Barrier film for display device, and display device using same

Abstract

Provided is a barrier film for a display device, the barrier film having good barrier properties even if silicon oxide is used and being capable of suppressing a deterioration in display quality of the display device. The barrier film for a display device comprises a base material, an inorganic oxide layer, and an overcoat layer in this order. The inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or greater. The overcoat layer contains an acrylic resin and has a thickness of greater than 2.0 μm.

Description

Barrier film for display device and display device using the same

[0001] The present disclosure relates to a barrier film for a display device and a display device using the same.

[0002] Electronic paper consumes power only when information is rewritten and can maintain display even after power supply is stopped, so it consumes less power than liquid crystal display devices and organic EL display devices. Electronic paper also has excellent properties such as being "excellent in flexibility" and "thin and light."

[0003] Electronic paper is composed of, for example, a rear electrode substrate having a rear substrate and a rear electrode, a transparent electrode substrate having a transparent substrate and a transparent electrode, and a display medium layer disposed between the rear electrode substrate and the transparent electrode substrate.

[0004] The display medium layer of electronic paper is, for example, configured by dispersing a pigment in a filler liquid. Electronic paper allows information displayed on the electronic paper to be rewritten by placing a desired pigment in the display medium layer on the viewer side through voltage control. The display medium layer's information rewriting performance is easily degraded when the filler liquid evaporates or moisture from the outside air invades. Furthermore, electronic paper often uses a plastic film for at least one of the rear substrate and the transparent substrate to achieve thinner, lighter, and more flexible electronic paper. Plastic films have inferior barrier properties compared to glass. Therefore, plastic films with good barrier properties are required for electronic paper. Plastic films with improved barrier properties may also be required for display devices other than electronic paper, such as organic electroluminescence (EL) display devices and liquid crystal display devices using wavelength conversion sheets.

[0005] For this reason, barrier films have been developed in which a layer with good barrier properties is formed on a plastic film. Barrier films for display devices have been proposed, for example, in Patent Document 1. Patent Documents 1 and 2 disclose barrier films having a vapor deposition layer on a substrate and further having a coating layer containing a hydrolyzate of alkoxysilane or the like on the vapor deposition layer.

[0006] JP 2017-202602 A JP 2019-188721 A

[0007] Barrier films for display devices such as electronic paper are required to have high barrier properties and good visibility. In order to achieve high barrier properties, the present inventors have investigated using silicon oxide as a material for the barrier layer of barrier films for display devices such as electronic paper, and increasing the thickness of the barrier layer containing silicon oxide.

[0008] Increasing the thickness of a barrier layer containing silicon oxide can improve the barrier properties of the barrier film. However, when the thickness of a barrier layer containing silicon oxide is increased, a minute ring-shaped rainbow pattern may be visible in part of the surface of the barrier layer. The rainbow pattern reduces the display quality of display devices such as electronic paper. In particular, the rainbow pattern is extremely noticeable in two-color electronic paper (black and white). Patent Documents 1 and 2 do not consider at all the above problems that arise when the thickness of a barrier layer containing silicon oxide is increased.

[0009] An object of the present disclosure is to provide a barrier film for a display device that has good barrier properties and can suppress deterioration in the display quality of the display device even when a silicon oxide is used, and to provide a display device using the barrier film for a display device.

[0010] The present disclosure provides the following [1] to [2]. [1] A barrier film for a display device, comprising a substrate, an inorganic oxide layer, and an overcoat layer in this order, wherein the inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or more, and the overcoat layer contains an acrylic resin and has a thickness of more than 2.0 μm. [2] A display device, comprising the barrier film for a display device according to [1] above.

[0011] The barrier film for a display device of the present disclosure and the display device using the same have good barrier properties and can suppress deterioration in display quality.

[0012] Fig. 1 is a cross-sectional view showing an embodiment of a barrier film for a display device according to the present disclosure; Fig. 2 is a cross-sectional view showing another embodiment of a barrier film for a display device according to the present disclosure; Fig. 3 is a cross-sectional view showing an embodiment of electronic paper according to the present disclosure; Fig. 4 is an optical microscope image of a ring-shaped rainbow pattern; Fig. 5 is an optical microscope image of a barrier film according to an embodiment of the present disclosure taken from a planar direction.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present specification, the term "barrier film for a display device" may be abbreviated to "barrier film".

[0014] [Barrier film for display device] The barrier film for a display device of the present disclosure has a substrate, an inorganic oxide layer, and an overcoat layer in this order, wherein the inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or more, and the overcoat layer contains an acrylic resin and has a thickness of more than 2.0 μm.

[0015] 1 and 2 are cross-sectional views showing one embodiment of a barrier film 100 according to the present disclosure. The barrier film 100 in FIGS. 1 and 2 includes a substrate 11, an inorganic oxide layer 12, and an overcoat layer 14, in this order. The barrier film 100 in FIG. 2 includes a coating layer 13 between the inorganic oxide layer 12 and the overcoat layer 14. In FIG. 1, the inorganic oxide layer 12 and the overcoat layer 14 are in contact with each other. In FIG. 2, the inorganic oxide layer 12 and the coating layer 13 are in contact with each other, and the coating layer 13 and the overcoat layer 14 are in contact with each other. FIGS. 1 and 2 are schematic cross-sectional views. That is, the scales of the layers constituting the barrier film 100 in FIGS. 1 and 2 are simplified for ease of illustration and differ from the actual scales. The same is true in FIG. 3.

[0016] <Characteristics of the Barrier Film of the Present Disclosure> The main characteristics of the barrier film of the present disclosure are that it has the following configurations (1) to (3): (1) A substrate, an inorganic oxide layer, and an overcoat layer, in this order; (2) The inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or more; (3) The overcoat layer contains an acrylic resin and has a thickness of more than 2.0 μm.

