Flexible electronic device module and production method for same

Abstract

The present invention relates to a flexible electronic device module that includes, in order, a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer. The flexible electronic device element and the resin layer are adjacent, and the resin layer is formed from a single resin composition. The resin composition has a saturated water absorption rate of 1–15 mass% at a temperature of 85°C and a relative humidity of 85% RH and has a water vapor transmission rate of no more than 600 g / m2·day at a temperature of 85°C and a relative humidity of 85% RH at a thickness of 100 μm. The water vapor barrier layer has a water vapor transmission rate of 1.0×10-6–1.0×10-1 g / m2·day at a temperature of 85°C and a relative humidity of 85% RH.

Description

Flexible electronic device module and manufacturing method thereof

[0001] The present invention relates to a flexible electronic device module and a method for manufacturing the same.

[0002] BACKGROUND ART In recent years, from the viewpoint of efficient use of resources and prevention of environmental pollution, solar cells that directly convert sunlight into electrical energy have come into widespread use and are being further developed.

[0003] A solar cell module typically has a photosensitive semiconductor layer (hereinafter sometimes referred to as a solar cell) with a transparent cover (usually glass) to protect it from external influences. The solar cell is usually installed between a glass plate and a glass plate or a back sheet, and fixed with an adhesive sealant. Solar cell modules using such glass are inexpensive and widely used. However, their rigidity and weight limit the places where they can be used.

[0004] For this reason, flexible solar cell modules are being developed. Flexible solar cells are lightweight and bendable, so they are expected to be used in a variety of applications, including automotive applications, building materials, and small electronic devices.

[0005] Examples of solar cells that constitute such flexible solar cell modules include various solar cell types, such as silicon-based solar cells (e.g., monocrystalline silicon, polycrystalline silicon, amorphous silicon), compound semiconductors (e.g., gallium-arsenide, CIGS, cadmium-tellurium) from the periodic table (III-V or II-VI groups), dye-sensitized solar cells, and organic solar cells (e.g., organic thin films). Organic and inorganic perovskite solar cells have been attracting attention as next-generation solar cells due to their high power generation efficiency and reduced manufacturing costs. However, they suffer from a fatal drawback: their vulnerability to water. Therefore, a sealing technology that blocks moisture (water and water vapor) is desired. Therefore, encapsulating solar cell cells using a barrier film with high moisture barrier properties has been proposed (e.g., Patent Documents 1 and 2). Patent Document 1 proposes using a film of ethylene-vinyl acetate copolymer (EVA), a hydrophobic resin, as an encapsulant. However, electronic device modules using EVA have a problem in that acetic acid produced by hydrolysis or thermal decomposition of EVA can cause corrosion of metals, such as wiring. Another problem with using EVA is that it is difficult to manufacture it using a roll-to-roll process because it is necessary to laminate it while the crosslinking reaction is progressing. Patent Document 2 proposes a film including a substrate and a water vapor barrier layer laminated on the substrate as a water vapor barrier film. However, barrier films with high barrier properties are difficult to manufacture and can be very expensive, so their adoption is sometimes hesitant.

[0006] In addition, for electronic devices other than solar cells, flexible materials that can replace conventionally used glass are required from the viewpoint of flexibility and weight reduction. Such flexible materials also require high barrier properties to block moisture, and in particular, organic light-emitting diode (OLED) devices, which are sensitive to moisture, require high barrier properties. －５ 10 from the table －６ It is said that a high barrier property of the base is necessary (Non-Patent Document 1).

[0007] Under these circumstances, as an alternative method, the use of polyvinyl butyral (hereinafter sometimes referred to as PVB), a thermoplastic resin, as a sealant has been proposed (Patent Document 3). However, the PVB described in Patent Document 3 is described as a sealant specifically for solar cell modules using glass. In other words, there is no need to consider moisture that can enter the solar cell module through the glass surface, and water resistance is improved by sealing the edges of the solar cell module with a waterproof seal.

[0008] JP 2013-202824 A JP 2013-258366 A International Publication No. 2013 / 002292

[0009] KONICA MINOLTA TECHNOLOGY REPORT VOL.11 (2014)

[0010] Since glass, which is moisture-impermeable but not flexible, cannot be used for flexible electronic device modules, it is necessary to consider not only moisture intrusion from the edges of the flexible electronic device module but also moisture intrusion from the surfaces of the flexible electronic device module. An object of the present invention is to provide a flexible electronic device module in which moisture intrusion into the interior is highly suppressed.

[0011] As a substitute for glass to prevent moisture from penetrating into an article, a film with low water vapor transmission rate and low water absorption rate, such as a hydrophobic resin film or a water vapor barrier film, is typically used. However, the present inventors conducted extensive research into the possibility of using a film other than such a film, and discovered that the intrusion of moisture into a flexible electronic device module can be dramatically prevented by combining a specific resin layer with a specific water vapor barrier film, thereby completing the present invention. That is, the present invention encompasses the following preferred embodiments: [1] A flexible electronic device module comprising, in this order, a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer, the flexible electronic device element and the resin layer are disposed adjacent to each other, the resin layer being composed of a single resin composition, the resin composition having a saturated water absorption rate of 1 to 15% by mass at a temperature of 85°C and a relative humidity of 85% RH, and a water vapor transmission rate of 600 g / m2 at a temperature of 85°C and a relative humidity of 85% RH when the resin composition is 100 μm thick. ２ days or less, and the water vapor barrier layer has a water vapor transmission rate of 1.0×10 at a temperature of 85° C. and a relative humidity of 85% RH. －６ ~1.0 x 10 －１ g / m ２A flexible electronic device module, wherein the resin composition contains a thermoplastic resin. [2] The flexible electronic device module according to [1], wherein the thermoplastic resin is at least one selected from the group consisting of polyvinyl acetal resin, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol resin. [3] The flexible electronic device module according to [2], wherein the thermoplastic resin has a hydroxyl group content of 10 to 80 mol%. [4] The flexible electronic device module according to any one of [1] to [4], wherein the resin layer has a thickness of 0.1 to 500 μm. [6] The flexible electronic device module according to any one of [1] to [5], wherein the flexible electronic device element is a solar cell power generation element, an organic EL element, an inorganic EL element, an organic EL display element, an inorganic EL display element, a liquid crystal device element, or an electronic paper element. [7] The flexible electronic device module according to any one of [1] to [6], wherein a weather-resistant film is disposed on the side of the water vapor barrier layer opposite to the resin layer. [8] A method for producing a flexible electronic device module according to any one of [1] to [7], comprising thermocompression bonding a flexible electronic device element, a resin layer, a flexible water vapor barrier layer, and an optional layer or film, wherein the water absorption of the resin layer before thermocompression bonding is 1 mass % or less.

[0012] According to the present invention, it is possible to provide a flexible electronic device module in which the intrusion of moisture into the interior is highly suppressed.

[0013] FIG. 1 is a schematic diagram showing the screw configuration of a production apparatus for a modified ethylene-vinyl alcohol copolymer used in the examples.

[0014] Hereinafter, embodiments of the present invention will be described in detail, but it is not intended that the present invention be limited to the following embodiments.

[0015] [Flexible Electronic Device Module] The flexible electronic device module of the present invention comprises a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer, in this order, with the flexible electronic device element and the resin layer being adjacent to each other. The resin layer is laminated on one side of the flexible electronic device element, or on both sides. When the resin layer is laminated on one side of the flexible electronic device element, the flexible electronic device module comprises a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer, in this order, with the flexible electronic device element and the resin layer being adjacent to each other. In this case, another flexible electronic device element encapsulant commonly used in the technical field is typically disposed on the side of the flexible electronic device element opposite the resin layer. When resin layers are laminated on both sides of the flexible electronic device element, the flexible electronic device module includes a flexible water vapor barrier layer, a resin layer, a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer, in this order, with the flexible electronic device element adjacent to and disposed between the two resin layers. When resin layers are laminated on both sides of the flexible electronic device element, the laminate structure laminated on one side of the flexible electronic device element and the laminate structure laminated on the other side may be the same or different. That is, the two resin layers, the two flexible water vapor barrier layers, any layers or films laminated on the two sides, and the laminate structures on the two sides of the flexible electronic device element may each be the same or different.

[0016] As used herein, "flexibility" refers to the ability to flexibly bend when an external force is applied. Furthermore, as used herein, "electronic device" refers to a device having a semiconductor and two or more electrodes, which controls the current flowing between the electrodes or the voltage generated between the electrodes using electricity, light, magnetism, chemicals, or the like, or a device that generates light, an electric field, a magnetic field, or the like using an applied voltage or current. Therefore, as used herein, "electronic device element" refers to a layer structure necessary to exhibit the function of the device, and examples thereof include a solar cell power generation element, an organic EL element, an inorganic EL element, an organic EL display element, an inorganic EL display element, a liquid crystal device element, and an electronic paper element. Furthermore, the flexible electronic device module of the present invention may be, for example, a solar cell module, an organic EL module, an inorganic EL module, an organic EL display module, an inorganic EL display module, a liquid crystal device module, or an electronic paper module, depending on the flexible electronic device element contained therein. Although this specification mainly describes in detail embodiments in which flexible solar cell power generation elements are used as the flexible electronic device elements of the present invention, the flexible electronic device module of the present invention is in no way limited to those in which flexible solar cell power generation elements are used as the flexible electronic device elements.

[0017] <Resin Layer> The resin layer included in the flexible electronic device module is flexible and composed of a single resin composition. A single resin composition means that the resin layers are formed from the same resin composition. Therefore, a single resin composition includes one type of resin that may optionally contain additives, and a mixture of two or more types of resins that may optionally contain additives.

[0018] The resin composition constituting the resin layer has a saturated water absorption rate of 1 to 15 mass % at a temperature of 85°C and a relative humidity of 85% RH, and a water vapor transmission rate of 600 g / m2 at a temperature of 85°C and a relative humidity of 85% RH when the thickness is set to 100 μm. ２days or less. Because the resin composition constituting the resin layer has a specific saturated water absorption rate and a specific water vapor permeability rate, the penetration of moisture into the flexible electronic device module is highly suppressed, even if the flexible water vapor barrier layer has a high water vapor permeability rate. This also contributes to achieving a longer lifespan for the flexible electronic device module. The change in the properties of the flexible electronic device module over time is affected by the amount of moisture reaching the flexible electronic device elements. The resin layer in the present invention does not have a water vapor permeability as high as that of the water vapor barrier layer, and the resin composition constituting the resin layer in the present invention has a relatively high saturated water absorption rate of 1% by mass or more. Therefore, moisture that permeates the flexible water vapor barrier layer is absorbed upon reaching the resin layer. In other words, the resin layer is thought to have the effect of delaying the time it takes for moisture to reach the flexible electronic device elements. This effect is exerted not only at the ends of the flexible electronic device module, but also over the entire surface of the resin layer included in the flexible electronic device module. Therefore, even if the water vapor permeability of the flexible water vapor barrier layer is high, by combining it with a resin layer that can take in and absorb water, the time it takes for water to reach the flexible electronic device elements can be significantly delayed, and the flexible electronic device module can extend the life of the flexible electronic device equipped with it. Of course, even if the water vapor permeability of the flexible water vapor barrier layer is low, the water that has permeated the flexible water vapor barrier layer will still be taken up and absorbed by the resin layer, so the time it takes for the water to reach the flexible electronic device elements can be significantly delayed, and the flexible electronic device module can extend the life of the flexible electronic device equipped with it. It is technically common knowledge to use a film with a low water vapor permeability and low water absorption rate to prevent water from penetrating into an article, but the idea of ​​deliberately having a resin layer, and in particular the entire surface of the resin layer, absorb water that has permeated the water vapor barrier layer to prevent water from penetrating into an article was unprecedented.

