JP7516784B2 - Laminated film and film laminate using same - Google Patents

Description

The present invention relates to a laminated film with excellent gas barrier properties and a film laminate using the same.

2. Description of the Related Art Gas barrier laminate films having a structure in which a plastic film is used as a substrate and a layer mainly made of an inorganic material, such as an inorganic oxide vapor deposition layer (referred to as an "inorganic layer"), is formed on the surface of the substrate, have been widely used for packaging items that require blocking various gases such as water vapor and oxygen, for example, for packaging to prevent deterioration of foods, industrial products, pharmaceuticals, etc.
In addition to packaging applications, new applications of this gas barrier laminate film have also been attracting attention in recent years, such as liquid crystal display elements, solar cells, electromagnetic wave shields, touch panels, EL substrates, and color filters.

Regarding such gas barrier laminate films having an inorganic layer, various improvements have been investigated.
For example, from the viewpoint of imparting transparency and gas barrier properties as well as boiling resistance and retort resistance without the occurrence of delamination or the like, a vapor deposition film has been disclosed in which a primer layer made of a composite of a functional group-containing silane coupling agent or a hydrolyzate of a silane coupling agent with a polyol and an isocyanate compound, and an inorganic oxide thin film layer having a thickness of 5 to 300 nm are sequentially laminated on at least one surface of a plastic substrate (Patent Document 1).

In addition, from the viewpoint of excellent gas barrier properties and adhesion strength between the constituent layers, an extremely thin gas barrier laminate film has been disclosed that is composed of a base film/inorganic thin film layer/anchor layer/inorganic thin film layer, and the thickness of the anchor layer is 0.1 to 10 nm (Patent Document 2).

Furthermore, a gas barrier laminate film has been disclosed in which a barrier film is formed by laminating a silicon oxide film (SiOx) as a barrier layer on one or both sides of a plastic substrate, the barrier layer is composed of at least two silicon oxide films, the thickness of each silicon oxide film is 10 nm or more and 50 nm or less, the thickness of the barrier layer composed of two or more silicon oxide films is 20 nm or more and 200 nm or less, and the proportion of carbon atoms in the barrier layer is 10 at. % or less (Patent Document 3).

On the other hand, various proposals have been made to improve the gas barrier properties of polylactic acid films, which are biodegradable films.
For example, it has been disclosed that adjusting the ratio of crystalline and amorphous regions in a polylactic acid film achieves both good adhesion and good gas barrier properties (Patent Document 4).

It has also been disclosed that by setting the planar orientation and heat of crystal fusion of the polylactic acid film within a specific range, it is possible to achieve both gas barrier properties and transparency (Patent Document 5).

Furthermore, a gas barrier film with good interlayer adhesion has been disclosed by providing an anchor layer containing a silane coupling agent on a polylactic acid film (Patent Document 6).

JP 2000-238172 A International Publication No. 2007-034773 JP 2009-101548 A Patent No. 4452574 JP 2006-69218 A JP 2013-233658 A

As mentioned above, various studies have been conducted on gas barrier laminate films having an inorganic layer to improve their gas barrier properties. However, it has been found that the gas barrier properties of such films can be reduced when exposed to heat during the manufacturing process or during use. This tendency is particularly pronounced when films with poor heat resistance, such as polylactic acid films or polyolefin films, are used as the base film, and the problem of reduced gas barrier properties when exposed to heat is prominent.

The object of the present invention is to provide a new laminate film that has an inorganic layer on at least one side of a base film and that can prevent a decrease in gas barrier properties even when a film with poor heat resistance, such as a polylactic acid film or a polyolefin film, is used as the base film, and a film laminate using the same.

The present invention proposes a laminated film having a structure in which an anchor layer and an inorganic layer are laminated in this order on at least one side of a base film (1), in which the storage modulus (E') of the anchor layer at 120°C is 10 MPa or more, and the thickness of the anchor layer is 0.02 to 5.00 μm.

The present invention also proposes a film laminate having a structure in which a base film (2) is bonded to the outermost surface of the laminate film via an adhesive layer.

The laminated film proposed by the present invention has a specific anchor layer on the substrate film, so that even if a substrate film with poor heat resistance is used, the deformation of the substrate film during heat treatment can be alleviated by the anchor layer. Therefore, it is possible to prevent cracks from occurring in the inorganic layer during heat treatment, and the desired gas barrier properties can be obtained. Therefore, the laminated film proposed by the present invention and the film laminate using the same can be widely used, for example, as a packaging material for packaging items that require blocking various gases such as water vapor and oxygen, for example, to prevent deterioration of foods, industrial products, and pharmaceuticals. In addition to packaging applications, the laminated film can also be suitably used for various components such as liquid crystal display elements, solar cells, electromagnetic shields, touch panels, EL substrates, and color filters.

Next, the present invention will be described based on an embodiment example. However, the present invention is not limited to the embodiment described below.

<<This laminate film>>
A laminate film according to one embodiment of the present invention (referred to as "the present laminate film") is a laminate film having a configuration in which an anchor layer and an inorganic layer are laminated in this order on at least one side of a base film (referred to as "the present base film").

<Base film>
The present base film constituting the present laminate film is not limited in material and configuration as long as it is a film having transparency and necessary and sufficient rigidity.

The substrate film may have a single layer structure or a multilayer structure.
When the present substrate film has a multi-layer structure, it may have a two-layer or three-layer structure, or may have four or more layers.

The less heat resistant the substrate film is, the more the effects of the present invention can be enjoyed. From this perspective, the substrate film is preferably, for example, a polylactic acid film or a polyolefin film. However, it is not limited to these.

In the present invention, the term "polylactic acid film" or "polyolefin film" refers to a film having a layer mainly made of polylactic acid resin or polyolefin resin, whether the film has a single-layer structure or a multilayer structure. Preferably, the film has a layer mainly made of polylactic acid resin or polyolefin resin.
Among these, it is preferable that the main component resin of each layer of the present substrate film is a polylactic acid resin or a polyolefin resin, whether the present substrate film has a single layer structure or a multilayer structure.

In this case, the "main layer" refers to the layer in question in the case of a single-layer film, and to the layer having the greatest thickness ratio among the layers constituting the film in the case of a multi-layer film.
Further, the term "main component resin" refers to the resin that is contained in the largest proportion among the resins constituting each layer, and is, for example, a resin that accounts for 50% by mass or more, particularly 70% by mass or more, and of these, 80% by mass or more (including 100% by mass) of the resins constituting each layer.

The polylactic acid film or polyolefin film may contain a layer whose main resin component is polylactic acid resin or polyolefin resin, or may contain a resin other than polylactic acid resin or a component other than resin.

(Polylactic acid resin)
The polylactic acid resin is a homopolymer of D-lactic acid or L-lactic acid, or a copolymer thereof. That is, the polylactic acid resin may be any one of poly(D-lactic acid) whose structural unit is D-lactic acid, poly(L-lactic acid) whose structural unit is L-lactic acid, and poly(DL-lactic acid) which is a copolymer of L-lactic acid and D-lactic acid, or a mixed resin thereof. It may also be a mixed resin of a plurality of the above-mentioned copolymers having different copolymerization ratios of D-lactic acid and L-lactic acid.

The copolymer of L-lactic acid and D-lactic acid has a copolymerization ratio of D-lactic acid to L-lactic acid (hereinafter abbreviated as "D/L ratio") of preferably "3/97" to "15/85" or "85/15" to "97/3", more preferably "5/95" to "15/85" or "85/15" to "95/5", even more preferably "8/92" to "15/85" or "85/15" to "92/8", and particularly preferably "10/90" to "15/85" or "85/15" to "90/10".

It is also possible to blend polylactic acid resins with different D/L ratios, and blending is more preferable since it is easier to adjust the D/L ratio of the polylactic acid resin. In this case, the average D/L ratio of multiple lactic acid polymers should be within the above range. By blending two or more polylactic acid resins with different D/L ratios and adjusting the crystallinity according to the intended use, it is possible to achieve a balance between heat resistance and heat shrinkage properties.

