Multilayer film and method for producing multilayer film

Abstract

The present disclosure provides a multilayer film which has excellent adhesion and in which cohesive failure is preferably suppressed. The multilayer film comprises: a resin layer containing a resin material, the resin layer having a first surface and a second surface; and a composite layer laminated on the second surface, the composite layer containing a resin material and a layered inorganic material. In a region within the composite layer in which the distance from the second surface is within 3 μm, the proportion of the layered inorganic material in which the angle formed by the first surface and the layers of the layered inorganic material is at least 45°, with respect to the total amount of the layered inorganic material, is 5 mass% or greater.

Description

Multilayer film and method for manufacturing the same

[0001] The present disclosure relates to multilayer films and methods for making multilayer films.

[0002] BACKGROUND ART Films containing a layered inorganic material and a resin material can exhibit gas barrier properties and are widely used in packaging, electronics, vehicles, construction, and other applications.

[0003] As such a film, Patent Document 1 describes a film that is made of denatured clay and additives, has water vapor barrier properties, and has a water vapor permeability of 0.2 g / m ２ / day (40°C, 90% relative humidity).

[0004] Patent Document 2 describes a film that is composed of denatured clay and additives, in which the weight ratio of the denatured clay to the total solids is 70% or more, that has gas barrier properties, and that has mechanical strength that allows it to be used as a free-standing film.

[0005] Patent Document 3 describes a free-standing clay film in which a clay film layer and a resin layer are laminated, in which clay particles are oriented and laminated, and a diffusion region exists near the interface between the clay film layer and the resin layer, in which the ratio of clay particles to resin changes in the thickness direction.

[0006] Patent Document 4 describes a gas barrier laminated paper having a laminated structure in which a base paper, a resin layer, and a clay layer are laminated in that order, and in which clay prepared as a water-dispersed clay dispersion is applied on top of the resin layer formed from a resin soluble in organic solvents, resulting in the clay particles being oriented and laminated in the clay layer.

[0007] Patent Document 5 describes a clay film made of only clay or clay and an additive, with a water vapor permeability of 1.0 g / m on at least one side. ２ A clay film composite is described that provides a water vapor barrier layer for 0.5 days or less.

[0008] JP 2011-001237 A JP 2007-277078 A JP 2013-179118 A JP 2009-018525 A JP 2011-131450 A

[0009] Conventionally known films have sometimes not provided fully satisfactory adhesion. The present disclosure aims to provide a multilayer film having good adhesion and preferably suppressing cohesive failure. The present disclosure also aims to provide a method for producing such a multilayer film.

[0010] The present disclosure relates to a multilayer film comprising: a resin layer containing a resin material and having a first surface and a second surface; and a composite layer laminated on the second surface and containing the resin material and a layered inorganic material, wherein in a region of the composite layer within 3 μm from the second surface, the layered inorganic material has an angle of 45 degrees or more with respect to the total amount of the layered inorganic material, and the ratio of the layered inorganic material layer, which is 5 mass % or more, relative to the total amount of the layered inorganic material, is 5 mass % or more. The present disclosure also relates to a method for producing a multilayer film, comprising: applying a first composition containing a resin material and a dispersion medium onto a substrate, and then removing the dispersion medium to form a resin layer precursor; applying a second composition containing a resin material, a layered inorganic material, and a dispersion medium onto the resin layer precursor to form a composite layer precursor; and simultaneously curing the resin layer precursor and the composite layer precursor to form a resin layer and a composite layer, thereby producing a multilayer film comprising the resin layer and the composite layer.

[0011] According to the present disclosure, it is possible to provide a multilayer film having good adhesion and preferably suppressing cohesive failure, and a method for producing such a multilayer film.

[0012] Fig. 1 is a cross-sectional view showing a first embodiment of a composite layer, Fig. 2 is a schematic diagram showing a method for determining a reference plane of a layered inorganic material, and Fig. 3 is a cross-sectional view showing an end portion of a multilayer film.

[0013] The multilayer film according to one aspect of the present disclosure will be described in detail below, but the present disclosure is not limited to such an embodiment. Furthermore, the shapes and arrangements of the multilayer film and each component of the following embodiment are not limited to the examples shown in the drawings.

[0014] (First embodiment: multilayer film) FIG. 1 is a cross-sectional view of a multilayer film 1. As shown in FIG. 1, the multilayer film includes a resin layer 11 and a composite layer 12. The resin layer 11 includes a resin material 101 and has a first surface 111 and a second surface 112. The composite layer 12 is laminated on the second surface 112 and includes a resin material 201 and a layered inorganic material 202. In the composite layer 12, in a region 120 that is within 3 μm of the second surface 112, the proportion of layered inorganic material 202a in which the layer of layered inorganic material 202 and the first surface 111 form an angle θ1 of 45 degrees or more is 5 mass % or more relative to the total amount of the layered inorganic material 202. The multilayer film 1 may exist alone, or two or more multilayer films 1 may be laminated. In one embodiment, when two multilayer films 1 are stacked, the composite layer 12 of the first multilayer film and the resin layer 11 of the second multilayer film may be stacked so as to face each other. When three or more multilayer films 1 are stacked, the resin layers 11 and composite layers 12 of the multiple multilayer films 1 may be stacked alternately.

[0015] In the present disclosure, the composite layer 12 starts from a plane including a portion of the layered inorganic material 202 that is located at the shortest distance from the first surface 111. In a preferred embodiment, the composite layer 12 includes a plane including a portion of the layered inorganic material 202 that is located closest to the first surface 111, and the region 120 that starts from a plane parallel to the first surface 111 includes a portion of the layered inorganic material 202 that is located closest to the first surface 111 (the portion of the layered inorganic material 202 that is located closest to the first surface 111), and is a region that starts from a plane parallel to the first surface 111 and is within 3 μm of the plane.

[0016] In the region 120, when the ratio of the layered inorganic material 202a to the total amount of the layered inorganic material 202 is within the above range, adhesion is improved. Although the present disclosure should not be interpreted as being limited to a particular theory, the reason why the composite membrane of the present disclosure can achieve such an effect is thought to be as follows. That is, in the composite membrane of the present disclosure, the orientation of the inorganic layered material is dispersed in the above region. Therefore, when bending stress is applied to the composite membrane, the stress is dispersed, improving bending stress resistance, which is thought to suppress cohesive failure and improve adhesion.

[0017] Furthermore, according to the present disclosure, since the adhesion is improved, the proportion of the layered inorganic material contained in the composite layer can be increased, and the gas barrier properties can be improved.

[0018] Gas barrier technology is a technology for providing a protective membrane and / or film that prevents gas from passing from the outside to the inside of the film, thereby preventing changes in the contents (for example, chemical reactions between the passed gas and the contents), and is being widely studied in, for example, the packaging field, such as food packaging, beverage packaging, pharmaceutical packaging, cosmetic / toiletry packaging, and home appliance / precision instrument packaging; the electronics field, such as solar cells, solid-state batteries, organic EL electronic paper, liquid crystal displays, LEDs, electronic ceramics, and fuel cells; the automotive and / or railway field, such as electronic devices, oil tanks / oil seals, and flooring materials; and the construction field, such as sealants, flooring materials / vacuum insulation materials, and piping equipment.

