multilayer structure as in the prior art.

SOLUTION: In a package in which a metal product producing rust by oxidation is hermetically packaged into a packaging bag 6, the packaging bag 6 is formed of a laminated film 1a obtained by at least laminating a barrier film 1 and a sealant layer 5. The periphery of the opposed sealant layers 5 of the laminated film 1a is hermetically joined. The barrier film 1 is formed by laminating a base material layer 2, an aluminum oxide vapor deposition layer 3, and an organic coating layer 4 in this order. The aluminum oxide vapor deposition layer 3 has an element-bonded structure part represented by an Al₂O₃ ^- structure part and an Al₃ ^- structure part. The barrier film 1 has a maximum intensity ratio (Al₃ ^-/Al₂O₃ ^-×100) measured by a time-of-flight secondary ion mass spectrometry from an organic coating layer 4 side is in the range of 1 or more to 20 or less.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates mainly to a packaging bag for packaging metal products.

Packaging bags for packaging metal products have been developed for the purpose of transporting metal products. Such packaging bags stably demonstrate higher barrier properties that are not affected by temperature, humidity, etc., in order to prevent deterioration of the metal products contained in them and maintain their functions and properties. required to obtain.

For example, Patent Document 1 describes a technology related to a packaging bag or the like formed by mixing a predetermined rust preventive composition into a thermoplastic resin. According to Patent Document 1, this packaging bag is , can prevent the occurrence of rust for a long period of time.

Further, in Patent Document 2, a substrate made of a thermoplastic resin, a first vapor deposition thin film layer provided on the substrate, and a first vapor deposition thin film layer provided on the first vapor deposition thin film layer containing at least a water-soluble polymer A laminate comprising a gas-barrier intermediate layer formed by applying a coating agent and a second vapor-deposited thin film layer provided on the intermediate layer, and between the substrate and the first vapor-deposited thin film layer A gas barrier laminate having a primer layer comprising a polyol, an isocyanate compound and a silane coupling agent is disclosed.

Patent Document 3 discloses a barrier laminate film in which an aluminum oxide vapor deposition film is formed on the surface of a PET film, and a barrier coating layer is laminated on the vapor deposition film. However, the invention relates to a plasma pretreatment apparatus, does not specify the amount of oxygen during vapor deposition, and does not disclose compatibility between high barrier properties and moderate transparency.

Japanese Patent Application Laid-Open No. 2007-308726 WO2002/083408 WO2013/100073

The packaging bag of Patent Literature 1 cannot be said to have sufficient barrier properties because the barrier properties are imparted by mixing the rust preventive composition into the thermoplastic resin.

In addition, the multi-layered barrier laminate film of Patent Document 2 requires many steps as a manufacturing method. For this reason, not only is the cost of raw materials and equipment operating costs increased, but complex work such as checking the quality of each layer, correcting quality control based on the results, and managing history is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a packaging body that has high barrier properties and transparency and that can prevent metal products from rusting without adopting a multi-layered structure as in the prior art.

The present inventors have made intensive studies to solve the above problems, and as a result ^, the ratio of the maximum strength of the Al ₃ structure ^to the strength of the Al ₂ O ₃ -structure included in the aluminum oxide vapor deposition layer of the barrier film By controlling the Al ₃ ⁻ maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100), the present inventors have found that high barrier properties and transparency can be achieved at the same time, and have completed the present invention.

(1) A package in which a metal product that rusts due to oxidation is hermetically packaged in a packaging bag, wherein the packaging bag is composed of a laminated film in which at least a barrier film and a sealant layer are laminated, and the laminated film The peripheries of the sealant layers facing each other are hermetically bonded, and the barrier film includes a substrate layer, an aluminum oxide deposition layer, and an organic coating layer laminated in this order, and the organic coating layer is , a metal alkoxide, and a hydroxyl group-containing water-soluble resin, and the vapor-deposited aluminum oxide layer contains an element represented by an Al ₂ O ₃ -structure portion ^and an Al ₃ ^-structure portion. The barrier film has a bonding structure portion, and the barrier film includes the Al ₂ O ₃ -structure portion ^and the A package having a maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) with respect to the Al ₃ ⁻ structural portion of 1 or more and 20 or less.

(2) The maximum strength of the Al ₃ ^-structure portion exists at a depth position of 4% or more and 45% or less from the surface of the organic coating layer in the film thickness direction of the vapor deposited aluminum oxide layer (1). Package as described.

(3) The maximum strength of the Al ₃ ^-structure portion exists at a depth position of 10% or more and 25% or less from the surface on the organic coating layer side in the film thickness direction of the vapor deposited aluminum oxide layer (1) or The package according to (2).

(4) The barrier film has an oxygen permeability of 0.15 cc/m2/day/atm or less and a water vapor permeability of 0.2 g/ ^m2 /day or less according to JIS K 7126 B method. The package according to any one of (3) to (3).

(5) The package according to any one of (1) to (4), further including a hygroscopic agent.

The packaging body of the present invention is a packaging body that achieves both high barrier properties and transparency without adopting a multi-layered structure as in the prior art, and that can prevent metal products to be packaged from rusting.

FIG. 3 is a cross-sectional view showing an example of a barrier film that constitutes the package according to the present embodiment; FIG. 2 is a perspective view showing the configuration of a packaging bag that constitutes the packaging body according to the present embodiment; 1 is a plan view showing an example of a vapor deposition apparatus for forming an aluminum oxide vapor deposition layer; FIG. FIG. 2 is a graphical analysis diagram of TOF-SIMS measurement results of the barrier film in Example 1. FIG. FIG. 4 is a plan view showing an example of a loop stiffness measuring device; FIG. 6 is a cross-sectional view along line VV of the loop stiffness measuring device of FIG. 5; FIG. 4 is a diagram for explaining a process of attaching a test piece to the loop stiffness measuring instrument; It is a figure for demonstrating the process of forming a loop part in a test piece. It is a figure for demonstrating the process of applying a load to the loop part of a test piece. It is a figure for demonstrating the process of applying a load to the loop part of a test piece. FIG. 10 is a graph analysis diagram showing TOF-SIMS measurement results of a barrier film in another example.

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments at all, and can be implemented with appropriate modifications within the scope of the purpose of the present invention. can do. Further, in this specification, the notation “X to Y” (X and Y are arbitrary numerical values) means “X or more and Y or less”.

<< package >>
A package according to the present embodiment is a package in which a metal product that rusts due to oxidation is hermetically packaged in a packaging bag. It is possible to prevent metal products from rusting with the packaging bag that constitutes the package according to the present embodiment. A packaging bag that constitutes the package according to the present embodiment will be described below.

<Packaging bag>
This packaging bag is composed of a laminated film in which at least a barrier film and a sealant layer are laminated. As shown in FIG. 1, the barrier film 1 constituting the laminated film 1a is formed by laminating a substrate layer 2, an aluminum oxide deposition layer 3, and an organic coating layer 4 in this order. In the laminate film 1 a , a sealant layer 5 is further laminated on the surface of the organic coating layer 4 of the barrier film 1 . As shown in FIG. 2, the packaging bag 6 is formed by hermetically joining the peripheries of the facing sealant layers of the two laminated films.

In the present specification, "laminating in this order" means that the substrate layer, the aluminum oxide deposition layer, and the coating layer are laminated in this order, and another layer is placed between these layers. Layers may be laminated.

The vapor deposited aluminum oxide layer 3 forming the packaging bag 6 has an element-bonded structure portion represented by an Al ₂ O ₃ -structure portion ^and an Al ₃ ^-structure portion. The Al ₂ O ₃ -structure portion ^and the Al ₃ -structure portion correspond ^to the intensity of the Al ₂ O ₃ -structure portion measured by time ^- of-flight secondary ion mass spectrometry (TOF-SIMS). "Al ₃ ^-maximum strength ratio (Al ₃ ^- /Al ₂ O ₃ ^- ×100)" (hereinafter simply referred to as maximum strength ratio), which is the ratio of the maximum strength of the Al ₃ structural part ^- , is 1 or more and 20 or less. It is characterized by

According to the inventors' view, the barrier properties of the barrier film can be improved by controlling the maximum strength ratio of the Al ₃ ^-structure . As a result, it is possible to impart sufficient barrier properties to the barrier film without using a barrier film having a multi-layer structure, and to prevent metal products to be packaged from rusting. The packaging bag and the barrier film laminated with the vapor-deposited aluminum oxide layer in which the maximum strength ratio of the Al ₃ ^-structure is specified are used at least only for the production of the package of the present invention, and the package of the present invention. It is indispensable for solving problems by

TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry) irradiates the surface of a solid sample to be analyzed with a primary ion beam from a primary ion gun, and sputters from the sample surface. In this method, emitted secondary ions are mass-separated by utilizing the time-of-flight difference (the time-of-flight is proportional to the square root of the weight) and subjected to mass analysis.

Here, by detecting the secondary ion intensity while the sputtering is progressing, the data of the time transition of the ion intensity of the secondary ions, i. is converted into depth, the concentration distribution of the element to be detected in the depth direction of the sample surface can be known.

Then, the depth of the depressions formed on the sample surface by the irradiation of the primary ions is measured in advance using a surface roughness meter, and the average sputtering speed is calculated from the depth of the depressions and the transition time. Under the assumption that the velocity is constant, the depth (sputter amount) can be calculated from the irradiation time (ie transition time) or the number of irradiation cycles.

