JP7365080B2 - photocurable composition - Google Patents

Description

The present invention relates to a photocurable composition, and more particularly to a photocurable resin composition containing a photocurable component and a photopolymerization initiator.

Dye-sensitized solar cells are solar cells that use dyes to convert light energy into electricity, and are attracting attention as next-generation solar cells. Dye-sensitized solar cells generally have a structure in which an electrolyte is sealed between two conductive substrates. Encapsulation of the electrolyte is important for the durability of the dye-sensitized solar cell. Several techniques have been proposed so far for encapsulating the electrolyte.

For example, Patent Document 1 below describes (A) 100 parts by weight of (meth)acrylate having a linear aliphatic hydrocarbon having 10 to 20 carbon atoms in the molecule, (B) 5 to 15 parts by weight of alicyclic (meth)acrylate. parts by weight, (C) 10 parts by weight or more of a styrene thermoplastic elastomer represented by a specific general formula, and (D) a photocurable sealant for dye-sensitized solar cells containing a photopolymerization initiator as a main component. is disclosed. Moreover, the following patent document 2 discloses a photocurable composition containing a specific monofunctional (meth)acrylate, a saturated thermoplastic elastomer, and a photopolymerization initiator.

Japanese Patent Application Publication No. 2005-302564 Japanese Patent Application Publication No. 2010-180324

In order to improve the durability of dye-sensitized solar cells, it is important to improve the performance of the sealing material used to encapsulate the electrolyte.
For example, when external water vapor passes through the sealing material and comes into contact with the electrolyte, the efficiency of converting light energy into electricity decreases. Therefore, the sealing material is required to have low moisture permeability.
Leakage of electrolyte also reduces the conversion efficiency. Therefore, the sealing material is also required to have high adhesiveness with the two conductive electrode plates.

Encapsulants used to encapsulate elements are also important for electronic devices. For example, electronic devices such as liquid crystals and organic EL have a structure in which an element is encapsulated in a resin composition, and it is desirable that the element does not come into contact with water vapor. Therefore, in order to protect the device from water vapor, the sealing material used for encapsulating the device is required to have low moisture permeability.

Based on the above, an object of the present invention is to provide a sealing material with low moisture permeability and excellent adhesiveness.

The present inventors have discovered that a photocurable composition having a specific composition can be used as a sealing material with low moisture permeability and excellent adhesiveness.

That is, the present invention provides component (A): an alicyclic monofunctional (meth)acrylate monomer having a Tg of 100° C. or higher in the case of a homopolymer;
Component (B): a (meth)acrylate monomer having a polar group, and Component (C): containing at least one functional group selected from the group consisting of a (meth)acryloyl group, a vinyl ether group, an epoxy group, and an oxetanyl group. A photocurable component consisting of a polyfunctional photocurable component , or
Component (A): an alicyclic monofunctional (meth)acrylate monomer whose Tg is 100°C or higher in the case of a homopolymer, and
Component (B): (meth)acrylate monomer having a polar group,
A photocurable component consisting of ;
a photopolymerization initiator;
A photocurable composition containing,
The total content of the photocurable components with respect to the total mass of the photocurable composition is 50% by mass to 99.8% by mass,
The mass ratio of component (A) and component (C) is 60:40 to 100:0, and
Contains 0.01 to 10 parts by mass of component (B) for a total of 100 parts by mass of component (A) and component (C),
Component (B) is a (meth)acrylate monomer having a phosphoric acid group , and
Component (B) is not a polyfunctional photocurable component of component (C),
A photocurable composition for encapsulating solar cells or electronic devices is provided.
The content of component (C) may be 0 to 35 parts by weight per 1 part by weight of the photopolymerization initiator.
The photopolymerization initiator may be an acylphosphine oxide-based, α-aminoacetophenone-based, α-hydroxyacetophenone-based, or oxime ester-based photopolymerization initiator.
The alicyclic monofunctional (meth)acrylate monomer of component (A) may have a dicyclopentanyl structure, a dicyclopentenyl structure, an adamantyl structure, or an isobornyl structure.
The component (C) is selected from polybutadiene-based polyfunctional (meth)acrylate, hydrogenated polybutadiene-based polyfunctional (meth)acrylate, polyisoprene-based polyfunctional (meth)acrylate, and hydrogenated polyisoprene-based polyfunctional (meth)acrylate. It may be one selected or a combination of two or more.
The content of the photopolymerization initiator in the photocurable composition may be 0.01 parts by mass to 10 parts by mass based on 100 parts by mass of the photocurable component.
The present invention also provides a cured product of the photocurable composition.
The present invention also provides a solar cell containing a cured product of the photocurable composition as a sealing material.
The present invention also provides an electronic device containing a cured product of the photocurable composition as a sealant.
The present invention also provides an alicyclic monofunctional compound containing a photocurable component and a photopolymerization initiator, wherein the photocurable component has a Tg of 100° C. or higher in the case of component (A): homopolymer. meth)acrylate monomer, component (B): a (meth)acrylate monomer having a polar group, and component (C): at least one selected from the group consisting of a (meth)acryloyl group, a vinyl ether group, an epoxy group, and an oxetanyl group. Contains a multifunctional photocurable component containing a species of functional group, the mass ratio of component (A) and component (C) is 60:40 to 100:0, and the total of components (A) and (C) A photocurable composition containing 0.01 to 10 parts by mass of component (B) per 100 parts by mass is provided.
The (meth)acrylate monomer having a polar group as component (B) may include a (meth)acrylate monomer having a carboxyl group or a phosphoric acid group.
The alicyclic monofunctional (meth)acrylate monomer of component (A) may have a dicyclopentanyl structure, a dicyclopentenyl structure, an adamantyl structure, or an isobornyl structure.
The total content of the photocurable component based on the total weight of the photocurable composition may be 20 to 100% by mass.
According to one embodiment of the present invention, the photocurable composition may be for encapsulating a solar cell.
According to another embodiment of the invention, the photocurable composition may be for encapsulating an electronic device.
The present invention also provides a cured product of the photocurable composition.
The present invention also provides a solar cell containing a cured product of the photocurable composition as a sealing material.
The present invention also provides an electronic device containing a cured product of the photocurable composition as a sealant.