The polylactic acid resin may be copolymerized with a small amount of a copolymer component within a range that does not impair the essential properties of the PLA resin.
Examples of the copolymerization component include at least one selected from the group consisting of α-hydroxycarboxylic acids other than lactic acid, non-aliphatic dicarboxylic acids such as terephthalic acid, aliphatic dicarboxylic acids such as succinic acid, non-aliphatic diols such as ethylene oxide adducts of bisphenol A, and aliphatic diols such as ethylene glycol.

Examples of α-hydroxycarboxylic acid units other than lactic acid include bifunctional aliphatic hydroxycarboxylic acids such as glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-n-butyric acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, and 2-hydroxycaproic acid, as well as lactones such as caprolactone, butyrolactone, and valerolactone.

Examples of the diol units include ethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. Examples of the dicarboxylic acid units include succinic acid, adipic acid, suberic acid, sebacic acid, and dodecanedioic acid.

The copolymerization ratio of lactic acid and an α-hydroxycarboxylic acid other than lactic acid is not particularly limited. In particular, a higher ratio of lactic acid is preferable because it reduces consumption of petroleum resources, and it is also preferable to copolymerize at a ratio not exceeding the range of the Vicat softening point described later.
Specifically, the copolymerization ratio of a copolymer of lactic acid with an α-hydroxycarboxylic acid other than lactic acid, an aliphatic diol, or an aliphatic dicarboxylic acid, i.e., lactic acid/α-hydroxycarboxylic acid other than lactic acid, an aliphatic diol, or an aliphatic dicarboxylic acid, is from 95/5 to 10/90, preferably from 90/10 to 20/80, and more preferably from 80/20 to 30/70.
If the copolymerization ratio is within the above range, a film having a good balance of physical properties such as rigidity, transparency, and impact resistance can be obtained. In addition, the structure of these copolymers may be a random copolymer, a block copolymer, or a graft copolymer, and any structure may be used. However, from the viewpoint of the impact resistance and transparency of the film, a block copolymer or a graft copolymer is preferable.

The polylactic acid resin may also contain a small amount of a chain extender, such as a diisocyanate compound, an epoxy compound, or an acid anhydride, to increase the molecular weight.

The mass average molecular weight of the polylactic acid resin is 20,000 or more, preferably 40,000 or more, and more preferably 60,000 or more, with an upper limit of 400,000 or less, preferably 350,000 or less, and more preferably 300,000 or less. If the mass average molecular weight of the polylactic acid resin is 20,000 or more, an appropriate resin cohesive force can be obtained, and the film can be prevented from having insufficient strength and elongation or from becoming embrittled. On the other hand, if the mass average molecular weight is 400,000 or less, the melt viscosity can be reduced, which is preferable from the viewpoint of improving production and productivity.

As the polymerization method for the polylactic acid resin, known methods such as condensation polymerization and ring-opening polymerization can be adopted. For example, in the case of condensation polymerization, D-lactic acid, L-lactic acid, or a mixture thereof can be directly dehydrated and condensed to obtain a polylactic acid resin having any composition. In the case of ring-opening polymerization, lactide, which is a cyclic dimer of lactic acid, can be ring-opened and polymerized in the presence of a specific catalyst, using a polymerization regulator as necessary, to obtain a polylactic acid resin having any composition. The lactide includes DL-lactide, which is a dimer of L-lactic acid, and these can be mixed and polymerized as necessary to obtain a polylactic acid resin having any composition and crystallinity.

A representative example of polylactic acid resin is commercially available "Nature Works" manufactured by Nature Works LLC. A specific example of a random copolymer of PLA resin, diol, and dicarboxylic acid is "GS-Pla" (manufactured by Mitsubishi Chemical Corporation), and a specific example of a block copolymer is "Plamate" (manufactured by DIC Corporation).

(Polyolefin resin)
Examples of the polyolefin resin include polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, etc. Among them, from the viewpoint of heat shrinkage rate and moldability, it is preferable to use polyethylene resin, polypropylene resin, or a mixture thereof.

Examples of polyethylene resins include medium density polyethylene resins (MDPE) having a density of 0.92 g/ ^cm3 or more and 0.94 g/ ^cm3 or less, low density polyethylene resins (LDPE) having a density of less than 0.92 g/ ^cm3 , and linear low density polyethylene resins (LLDPE). Among these, linear low density polyethylene resins (LLDPE) are preferably used from the viewpoints of stretchability, impact resistance of the film, transparency, etc.

The linear low density polyethylene resin (LLDPE) may be a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms, preferably 4 to 12 carbon atoms. Examples of α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-1-butene, and 4-methyl-1-pentene. Of these, 1-butene, 1-hexene, and 1-octene are preferably used. The α-olefins to be copolymerized may be used alone or in combination of two or more.

The polyolefin resin contains a polyethylene component, and the content is preferably 70% by mass or more, and more preferably 75% by mass or more. If the content is 70% by mass or more, the strength of the entire film can be maintained.

In particular, the density of the polyethylene resin is preferably 0.910 g/cm ³ or less, more preferably 0.905 g/cm ³ or less, and even more preferably 0.900 g/cm ³ or less. The lower limit is not particularly limited, but is preferably 0.800 g/cm ³ or more, more preferably 0.850 g/cm ³ or more, and even more preferably 0.880 g/cm ³ or more. If the density is 0.910 g/cm ³ or less, the affinity with polylactic acid is improved, and the stretchability is maintained, and the heat shrinkage rate in the practical temperature range (about 70 ° C. or more and 90 ° C. or less) can be sufficiently obtained. On the other hand, if the density is 0.800 g/cm ³ or more, the stiffness (rigidity at room temperature) and heat resistance of the entire film are not significantly reduced, which is practically preferable.

The polyethylene resin preferably has a melt flow rate (MFR: JIS K 7210, temperature: 190°C, load: 21.18N) of 0.1 g/10 min or more and 10 g/10 min or less. If the MFR is 0.1 g/10 min or more, good extrusion processability can be maintained, while if the MFR is 10 g/10 min or less, thickness unevenness of the laminated film and a decrease in mechanical strength are unlikely to occur, which is preferable.

The polypropylene resin mentioned above can be homopropylene resin, or a soft polypropylene resin that is more flexible than homopropylene resin. Examples of soft polypropylene resins include random polypropylene resin, block polypropylene resin, and propylene-ethylene rubber. Among these, random polypropylene resin is particularly suitable from the viewpoints of extensibility and resistance to breakage.

In the random polypropylene resin, the α-olefin to be copolymerized with propylene preferably has 2 to 20 carbon atoms, more preferably 4 to 12 carbon atoms, and examples thereof include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, and 1-decene.
Among them, a random polypropylene having a propylene unit content of 80% by mass or more, preferably 85% by mass or more, more preferably 90% by mass or more as an α-olefin is particularly preferably used from the viewpoints of stretchability, heat shrinkage characteristics, impact resistance, transparency, rigidity, etc. of the film. Moreover, the α-olefin to be copolymerized may be used alone or in combination of two or more kinds.

The melt flow rate (MFR) of polypropylene resin is usually 0.5 g/10 min or more, preferably 1.0 g/10 min or more, and 15 g/10 min or less, preferably 10 g/10 min or less, in terms of MFR (JIS K 7210, temperature: 230°C, load: 21.18 N).

Specific examples of commercially available products include polyethylene resins with trade names "Novatec LD, LL", "Kernel", and "Tafmer A, P" (manufactured by Nippon Polyethylene Co., Ltd.), "Suntech HD, LD" (manufactured by Asahi Kasei Chemicals Corporation), "HIZEX", "ULTZEX", and "EVOLUE" (manufactured by Mitsui Chemicals, Inc.), "Moatec" (manufactured by Idemitsu Kosan Co., Ltd.), "UBE Polyethylene" and "UMERIT" (manufactured by Ube Industries, Ltd.), "NUC Polyethylene" and "Nacflex" (manufactured by Nippon Unicar Co., Ltd.), and "Engage" (manufactured by The Dow Chemical Company).

