Cured product of photocurable composition, optical component, light-emitting device, and module

Abstract

To provide a cured product of a photocurable composition capable of achieving both a higher refractive index and heat resistance, an optical component, a light-emitting device, and a module.SOLUTION: The cured product of the photocurable composition contains metal oxide nanoparticles, an acrylate resin having a fluorene skeleton, and an acrylate resin having a tetrahydrofuran and ethylene skeleton. In a distribution of absorbance obtained for each wave number by infrared spectrometry, a ratio Io / Ie of an area Io in a wave number range of 3100 to 1130cm - 1 to an area Ie in a wave number range of 1075 to 3700cm - 1 is 2 or more and 5 or less.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a cured product of a photocurable composition, an optical component, a light-emitting device, and a module. [Background technology]

[0002] Conventionally, there is a technology for producing optical components that transmit light by curing a photocurable composition such as a resin. It is known that a resin material used for such optical components is an acrylate having a fluorene skeleton, which can provide a refractive index of 1.56 or more (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-127528 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for optical components with higher refractive indexes, while heat resistance is required for the manufacture and use of optical components. Therefore, the present invention provides a cured product of a photocurable composition that can achieve both a higher refractive index and heat resistance, as well as an optical component, a light-emitting device, and a module. [Means for solving the problem]

[0005] One aspect of the present disclosure is metal oxide nanoparticles; a first acrylate resin having a fluorene skeleton; a second acrylate resin having tetrahydrofuran and an ethylene skeleton; Including, In the absorbance distribution obtained for each wavenumber by infrared spectroscopy, the wavenumber is 1075 to 1130 cm -1 The wave number for the area Ie in the range of 3100 to 3700 cm-1 The cured product of the photocurable composition has an area ratio Io / Ie of 2 or more and 5 or less. [Effects of the Invention]

[0006] According to the present disclosure, a cured product of a photocurable composition can have both a higher refractive index and heat resistance. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a diagram illustrating an example of the absorbance distribution obtained from a cured product of the present disclosure by infrared spectroscopy. [Figure 2] FIG. 1 is a diagram illustrating the amount of ether (or COC) bonds. [Figure 3] 1A to 1C are diagrams illustrating an example of a sensor module including an optical component obtained using the photocurable composition of the present embodiment. [Figure 4] 1 is a table showing the refractive index and heat resistance according to the ratio of components of each resin. [Figure 5] 10 is a table showing the measurement results of fracture stress. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings. The photocurable composition for obtaining the photocured product of the present disclosure includes an acrylate resin that is cured by light, particularly ultraviolet light (UV). Adding metal oxide nanoparticles to this acrylate resin improves the refractive index. Furthermore, the photocurable composition includes tetrahydrofuran (THF) and an acrylate resin (second acrylate resin) having an ethylene chain (ethylene skeleton).

[0009] The metal oxide nanoparticles have an average particle size of 1-100 nm, more preferably 1-30 nm. The average particle size can be obtained, for example, by averaging the particle sizes of samples measured using a transmission electron microscope. Metal oxide nanoparticles of this size do not significantly suppress the transmission of light. The metal contained in the metal oxide is, for example, zirconium (Zr), but is not limited to this. Other metals include titanium (Ti), cerium (Ce), and niobium (Nb). Hydroxyl groups (OH groups) are usually bonded to the surface of the metal oxide nanoparticles.

[0010] The metal oxide nanoparticles may contain, for example, UV-polymerizable functional groups. This allows the metal oxide nanoparticles to be properly bonded to the acrylate resin when the resin is cured by UV irradiation. The metal oxide nanoparticles may also be surface-modified (coated) with a lipophilic dispersant or the like. The surface-modified metal oxide nanoparticles may be dispersed in a liquid acrylate resin (organic solvent) separate from the fluorene skeleton-containing acrylate resin described below (resin A). An example of such a resin A is Zircostar (registered trademark) from Nippon Shokubai (registered trademark), which uses a UV-curable acrylate resin such as benzyl acrylate, phenoxyethyl acrylate, or methyl ethyl ketone. The content of the metal oxide nanoparticles in this resin A can be, for example, 80% by mass. The surface modification allows the metal oxide nanoparticles to be properly dispersed in the organic solvent.

