UV curable resin composition

Abstract

To provide an ultraviolet ray-curable resin composition which can achieve improvement of end stopping property and flatness of a surface state, and element reliability.SOLUTION: An ultraviolet ray-curable resin composition contains a polymerizable compound (A) and a polymerization initiator (B), wherein the polymerizable compound (A) contains (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an ultraviolet curable resin composition.

Background Art

[0002] Organic electroluminescence (EL) elements are being used in displays, lighting devices, etc. because of their low power consumption. Since organic EL elements are easily deteriorated by moisture and oxygen in the air, it has been considered to use them sealed with a sealing member. Such a sealing material is usually formed by a method such as inkjet printing. Furthermore, in recent years, with the thinning and bezel-lessization of displays (the outer frame of the display is removed), improvement in the precision of printing during the formation of the sealing material has been desired.

[0003] As such a sealing member, in addition to a sealing agent using a thermosetting epoxy-based material, a sealing agent using an acrylic-based material has also been proposed. For example, in Patent Document 1 (International Publication No. 2019 / 82996), a sealing agent for an organic EL display element containing an acyclic alkane diol di(meth)acrylate having 6 or more carbon atoms, a specific cyclic monomer, and a photopolymerization initiator has been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the present inventors examined the sealing agent described in Patent Document 1 above, there was room for improvement in that there was a concern that moisture, oxygen, etc. from the outside might gradually penetrate into the element through the sealing agent, causing dark spots to occur and expand.

[0006] In addition, as a result of investigations by the present inventors, when a sealing material is formed by, for example, inkjet printing, although the appearance is good on the surface, upon closer inspection, there are problems such as the end portion slightly spreading. When making the appearance of the display more precise and improving the manufacturing stability, there was concern that the yield would decrease. Further, when attempting to satisfactorily fix the end portion, there is a trade-off problem in that, with an increase in the shrinkage of the composition used for the sealing material, for example, a liquid, the flatness of the surface after curing the sealing material decreases or pinholes are generated, indicating that there is room for improvement.

[0007] The present invention provides an ultraviolet curable resin composition capable of achieving both good end-stopping properties, flatness of the surface state, and element reliability when an inkjet print of a sealing material for an organic EL element or the like is performed.

Means for Solving the Problems

[0008] According to the present invention, there is provided an ultraviolet curable resin composition shown below. [1] An ultraviolet curable resin composition containing a polymerizable compound (A) and a polymerization initiator (B), wherein the polymerizable compound (A) includes a (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton. [2] The viscosity measured at 25°C and 20 rpm by an E-type viscometer is 4 mPa·s or more and 50 mPa·s or less, The ultraviolet curable resin composition according to [1]. [3] The content of the (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton in the ultraviolet curable resin composition is 20 parts by mass or less with respect to 100 parts by mass of the polymerizable compound (A) of the ultraviolet curable resin composition. The ultraviolet curable resin composition according to [1] or [2]. [4] The (meth)acrylate (A1) containing the polytetramethylene ether glycol skeleton is a bifunctional or higher-functional (meth)acrylate. [1] to [3] The ultraviolet curable resin composition according to any one of [1] to [3]. [5] The polymerizable compound (A) further contains a (meth)acrylate (A2) other than the (meth)acrylate (A1) containing the polytetramethylene ether glycol skeleton. The ultraviolet curable resin composition according to any one of [1] to [4]. [6] The (meth)acrylate (A2) contains a bifunctional (meth)acrylate. The ultraviolet curable resin composition according to [5]. [7] The (meth)acrylate (A2) contains both a bifunctional acrylate and a bifunctional methacrylate. The ultraviolet curable resin composition according to [5] or [6]. [8] The (meth)acrylate (A2) contains both an alicyclic bifunctional (meth)acrylate and a linear bifunctional (meth)acrylate. The ultraviolet curable resin composition according to any one of [5] to [7]. [9] The (meth)acrylate (A2) further contains a monofunctional (meth)acrylate. The ultraviolet curable resin composition according to any one of [6] to [8].

[10] The polymerization initiator (B) contains a photo radical polymerization initiator. The ultraviolet curable resin composition according to any one of [1] to [9].

[11] The photo radical polymerization initiator contains 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TPO). The ultraviolet curable resin composition according to

[10] .

[12] The ultraviolet curable resin composition according to any one of [1] to

[11] , which is used for coating by an inkjet method.

[13] The ultraviolet curable resin composition according to any one of [1] to

[12] , which is for a display element.

[14] The display element is an organic electroluminescence element. The ultraviolet curable resin composition according to

[13] .

[0009] In addition, any combination of these respective configurations, or those obtained by converting the expression of the present invention between methods, apparatuses, etc. are also effective as aspects of the present invention. For example, according to the present invention, it is also possible to provide a sealing agent composed of the ultraviolet curable resin composition in the present invention and a cured product thereof. Also, for example, according to the present invention, it is possible to provide a display device including a substrate, a display element disposed on the substrate, and a sealing layer covering the display element, wherein the sealing layer is composed of a cured product of the ultraviolet curable resin composition in the present invention.

Effects of the Invention

[0010] According to the present invention, it is possible to provide an ultraviolet curable resin composition capable of achieving both end-stopping properties, flatness of the surface state, and element reliability of an inkjet-printed sealing material.

Brief Description of the Drawings

[0011]

Figure 1

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by common reference numerals, and the description thereof will be omitted as appropriate. Also, in the present embodiment, for each component, one type may be used, or two or more types may be used in combination. Further, "~" representing a numerical range represents "above" and "below", and includes both the upper limit value and the lower limit value.

