Display device

Abstract

The display device (10) includes: a substrate (1); an optical element (2) mounted on one side of the substrate (1) in the thickness direction; a second sealing layer (6) for sealing the optical element (2); a second inorganic layer (5) existing between the optical element (2) and the second sealing layer (6) and comprising a metal nitride; and a polarizing plate (7) disposed on one side of the second sealing layer (6) in the thickness direction. The conductivity of the extracted water in the second sealing layer (6) is less than 100 μm / S.

Description

Technical Field

[0001] The invention relates to a display device. Prior Art

[0002] In recent years, organic electroluminescence (EL) displays have become known as display devices that include optical elements. In such display devices, the optical elements are sealed with multiple sealing layers to prevent degradation due to moisture in the atmosphere.

[0003] Examples of the multiple sealing layers include inorganic sealing layers and organic sealing layers. In a display device, for example, these sealing layers are alternately stacked. Among these sealing layers, the organic sealing layer is formed, for example, by applying a sealing composition using an inkjet method and then curing the sealing composition by irradiation with light.

[0004] As such a sealing composition, a sealant containing an alicyclic epoxy compound, an oxetane compound, and a cationic polymerization initiator has been proposed (for example, see Patent Document 1). [Prior art literature] [Patent Document]

[0005] [Patent Document 1] International Publication No. 2020 / 031941 Summary of the Invention

[0006] [Problems to be solved by the invention] On the other hand, the inorganic sealing layer material is selected to contain nitrogen. When water enters the inorganic sealing layer, the ions in the water react with the nitrogen, sometimes producing NH 3 + ions. Furthermore, these NH 3 + ions can cause discoloration of the polarizing plate.

[0007] The present invention provides a display device that suppresses discoloration of a polarizing plate. [Methods for solving the problem]

[0008] The present invention [1] is a display device comprising: a substrate; an optical element mounted on one side of the substrate in the thickness direction; a sealing layer for sealing the optical element; an inorganic layer interposed between the optical element and the sealing layer and comprising a metal nitride; and a polarizing plate disposed on at least a portion of one side of the sealing layer in the thickness direction, wherein the conductivity of extracted water of the sealing layer is less than 100 μm / S.

[0009] The present invention [2] is a display device as described in [1], wherein the sealing composition contains a cationically polymerizable compound and a cationic polymerization initiator, and the content ratio of the cationic polymerization initiator is 0.2 parts by mass or more and 0.8 parts by mass or less relative to 100 parts by mass of the cationically polymerizable compound.

[0010] The present invention [3] includes the display device described in [2], wherein the cationic polymerizable compound contains an epoxy compound and / or an oxetane compound.

[0011] The present invention [4] includes the display device described in [3], wherein the epoxy compound includes an alicyclic epoxy resin and an aliphatic epoxy resin.

[0012] The present invention [5] includes the display device described in [3] or [4], wherein the oxetane compound includes a difunctional oxetane compound.

[0013] The present invention [6] includes the display device described in any one of [2] to [5], wherein the sealing composition contains a leveling agent.

[0014] The present invention [7] includes the display device described in any one of [2] to [6], wherein the sealing composition contains a coupling agent. [Effects of the Invention]

[0015] In the display device of the present invention, the conductivity of extracted water in the sealing layer is 100 μm / S or less. Therefore, discoloration of the polarizing plate can be suppressed. Simple diagram description

[0016] FIG1 is a cross-sectional view showing an embodiment of a display device according to the present invention. Figures 2A to 2G are schematic diagrams showing an embodiment of a method for manufacturing a display device. Figure 2A shows a first step of preparing a substrate. Figure 2B shows a second step of mounting an optical element on one side of the substrate in the thickness direction. Figure 2C shows a third step of configuring a first inorganic layer on the substrate in a manner that covers the surface of the optical element. Figure 2D shows a fourth step of configuring a first sealing layer on the first inorganic layer in a manner that seals the optical element. Figure 2E shows a fifth step of configuring a second inorganic layer in a manner that covers the surface of the first sealing layer. Figure 2F shows a sixth step of configuring a second sealing layer on the second inorganic layer in a manner that seals the optical element. Figure 2G shows a seventh step of configuring a polarizing plate on one side of the second sealing layer in the thickness direction. Implementation Method

[0017] The display device of the present invention comprises: a substrate; an optical element mounted on one side of the substrate in the thickness direction; a sealing layer for sealing the optical element; an inorganic layer interposed between the optical element and the sealing layer and containing a metal nitride; and a polarizing plate disposed on at least a portion of one side of the sealing layer in the thickness direction.

[0018] Hereinafter, an embodiment of a display device of the present invention will be described in detail with reference to FIG. 1 .

[0019] The display device 10 includes a substrate 1 , an optical element 2 , a first inorganic layer 3 , a first sealing layer 4 , a second inorganic layer 5 as an inorganic layer, a second sealing layer 6 as a sealing layer, and a polarizing plate 7 .

[0020] Specifically, the display device 10 includes: a substrate 1; an optical element 2, mounted on one side of the substrate 1 in the thickness direction; a first inorganic layer 3, arranged on the substrate 1 in a manner of covering the surface of the optical element 2; a first sealing layer 4, arranged on the first inorganic layer 3 in a manner of sealing the optical element 2; a second inorganic layer 5, covering the surface of the first sealing layer 4; a second sealing layer 6, arranged on the second inorganic layer 5 in a manner of sealing the optical element 2; and a polarizing plate 7, arranged on one side of the second sealing layer 6 in the thickness direction.

[0021] <Substrate> The substrate 1 supports the optical element 2. The substrate 1 is the lowermost layer of the display device 10.

[0022] As the substrate 1, for example, a glass substrate and a plastic substrate can be mentioned. As the substrate 1, preferably a glass substrate can be mentioned.

[0023] The thickness of the substrate 1 is, for example, not less than 0.1 mm, and not more than 20 mm.

[0024] <Optical Components> An example of the optical element 2 is an organic EL element. The optical element 2 is mounted on the substrate 1. Although not shown, the optical element 2 includes a cathode reflective electrode, an organic EL layer, and an anode transparent electrode.

[0025] <First Inorganic Layer> The first inorganic layer 3 is an insulating layer for suppressing water from entering the optical element 2 .