[0019] (Resin Layer) The resin layer 11 contains a resin material. Examples of such resin materials include, but are not limited to, liquid crystal polymers, acrylic resins, alkyd resins, urethane resins, ethyl cellulose resins, epoxy resins, olefin resins, caproraptam, carboxymethyl cellulose resins, silicone resins, styrene resins, sulfonic acid polymers, cellulose-based resins, tetramethylammonium chloride resins, nylon resins, bismaleimide resins, phenolic resins, fluororesins, polyamide resins, polyamino resins, polyisobutylene, polyimideamide resins, polyimide resins, polyurethane resins, polyester resins, polyethylene glycol, polydiallylamine resins, polyvinyl alcohol, polyphenylene oxide resins, polyvinylidene chloride, polylactic acid, maleic acid resins, latex polymers, MPC (2-methacryloyloxyethyl phosphorylcholine) polymers, polycarbonates, and copolymers thereof.

[0020] The resin layer 11 may contain a biocompatible resin, such as polylactic acid, polycaprolactone, acrylic resin, MPC (2-methacryloyloxyethyl phosphorylcholine) polymer, polycarbonate, copolymers thereof, and acrylic urethane copolymers.

[0021] In one embodiment, the resin material is preferably a polyimide resin and / or a liquid crystal polymer. By using a polyimide resin and / or a liquid crystal polymer, the gas barrier property can be further improved.

[0022] The resin layer 11 may contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0023] The resin layer 11 has a first surface 111 and a second surface 112. The first surface 111 may typically be a flat surface. In one embodiment, the first surface 111 may be parallel to the surface of the multilayer film 1 on the composite layer 12 side. The second surface 112 may typically be a flat surface. The second surface may or may not be parallel to the first surface. In one embodiment, the second surface may be parallel to the first surface.

[0024] The thickness of the resin layer 11 may be preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 70 μm or less, and even more preferably 10 μm or more and 35 μm or less.

[0025] (Composite Layer) The composite layer 12 includes a resin material 201 and a layered inorganic material 202 .

[0026] In a preferred embodiment, the resin layer 11 is made of a resin material, such as a liquid crystal polymer, an acrylic resin, an alkyd resin, a urethane resin, an ethyl cellulose resin, an epoxy resin, an olefin resin, caproraptam, a carboxymethyl cellulose resin, a silicone resin, a styrene resin, a sulfonic acid polymer, a cellulose-based resin, a tetramethylammonium chloride resin, a nylon resin, a bismaleimide resin, a phenolic resin, a fluororesin, a polyamide resin, a polyamino resin, a polyisobutylene, a polyimideamide resin, a polyimide resin, a polyurethane resin, a polyester resin, polyethylene glycol, a polydiallylamine resin, a polyvinyl alcohol, a polyphenylene oxide resin, a polyvinylidene chloride, a polylactic acid, a maleic acid resin, and a latex polymer.

[0027] In one embodiment, the resin material is preferably a polyimide resin and / or a liquid crystal polymer. Polyimide resin and / or a liquid crystal polymer have high crystallinity, and the use of these resins can further improve the gas barrier properties.

[0028] The resin material 101 contained in the resin layer 11 and the resin material 102 contained in the composite layer 12 may be the same or different. In one embodiment, the resin material 101 and the resin material 102 are the same. In another embodiment, the resin material 101 and the resin material 102 are different. In the present disclosure, when a resin material and another resin material are the same, this includes not only a case where the resin compositions of these resin materials are completely the same, but also a case where the classifications of these resin materials are the same. For example, a case where the resin material 101 is one acrylic resin and the resin material 102 is another acrylic resin is also included when the resin materials 101 and 102 are the same. This definition of the same resin material applies not only to a case where the resin material is an acrylic resin, but also to a case where the resin material is another resin material.

[0029] The layered inorganic material 202 is preferably a two-dimensional material, and representative examples include carbon materials such as graphene; silica nanosheets; and inorganic material particles such as clay particles. Clay particles are preferred as the layered inorganic material 202. The clay constituting such clay particles may be either natural or synthetic. Examples of the clay include vermiculite (e.g., dioctahedral vermiculite, trioctahedral vermiculite), ylalite, amesite, illite, kaolinite, kanemite, chrysotile, saponite, stevensite, sericite, sauconite, talc, dickite, nontronite, vermulite, beidellite, pyrophyllite, paragonite, halloysite, hectorite, magadiite, montmorillonite, lizardite, lepidolite, mica (e.g., phlogopite, biotite, muscovite), iron-montmorillonite, and layered titanic acid.

[0030] The layered inorganic material 202 may be surface-treated. Such surface treatment may be performed using a silane coupling agent, a titanium-based coupling agent (titanate-based coupling agent), an aluminum-based coupling agent (aluminate-based coupling agent), and / or a zirconium-based coupling agent (zirconate-based coupling agent). Examples of such silane coupling agents include ureido-based silane coupling agents such as 3-ureidopropyltrialkoxysilane; epoxy-based silane coupling agents such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane; amino-based silane coupling agents such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane; and bisphenyl-based silane coupling agents such as 4-bis(trimethoxysilyl)benzene, 1,4-bis(triethoxysilyl)benzene, 4,4'-bis(trimethoxysilyl)-1,1'-biphenyl, and 4,4'-bis(triethoxysilyl)-1,1'-biphenyl. Examples of titanium-based coupling agents (titanate-based coupling agents) include isopropyl triisostearoyl titanate, etc. Examples of aluminum-based coupling agents (aluminate-based coupling agents) include acetoalkoxyaluminum diisopropylate, etc. Examples of zirconium-based coupling agents (zirconate-based coupling agents) include zirconium tetrakisacetylacetonate, etc.

[0031] The aspect ratio of the layered inorganic material 202 may be preferably 50 or more and 600 or less, more preferably 100 or more and 500 or less, and even more preferably 200 or more and 400 or less.

[0032] The particle size of the layered inorganic material 202 may be preferably 0.01 μm or more and 10 μm or less, more preferably 0.01 μm or more and 5 μm or less, and even more preferably 0.1 μm or more and 1 μm or less.

[0033] In the present disclosure, the particle diameter of the layered inorganic material 202 is the major axis (longest diameter) of the layered inorganic material 202. The particle diameter of the layered inorganic material 202 can be measured by dispersing the layered inorganic material 202 as a slurry, drying the slurry, and observing the slurry with a scanning electron microscope (SEM).

[0034] The proportion of the layered inorganic material 202 may be preferably 10% by mass or more and 80% by mass or less, more preferably 20% by mass or more and 70% by mass or less, and even more preferably 30% by mass or more and 60% by mass or less, based on the total amount of the composite layer.