[0019] The resin composition constituting the resin layer has a saturated water absorption of 1 to 15% by mass, preferably 1.5 to 14% by mass, more preferably 2.0 to 13% by mass, and particularly preferably 2.5 to 12% by mass at a temperature of 85°C and a relative humidity of 85% RH. When the saturated water absorption is below the upper limit, the risk of deformation of the flexible electronic device module due to volume expansion caused by absorbed moisture can be reduced. When the saturated water absorption is above the lower limit, the absorbed moisture diffuses into the resin layer, reducing the risk of moisture reaching the electronic device and reducing the durability of the flexible electronic device module. The saturated water absorption can be adjusted to within the above range by adjusting the composition of the resin composition. The saturated water absorption can be determined by leaving the resin composition at a temperature of 85°C and a relative humidity of 85% RH for a certain period of time and then using a Karl Fischer apparatus after the mass reaches a constant weight.

[0020] The resin composition constituting the resin layer has a water vapor permeability of 600 g / m at a temperature of 85°C and a relative humidity of 85% RH when the thickness is 100 μm. ２ ・day or less, preferably 575 g / m ２ ・day or less, more preferably 550 g / m ２ day or less, particularly preferably 525 g / m ２ By adjusting the composition of the resin composition, the water vapor transmission rate can be adjusted to the upper limit or less. The lower limit of the water vapor transmission rate is not particularly limited, but is usually 100 g / m ２ The water vapor transmission rate can be measured in accordance with ISO / TS 20175:2018 using a gas / water vapor transmission rate measuring device according to the method described in the examples below.

[0021] From the viewpoint of achieving the desired saturated water absorption and water vapor transmission rate, the resin composition constituting the resin layer preferably contains one or more thermoplastic resins. Thermoplastic resins are also preferred because they have high viscosity at the flow initiation temperature, making it less likely that the resin will flow out from the edges during thermocompression bonding in the manufacturing process of the flexible electronic device module, thereby contaminating the manufacturing equipment and the end faces of the flexible electronic device module. Furthermore, thermoplastic resins are preferred because they do not require a crosslinking step, making it possible to manufacture flexible electronic device modules using a roll-to-roll process.

[0022] The thermoplastic resin is preferably at least one selected from the group consisting of polyvinyl acetal resin, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol resin. Among these, from the viewpoint of low water vapor permeability, the thermoplastic resin is preferably at least one selected from the group consisting of polyvinyl acetal resin and ethylene-vinyl alcohol copolymer, and more preferably polyvinyl acetal resin.

[0023] The hydroxyl group content (amount of vinyl alcohol units) of a thermoplastic resin is preferably 10 to 80 mol%, more preferably 12 to 70 mol%, even more preferably 14 to 60 mol%, and particularly preferably 16 to 50 mol%, based on a unit consisting of two carbon atoms in the main chain of the raw material resin of the thermoplastic resin (e.g., a vinyl alcohol unit, a vinyl acetate unit, or an ethylene unit in the case of a polyvinyl acetal resin, an ethylene unit or a vinyl alcohol unit in the case of an ethylene-vinyl alcohol copolymer, or a vinyl alcohol unit or a vinyl acetate unit in the case of a polyvinyl alcohol resin) as a single repeating unit. When the hydroxyl group content is within this range, the resin layer tends to maintain electrical insulation while achieving a good balance between moisture absorption and barrier properties. When the thermoplastic resin is a polyvinyl acetal resin, the hydroxyl group content can be adjusted within this range by adjusting the amount of aldehyde used when acetalizing the polyvinyl alcohol resin. When the thermoplastic resin is an ethylene-vinyl alcohol copolymer, the amount of hydroxyl groups can be adjusted within the above range by adjusting the amount of raw materials ethylene and vinyl acetate and / or the degree of hydrolysis. When the thermoplastic resin is a polyvinyl alcohol resin, the amount of hydroxyl groups can be adjusted within the above range by adjusting the degree of saponification. When the resin layer contains two or more different thermoplastic resins, it is preferable that the amount of hydroxyl groups of at least one, preferably more than one, and more preferably all, of the thermoplastic resins is within the above range.

[0024] When the resin layer contains a thermoplastic resin, the content of the thermoplastic resin in the resin layer is preferably 83 to 100 mass%, more preferably 83 to 99.99 mass%, more preferably 88 to 99 mass%, even more preferably 93 to 99 mass%, and particularly preferably 96 to 99 mass%, based on the total mass of the resin layer.

[0025] (Polyvinyl acetal resin) The polyvinyl acetal resin that can be contained in the resin layer may be a resin obtained by acetalizing a polyvinyl alcohol resin by a reaction with an aldehyde. When the resin layer contains a polyvinyl acetal resin, the resin layer may contain one polyvinyl acetal resin, or two or more polyvinyl acetal resins that differ from each other in one or more of the weight-average polymerization degree, the acetalization degree, the amount of acetyl groups, the amount of hydroxyl groups, the ethylene content, the type of aldehyde used for acetalization, and the chain length.

[0026] The polyvinyl alcohol resin used as a raw material for preparing the polyvinyl acetal resin is not particularly limited. Polyvinyl alcohol resins are typically obtained by polymerizing a vinyl ester monomer and saponifying the resulting polyvinyl ester. Examples of vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl versatate, vinyl caproate, vinyl caprylate, vinyl laurate, vinyl palmitate, vinyl stearate, vinyl oleate, and vinyl benzoate. These may be used alone or in combination of two or more. From the viewpoint of availability, vinyl acetate is preferred.

[0027] Other monomers may be copolymerized with the vinyl ester monomer as long as the physical properties of the resin layer are not significantly deteriorated. Examples of such monomers include α-olefins such as ethylene, propylene, n-butene, and isobutylene; (meth)acrylic acid or salts thereof; (meth)acrylic acid esters such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate; (meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, diacetone acrylamide, (meth)acrylamidopropanesulfonic acid, and the like. Examples of suitable monomers include (meth)acrylamide derivatives such as (meth)acrylamidopropyldimethylamine or its salts or quaternary salts thereof; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, and stearyl vinyl ether; (meth)acrylonitrile; vinyl halides such as vinyl chloride and vinyl fluoride; vinylidene halides such as vinylidene chloride and vinylidene fluoride; allyl compounds such as allyl acetate and allyl chloride; maleic acid and its salts, esters, and anhydrides; vinylsilyl compounds such as vinyltrimethoxysilane; and carboxylic acid isopropenyl esters such as isopropenyl acetate. The content of these monomers, expressed as the number of monomer units relative to the number of vinyl ester monomer units, is usually less than 20 mol%, and preferably less than 10 mol%. In this specification, "(meth)acrylic acid" is a general term for methacrylic acid and acrylic acid, and refers to either or both of methacrylic acid and acrylic acid.

[0028] As a method for polymerizing a vinyl ester monomer or a method for copolymerizing a vinyl ester monomer with the other monomer, a conventionally known method such as solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization can be applied. A polymerization initiator is usually used, and an azo-based initiator, peroxide-based initiator, or redox-based initiator is appropriately selected depending on the polymerization method. The polymerization may also be carried out in the presence of a thiol compound such as thiolacetic acid or mercaptopropionic acid, or other chain transfer agent.

[0029] The saponification reaction of the polyvinyl ester obtained by polymerization can be carried out by conventional alcoholysis or hydrolysis using an alkali catalyst or an acid catalyst. Among these, the saponification reaction using methanol as a solvent and caustic soda (NaOH) as a catalyst is convenient. The degree of saponification is usually 90 mol% or more, preferably 95 mol% or more, more preferably 98 mol% or more, and may be 100 mol%. The degree of saponification can be measured according to JIS K 6726 "Test Method for Polyvinyl Alcohol."

[0030] A polyvinyl acetal resin can be obtained by reacting a polyvinyl alcohol resin with an aldehyde to form an acetal.

[0031] Examples of aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, hexylaldehyde, and benzaldehyde. Aldehydes having 1 to 12 carbon atoms are preferred, saturated aliphatic aldehydes having 1 to 6 carbon atoms are more preferred, and saturated aliphatic aldehydes having 1 to 4 carbon atoms are even more preferred. Butyraldehyde is particularly preferred from the viewpoint of the mechanical properties of the solar cell encapsulant. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin. Aldehydes may be used alone or in combination of two or more. Furthermore, compounds having multiple aldehyde groups in the molecule or aldehydes having functional groups other than aldehyde groups may be used in combination in an amount of 20% by mass or less of the total mass of all aldehydes.

[0032] The acetalization method is not particularly limited. The solvent used in the acetalization reaction is not particularly limited, and for example, water, ethanol, isopropanol, or a mixture thereof can be used. The catalyst used in the acetalization reaction is also not particularly limited, and any of organic acids such as acetic acid and paratoluenesulfonic acid, and inorganic acids such as nitric acid, sulfuric acid, hydrochloric acid, and carbonic acid can be used. From the viewpoint of ease of washing the polyvinyl acetal resin after the reaction, the use of an inorganic acid is preferred.

[0033] The hydroxyl group content of the polyvinyl acetal resin is preferably 10 to 80 mol%, more preferably 12 to 70 mol%, even more preferably 14 to 60 mol%, and particularly preferably 16 to 50 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of the polyvinyl alcohol resin used as the raw material for producing the polyvinyl acetal resin (e.g., a vinyl alcohol unit, a vinyl acetate unit, an ethylene unit, etc.). When the hydroxyl group content is within this range, the resin layer tends to maintain electrical insulation while achieving a good balance between moisture absorption and barrier properties. The hydroxyl group content of the polyvinyl acetal resin can be adjusted within this range by adjusting the amount of aldehyde used during acetalization of the polyvinyl alcohol resin. When the resin layer contains two or more different polyvinyl acetal resins, it is preferable that the hydroxyl group content of at least one, preferably more than one, and more preferably all, of the polyvinyl acetal resins be within the above range.

