Curable composition, polysiloxane film, optical member, and ultraviolet light-emitting device

Abstract

A curable composition containing a metal element and at least one of a polysilanol that contains an alkoxy group, a hydrogen silsesquioxane that contains an alkoxy group, and a hydrogen polysiloxane that contains an alkoxy group.

Description

Curable composition, polysiloxane film, optical member, and ultraviolet light-emitting device

[0001] The present disclosure relates to a curable composition, a polysiloxane film, an optical component, and an ultraviolet light-emitting device.

[0002] As a light-emitting device that emits ultraviolet light, a light-emitting device including a light-emitting element, a lens, and an adhesive layer that bonds the light-emitting element and the lens has been developed. From the viewpoint of improving output such as light extraction efficiency, an adhesive layer that has sufficient adhesiveness, can transmit ultraviolet light, and is light-resistant to ultraviolet light has been studied.

[0003] Light-emitting devices have been proposed that aim to suppress bias in the distribution of light radiation intensity and improve yield by keeping the positional misalignment between the light-emitting element and the lens within an acceptable range when bonding the light-emitting element and the lens. Specific examples of the organic adhesive used to form the bonding film between the light-emitting element and the lens include organopolysiloxane and an adhesive containing a combination of organopolysiloxane and a metal element (see, for example, Patent Document 1).

[0004] International Publication No. 2023 / 167024

[0005] An object of one embodiment of the present disclosure is to provide a curable composition capable of forming a polysiloxane film that is reduced in coloration and has excellent light resistance and light extraction efficiency.

[0006] A curable composition according to one embodiment of the present disclosure is a curable composition containing at least one of polysilanol having an alkoxy group, hydrogen silsesquioxane having an alkoxy group, and hydrogen polysiloxane having an alkoxy group, and a metal element.

[0007] According to one embodiment of the present disclosure, it is possible to provide a curable composition capable of forming a polysiloxane film that is reduced in coloration and has excellent light resistance and light extraction efficiency.

[0008] Fig. 1 is a cross-sectional view showing an optical member according to one embodiment. Fig. 2 is a cross-sectional view showing an ultraviolet light emitting device according to one embodiment. Fig. 3 is a cross-sectional view showing an ultraviolet light emitting device according to another embodiment. Fig. 4 is a cross-sectional view showing an ultraviolet light emitting device according to another embodiment. Fig. 5 is a graph showing the infrared absorption spectra of the polysiloxane films in Examples 14 and 15.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or similar components are denoted by the same reference numerals, and their description may be omitted. In the specification, the symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. The range of values ​​includes the range rounded up or down.

[0010] (Curable Composition) The curable composition of the present embodiment contains at least one curable siloxane selected from polysilanol having an alkoxy group, hydrogen silsesquioxane having an alkoxy group, and hydrogen polysiloxane having an alkoxy group, and a metal element, and further contains other components as necessary.

[0011] Silicone resins are transparent and have the advantage of being excellent in light transmittance and ultraviolet transmittance. However, the shorter the peak wavelength of ultraviolet light emitted by the light-emitting element, the more likely conventional organic materials (e.g., silicone resins having organic groups) forming the adhesive layer are to be discolored and deteriorate. Furthermore, the stronger the radiant flux of the light-emitting element is to improve output, the more likely the adhesive layer is to deteriorate, leading to the problem of cracks occurring in the adhesive layer. When the adhesive layer becomes discolored and deteriorates, the light transmittance decreases, and the light extraction efficiency decreases.

[0012] In the conventional adhesive described in Patent Document 1, which uses an organopolysiloxane in combination with a metal element, the organopolysiloxane has Si-R groups (Si-alkyl groups), and when the Si-R groups are irradiated with ultraviolet light, they decompose, generating colored components. It is hypothesized that the use of a metal element in combination promotes crosslinking of the colored components and suppresses the increase in the colored components. However, this mechanism cannot suppress the decomposition caused by ultraviolet light or the like, and may still not be able to sufficiently reduce degradation such as coloration and cracking.

[0013] The present inventors have conducted extensive research to solve the problems of the prior art and the above-mentioned problems, and as a result, have discovered Si—CH ３ The present inventors have found that a curable composition containing at least one of polysilanol having alkoxy groups, hydrogen silsesquioxane having alkoxy groups, and hydrogen polysiloxane having alkoxy groups, in combination with a metal element, which uses a specific curable siloxane that is substantially free of groups, can form a polysiloxane film that is reduced in coloration and has excellent light resistance and light extraction efficiency, leading to the completion of the present invention.

