Gas barrier film

Abstract

To provide a gas barrier film having stable water vapor barrier properties while having a gas barrier layer containing silicon oxide.SOLUTION: A gas barrier film 1 includes a base material layer 10 and a gas barrier layer 20 formed on the base material layer and containing silicon oxide, wherein the gas barrier layer has an intensity ratio H / Si of 1.0 or less based on measurement by time-of-flight secondary ion mass spectrometry at a position corresponding to 25% of the film thickness of the gas barrier layer from an interface a on the base material layer side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas barrier film, and more particularly to a gas barrier film suitable for packaging foods, medicines, precision electronic parts, and the like. [Background technology]

[0002] Packaging materials used for foods and pharmaceuticals are often required to have gas barrier properties that block oxygen, water vapor, and other gases that can cause deterioration of the contents and permeate the packaging material, in order to prevent deterioration of the contents and maintain their functions and properties. Gas barrier films, which use a metal foil such as aluminum as a gas barrier layer that is less affected by temperature, humidity, and the like, are known as packaging materials with gas barrier properties.

[0003] Another known gas barrier film configuration is one in which a vapor-deposited film of an inorganic oxide such as silicon oxide or aluminum oxide is formed on a base film made of a polymer material by vacuum deposition, sputtering, or the like (see, for example, Patent Document 1). These gas barrier films are transparent and have the ability to block gases such as oxygen and water vapor. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 60-049934 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have found that when the gas barrier layer is made of a vapor-deposited film of silicon oxide, there tends to be a relatively large variation in the water vapor barrier properties. The inventors have conducted extensive research to suppress this and have completed the present invention.

[0006] In view of the above circumstances, an object of the present invention is to provide a gas barrier film that has a gas barrier layer containing silicon oxide and has stable water vapor barrier properties. [Means for solving the problem]

[0007] A first aspect of the present invention is a gas barrier film comprising a substrate layer and a gas barrier layer formed on the substrate layer and containing silicon oxide. The gas barrier layer has an intensity ratio H / Si of 1.0 or less as measured by time-of-flight secondary ion mass spectrometry at a position corresponding to 25% of the thickness of the gas barrier layer from the interface on the substrate layer side. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a gas barrier film that has a gas barrier layer containing silicon oxide and has stable water vapor barrier properties. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of a gas barrier film according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of a manufacturing apparatus for the gas barrier film. [Figure 3] FIG. 2 is a schematic cross-sectional view of a gas barrier film according to a second embodiment of the present invention. [Figure 4] FIG. 2 is a schematic cross-sectional view showing a modified example of the gas barrier film. DETAILED DESCRIPTION OF THE INVENTION

[0010] A first embodiment of the present invention will be described below with reference to FIG. 1 is a schematic cross-sectional view of a gas barrier film 1 according to this embodiment. The gas barrier film 1 includes a base layer 10 and a gas barrier layer 20 provided on one surface of the base layer 10.

[0011] The base layer 10 is formed of a synthetic resin. There are no particular limitations on the material of the base layer 10, and various known materials can be used. Specific examples include polyolefins (polyethylene, polypropylene, etc.), polyesters (polyethylene terephthalate, polyethylene naphthalate, etc.), polyimides, polyamides (nylon-6, nylon-66, etc.), polystyrene, ethylene vinyl alcohol, polyvinyl chloride, polyimide, polyvinyl alcohol, polycarbonate, polyether sulfone, acrylic, and celluloses (triacetyl cellulose, diacetyl cellulose, etc.). In practice, it is preferable to select an appropriate material depending on the application and required physical properties. For packaging that protects contents that are extremely sensitive to moisture, such as electronic components and optical components, it is preferable to use materials that themselves have high gas barrier properties, such as polyethylene naphthalate, polyimides, and polyether sulfone.

[0012] There are no particular limitations on the thickness of the base layer 10, and it can be about 9 μm to 300 μm, taking into consideration the application, etc. A base layer 10 with a thickness within this range has appropriate flexibility and can be wound into a roll, making it easy to handle.

[0013] The base material layer 10 may be in the form of a continuous material or a sheet material, but a continuous material is preferably used. The longitudinal length of the continuous base material layer 10 is not particularly limited, but a resin film of, for example, 10 m or more is preferably used. The upper limit of the length is not limited, and it may be, for example, about 10 km.

[0014] The surface of the substrate layer 10 may contain additives such as antistatic agents, ultraviolet absorbers, plasticizers, and slip agents as needed. Furthermore, to improve adhesion, the surface of the substrate layer 10 may be subjected to physical treatments such as corona treatment, flame treatment, plasma treatment, and adhesion-enhancing treatment, or chemical treatment / modification treatments such as treatment with an acid or alkali chemical solution. The surface of the substrate layer 10 contributes to the density in the initial growth stage of vacuum film deposition when forming a gas barrier layer, and from this perspective, it is preferable that the surface be as smooth as possible.

[0015] The gas barrier layer 20 plays a major role in the gas barrier properties exhibited by the gas barrier film 1, and is made of silicon oxide (SiO x ) is a film made of an inorganic oxide containing at least

[0016] In the gas barrier layer 20 according to this embodiment, the ratio of the number of oxygen (O) atoms to the number of silicon (Si) atoms (O / Si) is 1.0 or more and 1.9 or less at least on the surface of the gas barrier layer 20. In consideration of the transparency of the gas barrier film 1 as a whole, O / Si is more preferably 1.3 or more. The O / Si ratio of the gas barrier layer 20 can be measured by a known method. For example, it can be evaluated using an analytical device such as an XPS (X-ray photoelectron spectrometer). Analytical devices such as an XPS (X-ray photoelectron spectrometer) sometimes use sputter etching with argon (Ar) ions to analyze the inside of the film. However, transparent oxide film layers containing silicon (Si) are reduced, making it impossible to obtain the correct ratio of silicon (Si) atoms to oxygen (O) atoms (O / Si). Therefore, it is preferable to analyze the surface of the layer.