[0034] The acetyl group content (amount of vinyl acetate units) of the polyvinyl acetal resin is preferably 0.1 to 10.0 mol%, more preferably 0.2 to 8.0 mol%, even more preferably 0.3 to 6.0 mol%, and particularly preferably 0.4 to 4.0 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of the polyvinyl alcohol resin, which is the raw material for producing the polyvinyl acetal resin. When the acetyl group content is within this range, corrosion of metal components such as wiring in flexible electronic device modules due to acetic acid generated from the resin layer tends to be suppressed, and / or the time required for saponification tends to be short, resulting in high mass productivity. The acetyl group content can be adjusted within this range by appropriately adjusting the saponification degree of the polyvinyl alcohol resin. When the resin layer contains two or more different polyvinyl acetal resins, it is preferable that the acetyl group content of at least one, preferably more than one, and more preferably all, of the polyvinyl acetal resins is within the above range.

[0035] The degree of acetalization of the polyvinyl acetal resin is preferably 20 to 90 mol%, more preferably 30 to 88 mol%, even more preferably 40 to 86 mol%, and particularly preferably 50 to 84 mol%. The degree of acetalization is the amount of the above-mentioned units forming the acetal, based on one repeating unit, where one repeating unit is a unit consisting of two carbon atoms in the main chain of the polyvinyl alcohol resin, which is the raw material for producing the polyvinyl acetal resin. When the degree of acetalization is within the above range, the resin layer tends to maintain electrical insulation while achieving a good balance between moisture absorption and barrier properties. The degree of acetalization of the polyvinyl acetal resin can be adjusted within the above range by appropriately adjusting the amount of aldehyde used when acetalizing the polyvinyl alcohol resin. When the resin layer contains two or more different polyvinyl acetal resins, it is preferable that the degree of acetalization of at least one, preferably more than one, and more preferably all, of the polyvinyl acetal resins is within the above range.

[0036] The amount of units constituting the polyvinyl acetal resin (for example, vinyl alcohol units, vinyl acetate units, units forming acetal, etc.) can be measured according to JIS K6728 "Testing Methods for Polyvinyl Butyral" or by nuclear magnetic resonance (NMR) spectroscopy.

[0037] The weight-average molecular weight of the polyvinyl acetal resin is preferably 10,000 to 60,000, more preferably 15,000 to 55,000, and particularly preferably 20,000 to 50,000. When the weight-average molecular weight of the polyvinyl acetal resin is within this range, the strength of the resin layer tends to be high and the moldability tends to be excellent. The weight-average molecular weight of the polyvinyl acetal resin can be adjusted within this range by adjusting the weight-average polymerization degree of the polyvinyl alcohol resin, which is the raw material for the polyvinyl acetal resin, or by combining polyvinyl alcohol resins with different weight-average polymerization degrees to prepare the polyvinyl acetal resin.

[0038] The weight average molecular weight in this specification is determined by gel permeation chromatography (GPC) using polystyrene of known molecular weight as a standard.

[0039] When the resin layer contains a polyvinyl acetal resin, the content of the polyvinyl acetal resin in the resin layer is preferably 83 to 100 mass %, more preferably 83 to 99.99 mass %, more preferably 88 to 99 mass %, even more preferably 93 to 99 mass %, and particularly preferably 96 to 99 mass %, based on the total mass of the resin layer.

[0040] (Ethylene-vinyl alcohol copolymer) The ethylene-vinyl alcohol copolymer that can be contained in the resin layer may be a resin obtained by hydrolyzing a copolymer of ethylene and vinyl acetate by a known method. When the resin layer contains an ethylene-vinyl alcohol copolymer, the resin layer may contain one ethylene-vinyl alcohol copolymer, or two or more ethylene-vinyl alcohol copolymers that differ from each other in any one or more of the weight-average degree of polymerization, the amount of hydroxyl groups, the ethylene content, the degree of hydrolysis, and the chain length.

[0041] The vinyl alcohol moiety of an ethylene-vinyl alcohol copolymer can be modified with another functional group, to the extent that the physical properties of the resin layer are not significantly impaired. In other words, the ethylene-vinyl alcohol copolymer can be modified with a compound containing another functional group. Such ethylene-vinyl alcohol copolymers are also encompassed by the ethylene-vinyl alcohol copolymer of the present invention. This can improve the adhesion between the resin layer and the flexible water vapor barrier layer or between the resin layer and the flexible electronic device. Examples of such functional groups include hydroxyl groups, epoxy groups, amino groups, and isocyanate groups. When modifying a side chain with such a functional group, the amount of the functional group, expressed as the number of functional groups relative to the number of vinyl acetate monomer units, is typically 1 to 20 mol %, preferably 3 to 15 mol %, and more preferably 5 to 10 mol %.

[0042] The hydroxyl group content of the ethylene-vinyl alcohol copolymer is preferably 10 to 80 mol%, more preferably 20 to 75 mol%, even more preferably 30 to 70 mol%, and particularly preferably 40 to 65 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of the ethylene-vinyl acetate copolymer, which is the raw material for producing the ethylene-vinyl alcohol copolymer. When the hydroxyl group content is within this range, the resin layer tends to maintain electrical insulation while exhibiting a good balance between moisture absorption and barrier properties. The hydroxyl group content of the ethylene-vinyl alcohol copolymer can be adjusted within the above range by adjusting the ratio of ethylene to vinyl acetate and / or the degree of hydrolysis of the ethylene-vinyl acetate copolymer when preparing the ethylene-vinyl acetate copolymer, which is the raw material for the ethylene-vinyl alcohol copolymer. When the resin layer contains two or more different ethylene-vinyl alcohol copolymers, it is preferable that the hydroxyl group content of at least one, preferably more than one, and more preferably all, of the ethylene-vinyl alcohol copolymers is within the above range.

[0043] The ethylene content of the ethylene-vinyl alcohol copolymer is preferably 20 to 90 mol%, more preferably 25 to 80 mol%, even more preferably 30 to 70 mol%, and particularly preferably 35 to 60 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of the ethylene-vinyl acetate copolymer, which is the raw material for producing the ethylene-vinyl alcohol copolymer (e.g., a vinyl acetate unit, an ethylene unit, etc.). When the ethylene content is within this range, the resin layer tends to maintain electrical insulation while exhibiting a good balance between moisture absorption and barrier properties. The ethylene content of the ethylene-vinyl alcohol copolymer can be adjusted within the above range by adjusting the ratio of ethylene to vinyl acetate when preparing the ethylene-vinyl acetate copolymer, which is the raw material for the ethylene-vinyl alcohol copolymer. When the resin layer contains two or more different ethylene-vinyl alcohol copolymers, it is preferable that the ethylene content of at least one, preferably more than one, and more preferably all, of the ethylene-vinyl alcohol copolymers is within the above range.

[0044] The weight-average molecular weight of the ethylene-vinyl alcohol copolymer is preferably 10,000 to 60,000, more preferably 15,000 to 55,000, particularly preferably 20,000 to 53,000, and even more particularly preferably 20,000 to 50,000. When the weight-average molecular weight of the ethylene-vinyl alcohol copolymer is within the above range, the strength of the resin layer tends to be high and the molding processability tends to be excellent. The weight-average molecular weight of the ethylene-vinyl alcohol copolymer can be adjusted to be within the above range by adjusting the weight-average degree of polymerization of the ethylene-vinyl acetate copolymer, which is a raw material for the ethylene-vinyl alcohol copolymer, or by combining ethylene-vinyl acetate copolymers with different weight-average degrees of polymerization to prepare the ethylene-vinyl alcohol copolymer.

[0045] The saponification degree of the ethylene-vinyl alcohol copolymer is preferably 90 mol% or more, more preferably 95 mol% or more, even more preferably 98 mol% or more, and particularly preferably 99 mol% or more. When the saponification degree is equal to or greater than the lower limit, the desired barrier properties and thermal stability can be obtained for the resin layer. The saponification degree of the ethylene-vinyl alcohol copolymer can be determined, for example, by the NMR method. When the resin layer contains two or more ethylene-vinyl alcohol copolymers with different saponification degrees, the average value calculated from the blending mass ratio is taken as the saponification degree of the ethylene-vinyl alcohol copolymer.

[0046] When the resin layer contains an ethylene-vinyl alcohol copolymer, the content of the ethylene-vinyl alcohol copolymer in the resin layer is preferably 83 to 100 mass%, more preferably 83 to 99.99 mass%, more preferably 88 to 99 mass%, even more preferably 93 to 99 mass%, and particularly preferably 96 to 99 mass%, based on the total mass of the resin layer.

[0047] (Polyvinyl alcohol resin) The polyvinyl alcohol resin that can be contained in the resin layer may be a resin obtained by saponifying polyvinyl acetate by a known method. When the resin layer contains a polyvinyl alcohol resin, the resin layer may contain one polyvinyl alcohol resin, or two or more polyvinyl alcohol resins that differ from each other in any one or more of the weight average polymerization degree, hydroxyl group amount, ethylene content, saponification degree, and chain length.

[0048] The hydroxyl group content of the polyvinyl alcohol resin is preferably 10 to 80 mol%, more preferably 20 to 78 mol%, even more preferably 30 to 76 mol%, and particularly preferably 40 to 74 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of polyvinyl acetate, the raw material for producing the polyvinyl alcohol resin. When the hydroxyl group content is within this range, the resin layer tends to maintain electrical insulation while achieving a good balance between moisture absorption and barrier properties. The hydroxyl group content of the polyvinyl alcohol resin can be adjusted within this range by adjusting the degree of saponification of the polyvinyl acetate. When the resin layer contains two or more different polyvinyl alcohol resins, it is preferable that the hydroxyl group content of at least one, preferably more than one, and more preferably all, of the polyvinyl alcohol resins be within this range.

[0049] The vinyl alcohol unit content of the polyvinyl alcohol resin is preferably 20 to 90 mol%, more preferably 22 to 80 mol%, even more preferably 24 to 70 mol%, and particularly preferably 26 to 60 mol%, based on a repeating unit consisting of two carbon atoms in the main chain of polyvinyl acetate, the raw material for producing the polyvinyl alcohol resin. When the vinyl alcohol unit content is within this range, the resin layer tends to maintain electrical insulation while achieving a good balance between moisture absorption and barrier properties. The vinyl alcohol unit content of the polyvinyl alcohol resin can be adjusted within this range by adjusting the degree of saponification of the polyvinyl acetate. When the resin layer contains two or more different polyvinyl alcohol resins, it is preferable that the vinyl alcohol units of at least one, preferably more than one, and more preferably all, of the polyvinyl alcohol resins be within this range.

