Ultraviolet-curable resin composition, optical component, method for manufacturing optical component, light-emitting device, and method for manufacturing light-emitting device

Abstract

To provide an ultraviolet-curable resin composition which prevents generation of stripe irregularities on the surface of a cured product when the cured product is manufactured by curing the resin composition by irradiation with ultraviolet rays.SOLUTION: An ultraviolet-curable resin composition contains a photopolymerizable compound (A) and a photopolymerization initiator (B). A coated film having a thickness of 10 μm from the ultraviolet-curable resin composition is produced, and an absolute value in a difference between a cure shrinkage when the coated film is irradiated with ultraviolet rays in any wavelength region from 385 nm to 405 nm of a peak wavelength under conditions of an illumination intensity of 7 W / cm2 and an integrated light quantity of 2.1 J / cm2, and a cure shrinkage when irradiated with ultraviolet rays under conditions of an illumination intensity of 3 W / cm2 and an integrated light quantity of 0.9 J / cm2 is 2 percentage point or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet-curable resin composition, an optical component, a method for manufacturing an optical component, a light-emitting device, and a method for manufacturing a light-emitting device, and more particularly to an ultraviolet-curable resin composition containing a photopolymerizable compound and a photopolymerization initiator, an optical component made from the ultraviolet-curable resin composition, a method for manufacturing an optical component using the ultraviolet-curable resin composition, a light-emitting device including the optical component, and a method for manufacturing a light-emitting device using the ultraviolet-curable resin composition. [Background technology]

[0002] In a light-emitting device that uses a light-emitting element such as an organic EL element as a light source, the organic EL element is disposed on a support substrate, a transparent substrate is disposed opposite the support substrate, and a transparent sealant is filled between the support substrate and the transparent substrate. The sealant is produced by, for example, an inkjet method.

[0003] For example, Patent Document 1 discloses a sealant for organic EL display elements, which contains a polymerizable compound and a polymerization initiator, and is characterized by having a viscosity of 5 to 50 mPa·s at 25°C, a surface tension of 15 to 35 mN / m at 25°C, and a Poisson's ratio of the cured product at 25°C of 0.28 to 0.40 (see claim 1 in Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 074506 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the inventor's research, when a cured product is produced by irradiating an ultraviolet-curable resin composition with ultraviolet light to cure it, streaky irregularities may form on the surface of the cured product. This is particularly likely to occur when the surface of a coating film of the ultraviolet-curable resin composition is irradiated with ultraviolet light from a light-emitting diode while the irradiation position is moved to cure the coating film. Such irregularities deteriorate the light-emitting characteristics of the light-emitting device.

[0006] An object of the present invention is to provide an ultraviolet-curable resin composition that is less likely to produce streaky irregularities on the surface of a cured product when the cured product is produced by irradiating ultraviolet light to cure the resin, an optical component produced from the ultraviolet-curable resin composition, a method for manufacturing an optical component using the ultraviolet-curable resin composition, a light-emitting device including the optical component, and a method for manufacturing a light-emitting device using the ultraviolet-curable resin composition. [Means for solving the problem]

[0007] An ultraviolet-curable resin composition according to one embodiment of the present invention contains a photopolymerizable compound (A) and a photopolymerization initiator (B). A coating film having a thickness of 10 μm is prepared from the ultraviolet-curable resin composition, and the coating film is irradiated with ultraviolet light having a peak wavelength in the wavelength range of 385 nm to 405 nm at an irradiation intensity of 7 W / cm. 2 and an integrated light output of 2.1 J / cm 2 The curing shrinkage rate when irradiated under the conditions of 3W / cm and the irradiation intensity 2 And the cumulative light intensity is 0.9J / cm 2 The absolute value of the difference between the cure shrinkage rate when irradiated under the conditions of is 2 percentage points or less.

[0008] An optical component according to one aspect of the present invention includes a cured product of the ultraviolet-curable resin composition.

[0009] A method for manufacturing an optical component according to one aspect of the present invention includes molding the ultraviolet-curable resin composition by an inkjet method, and then curing the ultraviolet-curable resin composition by irradiating it with ultraviolet light.

[0010] A light emitting device according to one aspect of the present invention includes a light source and an optical component that transmits light emitted by the light source, the optical component including a cured product of the ultraviolet-curable resin composition.

[0011] A method for manufacturing a light-emitting device according to one aspect of the present invention is a method for manufacturing a light-emitting device comprising a light source and an optical component that transmits light emitted by the light source, and includes manufacturing the optical component using a method for manufacturing an optical component. [Effects of the Invention]

[0012] According to one aspect of the present invention, there are provided an ultraviolet-curable resin composition that is less likely to produce streaky irregularities on the surface of a cured product when the cured product is produced by irradiating ultraviolet light to cure the resin, an optical component produced from the ultraviolet-curable resin composition, a method for manufacturing an optical component using the ultraviolet-curable resin composition, a light-emitting device including the optical component, and a method for manufacturing a light-emitting device using the ultraviolet-curable resin composition. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic cross-sectional view showing a first example of a light emitting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below.

[0015] The ultraviolet-curable resin composition according to this embodiment (hereinafter also referred to as composition (X)) contains a photopolymerizable compound (A) and a photopolymerization initiator (B). A coating film having a thickness of 10 μm was prepared from composition (X), and the coating film was irradiated with ultraviolet light having a peak wavelength in the wavelength range of 385 nm to 405 nm at an irradiation intensity of 7 W / cm. 2 and an integrated light output of 2.1 J / cm 2 The curing shrinkage rate when irradiated under the conditions of (hereinafter also referred to as the first curing shrinkage rate) and the irradiation intensity of 3W / cm 2 And the cumulative light intensity is 0.9J / cm 2The absolute value of the difference between the curing shrinkage rate when irradiated under the condition (hereinafter also referred to as the second curing shrinkage rate) and the curing shrinkage rate when irradiated under the condition (hereinafter also referred to as the curing shrinkage rate difference) is 2 percentage points or less.

[0016] In this embodiment, as long as the difference between the first and second curing shrinkage rates is 2 percentage points or less when ultraviolet light having a peak wavelength in the wavelength range from 385 nm to 405 nm is used, it is not necessary to achieve a difference between the first and second curing shrinkage rates of 2 percentage points or less when ultraviolet light having a peak wavelength in another wavelength range is used. It is particularly preferable if the difference between the first and second curing shrinkage rates is 2 percentage points or less when ultraviolet light having a peak wavelength of 395 nm is used. It is also preferable that the difference between the first and second curing shrinkage rates is 2 percentage points or less when the ultraviolet light has a peak wavelength in the wavelength range from 385 nm to 405 nm.

[0017] According to this embodiment, when a cured product is produced by irradiating composition (X) with ultraviolet light, streaky irregularities are unlikely to occur on the surface of the cured product. This is thought to be because the absolute value of the difference between the first cure shrinkage rate and the second cure shrinkage rate of composition (X) is small, which makes it less likely that differences in the amount of shrinkage will occur locally when composition (X) is cured, i.e., composition (X) as a whole will shrink more uniformly.

[0018] In particular, when the surface of a coating film of an ultraviolet-curable resin composition is irradiated with ultraviolet light from a light-emitting diode while the ultraviolet irradiation position is moved to cure the coating film, areas of the coating film where the ultraviolet irradiation dose is relatively high tend to appear along the linear locus of the ultraviolet irradiation position, and areas where the ultraviolet irradiation dose is relatively low tend to appear between these areas. Therefore, differences in the cure shrinkage between these areas are usually likely to cause streaky irregularities in the cured product of the coating film. However, in this embodiment, since the absolute value of the difference between the first cure shrinkage and the second cure shrinkage of composition (X) is small as described above, even if differences in the ultraviolet irradiation dose occur in parts of the coating film of composition (X), differences in the amount of shrinkage are unlikely to occur, and it is presumed that this makes it unlikely for irregularities to occur in the cured product.

[0019] The absolute value of the difference between the first cure shrinkage and the second cure shrinkage is preferably 1.5 percentage points or less, and even more preferably 1 percentage point or less. The smaller this value, the better, and ideally 0 percentage points. Specific examples of the measurement methods and measurement conditions for the first cure shrinkage and the second cure shrinkage of composition (X) will be described in detail in the Examples section below.

[0020] A coating film having a thickness of 10 μm was prepared from composition (X), and this coating film was irradiated with ultraviolet light having a peak wavelength of 395 nm at an irradiation intensity of 3 W / cm. 2 And the cumulative light intensity is 0.9J / cm 2When irradiated under these conditions, the reaction rate of the photopolymerizable compound (A) in the composition (X) is preferably 80% or higher. In this case, even if differences in the amount of UV light irradiated locally occur when curing the composition (X) by UV light irradiation, differences in the reaction rate of the photopolymerizable compound (A) are unlikely to occur within the cured product. Therefore, differences in the amount of shrinkage during curing of the composition (X) are particularly unlikely to occur, and therefore unevenness is unlikely to occur in the cured product. Such characteristics of the composition (X) can be achieved by increasing the reactivity of the photopolymerizable compound (A) through the composition of the composition (X) described below. The reduction rate of the reactive functional groups in the photopolymerizable compound (A), obtained by analyzing the composition (X) by infrared spectroscopy before and after UV light irradiation, is defined as the reaction rate of the photopolymerizable compound (A). Specific examples of how to determine the reaction rate are described in the Examples section below.

[0021] Optical components can be manufactured from composition (X), and light-emitting devices equipped with optical components can also be manufactured. Note that the use of composition (X) is not limited to the manufacture of optical components, and composition (X) can be used in various applications that utilize the properties of composition (X).

[0022] The composition (X) is preferably molded by an inkjet method. In this case, a cured product of the composition (X) can be easily produced with high positional accuracy. Furthermore, compared with molding by a printing method involving contact, such as a screen printing method, when the composition (X) is molded by the inkjet method, foreign matter is less likely to be mixed into the composition (X) and its cured product, and therefore the yield when manufacturing optical components is less likely to decrease.

[0023] At least one of the viscosities of composition (X) at 25° C. and 40° C. is preferably 30 mPa·s or less.

[0024] When the viscosity of composition (X) at 25°C is 30 mPa·s or less, composition (X) can be easily molded at room temperature, particularly by the inkjet method. A viscosity of 25 mPa·s or less is more preferable, 20 mPa·s or less is even more preferable, and 15 mPa·s or less is particularly preferable. A viscosity of 1 mPa·s or more is also preferable, and 5 mPa·s or more is also preferable.

[0025] When the viscosity of composition (X) at 40°C is 30 mPa·s or less, it is possible to lower the viscosity of composition (X) by slightly heating it, regardless of the viscosity of composition (X) at room temperature. Therefore, heating composition (X) makes it easier to mold, particularly by inkjet molding. Furthermore, because the viscosity of composition (X) can be lowered without significantly heating it, changes in the composition of composition (X) due to the volatilization of components in composition (X) are less likely to occur. It is more preferable for this viscosity to be 25 mPa·s or less, even more preferable for it to be 20 mPa·s or less, and particularly preferable for it to be 15 mPa·s or less. It is also preferable for this viscosity to be 1 mPa·s or more, and even more preferable for it to be 5 mPa·s or more.

[0026] Such a low viscosity of composition (X) at 25° C. or 40° C. can be achieved by the composition of composition (X) described in detail below. The method and conditions for measuring the viscosity of composition (X) at 25° C. and 40° C. will be described in detail in the Examples section below.

[0027] It is preferable that the rate of outgassing generated when a cured product of composition (X) is heated at 80°C for 30 minutes is 500 ppm or less. In this case, outgassing from the cured product is less likely to occur. This makes it less likely that voids due to outgassing will occur in, for example, a light-emitting device equipped with an optical component made of the cured product. This makes it less likely that water and oxygen will reach the light-emitting element through voids, making it less likely that the light-emitting element will deteriorate due to water and oxygen.

[0028] Preferably, composition (X) contains no solvent or contains 1% by mass or less of solvent. In this case, outgassing from composition (X) and the cured product of composition (X) is unlikely to occur. Furthermore, a drying step for removing the solvent from composition (X) and the cured product can be eliminated during the production of optical components and light-emitting devices. A drying step for removing the solvent from at least one of composition (X) and the cured product may be performed. This allows for at least one of a lower heating temperature and a shorter heating time in the drying step. Therefore, outgassing from the optical components can be reduced without reducing the production efficiency of optical components and light-emitting devices. Furthermore, when composition (X) is molded, particularly by an inkjet method, the thickness of the molded composition (X) is unlikely to decrease due to solvent evaporation, and therefore the thickness of the optical components is unlikely to decrease. Therefore, the thickness of the optical components can be maximized even when molded by the inkjet method. The solvent content is more preferably 0.5% by mass or less, even more preferably 0.3% by mass or less, and particularly preferably 0.1% by mass or less. It is particularly preferred that the composition (X) does not contain a solvent or contains only an unavoidably mixed solvent.

[0029] The glass transition temperature of the cured product of composition (X) is preferably 80°C or higher. In other words, composition (X) preferably has the property of curing to form a cured product with a glass transition temperature of 80°C or higher. In this case, the cured product can have good heat resistance. Therefore, for example, when the cured product is subjected to a process that increases the temperature, the cured product is less likely to deteriorate. Therefore, for example, when an inorganic material layer (e.g., passivation layer 6) that overlies an optical component is produced by a vapor deposition method such as plasma CVD, the optical component is less likely to deteriorate even when heated. Furthermore, by improving heat resistance, the optical component can be adapted for automotive applications that require strict heat resistance. The glass transition temperature of the cured product is more preferably 90°C or higher, and even more preferably 100°C or higher. This glass transition temperature of the cured product can be achieved by the composition of composition (X), which will be described in detail below.