Polypropylene resins are commercially available under the trade names "Novatec PP," "WINTEC," and "Tafmer XR" (manufactured by Japan Polypropylene), "Mitsui Polypro" (manufactured by Mitsui Chemicals), "Sumitomo Noblen," "Tafthren," and "Excellen EPX" (manufactured by Sumitomo Chemical), "IDEMITSU PP," and "IDEMITSU TPO" (manufactured by Idemitsu Kosan), "Adflex," "Adsyl" (manufactured by SunAllomer), and "VERSIFY" (manufactured by The Dow Chemical Company).

As the polyolefin resin, a copolymer of the above-mentioned ethylene and a monomer copolymerizable therewith can also be suitably used. Examples of copolymers of ethylene and a monomer copolymerizable therewith include ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer.

The ethylene content of the ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer is 70% by mass or more, preferably 75% by mass or more, and 95% by mass or less, preferably 90% by mass or less, and more preferably 85% by mass or less. If the ethylene content is 70% by mass or more, the break resistance and shrinkage characteristics of the entire film can be maintained well.

Commercially available ethylene-vinyl acetate copolymers (EVA) include, for example, "Evaflex" (manufactured by DuPont-Mitsui Polychemicals), "Novatec EVA" (manufactured by Mitsubishi Chemical), "Evaslen" (manufactured by DIC), and "Evatate" (manufactured by Sumitomo Chemical). Commercially available ethylene/ethyl acrylate copolymers (EEA) include, for example, "Evaflex EEA" (manufactured by DuPont-Mitsui Polychemicals), and an ethylene/methyl acrylate copolymer is, for example, "Elbaloy AC" (manufactured by DuPont-Mitsui Polychemicals).

The MFR of the copolymer of ethylene and a copolymerizable monomer is not particularly limited. Usually, the lower limit of the MFR (JIS K 7210, temperature: 190°C, load: 21.18 N) is preferably 0.5 g/10 min or more, more preferably 1.0 g/10 min or more, and the upper limit is preferably 15 g/10 min or less, more preferably 10 g/10 min or less.

The polyolefin resin has a lower limit of mass average molecular weight of preferably 50,000 or more, more preferably 100,000 or more, and an upper limit of 700,000 or less, more preferably 600,000 or less, and even more preferably 500,000 or less. If the mass average molecular weight of the polyolefin resin is within the above range, it can exhibit the desired practical physical properties such as mechanical properties and heat resistance, and also has an appropriate melt viscosity and good moldability.

The method for producing polyolefin resins is not particularly limited, and examples thereof include known polymerization methods using known olefin polymerization catalysts, such as slurry polymerization, solution polymerization, bulk polymerization, and gas phase polymerization using multi-site catalysts such as Ziegler-Natta catalysts or single-site catalysts such as metallocene catalysts, as well as bulk polymerization using radical initiators.

The present substrate film may contain particles for the main purposes of roughening the film surface to impart slipperiness and preventing the occurrence of scratches in each process.
The type of the particles is not particularly limited as long as they are particles that can impart slipperiness. For example, inorganic particles such as silica calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin can be mentioned. These can be used alone or in combination of two or more kinds.
The shape of the particles is not particularly limited, and may be, for example, spherical, blocky, rod-like, flat, or the like.
The particles are not particularly limited with respect to hardness, specific gravity, color, etc. Two or more kinds of these particles may be used in combination as necessary.

The average particle size of the particles is preferably 5.0 μm or less, more preferably 0.01 μm or more or 3.0 μm or less, and even more preferably 0.5 μm or more or 2.5 μm or less. If the average particle size of the particles is 5 μm or less, the surface roughness of the substrate film will not be too rough, and in that respect, problems when forming an anchor layer or an inorganic layer on the surface of the substrate film can be reduced.

The particle content is preferably 5% by mass or less of the substrate film, more preferably 0.0003% by mass or more or 3% by mass or less, and even more preferably 0.01% by mass or more or 2% by mass or less. By keeping the particle content within the above range, it is possible to achieve both the slipperiness and transparency of the film, which is preferable.

The method for adding particles to the substrate film is not particularly limited, and any conventional method can be used.

The substrate film may also contain conventionally known antioxidants, antistatic agents, heat stabilizers, lubricants, dyes, pigments, UV absorbers, etc., as necessary.

(Thickness of the base film)
The thickness of the present substrate film is not particularly limited as long as it is within a range that allows the substrate film to be formed into a film, and is preferably 9 μm to 100 μm, more preferably 12 μm or more or 75 μm or less, and even more preferably 15 μm or more or 60 μm or less.

The present substrate film can be formed, for example, by forming the resin composition into a film shape by a melt casting method or a solution casting method. In the case of a multi-layer structure, co-extrusion may be used.
The film may be uniaxially or biaxially stretched, and is preferably a biaxially stretched film from the viewpoint of rigidity.

<Main anchor layer>
The anchor layer constituting the present laminate film (hereinafter referred to as "the present anchor layer") is a layer having a function of enhancing the adhesion between the present substrate film and the present inorganic layer.

The anchor layer can usually be formed from an anchor coating agent.
Examples of the anchor coating agent include solvent-based or water-based polyesters, urethane resins, acrylic resins, vinyl alcohol resins, ethylene vinyl alcohol resins, vinyl modified resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, isocyanate group-containing resins, alkoxyl group-containing resins, modified styrene resins, and modified silicone resins, and these can be used alone or in combination of two or more. Among these, from the viewpoint of adhesion and hot water resistance, it is preferable to use at least one selected from polyesters, urethane resins, acrylic resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, isocyanate-containing resins, and copolymers thereof alone or in combination of two or more. Among these, at least one resin selected from the group consisting of polyesters, urethane resins, and acrylic resins is preferred.

The present anchor layer preferably contains a cured product obtained by curing a curable resin. The curable resin may be a photocurable resin or a thermosetting resin, and is particularly preferably one containing an isocyanate compound. In this case, the content of the isocyanate compound in the present anchor layer is preferably 1 to 50 parts by mass relative to 100 parts by mass of the curable resin, more preferably 5 parts by mass or more or 40 parts by mass or less, and even more preferably 10 parts by mass or more or 30 parts by mass or less.
Therefore, the present anchor layer is preferably a layer formed by coating the present substrate film with a resin composition containing a curable resin, and then subjecting the coated film to a curing treatment.

If the thickness of this anchor layer is 5.00 μm or less, the slip properties are good and there is almost no peeling from the substrate film due to internal stress of the anchor layer itself, and if the thickness is 0.02 μm or more, a uniform thickness can be maintained, which is preferable.
From this viewpoint, the thickness of the present anchor layer is preferably 0.02 to 5.00 μm, more preferably 0.03 μm or more or 3.00 μm or less, and even more preferably 0.05 μm or more or 1.00 μm or less.

The anchor layer preferably has a storage modulus (E') at 120°C of 10.0 MPa or more, more preferably 12.0 MPa or more, even more preferably 14.0 MPa or more, and even more preferably 15.0 MPa or more.
If the anchor layer has the above thickness and elastic modulus, even if a substrate film having poor heat resistance is used, the anchor layer can mitigate deformation of the substrate film during heat treatment, and the occurrence of cracks in the inorganic layer during heat treatment can be prevented, thereby obtaining the desired gas barrier properties.

Furthermore, the anchor layer preferably has a peak temperature of loss tangent (tan δ) in dynamic viscoelasticity measurement of 60.0°C or higher, more preferably 70.0°C or higher, even more preferably 80.0°C or higher, and even more preferably 85.0°C or higher.

In order to impart the viscoelasticity to the present anchor layer, for example, the present anchor layer is preferably made to contain a cured product obtained by curing a curable resin. Therefore, the present anchor layer is preferably formed by coating a resin composition containing a heat- or light-curable resin on the present substrate film and curing the heat- or light-curable resin with heat or light. However, the method for imparting the viscoelasticity to the present anchor layer is not limited to this method.
Among them, it is particularly preferable to select and use an isocyanate compound as the thermosetting resin.