[0035] The composite layer 12 may contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0036] In the composite layer 12, in a region 120 that is within 3 μm from the second surface 112, the proportion of the layered inorganic material 202a in which the layer of the layered inorganic material 202 and the first surface 111 form an angle θ1 of 45 degrees or more is 5 mass% or more relative to the total amount of the layered inorganic material 202. In the present disclosure, the proportion of the layered inorganic material 202a in which the layer of the layered inorganic material 202 and the first surface 111 form an angle θ1 of 45 degrees or more relative to the total amount of the layered inorganic material 202 in the region 120 is also referred to as the orientation ratio. The region 120 may include at least a portion of the layered inorganic material 202b in which the layer of the layered inorganic material 202 forms an angle of less than 45 degrees with the first surface 111.

[0037] The angle θ1 is preferably 40 degrees or more and 90 degrees or less, more preferably 45 degrees or more and 75 degrees or less, and even more preferably 45 degrees or more and 60 degrees or less. When the angle θ1 is in this range, good adhesion can be achieved.

[0038] In the present disclosure, the layer angle of the layered inorganic material 202 is understood to be the angle of the reference plane of the particles of the layered inorganic material 202 . As shown in Figure 2, the reference plane of the particle of the layered inorganic material 202 may be defined as follows: in a cross section perpendicular to the first surface 111 of the multilayer film, (i) connect both ends of the particle of the layered inorganic material 202 with a first line segment a, (ii) measure the distance from the surface of the layered inorganic material 202 to the first line segment a, (iii) determine the longest line segment d (i.e., a perpendicular line from the surface of the layered inorganic material 202 to the first line segment) obtained by connecting the first line segment from the surface of the layered inorganic material 202 so as to have the longest distance, as the second line segment b, and (iv) determine the longest line segment e (i.e., a perpendicular line from the surface of the layered inorganic material 202 to the first line segment) obtained by connecting the end points on the layered inorganic material 202 of the second line segment to both ends of the layered inorganic material 202, as the third line segment c, and the plane including the third line segment c may be defined as the reference plane of the layered inorganic material 202. 2(a) to 2(c) show specific examples of measurement methods according to the shape of the layered inorganic material 202. Note that when the length of the first line segment a is shorter than half the longest diameter of the layered inorganic material 202, and when a straight line extending from the first line segment a intersects with the layered inorganic material 202, no reference plane is defined.

[0039] The ratio of the layered inorganic material 202a to the total amount of the layered inorganic material 202 in the region 120 is preferably 5% by mass or more and 20% by mass or less, more preferably 6% by mass or more and 15% by mass or less, and even more preferably 6% by mass or more and 10% by mass or less. When the ratio is in this range, adhesion can be improved.

[0040] Preferably, there is at least one combination in which the angle θ2 between two adjacent layers of the layered inorganic material is 45 degrees or greater in the region 120. In the present disclosure, two adjacent layered inorganic materials refer to one layered inorganic material and a layered inorganic material adjacent to the one layered inorganic material in a cross section perpendicular to the first surface 111. Here, in the present disclosure, adjacent means that the distance to the one layered inorganic material is the shortest, and the number of layered inorganic materials adjacent to one layered inorganic material is not limited to one, and may be two or more.

[0041] The angle θ2 is preferably 45 degrees or more and 90 degrees or less, more preferably 45 degrees or more and 80 degrees or less, and even more preferably 45 degrees or more and 60 degrees or less. When the angle θ2 is in this range, good adhesion can be achieved.

[0042] The number of combinations in which the angle θ2 between the two adjacent layers of the layered inorganic material is 45 degrees or more can be preferably 1 to 10, more preferably 1 to 5, in any region in the cross section of the multilayer film 1 perpendicular to the first surface, within a distance of 3 μm from the second surface and a width of 20 μm.

[0043] In the present disclosure, the angle θ1 between the layer of layered inorganic material 202 and the first surface 111, and the angle θ2 between two adjacent layers of layered inorganic material 202, can be typically measured by observing the cross section of the multilayer film 1 with a scanning electron microscope (SEM) at a magnification of 10,000 times, and measuring the angle of the filler relative to the horizontal direction of the substrate within the field of view, with the direction parallel to the first surface 111 defined as the horizontal direction of the substrate in the obtained 20 μm × 20 μm observation field image. The layered inorganic material 202 and the resin material 101 can be identified by the difference in contrast in the STEM image. Typically, the brightness increases as the atomic weight of the element increases. Therefore, areas with high brightness can be identified as the layered inorganic material 202, and areas with low brightness can be identified as the resin material 101. The cross section of the multilayer film 1 can be formed using a focused ion beam (FIB) or a microtome. Furthermore, when processing using a focused ion beam, an apparatus that integrates a focused ion beam apparatus and a scanning electron microscope (focused ion beam-scanning electron microscope apparatus, FIB-SEM) may be used. The horizontal direction of the substrate may be understood to be the direction parallel to the first surface 111.

[0044] The composite layer 12 may have a first region 121 disposed on the resin layer 11 side and a second region 122 disposed on the opposite side to the resin layer 11. The region 120 may be included in the first region 121.

[0045] The first region 121 can be typically understood as a region in which the orientation directions of the layered inorganic material 202 are dispersed, and can be understood as, for example, a region in which the proportion of the layered inorganic material 202a that forms an angle of 45 degrees or more with the first surface 111 is 5 mass % or more with respect to the total amount of the layered inorganic material 202. In one aspect, the first region 121 and the second region 122 can be separated by a plane parallel to the surface of the multilayer film 1 on the composite layer 12 side.

[0046] The proportion of the layered inorganic material 202a in the first region 121 may be preferably 5% by mass or more and 20% by mass or less, more preferably 6% by mass or more and 15% by mass or less, and even more preferably 6% by mass or more and 10% by mass or less, relative to the total amount of the layered inorganic material 202.

[0047] The thickness of the first region 121 may be preferably 1 μm or more and 30 μm or less, more preferably 1 μm or more and 20 μm or less, and even more preferably 1 μm or more and 10 μm or less.

[0048] The second region 122 can typically be understood as a region in which the layered inorganic material 202 is oriented parallel to the first surface 111, and can be understood as, for example, a region in which the proportion of layered inorganic material 202a that forms an angle of 45 degrees or more with the first surface 111 is less than 5 mass% relative to the total amount of the layered inorganic material 202.

[0049] In the second region 122, the proportion of the layered inorganic material having an angle θ of 45 degrees or more with respect to the total amount of the layered inorganic material 202 may be preferably less than 5 mass%, more preferably 1 mass% to 4 mass%, and even more preferably 1 mass% to 3 mass%, relative to the total amount of the layered inorganic material 202. When the proportion is within this range, the gas barrier property may be good.

[0050] In the second region 122, the content of the layered inorganic material 202 may be preferably 30% by mass or more and 90% by mass or less, more preferably 40% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less, relative to the total amount of the second region.

[0051] The thickness of the second region 122 may be preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, and even more preferably 10 μm or more and 30 μm or less.

[0052] The ratio of the thickness of the first region 121 to the thickness of the second region (thickness of the second region / thickness of the first region) may be preferably 0.3 or more and 100 or less, more preferably 0.5 or more and 50 or less, and even more preferably 0.5 or more and 10 or less.