The present invention provides a photocurable composition that can be used as a sealing material that has low moisture permeability and excellent adhesiveness. The photocurable composition can improve the durability of solar cells. Furthermore, the photocurable composition can also improve the durability of electronic devices other than solar cells.
Note that the effects of the present invention are not necessarily limited to the effects described herein, and may be any of the effects described herein.

1 is a diagram showing an example of the structure of a dye-sensitized solar cell. 1 is a diagram showing an example of the structure of an electronic device. FIG. 3 is a diagram showing an example of a method for manufacturing a dye-sensitized solar cell.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail. Note that the embodiments described below are examples of typical embodiments of the present invention, and the present invention is not limited only to these embodiments.

1. photocurable composition

The photocurable composition of the present invention contains a photocurable component and a photopolymerization initiator, and the photocurable component is a component (A): an alicyclic compound having a Tg of 100° C. or higher in the case of a homopolymer. Monofunctional (meth)acrylate monomer of the formula, component (B): a (meth)acrylate monomer having a polar group, and component (C): from the group consisting of a (meth)acryloyl group, a vinyl ether group, an epoxy group, and an oxetanyl group. Contains a multifunctional photocurable component containing at least one selected functional group. In the photocurable composition, the mass ratio of component (A) and component (C) is 60:40 to 100:0; Component (B) is contained in an amount of 0.01 to 10 parts by mass based on a total of 100 parts by mass.
It is often difficult to achieve both low moisture permeability and excellent adhesiveness in a cured product of a photocurable composition. The present inventors have discovered that by containing specific amounts of component (A), component (B), and component (C) in the photocurable composition, the cured product of the photocurable composition exhibits low moisture permeability. It has been found that it has excellent adhesion properties. Since the cured product obtained by curing the photocurable composition of the present invention has low moisture permeability and excellent adhesive properties, the photocurable composition can be used for sealing, for example, solar cells and electronic devices. Suitable for use as wood. Below, the effects of the present invention will be explained in more detail while showing examples of specific structures of solar cells and electronic devices.

A schematic diagram of the basic structure of a dye-sensitized solar cell among solar cells is shown in FIG. FIG. 1 is a diagram schematically showing an example of a cross section of a dye-sensitized solar cell. A dye-sensitized solar cell 100 shown in FIG. 1 has a transparent substrate 101 on which a transparent conductive oxide (TCO) 102 is laminated. A porous metal oxide semiconductor layer 103 made of metal oxide semiconductor particles 104 is formed on the surface of the transparent conductive film 102 opposite to the surface in contact with the transparent substrate 101 . The metal oxide semiconductor layer 103 can be formed, for example, by baking metal oxide semiconductor particles such as porous titanium oxide. A dye 105 is adsorbed to the metal oxide semiconductor particles 104 . Further, a substrate 106 is arranged to face the transparent substrate 101, and a conductive film 107 is laminated on the surface of the substrate 106 on the transparent substrate 101 side. A space 108 between the transparent conductive film 102 and the conductive film 107 is filled with an electrolytic solution. A sealing material 109 is provided to seal the electrolyte in the space 108. The sealing material 109 is adhered to the transparent conductive film 102 and the conductive film 107.
The light irradiated onto the dye-sensitized solar cell 100 passes through the transparent substrate 101 and the transparent conductive film 102 and reaches the metal oxide semiconductor layer 103. The light is absorbed by the dye 105 of the metal oxide semiconductor layer 103, and electrons are emitted from the dye 105. The electrons move to the metal oxide semiconductor layer 103, propagate through the transparent conductive film 102, pass through the circuit 110, and reach the opposite conductive film 107. A reduction reaction occurs due to the electrons, and iodide ions (I ^- ), for example, are generated in the electrolyte. The iodide ions transfer electrons to the dye 105 and are oxidized again. By repeating the above cycle, light energy is converted into electrical energy.
Note that a solid electrolyte may be used instead of the electrolytic solution. A dye-sensitized solar cell using a solid electrolyte is also called an all-solid-state dye-sensitized solar cell.

In the dye-sensitized solar cell 100, it is undesirable for external water vapor to pass through the sealing material 109 and come into contact with the electrolytic solution, since this results in a decrease in the efficiency of converting light into electricity. The permeation of external moisture poses a problem even if the dye-sensitized solar cell is an all-solid-state type.
Furthermore, if the adhesiveness between the sealant 109 and the transparent conductive film 102 or the conductive film 107 is poor, the electrolyte may leak or external moisture or air may come into contact with the electrolyte. Such leakage and such contact are also undesirable because they result in a decrease in the efficiency of light to electricity conversion.
The cured product of the photocurable composition of the present invention has low moisture permeability and high adhesiveness. Therefore, the photocurable composition of the present invention is suitable for use as a sealing material for solar cells such as dye-sensitized solar cells.

Elements of electronic devices such as organic EL and liquid crystal are often encapsulated with a sealant. Encapsulants are used to protect elements of electronic devices from the outside, for example, from water vapor. FIG. 2 shows an example of an encapsulation pattern for elements of an electronic device.
In FIG. 2A, an element 201 to be protected from the outside is sandwiched between a pair of substrates 202 and 203 such as glass or film, and the sides of the element are surrounded by a sealing material 204. ing. FIG. 2A shows the sealing of the element by a method called frame sealing.
In FIG. 2B, an element 211 is placed on a single substrate 212, and all parts of the element 211 other than the portions that are in contact with the substrate are sealed with a sealing material 213. FIG. 2B shows the sealing of the element by a method called full-surface sealing.
FIG. 2C shows a sealing method in which a substrate 224 is further laminated on the sealing material 223 having the entire surface sealing structure shown in FIG. 2B. That is, the element 221 is placed on one substrate 222, all parts of the element 221 other than the portions that are in contact with the substrate are sealed with a sealing material 223, and the substrate is placed so as to face the substrate 222. 224 is laminated on the sealing material 223.
Even in electronic devices, it is undesirable for external moisture to pass through the sealing material and come into contact with the element. For example, in an organic EL panel, the light emitting area is reduced when water vapor passes through the sealing material and comes into contact with the element, or when moisture enters through the gap between the sealing material and the substrate. Therefore, also in the element of an electronic device, it is desirable that the sealing material has low moisture permeability and high adhesiveness.
The cured product of the photocurable composition of the present invention has low moisture permeability and high adhesiveness. Therefore, the photocurable composition of the present invention is suitable for use as a sealant for electronic devices.