[0013] (Ultraviolet Curable Resin Composition) In the present embodiment, the ultraviolet curable resin composition (hereinafter, also simply referred to as "resin composition" as appropriate) contains a polymerizable compound (A) and a polymerization initiator (B), and the polymerizable compound (A) includes a (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton.

[0014] From the perspective of reducing damage to the device, the resin composition is preferably for a display device, and the display device is preferably an organic electroluminescence (EL) device. Specifically, the resin composition is suitably used for sealing the device and is also suitably used as a sealing material.

[0015] The properties of the resin composition are not limited. From the perspective of improving the flexibility and plasma resistance of the cured product of the resin film, and from the perspective of being suitable for forming a cured material by a coating method such as an inkjet method, the resin composition is preferably liquid.

[0016] Also, from the perspective of stably forming a material such as a resin film, the resin composition is preferably used for coating, and more preferably used for coating by an inkjet method.

[0017] The viscosity of the resin composition measured at 25°C and 20 rpm using an E-type viscometer is preferably 4 mPa·s or more, more preferably 15 mPa·s or more, even more preferably 17 mPa·s or more, still more preferably 20 mPa·s or more, and preferably 50 mPa·s or less, more preferably 40 mPa·s or less, and even more preferably 30 mPa·s or less, from the perspective of achieving both end-stopping property and flatness of the surface state. Next, specific examples of the constituent components of the resin composition will be described.

[0018] (Component (A)) Component (A) is a polymerizable compound. Component (A) may be a compound having a polymerizable functional group, and is preferably a compound having a radically polymerizable functional group. Specific examples of the radically polymerizable functional group include a (meth)acryloyl group.

[0019] Here, in this specification, the (meth)acryloyl group means at least one of an acryloyl group and a methacryloyl group. (Meth)acrylic means at least one of acrylic or methacrylic. Also, (meth)acrylate means at least one of acrylate and methacrylate.

[0020] Component (A) includes a (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton. The (meth)acrylate containing a polytetramethylene ether glycol skeleton, that is, component (A1), specifically contains one or more polytetramethylene ether glycol skeletons represented by the following formula (1) and one or more (meth)acryloyl groups. When component (A1) contains two or more polytetramethylene ether glycol skeletons, it also includes the case where the plurality of polytetramethylene ether glycol skeletons are not continuous.

[0021]

Chemical formula

[0022] Component (A1) may further contain a urethane bond represented by the following formula (2) in its molecular structure.

[0023]

Chemical formula

[0024] The number of (meth)acryloyl groups contained in component (A1) is 1 or more, preferably 2 or more. That is, component (A1) is preferably a bifunctional or higher (meth)acrylate. Component (A1) is preferably a compound represented by the following general formula (X). Thereby, the end-stopping property of the sealing material can be improved, and the balance of the flatness of the surface state can be more stably improved.

[0025] [Chem.]

[0026] In the general formula (X), n is an average value and represents a number of 1 or more and 1000 or less. n is preferably 2 or more, more preferably 5 or more, still more preferably 7 or more, and is preferably 100 or less, more preferably 50 or less, still more preferably 20 or less, even more preferably 15 or less, and even more preferably 12 or less. In the general formula (X), R is H or CH3.

[0027] (A1) That is, by including the component (A1), when the resin composition of the present embodiment is inkjet printed, the end-stopping property of the sealing material can be made very good, and the surface state of the cured sealing material can be made flat.

[0028] The molecular weight of the (meth)acrylate having a polytetramethylene ether glycol skeleton, that is, the component (A1), is preferably 200 or more, more preferably 300 or more, still more preferably 400 or more, and even more preferably 500 or more. If the molecular weight is too small, the resin composition will volatilize at the tip of the inkjet head nozzle, and nozzle clogging is likely to occur. Further, the molecular weight of the component (A1) is, for example, 100000 or less, preferably 10000 or less, more preferably 5000 or less, still more preferably 3000 or less, even more preferably 2000 or less, and even more preferably 1000 or less.

[0029] From the viewpoint of further improving the end-stopping property of the sealing material and the flatness of the surface state, the content of the component (A1) in the resin composition is preferably 1 part by mass or more, more preferably 3 parts by mass or more, based on 100 parts by mass of the polymerizable compound (A) of the resin composition. From the viewpoint of achieving both end linearity, flatness of the surface state, and device reliability, the content of component (A1) in the resin composition is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less with respect to 100 parts by mass of the polymerizable compound (A) of the resin composition.

[0030] (Component (A2)) Component (A) preferably further contains (meth)acrylate (A2) other than component (A1) from the viewpoint of improving curability, separately from component (A1). Specific examples of (meth)acrylate (A2) other than component (A1) include mono(meth)acrylate and di(meth)acrylate.

[0031] From the viewpoint of improving the strength of the resin material obtained from the resin composition, preferably, (meth)acrylate other than component (A1), that is, component (A2), contains bifunctional (meth)acrylate, and more preferably component (A2) is bifunctional (meth)acrylate. From the same viewpoint, component (A2) preferably contains both bifunctional acrylate and bifunctional methacrylate.

[0032] (Bifunctional (meth)acrylate) Specific examples of bifunctional (meth)acrylate include alicyclic bifunctional (meth)acrylate and linear bifunctional (meth)acrylate. From the viewpoint of enhancing the effect of suppressing damage to the device, component (A2) preferably contains both alicyclic bifunctional (meth)acrylate and linear bifunctional (meth)acrylate.