[0030] When 20 mg of composition (X) is heated at 100°C for 30 minutes using a thermogravimetric analyzer, the volatility is preferably 40% or less. The volatility of composition (X) is defined as the percentage of the weight loss of composition (X) after treatment (the difference between the weight of composition (X) before and after treatment) relative to the weight of composition (X) before treatment. In this case, the low volatility of composition (X) enhances the storage stability of composition (X). Furthermore, outgassing is less likely to occur from cured compositions of composition (X) and optical components. Therefore, voids due to outgassing are even less likely to occur within light-emitting devices. The volatility of composition (X) can be determined by heating 20 mg of composition (X) at 100°C for 30 minutes using a thermogravimetric analyzer and calculating the weight loss after treatment relative to the weight before treatment. When 20 mg of composition (X) is heated at 100°C for 30 minutes using a thermogravimetric analyzer, the volatility is preferably 30% or less, and even more preferably 20% or less. The lower limit of the volatility of composition (X) is not particularly limited, but may be, for example, 0.1% or more.

[0031] The components contained in composition (X) will be explained in more detail below.

[0032] The photopolymerizable compound (A) is a component that can undergo a polymerization reaction upon irradiation with ultraviolet light in the presence or absence of a photopolymerization initiator (B). The photopolymerization initiator (B) may contain a curing catalyst. The photopolymerizable compound (A) contains, for example, at least one component selected from the group consisting of a monomer, an oligomer, and a prepolymer.

[0033] The photopolymerizable compound (A) contains, for example, at least one of a radically polymerizable compound (A1) and a cationically polymerizable compound (A2). When the photopolymerizable compound (A) contains the radically polymerizable compound (A1), the photopolymerization initiator (B) preferably contains a photoradical polymerization initiator (B1). When the photopolymerizable compound (A) contains a cationically polymerizable compound (A2), the photopolymerization initiator (B) preferably contains a photocationic polymerization initiator (B2) (cationic curing catalyst).

[0034] The case where the photopolymerizable compound (A) contains a radically polymerizable compound (A1) will be described.

[0035] The radically polymerizable compound (A1) preferably contains an acrylic compound (Y), which has one or more (meth)acryloyl groups in one molecule.

[0036] The viscosity of the entire acrylic compound (Y) at 25°C is preferably 50 mPa·s or less. In this case, the acrylic compound (Y) can particularly reduce the viscosity of the composition (X). The viscosity of the entire acrylic compound (Y) is more preferably 30 mPa·s or less, and particularly preferably 20 mPa·s or less. The viscosity of the entire acrylic compound (Y) is, for example, 3 mPa·s or more.

[0037] It is also preferable that the viscosity of the entire acrylic compound (Y) at 40°C is 50 mPa·s or less. In this case, the acrylic compound (Y) can particularly reduce the viscosity of the composition (X) when heated. The viscosity of the entire acrylic compound (Y) is more preferably 30 mPa·s or less, and particularly preferably 20 mPa·s or less. Furthermore, the viscosity of the entire acrylic compound (Y) is, for example, 3 mPa·s or more.

[0038] The percentage of components in the acrylic compound (Y) having a boiling point of 270°C or higher is preferably 80% by mass or higher. In this case, the storage stability of the composition (X) is particularly unlikely to be impaired, and outgassing from the cured product is particularly unlikely to occur. It is even more preferable that the percentage of components in the acrylic compound (Y) having a boiling point of 280°C or higher is 80% by mass or higher.

[0039] The acrylic compound (Y) preferably contains a component having a viscosity of 20 mPa·s or less at 25° C. In this case, the viscosity of the composition (X) can be reduced.

[0040] The proportion of the component having a viscosity of 20 mPa·s or less at 25°C relative to the total amount of acrylic compound (Y) is preferably 50% by mass or more and 100% by mass or less. In this case, the viscosity of composition (X) can be particularly reduced, making composition (X) particularly easy to apply by inkjet method. This proportion is more preferably 60% by mass or more, and even more preferably 70% by mass or more. Furthermore, this proportion is more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0041] The component having a viscosity of 20 mPa·s or less at 25°C preferably contains a compound having a glass transition temperature of 80°C or higher. In this case, the viscosity of composition (X) can be reduced while the glass transition temperature of the cured product can be increased. This component preferably contains a compound having a glass transition temperature of 90°C or higher, and even more preferably contains a compound having a glass transition temperature of 100°C or higher. There is no upper limit to the glass transition temperature of the compound contained in this component, but it is, for example, 150°C or lower.

[0042] The compounds that the acrylic compound (Y) may contain will be described below.

[0043] The acrylic compound (Y) preferably contains a polyfunctional acrylic compound (Y1) having two or more radically polymerizable functional groups, including a (meth)acryloyl group, in one molecule. In this case, the polyfunctional acrylic compound (Y1) can increase the glass transition temperature of the cured product, thereby improving the heat resistance of the cured product. The proportion of the polyfunctional acrylic compound (Y1) is preferably 50% by mass or more and 100% by mass or less based on the total amount of the acrylic compound (Y). The acrylic compound (Y) may contain only the polyfunctional acrylic compound (Y1).

[0044] Examples of the polyfunctional acrylic compound (Y1) include 1,3-butylene glycol di(meth)acrylate, 1,4-butanediol oligoacrylate, diethylene glycol diacrylate, 1,6-hexanediol oligoacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, tripropylene glycol diacrylate, dipropylene glycol diacrylate, cyclohexanedimethanol diacrylate, tricyclodecane dimethanol diacrylate, bisphenol A polyethoxydiacrylate, bisphenol F polyethoxydiacrylate, pentaerythritol tetraacrylate, propoxylated (2) neopentyl glycol diacrylate, trimethylolpropane triacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, pentaerythritol triacrylate, and ethoxylated (3) trimethylol Propane triacrylate, propoxylated (3) glyceryl triacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, ethoxylated (4) pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, 2-(2-ethoxyethoxy)ethyl acrylate, hexadiol diacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, tripropylene glycol triacrylate, bispentaerythritol hexaacrylate, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, ethoxylated 1,6-hexanediol diacrylate, polypropylene glycol diacrylate, 1,4-butanediol diacrylate, 1,9-nonanediol diacrylate, tetraethylene glycol diacrylate, 2-n-butyl-2-ethyl-1,3-Propanediol diacrylate, hydroxypivalic acid neopentyl glycol diacrylate, hydroxypivalic acid trimethylolpropane triacrylate, ethoxylated phosphoric acid triacrylate, ethoxylated tripropylene glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate, tetramethylolpropane triacrylate, tetramethylolmethane triacrylate, caprolactone modified trimethylolpropane triacrylate, propoxylated glyceryl triacrylate, tetramethylolmethane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, dipentaerythritol It contains at least one compound selected from the group consisting of erythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, neopentyl glycol oligoacrylate, trimethylolpropane oligoacrylate, pentaerythritol oligoacrylate, ethoxylated neopentyl glycol di(meth)acrylate, propoxylated neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, and 2-(2-vinyloxyethoxy)ethyl acrylate.

[0045] The polyfunctional acrylic compound (Y1) preferably has an acrylic equivalent of 150 g / eq or less, more preferably 90 g / eq or more and 150 g / eq or less. The polyfunctional acrylic compound (Y1) has a weight average molecular weight of, for example, 100 or more and 1,000 or less, more preferably 200 or more and 800 or less.

[0046] It is also preferable that the polyfunctional acrylic compound (Y1) contains a compound (Y11) having a structure represented by the following formula (200).

[0047] CH2=CR 1 -COO-(R 3 -O)n-CO-CR2 =CH2…(200) In equation (200), R 1 and R 2 Each of the groups is hydrogen or a methyl group, n is an integer of 1 or more, R 3 is an alkylene group having one or more carbon atoms, and when n is 2 or more, there are multiple R 3 may be the same or different from each other.

[0048] The compound (Y11) has a structure shown in formula (200), and in particular, R 3 Since the carbon number of R is 3 or more, it is difficult to increase the affinity of the cured product with water. 3 The number of carbon atoms in the formula (Y11) is, for example, 1 or more and 15 or less, and preferably 3 or more and 15 or less. Furthermore, compound (Y11) has the structure shown in formula (200), and in particular, has two (meth)acryloyl groups in one molecule, thereby increasing the glass transition temperature of the cured product and thereby improving the heat resistance of the cured product. Furthermore, n in formula (200) is, for example, an integer of 1 or more and 12 or less.

[0049] The percentage of the compound (Y11) relative to the acrylic compound (Y) is preferably 50% by mass or more. In this case, the affinity of the cured product for water is particularly difficult to increase. The percentage of the compound (Y11) relative to the acrylic compound (Y) is, for example, 100% by mass or less, or 95% by mass or less, and preferably 80% by mass or less.

[0050] The compound (Y11) preferably contains a component having a boiling point of 270°C or higher. That is, the acrylic compound (Y) preferably contains a component having a structure represented by formula (200) and a boiling point of 270°C or higher. In this case, the acrylic compound (Y) is less likely to volatilize from the composition (X) during storage or when the composition (X) is heated. Therefore, the storage stability of the composition (X) is less likely to be impaired. Furthermore, even if the compound (Y11) remains unreacted in the cured product of the composition (X), outgassing due to the compound (Y11) is less likely to occur from the cured product. Therefore, voids due to outgassing are less likely to occur in the light-emitting device 1. If voids exist in the light-emitting device 1, moisture may penetrate into the light-emitting element 4 through the voids. However, if voids are less likely to occur, moisture is less likely to penetrate into the light-emitting element 4. The boiling point is the boiling point under normal pressure obtained by converting the boiling point under reduced pressure, and is determined by the method described in, for example, Science of Petroleum, Vol. II, p. 1281 (1938). It is more preferable that compound (Y11) contains a component having a boiling point of 280°C or higher.

[0051] The percentage of the compound (Y11) relative to the acrylic compound (Y) is preferably 50% by mass or more. In this case, the storage stability of the composition (X) is effectively improved, outgassing from the cured product is effectively reduced, and the affinity of the cured product for water is particularly improved. The percentage of the compound (Y11) relative to the acrylic compound (Y) is, for example, 100% by mass or less, or 95% by mass or less, and preferably 80% by mass or less.

[0052] The viscosity of compound (Y11) at 25°C is preferably 25 mPa·s or less. In this case, compound (Y11) can reduce the viscosity of composition (X). The viscosity of compound (Y11) at 25°C is more preferably 25 mPa·s or less, even more preferably 20 mPa·s or less, and particularly preferably 15 mPa·s or less. The viscosity of compound (Y11) at 25°C is, for example, 1 mPa·s or more, preferably 3 mPa·s or more, and more preferably 5 mPa·s or more.

[0053] The compound (Y11) contains, for example, at least one compound selected from the group consisting of alkylene glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate, and alkylene oxide-modified alkylene glycol di(meth)acrylate.

[0054] Alkylene glycol di(meth)acrylate is a compound of formula (200) where n is 1. In this case, R 3 The number of carbon atoms in R is preferably 4 to 12. 3It may be linear or branched. In particular, the alkylene glycol di(meth)acrylate preferably contains at least one compound selected from the group consisting of 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and 1,12-dodecanediol dimethacrylate. In addition, alkylene glycol di(meth)acrylates include Sartomer product number SR213, Osaka Organic Chemical Industry Co., Ltd. product number V195, Sartomer product number SR212, Sartomer product number SR247, Kyoei Chemical Industry Co., Ltd. product name Light Acrylate NP-A, Sartomer product number SR238NS, Osaka Organic Chemical Industry Co., Ltd. product number V230, Daicel Corporation product number HDDA, Kyoei Chemical Industry Co., Ltd. product number 1,6HX-A, Osaka Organic Chemical Industry Co., Ltd. product number V260, Kyoei Chemical Industry Co., Ltd. product number 1,9-ND-A, Shin-Nakamura Chemical Co., Ltd. product number A-NOD-A, Sartomer product number CD595, Sartomer product number S It is preferable that the composition contains at least one compound selected from the group consisting of R214NS, Shin-Nakamura Chemical Co., Ltd. product number BD, Sartomer Co., Ltd. product number SR297, Sartomer Co., Ltd. product number SR248, Kyoei Chemical Co., Ltd. product name Light Ester NP, Sartomer Co., Ltd. product number SR239NS, Kyoei Chemical Co., Ltd. product name Light Ester 1,6HX, Shin-Nakamura Chemical Co., Ltd. product number HD-N, Kyoei Chemical Co., Ltd. product name Light Ester 1,9ND, Shin-Nakamura Chemical Co., Ltd. product number NOD-N, Kyoei Chemical Co., Ltd. product name Light Ester 1,10DC, Shin-Nakamura Chemical Co., Ltd. product number DOD-N, and Sartomer Co., Ltd. product number SR262.

[0055] Polyalkylene glycol di(meth)acrylate is, for example, a compound represented by formula (200) in which n is 2 or greater. n is, for example, 2 to 10, preferably 2 to 7, also preferably 2 to 6, and also preferably 2 to 3. R 3 The number of carbon atoms is, for example, 2 to 7, and preferably 2 to 5. The greater the number of carbon atoms, the more hydrophobic the cured product becomes, and the less moisture permeates the cured product. The polyalkylene glycol di(meth)acrylate preferably contains at least one compound selected from the group consisting of diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, hexaethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, tritetramethylene glycol diacrylate, polyethylene glycol 200 dimethacrylate, and polyethylene glycol 200 diacrylate. Furthermore, it is preferable that the polyalkylene glycol di(meth)acrylate contains at least one compound selected from the group consisting of Sartomer product number SR230, Sartomer product number SR508NS, Daicel product number DPGDA, Sartomer product number SR306NS, Daicel product number TPGDA, Osaka Organic Chemical Industry Ltd. product number V310HP, Shin-Nakamura Chemical Co., Ltd. product number APG200, Kyoei Chemical Industry Co., Ltd. product name Light Acrylate PTMGA-250, Sartomer product number SR231NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 2EG, Sartomer product number SR205NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 3EG, Sartomer product number SR210NS, Kyoei Chemical Industry Co., Ltd. product name Light Ester 4EG, Mitsubishi Chemical Corporation product name Acryester HX, and Shin-Nakamura Chemical Co., Ltd. product number 3PG.