[0050] The weight-average molecular weight of the polyvinyl alcohol resin is preferably 10,000 to 60,000, more preferably 15,000 to 55,000, and particularly preferably 20,000 to 50,000. When the weight-average molecular weight of the polyvinyl alcohol resin is within this range, the strength of the resin layer tends to be high and the molding processability tends to be excellent. The weight-average molecular weight of the polyvinyl alcohol resin can be adjusted within this range by adjusting the weight-average polymerization degree of polyvinyl acetate, which is the raw material for the polyvinyl alcohol resin, or by combining polyvinyl acetate copolymers with different weight-average polymerization degrees to prepare the polyvinyl alcohol resin.

[0051] When the resin layer contains a polyvinyl alcohol resin, the content of the polyvinyl alcohol resin in the resin layer is preferably 83 to 100 mass%, more preferably 83 to 99.99 mass%, more preferably 88 to 99 mass%, even more preferably 93 to 99 mass%, and particularly preferably 96 to 99 mass%, based on the total mass of the resin layer.

[0052] (Additives) When the resin layer contains a thermoplastic resin, the resin layer may further contain additives as necessary. Examples of such additives include plasticizers, silane coupling agents, antioxidants, ultraviolet absorbers, light stabilizers, antiblocking agents, heat-shielding materials (e.g., inorganic heat-shielding fine particles or organic heat-shielding materials having infrared absorption ability), adhesion modifiers, tackifying resins, emulsifiers, softeners, surfactants, etc. When the resin layer further contains any of these additives in addition to the thermoplastic resin, the content thereof can be appropriately selected depending on the type of additive.

[0053] The resin layer contains a plasticizer in addition to the thermoplastic resin, making the resin layer soft and flexible. When the resin layer contains a plasticizer in addition to the thermoplastic resin, one or more compounds selected from the following group are preferably used as the plasticizer: Esters of polyvalent aliphatic or aromatic acids. Examples thereof include dialkyl adipates (e.g., dihexyl adipate, di-2-ethylbutyl adipate, dioctyl adipate, di-2-ethylhexyl adipate, hexylcyclohexyl adipate, diheptyl adipate, dinonyl adipate, diisononyl adipate, and heptylnonyl adipate); esters of adipic acid with alcohols or alcohols containing ether compounds (e.g., di(butoxyethyl) adipate and di(butoxyethoxyethyl) adipate); dialkyl sebacates (e.g., dibutyl sebacate); esters of sebacic acid with alicyclic alcohols or alcohols containing ether compounds; esters of phthalic acid (e.g., butyl benzyl phthalate and bis-2-butoxyethyl phthalate); and esters of alicyclic polycarboxylic acids and aliphatic alcohols (e.g., 1,2-cyclohexanedicarboxylic acid diisononyl ester). Esters or ethers of polyhydric aliphatic or aromatic alcohols or oligoether glycols having one or more aliphatic or aromatic substituents. Examples include esters of glycerin, diglycol, triglycol, tetraglycol, etc. with linear or branched aliphatic or alicyclic carboxylic acids. Specific examples include diethylene glycol bis-(2-ethylhexanoate), triethylene glycol bis-(2-ethylhexanoate), triethylene glycol bis-(2-ethylbutanoate), tetraethylene glycol bis-(2-ethylhexanoate), tetraethylene glycol bis-n-heptanoate, triethylene glycol bis-n-heptanoate, triethylene glycol bis-n-hexanoate, tetraethylene glycol dimethyl ether, and dipropylene glycol dibenzoate. Phosphate esters of aliphatic or aromatic alcohols.Examples include tris(2-ethylhexyl) phosphate, triethyl phosphate, diphenyl-2-ethylhexyl phosphate, and tricresyl phosphate. Esters of citric, succinic and / or fumaric acid.

[0054] When the resin layer contains a plasticizer in addition to the thermoplastic resin, the content thereof is 0 to 15 parts by mass, preferably 0 to 10 parts by mass, more preferably 0 to 5 parts by mass, even more preferably 0 to less than 5 parts by mass, and even more preferably 0 to 3 parts by mass, per 100 parts by mass of the thermoplastic resin contained in the resin layer. When the plasticizer content is within this range, high adhesion can be maintained even in a high-temperature, high-humidity environment. Furthermore, when the plasticizer content is within this range, a flexible electronic device module manufactured by laminating a barrier layer adjacent to the resin layer can have a lower water vapor transmission rate.

[0055] By including a silane coupling agent (preferably a silane coupling agent having a functional group) in the resin layer in addition to a thermoplastic resin, the adhesion of the resin layer to adjacent members can be improved. From the viewpoint of adhesion, the silane coupling agent preferably has at least one functional group selected from the group consisting of an epoxy group, a (meth)acrylic group, and an isocyanate group. The functional group possessed by the silane coupling agent is preferably an epoxy group and / or an isocyanate group, from the viewpoint of achieving high adhesion even at lower bonding temperatures and maintaining high adhesion even in high-temperature, high-humidity environments. In one embodiment of the present invention, from the viewpoint of the uniformity of the resin layer containing a thermoplastic resin and a silane coupling agent and the adhesion of the resin layer to the bonded members, it is preferable that the silane coupling agent does not have an amino group. In another embodiment of the present invention, from the viewpoint of adhesion between the resin layer and the bonded members, the silane coupling agent only needs to be present on at least the surface of the resin layer that contacts the bonded members, and does not need to be uniformly dispersed within the resin layer.

[0056] In addition to the functional groups, the silane coupling agent may further have a hydrolyzable group. The hydrolyzable group is not particularly limited, and examples thereof include a chloro group, a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. The silane coupling agent may have one of these hydrolyzable groups or a combination of two or more of them. The number of hydrolyzable groups per molecule of the silane coupling agent is not particularly limited, but is preferably 2 or 3 from the viewpoint of adhesion to components included in the flexible electronic device module.

[0057] Examples of silane coupling agents having an epoxy group include, but are not limited to, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropyltrimethoxysilane.

[0058] Examples of silane coupling agents having a (meth)acrylic group include, but are not limited to, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-methacryloxypropyltrimethoxysilane.

[0059] Examples of silane coupling agents having an isocyanate group include, but are not limited to, 3-isocyanatepropyltriethoxysilane, an organosilane commercially available from Shin-Etsu Chemical Co., Ltd. under the trade name X-12-1159L.

[0060] When the resin layer contains a silane coupling agent, its content is preferably 0.001 to 8.0 parts by mass relative to 100 parts by mass of the thermoplastic resin contained in the resin layer. When the silane coupling agent is mixed throughout the resin layer, the content of the silane coupling agent in the resin layer is preferably 0.001 to 8.0 parts by mass, more preferably 0.01 to 7.0 parts by mass, more preferably 0.05 to 6.0 parts by mass, even more preferably 0.10 to 4.0 parts by mass, even more preferably 0.15 to 2.0 parts by mass, even more preferably 0.20 to 1.75 parts by mass, and even more preferably 0.25 to 1.5 parts by mass relative to 100 parts by mass of the thermoplastic resin (e.g., polyvinyl acetal resin) contained in the resin layer. When the silane coupling agent is present only on the surface of the resin layer that comes into contact with the non-bonded member (for example, when a silane coupling agent is applied to the surface of a resin layer that does not contain a silane coupling agent and that comes into contact with the non-bonded member), the content of the silane coupling agent in the resin layer is preferably 0.001 to 8.0 parts by weight, more preferably 0.001 to 6.0 parts by weight, more preferably 0.005 to 5.0 parts by weight, more preferably 0.005 to 4.0 parts by weight, even more preferably 0.010 to 3.0 parts by weight, even more preferably 0.015 to 2.0 parts by weight, even more preferably 0.015 to 1.5 parts by weight, and even more preferably 0.020 to 1.0 parts by weight, relative to 100 parts by weight of the thermoplastic resin (e.g., polyvinyl acetal resin) contained in the resin layer. When the content of the silane coupling agent is within the above range, improved adhesion to the members contained in the flexible electronic device module (initial adhesion and high adhesion maintained even in high temperature and high humidity environments) can be achieved. When the content of the silane coupling agent is equal to or less than the upper limit, the deterioration of moldability due to hardening of the resin layer and the possibility of damage to the bonded member (for example, a flexible electronic device element) can be reduced. In another embodiment of the present invention, when the silane coupling agent is present only near the surface of the resin layer that contacts the bonded member, the amount of the silane coupling agent can be calculated assuming that the silane coupling agent present on the surface is uniformly dispersed in the resin layer.

[0061] Examples of antioxidants include primary antioxidants such as hindered phenol-based antioxidants, amine-based antioxidants, lactone-based antioxidants, and hydroxylamine-based antioxidants, as well as secondary antioxidants such as sulfur-based oxidants and phosphorus-based oxidants. These antioxidants can be used alone or in combination of two or more. When the resin layer contains an antioxidant in addition to a thermoplastic resin, the content is not particularly limited, but is typically 0.01 to 1.5 parts by mass, preferably 0.02 to 1.0 part by mass, and more preferably 0.03 to 0.5 parts by mass per 100 parts by mass of the thermoplastic resin contained in the resin layer.

[0062] As the hindered phenol-based antioxidant, a phenol-based antioxidant having a hindered phenol structure or a mono-hindered phenol structure in the molecule is preferred from the viewpoint of light resistance. Such hindered phenol-based antioxidants are known. Examples of commercially available hindered phenol-based antioxidants include the SONGNOX (registered trademark) series manufactured by SONGWON, the SUMILIZER (registered trademark) series manufactured by Sumitomo Chemical Co., Ltd., the IRGANOX (registered trademark) series manufactured by BASF Japan Ltd., the MARK AO series manufactured by ADEKA Corporation, and the NOCRAC series manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

[0063] Examples of UV absorbers include benzotriazole-based UV absorbers, hydroxyphenyltriazine-based UV absorbers, salicylic acid ester-based UV absorbers, benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, cyanoacrylate-based UV absorbers, and nickel-based UV absorbers. These UV absorbers can be used alone or in combination of two or more. When the resin layer contains a UV absorber in addition to a thermoplastic resin, the content is not particularly limited, but is typically 0.01 to 3.0 parts by mass, preferably 0.02 to 2.5 parts by mass, and more preferably 0.03 to 2.0 parts by mass per 100 parts by mass of the thermoplastic resin contained in the resin layer.

[0064] From the viewpoint of UV absorption and photostability, and of being able to bring about excellent optical properties and transparency, UV absorbers selected from the group consisting of benzotriazole-based UV absorbers, hydroxyphenyltriazine-based UV absorbers, and benzophenone-based UV absorbers are preferred, with benzotriazole-based UV absorbers being more preferred. In particular, benzotriazole-based UV absorbers in which a phenyl group having a group with 6 or more carbon atoms and a hydroxyl group as a substituent is bonded to the nitrogen atom constituting the benzotriazole ring are preferred. Such benzotriazole-based UV absorbers are known. Examples of commercially available benzotriazole-based UV absorbers include the TINUVIN (registered trademark) series manufactured by BASF Japan Ltd., the Sumisorb (registered trademark) series manufactured by Sumitomo Chemical Co., Ltd., and the ADK STAB series manufactured by ADEKA Corporation.

