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, a first acrylate resin having a fluorene skeleton, and a second acrylate resin having tetrahydrofuran and an ethylene skeleton. In a distribution of absorbance obtained for each wave number by infrared spectrometry, a ratio Io / Ic of an area Io in a wave number range of 3100 to 1520cm - 1 to an area Ic in a wave number range of 1500 to 3700cm - 1 is 10 or more and 100 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 indices, such as those exceeding 1.6, 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 1500 to 1520 cm -1For the area Ic in the range of 3100 to 3700 cm -1 The ratio Io / Ic of the areas Io in the range is 10 or more and 100 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 abundance ratio of specific 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] 1 is a diagram showing the measurement results of fracture strain. 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, α-allyloxymethyl acrylate, methyl ethyl ketone, and phenoxyethyl acrylate. 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 three-ring 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, the presence of many ether (or C-O-C) bonds in this acrylate resin improves the flexibility of the resin in response to intermolecular interactions. The portions of resin B other than the fluorene skeleton are not particularly limited as long as they are UV-curable. For example, an acryloyloxyethoxy group is an example of a functional group containing an ether bond and having a polymerizable functional group at its end. Specific examples of compounds having a fluorene skeleton include 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene and 9,9-bis[4-(2-(meth)acryloyloxyethoxy)phenyl]fluorene.

[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. This THF has low thermal decomposition due to its ring structure, which improves heat resistance. Furthermore, since ethylene chains allow for easy molecular movement, the inclusion of resin C improves the flexibility of the UV-cured cured product. However, resin C has a 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 refractive index of approximately 1.62 or higher is considered to be high. 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 absorption of infrared light irradiated onto an object in a wavenumber band (wavelength, frequency) corresponding to the object's components and structural moieties (e.g., functional groups) to identify the components and their amounts in the object 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, reference positions are defined as wavenumbers located on both sides of the range including the target wavenumber band for which absorbance is to be detected, where light absorption is expected to be low. A line connecting the absorbance points at each reference position is defined as reference line L1, and the area occupied by the reference line L1 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 -1are assumed to be the minimum points (reference positions) of absorption. These reference positions may be fixed in advance. In other words, even if there is a slight deviation in the position where the minimum value is obtained in actual measurement, this deviation is not taken into consideration. In the infrared spectral distribution (horizontal axis wave number and vertical axis absorbance are both displayed linearly), the absorbance of these two points is connected, and the absorbance on this line and the above 3100-3700 cm -1 The 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, which has a fluorene skeleton, exhibits a C–C vibration of 1500–1520 cm due to the aromatic ring-derived C–C vibration. -1 Absorption is observed at 1790 cm on both sides of this wavenumber band. -1 and 850cm -1 is the reference position where the minimum absorption is expected. -1 and 1790 cm -1 The line connecting the absorbances of 1500-1520cm is the reference line L2. -1 The absorbance value at the same wavenumber on the reference line L2 is subtracted as an offset value from the absorbance in the range, and the resulting area Ic is taken as the absorbance due to the C—C vibration derived from the aromatic ring.

[0018] Furthermore, depending on the stretching vibration of the ether (or COC) in Resin B, the -1 This wavenumber band is the same as the above-mentioned reference band of 850-1790 cm -1 Therefore, the range is 850-1790 cm -1 Between 1127-1200 cm on the reference line L2 -1 The absorbance of each of these is subtracted from the measured value, and the area Ie of the range is taken as 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 aromatic ring-derived C-C bonds and ether (or C-O-C) bonds than the absorbance of resin A in the same wavenumber range. This indicates that resin B contains the aromatic ring-derived C-C bonds and ether (or C-O-C) bonds. The ratio of these C-C bonds and C-O bonds may vary depending on the type of acrylate resin, the composition ratio of the components (monomers), etc.