[0011] The acrylate resin (resin B; first acrylate resin) has a fluorene skeleton. The fluorene skeleton has a tricyclic aromatic ring. The fluorene skeleton has a large number of C-C bonds derived from the aromatic ring, resulting in high thermal stability. Furthermore, acrylate resins having a fluorene skeleton have a relatively high refractive index (e.g., 1.58) compared to various acrylate resins. Furthermore, this resin B has ether (or CO-C) bonds. The presence of many ether (or CO-C) bonds in the polymer resin improves the flexibility of the resin in response to intermolecular interactions. The portions of resin B other than the fluorene skeleton and ether (or CO-C) bonds are not particularly limited as long as they are UV-curable.

[0012] The acrylate resin (resin C) containing THF and an ethylene chain contains one oxygen atom in a saturated five-membered ring as THF. THF is liquid at room temperature and normal pressure, and contributes to the proper dispersion of each component when mixing resin A containing the metal oxide nanoparticles and resin B having a fluorene skeleton. In particular, since resins A and B have low compatibility, it is preferable to include another solvent. This THF has a ring structure that reduces thermal decomposition, i.e., improves heat resistance. Furthermore, since ethylene chains have easy molecular mobility, the inclusion of resin C improves the flexibility of the UV-cured cured product. However, resin C has a slightly lower refractive index (e.g., 1.44) than resins A and B.

[0013] The photocurable composition of the present disclosure achieves both a high refractive index and heat resistance by mixing the above-described resins A, B, and C in an appropriate blending ratio. Here, a high refractive index means a refractive index higher than the refractive index of 1.62 of the acrylate resin alone having a fluorene skeleton. The photocurable composition may contain, in addition to the above-described resins, a curing agent (photopolymerization initiator) for initiating photocuring. The curing agent may be a conventionally known agent that initiates photopolymerization by light of a specific wavelength, such as UV light, or a combination of multiple types may be used.

[0014] The ratio of each component in a cured product obtained from a photocurable composition containing these components can be determined using infrared spectroscopy. Infrared spectroscopy is a technique that utilizes the fact that infrared light irradiated onto an object is absorbed in a wavenumber band (wavelength, frequency) corresponding to the object's components and structural moieties (e.g., functional groups). This technique identifies the components and their amounts from the characteristics of the absorbed wavelength and the intensity of that absorption (absorbance). However, when quantitatively evaluating absorbance, offsets can occur in individual measured values ​​(absolute values) (this is particularly likely to occur in the microscopic ATR method described below). In the present disclosure, a reference line is defined as a line connecting the absorbances at wavenumbers where absorption is expected to be low, located on both sides of the range including the target wavenumber band for which absorbance is to be detected. The area occupied by the reference line and the distribution of absorbance measured in the target wavenumber band for which absorbance is to be detected is obtained as a value corresponding to the component amount.

[0015] 1(b) is a graph showing an example of the absorbance distribution obtained from the cured product of the present disclosure by infrared spectroscopy. -1 This is an enlarged view of the range. Although not particularly limited, here, an infrared spectrum (absorbance distribution) is obtained by a microscopic ATR method using a Nicolet (registered trademark) iN10MX manufactured by Thermofisher Scientific (registered trademark).

[0016] Metal oxide nanoparticles (Resin A) contain OH bonds as described above, and infrared light is emitted from the nanoparticles at wavelengths of 3100-3700 cm according to these OH bonds. -1 On both sides of this region, absorption occurs in a wide range of -1 and 3720 cm -1 is assumed to be the minimum point of absorption (in actual measurements, there may be some deviation in the minimum point, and the above two minimum points may be fixed regardless of the deviation). In the infrared spectral distribution (the horizontal axis is the wave number and the vertical axis is the absorbance, both of which are linearly displayed), the absorbance of these two points is connected, and the absorbance on the line and the above 3100-3700 cm -1The difference between the absorbances in this range is taken as the absorption amount, and the area Io is taken as the absorbance due to the OH bond. As shown in Figure 1(a), the absorbance in this wavenumber range is significantly higher in Resin A, which contains metal oxide nanoparticles. Accordingly, the absorbance is also higher in the cured product.

[0017] On the other hand, Resin B has a stretching vibration of 1075-1130 cm according to the stretching vibration of ether (or COC). -1 Absorption is observed in the range of 1790 cm on both sides of this wavenumber band. -1 and 850cm -1 These 850 cm are considered to be the reference positions where the minimum absorption value is expected. -1 and 1790cm -1 The line connecting the absorbance points is taken as the reference line. -1 The absorbance value at the same wavenumber on the reference line is subtracted as an offset value from the absorbance measurement value in the range, and the area Ie of the range is determined to be the absorbance due to the stretching vibration of the ether (or COC) in the object. As shown in Figure 1(b), in the acrylate resins of the present disclosure, the absorbance of Resin B is significantly greater in the wavenumber range associated with the stretching vibration of ether (or COC) than the absorbance of Resin A in the same wavenumber range. This indicates that Resin B contains the above-mentioned ether bond. Note that the ratio of these CO bonds present may vary depending on the type of acrylate resin, the composition ratio of the components (monomers), etc.