[0017] The reasons why the above configurations (1) to (3) can improve barrier properties and suppress deterioration in the display quality of a display device are explained below. As described in (2) above, the inorganic oxide layer of the barrier film of the present disclosure contains silicon oxide and has a thickness of 30 nm or more. By using silicon oxide as the inorganic oxide constituting the inorganic oxide layer, increases in the price of the barrier film can be suppressed. Furthermore, by making the thickness of the inorganic oxide 30 nm or more, high barrier properties can be imparted to the barrier film. However, when an inorganic oxide layer containing silicon oxide is formed by a vacuum deposition method or the like, minute black dots may be visible in the inorganic oxide layer. For example, minute black dots may form in an inorganic oxide layer formed by a vacuum deposition method due to a splash phenomenon. Since minute black dots are local defects during film formation, they are more likely to occur within the surface of the barrier film as the film formation time increases. In other words, the thicker the inorganic oxide layer containing silicon oxide, the more likely it is that minute black dots will occur within the surface of the barrier film. Although efforts to reduce the splash phenomenon in vacuum deposition have been underway, even at the time of filing this application, the splash phenomenon has not been completely eliminated. Thus, it is difficult to completely eliminate the tiny black dots. On the other hand, even if tiny black dots appear on a barrier film, they are unlikely to significantly affect the barrier properties. This is due to the configuration (1) above. That is, when an overcoat layer is provided on an inorganic oxide layer, defects in the inorganic oxide layer are filled by the overcoat layer, which is thought to make it easier to maintain a predetermined barrier property. However, barrier films having the configurations (1) and (2) above sometimes exhibited tiny ring-shaped rainbow patterns visible in parts of the barrier layer. That is, while barrier films having the configurations (1) and (2) above are advantageous in that they are inexpensive and easily achieve high barrier properties, they sometimes exhibited tiny ring-shaped rainbow patterns. The tiny ring-shaped rainbow patterns can degrade the display quality of display devices. Rainbow patterns are particularly noticeable in black-and-white electronic paper.However, the barrier film of the present disclosure, by including the above-mentioned feature (3) in addition to the features (1) and (2), can suppress the visibility of the minute ring-shaped rainbow pattern. Therefore, the barrier film of the present disclosure can suppress the deterioration of the display quality of the display device. The reason why the feature (3) can suppress the deterioration of the display quality of the display device will be explained below.

[0018] A layer that covers the inorganic oxide layer may be formed on the inorganic oxide layer to enhance its barrier properties. In Patent Documents 1 and 2, a coating layer containing an alkoxysilane hydrolysate is formed on a vapor-deposited inorganic oxide layer. The layer formed on the inorganic oxide layer is typically thin, as long as it has a thickness that enhances its barrier properties. The present inventors have discovered that a minute ring-shaped rainbow pattern occurs when a thin overcoat layer is formed on an inorganic oxide layer on which minute black dots have been formed due to a splash phenomenon. Figure 4 is an optical microscope image of the minute ring-shaped rainbow pattern. In Figure 4, the black area located at the center of the ring-shaped rainbow pattern is a minute black dot formed due to a splash phenomenon. The inorganic oxide layer has a height difference centered on the minute black dot. The height difference in the inorganic oxide layer is usually approximately 0.1 μm or more and 3.0 μm or less. Therefore, when a thin overcoat layer is formed on an inorganic oxide layer on which minute black dots have been formed, thickness unevenness occurs in the overcoat layer centered on the minute black dots. Furthermore, since interference is more likely to occur as the thickness approaches the wavelength of light, thickness unevenness in a thin overcoat layer causes interference unevenness. It is believed that the ring-shaped rainbow pattern occurs because interference unevenness occurs due to thickness unevenness in a thin overcoat layer. Thickness unevenness in the overcoat layer occurs over a wider area than the tiny black dots. Therefore, as shown in FIG. 4 , the size of the ring-shaped rainbow pattern is larger than the tiny black dots. By incorporating the above-described configuration (3), the barrier film of the present disclosure can prevent the tiny ring-shaped rainbow pattern from being visible. The above-described configuration (3) specifies that the thickness of the overcoat layer must be greater than 2.0 μm. By increasing the thickness of the overcoat layer to greater than 2.0 μm, even if thickness unevenness occurs in the overcoat layer centered on the tiny black dots in the inorganic oxide layer, the thickness is sufficiently thicker than the wavelength of light, making it less likely to cause interference unevenness. Therefore, the above-described configuration (3) can prevent the tiny ring-shaped rainbow pattern from being visible. In other words, the barrier film of the present disclosure prevents the minute ring-shaped rainbow pattern from being visible by intentionally increasing the thickness of the overcoat layer. Fig. 5 is an optical microscope image of the barrier film of the present disclosure taken from the planar direction.In the optical microscope image of Figure 5, no ring-shaped rainbow pattern can be confirmed around the tiny black dots. The above configuration (3) further specifies that the overcoat layer contains an acrylic resin. Silicon oxide, a typical example of silicon oxide, and acrylic resin have relatively similar refractive indices. Therefore, when the overcoat layer contains an acrylic resin, interference is less likely to occur, making it easier to prevent the tiny ring-shaped rainbow pattern from being visible. In addition, acrylic resins have good moisture resistance and light resistance. Therefore, when the overcoat layer contains an acrylic resin, it is easier to maintain the barrier properties of the barrier film over a long period of time.

[0019] <Layer Structure of Barrier Film> Examples of layer structures of the barrier film of the present disclosure include the following (1) to (4). In the following (1) to (4), " / " indicates the interface of the layers. The barrier film of the present disclosure may have layers other than the substrate, anchor coat layer, inorganic oxide layer, coating layer, and overcoat layer, as long as the effects of the present disclosure are not impaired. (1) Substrate / inorganic oxide layer / overcoat layer (2) Substrate / inorganic oxide layer / coating layer / overcoat layer (3) Substrate / anchor coat layer / inorganic oxide layer / overcoat layer (4) Substrate / anchor coat layer / inorganic oxide layer / coating layer / overcoat layer

[0020] The barrier film of the present disclosure preferably has no other layer on the surface of the overcoat layer opposite to the inorganic oxide layer. In other words, the barrier film of the present disclosure preferably has the overcoat layer as the outermost layer. By adopting the above-described configuration, it is possible to suppress the occurrence of a ring-shaped rainbow pattern without excessively increasing the thickness of the barrier film. In addition, in order to suppress scratches on the outermost overcoat layer, a protective film that can be peeled off at room temperature may be attached to the overcoat layer. The protective film is peeled off when the film is incorporated into a display device. Peelable means that the peel strength when peeling the protective film from the overcoat layer is 1.5 N / 25 mm or less.

[0021] <Substrate> The substrate is preferably a resin film having optical transparency. Examples of the resin film include resin films containing one or more resins selected from polyester, triacetyl cellulose, cellulose diacetate, cellulose acetate butyrate, polyamide, polyimide, polyethersulfone, polysulfone, polypropylene, polymethylpentene, polyvinyl chloride, polyvinyl acetal, polyether ketone, acrylic, polycarbonate, polyurethane, and amorphous olefin. Among these resin films, polyester film is preferred. Furthermore, in order to improve mechanical strength, dimensional stability, and heat resistance, stretched polyester film is more preferred, and biaxially stretched polyester film is even more preferred. Examples of polyester films include polyethylene terephthalate film and polyethylene naphthalate film.