[0065] Examples of the adhesion modifier include alkali metal salts, alkaline earth metal salts, and magnesium salts. The adhesion modifier can be used alone or in combination of two or more. When the resin layer contains an adhesion modifier in addition to a thermoplastic resin, the content is not particularly limited, but is usually 0.01 to 0.25 parts by mass, preferably 0.02 to 0.20 parts by mass, and more preferably 0.03 to 0.15 parts by mass per 100 parts by mass of the thermoplastic resin contained in the resin layer.

[0066] As the adhesion modifier, for example, an alkali metal salt of an organic acid having 2 to 16 carbon atoms, an alkaline earth metal salt of an organic acid having 2 to 16 carbon atoms, and / or a magnesium salt of an organic acid having 2 to 16 carbon atoms can be used. More specific examples include potassium acetate, potassium propionate, potassium 2-ethylbutanoate, potassium 2-ethylhexanoate, magnesium acetate, magnesium propionate, magnesium 2-ethylbutyrate, and magnesium 2-ethylhexanoate.

[0067] The thickness of the resin layer is preferably 0.1 to 500 μm, more preferably 1 to 475 μm, even more preferably 10 to 450 μm, and particularly preferably 20 to 425 μm. This thickness is the average thickness of the resin layer. Furthermore, when the resin layer is a single layer, this thickness refers to the thickness of the single layer. When the resin layer is a multilayer layer, this thickness refers to the total thickness of the layers constituting the multilayer. When the resin layer thickness is within this range, the resin layer can have the desired yellowness, transparency, lightness, and flexibility, while also having the desired moisture absorption and water vapor permeability. Furthermore, when the thickness is equal to or greater than the lower limit, a flexible electronic device module manufactured by laminating a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer can have better water sealing performance. The thickness (average thickness) of the resin layer and the flexible water vapor barrier layer described below can be determined by measuring the thickness at any three points using a thickness gauge and calculating the average value.

[0068] The ten-point mean roughness Rz of at least one surface, preferably both surfaces, of the resin layer, measured in accordance with JIS B0601-1994, is preferably 2 to 7 μm, more preferably 2.5 to 6.5 μm, even more preferably 3.0 to 6.0 μm, even more preferably 3.5 to 5.5 μm, even more preferably 3.5 to 5.0 μm, and even more preferably 3.5 to 4.5 μm. When the ten-point mean roughness Rz is within the above range, air at the interface between the resin layer and the bonded member can be easily removed, resulting in higher adhesion with the members included in the flexible electronic device module, and maintaining higher adhesion even in high-temperature, high-humidity environments. The ten-point mean roughness Rz can be adjusted within the above range by selecting an embossing roll as the surface that comes into contact with the resin layer when producing the resin layer. For example, when producing the resin layer by pressing with a compression molding machine, an embossed Teflon sheet or the like can be used as the material for the pressing surface. The ten-point average roughness Rz is measured using a surface roughness meter in accordance with JIS B0601-1994.

[0069] At least one surface of the resin layer may be embossed in a manner different from that which provides the ten-point height deviation Rz, thereby achieving better degassing properties at the interface between the embossed resin layer and the bonded member.

[0070] <Method for producing resin layer> The method for producing the resin layer is not particularly limited. For example, when the resin layer contains a thermoplastic resin, a resin composition is prepared by mixing a thermoplastic resin and optionally an additive and optionally a solvent described below, and the resin composition is formed into a film by a known film-forming method such as an extrusion method, a calendar method, a pressing method, a casting method, or an inflation method. The resin layer can also be produced by press-molding pellets of the resin composition. The produced resin layer may be stretch-molded.

[0071] When preparing the resin composition, it may be heated to, for example, 160 to 190° C., preferably 170 to 185° C. In one embodiment of the present invention, the resin layer can be produced by a method comprising mixing a thermoplastic resin, optionally an additive, and optionally a solvent described below under heating at 160 to 190° C. to obtain a resin composition.

[0072] When the pressing method is employed among known film-forming methods, the temperature of the resin composition during pressing may be selected depending on the composition of the resin composition, and is preferably 160 to 190° C., more preferably 170 to 185° C. The pressing pressure is usually 3 to 12 MPa, preferably 5 to 10 MPa, and the pressing time is usually 1 to 5 minutes, preferably 2 to 4 minutes.

[0073] When an extrusion method is employed among known film-forming methods, the melt extrusion temperature may be selected depending on the composition of the resin composition, and is preferably 160 to 190° C., more preferably 170 to 185° C. Moisture or volatile components that may be contained in the resin composition can be removed by venting, and this removal can reduce the possibility of voids occurring in the resin layer.

[0074] Furthermore, a resin layer can be formed on a bonded member (e.g., a flexible water vapor barrier layer or a flexible electronic device element) by coating or painting using various coating or painting devices. When forming a resin layer by coating or painting, components such as a thermoplastic resin and optional additives may be dissolved or dispersed in a solvent and applied and dried, or a solid resin composition comprising the components may be melted and applied as is. A solvent that can uniformly dissolve or disperse the thermoplastic resin and optional additives and can be removed from the coating film by drying after coating or painting is preferred. Examples of such solvents include water, methanol, ethanol, isopropanol, ethyl acetate, and mixtures of two or more thereof.

[0075] When the resin layer is embossed to form a concave-convex shape, the processing temperature is preferably 60 to 150° C., more preferably 80 to 140° C. The processing pressure is preferably 0.1 to 15 MPa, more preferably 0.3 to 8 MPa. The film transport speed during embossing is preferably 5 m / min or more, more preferably 10 to 30 m / min.

[0076] <Flexible Water Vapor Barrier Layer> The flexible water vapor barrier layer (hereinafter, sometimes simply referred to as "barrier layer") included in the flexible electronic device module of the present invention is a layer that can suppress the penetration of moisture, and has a water vapor transmission rate of 1.0×10 at a temperature of 85° C. and a relative humidity of 85% RH. －６ ~1.0 x 10 －１ g / m ２ The water vapor transmission rate of the barrier layer at a temperature of 85°C and a relative humidity of 85% RH is preferably 9 x 10 －２ g / m ２ days or less, more preferably 8 × 10 －２ g / m ２ days or less, more preferably 7 × 10 －２ g / m ２ days or less, particularly preferably 6 × 10 －２ g / m ２When the water vapor transmission rate is equal to or less than the upper limit, the water vapor barrier property of the barrier layer is enhanced. The lower the water vapor transmission rate, the less water vapor passes through the barrier layer, which is preferable. Therefore, the lower limit of the water vapor transmission rate is not particularly limited, but is usually 1.0 × 10 －６ or more, or 3 x 10 －６ g / m ２ ・day or more, or 5 x 10 －６ g / m ２ On the other hand, as described above, in the flexible electronic device module of the present invention, the resin composition constituting the resin layer has a specific saturated water absorption rate and a specific water vapor permeability, so that even if the flexible water vapor barrier layer has a high water vapor permeability, the penetration of water into the interior of the flexible electronic device module is highly suppressed. Therefore, the water vapor permeability of the barrier layer at a temperature of 85°C and a relative humidity of 85% RH is 5×10 －６ g / m ２ ・day or more, 1 x 10 －５ g / m ２ ・Day or more, 5 x 10 －５ g / m ２ ・day or more or 1 x 10 －４ g / m ２ ・day or more or 5 x 10 －４ g / m ２ The water vapor transmission rate may be 1.0×10 days or more. －６ ~9 x 10 －２ g / m ２ day, more preferably 1.0 x 10 －６ ~8 x 10 －２ g / m ２ day, more preferably 1.0 x 10 －６ ~7 x 10 －２ g / m ２ day, particularly preferably 1.0 × 10 －６ ~6 x 10 －２ g / m ２ The preferred water vapor transmission rate is 3×10 －６ ~9 x 10 －２ g / m ２ ・day, 5 x 10 －６ ~9 x 10 －２ g / m ２・day, 8 x 10 －６ ~9 x 10 －２ g / m ２ ・day or 1 x 10 －５ ~9 x 10 －２ g / m ２ ・day or 5 x 10 －５ ~9 x 10 －２ g / m ２ ・day or 1 x 10 －４ g / m ２ ・day~9×10 －２ g / m ２ ・day or 5 x 10 －４ g / m ２ ・day~9×10 －２ g / m ２ The water vapor transmission rate of the barrier layer can be measured in accordance with ISO / TS 20175:2018, and more specifically, can be measured by the method described in the examples below.

[0077] The barrier layer is, for example, a film formed by laminating a single-layer or multi-layer thermoplastic resin film and a single-layer or multi-layer inorganic material layer with or without an adhesive layer. When the barrier layer includes a multi-layer thermoplastic resin film, the two or more thermoplastic resin films may be the same or different. When the barrier layer includes a multi-layer inorganic material layer, the two or more inorganic material layers may be the same or different. When the barrier layer includes a multi-layer adhesive layer, the two or more adhesive layers may be the same or different. Furthermore, when barrier layers are laminated on both sides of the flexible electronic device module, the two barrier layers may be the same or different.

[0078] Examples of various thermoplastic resins include polyolefin resins such as polyethylene resins and polypropylene resins, cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), poly(meth)acrylic resins, polycarbonate resins, polyvinyl alcohol resins, saponified ethylene-vinyl ester copolymers, polyamide resins such as various nylons, polyurethane resins, acetal resins, cellulose resins, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, and polyethylene furanoate, polyether ether ketone, polyaryl ether ketone, polyacrylate, polyetherimide, polyarylsulfone, polyethersulfone, polyamideimide, polyimide, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer, and polyvinylidene fluoride.

[0079] The thickness of the thermoplastic resin film is preferably 0.3 to 1000 μm, more preferably 1 to 800 μm, even more preferably 5 to 600 μm, still more preferably 10 to 500 μm, and particularly preferably 20 to 400 μm. When the thickness of the thermoplastic resin film is within the above range, the barrier layer can have the desired barrier properties. The thickness of the thermoplastic resin film is determined by measuring the thickness at any three or more points on the thermoplastic resin film and averaging these values. The thickness of the thermoplastic resin film can be measured using a film thickness meter. When the barrier layer includes two or more thermoplastic resin films, the above ranges represent the thickness of each individual thermoplastic resin film.

[0080] Examples of inorganic materials include tin, phosphorus, aluminum, stainless steel, titanium, copper, silicon oxides such as silica, aluminum oxides such as alumina, titanium oxides such as titania, indium oxide, tin oxide, indium tin oxide (ITO), tantalum oxide, zirconium oxide, niobium oxide, aluminum nitride, silicon nitride, boron nitride, aluminum oxynitride, silicon oxynitride, boron oxynitride, zirconium oxyboride, titanium oxyboride, silicon oxycarbide, silicon oxycarbonitride, aluminum oxycarbide, and combinations of two or more thereof.