[0018] FIG. 2 is a graph showing the area ratio (Io / Ie), which is the ratio of the area (Ie) of the wavenumber band associated with the stretching vibration of ether (or COC) to the area (Io) of the wavenumber band associated with the OH bond, versus the blending ratio (B / A) of resin A to resin B.

[0019] It is clearly shown that there is a positive correlation between these two. Therefore, it is clear that the area ratio (Io / Ie) is a value that corresponds to the correspondence relationship between the metal oxide nanoparticles and the amount of ether (or COC) bonds.

[0020] The ratio of metal oxide nanoparticles to resin A may vary depending on the product. Therefore, the absolute values ​​of the blending ratios of each resin according to the area ratio are not specified here. Also, although Figure 2 also shows a linear regression line, it cannot be concluded from the graph alone that there is a linear correlation.

[0021] As mentioned above, the fluorene skeleton has many C-C bonds derived from aromatic rings, so the wavenumber band corresponding to the C-C bonds is 1500-1520 cm -1 This wavenumber band can be characterized by absorbance at the 850-1790 cm -1 Therefore, the area Ic, which indicates the amount of C-C bonds derived from aromatic rings, is within the range of 850-1790 cm -1 This can be obtained by offset adjustment using the reference line. Although not shown in the figure, the area ratio (Io / Ic) also has a positive correlation with the blending ratio (B / A). Therefore, the area ratio (Io / Ic) is a value that corresponds to the correspondence between the metal oxide nanoparticles and the amount of C-C bonds derived from aromatic rings.

[0022] It is difficult to identify the unique structure of THF in resin C from infrared spectroscopy. The blending ratio of resin C containing THF can be determined, for example, using gas chromatography-mass spectrometry (GC-MS). When estimating the blending ratio from a cured product obtained by copolymerizing and curing each acrylate resin and metal oxide nanoparticles in a photocurable composition, pyrolysis GC-MS is used. That is, the cured copolymer is first thermally decomposed into monomers. The blending ratio is then determined as the ratio of the measured value (area) of the content of the monomer derived from resin C to the measured value (area) of the content of the monomer derived from all resins A to C (see, for example, JP 2021-172558 A).

[0023] As described above, the refractive index of the cured product of the photocurable composition of the present disclosure is increased by the incorporation of metal oxide nanoparticles compared to the refractive index of 1.58 for Resin B alone. The refractive index increases as the incorporation ratio of metal oxide nanoparticles increases. However, if the incorporation ratio of metal oxide nanoparticles is too high, the thermal stability and flexibility provided by the acrylate resin having a fluorene skeleton and ether (or COC) bonds become insufficient. When preparing a desired cured product from the photocurable composition, heating (e.g., reflow) must be taken into consideration. Therefore, a lack of these components can cause thermal decomposition, or even if the resin components are intact, the resin can become brittle and break when stretching and bending due to thermal expansion, etc. By containing an appropriate ratio of ether (or COC) bonds and providing flexibility, thermal stability and durability against physical deformation are improved. The ether (or COC) bonds preferably have an area ratio (Io / Ie) of 2 or more and 5 or less. Furthermore, the area ratio (Io / Ic) is preferably 30 or more and 250 or less.

[0024] In addition, the addition of resin C improves heat resistance and flexibility. The blending ratio of resin C is preferably 5% by mass or more relative to the total mass of the cured product (solid components). Alternatively, for example, the blending ratio of resin C may be 10% by mass or less relative to the total mass of the cured product (solid components). Resin C increases flexibility and pliability, making the cured product of the photocurable composition less likely to break even when subjected to large stresses (tensile, shear, etc.). For example, by ensuring that the breaking stress of the cured product is 10 MPa or more, it is possible to effectively suppress the occurrence of breakage due to thermal deformation, etc.

[0025] 3A and 3B are diagrams illustrating an example of a sensor module 100 equipped with an optical component including a cured product obtained using the photocurable composition of this embodiment. Fig. 3A shows a schematic cross-sectional view of the sensor module 100. Fig. 3B and Fig. 3C show examples of the optical component in the cross section.

