JP7489608B2 - Ultraviolet-curable resin composition and light-emitting device - Google Patents

Description

The present disclosure relates to an ultraviolet-curable resin composition and a light-emitting device. In particular, the present disclosure relates to an ultraviolet-curable resin composition molded by an inkjet method, and a light-emitting device using the ultraviolet-curable resin composition.

Patent Document 1 discloses an ink composition that is ejected by inkjet. This ink composition contains a (meth)acrylate monomer, such as a polyethylene glycol dimethacrylate monomer, and a photoinitiator. The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

JP 2017-531049 A

However, in Patent Document 1, when the ink composition is irradiated with ultraviolet light in the atmosphere, the photopolymerization reaction of the ink composition is likely to be inhibited by oxygen. In addition, if the amount of photoinitiator in the ink composition is increased in order to sufficiently advance the photopolymerization reaction, the transparency of the cured product is likely to decrease.

The objective of the present disclosure is to provide an ultraviolet-curable resin composition that is easily cured in an oxygen-containing environment, such as the air atmosphere, and a light-emitting device that uses the ultraviolet-curable resin composition.

The ultraviolet-curable resin composition according to one embodiment of the present disclosure is a ultraviolet-curable resin composition formed by an inkjet method, and contains an acrylic compound (A) and a photopolymerization initiator (B). The photopolymerization initiator (B) contains a compound having an oxime ester structure.

A light-emitting device according to one aspect of the present disclosure includes a light-emitting element and a sealant that covers the light-emitting element. The sealant includes a cured product of the ultraviolet-curable resin composition.

The above aspect of the present disclosure has the advantage that a cured product can be easily obtained in an oxygen-containing environment such as the air atmosphere.

FIG. 1 is a schematic cross-sectional view showing a first example of a light emitting device according to an embodiment of the present disclosure. FIG. 2 is a schematic cross-sectional view showing a second example of a light emitting device according to an embodiment of the present disclosure.

One embodiment of the present disclosure will be described below. In the following description, "(meth)acrylic-" means at least one of "acrylic-" and "methacrylic-". For example, a (meth)acrylic monomer means at least one of an acrylic monomer and a methacrylic monomer.

The ultraviolet-curable resin composition according to this embodiment (hereinafter also referred to as composition (X)) is used to produce an optical component that transmits light emitted by a light source. The optical component is a component that transmits light emitted by a light source such as a light-emitting element in a device having an optical system (e.g., a light-emitting device). The optical component is, for example, a sealant for a light-emitting element. The optical member is, for example, a thin film, and more specifically, for example, a film having a thickness of 5 μm or more and 50 μm or less.

The composition (X) contains an acrylic compound (A) and a photopolymerization initiator (B). The photopolymerization initiator (B) contains an oxime ester-based photopolymerization initiator (B1).

Therefore, when composition (X) is irradiated with ultraviolet light, the oxime ester photopolymerization initiator (B1) absorbs the ultraviolet light and is decomposed into multiple radical species. These multiple radical species initiate the polymerization of the acrylic compound (A), so the amount of photopolymerization initiator (B) can be reduced. Moreover, the multiple radical species derived from the oxime ester photopolymerization initiator (B1) are not easily affected by oxygen, so composition (X) is easily cured in an oxygen-containing environment such as the air atmosphere.

The cured product obtained by irradiating composition (X) with light and then heating it preferably has a glass transition temperature of 80°C or higher. In this case, the cured product can have good heat resistance. Therefore, for example, when the cured product is subjected to a process that increases the temperature, the cured product is less likely to deteriorate. The glass transition temperature of the cured product is more preferably 90°C or higher, and even more preferably 100°C or higher.

It is preferable that composition (X) is liquid at 25°C.

The viscosity of composition (X) at 25°C is preferably 1 mPa·s or more and 35 mPa·s or less. In this case, composition (X) can be applied and molded at room temperature by a casting method, an inkjet method, or the like. It is more preferable that this viscosity is 30 mPa·s or less, even more preferable that it is 20 mPa·s or less, and particularly preferable that it is 15 mPa·s or less. It is also preferable that this viscosity is 5 mPa·s or more, and more preferable that it is 8 mPa·s or more. For example, it is preferable that this viscosity is 8 mPa·s or more and 35 mPa·s or less.

It is also preferable that the viscosity of the composition (X) at 40°C is 1 mPa·s or more and 35 mPa·s or less. In this case, no matter what the viscosity of the composition (X) at room temperature is, it is possible to reduce the viscosity by slightly heating the composition (X). Therefore, if the composition (X) is heated, it is easy to mold the composition (X) by a method such as a casting method, and it is also possible to mold the composition (X) by an inkjet method. In addition, since the viscosity of the composition (X) can be reduced without significantly heating it, it is possible to prevent the composition of the composition (X) from changing due to the volatilization of the components in the composition (X). It is more preferable that the viscosity is 30 mPa·s or less, even more preferable that the viscosity is 20 mPa·s or less, and particularly preferable that the viscosity is 15 mPa·s or less. It is also preferable that the viscosity is 5 mPa·s or more, and more preferable that the viscosity is 8 mPa·s or more. For example, it is preferable that the viscosity is 8 mPa·s or more and 35 mPa·s or less.

Such a low viscosity of composition (X) at 25°C or 40°C can also be achieved by the composition of composition (X) described in detail below.

When the cured product of composition (X) has a thickness dimension of 10 μm, the total light transmittance is preferably 90% or more. In this case, when the cured product is applied to the encapsulant 5 in the light-emitting device 1, the extraction efficiency of the light that passes through the encapsulant 5 and is emitted to the outside can be particularly improved. Such light transmittance of the cured product can also be achieved by the composition of composition (X), which will be described in detail below.

It is also preferable that the surface tension of composition (X) is 20 mN/cm or more and 40 mN/cm or less. In this case, when composition (X) is applied by an inkjet method in particular, the ejection stability is good, and defective droplets called satellites are less likely to be generated. It is more preferable that the surface tension is 30 mN/cm or more and 40 mN/cm or less, and even more preferable that the surface tension is 31 mN/cm or more and 38 mN/cm or less.

The components of composition (X) are explained in more detail below.

As described above, the composition (X) contains an acrylic compound (A) and a photopolymerization initiator (B), and the photopolymerization initiator (B) contains an oxime ester-based photopolymerization initiator (B1).

The oxime ester photopolymerization initiator (B1) has an oxime ester structure shown in the following formula (1).

In formula (1), ^R1 and ^R2 each independently represent ^R11 , ^OR11 , ^COR11 , ^SR11 , ^CONR12 , ^R13 , or CN. ^R11 , ^R12 , and ^R13 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms.

The hydrogen atoms of the substituents represented by R ¹¹ , R ¹² and R ¹³ may be further substituted by OR ²¹ , COR ²¹ , SR ²¹ , NR ²² R ²³ , CONR ²² R ²³ , -NR ²² -OR ²³ , -NCOR ²² -OCOR ²³ , -C(═N-OR ²¹ )-R ²² , -C(═N-OCOR ²¹ )-R ²² , CN, a halogen atom or COOR ²¹ .

R ²¹ , R ²² and R ²³ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms.

The hydrogen atoms of the substituents represented by R ²¹ , R ²² and R ²³ may be further substituted with CN, a halogen atom, a hydroxyl group or a carboxyl group.

The alkylene portion of the substituents represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² and R ²³ may be interrupted 1 to 5 times by -O-, -S-, -COO-, -OCO-, -NR ²⁴ -, -NR ²⁴ COO-, -OCONR ²⁴ -, -SCO-, -COS-, -OCS- or -CSO-. The alkyl portion may have a branched side chain or may be a cyclic alkyl. Furthermore, R ¹² and R ¹³ , and R ²² and R ²³ may each be joined together to form a ring.

R ²⁴ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms.

In this embodiment, it is preferable that at least one of the substituents of ^R1 and ^R2 is an alkyl group having 1 to 3 carbon atoms. In this case, during irradiation with ultraviolet light and before the composition (X) is cured, the oxime ester photopolymerization initiator (B1) is decomposed, and gas components derived from the alkyl group are volatilized. That is, the gas components are released outside the composition (X). This makes it difficult for outgassing to occur after the composition (X) is cured.

When ^R2 is an aryl group having 6 to 30 carbon atoms or an arylalkyl group having 7 to 30 carbon atoms, the oxime ester photopolymerization initiator (B1) is decomposed upon irradiation with ultraviolet light, and the substituent ^R2 becomes a radical species and is liberated.

When decomposing the oxime ester photopolymerization initiator (B1), it is preferable that the ultraviolet light has a long wavelength. This makes it difficult for the light-emitting element 4 to be damaged when the composition (X) is cured on the light-emitting element 4 as shown in Figures 1 and 2. The long wavelength ultraviolet light is, for example, ultraviolet light in the A region (UV-A). The wavelength of UV-A is, for example, 320 nm or more and 400 nm or less.

^R3 represents a substituent containing a structure shown in the following formula (2) or a substituent containing a heterofluorene structure shown in the following formula (3). That is, the oxime ester photopolymerization initiator (B1) contains at least one selected from the group consisting of a compound (B2) containing a structure shown in the following formula (2) and a compound (B3) containing a heterofluorene structure shown in the following formula (3).

The "*" in formula (2) and formula (3) indicates the site of binding to the oxime ester structure.