[0033] Alicyclic bifunctional (meth)acrylate is a bifunctional (meth)acrylate having an alicyclic hydrocarbon structure in its molecular structure. The number of carbon atoms in the alicyclic hydrocarbon structure is preferably 4 or more, more preferably 5 or more, still more preferably 6 or more, and also preferably 14 or less, more preferably 12 or less, and still more preferably 10 or less from the viewpoints of improving heat resistance and device reliability. The alicyclic hydrocarbon structure may be a saturated hydrocarbon structure or an unsaturated hydrocarbon structure. From the viewpoint of improving heat resistance, the alicyclic hydrocarbon structure is preferably a saturated hydrocarbon structure.

[0034] Also, the alicyclic hydrocarbon structure may be a monocyclic hydrocarbon structure, or a polycyclic hydrocarbon structure such as a condensed ring hydrocarbon structure or a bridged ring hydrocarbon structure. The alicyclic difunctional (meth)acrylate may contain a group containing these alicyclic hydrocarbon structures in the molecular structure, and preferably contains a divalent group containing an alicyclic hydrocarbon structure. Specific examples of the monocyclic hydrocarbon group include groups having a cycloalkane structure such as a cyclohexylene group and a cyclohexyl group; groups having a cycloalkene skeleton such as a cyclodecatrienediyl group and a cyclodecatriene group. Specific examples of the polycyclic hydrocarbon group include groups having a dicyclopentadiene skeleton such as a tricyclodecane diyl group, a dicyclopentanyl group, and a dicyclopentenyl group; groups having a norbornane skeleton such as a norbornane diyl group, an isobornane diyl group, a norbornyl group, and an isobornyl group; groups having an adamantane skeleton such as an adamantane diyl group and an adamantyl group.

[0035] The cyclic hydrocarbon group in the alicyclic difunctional (meth)acrylate is preferably a group having a dicyclopentadiene skeleton from the viewpoints of improving plasma resistance and low moisture permeability. Also, the alicyclic difunctional (meth)acrylate contains tricyclodecane dimethanol di(meth)acrylate from the viewpoints of improving plasma resistance and low moisture permeability, and more preferably is tricyclodecane dimethanol di(meth)acrylate.

[0036] From the viewpoint of improving heat resistance and device reliability, the content of the alicyclic difunctional (meth)acrylate in the ultraviolet curable resin composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 13 parts by mass or more with respect to 100 parts by mass of the polymerizable compound, i.e., component (A). Also, from the viewpoint of improving end-stopping property and making the flatness of the surface state more preferable, the content of the alicyclic difunctional (meth)acrylate in the ultraviolet curable resin composition is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, still more preferably 50 parts by mass or less, even more preferably 45 parts by mass or less with respect to 100 parts by mass of component (A).

[0037] The linear difunctional (meth)acrylate has a linear structure in its molecular structure and is a (meth)acrylate having two (meth)acryloyl groups. From the viewpoint of improving end-stopping property and making the flatness of the surface state more preferable, the linear structure preferably includes a divalent linear hydrocarbon group. The number of carbon atoms of the divalent linear hydrocarbon group is, for example, 1 or more, preferably 2 or more, and more preferably 4 or more from the viewpoint of easy availability of the monomer. Also, from the viewpoint of improving heat resistance and device reliability, the number of carbon atoms of the divalent linear hydrocarbon group is preferably 20 or less, and more preferably 14 or less.

[0038] Specific examples of the linear difunctional (meth)acrylate include di(meth)acrylates of alkanediols. As the linear difunctional (meth)acrylate, more specifically, 1,6 - hexanediol diacrylate (for example, A - HD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,9 - nonanediol diacrylate (for example, A - NOD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.; Light Acrylate 1,9ND - A, manufactured by Kyoeisha Chemical Co., Ltd.), 1,10 - decanediol diacrylate (for example, A - DOD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.), ethylene glycol diacrylate (for example, SR206NS, manufactured by Arkema), triethylene glycol diacrylate (for example, SR272, manufactured by Arkema), polyethylene glycol diacrylate (for example, A - 400, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,3 - butanediol dimethacrylate (for example, BG, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,4 - butanediol dimethacrylate (for example, BD, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,6 - hexanediol dimethacrylate (for example, HD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,9 - nonanediol dimethacrylate (for example, NOD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.; Light Acrylate 1,9 - ND - M, manufactured by Kyoeisha Chemical Co., Ltd.), 1,10 - decanediol dimethacrylate (for example, DOD - N, manufactured by Shin - Nakamura Chemical Co., Ltd.), 1,12 - dodecanediol dimethacrylate (for example, SR262, manufactured by Arkema) can be mentioned. From the viewpoint of improving the end - stopping property and enhancing the balance of the flatness of the surface state while further enhancing the element reliability, the linear difunctional (meth)acrylate is one or more (meth)acrylates selected from the group consisting of 1,12 - dodecanediol di(meth)acrylate and 1,9 - nonanediol di(meth)acrylate.

[0039] From the viewpoint of further improving the balance between the improvement of the end - stopping property and the flatness of the surface state, the content of the linear difunctional (meth)acrylate in the resin composition is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, still more preferably 20 parts by mass or more, and even more preferably 25 parts by mass or more with respect to 100 parts by mass of the component (A). From the viewpoint of enhancing the effect of suppressing damage to the element, the content of the linear bifunctional (meth)acrylate in the resin composition is preferably 99.5 parts by mass or less, more preferably 95 parts by mass or less, still more preferably 85 parts by mass or less, and even more preferably 60 parts by mass or less with respect to 100 parts by mass of the component (A).