[0026] As shown in FIG. 3(a), a sensor module 100, which is a module of this embodiment, includes a light-emitting device 1 of this embodiment and a light-receiving device 2. The light-emitting device 1 and the light-receiving device 2 are positioned side by side on a wiring substrate 3. The sensor module 100 is, for example, a photoelectric sensor that detects reflected light (incident light) of light emitted by the light-emitting device 1 using the light-receiving device 2 to perform object detection, but is not limited to this.

[0027] The light-emitting device 1 includes a light-emitting element 15, an optical component 10, and a concave substrate 16. The light-emitting element 15 is a surface-emitting laser, such as a vertical-cavity surface-emitting laser (VCSEL). The concave substrate 16 is a package having a shape with a recess with one open end, such as a box shape, in which the light-emitting element 15 is located. The concave substrate 16 also has signal lines and connection terminals for supplying power related to light emission to the light-emitting element 15 from an external source.

[0028] The optical component 10 covers the open surface of the concave substrate 16. The optical component 10 will be described later.

[0029] The light receiving device 2 includes a substrate 21, a light receiving element 22, an optical member 23, a support portion 24, and the like. The light receiving element 22 is, for example, a photodiode. The light receiving element 22 is capable of receiving incident light from above and is connected to a connection terminal on the substrate 21. The substrate 21 has a signal line that outputs a signal according to the amount of received light to the outside, and one end of the signal line is connected to the connection terminal.

[0030] The optical member 23 may include a lens, a filter, or the like. The optical member 23 focuses light incident from above onto the entrance of the light-receiving element 22. The optical member 23 may also include a bandpass filter that selectively passes light in the wavelength band emitted by the light-emitting element 15 and blocks light of other wavelengths (including non-visible light such as infrared). Alternatively, the bandpass filter may pass light different from the wavelength band emitted by the light-emitting element 15. In other words, the light-emitting device 1 that illuminates the surroundings and the light-receiving device 2 that receives light from the surroundings may be independent. The support portion 24 supports the optical member 23. The support portion 24 may also function as a light-blocking member that prevents light from entering the light-receiving element 22 without passing through the optical member 23.

[0031] As shown in FIG. 3(b), the optical component 10 includes, for example, a substrate 12 and a microlens array 11 (lens portion) bonded to the top (surface) of the substrate 12. The substrate 12 is optically transparent and preferably colorless and transparent, such as glass (glass substrate). The microlens array 11 has a plurality of convex lenses arranged in a two-dimensional plane, and diffuses light emitted from the light-emitting element 15 by directing the light toward the convex lenses. That is, the optical component 10 may be a diffuser plate. Each convex lens has a planar size (diameter) of, for example, several μm to several tens of μm. By increasing the refractive index of the microlens array 11 included in such an optical component 10, each convex lens becomes a wide-angle lens. In recent years, there has been a demand for small wide-angle lenses capable of irradiating light over a wider area. This demand can be met by obtaining the microlens array 11 as a cured product of the photocurable composition of this embodiment.

[0032] At the same time, the optical component 10 must be resistant to high-temperature environments not only during use but also during manufacturing. Furthermore, if the substrate 12 and the microlens array 11 are deformed due to different thermal expansion and contraction caused by high heat during manufacturing, the microlens array 11 will be pulled by the substrate 12. The microlens array 11 is required to have flexibility (flexibility) that can withstand such situations. As described above, the microlens array 11 (cured product) that combines a high refractive index and heat resistance, and is particularly flexible, is suitable for use in manufacturing the optical component 10.

[0033] Alternatively, as shown in FIG. 3(c), the optical component 10a may be a diffraction element having a substrate 12 and a diffraction member 11a positioned on the substrate 12. The diffraction member 11a has periodic convex and concave portions. These convex and concave portions may be linear and extend in the depth direction of the drawing, generating one-dimensional diffraction. Alternatively, the convex and concave portions may be arranged in a two-dimensional matrix, generating two-dimensional diffraction. Furthermore, the diffraction member 11a may have convex or concave portions arranged in a lattice pattern on a flat surface. The bottom surface of the concave portion need not be flat.

[0034] Such a diffractive member 11a may be a cured product of a photocurable composition. The diffractive member 11a can achieve both effects corresponding to a high refractive index, such as improved light output efficiency, and effects such as high heat resistance and flexibility.