In formula (2), R ⁴ and R ⁵ each independently represent R ¹¹ , OR ¹¹ , SR ¹¹ , COR ¹¹ , CONR ¹² R ¹³ , NR ¹² COR ¹¹ , OCOR ¹¹ , COOR ¹¹ , SCOR ¹¹ , OCSR ^{11 , COSR 11 ,} CSOR ¹¹ , CN, a halogen atom, or a hydrogen atom. a and b each independently represent an integer of 0 to 4. X represents an oxygen atom, a sulfur atom, a selenium atom, CR ³¹ R ³² , CO, NR ³³ , or PR ^34. R ³¹ , R ³² , R ³³ , and R ³⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms. The alkyl portion of the substituent represented by R ³¹ , R ³² , R ³³ and R ³⁴ may have a branched side chain or may be a cyclic alkyl. R ³¹ , R ³² , R ³³ and R ³⁴ may each independently form a ring together with any adjacent benzene ring. R ⁶ represents a hydrogen atom, OH, COOH or a group represented by the following formula (4).

In formula (4), "*" indicates the site of bonding to the benzene ring having the substituent ^R5 . ^Z1 represents -O-, -S-, ^{-NR22-, -NR22CO-} , ^-SO2- , -CS-, -OCO- or _-COO- . ^Z2 represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms or a heterocyclic group having 2 to 20 carbon atoms. c represents an integer from 1 to 3.

The alkylene moiety represented by ^Z2 may be interrupted 1 to 5 times by -O-, -S-, -COO-, -OCO-, ^-NR22- , ^-NR22COO- , ^-OCONR22- , -SCO-, -COS-, -OCS- or -CSO-. In addition, the alkylene moiety represented by ^Z2 may have a branched side chain or may be a cyclic alkylene.

R ⁹ represents OR ⁴¹ , SR ⁴¹ , CONR ⁴² R ⁴³ , NR ⁴² COR ⁴³ , OCOR ⁴¹ , COOR ⁴¹ , SCOR ⁴¹ , OCSR ⁴¹ , COSR ⁴¹ , CSOR ⁴¹ , CN or a halogen atom. R ⁴¹ , R ⁴² and R ⁴³ each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms or an arylalkyl group having 7 to 30 carbon atoms. The alkyl portion of the substituent represented by R ⁴¹ , R ⁴² and R ⁴³ may have a branched side chain or may be a cyclic alkyl. R ⁴² and R ⁴³ may be joined together to form a ring.

R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ in the above formula (1), and R ²² , R ⁴¹ , R ⁴² , and R in the above formula (4) Examples of the alkyl group having 1 to 20 carbon atoms represented by ⁴³ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, t-octyl, nonyl, isononyl, decyl, isodecyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, icosyl, cyclopentyl, cyclopentylmethyl, cyclopentylethyl, cyclohexyl, cyclohexylmethyl, cyclohexylethyl, and n-pentyl.

Examples of the aryl group having 6 to 30 carbon atoms represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ in the above formula (1), and R ²² , R ⁴¹ , R ⁴² , and R ⁴³ in the above formula (4) include phenyl, tolyl, xylyl, ethylphenyl, naphthyl, anthryl, phenanthrenyl, phenyl substituted with one or more of the above alkyl groups, biphenylyl, naphthyl, anthryl, and the like.

Examples of the arylalkyl group having 7 to 30 carbon atoms represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ in the above formula (1), and R ²² , R ⁴¹ , R ⁴² , and R ⁴³ in the above formula (4), include benzyl, α-methylbenzyl, α,α-dimethylbenzyl, ethylphenyl, methylphenyl, etc.

Preferred examples of the heterocyclic group having 2 to 20 carbon atoms represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , and R ²⁴ in the above formula (1) include 5- to 7-membered heterocyclic rings such as pyridyl, pyrimidyl, furyl, thienyl, tetrahydrofuryl, dioxolanyl, benzoxazol-2-yl, tetrahydropyranyl, pyrrolidyl, imidazolidyl, pyrazolidyl, thiazolidyl, isothiazolidyl, oxazolidyl, isoxazolidyl, piperidyl, piperazyl, and morpholinyl.

Preferred examples ^of the ring that can be formed by combining R ¹² and R ¹³ in the above formula (1), R ²² and R ²³ in the above formula ( ⁴ ), and the ring that can be formed by combining R ³¹ , R ³² , R ³³ , and R ³⁴ with the adjacent benzene ring include 5- to 7-membered rings such as a cyclopentane ring, a cyclohexane ring, a cyclopentene ring, a benzene ring, a piperidine ring, a morpholine ring, a lactone ring, and a lactam ring.

In the above formula (4), ^Z2 represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, or a heterocyclic group having 2 to 20 carbon atoms. ^Z2 is substituted with 1 to 3 ^R9 .

Examples of the alkyl group having 1 to 20 carbon atoms substituted with 1 to 3 ^R9 include, for example, when c is 1, alkylene groups such as methylene, ethylene, propylene, methylethylene, butylene, 1-methylpropylene, 2-methylpropylene, 1,2-dimethylpropylene, 1,3-dimethylpropylene, 1-methylbutylene, 2-methylbutylene, 3-methylbutylene, 4-methylbutylene, 2,4-dimethylbutylene, 1,3-dimethylbutylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, dodecylene, tridecylene, tetradecylene, pentadecylene, ethane-1,1-diyl, and propane-2,2-diyl.

Examples of the aryl group having 6 to 30 carbon atoms substituted with 1 to 3 ^R9 when c is 1 include arylene groups such as 1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 1,4-naphthylene, 2,5-dimethyl-1,4-phenylene, diphenylmethane-4,4'-diyl, 2,2-diphenylpropane-4,4'-diyl, diphenylsulfide-4,4'-diyl, and diphenylsulfone-4,4'-diyl.

Examples of the arylalkyl group having 7 to 30 carbon atoms substituted with 1 to 3 R ⁹ include, for example, when c is 1, arylalkylene groups such as the linking group represented by Chemical formula 3.

Examples of the heterocyclic group having 2 to 20 carbon atoms substituted with 1 to 3 ^R9 include, for example, when c is 1, divalent heterocyclic groups such as 2,5-pyridinediyl, 2,6-pyridinediyl, 2,5-pyrimidinediyl, 2,5-thiophenediyl, 3,4-tetrahydrofurandiyl, 2,5-tetrahydrofurandiyl, 2,5-furandiyl, 3,4-thiazolediyl, 2,5-benzofurandiyl, 2,5-benzothiophenediyl, N-methylindole-2,5-diyl, 2,5-benzothiazolediyl, and 2,5-benzoxazolediyl.

In addition, the hydrogen atoms contained in ^R3 and ^R4 in the above formula (1), ^R6 in the above formula (4), and ^R11 , ^R12 , ^R13 , ^R21 , ^R22 , and ^R23 in the above formula (1) may be substituted with halogen atoms, such as fluorine, chlorine, bromine, and iodine.

The substituents represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² and R ²³ and the alkylene portion of Z ² may be interrupted 1 to 5 times by a group (interrupting group) represented by -O-, -S-, -COO-, -OCO-, -SCO-, -COS-, -OCS- or -CSO-, etc. This interrupting group may be present at one or more locations in the middle of the substituent and the alkylene portion, and multiple interrupting groups may be consecutive.

In addition, the alkyl (alkylene) portions of the substituents represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² , R ²³ , R ³¹ , R ³² , R ³³ and R ³⁴ , and Z ² in the above formula (4), and the substituents represented by R ⁴¹ , R ⁴² and R ⁴³ may have a branched side chain or may be a cyclic alkyl.

In this embodiment, when R ³ has a structure represented by formula (2), the compound (B2) preferably contains a compound (B5) represented by the following formula (5).

When compound (B5) is irradiated with ultraviolet light, compound (B5) decomposes to generate diphenyl sulfide, benzene, and n-pentane as radical species. Of these, n-pentane volatilizes before composition (X) cures, and the diphenyl sulfide radical and the phenyl radical can initiate a polymerization reaction of acrylic compound (A). Furthermore, compound (B5) exhibits bleaching properties when irradiated with ultraviolet light, making it possible to impart translucency to the cured product of composition (X).

Next, compound (B3) will be described with reference to formula (3).

In formula (3), the heterofluorene structure contains nitrogen as a heteroatom.

^R7 represents ^{R11 , OR11 , SR11} , ^COR11 , ^CONR12R13 , ^NR12COR11 , ^OCOR11 , ^COOR11 , ^SCOR11 , ^OCSR11 , ^COSR11 , ^CSOR11 , CN or a halogen atom.

^R8 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms.

When ^R3 contains a heterofluorene structure represented by formula (3), the compound (B3) preferably contains a compound (B6) represented by the following formula (6).

When compound (B6) is irradiated with ultraviolet light, compound (B6) is decomposed to generate 3-carbonyl-9-ethylcarbazole, toluene, and methane as radical species. Of these, methane becomes carbon dioxide and volatilizes before composition (X) cures, and the 3-carbonyl-9-ethylcarbazole radical and tolyl radical can initiate a polymerization reaction of acrylic compound (A). Furthermore, compound (B6) exhibits bleaching properties when irradiated with ultraviolet light, so that the cured product of composition (X) can be given translucency. In addition, compound (B6) is more sensitive to ultraviolet light than compound (B5), so that the curing efficiency of composition (X) can be improved.

As described above, multiple radical species can be generated per molecule by decomposing the oxime ester photopolymerization initiator (B1) when irradiated with ultraviolet light. This allows the amount of photopolymerization initiator (B) to be reduced. By reducing the amount of photopolymerization initiator (B), the radical species are less susceptible to the effects of oxygen, even when composition (X) is cured in an environment containing oxygen, such as the air atmosphere, and a cured product can be easily obtained.