[0056] The alkylene oxide-modified alkylene glycol di(meth)acrylate includes, for example, propylene oxide-modified neopentyl glycol. The alkylene oxide-modified alkylene glycol di(meth)acrylate includes, for example, EBECRYL145 manufactured by Daicel Corporation.

[0057] When the acrylic compound (Y) contains a compound (Y11) having a structure represented by formula (200), it is preferable that the compound (Y11) does not contain a compound in which the value of n in formula (200) is 5 or more. (R 3 When —O)n is a polyethylene glycol skeleton, it is particularly preferred that the compound (Y11) does not contain a compound in which the value of n in formula (200) is greater than 5. Even when compound (Y11) contains a compound in which the value of n in formula (200) is greater than 5, the percentage of the compound in formula (200) in which the value of n is greater than 5 relative to the acrylic compound (Y) is preferably 20 mass% or less. Furthermore, even when compound (Y11) contains a compound in formula (200) in which the value of n is greater than 5, compound (Y11) preferably does not contain a compound in which the value of n is greater than 9, and more preferably does not contain a compound in which the value of n is greater than 7. In these cases, an increase in viscosity of composition (X) is particularly unlikely to occur.

[0058] It is particularly preferred that the polyfunctional acrylic compound (Y1) contains a polyalkylene glycol di(meth)acrylate, which has low viscosity and is not easily volatile, and therefore can contribute to lowering the viscosity of the composition (X), improving the storage stability of the composition (X), and reducing outgassing from the cured product.

[0059] When the polyfunctional acrylic compound (Y1) contains a polyalkylene glycol di(meth)acrylate, the proportion of the polyalkylene glycol di(meth)acrylate relative to the acrylic compound (Y) is preferably 40% by mass or more and 80% by mass or less. When the proportion of the polyalkylene glycol di(meth)acrylate is 40% by mass or more, the viscosity of the composition (X) can be effectively reduced. When the proportion of the polyalkylene glycol di(meth)acrylate is 80% by mass or less, the proportion of compounds having three or more (meth)acryloyl groups in the molecule increases, thereby increasing the reactivity of the composition (X) and the glass transition temperature of the cured product. This proportion is more preferably 42% by mass or more and 75% by mass or less, and even more preferably 45% by mass or more and 70% by mass or less.

[0060] The polyfunctional acrylic compound (Y1) may contain a compound having three or more radically polymerizable functional groups, including (meth)acryloyl groups, in one molecule. In this case, the polyfunctional acrylic compound (Y1) may contain, for example, at least one selected from the group consisting of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetra(meth)acrylate. In this case, the glass transition temperature of the cured product can be particularly increased, and therefore the heat resistance of the cured product can be particularly improved.

[0061] The polyfunctional acrylic compound (Y1) preferably contains pentaerythritol tetra(meth)acrylate. In this case, the glass transition temperature of the cured product can be particularly increased, and the reactivity of the composition (X) can be improved. The improved reactivity of the composition (X) allows the composition (X) to be easily cured even in an oxygen-containing environment such as the air atmosphere.

[0062] When the polyfunctional acrylic compound (Y1) contains pentaerythritol tetra(meth)acrylate, the ratio of pentaerythritol tetra(meth)acrylate to the acrylic compound (Y) is preferably 0.5% by mass or more and 10% by mass or less. In this case, high reactivity and low viscosity of the composition (X) can be achieved at the same time. This ratio is more preferably 1% by mass or more and 9% by mass or less, and even more preferably 2% by mass or more and 8% by mass or less.

[0063] The polyfunctional acrylic compound (Y1) may have at least one of a benzene ring, an alicyclic ring, and a polar group. The polar group is, for example, at least one of an OH group and an NHCO group. In this case, shrinkage during curing of the composition (X) can be particularly reduced. Furthermore, adhesion between the cured product and inorganic compounds such as silicon nitride and silicon oxide can be improved. The polyfunctional acrylic compound (Y1) preferably contains at least one compound selected from the group consisting of tricyclodecane dimethanol diacrylate, bisphenol A polyethoxydiacrylate, bisphenol F polyethoxydiacrylate, trimethylolpropane triacrylate, and pentaerythritol triacrylate. These compounds can particularly reduce shrinkage during curing of the composition (X). Furthermore, these compounds can also improve adhesion between the cured product and inorganic compounds such as silicon nitride and silicon oxide.

[0064] If the adhesion between the cured product and the inorganic material is improved, when the optical component is overlaid with a film made of an inorganic material (inorganic film) such as a SiN film, high adhesion between the optical component and the inorganic film is likely to be obtained.

[0065] It is particularly preferable that the polyfunctional acrylic compound (Y1) contains polyalkylene glycol di(meth)acrylate and pentaerythritol tetra(meth)acrylate. In this case, the composition (X) has low viscosity and excellent reactivity. Therefore, the composition (X) can be easily cured even in an oxygen-containing environment such as the air atmosphere.

[0066] The acrylic compound (Y) preferably contains a monofunctional acrylic compound (Y2) having only one (meth)acryloyl group as a radical polymerizable functional group in one molecule, which can suppress shrinkage of the composition (X) during curing.

[0067] When the acrylic compound (Y) contains a monofunctional acrylic compound (Y2), the amount of the monofunctional acrylic compound (Y2) relative to the total amount of the acrylic compounds (Y) is preferably greater than 0% by mass and less than 50% by mass. When the amount of the monofunctional acrylic compound (Y2) is greater than 0% by mass, shrinkage of the composition (X) during curing can be suppressed. Furthermore, when the amount of the monofunctional acrylic compound (Y2) is 50% by mass or less, the amount of the polyfunctional acrylic compound (Y1) can be 50% by mass or more, thereby particularly improving the heat resistance of the cured product. It is more preferable that the amount of the monofunctional acrylic compound (Y2) is 5% by mass or more. It is also more preferable that it is 30% by mass or less, and particularly preferable that it is 20% by mass or less.

[0068] Examples of the monofunctional acrylic compound (Y2) include tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methyl ... Toxidixylethyl acrylate, ethyl diglycol acrylate, cyclic trimethylolpropane formal monoacrylate, imide acrylate, isoamyl acrylate, ethoxylated succinic acid acrylate, trifluoroethyl acrylate, ω-carboxypolycaprolactone monoacrylate, cyclohexyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate, diethylene glycol monobutyl ether acrylate, lauryl acrylate, isodecyl acrylate, 3,3,5-trimethylcyclohexanol acrylate, isooctyl acrylate, octyl / decyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated (4) nonylphenol acrylate, methoxypolyethylene glycol (350) monoacrylate, methoxypolyethylene glycol (550) monoacrylate, phenoxyethyl acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tributary The composition contains at least one compound selected from the group consisting of bromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, an ethylene oxide adduct of 2-phenoxyethyl acrylate, a propylene oxide adduct of 2-phenoxyethyl acrylate, acryloylmorpholine, morpholin-4-yl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,4-cyclohexanedimethanol monoacrylate, 3-methacryloyloxymethyl cyclohexene oxide, and 3-acryloyloxymethyl cyclohexene oxide.

[0069] The monofunctional acrylic compound (Y2) may contain at least one compound selected from the group consisting of compounds having an alicyclic structure and compounds having a cyclic ether structure.

[0070] The compound having an alicyclic structure includes at least one compound selected from the group consisting of, for example, phenoxyethyl acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t-butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, an ethylene oxide adduct of 2-phenoxyethyl acrylate, a propylene oxide adduct of 2-phenoxyethyl acrylate, acryloylmorpholine, morpholin-4-yl acrylate, isobornyl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 1,4-cyclohexanedimethanol monoacrylate.

[0071] The number of ring members in the cyclic ether structure in the compound having a cyclic ether structure is preferably 3 or more, more preferably 3 to 4. The number of carbon atoms contained in the cyclic ether structure is preferably 2 to 9, more preferably 2 to 6. The compound having a cyclic ether structure contains, for example, at least one compound selected from the group consisting of 3-methacryloyloxymethyl cyclohexene oxide and 3-acryloyloxymethyl cyclohexene oxide.

[0072] The acrylic compound (Y) may contain a compound having silicon in its molecular skeleton. In this case, the adhesion between the cured product and the inorganic material is improved. The compound having silicon in its molecular skeleton may contain at least one compound selected from the group consisting of 3-(trimethoxysilyl)propyl acrylate (e.g., product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd.) and (meth)acrylic group-containing alkoxysilane oligomer (e.g., product number KR-513 manufactured by Shin-Etsu Chemical Co., Ltd.).

[0073] The acrylic compound (Y) may contain a compound having phosphorus in its molecular structure. In this case, the adhesion between the cured product and the inorganic material is improved. Examples of compounds having phosphorus in their molecular structure include acid phosphoxy (meth)acrylates, such as acid phosphoxy polyoxypropylene glycol monomethacrylate.

[0074] The acrylic compound (Y) may contain a compound having nitrogen in its molecular skeleton. In this case, the adhesion between the cured product and inorganic materials is improved. Furthermore, the reactivity of the acrylic compound (Y) is likely to be improved, thereby reducing the occurrence of outgassing from the cured product. Examples of compounds having nitrogen in their molecular skeleton include at least one compound selected from the group consisting of compounds having a morpholine skeleton, such as acryloylmorpholine and morpholin-4-yl acrylate, diethylacrylamide, dimethylaminopropylacrylamide, and pentamethylpiperidyl methacrylate.

[0075] It is particularly preferred that the acrylic compound (Y) contains a compound having a morpholine skeleton. In this case, the reactivity of the composition (X) can be further improved, and the curability of the composition (X) can be further enhanced even under atmospheric conditions. It is particularly preferred that the acrylic compound (Y) contains at least one of acryloylmorpholine and morpholin-4-yl acrylate. In this case, shrinkage during curing of the composition (X) can be suppressed. In addition, the viscosity of acryloylmorpholine and morpholin-4-yl acrylate is low, and therefore these compounds are unlikely to increase the viscosity of the composition (X). Furthermore, since these compounds are unlikely to volatilize, the storage stability of the composition (X) can be easily improved.

[0076] The ratio of the compound having a morpholine skeleton to the acrylic compound (Y) is preferably 5% by mass or more and 50% by mass or less. In this case, there is an advantage that outgassing from the cured product of the composition (X) is less likely to occur. This ratio is more preferably 7% by mass or more and 45% by mass or less, and even more preferably 10% by mass or more and 40% by mass or less.

[0077] The acrylic compound (Y) may contain a compound having an isobornyl skeleton, such as one or more compounds selected from the group consisting of isobornyl acrylate and isobornyl methacrylate.

[0078] The acrylic compound (Y) may contain a component consisting of a compound having at least one skeleton selected from the group consisting of a dicyclopentadiene skeleton, a dicyclopentanyl skeleton, a dicyclopentenyl skeleton, and a bisphenol skeleton. Specifically, the acrylic compound (Y) may contain at least one compound selected from the group consisting of tricyclodecane dimethanol diacrylate, bisphenol A polyethoxydiacrylate, and bisphenol F polyethoxydiacrylate. In this case, the adhesion between the cured product and inorganic materials can be improved.

[0079] The acrylic compound (Y) may contain a compound represented by the following formula (100): In this case, the reactivity of the composition (X) can be increased, and the adhesion between the cured product and the inorganic material can be improved.

[0080] [ka]

[0081] In formula (100), R 0 is H or a methyl group. X is a single bond or a divalent hydrocarbon group. R 1 From R 11 each of which is H, an alkyl group, or -R 12 -OH, R 12 is an alkylene group and R 1 From R 11 At least one of the groups is an alkyl group or -R 12 -OH. R 1 From R 11 are not chemically bonded to each other.

[0082] Specifically, for example, the acrylic compound (Y) may contain at least one compound selected from the group consisting of a compound represented by the following formula (110), a compound represented by the following formula (120), and a compound represented by the following formula (130).

[0083] [ka]

[0084] The radically polymerizable compound (A1) may contain a radically polymerizable compound (Z) other than the acrylic compound (Y). The amount of the radically polymerizable compound (Z) relative to the total amount of the acrylic compound (Y) and the radically polymerizable compound (Z) is, for example, 10% by mass or less. The radically polymerizable compound (Z) may contain either or both of a polyfunctional radically polymerizable compound (Z1) having two or more radically polymerizable functional groups per molecule and a monofunctional radically polymerizable compound (Z2) having only one radically polymerizable functional group per molecule. The polyfunctional radically polymerizable compound (Z1) may contain, for example, at least one compound selected from the group consisting of aromatic urethane oligomers, aliphatic urethane oligomers, epoxy acrylate oligomers, polyester acrylate oligomers, and other special oligomers, each having two or more ethylenic double bonds per molecule. However, the components that the polyfunctional radically polymerizable compound (Z1) may contain are not limited to those described above. The monofunctional radical polymerizable compound (Z2) contains at least one compound selected from the group consisting of, for example, N-vinylformamide, vinylcaprolactam, vinylpyrrolidone, phenylglycidyl ether, p-tert-butylphenylglycidyl ether, butylglycidyl ether, 2-ethylhexylglycidyl ether, allylglycidyl ether, 1,2-butylene oxide, 1,3-butadiene monoxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-vinylcyclohexene oxide, 4-vinylcyclohexene oxide, N-vinylpyrrolidone, and N-vinylcaprolactam. However, the components that the monofunctional radical polymerizable compound (Z2) can contain are not limited to those listed above.

[0085] When the radical polymerizable compound (A1) contains a radical polymerizable compound (Z), the radical polymerizable compound (Z) may contain a compound having nitrogen in its molecular skeleton. The compound having nitrogen in its molecular skeleton includes, for example, at least one compound selected from the group consisting of N-vinylformamide, N-vinylpyrrolidone, and N-vinylcaprolactam. In this case, the adhesion between the cured product and inorganic materials is improved, as in the case where the acrylic compound (Y) contains a compound having nitrogen in its molecular skeleton.

