JP2005336313A - Photocurable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocurable resin composition which can be used very suitably as an encapsulant of an organic EL element of the top emission type and which can give a cured product very little of coloring and high in transparency. <P>SOLUTION: The photocurable resin composition contains a photocationic polymerizable compound and an onium borate complex consisting of an onium cation that has iodine or sulfur as the center element. In the above onium cation at least one aryl group is bonded through an alkyl group to the center element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a photocurable resin composition capable of obtaining a cured product having very little coloration and high transparency.

Photocurable resin compositions are widely used for applications such as adhesives. In particular, in recent years, it has attracted attention as a sealing agent for organic electroluminescence elements.
An organic electroluminescent element (organic EL element) has a laminated structure in which an organic light emitting material layer is sandwiched between a pair of electrodes facing each other, and electrons are injected from one electrode into the organic light emitting material layer. By injecting holes from the other electrode, electrons and holes are combined in the organic light emitting material layer to emit light. Thus, since an organic EL element performs self-luminescence,
As a next-generation display, it has the advantages that it has better visibility than a liquid crystal display element that requires a backlight, can be thinned, and can be driven by low-voltage direct current. Yes.

However, in organic electroluminescent elements, the characteristics of organic light-emitting materials and electrodes constituting the laminate are likely to deteriorate due to oxidation by moisture, etc., and when driven in the air, the light-emitting characteristics deteriorate rapidly and the lifetime is short. there were. Therefore, in a general organic EL element, a lid made of glass or metal in which a desiccant is installed is put on the laminate, and the periphery thereof is an adhesive (sealing agent).
The structure which blocked | prevented the penetration | invasion of a water | moisture content by sealing by was taken. In this method, light emitted from the laminated body is taken out from the opposite side of the lid, that is, from the bottom side of the organic EL element, so that it is also called a bottom emission method (for example, Patent Document 1).

On the other hand, in recent years, attention has been paid to a top emission type organic EL element that takes out light emitted from a laminate from the upper surface side, instead of a conventional bottom emission type organic EL element.
This method has an advantage that it has a high aperture ratio and is driven at a low voltage, which is advantageous for extending the life. In such a top emission type organic EL device, usually, the laminate is sandwiched between two moisture-proof substrates made of a transparent material such as glass, and the space between the moisture-proof substrates is filled with a sealant. (For example, patent document 2 etc.).

The organic EL element sealant has a sufficiently low moisture permeability to ensure the lifetime of the organic EL element, and is highly transparent so that light emitted from the organic EL element can be extracted without losing as much as possible. In addition, it is required that the coloring be as small as possible so that accurate color reproduction can be achieved. However, a cured product obtained by curing a conventional photocurable resin composition is inevitably slightly colored, and cannot satisfy the performance required for a sealing agent for an organic EL element.

Japanese Patent Laid-Open No. 9-148066 JP 2001-375773 A

As a result of intensive studies, the present inventors have so far used a photocurable resin composition containing a photocationically polymerizable compound and an onium borate complex composed of an onium cation having iodine or sulfur as a central element. The present inventors have found that a cured product having extremely high curability and less transparency and high transparency can be obtained. The cured product obtained by curing the photo-curable resin composition was excellent in moisture resistance, and thus was considered suitable as a sealing agent for organic EL elements.

However, due to intense competition with liquid crystal elements, the performance required for organic EL elements is becoming stricter year by year, and the organic EL element sealant is required to be even less colored. It has become like this.
An object of this invention is to provide the photocurable resin composition which can obtain hardened | cured material with very little coloring and high transparency in view of the said present condition.

The present invention is a photocurable resin composition comprising a photocationically polymerizable compound and an onium borate complex composed of an onium cation having iodine or sulfur as a central element, wherein the onium cation is at least 1 in the central element. It is a photocurable resin composition in which two aryl groups are bonded via an alkyl group.
The present invention is described in detail below.