The ratio of the oxime ester photopolymerization initiator (B1) is preferably 0.5% by mass or more and 10% by mass or less relative to the acrylic compound (A). In this case, there is an advantage that the bleaching property exhibited upon irradiation with ultraviolet light can impart translucency to the cured product of the composition (X). This ratio is more preferably 0.8% by mass or more and 8% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less.

The photopolymerization initiator (B) may further contain a compound (B11) different from the oxime ester photopolymerization initiator (B1). Such a compound (B11) is not particularly limited as long as it is different from the oxime ester photopolymerization initiator (B1). The compound (B11) contains at least one compound selected from the group consisting of, for example, aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having carbon-halogen bonds, and alkylamine compounds. Among them, it is preferable that the compound (B11) contains an acylphosphine oxide compound. The acylphosphine oxide compound contains, for example, at least one selected from the group consisting of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)diphenylphosphine oxide.

When the composition (X) contains the oxime ester photopolymerization initiator (B1) and the compound (B11), the bleaching property of the oxime ester photopolymerization initiator (B1) can be strengthened as the exposure amount of the composition (X) to ultraviolet light increases. Therefore, even if coloring due to the compound (B11) occurs when the composition (X) is cured, this coloring can be suppressed by the bleaching property of the oxime ester photopolymerization initiator (B1). This can improve the transparency of the cured product. In order to further suppress coloring due to the compound (B11), the amount of the compound (B11) is preferably less than that of the oxime ester photopolymerization initiator (B1). The amount of the compound (B11) is, for example, 0.5% by mass or more and 5% by mass or less with respect to the solid content of the composition (X). The photopolymerization initiator (B) does not have to contain the compound (B11).

As described above, composition (X) contains acrylic compound (A). Acrylic compound (A) has one or more (meth)acryloyl groups in one molecule.

The viscosity of the entire acrylic compound (A) at 25°C is preferably 50 mPa·s or less. In this case, the acrylic compound (A) can particularly reduce the viscosity of the composition (X). The viscosity of the entire acrylic compound (A) is more preferably 30 mPa·s or less, and particularly preferably 20 mPa·s or less. The viscosity of the entire acrylic compound (A) is, for example, 3 mPa·s or more.

It is also preferable that the viscosity of the entire acrylic compound (A) at 40°C is 50 mPa·s or less. In this case, the acrylic compound (A) can particularly reduce the viscosity of the composition (X) when heated. It is more preferable that the viscosity of the entire acrylic compound (A) is 30 mPa·s or less, and particularly preferable that the viscosity is 20 mPa·s or less. In addition, the viscosity of the entire acrylic compound (A) is, for example, 3 mPa·s or more.

It is preferable that the percentage of components in the acrylic compound (A) having a boiling point of 270°C or higher is 80% by mass or higher. In this case, the storage stability of the composition (X) is particularly unlikely to be impaired, and outgassing is particularly unlikely to occur from the cured product and the sealant 5. It is even more preferable that the percentage of components in the acrylic compound (A) having a boiling point of 280°C or higher is 80% by mass or higher.

It is preferable that the acrylic compound (A) contains a component whose viscosity at 25°C is 20 mPa·s or less. In this case, the viscosity of the composition (X) can be reduced.

The proportion of the component having a viscosity of 20 mPa·s or less at 25°C relative to the total amount of acrylic compound (A) is preferably 50% by mass or more and 100% by mass or less. In this case, the viscosity of composition (X) can be particularly reduced, making composition (X) particularly easy to apply by the inkjet method. This proportion is more preferably 60% by mass or more, and even more preferably 70% by mass or more. This proportion is also more preferably 95% by mass or less, and even more preferably 90% by mass or less.

The component having a viscosity of 20 mPa·s or less at 25°C preferably contains a compound having a glass transition temperature of 80°C or higher. In this case, the glass transition temperature of the cured product can be increased while lowering the viscosity of composition (X). It is more preferable that this component contains a compound having a glass transition temperature of 90°C or higher, and even more preferable that this component contains a compound having a glass transition temperature of 100°C or higher. There is no upper limit to the glass transition temperature of the compound contained in this component, but it is, for example, 150°C or lower.

The following describes the compounds that the acrylic compound (A) may contain.

The acrylic compound (A) preferably contains a polyfunctional acrylic compound (A1) having two or more (meth)acryloyl groups in one molecule. In this case, the polyfunctional acrylic compound (A1) can increase the glass transition temperature of the cured product, and therefore the heat resistance of the cured product and the sealing material 5 can be improved. The proportion of the polyfunctional acrylic compound (A1) is preferably 50% by mass or more and 100% by mass or less based on the total acrylic compound (A). The acrylic compound (A) may contain only the polyfunctional acrylic compound (A1).

Examples of the polyfunctional acrylic compound (A1) include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol oligoacrylate, diethylene glycol diacrylate, 1,6-hexanediol oligoacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, cyclohexane dimethanol diacrylate, tricyclodecane dimethanol diacrylate, bisphenol A polyethoxy diacrylate, bisphenol F polyethoxy diacrylate, pentatriestrol tetraacrylate, propoxylated (2) neopentyl glycol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl)isocyanate, and the like. Anurate triacrylate, pentaerythritol triacrylate, ethoxylated (3) trimethylolpropane triacrylate, propoxylated (3) glyceryl triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated (4) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, hexadiol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, tripropylene glycol triacrylate, bispentaerythritol hexaacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethoxylated 1,6-hexanediol diacrylate , polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,9-nonanediol diacrylate, tetraethylene glycol diacrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, hydroxypivalic acid trimethylolpropane triacrylate, ethoxylated phosphoric acid triacrylate, ethoxylated tripropylene glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate, tetramethylolpropane triacrylate, tetramethylolmethane triacrylate, caprolactone modified trimethylolpropane triacrylate, propoxylated glyceryl tet It contains at least one compound selected from the group consisting of triacrylate, tetramethylolmethane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate.

The acrylic equivalent of the polyfunctional acrylic compound (A1) is preferably 150 g/eq or less, and more preferably 90 g/eq or more and 150 g/eq or less. The weight average molecular weight of the polyfunctional acrylic compound (A1) is, for example, 100 or more and 1000 or less, and more preferably 200 or more and 800 or less.

It is preferable that the polyfunctional acrylic compound (A1) contains a compound (A11) having a structure shown in the following formula (7).

CH ₂ ═CR ¹ —COO—(R ³ —O) _n —CO—CR ² ═CH ₂ … (7)
In formula (7), each of ^R1 and ^R2 is a hydrogen atom or a methyl group, n is an integer of 1 or more, and ^R3 is an alkylene group having 1 or more carbon atoms. When n is 2 or more, multiple ^R3s in one molecule may be the same or different.

Compound (A11) has a structure shown in formula (7), and in particular, the carbon number of R ³ in formula (7) is 3 or more, so that it is difficult to increase the affinity of the sealing material 5 with water. Therefore, the light-emitting element 4 is unlikely to be deteriorated by water. The carbon number of R ³ is, for example, 1 to 15, and preferably 3 to 15. In addition, compound (A11) has a structure shown in formula (7), and in particular, has two (meth)acryloyl groups in one molecule, so that the glass transition temperature of the cured product can be increased, and therefore the heat resistance of the cured product and the sealing material 5 can be increased. In addition, n in formula (7) is, for example, an integer of 1 to 12.

The percentage of compound (A11) relative to acrylic compound (A) is preferably 50% by mass or more. In this case, it is particularly difficult to increase the affinity of the cured product and the sealant 5 for water. The percentage of compound (A11) relative to acrylic compound (A) is, for example, 100% by mass or less, or 95% by mass or less, and preferably 80% by mass or less.

It is preferable that the compound (A11) contains a compound (A12) having a boiling point of 270°C or higher. That is, it is preferable that the acrylic compound (A) contains a compound (A12) having a structure shown in formula (7) and a boiling point of 270°C or higher. In this case, the acrylic compound (A) is unlikely to volatilize from the composition (X) during storage of the composition (X) and when the composition (X) is heated. Therefore, the storage stability of the composition (X) is unlikely to be impaired. In addition, even if the compound (A12) remains unreacted in the cured product of the composition (X) and in the sealing material 5, outgassing due to the compound (A12) is unlikely to occur from the cured product and the sealing material 5. Therefore, voids due to outgassing are unlikely to occur in the light-emitting device 1. If there are voids in the light-emitting device 1, moisture may penetrate into the light-emitting element 4 through the voids, but if voids are unlikely to occur, moisture is unlikely to penetrate into the light-emitting element 4. The boiling point is the boiling point under normal pressure obtained by converting the boiling point under reduced pressure, and is determined, for example, by the method shown in Science of Petroleum, Vol. II. P. 1281 (1938). The boiling point of compound (A12) is preferably 280°C or higher.

The percentage of compound (A12) relative to acrylic compound (A) is preferably 50% by mass or more. In this case, the storage stability of composition (X) is effectively increased, outgassing from the sealant 5 is effectively reduced, and the affinity of sealant 5 for water is not particularly increased. The percentage of compound (A12) relative to acrylic compound (A) is, for example, 100% by mass or less, or 95% by mass or less, and preferably 80% by mass or less.

The viscosity of compound (A12) at 25°C is preferably 25 mPa·s or less. In this case, compound (A12) can reduce the viscosity of composition (X). The viscosity of compound (A12) at 25°C is more preferably 25 mPa·s or less, even more preferably 20 mPa·s or less, and particularly preferably 15 mPa·s or less. The viscosity of compound (A12) at 25°C is, for example, 1 mPa·s or more, preferably 3 mPa·s or more, and even more preferably 5 mPa·s or more.