[0086] In other words, the radically polymerizable compound (A1) preferably contains a compound having nitrogen in its molecular skeleton. This compound having nitrogen in its molecular skeleton may contain a compound contained in the acrylic compound (Y) or a compound contained in the radically polymerizable compound (Z). In this case, the adhesion between the cured product and the inorganic material is improved. The proportion of the compound having nitrogen in its molecular skeleton relative to the total amount of the radically polymerizable compound (A1) is preferably 5% by mass or more and 80% by mass or less. A proportion of 5% by mass or more particularly improves the adhesion between the cured product and the inorganic material. A proportion of 80% by mass or less prevents the compound having nitrogen in its molecular skeleton from impairing the storage stability of the composition (X) and from generating satellites when the composition (X) is sprayed by an inkjet method. This prevents the inkjetability of the composition (X) from being impaired. Furthermore, outgassing due to the compound having nitrogen in its molecular skeleton can be reduced. This proportion is more preferably 10% by mass or more and 70% by mass or less, even more preferably 20% by mass or more and 60% by mass or less, and particularly preferably 25% by mass or more and 50% by mass or less.

[0087] The ratio of the total amount of monofunctional compounds in the radical polymerizable compound (A1) (i.e., the total amount of the monofunctional acrylic compound (Y2) and the monofunctional radical polymerizable compound (Z2)) to the total amount of the radical polymerizable compound (A1) is preferably 70% by mass or less. In this case, outgassing caused by the monofunctional compounds is less likely to occur. This ratio is more preferably 60% by mass or less, and even more preferably 50% by mass or less.

[0088] The radical polymerizable compound (A1) preferably contains at least one selected from the group consisting of acroylmorpholine, morpholin-4-yl acrylate, diethylacrylamide, and dimethylacrylamide. In this case, the absolute value of the difference between the first cure shrinkage and the second cure shrinkage tends to be small. The total percentage of acroylmorpholine, morpholin-4-yl acrylate, diethylacrylamide, and dimethylacrylamide relative to the radical polymerizable compound (A1) is preferably 15% by mass or more. In this case, the above-mentioned difference in cure shrinkage is particularly easily achieved. This percentage is more preferably 25% by mass or more, and even more preferably 35% by mass or more. The upper limit of this percentage is not particularly specified, but is, for example, 100% by mass or less. This percentage is preferably 85% by mass or less, which makes it easy to adjust the hardness of the cured film and improve its flexibility. It is more preferable that this percentage be 70% by mass or less. In order to reduce the absolute value of the difference between the first cure shrinkage rate and the second cure shrinkage rate, it is preferable that the radical polymerizable compound (A1) does not contain any of isobornyl methacrylate, lauryl methacrylate, and 1,6-hexanediol methacrylate.

[0089] The photoradical polymerization initiator (B1) is not particularly limited as long as it is a compound that generates radical species when irradiated with ultraviolet light. The photoradical polymerization initiator (B1) contains at least one compound selected from the group consisting of, for example, aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, oxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds.

[0090] The photoradical polymerization initiator (B1) preferably contains a component having a sensitizer skeleton in the molecule. The sensitizer skeleton includes, for example, at least one of a 9H-thioxanthen-9-one skeleton and an anthracene skeleton. That is, the photoradical polymerization initiator (B) preferably contains a component having at least one of a 9H-thioxanthen-9-one skeleton and an anthracene skeleton.

[0091] The photoradical polymerization initiator (B1) preferably contains an oxime ester photoinitiator. The oxime ester photoinitiator can improve the curability of the composition (X). Therefore, the composition (X) can be easily cured even in an oxygen-containing environment such as the air atmosphere, and the cured product can be made less likely to outgas.

[0092] The oxime ester photoinitiator preferably contains a compound having an aromatic ring, more preferably contains a compound having a fused ring containing an aromatic ring, and further preferably contains a compound having a fused ring containing a benzene ring and a heterocycle, in order to reduce the likelihood of contamination of composition (X) and a production equipment due to the generation of decomposition products from composition (X), and to further reduce the likelihood of outgassing from the cured product.

[0093] The oxime ester photoinitiator may contain at least one compound selected from the group consisting of 1,2-octadione-1-[4-(phenylthio)-, 2-(o-benzoyloxime)], and ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(o-acetyloxime), as well as oxime ester photoinitiators described in JP 2000-80068 A, JP 2001-233842 A, JP 2010-527339 A, JP 2010-527338 A, JP 2013-041153 A, JP 2015-93842 A, and the like. The oxime ester photoinitiator may contain at least one compound selected from the group consisting of commercially available products having a carbazole skeleton, such as Irgacure OXE-02 (manufactured by BASF), Adeka Arcles NCI-831, N-1919 (manufactured by ADEKA Corporation), and TR-PBG-304 (manufactured by Changzhou New Power Electronic Materials Co., Ltd.), diphenyl sulfide skeletons, such as Irgacure OXE-01, Adeka Arcles NCI-930 (manufactured by ADEKA Corporation), TR-PBG-345, and TR-PBG-3057 (all manufactured by Changzhou New Power Electronic Materials Co., Ltd.), and fluorene skeletons, such as TR-PBG-365 (manufactured by Changzhou New Power Electronic Materials Co., Ltd.) and SPI-04 (manufactured by Sanyang Co., Ltd.). In particular, it is preferable for the oxime ester photoinitiator to contain a compound having a diphenyl sulfide skeleton or a fluorene skeleton, as this makes the cured product less likely to discolor due to photobleaching. It is also preferable that the oxime ester photoinitiator contains a compound having a carbazole skeleton, since the exposure sensitivity is likely to be increased.

[0094] It is also preferable that the oxime ester photoinitiator contains two or more compounds. In this case, for example, by containing two or more compounds with different exposure sensitivity in the oxime ester photoinitiator, it is possible to reduce the amount of the photoradical polymerization initiator (B) while maintaining good exposure sensitivity, and therefore it is possible to further reduce the generation of outgassing from the cured product.

[0095] The ratio of the photoradical polymerization initiator (B1) to the radical polymerizable compound (A1) is preferably 6% by mass or more. In this case, the composition (X) can have good UV curability, and can also have good UV curability in the air. This ratio is more preferably 7% by mass or more, and even more preferably 8% by mass or more. This ratio is, for example, 30% by mass or less, preferably 20% by mass or less, and even more preferably 18% by mass or less.

[0096] The radical polymerization initiator (B) preferably contains a photobleachable radical polymerization initiator (B3). For example, the photoradical polymerization initiator (B1) preferably contains a photoradical polymerization initiator (B31) having photobleachability as the photopolymerization initiator (B3). The photobleachable photopolymerization initiator (B3) can increase the transparency of the composition (X) and its cured product when the composition (X) is irradiated with ultraviolet light. Therefore, when the composition (X) is irradiated with ultraviolet light, the ultraviolet light can easily reach the interior of the composition (X). This makes it easier for the composition (X) to be cured efficiently, and the difference between the first curing shrinkage and the second curing shrinkage is likely to be small.

[0097] The percentage of the photopolymerization initiator (B3) relative to the photopolymerization initiator (B) is preferably 50% by mass or more. In this case, the difference between the first cure shrinkage rate and the second cure shrinkage rate tends to be particularly small. This percentage is more preferably 60% by mass or more, and even more preferably 75% by mass or more. The upper limit of this percentage is not particularly specified, and may be 100% by mass. That is, this percentage is, for example, 100% by mass or less.

[0098] When the photoradical polymerization initiator (B1) contains a photoradical polymerization initiator (B31), the photoradical polymerization initiator (B31) contains, for example, at least one of an acylphosphine oxide-based photoinitiator and a compound having photobleachability among oxime ester-based photoinitiators.

[0099] The photobleachable oxime ester compound contains, for example, at least one of the compound represented by the following formula (401) and the compound represented by the following formula (402). Of these, the compound represented by formula (402) has particularly high sensitivity, and therefore is particularly likely to enhance the photocurability of composition (X), making it easy to achieve UV curability of composition (X) in the air.

[0100] [ka]

[0101] [ka]

[0102] The acylphosphine oxide compound contains, for example, at least one selected from the group consisting of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0103] The radical polymerization initiator (B) preferably contains a photopolymerization initiator (B4) having an absorption coefficient of 5 ml / g cm or more at a wavelength of 405 nm. For example, the photoradical polymerization initiator (B1) preferably contains a photoradical polymerization initiator (B41) having an absorption coefficient of 5 ml / g cm or more at a wavelength of 405 nm as the photopolymerization initiator (B4). The photopolymerization initiator (B4) can increase the reactivity of the composition (X) when the composition (X) is irradiated with ultraviolet light. This tends to reduce the difference between the first cure shrinkage and the second cure shrinkage.

[0104] The percentage of the photopolymerization initiator (B4) relative to the photopolymerization initiator (B) is preferably 50% by mass or more. In this case, the difference between the first cure shrinkage rate and the second cure shrinkage rate tends to be particularly small. This percentage is more preferably 60% by mass or more, and even more preferably 75% by mass or more. The upper limit of this percentage is not particularly specified, and may be 100% by mass. That is, this percentage is, for example, 100% by mass or less.

[0105] When the photoradical polymerization initiator (B1) contains the photoradical polymerization initiator (B41), the photoradical polymerization initiator (B41) contains at least one selected from the group consisting of, for example, 2-benzyl-2-(dimethylamino)-1-(4-morpholinophenyl)-1-butanone (e.g., Irgacure 369 manufactured by BASF), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (e.g., Irgacure 819 manufactured by BASF), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (e.g., Irgacure TPO manufactured by BASF), and bis(2,4-cyclopentadienyl)bis[2,6-difluoro-3-(1-pyrryl)phenyl]titanium(IV) (e.g., Irgacure 784 manufactured by BASF).

[0106] The compounds contained in the photopolymerization initiator (B3) and the compounds contained in the photoradical polymerization initiator (B4) may overlap. That is, when the composition (X) contains the photopolymerization initiator (B3), at least a part of the photoradical polymerization initiator (B4) may be contained in the photopolymerization initiator (B3). Furthermore, when the composition (X) contains the photopolymerization initiator (B4), at least a part of the photoradical polymerization initiator (B3) may be contained in the photopolymerization initiator (B4).

[0107] The composition (X) may further contain a polymerization accelerator in addition to the photoradical polymerization initiator (B1). The polymerization accelerator contains, for example, an amine compound such as ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, or butoxyethyl p-dimethylaminobenzoate. However, the components that the polymerization accelerator may contain are not limited to those listed above.

[0108] When the photopolymerizable compound (A) contains a cationically polymerizable compound (A2), the cationically polymerizable compound (A2) contains, for example, at least one of a polyfunctional cationically polymerizable compound (W1) and a monofunctional cationically polymerizable compound (W2).

[0109] The polyfunctional cationically polymerizable compound (W1) can contain either or both of a polyfunctional cationically polymerizable compound (W11) that does not have a siloxane skeleton and a polyfunctional cationically polymerizable compound (W12) that has a siloxane skeleton.

[0110] The polyfunctional cationically polymerizable compound (W11) does not have a siloxane skeleton and has two or more cationically polymerizable functional groups per molecule. The number of cationically polymerizable functional groups per molecule of the polyfunctional cationically polymerizable compound (W11) is preferably 2 to 4, and more preferably 2 to 3.

[0111] The cationically polymerizable functional group is, for example, at least one group selected from the group consisting of an epoxy group, an oxetane group, and a vinyl ether group.

[0112] The polyfunctional cationically polymerizable compound (W11) contains at least one compound selected from the group consisting of, for example, polyfunctional alicyclic epoxy compounds, polyfunctional heterocyclic epoxy compounds, polyfunctional oxetane compounds, alkylene glycol diglycidyl ethers, and alkylene glycol monovinyl monoglycidyl ethers.

[0113] The polyfunctional alicyclic epoxy compound contains, for example, either one or both of a compound represented by the following formula (1) and a compound represented by the following formula (20).

[0114] [ka]

[0115] In formula (1), R 1 ~R 18 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group. The hydrocarbon group preferably has 1 to 20 carbon atoms. Examples of the hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, and propyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl and allyl; and alkylidene groups having 2 to 20 carbon atoms, such as ethylidene and propylidene. The hydrocarbon group may contain an oxygen atom or a halogen atom. 1 ~R 18 are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0116] In formula (1), X is a single bond or a divalent organic group, and the organic group is, for example, —CO—O—CH 2 —.

[0117] Examples of the compound represented by formula (1) include a compound represented by the following formula (1a) and a compound represented by the following formula (1b).

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] In formula (20), R 1 ~R 12 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Examples of hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, and propyl; alkenyl groups having 2 to 20 carbon atoms such as vinyl and allyl; or alkylidene groups having 2 to 20 carbon atoms such as ethylidene and propylidene. The hydrocarbon group having 1 to 20 carbon atoms may contain an oxygen atom or a halogen atom.

[0122] R 1 ~R 12 are each independently preferably a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0123] Examples of the compound represented by formula (20) include tetrahydroindene diepoxide represented by formula (20a) below.

[0124] [ka]

[0125] The polyfunctional heterocyclic epoxy compound contains, for example, a trifunctional epoxy compound as shown in the following formula (2).

[0126] [ka]

[0127] The polyfunctional oxetane compound includes, for example, a bifunctional oxetane compound represented by the following formula (3).

[0128] [ka]

[0129] The alkylene glycol diglycidyl ether contains at least one compound selected from the group consisting of compounds represented by the following formulas (4) to (7).

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] The alkylene glycol monovinyl monoglycidyl ether contains, for example, a compound represented by the following formula (8).

[0135] [ka]

[0136] More specifically, the polyfunctional cationically polymerizable compound (W11) may contain at least one component selected from the group consisting of, for example, CELLOXIDE 2021P and CELLOXIDE 8010 manufactured by Daicel, TEPIC-VL manufactured by Nissan Chemical, OXT-221 manufactured by Toagosei, and 1,3-PD-DEP, 1,4-BG-DEP, 1,6-HD-DEP, NPG-DEP, and butylene glycol monovinyl monoglycidyl ether manufactured by Yokkaichi Chemical Industry.