For the aluminum oxide deposited layer of the barrier film, preferably, a Cs (cesium) ion gun is used to measure up to a deep region, and while repeating soft etching at a constant rate as described above, the aluminum oxide deposited layer derived from By measuring Al ₃ ⁻ and Al ₂ O ₃ ⁻ ions and C ₆ ions derived from the substrate layer and the organic coating layer, the intensity ratio of each ion can be calculated.

^For example _, an Al ion with a mass number of 27 is detected ^from _both the Al _{3 -structure} portion ^and the Al ₂ O ₃ ^-structure portion. It is not suitable as a guideline for quantifying the ratio. In the present invention, by calculating the intensity ratio between the Al ₃ ⁻ ion having a mass number of 80.94 and the Al ₂ O ₃ ⁻ ion having a mass number of 101.94, the Al ₃ ⁻ structure portion and the Al ₂ O ₃ ⁻ It is possible to quantify the ratio with the structural part.

Further, by specifying the interface between the deposited aluminum oxide layer and the base material layer, it is possible to know at what depth from the interface the maximum value of detected ions exists. That is, by defining the position where the _C6 ion intensity is half the maximum value as the interface between the substrate layer and the aluminum oxide deposition layer, the maximum value of the ion intensity detected is the aluminum oxide It is possible to know at what depth position in the vapor deposition layer it is.

The measurement result can be obtained as a graph as shown in FIG. 4, for example. In the graph of FIG. 4, the unit (intensity) of the vertical axis is the intensity of the measured ions, and the unit (cycle) of the horizontal axis is the number of times of etching.

Then, the depth, Al ₃ -strength, and Al ₂ O ₃ -strength in the aluminum oxide deposition layer in each cycle were obtained, ^and the Al _{3 -maximum intensity ratio Al 3} ^- _/ ^{when the} maximum Al ₃ ^-strength was exhibited. Al ₂ O ₃ ⁻ ×100 and the ratio of depth to aluminum layer thickness can be calculated.

If the maximum intensity ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) is less than 1, the Al ₃ ⁻ structure portion in the deposited aluminum oxide layer is too small, and the barrier properties tend to deteriorate. If the maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) is more than 20, the transparency of the vapor deposited aluminum oxide layer tends to decrease, impairing the printability as a packaging material. The problem that the visibility of the contents such as metal products that have been placed in the container is deteriorated tends to occur. The maximum intensity ratio is preferably 2 or more, and more preferably 10 or less.

The maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) is 1 or more and 20 or less, so that when the barrier resin film includes a barrier coating layer, the oxygen permeability is reduced to 0.02 cc/m ² /day/atm or more and 0.15 cc/m ² /day/atm or less, and a water vapor permeability of 0.02 g/m ² /day or more and 0.2 g/m ² /day or less. can do.

Each layer constituting the barrier film 1 will be described below.

[Base material layer]
The base material layer 2 is a layer mainly containing resin. The resin is not particularly limited, and known resin films or sheets can be used. For example, polyester-based resins including polyethylene terephthalate-based resins, polybutylene terephthalate-based resins, polyethylene naphthalate-based resins, polyamide-based resins; polyolefin-based resins including α-olefin polymers and copolymers such as polyethylene and polypropylene A resin film containing resin or the like can be used.

Among these resins, polyester-based resins are preferably used, and among polyester-based resins, polyethylene terephthalate-based resins and polybutylene terephthalate-based resins are preferably used.

As the polyethylene terephthalate film (PET film), biomass PET film, recycled PET film, and high stiffness PET film (tough PET film) may be used as the base layer 2 in addition to conventionally known PET films.

<Biomass PET film>
A biomass PET film is a resin film containing biomass-derived polyester, and the biomass-derived polyester has a diol unit of biomass-derived ethylene glycol and a dicarboxylic acid unit of fossil fuel-derived dicarboxylic acid.

Biomass-derived ethylene glycol has the same chemical structure as conventional fossil fuel-derived ethylene glycol. There is no inferiority in terms of physical properties such as Therefore, the substrate layer using a biomass-derived polyester film has a layer made of a carbon-neutral material, so compared to a substrate layer manufactured from a raw material obtained from a conventional fossil fuel, the amount of fossil fuel used is reduced. can be reduced, and the environmental load can be reduced.

Biomass-derived ethylene glycol is produced from biomass such as sugar cane and corn (biomass ethanol) as a raw material. For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

The dicarboxylic acid units of the polyester use dicarboxylic acids derived from fossil fuels. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used. Examples of aromatic dicarboxylic acids include terephthalic acid and isophthalic acid. Examples of derivatives of aromatic dicarboxylic acids include lower alkyl esters of aromatic dicarboxylic acids, specifically methyl esters, ethyl esters, propyl esters and butyl esters. Ester etc. are mentioned. Among these, terephthalic acid is preferred, and dimethyl terephthalate is preferred as the aromatic dicarboxylic acid derivative.

A biomass-derived polyester can be obtained by a conventionally known method of polycondensing a diol unit and a dicarboxylic acid unit. Specifically, after performing the esterification reaction and / or transesterification reaction of the dicarboxylic acid component and the diol component, a general method of melt polymerization such as performing a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using

The resin composition constituting the resin film containing biomass-derived polyester may be composed only of biomass-derived polyester, or may contain fossil fuel-derived polyester in addition to biomass-derived polyester. A fossil fuel-derived polyester consists of a diol unit and a dicarboxylic acid unit, and is obtained by a polycondensation reaction using a fossil fuel-derived diol, ethylene glycol, as the diol unit, and a fossil fuel-derived dicarboxylic acid as the dicarboxylic acid unit. It is a thing.

The resin in the resin composition that constitutes the resin film containing biomass-derived polyester may contain recycled polyester in addition to the biomass-derived polyester. The recycled polyester may be a recycled biomass-derived polyester or a recycled fossil fuel-derived polyester.

A resin composition that constitutes a resin film containing a biomass-derived polyester may contain various additives. Additives such as plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, friction reducers, release agents, antioxidants, ion exchange agents agents, coloring pigments, and the like. The additive is contained in the total resin composition containing PET in an amount of 5% by mass or more and 50% by mass or less, preferably 5% by mass or more and 20% by mass or less.

A resin film containing a biomass-derived polyester can be formed, for example, by forming a film using a T-die method. Specifically, after drying the above PET, it is supplied to a melt extruder heated to a temperature (Tm) above the melting point of PET to Tm + 70 ° C. to melt the resin composition, for example, a T die A film can be formed by extruding a sheet from a die such as the above, and rapidly cooling and solidifying the extruded sheet with a rotating cooling drum or the like. As the melt extruder, a single-screw extruder, a twin-screw extruder, a vent extruder, a tandem extruder, or the like can be used depending on the purpose. In addition, on this specification, Tm means melting|fusing point.

Since carbon dioxide in the atmosphere contains 14C at a certain rate (105.5 pMC), the 14C content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no 14C. Therefore, by measuring the ratio of 14C contained in the total carbon atoms in the polyester, the ratio of biomass-derived carbon can be calculated. In the present invention, the term "biomass degree" indicates the mass ratio of biomass-derived components. Taking PET (polyethylene terephthalate) as an example, PET is obtained by polymerizing ethylene glycol containing 2 carbon atoms and terephthalic acid containing 8 carbon atoms at a molar ratio of 1:1, and ethylene glycol is derived from biomass. When only is used, the mass ratio of the biomass-derived component in PET is 31.25%, so the biomass degree is 31.25% (molecular weight derived from biomass-derived ethylene glycol / molecular weight of one polymerized polyester unit = 60 ÷ 192). Further, the mass ratio of the biomass-derived component 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 degree of biomass in the resin film containing biomass-derived polyester is preferably 5.0% or more, more preferably 10.0% or more, and preferably 30.0% or less.

The resin film containing 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 obtain a longitudinally stretched film. This stretching is preferably carried out using a difference in circumferential speed between two or more rolls. Longitudinal stretching is usually carried out in a temperature range of 50 to 100°C. Further, the longitudinal stretching ratio is preferably 2.5 times or more and 4.2 times or less, although it depends on the properties required for the film application. If the draw ratio is less than 2.5 times, unevenness in the thickness of the polyester film increases, making it difficult to obtain a good film.

The longitudinally stretched film is then successively subjected to transverse stretching, heat setting, and heat relaxation steps to obtain a biaxially stretched film. Lateral stretching is usually carried out in a temperature range of 50 to 100°C. The lateral stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the properties required for the application. If it is less than 2.5 times, the thickness of the film becomes uneven and it is difficult to obtain a good film.

After the transverse stretching, the heat setting treatment is carried out, and the preferred temperature range for the heat setting is Tg+70 to Tm-10°C of the polyester. Moreover, the heat setting time is preferably 1 to 60 seconds. Furthermore, for applications that require a reduction in heat shrinkage, heat relaxation treatment may be performed as necessary. In addition, on this specification, Tg means a glass transition point.