[0035] [Example] FIG. 4 shows the refractive index and heat resistance according to the ratio of each component of the above-mentioned resins A to C and the above-mentioned area ratio. As mentioned above, resin A is a dispersion liquid in which metal oxide nanoparticles are dispersed in an acrylate resin such as phenoxyethyl acrylate, but the liquid component (organic solvent) is excluded from the ratio. The metal oxide nanoparticles are present in the dispersion liquid at 80 parts by mass. For resin B, OGSOL EA-0300 from Osaka Gas Chemicals (registered trademark) was used. For resin C, α-allyloxymethyl acrylate was used.

[0036] Here, the refractive index n is a value calculated by the following formula using the refractive indices nA to nC and densities ρA to ρC of each of the components (structural units) of Resin A to Resin C alone, the density ρ of the entire mixture, and the weight fractions gA to gC of each component (gA + gB + gC = 1). (n 2 -1) / (n 2 +2)=gA·ρ·(nA 2 -1) / (ρA·(nA 2 +2)) +gB·ρ·(nB 2 -1) / (ρB·(nB 2 +2)) +gC·ρ·(nC 2 -1) / (ρC·(nC 2 +2)) Here, ρA = 2.4, ρB = 1.2, ρC = 1.0 (g / cm 3 ) For each of the refractive indices nA to nC, a value at a wavelength of 940 nm is used. The refractive index may be measured by a spectroscopic ellipsometer, etc. For example, UVISEL2 manufactured by Horiba Ltd. may be used as the spectroscopic ellipsometer.

[0037] The heat resistance was evaluated by applying a photocurable composition mixed at each blend ratio to a thickness of approximately 100 μm on a 0.5 mm thick glass plate, and measuring the exposure dose at 1200 mJ / cm. 2 After UV curing, the resin is heated in a low-oxygen furnace (less than 10 ppm) at 260°C for 10 minutes. This indicates whether cracks are visible on the resin surface (NG) or not (OK).

[0038] Here, the results are shown when resin B and resin C were included in the same blending ratio. When resin B and resin C were present at 10% or less (Example 1-2), the refractive index was 1.62 or more and the heat resistance was OK. On the other hand, when resin B and resin C were 17%, the refractive index was 1.61, and the increase was insufficient (Comparative Example 1). Furthermore, when resin B and resin C were 3%, the heat resistance was NG (Comparative Example 2). In the above Example 1-2, the area ratio Io / Ie was in the range of 2 or more and 5 or less. In the case of Comparative Example 1, the area ratio Io / Ie was less than 2, and in the case of Comparative Example 2, the area ratio Io / Ie exceeded 5.

[0039] FIG. 5 shows the results of measuring the breaking stress in Example 1 of FIG. 4 above and Comparative Example 3, which has the same compounding ratio of resin A as Example 1, but does not contain resin B and the remainder is entirely resin C. The test specimens to be measured were prepared by pouring the photocurable compositions under each condition into a JIS K 6215 No. 8 dumbbell mold, curing them by irradiating them with UV light, and then removing them from the mold. A general-purpose load testing machine, HIT, manufactured by Japan Measurement Systems Co., Ltd., was used for the measurements. A load was applied to the test specimen at a tensile rate of 10 mm / min, and the fracture stress was calculated by dividing the displacement at the time of fracture by the initial length of the test specimen.

[0040] A breaking stress of 14.4 MPa was obtained in Example 1, which contained Resin B. Therefore, it can be said that this cured product has a breaking stress sufficient to withstand thermal deformation, further demonstrating that it has sufficient heat resistance.

[0041] On the other hand, in Comparative Example 3, which did not contain Resin B, the breaking stress was 31.1 MPa, which was significantly improved compared to the case where Resin B was included, but it failed the heat resistance test. In other words, Comparative Example 3 lacks the flexibility obtained by blending Resin B, and even though the thermal stability and breaking stress of the cured product were sufficient, it was brittle to distortion, etc.

[0042] As described above, the cured product (such as microlens array 11) of the photocurable composition of the present disclosure contains metal oxide nanoparticles, an acrylate resin having a fluorene skeleton (resin B), and an acrylate resin having tetrahydrofuran and ethylene skeletons (resin C). In the absorbance distribution (infrared spectrum distribution) obtained for each wavenumber by infrared spectroscopy, the absorbance distribution is in the range of 1075 to 1130 cm. -1 The wave number for the area Ie of the stretching vibration peak of ether (or COC) that appears in the range of 3100 to 3700 cm -1 The ratio Io / Ie of the area Io associated with the peak of the O-H bond corresponding to the metal oxide nanoparticles appearing in this range is 2 or more and 5 or less. By blending metal oxide nanoparticles corresponding to the O-H bond in this range with Resin B corresponding to the C-O bond, both the refractive index increase effect of the metal oxide nanoparticles and the flexibility increase effect of the ether (or C-O-C) bond can be achieved. Therefore, it is possible to obtain a cured product of the photocurable composition that has a refractive index higher than that of an acrylate resin having a fluorene skeleton, which is highly stable against high heat, and also has heat resistance.