As described above, by laminating an anchor layer having a storage modulus of 10.0 MPa or more at 120°C to a thickness of 0.02 μm or more and 5.00 μm or less as the anchor layer constituting the present laminate film, good barrier properties and adhesion can be obtained even when an inorganic substance-containing layer is provided on a substrate film having poor heat resistance, such as a polylactic acid film (PLA) or an oriented polypropylene film (OPP).
The mechanism by which such good barrier properties can be exhibited can be assumed as follows.
In general, when an inorganic substance-containing layer is vapor-deposited on a substrate film having poor heat resistance, the substrate film tends to shrink due to heat damage caused during vapor deposition.
In general, when an anchor layer is interposed between the substrate and the inorganic substance-containing layer, the adhesion between the substrate film and the inorganic substance-containing layer tends to be improved, and therefore the force of the substrate film shrinking is directly transmitted to the inorganic substance-containing layer, causing cracks and the like, thereby reducing the barrier properties.
In contrast, in the present laminate film, by focusing on the elastic modulus or tan δ (corresponding to Tg) of the anchor layer and setting said parameters to a certain value or more and a specific thickness or more, the anchor layer itself can be endowed with a force capable of resisting the force of shrinkage of the base film. As a result, it is possible to mitigate the shrinkage of the base film, suppress the occurrence of cracks in the inorganic substance-containing layer, and obtain good barrier properties that can withstand heat.

<Inorganic Layer>
The inorganic layer constituting the present laminate film (hereinafter referred to as the "present inorganic layer") is a layer containing an inorganic substance, particularly an inorganic oxide, as a main material.
The "main material" means a material that occupies 50% by weight or more, preferably 70% by weight or more, preferably 80% by weight or more, and preferably 90% by weight or more (including 100% by weight) of the inorganic layer.

This inorganic layer is a layer that can enhance the property of suppressing gas permeation (also called "gas barrier property"), particularly the water vapor barrier property. Furthermore, in the case of this inorganic layer, by including alkali metal ions, even higher gas barrier properties can be achieved.

The inorganic material that constitutes the inorganic layer as the main material may be, for example, one or more inorganic compounds selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon oxycarbonitride, aluminum oxide, aluminum nitride, aluminum oxynitride, and aluminum oxycarbide.

As the inorganic layer, for example, a PVD inorganic layer formed by a physical vapor deposition (PVD) method, a plasma-assisted deposition inorganic layer formed by a plasma-assisted deposition method, a CVD inorganic layer formed by a chemical vapor deposition (CVD) method, or a coated inorganic layer formed by a method in which inorganic particles are dispersed in an organic polymer and applied, is preferred.
Here, as representative examples of the inorganic layer, a PVD inorganic layer, a plasma-assisted deposition inorganic layer, and a CVD inorganic layer will be described.

(PVD Inorganic Layer)
If the present inorganic layer comprises at least one PVD inorganic layer formed by physical vapor deposition (PVD), this is preferable in that higher gas barrier properties can be exhibited.

An example of the PVD inorganic layer is a layer made of silicon oxide represented by SiOx (1.0<x≦2.0). In this case, if the value (lower limit) of x in the SiOx is small, the gas permeability is small, and the gas barrier property of the inorganic layer can be improved, but the silicon oxide film itself tends to be yellowish and low in transparency. From this point of view, x in the SiOx is more preferably 1.2≦x≦2.0, and more preferably 1.4≦x≦2.0.
The above composition can be confirmed by XPS analysis or the like.

The pressure during the formation of the PVD inorganic layer is preferably 1×10 ⁻⁷ Pa to 1 Pa, more preferably 1×10 ⁻⁶ or more or 1×10 ⁻¹ Pa or less, and even more preferably 1×10 ⁻⁴ or more or 1×10 ⁻² Pa or less, from the viewpoints of gas barrier properties, vacuum evacuation capability, and the degree of oxidation of the SiOx layer to be formed.
The partial pressure of oxygen during introduction is preferably in the range of 10 to 90% of the total pressure, and more preferably 20% or more or 80% or less.

As described above, the inorganic layer preferably has at least one PVD inorganic layer. In this case, the inorganic layer may be a single layer structure consisting of a PVD inorganic layer, or may be a multi-layer structure (two or more layers) in which a CVD inorganic layer described later or a PVD inorganic layer having the same or different composition is laminated on the PVD inorganic layer to ensure higher gas barrier properties. For example, a structure in which a PVD inorganic layer and a CVD inorganic layer are alternately formed (for example, a three-layer structure of a PVD inorganic layer, a CVD inorganic layer, and a PVD inorganic layer, etc.) can be used. In addition, by forming a CVD inorganic layer on a PVD inorganic layer, defects that occur in the PVD inorganic layer are filled, and the gas barrier properties and adhesion between layers tend to be improved.

(Plasma-assisted deposition inorganic layer)
If the present inorganic layer is formed from a plasma-assisted deposited inorganic layer, the transparency can be improved without deteriorating the gas barrier property.
The term "plasma-assisted deposition method" refers to a method in which, during vacuum deposition, the deposition material is deposited while being ionized by plasma, or by irradiating gaseous ions from a separately provided ion source.
By forming the inorganic layer by plasma-assisted deposition, oxygen can be efficiently incorporated into the inorganic layer, and as described above, transparency can be improved without deteriorating the gas barrier properties.
A thin film formed by normal vacuum deposition is not advantageous in terms of film strength or density, because the energy of the particles flying in is smaller than that of a thin film formed by sputtering or the like. On the other hand, according to the plasma-assisted deposition method, the deposition material obtains energy, so that a thin film with high strength and density can be formed even by vacuum deposition. In addition, since the excited species in the plasma are highly reactive, it is possible to form a thin film by optionally oxidizing, nitriding, or carbonizing the evaporation source by introducing gases such as oxygen, nitrogen, and acetylene. By providing the inorganic layer by this method, there is also the advantage that the film can be formed more quickly than by sputtering or plasma CVD.

An example of a plasma-assisted deposition inorganic layer is a layer composed of silicon oxide represented by SiOx (1.0<x≦2.0). As described above, by introducing oxygen gas into this inorganic layer by the plasma-assisted deposition method, the oxygen molar ratio of silicon oxide can be increased, so that x in the SiOx can be set to 1.2≦x≦2.0, and even 1.4≦x≦2.0, thereby further increasing transparency. Note that as the oxygen molar ratio (x) increases, the gas barrier properties usually decrease. With this laminate film, excellent gas barrier properties can be maintained.

(CVD Inorganic Layer)
When the inorganic layer comprises at least one CVD inorganic layer, the CVD inorganic layer is preferably composed of a thin film formed by chemical vapor deposition of at least one selected from metals, metal oxides, metal nitrides, and silicon compounds.
As the metal oxide or metal nitride, it is preferable to use the oxide or nitride of the metal described above or a mixture thereof from the viewpoints of gas barrier property and adhesion. In addition, the metal oxide or metal nitride obtained by plasma decomposition of an organic compound may be used.
From the viewpoint of gas barrier properties and adhesion, it is also preferable to use metals such as silicon and aluminum or compounds thereof.

A preferred example of the inorganic layer is a thin film formed by chemical vapor deposition of at least one selected from silicon compounds such as silicon oxide, silicon oxide carbide, silicon oxynitride, silicon oxycarbonitride, and silicon nitride, and aluminum oxide.
Examples of the silicon compound include silane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetra-t-butoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, phenyltriethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, hexafluoro ... trimethyldisiloxane, bis(dimethylamino)dimethylsilane, bis(dimethylamino)methylvinylsilane, bis(ethylamino)dimethylsilane, N,O-bis(trimethylsilyl)acetamide, bis(trimethylsilyl)carbodiimide, diethylaminotrimethylsilane, dimethylaminodimethylsilane, hexamethyldisilazane, hexamethylcyclotrisilazane, heptamethyldisilazane, nonamethyltrisilazane, octamethylcyclotetrasilazane, tetrakis dimethylaminosilane, tetraisocyanatosilane, tetramethyldisilazane, tris(dimethylamino)silane, triethoxyfluorosilane, allyldimethylsilane, allyltrimethylsilane, benzyltrimethylsilane, bis(trimethylsilyl)acetylene, 1,4-bistrimethylsilyl-1,3-butadiyne, di-t-butylsilane, 1,3-disilabutane, bis(trimethylsilyl)methane, cyclopentadienyltrimethylsilane, phenyldimethylsilane, Examples of the silane include phenyltrimethylsilane, propargyltrimethylsilane, tetramethylsilane, trimethylsilylacetylene, 1-(trimethylsilyl)-1-propyne, tris(trimethylsilyl)methane, tris(trimethylsilyl)silane, vinyltrimethylsilane, hexamethyldisilane, octamethylcyclotetrasiloxane, tetramethylcyclotetrasiloxane, hexamethyldisiloxane, hexamethylcyclotetrasiloxane, and M silicate 51.