[0019] 2(a) is a graph showing the area ratio (Io / Ic), which is the ratio of the area Io of the wavenumber band associated with OH bonds to the area Ic of the wavenumber band associated with C-C bonds derived from aromatic rings, versus the blending ratio (B / A) of resin A to resin B. Also, FIG. 2(b) is a graph showing the area ratio (Io / Ie), which is the ratio of the area Io of the wavenumber band associated with OH bonds to the area Ie of the wavenumber band associated with ether (or C-O-C) bonds, versus the blending ratio (B / A) of resin A to resin B.

[0020] It is clearly shown that there is a positive correlation between the area ratio (Io / Ic) and the amount of fluorene skeletons, and the area ratio (Io / Ie) corresponds to the relationship between the amount of metal oxide nanoparticles and the amount of ether (or COC) bonds.

[0021] The ratio of metal oxide nanoparticles to resin A and the proportion of fluorene skeletons in the fluorene skeleton-containing acrylate resin of resin B 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, while Figure 2 also shows linear regression lines for each, it cannot be concluded from the graph alone that there is a linear correlation.

[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 increases from 1.58 for Resin B alone to 1.62 or more due to the incorporation of metal oxide nanoparticles. The refractive index increases as the incorporation ratio of metal oxide nanoparticles increases. To obtain a refractive index of 1.62 or more, the area ratio Io / Ic of the combination of metal oxide nanoparticles (OH bonds) and fluorene skeletons (C-C bonds derived from aromatic rings) using the above area ratio needs to be 10.0 or more.

[0024] On the other hand, if the blending ratio of metal oxide nanoparticles is too high, the heat resistance effect of the acrylate resin having a fluorene skeleton becomes insufficient. Considering heating (reflow, etc.) during the preparation of a desired cured product from the photocurable composition, the area ratio Io / Ic is preferably 100 or less.

[0025] Furthermore, it is preferable that resin B has an ether (or COC) bond in addition to the fluorene skeleton. This CO bond facilitates intermolecular interactions, thereby improving the flexibility of the resin. Although the fluorene skeleton has high thermal stability as described above, it is brittle when stretching, bending, or the like occurs due to thermal expansion or the like. The flexibility provided by the inclusion of ether (or COC) bonds improves durability against physical deformation. The required amount of ether (or COC) bonds depends on the degree of thermal expansion / contraction during production and use of the cured product, as well as the difference in the thermal expansion coefficient between the cured product and the member to which it is bonded (such as substrate 12, described below). Here, for example, it is preferable that the above area ratio (I0 / Ie) is 1 or more and 5 or less.

[0026] In addition, the addition of resin C improves heat resistance and flexibility. As described above, because resin C has a low refractive index, it is not expected that resin C will be blended in a proportion large enough to replace heat-resistant resin B. The blending proportion of resin C is preferably 5% by mass or more and 10% by mass or less, based on 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 (fracture) even when subjected to large stresses (such as tension or shear). For example, by ensuring that the breaking strain of the cured product is 3.0% or more, the occurrence of breakage due to strain can be effectively suppressed.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The optical component 10 covers the open surface of the concave substrate 16. The optical component 10 will be described later.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] [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.

[0038] 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. (registered trademark) may be used as the spectroscopic ellipsometer.

[0039] 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).

[0040] When resin C is contained at 5-6%, the higher the blending ratio of resin A, the closer the refractive index to 1.73 of resin A (Comparative Example 1, Examples 1-4, Comparative Example 2). When the area ratio Io / Ic is 9.1 as in Comparative Example 1, the refractive index is 1.61, and when the area ratio Io / Ic is 11.7 as in Example 1, the refractive index is 1.62. As mentioned above, a refractive index of 1.62 or higher is considered to be high (Examples 1-4, Comparative Example 2). Therefore, the area ratio Io / Ic needs to be 10 or higher.

[0041] On the other hand, if the amount of resin B is reduced, the heat resistance decreases. As in Example 4, if the area ratio Io / Ic is in the double-digit range (94.5), the required heat resistance is obtained. However, if the amount of resin B is further reduced, as in Comparative Example 2, the required heat resistance cannot be obtained.