Compound (A11) contains, for example, at least one compound selected from the group consisting of alkylene glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate, and alkylene oxide-modified alkylene glycol di(meth)acrylate.

The alkylene glycol di(meth)acrylate is a compound in which n is 1 in formula (7). In this case, the carbon number of R ³ in formula (7) is preferably 4 to 12. R ³ may be linear or branched. In particular, the alkylene glycol di(meth)acrylate preferably contains at least one compound selected from the group consisting of 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and 1,12-dodecanediol dimethacrylate. Examples of alkylene glycol di(meth)acrylate include Sartomer product number SR213, Osaka Organic Chemical Industry Co., Ltd. product number V195, Sartomer product number SR212, Sartomer product number SR247, Kyoei Chemical Industry Co., Ltd. product name Light Acrylate NP-A, Sartomer product number SR238NS, Osaka Organic Chemical Industry Co., Ltd. product number V230, Daicel Corporation product number HDDA, Kyoei Chemical Industry Co., Ltd. product number 1,6HX-A, Osaka Organic Chemical Industry Co., Ltd. product number V260, Kyoei Chemical Industry Co., Ltd. product number 1,9-ND-A, Shin-Nakamura Chemical Co., Ltd. product number A-NOD-A, Sartomer product number CD595, Sartomer product number S It is preferable that the composition contains at least one compound selected from the group consisting of R214NS, product number BD manufactured by Shin-Nakamura Chemical Co., Ltd., product number SR297 manufactured by Sartomer Co., Ltd., product number SR248 manufactured by Sartomer Co., Ltd., product name Light Ester NP manufactured by Kyoei Chemical Co., Ltd., product number SR239NS manufactured by Sartomer Co., Ltd., product name Light Ester 1,6HX manufactured by Kyoei Chemical Co., Ltd., product number HD-N manufactured by Shin-Nakamura Chemical Co., Ltd., product name Light Ester 1,9ND manufactured by Kyoei Chemical Co., Ltd., product number NOD-N manufactured by Shin-Nakamura Chemical Co., Ltd., product name Light Ester 1,10DC manufactured by Kyoei Chemical Co., Ltd., product number DOD-N manufactured by Shin-Nakamura Chemical Co., Ltd., and product number SR262 manufactured by Sartomer Co., Ltd.

Polyalkylene glycol di(meth)acrylate is, for example, a compound in which n is 2 or more in formula (7). n is, for example, 2 to 10, preferably 2 to 7, also preferably 2 to 6, and also preferably 2 to 3. The number of carbon atoms in R ³ is, for example, 2 to 7, preferably 2 to 5. The greater the number of carbon atoms, the higher the hydrophobicity of the cured product, and the less moisture permeable the cured product is. The polyalkylene glycol di(meth)acrylate preferably contains at least one compound selected from the group consisting of diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, hexaethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, tritetramethylene glycol diacrylate, polyethylene glycol 200 dimethacrylate, and polyethylene glycol 200 diacrylate. In addition, the polyalkylene glycol di(meth)acrylate preferably contains at least one compound selected from the group consisting of Sartomer Corporation product number SR230, Sartomer Corporation product number SR508NS, Daicel Corporation product number DPGDA, Sartomer Corporation product number SR306NS, Daicel Corporation product number TPGDA, Osaka Organic Chemical Industry Co., Ltd. product number V310HP, Shin-Nakamura Chemical Co., Ltd. product number APG200, Kyoei Chemical Industry Co., Ltd. product name Light Acrylate PTMGA-250, Sartomer Corporation product number SR231NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 2EG, Sartomer Corporation product number SR205NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 3EG, Sartomer Corporation product number SR210NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 4EG, Mitsubishi Chemical Corporation product name Acrylate HX, and Shin-Nakamura Chemical Co., Ltd. product number 3PG.

The alkylene oxide modified alkylene glycol di(meth)acrylate contains, for example, propylene oxide modified neopentyl glycol. The alkylene oxide modified alkylene glycol di(meth)acrylate contains, for example, EBECRYL145 manufactured by Daicel Corporation.

When the acrylic compound (A) contains a compound (A11) having a structure represented by formula (7), it is preferable that the compound (A11) does not contain a compound in which the value of n in formula (7) is 5 or more. When (R ³ -O) _n is a polyethylene glycol skeleton, it is particularly preferable that the compound in which the value of n in formula (7) is greater than 5 is not contained. Even when the compound (A11) contains a compound in which the value of n in formula (7) is greater than 5, the percentage of the compound in which the value of n in formula (7) is greater than 5 relative to the acrylic compound (A) is preferably 20 mass% or less. Also, even when the compound (A11) contains a compound in which the value of n in formula (7) is greater than 5, it is preferable that the compound (A11) does not contain a compound in which the value of n is greater than 9, and more preferably does not contain a compound in which the value of n is greater than 7. In these cases, the viscosity increase of the composition (X) is particularly unlikely to occur.

It is particularly preferable that the polyfunctional acrylic compound (A1) contains a polyalkylene glycol di(meth)acrylate. Since polyalkylene glycol di(meth)acrylate has a low viscosity and is not easily volatile, it can contribute to lowering the viscosity of the composition (X), improving the storage stability of the composition (X), and reducing outgassing from the cured product.

When the polyfunctional acrylic compound (A1) contains polyalkylene glycol di(meth)acrylate, the ratio of polyalkylene glycol di(meth)acrylate to the acrylic compound (A) is preferably 40% by mass or more and 80% by mass or less. When the ratio of polyalkylene glycol di(meth)acrylate is 40% by mass or more, the viscosity of the composition (X) can be effectively reduced. When the ratio of polyalkylene glycol di(meth)acrylate is 80% by mass or less, the ratio of compounds having three or more (meth)acryloyl groups in the molecule increases, and the reactivity of the composition (X) and the glass transition temperature of the cured product can be increased. This ratio is more preferably 42% by mass or more and 75% by mass or less, and even more preferably 45% by mass or more and 70% by mass or less.

The polyfunctional acrylic compound (A1) may contain a compound having three or more (meth)acryloyl groups in one molecule. In this case, the polyfunctional acrylic compound (A1) may contain at least one selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetra(meth)acrylate. In this case, the glass transition temperature of the cured product can be particularly increased, and therefore the heat resistance of the cured product can be particularly increased.

It is particularly preferred that the polyfunctional acrylic compound (A1) contains pentaerythritol tetra(meth)acrylate. In this case, the glass transition temperature of the cured product can be particularly increased, and the reactivity of the composition (X) can be improved. When the reactivity of the composition (X) is improved, the composition (X) can be easily cured in an oxygen-containing environment such as the air atmosphere.

When the polyfunctional acrylic compound (A1) contains pentaerythritol tetra(meth)acrylate, the ratio of pentaerythritol tetra(meth)acrylate to the acrylic compound (A) is preferably 0.5% by mass or more and 10% by mass or less. In this case, it is possible to achieve both high reactivity and low viscosity of the composition (X). This ratio is more preferably 1% by mass or more and 9% by mass or less, and even more preferably 2% by mass or more and 8% by mass or less.

The polyfunctional acrylic compound (A1) may have at least one of a benzene ring, an alicyclic ring, and a polar group. The polar group is, for example, at least one of an OH group and an NHCO group. In this case, the shrinkage when the composition (X) is cured can be particularly reduced. Furthermore, the adhesion between the cured product and inorganic compounds such as silicon nitride and silicon oxide can also be increased. The polyfunctional acrylic compound (A1) preferably contains at least one compound selected from the group consisting of tricyclodecane dimethanol diacrylate, bisphenol A polyethoxy diacrylate, bisphenol F polyethoxy diacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate. These compounds can particularly reduce the shrinkage when the composition (X) is cured. Furthermore, these compounds can also increase the adhesion between the cured product and inorganic compounds such as silicon nitride and silicon oxide.

It is particularly preferable that the polyfunctional acrylic compound (A1) contains polyalkylene glycol di(meth)acrylate and pentaerythritol tetra(meth)acrylate. In this case, the composition (X) has low viscosity and excellent reactivity. Therefore, the composition (X) can be easily cured in an oxygen-containing environment such as the air atmosphere.

It is also preferable that the acrylic compound (A) contains a monofunctional acrylic compound (A2) having only one (meth)acryloyl group in one molecule. The monofunctional acrylic compound (A2) can suppress shrinkage of the composition (X) during curing.

The amount of the monofunctional acrylic compound (A2) relative to the total amount of the acrylic compound (A) is preferably more than 0% by mass and not more than 50% by mass. If the amount of the monofunctional acrylic compound (A2) is more than 0% by mass, shrinkage during curing of the composition (X) can be suppressed. In addition, if the amount of the monofunctional acrylic compound (A2) is 50% by mass or less, the amount of the polyfunctional acrylic compound (A1) can be 50% by mass or more, and the heat resistance of the cured product and the sealing material 5 can be particularly improved. It is more preferable that the amount of the monofunctional acrylic compound (A2) is 5% by mass or more, and it is even more preferable that it is 30% by mass or less.