The CVD inorganic layer preferably contains carbon, and the carbon content of the CVD inorganic layer is preferably 0.5 at. % or more, more preferably 1 at. % or more, and even more preferably 2 at. % or more.
By containing a small amount of carbon in the CVD inorganic layer, stress relaxation is efficiently performed, and curling of the barrier film itself can also be reduced. On the other hand, from the viewpoint of gas barrier properties, the carbon content in the CVD inorganic layer is preferably less than 20 at. %, more preferably 10 at. % or less, and most preferably 5 at. % or less.
By setting the carbon content within the above range, the surface energy of the inorganic layer is increased, and the adhesion between the inorganic layers is improved, thereby improving the folding resistance and peeling resistance of the barrier film. Note that "at.%" indicates the atomic composition percentage (atomic%). The composition can be confirmed by XPS analysis or the like.

The CVD inorganic layer can be formed, for example, by the method described in JP-A-2013-226829.
For example, when a layer made of silicon oxide is formed by a chemical vapor deposition (CVD) method, any silicon compound can be used as a raw material in any state of gas, liquid, or solid at room temperature and normal pressure. In the case of a gas, it can be introduced directly into the discharge space. In the case of a liquid or solid, it is preferable to vaporize it by means of heating, bubbling, decompression, ultrasonic irradiation, or the like before use. It may also be used after dilution with a solvent. As the solvent, an organic solvent such as methanol, ethanol, or n-hexane, or a mixture of these solvents, can be used.

When carrying out the chemical vapor deposition (CVD) method, it is preferable to carry out the chemical vapor deposition (CVD) method while transporting the present substrate film, particularly the present substrate film provided with an anchor layer, at a speed of 100 m/min or more in a reduced pressure environment of 10 Pa or less.
The pressure at which a thin film is formed by chemical vapor deposition (CVD) is preferably reduced in order to form a dense thin film, and from the viewpoints of film formation rate and barrier properties, the pressure is preferably 10 Pa or less, more preferably 1×10 ⁻² or more or 10 Pa or less, and even more preferably 1×10 ⁻¹ or more or 1 Pa or less.

If necessary, the CVD inorganic layer may be cross-linked by electron beam irradiation to improve water resistance and durability.

(Layer structure of the inorganic layer)
The inorganic layer may be of a single layer construction or a multi-layer construction of two or more layers.
For example, as an example of a multi-layer structure having two or more layers, one layer may be an inorganic layer consisting of only an inorganic material, such as an inorganic oxide, and the other layer may be an inorganic-organic mixed layer consisting of an inorganic material, such as an inorganic oxide, and an organic material.

By mixing an organic material with an inorganic material to form the inorganic layer, the inorganic layer can be made relatively flexible, and the provision of such a flexible layer may improve the gas barrier properties. That is, the coarse protrusions of the base film may cause minute defects called pinholes on the surface of the inorganic layer, or the raw material may fly in clumps during heating and vapor deposition and adhere to the surface of the inorganic layer, causing minute defects. Gas may pass through the gaps caused by these defects, resulting in a decrease in gas barrier properties. Therefore, by laminating a flexible layer as described above on the surface, the defects may be filled, and the gas barrier properties may be improved.
The term "flexible layer" as used herein includes the meaning of a layer that relieves stress on the inorganic layer so as to accommodate applications requiring flexibility, such as flexible applications.

As mentioned above, in order to form a flexible layer, an organic material may be mixed with the inorganic material to form the layer. Examples of the organic material include polyester resin, acrylic resin, urethane resin, PVA, and other organic materials, as well as organic fillers.

(Thickness of inorganic layer)
The thickness of the inorganic layer (when the inorganic layer has a multi-layer structure, the total thickness of the layers) is preferably 0.1 nm to 500 nm, more preferably 1 nm or more or 300 nm or less, and even more preferably 5 nm or more or 100 nm or less.
If the thickness of the present inorganic layer is within the above range, it is possible to ensure the desired gas barrier properties.

(Crosslinked Resin Layer)
The present laminate film may further include a crosslinked resin layer (hereinafter referred to as "the present crosslinked resin layer") on the present inorganic layer, if necessary.

The crosslinked resin layer may be any layer containing a crosslinked resin formed by crosslinking a resin, and is preferably a layer having a crosslinked resin as a basic skeleton.

The crosslinked resin layer is more flexible than the inorganic layer, and can absorb the surface irregularities of the inorganic layer, thereby improving the gas barrier properties. It can also suppress yellowing or yellow-browning caused by the inorganic layer.

(Composition of the present crosslinked resin layer)
The present crosslinked resin layer is preferably a layer having a crosslinked resin structure obtained by crosslinking and curing a crosslinkable resin composition containing a binder resin as a main component resin and other components such as a curing agent or a crosslinking initiator.
In this case, the term "main component resin" refers to the resin that is the most abundant (mass %) among the resins constituting the present crosslinked resin layer. The content of the present crosslinked resin layer is preferably 50 mass % or more, more preferably 70 mass % or more, more preferably 80 mass % or more, and even more preferably 90 mass % or more (including 100 mass %).

(Binder resin)
Examples of the binder resin include water-soluble epoxy resins, water-dispersible polyurethane resins, and water-dispersible urethane acrylates, which will be described below.

[Water-soluble epoxy resin]
As the water-soluble epoxy resin, it is preferable to use a water-soluble epoxy resin which is a prepolymer having an epoxy group at the terminal.
Among them, those in which the prepolymer chain is aromatic are preferred.Specific examples include epoxy resins having a glycidylamine moiety derived from metaxylylenediamine, epoxy resins having a glycidylamine moiety derived from 1,3-bis(aminomethyl)cyclohexane, epoxy resins having a glycidylamine moiety derived from diaminodiphenylmethane, epoxy resins having a glycidylamine moiety and/or a glycidyl ether moiety derived from paraaminophenol, epoxy resins having a glycidyl ether moiety derived from bisphenol A, epoxy resins having a glycidyl ether moiety derived from bisphenol F, epoxy resins having a glycidyl ether moiety derived from phenol novolac, and epoxy resins having a glycidyl ether moiety derived from resorcinol.Among these, epoxy resins having a glycidylamine moiety derived from metaxylylenediamine are particularly preferred.

[Water-dispersible polyurethane resin]
The water-dispersible polyurethane resin may be, but is not limited to, a polyurethane resin obtained by reacting a polyol compound not containing a carboxyl group in the molecule with a polyisocyanate compound, and forcibly emulsifying the polyurethane compound in water using a surfactant.

[Water-dispersible urethane acrylate]
The water-dispersed urethane acrylate may be, for example, a water-dispersed urethane acrylate obtained by mixing a urethane acrylate raw material with an emulsifier, for example, an anionic and/or nonionic reactive emulsifier, and an oil-soluble polymerization initiator, and then subjecting the mixture to emulsion polymerization in a manner that disperses the mixture while subjecting it to heat treatment using an emulsifier, for example, a homomixer or an ultrasonic disperser, etc. However, the water-dispersed urethane acrylate is not limited thereto.

As the urethane acrylate raw material, a radical polymerizable oligomer having two or more acryloyl groups or methacryloyl groups in one molecule can be used.
Examples of commercially available urethane acrylates include Beamset 505A-6 (manufactured by Arakawa Chemical Industries, Ltd.), Ebecryl 270 (manufactured by Daicel Industries, Ltd.), UA-160TM, UA-7100, (Shin-Nakamura Chemical Co., Ltd.), and the like.