[0053] The thickness of the composite layer 12 may be preferably 3 μm or more and 60 μm or less, more preferably 5 μm or more and 50 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0054] (Substrate) The multilayer film 1 may further include a substrate 13 laminated on the first surface 111. In one embodiment, the substrate 13 is preferably in contact with the first surface 111. When the multilayer film 1 includes the substrate 13, it is believed that the adhesion of the multilayer film 1 is improved. It is also expected that the gas barrier properties of the multilayer film 1 will be further improved.

[0055] Typically, the substrate 13 preferably contains one or more materials selected from a resin material, a ceramic material, and a metal material. In a preferred embodiment, the substrate 13 contains a resin material, and in a more preferred embodiment, the substrate 13 is made of a resin material.

[0056] Examples of such resin materials include liquid crystal polymers, acrylic resins, alkyd resins, urethane resins, ethyl cellulose resins, epoxy resins, olefin resins, caprolactam, carboxymethyl cellulose resins, silicone resins, styrene resins, sulfonic acid polymers, cellulose-based resins, tetramethylammonium chloride resins, nylon resins, bismaleimide resins, phenolic resins, fluororesins, polyamide resins, polyamino resins, polyisobutylene, polyimideamide resins, polyimide resins, polyurethane resins, polyester resins, polyethylene glycol, polydiallylamine resins, polyvinyl alcohol, polyphenylene oxide resins, polyvinylidene chloride, polylactic acid, maleic acid resins, and latex polymers.

[0057] The ceramic material is not particularly limited, but includes metal oxides, metal nitrides, and solid solutions thereof, etc. The metal contained in the metal oxides and / or metal nitrides is not particularly limited, but includes Si, Al, Mg, Ti, Zr, Ca, Ba, etc.

[0058] The metal material is not particularly limited, but examples thereof include Cu, Fe, Ag, Au, Pt, and alloys containing these metals. Examples of alloys containing Fe include stainless steel.

[0059] The resin material of the substrate 13 may be the same as or different from the resin material of the resin layer 11. Also, the resin material of the substrate 13 may be the same as or different from the resin material of the composite layer 12. In one embodiment, the resin material of the substrate 13 is different from the resin material of the resin layer 11. Also, in one embodiment, the resin material of the substrate 13 is different from the resin material of the composite layer 12.

[0060] The substrate 13 may contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0061] The thickness of the substrate 13 may be preferably 50 μm or more and 10 cm or less, more preferably 100 μm or more and 5 cm or less, and even more preferably 100 μm or more and 10,000 μm or less.

[0062] (Protective Layer) The multilayer film 1 may further include a protective layer 14 laminated on the surface of the composite layer 12 opposite to the resin layer 11. It is believed that the inclusion of the protective layer 13 in the multilayer film 1 can improve the durability of the multilayer film by mitigating physical impact and friction on the multilayer film. It is also believed that forming a smooth surface facing the outside can prevent the formation of defects such as localized unevenness and dirt.

[0063] Typically, the protective layer 14 preferably contains a resin material. In a preferred embodiment, the substrate 13 is made of a resin material. Examples of such resin materials include, but are not limited to, liquid crystal polymers, acrylic resins, alkyd resins, urethane resins, ethyl cellulose resins, epoxy resins, olefin resins, caproraptam, carboxymethyl cellulose resins, silicone resins, styrene resins, sulfonic acid polymers, cellulose-based resins, tetramethylammonium chloride resins, nylon resins, bismaleimide resins, phenolic resins, fluororesins, polyamide resins, polyamino resins, polyisobutylene, polyimideamide resins, polyimide resins, polyurethane resins, polyester resins, polyethylene glycol, polydiallylamine resins, polyvinyl alcohol, polyphenylene oxide resins, polyvinylidene chloride, polylactic acid, maleic acid resins, latex polymers, MPC (2-methacryloyloxyethyl phosphorylcholine) polymers, polycarbonates, and copolymers thereof.

[0064] In one embodiment, the resin material is preferably a polyimide resin and / or a liquid crystal polymer. By using a polyimide resin and / or a liquid crystal polymer, the gas barrier property can be further improved.

[0065] The resin material of the protective layer 14 may be the same as or different from the resin material of the resin layer 11. Also, the resin material of the protective layer may be the same as or different from the resin material of the composite layer 12. In one embodiment, the resin material of the protective layer 14 is the same as the resin material of the resin layer 11. Also, in another embodiment, the resin material of the protective layer 14 is the same as the resin material of the composite layer 12.

[0066] The protective layer 14 may contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, a silane coupling agent, and an inorganic filter.

[0067] As the inorganic filler, SiO ２ , Al ２ O ３ , Ti ２Examples include metal oxides such as O and ZrO; and the compounds shown above as the layered inorganic material 202. The shape of the inorganic filler is not limited, and may be particulate, spherical, layered, rod-like, or fibrous. The content of the inorganic filler is preferably 0% by mass or more and 50% by mass or less with respect to the total amount of the resin material contained in the protective layer.

[0068] The thickness of the protective layer 14 may be preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 70 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0069] The multilayer film 1 may be a planar film or a three-dimensional electronic component. The planar film may be rectangular in plan view, or may have a polygonal shape other than a rectangle. The polygonal shape may be a polygonal shape with an outwardly convex vertex, or a polygonal shape with an inwardly concave vertex. The thickness of the planar film may be preferably 5 μm or more and 200 μm or less, more preferably 10 μm or more and 100 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[0070] The three-dimensional electronic component may be rectangular or may have a polyhedral shape other than a rectangular. The polyhedral shape may be a polyhedral shape with outwardly convex vertices or a polyhedral shape with inwardly concave vertices. The thickness of the three-dimensional electronic component is preferably 50 μm or more and 10,000 μm or less, more preferably 50 μm or more and 7,000 μm or less, and even more preferably 100 μm or more and 5,000 μm or less. The thickness of the three-dimensional electronic component may be more than 50 μm.

[0071] The multilayer film 1 comprises, at least in part, a resin layer 11 having a first surface 111 and a second surface 112; and a composite layer 12 laminated on the second surface 112 and containing a resin material 201 and a layered inorganic material 202, wherein in a region 120 of the composite layer 12 that is within 3 μm of the second surface 112, the proportion of layered inorganic material 202a in which the layer of layered inorganic material 202 and the first surface 111 form an angle θ1 of 45 degrees or more is 5 mass % or more relative to the total amount of the layered inorganic material 202.

[0072] In a preferred embodiment, the multilayer film 1 includes, in a cross section that intersects at least a portion of a region within 200 μm from the center of gravity of the multilayer film 1 and is perpendicular to the first surface 111, a resin layer 11 having a first surface 111 and a second surface 112; and a composite layer 12 that is laminated on the second surface 112 and contains a resin material 201 and a layered inorganic material 202, wherein in a region 120 within 3 μm from the second surface 112, the composite layer 12 may include a structure in which the proportion of layered inorganic material 202a in which the layer of layered inorganic material 202 and the first surface 111 form an angle θ1 of 45 degrees or more is 5 mass % or more relative to the total amount of layered inorganic material 202.