[0026] The first inorganic layer 3 is disposed on the substrate 1 so as to cover the surface of the optical element 2. Specifically, the first inorganic layer 3 covers the upper surface (one side in the thickness direction) and side surfaces of the optical element 2 and also covers the upper surface of the substrate 1. In other words, the first inorganic layer 3 is in contact with the substrate 1 and the optical element 2.

[0027] Examples of the material of the first inorganic layer 3 include metal oxides and metal nitrides. That is, the first inorganic layer 3 includes, for example, metal oxides and / or metal nitrides.

[0028] Examples of the metal oxide include aluminum oxide, silicon oxide, and copper oxide.

[0029] Examples of the metal nitride include aluminum nitride and silicon nitride.

[0030] As the material of the first inorganic layer 3, metal nitrides are preferred from the viewpoint of further suppressing water intrusion into the optical element 2. As the material of the first inorganic layer 3, silicon nitride is more preferred.

[0031] The material of the first inorganic layer 3 may be used alone or in combination of two or more.

[0032] The thickness of the first inorganic layer 3 is, for example, not less than 0.1 μm, and not more than 2.0 μm.

[0033] <First Sealing Layer> The first sealing layer 4 is an insulating layer for protecting the optical element 2 and flattening the step difference caused by the optical element 2 .

[0034] The first sealing layer 4 is disposed on the first inorganic layer 3 so as to seal the optical element 2. That is, the first sealing layer 4 is in contact with the first inorganic layer 3.

[0035] As a material of the first sealing layer 4, resin can be cited, for example. That is, the first sealing layer 4 contains resin, for example.

[0036] Examples of the resin include acrylic resins, epoxy resins, polyimide resins, silicone resins, and fluororesins.

[0037] The sealing composition described below may also be used as the material of the first sealing layer 4. In this case, the first sealing layer 4 includes a cured product of the sealing composition.

[0038] The materials of the first sealing layer 4 may be used alone or in combination of two or more.

[0039] The thickness of the first sealing layer 4 is, for example, not less than 0.2 μm, and not more than 30 μm.

[0040] <Second Inorganic Layer> The second inorganic layer 5 is an insulating layer for suppressing water from entering the optical element 2 .

[0041] The second inorganic layer 5 covers the surface (top and side surfaces) of the first sealing layer 4. That is, the second inorganic layer 5 is in contact with the first sealing layer 4. The second inorganic layer 5 is interposed between the optical element 2 and the second sealing layer 6.

[0042] As a material for the second inorganic layer 5, metal nitrides (such as aluminum nitride and silicon nitride) can be cited from the viewpoint of suppressing water intrusion into the optical element 2. That is, the second inorganic layer 5 contains a metal nitride.

[0043] In addition, the second inorganic layer 5 may also contain metal nitrides and other materials. Examples of other materials include metal oxides (such as aluminum oxide, silicon oxide, and copper oxide).

[0044] Other materials may be used alone or in combination of two or more.

[0045] The second inorganic layer 5 preferably does not contain other materials but contains metal nitride.

[0046] The thickness of the second inorganic layer 5 is, for example, not less than 0.1 μm, and not more than 2.0 μm.

[0047] <Second Sealing Layer> The second sealing layer 6 is an insulating layer for protecting the optical element 2 .

[0048] The second sealing layer 6 is disposed on the second inorganic layer 5 so as to seal the optical element 2. Specifically, the second sealing layer 6 covers the surface (upper surface and side surfaces) of the second inorganic layer 5 so as to seal the optical element 2. That is, the second sealing layer 6 is in contact with the second inorganic layer 5 .

[0049] The second sealing layer 6 includes a cured product of the sealing composition.

[0050] The sealing composition includes a cationically polymerizable compound and a cationic polymerization initiator.

[0051] <<Cationically polymerizable compound>> Examples of cationically polymerizable compounds include epoxy compounds and oxetane compounds. Specifically, from the perspective of further suppressing discoloration of the polarizing plate 7, the cationically polymerizable compound preferably includes an epoxy compound and / or an oxetane compound. Furthermore, the cationically polymerizable compound is more preferably an epoxy compound and an oxetane compound.

[0052] [Epoxides] Examples of epoxy compounds include alicyclic epoxy resins, aliphatic epoxy resins, and aromatic epoxy resins. Preferred epoxy compounds include alicyclic epoxy resins and aliphatic epoxy resins. Specifically, from the perspective of further suppressing discoloration of the polarizing plate 7, the epoxy compound preferably includes alicyclic epoxy resins and aliphatic epoxy resins.

[0053] (Alicyclic epoxy resin) Alicyclic epoxy resin is a curable resin (photocurable resin, preferably ultraviolet curable resin) having an epoxy group and an aliphatic ring (alicyclic skeleton) but no aromatic ring.

[0054] Examples of the alicyclic epoxy resin include a glycidyl group-containing alicyclic epoxy resin, a glycidyl ether group-containing alicyclic epoxy resin, and an epoxy resin containing an epoxy ring structure.

[0055] ((Glycidyl-containing alicyclic epoxy resin)) The glycidyl group-containing alicyclic epoxy resin has, for example, a glycidyl group bonded to an aliphatic ring. Such a glycidyl group-containing alicyclic epoxy resin is represented by, for example, the following general formula (1).

[0056] [Chemistry 1] In formula (1), R1 represents a monovalent organic group, and n represents the degree of polymerization. Furthermore, a substituent such as an alkyl group may be bonded to the carbon atoms constituting the cyclohexane ring.

[0057] Specific examples of the glycidyl group-containing alicyclic epoxy resin represented by the general formula (1) include 1,2-epoxy-4-(2-oxiranyl)cyclohexane adducts of 2,2-bis(hydroxymethyl)-1-butanol.

[0058] A commercially available product may be used as the glycidyl group-containing alicyclic epoxy resin represented by the general formula (1). Examples of commercially available glycidyl group-containing alicyclic epoxy resins represented by the general formula (1) include EHPE3150 (epoxy equivalent 170 g / eq. to 190 g / eq., manufactured by Daicel Corporation).

[0059] ((Alicyclic epoxy resin containing glycidyl ether group)) The glycidyl ether group-containing alicyclic epoxy resin has a glycidyl ether unit bonded to an aliphatic ring. Preferably, the glycidyl ether group-containing alicyclic epoxy resin is a polyglycidyl ether-containing alicyclic epoxy resin having a plurality of glycidyl ether units bonded to an aliphatic ring.