The photocurable component and photopolymerization initiator contained in the photocurable composition of the present invention will be explained below.

[Photocurable component]

The photocurable components contained in the photocurable composition of the present invention are component (A): an alicyclic monofunctional (meth)acrylate monomer having a Tg of 100° C. or higher in the case of a homopolymer, and component (B). ): Contains a (meth)acrylate monomer having a polar group. The photocurable component contained in the photocurable composition of the present invention further includes at least one type selected from the group consisting of (meth)acryloyl group, vinyl ether group, epoxy group, and oxetanyl group as component (C). It may also contain a polyfunctional photocurable component containing a functional group. In the photocurable composition of the present invention, the mass ratio of component (A) and component (C) is 60:40 to 100:0, and component (B) is the same as component (A) and component (C). ) is contained in an amount of 0.01 to 10 parts by mass based on a total of 100 parts by mass. Since the photocurable component contains component (A), component (B), and component (C) in the above amounts, the cured product of the photocurable composition has low moisture permeability and excellent adhesiveness. There is.

In the present invention, (meth)acrylate monomer means an acrylate monomer or a methacrylate monomer or a mixture thereof.
In the present invention, monofunctional means that one molecule has one photopolymerizable carbon-carbon double bond, that is, it has one acryloyl group or methacryloyl group. That is, the alicyclic monofunctional (meth)acrylate monomer of component (A) is a monomer having one acryloyl group or methacryloyl group.
In the present invention, alicyclic means having one alicyclic hydrocarbon group in one molecule. That is, the alicyclic monofunctional (meth)acrylate monomer of component (A) is a monofunctional (meth)acrylate in which the ester residue [-C(=O)OR R] is an alicyclic hydrocarbon group. be. Preferably, the alicyclic hydrocarbon group is an alicyclic hydrocarbon group that does not have a polar group such as a carboxyl group, an epoxy group, a phosphate group, or a halogen group.

The alicyclic monofunctional (meth)acrylate monomer of component (A) has a Tg of 100°C or higher in the case of a homopolymer, preferably 105°C or higher, more preferably 110°C or higher, and even more preferably 115°C. That's all. By combining an alicyclic monofunctional (meth)acrylate monomer having such a Tg with the component (B) in the above ratio, low moisture permeability and high adhesiveness can be achieved. A Tg of 100° C. or higher particularly contributes to lowering moisture permeability.
Further, the Tg of the alicyclic monofunctional (meth)acrylate monomer of the component (A) may be, for example, 260°C or lower, particularly 230°C or lower, and more particularly 200°C or lower.
In the present invention, Tg is the Tg of a homopolymer composed of only one alicyclic monofunctional (meth)acrylate monomer, and is measured by differential scanning calorimetry (DSC).

The alicyclic monofunctional (meth)acrylate monomer of component (A) preferably has a dicyclopentanyl structure, a dicyclopentenyl structure, an adamantyl structure, or an isobornyl structure, and more preferably has a dicyclopentanyl structure. structure, adamantyl structure, or isobornyl structure. That is, the alicyclic hydrocarbon group contained in the monomer is preferably a dicyclopentanyl group, a dicyclopentenyl group, an adamantyl group, or an isobornyl group. The fact that the alicyclic hydrocarbon group contained in the alicyclic monofunctional (meth)acrylate monomer of component (A) has one of these structures reduces the moisture permeability of the sealing material and improves the adhesiveness. Contribute to

The total carbon number of the alicyclic monofunctional (meth)acrylate monomer of component (A) is preferably 13 or more, more preferably 13 to 16, even more preferably 13 to 15, particularly preferably 13 or 14. It is. This lowers the moisture permeability of the sealing material and further increases its adhesiveness.

Preferred compounds used as the component (A) include, for example, the following:
Isobornyl methacrylate (Tg: 110°C),
Dicyclopentenyl acrylate (Tg: 120℃),
Dicyclopentenyl methacrylate (Tg: 120°C),
Dicyclopentanyl acrylate (Tg: 120℃),
Dicyclopentanyl methacrylate (Tg: 175°C),
1-adamantyl acrylate (Tg: 153°C),
1-adamantyl methacrylate (Tg: 250°C),
2-methyladamantyl acrylate (Tg: 120°C), and 2-methyladamantyl methacrylate (Tg: 170°C).
In the present invention, one of these compounds may be used as the component (A), or a combination of two or more may be used.
In a particularly preferred embodiment of the invention, component (A) is dicyclopentanyl (meth)acrylate and/or dicyclopentenyl (meth)acrylate. In a particularly preferred embodiment of the invention, component (A) is dicyclopentanyl (meth)acrylate.

The polar group contained in the (meth)acrylate monomer of component (B) is preferably a carboxyl group, a phosphoric acid group, a hydroxyl group, or an amino group, and more preferably a carboxyl group or a phosphoric acid group. In particular, component (B) is not a cycloaliphatic (meth)acrylate monomer. By combining a (meth)acrylate monomer having a polar group with the component (A) in the above ratio, low moisture permeability and high adhesion can be achieved. Polar groups particularly contribute to increasing adhesion.

Examples of (meth)acrylate monomers having a carboxyl group include mono(2-acryloyloxyethyl) succinate, mono(2-acryloyloxyethyl) hexahydrophthalate, mono(2-acryloyloxyethyl) phthalate, and mono(2-acryloyloxyethyl) succinate. -Hydroxyethyl phthalate mono(2-acryloyloxyethyl). As the (meth)acrylate having a carboxyl group, one of these compounds may be used, or a combination of two or more may be used.

Examples of (meth)acrylate monomers having a phosphoric acid group include phosphoric acid (2-acryloyloxyethyl), phosphoric acid (2-methacryloyloxyethyl), bis(2-acryloyloxyethyl) phosphate, and bishydrogen phosphate. (2-methacryloyloxyethyl). As (meth)acrylate monomer having a phosphate group, one of these compounds or a combination of two or more may be used.