[0014] The curable siloxane is Si—CH ３ Since it is substantially free of Si—CH groups, it is ３ Discoloration caused by Si-OR groups does not occur substantially. In addition, although the mechanism by which discoloration is reduced is unclear, it is believed that while thermal condensation curing causes curing by elimination of Si-OR groups (Si-alkoxy groups), the use of a metal element in combination with the composition promotes the thermal condensation curing reaction and reduces the generation of unreacted Si-OR groups. Therefore, although coloring components are generated when unreacted Si-OR groups are decomposed by ultraviolet light, it is believed that discoloration can be reduced by reducing the number of unreacted Si-OR groups.

[0015] Furthermore, conventional Si-CH ３In curable silicones having a group, low molecular weight siloxanes generated from the material, particularly low molecular weight polydimethylsiloxane (PDMS) which is a bifunctional Si, can be problematic. Low molecular weight polydimethylsiloxanes are highly volatile and can adhere to and react with other components, which can cause contact failure when used in electrical circuits. On the other hand, the curable siloxanes are Si-CH ３ Since it is substantially free of groups and is a polyfunctional silicon having three or more functional groups, it has the advantage of being less likely to volatilize and reducing contact failures.

[0016] <Curable Siloxane> The curable siloxane is at least one of polysilanol having an alkoxy group, hydrogen silsesquioxane having an alkoxy group, and hydrogen polysiloxane having an alkoxy group. The curable siloxane may be linear, random, cage, or ladder-shaped. These curable siloxanes may be used alone or in combination of two or more.

[0017] -Polysilanol Having an Alkoxy Group- The polysilanol having an alkoxy group is preferably a compound represented by the following general formula (1): ((HO)SiO ３／２ ) ａ ((HO)Si(OR)O ２／２ ) ｂ ((HO) ２ SiO ２／２ ) ｃ ((HO)Si(OR) ２ O １／２ ) ｄ ((HO) ２ Si(OR)O １／２ ) ｅ ((HO) ３ SiO １／２ ) ｆ (1) (In the general formula (1), —OR is an alkoxy group, a, b, c, d, e, and f are each independently an integer of 0 or more, and b+d+e is an integer of 1 or more.)

[0018] Examples of the alkyl group R in the alkoxy group -OR include a methyl group, an ethyl group, an isopropyl group, an n-propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, etc. Among these, a methyl group, an ethyl group, and an isopropyl group are preferred, and a methyl group and an ethyl group are more preferred.

[0019] -Hydrogen silsesquioxane having an alkoxy group- The hydrogen silsesquioxane having an alkoxy group is preferably a compound represented by the following general formula (2): (HSiO ３／２ ) ｇ (HSi(OR)O ２／２ ) ｈ (HSi(OH)O ２／２ ) ｉ (HSi(OR) ２ O １／２ ) ｊ (HSi(OR)(OH)O １／２ ) ｋ (HSi(OH) ２ O １／２ ) ｌ (2) (In the general formula (2), -OR is an alkoxy group, g, h, i, j, k, and l each independently represent an integer of 0 or more, and h+j+k is an integer of 1 or more.)

[0020] -Hydrogen polysiloxane having an alkoxy group- The hydrogen polysiloxane having an alkoxy group is preferably a compound represented by the following general formula (3): (HSiO ３／２ ) ｍ (HSi(OR)O ２／２ ) ｎ (HSi(OH)O ２／２ ) ｏ (HSi(OR) ２ O １／２ ) ｐ (HSi(OR)(OH)O １／２ ) ｑ (HSi(OH) ２ O １／２ ) ｒ (Si(OR １ ) ｓ O （４－ｓ）／２ ) ｔ(3) (In the general formula (3), —OR is an alkoxy group, and —OR １ represents an alkoxy group or a hydroxy group, m, n, o, p, q, and r each independently represent an integer of 0 or greater, n+p+q represents an integer of 1 or greater, s represents an integer of 0 or greater and 3 or less, and t represents an integer of 1 or greater.

[0021] The ratio of the number of Si atoms bonded to alkoxy groups to the total number of Si atoms in the curable siloxane: (number of Si atoms bonded to alkoxy groups) / (total number of Si atoms)×100 [%] is preferably more than 0% and not more than 90%, more preferably 1% to 80%, and even more preferably 5% to 70%. This ratio is a value that can vary depending on the type of curable siloxane. Specifically, in the case of a curable siloxane represented by general formula (1), (b+d+e) / (a+b+c+d+e+f) should be more than 0 and not more than 0.9.