[0017] There are no limitations on the method for forming the gas barrier layer 20, and known film-forming methods such as vacuum deposition, ion plating, sputtering, and plasma-enhanced chemical vapor deposition (PECVD) can be used. However, vacuum deposition is particularly preferred due to its superior productivity. Materials heating methods for vacuum deposition include resistance heating, high-frequency induction heating, and electron beam heating. Furthermore, combining a plasma-assisted method or an ion-beam-assisted method can result in a dense gas barrier layer 20, improving its barrier properties.

[0018] When the gas barrier layer 20 is formed by vacuum deposition, the partial pressure value of m / z18 measured with a partial pressure meter (quadrupole mass spectrometer using a Faraday cup) during film formation is set to be 0.05 Pa or less. If the partial pressure of m / z18 measured with the mass spectrometer during film formation exceeds 0.05 Pa, the amount of water molecules in the deposition atmosphere increases, which increases the amount of H bonded to Si, which is undesirable. Here, m / z (more precisely, italics) is a dimensionless quantity obtained by dividing the mass of an ion by the unified atomic mass unit, and further dividing it by the absolute value of the charge on the ion. It is the value used on the horizontal axis of a mass spectrum measured by a mass spectrometer. m / z is an academic term defined by the International Union of Pure and Applied Sciences (IUPAC). m / z 18 is the HO related to water. + In addition to m / z 18, there are also fragment ions such as m / z 17 associated with water, but in the present invention, the HO ion with the strongest spectral intensity is used. + The m / z 18 derived from the ion was used as an index. A typical method for adjusting the partial pressure of m / z 18 during film formation is to provide a mechanism for adsorbing gas in the film formation environment. For example, by providing a device for condensing and adsorbing gas (water vapor) (hereinafter referred to as a "gas adsorption device") in the film formation chamber of the film formation apparatus and also in the unwinding / winding chamber, particularly near the unwinding roll, the partial pressure of m / z 18 during film formation can be kept below 0.05 Pa by both reducing water vapor in the film formation chamber and reducing water vapor derived from moisture released from the substrate. As the gas adsorption device, a Meissner coil, a cryopanel, a cryopump, a sorption pump, an ion pump, or a getter pump is preferably used, with a Meissner coil and a cryopanel being more preferred because they can increase the adsorption area. For example, when a Meissner coil or a cryopanel is used, the cooling temperature is preferably −100° C. or lower, and more preferably −110° C. or lower, from the viewpoint of obtaining sufficient gas condensation and adsorption performance.

[0019] By adjusting the above-mentioned O / Si value and the m / z18 partial pressure during film formation within a predetermined range, the amount of water molecules present in the atmosphere during inorganic oxide film formation is reduced compared to a typical vapor deposition process, resulting in a reduced amount of OH in the inorganic oxide film. Furthermore, the amount of OH and H in the water molecules that can bond with Si is also reduced. Furthermore, the reduced number of Si-OH bonds and Si-H bonds reduces the gaps between molecules in the inorganic oxide film. As a result, the gas barrier layer 20 has a dense structure, which improves the stability of the water vapor barrier properties it exhibits.

[0020] The above-described state of the gas barrier layer 20 can be evaluated by calculating the intensity ratios (H / Si, SiOH / Si, SiH / Si) using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Specifically, the surface of the gas barrier layer of the gas barrier film is etched using a sputter ion source to expose the area at the desired depth, and then various secondary ion intensities (secondary ion intensities of H, SiOH, SiH, and Si) are measured in the depth direction using a primary ion source. Examples of the sputter ion source include cesium, and examples of the primary ion source include bismuth. The inventors calculated the ratios of various secondary ion intensities (H / Si, SiOH / Si, SiH / Si) at various positions from the interface a on the substrate layer side of the gas barrier layer that correspond to 75%, 50%, 25%, etc. of the film thickness of the gas barrier layer. The position of the interface a was defined as the position where the concentration of C (carbon) derived from the substrate layer was approximately half of its maximum value.

[0021] Details will be described later using examples, but in the study by the inventors, At a position from the interface a on the base layer side of the gas barrier layer that corresponds to 25% of the thickness of the gas barrier layer, the ratio of the secondary ion intensity of H to the secondary ion intensity of Si, H / Si, is 1.0 or less. At a position from the interface a on the base layer side of the gas barrier layer that corresponds to 25% of the thickness of the gas barrier layer, the ratio of the secondary ion intensity of SiOH to the secondary ion intensity of Si (SiOH / Si) is 0.20 or less. At a position from the interface a on the base layer side of the gas barrier layer that corresponds to 25% of the thickness of the gas barrier layer, the ratio of the secondary ion intensity of SiH to the secondary ion intensity of Si, SiH / Si, is 0.20 or less. It has been revealed that these are both independent indicators that the gas barrier layer 20 has few intermolecular gaps and is dense as a film. The position corresponding to 25% of the thickness from interface a on the substrate layer side of the gas barrier layer corresponds to a position relatively close to the substrate layer and is formed early in the gas barrier layer formation process. At positions corresponding to 50% and 70% of the thickness, no clear difference in secondary ion intensity was observed between well-formed and poorly formed gas barrier layers. However, at the position corresponding to 25%, the secondary ion intensity was clearly different between the two, and the ratios of various secondary ion intensities (H / Si, SiOH / Si, SiH / Si) in well-formed gas barrier layers satisfied at least one of the above-mentioned criteria. This is thought to be because, if the gas barrier layer is not dense, it is susceptible to the influence of moisture present in the adjacent substrate layer, etc., and the ratios of various secondary ion intensities (H / Si, SiOH / Si, SiH / Si) in the depth direction of the gas barrier layer near the substrate layer or undercoat layer become high.