Examples of the monofunctional acrylic compound (A2) include tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydixylethyl acrylate, ethyl diglycol acrylate, cyclic triacrylate, ethyl ... trimethylolpropane formal monoacrylate, imide acrylate, isoamyl acrylate, ethoxylated succinic acid acrylate, trifluoroethyl acrylate, ω-carboxypolycaprolactone monoacrylate, cyclohexyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate, diethylene glycol monobutyl ether acrylate, lauryl acrylate, isodecyl acrylate, 3,3,5-trimethylcyclohexanol acrylate, isooctyl acrylate, octyl/decyl acrylate, tridecyl acrylate, caprolactone acrylate acrylate, ethoxylated (4)nylphenol acrylate, methoxypolyethylene glycol (350) monoacrylate, methoxypolyethylene glycol (550) monoacrylate, phenoxyethyl acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-furan It contains at least one compound selected from the group consisting of phenoxyethyl acrylate, ethylene oxide adduct of 2-phenoxyethyl acrylate, propylene oxide adduct of 2-phenoxyethyl acrylate, acryloylmorpholine, morpholin-4-yl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, 3-methacryloyloxymethylcyclohexene oxide, and 3-acryloyloxymethylcyclohexene oxide.

The monofunctional acrylic compound (A2) may contain at least one compound selected from the group consisting of compounds having an alicyclic structure and compounds having a cyclic ether structure.

The compound having an alicyclic structure contains at least one compound selected from the group consisting of, for example, phenoxyethyl acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, ethylene oxide adduct of 2-phenoxyethyl acrylate, propylene oxide adduct of 2-phenoxyethyl acrylate, acryloyl morpholine, morpholin-4-yl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 1,4-cyclohexanedimethanol monoacrylate.

The number of ring members in the cyclic ether structure in the compound having a cyclic ether structure is preferably 3 or more, more preferably 3 to 4. The number of carbon atoms contained in the cyclic ether structure is preferably 2 to 9, more preferably 2 to 6. The compound having a cyclic ether structure contains, for example, at least one compound selected from the group consisting of 3-methacryloyloxymethylcyclohexene oxide and 3-acryloyloxymethylcyclohexene oxide.

The acrylic compound (A) may contain a compound having silicon in its molecular skeleton. In this case, the adhesion between the cured product and the inorganic material is improved. The compound having silicon in its molecular skeleton contains at least one compound selected from the group consisting of 3-(trimethoxysilyl)propyl acrylate (e.g., product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd.) and (meth)acrylic group-containing alkoxysilane oligomer (e.g., product number KR-513 manufactured by Shin-Etsu Chemical Co., Ltd.).

The acrylic compound (A) may contain a compound having phosphorus in the molecular skeleton. In this case, the adhesion between the cured product and the inorganic material is improved. Compounds having phosphorus in the molecular skeleton include acid phosphoxy (meth)acrylates, such as acid phosphoxy polyoxypropylene glycol monomethacrylate.

The acrylic compound (A) may contain a compound having nitrogen in the molecular skeleton. In this case, the adhesion between the cured product and the inorganic material is improved. In addition, the reactivity of the acrylic compound (A) is likely to be improved, and therefore outgassing from the cured product is less likely to occur. The compound having nitrogen in the molecular skeleton includes at least one compound selected from the group consisting of compounds having a morpholine skeleton, such as acryloylmorpholine and morpholin-4-yl acrylate, diethylacrylamide, dimethylaminopropylacrylamide, and pentamethylpiperidyl methacrylate.

It is particularly preferred that the acrylic compound (A) contains a compound having a morpholine skeleton. In this case, the reactivity of the composition (X) containing the oxime ester-based photopolymerization initiator can be further improved, and the curability of the composition (X) in an air atmosphere can be further enhanced. It is particularly preferred that the acrylic compound (A) contains at least one of acryloylmorpholine and morpholin-4-yl acrylate. In this case, shrinkage during curing of the composition (X) can be suppressed. In addition, the viscosity of acryloylmorpholine and morpholin-4-yl acrylate is low, and therefore these compounds are unlikely to increase the viscosity of the composition (X). Furthermore, since these compounds are unlikely to volatilize, it is easy to improve the storage stability of the composition (X).

The ratio of the compound having a morpholine skeleton to the acrylic compound (A) is preferably 5% by mass or more and 50% by mass or less. In this case, there is an advantage that outgassing is less likely to occur from the cured product of the composition (X). This ratio is more preferably 7% by mass or more and 45% by mass or less, and even more preferably 10% by mass or more and 40% by mass or less.

The acrylic compound (A) may contain a compound having an isobornyl skeleton. The compound having an isobornyl skeleton may contain, for example, one or more compounds selected from the group consisting of isobornyl acrylate and isobornyl methacrylate.

The acrylic compound (A) may contain a component consisting of a compound having at least one skeleton selected from the group consisting of a dicyclopentadiene skeleton, a dicyclopentanyl skeleton, a dicyclopentenyl skeleton, and a bisphenol skeleton. Specifically, the acrylic compound (A) may contain at least one compound selected from the group consisting of, for example, tricyclodecane dimethanol diacrylate, bisphenol A polyethoxydiacrylate, and bisphenol F polyethoxydiacrylate. In this case, the adhesion between the cured product and the inorganic material can be increased.

The acrylic compound (A) may contain a compound represented by the following formula (100). In this case, the reactivity of the composition (X) can be increased, and the adhesion between the cured product and the inorganic material can be improved.

In formula (100), R ⁰ is H or a methyl group. X is a single bond or a divalent hydrocarbon group. Each of R ¹ to R ¹¹ is H, an alkyl group or -R ¹² -OH, R ¹² is an alkylene group, and at least one of R ¹ to R ¹¹ is an alkyl group or -R ¹² -OH. R ¹ to R ¹¹ are not chemically bonded to each other.

Specifically, for example, the acrylic compound (A) may contain at least one compound selected from the group consisting of the compound shown in the following formula (110), the compound shown in the formula (120), and the compound shown in the formula (130).

The composition (X) may further contain a radical polymerizable compound (E) other than the acrylic compound (A). The radical polymerizable compound (E) may contain either one or both of a polyfunctional radical polymerizable compound (E1) having two or more radical polymerizable functional groups in one molecule and a monofunctional radical polymerizable compound (E2) having only one radical polymerizable functional group in one molecule. The amount of the radical polymerizable compound (E) relative to the total amount of the acrylic compound (A) and the radical polymerizable compound (E) is, for example, 10 mass% or less. The polyfunctional radical polymerizable compound (E1) may contain at least one compound selected from the group consisting of aromatic urethane oligomers, aliphatic urethane oligomers, epoxy acrylate oligomers, polyester acrylate oligomers, and other special oligomers having two or more ethylenic double bonds in one molecule. The monofunctional radical polymerizable compound (E2) contains at least one compound selected from the group consisting of, for example, N-vinylformamide, vinylcaprolactam, vinylpyrrolidone, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monoxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-vinylcyclohexene oxide, 4-vinylcyclohexene oxide, N-vinylpyrrolidone, and N-vinylcaprolactam.

The composition (X) may further contain a moisture absorbent (C). When the composition (X) contains the moisture absorbent (C), the cured product of the composition (X) and the sealant 5 can have moisture absorption properties. Therefore, the sealant 5 can further prevent moisture from penetrating into the organic EL element 4 in the organic EL light-emitting device 1. The average particle size of the moisture absorbent (C) is preferably 200 nm or less. In this case, the cured product can have high transparency.

The moisture absorbent (C) is preferably an inorganic particle having moisture absorbing properties, and preferably contains at least one component selected from the group consisting of zeolite particles, silica gel particles, calcium chloride particles, and titanium oxide nanotube particles. It is particularly preferable that the moisture absorbent (C) contains zeolite particles.

Zeolite particles with an average particle size of 200 nm or less can be produced, for example, by crushing general industrial zeolite. When producing zeolite particles, the zeolite may be crushed and then crystallized by hydrothermal synthesis or the like, in which case the zeolite particles can have particularly high hygroscopicity. Examples of methods for producing such zeolite particles are disclosed in JP 2016-69266 A, JP 2013-049602 A, and the like.

The zeolite particles preferably contain sodium ions. For this reason, the zeolite particles are preferably made from at least one type selected from the group consisting of A-type zeolite, X-type zeolite, and Y-type zeolite. It is particularly preferable that the zeolite particles are made from 4A-type zeolite among A-type zeolites. In these cases, the zeolite particles have a crystal structure suitable for adsorbing moisture.

The pH of the zeolite particles is preferably 7 or more and 10 or less. When the pH of the zeolite particles is 7 or more, the crystals of the zeolite particles are less likely to be destroyed, and therefore a sealant made from the composition (X) containing the zeolite particles can have particularly high moisture absorption. When the pH of the zeolite particles is 10 or less, the zeolite particles are less likely to inhibit the curing of the composition (X) when it is cured. The pH of the zeolite particles is a value obtained by heating a dispersion obtained by adding 0.05 g of zeolite particles to 99.95 g of ion-exchanged water at 90°C for 24 hours, and then measuring the pH of the supernatant of the dispersion with a pH meter. As the pH meter, for example, a compact pH meter <LAQUAtwin> B-711 manufactured by Horiba, Ltd. can be used.

The average particle size of the moisture absorbent (C) is preferably 10 nm or more and 200 nm or less. If the average particle size is 200 nm or less, the cured product can have particularly high transparency. If the average particle size is 10 nm or more, the moisture absorbent (C) can maintain good moisture absorption. Note that this average particle size is the median diameter calculated from the measurement results by dynamic light scattering, that is, the cumulative 50% diameter (D50). Note that the Nanotrac Wave series from Microtrac Bell Co., Ltd. can be used as a measuring device.