The emulsifier is not particularly limited as long as it is an emulsifier that can be used in emulsion polymerization.
Examples of the anionic reactive emulsifier include commercially available products such as the Aqualon series: KH-05, KH-10, AR-10, and AR-20 (trade names: manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Antox-MS-60 and Antox-MS-2N (manufactured by Nippon Nyukazai Co., Ltd.), and the Adeka Reasoap series: SE-10N, SE-20N, and SR-10 (manufactured by Adeka Co., Ltd.). Among these, those made of sulfonate salts are preferred.
Examples of the nonionic reactive emulsifier include commercially available products such as Adeka Reasoap series: NE-10, NE-20, NE-30, ER-10, ER-20, ER-30, and ER-40 (manufactured by Adeka Co., Ltd.), and Latemul series: PD-420, PD-430, and PD-450 (manufactured by Kao Co., Ltd.).

Examples of the oil-soluble polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis-(2-methylpropanenitrile), 2,2'-azobis-(2,4-dimethylpentanenitrile), 2,2'-azobis-(2-methylbutanenitrile), 1,1'-azobis-(cyclohexanecarbonitrile), 2,2'-azobis-(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis-(2,4-dimethylvaleronitrile), Examples of initiators include azo (azobisnitrile) type initiators such as 2,2'-azobis-(2-amidinopropane) hydrochloride, and peroxide type initiators such as benzoyl peroxide, cumene hydroperoxide, hydrogen peroxide, acetyl peroxide, lauroyl peroxide, persulfates (e.g., ammonium persulfate), and peresters (e.g., t-butyl peroctate, α-cumyl peroxypivalate, and t-butyl peroctate).

(Curing agent or crosslinking initiator)
It is preferable to use a curing agent or a crosslinking initiator appropriately depending on whether a crosslinking method, thermal crosslinking or photocrosslinking, is selected and further depending on what is used as the binder resin.
For example, when a water-soluble epoxy resin is used as the binder resin, it is preferable to use an amine compound as the curing agent, and among these, aromatic amines such as metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone are preferable.

When the crosslinkable resin composition is to be photocrosslinked, it is preferable to add a photopolymerization initiator.
The photopolymerization initiator is not particularly limited, and examples thereof include ketone-based photopolymerization initiators and amine-based photopolymerization initiators.

(solvent)
As the aqueous solvent, water or an alcohol solvent can be used as the main solvent.
Specific examples of the alcohol solvent include, but are not limited to, methanol, ethanol, isopropyl alcohol, and butanol.

(Other ingredients)
The crosslinked resin layer may contain other components or materials in addition to the materials described above.
The "other components or materials" may include inorganic fillers, oxygen scavengers, coupling agents, curing accelerators, and the like.

The inorganic filler may contain inorganic fillers such as silica, alumina, mica, talc, aluminum flakes, and glass flakes in order to improve the gas barrier properties, impact resistance, heat resistance, and other properties of the crosslinked resin layer. In addition, when the transparency of the topcoat layer is taken into consideration, it is preferable that the inorganic filler be flat.

The oxygen scavenger may be any compound that has an oxygen scavenging function. Examples include low molecular weight organic compounds that react with oxygen, such as hindered phenols, vitamin C, vitamin E, organic phosphorus compounds, gallic acid, and pyrogallol, and transition metal compounds, such as cobalt, manganese, nickel, iron, and copper.

The above coupling agent may be contained in the present crosslinked resin layer, if necessary, from the viewpoint of improving the adhesion between the present crosslinked resin layer and the present inorganic layer or improving the gas barrier property.
As the coupling agent, a silane coupling agent or a titanium coupling agent may be added.
As the coupling agent, commercially available products can be used. Specifically, amino-based silane coupling agents such as N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, and N,N'-bis[3-trimethoxysilyl]propyl]ethylenediamine, available from Chisso Corporation, Dow Corning Toray Co., Ltd., Shin-Etsu Chemical Co., Ltd., etc., are available. Examples of suitable silane coupling agents include epoxy-based silane coupling agents such as 3-glycidoxypropyltriethoxysilane, methacryloxy-based silane coupling agents such as 3-methacryloxypropyltrimethoxysilane, mercapto-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, isocyanate-based silane coupling agents such as 3-isocyanatepropyltriethoxysilane, aminosilane-based coupling agents such as SH-6026 and Z-6050 manufactured by Dow Corning Toray Co., Ltd., and amino group-containing alkoxysilanes such as KP-390 and KC-223 manufactured by Shin-Etsu Chemical Co., Ltd.
Among them, those having an organic functional group that reacts with the binder resin composition of the present crosslinked resin layer are preferred.
The amount of the coupling agent added is preferably within a range of 0.01% by mass to 5.0% by mass based on the total mass of the binder resin composition.

The above curing accelerator can be added in the required proportions of each component, such as curing accelerator catalysts such as N-ethylmorpholine, dibutyltin dilaurate, cobalt naphthenate, and stannous chloride, organic solvents such as benzyl alcohol, rust inhibitors such as zinc phosphate, iron phosphate, calcium molybdate, vanadium oxide, water-dispersed silica, and fumed silica, organic pigments such as phthalocyanine organic pigments and condensed polycyclic organic pigments, and inorganic pigments such as titanium oxide, zinc oxide, calcium carbonate, barium sulfate, alumina, and carbon black, so that crosslinking can be achieved at low temperatures when crosslinking the crosslinkable resin composition.

(Amount of each ingredient)
The ratio of the binder resin to the total solid components (100 parts by mass) in the crosslinkable resin composition is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, while it is preferably 90 parts by mass or less, more preferably 80 parts by mass or less. When two or more types of binder resins are used in combination, it is preferable that the ratio of their total amount is within the above range. When two or more types of binder resins are used in combination, it is preferable that the ratio of their total amount is within the above range.

The ratio of the curing agent or crosslinking initiator to the total solid components (100 parts by mass) in the crosslinkable resin composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more. On the other hand, the upper limit is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less.

The ratio of solid components other than the binder resin and the curing agent or crosslinking initiator to the total solid components (100 parts by mass) in the crosslinkable resin composition is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.1 parts by mass or more or 10 parts by mass or less, and even more preferably 1 part by mass or more or 10 parts by mass or less.

<Layer structure of the present laminated film>
The present laminate film only needs to have a configuration in which an anchor layer and an inorganic layer are laminated in this order on one side (referred to as the "front side") of a base film, and may also have "other layers" such as a crosslinked resin layer on the back side of the base film, between the anchor layer and the inorganic layer, or on the front side of the inorganic layer.

<Thickness of this laminated film>
By adjusting the total thickness of the present laminate film, it is possible to suppress the occurrence of wrinkles while ensuring light transmittance. From this viewpoint, the total thickness of the present laminate film is preferably 10 μm or more, more preferably 15 μm or more or 500 μm or less, even more preferably 20 μm or more or 250 μm or less, and even more preferably 23 μm or more or 125 μm or less.

<Characteristics of this laminated film>
The present laminate film can have a water vapor transmission rate (WvTR) at a temperature of 40°C and a relative humidity of 90% of 6.0 g/ ^m2 /day or less, preferably 4.0 g/ ^m2 /day or less, and particularly preferably 2.0 g/ ^m2 /day or less.
In addition, under conditions of a temperature of 25°C and a relative humidity of 80%, the oxygen permeability (cc/( ^m2 ·24hr·atm)) can be set to 8.0 cc/( ^m2 ·24hr·atm) or less, preferably 6.0 cc/( ^m2 ·24hr·atm) or less, and particularly preferably 2.0 cc/( ^m2 ·24hr·atm) or less.

<Method of manufacturing the present laminate film>
An example of a method for producing the present laminated film includes, but is not limited to, a method in which an anchor layer is formed on one side of a base film as necessary, and the present inorganic layer is formed on the surface of the anchor layer.

The anchor layer can be formed by applying the above-mentioned anchor coating agent to one side of the substrate film and drying it as necessary.
As described above, the inorganic layer can be formed by, for example, physical vapor deposition (PVD), plasma-assisted deposition, chemical vapor deposition (CVD), or a method in which inorganic particles are dispersed in an organic polymer and then applied.