[0042] Furthermore, when resin C is not included (the blending ratio is 0), as in Comparative Example 3, the refractive index is higher than when resin C is blended at the same blending ratio of resin A, but the heat resistance is also reduced. In Comparative Example 3, sufficient heat resistance is not obtained despite the blending ratio of resin A being the same as in Example 3. Therefore, the area ratio Io / Ic that can achieve both a high refractive index and heat resistance is 10 or more and 100 or less. Furthermore, in these Examples 1 to 4, the condition that the area ratio Io / Ie is 1 or more and 5 or less is also satisfied.

[0043] Figure 5 shows the results of measuring the fracture strain under some of the conditions shown in Figure 4 above. 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 breaking strain was determined by dividing the load at break by the initial cross-sectional area of ​​the test specimen.

[0044] In Comparative Example 3, which does not contain Resin C, the refractive index is high, but the breaking strain is a low value of 2.6%. As in Example 2, by blending a small amount of Resin C, here 6%, the breaking strain becomes 3.0% or more without significantly increasing the blending ratio of Resin B. Furthermore, by increasing the ratio of Resin B to Resin A while maintaining Resin C (Example 1), the breaking strain is significantly increased, and the required refractive index is obtained while improving heat resistance and flexibility.

[0045] As described above, the cured product (such as microlens array 11) of the photocurable composition of the present disclosure contains metal oxide nanoparticles, a first acrylate resin having a fluorene skeleton, and a second acrylate resin having tetrahydrofuran and ethylene skeletons. In the absorbance distribution obtained for each wave number by infrared spectroscopy, the wave number corresponding to the OH group characteristic of metal oxide nanoparticles is 1500 to 1520 cm. -1 For the area Ic in the range of 3100 to 3700 cm, the wavenumber related to the C-C bond of the aromatic ring, which is characteristic of the fluorene skeleton, is -1 The area ratio (Iо / Ic), which is the ratio of the area Iо in the range, is said to be between 10 and 100. In this way, the blending ratio of the metal oxide nanoparticles (Resin A) and the fluorene-based acrylate resin (Resin B) is appropriately determined, and the inclusion of THF and ethylene groups allows for a high refractive index of 1.62 or higher and suitable heat resistance, allowing the cured product to maintain the required properties even in high-temperature environments during production and use.

[0046] In addition, the cured product has a wave number of 1127 to 1200 cm in the absorbance distribution of the infrared spectrum. -1 The area ratio (Io / Ie), which is the ratio of the area Io to the area Ie in the range, is more preferably from 1 to 5. This allows for a more flexible cured product based on the ether (or COC) bond, and the cured product can be used more stably.

[0047] Furthermore, the cured product of the photocurable composition preferably has a breaking strain of 3.0% or more. This can prevent breakage due to strain caused by shrinkage when high heat is applied. This also makes it possible to more reliably avoid breakage due to strain caused not only by temperature changes but also by impacts during use.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] Furthermore, the areas Io, Ic, and Ie may be calculated, for example, from the number of pixels on a pixel image.

[0053] 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. Any cured product may be used as long as it is light-transmitting and the refractive index of transmitted light is important.

[0054] 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 another light source independent of the light-emitting element 15 and output light from that light source.

[0055] 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.

[0056] 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]

[0057] 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 1500 to 1520 cm －１ For the area Ic in the range of 3100 to 3700 cm －１ A cured product of the photocurable composition, wherein the ratio Io / Ic of the areas Io in the range is 10 or more and 100 or less.

2. In the absorbance distribution, the wave number is 1127 to 1200 cm －１ 2. The cured product of the photocurable composition according to claim 1, wherein the ratio Io / Ie of the area Io to the area Ie in the range is 1 or more and 5 or less.

3. 2. A cured product of the photocurable composition according to claim 1, which has a breaking strain of 3.0% or more.

4. a lens portion formed of a cured product of the photocurable composition according to any one of claims 1 to 3; a glass substrate to which the lens portion is bonded; An optical component comprising:

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

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

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