[0022] Methods for measuring the ratio of the number of Si atoms bonded to alkoxy groups to the total number of Si atoms in the curable siloxane include, for example, secondary ion mass spectrometry (SIMS) and nuclear magnetic resonance (NMR) measurement methods.

[0023] -Metal Element- Suitable examples of the metal element include 3d transition metals, 4d transition metals, lanthanoid metals, bismuth, aluminum, tin, and zinc. This suppresses coloration in the polysiloxane film obtained by curing the curable composition during heat treatment in an air atmosphere (e.g., 200°C to 300°C). The reason (mechanism) for achieving this effect is unclear, but it is thought that the condensation curing reaction of Si-OR groups (Si-alkoxy groups) in the curable siloxane is promoted in the presence of the metal element, thereby reducing the number of unreacted Si-OR groups and preventing them from being decomposed by ultraviolet light to produce colored components.

[0024] Among the metal elements, zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel are preferred, with zirconium, zinc, iron, and cobalt being more preferred, in terms of further reducing coloration. These may be used alone or in combination of two or more. The form of the metal element may be any of metal, ion, compound, and complex.

[0025] From the viewpoint of reducing discoloration, the content of the metal element is preferably 0.0001 mass % or more and 0.5 mass % or less, more preferably 0.0005 mass % or more and 0.3 mass % or less, and even more preferably 0.001 mass % or more and 0.2 mass % or less, relative to the total amount of solids in the curable composition.

[0026] The form of the curable composition may be a liquid or sol, or may be a film or sheet, but is preferably a film from the viewpoint of handleability. It can be used in a method in which a film-like curable composition (hereinafter sometimes referred to as a curable composition film) formed on a release substrate is transferred to a light-emitting element or an optical glass member such as a lens, and if necessary, after transfer, it is deformed according to the member and then cured.

[0027] In the case of a film-like composition, the average thickness of the film-like curable composition is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 μm or less, more preferably 3 μm or less in terms of reducing coloration, and is preferably 0.3 μm or more, more preferably 0.5 μm or more in terms of adhesiveness.

[0028] The method for forming the film-like curable composition is not particularly limited, and any known method can be appropriately selected depending on the purpose. For example, a method of applying a liquid or sol-like curable composition to a release substrate such as a release film and drying the composition can be used.

[0029] Examples of methods for applying a liquid or sol curable composition include spin coating, spray coating, bar coating, gravure coating, screen printing, inkjet coating, etc. Methods for drying a liquid or sol curable composition may be any methods capable of removing a solvent, if any, and examples include a method of drying at 100°C to 140°C for 1 minute to 30 minutes.

[0030] (Polysiloxane Film) The polysiloxane film of the present embodiment contains polysiloxane and a metal element, and may further contain other components as necessary.

[0031] In the infrared absorption spectrum, －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１ The maximum absorbance at 1000 nm is 0.1 or less.

[0032] The polysiloxane film can be suitably produced by curing the curable composition of this embodiment.

[0033] <Polysiloxane> The polysiloxane is a polymer component having an Si—O—Si bond, and in the infrared absorption spectrum of a polysiloxane film, a 1000 cm wavelength band derived from Si—O—Si stretching is observed. －１ More than 1200cm －１ This can be confirmed by detecting the absorbance as follows: The infrared absorption spectrum of the polysiloxane film can be measured by the attenuated total reflection method (ATR method) of infrared spectroscopy (FT-IR).

[0034] The polysiloxane corresponds to a component obtained by curing the curable siloxane in the curable composition, and is Si—CH ３ Since the compound has substantially no Si—C group, the peak at 1250 cm corresponds to the Si—C group. －１ More than 1300cm －１ Below cm －１ Specifically, the absorbance at 1000 cm in the infrared absorption spectrum is low. －１ More than 1200cm－１ When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１ The maximum absorbance at 1000 nm is 0.1 or less.

[0035] The polysiloxane is Si—CH ３ Since there are few unreacted Si-OR groups and unreacted Si-OR groups, the C-H group-corresponding 2800 cm －１ More than 3000cm －１ Specifically, the absorbance is low at 1000 cm or less in the infrared absorption spectrum. －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 2800 cm －１ More than 3000cm －１ The maximum absorbance value below is preferably 0.04 or less, more preferably 0.03 or less, and even more preferably 0.025 or less.