As a result of further intensive studies, the present inventors have used, as a cationic polymerization initiator, an onium borate complex composed of an onium cation in which at least one aryl group is bonded to the central element iodine or sulfur via an alkyl group. In some cases, it was found that a cured product having extremely excellent transparency and very little coloring was obtained, and the present invention was completed.
Conventionally, when an onium borate complex composed of an onium cation having iodine or sulfur as a central element is used as a cationic polymerization initiator, it is necessary to have at least one aryl group for the purpose of adjusting the photosensitive area. It seems that sometimes the central element and the benzene ring of the aryl group interacted to cause coloring. On the other hand, in the present invention, when an alkyl group is interposed between the aryl group and the central element, such an interaction does not occur, and excellent performance as a photo radical polymerization initiator is maintained. It seems that a cured product with less coloring can be produced.

The alkyl group interposed between the aryl group and the central element is not particularly limited, and may be linear, branched or cyclic.
The upper limit with preferable carbon number of the said alkyl group is 18. If it exceeds 18, the solubility in the resin is deteriorated, and the curability may be affected, or undissolved substances may remain as impurities.

Although it does not specifically limit as another group couple | bonded with the central element of the said onium cation, An alkyl group or an aryl group is suitable. However, when the other group includes an aryl group, the aryl group is preferably not bonded directly to the central element but bonded via an alkyl group.

Although it does not specifically limit as an onium cation of the said onium borate complex, For example, what is represented by the following general formula (1-1), (1-2), (1-3), and general formula (2-1)
And those represented by (2-2).

式（１−１）、（１−２）、（１−３）中、Ａｒはアリール基を表し、Ｒ^１は、炭素数１
〜１８の直鎖状、分岐状又は環状のアルキル基を表し、Ｒ^２、Ｒ^３は、アルキル基又はア
リール基を表す。
式（２−１）、（２−２）中、Ａｒはアリール基を表し、Ｒ^４は、炭素数１〜１８の直鎖
状、分岐状又は環状のアルキル基を表し、Ｒ^５は、アルキル基又はアリール基を表す。

In formulas (1-1), (1-2), and (1-3), Ar represents an aryl group, and R ¹ has 1 carbon atom.
Represents a linear, branched or cyclic alkyl group of -18, and R ² and R ³ represent an alkyl group or an aryl group.
In formulas (2-1) and (2-2), Ar represents an aryl group, R ⁴ represents a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, and R ⁵ represents an alkyl group. Represents a group or an aryl group.

Although it does not specifically limit as a counter ion of the onium cation in the said onium borate complex, The anion represented by following General formula (3) is suitable.

式（３）中、Ｂは、３価のホウ素を表し、Ｒ^６〜Ｒ^９の少なくとも１個は、炭素数６〜３
０のハロゲン置換芳香族基を表す。
上記オニウムボレート錯体におけるオニウムカチオンの対イオンが、このようなホウ素を
中心元素とするものである場合には、光カチオン重合開始剤として用いたときの酸強度が
強くなるため、光硬化性樹脂組成物の硬化性が向上し、高いガラス転移温度を有する硬化
物を得ることができる。その結果、光硬化性樹脂組成物の硬化物の透湿性（透湿度）が低
下するため、この光硬化性樹脂組成物を用いて作製した例えば有機ＥＬ素子の寿命を長く
することができ、信頼性を高めることができる。

In formula (3), B represents trivalent boron, and at least one of R ^{6 to} R ^{9 has 6} to 3 carbon atoms.
0 represents a halogen-substituted aromatic group.
When the counter ion of the onium cation in the onium borate complex is one having such a boron as a central element, the acid strength when used as a photocationic polymerization initiator is increased, so that the photocurable resin composition The curability of the product is improved, and a cured product having a high glass transition temperature can be obtained. As a result, since the moisture permeability (moisture permeability) of the cured product of the photocurable resin composition is lowered, the lifetime of, for example, an organic EL device produced using this photocurable resin composition can be increased, Can increase the sex.

In the general formula (3), at least one of R ^{6 to} R ⁹ is a halogen-substituted aromatic group having 6 to 30 carbon atoms. Although it does not specifically limit as said aromatic group, For example, a phenyl group, a naphthyl group, an anthracenyl group etc. are mentioned. In addition, as a halogen substituent,
Although not particularly limited, for example, chlorine, fluorine and the like can be mentioned, among which fluorine is preferably used. The halogen substituent may be a halogen group directly bonded to the aromatic ring of the aromatic group, or it is introduced as a part of another substituent as in the case of a halo-hydrocarbyl substituent. There may be a fluoro-hydrocarbyl substituent among them.