[0073] In a more preferred embodiment, when the multilayer film 1 is a rectangular planar film, the multilayer film 1 comprises, in a cross section perpendicular to the first surface 111, a resin layer 11 having a first surface 111 and a second surface 112, which intersects with at least a portion of a region within 200 μm of the intersection of two diagonals of the multilayer film 1; and a composite layer 12 laminated on the second surface 112 and containing a resin material 201 and a layered inorganic material 202, wherein in a region 120 within 3 μm from the second surface 112, the proportion of layered inorganic material 202a in which the layer of layered inorganic material 202 forms an angle θ1 with the first surface 111 of 45 degrees or more with respect to the total amount of the layered inorganic material 202 is 5 mass % or more.

[0074] In a more preferred embodiment, when the multilayer film 1 is a rectangular parallelepiped three-dimensional electronic component, the multilayer film 1 may include, in a cross section perpendicular to the first surface 111, a resin layer 11 having a first surface 111 and a second surface 112, the cross section intersecting with at least a portion of a region within 200 μm from the intersection of two diagonals of a plane including the two longest sides of the three sides of the multilayer film 1; and a composite layer 12 laminated on the second surface 112 and including a resin material 201 and a layered inorganic material 202, wherein in a region 120 within 3 μm from the second surface 112, the proportion of layered inorganic material 202a in which the layer of layered inorganic material 202 forms an angle θ1 of 45 degrees or more with respect to the total amount of layered inorganic material 202 is 5 mass % or more.

[0075] 3, the multilayer film 1 may have a structure in which one or both of the first region 121 and the second region 122 are in direct contact with a substrate 13 (not shown) at an end 1A of the multilayer film 1. At the end 1A of the multilayer film, the protective layer may be in direct contact with the substrate 13.

[0076] At the end 1A, even in the second region 122 that is in direct contact with the substrate 13, the layered inorganic material 202 is aligned parallel to the first surface 111. As a result, at the end 1A of the multilayer film 1, the layered inorganic material 202 is aligned parallel to the substrate 13, which can further improve the adhesion at the end 1A. As a result, it is believed that the gas barrier property and peel resistance at the end 1A can be further improved.

[0077] In the end portion 1A, the first region 121 may include a layered inorganic material 202 that forms an angle θ3 with the first surface 111 of 45 degrees or more and 90 degrees or less.

[0078] (Second embodiment: method for manufacturing a multilayer film) The multilayer film can be manufactured by a manufacturing method including: applying a first composition containing a resin material and a dispersion medium onto a substrate, and then removing the dispersion medium to form a resin layer precursor; applying a second composition containing a resin material, a layered inorganic material, and a dispersion medium onto the resin layer precursor to form a composite layer precursor; and simultaneously curing the resin layer precursor and the composite layer precursor to form a resin layer and a composite layer, thereby manufacturing a multilayer film including a resin layer and a composite layer.

[0079] According to the above-described manufacturing method, a multilayer film having good adhesion can be manufactured. Although the present disclosure should not be interpreted as being limited to a particular theory, the reason why the manufacturing method of the present disclosure can achieve such an effect is believed to be as follows. That is, in the manufacturing method of the present disclosure, after forming the resin layer precursor, a composite layer precursor is formed without curing the resin layer precursor, and the resin layer precursor and the composite layer precursor are cured simultaneously. Therefore, when the second composition is applied, the orientation of the layered inorganic material can be dispersed, and by curing it as is, it is believed that the orientation of the layered inorganic material becomes dispersed near the interface between the resin layer and the composite layer. As a result, it is believed that a multilayer film having good adhesion can be obtained.

[0080] (Formation of Resin Layer Precursor) After the first composition containing a resin material and a dispersion medium is applied onto the substrate, the dispersion medium is removed to form the resin layer precursor.

[0081] The substrate and resin material are the same as the resin material contained in the substrate and resin layer in Embodiment 1. That is, examples of such resin materials include, but are not limited to, liquid crystal polymers, acrylic resins, alkyd resins, urethane resins, ethyl cellulose resins, epoxy resins, olefin resins, caproraptam, carboxymethyl cellulose resins, silicone resins, styrene resins, sulfonic acid polymers, cellulose-based resins, tetramethylammonium chloride resins, nylon resins, bismaleimide resins, phenolic resins, fluororesins, polyamide resins, polyamino resins, polyisobutylene, polyimideamide resins, polyimide resins, polyurethane resins, polyester resins, polyethylene glycol, polydiallylamine resins, polyvinyl alcohol, polyphenylene oxide resins, polyvinylidene chloride, polylactic acid, maleic acid resins, latex polymers, MPC (2-methacryloyloxyethyl phosphorylcholine) polymers, polycarbonates, and copolymers thereof.

[0082] The resin layer 11 may contain a biocompatible resin, such as polylactic acid, polycaprolactone, acrylic resin, MPC (2-methacryloyloxyethyl phosphorylcholine) polymer, polycarbonate, copolymers thereof, and acrylic urethane copolymers.

[0083] In the first composition, the content of the resin material may be preferably 0.1% by mass or more and 60% by mass or less, more preferably 0.5% by mass or more and 40% by mass or less, and even more preferably 1% by mass or more and 20% by mass or less, based on the total amount of the first composition. When the content of the resin material is in this range, the resin layer precursor can be formed uniformly.

[0084] The dispersion medium is not particularly limited as long as it is a solvent capable of dispersing the resin material, and examples of such dispersion media include water, acetonitrile, alcohol, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and 1-methyl-2-pyrrolidone.

[0085] The first composition may further contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0086] The method for applying the first composition is not particularly limited, and for example, bar coating, spray coating, dip coating, or spin coating can be used, and preferably, spray coating or dip coating can be used.

[0087] The dispersion medium can be removed, typically, by heating the applied product of the first composition. The heating temperature can be preferably 30°C or higher and 200°C or lower, more preferably 50°C or higher and 200°C or lower, and even more preferably 100°C or higher and 150°C or lower. Such a heating temperature can be understood as the maximum temperature during heating. The heating time can be preferably 10 minutes or higher and 500 minutes or lower, more preferably 20 minutes or higher and 150 minutes or lower, and even more preferably 30 minutes or higher and 120 minutes or lower. This makes it easy to remove at least a portion of the dispersion medium without curing the resin layer precursor.

[0088] (Formation of Composite Layer Precursor) A second composition containing a resin material, a layered inorganic material, and a dispersion medium is applied onto the resin layer precursor to form a composite layer precursor.

[0089] The resin material and layered inorganic material are the same as the resin material and layered inorganic material contained in the composite layer in the first embodiment.

[0090] In the second composition, the content of the resin material may be preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.1% by mass or more and 30% by mass or less, and even more preferably 0.1% by mass or more and 20% by mass or less, based on the total amount of the second composition. When the content of the resin material is in this range, the resin layer precursor can be formed uniformly.

[0091] In the second composition, the content of the layered inorganic material is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 40% by mass or more and 80% by mass or less, based on the total of the resin material and the layered inorganic material. When the content of the layered inorganic material is in this range, it is thought that the orientation of the layered inorganic material is easily dispersed near the surface of the resin layer precursor.