[0022] The substrate may be a single layer of a resin film, or may be a laminate of a plurality of resin films bonded together. A substrate having a plurality of resin films laminated together may be a laminate of the resin films bonded together directly, or may be a laminate of the resin films bonded together via an adhesive layer.

[0023] The thickness of the substrate is preferably 5 μm or more, more preferably 8 μm or more, and even more preferably 10 μm or more. By making the thickness of the substrate 5 μm or more, the strength of the barrier film can be easily improved. From the viewpoint of thinning the substrate and easily suppressing the intrusion of water vapor and oxygen from the edges, the thickness of the substrate is preferably 200 μm or less, more preferably 150 μm or less, more preferably 100 μm or less, more preferably 75 μm or less, and more preferably 50 μm or less.

[0024] In the configuration requirements described herein, when multiple upper limit and lower limit options are shown, it is assumed that the range described is a combination of one selected from the upper limit options and one selected from the lower limit options. For example, embodiments of the thickness range of the above-mentioned substrate include 5 μm to 200 μm, 5 μm to 150 μm, 5 μm to 100 μm, 5 μm to 75 μm, 5 μm to 50 μm, 8 μm to 200 μm, 8 μm to 150 μm, 8 μm to 100 μm, 8 μm to 75 μm, 8 μm to 50 μm, 10 μm to 200 μm, 10 μm to 150 μm, 10 μm to 100 μm, 10 μm to 75 μm, and 10 μm to 50 μm.

[0025] In this specification, the thickness of each layer constituting the barrier film, such as the thickness of the substrate, the thickness of the overcoat layer, the thickness of the inorganic oxide layer, etc., refers to the average value of the thickness measured at 18 points on a cross-sectional image taken with a scanning transmission electron microscope, excluding the minimum and maximum values.

[0026] In this specification, the layer thickness, haze, b ＊ Unless otherwise specified, the measurement of various parameters such as the value is carried out in an atmosphere at a temperature of 23°C ± 5°C and a relative humidity of 40% to 65%. Furthermore, before measuring the various parameters, the sample is exposed to the atmosphere for 30 minutes to 60 minutes.

[0027] The substrate preferably has a total light transmittance of 80% or more, more preferably 85% or more, and even more preferably 87% or more according to JIS K7361-1:1997.The substrate preferably has a haze of 10% or less, more preferably 5% or less, and even more preferably 2% or less according to JIS K7136:2000.

[0028] The surface of the substrate on which the inorganic oxide layer is formed may be subjected to a surface treatment in order to improve adhesion, etc. Examples of the surface treatment include corona discharge treatment, ozone treatment, low-temperature plasma treatment, glow discharge treatment, and oxidation treatment.

[0029] <Inorganic oxide layer> The inorganic oxide layer must contain silicon oxide. Furthermore, the inorganic oxide layer must have a thickness of 30 nm or more. By containing silicon oxide as the inorganic oxide constituting the inorganic oxide layer, it is possible to suppress an increase in the price of the barrier film. By making the thickness of the inorganic oxide 30 nm or more, it is possible to impart high barrier properties to the barrier film. Silicon oxide is an oxide containing silicon. A typical example of silicon oxide is silicon oxide (SiOx) such as silicon dioxide. That is, it is preferable that the inorganic oxide layer contains silicon oxide.

[0030] The total content of silicon and oxygen in the inorganic oxide layer is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more. A total content of silicon and oxygen of 90% by mass or more means that the carbon content in the inorganic oxide layer is low. Reducing the carbon content in the inorganic oxide layer can more easily improve transparency, barrier properties, heat resistance, and weather resistance. The inorganic oxide layer may contain elements other than silicon and oxygen as long as the effects of the present disclosure are not impaired.

[0031] To improve the barrier properties, the thickness of the inorganic oxide layer is preferably 40 nm or more, more preferably 50 nm or more, and even more preferably 60 nm or more. If the inorganic oxide layer is too thick, cracks tend to occur in the inorganic oxide layer. Furthermore, when the inorganic oxide layer reaches a predetermined thickness, the barrier properties tend to saturate. Therefore, the thickness of the inorganic oxide layer is preferably 200 nm or less, more preferably 150 nm or less, even more preferably 120 nm or less, and even more preferably 100 nm or less. It is preferable that the barrier film has only one inorganic oxide layer.

[0032] The inorganic oxide layer can be formed by, for example, physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating; chemical vapor deposition (CVD) methods such as plasma-enhanced chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition; and the like. Among these, vacuum deposition is preferred because it has a high deposition rate and is therefore highly productive. PVD is preferred because it is less likely to introduce carbon into the inorganic oxide layer than CVD.

[0033] <Overcoat layer> The overcoat layer is disposed on the opposite side of the inorganic oxide layer from the substrate. When a coating layer (described later) is not present between the inorganic oxide layer and the overcoat layer, the overcoat layer is preferably in contact with the inorganic oxide layer. When a coating layer (described later) is present between the inorganic oxide layer and the overcoat layer, the overcoat layer is preferably in contact with the coating layer.

[0034] The overcoat layer must contain an acrylic resin and have a thickness of more than 2.0 μm. By making the overcoat layer thicker than 2.0 μm, even if thickness unevenness occurs in the overcoat layer centered around minute black dots in the inorganic oxide layer, interference unevenness is less likely to occur. Therefore, by making the overcoat layer thicker than 2.0 μm, minute ring-shaped rainbow patterns can be suppressed. By making the overcoat layer contain an acrylic resin, interference is more unlikely to occur, making it easier to suppress minute ring-shaped rainbow patterns. Furthermore, by making the overcoat layer contain an acrylic resin, the barrier properties of the barrier film can be more easily maintained over a long period of time.

[0035] The thickness of the overcoat layer is preferably 2.5 μm or more, more preferably 3.0 μm or more, and even more preferably 4.0 μm or more. If the thickness of the overcoat layer is too thick, winding defects such as blocking may occur during winding, and production efficiency is likely to decrease. Therefore, the thickness of the overcoat layer is preferably 40.0 μm or less, more preferably 30.0 μm or less, even more preferably 20.0 μm or less, and even more preferably 10.0 μm or less.

