JP7281758B2 - Ultraviolet curable resin composition for encapsulating organic EL element, method for manufacturing organic EL light emitting device, and organic EL light emitting device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ultraviolet curable resin composition for encapsulating an organic EL element, a method for manufacturing an organic EL light emitting device, and an organic EL light emitting device. The present invention relates to an ultraviolet curable resin composition for sealing an EL element, a method for manufacturing an organic EL light emitting device using the ultraviolet curable resin composition for sealing an organic EL element, and an organic EL light emitting device provided with the sealing material.

Organic EL light-emitting devices are applied to lighting, displays, and the like, and are expected to spread in the future.

Among organic EL light emitting devices, what is called a top emission type has, for example, an organic EL element arranged on a supporting substrate, a transparent substrate arranged so as to face the supporting substrate, and a transparent substrate between the supporting substrate and the transparent substrate. It is configured by filling with a suitable sealing material. In this case, the light emitted by the organic EL element passes through the sealing material and the transparent substrate and is emitted to the outside.

It has been proposed to produce a sealing material in an organic EL light-emitting device by an inkjet method. For example, in Patent Document 1, 75 to 95 wt. % polyethylene glycol dimethacrylate monomer or the like, and 4 to 10 wt. % pentaerythritol tetraacrylate or the like and 1-15 wt. % of a spreading modifier and ink jet method to prepare the encapsulant.

Japanese Patent Publication No. 2017-531049

In organic EL light-emitting devices, members made of inorganic materials are often used as transparent substrates, passivation layers for protecting organic EL elements, and the like. If the adhesion between the sealing material and the member made of an inorganic material is low, moisture that has entered the organic EL light-emitting device reaches the organic EL element through the gap between the sealing material and the member, resulting in an organic EL element. There is a risk that the EL element will deteriorate and a defect called a dark spot will occur. For this reason, the sealing material is sometimes required to have adhesiveness to members made of inorganic materials.

However, when a sealing material is produced from an acrylic composition as described in Patent Document 1, the viscosity of the composition is reduced so that it can be molded by an inkjet method, while the sealing material and the inorganic material are combined. It was difficult to secure the adhesion between the members. In particular, when reducing the diameter of the droplets ejected by the inkjet method in order to make the sealing material thinner, it is necessary to reduce the viscosity of the composition to a very low level. It was very difficult to secure the adhesion between the material members.

An object of the present invention is to provide an organic EL that can be used to produce a sealing material in an organic EL light emitting device, can provide the sealing material with adhesion to a member made of an inorganic material, and does not easily cause a viscosity increase. UV curable resin composition for element sealing, method for manufacturing organic EL light emitting device using this UV curable resin composition for sealing organic EL element, and curing of this UV curable resin composition for sealing organic EL element An object of the present invention is to provide an organic EL light-emitting device having a sealing material made of a material.

An ultraviolet curable resin composition for encapsulating an organic EL element according to one aspect of the present invention contains an acrylic compound (A) and a photopolymerization initiator (B), and the acrylic compound (A) is represented by the following formula (1 ), a compound (A1) which is at least one component selected from the group consisting of morpholine acrylate, diethylacrylamide, dimethylaminopropylacrylamide and pentamethylpiperidyl methacrylate, and in the formula (1) , 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, and R ¹ to R ¹¹ are not chemically bonded to each other.

A method for manufacturing an organic EL light-emitting device according to one aspect of the present invention is a method for manufacturing an organic EL light-emitting device including an organic EL element and a sealing material covering the organic EL element. After molding an ultraviolet curable resin composition by an inkjet method, the ultraviolet curable resin composition for encapsulating an organic EL element is irradiated with ultraviolet rays to be cured, thereby producing the encapsulant.

An organic EL light-emitting device according to one aspect of the present invention includes an organic EL element and a sealing material that covers the organic EL element, and the sealing material is an ultraviolet curable resin composition for sealing the organic EL element. is a cured product of

According to one aspect of the present invention, it can be used to produce a sealing material in an organic EL light-emitting device, can impart adhesion to a member made of an inorganic material, and causes an increase in viscosity. UV curable resin composition for encapsulating organic EL elements, method for manufacturing organic EL light emitting device using this UV curable resin composition for sealing organic EL elements, and this UV curable resin composition for sealing organic EL elements It is possible to provide an organic EL light-emitting device provided with a sealing material made of a cured product.

FIG. 1 is a schematic cross-sectional view of a first example of an organic EL light emitting device. FIG. 2 is a schematic cross-sectional view of a second example of the organic EL light emitting device.

An embodiment of the present invention will be described below.

1. Overview of Embodiment An organic EL light-emitting device 1 according to the present embodiment includes an organic EL element 4 and a sealing material 5 covering the organic EL element 4 .

A first example of the structure of the organic EL light emitting device 1 will be described with reference to FIG. This organic EL light emitting device 1 is of a top emission type. The organic EL light emitting device 1 includes a supporting substrate 2, a transparent substrate 3 facing the supporting substrate 2 with a gap therebetween, an organic EL element 4 on the surface of the supporting substrate 2 facing the transparent substrate 3, and the supporting substrate 2. A sealing material 5 filled between the transparent substrate 3 and the transparent substrate 3 is provided. In the example shown in FIG. 1, the organic EL light-emitting device 1 includes a passivation layer 6 that covers the surface of the support substrate 2 facing the transparent substrate 3 and the organic EL elements 4 .

The support substrate 2 is made of, for example, a resin material, but is not limited to this. The transparent substrate 3 is made of a translucent material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate. The organic EL element 4 is also called an organic light emitting diode. The organic EL element 4 includes, for example, a pair of electrodes and an organic light-emitting layer between the electrodes. Passivation layer 6 is preferably made of silicon nitride or silicon oxide.

A second example of the structure of the organic EL light emitting device 1 will be described with reference to FIG. Elements common to those in the first example shown in FIG. 1 are assigned the same reference numerals as those in FIG. 1, and detailed description thereof will be omitted as appropriate. The organic EL light emitting device 1 shown in FIG. 2 is also of the top emission type. The organic EL light emitting device 1 includes a support substrate 2, a transparent substrate 3 facing the support substrate 2 with a gap therebetween, an organic EL element 4 on the surface of the support substrate 2 facing the transparent substrate 3, and an organic EL element 4. is provided with a sealing material 5 that covers the

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

The organic EL light-emitting device 1 has a plurality of organic EL elements 4 , and the plurality of organic EL elements 4 form an array 9 (hereinafter referred to as element array 9 ) on the support substrate 2 . The element array 9 also comprises partition walls 7 . The partition wall 7 is located on the support substrate 2 and partitions between two adjacent organic EL elements 4 . The partition wall 7 is produced by molding a photosensitive resin material by photolithography, for example. The element array 9 also includes connection wirings 8 that electrically connect the electrodes 43 and the electron transport layers 424 of the adjacent organic EL elements 4 to each other. The connection wiring 8 is provided on the partition wall 7 .

The organic EL light-emitting device 1 also includes a passivation layer 6 covering the organic EL elements 4 . Passivation layer 6 is preferably made of silicon nitride or silicon oxide. Passivation layer 6 includes a first passivation layer 61 and a second passivation layer 62 . The first passivation layer 61 covers the organic EL elements 4 by covering the element array 9 while being in direct contact with the element array 9 . The second passivation layer 62 is arranged on the side opposite to the element array 9 with respect to the first passivation layer 61, and a space is provided between the second passivation layer 62 and the first passivation layer 61. ing. A sealing material 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 organic EL element 4 and the sealing material 5 covering the organic EL 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 that of the sealing material 5 .