The average particle size of the moisture absorbent (C) is preferably 150 nm or less, more preferably 100 nm or less, and particularly preferably 70 nm or less. The average particle size of the moisture absorbent (C) is preferably 20 nm or more, and more preferably 50 nm or more. In this case, the cured product can have particularly good transparency and moisture absorption.

It is also preferable that the cumulative 90% diameter (D90) of the moisture absorbent (C) is 100 nm or less. In this case, the cured product can have particularly high transparency.

When the composition (X) contains the moisture absorbent (C), the ratio of the moisture absorbent (C) to the total amount of the composition (X) is preferably 1% by mass or more and 20% by mass or less. If the ratio of the moisture absorbent (C) is 1% by mass or more, the cured product can have particularly high moisture absorption. If the ratio of the moisture absorbent (C) is 20% by mass or less, the viscosity of the composition (X) can be particularly reduced, and the composition (X) can have a sufficiently low viscosity to be applicable by the inkjet method. The ratio of the moisture absorbent (C) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. The ratio of the moisture absorbent (C) is more preferably 15% by mass or less, and particularly preferably 13% by mass or less.

The composition (X) may further contain an inorganic filler other than the moisture absorbent (C). In particular, the composition (X) preferably contains nano-sized high refractive index particles. An example of the high refractive index particles includes zirconia particles. When the composition (X) contains high refractive index particles, the refractive index of the cured product can be increased while maintaining good transparency of the cured product. Therefore, when the cured product is applied to the encapsulant 5 in the light-emitting device 1, the extraction efficiency of the light that passes through the encapsulant 5 and is emitted to the outside can be improved. The average particle size of the high refractive index particles is preferably within the range of 5 to 30 nm, and more preferably within the range of 10 to 20 nm.

The proportion of high refractive index particles in composition (X) is appropriately designed so that the cured product has the desired refractive index. In particular, it is preferable that the high refractive index particles are contained in composition (X) so that the refractive index of the cured product is in the range of 1.45 or more and less than 1.55. In this case, the light extraction efficiency of the light emitting device 1 is particularly improved.

When composition (X) contains moisture absorbent (C), composition (X) preferably further contains dispersant (D). In this case, dispersant (D) can improve the dispersibility of moisture absorbent (C) in composition (X). Therefore, composition (X) is less likely to experience an increase in viscosity and a decrease in storage stability due to moisture absorbent (C).

The dispersant (D) is a surfactant that can be adsorbed to particles. The dispersant (D) has an adsorption group (generally also called an anchor) that can be adsorbed to particles, and a molecular skeleton (generally also called a tail) that attaches to the particles by adsorbing the adsorption group to the particles. The dispersant (D) contains at least one component selected from the group consisting of, for example, an acrylic dispersant in which the tail is an acrylic molecular chain, a urethane dispersant in which the tail is a urethane molecular chain, and a polyester dispersant in which the tail is a polyester molecular chain. The adsorption group includes, for example, at least one of a basic polar functional group and an acidic polar functional group. The basic polar functional group includes, for example, at least one group selected from the group consisting of an amino group, an imino group, an amide group, an imide group, and a nitrogen-containing heterocyclic group. The acidic polar functional group includes, for example, at least one group selected from the group consisting of a carboxyl group and a phosphate group. The dispersant (D) can contain at least one compound selected from the group consisting of, for example, the Solsperse series manufactured by Nippon Louvre Resol Co., Ltd., the DISPERBYK series manufactured by BYK Japan Co., Ltd., and the AJISPER series manufactured by Ajinomoto Fine-Techno Co., Ltd.

When the composition (X) contains a dispersant (D), the amount of the dispersant (D) relative to the moisture absorbent (C) is preferably 5 parts by mass or more and 60 parts by mass or less. When the amount of the dispersant (D) is 5 parts by mass or more, the function of the dispersant (D) can be effectively expressed, and when the amount is 60 parts by mass or less, free molecules of the dispersant (D) in the sealant 5 can be prevented from impairing the adhesion between the sealant 5 and the member made of an inorganic material. In addition, the amount of the dispersant (D) is more preferably 15 parts by mass or more, more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less.

It is preferable that composition (X) does not contain a solvent or that the solvent content is 1 mass% or less. In this case, when preparing a cured product from composition (X), it is not necessary to dry composition (X) to volatilize the solvent. In addition, the storage stability of composition (X) is further improved. The solvent content is more preferably 0.5 mass% or less, even more preferably 0.3 mass% or less, and particularly preferably 0.1 mass% or less. It is particularly preferable that composition (X) does not contain a solvent or contains only a solvent that is inevitably mixed in.

This embodiment will be explained in more detail below.

First, the structure of the light-emitting device 1 will be described. The light-emitting device 1 includes a light-emitting element 4 and a sealing material 5 that covers the light-emitting element 4. The sealing material 5 may cover the light-emitting element 4 in direct contact with the light-emitting element 4, or may cover the light-emitting element 4 with some layer interposed between the sealing material 5 and the light-emitting element 4. The light-emitting device 1 may be, for example, a lighting device or a display device (display). The light-emitting element 4 is also called a light source.

The light-emitting element 4 includes, for example, a light-emitting diode. The light-emitting diode includes, for example, at least one of an organic EL element (organic light-emitting diode) and a micro light-emitting diode. When the light-emitting element 4 includes an organic light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, an organic EL display. When the light-emitting element 4 includes a micro light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, a micro LED display. Note that EL stands for electroluminescence, and LED stands for light-emitting diode.

A first example of the structure of the light-emitting device 1 will be described with reference to FIG. 1. This light-emitting device 1 is a top-emission type. The light-emitting device 1 comprises a support substrate 2, a transparent substrate 3 that faces the support substrate 2 with a gap therebetween, a light-emitting element 4 on the surface of the support substrate 2 that faces the transparent substrate 3, and a sealant 5 that is filled between the support substrate 2 and the transparent substrate 3. In addition, in the first example, the light-emitting device 1 comprises a passivation layer 6 that covers the surface of the support substrate 2 that faces the transparent substrate 3 and the light-emitting element 4. That is, the passivation layer 6 is interposed between the light-emitting element 4 and the sealant 5 that covers the light-emitting element 4.

The support substrate 2 is made of, for example, a resin material, but is not limited thereto. The transparent substrate 3 is made of a material having light transmissivity. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate. When the light-emitting element 4 includes an organic EL element, the organic EL element includes, for example, a pair of electrodes and an organic light-emitting layer between the electrodes. The organic light-emitting layer includes, for example, a hole injection layer, a hole transport layer, an organic light-emitting layer, and an electron transport layer, and these layers are stacked in the above order. Although only one light-emitting element 4 is shown in FIG. 1, the light-emitting device 1 may include multiple light-emitting elements 4, and the multiple light-emitting elements 4 may form an array on the support substrate 2. The passivation layer 6 is preferably made of silicon nitride or silicon oxide.

A second example of the structure of the light-emitting device 1 will be described with reference to FIG. 2. Elements in FIG. 2 that are common to the first example shown in FIG. 1 are given the same reference numerals as in FIG. 1, and detailed descriptions will be omitted as appropriate. The light-emitting device 1 shown in FIG. 2 is also of a top-emission type. The light-emitting device 1 comprises a support substrate 2, a transparent substrate 3 that faces the support substrate 2 with a gap therebetween, a light-emitting element 4 on the surface of the support substrate 2 that faces the transparent substrate 3, and a sealant 5 that covers the light-emitting element 4.

When the light-emitting element 4 includes an organic EL element, the organic EL element, as in the first example, includes, for example, a pair of electrodes 41, 43 and an organic light-emitting layer 42 between the electrodes 41, 43. The organic light-emitting layer 42 includes, for example, a hole injection layer 421, a hole transport layer 422, an organic light-emitting layer 423, and an electron transport layer 424, and these layers are stacked in the above order.

The light-emitting device 1 includes a plurality of light-emitting elements 4, which form an array 9 (hereinafter referred to as element array 9) on a support substrate 2. The element array 9 also includes a partition 7. The partition 7 is on the support substrate 2 and separates two adjacent light-emitting elements 4. The partition 7 is fabricated, for example, by forming a photosensitive resin material using a photolithography method. The element array 9 also includes connection wiring 8 that electrically connects the electrodes 43 and the electron transport layers 424 of adjacent light-emitting elements 4. The connection wiring 8 is provided on the partition 7.

The light emitting device 1 also includes a passivation layer 6 that covers the light emitting element 4. The passivation layer 6 is preferably made of silicon nitride or silicon oxide. The passivation layer 6 includes a first passivation layer 61 and a second passivation layer 62. The first passivation layer 61 covers the element array 9 in a state where the first passivation layer 61 is in direct contact with the element array 9, thereby covering the light emitting element 4. The second passivation layer 62 is disposed on the opposite side of the element array 9 with respect to the first passivation layer 61, and a gap is provided between the second passivation layer 62 and the first passivation layer 61. The sealant 5 is filled between the first passivation layer 61 and the second passivation layer 62. That is, the first passivation layer 61 is interposed between the light emitting element 4 and the sealant 5 that covers the light emitting element 4.

Furthermore, a second sealing material 52 is filled between the second passivation layer 62 and the transparent substrate 3. The second sealing material 52 is made of, for example, a transparent resin material. The material of the second sealing material 52 is not particularly limited. The material of the second sealing material 52 may be the same as or different from the sealing material 5.

Next, a method for producing the encapsulant 5 using the composition (X) and a method for producing the light emitting device 1 will be described.