[0036] The acrylic resin is a polymer containing, as a monomer component, at least one ethylenically unsaturated monomer having a carboxyl group or a carboxylic acid ester group selected from the group consisting of methacrylic acid, acrylic acid, methacrylic acid esters, and acrylic acid esters. The acrylic resin may have a functional group other than a carboxyl group or a carboxylic acid ester group, such as a urethane group, as long as the effects of the present disclosure are not impaired. The content of the acrylic resin is preferably 30% by mass or more of the total solids content of the overcoat layer, more preferably 40% by mass or more, more preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and more preferably 95% by mass or more.

[0037] To facilitate suppression of blocking, the acrylic resin preferably has a glass transition temperature of 40° C. or higher, more preferably 60° C. or higher, and even more preferably 80° C. or higher. The upper limit of the glass transition temperature is about 200° C.

[0038] Examples of acrylic resins include curable resins and thermoplastic resins. Examples of curable resins include thermosetting resins and ionizing radiation-curable resins. Among these, thermoplastic resins and thermosetting resins are preferred, with thermoplastic resins being more preferred. That is, thermoplastic acrylic resins and thermosetting acrylic resins are preferred as acrylic resins, with thermoplastic acrylic resins being more preferred. Thermoplastic resins and thermosetting resins are less likely to generate shrinkage stress and less likely to cause cracks in the inorganic oxide layer than ionizing radiation-curable resins, making them preferable in that they can more easily improve barrier properties. Furthermore, an overcoat layer formed from a thermoplastic resin or a thermosetting resin can more easily achieve good adhesion to other layers than an overcoat layer formed from an ionizing radiation-curable resin. Therefore, forming an overcoat layer from a thermoplastic resin or a thermosetting resin makes it easier to laminate a functional film, described below, on the overcoat layer of the barrier film of the present disclosure with high adhesion. Thermoplastic resins are more preferred than thermosetting resins in that they can more easily achieve the above-mentioned effects.

[0039] The overcoat layer may contain particles to suppress blocking, but preferably does not substantially contain particles. This is because if particles aggregate, the visibility of the particle-aggregated areas changes from that of other areas, resulting in a deterioration in display characteristics. "Substantially does not contain particles" means that the content of particles is 1.0% by mass or less of the total solid content of the overcoat layer, preferably 0.1% by mass or less, more preferably 0.01% by mass or less, and most preferably 0% by mass.

[0040] The overcoat layer is preferably a non-adhesive layer to facilitate suppression of blocking. In this specification, a non-adhesive layer refers to a layer in which a ball does not stop in the measurement section for 5 seconds or more under the conditions of "inclination angle: 20°" and "ball number: No. 1" in the inclined ball tack test of JIS Z0237:2022. "Inclination angle: 20°" is the smallest inclination angle specified in the test. "Ball number: No. 1" is the smallest ball specified in the test, with a diameter of approximately 0.8 mm.

[0041] The barrier film preferably has a pencil hardness, as defined in JIS K5600-5-4:1999, of a surface on the overcoat layer side of B or more and 3H or less, more preferably HB or more and 2H or less, and even more preferably F or more and H or less. By making the pencil hardness B or more, scratches on the surface of the overcoat layer can be easily suppressed, and therefore, deterioration of the barrier properties due to scratches on the overcoat layer can be easily suppressed. By making the pencil hardness 3H or less, it becomes easier to attach other members for a display device to the surface of the barrier film on the overcoat layer side.

[0042] The overcoat layer may contain additives such as a silane coupling agent, an antioxidant, an ultraviolet absorber, etc. The overcoat layer can be formed, for example, by applying a coating liquid containing components constituting the overcoat layer onto the inorganic oxide layer and drying it.

[0043] It is preferable to reduce the viscosity of the coating liquid for the overcoat layer. By reducing the viscosity of the coating liquid for the overcoat layer, it is possible to more easily prevent the elevation difference near the black dots of the inorganic oxide layer from being reflected in the overcoat layer. Therefore, by reducing the viscosity of the coating liquid for the overcoat layer, it is possible to more easily prevent the ring-shaped rainbow pattern from being observed. Furthermore, by reducing the viscosity of the coating liquid for the overcoat layer, it is possible to more easily stably form a thick overcoat layer. By reducing the solid content of the coating liquid for the overcoat layer, it is possible to more easily reduce the viscosity of the coating liquid for the overcoat layer.

[0044] <Coating Layer> The barrier film may have a coating layer between the inorganic oxide layer and the overcoat layer. By having the coating layer, it is possible to more easily improve the barrier properties. When the coating layer is present, it is preferable that the inorganic oxide layer and the coating layer are in contact with each other, and that the coating layer and the overcoat layer are in contact with each other.

[0045] The coating layer preferably contains one or more selected from a water-soluble polymer and a metal alkoxide compound. Of the water-soluble polymer and the metal alkoxide compound, the coating layer more preferably contains one or more selected from the water-soluble polymer, and even more preferably contains one or more selected from the water-soluble polymer and one or more selected from the metal alkoxide compound.

[0046] Examples of water-soluble polymers include polyvinyl alcohol, polyvinylpyrrolidone, and ethylene-vinyl alcohol copolymers, and among these, polyvinyl alcohol and ethylene-vinyl alcohol copolymers are preferred for their barrier properties, with polyvinyl alcohol being more preferred. That is, the coating layer preferably contains one or more selected from polyvinyl alcohol and ethylene-vinyl alcohol copolymers, and more preferably contains polyvinyl alcohol.

[0047] When the coating layer contains a water-soluble polymer and a metal alkoxide-based compound, the content of the water-soluble polymer relative to 100 parts by mass of the total amount of the metal alkoxide-based compounds is preferably 5 parts by mass or more and 500 parts by mass or less, more preferably 7 parts by mass or more and 100 parts by mass or less, and even more preferably 8 parts by mass or more and 50 parts by mass or less.

[0048] Examples of the metal alkoxide-based compound include metal alkoxides, metal alkoxide hydrolysates, and metal alkoxide polymers. The metal alkoxides are M(OR) ｎ In the formula, M represents a metal such as Si, Ti, Al, or Zr, and R represents an alkyl group such as a methyl group or an ethyl group. Specific examples of metal alkoxides include tetramethoxysilane, tetraethoxysilane, and isopropoxyaluminum.

[0049] To improve the barrier properties, the thickness of the coating layer is preferably 70 nm or more, more preferably 100 nm or more, and even more preferably 150 nm or more. Furthermore, the thickness of the coating layer is preferably 600 nm or less, more preferably 480 nm or less, more preferably 370 nm or less, and even more preferably 300 nm or less. By setting the thickness to 600 nm or less, the barrier film can be made thinner, and the occurrence of cracks in the coating layer can be easily suppressed.