[0060] Examples of glycidyl ether-containing alicyclic epoxy resins include bifunctional glycidyl ether-containing alicyclic epoxy resins. Examples of bifunctional glycidyl ether-containing alicyclic epoxy resins include hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, and hexahydrophthalic acid diglycidyl ether.

[0061] ((Epoxy resin containing epoxy ring structure)) The epoxy resin containing an epoxy ring structure contains an epoxy ring structure having an epoxy group, wherein the epoxy group includes two adjacent carbon atoms forming an aliphatic ring and one oxygen atom bonded to the two carbon atoms.

[0062] Examples of the epoxy resin containing an epoxy ring structure include epoxy resins containing an epoxy cyclohexane structure (hereinafter referred to as epoxy resins containing an ECH structure).

[0063] Examples of epoxy resins containing an ECH structure include an epoxy resin containing one ECH structure represented by the following chemical formula (2), an epoxy resin containing one ECH structure represented by the following chemical formula (3), an epoxy resin containing two ECH structures represented by the following general formula (4), and modified products thereof.

[0064] [Chemistry 2]

[0065] [Chemistry 3]

[0066] [Chemistry 4]

[0067] In formula (4), X represents a linking group (a divalent group having one or more atoms). R2 represents an atom or substituent selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, a fluoroalkyl group, an aryl group, a furyl group, and a thienyl group. The two R2 groups in formula (4) may be the same or different.

[0068] The epoxy resin containing two ECH structures represented by general formula (4) (hereinafter referred to as the epoxy resin containing an ECH structure represented by general formula (4)) has ECH structures (epoxycyclohexyl groups) at both ends of the molecule, and the two epoxycyclohexyl groups are bonded via a linking group. Furthermore, the epoxycyclohexyl group is a functional group containing a cyclohexane ring and an epoxy group, wherein the epoxy group includes two adjacent carbon atoms forming the cyclohexane ring and an oxygen atom bonded to the two carbon atoms.

[0069] Examples of the alkyl group represented by R 2 in the general formula (4) include linear or branched alkyl groups having 1 to 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl).

[0070] Examples of the fluoroalkyl group represented by R 2 in the general formula (4) include linear or branched fluoroalkyl groups having 1 to 6 carbon atoms (such as perfluoromethyl, perfluoroethyl, and perfluoropropyl).

[0071] Examples of the aryl group represented by R 2 in the general formula (4) include aryl groups having 6 to 18 carbon atoms (such as phenyl and naphthyl).

[0072] Examples of the linking group represented by X in the general formula (4) include an oxygen atom, a sulfur atom, a divalent hydrocarbon group, a polyoxyalkylene group, a carbonyl group, an ether group, a thioether group, an ester group, a carbonate group, an amide group, and groups formed by linking these groups.

[0073] Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 20 carbon atoms (e.g., methylene, methylmethylene, dimethylmethylene, ethylene, propylene, trimethylene, and butylene), and linear or branched unsaturated hydrocarbon groups having 1 to 20 carbon atoms (e.g., propenylene, methpropenylene, and butenylene).

[0074] Examples of the polyoxyalkylene group include linear or branched polyoxyalkylene groups having 1 to 120 carbon atoms (e.g., polyoxyethylene and polyoxypropylene).

[0075] Specific examples of the epoxy resin containing an ECH structure represented by the general formula (4) include (3,3',4,4'-diepoxy)biscyclohexyl, bis(3,4-epoxycyclohexylmethyl)ether, 1,2-bis(3,4-epoxycyclohexane-1-yl)ethane, 2,2-bis(3,4-epoxycyclohexane-1-yl)propane, 3',4'-epoxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate, and ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl3,4-epoxycyclohexanecarboxylate. Preferred examples of the epoxy resin containing an ECH structure represented by the general formula (4) include (3,3',4,4'-diepoxy)biscyclohexyl and 3',4'-epoxycyclohexylmethyl(3,4-epoxy)cyclohexanecarboxylate. As the epoxy resin containing the ECH structure represented by the general formula (4), from the viewpoint of further suppressing discoloration of the polarizing plate 7 , a (3,3′,4,4′-diepoxy)biscyclohexyl group is more preferably mentioned.

[0076] Furthermore, commercially available epoxy resins containing an ECH structure represented by the general formula (4) may be used. Examples of commercially available epoxy resins containing an ECH structure represented by the general formula (4) include Celloxide 8010 ((3,3',4,4'-diepoxy)dicyclohexyl) and Celloxide 2021P (3',4'-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate) (both manufactured by Daicel Corporation).

[0077] Preferred examples of the epoxy resin containing an ECH structure include the epoxy resin containing an ECH structure represented by the general formula (4).

[0078] Furthermore, as the alicyclic epoxy resin, preferably, an epoxy resin containing an epoxy ring structure can be mentioned.

[0079] The weight average molecular weight of the alicyclic epoxy resin is, for example, 200 or more, for example, 1000 or less, and preferably 500 or less. The weight average molecular weight (Mw) can be determined by gel permeation chromatography (GPC) using polystyrene as a standard substance (the same applies hereinafter).

[0080] The epoxy equivalent of the alicyclic epoxy resin is, for example, 90 g / eq. or more, preferably 100 g / eq. or more, and for example, 250 g / eq. or less, preferably 190 g / eq. or less. The epoxy equivalent can be measured in accordance with Japanese Industrial Standards (JIS) K7236:2001.

[0081] (Aliphatic Epoxy Resin) Examples of the aliphatic epoxy resin include bifunctional aliphatic epoxy resins. Examples of bifunctional aliphatic epoxy resins include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether. Preferred bifunctional aliphatic epoxy resins include neopentyl glycol diglycidyl ether.

[0082] The weight average molecular weight of the aliphatic epoxy resin is, for example, 150 or more, and for example, 400 or less.

[0083] The epoxy equivalent of the aliphatic epoxy resin is, for example, 60 g / eq. or more, and for example, 250 g / eq. or less.