Although it does not specifically limit as a boron center anion represented by the said General formula (3), For example,
[3,5- (CF ₃ ) ₂ C ₆ H ₃ ] ₄ B ⁻ , (C ₆ F ₅ ) ₄ B ⁻ , (C ₆ H ₄ -p-CF
^{_{3) 4 B -, (C}} 6 H 4 -m-CF 3) 4 B -, (C 6 H 4 -p-F) 4 B -, (C 6
^{_{F 5) 3 (CH 3)}} B -, (C 6 F 5) 3 (n-C 4 H 9) B -, (C 6 H 4 -p-CH
₃ ) ₃ (C ₆ F ₅ ) B ⁻ , (C ₆ F ₅ ) ₃ FB ⁻ , (C ₆ H ₅ ) ₃ (C ₆ F ₅ ) B ⁻ , (
_{CH 3) 2 (C 6 H} 4 -p-CF 3) 2 B -, (C 6 F 5) 3 (n-C 18 H 37 O) B
^- and the like are suitable.

The preferred boron center anion contains three or more halogen-substituted aromatic groups bonded to boron, and fluorine is most preferred as the halogen substituent. Examples of the most preferred boron center anion include, for example, [3,5- (CF ₃ ) ₂ C ₆ H ₅ ] ₄ B ⁻ , (C
^{_{6 F 5) 4 B -,}} (C 6 F 5) 3 (CH 3) B -, (C 6 F 5) 3 (n-C 4 H 9) B -
_{, (C 6 F 5) 3} FB - , and the like.

The boron center anion molecular weight represented by the general formula (3) is preferably 400 or more. When the molecular weight is less than 400, the molecules easily move, and when the photocurable resin composition of the present invention using the onium borate complex as a photocationic polymerization initiator is used in the production of an organic EL device, electrode corrosion is caused. It may happen.

As a counter ion of the onium cation in the onium borate complex, the general formula (
In addition to the boron center anion represented by 3), for example, [3,5- (CF ₃ ) ₂ C ₆ H _{3
^{] 4 Al -, (C 6}} F 5) 4 Al -, (C 6 F 5) 2 F 4 P -, (C 6 F 5) F 5 Sb -
, (C ₆ F ₅ ) F ₅ P ^{− and the} like; other boron-centered non-nucleophilic salts; other useful anions containing other metals and metalloids, and the like can also be used.

The preferable lower limit of the absorption wavelength of the onium borate complex is 300 nm, and the preferable upper limit is 40.
0 nm. In the photocurable resin composition of the present invention using the onium borate complex as a photocationic polymerization initiator, the ordinary light using a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, or the like as a light source. When used, curing may be insufficient. If it absorbs light having a wavelength exceeding 400 nm, coloring may occur in the course of curing.

The photocurable resin composition of the present invention contains a photocationically polymerizable compound.
The photocationically polymerizable compound is not particularly limited as long as it has at least one photocationically polymerizable functional group in the molecule. For example, at least one epoxy group or oxetanyl group in the molecule. , Compounds having a hydroxyl group, a vinyl ether group, an episulfide group, an ethyleneimine group, and the like. Among them, since it has high photocationic polymerizability and photocuring proceeds efficiently even with a small amount of light, it is a compound having at least one epoxy group in the molecule (hereinafter also referred to as an epoxy compound), or in the molecule. A compound having at least one oxetanyl group (hereinafter also referred to as an oxetanyl compound) is preferably used.
The property (molecular weight) of these photocationically polymerizable compounds is not particularly limited and may be any of a monomer, an oligomer and a polymer. Moreover, these photocationic polymerizable compounds may be used independently and 2 or more types may be used together.