According to a particularly preferred embodiment of the invention, component (B) is a (meth)acrylate monomer having a phosphoric acid group, more preferably (2-acryloyloxyethyl) phosphoric acid, (2-methacryloyloxyethyl phosphoric acid) ), bis(2-acryloyloxyethyl) phosphate, and bis(2-methacryloyloxyethyl) hydrogen phosphate, or a combination of two or more thereof, and still more preferably phosphoric acid (2-methacryloyloxyethyl). acryloyloxyethyl) and/or phosphoric acid (2-methacryloyloxyethyl).

The amount of component (C) among the photocurable components contained in the photocurable composition of the present invention may be 0 parts by mass, that is, the photocurable component does not need to contain component (C). In this case, the content of component (B) is, for example, 0.01 parts by mass to 10 parts by mass, preferably 0.05 parts to 10 parts by mass, more preferably 1 to 10 parts by mass, per 100 parts by mass of component (A). 5 parts by weight. By including the component (A) and the component (B) in such a mass ratio, the photocurable composition of the present invention can have both low moisture permeability and high adhesiveness. Although it is often difficult to achieve both low moisture permeability and high adhesion, the present inventors have discovered that by using the composition described above, it is possible to achieve both low moisture permeability and high adhesion. .
When the photocurable component does not contain component (C), the photocurable composition of the present invention may contain only component (A) and component (B) as photocurable components.

The photocurable component further comprises, as component (C), a polyfunctional photocurable component containing at least one functional group selected from the group consisting of (meth)acryloyl group, vinyl ether group, epoxy group, and oxetanyl group. May include. Component (C) is a photocurable component other than component (A) and component (B). More specific compounds of component (C) are as described below. As component (C), one or a combination of two or more of these compounds (for example, a combination of two or three) can be used. Inclusion of component (C) can reduce moisture permeability and improve adhesiveness of the cured product of the photocurable composition of the present invention. In particular, it is thought that the fact that component (C) is polyfunctional contributes to lowering the moisture permeability and improving adhesiveness of the cured product. In the present invention, polyfunctionality may mean having, for example, two or more functional groups included in the above group in total, particularly 2 to 20, more particularly 2 to 10.
Including component (C) is also preferred from the viewpoint of improving the flexibility of the cured product of the photocurable composition of the present invention. The improved flexibility is beneficial for manufacturing flexible solar cells or electronic devices.

As the polyfunctional photocurable component containing the (meth)acryloryl group, for example, a photocurable component having two or more (meth)acryloryl groups, preferably 2 to 6, more preferably 2 to 4. can be mentioned. More specifically, the polyfunctional photocurable component containing the (meth)acryloryl group includes 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9 -nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, cyclohexanedimethanol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, meth)acrylate, bisphenol A di(meth)acrylate, trimethylolpropane triacrylate, isocyanuric acid di(meth)acrylate, isocyanuric acid tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate can be mentioned.
In addition, as the polyfunctional photocurable component containing the (meth)acryloyl group, for example, a photocurable component having one (meth)acryloyl group and one epoxy group or oxetanyl group, that is, two kinds of photocurable components, A photocurable component having a functional group can be mentioned. More specifically, the photocurable component includes glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, (3-ethyl-3-oxetanyl)methyl methacrylate, and (3-methyl-3 -oxetanyl) methyl (meth)acrylate.
In addition, examples of the photocurable component having two or more (meth)acryloryl groups, preferably two to six, include polyether-based polyfunctional urethane (meth)acrylate, polyester-based polyfunctional urethane (meth)acrylate, and polyester-based polyfunctional urethane (meth)acrylate. Functional epoxy (meth)acrylate, polyfunctional polyester (meth)acrylate, silicone-based polyfunctional (meth)acrylate, polybutadiene-based polyfunctional (meth)acrylate, hydrogenated polybutadiene-based polyfunctional (meth)acrylate (especially hydrogenated polybutadiene-based) (urethane acrylate), polyisoprene-based polyfunctional (meth)acrylate, and hydrogenated polyisoprene-based polyfunctional (meth)acrylate. The number of functional groups contained in these compounds is, for example, 2 to 6.
One or a combination of two or more of the compounds mentioned above may be used as component (C).

As the polyfunctional photocurable component containing vinyl ether groups, for example, a photocurable component having two or more vinyl ether groups, preferably 2 to 6, more preferably 2 to 4, particularly preferably 2 vinyl ether groups. can be mentioned. More specific examples of the polyfunctional photocurable component containing a vinyl ether group include 1,4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, and triethylene glycol divinyl ether. .
Further, as the polyfunctional photocurable component containing a vinyl ether group, for example, a photocurable component having one vinyl ether group and one epoxy group or (meth)acryloyl group, that is, two types of functional groups. Examples of photocurable components include photocurable components. More specifically, the photocurable component includes glycidyl vinyl ether, glycidyloxymethyl vinyl ether, glycidyloxyethyl vinyl ether, glycidyloxybutyl vinyl ether, glycidyloxypentyl vinyl ether, glycidyloxycyclohexyl vinyl ether, and (meth)acrylic acid 2-( Mention may be made of 2-vinyloxyethoxy)ethyl.
One or a combination of two or more of these may be used as component (C).

Examples of the polyfunctional photocurable component containing an epoxy group include photocurable components having two or more epoxy groups, preferably 2 to 6, more preferably 2 to 4, particularly preferably 2. be able to. Examples of the photocurable component include 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Glycidyl ether, glycerin diglycidyl ether, polyglycerin diglycidyl ether, cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether, hexahydrophthalic acid diglycidyl ether, trimethylolpropane triglycidyl ether, 3',4'-epoxy Mention may be made of cyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, ε-caprolactone-modified 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, and bis(3,4-epoxycyclohexylmethyl)adipate. .
Further, as the polyfunctional photocurable component containing an epoxy group, for example, a polyfunctional epoxy resin can be mentioned, and more specifically, an epoxy resin having two or more epoxy groups can be mentioned.
Examples of epoxy resins having two or more (especially two) epoxy groups include bisphenol A type polyfunctional epoxy resin, bisphenol F type polyfunctional epoxy resin, bisphenol AF type polyfunctional epoxy resin, and hydrogenated bisphenol A type polyfunctional epoxy resin. Examples include resins and biphenyl-type polyfunctional epoxy resins.
In addition, examples of epoxy resins having two or more (particularly three or more) epoxy groups include naphthalene type polyfunctional epoxy resins, phenol novolac type polyfunctional epoxy resins, cresol novolak type polyfunctional epoxy resins, dicyclopentadiene type polyfunctional epoxy resins, and dicyclopentadiene type polyfunctional epoxy resins. Epoxy resin, glycidylamine type polyfunctional epoxy resin, glycidyl ester type polyfunctional epoxy resin, rubber modified type polyfunctional epoxy resin, chelate modified type polyfunctional epoxy resin, polyfunctional alicyclic epoxy resin, and polyfunctional epoxidized polybutadiene. can be mentioned.
One or a combination of two or more of these may be used as component (C).