[0036] <Metal Element> The metal element can be appropriately selected from those described in the curable composition of this embodiment.

[0037] Among the metal elements, zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel are preferred, with zirconium, zinc, iron, and cobalt being more preferred, in terms of further reducing coloration. These may be used alone or in combination of two or more. The form of the metal element may be any of metal, ion, compound, and complex.

[0038] In terms of reducing coloration, the content of the metal element is preferably 0.0001 mass % or more and 0.5 mass % or less, more preferably 0.0005 mass % or more and 0.3 mass % or less, and even more preferably 0.001 mass % or more and 0.2 mass % or less, relative to the total amount of the polysiloxane film.

[0039] The method for measuring metal elements in the polysiloxane film is not particularly limited, and known methods can be used, such as inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectroscopy (ICP-MS), etc. Examples of devices that can be used in the above method include an inductively coupled plasma atomic emission spectroscopy analyzer PS3520UVDDII (Hitachi High-Tech Corporation) and an inductively coupled plasma (triple quadrupole) mass spectrometer Agilent 8800 (Agilent Technologies).

[0040] The average thickness of the polysiloxane film is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 μm or less, more preferably 3 μm or less from the viewpoint of reducing coloration, and is preferably 0.3 μm or more, more preferably 0.5 μm or more from the viewpoint of adhesiveness.

[0041] (Optical Member) The optical member of this embodiment includes a light-transmitting member and the curable composition of this embodiment or the polysiloxane film described above, and may further include other members as necessary.

[0042] <Light-Transmitting Member> The light-transmitting member is not particularly limited as long as it has a light incident surface and a light exit surface and is a light-transmitting member, and can be appropriately selected depending on the purpose, and examples thereof include lenses such as spherical lenses and aspherical lenses; light-transmitting substrates; etc. Examples of materials for the light-transmitting member include glass, sapphire, quartz, spinel, etc.

[0043] The curable composition and the polysiloxane film may be appropriately selected from the items described for the curable composition and the polysiloxane film of this embodiment. The curable composition or the polysiloxane film may be provided on either the light incident surface or the light exit surface of the light-transmitting member, but is preferably provided on the light incident surface of the light-transmitting member in order to reduce coloration and deterioration due to ultraviolet rays.

[0044] An optical member 10 according to one embodiment will be described with reference to Fig. 1. The optical member 10 includes a lens 3 and a curable composition film 6 provided on an opposing surface 31, which is the light incident surface of the lens 3. The lens 3 is an example of a light-transmitting member. The lens 3 has an opposing surface 31 that faces the light emission surface 21 of the light-emitting element 2, and a convex curved surface 32 facing away from the opposing surface 31.

[0045] A polysiloxane film can be formed by curing the curable composition film 6. By bonding the optical element 10 to the light-emitting surface of the light-emitting element via the curable composition film 6, for example, an ultraviolet light-emitting device 100 shown in FIG.

[0046] (Ultraviolet Light Emitting Device) The ultraviolet light emitting device of this embodiment includes a light emitting element that emits ultraviolet light and the polysiloxane film of this embodiment described above, and preferably further includes a light-transmitting member, and may further include other members as necessary.

[0047] The polysiloxane film is preferably provided on the light incident surface of the ultraviolet light emitting device, since it can reduce coloration and deterioration caused by ultraviolet light.

[0048] If the ultraviolet light emitting device further includes a light-transmitting member, the polysiloxane film is preferably provided between the light emission surface of the light emitting element and the light incidence surface of the optical glass member, since this can reduce coloration and deterioration due to ultraviolet light.

[0049] An ultraviolet light-emitting device according to one embodiment will be described with reference to Fig. 2. The ultraviolet light-emitting device 100 shown in Fig. 2 includes a light-emitting element 2, a lens 3, and a polysiloxane film 5 that bonds the light-emitting element 2 and the lens 3. The lens 3 is an example of a light-transmitting member. The lens 3 has an opposing surface 31 that faces the light-emitting surface 21 of the light-emitting element 2, and a convex curved surface 32 that faces away from the opposing surface 31.