[0022] The gas barrier film according to the present invention exhibits stable gas barrier properties by including a gas barrier layer 20 that satisfies at least one of the above-mentioned criteria. Furthermore, the gas barrier properties are stable at a high level even in mass production processes, allowing for efficient production of high-quality gas barrier films.

[0023] The chemical bonding state of the gas barrier layer 20 can also be analyzed using X-ray photoelectron spectroscopy (hereinafter sometimes referred to as "XPS"). XPS is a technique in which an object to be measured is irradiated with X-rays and the photoelectrons emitted from the surface of the object are energy analyzed, and it is possible to analyze the composition and chemical bonding state of elements in a region several nanometers deep from the surface of the object to be measured. The chemical bonding state of silicon oxide in the inorganic oxide film layer 13 can be analyzed by SiO2 (Si4+ ) as well as Si 3+ , Si 2+ , Si + It is known that there are three suboxide components of Si and five of Si. These are Si 2p When measuring the narrow spectrum of SiO2, SiO2 is observed around 103.5 to 104.5 eV, and Si 3+ , Si 2+ , Si + and Si are observed at positions shifted to lower energy than SiO2, each separated by approximately 1 eV.

[0024] In addition, the commonly used X-ray source is MgKα or AlKα, and Si is detected using XPS with a pass energy of about 10 eV. 2p When measuring the narrow spectrum of Si, the peaks of each bond are not separated and are observed in a composite form. 2p In the narrow spectrum of the SiO2 film, a peak top is detected in the vicinity of 103.5 to 104.5 eV, but in the case of a silicon oxide film that is mainly composed of SiO2 and contains multiple other chemical bonding states, the peak top shifts to the range of 101 to 103.5 eV. In addition, compared to the case of the SiO2 film, in the case of a silicon oxide film that is mainly composed of SiO2 and contains multiple other chemical bonding states, the peak top shifts to the range of 101 to 103.5 eV. 2p The full width at half maximum (FWHM) of the peak is broadened. Note that the peak shift caused by charging increases the C detected due to surface contaminant hydrocarbons. 1s In the present invention, the C peak detected due to surface contaminant hydrocarbons must be corrected. 1s The peak was set to 284.6 eV. In XPS, sputter etching with argon (Ar) ions is sometimes used for depth analysis, but reduction and mixing occur due to collisions with argon (Ar) ions, which may change the chemical bonding state in the original silicon oxide film, so it is preferable to analyze the surface without using sputter etching.

[0025] On the surface of the gas barrier layer 20 according to this embodiment, Si measured by X-ray photoelectron spectroscopy (XPS)2p All peaks (a = Si 4+ , Si 3+ , Si 2+ , Si + , Si) to Si 3+ , Si 2+ , Si + , Si peak (b=Si 3+ , Si 2+ , Si + It is preferable that the ratio b / a of Si (SiO2, Si) is greater than 0.122. When the b / a value is greater than 0.122, the silicon oxide film contains many chemical bonding states other than SiO2, resulting in a dense structure and reducing the permeation paths for gas molecules.

[0026] The gas barrier layer 20 according to this embodiment is preferably amorphous. When the gas barrier layer 20 is an amorphous film, the film is free of grain boundaries that occur in polycrystalline films, thereby reducing the permeation paths for gas molecules. Whether the gas barrier layer 20 is amorphous or not can be evaluated by a known method. For example, this can be evaluated by determining whether an X-ray diffraction pattern obtained using an analytical device such as an XRD (X-ray diffractometer) has a crystalline diffraction peak.

[0027] The thickness of the gas barrier layer 20 varies depending on the configuration and film-forming method used, but can generally be set appropriately within the range of 1 to 200 nm. If the thickness of the gas barrier layer 20 is less than 1 nm, a uniform film may not be obtained or the film thickness may be insufficient, and the gas barrier layer may not fully function. If the thickness of the gas barrier layer 20 exceeds 200 nm, external factors such as bending or pulling may cause cracks after film formation, resulting in a loss of barrier properties. The thickness is preferably within the range of 5 to 150 nm, and more preferably within the range of 10 to 120 nm.

[0028] 2 is a schematic diagram showing an example of a gas barrier film manufacturing apparatus according to an embodiment of the present invention. For manufacturing, a film-forming apparatus 100 is used, which includes a vacuum film-forming chamber 40 and an unwinding / winding chamber 50 in which an unwinding roll 42 is disposed. The film-forming chamber 40 and the unwinding / winding chamber 50 are separated by a partition wall and have independent exhaust systems. A gas adsorption device 48 is installed in the film-forming chamber 40, and a gas adsorption device 49 having a function similar to that of the gas adsorption device 48 is also installed near the unwinding roll 42 in the unwinding / winding chamber 50. The gas adsorption device 49 may be of the same type as the gas adsorption device 48, as long as it condenses and adsorbs gases. A plastic film 41 that will become the base layer 10 is set on a winding roll 42. The plastic film 41 pulled out from the winding roll 42 passes through a film-forming roll 43 exposed inside the film-forming chamber 40, and is then taken up by a take-up roll 44. A vapor deposition material 45 for forming the gas barrier layer 20 is set inside the film-forming chamber 40, and an electron beam gun 46 is installed as a vapor deposition means. The vapor deposition material 45 is heated by the electron beam and becomes vapor deposition particles 47, which are vapor-deposited on the plastic film. In this way, the gas barrier layer 20 is formed on the plastic film 41.