Examples of the polyfunctional photocurable component containing an oxetanyl group include photocurable components having two or more oxetanyl groups, preferably two to six, and more preferably two to four. More specific examples of the polyfunctional photocurable component containing an oxetanyl group include xylylene bisoxetane and 3-ethyl-3-[(3-ethyloxetan-3-yl)methoxymethyl]oxetane. can.
Further, as the polyfunctional photocurable component containing an oxetanyl group, a photocurable component having one oxetanyl group and one epoxy group or vinyl ether group, that is, a photocurable component having two types of functional groups. can be mentioned. More specifically, the photocurable component includes 3-ethyl-3-(glycidyloxymethyl)oxetane, 3-ethyl-3-(oxiranylmethoxy)oxetane, and 3-ethyl-3-(vinyloxy). Mention may be made of methyl)oxetane.
One or a combination of two or more of these may be used as component (C).

Particularly preferably, the component (C) is a polyfunctional photocurable component containing a (meth)acryloyl group, more preferably a polybutadiene-based polyfunctional (meth)acrylate, a hydrogenated polybutadiene-based polyfunctional (meth)acrylate. , polyisoprene-based polyfunctional (meth)acrylate, and hydrogenated polyisoprene-based polyfunctional (meth)acrylate, or a combination of two or more thereof.

When the photocurable composition of the present invention contains the component (C), preferably the mass ratio of component (A):component (C) is from 60:40 to less than 100:more than 0, and The curable composition contains 0.01 to 10 parts by mass of component (B) based on a total of 100 parts by mass of components (A) and (C).
The mass ratio of component (A):component (C) is more preferably 60:40 to 99.9:0.1, more preferably 60:40 to 99:1, and more preferably 63:37. 98:2, even more preferably 65:35 to 95:5, particularly preferably 70:30 to 85:15.
The content of component (B) is more preferably 0.03 to 10 parts by mass, particularly preferably 0.05 to 10 parts by mass, based on a total of 100 parts by mass of components (A) and (C). .
For example, when the photocurable composition of the present invention contains the component (C), the mass ratio of component (A):component (C) is 70:30 to 85:15, and the photocurable composition The product contains 0.05 to 10 parts by mass of component (B) based on a total of 100 parts by mass of components (A) and (C).
When the photocurable composition of the present invention contains the component (C), the above mass ratio of component (A) and component (C) is 100 parts by mass of the total mass of component (A) and component (C). This is the breakdown of the 100 parts by mass when In addition, when the photocurable composition of the present invention contains component (C), the content of component (B) is 100 parts by mass when the total mass of component (A) and component (C) is 100 parts by mass. The amount is based on parts by mass.
The above mass ratios for components (A) to (C) are particularly preferred from the viewpoints of reducing moisture permeability, improving adhesiveness, and improving flexibility of the cured product.
When the photocurable component includes component (C), the photocurable composition of the present invention may include only component (A), component (B), and component (C) as the photocurable component.

The total content of the photocurable components relative to the total mass of the photocurable composition is preferably 20% by mass to 99.9% by mass, more preferably 30% by mass to 99.8% by mass, More preferably 50% to 99.5% by weight, even more preferably 80% to 99.5% by weight, particularly preferably 90% to 99.5% by weight. If the total content of photocurable components is too low, curing may be insufficient.

[Photopolymerization initiator]

The photocurable composition of the present invention contains a photopolymerization initiator. In the present invention, as the photopolymerization initiator, preferably an acylphosphine oxide-based, α-aminoacetophenone-based, α-hydroxyacetophenone-based, or oxime ester-based photopolymerization initiator is used, more preferably an acylphosphine oxide-based photopolymerization initiator. A type of photopolymerization initiator can be used.
Examples of the acylphosphine oxide-based photopolymerization initiator include bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. Particularly preferably, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide is used as a photopolymerization initiator in the present invention.
Examples of α-aminoacetophenone-based photopolymerization initiators include 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4- Mention may be made of morpholinophenyl)-butanone-1 and 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone. .
Examples of α-hydroxyacetophenone-based photopolymerization initiators include 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxy ethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-[4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl ]-2-methyl-propan-1-one.
Examples of oxime ester photopolymerization initiators include 1.2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], and ethanone, 1-[9-ethyl-6-( Mention may be made of 2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(0-acetyloxime).

The content of the photopolymerization initiator in the photocurable composition is, for example, within the range of 0.01 parts by mass to 10 parts by mass, and preferably 0.01 parts by mass to 10 parts by mass, based on 100 parts by mass of the photocurable component. It is within the range of 1 part by mass to 8 parts by mass, and more preferably within the range of 0.2 to 5 parts by mass.

[Filling material]

The photocurable composition of the present invention may contain a filler. By adjusting the amount of filler, the viscosity of the photocurable composition can be adjusted. Fillers may be inorganic particles, for example, including silica, alumina, titanium oxide, calcium carbonate, boron nitride, aluminum nitride, mica, talc, kaolin, bentonite. For example, fumed silica (especially hydrophilic fumed silica) having a specific surface area of 100 to 500 m ² /g, preferably 200 to 400 m ² /g is preferred as a filler for the photocurable composition of the invention.

The amount of filler may be appropriately selected by those skilled in the art depending on, for example, the type of filler or the desired viscosity of the photocurable composition. When the filler is fumed silica, the amount of fumed silica is, for example, 1% to 10% by weight, preferably 2% to 9% by weight, more preferably 3% by weight, based on the total weight of the photocurable composition. It may be contained at a content rate of 8% by mass. With the above content ratio, the photocurable composition of the present invention has a viscosity that makes it easy to use as a sealing material.