[0050] The coating layer may contain additives such as a silane coupling agent, a curing agent, a dispersant, etc. The coating layer can be formed, for example, by applying a coating liquid containing components that constitute the coating layer onto the inorganic oxide layer and drying it.

[0051] <Anchor Coat Layer> The barrier film may have an anchor coat layer between the substrate and the inorganic oxide layer. By having the anchor coat layer, the adhesion of the inorganic oxide layer is improved, and therefore the barrier property can be more easily improved. When the anchor coat layer is present, it is preferable that the substrate and the anchor coat layer are in contact with each other, and that the anchor coat layer and the inorganic oxide layer are in contact with each other.

[0052] The anchor coat layer preferably contains a resin such as a thermoplastic resin or a thermosetting resin. The proportion of the resin to the total solid content of the anchor coat layer is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0053] The resin may be one or more selected from thermoplastic resins such as polystyrene resins, polyolefin resins, ABS resins, AS resins, AN resins, polyphenylene oxide resins, polycarbonate resins, polyacetal resins, polyethylene terephthalate resins, polybutylene terephthalate resins, polysulfone resins, polyphenylene sulfide resins, acrylic resins, and cellulose resins; and thermosetting resins such as oxazoline group-containing resins. Among these, a mixed resin of an oxazoline group-containing resin and a thermoplastic resin is preferred. The mass ratio of the oxazoline group-containing resin to the thermoplastic resin (oxazoline group-containing resin:thermoplastic resin) is preferably 5:95 to 80:20, more preferably 10:90 to 70:30. Examples of oxazoline group-containing resins include those described in JP-A-11-179836.

[0054] The thickness of the anchor coat layer is preferably 0.005 μm or more and 5 μm or less, more preferably 0.008 μm or more and 3 μm or less, and even more preferably 0.01 μm or more and 1 μm or less.

[0055] The anchor coat layer may contain additives such as antioxidants and leveling agents within a range that does not impair the effects of the present disclosure. The anchor coat layer can be formed, for example, by applying a coating liquid containing components that constitute the anchor coat layer onto a substrate and drying it.

[0056] The total thickness of the barrier film is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. The total thickness of the barrier film is preferably 180 μm or less, more preferably 150 μm or less, and even more preferably 130 μm or less. By making the total thickness of the barrier film 10 μm or more, the handleability of the barrier film can be improved. By making the total thickness of the barrier film 180 μm or less, it is possible to make display devices such as electronic paper thinner. In this specification, the total thickness of the barrier film is the average value of the measurements taken at 18 locations, excluding the minimum and maximum values ​​from the measurements taken at 20 locations. The total thickness at each measurement location is measured using a general-purpose film thickness measuring device. Examples of film thickness measuring devices include a Mitutoyo Digimatic Standard Outside Micrometer (product number: MDC-25SX).

[0057] <Physical properties> The barrier film has a water vapor permeability of 0.02 g / m according to JIS K7129-2:2019. ２ It is preferable that the density is 0.01 g / m or less. ２ It is more preferable that the water vapor permeability is measured at a temperature and humidity of 40°C and a relative humidity of 90%. Prior to measuring the water vapor permeability, the sample to be measured is exposed to an atmosphere at a temperature of 23°C ± 5°C and a relative humidity of 40% to 65% for 30 to 60 minutes. In this specification, the water vapor permeability refers to the average value of three measurements.

[0058] The barrier film has an oxygen permeability of 0.5 cc / m according to JIS K7126-2:2006. ２ It is preferable that the oxygen permeability is 23°C and 90% relative humidity. The temperature and humidity conditions for measuring the oxygen permeability are 23°C ± 5°C and 40% to 65% relative humidity for 30 to 60 minutes before measuring the oxygen permeability. In this specification, the oxygen permeability means the average value of three measurements.

[0059] The barrier film preferably has a total light transmittance according to JIS K7361-1:1997 of 80% or more, more preferably 85% or more, and even more preferably 87% or more. The upper limit of the total light transmittance is about 95%. In this specification, the total light transmittance means the average value of three measured values. The barrier film preferably has a haze according to JIS K7136:2000 of 10% or less, more preferably 5% or less, and even more preferably 2% or less. The lower limit of the haze is about 0.1%. In this specification, the haze means the average value of three measured values. When measuring the total light transmittance and haze, the light incident surface is the surface on the substrate side.

[0060] The barrier film is designed to reduce the L caused by reflected light when the overcoat layer side is the light incident surface. ＊ a ＊ b ＊ Color system b ＊ It is preferable that the value is -1.0 or more and 5.0 or less. ＊ The value is more preferably −0.5 or more and 4.0 or less, and further preferably −0.1 or more and 3.0 or less. ＊ The values ​​represent the average of three measurements. ＊ The larger the value, the thicker the inorganic oxide layer containing silicon oxide tends to be. ＊ By setting the value to -1.0 or more, it is possible to easily improve the barrier properties. ＊ By setting the value to 5.0 or less, it is possible to suppress the yellowish color from becoming too strong, and therefore it is possible to more easily suppress the deterioration of the display quality of the display device. ＊ The reflected light used to calculate the value is measured based on geometric condition d of JIS Z8722:2009, including a specular reflection component. <Geometric condition d of JIS Z8722:2009> The sample is irradiated with a single beam of light whose optical axis is angled no more than 10° relative to the normal to the sample surface, and the light reflected in all directions is collected and received. In this case, the irradiated beam of light must not include any rays inclined at an angle of 5° or more relative to its center line.

[0061] The above-mentioned barrier film b ＊ The value is the b ＊ In addition, light transmitted through the barrier film is reflected by the display element. For example, in the case of a barrier film for electronic paper, light transmitted through the barrier film is reflected by the electronic paper display element. Therefore, the b ＊ When measuring the value, the reflection of the display element is taken into consideration. Specifically, a sample is prepared by placing a perfectly diffusing standard white reflector on the surface of the barrier film opposite to the light incident surface, and the b value of the barrier film is measured using the sample. ＊ Measure the value. ＊ a ＊ b ＊ The color system is the L color system standardized by the International Commission on Illumination (CIE) in 1976. ＊ a ＊ b ＊ It is based on the color system and is adopted in JIS Z8781-4:2013.

[0062] The barrier film of the present disclosure preferably satisfies the following formula (1): Y / X<1.0 (1) [In formula (1), "X" represents the maximum diameter of black dots having a maximum diameter of 100 μm or more and 2000 μm or less observed within the plane of the inorganic oxide layer. ２ In formula (1), "Y" is the average number of black dots per square meter of a ring-shaped rainbow pattern formed in a wider area than the black dots, centered on the black dots, observed within the plane of the barrier film. ２ This is the average number of hits.]