[0040] (monofunctional (meth)acrylate) From the viewpoint of improving the strength of the resin material obtained from the resin composition, preferably the component (A2) further contains a monofunctional (meth)acrylate. Examples of the monofunctional (meth)acrylate include aromatic ring monofunctional (meth)acrylate; alicyclic monofunctional (meth)acrylate; linear monofunctional (meth)acrylate, and chain monofunctional (meth)acrylate such as monofunctional (meth)acrylate having a branched chain.

[0041] As monofunctional (meth)acrylates, more specifically, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate (e.g., FA-511AS, manufactured by Hitachi Chemical Co., Ltd.), dicyclopentenyl oxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, isooctyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, methoxy triethylene glycol (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethoxyethyl (meth)acrylate, butoxyethyl (meth)acrylate, ethoxy diethylene glycol (meth)acrylate, methoxy dixylyl ethyl (meth)acrylate, ethyl diglycol (meth)acrylate, cyclic trimethylolpropane formal mono(meth)acrylate, imide (meth)acrylate, isoamyl (meth)acrylate, ethoxylated succinic acid (meth)acrylate, trifluoroethyl (meth)acrylate, ω-carboxypolycaprolactone mono(meth)acrylate, cyclohexyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate (e.g., S-1800A, manufactured by Shin-Nakamura Chemical Co., Ltd.), diethylene glycol monobutyl ether (meth)acrylate, lauryl (meth)acrylate (e.g., LA, manufactured by Osaka Organic Chemical Industry Co., Ltd.), isodecyl (meth)acrylate, isooctyl (meth)acrylate, octyl / decyl (meth)acrylate, tridecyl (meth)acrylate, caprolactone (meth)acrylate, ethoxylated (4) nonylphenol (meth)acrylate, methoxypolyethylene glycol (350) mono(meth)acrylate, methoxypolyethylene glycol (550) mono(meth)acrylate, phenoxyethyl (meth)acrylate,Cyclohexyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, methylphenoxyethyl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, tribromophenyl (meth)acrylate, ethoxylated tribromophenyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, ethylene oxide adduct of 2-phenoxyethyl (meth)acrylate, propylene oxide adduct of 2-phenoxyethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-methacryloyloxymethylcyclohexene oxide, 3-(meth)acryloyloxymethylcyclohexene oxide, ethoxylated-o-phenylphenol (meth)acrylate (for example, A-LEN-10, manufactured by Shin-Nakamura Chemical Co., Ltd.), etc. are mentioned.

[0042] From the viewpoints of improving the end-stopping property and achieving both flatness of the surface state, the content of the monofunctional (meth)acrylate in the resin composition is preferably 20 parts by mass or less, more preferably 17 parts by mass or less, still more preferably 15 parts by mass or less, with respect to 100 parts by mass of component (A). Also, the content of the monofunctional (meth)acrylate in the resin composition may be, for example, 0.1 part by mass or more with respect to 100 parts by mass of component (A).

[0043] From the viewpoint of improving the strength of the cured product, the content of component (A) in the resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 85% by mass or more, even more preferably 90% by mass or more, and even more preferably 93% by mass or more, with respect to the total composition of the resin composition. Also, from the viewpoint of improving the weather resistance of the sealing material, the content of component (A) in the resin composition is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, still more preferably 99% by mass or less, and even more preferably 98% by mass or less, with respect to the total composition of the resin composition.

[0044] (Component (B)) Component (B) is a polymerization initiator. From the viewpoint of stably forming a cured product at a low temperature, component (B) is preferably a photo radical polymerization initiator which is a compound that generates radicals by irradiation with ultraviolet rays or visible light. Examples of the photo radical polymerization initiator include acylphosphine oxide-based initiators, oxyphenylacetic acid ester-based initiators, benzoylformic acid-based initiators, and hydroxy phenyl ketone-based initiators.

[0045] Specific examples of the photoinitiator include benzophenone, Michler's ketone, 4,4'-bis(diethylamino)benzophenone, xanthone, thioxanthone, isopropylxanthone, 2,4-diethylthioxanthone, 2-ethylanthraquinone, acetophenone, 2-hydroxy-2-methyl-4'-isopropylpropiophenone, isopropyl benzoin ether, isobutyl benzoin ether, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, camphorquinone, benzanthrone, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, 4,4'-di(t-butylperoxycarbonyl)benzophenone, 3,4,4'-tri(t-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, 3,3',4,4'-tetra(t-hexylperoxycarbonyl)benzophenone, 3,3'-di(methoxycarbonyl)-4,4'-di(t-butylperoxycarbonyl)benzophenone, 3,4'-di(methoxycarbonyl)-4,3'-di(t-butylperoxycarbonyl)benzophenone, 4,4'-di(methoxycarbonyl)-3,3'-di(t-butylperoxycarbonyl)benzophenone, 2-(4'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(2'-methoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-pentyloxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 4-[p-N,N-di(ethoxycarbonylmethyl)]-2,6-bis(trichloromethyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(2'-chlorophenyl)-s-triazine, 1,3-bis(trichloromethyl)-5-(4'-methoxyphenyl)-s-triazine, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzothiazole, 2-mercaptobenzothiazole, 3,3'-Carbonylbis(7-diethylaminocoumarin), 2-(o-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetrakis(4-ethoxycarbonylphenyl)-1,2'-biimidazole, 2,2'-bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4-dibromophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 3-(2-methyl-2-dimethylaminopropionyl)carbazole, 3,6-bis(2-methyl-2-morpholinopropionyl)-9-n-dodecylcarbazole, bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy]-ethyl ester, oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester, methyl benzoylformate, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphinic acid ester, 1-[4-(phenylthio)phenyl]-1,2-octanedione 2-(O-benzoyloxime)], 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-ethanone-1-(O-acetyloxime), etc.