[0029] 2, electron beam evaporation using an electron beam gun 46 is shown as a method for heating the evaporation material 45, but resistance heating or high-frequency induction heating may also be used to heat and evaporate the evaporation material 45. The resistance heating may be a method in which a crucible filled with the material is directly resistance heated, or another method may also be used.

[0030] The manufacturing apparatus for the gas barrier layer vapor-deposited film is not limited to this form, and if necessary, a plasma pretreatment device may be installed in the unwinding / winding chamber, or a reactive gas introduction device may be installed in the film-forming chamber. The arrangement of the rolls is also not particularly limited.

[0031] In this embodiment, the following modifications are also possible. Gas barrier layers are provided on both sides of the base layer 10. In this case, the two gas barrier layers may be the same or different. Plasma treatment is performed on the substrate layer 10, and the gas barrier layer 20 is then laminated on the plasma-treated surface, thereby improving the adhesion and gas barrier properties between the substrate layer 10 and the gas barrier layer 20. The plasma treatment of the substrate layer 10 can be performed by various known plasma treatments such as RIE (Reactive Ion Etching), corona treatment, hollow anode plasma treatment, and planar plasma treatment, as well as various known surface treatments such as ozone treatment and ion beam treatment, which have the same effect as plasma treatment. Known discharge gases such as argon, oxygen, nitrogen, and helium can be used for the plasma treatment.

[0032] A second embodiment of the present invention will be described with reference to Fig. 3. In the following description, components common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0033] 3 is a schematic cross-sectional view of a gas barrier film 2 according to this embodiment. The gas barrier film 2 further includes an overcoat layer 30 provided on the gas barrier layer 20.

[0034] The overcoat layer 30 is a layer containing an organic polymer resin, and has the function of protecting the gas barrier layer 20 and preventing cracks from occurring due to friction or bending.

[0035] Various known gas barrier films can also be used as the overcoat layer 30. In this case, the barrier properties of the gas barrier film as a whole can be further improved. The overcoat layer 30 is obtained, for example, by forming a coating film made of a coating agent on the gas barrier layer 20 by a wet coating method and drying the coating film. In this specification, the term "coating film" refers to a wet film, and the term "film" refers to a dry film.

[0036] The overcoat layer 30 may be a film containing at least one of a metal alkoxide, its hydrolysate, or its reaction product, and a water-soluble polymer (hereinafter, this may be referred to as an "organic-inorganic composite film.") It is preferable that the overcoat layer 30 further contains at least one of a silane coupling agent and its hydrolysate.

[0037] Examples of metal alkoxides and their hydrolysates contained in the organic-inorganic composite film include those represented by the general formula M(OR)n, such as tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(OC3H7)3], and their hydrolysates. One of these may be contained alone, or two or more may be contained in combination.

[0038] The total content of at least one of a metal alkoxide and its hydrolysate, or its reaction product in the organic-inorganic composite film can be, for example, 40 to 70 mass%. From the viewpoint of further improving gas barrier properties, the lower limit of the total content of at least one of a metal alkoxide and its hydrolysate, or its reaction product in the organic-inorganic composite film can be 50 mass%. From the same viewpoint, the upper limit of the total content of at least one of a metal alkoxide and its hydrolysate, or its reaction product in the organic-inorganic composite film can be 65 mass%.

[0039] The water-soluble polymer contained in the organic-inorganic composite film is not particularly limited, and examples thereof include polyvinyl alcohol-based polymers, acrylic polyol-based polymers, and polysaccharides such as starch, methyl cellulose, and carboxymethyl cellulose. From the viewpoint of further improving gas barrier properties, it is preferable to include a polyvinyl alcohol-based polymer. The number-average molecular weight of the water-soluble polymer can be, for example, 40,000 to 180,000.

[0040] A water-soluble polymer such as polyvinyl alcohol can be obtained by, for example, saponifying (including partial saponification) polyvinyl acetate. This water-soluble polymer may have several tens of percent or only a few percent of acetate groups remaining.

[0041] The content of the water-soluble polymer in the organic-inorganic composite film can be, for example, 15 to 50 mass %. If the content of the water-soluble polymer is 20 to 45 mass %, the gas barrier property of the organic-inorganic composite film can be further improved, which is preferable.

[0042] Silane coupling agents and their hydrolysates contained in the organic-inorganic composite film include silane coupling agents having organic functional groups. Examples of such silane coupling agents and their hydrolysates include ethyltrimethoxysilane, vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, and their hydrolysates. One of these may be contained alone, or two or more may be contained in combination.

[0043] At least one of the silane coupling agent and its hydrolysate preferably has an epoxy group as an organic functional group. Examples of silane coupling agents having an epoxy group include γ-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. The silane coupling agent having an epoxy group and its hydrolysate may have an organic functional group other than the epoxy group, such as a vinyl group, an amino group, a methacryl group, or a ureyl group.

[0044] A silane coupling agent having an organic functional group and its hydrolysate can further improve the gas barrier properties of the overcoat layer 30 and the adhesion to the gas barrier layer 20 through interaction between the organic functional group and the hydroxyl group of the water-soluble polymer. In particular, the adhesion between the overcoat layer 30 and the gas barrier layer 20 can be improved through interaction between the epoxy group of the silane coupling agent and its hydrolysate and the hydroxyl group of the polyvinyl alcohol.

[0045] The total content of the silane coupling agent and its hydrolysate or at least one of its reaction products in the organic-inorganic composite film can be, for example, 1 to 15 mass %. If the total content of the silane coupling agent and its hydrolysate or at least one of its reaction products is 2 to 12 mass %, the gas barrier properties of the organic-inorganic composite film can be further improved, which is preferable.