[0084] When the epoxy compound includes an alicyclic epoxy resin and an aliphatic epoxy resin, the content of the alicyclic epoxy resin relative to 100 parts by mass of the total amount of the alicyclic epoxy resin and the aliphatic epoxy resin is, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and for example, 50 parts by mass or less, preferably 40 parts by mass or less. Furthermore, the content of the alicyclic epoxy resin relative to the cationically polymerizable compound is, for example, 5% by mass or more, preferably 10% by mass or more, and for example, 30% by mass or less, preferably 20% by mass or less.

[0085] When the epoxy compound includes an alicyclic epoxy resin and an aliphatic epoxy resin, the content of the aliphatic epoxy resin relative to 100 parts by mass of the total amount of the alicyclic epoxy resin and the aliphatic epoxy resin is, for example, 40 parts by mass or more, preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and for example, 90 parts by mass or less, preferably 80 parts by mass or less. Furthermore, the content of the aliphatic epoxy resin relative to the cationically polymerizable compound is, for example, 20% by mass or more, preferably 30% by mass or more, and for example, 50% by mass or less, preferably 40% by mass or less.

[0086] The epoxy compound may be used alone or in combination of two or more. Preferred examples of the epoxy compound include alicyclic epoxy resins used alone and alicyclic epoxy resins and aliphatic epoxy resins used in combination.

[0087] The content ratio of the epoxy compound relative to the cationically polymerizable compound is, for example, 30 mass % or more, preferably 40 mass % or more, and for example, 70 mass % or less, preferably 60 mass % or less.

[0088] [Oxetane compounds] The oxetane compound contains, for example, 1 to 5 oxetane rings.

[0089] Examples of the oxetane compound include a monofunctional oxetane compound having one oxetane ring, a difunctional oxetane compound having two oxetane rings, and a trifunctional or higher functional oxetane compound having three or more oxetane rings.

[0090] Examples of monofunctional oxetane compounds include 2-ethylhexyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-(methyl)allyloxymethyl-3-ethyloxetane, (3-ethyl-3-oxetanylmethoxy)methylbenzene, 2-ethylhexyl (3-ethyl-3-oxetanylmethyl) ether, ethyldiethylene glycol (3-ethyl-3-oxetanylmethyl) ether, and 3-cyclohexylmethyl-3-ethyl-oxetane. Preferred monofunctional oxetane compounds include 2-ethylhexyloxetane.

[0091] A commercially available monofunctional oxetane compound may also be used. Examples of commercially available monofunctional oxetane compounds include Aron Oxetane OXT-212 (2-ethylhexyloxetane, manufactured by Toagosei Chemical Co., Ltd.).

[0092] Examples of the difunctional oxetane compound include 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]methyl}benzene, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, 1,4-bis{[(3-ethyl-3-oxetanyl)methoxy]benzene, 1,3-bis{[3-ethyl-3-oxetanyl)methoxy]benzene, 3,7-bis(3- [(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, and dicyclopentenyl bis(3-ethyl-3-oxetanylmethyl)ether. Preferred examples of difunctional oxetane compounds include 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.

[0093] Commercially available difunctional oxetane compounds can also be used. Examples of commercially available difunctional oxetane compounds include Aron Oxetane OXT-221 (3-ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, manufactured by Toagosei Chemical Co., Ltd.).

[0094] Examples of trifunctional or higher-functional oxetane compounds include trimethylolpropane tris(3-ethyl-3-oxetanylmethyl)ether, pentaerythritol tris(3-ethyl-3-oxetanylmethyl)ether, pentaerythritol tetra(3-ethyl-3-oxetanylmethyl)ether, and dipentaerythritol penta(3-ethyl-3-oxetanylmethyl)ether.

[0095] Preferred oxetane compounds include monofunctional oxetane compounds and difunctional oxetane compounds. From the perspective of further suppressing discoloration of the polarizing plate 7, difunctional oxetane compounds are more preferred. Specifically, from the perspective of further suppressing discoloration of the polarizing plate 7, the oxetane compound preferably includes a difunctional oxetane compound.

[0096] The oxetane compounds may be used alone or in combination of two or more.

[0097] The content ratio of the oxetane compound relative to the cationically polymerizable compound is, for example, 30 mass % or more, preferably 40 mass % or more, and for example, 70 mass % or less, preferably 60 mass % or less.

[0098] The content of the cationically polymerizable compound relative to the sealing composition is, for example, 80 mass % or more, preferably 90 mass % or more, and for example, 98 mass % or less.

[0099] <<Cationic Polymerization Initiator>> The cationic polymerization initiator is, for example, a photoacid generator that generates an acid upon irradiation with light.

[0100] The cationic polymerization initiator is not particularly limited, and known cationic polymerization initiators can be used. Specifically, examples of cationic polymerization initiators include coronium salts, phosphonium salts, quaternary ammonium salts, diazonium salts, and iodonium salts. Preferred cationic polymerization initiators include coronium salts.

[0101] Examples of the coronium salt include triaryl coronium salts.

[0102] In addition, in these cationic polymerization initiators, the counter anion forming the salt includes, for example, a central atom and a ligand coordinated to the central atom.

[0103] Examples of the central atom include P, As, and Sb. Preferred central atom is P.

[0104] Examples of the ligand include F-, Cl-, and (CF2CF3)nF(6-n)-.

[0105] Specific examples of such counter anions include PF 6 -, (CF 2CF 3) nPF (6-n) -, AsF 6 -, SbF 6 -, BF 4 -, SbCl 6 -, and FG anions.

[0106] Preferred cationic polymerization initiators include coronium salts (preferably triaryl coronium salts) having (CF2CF3)nPF(6-n)- as a counter anion and coronium salts (preferably triaryl coronium salts) having FG anion as a counter ion.

[0107] In addition, as the cationic polymerization initiator, an acid generator described in Japanese Patent Application Laid-Open No. 2022-80366 (specifically, a cationic polymerization initiator in which the central metal of the counter anion is gallium) can also be used.

[0108] Commercially available cationic polymerization initiators may also be used. Examples of commercially available cationic polymerization initiators include CPI-210S (a coronium salt (specifically, a triaryl coronium salt) with (CF2CF3)nPF(6-n)- as a counter anion, manufactured by San-Apro Co., Ltd.) and CPI-310FG (a coronium salt (specifically, a triaryl coronium salt) with an FG anion as a counter ion, manufactured by San-Apro Co., Ltd.).

[0109] The cationic polymerization initiators may be used alone or in combination of two or more.