The thickness of the resin film containing biomass-derived polyester is arbitrary depending on its use, 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 ² in the MD direction and 5 to 35 kgf/mm ² in the TD direction, and the breaking elongation is 50 to 350% in the MD direction. 50 to 300% in the TD direction. Also, the shrinkage rate when left in a temperature environment of 150° C. for 30 minutes is 0.1 to 5%.

Resin films containing biomass-derived polyester can be suitably used for packaging products such as bags, lids, laminated tubes, various label materials, sheet molded products, etc., in addition to the adhesive barrier film application in this case. can be done. When a resin film containing recycled PET is used for packaging products, the stretched film preferably has a thickness of 5 to 30 μm.

<Recycled PET film>
A recycled PET film is a resin film containing recycled PET, and contains PET recycled by mechanical recycling. Specifically, it includes PET obtained by mechanically recycling PET bottles, and this PET contains ethylene glycol as a diol component and terephthalic acid and isophthalic acid as dicarboxylic acid components.

Here, mechanical recycling generally refers to the process of pulverizing collected PET bottles and other polyethylene terephthalate resin products, washing with alkali to remove dirt and foreign matter from the surface of the PET resin products, and then drying for a certain period of time under high temperature and reduced pressure. In this method, the contaminants remaining inside the PET resin are diffused and decontaminated, the dirt on the resin product made of the PET resin is removed, and the resin product is returned to the PET resin.

Hereinafter, polyethylene terephthalate obtained by recycling PET bottles is referred to as "recycled polyethylene terephthalate (hereinafter also referred to as recycled PET)", and polyethylene terephthalate that is not recycled is referred to as "virgin polyethylene terephthalate (hereinafter also referred to as virgin PET)". .

Among the PET contained in the base material layer, the content of the isophthalic acid component is preferably 0.5 mol % or more and 5 mol % or less, and 1.0 mol %, in the total dicarboxylic acid components constituting the PET. It is more preferable that the content is at least 2.5 mol % or less. If the content of the isophthalic acid component is less than 0.5 mol %, the flexibility may not be improved.

The PET may be PET derived from biomass as well as PET derived from ordinary fossil fuels. This biomass-derived PET is PET containing biomass-derived ethylene glycol as a diol component and fossil fuel-derived dicarboxylic acid as a dicarboxylic acid component.

PET used for PET bottles can be obtained by a conventionally known method of polycondensing the above diol component and dicarboxylic acid component. Specifically, a general method of melt polymerization such as performing an esterification reaction and/or a transesterification reaction between the diol component and the dicarboxylic acid component and then performing a polycondensation reaction under reduced pressure, or an organic solvent can be produced by a known solution heating dehydration condensation method using The amount of the diol component used in the production of the PET is substantially equimolar to 100 mol of the dicarboxylic acid or derivative thereof. Since there is distillation during the reaction, it is used in excess of 0.1 mol % or more and 20 mol % or less. Moreover, 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, and it may be added at the time of charging the raw materials or at the start of depressurization.

After the PET from recycled PET bottles is polymerized and solidified as described above, solid state polymerization is performed as necessary to further increase the degree of polymerization and remove oligomers such as cyclic trimers. you can go Specifically, in the solid state polymerization, PET is chipped and dried, and then heated at a temperature of 100° C. or higher and 180° C. or lower for about 1 to 8 hours to pre-crystallize the PET, followed by 190° C. It is carried out by heating at a temperature of 230° C. or higher in an inert gas atmosphere or under reduced pressure for one hour to several tens of hours.

The intrinsic viscosity of PET contained in 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 the resin base material may be insufficient. On the other hand, when the intrinsic viscosity exceeds 0.80 dl/g, the productivity in the film forming process may be impaired. In addition, the intrinsic viscosity is measured at 35° C. with an orthochlorophenol solution.

Recycled PET preferably contains recycled PET at a ratio of 50% by mass or more and 95% by mass or less, and may contain virgin PET in addition to recycled PET. The virgin PET may be PET containing ethylene glycol as the diol component and terephthalic acid and isophthalic acid as the dicarboxylic acid component, or PET containing no isophthalic acid as the dicarboxylic acid component. good too. For example, the dicarboxylic acid component may include an aliphatic dicarboxylic acid and the like in addition to aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid.

Specific examples of aliphatic dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid, which usually have 2 to 40 carbon atoms. cyclic or alicyclic dicarboxylic acids. Examples of derivatives of aliphatic dicarboxylic acids include lower alkyl esters such as methyl esters, ethyl esters, propyl esters and butyl esters of the above aliphatic dicarboxylic acids, and cyclic acid anhydrides of the above aliphatic dicarboxylic acids such as succinic anhydride. . Among these, as the aliphatic dicarboxylic acid, adipic acid, succinic acid, dimer acid, or a mixture thereof is preferable, and those containing succinic acid as a main component are particularly preferable. More preferred derivatives of aliphatic dicarboxylic acids are methyl esters of adipic acid and succinic acid, or mixtures thereof.

The resin in the resin composition that constitutes the resin film containing recycled PET may be composed only of recycled PET, or may contain virgin PET in addition to recycled PET. Further, the recycled PET film may be a single layer or multiple layers. When the resin film containing recycled PET has three layers of innermost layer/intermediate layer/outermost layer, the intermediate layer is a layer composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the innermost layer and The outermost layer is preferably a layer composed only of virgin PET. Thus, by using only virgin PET for the innermost layer and the outermost layer, it is possible to prevent the recycled PET from coming out from the front surface or the rear surface of the resin film. Therefore, the sanitation of the laminate can be ensured. When the resin film containing recycled PET has two layers, one layer is composed only of recycled PET or a mixed layer of recycled PET and virgin PET, and the other layer is composed only of virgin PET. It is preferable to use a layer that When recycled PET and virgin PET are mixed to form a single-layer resin film containing recycled PET, there are a method of supplying them separately to a molding machine, and a method of supplying them after mixing by dry blending or the like. Among them, the method of mixing by dry blending is preferable from the viewpoint of simple operation.

A resin composition that constitutes a resin film containing recycled polyethylene PET may contain various additives in the production process or after the production, as long as the properties are not impaired. Additives such as plasticizers, UV stabilizers, color inhibitors, matting agents, deodorants, flame retardants, weathering agents, antistatic agents, friction reducers, release agents, antioxidants, ion exchange agents agents, coloring pigments, and the like. The additive is contained in the total resin composition containing PET in an amount of 5% by mass or more and 50% by mass or less, preferably 5% by mass or more and 20% by mass or less.

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

The resin film containing recycled PET is preferably biaxially oriented. 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 obtain a longitudinally stretched film. This stretching is preferably carried out using a difference in circumferential speed between two or more rolls. Longitudinal stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. Further, the longitudinal stretching ratio is preferably 2.5 times or more and 4.2 times or less, although it depends on the properties required for the film application. If the draw ratio is less than 2.5 times, the thickness unevenness of the PET film becomes large, making it difficult to obtain a good film. The longitudinally stretched film is then successively subjected to transverse stretching, heat setting, and heat relaxation steps to obtain a biaxially stretched film. Lateral stretching is usually performed in a temperature range of 50°C or higher and 100°C or lower. The lateral stretching ratio is preferably 2.5 times or more and 5.0 times or less, although it depends on the properties required for the application. If it is less than 2.5 times, the thickness of the film becomes uneven and it is difficult to obtain a good film. After the transverse stretching, heat setting treatment is carried out, and the preferable temperature range for heat setting is Tg+70 to Tm−10° C. of PET. Moreover, the heat setting time is preferably 1 second or more and 60 seconds or less. Furthermore, for applications that require a reduction in heat shrinkage, heat relaxation treatment may be performed as necessary.

The thickness of the resin film containing recycled PET is arbitrary depending on its use, but is usually about 5 to 500 μm. The breaking strength of the resin film containing recycled PET is 5 kgf/mm ² or more and 40 kgf/mm ² or less in the MD direction, and 5 kgf/mm ² or more and 35 kgf/mm ² or less in the TD direction. is 50% or more and 350% or less in the TD direction, and 50% or more and 300% or less in the TD direction. Moreover, the shrinkage rate when left in a temperature environment of 150° C. for 30 minutes is 0.1% or more and 5% or less.

Virgin PET may be fossil fuel polyethylene terephthalate (hereinafter also referred to as fossil fuel PET) or biomass PET. Here, the term "fossil fuel PET" means that a fossil fuel-derived diol is used as a diol component, and a fossil fuel-derived dicarboxylic acid is used as a dicarboxylic acid component. Recycled PET may be obtained by recycling PET resin products formed using fossil fuel PET, or obtained by recycling PET resin products formed using biomass PET. There may be.

Resin films containing recycled PET can be suitably used for packaging products such as bags, lids, and laminated tubes, various label materials, sheet moldings, etc., in addition to the present adhesive barrier film application. . When a resin film containing recycled PET is used for packaging products, the stretched film preferably has a thickness of 5 to 30 μm.

<High stiffness PET film (tough PET film)>
The high-stiffness PET film contains polyester as a main component and has a loop stiffness of 0.0017 N or more in at least one direction with a test piece having a width of 15 mm. A high stiffness film, for example, has a loop stiffness of 0.0017 N or greater in at least one of the machine direction (MD) or the vertical direction (TD). A high stiffness film may, for example, have a loop stiffness of 0.0017 N or greater in both the machine direction (MD) and the vertical direction (TD).