The epoxy compound is not particularly limited. For example, bisphenol type epoxy resins such as bisphenol A type epoxy resin and bisphenol F type epoxy resin; novolak type epoxy resins such as phenol novolac type epoxy resin and cresol novolak type epoxy resin; Group epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, polyfunctional epoxy resin, biphenyl type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin; hydrogenated bisphenol A
Type epoxy resins, alcohol type epoxy resins, halogenated epoxy resins such as brominated epoxy resins, rubber-modified epoxy resins, urethane-modified epoxy resins, epoxidized polybutadiene, epoxidized styrene-butadiene-styrene block copolymers, containing epoxy groups Examples include polyester resins, epoxy group-containing polyurethane resins, epoxy group-containing acrylic resins, and the like. These epoxy compounds may be used alone or in combination of two or more.

Examples of commercially available epoxy compounds include trade names “Epicoat 806”, “Epicoat 828”, and “Epicoat 1001” manufactured by Japan Epoxy Resin Co., Ltd.
"Epicoat" series such as "Epicoat 1002" and "Celoxide" series such as "Celoxide 2021" manufactured by Daicel Chemical Industries.

The oxetanyl compound is not particularly limited, and examples thereof include phenoxymethyl oxetane, 3,3-bis (methoxymethyl) oxetane, 3,3-bis (phenoxymethyl) oxetane, and 3-ethyl-3- (phenoxymethyl) oxetane. , 3-ethyl-3- (2-
Ethylhexyloxymethyl) oxetane, 3-ethyl-3-{[3- (triethoxysilyl) propoxy] methyl} oxetane, di [1-ethyl (3-oxetanyl)] methyl ether, oxetanylsilsesquioxane, phenol novolak Oxetane, 1,4-
And bis {[(3-ethyl-3-oxetanyl) methoxy] methyl} benzene. These oxetanyl compounds may be used alone or in combination of two or more.

As the photo cationic polymerizable compound other than the epoxy compound and the oxetanyl compound,
For example, epoxides, cyclic ethers, vinyl ethers, vinylamines, unsaturated hydrocarbons, lactones and other cyclic esters, lactams, cyclic carbonates, cyclic acetals, aldehydes, cyclic amines, cyclic sulfides , Cyclosiloxanes,
At least one of cyclotriphosphazenes and other photocationically polymerizable groups and monomers
Examples thereof include a photocationically polymerizable compound having one photocationically polymerizable group. Among these, cyclic ether monomers such as epoxide monomers and vinyl organic monomers are preferably used.

In the photocurable resin composition of the present invention, the compounding ratio of the photocationically polymerizable compound and the onium borate complex is not particularly limited, but the compounding amount of the onium borate complex with respect to 100 parts by weight of the photocationic polymerizable compound is not limited. A preferred lower limit is 0.1 parts by weight and a preferred upper limit is 10 parts by weight. When the amount is less than 0.1 parts by weight, the photocationic polymerization of the photocationically polymerizable compound may not sufficiently proceed, or the photocuring of the photocurable resin composition may be too slow. The photo-curing of the photo-curable resin composition becomes too fast, and the workability may be deteriorated or a non-uniform cured product may be easily obtained. A more preferred lower limit is 0.4 parts by weight, and a more preferred upper limit is 5 parts by weight.

The photocurable resin composition of the present invention may contain a photosensitizer as necessary as long as the object of the present invention is not impaired. The photosensitizer is not particularly limited, and examples thereof include carbonyl compounds, organic sulfur compounds, persulfides, redox compounds, azo compounds, diazo compounds, halogen compounds, and photoreductive dyes. Specifically, for example, benzoin derivatives such as benzoin methyl ether and benzoin isopropyl ether; benzophenone, 2,4-
Benzophenone derivatives such as dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis (dimethylamino) benzophenone; thioxanthone derivatives such as 2-chlorothioxanthone and 2-isopropylthioxanthone; 2-chloroanthraquinone, 2-methylanthraquinone And anthraquinone derivatives. These photosensitizers may be used independently and 2 or more types may be used together.
The minimum with preferable content of the said photosensitizer in the photocurable resin composition of this invention is 1 weight part with respect to 100 weight part of photocationic polymerization initiators, and a preferable upper limit is 500 weight part. A more preferred lower limit is 10 parts by weight, and a more preferred upper limit is 100 parts by weight.