[Curing means]

In the present invention, the photocurable composition is a composition that has the property of being cured by irradiating the composition with light. The light irradiated to cure the photocurable composition of the present invention is, for example, ultraviolet rays, electron beams (beta rays), gamma rays, or alpha rays, more preferably ultraviolet rays and electron beams, and even more preferably. can be ultraviolet light.
A device for irradiating light can be appropriately selected by a person skilled in the art depending on the type of light to be irradiated. Any commercially available device may be used as the device. For example, to irradiate an electron beam, an accelerated electron beam extracted from an electron beam accelerator with a voltage of 20 to 2000 kV is usually used. The electron beam irradiation dose may be, for example, 1 to 300 kGy, preferably 5 to 200 kGy. In addition, UV irradiation equipment such as germicidal lamps, ultraviolet fluorescent lamps, carbon arcs, xenon lamps, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and electrodeless lamps are used to irradiate ultraviolet rays. May be used. The wavelength of the irradiated ultraviolet light may be, for example, 200 nm to 400 nm.

[Application]

The photocurable composition of the present invention may be used, for example, as a sealant. The cured product of the photocurable composition of the present invention is suitable for protecting the sealed interior from external water vapor. Since the cured product has excellent adhesive properties, it is possible to prevent leakage of the liquid sealed by the sealant, such as an electrolyte. That is, the present invention also provides a cured product of the photocurable composition of the present invention.

According to one preferred embodiment of the invention, the photocurable composition of the invention may be used for encapsulating solar cells, more particularly for encapsulating the electrolyte or electrolyte that constitutes the solar cell. May be used for The solar cell is preferably a dye-sensitized solar cell, a perovskite solar cell, or an organic thin film solar cell, and particularly preferably a dye-sensitized solar cell. The cured product of the photocurable composition of the present invention is particularly suitable for sealing the electrolyte solution or solid electrolyte of a dye-sensitized solar cell.

According to another preferred embodiment of the invention, the photocurable composition of the invention may be used to encapsulate electronic devices. The electronic device may preferably be a liquid crystal panel or an organic EL panel. The cured product of the photocurable composition of the present invention is particularly suitable for sealing elements of liquid crystal panels or organic EL panels.

[Production method]

The photocurable composition of the present invention may be produced using stirring means known in the technical field to which the present invention pertains. For example, the photocurable composition of the present invention can be produced by stirring the photocurable component and the photopolymerization initiator contained in the photocurable composition in a container using a stirrer. As a stirrer, devices known in the art may be used. For example, stirring conditions such as stirring time and temperature during stirring may be appropriately set by those skilled in the art.

[how to use]

A method of using the photocurable composition of the present invention will be described below with reference to FIG.
First, as shown in FIG. 3(a), a photocurable composition 302 of the present invention is applied onto a substrate 301. The application can be performed, for example, so that the photocurable composition 302 surrounds a desired area. Next, as shown in FIG. 3(b), the substrate 303 is stacked so as to face the substrate 301 with the photocurable composition 302 in between. Thereafter, as shown in FIG. 3(c), light (for example, ultraviolet light) is irradiated so as to reach the photocurable composition 302. The photocurable composition 302 is cured by the irradiation. As a result, a space defined by the substrates 301 and 303 and the cured product of the photocurable composition 302 is formed.
For example, when producing a dye-sensitized solar cell, the substrates 301 and 303 are, for example, substrates on which a conductive film is laminated, and the photocurable composition is applied onto the conductive film. Then, an electrolytic solution is sealed in a space defined by the conductive film and the cured product of the photocurable composition, thereby producing a flexible dye-sensitized solar cell. The cured product of the photocurable composition of the present invention has excellent adhesiveness to the conductive film. Therefore, the photocurable composition of the present invention is suitable for use as a sealant.
The photocurable composition of the present invention may also be used as an encapsulant in other types of solar cells (for example perovskite solar cells or organic thin film solar cells) or electronic devices.

2. solar cells

The present invention also provides a solar cell containing a cured product of the photocurable composition of the present invention. In the solar cell, the cured product is preferably included as a sealant, more preferably as a sealant for sealing an electrolytic solution or a solid electrolyte. The solar cell is preferably a dye-sensitized solar cell, a perovskite solar cell, or an organic thin film solar cell, and more preferably a dye-sensitized solar cell. When the photocurable composition of the present invention is used as a sealing material in these solar cells, the effects of the present invention are more prominently exhibited.

The dye-sensitized solar cell of the present invention may have, for example, a structure as shown in FIG. 1, which is explained in "1. Photocurable composition" above. Each of the components shown in FIG. 1 will be described in more detail below.

As the transparent substrate 101, a transparent glass plate or a plastic film may be used. As the plastic film, a polyethylene terephthalate (PET) film may be used, or other transparent and heat-resistant films may be used.

As the transparent conductive film (transparent electrode) 102, for example, an ITO film containing indium oxide and tin oxide may be used. The mass proportions of indium oxide and tin oxide can be, for example, 90-99% by weight and 10-1% by weight, preferably 92-98% by weight and 8-2% by weight, respectively. Furthermore, a film in which tin oxide is doped with fluorine (FTO) may be used as the transparent conductive film.
As the substrate 106 constituting the counter electrode substrate of the transparent conductive film 102, for example, glass, a glass plate, or a plastic film may be used. The conductive film 107, like the transparent conductive film 102, may be an ITO film or an FTO film.

Examples of the metal oxide semiconductor forming the metal oxide semiconductor layer 103 include oxides of titanium, zirconium, hafnium, strontium, zinc, indium, yttrium, lanthanum, vanadium, niobium, tantalum, chromium, molybdenum, or tungsten. . Among these, titanium dioxide is particularly preferred. As the metal oxide semiconductor, ultrafine titanium dioxide particles having a diameter of 10 to 30 nm are more preferably used. The titanium dioxide particles can form a titanium dioxide film having a large specific surface area suitable for adsorbing a dye.

As the dye 105, dyes known in the art may be used, such as metal-containing dyes or organic dyes. Examples of the dye 105 include ruthenium complexes [RuL ₂ (NCS) ₂ , L=4,4'-dicarboxy-2,2'-bipyridine], porphyrin dyes, cyanine dyes, C ⁶⁰ derivatives, styrylbenzothiazolium Examples include propyl sulfonate (BTS) and plant pigments.