The encapsulant 5 can be produced from the ultraviolet curable resin composition for encapsulating an organic EL element according to this embodiment. That is, the ultraviolet curable resin composition for encapsulating the organic EL element is used for producing the encapsulant 5 for the organic EL element 4 . In other words, the UV-curable resin composition for sealing an organic EL element is preferably a composition for producing a sealing material, a composition for sealing an organic EL element, or a composition for manufacturing an organic EL light-emitting device. be.

2. UV-Curable Resin Composition for Sealing Organic EL Elements The UV-curable resin composition for sealing organic EL elements (hereinafter, also referred to as composition (X)) will be described.

Composition (X) contains an acrylic compound (A) and a photopolymerization initiator (B).

The acrylic compound (A) is a compound (A1 ). The compound (A1) can provide the sealing material 5 made from the composition (X) with adhesion to a member made of an inorganic material such as the passivation layer 6 . Moreover, the compound (A1) has a low viscosity as an acrylic compound, and therefore the inclusion of the compound (A1) hardly causes an increase in the viscosity of the composition (X). Furthermore, the compound (A1) is difficult to volatilize, and therefore the composition (X) is less likely to increase in viscosity over time during storage.

Therefore, when the composition (X) is used to produce a sealing material in an organic EL light emitting device, the sealing material 5 can be provided with adhesion to members made of an inorganic material, and the composition ( The increase in viscosity of X) is less likely to occur.

In formula (1), 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.

When X is a divalent hydrocarbon group, X preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. Divalent hydrocarbon radicals are, for example, methylene, ethylene or propylene radicals. It is particularly preferred if X is a single bond or a methylene group. In this case, there is an advantage that the compound (A1) has a small molecular weight and a low viscosity.

When at least one of R ¹ to R ¹¹ is an alkyl group, the alkyl group preferably has 1 to 8 carbon atoms. Alkyl is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. Alkyl groups may be linear or branched. That is, for example, when the alkyl group is a butyl group, the butyl group may be a t-butyl group, an n-butyl group, or a sec-butyl group. When the alkyl group is a hexyl group, the hexyl group may be a t-hexyl group, an n-hexyl group, or a sec-hexyl group. If the alkyl group is an octyl group, the octyl group can be, for example, a t-octyl group. It is particularly preferred if the alkyl group is methyl or t-butyl. In this case, there is an advantage that the compound (A1) has a small molecular weight and a low viscosity.

In formula (1), an alkyl group or -R ¹² -OH is preferably connected only to the 4-position of the cyclohexane ring. That is, of R ¹ to R ¹¹ , it is preferred that at least one of R ⁶ and R ⁷ is an alkyl group or -R ¹² -OH and each of the remaining is H. Of R ¹ to R ¹¹ , it is particularly preferred that only R ⁶ is an alkyl group or -R ¹² -OH and each of the remainder is H. In this case, the compound represented by the formula (1) can have good reactivity, and it is particularly easy to provide the sealing material 5 with adhesion to members made of an inorganic material. This is because the cyclohexane ring in the compound represented by formula (1) has a boat-shaped conformation, and the bulky alkyl group or —R ¹² —OH at the 4-position tends to be positioned at the pseudoequatorial position. it is conceivable that. It is believed that the compound represented by formula (1) having such a structure enhances the reactivity of the (meth)acryloyl group in the compound represented by formula (1). Moreover, when the compound represented by formula (1) has such a structure, the compound represented by formula (1) can increase the free volume in the sealing material 5 . Therefore, it is considered that the interfacial free energy between the sealing material 5 and the member made of the inorganic material tends to decrease, and the adhesion between the sealing material 5 and the member made of the inorganic material tends to increase. The bulkier the alkyl group or —R ¹² —OH, the more likely it ^is to be positioned in the pseudoequatorial position. From this point of view, the alkyl group or -R ¹² -OH preferably has as many carbon atoms as possible, and the alkyl group or -R ¹² -OH preferably has a branch. For example, an alkyl group or --R ¹² --OH is preferably a t-butyl group.

In formula (1), it is also preferred that an alkyl group or -R ¹² -OH is attached only to each of the 3- and 5-positions of the cyclohexane ring. That is, among R ¹ to R ¹¹ , at least one of R ⁴ and R ⁵ is an alkyl group or -R ¹² -OH, at least one of R ⁸ and R ⁹ is an alkyl group or -R ¹² -OH, It is preferred that each of the remaining is H. Of R ¹ to R ¹¹ , only one of R ⁴ and R ⁵ is an alkyl group or -R ¹² -OH, at least one of R ⁸ and R ⁹ is an alkyl group or -R ¹² -OH, and the remaining More preferably each is H. Of R ¹ to R ¹¹ , at least one of R ⁴ and R ⁵ is an alkyl group or -R ¹² -OH, only one of R ⁸ and R ⁹ is an alkyl group or -R ¹² -OH, and the remaining It is also more preferred that each is H. Also in this case, the compound represented by the formula (1) can have good reactivity, and can particularly easily provide the sealing material 5 with adhesion to members made of an inorganic material. This is because the cyclohexane ring in the compound shown in formula (1) has a boat-shaped conformation, and the bulky alkyl groups or —R ¹² —OH at each of the 3- and 5-positions are located in the pseudoequatorial position. This is probably because it is easy. For this reason, the reactivity of the ( ^meth )acryloyl group in the compound represented by formula (1) is enhanced, and It is considered that the adhesion between the sealing material 5 and the member made of the inorganic material tends to be high. The bulkier the alkyl group or —R ¹² —OH, the more likely it ^is to be positioned in the pseudoequatorial position. From this point of view, the alkyl group or -R ¹² -OH preferably has as many carbon atoms as possible, and the alkyl group or -R ¹² -OH preferably has a branch. For example, an alkyl group or --R ¹² --OH is preferably a t-butyl group.

When at least one of R ¹ to R ¹¹ is —R ¹² —OH, R ¹² preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms. R ¹² is, for example, methylene, ethylene or propylene. It is particularly preferred if R ¹² is a methylene group. In this case, there is an advantage that the compound (A1) has a small molecular weight and a low viscosity.

In formula (1) it is particularly preferred if each of R ¹ to R ¹¹ is H or an alkyl group and at least one of R ¹ to R ¹¹ is an alkyl group. In this case, the compound of formula (1) can have a particularly low viscosity, so that composition (X) can have a particularly low viscosity. Therefore, the composition (X) can be particularly easily molded by an inkjet method.

The compound (A1) preferably contains at least one compound selected from the group consisting of a compound represented by the following formula (11), a compound represented by the following formula (12), and a compound represented by the following formula (13).

It is particularly preferable if compound (A1) contains at least one of the compound represented by formula (11) and the compound represented by formula (12). In this case, it is particularly easy to reduce the viscosity of the composition (X), to increase the glass transition temperature of the sealing material 5, and to increase the adhesion between the sealing material 5 and the member made of an inorganic material. In addition, since the compound represented by the formula (11) and the compound represented by the formula (12) are difficult to volatilize, the storage stability of the composition (X) is likely to be improved.