The photocurable resin composition of the present invention preferably further contains a curing control agent. By containing an appropriate amount of curing control agent, it functions as a reaction regulator that controls the usable time and curing time after light irradiation, and can greatly improve the workability of the photocurable resin composition. it can.
The curing control agent is not particularly limited, and examples thereof include aliphatic hydrocarbons having a hydroxyl group and polyether compounds. These hardening control agents may be used independently and 2 or more types may be used together.

The aliphatic hydrocarbon having a hydroxyl group is not particularly limited, and examples thereof include polyfunctional hydroxyl group-containing compounds such as glycerin and pentaerythritol.
It does not specifically limit as said polyether compound, For example, polyalkylene oxides, such as polyethyleneglycol, polypropylene glycol, polyoxytetramethylene glycol, crown ether, etc. are mentioned.

Among these, polyalkylene oxide and crown ether are preferably used, and polyoxytetramethylene glycol is more preferably used as the polyalkylene oxide.
The terminal of the polyalkylene oxide is not particularly limited, and may be a hydroxyl group, etherified or esterified with another compound, or a functional group such as an epoxy group. Especially, since it has the reactivity with the said photocationic polymerizable compound, a hydroxyl group and an epoxy group are suitable.
In addition, polyalkylene oxide-added bisphenol derivatives can also be suitably used,
In particular, polyalkylene oxide-added bisphenol derivatives having a hydroxyl group or an epoxy group at the terminal are more preferred. Among these, as commercial products, for example, trade names “Lika Resin BPO-20E”, “Lika Resin BEO-60E”, “Lika Resin PO—
“Lika Resin” series such as “20”.

Examples of the crown ether include 12-crown-4,15-crown-5,1.
8-crown-6 etc. are mentioned.

The minimum with preferable content of the said hardening control agent in the photocurable resin composition of this invention is 0.1 weight part with respect to 100 weight part of photocationic polymerization initiators, and a preferable upper limit is 100 weight part. A more preferred lower limit is 10 parts by weight, and a more preferred upper limit is 50 parts by weight.

The photo-curable resin composition of the present invention is, for example, an adhesive polymer or an adhesive-imparting agent (for improving the adhesive properties) as necessary within a range not impairing the object of the present invention. Tackifiers), fillers for further improving mechanical properties and durability, viscosity modifiers for adjusting viscosity, thixotropic agents for imparting thixotropic properties (thixotropic properties)
, Physical property modifiers, coupling agents, reinforcing agents, bulking agents, softeners to improve mechanical properties (
Plasticizers), sagging inhibitors, antioxidants (anti-aging agents), heat stabilizers, flame retardants, antistatic agents, organic solvents and the like may be included. Moreover, you may use a general photocationic polymerization initiator together in the range which does not inhibit coloring property.

It does not specifically limit as a method to manufacture the photocurable resin composition of this invention, For example, well-known various kneaders, such as a universal mixer, a Banbury mixer, a kneader, 2 rolls, 3 rolls, an extruder, are used independently. Use or in combination, the photocationically polymerizable compound, onium borate complex and additives blended as necessary, at normal temperature or under heating, under normal pressure, under reduced pressure, under pressure, or under an inert gas stream And a method of uniformly kneading under such conditions.

The photocurable resin composition of the present invention preferably has a wavelength of 300 nm or more, more preferably a wavelength of 3
It hardens | cures by irradiating the light containing light of 00-400 nm.
The light source for irradiating the light is not particularly limited. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an excimer laser, a chemical lamp, a black light lamp, a microwave excited mercury lamp, a metal halide lamp, sodium. Examples thereof include lamps, halogen lamps, xenon lamps, fluorescent lamps, sunlight, and electron beam irradiation devices. These light sources may be used independently and 2 or more types may be used together.

When using these light sources, for example, using a light cut filter or the like, heat rays or a wavelength of 30
It is preferable to remove light of less than 0 nm. Examples of the irradiation procedure of the light source to the photocurable resin composition include simultaneous irradiation of various light sources, sequential irradiation with a time difference, combined irradiation of simultaneous irradiation and sequential irradiation, and the like. An irradiation procedure may be taken.
In curing the photocurable resin composition of the present invention, heating may be performed simultaneously with light irradiation in order to further accelerate the photocationic polymerization of the photocationically polymerizable compound and further shorten the curing time. Although it does not specifically limit as heating temperature in the case of using the said heat curing together, 50-100 degreeC
It is preferable that it is a grade.