The electrolytic solution filling the space 108 may be a solution in which an electrolyte is dissolved or dispersed in an organic solvent. The cured product of the photocurable composition of the present invention is suitable for sealing the electrolyte, and is particularly suitable for preventing leakage of the electrolyte.
As the electrolyte, redox pairs (redox systems) such as iodine/iodine compounds and bromine/bromine compounds may be used, and the combination of iodine/iodine compounds is particularly preferred.
As the organic solvent for dissolving or dispersing the electrolyte, ethylene carbonate, propylene carbonate, polyethylene glycol, acetonitrile, 3-methoxypropionitrile, or a mixture of two or more thereof may be used.
In addition to an electrolyte and a solvent, the electrolytic solution may include various additives used in the art. Examples of additives include thickeners, cold-molten salts (such as 1-propyl-2,3-dimethylimidazolium iodide) to reduce viscosity and facilitate ion diffusion, and to prevent reverse current flow. Examples include 4-tert-butylpyridine for increasing open electromotive force.
According to a particularly preferred embodiment of the invention, the electrolyte may be an acetonitrile/ethylene carbonate solution containing iodine and lithium iodide. The cured product of the photocurable composition of the present invention has excellent chemical resistance to the electrolyte.

The dye-sensitized solar cell of the present invention may be appropriately manufactured by a manufacturing method known to those skilled in the art. The dye-sensitized solar cell of the present invention can be manufactured, for example, by a manufacturing method including the following steps.

(1) Photocurable composition coating step In this step, a conductive substrate on which a transparent substrate layer, a transparent conductive film layer, and a metal oxide semiconductor layer adsorbing a dye are laminated in this order, or a conductive film layer and a substrate The photocurable composition of the present invention is applied to a conductive substrate having layers laminated in this order. The application may be performed, for example, by screen printing or an application means such as a dispenser. The application location can be appropriately determined by a person skilled in the art depending on the location where the electrolytic solution or solid electrolyte to be sealed is placed. The coating pattern of the photocurable composition of the present invention may be determined depending on the shape of the dye-sensitized solar cell to be manufactured, such as annular, rectangular, or square. For example, the photocurable composition of the present invention can be applied to form a line with a width of 0.5 mm to 1 mm surrounding the position where the electrolytic solution or solid electrolyte is placed.

(2) Bonding step In this step, the two conductive substrates are bonded together. The amount applied in the coating step can be set so that the thickness of the sealing material after bonding is, for example, 5 μm to 100 μm, more preferably 20 μm to 50 μm.

(3) Curing step In this step, the photocurable composition of the present invention is irradiated with light. The photocurable composition of the present invention is cured by the irradiation with the light. The light may be irradiated through the conductive substrate in which a transparent substrate layer, a transparent conductive film layer, and a metal oxide semiconductor layer are laminated, or the light may be transmitted between the two conductive substrates. may be irradiated.

(4) Electrolyte Enclosing Step In this step, an electrolyte is enclosed in a space defined by the cured photocurable composition of the present invention and the two conductive substrates.
In order to perform the encapsulation, an opening may be provided in a part of the substrate, or the photocurable composition of the present invention may be applied so as to form an opening. An electrolytic solution can be injected into the space through the opening. After the injection, the opening may be sealed with the photocurable composition of the present invention, and the photocurable composition may be cured by irradiating it with light. Alternatively, the opening may be sealed using other cold-curing adhesives.
Note that when a solid electrolyte is used, the solid electrolyte is placed between the two conductive substrates before the bonding step. After the arrangement, a bonding step and an effecting step are performed to manufacture the dye-sensitized solar cell of the present invention.

3. electronic device

The present invention also provides an electronic device containing a cured product of the photocurable composition of the present invention. In the electronic device, the cured product is preferably included as a sealant, more preferably as a sealant for sealing an element. The electronic device is preferably a liquid crystal panel or an organic EL panel. When the photocurable composition of the present invention is used as a sealing material in these electronic devices, the effects of the present invention are more prominently exhibited. The sealing method when the photocurable composition of the present invention is used as a sealant in these electronic devices may be, for example, a frame sealing method or a full-surface sealing method as explained above. It may be. The sealing method is not limited to these, and it is sufficient that at least a part of the element to be protected is in contact with the cured product of the photocurable composition of the present invention.

The electronic device of the present invention may be manufactured as appropriate by any manufacturing method known to those skilled in the art. For example, arranging the element and the photocurable composition of the present invention so that at least a part of the element of the electronic device is in contact with the photocurable composition of the present invention; The method includes curing the photocurable composition by irradiating it with light. As a method of arranging the element and the photocurable composition, for example, the frame sealing method or the entire surface sealing method described above may be adopted.

Hereinafter, the present invention will be explained in more detail based on Examples. It should be noted that the examples described below are only representative examples of the present invention, and the scope of the present invention is not limited only to these examples.

(1) Production method Each component shown in Table 1 was weighed and stirred for 30 minutes with a stirrer to obtain the composition shown in Table 1 below. Examples 1 to 9 and Comparative Examples 1 to A photocurable composition No. 5 was obtained. All numerical units in Table 1 are parts by mass.
The compound names of the materials shown in Table 1 are as follows.
FA-513AS: Dicyclopentanyl acrylate (Tg 120℃)
FA-512AS: Dicyclopentenyloxyethyl acrylate (TG15℃)
SR-217: 4-t-butylcyclohexyl acrylate (TG34℃)
KAYAMER PM-2: Bis(2-methacryloyloxyethyl) hydrogen phosphate
CN-9014NS: Hydrogenated polybutadiene urethane acrylate Aerosil 300: Fumed silica IRGACURE 819: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide

(2) Evaluation of moisture permeability
According to JIS Z 0208, the moisture permeability of the cured product of the produced photocurable composition was measured. That is, a photocurable composition is applied to a thickness of 100 μm on a Teflon (registered trademark) coated metal plate, and the photocurable composition is irradiated with ultraviolet light using a metal halide lamp at a cumulative light intensity of 3,000 mJ/cm ² . The composition was cured. The obtained cured product was cut into a shape specified by the standard, and placed in a container containing approximately 5 g of calcium chloride. The container was stored in a constant temperature and humidity chamber at 60° C./90% RH for 24 hours, and the moisture permeability (g/m ² ·day) was calculated from the difference in weight before and after storage. When the moisture permeability of the cured product was 100 g/m ² ·day or less, the cured product was determined to have good performance from the viewpoint of moisture permeability. The measurement results are shown in Table 1 below.