[0081] The content of the inorganic material in the inorganic material layer is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, and even more preferably 70 to 100% by mass, 80 to 100% by mass, 85 to 99% by mass, or 90 to 98% by mass, relative to the mass of the inorganic material layer. When the content of the inorganic material in the inorganic material layer is within the above range, desired barrier properties can be exhibited.

[0082] The inorganic material layer may be formed by any method capable of forming a thin film. For example, the inorganic material layer may be formed by a known method such as an etching method, a printing method, a physical vapor deposition (PVD) method such as a vacuum heating evaporation method, an electron beam method, a sputtering method, or an ion plating method, a chemical vapor deposition (CVD) method, or a coating method. A plasma assist method may be combined with the PVD method or the CVD method. Alternatively, a thin film metal or the like may be used. When the inorganic material layer is a multi-layer structure, multiple methods may be used. Each method may be carried out by a method commonly used in the relevant technical field.

[0083] The thickness of the inorganic material layer is preferably 5 nm to 4 μm, more preferably 10 nm to 3 μm, even more preferably 50 nm to 2 μm, even more preferably 0.1 to 1 μm, and particularly preferably 0.2 to 0.8 μm. When the thickness of the inorganic material layer is within the above range, the barrier layer can have the desired barrier properties. The thickness of the inorganic material layer is determined by measuring the thickness at any three or more points on the inorganic material layer and averaging the measured values. The thickness of the inorganic material layer can be measured by cross-sectional observation using a TEM (transmission electron microscope). When the barrier layer can include two or more inorganic material layers, the above ranges represent the thickness of each individual inorganic material layer.

[0084] In a preferred embodiment of the present invention, the barrier layer preferably includes at least one inorganic material layer. By including at least one inorganic material layer, the barrier layer can have higher barrier properties even when its thickness is reduced. In this embodiment, the barrier layer may include only at least one inorganic material layer, but preferably includes at least one inorganic material layer and at least one thermoplastic resin film, from the viewpoint of achieving both barrier properties and flexibility.

[0085] In another preferred embodiment of the present invention, the barrier layer preferably includes two or more inorganic material layers. By including two or more inorganic material layers in the barrier layer, the barrier properties of the barrier layer can be further improved. In this embodiment, the barrier layer may include only two or more inorganic material layers, but it is preferable to include at least two or more inorganic material layers and at least one thermoplastic resin film layer in order to achieve both barrier properties and flexibility.

[0086] When the barrier layer includes two or more inorganic material layers (hereinafter sometimes referred to as "I") and at least one thermoplastic resin film (hereinafter sometimes referred to as "O"), for example, when it includes two inorganic material layers and one thermoplastic resin film, the layer structure is not particularly limited, but possible examples from the flexible electronic device element side are O / I / I, I / O / I, and I / I / O. When it includes two inorganic material layers and two thermoplastic resin films, possible examples from the flexible electronic device element side are O / I / O / I, O / I / I / O / , O / O / I / I, I / O / O / I, I / O / I / O, and I / I / O / O. When the barrier layer includes two or more inorganic material layers and at least one thermoplastic resin film, it is preferable that the inorganic material layers or the thermoplastic resin films are not continuous with each other from the viewpoint of flexibility. Furthermore, the more inorganic material layers contained in the barrier layer, the higher the barrier properties can be, but from the viewpoint of flexibility and transparency, it is preferable that the number of inorganic material layers contained in the barrier layer be 5 or less.

[0087] In addition to the thermoplastic resin film and the inorganic material layer, the barrier layer may include layers such as an adhesive layer and a primer layer, as long as the effects of the present invention are not impaired. Furthermore, the surface of the thermoplastic resin film and / or the inorganic material layer may be subjected to a known surface treatment such as a plasma treatment or a corona treatment.

[0088] Examples of adhesives constituting the adhesive layer include dry-hardening adhesives and chemically reactive adhesives. Examples of chemically reactive adhesives include active energy ray-curable adhesives. Adhesives known in the art can be used as such adhesives. Specific examples of adhesives include polycarbonate-based adhesives, polyether-based adhesives, acrylic-based adhesives, polyurethane-based adhesives, and polyester-based adhesives.

[0089] The thickness of the adhesive layer is not particularly limited as it is determined depending on the type or adhesive strength, etc., but from the viewpoint of processability or durability, it is preferably 0.01 to 10 μm, more preferably 0.1 to 5 μm.

[0090] The primer layer may be made of, but is not limited to, a polyol or a polyisocyanate, etc. From the viewpoint of the flexibility of the barrier layer, the thickness of the primer layer is, for example, 0.001 to 5 μm, preferably 0.005 to 2 μm, and more preferably 0.1 to 2 μm.

[0091] The average thickness of the barrier layer is preferably 0.3 to 500 μm, more preferably 1 to 400 μm, even more preferably 5 to 300 μm, and particularly preferably 10 to 200 μm. When the thickness of the barrier layer is within the above range, the desired barrier properties can be exhibited and the adhesion to the resin layer can be improved. Furthermore, the flexibility and mechanical strength of the barrier layer can be achieved at the same time. The thickness of the barrier layer is determined by measuring the thickness at any three or more points on the barrier layer and averaging the measured values. The thickness of the barrier layer can be measured using a film thickness meter or the like.

[0092] The method for producing the barrier layer is not particularly limited. For example, when the barrier layer includes a thermoplastic resin film and an inorganic material layer, the inorganic material layer can be formed on the thermoplastic resin film by the above-mentioned method. The barrier layer may have convex portions and / or concave portions, and in this case, the barrier layer can be produced by processing and molding using a mold having convex portions and / or concave portions.

[0093] Commercially available barrier layers can also be used, and examples thereof include the oxygen / water vapor high barrier film "CLARISTA (registered trademark)" (manufactured by Kuraray Co., Ltd.), the transparent silica vapor-deposited high gas barrier film "TECHBARIER (registered trademark)" (manufactured by Mitsubishi Chemical Corporation), the DNP transparent vapor-deposited film "IB-Film (registered trademark)" (manufactured by Dai Nippon Printing Co., Ltd.), and the transparent barrier film "GL BARRIER" (manufactured by TOPPAN Corporation).

[0094] <Flexible Electronic Device Element> Examples of flexible electronic device elements included in the flexible electronic device module of the present invention include flexible solar cell power generation elements, organic EL elements, inorganic EL elements, organic EL display elements, inorganic EL display elements, liquid crystal device elements, and electronic paper elements. Each of the flexible electronic device elements exemplified above can be any known flexible electronic device element. Hereinafter, a flexible solar cell power generation element, which is one of the flexible electronic device elements of the present invention, will be described, but the flexible electronic device element of the present invention is not limited to a solar cell power generation element.

[0095] (Solar Cell Power Generation Element) The solar cell constituting the solar cell power generation element is not particularly limited, and solar cells commonly used in the art can be used. Examples of such solar cells include compound solar cells using compound semiconductors of Groups I-III-VI, I-II-IV-VI, III-V, or II-VI of the periodic table, such as CIGS (copper (Cu)-indium (In)-gallium (Ga)-selenium (Se)), CIS (Cu-In-Se), CZTS, gallium-arsenic, and cadmium-tellurium, as the photoelectric conversion unit; and organic solar cells such as dye-sensitized, organic thin film, and organic-inorganic hybrid perovskite. The use of compound solar cells as the solar cell is preferable because it can impart flexibility to the solar cell. Furthermore, the use of organic-inorganic hybrid perovskite solar cells is even more preferable because they have excellent conversion efficiency and can impart flexibility.

[0096] Here, a solar cell is the smallest structural unit of a solar cell used for photovoltaic power generation, and includes at least a photoelectric conversion unit and an electrode. The electrode is made of a conductive material, such as a metal or a metal compound such as a metal oxide, or a carbon-based material such as graphene or carbon nanotubes. The material, shape, and mounting position of the electrode used in a solar cell are determined appropriately depending on the material or combination of materials used in the photoelectric conversion unit. Furthermore, depending on the type of solar cell, various components such as an anti-reflective film or a cell substrate may be included. For example, thin-film solar cells such as amorphous silicon or CIGS typically include at least a transparent electrode layer, a photoelectric conversion unit, and a back electrode. In the case of a solar cell using amorphous silicon, the photoelectric conversion unit typically includes a p-layer amorphous silicon film, an i-layer amorphous silicon film, and an n-layer amorphous silicon film. In the case of a solar cell using CIGS, the photoelectric conversion unit typically includes CIGS. If necessary, the photoelectric conversion unit may include other components. Examples of materials for the transparent electrode layer include inorganic oxides such as ITO, GZO, BZO, AZO, and IZO, and carbon-based materials such as carbon nanotubes.

[0097] The thin-film solar cell is preferably formed on a substrate, examples of which include plastic films such as polyimide films, polyethylene naphthalate (PEN) films, polyethersulfone (PES) films, polyethylene terephthalate (PET) films, and aramid films, flexible or inflexible metal substrates (e.g., titanium, molybdenum, stainless steel, or aluminum), ceramic sheets, and glass.

[0098] <Optional Layer> The flexible electronic device module may optionally include another layer on the opposite side of the flexible water vapor barrier layer from the resin layer. Examples of the other layer that may be optionally included include a surface protection layer, a light diffusion layer, an ultraviolet / infrared absorbing layer, an ultraviolet / infrared reflective layer, an anti-reflection layer, a wavelength conversion layer, a water-repellent layer, an impact absorbing layer, a hard coat layer, or a combination of two or more thereof. One film or layer may have two or more functions. For example, by including an ultraviolet absorber in the surface protection layer, the surface protection layer can function as both a surface protection layer and an ultraviolet absorbing layer.

[0099] The flexible electronic device module preferably includes a surface protective layer as the outermost layer. The surface protective layer is disposed on the opposite side of the flexible water vapor barrier layer from the resin layer. In one embodiment, the surface protective layer is disposed adjacent to the flexible water vapor barrier layer. Examples of stacking orders in the flexible electronic device module include an example in which a surface protective layer is added to the rightmost side of each stacking order example described in the section "Method for Manufacturing a Flexible Electronic Device Module" below (e.g., element / resin layer / barrier layer / surface protective layer). Note that when the flexible electronic device element is a solar cell power generation element, the flexible electronic device module is a solar cell module. In this case, the laminated portion of the resin layer and the flexible water vapor barrier layer in the solar cell module can be referred to as a solar cell module front sheet if it is on the side exposed to sunlight, or as a solar cell module back sheet if it is on the side not exposed to sunlight (the side opposite to the side exposed to sunlight).