Loop stiffness is a parameter representing the stiffness of a film. A method of measuring loop stiffness will be described below with reference to FIGS. 5 to 10. FIG. 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 layer formed on the single-layer film. A laminated film is a film comprising a plurality of laminated films.

5 is a plan view showing the test piece 40 and the loop stiffness measuring device 45, and FIG. 6 is a cross-sectional view of the test piece 40 and the loop stiffness measuring device 45 of FIG. 5 along line IV-IV. The test piece 40 is a rectangular film having long sides and short sides. In the present application, the length L1 of the long side of the test piece 40 was set to 150 mm, and the length L2 of the short side was set to 15 mm. As the loop stiffness measuring device 45, for example, No. 1 manufactured by Toyo Seiki Co., Ltd. A 581 Loop Stiffness Tester® LOOP STIFFNESS TESTER Model DA can be used. The length L1 of the long side of the test piece 40 can be adjusted as long as the test piece 40 can be gripped by a pair of chuck portions 46, which will be described later.

The loop stiffness measuring instrument 45 has a pair of chuck portions 46 for gripping a pair of longitudinal ends of the test piece 40 and a support member 47 supporting the chuck portions 46 . The chuck part 46 includes a first chuck 461 and a second chuck 462 . 5 and 6, the test piece 40 is placed on the pair of first chucks 461, and the second chuck 462 still grips the test piece 40 between itself and the first chucks 461. not As will be described later, the test piece 40 is gripped between the first chuck 461 and the second chuck 462 of the chuck portion 46 during measurement. The second chuck 462 may be connected to the first chuck 461 via a hinge mechanism.

If the film to be measured, such as a stretched plastic film, vapor-deposited film, or laminated film, is available in a state before the film is processed into a packaging product, the test piece 40 is prepared by cutting the film to be measured. may Alternatively, the test piece 40 may be produced by cutting a packaged product made of packaging material, such as a packaging bag, and taking out the film to be measured.

A method of measuring the loop stiffness of the test piece 40 using the loop stiffness measuring device 45 will be described. First, as shown in FIGS. 5 and 6, the test piece 40 is placed on the first chucks 461 of the pair of chuck portions 46 arranged with an interval L3 therebetween. In the present application, the interval L3 is set so that the length of the loop portion 41 described later (hereinafter also referred to as loop length) is 60 mm. The test piece 40 includes an inner surface 40x positioned on the side of the first chuck 461 and an outer surface 40y positioned on the opposite side of the inner surface 40x. If test strip 40 is made of packaging material, inner surface 40x and outer surface 40y of test strip 40 match the inner and outer surfaces of the packaging material. When the loop portion 41 to be described later is formed in the test piece 40 , the inner surface 40 x is positioned inside the loop portion 41 and the outer surface 40 y is positioned outside the loop portion 41 . Subsequently, as shown in FIG. 7 , the second chuck 462 is placed on the test strip 40 so as to grip the longitudinal end of the test strip 40 between itself and the first chuck 461 .

Subsequently, as shown in FIG. 8, at least one of the pair of chuck portions 46 is slid on the support member 47 in the direction in which the distance between the pair of chuck portions 46 is reduced. Thereby, the loop portion 41 can be formed in the test piece 40 . A test piece 40 shown in FIG. 8 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 held by the pair of chuck portions 46 . The pair of intermediate portions 42 are portions of the test piece 40 located between the loop portion 41 and the pair of intermediate portions 42 . As shown in FIG. 8, 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. Thereby, the loop portion 41 having a loop length of 60 mm can be formed. The loop length of the loop portion 41 is defined by the position P1 where the surface of the second chuck 462 on the loop portion 41 side and the test piece 40 intersect, and the surface of the other second chuck 462 on the loop portion 41 side and the test piece 40 . is the length of the test piece 40 between the crossing position P2. When ignoring the thickness of the test piece 40, the above-mentioned interval L3 is a value obtained by adding 2×t to the length of the loop portion 41. As shown in FIG. t is the thickness of the second chuck 462 of the chuck portion 46 .

After that, as shown in FIG. 9, the posture of the chuck portion 46 is adjusted so that the projection direction Y of the loop portion 41 with respect 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 faces the horizontal direction. In the example shown in FIG. 9, the projecting direction Y of the loop portion 41 coincides with the thickness direction of the chuck portion. Also, the load cell 48 is prepared at a position separated from the second chuck 462 by a distance Z1 in the projecting direction Y of the loop portion 41 . In this application, the distance Z1 is set to 50 mm. Subsequently, 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. The distance Z2 is set so that the load cell 48 contacts the loop portion 61 and then the load cell 48 pushes the loop portion 41 toward the chuck portion 46, as shown in FIGS. 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 pushes the loop portion 41 toward the chuck portion 46 is 10 mm. A speed V for moving the load cell 48 was set to 3.3 mm/sec.

Subsequently, as shown in FIG. 10, the load cell 48 is moved toward the chuck portion 46 by a distance Z2, and in a state in which the load cell 48 pushes the loop portion 41 of the test piece 40, the load is applied from the loop portion 41 to the load cell 48. After the load value stabilizes, record the load value. The value of the load thus obtained is adopted as the loop stiffness of the film forming the test piece 40 . In the present application, unless otherwise specified, the environment during the loop stiffness measurement is 23° C. temperature and 50% relative humidity.

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 enhanced. As a result, in the laminated film provided with a high-stiffness film, the puncture strength of the laminated film can be, for example, 13 N or more, more preferably 14 N or more, and still more preferably 15 N or more or 16 N or more. can.

Examples of high-stiffness films include high-stiffness PET films 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 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 14 μm or more. Also, the thickness of the high stiffness film is preferably 30 μm or less, may be 25 μm or less, or may be 20 μm or less.

Preferred mechanical properties of high stiffness films are further described. 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 higher, more preferably 280 MPa or higher. For example, the tensile strength of the high stiffness film in the machine direction is preferably 250 MPa or higher, more preferably 280 MPa or higher. The tensile strength of the high stiffness film in the vertical direction is preferably 250 MPa or higher, more preferably 280 MPa or higher. 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 vertical direction is preferably 120% or less, more preferably 110% or less. Preferably, the value obtained by dividing the tensile strength of the high stiffness film by the tensile elongation is 2.0 [MPa/%] or more in at least one direction. For example, the value obtained by dividing the tensile strength of the high-stiffness film in the vertical direction (TD) by the tensile elongation is preferably 2.0 [MPa/%] or more, more preferably 2.2 [MPa/%] or more. is. The value obtained by dividing the tensile strength of the high-stiffness film in the machine direction (MD) by the tensile elongation is preferably 1.8 [MPa/%] or more, more preferably 2.0 [MPa/%] or more. .

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 vertical direction is preferably 0.7% or less, more preferably 0.5% or less. The heating temperature for measuring the thermal shrinkage is 100° C., and the heating time is 40 minutes.

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

Young's modulus, like tensile strength and tensile elongation, can be measured according to JIS K7127. As a measuring instrument, a tensile tester STA-1150 manufactured by Orientec Co., Ltd. can be used. As the test piece, a rectangular film having a width of 15 mm and a length of 150 mm cut out from the high stiffness film can be used. The distance between the pair of chucks holding the specimen at the start of the measurement is 100 mm, and the pulling speed is 300 mm/min. Note that the length of the test piece can be adjusted as long as the test piece can be gripped by the pair of chucks. In the present application, unless otherwise specified, the environment for Young's modulus measurement is a temperature of 25° C. and a relative humidity of 50%.

A high-stiffness film, even when provided with a vapor-deposited layer, has mechanical properties equivalent to those of a single high-stiffness film. For example, a high stiffness film provided with an aluminum oxide deposition layer 3 has a loop stiffness of 0.0017 N or more in at least one direction. Further, even when an organic coating layer is further provided on the deposited layer, the film has mechanical properties equivalent to those of a single high-stiffness film. For example, a high stiffness film provided with an aluminum oxide deposition layer 3 and an organic coating layer 4 has a loop stiffness of 0.0017 N or greater in at least one direction.

In the process of producing a high-stiffness film, for example, first, a plastic film obtained by melting and molding polyester is stretched 3 to 4.5 times at 90 to 145° C. in the machine direction and the vertical direction, respectively. A first stretching step is carried out. Subsequently, the plastic film is stretched 1.1 to 3.0 times at 100 to 145° C. in the machine direction and the vertical direction, respectively. After that, heat setting is performed at a temperature of 190 to 220°C. Subsequently, a relaxation treatment (a treatment to reduce the width of the film) of about 0.2 to 2.5% is performed at a temperature of 100 to 190° C. in the machine direction and the vertical direction. By adjusting the draw ratio, draw temperature, heat setting temperature, and relaxation treatment rate in these steps, a high stiffness film having the above mechanical properties can be obtained.

As a specific example of the high stiffness film, XP-55 manufactured by Toray Industries, Inc. can be used. This high stiffness film is biaxially oriented, contains 90% by weight or more of PET, and has a thickness of 16 μm. The measured loop stiffness of this high stiffness PET film was 0.0021 N in both the machine and vertical directions. Also, 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 vertical direction was 4.7 GPa. Also, 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 vertical direction was 257 MPa. Also, 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 vertical direction was 102%. In this case, the value obtained by dividing the tensile strength of the high-stiffness PET film in the machine direction by the tensile elongation is 2.73 [MPa/%], and the value obtained by dividing the tensile strength of the high-stiffness PET film in the vertical direction by the tensile elongation The value is 2.52 [MPa/%]. In addition, the thermal shrinkage of the high stiffness PET film in both the machine direction and the vertical direction was 0.4%.