[0092] In the second composition, the total content of the resin material and the layered inorganic material may be preferably 0.1 mass % or more and 40 mass % or less, more preferably 0.1 mass % or more and 20 mass % or less, and even more preferably 0.1 mass % or more and 10 mass % or less, relative to the total content of the second composition. When the total content of the resin material and the layered inorganic material is in this range, it is thought that when the second composition is applied to the resin layer precursor, the orientation of the layered inorganic material in the vicinity of the surface of the resin layer precursor is easily dispersed.

[0093] The dispersion medium is not particularly limited as long as it is a solvent capable of dispersing the resin material and the layered inorganic material, and examples of such dispersion media include water, acetonitrile, alcohol, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and 1-methyl-2-pyrrolidone.

[0094] The second composition may further contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0095] The method for applying the second composition is not particularly limited, and for example, bar coating, spray coating, dip coating, or spin coating can be used, and preferably, spray coating or dip coating can be used.

[0096] (Formation of Resin Layer and Composite Layer) The resin layer precursor and the composite layer precursor are simultaneously cured to form a resin layer and a composite layer, thereby producing a multilayer film including a resin layer and a composite layer.

[0097] The curing of the resin layer precursor and the composite layer precursor can typically be carried out by heating the resin layer precursor and the composite layer precursor. The heating temperature is preferably 100°C or higher, more preferably 200°C or higher and 450°C or lower, more preferably 200°C or higher and 400°C or lower, and even more preferably 250°C or higher and 350°C or lower. In one embodiment, when at least one of the resin layer precursor and the composite layer precursor contains a polyimide resin, the heating temperature can be preferably 200°C or higher and 400°C or lower, more preferably 250°C or higher and 350°C or lower. In another embodiment, when at least one of the resin layer precursor and the composite layer precursor contains a liquid crystal polymer, the heating temperature can be preferably 200°C or higher and 400°C or lower, more preferably 250°C or higher and 350°C or lower. Such a heating temperature can be understood as the maximum temperature during heating and is also referred to as the curing temperature.

[0098] The heating time may be preferably from 10 to 600 minutes, more preferably from 20 to 300 minutes, and even more preferably from 30 to 90 minutes, which allows the resin layer and the composite layer to be cured in a state in which the orientation of the layered inorganic material is dispersed.

[0099] Before curing the resin layer precursor and the composite layer precursor, the composite layer precursor may be preheated. This allows at least a portion of the dispersion medium that may be contained in the resin layer precursor to be removed. The preheating temperature may be preferably 30°C or higher and 200°C or lower, more preferably 50°C or higher and 200°C or lower, and even more preferably 100°C or higher and 150°C or lower. This preheating temperature may be understood as the maximum temperature during preheating. The preheating time may be preferably 10 minutes or higher and 500 minutes or lower, more preferably 20 minutes or higher and 150 minutes or lower, and even more preferably 30 minutes or higher and 120 minutes or lower. This makes it easy to remove the dispersion medium without curing the resin layer precursor and the composite layer precursor.

[0100] After the resin layer and the composite layer are formed, the substrate may be removed, typically by peeling.

[0101] (Formation of Protective Layer) The method for manufacturing the multilayer film may further include applying a second composition containing a resin material and a dispersion medium onto the composite layer to form a protective layer precursor, and curing the protective layer precursor to form a protective layer.

[0102] The formation of a protective layer can improve the durability of the multilayer film by mitigating physical impact and friction on the multilayer film. In addition, by forming a smooth surface on the outside, it is possible to prevent the formation of defects such as localized unevenness and dirt.

[0103] The resin material has the same meaning as the resin material in the protective layer of Embodiment 1. That is, examples of the resin material include, but are not limited to, liquid crystal polymers, acrylic resins, alkyd resins, urethane resins, ethyl cellulose resins, epoxy resins, olefin resins, caproraptam, carboxymethyl cellulose resins, silicone resins, styrene resins, sulfonic acid polymers, cellulose-based resins, tetramethylammonium chloride resins, nylon resins, bismaleimide resins, phenolic resins, fluororesins, polyamide resins, polyamino resins, polyisobutylene, polyimideamide resins, polyimide resins, polyurethane resins, polyester resins, polyethylene glycol, polydiallylamine resins, polyvinyl alcohol, polyphenylene oxide resins, polyvinylidene chloride, polylactic acid, maleic acid resins, latex polymers, MPC (2-methacryloyloxyethyl phosphorylcholine) polymers, polycarbonates, and copolymers thereof.

[0104] The content of the resin material in the third composition may be preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.5% by mass or more and 20% by mass or less, and even more preferably 1% by mass or more and 20% by mass or less. When the content of the resin material in the third composition is in this range, it is believed that the protective layer can be formed more uniformly.

[0105] The dispersion medium is not particularly limited as long as it is a solvent capable of dispersing the resin material, and examples of such dispersion media include water, acetonitrile, alcohol, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and 1-methyl-2-pyrrolidone.

[0106] The third composition may further contain additives such as a sensitizer, an antifoaming agent, a dispersant, an anti-settling agent, and a silane coupling agent.

[0107] The method for applying the third composition is not particularly limited, and for example, bar coating, spray coating, dip coating, or spin coating can be used, and preferably, spray coating or dip coating can be used.

[0108] The curing of the protective layer precursor can typically be carried out by heating the protective layer precursor. The heating temperature is, for example, preferably 100°C or higher, more preferably 200°C or higher and 450°C or lower, more preferably 200°C or higher and 400°C or lower, and even more preferably 250°C or higher and 350°C or lower. In one embodiment, when the protective layer precursor contains a polyimide resin, the heating temperature can be 100°C or higher and 400°C or lower, more preferably 250°C or higher and 350°C or lower, and even more preferably 300°C or higher and 350°C or lower. In one embodiment, when the protective layer precursor contains a liquid crystal polymer, the heating temperature can be 100°C or higher and 400°C or lower, more preferably 250°C or higher and 350°C or lower, and even more preferably 300°C or higher and 350°C or lower. The heating time can be preferably 30 minutes or higher and 180 minutes or lower, more preferably 30 minutes or higher and 120 minutes or lower, and even more preferably 30 minutes or higher and 60 minutes or lower. This makes it easy to form the protective layer while suppressing deterioration of the resin layer and the composite layer.

[0109] Although the multilayer film according to one embodiment of the present disclosure has been described in detail above, various modifications are possible. Note that the multilayer film according to the present disclosure may be manufactured by a method different from the manufacturing method according to the above embodiment, and the manufacturing method of the multilayer film according to the present disclosure is not limited to the method for producing the multilayer film according to the above embodiment.