[0100] The surface protective layer is not particularly limited, and a surface protective layer commonly used in the art can be used. A highly transparent and scratch-resistant resin layer is preferred as the surface protective layer. Furthermore, the surface protective layer of a device (e.g., a solar cell) that may be used outdoors is preferably made of a resin with high weather resistance (e.g., light resistance). Furthermore, when protecting a surface that requires light transmission, a surface protective layer with high light transmittance is preferred. Examples of materials for the surface protective layer (surface protective film) include acrylic resin, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, triacetyl cellulose, cycloolefin polymer, ethylene-tetrafluoroethylene copolymer (ETFE), polytetrafluoroethylene, 4-fluoroethylene-perchloroalkoxy copolymer, 4-fluoroethylene-6-fluoropropylene copolymer, 2-ethylene-4-fluoroethylene copolymer, poly-3-chlorofluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, and the like.

[0101] In order to improve the durability of the surface protective layer, various additives (e.g., ultraviolet absorbers) may be added to the surface protective layer. A preferred example of a surface protective layer with high weather resistance is an acrylic resin layer to which an ultraviolet absorber has been added. As the ultraviolet absorber, the ultraviolet absorbers exemplified in the previous paragraph as ultraviolet absorbers that can be added to the resin layer can be used. In addition, other stabilizers, light stabilizers, antioxidants, etc. may be used in combination.

[0102] Furthermore, in order to enhance the durability of the surface protective layer, a weather-resistant coating such as a weather-resistant hard coat may be applied to the surface of the surface protective layer. The type of coating is not particularly limited, and known materials can be used.

[0103] In one embodiment of the present invention, a weather-resistant film is disposed on the opposite side of the flexible water vapor barrier layer from the resin layer in the flexible electronic device module. The weather-resistant film may be, for example, a layer made of a highly weather-resistant resin, a resin layer to which an ultraviolet absorber has been added, or a resin layer to which a weather-resistant hard coat has been applied on the surface. These layers may be disposed as the outermost layer (surface protection layer) of the flexible electronic device module, or may be disposed between the outermost layer and the flexible water vapor barrier layer. A commercially available weather-resistant film may be used as the weather-resistant film.

[0104] The thickness of any layer such as a surface protective layer or a weather-resistant film is usually 10 to 100 μm, preferably 15 to 80 μm. Commercially available surface protective layers can also be used, examples of which include a 50 μm thick pressure-sensitive adhesive (PSA, 3M Optically Clear Adhesive 8172P) and a 50 μm thick ethylene tetrafluoroethylene polymer sheet (ETFE, NORTON (registered trademark) ETFE).

[0105] [Method for Manufacturing Flexible Electronic Device Module] A known manufacturing method can be used to manufacture a flexible electronic device module. For example, a flexible electronic device module can be manufactured by a method including the steps of stacking a flexible electronic device element (hereinafter sometimes abbreviated as "element"), a resin layer, a barrier layer, and any optional layers or films, if any, and vacuum-suctioning and heat-pressing the stacked structure. Examples of stacking orders include: when the resin layer is stacked on one side of the flexible electronic device element, element / resin layer / barrier layer, element / resin layer / barrier layer / any layer or film, element / resin layer / any layer or film / barrier layer, element / resin layer / any layer or film / barrier layer / any layer or film; when the resin layer is stacked on both sides of the flexible electronic device element, barrier layer / resin layer / element / resin layer / barrier layer, barrier layer / resin layer / element / resin layer / barrier layer / any layer or film, barrier layer / resin layer / element / resin layer / any layer or film / barrier layer, barrier layer / resin layer / element / resin layer / any layer or film / barrier layer / any layer or film, any layer or film / barrier layer / resin layer / element / resin layer / barrier layer / any layer or film, any layer or film / barrier layer / any layer or film / resin layer / element / resin layer / barrier layer / any layer or film, any layer or film / barrier layer / any layer or film / resin layer / element / resin layer / any layer or film / barrier layer / any layer or film.

[0106] An example of a method for manufacturing a flexible electronic device module includes a method that includes stacking and thermocompressing a flexible electronic device element, a resin layer, a flexible water vapor barrier layer, and any optional layer or film.

[0107] The water absorption rate of the resin layer before thermocompression bonding is preferably 1% by mass or less, more preferably 0.5% by mass or less. When the water absorption rate of the resin layer before thermocompression bonding is the above-mentioned upper limit or less, the initial water absorption rate of the resin layer included in the flexible electronic device module is low, and therefore penetration of moisture into the interior of the flexible electronic device module can be highly suppressed. The water absorption rate of the resin layer before thermocompression bonding can be adjusted to the above-mentioned upper limit or less by drying the resin layer using a general method. The lower limit of the water absorption rate of the resin layer before thermocompression bonding is 0% by mass or more. The water absorption rate of the resin layer can be measured, for example, using a Karl Fischer apparatus.

[0108] The present invention also provides a method for producing a flexible electronic device module, comprising thermocompression bonding a flexible electronic device element, a resin layer, a flexible water vapor barrier layer, and any layer or film, wherein the resin layer has a water absorption rate of 1% by mass or less before thermocompression bonding. This method can produce a flexible electronic device module that can highly inhibit moisture penetration into the interior. The produced flexible electronic device module can have a long life.

[0109] When manufacturing a flexible electronic device module including a flexible electronic device element, a resin layer, a flexible water vapor barrier layer, and an optional layer or film, the flexible electronic device module can be manufactured by a method including, for example, a step of stacking the manufactured resin layer and optional layer, vacuum suctioning them, and thermocompression bonding them to obtain a laminate, and a step of stacking the laminate with components such as the flexible electronic device element and the flexible water vapor barrier layer, and vacuum suctioning them and thermocompression bonding them. However, a flexible electronic device module can also be manufactured in an integrated manner without manufacturing the laminate. That is, a flexible electronic device module can also be manufactured by a method including a step of stacking the flexible electronic device element, the resin layer, the flexible water vapor barrier layer, and optional layer or film, and vacuum suctioning them and thermocompression bonding them. The flexible electronic device element, the resin layer, the flexible water vapor barrier layer, and optional layer or film, if included, can be subjected to a known surface treatment such as a primer treatment or a corona treatment before stacking them, in order to improve adhesion to adjacent components.

[0110] In the step of vacuum suction and heat-pressure bonding, for example, a vacuum laminator is used. Typically, lamination is performed at a predetermined bonding temperature under reduced pressure of 1 to 30,000 Pa. The bonding temperature is preferably 90 to 170°C, more preferably 100 to 160°C, and even more preferably 110 to 150°C.

[0111] In the manufacturing process of a flexible electronic device module, when a vacuum bag or a vacuum ring is used to heat-pressure-bond the flexible electronic device element, the resin layer, the flexible water vapor barrier layer, any optional layers or films, etc., it is preferable to reduce the pressure of the stack of the above-mentioned materials to about 20,000 Pa and then laminate them at the above-mentioned temperature.

[0112] In the manufacturing process of a flexible electronic device module, for example, when nip rolls are used to heat and pressure bond a resin layer containing a thermoplastic resin, a flexible water vapor barrier layer, or any layer or film, if any, to a flexible electronic device element, an example method is to perform temporary pressure bonding at a temperature equal to or lower than the flow initiation temperature of the thermoplastic resin, and then perform main pressure bonding under conditions close to the flow initiation temperature. Specifically, the materials may be heated to 30 to 100°C (e.g., 30 to less than 100°C) using an infrared heater or the like, degassed with a roll, further heated to the above temperature, and then pressure bonded with a roll.

[0113] The autoclave step, which is additionally performed after the main pressure bonding, is performed, for example, for about 2 hours at the above temperature under a pressure of about 1 to 1.5 MPa, although this depends on the thickness or configuration of the laminate and the flexible electronic device module, etc. However, in the present invention, high initial adhesiveness can be achieved without performing the autoclave step, and high adhesiveness can be maintained even in a high-temperature, high-humidity environment.

[0114] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. The methods for measuring the physical properties of the flexible electronic device module are described below. The physical properties and measurements (or physical property values ​​and measured values) described in this specification, including the examples, are based on values ​​determined by the following methods.

[0115] <Saturated Water Absorption at a Temperature of 85°C and a Relative Humidity of 85% RH> The saturated water absorption at a temperature of 85°C and a relative humidity of 85% RH of the resin composition constituting the resin layer was determined by leaving the resin composition to stand in this environment for 50 hours, confirming that the mass of the resin composition had reached a constant weight, and then measuring the moisture content using a Karl Fischer apparatus (CA200, manufactured by Nitto Seiko Analytech Co., Ltd.).

[0116] <Water vapor transmission rate at a temperature of 85°C and a relative humidity of 85% RH> The water vapor transmission rates of the resin films and water vapor barrier layers used in the examples and comparative examples at a temperature of 85°C and a relative humidity of 85% RH were measured using a gas and water vapor transmission rate measuring device (manufactured by TI Corporation) in accordance with ISO / TS 20175: 2018. Note that, since the water vapor transmission rate and the film thickness are inversely proportional to each other, the water vapor transmission rate of the resin film was calculated based on a film thickness of 100 µm.

[0117] <Amount of Hydroxyl Groups in Polyvinyl Acetal Resin> The amount of hydroxyl groups in the polyvinyl acetal resin was measured in accordance with JIS K6728-1977.

[0118] <Average Thickness> The average thickness of the resin layer was determined by measuring the thickness at any three points with a thickness meter and calculating the average value.

[0119] <Conversion Efficiency of Solar Cell Module and Its Decrease Rate> The solar cell modules fabricated in the examples and comparative examples were subjected to a high-temperature, high-humidity test in accordance with JIS C 61215-2. Specifically, the solar cell modules were exposed for 250 hours at a temperature of 85°C and a relative humidity of 85% RH using a thermo-hygrostat (manufactured by Hitachi Appliances, Inc.). The conversion efficiencies of the solar cell modules before the high-temperature, high-humidity test, after 125 hours of exposure, after 250 hours of exposure, after 500 hours, 1000 hours, and after 2000 hours were measured by irradiating them with reference sunlight, and the rate of decrease was calculated according to the following formula: Conversion efficiency decrease rate (%) = {(conversion efficiency before test - conversion efficiency after test) / (conversion efficiency before test)} × 100. The conversion efficiency of the solar cell modules was measured using a Super Solar Simulator (manufactured by ADTEC Engineering Co., Ltd.) in accordance with JIS C 8918:2013.