(3) Evaluation of tensile shear adhesive strength
In accordance with JIS K 6850, the tensile shear adhesive strength of the cured product of the produced photocurable composition was measured. That is, the photocurable composition was applied and bonded between two 25 mm x 100 mm ITO-coated PEN films so that the coating area was 25 mm x 12.5 mm and the coating thickness was 100 μm, and the cumulative light intensity was measured using a metal halide lamp. The photocurable composition was cured by irradiating it with ultraviolet rays at a rate of 3,000 mJ/cm ² . The produced test piece was pulled at a test speed of 10 mm/min using a tensile tester, and the tensile shear adhesive strength (MPa) was measured. When the tensile shear adhesive strength was 1.0 MPa or more, it was determined that the cured product of the photocurable composition had good performance from the viewpoint of adhesiveness. The measurement results are shown in Table 1 below.

As shown in Table 1, the cured products of the photocurable compositions of Examples 1 to 9 all had a strength of 100 g/m ² ·day or less, and a shear adhesive strength of 1.0 MPa or more. That is, the cured products of the photocurable compositions of Examples 1 to 9 all had low moisture permeability and high tensile shear adhesive strength.
The cured product of the photocurable composition of Comparative Example 1 in which the amounts of component (A) and component (C) were 55 parts by mass and 45 parts by mass, respectively, had a moisture permeability of 118 g/m ² ·day; It did not have good performance from the point of view. Comparing the results of Comparative Example 1 and Examples 1 to 6 (particularly Example 4), it was found that adjusting the amounts of component (A) and component (C) lowers the moisture permeability of the cured product. It can be seen that this contributes to
The compositions of Comparative Examples 2 and 3 were the same as those of Example 3, except that an alicyclic (meth)acrylate monomer having a homopolymer Tg of less than 100°C was used instead of component (A). The composition is the same. The moisture permeability of the cured products of the photocurable compositions of Comparative Examples 2 and 3 was 230 g/m ² ·day and 340 g/m ² ·day, respectively, and did not have good performance from the viewpoint of moisture permeability. . Comparing the results of Comparative Examples 2 and 3 with the results of Example 3, it can be seen that the Tg of component (A) of 100° C. or higher contributes to lowering the moisture permeability of the cured product.
The compositions of Examples 3 and 7 to 9 and Comparative Examples 4 and 5 are the same except for the difference in the amount of component (B). A comparison of the results of Example 7 and Comparative Example 5 reveals that component (B) is necessary to provide adhesiveness to the cured product. Further, from the results of Examples 3 and 7 to 9 and the results of Comparative Examples 4 and 5, it can be seen that the moisture permeability can be lowered by adjusting the amount of component (B).
As described above, by adjusting the amounts of component (A), component (B), and component (C), low moisture permeability and excellent adhesiveness can be provided to the cured product of the photocurable composition.

Furthermore, among Examples 1 to 6, the cured product of the photocurable composition of Example 1 had particularly low moisture permeability. Therefore, the content ratio of components (A) and (C) in Example 1 or a similar content ratio (for example, parts by mass of component (A): parts by mass of component (C) = 90:10 to 97:3) By adopting this, moisture permeability can be particularly reduced.

The cured products of the photocurable compositions of Examples 1 to 5 containing component (C) were more flexible than the cured products of the photocurable composition of Example 6 that did not contain component (C). Therefore, by including component (C), the cured product can be made more flexible.

Claims (9)

Component (A): an alicyclic monofunctional (meth)acrylate monomer whose Tg is 100°C or higher in the case of a homopolymer;
Component (B): a (meth)acrylate monomer having a polar group, and Component (C): containing at least one functional group selected from the group consisting of a (meth)acryloyl group, a vinyl ether group, an epoxy group, and an oxetanyl group. A photocurable component consisting of a polyfunctional photocurable component , or
Component (A): an alicyclic monofunctional (meth)acrylate monomer whose Tg is 100°C or higher in the case of a homopolymer, and
Component (B): (meth)acrylate monomer having a polar group,
A photocurable component consisting of ;
a photopolymerization initiator;
A photocurable composition containing,
The total content of the photocurable components with respect to the total mass of the photocurable composition is 50% by mass to 99.8% by mass,
The mass ratio of component (A) and component (C) is 60:40 to 100:0, and
Contains 0.01 to 10 parts by mass of component (B) for a total of 100 parts by mass of component (A) and component (C),
Component (B) is a (meth)acrylate monomer having a phosphoric acid group , and
Component (B) is not a polyfunctional photocurable component of component (C),
A photocurable composition for encapsulating solar cells or electronic devices. The photocurable composition according to claim 1, wherein the content of component (C) is 0 to 35 parts by weight per 1 part by weight of the photopolymerization initiator. The photocurable composition according to claim 1 or 2, wherein the photopolymerization initiator is an acylphosphine oxide-based, α-aminoacetophenone-based, α-hydroxyacetophenone-based, or oxime ester-based photopolymerization initiator. . Any one of claims 1 to 3, wherein the alicyclic monofunctional (meth)acrylate monomer of component (A) has a dicyclopentanyl structure, a dicyclopentenyl structure, an adamantyl structure, or an isobornyl structure. The photocurable composition described in . The component (C) is selected from polybutadiene-based polyfunctional (meth)acrylate, hydrogenated polybutadiene-based polyfunctional (meth)acrylate, polyisoprene-based polyfunctional (meth)acrylate, and hydrogenated polyisoprene-based polyfunctional (meth)acrylate. The photocurable composition according to any one of claims 1 to 4, which is one or a combination of two or more selected. Any one of claims 1 to 5, wherein the content of the photopolymerization initiator in the photocurable composition is 0.01 parts by mass to 10 parts by mass based on 100 parts by mass of the photocurable component. 1. Photocurable composition according to item 1. A cured product of the photocurable composition according to any one of claims 1 to 6. A solar cell comprising a cured product of the photocurable composition according to any one of claims 1 to 6 as a sealant. An electronic device comprising a cured product of the photocurable composition according to any one of claims 1 to 6 as a sealant.