The resin substrate may have a single layer structure or a multilayer structure of two or more layers. In the case of a multilayer structure, the layers may have the same composition or may have different compositions. Moreover, in the case of a multilayer structure, each layer may be adhered with an adhesive layer or the like interposed therebetween.

Although the thickness of the base layer 2 is not particularly limited, it is preferably 5 μm or more and 25 μm or less, more preferably 8 μm or more and 15 μm or less. When the thickness is 5 μm or more, the strength of the barrier film can be made preferable. When the thickness is 25 μm or less, the thickness of the entire barrier film can be reduced, so that the transparency is increased and the visibility of the contents is improved.

[Aluminum oxide deposition layer]
The aluminum oxide deposition layer 3 is an inorganic oxide thin film containing aluminum oxide as a main component. The aluminum oxide deposition layer 3 has an element ^- bonded structure represented ^by an Al ₂ O _{3 -structure} ^and an Al _{3 -structure} . The maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) with respect to the Al ₃ ⁻ structure is 1 or more and 20 or less.

In this way, the barrier properties of the barrier film are improved by controlling the maximum strength ratio of the Al ₂ O ₃ ^{-structure and} the Al ₃ ^-structure rather than the aluminum oxide consisting of only the Al ₂ O ₃ -structure. can be made

Specifically, the intensity ratio Al ₃ ⁻ /Al, which is the ratio between the intensity of Al ₃ ⁻ detected by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and the intensity of Al ₂ O ₃ ⁻ ₂ O ₃ ^— . In the present invention, the Al ₃ ^- structure part and the Al ₂ O ₃ ^- structure part refer to the strength of Al ₃ ^- (strength derived from elemental bond Al ₃ ) and the strength of Al ₂ O ₃ ^- (element strength from bound Al ₂ O ₃ ). The strength of Al ₃ ⁻ is derived from aluminum, and the strength of Al ₂ O ₃ ⁻ is derived from aluminum oxide.

Here, time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a method in which a solid sample is irradiated with an ion beam (primary ions), and some of the molecules that make up the surface are ionized. ions) are mass-separated by using their flight time difference (the flight time is proportional to the square root of the weight). In this specification, the intensity ratio Al ₃ ⁻ /Al ₂ O ₃ ⁻ is obtained by irradiating an ion beam from the organic coating layer side of the barrier film, and determining the Al ₂ O ₃ ⁻ structure derived from the aluminum oxide deposition layer and the Al ₃ ^- identified by the secondary ions of the structure and

Determination of the aluminum oxide deposited layer in the TOF-SIMS measurement results is based on the interface between the barrier organic coating layer and the aluminum oxide deposited layer where the strength of SiO ₂ , which is a constituent element of the organic coating layer, is half the maximum strength. Then, the position where the strength of C6, which is the constituent material of the base material layer, becomes half of the maximum strength is defined as the interface between the film base material and the aluminum oxide vapor deposition layer, and the first interface to the second interface is aluminum oxide vapor deposition. layer.

Then, the peak position (maximum intensity) where the intensity of Al ₃ ⁻ is highest in the vapor deposited aluminum oxide layer is determined, and the ratio of the intensity of Al ₃ ⁻ to the intensity of Al ₂ O ₃ ⁻ at that position, that is, the Al ₃ ⁻ maximum Calculate the intensity ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) and the ratio of the maximum intensity of Al ₃ ⁻ to the thickness of the deposited aluminum oxide layer (depth from the organic coating layer side in the deposited aluminum oxide layer). .

In addition, the maximum strength of this Al ₃ ^-structure portion is at a depth position of 4% or more and 45% or less of the film thickness of the aluminum oxide vapor deposition layer from the surface of the aluminum oxide vapor deposition layer on the organic coating layer side (the side irradiated with the ion beam). It is preferable to exist at a depth position of 10% or more and 25% or less. This will be explained using FIG. FIG. 11 is a graph analysis diagram showing measurement results by TOF-SIMS in a barrier film having a structure of substrate/vapor-deposited layer. FIG. 4, which will be described later, shows the measurement results (substrate/vapor-deposited layer/organic coating layer) by TOF-SIMS in Example 1. Although there is a difference in the layer structure that the organic coating layer does not exist in FIG. can be pseudo-understood as an enlarged view of the vicinity of the deposited film of . In FIG. 11, the maximum intensity of the Al ₃ ^-structure portion has a peak between 0 cycle and 10 cycles on the horizontal axis, while the Al ₂ O ₃ ^-structure portion exists widely from 0 cycle to slightly less than 100 cycles. ing. This means that the Al ₃ ^-structure part is unevenly distributed on the side of the organic coating layer in the vapor deposited aluminum oxide layer. doing. Conversely, it means that the maximum strength of the Al ₃ ^-structure portion does not exist near the substrate interface in the deposited film, and the Al ₂ O ₃ ^-structure portion mainly exists. Thus, in spite of being a single vapor deposition film, the main region of the Al ₃ ^-structure portion exists in addition to the region of the Al ₂ O ₃ ^-structure portion on the organic coating layer side of the vapor deposition film. By adopting a structure in which a region of the Al ₂ O ₃ ^-structure portion mainly exists on the substrate layer side of the film ^, _high barrier properties derived from the Al _{3 -structure} portion ^and We have succeeded in reconciling the inherently contradictory physical properties of transparency and adhesion to the substrate layer.

In order to set the maximum strength of the Al ₃ -structure part ^to 4% or more and 45% or less of the film thickness of the aluminum oxide vapor deposition layer from the surface of the aluminum oxide vapor deposition layer on the organic coating layer side (the ion beam irradiation side), It can be adjusted by controlling the oxygen concentration at the time of vapor deposition during the formation of the vapor deposited aluminum oxide layer. It can be adjusted by controlling the combination with the oxygen concentration during vapor deposition during formation. Appropriate pretreatment with oxygen plasma accelerates the oxidation of Al _on the substrate layer side of the vapor deposition film compared ^to the organic coating layer side. We have succeeded in maintaining transparency as a whole.

In addition, the aluminum oxide deposition layer contains a trace amount of aluminum compounds such as aluminum nitrides, carbides, and hydroxides alone or mixtures thereof, silicon oxides, silicon nitrides, silicon oxynitrides, silicon carbides, and oxides. Metal oxides such as magnesium, titanium oxide, tin oxide, indium oxide, zinc oxide and zirconium oxide, or metal nitrides, carbides and mixtures thereof may also be included.

The thickness of the deposited aluminum oxide layer is not particularly limited, but is preferably 5 nm or more and 100 nm or less, more preferably 8 nm or more and 30 nm or less. The barrier properties of the barrier film are improved when the thickness of the aluminum oxide deposited layer is 5 nm or more. When the thickness of the deposited aluminum oxide layer is 100 nm or less, the transparency of the adhesive barrier film can be further improved.

Also ^, the Al ₃ -structure has less transparency than the Al ₂ O ₃ ^-structure . Therefore, in addition to the above maximum intensity ratio, the Al ₃ ^-structure part can be quantified by total light transmittance (total light transmittance), haze, and color difference (L value in Lab color system). Specifically, the total light transmittance of the barrier film in which the substrate layer, the aluminum oxide deposition layer, and the organic coating layer are laminated is preferably 85% or more and 89.0% or less, and 86% or more and 88.0%. 5% or less is more preferable. The haze of the barrier film in which the substrate layer, the aluminum oxide deposition layer, and the organic coating layer are laminated is preferably 2.15% or more and 3.0% or less, and 2.2% or more and 2.5% or less. more preferred. As for the color difference (L ^* a ^* b ^* color system), L ^* is preferably 98 or more and less than 100. b ^* is preferably 0.50 or more and 1.00 or less, more preferably 0.80 or more and 1.00 or less, and particularly preferably 0.90 or more and 1.00 or less. The total light transmittance is measured according to JIS K7361, and the haze is measured according to JIS K7136. Moreover, the color difference (L ^* a ^* b ^* color system) is measured based on JIS Z8722.

[Organic coating layer]
The organic coating layer 4 mechanically and chemically protects the deposited aluminum oxide layer and improves the barrier performance of the barrier film.

The organic coating layer 4 is formed from a coating agent for an organic coating layer containing a metal alkoxide and preferably a hydroxyl group-containing water-soluble resin having a degree of saponification of 90% or more and 100% or less. In the organic coating layer, the metal alkoxide forms a condensation reaction product, but may form a co-condensate with the hydroxyl group-containing water-soluble resin.

The weight ratio of hydroxyl group-containing water-soluble resin/metal alkoxide is preferably 5/95 or more and 20/80 or less, more preferably 8/92 or more and 15/85 or less. If it is smaller than the above range, the barrier effect of the organic coating layer tends to be insufficient, and if it is larger than the above range, the rigidity and brittleness of the organic coating layer tend to increase.