[0046] Among these, from the viewpoint of improving curability, the photopolymerization initiator is preferably 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-1-propanone, 2,2-dimethoxy-2-phenylacetophenone, oxy and one or more compounds selected from the group consisting of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), and 2,4,6-trimethylbenzoyldiphenylphosphinic acid ester.

[0047] Preferred commercially available photopolymerization initiators include Irgacure 184, Irgacure 651, Irgacure 127, Irgacure 1173, Irgacure 500, Irgacure 2959, Irgacure 754, Irgacure MBF, and Irgacure TPO (all manufactured by BASF), and Omnirad TPO H (manufactured by IGM Resins).

[0048] From the viewpoint of improving curability, the content of component (B) in the resin composition is preferably 0.1 mass% or more, more preferably 0.5 mass% or more, even more preferably 1 mass% or more, and still more preferably 2 mass% or more, based on the total composition of the resin composition. Furthermore, from the viewpoint of improving the storage stability of the resin composition, the content of component (B) in the resin composition is preferably 10 mass% or less, more preferably 8 mass% or less, even more preferably 6 mass% or less, and even more preferably 5 mass% or less, based on the total composition of the resin composition.

[0049] (Other ingredients) In this embodiment, the resin composition may be composed of component (A) and component (B), or may contain other components, such as one or more additives selected from the group consisting of fillers, curing accelerators, plasticizers, heat stabilizers, flame retardants, antistatic agents, antifoaming agents, silane coupling agents, and ultraviolet absorbers. In addition, from the viewpoint of improving bleed-out resistance during heating, the resin composition preferably does not contain a surfactant. In addition, from the viewpoint of preventing penetration into elements and reducing element reliability, the resin composition preferably does not contain a leveling agent.

[0050] Next, a method for producing the resin composition will be described. The method for producing the resin composition is not limited, and may include, for example, mixing component (A) and component (B), and appropriately other components, such as various additives added as needed. Examples of methods for mixing the components include methods in which the components are uniformly kneaded using various known kneading machines, such as a planetary mixer, a homodisper, a universal mixer, a Banbury mixer, a kneader, a two-roll mill, a three-roll mill, or an extruder, either alone or in combination, at room temperature or under heated conditions, under normal pressure, reduced pressure, increased pressure, or in an inert gas stream.

[0051] The resulting resin composition can also be used to form a resin film. For example, the resin composition can be applied to a substrate and then dried. Known techniques such as inkjet printing, screen printing, and dispenser application can be used for application. Drying can be performed, for example, by heating to a temperature at which component (A) does not polymerize. There are no limitations on the shape of the resulting resin film, and it can be, for example, a film or layer.

[0052] In addition, the resulting resin film is suitably used, for example, as a sealing material. The sealing material is, for example, a cured product obtained by curing the resin composition in this embodiment, and more specifically, a photocured product of the resin composition. Examples of the method for photocuring the resin composition include a method of irradiating light using a light source such as a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an excimer laser, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, a sodium lamp, a halogen lamp, a xenon lamp, an LED lamp, a fluorescent lamp, sunlight, an electron beam irradiation device, etc. to cure it.

[0053] In this embodiment, since the resin composition contains component (A) and component (B), by using this, damage to display elements such as organic EL elements can be reduced. Further, according to this embodiment, for example, by using the resin layer obtained from the resin composition as a sealing material, it is also possible to obtain a display device with excellent reliability. Taking an organic EL display device as an example of the display device, the organic EL display device has a layer constituted by a cured product of the resin composition, for example, a sealing layer.

[0054] In addition, the resin composition obtained in this embodiment is, for example, for display elements, and is preferably suitably used for sealing organic EL display elements. By using the resin composition of this embodiment, the end-stopping property in the sealing material of the organic EL display element is improved, the flatness of the surface state is made good, and the generation of dark spots during element light emission is effectively suppressed, thereby improving the element reliability of the organic EL element. That is, it is possible to achieve both the printability when the sealing material of the organic EL display element is inkjet-printed and the element reliability of the organic EL element. Hereinafter, a configuration example of a display device will be given taking an organic EL display device as an example.

[0055] (Organic EL display device) In this embodiment, the organic EL display device has a layer composed of a cured product of a sealant. By protecting the organic EL element with a resin layer obtained by curing the ultraviolet curable resin composition of this embodiment, it is possible to sufficiently prevent moisture from entering the organic EL element and maintain high performance and durability of the organic EL element.

[0056] The organic EL display device may have a top emission structure or a bottom emission structure. The organic EL element is disposed on a substrate and is preferably coated with an inorganic material film in advance so as to cover the region including the organic EL element before being protected by a resin layer obtained by curing the ultraviolet curable resin composition in this embodiment.

[0057] FIG. 1 is a cross-sectional view showing a configuration example of the organic EL display device in this embodiment. The display device 100 shown in FIG. 1 is an organic EL display device, and includes a substrate (base material layer 50), an organic EL element (light emitting element 10) disposed on the base material layer 50, and a sealing layer 22 (which may be an overcoat layer 22 or a barrier layer 22) that covers the light emitting element 10. And, for example, the sealing layer 22 is composed of a cured product of the ultraviolet curable resin composition in this embodiment. Also, in FIG. 1, as layers located on the observation side of the light emitting element 10, the display device 100 has a barrier layer 21 (which may be a touch panel layer 21 or a surface protection layer 21), a sealing layer 22 (which may be an overcoat layer 22 or a barrier layer 22), a planarization layer 23 (which may be a sealing layer 23), and a barrier layer 24. The planarization layer 23 is provided on the base material layer 50 so as to cover the light emitting element 10, and the barrier layer 24 is provided on the surface of the planarization layer 23. The sealing layer 22 is provided on the base material layer 50 so as to cover the planarization layer 23 and the barrier layer 24. Also, a barrier layer 21 is provided on the sealing layer 22.