[0046] The thickness of the overcoat layer 30 can be set according to the required gas barrier properties, and can be, for example, 0.05 to 5 μm. The thickness of the overcoat layer 30 is preferably 0.05 to 1 μm, and more preferably 0.1 to 0.5 μm. If the thickness of the overcoat layer 30 is 0.05 μm or more, sufficient oxygen barrier properties are likely to be obtained. If the thickness of the overcoat layer 30 is 1 μm or less, it is easy to form a uniform coated surface, and drying load and production costs can be reduced.

[0047] The gas barrier film having the above-described organic-inorganic composite coating as the overcoat layer 30 maintains excellent gas barrier properties even after undergoing boiling treatment or retort sterilization treatment.

[0048] In the gas barrier films according to the above-described embodiments, an undercoat layer 15 may be further provided between the base layer 10 and the gas barrier layer 20, as in the modified example shown in Fig. 4. That is, Fig. 4 shows a modified gas barrier film 2A according to the second embodiment, but the same modifications may be made to the first embodiment shown in Fig. 1. Furthermore, a pair of an undercoat layer 15 and a gas barrier layer 20 may be provided on both sides of the base layer 10. In the gas barrier film 2 A, the above-mentioned interface a is located at the boundary between the gas barrier layer 20 and the undercoat layer 15 .

[0049] The undercoat layer 15 is provided on the base material layer 10 to increase adhesion between the base material layer 10 and the gas barrier layer 20, prevent peeling of the gas barrier layer 20, and protect the gas barrier layer 20 from mechanical damage such as scratches and abrasions. The material for the undercoat layer 15 is not particularly limited, but examples thereof include thermosetting resins, thermoplastic resins, ultraviolet-curable resins, and electron beam-curable resins.

[0050] Examples of thermosetting resins that form the undercoat layer 15 include thermosetting urethane resins made of acrylic polyol resins and isocyanate prepolymers, phenolic resins, urea melamine resins, epoxy resins, unsaturated polyester resins, silicone resins, etc. Among these, by forming the undercoat layer 15 using a composite of an acrylic polyol resin containing a hydroxy group and an isocyanate compound having at least two NCO groups in the molecule, the adhesion between the base material layer 10 and the gas barrier layer 20 can be improved.

[0051] Acrylic polyol resins are polymeric compounds obtained by polymerizing (meth)acrylic acid derivative monomers or polymeric compounds obtained by copolymerizing (meth)acrylic acid derivative monomers with other monomers, and have hydroxy groups at the terminals and side chains, and react with the NCO groups of isocyanate compounds. (Meth)acrylic acid derivative monomers have hydroxy groups at the terminals and side chains. Examples of (meth)acrylic acid derivative monomers include hydroxyethyl (meth)acrylate and hydroxybutyl (meth)acrylate.

[0052] The above-mentioned other monomers can be copolymerized with (meth)acrylic acid derivative monomers having hydroxy groups at their terminals and side chains. Examples of the above-mentioned other monomers include (meth)acrylic acid derivative monomers having an alkyl group at their side chains, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, and t-butyl (meth)acrylate; (meth)acrylic acid derivative monomers having a carboxy group at their side chains, such as (meth)acrylic acid; and (meth)acrylic acid derivative monomers having an aromatic ring or cyclic structure at their side chains, such as benzyl (meth)acrylate and cyclohexyl (meth)acrylate. Other than the (meth)acrylic acid derivative monomers, styrene monomers, cyclohexyl maleimide monomers, and phenyl maleimide monomers are also possible. The above-mentioned other monomers may themselves have hydroxy groups at their terminals and side chains.

[0053] The acrylic polyol resin is preferably a polymer compound obtained by polymerizing a (meth)acrylic acid derivative monomer having a carboxy group in the side chain, such as (meth)acrylic acid. When forming the undercoat layer 15, a gas barrier laminate film with higher water vapor barrier properties can be obtained by forming it using a composite of an acrylic polyol resin obtained by polymerizing a monomer having a carboxy group and an isocyanate compound.

[0054] The hydroxyl group-containing acrylic polyol resin that can be used for the undercoat layer 15 is not particularly limited, but preferably has a hydroxyl group value of 50 mg KOH / g or more and 250 mg KOH / g or less. Here, the hydroxyl group value (mg KOH / g) is an index of the amount of hydroxyl groups in the acrylic polyol resin, and indicates the number of mg of potassium hydroxide required to acetylate the hydroxyl groups per gram of acrylic polyol resin. The weight-average molecular weight of the acrylic polyol resin is not particularly limited, but is preferably 3,000 or more and 200,000 or less. It is particularly preferably 5,000 or more and 100,000 or less. It is even more preferably 5,000 or more and 40,000 or less.

[0055] The isocyanate compound used has two or more NCO groups in its molecule. Examples of monomeric isocyanates include aromatic isocyanates such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylene diisocyanate (XDI), and tetramethylxylylene diisocyanate (TMXDI), and aliphatic isocyanates such as hexamethylene diisocyanate (HDI), bisisocyanate methylcyclohexane (H6XDI), isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (H12MDI). Polymers or derivatives of these monomeric isocyanates can also be used. Examples include trimer nurate types, adduct types reacted with 1,1,1-trimethylolpropane, and biuret types reacted with biuret.

[0056] The isocyanate compound can be arbitrarily selected from the above-mentioned isocyanate compounds or their polymers and derivatives, and one or more of them can be used in combination.

[0057] An example of the undercoat layer 15 is formed by applying a solution consisting of a composite of the above-mentioned acrylic polyol resin and the above-mentioned isocyanate compound and a solvent onto the substrate layer 10, followed by reactive curing. The equivalent ratio (NCO / OH) of the NCO groups of the isocyanate compound to the hydroxy groups of the acrylic polyol resin is preferably 0.3 or more and 2.5 or less. The solvent used here may be any solvent that dissolves the above-mentioned acrylic polyol resin and the isocyanate compound. Examples of solvents include methyl acetate, ethyl acetate, butyl acetate, cyclohexanone, acetone, methyl ethyl ketone, dioxolane, and tetrahydrofuran. In practice, these solvents may be used alone or in combination of two or more.