The metal alkoxide has the general formula R _1n M(OR ₂ ) _m (wherein R ₁ and R ₂ represent a hydrogen atom or an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and each of a plurality of R ₁ and R ₂ in one molecule may be the same or different. be.

Examples of specific metal atoms represented by M in metal alkoxides include silicon, zirconium, titanium, aluminum, tin, lead, borane, and the like. It is preferred to use silanes.

Alkoxysilane is represented by the general formula R _1n Si(OR ₂ ) _m (where n+m=4). Therefore, when alkoxysilane is used, the organic coating layer will have an element-bonded structure represented by the SiO ₂ structure.

Specific examples of OR ₂ in the above are hydroxyl, methoxy, ethoxy, n-propoxy, n-butoxy, i-propoxy, butoxy and 3-methacryloxy. Alkoxy groups such as 3-acryloxy group and phenoxy group, phenoxy group and the like can be mentioned.

In the above, specific examples of R ₁ include methyl group, ethyl group, n-propyl group, isopropyl group, phenyl group, p-styryl group, 3-chloropropyl group, trifluoromethyl group, vinyl group, γ-glycan sidoxypropyl group, methacryl group, γ-aminopropyl group and the like.

Specific examples of alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, tetraphenoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltributoxysilane, methyltriphenoxysilane, phenylphenoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane silane, isopropyltriethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, p-styryltrimethoxysilane, 3- methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltri Examples include various alkoxysilanes such as ethoxysilane, 3-chloropropyltriethoxysilane, trifluoromethyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, and phenoxysilane.

In alkoxysilanes, when _R1 is an organic group having a functional group such as a vinyl group, an epoxy group, a methacryl group, an amino group, etc., it is generally called a silane coupling agent.

Specific examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and the like. and γ-glycidoxypropyltrimethoxysilane is preferred.

The above metal alkoxides may be used singly or in combination of two or more. In particular, it is preferable to use a silane coupling agent together. When a silane coupling agent is used together, the silane coupling agent preferably accounts for 2% by mass or more and 15% by mass or less of the total metal alkoxide.

(Hydroxyl group-containing water-soluble resin)
The hydroxyl group-containing water-soluble resin is capable of undergoing dehydration co-condensation with a metal alkoxide. % or less is more preferable. If the degree of saponification is less than the above range, the hardness of the organic coating layer tends to decrease.

Specific examples of hydroxyl group-containing water-soluble resins include, for example, polyvinyl alcohol-based resins, ethylene-vinyl alcohol copolymers, polymers of bifunctional phenol compounds and bifunctional epoxy compounds, and the like. They may be used, two or more of them may be mixed and used, or they may be copolymerized and used. Among these, polyvinyl alcohol is preferred, and polyvinyl alcohol-based resins are particularly preferred, because they are excellent in flexibility and affinity.

Specifically, for example, a polyvinyl alcohol-based resin obtained by saponifying polyvinyl acetate or an ethylene-vinyl alcohol copolymer obtained by saponifying a copolymer of ethylene and vinyl acetate is used. can do.

Examples of such polyvinyl alcohol-based resins include RS resin "RS-110 (degree of saponification = 99%, degree of polymerization = 1000)" manufactured by Kuraray Co., Ltd., "Gosenol NM-" manufactured by Nippon Synthetic Chemical Industry Co., Ltd. 14 (degree of saponification = 99%, degree of polymerization = 1400)".

Although the thickness of the organic coating layer is not particularly limited, it is preferably 150 nm or more and 800 nm or less, more preferably 250 nm or more and 600 nm or less. When the thickness of the organic coating layer is 150 nm or more, barrier properties can be imparted more effectively. When the thickness of the organic coating layer is 800 nm or less, the transparency can be further improved.

Next, the sealant layer constituting the laminated film will be described.

[Sealant layer]
A sealant layer is a layer which layers are joined mainly by heat-sealing sealant layers. The sealant layer is mainly composed of a resin, and the melting point of the resin is usually lower than that of the resin composing other layers such as the base material layer.

As the sealant layer, for example, one or more resins selected from polyethylene such as low-density polyethylene and linear low-density polyethylene, polypropylene, and the like can be used. The sealant layer may be a single layer or multiple layers.

The thickness of the sealant layer is preferably 20 μm or more and 100 μm or less, more preferably 30 μm or more and 80 μm or less.

Next, metal products to be packaged in the packaging bag will be described.

[Metal products]
A metal product is a metal product that rusts due to oxidation. A metal product is a product containing metal at least in part, and includes various electrical appliances, electronic devices, and the like.

Then, this metal product is hermetically packaged in a packaging bag. As described above, since the packaging bag has excellent barrier properties, it is possible to prevent rusting of the packaged metal product by hermetic packaging.

In addition, it is preferable that the hermetic packaging is carried out in such a manner that the metal product is prevented from coming into contact with oxygen and/or water vapor as much as possible. For example, a method of packaging a metal product in a packaging bag and sealing while sucking the air in the packaging bag, a method of sealing and packaging in the presence of an oxygen absorber and / or a moisture absorbent, a low oxygen and low humidity condition ( For example, air with an oxygen concentration of 10% by mass or less, preferably 1% by mass or less, or air with a humidity of 10% or less, preferably 1% or less, or in the presence of nitrogen or rare gas). Note that these methods may be combined.

Next, a method for producing a barrier film will be described.

<Method for producing barrier film>
A method for producing a barrier film includes, for example, treating a resin film (base material layer) with oxygen plasma, vapor-depositing aluminum on the surface of the plasma-treated resin film in an oxygen atmosphere to form an aluminum oxide vapor-deposited layer, and oxidizing the film. A method of applying a coating agent composition for a coating layer to the surface of an aluminum deposition layer, drying to form a coating layer, and laminating a sealant layer on the coating layer using a melt extrusion method can be exemplified.

[Plasma treatment]
In the barrier film according to the present embodiment, the adhesion between the aluminum oxide vapor deposition layer and the substrate tends to decrease due to the increase in the Al ₃ ^-structure portion in the aluminum oxide vapor deposition layer. Therefore, by subjecting the resin film (substrate layer) to oxygen plasma treatment, the degree of oxidation of the deposited aluminum oxide layer on the surface of the substrate can be increased, and the adhesion between the deposited aluminum oxide layer and the substrate can be increased.

In the plasma processing, it is preferable that oxygen alone or a mixed gas with an inert gas having a high oxygen partial pressure be used as the plasma raw material gas to be supplied.

FIG. 3 shows an example (plan view) of an apparatus for plasma processing and depositing an aluminum oxide deposition layer. In the plasma pretreatment chamber 12B, a part of a plasma pretreatment roller 20 that conveys the resin substrate S to be pretreated and enables plasma treatment is provided so as to be exposed to the resin substrate transfer chamber 12A. The resin base material S is moved to the plasma pretreatment chamber 12B while being wound up.

The plasma pretreatment chamber 12B is configured so that the space in which plasma is generated is separated from other regions and the facing space can be efficiently evacuated, thereby facilitating control of the plasma gas concentration and improving productivity. do. The pretreatment pressure formed by reducing the pressure can be set and maintained at about 0.1 Pa or more and 100 Pa or less, and particularly preferably 1 Pa or more and 20 Pa or less.

The conveying speed of the resin base material S is not particularly limited, but from the viewpoint of production efficiency, it can be 200 m/min or more and 1000 m/min or less, and particularly preferably 300 m/min or more and 800 m/min or less.

Plasma processing includes plasma supply means and magnetic forming means. The plasma treatment cooperates with the plasma pretreatment roller 20 to confine the oxygen plasma P near the resin substrate S surface. Specifically, the plasma supply means and the magnetism forming means constituting the plasma pretreatment means are arranged along the surface of the pretreatment roller 20 in the vicinity of the outer periphery, and the pretreatment roller 20 and the plasma raw material gas are supplied and the plasma P Plasma supply nozzles 22a to 22c, which also serve as electrodes for generating plasma P, and magnetism forming means having a magnet 21 and the like for promoting the generation of plasma P are installed so as to form a gap sandwiched between them.

The voltage between the pretreatment roller 20 and the plasma supply nozzles 22a to 22c has a frequency of 10 Hz to 2.5 GHz, an AC voltage of 50 volts or more and 1000 volts or less, input power control, impedance control, or the like. is an arbitrary stable applied voltage.

Plasma supply means in plasma processing includes a raw material volatilization supply device 18 connected to a plasma supply nozzle provided outside the decompression chamber 12, and a raw material gas supply line for supplying raw material gas from the device. The supplied plasma material gas is oxygen alone or a mixed gas of an oxygen gas and an inert gas, which is supplied from the gas reservoir via a flow rate controller while measuring the flow rate of the gas. The inert gas includes one or a mixed gas of two or more selected from the group consisting of argon, helium and nitrogen.

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

By setting the mixing ratio to 6/1 to 1/1, the film-forming energy of the vapor-deposited aluminum on the resin substrate is increased, and further, by setting the mixture ratio to 5/2 to 3/2, the vapor-deposited aluminum oxide film is oxidized. By increasing the degree, it is possible to ensure the adhesion between the deposited aluminum oxide film and the substrate.