[0137] The polyfunctional cationically polymerizable compound (W11) preferably contains a polyfunctional alicyclic epoxy compound, in which case the composition (X) can have particularly high cationic polymerization reactivity.

[0138] The polyfunctional alicyclic epoxy compound preferably contains either or both of the compound represented by formula (1) and the compound represented by formula (20). In this case, composition (X) can have higher cationic polymerization reactivity.

[0139] When the polyfunctional alicyclic epoxy compound contains a compound represented by formula (1), the compound represented by formula (1) preferably contains a compound represented by formula (1a). In this case, composition (X) can have higher cationic polymerization reactivity and particularly low viscosity.

[0140] Furthermore, since the compound represented by formula (20) in particular has a low viscosity, when the compound represented by formula (20) is contained, the composition (X) can have good UV curability and a particularly low viscosity. Furthermore, the compound represented by formula (20) has a low viscosity but is not easily volatile. Therefore, even if the composition (X) contains the compound represented by formula (20), the composition (X) is not likely to undergo a change in composition due to the volatilization of the compound represented by formula (20). Therefore, by containing the compound represented by formula (20), the viscosity of the composition (X) can be reduced without impairing storage stability.

[0141] The compound represented by formula (20) can be synthesized, for example, by oxidizing a cyclic olefin compound having a tetrahydroindene skeleton using an oxidizing agent.

[0142] The compound represented by formula (20) may contain four stereoisomers based on the configuration of the two epoxy rings. The compound represented by formula (20) may contain any of the four stereoisomers. That is, the compound represented by formula (20) may contain at least one component selected from the group consisting of the four stereoisomers. In the compound represented by formula (20), the total proportion of the exo-endo isomer and the endo-endo isomer among the four stereoisomers is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total epoxy compound (A1). In this case, the heat resistance of the cured product can be improved. The proportion of a specific stereoisomer in the compound represented by formula (20) can be determined based on the peak area ratio appearing in a chromatogram obtained by gas chromatography.

[0143] In order to reduce the amount of exo-endo isomer and endo-endo isomer in the compound represented by formula (20), an appropriate method can be applied, such as a method of subjecting the compound represented by formula (20) to precision distillation or a method of applying column chromatography using silica gel or the like as a packing material.

[0144] When composition (X) contains a polyfunctional cationically polymerizable compound (W11), the proportion of the polyfunctional cationically polymerizable compound (W11) relative to the total amount of resin components is preferably 5% by mass or more and 95% by mass or less. The term "resin components" refers to the cationically polymerizable compounds in composition (X), including the polyfunctional cationically polymerizable compound (W1) and the monofunctional cationically polymerizable compound (W2). When the proportion of the polyfunctional cationically polymerizable compound (W11) is 5% by mass or more, composition (X) can exhibit particularly excellent reactivity during the photocationic polymerization reaction, thereby resulting in a cured product with high strength (hardness). When composition (X) contains a moisture absorbent (E), when the proportion of the polyfunctional cationically polymerizable compound (W11) is 95% by mass or less, the moisture absorbent (E) can be dispersed particularly uniformly in composition (X). The proportion of this polyfunctional cationically polymerizable compound (W11) is more preferably 12% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and particularly preferably 25% by mass or more. The proportion of this polyfunctional cationically polymerizable compound (W11) is more preferably 85% by mass or less, even more preferably 60% by mass or less. For example, the proportion of the polyfunctional cationically polymerizable compound (W11) is preferably 20% by mass or more and 60% by mass or less.

[0145] When the polyfunctional cationically polymerizable compound (W11) contains a polyfunctional alicyclic epoxy compound, the polyfunctional alicyclic epoxy compound may be a part or the whole of the polyfunctional cationically polymerizable compound (W11). The ratio of the polyfunctional alicyclic epoxy compound to the polyfunctional cationically polymerizable compound (W11) is preferably within the range of 15 to 100% by mass. When this ratio is 15% by mass or more, the polyfunctional alicyclic epoxy compound can particularly contribute to improving the UV curability of the composition (X).

[0146] The polyfunctional cationically polymerizable compound (W12) has a siloxane skeleton and two or more cationically polymerizable functional groups per molecule. The number of cationically polymerizable functional groups per molecule of the polyfunctional cationically polymerizable compound (W12) is preferably 2 to 6, more preferably 2 to 4. The polyfunctional cationically polymerizable compound (W12) can contribute to improving the cationic polymerization reactivity of the composition (X) and also contribute to improving the heat discoloration resistance of the cured product and optical components. The polyfunctional cationically polymerizable compound (W12) can also contribute to lowering the elastic modulus of the cured product and optical components. When the composition (X) contains a moisture absorbent, the polyfunctional cationically polymerizable compound (W12) can also contribute to improving the dispersibility of the moisture absorbent in the composition (X) and the cured product.

[0147] The polyfunctional cationically polymerizable compound (W12) is preferably a liquid at 25° C. In particular, the viscosity of the polyfunctional cationically polymerizable compound (W12) at 25° C. is preferably within the range of 10 to 300 mPa s. In this case, an increase in the viscosity of the composition (X) can be suppressed.

[0148] The cationically polymerizable functional group contained in the polyfunctional cationically polymerizable compound (W12) is, for example, at least one group selected from the group consisting of an epoxy group, an oxetane group, and a vinyl ether group.

[0149] The siloxane skeleton of the polyfunctional cationically polymerizable compound (W12) may be linear, branched, or cyclic. The number of Si atoms in the siloxane skeleton is preferably within the range of 2 to 14. In this case, the composition (X) can have a particularly low viscosity. The number of Si atoms is more preferably within the range of 2 to 10, even more preferably within the range of 2 to 7, and particularly preferably within the range of 3 to 6.

[0150] The polyfunctional cationically polymerizable compound (W12) contains, for example, at least one of a compound represented by formula (10) and a compound represented by formula (11).

[0151] [ka]

[0152] [ka]

[0153] In each of formulas (10) and (11), R is a single bond or a divalent organic group, and is preferably an alkylene group. Y is a siloxane skeleton, which may be linear, branched, or cyclic, and the number of Si atoms therein is preferably within a range of 2 to 14, more preferably within a range of 2 to 10, even more preferably within a range of 2 to 7, and particularly preferably within a range of 3 to 6. n is an integer of 2 or greater, and is preferably within a range of 2 to 4.

[0154] More specifically, for example, the polyfunctional cationically polymerizable compound (W12) contains a compound represented by the following formula (10a).

[0155] [ka]

[0156] R in formula (10a) is a single bond or a divalent organic group, and is preferably an alkylene group having 1 to 4 carbon atoms. n in formula (10a) is an integer of 0 or greater. n is preferably within the range of 0 to 12, more preferably within the range of 0 to 8, even more preferably within the range of 0 to 5, and particularly preferably within the range of 1 to 4.

[0157] The compound represented by formula (10a) preferably contains a compound represented by the following formula (30): That is, the polyfunctional cationically polymerizable compound (W12) preferably contains a compound represented by the following formula (30):

[0158] More specifically, the polyfunctional cationically polymerizable compound (W12) preferably contains at least one component selected from the group consisting of product numbers X-40-2669, X-40-2670, X-40-2715, X-40-2732, X-22-169AS, X-22-169B, X-22-2046, X-22-343, X-22-163, and X-22-163B manufactured by Shin-Etsu Chemical Co., Ltd.

[0159] The polyfunctional cationically polymerizable compound (W12) preferably has an alicyclic epoxy structure, and it is particularly preferred if the polyfunctional cationically polymerizable compound (W12) contains a compound represented by formula (10a). The compound represented by formula (10a) can particularly contribute to improving the cationic polymerization reactivity and reducing the viscosity of the composition (X), as well as to improving the heat discoloration resistance and reducing the elastic modulus of the cured product and optical components. When the composition (X) contains a moisture absorbent (E), it can also particularly contribute to improving the dispersibility of the moisture absorbent (E) in the composition (X).

[0160] When the composition (X) contains a polyfunctional cationically polymerizable compound (W12), the proportion of the polyfunctional cationically polymerizable compound (W12) relative to the total amount of the resin components is preferably within the range of 5 to 95 mass %. In this case, when the composition (X) contains a moisture absorbent (E), the dispersibility of the moisture absorbent (E) in the composition (X) and in the cured product is particularly improved, and the composition (X) can have particularly high photocationic polymerization reactivity.

[0161] The monofunctional cationically polymerizable compound (W2) has only one cationically polymerizable functional group per molecule, which is, for example, at least one group selected from the group consisting of an epoxy group, an oxetane group, and a vinyl ether group.

[0162] The viscosity of the monofunctional cationically polymerizable compound (W2) at 25°C is preferably 8 mPa·s or less. In this case, even if the composition (X) does not contain a solvent, the monofunctional cationically polymerizable compound (W2) can reduce the viscosity of the composition (X). In particular, the viscosity of the monofunctional cationically polymerizable compound (W2) at 25°C is preferably within the range of 0.1 to 8 mPa·s.

[0163] The monofunctional cationically polymerizable compound (W2) may contain, for example, at least one compound selected from the group consisting of compounds represented by the following formulas (12) to (17) and limonene oxide.

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] [ka]

[0170] The proportion of the monofunctional cationically polymerizable compound (W2) relative to the total amount of resin components is preferably within the range of 5 to 50% by mass. When the proportion of the monofunctional cationically polymerizable compound (W2) is 5% by mass or more, the viscosity of the composition (X) can be particularly reduced. When the proportion of the monofunctional cationically polymerizable compound (W2) is 50% by mass or less, the composition (X) can exhibit particularly excellent reactivity during the photocationic polymerization reaction, thereby enabling the cured product to have high strength (hardness). The proportion of this monofunctional cationically polymerizable compound (W2) is more preferably 10% by mass or more, and even more preferably 15% by mass or more. The proportion of this monofunctional cationically polymerizable compound (W2) is more preferably 40% by mass or less, even more preferably 35% by mass or less, and particularly preferably 30% by mass or less. When the proportion of the monofunctional cationically polymerizable compound (W2) is particularly 35% by mass or less, the amount of volatilization of the components in the composition (X) during storage can be effectively reduced, and therefore the properties of the composition (X) are less likely to be impaired even when the composition (X) is stored for a long period of time. Furthermore, the occurrence of tackiness in the cured product can be particularly suppressed. For example, the proportion of the monofunctional cationically polymerizable compound (W2) is preferably within the range of 10 to 35% by mass.

[0171] In particular, when the composition (X) contains a polyfunctional cationically polymerizable compound (W11) and a polyfunctional cationically polymerizable compound (W12), the proportion of the polyfunctional cationically polymerizable compound (W11) is preferably within a range of 30 to 60% by mass, the proportion of the polyfunctional cationically polymerizable compound (W12) is preferably within a range of 15 to 30% by mass, and the proportion of the monofunctional cationically polymerizable compound (W2) is preferably within a range of 15 to 40% by mass, based on the total amount of the resin components. In this case, the composition (X) can achieve a good balance of good storage stability, low viscosity, and good cationic polymerization reactivity, and further achieve a good balance of excellent transparency, excellent hygroscopicity, and a high refractive index of the cured product.

[0172] When the cationically polymerizable compound (A2) contains a compound represented by formula (3) and a compound represented by formula (16), by adjusting the ratio of the two compounds, it is possible to appropriately adjust the ease of progress of the curing reaction when preparing a photocured product from the composition (X), while also achieving a low viscosity and improved storage stability of the composition (X).

[0173] The amount of the compound represented by formula (16) is appropriately adjusted so that composition (X) has the above-mentioned properties. For example, the amount of the compound represented by formula (16) is preferably 10% by mass or more and 40% by mass or less based on the total amount of the resin components.

[0174] The cationically polymerizable compound (A2) preferably contains a compound (f1) represented by the following formula (30) (hereinafter also referred to as aromatic epoxy compound (f1)).

[0175] [ka]

[0176] In formula (30), X is at least one selected from the group consisting of halogen, H, a hydrocarbon group, and an alkylene glycol group, and when there are multiple Xs in one molecule, they may be the same or different. The hydrocarbon group is, for example, an alkyl group or an aryl group. When X is a hydrocarbon group, the number of carbon atoms in X is, for example, in the range of 1 to 10. R is a single bond or a divalent organic group. When R is a divalent organic group, the divalent organic group is, for example, an alkylene group, an oxyalkylene group, a carbonyloxyalkylene group (e.g., -CO-O-CH2-), or a -C(Ph)2-O-CH2- group. Y is H or a monovalent organic group. When Y is a monovalent organic group, the monovalent organic group is, for example, an alkyl group or an aryl group.

[0177] When the cationically polymerizable compound (A2) contains an aromatic epoxy compound (f1), the aromatic epoxy compound (f1) has a low viscosity, which makes it easy to lower the viscosity of the composition (X). Furthermore, the aromatic epoxy compound (f1) is not easily volatilized, so even when the composition (X) is stored, the composition (X) is less likely to change in composition due to the volatilization of the aromatic epoxy compound (f1). Therefore, the aromatic epoxy compound (f1) tends to improve the storage stability of the composition (X). Furthermore, the aromatic epoxy compound (f1) is highly reactive, so unreacted components are less likely to remain in the cured product, and therefore, the cured product is less likely to outgas. Furthermore, the aromatic epoxy compound (f1) tends to increase the glass transition temperature of the cured product, which in turn increases the heat resistance of the cured product.

[0178] Furthermore, when the composition (X) is ejected by an ink jet method, the aromatic epoxy compound (f1) is less likely to produce defective droplets called satellites.

[0179] R in formula (30) is preferably a single bond or an alkylene group. When n in formula (30) is 2 or 3, at least one of the multiple R in formula (30) is preferably a single bond or an alkylene group. In these cases, the reactivity of the aromatic epoxy compound (f1) tends to be high, and therefore the curability of composition (X) tends to be high when composition (X) is irradiated with ultraviolet light.

[0180] The aromatic epoxy compound (f1) preferably contains at least one compound selected from the group consisting of compounds represented by the following formulas (301) to (318).