[0058] The thermoplastic resin forming the undercoat layer 15 may be appropriately selected from polyols having two or more hydroxy groups, such as acrylic polyols, polyester polyols, polycarbonate polyols, polyether polyols, polycaprolactone polyols, and epoxy polyols; polyvinyl resins such as polyvinyl acetate and polyvinyl chloride; polyvinylidene chloride resins; polystyrene resins; polyethylene resins; polypropylene resins; and polyurethane resins. These may also be mixed in any ratio. The hydroxyl value of the polyol is not particularly limited, but is preferably 10 mgKOH / g or more and 250 mgKOH / g or less.

[0059] The UV-curable or electron beam-curable resin forming the undercoat layer 15 preferably contains, but is not limited to, an organic polymer resin having a hydroxyl value in the range of 10 to 100 mgKOH / g. The organic polymer resin preferably contains, but is not limited to, an acid value in the range of 10 to 100 mgKOH / g. Here, the acid value (mgKOH / g) refers to the number of milligrams of potassium hydroxide required to neutralize the free fatty acids, resin acids, etc. contained in 1 g of sample. The organic polymer resin preferably contains at least a thermoplastic resin. If the hydroxyl value or acid value is less than 10 mgKOH / g, the chemical bonding strength between the functional groups and the surface of the gas barrier layer 20 is weakened, tending to reduce adhesion to the gas barrier layer 20. If the hydroxyl value or acid value exceeds 100 mgKOH / g, precipitates containing hydroxyl groups produced by decomposition of the undercoat layer 15 during durability tests such as a moist heat resistance test tend to inhibit adhesion between the undercoat layer 15 and the gas barrier layer 20.

[0060] Monomers that can be used in the ultraviolet-curable resin or electron beam-curable resin that forms the undercoat layer 15 include monofunctional monomers such as ethyl(meth)acrylate, ethylhexyl(meth)acrylate, styrene, methylstyrene, and N-vinylpyrrolidone, as well as polyfunctional monomers such as trimethylolpropane(meth)acrylate, hexanediol(meth)acrylate, tripropylene glycol di(meth)acrylate, diethylene glycol (meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and neopentyl glycol (meth)acrylate. Oligomers that can be used in these ultraviolet-curable resins or electron beam-curable resins include urethane acrylate, epoxy acrylate, and polyester acrylate.

[0061] When two or more types of organic polymer resins selected from thermosetting resins, thermoplastic resins, ultraviolet curable resins, and electron beam curable resins are used in combination as the organic polymer resins forming the undercoat layer 15, the blending ratio thereof is not particularly limited.

[0062] The undercoat layer 15 may further contain additives other than the organic polymer resin, as needed, such as antioxidants, weathering agents, heat stabilizers, lubricants, nucleating agents, ultraviolet absorbers, plasticizers, antistatic agents, colorants, fillers, surfactants, and silane coupling agents.

[0063] The thickness of the undercoat layer 15 is preferably 0.05 μm or more and 10.0 μm or less. It is particularly preferably 0.05 μm or more and 5.0 μm or less. If the thickness is thinner than 0.05 μm, the adhesion between the base layer 10 and the gas barrier layer 20 will be insufficient. If the thickness is thicker than 10.0 μm, the influence of internal stress will be greater, the gas barrier layer 20 will not be laminated neatly, the barrier properties will be insufficient, and the transparency and coating accuracy will also be insufficient.

[0064] The undercoat layer 15 can be formed by a conventional coating method. Examples of well-known methods that can be used include dipping, roll coating, gravure coating, reverse coating, air knife coating, comma coating, die coating, screen printing, spray coating, gravure offset, and organic vapor deposition. The drying method can be one or a combination of two or more heat application methods, such as hot air drying, heat roll drying, high frequency irradiation, infrared irradiation, UV irradiation, and electron beam irradiation. Alternatively, a film previously coated on another resin substrate by the above-mentioned formation method can be transferred to the substrate layer 10 by a transfer method such as adhesive transfer, thermal transfer, or UV transfer.

[0065] The gas barrier film according to each embodiment of the present invention will be further described using examples and comparative examples. The technical scope of the present invention is not limited solely by the specific content of the examples and comparative examples.

[0066] Example 1 A 20 μm-thick biaxially oriented polypropylene film was used as the substrate layer. The partial pressure of m / z 18 in the deposition chamber, measured with a partial pressure meter, was adjusted to 0.02 Pa during deposition using Meissner coils (cooling temperature: -120°C) installed near the unwinding roll in both the deposition chamber and the unwinding / winding chamber. An SiOx deposition material with an appropriately adjusted ratio of Si material to SiO2 material was sublimated in the deposition chamber, and a gas barrier layer (film thickness 40 nm, O / Si 1.7) made of silicon oxide (SiOx) was formed on the substrate layer by electron beam deposition. In this manner, a gas barrier film according to Example 1 was produced.

[0067] Example 2 The gas barrier film of Example 2 was produced in the same manner as in Example 1, except that the partial pressure of m / z 18 was adjusted to 0.01 Pa and the ratio of Si material to SiO2 material was appropriately adjusted to set the O / Si of the gas barrier layer to 1.3.

[0068] Example 3 The gas barrier film of Example 3 was produced in the same manner as in Example 1, except that the partial pressure of m / z 18 was adjusted to 0.04 Pa and the ratio of Si material to SiO2 material was appropriately adjusted to set the O / Si of the gas barrier layer to 1.8.