It is also preferred that compound (A1) contains at least one component selected from the group consisting of morpholine acrylate, diethylacrylamide, dimethylaminopropylacrylamide and pentamethylpiperidyl methacrylate. Since these compounds contain nitrogen, they have good affinity with inorganic materials, so that the adhesion between the sealing material 5 and members made of inorganic materials can be particularly easily improved. In addition, these compounds have low viscosities, and are therefore less likely to increase the viscosity of composition (X). Furthermore, since these compounds are difficult to volatilize, it is easy to improve the storage stability of the composition (X).

The boiling point of the compound contained in compound (A1) is preferably 200° C. or higher, more preferably 250° C. or higher. In this case, compound (A1) particularly tends to improve the storage stability of composition (X). The boiling point of the compound represented by formula (11) is 265°C, the boiling point of the compound represented by formula (12) is 234°C, the boiling point of the compound represented by formula (13) is 294°C, the boiling point of morpholine acrylate is 255°C, and the boiling point of diethylacrylamide is 255°C. The boiling point is 205° C., the boiling point of dimethylaminopropylacrylamide is 285° C., and the boiling point of pentamethylpiperidyl methacrylate is 265° C. From this point as well, these compounds are preferable.

The amount of compound (A1) is preferably 5% by mass or more and 80% by mass or less with respect to the entire acrylic compound (A). In this case, the sealing material 5 can achieve both a high glass transition temperature and adhesion to members made of an inorganic material. The amount of compound (A1) is more preferably 5% by mass or more and 60% by mass or less, and particularly preferably 5% by mass or more and 50% by mass or less.

When the composition (X) contains a hygroscopic agent (E) described later, particularly when the hygroscopic agent (E) is contained and the hygroscopic agent (E) contains zeolite particles, the compound (A1) is represented by the formula ( It is preferable that the acrylic compound (A) contains only the compounds shown in 1) and that the acrylic compound (A) does not contain a compound having a nitrogen atom. In this case, the composition (X) is less likely to increase in viscosity during storage. This is probably because when the composition (X) contains the nitrogen-containing compound and the moisture absorbent (E), the nitrogen-containing compound easily reacts with the moisture absorbent (E). Further, regardless of the presence or absence of the moisture absorbent (E), when the compound (A1) contains only the compound represented by the formula (1) and the acrylic compound (A) does not contain a compound having a nitrogen atom, There is also an advantage that the sealing material 5 becomes difficult to discolor.

The acrylic compound (A) may further contain a compound (A2) other than the compound (A1).

Compound (A2) contains, for example, a polyfunctional acrylic compound (A21) having two or more (meth)acryloyl groups in one molecule. In this case, the polyfunctional acrylic compound (A21) can increase the glass transition temperature of the cured product of the composition (X), and therefore can increase the heat resistance of the cured product and the sealing material 5 .

When the acrylic compound (A) contains the polyfunctional acrylic compound (A21), the amount of the polyfunctional acrylic compound (A21) relative to the total amount of the acrylic compound (A) is preferably 5% by mass or more and 85% by mass or less. When the amount of the polyfunctional acrylic compound (A21) is 5% by mass or more, the polyfunctional acrylic compound (A21) particularly tends to increase the glass transition temperature of the cured product. When the amount of the polyfunctional acrylic compound (A21) is 85% by mass or less, the adhesion of the sealing material 5 to the member made of an inorganic material can be enhanced.

Polyfunctional acrylic compounds (A21) include, for example, 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, cyclohexanedimethanol diacrylate, tricyclodecanedimethanol diacrylate, bisphenol A polyethoxy diacrylate, bisphenol F polyethoxy diacrylate, pentatriestol tetra Acrylates, propoxylated (2) neopentyl glycol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl) isocyanurate 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 Acrylates, 1,4-butanediol diacrylate, 1,9-nonanediol diacrylate, tetraethylene glycol diacrylate, 2-n-butyl-2-ethyl-1,3-propanediol diacrylate, neopentyl hydroxypivalate 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 acrylates, tetramethylolmethane triacrylate, caprolactone-modified trimethylolpropane triacrylate, propoxylate glyceryl triacrylate, tetramethylolmethane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, di Pentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, tripropylene glycol di( It contains at least one compound selected from the group consisting of meth)acrylate, ethoxylated trimethylolpropane triacrylate, and propoxylated trimethylolpropane triacrylate.

The acrylic equivalent of the polyfunctional acrylic compound (A21) is preferably 150 g/eq or less, more preferably 90 g/eq or more and 150 g/eq or less. The weight average molecular weight of the polyfunctional acrylic compound (A21) is, for example, 100 or more and 1000 or less, more preferably 200 or more and 800 or less.

The polyfunctional acrylic compound (A21) preferably has at least one of a benzene ring, an alicyclic ring and a polar group. A polar group is, for example, at least one of an OH group and an NHCO group. In this case, shrinkage during curing of the composition (X1) can be particularly reduced. Furthermore, adhesion between the cured product and inorganic compounds such as silicon nitride and silicon oxide can be enhanced. Polyfunctional acrylic compounds (A21) are selected in particular from the group consisting of tricyclodecanedimethanol diacrylate, bisphenol A polyethoxy diacrylate, bisphenol F polyethoxy diacrylate, trimethylolpropane triacrylate and pentatriestol tetraacrylate It preferably contains at least one compound. These compounds can particularly reduce shrinkage when the composition (X) is cured. Furthermore, these compounds can further enhance the adhesion between the cured product and members made of inorganic materials such as silicon nitride and silicon oxide.

Compound (A2) also preferably contains a monofunctional acrylic compound (A22) having only one (meth)acryloyl group in one molecule, other than compound (A1). The monofunctional acrylic compound (A22) can suppress shrinkage of the composition (X) during curing.

The amount of the monofunctional acrylic compound (A22) relative to the total amount of the acrylic compound (A) is preferably more than 0% by mass and 70% by mass or less. When the amount of the monofunctional acrylic compound (A22) is more than 0% by mass, the shrinkage of the composition (X) during curing can be suppressed by the monofunctional acrylic compound (A22).

Monofunctional acrylic compounds (A22) are, for example, 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 trimethylolpropane formal monoacrylate, imido 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, 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, 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, isobornyl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 3-methacryloyloxymethylcyclohexene oxide, 3-acryloyloxymethylcyclohexene oxide and dicyclopentenyloxyethyl acrylate; contains at least one compound that

The monofunctional acrylic compound (A22) preferably contains at least one compound selected from the group consisting of compounds having an alicyclic structure and compounds having a cyclic ether structure.

Compounds having an alicyclic structure include, for example, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, It contains at least one compound selected from the group consisting of dicyclopentenyloxyethyl acrylate and dicyclopentenyloxyethyl acrylate.

In particular, acrylic compound (A) preferably contains at least one of isobornyl acrylate and dicyclopentenyloxyethyl acrylate. Isobornyl acrylate and dicyclopentenyloxyethyl acrylate have high glass transition temperatures and can particularly increase the glass transition temperature of the sealing material 5 .

The number of ring members of the cyclic ether structure in the compound having the cyclic ether structure is preferably 3 or more, more preferably 3 or more and 4 or less. The number of carbon atoms contained in the cyclic ether structure is preferably 2 or more and 9 or less, more preferably 2 or more and 6 or less. 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.