[0120] Example 1 PVB resin (1) (Mowital B30H manufactured by Kuraray Co., Ltd.; hydroxyl group content 26.2 to 30.2 mol %, acetyl group content 0.7 to 3.0 mol %, weight average molecular weight 28,000 to 38,000) and PVB resin (2) (Mowital B30H manufactured by Kuraray Co., Ltd.; B75H; hydroxyl group content 26.2 to 30.2 mol%, acetyl group content 0 to 3.0 mol%, weight average molecular weight 96,000 to 106,000 were dry blended at an 85:15 ratio. To 100 parts by mass of the resulting resin mixture, 0.073 parts by mass of the hindered phenol-based antioxidant Irganox 245 (manufactured by BASF Japan Ltd.) and 2.3 parts by mass of the benzotriazole-based ultraviolet absorber Tinuvin 360 were added and mixed to obtain a dry blend mixture. The dry blend mixture was melt-kneaded at a temperature of 180 ° C and a rotation speed of 150 rpm using a twin-screw extruder KZW15-45MG (D = 15 mmφ, L / D = 45, manufactured by Technovel Co., Ltd.), and melt-extruded from a T-die head to produce a 100 μm thick PVB resin film. The saturated water absorption and water vapor transmission rate of the resulting resin film were as shown in Table 1. A flexible solar cell module was manufactured by thermocompression bonding using a vacuum laminator (manufactured by Nisshinbo Mechatronics Inc.) at a temperature of 140°C, 12 minutes of evacuation, a press pressure of 30 kPa, and a press time of 18 minutes. Various physical property values ​​and measured values ​​are shown in Table 1. In all of the examples and comparative examples (in which a resin layer was used), the water absorption rate of the resin layer before thermocompression bonding was 1% by mass or less.

[0121] Example 2 A flexible solar cell module was produced in the same manner as in Example 1, except that two sheets of the above-mentioned PVB resin film were used as each of the two resin layers instead of four sheets of the above-mentioned PVB resin film, and a CIGS solar cell (2) (manufactured by Sun Harmonics, 41 mm × 100 mm) was used as the solar cell power generation element.

[0122] Example 3 First, an ethylene-vinyl alcohol copolymer (EVOH) resin modified with 1,2-epoxybutane (hereinafter also referred to as "modified EVOH") was prepared by the preparation method described below. Five kg of dried EVOH pellets having an ethylene content of 44 mol%, a degree of saponification of 99.8 mol%, an MFR of 5 g / 10 min (190°C, under a load of 2160 g), and a weight-average molecular weight of 42,000 to 52,000 were placed in a polyethylene bag as raw EVOH pellets. 395 g of a catalyst solution (a solution containing 3.3 mass% zinc trifluoromethanesulfonate, 0.6 mass% methanol, and 96.0 mass% acetone) was added to the polyethylene bag. With the polyethylene bag closed, the mixture of the raw EVOH pellets and the catalyst solution was heated at 50°C for 10 hours with occasional shaking to impregnate the raw EVOH pellets with the catalyst solution. Next, the pellets were vacuum dried at 30°C to obtain EVOH pellets containing zinc ions and sulfonate ions. 10 parts by mass of the obtained EVOH pellets were dry-blended with 90 parts by mass of the raw EVOH pellets to obtain mixed EVOH pellets. Hereinafter, the obtained mixed EVOH pellets will be referred to as "EVOH (A)." Next, a TEM-35BS extruder (37 mmφ, L / D=52.5) ​​manufactured by Toshiba Machine Co., Ltd. was prepared, and a screw configuration, vent, and pressure inlet were installed as shown in Figure 1. Barrel C1 was water-cooled, barrels C2 and C3 were set to 200°C, and barrels C4 to C15 were set to 220°C. The extruder was operated at a screw rotation speed of 200 rpm. EVOH (A) was fed at a rate of 11 kg / hr through the resin feed port of C1, the internal pressure of vent 1 was reduced to 60 mmHg, and 1,2-epoxybutane was fed at a rate of 2.5 kg / hr through pressure inlet 1 of C8 (feed pressure: 3.5 MPa). The internal pressure of vent 2 was reduced to 200 mmHg, unreacted 1,2-epoxybutane was removed, and an 8.2 mass% aqueous solution of trisodium ethylenediaminetetraacetate trihydrate was added through pressure inlet 2 of C13 at a rate of 0.14 kg / hr. The proportion of 1,2-epoxybutane was 22.7 parts by mass per 100 parts by mass of EVOH (A). The molar number of zinc ions relative to the mass of EVOH (A) was 0.78 μmol / g.The internal pressure of vent 3 was reduced to 20 mmHg, and water was removed to obtain a modified EVOH. The resulting modified EVOH had an MFR of 5 g / 10 min (190°C, under a load of 2160 g) and a melting point of 109°C. The chemical structure of the modified EVOH thus obtained was determined by trifluoroacetylating the modified EVOH and then subjecting it to NMR spectroscopy according to the procedure described in WO 2002 / 092643. As a result, the ethylene content of the modified EVOH was 44 mol%, and the content of the following structural unit (I) was 7.0 mol%. Structural unit (I): In the above formula, R １ , R ２ , R ３ and R ４ each independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or a phenyl group, and the aliphatic hydrocarbon group, alicyclic hydrocarbon group, and phenyl group may have a hydroxyl group, an alkoxy group, a carboxyl group, or a halogen atom; R ３ and R ４ and may be bonded. Next, the prepared modified EVOH was extruded into a film under the following extrusion conditions using a film-forming machine consisting of a 40φ extruder (PLABOR GT-40-A manufactured by Plastics Engineering Research Institute) and a T-die to obtain a 20 μm-thick monolayer film. Type: Single-screw extruder (non-vent type) L / D: 24 Diameter: 40 mmφ Screw: Single-row full-flight type, surface-nitrided steel Screw rotation speed: 40 rpm Die: 550 mm wide coat hanger die Lip gap: 0.3 mm Cylinder and die temperature settings: C1 / C2 / C3 / adapter / die = 180 / 200 / 210 / 210 / 210 (°C) Then, a flexible solar cell module was produced in the same manner as in Example 2, except that a film formed by laminating 10 sheets of 20 μm-thick modified EVOH monolayer film was used as each of the two resin layers.

[0123] Example 4 A flexible solar cell module was produced in the same manner as in Example 3, except that a 12 μm thick barrier film (GX-PF, manufactured by TOPPAN Corporation) was used as the flexible water vapor barrier layer.

[0124] Comparative Example 1 Only the CIGS solar cell (1) was subjected to a high temperature and high humidity test, and the rate of decrease in the conversion efficiency of the solar cell module was determined. The results are shown in Table 2.

[0125] Comparative Example 2 A flexible solar cell module was produced and evaluated in the same manner as in Example 1, except that the flexible water vapor barrier layer was not used.

[0126] Comparative Example 3 A flexible solar cell module was manufactured and evaluated in the same manner as in Example 1, except that a 400 μm thick olefin-based thermoplastic elastomer (TPO) film (PV-FS CVF, manufactured by DNP) was used as each of the two resin layers instead of the four PVB resin films.

[0127] Comparative Example 4 A flexible solar cell module was manufactured and evaluated in the same manner as in Example 1, except that 450 μm thick ethylene-vinyl acetate copolymer (EVA) films (MLCE-62, manufactured by C.I. Kasei Co., Ltd.) were used as the two resin layers instead of the four PVB resin films.

[0128] Comparative Example 5 Only the CIGS solar cell (2) was subjected to a high temperature and high humidity test to determine the rate of decrease in the conversion efficiency of the solar cell module. The results are shown in Table 2.

[0129] Comparative Example 6 A flexible solar cell module was manufactured and evaluated in the same manner as in Example 2, except that a 200 μm thick EVA film was used as each of the two resin layers. The 200 μm thick EVA film was produced by pressing the 450 μm thick EVA film (MLCE-62, manufactured by C.I. Kasei Co., Ltd.) used in Comparative Example 4 at a temperature of 190°C and a pressure of 10 MPa for 2 minutes using a hot / cooled press (NF-37HH / NF-37C, both presses manufactured by Shindo Metal Works Co., Ltd.).

[0130] Comparative Example 7 When obtaining the dry blend mixture, not only 0.073 parts by mass of the hindered phenol-based antioxidant Irganox 245 (manufactured by BASF Japan Ltd.) and 2.3 parts by mass of the benzotriazole-based ultraviolet absorber Tinuvin 360, but also 20 parts by mass of the plasticizer 3G8 (triethylene glycol-bis-(2-ethylhexanoate)) were added relative to 100 parts by mass of the resin mixture, and the film thickness was changed from 100 μm to 200 μm. A PVB resin film containing a plasticizer (hereinafter referred to as a "plasticized PVB resin film") was produced in the same manner as in Example 1. Next, a flexible solar cell module was produced and evaluated in the same manner as in Example 2, except that plasticized PVB resin films were used as the two resin layers.

[0131]

[0132]

[0133] The flexible electronic device module of the present invention highly suppresses moisture penetration into the interior thereof, and therefore exhibits little deterioration in properties after a high-temperature, high-humidity test. For example, when the flexible electronic device module is a solar cell module, the rate of decrease in conversion efficiency after the high-temperature, high-humidity test is small or the conversion efficiency is high. Therefore, even when placed in a high-temperature, high-humidity environment, the flexible electronic device module of the present invention can extend the life of a flexible electronic device incorporating it.

Claims

1. A flexible electronic device comprising, in this order, a flexible electronic device element, a resin layer, and a flexible water vapor barrier layer, wherein the flexible electronic device element and the resin layer are disposed adjacent to each other, and the resin layer is composed of a single resin composition, wherein the resin composition has a saturated water absorption of 1 to 15 mass % at a temperature of 85°C and a relative humidity of 85% RH, and a water vapor transmission rate of 600 g / m at a temperature of 85°C and a relative humidity of 85% RH when the resin composition has a thickness of 100 μm. ２ days or less, and the water vapor barrier layer has a water vapor transmission rate of 1.0×10 at a temperature of 85° C. and a relative humidity of 85% RH. －６ ~1.0 x 10 －１ g / m ２ A flexible electronic device module.

2. The flexible electronic device module according to claim 1, wherein the resin composition comprises a thermoplastic resin.

3. The flexible electronic device module according to claim 2, wherein the thermoplastic resin is at least one selected from the group consisting of polyvinyl acetal resin, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol resin.

4. The flexible electronic device module according to claim 3, wherein the amount of hydroxyl groups in the thermoplastic resin is 10 to 80 mol %.

5. The flexible electronic device module according to claim 1, wherein the resin layer has a thickness of 0.1 to 500 μm.

6. The flexible electronic device module according to claim 1, wherein the flexible electronic device element is a solar cell power generation element, an organic EL element, an inorganic EL element, an organic EL display element, an inorganic EL display element, a liquid crystal device element, or an electronic paper element.

7. The flexible electronic device module according to claim 1, wherein a weather-resistant film is disposed on the opposite side of the water vapor barrier layer from the resin layer.

8. A method for producing a flexible electronic device module according to any one of claims 1 to 7, comprising thermocompression bonding a flexible electronic device element, a resin layer, a flexible water vapor barrier layer, and any layer or film, wherein the water absorption rate of the resin layer before thermocompression bonding is 1% by mass or less.

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