[0110] The content ratio of the cationic polymerization initiator relative to 100 parts by mass of the cationic polymerizable compound is 0.2 parts by mass or more, preferably 0.3 parts by mass or more, for example, from the viewpoint of further suppressing the discoloration of the polarizing plate 7. In addition, the content ratio is 0.8 parts by mass or less, preferably 0.7 parts by mass or less, for example, from the viewpoint of further suppressing the discoloration of the polarizing plate 7.

[0111] In addition, the content ratio of the cationic polymerization initiator relative to the sealing composition is 0.2 mass % or more, preferably 0.3 mass % or more, for example, from the viewpoint of further suppressing discoloration of the polarizing plate 7. In addition, in order to further suppress discoloration of the polarizing plate 7, it is 0.8 mass % or less, preferably 0.7 mass % or less.

[0112] <<Additives>> The sealing composition may contain additives in appropriate proportions as needed.

[0113] Examples of additives include tackifiers, photosensitizers, levelers, coupling agents, antioxidants, polymerization initiation aids, anti-aging agents, wettability improvers, surfactants, plasticizers, ultraviolet absorbers, preservatives, and antimicrobial agents. Preferred additives include tackifiers, photosensitizers, levelers, and coupling agents.

[0114] [Adhesive] The tackifier is a component for imparting tackiness to the second sealing layer 6 .

[0115] Examples of the tackifier include aliphatic tackifiers, alicyclic tackifiers, aromatic tackifiers, rosin tackifiers, terpene tackifiers, and hydrogenated forms thereof. Preferred tackifiers include aromatic tackifiers and terpene tackifiers.

[0116] Examples of aromatic tackifiers include styrene oligomers.

[0117] Examples of the styrene-based oligomer include homopolymers of a styrene-skeleton-containing monomer and copolymers of a styrene-skeleton-containing monomer and other polymerizable monomers.

[0118] Examples of the monomer containing a styrene skeleton include styrene, α-methylstyrene, vinyltoluene, and isopropenyltoluene. Preferred examples of the monomer containing a styrene skeleton include isopropenyltoluene.

[0119] The styrene skeleton-containing monomers may be used alone or in combination of two or more.

[0120] The other polymerizable monomer is a monomer that can be polymerized with the monomer containing a styrene skeleton, and has, for example, an ethylenically unsaturated double bond.

[0121] Examples of other polymerizable monomers include unsaturated aliphatic monomers with 2 to 10 carbon atoms (e.g., ethylene, propylene, and butene), unsaturated alicyclic monomers with 5 to 20 carbon atoms (e.g., cyclopentadiene and dicyclopentadiene), α,β-unsaturated carboxylic acids (e.g., acrylic acid and methacrylic acid), alkyl (meth)acrylates, and C5 fractions. The C5 fraction is obtained, for example, by refining and cracking petroleum. Specifically, it is a fraction with a boiling point generally ranging from -15°C to +45°C at atmospheric pressure, and includes 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-pentene, isoprene, 1,3-pentadiene, and cyclopentadiene.

[0122] Other polymerizable monomers may be used alone or in combination of two or more.

[0123] As the styrene-based oligomer, a homopolymer of a monomer containing a styrene skeleton is preferred, and as the styrene-based oligomer, a homopolymer of isopropenyltoluene is more preferred.

[0124] Examples of the terpene-based tackifier include terpene phenol resins.

[0125] The tackifiers may be used alone or in combination of two or more.

[0126] The content ratio of the tackifier relative to 100 parts by mass of the cationically polymerizable compound is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and for example, 20 parts by mass or less, preferably 15 parts by mass or less.

[0127] The content ratio of the tackifier relative to the sealing composition is, for example, 1 mass % or more, preferably 3 mass % or more, and for example, 20 mass % or less, preferably 15 mass % or less.

[0128] [Photosensitizer] The photosensitizer is a component for further accelerating the curing reaction of the sealing composition.

[0129] Examples of the photosensitizer include thioxanthone compounds and anthracene compounds.

[0130] As a thioxanthone compound, 2,4-diethylthioxanthone is mentioned, for example.

[0131] Examples of the anthracene compound include 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, and 9,10-bis(octanoyloxy)anthracene.

[0132] Preferred examples of the photosensitizer include anthracene compounds, and more preferred examples of the photosensitizer include 9,10-dibutoxyanthracene and 9,10-bis(octanoyloxy)anthracene.

[0133] The photosensitizers may be used alone or in combination of two or more.

[0134] The content ratio of the photosensitizer relative to 100 parts by mass of the cationically polymerizable compound is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, and for example, 5 parts by mass or less, preferably 1 part by mass or less.

[0135] The content ratio of the photosensitizer relative to the sealing composition is, for example, 0.1 mass % or more, preferably 0.3 mass % or more, and for example, 5 mass % or less, preferably 1 mass % or less.

[0136] [Leveling agent] The leveling agent is a component for improving the flatness of the second sealing layer 6 .

[0137] Examples of the leveling agent include silicone leveling agents, acrylic leveling agents, and fluorine leveling agents. Preferred leveling agents include silicone leveling agents.

[0138] The leveling agents may be used alone or in combination of two or more.

[0139] The content ratio of the leveling agent relative to 100 parts by mass of the cationically polymerizable compound is, for example, 0.1 parts by mass or more, preferably 0.3 parts by mass or more, and for example, 5 parts by mass or less, preferably 1 part by mass or less.

[0140] The content ratio of the leveling agent relative to the sealing composition is, for example, 0.1 mass % or more, preferably 0.3 mass % or more, and for example, 5 mass % or less, preferably 1 mass % or less.

[0141] [Coupling agent] The coupling agent is a component for improving the adhesion of the second sealing layer 6 .

[0142] Examples of coupling agents include epoxy-containing silane coupling agents, amino-containing silane coupling agents, and (meth)acryl-containing silane coupling agents. Preferred coupling agents include epoxy-containing silane coupling agents.

[0143] Examples of epoxy-containing silane coupling agents include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane. Preferred epoxy-containing silane coupling agents include 3-glycidoxypropyltrimethoxysilane.

[0144] The coupling agents may be used alone or in combination of two or more.

[0145] The content ratio of the coupling agent relative to 100 parts by mass of the cationically polymerizable compound is, for example, 1 part by mass or more, preferably 3 parts by mass or more, and for example, 20 parts by mass or less, preferably 10 parts by mass or less.