[0043] Furthermore, the cured product of the photocurable composition preferably has a breaking stress of 10 MPa or more. This makes the cured product less likely to break even when tension or distortion occurs due to thermal expansion / contraction, etc. Therefore, the heat resistance of this cured product is more reliably improved.

[0044] The optical component 10 of this embodiment includes a microlens array 11 made of the cured product of the photocurable composition, and a glass substrate 12 to which the microlens array 11 is bonded. The high refractive index of the optical component 10 allows the light to be dispersed and focused over a wider angle. Furthermore, damage caused by distortion due to differences in the thermal expansion coefficients of the lenses and the substrate 12 can be suppressed.

[0045] Furthermore, the light-emitting device 1 of the present disclosure includes the above-described optical component 10. Such a light-emitting device 1 can widely diffuse and radiate emitted light, thereby enabling the light-emitting device 1 to be used more reliably and widely in applications requiring wide-area illumination.

[0046] The sensor module 100 of the present disclosure includes the above-described light-emitting device 1. Such a sensor module 100 is small and can stably emit light over a wide area. Therefore, the sensor module 100 can use the light-emitting device 1 more efficiently.

[0047] The above embodiment is merely an example, and various modifications are possible. For example, in the above embodiment, the absorbance is plotted linearly against the wavenumber to calculate the area, but the axes can be changed as appropriate as long as an equivalent area is obtained. For example, the area of ​​the downward convex portion may be calculated using transmittance instead of absorbance.

[0048] Furthermore, the areas Io, Ie, Ic, etc. may be calculated from the number of pixels on a pixel image, for example.

[0049] Furthermore, although the cured product such as the microlens array 11 has been described as being positioned on the glass substrate 12, it may function independently. Alternatively, the cured product may be partially supported by some kind of member. Furthermore, the cured product may be something other than the microlens array 11 or the diffractive member 11a. The cured product may be any product that is light-transmitting and for which the refractive index of transmitted light is important.

[0050] In the above embodiment, the light-emitting device 1 has been described as having the optical component 10 that diffuses and outputs the light emitted from the light-emitting element 15, but the present invention is not limited to this. The light-emitting device 1 may have a light source separate from the light-emitting element 15 and output light from that light source.

[0051] In the above embodiment, the sensor module 100 has been described in which the light-emitting device 1 and the light-receiving device 2 are positioned on the wiring substrate 3 and the light-receiving device 2 detects reflected light of light emitted from the light-emitting device 1, but the present invention is not limited to this. The light-emitting device 1 may be used alone for other purposes.

[0052] In the above description, a UV curing agent is added in addition to resins A to C, but other components may also be included. The other components may include acrylate resins other than resins A to C. In addition, the specific materials, components, structures, amounts, and ratios shown in the above embodiments can be changed as appropriate without departing from the spirit of the present invention. The scope of the present invention includes the scope of the invention described in the claims and its equivalents. [Explanation of symbols]

[0053] 1 Light-emitting devices 2. Light receiving device 3. Wiring board 10, 10a Optical components 11 Microlens Array 11a Diffraction member 12 PCB 15 Light-emitting element 16 Concave board 21 PCB 22 Photodetector 23 Optical Components 24 Support part 100 Sensor Module

Claims

1. metal oxide nanoparticles; a first acrylate resin having a fluorene skeleton; a second acrylate resin having tetrahydrofuran and an ethylene skeleton; Including, In the absorbance distribution obtained for each wave number by infrared spectroscopy, the wave number is 1075 to 1130 cm －１ The wave number for the area Ie in the range of 3100 to 3700 cm －１ A cured product of the photocurable composition, wherein the ratio Io / Ie of the area Io in the range is 2 or more and 5 or less.

2. 2. A cured product of the photocurable composition according to claim 1, which has a breaking stress of 10 MPa or more.

3. a lens portion formed of a cured product of the photocurable composition according to claim 1 or 2; a glass substrate to which the lens portion is bonded; An optical component comprising:

4. A light emitting device comprising the optical component according to claim 3.

5. A module comprising the light emitting device according to claim 4.

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