[0110] The multilayer film of the present disclosure has good adhesion, and preferably suppresses cohesive failure.Therefore, the multilayer film of the present disclosure is used in the following fields: packaging fields such as food packaging, beverage packaging, pharmaceutical packaging, cosmetic packaging, toiletry packaging, home appliance packaging, precision instrument packaging, etc.; electronics fields such as solar cells, solid-state batteries, organic electroluminescence (EL), electronic paper, liquid crystal, LED, electronic ceramics (for example, thermistors, multilayer ceramic capacitors (MLCC), quartz oscillators, etc.), fuel cells, etc.; vehicles fields such as electronic devices, oil tanks, oil seals, flooring materials, etc.; construction fields such as sealants, flooring materials, vacuum insulation materials, piping equipment, etc.

[0111] The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0112] Example 1: A polyimide precursor varnish (UPIA-ST, UBE Corporation) was applied as resin 1 to a stainless steel substrate using a bar coater (gap 0.2 mm) and dried at 100°C for 1 hour. Subsequently, a polyimide precursor varnish (UPIA-AT, UBE Corporation) was used as resin 2, and lithium-exchanged purified bentonite particles (Kunipia M, Kunimine Industries Co., Ltd.) were added at a ratio of 40 wt% relative to the solid content of resin 2. A slurry was prepared using the following procedure. 1 g of Kunipia M was added to 10 g of distilled water, and a dispersion was prepared using a magnetic stirrer and a planetary mixer (2000 rpm, 5 minutes). N-methyl-2-pyrrolidone (35 g) was then added and mixed using an ultrasonic homogenizer. The Kunipia M content in the composite layer was adjusted to 40 wt% of the solid content of the UPIA-AT in the composite layer, yielding a slurry. This slurry was applied to the dried resin 1 with a bar coater (gap 0.4 mm) and dried for 1 hour at 100° C. Thereafter, resin 1 and resin 2 were cured by heating for 2 hours at 350° C. in an electric furnace (FO-300, Yamato Scientific Co., Ltd.) to obtain a multilayer film.

[0113] The cured multilayer film maintained its pre-curing shape, and the total thickness of the multilayer film was 45 μm. A cross-cut test was performed on the multilayer film formed on the SUS substrate, and 25 / 25 of the masses maintained adhesion, which was classified as Class 1. Furthermore, when the center of this film was observed with an FIB, particles forming an angle with respect to the substrate were observed, and the proportion of particles with an average angle θ1 of 45 degrees was 6.7 mass%.

[0114] The same procedure was also performed on a 100 μm thick polyimide film (Kapton, Toray Industries, Inc.) to obtain a membrane for gas permeation testing. The water vapor permeability was 1×10 s at 40°C and 90% RH according to JIS K 7126 Method A. －１ (g / m ２ / day).

[0115] Example 2 A multilayer film was obtained and measured in the same manner as in Example 1, except that Resin 1 was dried at 150°C.

[0116] Example 3 A multilayer film was obtained and measured in the same manner as in Example 1, except that Resin 1 was dried at 150°C and the mass ratio of "Kunipia M" in the composite layer was 80 mass% in terms of the solid content ratio of "UPIA-AT".

[0117] (Example 4) A multilayer film was obtained and measured in the same manner as in Example 1, except that the bar coater application gap of Resin 1 onto the SUS substrate was 0.4 mm, the drying temperature was 100°C, and the bar coat application gap of the slurry onto the dried Resin 1 was 0.2 mm.

[0118] (Example 5) A multilayer film was obtained and measured in the same manner as in Example 1, except that the bar coater application gap of Resin 1 onto the SUS substrate was 0.4 mm, the drying temperature was 100°C, and the bar coat application gap of the slurry onto the dried Resin 1 was 0.8 mm.

[0119] (Example 6) A multilayer film was obtained and measured in the same manner as in Example 1, except that the bar coater application gap of Resin 1 onto the SUS substrate was set to 0.4 mm, the drying temperature was set to 150°C, and the bar coat application gap of the slurry onto the dried Resin 1 was set to 0.2 mm.

[0120] Example 7: A liquid crystal polymer varnish ("VR300," Sumitomo Chemical Co., Ltd.) was applied as resin 1 to a stainless steel substrate using a bar coater (gap 0.4 mm) and dried at 100°C for 1 hour. Subsequently, the liquid crystal polymer varnish ("VR300," Sumitomo Chemical Co., Ltd.) was used as resin 2, and lithium-exchanged purified bentonite particles ("Kunipia M," Kunimine Industries Co., Ltd.) were added at a ratio of 40 wt.% relative to the solid content of resin 2. A slurry was prepared using the following procedure. 1 g of "Kunipia M" was added to 10 g of distilled water, and a dispersion was prepared using a magnetic stirrer and a planetary mixer (2000 rpm, 5 minutes). N-methyl-2-pyrrolidone (90 g) was then added and mixed using an ultrasonic homogenizer. The mixture was added so that the "Kunipia M" in the composite layer accounted for 80 wt.% of the solid content of "VR300" in the composite layer, yielding a slurry. This slurry was applied to the dried resin 1 using a bar coater (gap 0.6 mm) and dried by heating at 100°C for 1 hour. Resin 1 and resin 2 were then cured at 300°C for 2 hours in a low-oxygen furnace (IPHH-202MS, Espec Corporation) to obtain a multilayer film.

[0121] (Comparative Example 1) A multilayer film was obtained and measurements were carried out in the same manner as in Example 1, except that the drying temperature for Resin 1 in Example 1 was set to 250° C. (Comparative Example 2) A multilayer film was obtained and measurements were carried out in the same manner as in Example 1, except that the drying temperature for Resin 1 in Example 1 was set to 250° C. and the content of "Kunipia M" in the composite layer was set to 80 mass % in terms of the solid content ratio of "UPIA-AT" in the composite layer.

[0122]

[0123] The multilayer films obtained in the examples and comparative examples were subjected to the following measurements.

[0124] (Measurement of Orientation Ratio) The multilayer films produced in the examples and comparative examples were processed using a focused ion beam scanning electron microscope (FEI HELIOS NANORAB 660i), and cross sections perpendicular to the substrate were cut out. The cross sections were then observed at a magnification of 10,000 times using the same microscope. Regions with high brightness were identified as the layered inorganic material, and regions with low brightness were identified as the resin material. In a 20 μm × 20 μm observation field of view, the surface where the substrate and the resin layer meet was set as the horizontal direction of the substrate, and the angle of the layer of the layered inorganic material relative to the horizontal direction of the substrate within the field of view was measured to measure the angle θ1 between the layer of the layered inorganic material and the first surface, and the angle θ2 between two adjacent layered inorganic materials.

[0125] The layer angles of the layered inorganic material, which are the basis for θ1 and θ2, were defined as the angle of the reference plane of the layered inorganic material. The reference plane of the layered inorganic material was determined by: (i) connecting both ends of a particle of the layered inorganic material with a first line segment in the observation field; (ii) measuring the distance from the surface of the layered inorganic material to the first line segment; (iii) determining the longest line segment (i.e., the perpendicular line from the surface of the layered inorganic material to the first line segment) obtained by connecting the longest distance from the surface of the layered inorganic material to the first line segment as the second line segment; and (iv) determining the longest line segment (i.e., the perpendicular line from the surface of the layered inorganic material to the first line segment) obtained by connecting the end points of the second line segment on the layered inorganic material to both ends of the layered inorganic material, and defining the third line segment as the plane including the third line segment.