Compound (A2) may contain an acrylic component (A23) consisting of at least one of polyethylene glycol dimethacrylate and polyethylene glycol diacrylate. The acrylic component (A23) preferably has a number average molecular weight of 230 or more and 430 or less.

When the acrylic component (A23) contains polyethylene glycol dimethacrylate, polyethylene glycol dimethacrylate includes, for example, polyethylene glycol 200 dimethacrylate represented by the following formula (21). n in equation (21) is 4 on average. When the first acrylic component (A23) contains polyethylene glycol diacrylate, polyethylene glycol diacrylate includes, for example, polyethylene glycol 200 diacrylate represented by the following formula (22). n in equation (22) is 4 on average.

_CH2 =C( _CH3 )-CO-( _OCH2CH2 ) _n -OCO-C( _CH3 ) _{= CH2} (21)
_CH2 =CH-CO-( _OCH2CH2 ) _n -OCO-CH _{= CH2} (22)
When compound (A2) contains acrylic component (A23), compound (A2) preferably further contains acrylic component (A24) consisting of at least one of pentaerythritol tetraacrylate and pentaerythritol tetramethacrylate.

When the compound (A2) contains the acrylic component (A23), the composition (X) may further contain a spreading agent (C). The spreading agent (C) has a viscosity of 14 mPa·s or more and 18 mPa·s or less at 22°C and a surface tension of 35 mN/m or more and 39 mN/m or less at 22°C. The spreading agent (C) can adjust the spreading properties of the composition (X). The spreading agent (C) is preferably a liquid having a lower surface tension than the acrylic component (A23) at the molding temperature. The molding temperature is the temperature of the composition (X) when the composition (X) is molded by a method such as an inkjet method.

The spreading agent (C) preferably contains at least one component selected from the group consisting of alkoxylated aliphatic diacrylates and alkoxylated aliphatic dimethacrylates.

Alkoxylated aliphatic diacrylates are represented, for example, by the following formula (3). In formula (3), n is a number from 3 to 12. Alkoxylated aliphatic dimethacrylates are represented, for example, by the following formula (4). In formula (4), n is a number from 3 to 12.

_CH2 =CH-COO-( _CH2 ) _n -OCO-CH= _CH2 (3)
_CH2 =C( _CH3 )-COO-( _CH2 ) _n -OCO-C( _CH3 )= _CH2 (4)
Specific examples of components that the alkoxylated aliphatic diacrylate can contain are Sartomer Part No. SR-238B (1,6 hexanediol diacrylate; surface tension at 25° C. about 35 mN/m) and Sartomer Part No. SR -9209A (surface tension of about 35 mN/m at 22°C, viscosity of about 25 mN/m at 22°C).

When the acrylic compound (A) contains the acrylic component (A23), the amount of the acrylic component (A23) with respect to the total amount of the acrylic compound (A) is preferably 5% by mass or more and 60% by mass or less. When the acrylic compound (A) contains the acrylic component (A24), the amount of the acrylic component (A24) relative to the total amount of the acrylic compound (A) is preferably 1% by mass or more and 20% by mass or less.

The composition (X) may further contain a radically polymerizable compound (D) other than the acrylic compound (A). The radically polymerizable compound (D) includes a polyfunctional radically polymerizable compound (E1) having two or more radically polymerizable functional groups per molecule and a monofunctional compound having only one radically polymerizable functional group per molecule. Either one or both of the radically polymerizable compound (E2) can be contained.

The amount of the radically polymerizable compound (D) with respect to the total amount of the acrylic compound (A) and the radically polymerizable compound (D) is, for example, 10% by mass or less.

The polyfunctional radically polymerizable compound (E1) is, for example, a 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. It may contain at least one compound selected from More specifically, the polyfunctional radically polymerizable compound (A) is, for example, UV-2000B, UV-2750B, UV-3000B, UV-3010B, UV-3200B, UV-3300B manufactured by Nippon Synthetic Chemical Industry Co., Ltd., UV-3700B, UV-6640B, UV-8630B, UV-7000B, UV-7610B, UV-1700B, UV-7630B, UV-6300B, UV-6640B, UV-7550B, UV-7600B, UV-7605B, UV- 7610B, UV-7630B, UV-7640B, UV-7650B, UT-5449, UT-5454; CN902, CN902J75, CN929, CN940, CN944, CN944B85, CN959, CN961E75, CN961H81, CN9 manufactured by Sartomer 62, CN963, CN963A80, CN963B80, CN963E75, CN963E80, CN963J85, CN964, CN965, CN965A80, CN966, CN966A80, CN966B85, CN966H90, CN966J75, CN968, CN969, CN970, CN97 0A60, CN970E60, CN971, CN971A80, CN971J75, CN972, CN973, CN973A80, CN973H85, CN973J75, CN975, CN977, CN977C70, CN978, CN980, CN981, CN981A75, CN981B88, CN982, CN982A75, CN982B88, CN982E75, CN983, CN984, CN985, CN985B88, CN98 6, CN989, CN991, CN992, CN994, CN996, CN997, CN999, CN9001, CN9002, CN9004, CN9005, CN9006, CN9007, CN9008, CN9009, CN9010, CN9011, CN9013, CN9018, CN9019, CN9024, CN9025, CN9026, CN9028, CN9029, CN 9030, CN9060, CN9165, CN9167, CN9178, CN9290, CN9782, CN9783, CN9788, CN9893; and EBECRYL210, EBECRYL220, EBECRYL230, EBECRYL270, KRM8200, EBECRYL5129, EBECRYL8210, EBECRYL8301, EBECRYL8804, EBECRYL manufactured by Daicel Cytec Co., Ltd. from 8807, EBECRYL9260, KRM7735, KRM8296, KRM8452, EBECRYL4858, EBECRYL8402, EBECRYL9270, EBECRYL8311, EBECRYL8701 containing at least one compound selected from the group consisting of

Monofunctional radically polymerizable compounds (E2) include, 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-epoxidedecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-vinylcyclohexene oxide, 4-vinylcyclohexene It contains at least one compound selected from the group consisting of oxide, N-vinylpyrrolidone and N-vinylcaprolactam.

The photopolymerization initiator (B) is not particularly limited as long as it is a compound that generates radical species when irradiated with ultraviolet rays. The photopolymerization initiator (B) includes, for example, aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds. , a ketoxime ester compound, a borate compound, an azinium compound, a metallocene compound, an active ester compound, a compound having a carbon-halogen bond, and an alkylamine compound.

The photopolymerization initiator (B) preferably contains an acylphosphine oxide photopolymerization initiator. Examples of acylphosphine oxide photoinitiators include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphinate. Examples of product names for acylphosphine oxide photoinitiators include Irgacure TPO, Irgacure TPO-L and Irgacure 819 from BASF.

The amount of the photopolymerization initiator (B) relative to 100 parts by mass of the composition (X) is, for example, 1 part by mass or more and 10 parts by mass or less.

The photoinitiator (B) may contain a sensitizer as part of the photoinitiator (B). The sensitizer can promote the radical generation reaction of the photopolymerization initiator (B), improve the reactivity of radical polymerization, and improve the crosslink density. Sensitizers are, for example, 9,10-dibutoxyanthracene, 9-hydroxymethylanthracene, thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, anthraquinone, 1,2- dihydroxyanthraquinone, 2-ethylanthraquinone, 1,4-diethoxynaphthalene, p-dimethylaminoacetophenone, p-diethylaminoacetophenone, p-dimethylaminobenzophenone, p-diethylaminobenzophenone, 4,4′-bis(dimethylamino)benzophenone, It can contain at least one compound selected from the group consisting of 4,4'-bis(diethylamino)benzophenone, p-dimethylaminobenzaldehyde, and p-diethylaminobenzaldehyde.