[0146] The content ratio of the coupling agent relative to the sealing composition is, for example, 1 mass % or more, preferably 3 mass % or more, and for example, 20 mass % or less, preferably 10 mass % or less.

[0147] [Preparation of Sealing Composition] To prepare the sealing composition, a cationic polymerizable compound, a cationic polymerization initiator, and optionally, additives are mixed. Thus, the sealing composition is prepared.

[0148] The sealing composition can also be diluted with a known solvent to form a varnish. In this case, the solid content concentration of the varnish of the sealing composition is, for example, 10% by mass or more, and for example, 70% by mass or less.

[0149] Then, as will be described in detail later, the sealing composition is cured to form the second sealing layer 6 .

[0150] The conductivity of the extracted water of the second sealing layer 6 is 100 μm / S or less, preferably 85 μm / S or less, more preferably 75 μm / S or less, further preferably 50 μm / S or less, particularly preferably 38 μm / S or less, and for example 1 μm / S or more.

[0151] When the electrical conductivity is equal to or lower than the upper limit, discoloration of the polarizing plate 7 can be suppressed.

[0152] On the other hand, if the electrical conductivity is less than the upper limit, discoloration of the polarizing plate 7 cannot be suppressed.

[0153] For example, the conductivity can be adjusted to the above range by adjusting the content ratio of the cationic polymerization initiator.

[0154] Furthermore, the method for measuring the conductivity is described in detail in the examples described below.

[0155] The thickness of the second sealing layer 6 is, for example, not less than 0.2 μm, and for example, not more than 200 μm, preferably not more than 100 μm, and more preferably not more than 30 μm.

[0156] <Polarizing plate> The polarizing plate 7 is a layer for preventing reflection of external light.

[0157] The polarizing plate 7 is disposed on the entire surface of one thickness direction side of the second sealing layer 6. Specifically, the polarizing plate 7 is disposed on the entire surface of one thickness direction side of the second sealing layer 6 via a known optical adhesive tape (described later).

[0158] A known polarizing plate can be used as the polarizing plate 7. For example, the polarizing plate 7 is obtained by dyeing a hydrophilic polymer film (eg, a polyvinyl alcohol film) with iodine and then stretching it. That is, the polarizing plate 7 contains iodine.

[0159] The thickness of the polarizing plate 7 is, for example, not less than 50 μm, and not more than 200 μm.

[0160] <Method for Manufacturing Display Device> One embodiment of a method for manufacturing the display device 10 will be described with reference to FIG. 2A to FIG. 2G .

[0161] The manufacturing method of the display device 10 includes: a first step of preparing a substrate 1; a second step of installing an optical element 2 on one side of the substrate 1 in the thickness direction; a third step of configuring a first inorganic layer 3 on the substrate 1 in a manner that covers the surface of the optical element 2; a fourth step of configuring a first sealing layer 4 on the first inorganic layer 3 in a manner that seals the optical element 2; a fifth step of configuring a second inorganic layer 5 in a manner that covers the surface of the first sealing layer 4; a sixth step of configuring a second sealing layer 6 on the second inorganic layer 5 in a manner that seals the optical element 2; and a seventh step of configuring a polarizing plate 7 on one side of the second sealing layer 6 in the thickness direction.

[0162] [Step 1] In the first step, as shown in FIG2A , a substrate 1 is prepared.

[0163] [Step 2] In the second step, as shown in FIG2B , an optical element 2 is mounted on one side of the substrate 1 in the thickness direction.

[0164] Examples of a method for mounting the optical element 2 include vapor deposition (vacuum vapor deposition), sputtering, ion plating, and plasma vapor phase growth (chemical vapor deposition, CVD).

[0165] [Step 3] In the third step, as shown in FIG2C , a first inorganic layer 3 is disposed on the substrate 1 so as to cover the surface of the optical element 2. Specifically, the first inorganic layer 3 covers the upper surface and side surfaces of the optical element 2 and the upper surface of the substrate 1.

[0166] As a method for configuring the first inorganic layer 3 , for example, the same method as the method for mounting the optical element 2 can be cited.

[0167] [Step 4] In the fourth step, as shown in FIG. 2D , a first sealing layer 4 is disposed on the first inorganic layer 3 in a manner to seal the optical element 2 .

[0168] An example of a method for placing the first sealing layer 4 is an inkjet method. Specifically, the material for the first sealing layer 4 is applied by the inkjet method and then cured. In this way, the first sealing layer 4 is placed.

[0169] [Step 5] In the fifth step, as shown in FIG2E , the second inorganic layer 5 is disposed so as to cover the surface of the first sealing layer 4. Specifically, the second inorganic layer 5 is disposed so as to cover the surface (upper surface and side surfaces) of the first sealing layer 4.

[0170] As a method for configuring the second inorganic layer 5 , for example, the same method as the method for mounting the optical element 2 can be cited.

[0171] [Step 6] In the sixth step, as shown in FIG2F , a second sealing layer 6 is disposed on the second inorganic layer 5 to seal the optical element 2. Specifically, the surface (top and side surfaces) of the second inorganic layer 5 is covered to seal the optical element 2.

[0172] An example of a method for disposing the second sealing layer 6 is an inkjet method. Specifically, the sealing composition is applied by the inkjet method, and then the sealing composition is irradiated with light to cure. In this way, the second sealing layer 6 is disposed.

[0173] [Step 7] In the seventh step, as shown in FIG2G , a polarizing plate 7 is placed on one side of the second sealing layer 6 in the thickness direction. Specifically, for example, the polarizing plate 7 is placed on one side of the second sealing layer 6 in the thickness direction via a known optical adhesive tape. The display device 10 is manufactured in the above manner.

[0174] <Effects> In the display device 10, the conductivity of the extracted water of the second sealing layer 6 is 100 μm / S or less. Therefore, discoloration of the polarizing plate 7 can be suppressed.

[0175] Specifically, in the display device 10, the second inorganic layer 5 includes a metal nitride. When water enters the second inorganic layer 5, the ions in the water may react with nitrogen to produce NH 3 + ions. Furthermore, these NH 3 + ions can cause discoloration of the polarizing plate 7.