In the photocurable resin composition of the present invention, the total light transmittance of the cured product is preferably 80% or more. When it is less than 80%, when the photocurable resin composition of the present invention is used as an encapsulant for an organic EL device, the optical characteristics of the obtained organic EL device may be insufficient.
The total light transmittance is measured with a spectrometer (for example, “AUTOMATIC HAZE manufactured by Tokyo Denshoku Co., Ltd.).
MATER MODEL TC-III DPK ”) and the like.

The photocurable resin composition of the present invention has a light absorption rate of 80% for a cured product having a wavelength of 350 to 700 nm.
The above is preferable. When it is less than 80%, the photocurable resin composition of the present invention is organic E.
When used as an encapsulant for an L element, the optical characteristics of the resulting organic EL element may be insufficient.
The absorption rate of light having a wavelength of 350 to 700 nm is measured by a chromaticity meter (for example, “COL” manufactured by Tokyo Denshoku Co., Ltd.).
OR ANALYZER TC-1800M ") or the like.

The photocurable resin composition of the present invention is 85 ° C.-85 based on JIS Z 0208 of the cured product.
The moisture permeability measured under the condition of% RH is preferably 150 g / m ² · 24 h / 100 μm or less. When it exceeds 150 g / m ² · 24 h / 100 μm, when the photocurable resin composition of the present invention is used as an encapsulant for an organic EL element, the life of the obtained organic EL element may be shortened.

The use of the photocurable resin composition of the present invention is not particularly limited. For example, an adhesive, a sealant,
It can be suitably used for various applications such as single-sided tapes, double-sided tapes, sealing films, sealing agents, coating agents, lining agents, printing inks, and electronic materials. Especially, it is preferable to use as an adhesive agent or a sealing agent. Moreover, it can use suitably for transparent or translucent structures, such as a display part, using these adhesive agents, sealing agents, single-sided tapes, double-sided tapes, sealing films and the like. Especially, it is very suitable as a sealing agent for top emission type organic EL elements.
The sealing agent using the photocurable resin composition of the present invention is also one aspect of the present invention.
The display element using the photocurable resin composition or sealant of the present invention is also one aspect of the present invention. Examples of such display elements include organic EL elements.

According to the present invention, it is possible to provide a photocurable resin composition capable of obtaining a cured product with extremely little coloration and high transparency.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
(1) Preparation of onium borate complex Sodium tetrakis (pentafluorophenyl) was dissolved in 50 parts by weight of distilled water with 0.213 parts by weight of diphenyl (benzyl) sulfonium chloride and stirred at 20 ° C.
50 parts by weight of an aqueous solution containing 1 part by weight of borate was added dropwise over 10 minutes. The produced white crystals were filtered, washed with distilled water, and then dried under reduced pressure to obtain an onium borate complex represented by the following formula (4).

（２）光硬化性樹脂組成物の調製
ビスフェノールＦ型エポキシ樹脂（商品名「エピコート８０６」、ジャパンエポキシレジ
ン社製）１００重量部に対して、得られたオニウムボレート錯体４重量部及び光増感剤（
商品名「ＤＥＴＸ−Ｓ」、日本化薬社製）０．１重量部を添加し、均一に攪拌混練した後
、脱泡して、光硬化性樹脂組成物を製造した。

(2) Preparation of photocurable resin composition 4 parts by weight of the obtained onium borate complex and photosensitization with respect to 100 parts by weight of bisphenol F type epoxy resin (trade name “Epicoat 806”, manufactured by Japan Epoxy Resin Co., Ltd.) Agent (
0.1 part by weight of a trade name “DETX-S” (manufactured by Nippon Kayaku Co., Ltd.) was added, and the mixture was uniformly stirred and kneaded and then defoamed to produce a photocurable resin composition.