[0050] An ultraviolet light-emitting device according to another embodiment will be described with reference to Figures 3 and 4. The ultraviolet light-emitting device 200 shown in Figure 3 includes a light-emitting element 2 on a mounting substrate 7, a rectangular frame 8 surrounding the periphery of the light-emitting element 2, a light-transmitting substrate 4, a lens 3, and a polysiloxane film 5 bonding the light-transmitting substrate 4 and the lens 3 together. The lens 3 and the light-transmitting substrate 4 are examples of a light-transmitting member. The ultraviolet light-emitting device 300 shown in Figure 4 includes a light-emitting element 2 on a mounting substrate 7, a rectangular frame 8 surrounding the periphery of the light-emitting element 2, the light-transmitting substrate 4, and a polysiloxane film 5 bonding the light-transmitting substrate 4 and the frame 8 together. The light-transmitting substrate 4 is an example of a light-transmitting member.

[0051] <Light-Emitting Element> The light-emitting element 2 is not particularly limited as long as it is an element that emits ultraviolet light and can be appropriately selected depending on the purpose, but an element that emits light with ultraviolet light as its emission peak wavelength is preferred. A portion of the light-emitting element 2, the polysiloxane film 5, and the lens 3 transmit light in this order. The ultraviolet light preferably has a wavelength of 200 nm to 320 nm, more preferably UVC (e.g., 200 nm to 280 nm) or a wavelength of 240 nm to 290 nm, and may be, for example, a wavelength of 265 nm or 280 nm. The "emission peak wavelength" refers to the wavelength with the highest output value in the spectral distribution of the emitted light. The radiant flux of the light-emitting element 2 is, for example, greater than 20 mW, preferably 35 mW or more, and more preferably 40 mW or more. From the perspective of the heat dissipation properties of the light-emitting element 2, the radiant flux of the light-emitting element 2 may be 1 W or less. The radiant flux is the radiant energy emitted per unit time. The radiant flux is measured in accordance with CIE 127:2007.

[0052] The light-emitting element 2 has, for example, a substrate 22 and a semiconductor layer 23. The light-emitting element 2 has, for example, a flip-chip structure. When the light-emitting element 2 has a flip-chip structure, light generated in the semiconductor layer 23 is emitted through the substrate 22. The substrate 22 is a transparent substrate that transmits light. The surface of the substrate 22 facing the lens 3 is the light-emitting surface 21 of the light-emitting element 2.

[0053] The substrate 22 is made of, for example, a sapphire substrate or an aluminum nitride substrate. An aluminum nitride substrate is a substrate made of a single crystal of aluminum nitride. A sapphire substrate or an aluminum nitride substrate is a transparent substrate that transmits ultraviolet light. The thickness t of the substrate 22 is, for example, 0.05 mm to 2 mm.

[0054] The semiconductor layer 23 is provided on the opposite side of the substrate 22 from the lens 3. The semiconductor layer 23 emits light when a voltage is applied to it. An electrode for applying a voltage to the semiconductor layer 23 is formed on the opposite side of the substrate 22 from the semiconductor layer 23 so as not to block the light traveling from the semiconductor layer 23 to the substrate 22, although this is not shown. This makes it possible to prevent a decrease in light extraction efficiency.

[0055] The light-emitting element 2 may be bonded to a mounting substrate via solder bumps. The mounting substrate is, for example, a ceramic substrate made of sintered aluminum nitride, sintered aluminum oxide, or LTCC (Low Temperature Co-fired Ceramics) on which electrodes are formed.

[0056] The surface roughness Ra of the light emitting surface 21 of the light emitting element 2 is, for example, 0.01 nm to 5 nm. When a fine uneven structure is formed on the light emitting surface 21 to improve the extraction efficiency of ultraviolet light, the surface roughness Ra of the light emitting surface 21 is 5 nm to 50 nm. The surface roughness Ra of the opposing surface 31 of the lens 3 is, for example, 0.01 nm to 5 nm. The surface roughness Ra is the arithmetic mean roughness as defined in JIS B0601:2001.

[0057] <Optical Glass Member> The lens 3 suppresses total reflection of light and improves light extraction efficiency. The lens 3 has an opposing surface 31 facing the light emission surface 21 of the light-emitting element 2, and a convex curved surface 32 facing away from the opposing surface 31. The ultraviolet light emitted by the light-emitting element 2 is incident on the opposing surface 31 and exits from the convex curved surface 32. The convex curved surface 32 is preferably a dome-shaped curved surface whose center protrudes further than the periphery.