[0058] The material of the base layer 50 is not limited, and various materials such as a glass substrate, a silicon substrate, and a plastic substrate can be used, for example. A TFT substrate provided with a plurality of TFTs (thin film transistors) and a planarization layer on the substrate can also be used.

[0059] Examples of the inorganic material that constitutes the barrier layer 24, that is, the aforementioned inorganic material film, include silicon nitride (SiN x ), silicon oxide (SiO x ), aluminum oxide (Al2O3), and the like. The inorganic material film may be a single layer or a laminate of a plurality of layers. Examples of the method of coating the light-emitting element 10 with the inorganic material film include a sputtering method and an electron cyclotron resonance (ECR) plasma CVD method when the inorganic material film is made of silicon nitride or silicon oxide, for example.

[0060] Among these, the sputtering method can be performed, for example, using argon, nitrogen, or a mixed gas thereof as a carrier gas under the conditions of room temperature, a power of 50 to 1000 W, and a pressure of 0.001 to 0.1 Torr. Also, the ECR plasma CVD method can be performed, for example, using a mixed gas of SiH4 and O2 or a mixed gas of SiH4 and N2 under the conditions of a temperature of 30°C to 100°C, a pressure of 10 mTorr to 1 Torr, a frequency of 2.45 GHz, and a power of 10 to 1000 W.

[0061] Examples of the method of protecting the light-emitting element 10 with a resin layer obtained by curing the ultraviolet curable resin composition of the present embodiment, for example, the sealing layer 22, include a method of coating and curing a sealing agent on the light-emitting element 10. As the coating method, it is preferable to use an inkjet method. The thickness of the resin layer is not limited, but from the viewpoint of improving the sealing performance and the flexible performance, it is, for example, 0.1 to 50 μm, preferably 1 to 20 μm.

[0062] In the display device 100, in order to enhance the effect of protecting the light-emitting element 10 from moisture and oxygen in the atmosphere, it is preferable to further laminate an inorganic material film (barrier layer 24) on the above-described resin layer. The inorganic material and the forming method for the inorganic material film laminated on the resin layer are the same as those for the inorganic material film covering the light-emitting element 10 described above. The thickness of the inorganic material film formed on the resin layer is not limited, but from the viewpoint of improving the sealing performance, it is, for example, 0.01 to 10 μm, preferably 0.1 to 5 μm.

[0063] In the display device 100, the barrier layer 24 and the sealing layer 22 are provided in the layer located on the observation side with respect to the light-emitting element 10. Since the sealing layer 22 is composed of a resin layer obtained by curing the ultraviolet curable resin composition in the present embodiment, due to the good end-stopping property and surface state of the sealing layer 22, even when making the appearance of the display precise, a display device 100 excellent in manufacturing stability and element reliability can be obtained. Specifically, even when performing a plasma treatment step when forming the barrier layer 24 on the upper part of the sealing layer 22, damage to the barrier layer 24 can be suppressed. Also, for example, the generation of pinholes in the barrier layer 24 which is a SiN x film can be suppressed. For this reason, for example, when stored in a temperature range of about 85°C, outgas is less likely to be generated, so damage to the light-emitting element 10 can be suppressed. Also, since the resin layer itself constituting the sealing layer 22 is less likely to be deteriorated by plasma treatment, damage to the light-emitting element 10 can be suppressed.

Example

[0064] Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited thereto. First, the materials used in the following examples are shown.

[0065] · (Meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton The bifunctional polytetramethylene glycol acrylate 1 represented by the general formula (X) described above: PTMG-65 (Compound name: Polytetramethylene glycol #650 diacrylate, CAS.No.: 52277-33-5), manufactured by Shin-Nakamura Chemical Co., Ltd. · (Meth)acrylate (A2) Bifunctional linear methacrylate 1: SR-262 (1,12-dodecanediol dimethacrylate, CAS.No. 72829-09-5), manufactured by Arkema Mono-functional linear acrylate 1: LA (lauryl acrylate, CAS.No. 2156-97-0), manufactured by Osaka Organic Chemical Industry Co., Ltd. Bifunctional alicyclic methacrylate 1: DCP (tricyclodecane dimethanol dimethacrylate, CAS.No. 43048-08-4), manufactured by Shin-Nakamura Chemical Co., Ltd. Bifunctional alicyclic acrylate 1: A-DCP (tricyclodecane dimethanol diacrylate, CAS.No. 42594-17-2), manufactured by Shin-Nakamura Chemical Co., Ltd. Bifunctional linear acrylate 1: A-NOD-N (1,9-nonanediol diacrylate, CAS.No. 107481-28-7), manufactured by Shin-Nakamura Chemical Co., Ltd. Bifunctional linear methacrylate 2: NOD-N (1,9-nonanediol dimethacrylate, CAS.No. 65833-30-9), manufactured by Shin-Nakamura Chemical Co., Ltd. Mono-functional branched acrylate 1: S-1800A (isostearyl acrylate, CAS.No. 93841-48-6), manufactured by Shin-Nakamura Chemical Co., Ltd. Bifunctional linear acrylate 2: SR508 (dipropylene glycol diacrylate), manufactured by Ciba Specialty Chemicals Bifunctional linear acrylate 3: SR306H (tripropylene glycol diacrylate), manufactured by Ciba Specialty Chemicals · Polymerization initiator (B) Polymerization initiator 1: Omnirad TPO H (CAS.No. 75980-60-8), manufactured by IGM Resins · Silane coupling agent Silane coupling agent 1: KBM5103 (3-acryloxypropyltrimethoxysilane, CAS.No. 4369-14-6), manufactured by Shin-Etsu Chemical Co., Ltd. ·Leveling agent Leveling agent 1: Polyflow No. 90 (acrylic copolymer), manufactured by Kyoeisha Chemical Co., Ltd.