<<Present film laminate>>
Next, as an example of an embodiment using the present laminate film, a film laminate using the present laminate film (hereinafter referred to as "the present film laminate") will be described.

One example of the film laminate is a film laminate having a configuration in which an anchor layer and an inorganic layer are laminated in sequence on at least one side of the laminate film, i.e., the base film (1), and a base film (2) is bonded to the outermost surface of the laminate film, i.e., the surface of the inorganic layer or the surface of the crosslinked resin layer, via an adhesive layer.

<Base film (2)>
As the base film (2), the base film (1), i.e., the one explained as the present base film, can be used.

Moreover, a biodegradable film or a polyolefin film can also be used as the base film (2).
The biodegradable film means a film having a layer containing a biodegradable resin as a main component resin, whether the film has a single layer structure or a multilayer structure. A film having a layer containing a biodegradable resin as a main component resin as a main layer is preferable. Among them, a film having a base film (2) having a single layer structure or a multilayer structure, in which the main component resin of each layer is a biodegradable resin, is preferable.

Here, the term "biodegradable resin" refers to a resin having biodegradability, and "biodegradability" refers to a property of being ultimately decomposed into water and carbon dioxide by the action of microorganisms, and preferably refers to a property that satisfies the requirement that, in a pilot-scale aerobic compost environment at 58°C as described in ISO 16929 or JIS K 6952, within 12 weeks, 10% or less of a 100 mm square film remains on a 2 mm sieve.
Examples of biodegradable resins include biodegradable aliphatic polyesters such as polylactic acid (PLA), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), polybutylene adipate, polyethylene succinate (PES), and 3-hydroxybutyrate-co-3-hydroxyhexanoate polymer (PHBH), and biodegradable aliphatic aromatic polyesters such as polybutylene adipate terephthalate (PBAT).

The polyolefin film used for the base film (2) is the same as the polyolefin film used for the base film (1).

The structure and thickness of the base film (2) are the same as those of the base film (1).

<Adhesive Layer>
The adhesive layer of the film laminate can be formed using a known adhesive composition. From the viewpoint of achieving both adhesiveness and barrier properties, it is preferable to use an adhesive composition containing a binder resin and a curing agent or a crosslinking initiator, and it is preferable to use, for example, a water-soluble epoxy resin, a water-dispersible polyurethane resin, or a water-dispersible urethane acrylate oligomer as the binder resin.

<Thickness of the present film laminate>
By adjusting the total thickness of the present film laminate, it is possible to ensure light transmittance while suppressing the occurrence of wrinkles, etc. From this viewpoint, the total thickness of the present film laminate is preferably 40 μm or more, more preferably 50 μm or more or 500 μm or less, even more preferably 50 μm or more or 250 μm or less, and particularly preferably 50 μm or more or 125 μm or less.

<<Uses of the present laminate film and the present film laminate>>
The present laminate film and the present film laminate can be widely used in applications requiring the blocking of various gases such as water vapor and oxygen, for example, as packaging materials requiring the blocking of various gases, for example, packaging materials for preventing deterioration of foods, industrial products, medicines, etc. In addition to packaging applications, the present laminate film and the present film laminate are also suitable for various members such as liquid crystal display elements, solar cells, electromagnetic wave shields, touch panels, EL substrates, color filters, etc.

<<Terminology explanation>>
In the present invention, the term "film" includes the term "sheet", and the term "sheet" includes the term "film".
Furthermore, when the term "panel" is used, such as an image display panel or a protective panel, it encompasses a plate, a sheet, and a film.
In the present laminate film, the substrate film side is referred to as the lower side or back side, and the opposite side is referred to as the upper side or front side.

In the present invention, when it is described as "X to Y" (X and Y are arbitrary numbers), unless otherwise specified, it includes the meaning of "X or more and Y or less", as well as the meaning of "preferably larger than X" or "preferably smaller than Y".
In addition, when it is stated that the amount is "X or more" (X is any number), it also means that the amount is "preferably greater than X" unless otherwise specified, and when it is stated that the amount is "Y or less" (Y is any number), it also means that the amount is "preferably smaller than Y" unless otherwise specified.

The present invention will be specifically described below with reference to examples, although the present invention is not limited to the following examples in any way.
The measurement and evaluation methods used in the present invention are as follows.

(1) Film thickness of inorganic layer formed by vacuum deposition (PVD) The film thickness of the inorganic layer was measured using fluorescent X-rays. This method utilizes the phenomenon that atoms emit fluorescent X-rays specific to the atoms when irradiated with X-rays, and the number (amount) of atoms can be known by measuring the intensity of the fluorescent X-rays emitted. Specifically, two thin films of known thicknesses were formed on a film, and the specific fluorescent X-ray intensity emitted from each was measured, and a calibration curve was created from this information. Then, the fluorescent X-ray intensity of the measurement sample was measured in the same manner, and the film thickness was measured from the calibration curve.

(2) Dynamic Viscoelasticity Measurement The anchor coating liquid used in the Examples and Comparative Examples was dried at 80° C. to prepare a sheet having a thickness of 200 μm. Viscoelasticity measurements were performed on the sheet using a dynamic viscoelasticity measuring device "DVA-200" manufactured by IT Measurement & Control Co., Ltd. under the conditions of a frequency of 1 Hz, a heating rate of 3° C./min, and a measurement temperature of -50 to 200° C., and the storage modulus and the peak temperature of the loss tangent (tan δ) at 120° C. were obtained.

(3) Water vapor transmission rate (WvTR)
In Examples 3 and 6, the prepared film laminates (samples) were used as the measurement samples, and in the other Examples and Comparative Examples, the prepared laminate films (samples) were used as the measurement samples.
In a water vapor transmission rate measuring device DELTAPERM (manufactured by Technolox), the laminate film (measurement sample) was set so that the inorganic layer side and the film laminate (measurement sample) were set so that the PBS film side or the CPP film side faced the detector (the substrate film was the side exposed to water vapor), and the water vapor transmission rate (g/ ^m2 /day) was measured under conditions of a temperature of 40°C and a relative humidity of 90% RH.
In the table, when the object for measuring water vapor transmission rate, i.e., the measurement sample, is a laminate film, the configuration at the time of barrier measurement is indicated as "film", and when it is a film laminate, it is indicated as "laminate".

(4) Oxygen permeability For Examples 3 and 6, the prepared film laminate (sample) was used as the measurement sample. For the other Examples and Comparative Examples, the measurement samples were prepared as follows. That is, a urethane adhesive (AD900 and CAT-RT85 manufactured by Toyo-Morton Co., Ltd., mixed in a ratio of 10:1.5) was applied to the surface of a 60 μm-thick non-axially oriented polypropylene (CPP) film ("P1146" manufactured by Toyobo Co., Ltd.) as a lamination film, dried to form an adhesive layer with a thickness of about 3 μm, and the inorganic layer side of the laminate film (sample) prepared in each Example and Comparative Example was laminated on this adhesive layer, and the obtained film laminate was used as the measurement sample.
For each film laminate (measurement sample), the oxygen permeability (cc/(m2·24hr·atm)) was measured under conditions of a temperature of 25° C. and a relative humidity of 80% using an oxygen permeability measuring device ("OX-TRAN ^2/21 type oxygen permeability measuring device" manufactured by MOCON Corporation) in accordance with JIS K 7126B method.

(5) Lamination Strength As in the measurement of oxygen permeability, for Examples 3 and 6, the prepared film laminates (samples) were used as measurement samples, and for the other Examples and Comparative Examples, measurement samples were prepared as described above.
Each film laminate (measurement sample) was cut into a strip with a width of 15 mm, and an end portion was partially peeled off. Using a tensile tester ("STA-1150" manufactured by Orientec Co., Ltd.), the CPP film was peeled off at 180° at a speed of 300 mm/min to measure the laminate strength (g/15 mm) after retort.

<Preparation of anchor coat solution>
(Preparation of anchor coating solution 1)
Anchor coat solution 1 was prepared by blending an amorphous polyester resin (Vylon 200, manufactured by Toyobo Co., Ltd.) and an isocyanate compound (Coronate L, manufactured by Tosoh Corporation) in a mass ratio of 10:1.