[0181] [ka]

[0182] In particular, it is preferred that the aromatic epoxy compound (f1) contains at least one component selected from the group consisting of the compounds represented by the formulae (301) to (305), (312), (314), and (318). These compounds tend to have high reactivity because at least one epoxy group (oxirane) in the compound is bonded to a benzene ring via a single bond or an alkylene group, and therefore tend to enhance the curability of the composition (X).

[0183] The proportion of the aromatic epoxy compound (f1) relative to the total amount of the cationically polymerizable compound (A2) is preferably 5% by mass or more. In this case, the above-mentioned effects of the aromatic epoxy compound (f1) are particularly easily achieved. This proportion is also preferably 95% by mass or less. In this case, the storage stability of the composition (X) is likely to be improved. This proportion is more preferably 10% by mass or more and 90% by mass or less, and even more preferably 20% by mass or more and 85% by mass or less.

[0184] It is also preferred that the cationically polymerizable compound (A2) contains a compound (f2) having an oxyalkylene skeleton. The oxyalkylene skeleton is a linear skeleton consisting of one or more linear oxyalkylene units.

[0185] When the cationically polymerizable compound (A2) contains the compound (f2), the compound (f2) has a low viscosity, and therefore the compound (f2) tends to lower the viscosity of the composition (X). Furthermore, the compound (f2) is not easily volatilized, and therefore, even when the composition (X) is stored, the composition (X) is not likely to undergo a change in composition due to the volatilization of the aromatic epoxy compound (f1). Therefore, the compound (f2) tends to improve the storage stability of the composition (X).

[0186] Furthermore, compound (f2) reduces the formation of defective droplets known as satellites when composition (X) is ejected by an inkjet method. Furthermore, compound (f2) can reduce the formation of satellites even when the droplet speed is increased by the inkjet method. Therefore, depending on the inkjet conditions, it is possible to increase the droplet ejection speed by the inkjet method to 4 m / s or more without generating satellites. Increasing the droplet speed reduces the influence of external disturbances on the droplet trajectory, thereby improving the dimensional accuracy of the cured product produced from composition (X). Furthermore, as described above, compound (f2) can improve the storage stability of composition (X), so that composition (X)'s characteristic of being less susceptible to satellite formation is likely to be maintained even when composition (X) is stored for a long period of time.

[0187] The oxyalkylene skeleton preferably contains a "-CCO-" structure, i.e., an oxymethylene unit. In this case, satellites are particularly unlikely to form, even when the driving frequency is changed when ejecting composition (X) by an inkjet method. In addition, compound (f2) is less likely to volatilize and tends to have a lower viscosity, and the affinity (wettability) of composition (X) for inorganic materials is likely to be increased.

[0188] The number of oxyalkylene units in the oxyalkylene skeleton of compound (f2) is preferably 1 to 8. In this case, compound (f2) tends to have a lower viscosity, which makes it particularly unlikely that satellites will be formed, and the crosslink density of the cured product tends to be high, which tends to make the glass transition temperature of the cured product particularly high. The number of oxyalkylene units is more preferably 1 to 6, and even more preferably 1 to 4.

[0189] The oxyalkylene units in the oxyalkylene skeleton of compound (f2) may have a substituent other than hydrogen. For example, the oxymethylene units contained in the oxyalkylene skeleton may have the structure "-CH(CH)-CH-O-".

[0190] The proportion of compound (f2) is preferably 10% by mass or more relative to the cationically polymerizable compound (A2). In this case, inkjet properties are improved and wettability to the substrate is improved. It is also preferable that this proportion is 70% by mass or less. In this case, the glass transition temperature can be sufficiently increased. This proportion is more preferably 15% by mass or more and 60% by mass or less, and even more preferably 20% by mass or more and 50% by mass or less.

[0191] The compound (f2) contains, for example, at least one compound selected from the group consisting of a compound (f21) having an oxyalkylene skeleton and an epoxy group, and a compound (f22) having an oxyalkylene group and an oxetane group.

[0192] Compound (f21) contains at least one compound selected from the group consisting of, for example, the compound represented by formula (1b), the compound represented by formula (4), the compound represented by formula (5), the compound represented by formula (6), the compound represented by formula (7), the compound represented by formula (8), the compound represented by formula (13), the compound represented by formula (14), etc. However, the components that compound (f21) can contain are not limited to those mentioned above.

[0193] Compound (f22) contains at least one compound selected from the group consisting of compounds represented by the above formula (3), compounds represented by formula (12), compounds represented by formula (16), and compounds represented by formula (17). Note that the components that compound (f22) can contain are not limited to those listed above.

[0194] The cationically polymerizable compound (A2) preferably contains an epoxy compound and the above-mentioned compound (f22). The epoxy compound contains at least one compound selected from the compounds containing an epoxy group that can be included in the cationically polymerizable compound (A2). When the cationically polymerizable compound (A2) contains an epoxy compound and compound (f22), the curability of the composition (X) when irradiated with ultraviolet light is enhanced, and the composition (X) is less likely to cure too rapidly. This reduces the likelihood of the cured product becoming cloudy or otherwise losing transparency. The mechanism behind this effect is presumed to be as follows: Because the reactivity of compound (f22) is lower than that of the epoxy compound, the epoxy compound reacts first when the composition (X) is irradiated with ultraviolet light. This reaction of the epoxy compound increases the curability of the composition (X). Subsequently, the reaction of compound (f22) reduces the likelihood of simultaneous reaction of the epoxy compound and compound (f22). This is thought to reduce the likelihood of an excessively rapid reaction. In this case, the ratio of compound (f22) to the cationically polymerizable compound (A2) is preferably 20% by mass or more. In this case, compound (f22) particularly easily reduces the viscosity of composition (X) and particularly easily enhances the storage stability of composition (X). Furthermore, compound (f22) particularly easily enhances the curability of composition (X). The ratio of compound (f22) is also preferably 90% by mass or less. In this case, the curability of the cured product can be sufficiently enhanced. The ratio of compound (f22) is more preferably 10% by mass or more and 90% by mass or less, and even more preferably 20% by mass or more and 80% by mass or less. In addition, the ratio of the epoxy compound in this case is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, based on the total amount of cationically polymerizable compound (A2), and even more preferably 25% by mass or more and 75% by mass or less. In these cases, the unreacted groups in the cured product can be sufficiently reduced, thereby sufficiently enhancing the curability of the cured product.

[0195] The epoxy compound preferably contains a compound having at least one oxirane ring that does not constitute a glycidyl ether group. In this case, the epoxy compound is particularly likely to enhance the curability of the composition (X). It is more preferable that the epoxy compound contains a compound having two or more oxirane rings that do not constitute a glycidyl ether group. It is also preferable that the epoxy compound contains a compound that does not contain a glycidyl ether group. It is particularly preferable that the epoxy compound contains a compound that has two or more oxirane rings that do not constitute a glycidyl ether group and does not contain a glycidyl ether group.

[0196] It is particularly preferred that the cationically polymerizable compound (A2) contains a compound (f2) and an epoxy compound, and that the epoxy compound further contains the above-mentioned aromatic epoxy compound (f1). In this case, the composition (X) is likely to have particularly excellent storage stability, and when the composition (X) is ejected by an inkjet method, it is particularly unlikely to produce defective droplets called satellites. Furthermore, even when the speed of the droplets ejected by the inkjet method is increased, it is possible to particularly prevent the formation of satellites. Furthermore, even when the composition (X) is stored for a long period of time, the characteristic of the composition (X) of being less likely to produce satellites is particularly likely to be maintained. In this case, it is particularly preferred that the compound (f2) contains a compound (f22).

[0197] The total ratio of the aromatic epoxy compound (f1) and the compound (f22) to the cationically polymerizable compound (A2) is preferably 55% by mass or more. In this case, the effect of the combination of the aromatic epoxy compound (f1) and the compound (f22) is particularly pronounced. This ratio is more preferably 60% by mass or more, and even more preferably 70% by mass or more. It is particularly preferred that the cationically polymerizable compound (A2) contains only the aromatic epoxy compound (f1) and the compound (f22).

[0198] The cationically polymerizable compound (A2) is preferably an alicyclic epoxy from the viewpoint of reactivity. Specifically, the cationically polymerizable compound (A2) contains at least one selected from the group consisting of a compound represented by formula (20a) (e.g., THI-DE manufactured by JX Nippon Oil & Energy Corporation), a compound represented by formula (1a) (e.g., CELLOXIDE 8010 manufactured by Daicel Corporation), a compound represented by formula (1b) (e.g., CELLOXIDE 2021P manufactured by Daicel Corporation), and limonene dioxide (e.g., LDO manufactured by Arkema). The percentage of the cationically polymerizable compound (A2) relative to the total amount of the cationically polymerizable compound (A) is preferably 40% by mass or more.

[0199] The photocationic polymerization initiator (B2) is not particularly limited as long as it is a catalyst that generates a protonic acid or a Lewis acid upon exposure to light. The photocationic polymerization initiator (B2) may contain at least one of an ionic photoacid-generating cationic curing catalyst and a nonionic photoacid-generating cationic curing catalyst.

[0200] The ionic photoacid-generating cationic curing catalyst can contain at least one of onium salts and organometallic complexes. Examples of onium salts include aromatic diazonium salts, aromatic halonium salts, and aromatic sulfonium salts. Examples of organometallic complexes include iron-arene complexes, titanocene complexes, and arylsilanol-aluminum complexes. The ionic photoacid-generating cationic curing catalyst can contain at least one of these components.

[0201] The nonionic photoacid-generating cationic curing catalyst may contain at least one component selected from the group consisting of, for example, nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenolsulfonic acid esters, diazonaphthoquinones, and N-hydroxyimide phosphonates. However, the components that the nonionic photoacid-generating cationic curing catalyst may contain are not limited to those listed above.

[0202] More specific examples of compounds that can contain the photocationic polymerization initiator (B2) include Midori Chemical's DPI series (105, 106, 109, 201, etc.), BI-105, MPI series (103, 105, 106, 109, etc.), BBI series (101, 102, 103, 105, 106, 109, 110, 200, 210, 300, 301, etc.), and TSP series. Series (102, 103, 105, 106, 109, 200, 300, 1000, etc.), HDS-109, MDS series (103, 105, 109, 203, 205, 209, etc.), BDS-109, MNPS-109, DTS series (102, 103, 105, 200, etc.), NDS series (103, 105, 155, 165, etc.), DAM series (1 01, 102, 103, 105, 201, etc.), SI series (105, 106, etc.), PI-106, NDI series (105, 106, 109, 1001, 1004, etc.), PAI series (01, 101, 106, 1001, 1002, 1003, 1004, etc.), MBZ-101, PYR-100, NB series (101, 201, etc.), NAI series Series (100, 1002, 1003, 1004, 101, 105, 106, 109, etc.), TAZ series (100, 101, 102, 103, 104, 107, 108, 109, 110, 113, 114, 118, 122, 123, 203, 204, etc.), NBC-101, ANC-101, TPS-Acetate, DTS-Acetate, Di-Boc Bisphinol A, tert-Butyl lithocholate, tert-Butyl deoxycholate, tert-Butyl cholate, BX, BC-2, MPI-103, BDS-105, TPS-103, NAT-103, BMS-105, and TMS-105; Cyracure UVI-6970, Cyracure UVI-6974, Cyracure UVI-6990, and Cyracure UVI-950 manufactured by Union Carbide Corporation, USA; Irgacure 250, Irgacure 261 and Irgacure 264 manufactured by BASF; Ciba-Geigy CG-24-61; ADEKA Optomer SP-150, ADEKA Optomer SP-151, ADEKA Optomer SP-170 and ADEKA Optomer SP-171 manufactured by ADEKA Corporation; DAICAT II manufactured by Daicel Corporation; UVAC1590 and UVAC1591 manufactured by Daicel-Cytec Co., Ltd.; CI-2064, CI-2639, CI-2624, CI-2481, CI-2734, CI-2855, CI-2823, CI-2758, and CIT-1682 manufactured by Nippon Soda Co., Ltd.; PI-2074, tetrakis(pentafluorophenyl)borate toluylcumyl iodonium salt, from Rhodia; 3M FFC509; CD-1010, CD-1011 and CD-1012 manufactured by Sartomer, USA; San-Apro Co., Ltd. CPI-100P, CPI-101A, CPI-110P, CPI-110A, and CPI-210S; and UVI-6992 and UVI-6976 manufactured by The Dow Chemical Company are included. The cationic photopolymerization initiator (B2) may contain at least one compound selected from the group consisting of these compounds.

[0203] The ratio of the cationic photopolymerization initiator (B2) to the cationic polymerizable compound (A2) is preferably within the range of 1 to 4% by mass. When this ratio is 1% by mass or more, the composition (X) can have particularly good cationic polymerization reactivity. When this ratio is 4% by mass or less, the composition (X) can have good storage stability, and the absence of excessive cationic photopolymerization initiator (B2) can reduce production costs.

[0204] The composition (X) may contain a sensitizer (C). In this case, the sensitizer (C) can accelerate the reaction of the photopolymerization initiator (B), which makes it easier to reduce the difference between the first cure shrinkage and the second cure shrinkage of the composition (X).

[0205] The sensitizer (C) may contain at least one compound selected from the group consisting of, for example, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 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, 4,4'-bis(diethylamino)benzophenone, p-dimethylaminobenzaldehyde, and p-diethylaminobenzaldehyde. However, the components that the sensitizer (C) may contain are not limited to those listed above.

[0206] The sensitizer (C) preferably contains at least one of an anthracene-based compound and an anthraquinone-based compound. The anthracene-based compound is, for example, 9,10-dibutoxy. The thioxanthone compound contains at least one selected from the group consisting of cyanoanthracene, 9,10-diethoxyanthracene, 9-hydroxymethylanthracene, etc. The thioxanthone compound contains at least one selected from the group consisting of thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, etc.

[0207] It is particularly preferred that the sensitizer (C) contains an anthracene-based compound. In this case, the transparency of the composition (X) is not easily impaired, and the coating film of the composition (X) is easily cured uniformly from the surface to the depth, and therefore, the cured product is particularly unlikely to have unevenness.