[0058] The lens 3 may be a spherical lens or an aspherical lens. Although not shown, the lens 3 may have a flange that protrudes radially outward from the periphery of the convex curved surface 32.

[0059] Although not shown, the convex curved surface 32 of the lens 3 may have irregularities that prevent reflection of light generated by the light emitting element 2. The irregularities of the convex curved surface 32 have, for example, a moth-eye structure, and prevent light traveling from the inside of the lens 3 to the outside from being reflected back into the lens 3, thereby improving the light extraction efficiency.

[0060] Although not shown, the ultraviolet light emitting device 100 may be provided with an anti-reflection coating on the convex curved surface 32 of the lens 3. The anti-reflection coating prevents light traveling from the inside of the lens 3 to the outside from being reflected back into the lens 3, thereby improving the light extraction efficiency. A general anti-reflection coating is used.

[0061] Although not shown, the convex curved surface 32 of the lens 3 may have irregularities that scatter the ultraviolet light generated by the light emitting element 2. The irregularities of the convex curved surface 32 scatter the ultraviolet light emitted from the convex curved surface 32, thereby emitting the ultraviolet light over a wider range.

[0062] The material of the lens 3 is, for example, oxide glass. Oxide glass can be processed by various processing methods such as thermoforming or grinding and polishing, and a processing method suitable for the shape of the lens 3 can be selected. Examples of oxide glass include soda-lime glass, alkali-free glass, chemically strengthened glass, and lanthanum borate glass. In order to reduce the loss of ultraviolet light caused by the lens 3, a material with low ultraviolet light absorption is suitable as the material of the lens 3, and the material of the lens 3 may be quartz, quartz glass, or sapphire.

[0063] <Polysiloxane film> The polysiloxane film 5 can be appropriately selected from the items described above for the polysiloxane film of this embodiment. The polysiloxane film 5 can be suitably produced by curing the curable composition of this embodiment, and functions as an adhesive layer.

[0064] The polysiloxane film 5 is bonded to the light-emitting surface 21 of the light-emitting element 2 and the opposing surface 31 of the lens 3 so that they face each other. It is preferable that the light-emitting surface 21 of the light-emitting element 2 and the opposing surface 31 of the lens 3 each have a flat surface at least in the area where they overlap. The opposing surface 31 of the lens 3 is larger than the light-emitting surface 21 of the light-emitting element 2, and may have a curved surface in the area extending beyond the light-emitting surface 21.

[0065] The interface between the polysiloxane film 5 and the light-emitting element 2 is called the first interface. In this embodiment, the first interface is the entire light-emitting surface 21, but it may be a part of the light-emitting surface 21. In addition, the interface between the polysiloxane film 5 and the lens 3 is called the second interface. In this embodiment, the second interface is the entire opposing surface 31, but it may be a part of the opposing surface 31.

[0066] The thickness of the polysiloxane film 5 can be determined as the thickness of the adhesive layer by scratching any five points on the bonding portion of the polysiloxane film 5 remaining on the bottom surface of the light emitting element 2 and / or lens 3 after removing the glass lens from the light emitting element, and measuring the step portion of the scratches using a non-contact surface texture measuring device (for example, PF-60, manufactured by Mitaka Kohki Co., Ltd.). The average thickness of the polysiloxane film 5 can be determined by measuring the thickness of the adhesive layer at any five or more points and calculating the average value.

[0067] The indentation modulus of the polysiloxane film 5 is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 GPa or more and 10 GPa or less. The indentation modulus can be measured using an ultra-microindentation hardness tester (for example, ENT-NEXUS, manufactured by Elionix Co., Ltd.) by setting the load so that the indentation depth is one-tenth or less of the thickness of the adhesive layer.

[0068] The experimental data will be explained below. Examples 1 to 12 and 14 are working examples, and Examples 13 and 15 to 16 are comparative examples.

[0069] Example 1 Preparation of Curable Composition 10 g of hydrogen silsesquioxane (manufactured by Max Electronic Materials Co., Ltd., solids concentration 30 mass %, solvent: methyl isobutyl ketone) and 0.2 mg of zinc bis(2-ethylhexanoate) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Zn content 15 mass %) as a metal compound were mixed, and the resulting mixture was filtered using a filter with a pore size of 0.45 μm, to prepare the curable composition of Example 1.