[0066] (Examples 1 - 6, Comparative Examples 1 - 7) Each component was blended so as to have the composition shown in Table 1 to obtain a liquid ultraviolet curable resin composition. The properties of the resin composition or its cured product obtained in each example were measured by the following methods. The measurement results are shown in accordance with Table 1.

[0067] (Viscosity) The viscosity of the resin composition obtained in each example was measured at 25°C and 20 rpm using an E-type viscometer (LV-DV-II+ Pro, manufactured by BROOKFIELD).

[0068] (Production of evaluation samples) For the evaluation samples of pinholes, end linearity, and end width, cured products used as evaluation samples were formed by the following procedure. That is, the resin composition obtained in each example was introduced into an inkjet head (KM1024IMHE, manufactured by Konica Minolta). After adjusting the ejection state, it was applied onto an alkali-free glass whose surface had been subjected to vacuum plasma treatment, with a size of 30 mm in width × 30 mm in length so that the cured thickness would be 10 μm, to obtain a coating film. The obtained coating film was left at room temperature (25°C) for 3 minutes while purging with nitrogen, and then cured with a UV-LED having a wavelength of 395 nm at an illuminance of 100 mW / cm 2 , and an integrated light quantity of 1500 mJ / cm 2 to obtain a cured product.

[0069] (Pinholes) For the cured products obtained in each example, the pinholes on the surface of the cured product were visually evaluated as an index of the flatness of the surface state. Also, using a scanning white interferometer (VertScan, manufactured by Mitsubishi Chemical Systems Co., Ltd.), the presence or absence of foreign matter inside the pinholes was confirmed, and pinholes without foreign matter were counted. The evaluation criteria are shown below. A: No pinholes are generated B: Pinholes are partially generated C: Pinholes are generated over the entire surface.

[0070] (End linearity) For the cured products obtained in each example, the linearity of the cured product end was visually evaluated. The evaluation criteria are shown below. A: The end is linear. B: Some disorder is seen at the end. C: The end is greatly disordered like waves.

[0071] (End width) As an index of end stopping property, the end width was evaluated as follows. For the cured products obtained in each example, using a stylus type step gauge (Alpha-Step, manufactured by KLA-Techore), scanning was performed in a direction perpendicular to the end, and the width between the point where the surface of the cured product starts to rise and the point where the rise of the surface ends was measured as the width (μm) of the cured product. The width obtained by subtracting the target width (μm) from the width (μm) of the cured product was calculated as the end spread width (μm), and the end spreading property was evaluated according to the following criteria. A: The end spread width is 600 μm or less. B: The end spread width is 700 μm to 900 μm. C: The end spread width is 1000 μm or more.

[0072] (Element reliability (OLED damage)) As an index of EL element damage, the reliability of the organic EL display element was evaluated by the following method. For the glass substrate on which the ITO electrode was formed, after the above substrate was treated with a UV-ozone treatment apparatus (manufactured by Sen Special Light Source Co., Ltd., PL21-200(S) / UVE-200J), ultrasonic cleaning was performed for 15 minutes each in an alkaline aqueous solution, pure water, acetone, and isopropyl alcohol, and finally ultrasonic cleaning was performed in acetone for 10 minutes. Next, fix this substrate to the substrate holder of a vacuum evaporation apparatus. Put 200 mg of Dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11,hexacarbonitrile (HAT-CN) into a fired crucible and 200 mg of 9-Phenyl-3,6-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (Tris-PCz) into another fired crucible. Reduce the pressure inside the vacuum chamber to 1×10 -4 Pa. Then, heat the crucible containing HAT-CN and deposit HAT-CN on the substrate at a deposition rate of 0.4 Å / s to form a film with a thickness of 100 nm. Subsequently, heat the crucible containing Tris-PCz and deposit it on the substrate at a deposition rate of 1.0 Å / s to form a film with a thickness of 400 nm. Next, put 200 mg of Tris(8-hydroxyquinolinato)aluminium (Alq3) into another fired crucible and reduce the pressure inside the vacuum chamber to 1×10 4 Pa again. Then, heat the crucible containing Alq3 and deposit a thick film with a thickness of 700 nm at a deposition rate of 0.5 Å / s. After that, put 200 mg of lithium fluoride into a tungsten resistive heating boat, reduce the pressure of the vacuum chamber to 1×10 -4 Pa, and deposit 5 nm of lithium fluoride at a deposition rate of 0.03 Å / s. Finally, put 1 g of magnesium and 200 mg of silver into a tungsten resistive heating boat, reduce the pressure of the vacuum chamber to 1×10 -4 Pa, and deposit 150 nm at a deposition rate of 0.9 Å / s for magnesium and 0.1 Å / s for silver so that the ratio of magnesium / silver is 1 / 9. Return the pressure inside the evaporator to atmospheric pressure with nitrogen, and take out the substrate on which a laminate having an 8 mm×8 mm organic light-emitting material layer is disposed.