(Comparative Example 1)
Photocationic polymerization initiator (trade name) containing iodine (I) represented by the following formula (5) with respect to 100 parts by weight of bisphenol F type epoxy resin (trade name “Epicoat 806”, manufactured by Japan Epoxy Resin Co., Ltd.) After adding 0.6 parts by weight of “Rhotoinitiator 2074” (manufactured by Rhodia) and 0.1 part by weight of a photosensitizer (trade name “DETX-S”, manufactured by Nippon Kayaku Co., Ltd.), the mixture was stirred and kneaded uniformly, It foamed and the photocurable resin composition was manufactured.

（比較例２）
（１）オニウムボレート錯体の調製
常温下で、トリフェニルスルホニウムブロマイド２００ｍｇを含有する水溶液に対して、
ソジウムテトラキス（ペンタフルオロフェニル）ボレートの１０重量％水分散液５ｇを滴
下した。その後、遠心分離を５回行って、生成した沈殿物を濾別し、精製した後、乾燥し
て、下記式（６）で表されるオニウムボレート錯体を得た。

(Comparative Example 2)
(1) Preparation of onium borate complex With respect to an aqueous solution containing 200 mg of triphenylsulfonium bromide at room temperature,
5 g of a 10 wt% aqueous dispersion of sodium tetrakis (pentafluorophenyl) borate was added dropwise. Then, centrifugation was performed 5 times, the produced | generated deposit was separated by filtration, refine | purified, and it dried, and obtained the onium borate complex represented by following formula (6).

（２）光硬化性樹脂組成物の調製
ビスフェノールＦ型エポキシ樹脂（商品名「エピコート８０６」、ジャパンエポキシレジ
ン社製）１００重量部に対して、得られたオニウムボレート錯体４重量部及び光増感剤（
商品名「ＤＥＴＸ−Ｓ」、日本化薬社製）０．１重量部を添加し、均一に攪拌混練した後
、脱泡して、光硬化性樹脂組成物を製造した。

(2) Preparation of photocurable resin composition 4 parts by weight of the obtained onium borate complex and photosensitization with respect to 100 parts by weight of bisphenol F type epoxy resin (trade name “Epicoat 806”, manufactured by Japan Epoxy Resin Co., Ltd.) Agent (
0.1 part by weight of a trade name “DETX-S” (manufactured by Nippon Kayaku Co., Ltd.) was added, and the mixture was uniformly stirred and kneaded and then defoamed to produce a photocurable resin composition.

(Evaluation)
A release treatment surface of a polyester film (trade name “# 5011”, manufactured by Lintec Corporation) on which the photocurable resin composition prepared in Example 1 and Comparative Examples 1 and 2 was subjected to a release treatment using an applicator. After coating so that the thickness of the coating film becomes 150 μm, using an ultra-high pressure mercury lamp, 20
The coating film was cured by irradiating mW light for 100 seconds (light irradiation amount 2000 mJ) to obtain a measurement sample.
The following evaluation was performed about the obtained sample for a measurement.
The results are shown in Table 1.

(1) Measurement of yellow index The sample for measurement was left in an atmosphere at 80 ° C. for 150 hours, and then the color difference meter “COLOR AN”
The yellow index was measured using ALYZER TC-1800M.

(2) Measurement of total light transmittance The total light transmittance at a wavelength of 380 to 780 nm of the measurement sample was measured using a spectrophotometer (trade name “COLOR ANALYZER TC-1800M”, manufactured by Tokyo Denshoku Co., Ltd.).

(3) Measurement of moisture permeability JIS in which calcium chloride was installed after cutting the measurement sample into a circle with a diameter of 6 cm
It was placed on a cup specified in Z 0208 and the periphery was fixed with wax. Then 85 ° C-85
After being left in an atmosphere of% RH for 24 hours, the change in weight was measured to determine the moisture permeability.

According to the present invention, it is possible to provide a photocurable resin composition capable of obtaining a cured product with extremely little coloration and high transparency.

Claims (4)

A photocurable resin composition comprising a photocationically polymerizable compound and an onium borate complex composed of an onium cation having iodine or sulfur as a central element, wherein the onium cation has at least one aryl group as a central element. A photocurable resin composition, which is bonded via an alkyl group. The photocurable resin composition according to claim 1, further comprising a curing control agent. An encapsulant comprising the photocurable resin composition according to claim 1 or 2. A display element comprising the photocurable resin composition according to claim 1 or 2 or the sealant according to claim 3.