[0126] The observation field was divided by a line segment parallel to the surface where the substrate and the resin layer meet, so that the area of ​​the region containing only the resin in the observation field was maximized, and this line segment was designated as the second surface. In a region 3 μm from the second surface, the mass ratio of the layered inorganic material in which θ1 was 45° or more relative to the total amount of the layered inorganic material was calculated as the orientation ratio. The area ratio in the observation field is understood to correspond to the mass ratio in the multilayer film.

[0127] (Adhesion Test) The adhesion of the multilayer film was evaluated by a cross-cut test in accordance with JIS K5600-5-6. The evaluation results were classified as follows: ◯: Adhesion mass was classified as 0 to 2; ×: Adhesion mass was classified as 3 to 5.

[0128] (Gas Barrier Property Test) The moisture permeability was evaluated under the conditions of (40°C, 90% RH) according to JIS K 7126 Method A. The evaluation results were as follows: ◯: 10 －１ [g / m ２ / day] or less △: 10 －１ [g / m ２ / day] or more.

[0129] <1> A multilayer film comprising: a resin layer containing a resin material and having a first surface and a second surface; and a composite layer laminated on the second surface and containing the resin material and a layered inorganic material, wherein in a region of the composite layer that is within 3 μm from the second surface, a layer of the layered inorganic material that forms an angle of 45 degrees or more with the first surface accounts for 5 mass % or more of the total amount of the layered inorganic material. <2> The multilayer film according to <1>, wherein in a region of the composite layer that is within 3 μm from the second surface, there is one or more combinations in which the angle formed by two adjacent layers of the layered inorganic material is 45 degrees or more. <3> The multilayer film according to <1> or <2>, wherein the composite layer has a first region disposed on the resin layer side and a second region disposed on the opposite side from the resin layer, wherein in the first region, the layered inorganic material forming an angle of 45 degrees or more with the first surface accounts for 5% by mass or more of the total amount of the layered inorganic material, and in the second region, the layered inorganic material forming an angle of 45 degrees or more with the first surface accounts for less than 5% by mass of the total amount of the layered inorganic material, and the content of the layered inorganic material in the second region is 30% by mass or more. <4> The multilayer film according to <3>, wherein the thickness of the first region is 1 μm or more and 100 μm or less, and the thickness of the second region is 1 μm or more and 100 μm or less. <5> The multilayer film according to any one of <1> to <4>, further comprising a substrate laminated on the first surface. <6> The multilayer film according to any one of <1> to <5>, further comprising a protective layer laminated on the surface of the composite layer opposite to the resin layer. <7> The multilayer film according to any one of <1> to <6>, wherein the layered inorganic material contains clay particles. <8> The multilayer film according to any one of <1> to <7>, wherein the resin material contained in the resin layer and the resin material contained in the composite layer are the same.<9> A method for producing a multilayer film, comprising: applying a first composition containing a resin material and a dispersion medium onto a substrate, and then removing the dispersion medium to form a resin layer precursor; applying a second composition containing a resin material, a layered inorganic material, and a dispersion medium onto the resin layer precursor to form a composite layer precursor; and simultaneously curing the resin layer precursor and the composite layer precursor to form a resin layer and a composite layer, thereby producing a multilayer film including the resin layer and the composite layer. <10> The method for producing a multilayer film according to <9>, further comprising: applying a third composition containing a resin material and a dispersion medium onto the composite layer to form a protective layer precursor; and curing the protective layer precursor to form a protective layer.

[0130] The multilayer film of the present disclosure has good adhesion, and preferably suppresses cohesive failure.Therefore, the multilayer film of the present disclosure is used in the following fields: packaging fields such as food packaging, beverage packaging, medicine packaging, cosmetics packaging, toiletry packaging, home appliance packaging, precision instrument packaging, etc.; electronics fields such as solar cells, solid-state batteries, organic electroluminescence (EL), electronic paper, liquid crystal, LED, electronic ceramics, fuel cells, etc.; vehicle fields such as electronic devices, oil tanks, oil seals, flooring materials, etc.; construction fields such as sealants, flooring materials, vacuum insulation materials, piping equipment, etc.

[0131] REFERENCE SIGNS LIST 1 Multilayer film 1A End of multilayer film 11 Resin layer 12 Composite layer 14 Protective layer 111 First surface 112 Second surface 120 Region within 3 μm from second surface 121 First region 122 Second region 201 Resin material 202 Layered inorganic material a First line segment b Second line segment c Third line segment d Line segment e Line segment

Claims

1. A multilayer film comprising: a resin layer containing a resin material and having a first surface and a second surface; and a composite layer laminated on the second surface and containing a resin material and a layered inorganic material, wherein in a region of the composite layer within 3 μm of the second surface, the layer of the layered inorganic material forms an angle of 45 degrees or more with the first surface, and the proportion of the layered inorganic material is 5 mass % or more relative to the total amount of the layered inorganic material.

2. The multilayer film according to claim 1, wherein in the composite layer, in a region within 3 μm of the second surface, there is at least one combination in which the angle between two adjacent layers of the layered inorganic material is 45 degrees or more.

3. The multilayer film according to claim 1 or 2, wherein the composite layer has a first region arranged on the resin layer side and a second region arranged on the opposite side of the resin layer, wherein in the first region, the proportion of the layered inorganic material that forms an angle of 45 degrees or more with the first surface relative to the total amount of the layered inorganic material is 5 mass% or more, and in the second region, the proportion of the layered inorganic material that forms an angle of 45 degrees or more with the first surface relative to the total amount of the layered inorganic material is less than 5 mass%, and the content of the layered inorganic material in the second region is 30 mass% or more.

4. The multilayer film according to claim 3, wherein the thickness of the first region is 1 μm or more and 100 μm or less, and the thickness of the second region is 1 μm or more and 100 μm or less.

5. The multilayer film according to any one of claims 1 to 4, further comprising a substrate laminated on the first surface.

6. The multilayer film according to any one of claims 1 to 5, further comprising a protective layer laminated on the surface of the composite layer opposite to the resin layer.

7. The multilayer film according to any one of claims 1 to 6, wherein the layered inorganic material comprises clay particles.

8. The multilayer film according to any one of claims 1 to 7, wherein the resin material contained in the resin layer and the resin material contained in the composite layer are the same.

9. A method for producing a multilayer film, comprising: applying a first composition containing a resin material and a dispersion medium onto a substrate, and then removing the dispersion medium to form a resin layer precursor; applying a second composition containing a resin material, a layered inorganic material, and a dispersion medium onto the resin layer precursor to form a composite layer precursor; and simultaneously curing the resin layer precursor and the composite layer precursor to form a resin layer and a composite layer, thereby producing a multilayer film comprising a resin layer and a composite layer.

10. The method for producing a multilayer film according to claim 9, further comprising: applying a third composition containing a resin material and a dispersion medium onto the composite layer to form a protective layer precursor; and curing the protective layer precursor to form a protective layer.

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