[0069] Example 4 A gas barrier film according to Example 4 was produced in the same manner as in Example 1, except that the partial pressure of m / z 18 was adjusted to 0.01 Pa.

[0070] Example 5 A gas barrier film according to Example 5 was produced in the same manner as in Example 1, except that the partial pressure of m / z 18 was adjusted to 0.04 Pa.

[0071] Example 6 A gas barrier film according to Example 6 was produced in the same manner as in Example 1, except that the thickness of the gas barrier layer was adjusted to 10 nm. Example 7 A gas barrier film according to Example 7 was produced in the same manner as in Example 1, except that the thickness of the gas barrier layer was adjusted to 120 nm.

[0072] Example 8 A coating agent prepared by mixing the following (1) liquid and (2) liquid in a weight ratio of 6:4 was applied onto the gas barrier layer of the gas barrier film of Example 1 by gravure coating, and then dried to form an overcoat layer with a thickness of 0.4 μm. (1) Solution: 10.4 g of tetraethoxysilane was mixed with 89.6 g of hydrochloric acid (0.1 N), and the mixture was stirred for 30 minutes to hydrolyze the solution, resulting in a solid content of 3 wt% (SiO2 equivalent). (2) Liquid: 3 wt% polyvinyl alcohol solution in water / isopropyl alcohol (water:isopropyl alcohol weight ratio 90:10) In this manner, a gas barrier film according to Example 8 was produced.

[0073] Example 9 A coating agent having a solid content of 5 wt % was applied onto the gas barrier layer of the gas barrier film of Example 1 by gravure coating, and dried, the coating agent being a mixture of an aqueous solution of polyvinyl alcohol, a hydrolyzed solution of tetraethoxysilane, and a hydrolyzed solution of 1,3,5-tris(3-trimethoxysilylpropyl)isocyanurate silane coupling agent, such that the solid content weight ratio after drying was 30:60:10, to form an overcoat layer having a thickness of 0.4 μm. In this manner, a gas barrier film according to Example 9 was produced.

[0074] Example 10 A mixed solution of acrylic polyol and isocyanate was applied to the substrate layer by gravure coating and dried to form an undercoat layer having a thickness of 0.2 μm. A gas barrier layer 20 was formed on the undercoat layer in the same manner as in Example 1, thereby producing a gas barrier film according to Example 10.

[0075] (Comparative Example 1) The gas barrier film of Comparative Example 1 was produced in the same manner as in Example 1, except that neither the Meissner coils installed in the film formation chamber nor the unwinding / winding chamber were used, the partial pressure of m / z 18 in the film formation chamber measured with a partial pressure meter during film formation was set to 0.10 Pa, and the ratio of Si material to SiO2 material was appropriately adjusted to set the O / Si of the gas barrier layer to 1.9.

[0076] (Comparative Example 2) A gas barrier film 1 according to Comparative Example 2 was produced in the same manner as in Example 1, except that the partial pressure of m / z 18 was adjusted to 0.04 Pa and that only an SiO2 material was used as the SiOx material without mixing in an Si material. The O / Si ratio of the gas barrier layer in Comparative Example 2 was 2.0.

[0077] (Comparative Example 3) A gas barrier film according to Comparative Example 3 was produced in the same manner as in Example 1, except that neither the Meissner coils installed in the film-forming chamber nor the unwinding / winding chamber were used, and the partial pressure of m / z18 in the film-forming chamber measured with a partial pressure meter during film formation was set to 0.10 Pa.

[0078] Comparative Example 4 A gas barrier film according to Comparative Example 4 was produced in the same manner as in Example 1, except that only a Meissner coil was used in the film formation chamber, and the partial pressure of m / z 18 in the film formation chamber measured with a partial pressure meter during film formation was set to 0.07 Pa.

[0079] The laminates according to the examples and comparative examples were evaluated as follows: The evaluation was carried out on three samples for each example. (25% thickness secondary ion measurement by TOF-SIMS) TOF-SIMS was performed using a time-of-flight secondary ion mass spectrometer (TOF-SIMS5) manufactured by ION-TOF under the following measurement conditions: A portion corresponding to 25% of the gas barrier layer thickness (25% thickness) was exposed from the surface side of the gas barrier layer of the gas barrier film by etching with a sputter ion source, and then various secondary ion intensities (H, SiOH, SiH, and Si secondary ion intensities) were measured in the depth direction using a primary ion source. The position from interface a on the substrate layer side of the gas barrier layer was defined as the position where the C concentration was approximately half of its maximum value, and the ratios of various secondary ion intensities (H / Si, SiOH / Si, SiH / Si) at a position corresponding to 25% of the gas barrier layer thickness were calculated based on the actual measurements. The ion sources used were as follows: Sputter ion source: Cs Primary ion source: Bi3 ++

[0080] (XPS analysis of gas barrier layer) The composition ratio and bonding state of the inorganic oxide film, which is the gas barrier layer, were measured using a JEOL X-ray photoelectron spectrometer (JPS-9010MX). The X-ray source was MgKα, and the pass energy was set to 5 eV. 2p The narrow spectrum of O is in the range of 95-106 eV. 1s The narrow spectrum of C covers the range of 525-538 eV. 1sThe narrow spectrum was measured in the range of 278 to 290 eV. To avoid the influence of noise, each narrow spectrum was repeatedly scanned and integrated more than 30 times. In this case, the composition of the outermost surface was measured without argon etching to avoid changes in the chemical bonding state in the silicon oxide film due to reduction and mixing caused by argon (Ar) ion collisions. In addition, because a peak shift occurs due to charging, the C detected due to surface contaminating hydrocarbons was 1s Correction was made so that the peak was at 284.6 eV.