The content of the sensitizer in the composition (X) is, for example, 0.1 parts by mass or more and 5 parts by mass or less, preferably 0.1 parts by mass with respect to 100 parts by mass of the solid content of the composition (X) part or more and 3 parts by mass or less. If the content of the sensitizer is within this range, the composition (X) can be cured in the air, and it is necessary to cure the composition (X) in an inert atmosphere such as a nitrogen atmosphere. Gone.

The composition (X) may contain a polymerization accelerator in addition to the photopolymerization initiator (B). Polymerization accelerators include, for example, ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, butoxy p-dimethylaminobenzoate. Contains amine compounds such as ethyl.

Composition (X) may further contain a moisture absorbent (E). The hygroscopic agent (E) is preferably inorganic particles having hygroscopicity, and contains at least one component selected from the group consisting of, for example, zeolite particles, silica gel particles, calcium chloride particles, and titanium oxide nanotube particles. is preferred. It is particularly preferred that the moisture absorbent (E) contains zeolite particles.

Zeolite particles having an average particle size of 200 nm or less can be produced, for example, by pulverizing general industrial zeolite. In producing the zeolite particles, the zeolite may be pulverized and then crystallized by hydrothermal synthesis or the like. In this case, the zeolite particles can have particularly high hygroscopicity. Methods for producing such zeolite particles are known from JP-A-2016-69266, JP-A-2013-049602, and the like.

The zeolite particles preferably contain sodium ions. For that purpose, the zeolite particles are preferably produced from zeolite containing sodium ions, and produced from at least one material selected from the group consisting of A-type zeolite, X-type zeolite and Y-type zeolite among sodium ions. more preferably. It is particularly preferred that the zeolite particles are produced from 4A-type zeolite among A-type zeolites. In these cases, the zeolite particles have a crystal structure suitable for moisture adsorption.

A specific example of a method for producing zeolite particles having an average particle size of 200 nm or less is shown. First, zeolite powder as a raw material is prepared, and this zeolite powder is physically pulverized. For example, zeolite powder can be physically pulverized by mixing zeolite powder with water to prepare a slurry and applying this slurry to a bead mill pulverizer.

Subsequently, the zeolite powder is crystallized by hydrothermal synthesis. For example, hydrothermal synthesis can be performed by heating a slurry containing zeolite powder after physical pulverization in an autoclave. Conditions for hydrothermal synthesis are, for example, a heating temperature range of 150 to 200° C. and a heating time range of 15 to 24 hours.

The zeolite powder is then dried. The drying temperature is, for example, in the range of 150-200° C., and the drying time is, for example, in the range of 2-3 hours. Subsequently, if necessary, the dried zeolite powder is pulverized using a mortar or the like, and then sieved to adjust the particle size.

Subsequently, if necessary, the zeolite powder may be subjected to an ion exchange treatment. The ion exchange treatment is carried out by, for example, dispersing zeolite powder in an aqueous solution containing magnesium ions to prepare a mixture, and heating the mixture. More specifically, the ion exchange treatment is performed, for example, as follows. First, zeolite powder is mixed with magnesium chloride and water, and the resulting mixture is heated and stirred. During this process, it is preferable to repeat the operation of temporarily stopping the stirring, discarding the supernatant of the mixture, then replenishing the mixture with water, and then restarting the stirring a plurality of times at appropriate intervals. . The heating temperature in this treatment is preferably in the range of 40 to 80° C., and the treatment time is preferably in the range of 6 to 8 hours.

After the ion exchange treatment, the zeolite powder is dried. The drying temperature is, for example, in the range of 150-200° C., and the drying time is, for example, in the range of 2-3 hours. Subsequently, if necessary, the dried zeolite powder is pulverized using a mortar or the like, and then sieved to adjust the particle size. Thereby, zeolite particles having an average particle size of 200 nm or less can be obtained.

Crystallization of zeolite powder can also be carried out in the presence of silicates and alkali metal oxides. A specific example of a method for producing zeolite particles having an average particle size of 200 nm or less in that case will be shown. First, zeolite powder is prepared. The zeolite powder preferably has _{a composition of aM12O.bSiO2.Al2O3.cMe} . M1 is an alkali metal, proton, or ammonium ion (NH ₄ ⁺ ), Me is an alkaline earth metal, a is a number in the range of 0.01 to 1, and b is in the range of 20 to 80 and c is a number in the range of 0-1. The zeolite powder preferably contains zeolite containing sodium ions, and more preferably contains at least one material selected from the group consisting of A-type zeolite, X-type zeolite and Y-type zeolite among sodium ions. It is particularly preferred that the zeolite powder contains 4A-type zeolite among the A-type zeolites. This zeolite powder is physically pulverized. For example, zeolite powder can be physically pulverized by using a bead mill pulverizer.

The physically pulverized zeolite powder is dispersed in a solution containing M2 ₂ O, SiO ₂ and H ₂ O to prepare a slurry. M2 is an alkali metal, preferably K or Na. The M2 ₂ O/H ₂ O molar ratio is, for example, in the range from 0.003 to 0.01, and the SiO ₂ /H ₂ O molar ratio is, for example, in the range from 0.006 to 0.025. The amount of zeolite powder is, for example, 0.5-10 g per 100 ml of solution.

Zeolite powder can be crystallized by heating this slurry in an autoclave. The conditions are, for example, a heating temperature range of 100 to 230° C. and a heating time range of 1 to 24 hours. Subsequently, the zeolite powder is washed and then dried. Thereby, zeolite particles having an average particle size of 200 nm or less can be obtained.

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 higher, the crystals of the zeolite particles are less likely to be broken, so that the sealing material produced from the composition (X) containing the zeolite particles can have particularly high hygroscopicity. Further, when the pH of the zeolite particles is 10 or less, the zeolite particles are less likely to inhibit curing when the composition (X) is cured.

The pH of the zeolite particles was obtained by adding 0.05 g of the zeolite particles to 99.95 g of ion-exchanged water, heating the resulting dispersion at 90° C. for 24 hours, and measuring the pH of the supernatant of the dispersion with a pH measuring instrument. It is a value obtained by measuring with As a pH measuring device, for example, a compact pH meter <LAQUAtwin> B-711 manufactured by Horiba, Ltd. can be used.

In order for the pH of the zeolite particles to be 7 or more and 10 or less, the zeolite particles are preferably made of FAU Y-type zeolite having protons as counter cations.

In the process of producing zeolite particles, when performing hydrothermal synthesis of zeolite, a treatment for adjusting pH may be performed. The treatment for adjusting the pH is performed, for example, before heating the slurry containing the zeolite powder prepared for hydrothermal synthesis, during heating the slurry, or after heating the slurry. Adjustment of pH is performed by adding an acid to a slurry, for example. The acid contains at least one component selected from the group consisting of inorganic acids such as hydrochloric acid, sulfuric acid and nitric acid, and organic acids such as formic acid, acetic acid and oxalic acid.