[0070] <Preparation of polysiloxane film and optical component> The curable composition was applied to a 0.5 mm thick quartz substrate and dried at 120 ° C for 5 minutes to form a curable composition film with an average thickness of 2.2 μm. Then, another 0.17 mm thick quartz substrate was bonded to the curable composition film via the curable composition film, and heated at 200 ° C for 30 minutes to cure the curable composition film, thereby forming a polysiloxane film with an average thickness of 2.0 μm. In this way, the polysiloxane film of Example 1 and a quartz laminate sample as an optical component having a polysiloxane film were prepared.

[0071] (Examples 2 to 13) Curable compositions, polysiloxane films, and quartz laminate samples of Examples 2 to 13 were prepared in the same manner as in Example 1, except that the type of metal compound and the content (mass%) of the metal element in Example 1 were changed as shown in Table 1.

[0072] <Evaluation> Each of the obtained quartz laminate samples was evaluated for the degree of coloration and the presence or absence of cracks according to the following procedures. The results are shown in Table 1.

[0073] <<Degree of Coloring>> - Ultraviolet Irradiation Test - The obtained quartz laminate sample was placed on an ultraviolet light emitting device with the 0.17 mm thick quartz substrate surface facing downward. The ultraviolet light emitting device was turned on and ultraviolet light was irradiated onto the quartz laminate sample, thereby evaluating the ultraviolet resistance of the adhesive. The ultraviolet light emitting device used had an emission wavelength of 265 nm and a radiant flux of 40 mW. The quartz laminate sample was irradiated with ultraviolet light for 100 hours.

[0074] Before and after the ultraviolet irradiation test, the illuminance was measured when the ultraviolet light emitting element was turned on with the quartz laminate sample placed on top. The illuminance was measured using a UV irradiance meter manufactured by SGlux. The illuminance ratio before and after the ultraviolet irradiation test was calculated using the following formula, and the degree of coloration of the polysiloxane film sandwiched between the quartz substrates was evaluated according to the following evaluation criteria.

[0075] Here, since coloration of the polysiloxane film results in absorption of ultraviolet light, a higher illuminance ratio indicates a lighter coloration and a curable composition and polysiloxane film with high ultraviolet resistance, and a lower illuminance ratio indicates a darker coloration and a curable composition and polysiloxane film with low ultraviolet resistance. Illuminance ratio: (illuminance when the ultraviolet light-emitting device is turned on with the quartz laminate sample after ultraviolet irradiation test placed on top) / (illuminance when the ultraviolet light-emitting device is turned on with the quartz laminate sample before ultraviolet irradiation test placed on top) x 100 (%) - Evaluation criteria - A: The illuminance ratio is 75% or more and 100% or less B: The illuminance ratio is 50% or more and less than 75% C: The illuminance ratio is 25% or more and less than 50% D: The illuminance ratio is 0% or more and less than 25%

[0076] <<Presence or Absence of Cracks>> After the ultraviolet irradiation test, the presence or absence of cracks in the polysiloxane film sandwiched between the quartz substrates was evaluated according to the following evaluation criteria. -Evaluation criteria- "None": No cracks were found in the polysiloxane film when observed under a microscope "Present": Cracks were found in the polysiloxane film when observed under a microscope

[0077]

[0078] (Example 14) <Preparation of ultraviolet light emitting device> Glass (SiO ２ :5.8mol%, B ２ O ３ :66.58mol%, La ２ O ３ :19.3mol%, Y ２ O ３The curable composition of Example 1 was applied to the lens bonding surface of a hemispherical lens consisting of 8.3 mol% ZnO and dried at 120°C for 5 minutes to form a curable composition film with an average thickness of 1.0 μm. Next, an ultraviolet light-emitting element was placed on top of the curable composition film, and the curable composition film was softened by heating on a hot plate at 180°C for 15 minutes. The curable composition film was then cured by heating at 200°C for 30 minutes to form a polysiloxane film with an average thickness of 0.8 μm, and the lens and the light-emitting element were firmly bonded to each other, thereby producing the ultraviolet light-emitting device of Example 14. The ultraviolet light-emitting element used had an emission wavelength of 265 nm and a radiant flux of 40 mW.

[0079] Example 15 An ultraviolet light emitting device of Example 15 was produced and evaluated in the same manner as in Example 14, except that zinc bis(2-ethylhexanoate) was not added. The results are shown in Table 2.