[0208] The percentage of sensitizer (C) relative to composition (X) is preferably 0.05% by mass or more. In this case, the reactivity of composition (X) is likely to be particularly high, and therefore the difference between the first cure shrinkage and the second cure shrinkage is likely to be particularly small. This percentage is more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more. Furthermore, the percentage of sensitizer (C) is preferably 2.0% by mass or less. In this case, the coating film of composition (X) is likely to cure uniformly from the surface to the depth, and therefore unevenness is particularly unlikely to occur in the cured product. This percentage is more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less.

[0209] The composition (X) may contain a leveling agent (D). The leveling agent (D) tends to smooth the surface of the coating film of the composition (X). Therefore, when the coating film is irradiated with ultraviolet light, the coating film tends to cure uniformly, and therefore, the cured product is particularly unlikely to have unevenness.

[0210] The leveling agent (D) preferably contains a silane compound (D1). The silane compound (D1) preferably contains a silane compound (D11) having a nitrogen atom and an alkoxysilyl group. In this case, the affinity of the composition (X) and the cured product with inorganic materials such as silicon nitride is enhanced, which makes it easier to produce coating films and cured films with particularly high smoothness. The silane compound (D11) preferably contains a silane compound (D12) having an azacyclopentane skeleton (pyrrolidine skeleton). In this case, the smoothness of the coating films and cured films is particularly easy to produce. The silane compound (D12) has a structure in which, for example, an alkoxy group is bonded to Si in the azacyclopentane skeleton, and an organic group such as a hydrocarbon group is bonded to nitrogen in the azacyclopentane skeleton. The hydrocarbon group is, for example, an aryl group, an alkyl group, an alkenyl group, or an alkynyl group.

[0211] The silane compound (D12) preferably contains an azasilacyclopentane-type silane, which has, for example, the structure shown in the following formula (4).

[0212] [ka]

[0213] In equation (4), R 1 and R 2 Each of X is an alkyl group. X is an organic group, for example a hydrocarbon group.

[0214] R 1 and R 2 The number of carbon atoms in each of these is preferably 1 or more and 5 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or more and 2 or less.

[0215] When X is a hydrocarbon group, the hydrocarbon group is, for example, an aryl group, an alkyl group, an alkenyl group, or an alkynyl group. The hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 4 to 17 carbon atoms, and even more preferably 6 to 14 carbon atoms. Specific examples of the hydrocarbon group include linear alkyl groups such as methyl, ethyl, propyl, butyl, hexyl, decyl, octyl, and tetradecyl groups; branched alkyl groups such as isopropyl, tertiary butyl, and isobutyl groups; cyclic alkyl groups such as cyclohexyl groups; aryl groups such as phenyl, tolyl, and xylyl groups; and aralkyl groups such as phenethyl and diphenylmethyl groups.

[0216] The silane compound (D11) contains at least one selected from the group consisting of, for example, 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane, 2,2-dimethoxy-1-octyl-1-aza-2-silacyclopentane, and 2,2-dimethoxy-1-tetradecyl-1-aza-2-silacyclopentane.

[0217] The compounds that the silane compound (D1) can contain are not limited to the silane compound (D11). The silane compound (D1) can contain an appropriate organic alkoxysilane, for example, the silane compound (D1) can contain at least one compound selected from the group consisting of N-phenyl-3-aminopropyltrimethoxysilane, phenyltrimethoxysilane, and hexyltrimethoxysilane.

[0218] Furthermore, the compound that the leveling agent (D) may contain is not limited to the silane compound (D1). For example, the leveling agent (D) may contain at least one compound selected from the group consisting of a fluorine compound, an acrylic copolymer, and an alcohol alkoxylate compound.

[0219] The percentage of the leveling agent (D) relative to the composition (X) is preferably 0.1% by mass or more. In this case, the cured product is less likely to have unevenness. This percentage is more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. Furthermore, the percentage of the leveling agent (D) is preferably 3.0% by mass or less. In this case, there is an advantage in that it is possible to prevent deterioration of inkjet ejection properties due to an excessive decrease in surface tension. This percentage is more preferably 2.5% by mass or less, and even more preferably 2.0% by mass or less.

[0220] The composition (X) may further contain a moisture absorbent (E). When the composition (X) contains the moisture absorbent (E), the cured product of the composition (X) and the encapsulant 5 can have moisture absorption properties. Therefore, the encapsulant 5 can further prevent moisture from penetrating into the light emitting element 4 in the light emitting device 1. The average particle size of the moisture absorbent (E) is preferably 200 nm or less. In this case, the cured product can have high transparency.

[0221] The moisture absorbent (E) is preferably inorganic particles having moisture absorption properties, and preferably contains at least one component selected from the group consisting of zeolite particles, silica gel particles, calcium chloride particles, and titanium oxide nanotube particles. It is particularly preferred that the moisture absorbent (E) contains zeolite particles.

[0222] Zeolite particles with an average particle size of 200 nm or less can be produced, for example, by pulverizing common industrial zeolite. To produce 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. Examples of methods for producing such zeolite particles are disclosed in JP 2016-69266 A, JP 2013-049602 A, and the like.

[0223] The zeolite particles preferably contain sodium ions. Therefore, the zeolite particles are preferably made from at least one type selected from the group consisting of A-type zeolite, X-type zeolite, and Y-type zeolite. It is particularly preferable that the zeolite particles be made from 4A-type zeolite, among A-type zeolites. In these cases, the zeolite particles have a crystalline structure suitable for adsorbing moisture.

[0224] The pH of the zeolite particles is preferably 7 or more and 10 or less. When the pH of the zeolite particles is 7 or more, the crystals of the zeolite particles are less likely to be destroyed, and therefore, a sealing material made from the composition (X) containing the zeolite particles can have particularly high moisture absorption. Furthermore, when the pH of the zeolite particles is 10 or less, the zeolite particles are less likely to inhibit the curing of the composition (X) when it is cured. The pH of the zeolite particles is a value obtained by heating a dispersion obtained by adding 0.05 g of zeolite particles to 99.95 g of ion-exchanged water at 90°C for 24 hours, and then measuring the pH of the supernatant of the dispersion with a pH meter. Examples of pH meter include a compact pH meter manufactured by Horiba, Ltd. <laquatwin>B-711 can be used.

[0225] The average particle size of the moisture absorbent (E) is preferably 10 nm or more and 200 nm or less. If this average particle size is 200 nm or less, the cured product can have particularly high transparency. Furthermore, if this average particle size is 10 nm or more, the moisture absorbent (E) can maintain good moisture absorption. Note that this average particle size is the median diameter calculated from the measurement results using dynamic light scattering, i.e., the cumulative 50% diameter (D50). Note that the Nanotrac Wave series from Microtrac Bell Co., Ltd. can be used as a measuring device.

[0226] The average particle size of the moisture absorbent (E) is preferably 150 nm or less, more preferably 100 nm or less, and particularly preferably 70 nm or less. The average particle size of the moisture absorbent (E) is preferably 20 nm or more, and more preferably 50 nm or more. In this case, the cured product can have particularly good transparency and moisture absorption.

[0227] It is also preferable that the cumulative 90% diameter (D90) of the moisture absorbent (E) is 100 nm or less, in which case the cured product can have particularly high transparency.

[0228] When composition (X) contains a moisture absorbent (E), the proportion of the moisture absorbent (E) relative to the total amount of composition (X) is preferably 1% by mass or more and 20% by mass or less. If the proportion of moisture absorbent (E) is 1% by mass or more, the cured product can have particularly high moisture absorption. Furthermore, if the proportion of moisture absorbent (E) is 20% by mass or less, the viscosity of composition (X) can be particularly reduced, and composition (X) can have a sufficiently low viscosity that it can be applied by an inkjet method. The proportion of moisture absorbent (E) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. Furthermore, the proportion of moisture absorbent (E) is more preferably 15% by mass or less, and particularly preferably 13% by mass or less.

[0229] 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 refractive index of the cured product can be increased while maintaining good transparency of the cured product. Therefore, when the cured product is used as the encapsulant 5 in the light-emitting device 1, the extraction efficiency of light that passes through the encapsulant 5 and is emitted to the outside can be improved. The average particle size of the high refractive index particles is preferably within a range of 5 to 30 nm, and more preferably within a range of 10 to 20 nm.

[0230] The proportion of high-refractive-index particles in composition (X) is appropriately designed so that the cured product has a desired refractive index. In particular, it is preferable that the high-refractive-index particles are contained in composition (X) so that the refractive index of the cured product is in the range of 1.45 or more and less than 1.55. In this case, the light extraction efficiency of the light-emitting device 1 is particularly improved.

[0231] When the composition (X) contains the moisture absorbent (E), the composition (X) preferably further contains a dispersant (F). In this case, the dispersant (F) can improve the dispersibility of the moisture absorbent (E) in the composition (X). Therefore, the composition (X) is less likely to experience an increase in viscosity and a decrease in storage stability due to the moisture absorbent (E).

[0232] The dispersant (F) is a surfactant capable of adsorbing to particles. The dispersant (F) has an adsorption group (commonly referred to as an anchor) capable of adsorbing to particles and a molecular skeleton (commonly referred to as a tail) that adheres to the particles when the adsorption group adsorbs to the particles. The dispersant (F) contains at least one component selected from the group consisting of, for example, an acrylic dispersant in which the tail is an acrylic molecular chain, a urethane dispersant in which the tail is a urethane molecular chain, and a polyester dispersant in which the tail is a polyester molecular chain. The adsorption group includes, for example, at least one of a basic polar functional group and an acidic polar functional group. The basic polar functional group includes, for example, at least one group selected from the group consisting of an amino group, an imino group, an amide group, an imide group, and a nitrogen-containing heterocyclic group. The acidic polar functional group includes, for example, at least one group selected from the group consisting of a carboxyl group and a phosphate group. The dispersant (F) may contain at least one compound selected from the group consisting of, for example, the Solsperse series manufactured by Nippon Louvre Resol Co., Ltd., the DISPERBYK series manufactured by BYK Japan Co., Ltd., and the Ajisper series manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0233] When composition (X) contains moisture absorbent (E), the amount of dispersant (F) per 100 parts by mass of moisture absorbent (E) is preferably 5 parts by mass or more and 60 parts by mass or less. When the amount of dispersant (F) is 5 parts by mass or more, the function of dispersant (F) can be effectively exhibited, and when the amount is 60 parts by mass or less, free molecules of dispersant (F) in sealant 5 can be prevented from impairing the adhesion between sealant 5 and an inorganic material component. Furthermore, the amount of dispersant (F) is more preferably 15 parts by mass or more, more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less.

[0234] The structure of the light emitting device 1 will be described. The light emitting device 1 includes a light source and an optical component that transmits light emitted by the light source. For example, the light emitting device 1 includes a light emitting element 4, and a sealant 5 and a passivation layer 6 that cover the light emitting element 4. In this case, the light emitting element 4 is the light source, the sealant 5 is the optical component, and the passivation layer 6 is an inorganic layer. The sealant 5 and the passivation layer 6 overlap each other.

[0235] The light-emitting element 4 includes, for example, a light-emitting diode. The light-emitting diode includes, for example, at least one of an organic EL element (organic light-emitting diode) and a micro light-emitting diode. When the light-emitting element 4 includes an organic light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, an organic EL display. When the light-emitting element 4 includes a micro light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, a micro LED display. Note that EL is an abbreviation for electroluminescence.

[0236] An example of the structure of light-emitting device 1 will be described with reference to Fig. 1. This light-emitting device 1 is a top-emission type. Light-emitting device 1 includes a support substrate 2, a transparent substrate 3 facing the support substrate 2 with a gap therebetween, a light-emitting element 4 on the surface of support substrate 2 facing the transparent substrate 3, and a passivation layer 6 and a sealing material 5 that cover the light-emitting element 4.

[0237] The support substrate 2 is made of, for example, but not limited to, a resin material. The transparent substrate 3 is made of a light-transmitting material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate. The light-emitting element 4 includes, for example, a pair of electrodes 41, 43 and an organic light-emitting layer 42 between the electrodes 41, 43. The organic light-emitting layer 42 includes, for example, a hole injection layer 421, a hole transport layer 422, an organic light-emitting layer 423, and an electron transport layer 424, which are stacked in the above order.

[0238] The light emitting device 1 includes a plurality of light emitting elements 4, and the plurality of light emitting elements 4 form an array 9 (hereinafter referred to as element array 9) on a support substrate 2. The element array 9 also includes a partition wall 7. The partition wall 7 is located on the support substrate 2 and separates two adjacent light emitting elements 4. The partition wall 7 is fabricated, for example, by molding a photosensitive resin material using a photolithography method. The element array 9 also includes connection wiring 8 that electrically connects the electrodes 43 and the electron transport layers 424 of adjacent light emitting elements 4. The connection wiring 8 is provided on the partition wall 7.

[0239] The passivation layer 6 is preferably made of silicon nitride or silicon oxide, and particularly preferably made of silicon nitride. In the example shown in FIG. 1 , the passivation layer 6 includes a first passivation layer 61 and a second passivation layer 62. The first passivation layer 61 is in direct contact with the element array 9 and covers the element array 9, thereby covering the light-emitting elements 4. The second passivation layer 62 is disposed on the opposite side of the first passivation layer 61 from the element array 9, and a gap is provided between the second passivation layer 62 and the first passivation layer 61. An encapsulant 5 is filled between the first passivation layer 61 and the second passivation layer 62. That is, the first passivation layer 61 is interposed between the light-emitting elements 4 and the encapsulant 5 covering the light-emitting elements 4.

[0240] Furthermore, a second sealing material 52 is filled between the second passivation layer 62 and the transparent substrate 3. The second sealing material 52 is made of, for example, a transparent resin material. The material of the second sealing material 52 is not particularly limited. The material of the second sealing material 52 may be the same as or different from the sealing material 5.

[0241] A method for producing the encapsulant 5 using the composition (X) and a method for producing the light emitting device 1 will be described.