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

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

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

The ratio of the moisture absorbent (E) to the total amount of the composition (X) is preferably 1% by mass or more and 20% by mass or less. If the proportion of the hygroscopic agent (E) is 1% by mass or more, the cured product can have particularly high hygroscopicity. In addition, if the proportion of the moisture absorbent (E) is 20% by mass or less, the viscosity of the composition (X) can be particularly reduced, and the composition (X) must have a sufficiently low viscosity to the extent that it can be applied by an inkjet method. can also The proportion of the moisture absorbent (E) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. Moreover, the proportion of the moisture absorbent (E) 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 (E). In particular, the composition (X) preferably contains nano-sized high refractive index particles. Examples of high refractive index particles include zirconia particles. When the composition (X) contains high refractive index particles, the cured product can have a high refractive index while maintaining good transparency of the cured product. Therefore, when the cured product is applied to the sealing material 5 in the organic EL light-emitting device 1, the extraction efficiency of the light transmitted through the sealing material 5 and emitted to the outside can be improved. The average particle size of the high refractive index particles is preferably in the range of 5 to 30 nm, more preferably in the range of 10 to 20 nm.

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

Composition (X) preferably does not contain a solvent. In this case, there is no need to dry the composition (X) to volatilize the solvent when producing a cured product from the composition (X).

Composition (X) can be prepared by mixing the above components. Composition (X) is preferably liquid at 25°C.

Composition (X) may further contain a dispersant (F). The dispersant (F) is a surfactant that can be adsorbed by the moisture absorbent (E). The dispersant (F) includes, for example, an adsorbing group (also referred to as an anchor) that can adsorb to the particles of the moisture absorbent (E), and a chain-like adsorbing group that attaches to the particles of the moisture absorbent (E) by adsorbing the particles. or a tail, which is a comb-shaped molecular skeleton. The dispersant (F) includes, for example, an acrylic dispersant whose tail is an acrylic molecular chain, a urethane dispersant whose tail is a urethane molecular chain, and a polyester dispersant whose tail is a polyester molecular chain. It contains at least one component selected from the group consisting of agents.

When the composition (X) contains the dispersant (F), the moisture absorbent (E) can be well dispersed in the composition (X) and in the cured product. Therefore, although the cured product and the sealing material 5 contain the moisture absorbent (E), the transparency of the cured product and the sealing material 5 is less likely to be lowered by the moisture absorbent (E). In addition, the dispersant (F) can effectively suppress aggregation of the moisture absorbent (E) during storage of the composition (X). Therefore, the storage stability of the composition (X) is less likely to be lowered by the hygroscopic agent (E). Furthermore, the adhesion between the cured product and silicon nitride or silicon oxide is less likely to be lowered by the dispersant (F). This is because the dispersant (F) is easily adsorbed by the moisture absorbent (E) as described above, and thus the dispersant (F) hardly affects the interface between the cured product and the silicon nitride and silicon oxide. It is believed that there is. For this reason, the sealing material 5 can have high adhesion to the base material made of glass. Silicon nitride and silicon oxide are sometimes used as materials for the passivation layer 6 in the organic EL light emitting device 1 . Therefore, when the passivation layer 6 is made of silicon nitride or silicon oxide, the sealing material 5 can have high adhesion to the passivation layer 6 .

The boiling point of the dispersant (F) is preferably 200°C or higher. In this case, since the dispersant (F) is difficult to volatilize from the composition (X), the storage stability of the composition (X) is further improved.

It is preferable that the dispersant (F) has one or both of a basic polar functional group and an acidic polar functional group as adsorptive groups. In this case, the moisture absorbent (E) can be dispersed particularly well in the composition (X) and in the cured product. This is because the dispersant (F) has one or both of a basic polar functional group and an acidic polar functional group, so that it easily adsorbs to the hygroscopic agent (E), so that the hygroscopic agent (E) It is considered that the effect of dispersing is remarkably expressed.

The dispersant (F) may contain a polymer. The weight average molecular weight of the polymer is, for example, 1000 or more. Polymers include, for example, hydroxyl-containing carboxylic acid esters, salts of long-chain polyaminoamides and high-molecular-weight acid esters, salts of high-molecular-weight polycarboxylic acids, salts of long-chain polyaminoamides and polar acid esters, and high-molecular-weight unsaturated acid esters. , modified polyurethane, modified polyacrylate, polyether ester type anionic surfactant, naphthalene sulfonic acid formalin condensate salt, polyoxyethylene alkyl phosphate, polyoxyethylene nonylphenyl ether, polyester polyamine, and stearylamine acetate It contains at least one component selected from the group. When the dispersant (F) contains a polymer, the steric hindrance effect that occurs when the polymer is adsorbed to the particles of the moisture absorbent (E) can be improved, thereby improving the dispersibility of the moisture absorbent (E).

The dispersant (F) can contain, for example, one or both of a dispersant (F1) having a basic polar functional group and a dispersant (F2) having an acidic polar functional group.

The basic polar functional group in the dispersant (F1) having a basic polar functional group is, for example, at least one selected from the group consisting of an amino group, an imino group, an amide group, an imide group, and a nitrogen-containing heterocyclic group. Including the group of When the dispersant (F1) has a basic polar functional group, the dispersant (F1) easily adsorbs to the moisture absorbent (E), and thus the dispersibility of the moisture absorbent (E) can be improved. The basic polar functional group can particularly enhance the adsorption ability of the dispersant (F1) to the moisture absorbent (E), can particularly improve the dispersibility of the moisture absorbent (E), and can improve the composition (X). It preferably contains an amino group, since it can particularly reduce the viscosity.

The dispersant (F1) having a basic polar functional group is, for example, trade name: Solsperse 24000 (amine value: 41.6 mgKOH/g), trade name: Solsperse 32000 (amine value: 31.2 mgKOH/g), trade name : Solsperse 39000 (amine value: 25.7 mgKOH/g), trade name: Solsperse J100, trade name: Solsperse series manufactured by Nihon Luvre Resol Co., Ltd. such as Solsperse J200; trade names: DISPERBYK-108, DISPERBYK-2013, DISPERBYK -180, DISPERBYK-106, DISPERBYK-162 (amine value: 13 mgKOH/g), product name: DISPERBYK-163 (amine value: 10 mgKOH/g), product name: DISPERBYK-168 (amine value: 11 mgKOH/g), product Name: DISPERBYK-2050 (amine value: 30.7 mgKOH/g), trade name: DISPERBYK-2150 (amine value: 56.7 mgKOH/g), etc. DISPERBYK series manufactured by BYK-Chemie Japan Co., Ltd.; trade name: BYKJET-9151 (amine value: 17.2 mgKOH / g), trade name: BYKJET-9152 (amine value: 27.3 mgKOH / g) BYKJET series manufactured by BYK Chemie Japan Co., Ltd.; and trade name: Ajisper PB821 (amine value: 11.2 mg KOH / g), trade name: Ajisper PB822 (amine value: 18.2 mg KOH / g), trade name: Ajisper PB881 (amine value: 17.4 mg KOH / g), etc. Ajinomoto Fine-Techno Co., Ltd. Ajisper series including.