In this embodiment, it is preferable to form a coating film by forming the composition (X) by the inkjet method, irradiate the coating film with ultraviolet light, and then heat the composition (X) to form the sealing material 5. In this embodiment, the composition (X) can be applied and formed by the inkjet method.

When applying composition (X) by the inkjet method, if composition (X) has a sufficiently low viscosity at room temperature, for example, if the viscosity at 25°C is 50 mPa·s or less, composition (X) can be molded by applying it by the inkjet method without heating.

When composition (X) has the property of being reduced in viscosity by heating, composition (X) may be heated and then applied and molded by an inkjet method. When composition (X) has a viscosity of 50 mPa·s or less at 40°C, composition (X) can be reduced in viscosity by simply heating it slightly, and this reduced-viscosity composition (X) can be ejected by an inkjet method. The heating temperature of composition (X) is, for example, 20°C or higher and 50°C or lower.

When the coating film obtained by molding the composition (X) is irradiated with light to cure it, the light irradiated to the coating film is, for example, ultraviolet light. By ultraviolet light, we mean light rays having a wavelength of 200 nm or more and 410 nm or less. The wavelength of the light irradiated to the coating film is preferably 350 nm or more and 410 nm or less, and more preferably 385 nm or more and 405 nm or less. A representative example of light irradiated to the coating film is light with a wavelength of 395 nm. Note that the wavelength of the light irradiated to the coating film is not limited to the above explanation, so long as it can cure the coating film.

When the photopolymerization initiator (B) contains an oxime ester-based photopolymerization initiator (B1) and a compound (B11), it is preferable that the wavelength of the ultraviolet light acting on the oxime ester-based photopolymerization initiator (B1) is different from the wavelength of the ultraviolet light acting on the compound (B11). In particular, it is preferable to expose the composition (X) to ultraviolet light having a wavelength that acts on the compound (B11), and then expose the composition (X) to ultraviolet light having a wavelength that acts on the oxime ester-based photopolymerization initiator (B1). As a result, even if coloring occurs due to the compound (B11) during exposure, this coloring can be suppressed by the bleaching property of the oxime ester-based photopolymerization initiator (B1). Therefore, it is possible to impart translucency to the sealing material 5, which is a cured product of the composition (X). It is preferable that the wavelength of the ultraviolet light acting on the compound (B11) is lower than the wavelength of the ultraviolet light acting on the oxime ester-based photopolymerization initiator (B1). For example, the wavelength of ultraviolet light acting on compound (B11) is 380 nm or more and 405 nm or less, and the wavelength of ultraviolet light acting on oxime ester-based photopolymerization initiator (B1) is 330 nm or more and 395 nm or less.

The irradiation intensity of the light irradiated to the coating film is preferably 20 mW/m ² or more and 20 W/cm ² or less. Note that the irradiation intensity of the light is not limited to the above explanation as long as it can cure the coating film.

When irradiating the coating with light, the shape of the portion irradiated with light may be an area type having a certain area, or a line type. In the case of a line type, light can be irradiated to the entire coating by moving the coating relative to the light source, or by moving the light source relative to the coating. In this case, it is easy to adjust the time that the coating is irradiated with light, and by adjusting this time, it is easy to adjust the accumulated amount of light.

When the cured coating is further heated, the heating temperature is preferably 90°C or higher. In this case, the curing of the coating is further accelerated, and the linear expansion coefficient of the sealing material 5 is easily reduced, and thus the linear expansion coefficient of the sealing material 5 is easily achieved to be 100 ppm/°C or higher and 130 ppm/°C or lower. The heating temperature is preferably 150°C or lower. In this case, the light-emitting element 4 is less likely to deteriorate due to heat.

More specifically, for example, first, a support substrate 2 is prepared. A partition wall is fabricated on one surface of the support substrate 2 by photolithography using, for example, a photosensitive resin material. Next, a plurality of light-emitting elements 4 are provided on one surface of the support substrate 2. The light-emitting elements 4 can be fabricated by an appropriate method such as a vapor deposition method or a coating method. It is particularly preferable to fabricate the light-emitting elements 4 by a coating method such as an inkjet method. In this way, an element array 9 is fabricated on the support substrate 2.

Next, a first passivation layer 61 is provided on the element array 9. The first passivation layer 61 can be produced by a deposition method such as a plasma CVD method.

Next, the composition (X) is formed on the first passivation layer 61, for example, by an inkjet method to form a coating film. If the inkjet method is used for both the formation of the light-emitting element 4 and the application of the composition (X), the manufacturing efficiency of the light-emitting device 1 can be particularly improved. That is, as described above, the composition (X) contains the acrylic compound (A) and the oxime ester photopolymerization initiator (B1), and therefore can be cured even in an atmosphere containing oxygen, such as the air atmosphere. Therefore, when producing the sealing material 5 from the composition (X), it is possible to reduce the manufacturing costs and the manufacturing man-hours.

The coating is then cured by irradiating it with ultraviolet light to produce the sealant 5. The thickness of the sealant 5 is, for example, 5 μm or more and 50 μm or less.

It is also preferable that the thickness of the sealing material 5 is 4 μm or more and 50 μm or less, and more preferably 4 μm or more and 15 μm or less. As described above, in this embodiment, since small droplets of the composition (X) can be easily formed at high density by the inkjet method, it is easy to realize a thin sealing material 5 of 4 μm or more and 15 μm or less. By thinning the sealing material 5 in this way, tensile stress and compressive stress are less likely to occur in the sealing material 5 within the light-emitting device 1. Therefore, it is easier to realize a flexible light-emitting device 1.

Next, a second passivation layer 62 is provided on the sealing material 5. The second passivation layer 62 can be produced by a deposition method such as plasma CVD.

Next, an ultraviolet-curable resin material is applied to one surface of the support substrate 2 so as to cover the second passivation layer 62, and then the transparent substrate 3 is placed on top of this resin material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate.

Next, ultraviolet light is applied from the outside toward the transparent substrate 3. The ultraviolet light passes through the transparent substrate 3 and reaches the ultraviolet-curable resin material. This causes the ultraviolet-curable resin material to harden, producing the second sealing material 52.

The optical component is not limited to the sealing material 5 for the light-emitting element 4. The composition (X) can be used to produce various optical components. For example, the optical component may be a color resist. In this case, for example, a phosphor is contained in the composition (X), and a color resist in a color filter is produced from this composition (X). In this case, it is easy to produce the color resist in the color filter with high density and precision. This color filter can be provided in a display device such as an organic EL display or a micro LED display.

Specific examples of the present disclosure are presented below. However, the present disclosure is not limited to the examples.

1. Preparation of Compositions Compositions of the examples and comparative examples were prepared by mixing the components shown in Tables 1 and 2 below.

The details of the ingredients shown in Tables 1 and 2 are as follows:

(1) Polyfunctional acrylic compound: Tripropylene glycol diacrylate; a bifunctional compound, n=3 in formula (7),
Polyethylene glycol 200 dimethacrylate; a bifunctional compound, n=4 in formula (7),
Polyethylene glycol 200 diacrylate; a bifunctional compound, n=4 in formula (7),

(2) Photopolymerization initiator: TPO; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. Acylphosphine oxide photopolymerization initiator, manufactured by BASF Corporation, product name: Irgacure TPO.
OXE01: A compound represented by the formula (5), manufactured by BASF Corporation, product name: Irgacure OXE01.
OXE02: A compound represented by the formula (6), manufactured by BASF Corporation, product name: Irgacure OXE02.

(3) Sensitizer: EPA; ethyl 4-dimethylaminobenzoate, a tertiary amine sensitizer manufactured by Nippon Kayaku Co., Ltd., product number Kayacure EPA.

(4) Moisture absorbent (4-1) Zeolite particles 1
Zeolite particles 1 are produced by the following method, and have a D50 of 60 nm, a D90 of 110 nm, and a pH of 11.

Zeolite 4A sodium ion powder with an average particle size of 5 μm was prepared as the starting material, and 100 g of this zeolite powder was mixed with 100 g of ion-exchanged water to prepare a slurry.

400 g of zirconia beads with a particle size of 100 μm were added to this slurry, and the zeolite powder in the slurry was pulverized in a bead mill for 3 hours to obtain an average particle size of 120 nm for the Na-based zeolite. The slurry flow rate at this time was 10 kg/h, and the slurry viscosity was 10 mPa·s.

Next, the zirconia beads with a particle size of 100 μm were removed from the slurry and replaced with 400 g of zirconia beads with a particle size of 50 μm. The Na-based zeolite in the slurry was then pulverized for 1 hour using a bead mill pulverizer, resulting in an average particle size of the zeolite powder of 70 nm. The slurry flow rate at this time was 10 kg/h, and the slurry viscosity was 6 mPa·s.

Next, the zirconia beads with a particle size of 50 μm were removed from the slurry and replaced with 450 g of zirconia beads with a particle size of 30 μm. The zeolite powder in the slurry was then pulverized for 1 hour using a bead mill pulverizer, resulting in an average particle size of the zeolite powder of 60 nm. The slurry flow rate at this time was 10 kg/h, and the slurry viscosity was 4 mPa·s.

The slurry was then left to stand at 180°C for 2 to 3 hours to obtain finely pulverized zeolite powder. This zeolite powder was crushed in a mortar and passed through a mesh to adjust the particle size, obtaining zeolite particles 1.

The pH of the zeolite particles was measured as follows: 0.05 g of zeolite particles and 99.95 g of ion-exchanged water were placed in a polyethylene bottle, which was then placed in a thermostatic chamber and heated at 90°C for 24 hours. The pH of the supernatant liquid in the bottle was then measured using a compact pH meter (LAQUAtwin) B-711 manufactured by Horiba, Ltd.