[0081] (Water vapor barrier performance evaluation) The gas barrier films of each example were measured using a water vapor transmission rate measuring device manufactured by Mocon (product name: PERMATRAN3 / 34G, measurement conditions: 40°C-90% RH, unit: g / (m 2 The water vapor transmission rate (WVTR) was evaluated using the FTIR (TfL) method. The results are shown in Table 1.

[0082] [Table 1]

[0083] In all of the gas barrier films according to the examples, at the 25% thickness position of the gas barrier layer 20, the ratio of the secondary ion intensity of H to the secondary ion intensity of Si, H / Si, measured by TOF-SIMS, was 1.0 or less, the ratio of the secondary ion intensity of SiOH to the secondary ion intensity, SiOH / Si, was 0.20 or less, and the ratio of the secondary ion intensity of SiH to the secondary ion intensity, SiH / Si, was 0.20 or less. The variations in WVTR in the examples were all within ±0.5 g (standard deviation 0.5 g or less), and were stable.

[0084] On the other hand, in the gas barrier films according to the comparative examples, the ratio H / Si exceeded 1.0, the ratio SiOH / Si exceeded 0.20, and the ratio SiH / Si exceeded 0.20 at the 25% thickness position of the gas barrier layer 20. The WVTR variation in the comparative examples exceeded ±0.5 g (standard deviation exceeded 0.5 g), and the quality was unstable. 2 For Lot 3 of Comparative Example 4, in which the O / Si ratio was less than 1.0, the SiOH / Si ratio was 0.20 or less, and the SiH / Si ratio was 0.20 or less at the 25% thickness position of the gas barrier layer 20. This indicates that these three parameters are useful for evaluating the performance of transparent inorganic oxide films, and can provide information that cannot be obtained by looking at O / Si alone. For reference, Table 2 shows the results of secondary ion measurements of Lot 1 listed in Table 1 at 50% and 75% thickness from the interface. Although a certain difference is observed between the Examples and Comparative Examples even at 50% thickness, some of the Examples and Comparative Examples have similar values, making the difference less clear than at 25% thickness. Furthermore, at 75% thickness, no clear difference is observed between the Examples and Comparative Examples. Therefore, it can be said that secondary ion measurements at 25% thickness using TOF-SIMS are a sensitive indicator of the state of the gas barrier layer and are useful.

[0085] [Table 2]

[0086] Furthermore, the results of the examples and comparative examples show that the gas barrier film according to this embodiment can be stably produced by using a gas adsorption device to maintain the m / z18 partial pressure value in the film formation chamber at 0.05 Pa or less, and forming a gas barrier layer on a substrate layer passing through the film formation chamber using a vapor deposition material that is a mixture of Si material and SiO2 material.

[0087] The above describes each embodiment and example of the present invention, but the specific configuration is not limited to these embodiments, and includes modifications and combinations of configurations within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0088] 1, 2, 2A gas barrier film 10 Base material layer 15 Undercoat layer 20 Gas barrier layer 30 Overcoat layer 40 Deposition chamber 41 Plastic Film 42 Unwinding roll 43 Coating roll 44 Winding roll 45 Evaporation materials 46 Electron Beam Gun 47 Vapor deposition particles 48, 49 Gas adsorption device 50 Unwinding and winding room 100 Film deposition equipment a interface

Claims

1. a substrate layer; a gas barrier layer formed on the base layer and containing silicon oxide; Equipped with the gas barrier layer has an intensity ratio H / Si of 1.0 or less at a position corresponding to 25% of the film thickness of the gas barrier layer from the interface on the base layer side, as measured by time-of-flight secondary ion mass spectrometry; Gas barrier film.

2. the gas barrier layer has an intensity ratio (SiOH / Si) based on the measurement of 0.20 or less at a position corresponding to 25% of the film thickness of the gas barrier layer from the interface on the base layer side; The gas barrier film according to claim 1 .

3. the gas barrier layer has an intensity ratio SiH / Si based on the measurement of 0.20 or less at a position corresponding to 25% of the film thickness of the gas barrier layer from the interface on the base layer side; The gas barrier film according to claim 1 .

4. The surface of the gas barrier layer is measured by X-ray photoelectron spectroscopy (XPS). All peaks of Si 2p peaks (a = Si ４＋ , Si ３＋ , Si ２＋ , Si ＋ , Si) ３＋ , Si ２＋ , Si ＋ , Si peak (b=Si ３＋ , Si ２＋ , Si ＋ , Si) the ratio b / a is greater than 0.122; The gas barrier film according to claim 1 .

5. The thickness of the gas barrier layer is 1 nm or more and 200 nm or less. The gas barrier film according to claim 1 .

6. Further comprising an overcoat layer formed on the gas barrier layer. The gas barrier film according to claim 1 .

7. the overcoat layer contains at least one of a metal alkoxide, a hydrolyzate of a metal alkoxide, a reaction product of a metal alkoxide, and a reaction product of a hydrolyzate of a metal alkoxide, and a water-soluble polymer; The gas barrier film according to claim 6 .

8. the overcoat layer contains at least one of a silane coupling agent, a hydrolysate of a silane coupling agent, a reaction product of a silane coupling agent, and a reaction product of a hydrolysate of a silane coupling agent; The gas barrier film according to claim 6 .

9. an undercoat layer provided between the substrate layer and the gas barrier layer; The undercoat layer contains at least one of a thermosetting resin, a thermoplastic resin, an ultraviolet curable resin, and an electron beam curable resin. The gas barrier film according to claim 1 .

10. an undercoat layer provided between the substrate layer and the gas barrier layer; the undercoat layer is made of a cured product of a composition containing an acrylic polyol resin and an isocyanate compound; The gas barrier film according to claim 1 .

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