[0176] Meanwhile, in the display device 10, the conductivity of the extracted water in the second sealing layer 6 is 100 μm / S or less. Therefore, even if water infiltrates the second inorganic layer 5, the ionic components in the water are prevented from reacting with nitrogen to produce NH 3 + ions. Therefore, the reaction between water and nitrogen to produce NH 3 + ions in the second inorganic layer 5 is suppressed. Consequently, discoloration of the polarizing plate 7 is suppressed.

[0177] In the display device 10 , if the conductivity of the extracted water of the second sealing layer 6 is 100 μm / S or less, discoloration of the polarizing plate 7 can be suppressed. The composition and thickness of the second sealing layer 6 are not limited thereto.

[0178] <Modification> In the modified examples, components and steps identical to those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. Furthermore, unless otherwise noted, the modified examples can achieve the same functions and effects as the first embodiment. Furthermore, the first embodiment and the modified examples can be appropriately combined.

[0179] In the above description, the display device 10 includes a substrate 1, an optical element 2, a first inorganic layer 3, a first sealing layer 4, a second inorganic layer 5, a second sealing layer 6, and a polarizer 7. However, the display device 10 may also not include the first inorganic layer 3 and the first sealing layer 4. In this case, the display device 10 includes the substrate 1, the optical element 2, the second inorganic layer 5, the second sealing layer 6, and the polarizer 7.

[0180] In the above description, the polarizing plate 7 is disposed on the entire surface of one side in the thickness direction of the second sealing layer 6 , but the present invention is not limited thereto. The polarizing plate 7 only needs to be disposed on at least a portion of one side in the thickness direction of the second sealing layer 6 . [Example]

[0181] Next, the present invention will be described based on Examples and Comparative Examples. However, the present invention is not limited to the following Examples. Furthermore, unless otherwise specified, "parts" and "%" are by mass. Furthermore, specific numerical values ​​such as blending ratios (content ratios), physical property values, and parameters used below may be replaced with the corresponding upper limits (defined as "less than" or "less than") or lower limits (defined as "more than" or "exceeding") listed in the "Embodiments" for those blending ratios (content ratios), physical property values, and parameters.

[0182] <Ingredient Details> The trade names and abbreviations of the components used in each example and each comparative example are described in detail. CEL8010: (3,3',4,4'-diepoxy)dicyclohexyl, trade name "Celloxide 8010", manufactured by Daicel Corporation CEL2021P: 3',4'-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate, the epoxy resin containing the ECH structure represented by the general formula (4), trade name "Celloxide 2021P", molecular weight: 252.3, epoxy equivalent: 128 g / eq. to 145 g / eq., manufactured by Daicel Corporation NPG(D): Neopentyl glycol diglycidyl ether, manufactured by Sakamoto Pharmaceutical Industry Co., Ltd. OXT221: 3-Ethyl-3-{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, trade name "Aron Oxetane OXT-221", manufactured by Toa Gosei Chemical Co., Ltd. OXT212: 2-Ethylhexyloxetane, trade name "Aron Oxetane OXT-212", manufactured by Toa Gosei Chemical Co., Ltd. CPI-210S: Copper salt (specifically, triaryl copper salt) with (CF2CF3)nPF(6-n)- as the counter anion, manufactured by San-Apro CPI-310FG: Copper salt (specifically, triaryl copper salt) with FG anion as counterion, manufactured by San-Apro Styrene oligomers: homopolymers of isopropenyltoluene K-125: Terpene phenol resin, trade name "YS Polystar K-125", manufactured by Yasuhara Chemical Co., Ltd. UVS-1331:9,10-Dibutoxyanthracene UVS-581:9,10-Bis(octanoyloxy)anthracene BYK-378: Silicone-based leveling agent KBM-403:3-Glycidoxypropyltrimethoxysilane HALS: Bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate, trade name "Tinuvin 123", manufactured by BASF

[0183] <Manufacturing of Display Device> [Preparation of Sealing Composition] Examples 1 to 6 and Comparative Examples 1 to 4 Based on the formulation described in Table 1, the cationically polymerizable compound, cationic polymerization initiator, and additives were mixed and dissolved using a magnetic stirrer. This prepared a sealing composition. In Table 1, the unit for each component is "parts by mass."

[0184] [Manufacturing of Display Device] Manufacturing of the display device will be described with reference to FIG. 2A to FIG. 2G . (First step) As shown in FIG2A , a glass substrate is prepared as substrate 1 .

[0185] (Step 2) As shown in FIG2B, an optical element 2 is mounted on one side of the substrate 1 in the thickness direction by a plasma vapor deposition method (CVD method). In addition, an organic EL element is used as the optical element 2.

[0186] (Step 3) As shown in FIG2C , a first inorganic layer 3 is disposed on substrate 1 to cover the surface of optical element 2. Specifically, first inorganic layer 3 (1.0 μm thick) is deposited by plasma vapor deposition (CVD). Silicon nitride is used as the material for first inorganic layer 3.

[0187] (Step 4) As shown in FIG2D , a first sealing layer 4 is disposed on the first inorganic layer 3 to seal the optical element 2. Specifically, the material for the first sealing layer 4 (UV-curable epoxy resin) is applied by inkjet coating and then cured. This results in the formation of the first sealing layer 4 (10 μm thick).

[0188] (Step 5) As shown in FIG2E , a second inorganic layer 5 is formed to cover the surfaces (top and side surfaces) of the first sealing layer 4. Specifically, the second inorganic layer 5 (1.0 μm thick) is formed by plasma vapor deposition (CVD). Silicon nitride is used as the material for the second inorganic layer 5.

[0189] (Step 6) As shown in FIG2F , a second sealing layer 6 was disposed on the second inorganic layer 5 to seal the optical element 2. Specifically, the sealing composition of each Example and Comparative Example was applied by inkjet coating and then irradiated with ultraviolet light (1 W / cm², 4 J / cm²) to cure. This formed the second sealing layer 6 (10 μm thick).

[0190] (Step 7) As shown in FIG2G , a polarizing plate 7 (a polarizing film manufactured by Kenis, an iodine-based polarizing plate, 200 μm thick) was placed on one side of the second sealing layer 6 in the thickness direction via an optical adhesive tape (HJ-9150W manufactured by Nitto Denko Corporation). Display device 10 was manufactured in this manner.