(4-2) Zeolite particles 2
Zeolite particles 2 are produced by the following method, and have a D50 of 150 nm, a D90 of 250 nm, and a pH of 11.

Zeolite 4A sodium ion with an average particle size of 5 μm was prepared as the starting zeolite powder, and 100 g of this zeolite powder was mixed with 100 g of ion-exchanged water to prepare a slurry. The zeolite powder in this slurry was pulverized to an average particle size of 150 nm using a method similar to that for zeolite particles 1.

The slurry was then left to stand at 180°C for 2 to 3 hours to obtain finely pulverized zeolite powder. This zeolite powder was crushed in a mortar and passed through a mesh to adjust the particle size, obtaining zeolite particles 2.

(5) Dispersant - Solsperse 32000: manufactured by Lubrizol Corporation, product name SOLSPERSE 32000, a surfactant containing a tertiary amino group.

2. Evaluation Test 2.1. Bleaching Property Each composition of the Examples and Comparative Examples was applied onto a substrate to prepare a coating film so that the thickness of the cured film was 10 μm. The coating film was then exposed once to ultraviolet light with a wavelength of 395 nm (first exposure). After the first exposure, the composition was further exposed to ultraviolet light with a wavelength of 365 nm and an exposure amount of 1500 mJ/ ^cm2 (second exposure). This resulted in a film, which was a cured product of the composition. The bleaching property of each Example and Comparative Example was evaluated according to the following items.
A: The transmittance of the film after the second exposure (total light transmittance in accordance with JIS K7361-1) is 95% or more.
B: The transmittance of the film after the second exposure is 90% or more and less than 95%;
C: The transmittance of the film after the second exposure is less than 90%.

2.2. Water Content The water content of the composition was measured using a Karl Fischer water content meter (manufactured by Mitsubishi Analytech Co., Ltd., model number CA-200) and a water vaporizer (manufactured by Mitsubishi Analytech Co., Ltd., model number VA-200).

2.3. Initial light emission characteristics An ITO electrode having a thickness of 100 nm was prepared on a glass substrate. On this ITO electrode, a layer of α-NPD having a thickness of 60 nm, a layer of _Alq3 having a thickness of 60 nm, a layer of lithium fluoride having a thickness of 0.5 nm, a layer of MgAg having a thickness of 10 nm, and a layer of IZO (indium zinc oxide) having a thickness of 100 nm were sequentially prepared by a vacuum deposition method. As a result, an organic EL element having a planar dimension of 10 mm x 10 mm was prepared on the substrate. Next, a silicon nitride layer having a planar dimension of 13 mm x 13 mm and a thickness of about 250 nm covering the organic EL element was prepared on the substrate by a plasma CVD method. A composition was applied on this silicon nitride layer using an inkjet printer (Microjet Corporation, "NanoPrinter 300"). Next, the composition was exposed to light with a peak wavelength of 395 nm for 15 seconds in an oxygen-containing atmosphere (oxygen concentration 210 L/m ³ ) and at about 30 mW/cm ^2. Then, under the same conditions, the composition was further exposed to light with a peak wavelength of 365 nm for 15 seconds to harden the composition and produce an encapsulant. After producing the encapsulant, a silicon nitride layer (passivation layer) with a planar dimension of 12 mm×12 mm and a thickness of about 250 nm that covers the organic EL element was produced on the substrate by plasma CVD. This resulted in an organic EL light-emitting device.

A voltage of 3 V was applied to the organic EL element immediately after production to cause the organic EL element to emit light. The luminescence state of the organic EL element at this time (presence or absence of dark spots and peripheral quenching of the organic EL element) was visually observed.

As a result, the organic EL element was rated as "A" when it emitted light uniformly without dark spots or peripheral quenching. The organic EL element was rated as "B" when either dark spots or peripheral quenching was observed in an area of 20% or less of the entire element. The organic EL element was rated as "C" when either dark spots or peripheral quenching was observed in an area of 20% or more but less than 70% of the entire element.

The organic EL light-emitting device prepared for the test in 2.3 above was exposed to conditions of 85° C. and 85% RH for 100 hours, and then a voltage of 3 V was applied to the organic EL element to cause the organic EL element to emit light. The light-emitting state of the organic EL element at this time (presence or absence of dark spots and peripheral quenching of the organic EL element) was visually observed.

As a result, the organic EL element was rated as "A" when it emitted light uniformly without dark spots or peripheral quenching. The organic EL element was rated as "B" when either dark spots or peripheral quenching was observed in an area of 20% or less of the entire element.

2.5. Inkjet properties (inkjet printability)
Ricoh model MH2420 was used as an inkjet printer, the composition was placed in an inkjet printer cartridge, and after confirming that the composition in the cartridge could be discharged from the nozzle of the inkjet printer, the composition was discharged from the nozzle to continuously print a test pattern. As a result, the case where the composition could be discharged for one hour and the discharge operation was stable was rated as "A", the case where the composition could be discharged for one hour but the discharge operation became intermittently unstable was rated as "B", and the case where the nozzle became clogged before one hour had passed since the start of discharge and the composition could no longer be discharged was rated as "C".

2.6. Tackiness (curability) 365 nm LED
The compositions of each Example and Comparative Example were applied onto a smooth table, and then photocured by irradiating the composition with light for 15 seconds using an LED-UV irradiator manufactured by CCS Inc. under the conditions of a peak wavelength of 365 nm and an output of 100 mW/ ^cm2 . When irradiating the composition with light, an oxygen-containing atmosphere (oxygen concentration 210 L/ ^m3 ) was used. This resulted in the production of a film with a thickness of 10 μm. A tester touched the surface of the film with his/her finger to evaluate the tackiness. As a result, the tester rated the film as "A" when no tackiness was felt by the tester, "B" when slight tackiness was felt, and "C" when strong tackiness was felt.

2.7. Tackiness (curability) 395 nm LED
The tackiness was evaluated in the same manner as in 2.6 above, except that the peak wavelength was set to 395 nm.

2.8. Transmittance A coating film was prepared by applying the composition of each Example and Comparative Example, and this coating film was irradiated with light for 15 seconds using an LED-UV irradiator manufactured by CCS Inc. under conditions of a peak wavelength of 395 nm and approximately 100 mW/ ^cm2 to photocure, thereby preparing a film having a thickness of 10 μm. The atmosphere during light irradiation was the same as in the case of 2.6 above. The total light transmittance of this film was measured according to JIS K7361-1.

2.9. Outgassing of cured product When the cured product of the composition was heated, the outgassing was sampled by the headspace method and measured by gas chromatography. 100 mg of the composition was placed in a headspace vial, and the composition was irradiated with light at a peak wavelength of 395 nm and approximately 100 mW/ ^cm2 using an LED-UV irradiator manufactured by CCS Inc. to cure the composition, and then the vial was sealed and heated at 80°C for 30 minutes, after which the gas phase in the vial was introduced into a gas chromatograph for analysis. As a result, the case where the generated gas was 300 ppm or less was evaluated as "A", the case where the generated gas was more than 300 ppm but less than 500 ppm was evaluated as "B", and the case where the generated gas was 500 ppm or more was evaluated as "C".

Claims (9)

An acrylic compound (A),
A photopolymerization initiator (B),
The composition does not contain a solvent, or contains the solvent and the content of the solvent is 1% by mass or less,
The photopolymerization initiator (B) contains an oxime ester-based photopolymerization initiator (B1) and a compound (B11) other than the oxime ester-based photopolymerization initiator (B1),
The compound (B11) contains an acylphosphine oxide initiator,
The amount of the compound (B11) relative to the solid content of the ultraviolet-curable resin composition is 0.5% by mass or more and 5% by mass or less,
The ratio of the oxime ester photopolymerization initiator (B1) is 0.5% by mass or more and 10% by mass or less with respect to the acrylic compound (A),
The viscosity at 25°C is 1 mPa·s or more and 35 mPa·s or less,
To produce an optical component that transmits light emitted by a light source,
An ultraviolet-curable resin composition. The acrylic compound (A) contains a polyalkylene glycol di(meth)acrylate.
The ultraviolet-curable resin composition according to claim 1 . The proportion of the polyalkylene glycol di(meth)acrylate is 40% by mass or more and 80% by mass or less with respect to the acrylic compound (A).
The ultraviolet-curable resin composition according to claim 2 . The acrylic compound (A) contains pentaerythritol tetra(meth)acrylate.
The ultraviolet-curable resin composition according to any one of claims 1 to 3. The ratio of the pentaerythritol tetra(meth)acrylate to the acrylic compound (A) is 0.5% by mass or more and 10% by mass or less.
The ultraviolet-curable resin composition according to claim 4. The acrylic compound (A) contains a compound having a morpholine skeleton.
The ultraviolet-curable resin composition according to any one of claims 1 to 5. The ratio of the compound having a morpholine skeleton to the acrylic compound (A) is 5% by mass or more and 50% by mass or less.
The ultraviolet-curable resin composition according to claim 6 . A method for manufacturing a light emitting device including a light source and an optical component that transmits light emitted by the light source, comprising the steps of:
The ultraviolet-curable resin composition according to any one of claims 1 to 7 is molded by an inkjet method to prepare a coating film;
and producing the optical component by irradiating the coating with ultraviolet light.
A method for manufacturing a light emitting device. A light source;
an optical component that transmits light emitted by the light source;
The optical component is made of a cured product of the ultraviolet-curable resin composition according to any one of claims 1 to 7.
Light emitting device.

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