(Preparation of anchor coating liquid 2)
Anchor coating solution 2 was prepared by blending an amorphous polyester resin (Vylon 103, manufactured by Toyobo Co., Ltd.) and an isocyanate compound (Coronate L, manufactured by Toyo Co., Ltd.) in a mass ratio of 10:1.

(Preparation of anchor coating solution 3)
Anchor coat solution 3 was prepared by blending an amorphous polyester resin (Vylon 300, manufactured by Toyobo Co., Ltd.) and an isocyanate compound (Coronate L, manufactured by Tosoh Corporation) in a mass ratio of 10:1.

(Preparation of Crosslinked Resin Layer Composition)
439.1 g of hydrogenated XDI (1,4-bis(isocyanatomethyl)cyclohexane), 35.4 g of dimethylolpropionic acid, 61.5 g of ethylene glycol, and 140 g of acetonitrile as a solvent were mixed and reacted for 3 hours under a nitrogen atmosphere at 70°C to obtain a carboxyl group-containing polyurethane prepolymer solution. Next, this carboxyl group-containing polyurethane prepolymer solution was neutralized with 24.0 g of triethylamine at 50°C. 267.9 g of this polyurethane prepolymer solution was dispersed in 750 g of water using a homodisper, and a chain extension reaction was carried out with 35.7 g of 2-[(2-aminoethyl)amino]ethanol, and acetonitrile was distilled off to obtain an aqueous dispersion of polyurethane resin with a solid content of 25% by mass. 4 wt% of commercially available 3-glycidyloxypropyltrimethoxysilane was added to this aqueous dispersion to prepare a crosslinked resin layer composition.

Example 1
Poly-L-lactic acid having a mass average molecular weight of 200,000 (Lacty 1012 manufactured by Shimadzu Corporation) was extruded through a T-die using a 60 mmφ single screw extruder, and then quenched with a cast roll to obtain a sheet. Next, this sheet was stretched 2.5 times longitudinally at 70°C using a film tenter manufactured by Mitsubishi Heavy Industries, Ltd., and then stretched 2.5 times laterally at 70°C, and then heat-treated (heat-set) at 120°C for 30 seconds to obtain a polylactic acid film (substrate film (1)) having a thickness of 20 μm.
Next, one side of this polylactic acid film was subjected to a corona treatment, and the anchor coating solution 1 was applied to the corona surface and dried at 80° C. for 1 minute to form an anchor layer having a thickness (after drying) of 0.03 μm.
Next, SiO was evaporated by heating under a vacuum of 2×10 ⁻³ Pa using a vacuum deposition apparatus to form a 30 nm-thick SiO _x thin film layer (inorganic layer) on the anchor layer, thereby obtaining a laminated film (sample).

Example 2
A laminated film (sample) was obtained in the same manner as in Example 1, except that the thickness (after drying) of the anchor layer was changed to 0.10 μm.

Example 3
A polybutylene succinate (PBS) film having a thickness of 30 μm was laminated as a base film (2) on the surface of the SiO _x thin film layer of the laminated film (sample) produced in Example 1 to obtain a film laminate (sample).

Example 4
A laminated film (sample) was obtained in the same manner as in Example 1, except that a biaxially oriented polypropylene film (FOR manufactured by Futamura Chemical Co., Ltd., thickness 20 μm) was used as the base film (1).

Example 5
A laminated film (sample) was obtained in the same manner as in Example 4, except that a crosslinked resin layer composition was applied onto the _SiOx thin film layer and dried to form a crosslinked resin layer having a thickness of 0.5 μm.

Example 6
A 60 μm-thick non-oriented polypropylene (CPP) film was laminated as a base film (2) on the surface of the crosslinked resin layer of the laminated film (sample) produced in Example 4 to obtain a film laminate (sample).

<Comparative Example 1>
A laminated film (sample) was obtained in the same manner as in Example 1, except that anchor coating liquid 2 was used instead of anchor coating liquid 1 in Example 1.

<Comparative Example 2>
A laminated film (sample) was obtained in the same manner as in Example 1, except that anchor coating liquid 3 was used instead of anchor coating liquid 1 in Example 1.

<Comparative Example 3>
A laminated film (sample) was obtained in the same manner as in Example 1, except that the thickness (after drying) of the anchor layer was changed to 0.01 μm.

<Comparative Example 4>
A laminated film (sample) was obtained in the same manner as in Example 1, except that the anchor layer was not formed.

<Comparative Example 5>
A laminated film (sample) was obtained in the same manner as in Example 4, except that anchor coating liquid 2 was used instead of anchor coating liquid 1 in Example 4.

<Evaluation Results>
The properties of each of the laminated films and film laminates obtained in the above Examples and Comparative Examples are shown in Table 1 below.

In the table, "PLA" stands for polylactic acid film, "OPP" stands for oriented polypropylene film, "CPP" stands for unoriented polypropylene film, and "PBS" stands for polybutylene succinate.

<Considerations>
It was found that in Comparative Examples 1, 2, and 5, the elastic modulus of the anchor layer did not satisfy the specified range, and therefore the barrier property was affected by the shrinkage of the base film and deteriorated. Also, it was found that in Comparative Example 3, the thickness of the anchor layer was out of the range, and therefore the barrier property was affected by the shrinkage of the base film and deteriorated. In contrast, in all of the Examples, the elastic modulus and coating thickness of the anchor layer both satisfied the range, and therefore the barrier property was good.

From the above examples and the results of tests conducted by the inventors, it has been found that by providing an anchor layer with a storage modulus of 10.0 MPa or more at 120°C and a thickness of 0.02 μm to 5.00 μm, it is possible to obtain good barrier properties and adhesion even when an inorganic substance-containing layer is provided on a substrate film with poor heat resistance, such as a polylactic acid film (PLA) or an oriented polypropylene film (OPP).

The mechanism by which good barrier properties can be achieved (speculated) is that if the modulus of elasticity of the anchor layer is equal to or greater than a certain value and is equal to or greater than a specific thickness, the anchor layer itself can have the strength to resist the force of shrinkage of the base film, and the anchor layer can mitigate the shrinkage of the base film when heated. In other words, it is speculated that the anchor layer functions as a so-called shrinkage mitigation layer, which can suppress the occurrence of cracks in the inorganic-containing layer even when heated, resulting in good barrier properties.

The laminate film and film laminate of the present invention can be widely used as packaging materials for packaging items that require blocking of various gases such as water vapor and oxygen, for example, packaging materials for preventing deterioration of foods, industrial products, medicines, etc. In addition to packaging applications, the laminate film and film laminate can also be suitably used for various members such as liquid crystal display elements, solar cells, electromagnetic wave shields, touch panels, EL substrates, color filters, etc.

Claims (7)

A laminated film having a configuration in which an anchor layer , an inorganic layer and a crosslinked resin layer are laminated in this order on at least one side of a base film (1), the anchor layer has a storage modulus (E') at 120°C of 10.0 MPa or more and a thickness of the anchor layer of 0.02 to 5.00 µm , the inorganic material as a main material constituting the inorganic material layer is one or more selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, silicon oxycarbonitride, aluminum oxide, aluminum nitride, aluminum oxynitride and aluminum oxycarbide, and the binder resin as a main component resin of the crosslinked resin layer is a water-soluble epoxy resin, a water-dispersible polyurethane resin or a water-dispersible urethane acrylate . The laminated film according to claim 1, wherein the base film (1) is a polylactic acid film or a polyolefin film. The laminated film according to claim 1 or 2, in which the peak temperature of the loss tangent (tan δ) in dynamic viscoelasticity measurement of the anchor layer is 60.0°C or higher. 4. The laminated film according to claim 1, wherein the anchor layer is made of at least one resin selected from the group consisting of polyester resins, urethane resins, and acrylic resins. The laminated film according to any one of claims 1 to 4, wherein the anchor layer contains an isocyanate compound. A film laminate comprising a base film (2) bonded to the outermost surface of the laminate film according to any one of claims 1 to 5 via an adhesive layer. The film laminate according to claim 6 , wherein the substrate film (2) is a biodegradable film or a polyolefin film.