[0191] <Evaluation> [Conductivity of extracted water of the second sealing layer] The sealing composition of each Example and Comparative Example was applied to one side of a polyethylene terephthalate (PET) film (100 μm) in the thickness direction to a thickness of 10 μm, forming a coating film of the sealing composition. A PET film (100 μm) was then placed on one side of the coating film in the thickness direction via a frame.

[0192] The coating film was then irradiated with ultraviolet light (1 W / cm², 4 J / cm²) to obtain a cured product of the sealing composition. The PET film was then peeled off. This produced a sample for conductivity measurement containing the cured product of the sealing composition.

[0193] The conductivity measurement sample was cut into 20 mm × 20 mm × 10 μm pieces. 0.5 g of the conductivity measurement sample was then placed in a cleaned polytetrafluoroethylene (PTEF) container with a lid.

[0194] Then, 17.5 g of ultrapure water of known conductivity was added to the container, the sample for conductivity measurement was immersed in the ultrapure water, and the container was capped.

[0195] Then, the mixture was placed in a thermostatic bath at 85°C and 85% RH for 24 hours and then cooled to room temperature to obtain an ultrapure water measurement solution.

[0196] The conductivity of the ultrapure water solution was measured using a conductivity meter SC-72 (manufactured by Yokogawa Electric Corporation). The conductivity of the blank (ultrapure water) was subtracted from the resulting value, which was used as the conductivity of the extracted water in the second sealing layer. The results are shown in Table 1.

[0197] Furthermore, if the thickness of the second sealing layer 6 (the cured product of the sealing composition) is 100 μm or less, the thickness has no effect on the conductivity. Furthermore, using this test method, the conductivity of a sealing layer with a thickness of 10 μm in a display device can produce the same results as measured. In other words, if a cured product of a sealing composition with a thickness of X μm is prepared according to the test method, and the conductivity is measured, the conductivity of a sealing layer with a thickness of X μm in a display device can produce the same results as measured.

[0198] [Polarizing plate discoloration test] (Preparation of Polarizing Plate Discoloration Test Samples) A silicon nitride film as an inorganic layer is deposited on one side of the glass plate in the thickness direction by a plasma vapor deposition method (CVD method).

[0199] Next, the sealing composition of each example and each comparative example was applied to one side of the inorganic layer in the thickness direction using an applicator (coating thickness 10 μm), and then irradiated with ultraviolet light (1 W / cm2, 4 J / cm2) to obtain a sealing layer (cured sealing composition).

[0200] Then, a polarizing plate (an iodine-based polarizing plate manufactured by Kenis) was placed on one side of the sealant layer in the thickness direction via an optical adhesive tape (HJ-9150W manufactured by Nitto Denko Corporation). This was done to prepare a sample for the polarizing plate discoloration test.

[0201] (Polarizing plate discoloration test) The polarizing plate discoloration test sample was placed in a thermostat at 85°C and 85% RH for 24 hours, and the color change of the polarizing plate was observed visually.

[0202] The discoloration of the polarizing plate was evaluated according to the following criteria. The results are shown in Table 1. {Benchmark} ○: The color of the polarizing plate does not change. ×: The color of the polarizing plate becomes lighter.

[0203] [Table 1] Example / Comparative Example No. Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Sealing composition Cationic polymerizable compounds Epoxides Cycloaliphatic epoxy resin CEL8010 15 15 30 30 15 30 30 15 - - CEL2021P - - - - - - - - 15 15 Aliphatic epoxy resin NPG(D) 35 35 - - 35 - - 35 35 35 Oxetane compounds Difunctional oxetane compounds OXT-221 50 50 - - 50 - - 50 50 50 Monofunctional oxetane compounds OXT-212 - - 60 55 - 60 55 - - - Cationic polymerization initiator CPI-210S 1 1 1 1 0.5 0.5 0.5 - 0.5 0.5 CPI-310FG - - - - - - - 0.5 - - additive Adhesive Styrene oligomers - - 10 - - 10 - - - - K-125 - - - 5 - - 5 - - - photosensitizer UVS-1331 1 1 0.5 0.5 1 0.5 0.5 0.5 0.5 - UVS-581 - - - - - - - - - 0.5 Leveling agent BYK-378 0.5 0.5 - - 0.5 - - 0.5 0.5 0.5 coupling agent KBM-403 5 5 - - 5 - - 5 5 5 Hindered amines HALS - 0.5 - - - - - - - - Conductivity of extracted water of the second sealing layer (sealing layer) (μm / S) 120 103 208 220 35 90 90 30 80 40 evaluate Polarizing plate discoloration test × × × × ○ ○ ○ ○ ○ ○

[0204] Furthermore, the invention described above is provided as an exemplary embodiment of the present invention and is for illustrative purposes only and should not be construed as limiting. Modifications of the present invention that are apparent to those skilled in the art are included in the scope of the following claims. [Industrial Applicability]

[0205] The display device of the present invention can be suitably used in, for example, an organic EL display.

[0206] 1:Substrate 2: Optical components 3: First inorganic layer 4: First sealing layer 5: Second inorganic layer 6: Second sealing layer 7:Polarizing plate 10: Display device

Claims

1. A display device, comprising: substrate; An optical element is mounted on one side of the substrate in the thickness direction; a sealing layer seals the optical element; an inorganic layer exists between the optical element and the sealing layer and contains a metal nitride; and a polarizing plate is disposed on at least a portion of one side of the sealing layer in the thickness direction, wherein the conductivity of the extracted water in the sealing layer is less than 100 μm / S, the sealing layer contains a hardened form of a sealing composition, the sealing composition contains a cationic polymerizable compound and a cationic polymerization initiator, and the cationic polymerization initiator is present in a proportion of 0.2 parts by mass or more and 0.8 parts by mass or less relative to 100 parts by mass of the cationic polymerizable compound.

2. The display device as claimed in claim 1, wherein, The cationic polymerizable compound comprises at least one selected from epoxy compounds and oxobutane compounds.

3. The display device as claimed in claim 2, wherein, The epoxy compounds include alicyclic epoxy resins and aliphatic epoxy resins.

4. The display device as claimed in claim 2, wherein, Oxycyclic butane compounds include difunctional oxycyclic butane compounds.

5. The display device as claimed in claim 1, wherein, The sealing composition includes a leveling agent.

6. The display device as claimed in claim 1, wherein, The sealing composition includes a coupling agent.

Images