[0242] In this embodiment, it is preferable to mold the composition (X) by an inkjet method and then irradiate the composition (X) with ultraviolet light to cure it, thereby producing the encapsulant 5. In this embodiment, the composition (X) can be applied and molded by an inkjet method.

[0243] When applying composition (X) by the inkjet method, if composition (X) has a sufficiently low viscosity at room temperature, for example, if the viscosity at 25°C is 30 mPa s or less, particularly 15 mPa s or less, composition (X) can be molded by applying it by the inkjet method without heating.

[0244] If composition (X) has the property of decreasing viscosity when heated, composition (X) may be heated and then applied by inkjet printing to form a mold. If composition (X) has a viscosity of 30 mPa·s or less, particularly 15 mPa·s or less at 40°C, composition (X) can be made to have a low viscosity by simply heating it slightly, and this low-viscosity composition (X) can be ejected by inkjet printing. The heating temperature for composition (X) is, for example, 20°C or higher and 50°C or lower.

[0245] More specifically, for example, first, a support substrate 2 is prepared. On one surface of this support substrate 2, partition walls 7 are fabricated by photolithography using, for example, a photosensitive resin material. Next, a plurality of light-emitting elements 4 are provided on one surface of the support substrate 2. The light-emitting elements 4 can be fabricated by an appropriate method such as a vapor deposition method or a coating method. In particular, it is preferable to fabricate the light-emitting elements 4 by a coating method such as an inkjet method. In this way, an element array 9 is fabricated on the support substrate 2.

[0246] Next, a first passivation layer 61 is provided on the element array 9. The first passivation layer 61 can be formed by a vapor deposition method such as a plasma CVD method.

[0247] Next, composition (X) is applied to the first passivation layer 61 by, for example, an inkjet method to form a coating film. If the inkjet method is used for both forming the light-emitting element 4 and applying composition (X), the manufacturing efficiency of the light-emitting device 1 can be particularly improved. Next, the coating film of composition (X) is cured by irradiating it with ultraviolet light to form the encapsulant 5. The thickness of the encapsulant 5 is, for example, 5 μm or more and 50 μm or less.

[0248] When irradiating composition (X) with ultraviolet light, the composition (X) may be irradiated with ultraviolet light in an oxygen-containing atmosphere, such as air, or in an inert atmosphere, such as a nitrogen atmosphere. In this embodiment, as described above, the oxygen content of composition (X) is 75 mass% or less, so oxygen inhibition is unlikely to occur, especially even when photopolymerizable compound (A) contains radically polymerizable compound (A1). Therefore, composition (X) can be easily cured even when irradiated with ultraviolet light in an oxygen-containing atmosphere.

[0249] Next, a second passivation layer 62 is provided on the sealing material 5. The second passivation layer 62 can be formed by a vapor deposition method such as a plasma CVD method.

[0250] 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 then the transparent substrate 3 is placed on top of this resin material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate.

[0251] Next, ultraviolet light is irradiated from the outside toward the transparent substrate 3. The ultraviolet light passes through the transparent substrate 3 and reaches the ultraviolet-curable resin material, which then hardens, forming the second sealing member 52.

[0252] In this embodiment, as described above, it is possible to make it difficult for the light emitting efficiency to decrease due to the passivation layer 6 and the sealing material 5 in the light emitting device 1 to decrease.

[0253] The thickness of the sealing material 5 is, for example, 1 μm or more and 20 μm or less. The thickness of the sealing material 5 may be 15 μm or less. In this case, by thinning the sealing material 5, the light emitting device 1 can be thinned, and a flexible light emitting device 1 can be obtained. Furthermore, even if the thickness of the sealing material 5 is 10 μm or less, in this embodiment, a decrease in luminous efficiency caused by the passivation layer 6 and the sealing material 5 in the light emitting device 1 can be made less likely to occur. It is more preferable that the thickness of the sealing material 5 is 8 μm or less. Furthermore, in order for the sealing material 5 to effectively suppress moisture from entering the light emitting element 4, the thickness of the sealing material 5 is preferably 3 μm or more, and more preferably 5 μm or more.

[0254] The thickness of the passivation layer 6 overlapping the sealing material 5 is, for example, not less than 0.1 μm and not more than 2 μm. When the passivation layer 6 includes the first passivation layer 61 and the second passivation layer 62 as described above, it is preferable that the thickness of each of the first passivation layer 61 and the second passivation layer 62 is not less than 0.1 μm and not more than 2 μm.

[0255] The use of the composition (X) according to this embodiment is not limited to the production of the encapsulant 5 for the light-emitting element 4. The composition (X) can be used to produce various optical components that transmit light emitted by a light source. For example, the optical component may be a color resist. That is, for example, a phosphor may be contained in the composition (X), and a color resist for a color filter may be produced from this composition (X). This color filter can be provided in a display device such as an organic EL display or a micro LED display, which is a light-emitting device. [Example]

[0256] 1. Preparation of the Composition Compositions of the examples and comparative examples were prepared by mixing the components shown in the table below.

[0257] The details of the components shown in the table are as follows. The viscosity of each component was measured using a rheometer (Anton Paar Japan, model number DHR-2) at a temperature of 25°C and a shear rate of 1000 s -1 The values ​​were measured under the following conditions. -Acryloylmorpholine, viscosity 12 mPa·s. -Morpholin-4-yl acrylate: Viscosity 16 mPa·s. -Polyethylene glycol 200 dimethacrylate: manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 14 mPa·s. -Tripropylene glycol diacrylate: viscosity 15 mPa·s. -Pentaerythritol tetraacrylate: viscosity 350 mPa·s. -Irgacure TPO: BASF, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, with an absorption coefficient of 165 ml / g·cm at 405 nm, and photobleachable. -Irgacure 819: BASF, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, with an absorption coefficient of 900 ml / g·cm at 405 nm, and photobleachable. -Irgacure907: BASF, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, absorbance coefficient of 0 ml / g·cm at 405 nm, non-photobleachable. -Irgacure 184: BASF, 1-hydroxy-cyclohexyl-phenyl-ketone, absorbance coefficient of 0 ml / g·cm at 405 nm, non-photobleachable. Sensitizer 1: anthracene-based sensitizer, manufactured by Kawasaki Chemical Industries, Ltd., product name Anthracure (registered trademark) UVS-581. -Sensitizer 2: Thioxanthone-based sensitizer, 2,4-diethylthioxanthone, manufactured by Nippon Kayaku Co., Ltd., product name KAYACURE DETX-S. -Leveling agent 1: 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane. -Leveling agent 2: 2,2-dimethoxy-1-tetradecyl-1-aza-2-silacyclopentane. Leveling agent 3: Phenyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name KBM-103. Leveling agent 4: hexyltriethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name KBM-3063.

[0258] 2.Evaluation Test The following evaluation tests were carried out on the examples and comparative examples, and the results are shown in the table below.

[0259] (1) Viscosity The viscosity of the composition was measured using a rheometer (Anton Paar Japan, model number DHR-2) at a temperature of 25°C and a shear rate of 1000 s -1 The measurement was carried out under the following conditions.

[0260] (2) Inkjet compatibility The composition was placed in a cartridge of an inkjet printer (Fujifilm, Model DMP2831), and droplets of the composition were ejected from the nozzle of the inkjet printer at a temperature of 30°C and a frequency of 1 kHz. The droplets were observed with a high-speed camera, and were rated as "A" when neither mist nor satellites were observed, and "B" when at least one of mist or satellites was observed.

[0261] (3) Transmittance The composition was applied to form a coating film with a thickness of 10 μm, and ultraviolet light was irradiated onto the coating film at 3 W / cm under atmospheric pressure using an LED-UV irradiator (model number E075IIHD, peak wavelength 395 nm) manufactured by Ushio Inc. 2 A film was produced by irradiating the film with an irradiation intensity of 100° C. for 5.3 seconds, followed by heating for 5 minutes at 100° C. The total light transmittance of this film was measured according to JIS K7361-1.

[0262] (4) Response rate The composition was measured using an infrared spectrometer (Agilent Technologies, Model No. Agilent Cary 610 FTIR Microscope System) to obtain an IR spectrum.

[0263] The composition was applied to form a coating film with a thickness of 10 μm, and the coating film was irradiated with ultraviolet light having a peak wavelength of 395 nm at an irradiation intensity of 3 W / cm using a UV irradiator (manufactured by CCS Corporation, model number CKL-200). 2 And the cumulative light intensity is 0.9J / cm 2 The composition (cured product) after irradiation with ultraviolet light was then measured using the infrared spectrometer described above to obtain an IR spectrum.

[0264] In each of the two IR spectra, -1 The peak intensity of the absorption of the acryloyl group appearing in the sample was measured. Using the peak intensity I0 for the coating film and the peak intensity I1 for the cured product, the reduction rate of the reactive functional group ((meth)acryloyl group) in the composition before and after UV irradiation was calculated using the formula {1-(I0-I1) / I0} x 100 (%). The result was taken as the reaction rate.

[0265] (5) Shrinkage rate difference Composition thickness: 10 μm, UV irradiator (manufactured by CCS Corporation, model number CKL-200), peak wavelength: 395 nm, irradiation intensity: 7 W / cm 2 and an integrated light output of 2.1 J / cm 2 The cure shrinkage of the ultraviolet curable resin was measured according to JIS K6941 under the conditions above, and the cure shrinkage of the composition was calculated.

[0266] The ultraviolet irradiation conditions were an irradiation intensity of 3W / cm 2 And the cumulative light intensity is 0.9J / cm 2 The cure shrinkage of the composition was calculated in the same manner except for changing the temperature to

[0267] The absolute value of the difference between the two curing shrinkage rates obtained above was calculated.

[0268] (6) Streaks The composition was applied to a quartz glass piece (50 mm × 25 mm × 1 mm) on the surface of which a silicon oxynitride film (SiON film) had been formed by plasma CVD to produce a coating film with a thickness of 10 μm. This coating film was irradiated with ultraviolet light at an intensity of 5 W / cm using a Unijet E075IIHD (peak wavelength 395 nm) manufactured by Ushio Inc. in an air atmosphere. 2 , and the cumulative light intensity is 3000mJ / cm 2 The coating was cured by irradiation under the conditions of 1. to 3. to obtain a cured film.

[0269] The surface of the cured film was visually observed, and the film was rated as "A" if no streaky irregularities were observed on the cured film, "B" if streaky irregularities were observed in less than 10% of the surface area of ​​the cured film, and "C" if streaky irregularities were observed in 10% or more of the surface area of ​​the cured film.

[0270] [Table 1] < / laquatwin>

Claims

1. An ultraviolet-curable resin composition containing a photopolymerizable compound (A) and a photopolymerization initiator (B), the photopolymerizable compound (A) contains a radically polymerizable compound (A1), the radically polymerizable compound (A1) contains an acrylic compound (Y), and the acrylic compound (Y) contains a polyfunctional acrylic compound (Y1) and a monofunctional acrylic compound (Y2), the polyfunctional acrylic compound (Y1) contains a polyalkylene glycol di(meth)acrylate and pentaerythritol tetra(meth)acrylate, and the monofunctional acrylic compound (Y2) contains a compound having a morpholine skeleton; the photopolymerization initiator (B) contains phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide in a total amount of 75% by mass or more and 100% by mass or less, based on the photopolymerization initiator (B); A coating film having a thickness of 10 μm was prepared from the ultraviolet-curable resin composition, and ultraviolet light having a peak wavelength in the wavelength range of 385 nm to 405 nm was irradiated onto the coating film at an irradiation intensity of 7 W / cm. 2 And the cumulative light intensity is 2.1 J / cm 2 The curing shrinkage rate when irradiated under the conditions of 3 W / cm 2 And the cumulative light intensity is 0.9 J / cm 2 The absolute value of the difference between the curing shrinkage rate when irradiated under the conditions of (a) and (b) is 2 percentage points or less. UV curable resin composition.

2. A coating film having a thickness of 10 μm was prepared from the ultraviolet-curable resin composition, and the coating film was irradiated with ultraviolet light having a peak wavelength of 395 nm at an irradiation intensity of 3 W / cm 2 And the cumulative light intensity is 0.9 J / cm 2 When irradiated under the conditions of The ultraviolet-curable resin composition according to claim 1 .

3. The photopolymerization initiator (B) contains a photopolymerization initiator (B4) having an absorption coefficient of 5 ml / g cm or more for light having a wavelength of 405 nm, and the percentage of the photopolymerization initiator (B4) to the photopolymerization initiator (B) is 50 mass% or more. The ultraviolet-curable resin composition according to claim 1 or 2.

4. Further containing a sensitizer (C), the percentage of the sensitizer (C) relative to the ultraviolet-curable resin composition is 0.05 mass% or more, The ultraviolet-curable resin composition according to claim 1 .

5. Further containing a leveling agent (D), the percentage of the leveling agent (D) relative to the ultraviolet-curable resin composition is 0.1 mass% or more, The ultraviolet-curable resin composition according to claim 1 .

6. A method for producing an optical component that transmits light emitted by a light source, The ultraviolet-curable resin composition according to claim 1 .

7. Formed by an inkjet method, The ultraviolet-curable resin composition according to claim 1 .

8. At least one of the viscosity at 25°C and the viscosity at 40°C is 30 mPa·s or less. The ultraviolet-curable resin composition according to claim 1 .

9. A cured product of the ultraviolet-curable resin composition according to any one of claims 1 to 8. Optical components.

10. A method for manufacturing an optical component, comprising molding an ultraviolet-curable resin composition described in any one of claims 1 to 8 using an inkjet method, and then irradiating the ultraviolet-curable resin composition with ultraviolet light to cure it.

11. A light source and an optical component that transmits light emitted by the light source, wherein the optical component includes a cured product of the ultraviolet-curable resin composition according to any one of claims 1 to 8. Light-emitting device.

12. A method for manufacturing a light emitting device comprising a light source and an optical component that transmits light emitted by the light source, comprising:

11. The method of claim 10, A method for manufacturing a light-emitting device.

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