[0073] For the laminate having this organic light-emitting material layer, under a nitrogen atmosphere, drop 30 mg of the resin composition obtained in each example as a sealing material, cover it with glass, and irradiate it with light having a wavelength of 395 nm at 400 mW for 4 seconds using a UV irradiation device to cure the sealing material and obtain an organic EL display element. The obtained organic EL display element was exposed in an environment at a temperature of 85°C for 500 hours, and then a voltage of 3V was applied, and the light emission state of the organic EL display element was visually confirmed. The evaluation criteria are shown below. A: No dark spots are generated during element light emission. B: Some dark spots are generated during element light emission. C: Dark spots are generated on most of the surface during element light emission.

[0074] (Bleed-out) The presence or absence of bleed-out under high-temperature conditions was evaluated by the following procedure. 1. The resin composition obtained in each example was applied to a 50 mm × 50 mm non-alkali glass using a spin coater to an average film thickness of 8 μm. 2. It was enclosed in a nitrogen purge box, and nitrogen was flowed for 3 minutes. 3. It was irradiated with 1500 mW 5600 mJ (UVA2) and cured. 4. It was placed in a thermo-hygrostat at 110°C, taken out after 1000 hours. 5. Regarding the surface of the obtained cured film, the presence or absence of bleed-out was evaluated according to the following criteria. Evaluation criteria: A: No bleed-out occurs on the surface. B: Bleed-out occurs on the surface.

[0075] [Table 1]

[0076] From Table 1, the resin compositions obtained in each example were excellent in the balance of improving the end-stopping property, flatness of the surface state, and element reliability. [Explanation of symbols]

[0077] 10 Light-emitting element 21 Barrier layer, touch panel layer, or surface protection layer 22 Encapsulation layer, overcoat layer, or barrier layer 23 Planarization or sealing layer 24 Barrier layer 50 Base material layer 100 display device

Claims

1. An ultraviolet-curable resin composition containing a polymerizable compound (A) and a polymerization initiator (B), wherein the polymerizable compound (A) includes a (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton, the content of the (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton in the ultraviolet-curable resin composition is 20 parts by mass or less with respect to 100 parts by mass of the polymerizable compound (A) of the ultraviolet-curable resin composition, the (meth)acrylate (A1) containing a polytetramethylene ether glycol skeleton contains two or more polytetramethylene ether glycol skeletons, an ultraviolet-curable resin composition used for coating by an inkjet method (however, an active energy ray-curable composition containing N-substituted (meth)acrylamide (A), a bifunctional (meth)acrylate (B) represented by the general formula (1), a bifunctional (meth)acrylate (C) represented by the general formula (2), a trifunctional or tetrafunctional (meth)acrylate (D), a phosphoric acid (meth)acrylate (E) and an acylphosphine photoinitiator (F), wherein the (D) is a trifunctional or tetrafunctional (meth)acrylate which is an ester of at least one polyhydric alcohol selected from the group consisting of glycerin, trimethylolpropane, pentaerythritol and alkylene oxide adducts thereof and (meth)acrylic acid, the addition mole number of the alkylene oxide adduct is an integer of 1 to 4, the content of the (A) is 5% by weight to 60% by weight based on the total weight of the (A) to (E), the content of the (B) is 15% by weight to 60% by weight based on the total weight of the (A) to (E), the content of the (C) is 12% by weight to 60% by weight based on the total weight of the (A) to (E), the content of the (D) is 0.5% by weight to 6% by weight based on the total weight of the (A) to (E), and the content of the (E) is 0.5% by weight to 6% by weight based on the total weight of the (A) to (E) is excluded). CH₂=CR₂-COO-(R₁O)ₙ-COCR₂=CH₂ (1) [In the general formula (1), R₁ represents an alkylene group having 2 to 4 carbon atoms, n is an integer of 2 to 4, a plurality of R₁ may be the same or different, and two R₂ are each independently a hydrogen atom or a methyl group.] CH₂=CR⁴-COO-R³-OCOCR⁴=CH₂ (2) [In general formula (2), R³ represents an alkylene group having 5 to 10 carbon atoms, and the two R⁴s are each independently a hydrogen atom or a methyl group.].

2. The viscosity measured by an E-type viscometer under the conditions of 25°C and 20 rpm is 4 mPa·s or more and 50 mPa·s or less, The ultraviolet curable resin composition according to claim 1.

3. The (meth)acrylate (A1) containing the polytetramethylene ether glycol skeleton is a bifunctional or higher functional (meth)acrylate, The ultraviolet curable resin composition according to claim 1 or 2.

4. The polymerizable compound (A) further contains a (meth)acrylate (A2) other than the (meth)acrylate (A1) containing the polytetramethylene ether glycol skeleton, and the ultraviolet curable resin composition according to any one of claims 1 to 3.

5. The (meth)acrylate (A2) contains a bifunctional (meth)acrylate, and the ultraviolet curable resin composition according to claim 4.

6. The (meth)acrylate (A2) contains both a bifunctional acrylate and a bifunctional methacrylate, and the ultraviolet curable resin composition according to claim 4 or 5.

7. The (meth)acrylate (A2) contains both an alicyclic bifunctional (meth)acrylate and a linear bifunctional (meth)acrylate, and the ultraviolet curable resin composition according to any one of claims 4 to 6.

8. The (meth)acrylate (A2) further contains a monofunctional (meth)acrylate, and the ultraviolet curable resin composition according to any one of claims 5 to 7.

9. The polymerization initiator (B) contains a photo radical polymerization initiator, and the ultraviolet curable resin composition according to any one of claims 1 to 8.

10. The photo radical polymerization initiator contains 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO), and the ultraviolet curable resin composition according to claim 9.

11. It is for a display element, and the ultraviolet curable resin composition according to any one of claims 1 to 10.

12. The display element is an organic electroluminescence element, and the ultraviolet curable resin composition according to claim 11.

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