The plasma intensity per unit area in the plasma treatment is 50 W·sec/m ² or more and 8000 W·sec/ ^{m 2 or} less. At sec/m ² or more, there is a tendency for deterioration of the resin base material due to plasma, such as consumption of the resin base material, breakage coloring, and firing. In particular, the plasma intensity of the plasma pretreatment to form an aluminum oxide layer is preferably 100 W·sec/m ² or more and 1000 W·sec/m ² or less.

[Formation of vapor-deposited aluminum oxide layer]
Various vapor deposition methods selected from physical vapor deposition and chemical vapor deposition can be applied as the vapor deposition method for forming the vapor deposited layer of aluminum oxide. The physical vapor deposition method can be selected from the group consisting of vapor deposition method, sputtering method, ion plating method, ion beam assist method, and cluster ion beam method, and the chemical vapor deposition method includes plasma CVD method, plasma polymerization method, thermal It can be selected from the group consisting of CVD method and catalytic CVD method. For the tacky-adhesive barrier film according to the present embodiment, a physical vapor deposition method is suitable.

The vapor deposition film forming apparatus is arranged in the depressurized film forming chamber 12C, and transports the resin base material S pretreated by the plasma pretreatment apparatus with the treated surface facing outward, A deposition film (aluminum oxide deposition layer) is formed on the surface of the resin base material by evaporating a film forming roller 23 for film forming and a target of a vapor deposition film forming means 24 arranged opposite to the film forming roller.

The vapor deposition film forming means 24 is of a resistance heating type, uses aluminum as an evaporation source, uses aluminum metal wires, supplies oxygen to oxidize aluminum vapor, and forms an aluminum oxide vapor deposition layer on the surface of the resin base material S. Form.

_{Oxygen may} be ^oxygen _alone ^or may be supplied as a mixed gas with an ^inert gas such as _argon . The amount of oxygen is controlled to be 20 or less. As an example in the embodiment, the oxygen supply amount is preferably 7000 sccm or more and 12000 sccm or less, more preferably 8000 sccm or more and 10000 sccm or less. By setting the content within this range, it is possible to achieve both barrier properties, transparency, and adhesion.

Evaporation of aluminum can be performed, for example, by arranging a plurality of aluminum metal wires in the axial direction of the roller 23 in a boat-shaped (referred to as a “boat type”) vapor deposition container and heating them by resistance heating.

In this manner, aluminum is evaporated while adjusting the amount of heat and the amount of heat supplied, and the amount of oxygen supplied is adjusted to control the reaction between aluminum and oxygen to form an aluminum oxide deposited layer. be able to.

[Formation of organic coating layer]
First, a metal alkoxide, a hydroxyl-containing water-soluble resin, a reaction accelerator (sol-gel process catalyst, acid, etc.), and an organic solvent such as water, methyl alcohol, ethyl alcohol, isopropanol, etc. are mixed to form an organic coating layer. A coating agent composition for is prepared.

Next, the coating agent composition for an organic coating layer is applied to the surface of the vapor-deposited aluminum oxide layer or the like by a conventional method, followed by drying. This drying step further promotes the condensation or co-condensation reaction to form a coating film. A plurality of coating films consisting of two or more layers may be formed on the first coating film by repeating the coating operation described above.

Further, heat treatment is performed at a temperature in the range of 20° C. to 200° C., preferably 50° C. to 180° C. and a temperature not higher than the melting point of the resin base material for 3 seconds to 10 minutes. As a result, an organic coating layer of the organic coating layer coating composition can be formed on the surface of the deposited aluminum oxide layer.

In addition, it is preferable that the formation of the organic coating layer is performed in-line after the formation of the vapor deposited aluminum oxide layer without being exposed to the outside air.

[Lamination of Sealant Layer]
The sealant layer may be laminated on the surface of the organic coating layer using a melt extrusion method, or a sealant layer made of a thermoplastic resin film formed in advance using a dry lamination method and an organic coating layer are laminated together. may Also, the sealant layer is preferably unstretched.

<Method for manufacturing packaging bag>
The packaging bag is manufactured by joining the sealant layers of the barrier film together and sealing the periphery by heat-sealing at a temperature equal to or higher than the melting point of the resin constituting the sealant layer.

The shape of the packaging bag may be a conventionally known shape, for example, a gusset shape, a lateral gusset shape, or a stand bag shape using another barrier film. It is preferable to be sealed for the purpose of improving the rust prevention of metal products.

<Method for manufacturing package>
The package according to the present embodiment is manufactured by hermetically packaging a metal product with the packaging bag described above. A method for hermetically packaging a metal product can be produced by hermetically joining sealant layers around their peripheries while sucking air. Metal products may also be hermetically packaged under low-oxygen conditions.

The package is not particularly limited as long as it seals and packages only the metal product, but it is preferable to seal and package the moisture absorbent and/or the oxygen absorber together with the metal product. This makes it possible to more effectively prevent the metal products to be packaged from rusting.

The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these descriptions.

<Formation of vapor deposition layer of aluminum oxide>
First, a roll was prepared by winding a 12 μm-thick polyester film (hereinafter referred to as PET film) as a resin base material.

Next, on the surface of the PET film on which the aluminum oxide vapor deposition layer is to be formed, using a continuous vapor deposition film forming apparatus in which the pretreatment section in which the plasma pretreatment apparatus is arranged and the film formation section are separated, the following plasma conditions are applied in the pretreatment section: Plasma is introduced from the plasma supply nozzle below, plasma pretreatment is performed at a conveying speed of 400 m / min, and in the film formation section where it is continuously conveyed, a reactive resistance as a heating means for vacuum deposition is placed on the plasma processing surface under the following conditions. A 12 nm-thick aluminum oxide deposition layer was formed on a PET film by a heating method to obtain a barrier film roll, and various evaluations were performed.

(Plasma pretreatment conditions)
・Plasma intensity: 150W・sec/m2
- Plasma forming gas ratio: oxygen/argon = 2/1
・Applied voltage between pretreatment drum and plasma supply nozzle: 340V
・Pretreatment pressure: 3.8 Pa

(Aluminum oxide deposition conditions)
・ Degree of vacuum: 8.1 × 10 ^-2 Pa
・Conveyance speed: 400m/min
・Oxygen gas supply amount: 8000 sccm

<Preparation of Coating Agent Composition for Coating Layer>
226 g of water, 39 g of isopropyl alcohol and 5.3 g of 0.5N hydrochloric acid were mixed to adjust the pH to 2.2, and 167 g of tetraethoxysilane and 9.2 g of glycidoxypropyltrimethoxysilane were cooled to 10°C. A solution A was prepared by mixing while stirring.

A solution B was prepared by mixing 23.3 g of polyvinyl alcohol having a degree of polymerization of 2400 and a degree of saponification of 99% or more, 513 g of water and 27 g of isopropyl alcohol.

A solution obtained by mixing A solution and B solution in a weight ratio of 4.4:5.6 was used as a coating agent composition for an organic coating layer.

The above-prepared coating agent composition for coating layer was coated on the aluminum oxide deposited layer of the PET film by spin coating. After that, heat treatment was performed in an oven at 180° C. for 60 seconds to form a coating layer having a thickness of about 400 nm on the vapor-deposited aluminum oxide layer, thereby obtaining a barrier film with an organic coating layer.

[Intensity ratio Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100 in TOF-SIMS]
For the barrier film with the organic coating layer, Cs (cesium ) While repeating soft etching at a constant rate with an ion gun, C ₆ (mass number 72.00) derived from the resin base material, Al ₃ ⁻ (mass number 80.94) derived from the aluminum oxide deposition layer, and Al ₂ O ₃ ^- (mass number 101.94) and SiO ₂ (mass number 59.96) ions originating from the coating layer were analyzed by mass spectrometry. FIG. 4 shows a graphical analysis of the measurement results.

The position where the strength of _SiO2 , which is a constituent element of the organic coating layer, becomes half the maximum strength is defined as the interface between the coating layer and the aluminum oxide deposition layer, and then the strength of _C6 , which is the constituent material of the resin base material, is the maximum. The interface between the resin substrate and the deposited aluminum oxide layer was defined as the position where the strength was half, and the deposited aluminum oxide layer was defined from the first interface to the second interface.

Then, the position (maximum intensity) where the intensity of Al ₃ ⁻ is the highest in the deposited aluminum oxide layer is obtained, and the ratio of the intensity of Al ₃ ⁻ to the intensity of Al ₂ O ₃ ⁻ at that position is the Al ₃ ⁻ maximum intensity. The ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) and the ratio of Al ₃ ⁻ to the aluminum oxide deposition layer thickness of maximum strength (depth from the organic coating layer side in the aluminum oxide deposition layer, unit %) are Calculated.

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

The maximum intensity ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) between the Al ₂ O ₃ ^-structure portion ^and the Al ₃ -structure portion of the vapor-deposited aluminum oxide layer was 5.1.

[Example 1]
<Production of laminated film>
A laminate film was produced by applying an adhesive to the surface of the organic coating layer of the barrier film produced above and laminating a non-stretched polypropylene (sealant layer) having a thickness of 70 μm.

<Production of packaging bags>
The packaging bag of Example 1 was manufactured by bringing the sealant layers of two barrier films 1 into contact with each other and heat-sealing the periphery at a melting point higher than that of unstretched polypropylene.