The amine value of the dispersant (F1) is preferably 10 mgKOH/g or more, more preferably 10 mgKOH/g or more and 30 mgKOH/g or less, and even more preferably 15 mgKOH/g or more and 30 mgKOH/g or less. Moreover, it is preferable that the dispersant (F1) does not have a phosphate group. When the dispersant (F1) has a phosphoric acid group, the acid value derived from the phosphoric acid group is preferably equal to or less than the amine value. In this case, the dispersant (F1) can disperse the moisture absorbent (E) particularly well, can particularly enhance the storage stability of the composition (X), and can particularly enhance the transparency of the cured product. Furthermore, the adhesion between the cured product and silicon nitride and silicon oxide can be particularly enhanced. Among the components that can be contained in the dispersant (F1), an example of a dispersant having an amino group and no phosphoric acid group includes DISPERBYK-108 manufactured by BYK-Chemie. Examples of dispersants having an amino group and a phosphate group and having an acid value derived from the phosphate group equal to or less than the amine value include DISPERBYK-2013 manufactured by BYK-Chemie and DISPERBYK-180 manufactured by BYK-Chemie.

The acidic polar functional group in the dispersant (F2) having an acidic polar functional group is, for example, a carboxyl group. Dispersant (F2) contains, for example, DISPERBYK-P105 manufactured by BYK-Chemie.

The amount of the dispersant (F) is preferably 5 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the moisture absorbent (E). If the amount of the dispersant (F) is 5 parts by mass or more, the advantages of the dispersant (F) can be particularly exhibited. If the amount of the dispersant (F) is 60 parts by mass or less, the adhesion between the cured product and silicon nitride or silicon oxide can be further enhanced. More preferably, the amount of the dispersant (F) is 15 parts by mass or more. The amount of the dispersant (F) is 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.

The viscosity of composition (X) at 25° C. is preferably 50 mPa·s or less. In this case, the composition (X) can be easily molded at normal temperature by a method such as casting, and the composition (X) can also be molded at normal temperature by an inkjet method. Composition (X) contains compound (A1), particularly at least one compound selected from the group consisting of the compound represented by formula (11) above, the compound represented by formula (12), and morpholine acrylate, It is possible to lower the viscosity of such composition (X). Further, the viscosity of composition (X) at 25° C. is more preferably 20 mPa·s or less, and particularly preferably 13 mPa·s or less. The viscosity of the composition (X) is, for example, 1 mPa·s or more, 5 mPa·s or more, or 10 mPa·s or more.

It is also preferable that the composition (X) has a viscosity of 1 mPa·s or more and 50 mPa·s or less at 40°C. In this case, even if the viscosity of the composition (X) at room temperature is any value, the viscosity of the composition (X) can be lowered by slightly heating the composition (X). Therefore, if heated, the composition (X) can be easily molded by a method such as a casting method, and the composition (X) can also be molded by an inkjet method. This viscosity is more preferably 20 mPa·s or less, and particularly preferably 13 mPa·s or less. The viscosity of the composition (X) at 40° C. is, for example, 1 mPa·s or more, 5 mPa·s or more, or 10 mPa·s or more.

Composition (X) is preferably cured into a cured product having a glass transition temperature of 90° C. or higher. That is, the glass transition temperature of the cured product of composition (X) and the glass transition temperature of sealing material 5 produced from composition (X) are preferably 90° C. or higher. In this case, the sealing material 5 made from the composition (X) can have heat resistance. Therefore, for example, when the organic EL light-emitting device 1 is manufactured at a high temperature, when the passivation layer 6 is formed over the sealing material 5 by plasma CVD or the like, and when the organic EL light-emitting device 1 is in use. When exposed to high temperatures, the sealing material 5 is less likely to deteriorate. A glass transition temperature of 100° C. or higher is more preferable, and a glass transition temperature of 120° C. or higher is particularly preferable. In particular, when the composition (X) contains a polyfunctional compound such as the acrylic component (A23), the molecular structure of the cured product is likely to be three-dimensional, making it possible to achieve such a glass transition temperature of the cured product. is.

When the cured product of composition (X) has a thickness of 10 μm, the total light transmittance is preferably 90% or more. In this case, when the cured product is applied to the sealing material 5 in the organic EL light emitting device 1, the extraction efficiency of light passing through the sealing material 5 and emitted to the outside can be particularly improved. Such high optical transparency of the cured product can be achieved by the composition of composition (X) detailed above.

3. Method for Producing Encapsulating Material and Method for Producing Organic EL Light-Emitting Device A method for producing the encapsulating material 5 using the composition (X) and a method for producing the organic EL light-emitting device 1 will be described.

In the present embodiment, the encapsulant 5 is preferably produced by molding the composition (X) by an inkjet method and then curing the composition (X) by irradiating it with ultraviolet rays. Since the viscosity of the composition (X) can be lowered in the present embodiment, the composition (X) can be molded by an inkjet method.

In applying the composition (X) by an inkjet method, when the composition (X) has a sufficiently low viscosity at room temperature, for example, when the viscosity at 25° C. is 50 mPa·s or less, particularly 20 mPa·s or less. can be molded by applying the composition (X) by an inkjet method without heating.

In the case where the composition (X) has a property of decreasing the viscosity when heated, the composition (X) may be heated and then applied by an ink jet method for molding. When the viscosity of the composition (X) at 40° C. is 50 mPa·s or less, particularly 20 mPa·s or less, the viscosity of the composition (X) can be lowered by only slightly heating the composition (X). Composition (X) can be discharged by an inkjet method. The heating temperature of the composition (X) is, for example, 20°C or higher and 50°C or lower.

A method for manufacturing the organic EL light-emitting device 1 of the first example shown in FIG. 1 will be described. For example, first, the support substrate 2 is prepared. An organic EL element 4 is provided on one surface of the support substrate 2 . The organic EL element 4 can be produced by an appropriate method such as a vapor deposition method or a coating method. In particular, it is preferable to fabricate the organic EL element 4 by a coating method such as an inkjet method.

A passivation layer 6 is then provided. The passivation layer 6 can be produced by vapor deposition, for example.

Next, the composition (X) is molded by an inkjet method so as to cover one surface of the support substrate 2 and the organic EL element 4 . In addition, when the passivation layer 6 is provided, the composition (X) is molded so as to cover the passivation layer 6 . If the inkjet method is applied to both the formation of the organic EL element 4 and the application of the composition (X), the manufacturing efficiency of the organic EL light-emitting device 1 can be particularly improved.

Next, the transparent substrate 3 is overlaid on the composition (X). The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate.

Next, the transparent substrate 3 is irradiated with ultraviolet rays from the outside. The ultraviolet rays pass through the transparent substrate 3 and reach the composition (X). As a result, a radical polymerization reaction proceeds in the composition (X), the composition (X) is cured, and the encapsulant 5 made of a cured product is produced. The thickness of the sealing material 5 is, for example, 5 μm or more and 50 μm or less.

The composition (X) may be molded by a method other than the inkjet method, for example, by a casting method.

A method for manufacturing the organic EL light-emitting device 1 of the second example shown in FIG. 2 will be described.

First, the support substrate 2 is prepared. A partition wall 7 is formed on one surface of the support substrate 2 by photolithography using, for example, a photosensitive resin material. Subsequently, a plurality of organic EL elements 4 are provided on one surface of the support substrate 2 . The organic EL element 4 can be produced by an appropriate method such as a vapor deposition method or a coating method. In particular, it is preferable to fabricate the organic EL element 4 by a coating method such as an inkjet method. Thus, an element array 9 is produced on the support substrate 2 .