[0063] As described above, when a ring-shaped rainbow pattern occurs centered around a tiny black dot, the ring-shaped rainbow pattern occurs over a wider area than the tiny black dot. Therefore, a barrier film that satisfies formula (1) suppresses the occurrence of a ring-shaped rainbow pattern. In formula (1), black dots with a maximum diameter of 100 μm or more are counted because rainbow patterns are less noticeable when they occur when the maximum diameter is less than 100 μm. In formula (1), black dots with a maximum diameter of 2000 μm or less are counted because black dots with a maximum diameter of more than 2000 μm are unlikely to occur, and a portion containing a black dot with a maximum diameter of more than 2000 μm is unsuitable for use as a barrier film. In formula (1), Y / X is preferably 0.5 or less, more preferably 0.2 or less, even more preferably 0.1 or less, and most preferably 0. Y / X being 0 means that X is greater than 0 and Y is 0. X varies depending on how much the splash phenomenon is to be suppressed, but is usually 1 particle / m ２ More than 100 pieces / m ２ The barrier film of the present disclosure may have black dots with a maximum diameter of 100 μm or more and 2000 μm or less in the plane of the inorganic oxide layer. In addition, the barrier film of the present disclosure may have black dots with a maximum diameter of 100 μm or more and 2000 μm or less in the plane of the inorganic oxide layer, and the average number of black dots with a maximum diameter of 100 μm or more and 2000 μm or less in the plane of the inorganic oxide layer is less than 1 m. ２ 1 piece per m ２ More than 100 pieces / m ２ It may be the following:

[0064] The maximum diameter of each black dot is measured according to the procedures A1 to A3 below. The number of ring-shaped rainbow patterns formed around a black dot and extending beyond the black dot is determined by placing a black plate on the substrate-side surface of the cut sample described in A3 below and observing with a magnifying glass. The observation is carried out in a bright room environment where the illuminance on the surface of the cut sample is 500 lux to 1000 lux.

[0065] A1: Place a black plate and a barrier film on top of each other in that order on a horizontal table. The barrier film is placed on top of the black plate with the substrate side facing the black plate. A2: In a bright room environment where the illuminance on the barrier film surface is 500 lux or more and 1000 lux or less, the presence of black dots is observed with a magnifying glass. A3: A cut sample is prepared by cutting out an area from the barrier film where black dots and ring-shaped rainbow patterns have been confirmed. A planar photograph is taken with an optical microscope from the side of the cut sample opposite the substrate. The maximum diameter of the black dot is calculated from the obtained planar photograph. The maximum diameter of the black dot means the maximum distance between two parallel lines when the black dot is sandwiched between the two lines.

[0066] The barrier film of the present disclosure can be used in displays such as electronic paper, liquid crystal displays, EL displays such as organic EL displays and inorganic EL displays, plasma displays, LED displays such as mini LED and micro LED display elements, etc. Liquid crystal displays include liquid crystal displays using a wavelength conversion sheet.

[0067] [Display Device] The display device of the present disclosure includes the above-described barrier film for a display device of the present disclosure.

[0068] Examples of the display device include electronic paper, liquid crystal display devices, EL display devices such as organic EL display devices and inorganic EL display devices, plasma display devices, LED display devices such as mini LED and micro LED display elements, etc. The liquid crystal display device includes a liquid crystal display device using a wavelength conversion sheet.

[0069] The display device of the present disclosure may be electronic paper, and the electronic paper may include an electronic paper display element and the barrier film of the present disclosure described above. The barrier film may be disposed so that the surface of the substrate faces the electronic paper display element, or so that the surface of the overcoat layer faces the electronic paper display element.

[0070] Fig. 3 is a cross-sectional view showing one embodiment of electronic paper 300 of the present disclosure. The electronic paper 300 of Fig. 3 includes an electronic paper display element 210 and a barrier film 100 of the present disclosure. The electronic paper 300 of Fig. 3 is formed by laminating the electronic paper display element 210 and the barrier film 100 with an adhesive layer 220 interposed therebetween. The electronic paper 300 of Fig. 3 further includes a functional film 230. The functional film 230 and the barrier film 100 are laminated with the adhesive layer 220 interposed therebetween.

[0071] The electronic paper display element may be a general-purpose electronic paper display element, for example, an electronic paper display element having a rear electrode substrate having a rear substrate and a rear electrode, a transparent electrode substrate having a transparent substrate and a transparent electrode, and a display medium layer disposed between the rear electrode substrate and the transparent electrode substrate.

[0072] The back electrode substrate, transparent electrode substrate, and display medium layer may be general-purpose back electrode substrate, transparent electrode substrate, and display medium layer. For example, the display medium layer may be appropriately selected depending on the display method of the electronic paper. Examples of display methods for electronic paper include electrophoresis, twist ball, powder migration, liquid crystal display, and electrochromic.

[0073] The electronic paper display element and the barrier film of the present disclosure are preferably laminated via an adhesive layer. A general-purpose adhesive can be used as the adhesive constituting the adhesive layer. The adhesive layer is preferably an optical adhesive layer.

[0074] The electronic paper of the present disclosure may have components other than the electronic paper display element and the barrier film of the present disclosure. Examples of components other than the electronic paper display element and the barrier film of the present disclosure include a touch panel; a functional film such as an anti-reflection film, an anti-glare film, or a protective film; an adhesive layer; and the like. The touch panel is preferably disposed between the electronic paper display element and the barrier film of the present disclosure. The functional film is preferably disposed on the opposite side of the barrier film of the present disclosure from the electronic paper display element. When the electronic paper of the present disclosure includes a functional film, the barrier film and the functional film are preferably laminated via an adhesive layer. The functional film and / or the adhesive layer preferably contain an ultraviolet absorber.

[0075] The display device of the present disclosure may be a liquid crystal display device, the liquid crystal display device including a backlight and a liquid crystal display element, the backlight including at least one light source that emits primary light, an optical plate that is disposed adjacent to the light source and that guides or diffuses light, and a wavelength conversion sheet that is disposed on the light emission side of the optical plate, and the wavelength conversion sheet includes the barrier film for a display device.