[Example 2]
A packaging bag of Example 2 was produced by packaging a moisture absorbent (5 g of Oasis Silica Gel, manufactured by Oasis Planning Co., Ltd.) inside the packaging bag of Example 1.

[Example 3]
A packaging bag of Example 3 was produced by packing an oxygen absorber (Everfresh QJ-50 manufactured by Tori Shigeru Sangyo Co., Ltd.) inside the packaging bag of Example 1.

[Comparative Example 1]
A packaging bag of Comparative Example 1 was manufactured by contacting the sealant layers of volatile rust prevention films (PIPAK manufactured by Nihon Parkerizing Co., Ltd.) instead of barrier film 1 and heat-sealing the periphery.

[Comparative Example 2]
A packaging bag of Comparative Example 2 was produced by packing a moisture absorbent (silica gel) inside the packaging bag of Comparative Example 1.

[Comparative Example 3]
A packaging bag of Comparative Example 3 was produced by packing an oxygen scavenger inside the packaging bag of Comparative Example 1.

<Rust prevention test>
A rust prevention test was conducted using the packaging bags of Examples and Comparative Examples. Specifically, an iron plate (cold-rolled steel plate (SPCC), 50 mm × 50 mm × 1 mm) and a copper plate (tough pitch copper plate C1100P-1/4H, 50 mm × 50 mm × 1 mm) were degreased in the packaging bags of Examples and Comparative Examples. After that, it was packaged to produce a package, and a standing test (temperature: 60°C, humidity: 90% RH, 14 days) was performed, and the appearance after the standing test was evaluated according to the following evaluation criteria.
[Evaluation criteria]
◎: No rust or discoloration ◎ ~ 〇: Spot rust, slight discoloration O: Rust generated in less than 10% of the area of the test piece ×: Rust generated in 10% or more and less than 50% of the area of the test piece XX: Rust occurred in 50% or more of the area of the test piece

From Table 1, it can be seen that the packaging bags (packaging bodies) of Examples can prevent the metal products to be packaged from rusting without adopting a multi-layer structure.

<Preparation and evaluation of laminated film>
(Laminated film 3)
Laminated film 3 was obtained in the same manner as in laminated film 1 except that the oxygen gas supply rate was changed to 10000 sccm. The Al _{3 -maximum intensity ratio (Al 3 -} ^/ Al ₂ O ₃ ^- ×100) of the vapor deposited aluminum oxide layer in the barrier film with the organic coating layer was measured in the same manner as described above ^and was 3.7.

(Laminated film 4)
A laminate film 4 was obtained in the same manner as in the laminate film 1 except that the pretreatment (plasma treatment) was not performed. The Al _{3 -maximum intensity ratio (Al 3 -} ^/ Al ₂ O ₃ ^- ×100) of the vapor deposited aluminum oxide layer in the barrier film with the organic coating layer was measured in the same manner as above ^and was 4.5.

(Laminated film 5)
The base material in laminated film 1 was the following biomass-derived biaxially stretched polyester film (biomass PET film), and the plasma intensity in the pretreatment was set to 250 W sec / m ² . Obtained. The Al _{3 -maximum intensity ratio (Al 3 -} ^/ Al ₂ O ₃ ^- ×100) of the vapor deposited aluminum oxide layer in the barrier film with the organic coating layer was measured in the same manner as above ^and was 4.9.
<Synthesis of biomass-derived polyester>
83 parts by mass of terephthalic acid and 62 parts by mass of biomass ethylene glycol (manufactured by India Glycol) were subjected to an esterification reaction by a conventional direct polymerization method, followed by a condensation polymerization reaction under reduced pressure to obtain biomass-derived polyethylene. terephthalate was obtained.
<Preparation of resin film>
60 parts by mass of the biomass-derived polyethylene terephthalate, 30 parts by mass of the fossil fuel-derived polyethylene terephthalate, and 10 parts by mass of the masterbatch containing the fossil fuel-derived polyethylene terephthalate are supplied to an extruder, and a sheet form is obtained from a T die. and cooled and solidified by cooling rolls to obtain an unstretched sheet. Next, this unstretched sheet was stretched in the longitudinal direction and then stretched in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 12 mμ. The biomass degree of the obtained biaxially stretched polyester film was measured and found to be 18.8%.

(Laminated film 6)
Laminated film 6 was obtained in the same manner as in laminated film 1 except that the oxygen gas supply amount was changed to 20000 sccm. The Al _{3 -maximum intensity ratio (Al 3 -} ^/ Al ₂ O ₃ ^- ×100) of the vapor deposited aluminum oxide layer in the barrier film with the organic coating layer was measured in the same manner as described above ^and found to be 0.8.

(Laminated film 7)
Laminated film 7 was obtained in the same manner as in laminated film 1 except that the oxygen gas supply rate was changed to 6000 sccm. The Al _{3 -maximum strength ratio (Al 3} ^{-/Al 2 O 3 -} _× ¹⁰⁰ _{) of} ^the vapor deposited aluminum oxide layer in the barrier film with the organic coating layer was 25 when measured in the same manner as described above. Since it was visually colored and poor in printability, it was not subjected to further evaluation.

Regarding the barrier film with the organic coating layer before laminating the adhesive layer in laminated films 1, 3 to 7, pre-deposition treatment conditions, deposition conditions, TOF-SIMS analysis values, evaluation results (oxygen / water vapor barrier, total light Table 2 summarizes the transmittance, haze, color difference).

<Oxygen permeability>
Using an oxygen permeability measuring device (OX-TRAN2/21, manufactured by MOCON), the barrier film with an organic coating layer was set so that the resin substrate side of the barrier film was on the oxygen supply side, and was measured in accordance with JIS K 7126 B method. Then, the oxygen permeability was measured in an atmosphere of 23°C and 90% RH.

<Water vapor permeability>
Using a water vapor permeability measuring device (PERMATRAN 3/33, manufactured by MOCON), the barrier film with an organic coating layer was set so that the resin substrate layer side was on the sensor side, and was measured according to JIS K 7126 B method. The water vapor transmission rate was measured under an atmosphere of 40° C. and 100% RH.

<Optical properties>
The total light transmittance was measured based on JIS K7136 using a haze meter. Color difference (L ^* a ^* b ^* color system) was measured according to JIS Z8722 using a spectrophotometer CM-700d. The barrier film with the organic coating layer was placed on a white plate and measured. Regarding "visual coloration", the barrier film with the organic coating layer was placed on a white plate and visually observed.

From Table 2, it can be seen that the laminated films 1 and 3 to 5 having a maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) of 1 or more and 20 or less have both high barrier properties and transparency. .

On the other hand, the laminated film 6 having a maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) of less than 1 has an oxygen permeability of 0.2 cc/m ² /day/atm and a water vapor permeability of 0. .5 g/m ² /day. On the other hand, the laminated film 7 with the maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) exceeding 20 had good oxygen permeability and water vapor permeability, but the barrier film was darkened. It was less transparent.

As described above, the maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100) between the Al ₂ O ₃ ⁻ structure portion and the Al ₃ ⁻ structure portion of the vapor deposited aluminum oxide layer is 1 or more and 20 or less. It can be seen that the barrier film is a packaging material that achieves both high barrier properties and transparency, even if it does not have a multi-layered structure, and that can prevent metal products to be packaged from rusting.

1 Barrier film 1a Laminated film 2 Base material layer 3 Aluminum oxide vapor deposition layer 4 Organic coating layer 5 Sealant layer 6 Package 10 Roller type continuous vapor deposition film forming apparatus S Resin base material P Plasma 12 Decompression chamber 12A Resin base material transfer chamber 12B Plasma pretreatment chamber 12C Film formation chambers 14a to d Guide roll 18 Raw material gas volatilization supply device 20 Pretreatment roller 21 Magnet 22 Plasma supply nozzle 23 Film formation roller 24 Vapor deposition film formation means 31 Power supply wiring 32 Power supply 35a to 35c Partition wall

Claims (2)

A packaging body in which a metal product that rusts due to oxidation is hermetically packaged in a packaging bag,
The packaging bag is composed of a laminated film in which at least a barrier film and a sealant layer are laminated, and the periphery of the sealant layers facing each other of the laminated film is sealed and joined,
The barrier film comprises a substrate layer, an aluminum oxide deposition layer, and an organic coating layer laminated in this order,
The organic coating layer is formed from a resin composition containing a metal alkoxide and a hydroxyl group-containing water-soluble resin,
The aluminum oxide deposition layer has an element-bonded structure portion represented by an Al ₂ O ₃ -structure portion ^and an Al ₃ ^-structure portion,
_{The barrier} ^{film has} a _maximum Al ₃ ⁻ maximum strength ratio (Al ₃ ⁻ /Al ₂ O ₃ ⁻ ×100), which is a ratio of strength, is 1 or more and 20 or less,
The maximum strength of the Al ₃ ^-structure portion exists at a depth position of 10% or more and 25% or less from the surface on the organic coating layer side in the film thickness direction of the vapor deposited aluminum oxide layer,
The packaging body, wherein the barrier film has an oxygen permeability of 0.15 cc/m ² /day/atm or less and a water vapor permeability of 0.2 g/m ² /day or less according to JIS K 7126 B method. 2. The package according to claim 1, further comprising a moisture absorbent in a sealed package.

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