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

Next, the composition (X) is formed on the first passivation layer 61 by, for example, an inkjet method to form a coating film. If the inkjet method is applied to both the formation of the organic EL element 4 and the application of the composition (X), the manufacturing efficiency of the organic EL light-emitting device 1 can be particularly improved. Subsequently, the coating film is cured by irradiating it with ultraviolet rays, and the encapsulant 5 is produced. The thickness of the sealing material 5 is, for example, 5 μm or more and 50 μm or less.

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

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

Next, the transparent substrate 3 is irradiated with ultraviolet rays from the outside. Ultraviolet rays pass through the transparent substrate 3 and reach the ultraviolet curable resin material. Thereby, the ultraviolet curable resin material is cured, and the second sealing material 52 is produced.

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

1. Preparation of Composition Compositions of Examples and Comparative Examples were prepared by mixing the components shown in the table below. The details of the components shown in the table are as follows.
TBCHA: 4-tert-butyl cyclohexyl acrylate, which is a compound represented by formula (11), viscosity at 25°C: 7 mPa·s, glass transition temperature: 77°C, boiling point: 265°C.
・Viscoat #196: 3,3,5-trimethylcyclohexyl acrylate, which is a compound represented by formula (12), viscosity at 25 ° C. of 3 mPa s, glass transition temperature of 52 ° C., boiling point of 234 ° C., manufactured by Osaka Organic Chemical Industry Co., Ltd. .
- CHDMMA: cyclohexanedimethanol monoacrylate which is a compound represented by the formula (13), viscosity at 25°C of 88 mPa·s, glass transition temperature of 18°C, boiling point of 294°C.
• ACMO: morpholine acrylate, viscosity at 25°C 12 mPa·s, glass transition temperature 145°C.
• IBXA: isobornyl acrylate, viscosity at 25°C 8 mPa·s, glass transition temperature 97°C.
• TMPTA: trimethylolpropane triacrylate, viscosity 106 mPa·s at 25°C.
- Polyethylene glycol 200 dimethacrylate: manufactured by Shin-Nakamura Chemical Co., Ltd., molecular weight 330, viscosity at 25°C 14 mPa·s, glass transition temperature 41°C.
• Polyethylene glycol 200 diacrylate, manufactured by Osaka Organic Chemical, molecular weight 308, viscosity at 25°C 17 mPa·s, glass transition temperature 41°C.
- Bisphenol A polyethoxy diacrylate: manufactured by Nippon Kayaku, product number R551, viscosity at 25°C of 800 mPa·s.
- Irgacure 184: 1-hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, trade name Irgacure 184.
- Irgacure TPO: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, manufactured by BASF, trade name Irgacure TPO.

2. Evaluation Tests The following evaluation tests were conducted for Examples and Comparative Examples. The results are shown in the table.

(1) Transmittance A coating film is prepared by applying the composition, and this coating film is applied under the conditions of about 100 mW/cm ² using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. A film having a thickness of 10 μm was produced by photocuring the film by irradiating it with ultraviolet rays for 15 seconds. The total light transmittance of this film was measured according to JIS K7361-1.

After heating the film at 120° C. for 500 hours, the total light transmittance of the film was measured in the same manner.

(2) Viscosity The viscosity of the composition was measured using a rheometer (manufactured by Anton Paar Japan, Model No. DHR-2) under conditions of a temperature of 25° C. and a shear rate of 1000 s ⁻¹ .

(3) Glass transition temperature A coating film is prepared by applying the composition, and the coating film is applied with an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. under the conditions of about 100 mW / cm ² . The film was photocured by irradiating with ultraviolet rays for 15 seconds to prepare a film having a thickness of 100 μm.

Using a viscoelastic spectrometer "DMS6100" manufactured by Seiko Instruments Inc., the glass transition temperature of the film obtained above was measured. At this time, dynamic viscoelasticity measurement (DMA) is performed with a tensile module at a frequency of 10 Hz, and the temperature at which tan δ when the temperature is raised from room temperature to 200 ° C. at a temperature increase rate of 5 ° C./min is the glass transition temperature. temperature.

(4) Inkjet properties The composition is placed in a cartridge of an inkjet printer (manufactured by Microjet, "NanoPrinter300"), and after confirming that the composition in the cartridge can be ejected from the nozzle of the inkjet printer, the composition is ejected from the nozzle. was ejected to continuously print test patterns. As a result, "A" indicates that the composition could be ejected for 1 hour and the ejection operation was stable, "B" if the composition could be ejected for 1 hour but the ejection operation became intermittent and unstable. A case where the nozzle was clogged and the composition could not be discharged before 1 hour from the start of discharge was evaluated as "C".

(5) Adhesion Two substrates were prepared by forming a SiON film with a thickness of 100 nm on each of two glass slides (dimensions: 76 mm x 52 mm x 1 mm). The composition was applied to the SiON film of one substrate to form a coating film having a thickness of 50 μm, and the SiON film of the other substrate was superimposed on this coating film. Subsequently, the coating film was cured by ultraviolet irradiation for 20 seconds under conditions of about 30 mW/cm ² using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. Next, the adhesion strength between the two substrates was evaluated by performing a T-shaped peel test based on JIS K6854.

Claims (7)

Containing an acrylic compound (A) and a photopolymerization initiator (B),
The acrylic compound (A) is a compound ( A1) containing

In the above formula (1), 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, 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,
Viscosity at 25 ° C. is 20 mP s or less,
The compound (A1) contains only the compound represented by the formula (1),
The acrylic compound (A) does not contain a compound having a nitrogen atom,
An ultraviolet curable resin composition for encapsulating an organic EL element. Containing an acrylic compound (A) and a photopolymerization initiator (B),
The acrylic compound (A) is a compound ( A1) containing

In the formula (1), R ⁰ is H or a methyl group, X is a single bond or a divalent hydrocarbon group, and R ¹ from R ¹¹ each of H, an alkyl group or -R ¹² —OH, R ¹² is an alkylene group
Arikatsu R ¹ from R ¹¹ At least one of the alkyl group or -R ¹² —OH and R ¹ from R ¹¹ are not chemically bonded to each other,
Viscosity at 25 ° C. is 20 mP s or less,
By curing, it becomes a cured product having a glass transition temperature of 90 ° C. or higher,
An ultraviolet curable resin composition for encapsulating an organic EL element. The compound (A1) contains only the compound represented by the formula (1),
The acrylic compound (A) does not contain a compound having a nitrogen atom,
The UV-curable resin composition for encapsulating an organic EL element according to claim 2. The compound (A1) is selected from the group consisting of a compound represented by the following formula (11), a compound represented by the following formula (12), and a compound represented by the following formula (13).

The UV-curable resin composition for encapsulating an organic EL element according to any one of claims 1 to 3 . Molded by the inkjet method,
The UV-curable resin composition for encapsulating an organic EL element according to any one of claims 1 to 4 . A method for manufacturing an organic EL light-emitting device comprising an organic EL element and a sealing material covering the organic EL element,
After molding the ultraviolet curable resin composition for sealing an organic EL element according to any one of claims 1 to 5 by an inkjet method, ultraviolet rays are applied to the ultraviolet curable resin composition for sealing an organic EL element. forming the encapsulant by irradiating and curing;
A method for manufacturing an organic EL light emitting device. An organic EL element and a sealing material covering the organic EL element, wherein the sealing material is the ultraviolet curable resin composition for sealing the organic EL element according to any one of claims 1 to 5. An organic EL light-emitting device which is a cured product.

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