[0076] The liquid crystal display element and the backlight can be general-purpose ones. Furthermore, the light source and the optical plate constituting the backlight can be general-purpose ones. Examples of wavelength conversion sheets constituting the backlight include those having a first quantum dot protective film, a quantum dot-containing layer, and a second quantum dot protective film in this order. In such wavelength conversion sheets, at least one of the first quantum dot protective film and the second quantum dot protective film is preferably the barrier film for a display device of the present disclosure. In the wavelength conversion sheet, the barrier film is preferably arranged so that the surface on the overcoat layer side faces the quantum dot-containing layer. A general-purpose quantum dot-containing layer can be used as the quantum dot-containing layer. Of the first quantum dot protective film and the second quantum dot protective film, the one that does not use the barrier film of the present disclosure can be a general-purpose protective film.

[0077] The present disclosure includes the following items [1] to

[11] . [1] A barrier film for a display device, comprising a substrate, an inorganic oxide layer, and an overcoat layer in this order, wherein the inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or more, and the overcoat layer contains an acrylic resin and has a thickness of more than 2.0 μm. [2] The barrier film for a display device according to item [1], wherein the inorganic oxide layer and the overcoat layer are in contact with each other. [3] The barrier film for a display device according to item [1], wherein the barrier film for a display device further comprises a coating layer between the inorganic oxide layer and the overcoat layer, wherein the inorganic oxide layer and the coating layer are in contact with each other and the coating layer is in contact with the overcoat layer. [4] The barrier film for a display device according to any one of items [1] to [3], wherein the barrier film for a display device further comprises an anchor coat layer between the substrate and the inorganic oxide layer, wherein the substrate and the anchor coat layer are in contact with each other and the anchor coat layer is in contact with the inorganic oxide layer. [5] The barrier film for a display device according to any one of [1] to [4], wherein the inorganic oxide layer has a thickness of 40 nm or more and 200 nm or less. [6] The barrier film for a display device according to any one of [1] to [5], wherein the overcoat layer has a thickness of 2.5 μm or more and 40.0 μm or less. [7] The barrier film for a display device according to [3], wherein the coating layer has a thickness of 70 nm or more and 600 nm or less. [8] The barrier film for a display device according to any one of [1] to [4], wherein the overcoat layer has a thickness of 70 nm or more and 600 nm or less. [9] The barrier film for a display device according to ＊ a ＊ b ＊ Color system b ＊The barrier film for a display device according to any one of [1] to [7], wherein the value of λ / λ is -1.0 or more and 5.0 or less. [9] A display device comprising the barrier film for a display device according to any one of [1] to [8].

[10] The display device according to [9], wherein the display device is electronic paper, and the electronic paper comprises an electronic paper display element and the barrier film for a display device.

[11] The display device according to [9], wherein the display device is a liquid crystal display device, and the liquid crystal display device comprises a backlight and a liquid crystal display element, and the backlight comprises at least one light source that emits primary light, an optical plate that is arranged adjacent to the light source and for guiding or diffusing light, and a wavelength conversion sheet that is arranged on the light emission side of the optical plate, and the wavelength conversion sheet has a first protective film for quantum dots, a quantum dot-containing layer, and a second protective film for quantum dots in this order, and at least one of the first protective film for quantum dots and the second protective film for quantum dots is the barrier film for a display device.

[0078] Next, the present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to these examples. "Parts" and "%" are based on mass unless otherwise specified.

[0079] The following measurements and evaluations were carried out on the barrier films for display devices of the Examples and Comparative Examples. The results are shown in Table 1. The evaluations or measurements of 1-1 to 1-3 were carried out in an atmosphere at a temperature of 23°C ± 5°C and a relative humidity of 40% to 65%. Furthermore, before the evaluation or measurement, the samples were exposed to the above atmosphere for 30 minutes.

[0080] 1-1. Total light transmittance and haze The total light transmittance and haze of the barrier films of the examples and comparative examples were measured using a haze meter (manufactured by Murakami Color Research Laboratory, product number: HM-150). The light incident surface was the surface on the substrate side.

[0081] 1-2. b ＊ Samples were prepared by placing a perfectly diffusing standard white reflector on the substrate side of the barrier film of each of the examples and comparative examples. The surface of the sample on the overcoat layer side was used as the light incident surface, and the L based on the reflected light of the sample was measured. ＊ a ＊ b＊ Color system b ＊ The measurement device used was a spectrophotometer manufactured by JASCO Corporation (product name: V670), and the following accessory units were used: Accessory unit: integrating sphere unit (manufactured by JASCO Corporation, product number: ISN-723) Light source: deuterium lamp (190 to 350 nm), halogen lamp (330 to 2700 nm) Measurement spot diameter: 2 mm

[0082] 1-3. Ring-Shaped Rainbow Pattern Samples were cut out from the barrier films of the Examples and Comparative Examples, including portions in which black dots with a maximum diameter of 100 μm or more and 2000 μm or less were observed within the surface of the inorganic oxide layer. The black dots were confirmed using a magnifying glass with a scale in a bright room environment. A black plate and the sample were placed on top of each other, in that order, on a horizontal table. The sample was placed on the black plate with the substrate side facing the black plate. The presence of a ring-shaped rainbow pattern was evaluated visually in a bright room environment where the illuminance on the sample surface was 500 lux or more and 1000 lux or less. Samples in which no ring-shaped rainbow pattern was observed were rated "A," and samples in which a ring-shaped rainbow pattern was observed were rated "C."

[0083] 1-4. Water Vapor Permeability (Barrier Properties) The water vapor permeability values ​​of the barrier films of the Examples and Comparative Examples were measured according to JIS K7129-2:2019. The measurement device used was a MOCON ultra-high sensitivity water vapor permeability measuring device (product name: AQUATRAN 3) manufactured by Hitachi High-Tech Science Corporation. The temperature and humidity conditions for measuring the water vapor permeability were 40°C and 90% relative humidity. Furthermore, prior to measuring the water vapor permeability, the measurement sample was exposed to an atmosphere with a temperature of 23°C ± 5°C and a relative humidity of 40% to 65% for 30 minutes. When the water vapor permeability was 0.020 g / m ２ ・The passing level is less than 1 day.

[0084] 2. Preparation of a barrier film for a display device [Example 1] Silicon oxide (SiO ２) was vapor-deposited to form an inorganic oxide layer with a thickness of 50 nm. Next, the following coating solution for forming a coating layer was applied onto the inorganic oxide layer by gravure printing, and the resulting mixture was heat-treated at 180°C for 60 seconds to form a coating layer with a thickness of 300 nm. Next, the following coating solution 1 for forming an overcoat layer was applied onto the coating layer by gravure printing, and the resulting mixture was heat-treated at 150°C for 10 seconds to form an overcoat layer with a thickness of 2.1 μm, thereby obtaining the barrier film for a display device of Example 1. The barrier film for a display device of Example 1 has a substrate, an inorganic oxide layer, a coating layer, and an overcoat layer, in this order.

[0085] <Preparation of Coating Liquid for Forming Covering Layer> Solution A was prepared by mixing tetraethoxysilane into a solution (pH 2.2) containing water, isopropyl alcohol, and 0.5N hydrochloric acid while cooling to 10°C. Separately, solution B was prepared by mixing polyvinyl alcohol with a saponification value of 99% or more and isopropyl alcohol. Solutions A and B were mixed to prepare a coating liquid for forming a covering layer (solid content: 5% by mass). In the coating liquid for forming a covering layer, the mass ratio of tetraethoxysilane to polyvinyl alcohol was 29:4.

[0086] <Coating Solution 1 for Overcoat Layer> A thermoplastic acrylic resin (manufactured by DIC Corporation, trade name: ACRYDIC A-166) was diluted with a solvent to a solid content of 10% by mass to prepare Coating Solution 1 for overcoat layer.

[0087] Examples 2 to 5 Barrier films for displays of Examples 2 to 5 were obtained in the same manner as in Example 1, except that the thicknesses of the inorganic oxide layer and the overcoat layer were set to the values ​​shown in Table 1.

[0088] [Example 6] The coating solution 1 for the overcoat layer was changed to the coating solution 2 for the overcoat layer described below, and after the heat treatment of the coating solution 2 for the overcoat layer, the accumulated light amount was 500 mJ / cm ２A barrier film for a display device of Example 6 was obtained in the same manner as in Example 1, except for adding a step of irradiating with ultraviolet light of 100° C. <Coating Solution 2 for Overcoat Layer> A composition obtained by mixing an ionizing radiation curable acrylic resin (ultraviolet-curable polyfunctional acrylate, trade name "EBECRYL 895C" manufactured by Daicel Allnex Corporation) and a photopolymerization initiator (trade name "Omnirad 184" manufactured by IGM Resins) in a mass ratio of 100:2.

[0089] Comparative Example 1 A barrier film for a display device of Comparative Example 1 was obtained in the same manner as in Example 1, except that no overcoat layer was provided on the coating layer.

[0090] Comparative Example 2 A barrier film for a display device of Comparative Example 2 was obtained in the same manner as in Example 1, except that the thickness of the overcoat layer was changed to 0.8 μm.

[0091] Comparative Example 3 A barrier film for a display device of Comparative Example 3 was obtained in the same manner as in Example 1, except that the thickness of the inorganic oxide layer was changed to 25 nm.

[0092] [Comparative Example 4] A barrier film for a display device of Comparative Example 4 was obtained in the same manner as in Example 1, except that the inorganic oxide layer was changed to an inorganic oxide layer having a thickness of 10 nm, on which aluminum oxide was vapor-deposited by a vacuum vapor deposition method.

[0093]

[0094] From the results in Table 1, it can be confirmed that the barrier films for display devices of the Examples have good barrier properties because they have low water vapor permeability. Furthermore, from the results in Table 1, it can be confirmed that the barrier films for display devices of the Examples do not have ring-shaped rainbow patterns, so that deterioration of display quality can be suppressed. The barrier films for display devices of Examples 1 to 6 have a low water vapor permeability because the number of "X" in the main text of the specification is 1 / m. ２ More than 100 pieces / m ２ or less, and the number of "Y" in the specification is 0 / m ２The barrier property of the barrier film for a display device of Example 6 was slightly lower than that of Examples 1 to 5. It is believed that the barrier property of the barrier film for a display device of Example 6 was slightly lowered because the overcoat layer was formed from an ionizing radiation-curable acrylic resin, which caused strong shrinkage stress in the overcoat layer and slight cracks in the inorganic oxide layer. Although not shown in Table 1, the barrier films for a display device of Examples 1 to 6 were capable of laminating an optical film with high adhesion onto the overcoat layer via a general-purpose optical adhesive layer.

[0095] 11: Substrate 12: Inorganic oxide layer 13: Coating layer 14: Overcoat layer 100: Barrier film for display device 210: Electronic paper display element 220: Adhesive layer 230: Functional film 300: Electronic paper

Claims

1. A barrier film for a display device, comprising a substrate, an inorganic oxide layer, and an overcoat layer in this order, wherein the inorganic oxide layer contains silicon oxide and has a thickness of 30 nm or more, and the overcoat layer contains an acrylic resin and has a thickness of more than 2.0 μm.

2. The barrier film for a display device according to claim 1, wherein the inorganic oxide layer and the overcoat layer are in contact with each other.

3. The barrier film for a display device according to claim 1, further comprising a coating layer between the inorganic oxide layer and the overcoat layer, the inorganic oxide layer and the coating layer being in contact with each other, and the coating layer and the overcoat layer being in contact with each other.

4. The barrier film for a display device according to claim 1, further comprising an anchor coat layer between the substrate and the inorganic oxide layer, wherein the substrate and the anchor coat layer are in contact with each other, and the anchor coat layer and the inorganic oxide layer are in contact with each other.

5. The barrier film for a display device according to claim 1, wherein the inorganic oxide layer has a thickness of 40 nm or more and 200 nm or less.

6. The barrier film for a display device according to claim 1, wherein the thickness of the overcoat layer is 2.5 μm or more and 40.0 μm or less.

7. The barrier film for a display device according to claim 3, wherein the thickness of the covering layer is 70 nm or more and 600 nm or less.

8. The barrier film for a display device has an L based on reflected light when the overcoat layer side is the light incident surface. ＊ a ＊ b ＊ Color system b ＊ 2. The barrier film for a display device according to claim 1, wherein the value is −1.0 or more and 5.0 or less.

9. A display device comprising the barrier film for a display device according to any one of claims 1 to 8.

10. The display device according to claim 9, wherein the display device is electronic paper, and the electronic paper includes an electronic paper display element and the barrier film for the display device.

11. The display device according to claim 9, wherein the display device is a liquid crystal display device, the liquid crystal display device includes a backlight and a liquid crystal display element, the backlight includes at least one light source that emits primary light, an optical plate that is arranged adjacent to the light source and for guiding or diffusing light, and a wavelength conversion sheet that is arranged on the light emission side of the optical plate, the wavelength conversion sheet having a first protective film for quantum dots, a quantum dot-containing layer, and a second protective film for quantum dots in this order, and at least one of the first protective film for quantum dots and the second protective film for quantum dots is a barrier film for the display device.

Images