[0080] Example 16 Preparation of Curable Composition Triethoxymethylsilane (179 g), toluene (300 g), and acetic acid (5 g) were added to a 1 L flask, and the mixture was stirred at 25°C for 20 minutes. The mixture was then heated to 60°C and reacted for 12 hours. The resulting crude reaction liquid was cooled to 25°C, and then washed three times with water (300 g). Chlorotrimethylsilane (70 g) was added to the washed crude reaction liquid, and the mixture was stirred at 25°C for 20 minutes. The mixture was then heated to 50°C and reacted for 12 hours. The resulting crude reaction liquid was cooled to 25°C, and then washed three times with water (300 g). Toluene was removed from the washed crude reaction liquid under reduced pressure to form a slurry. The resulting slurry was then dried overnight in a vacuum dryer, yielding a white organopolysiloxane compound.

[0081] The obtained organopolysiloxane (30 g), toluene (56 g), isopropanol (14 g), and zinc bis(2-ethylhexanoate) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Zn content 15% by mass) (0.2 g) were mixed, and the resulting mixture was filtered using a filter with a pore size of 0.45 μm, thereby preparing the curable composition of Example 16.

[0082] <Preparation of Ultraviolet Light-Emitting Device> An ultraviolet light-emitting device of Example 16 was prepared and evaluated in the same manner as in Example 14, except that the curable composition of Example 16 was used instead of the curable composition of Example 1. The results are shown in Table 2.

[0083] <Evaluation> After 100 hours of UV irradiation testing, each of the obtained UV light-emitting devices was observed for any deterioration due to UV irradiation, such as discoloration, cracks, or peeling, in the polysiloxane film bonding the lens and light-emitting element. The presence or absence of cracks was evaluated in the same manner as in Example 1. Note that in the UV light-emitting devices of Examples 14 to 16, the polysiloxane film is in direct contact with the light-emitting element, and therefore, it is presumed that, compared to the quartz laminate samples of Examples 1 to 13, stronger UV rays are incident on the polysiloxane film, and the heat generated by the light-emitting element has a greater impact on the polysiloxane film.

[0084] <<Presence or Absence of Coloring>> After the ultraviolet irradiation test, the presence or absence of coloring of the polysiloxane film in the ultraviolet light emitting device was evaluated by observing the presence or absence of coloring under a microscope.

[0085] <<Presence or Absence of Peeling>> After the ultraviolet irradiation test, the presence or absence of peeling of the polysiloxane film in the ultraviolet light emitting device was evaluated by visually checking for peeling and by checking for the presence or absence of falling off of the lens.

[0086] <Measurement of absorbance of polysiloxane film> For the polysiloxane films in the ultraviolet light-emitting devices of Examples 14 and 15, infrared absorption spectra were obtained by attenuated total reflection (ATR) measurement in infrared spectroscopy (FT-IR), and ATR correction was performed. Figure 5 shows a graph of the infrared absorption spectra of the polysiloxane films in Examples 14 and 15.

[0087] For the polysiloxane film in the ultraviolet light-emitting device of Example 14, 1000 cm －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１The maximum absorbance at 1000 nm was calculated to be 0.1 or less (0.059). Therefore, it was confirmed that the polysiloxane in the polysiloxane film was substantially free of Si—C groups.

[0088] Also, 1000 cm －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 2800 cm －１ More than 3000cm －１ The maximum absorbance was calculated to be 0.04 or less (0.020). ３ It was confirmed that there were few unreacted Si—OR groups.

[0089] For the polysiloxane film in the ultraviolet light emitting device of Example 15, 1000 cm －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１ The maximum absorbance at 1000 cm was calculated to be 0.1 or less (0.042). －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 2800 cm －１ More than 3000cm －１ The maximum absorbance was calculated to be 0.042, which exceeded 0.04. Therefore, in the polysiloxane film of Example 16 in which no metal element was used, Si—CH ３ It was found that the polysiloxane film of Example 15 contained more Si—OR groups and unreacted Si—OR groups.

[0090]

[0091] The curable composition, polysiloxane film, optical member, and ultraviolet light-emitting device according to the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0092] The following supplementary notes are disclosed regarding the above-described embodiments. [Supplementary Note 1] A curable composition comprising at least one of a polysilanol having one or more alkoxy groups, a hydrogen silsesquioxane having one or more alkoxy groups, and a hydrogen polysiloxane having one or more alkoxy groups, and a metal element. [Supplementary Note 2] The curable composition according to Supplementary Note 1, wherein the polysilanol having one or more alkoxy groups is represented by the following general formula (1), the hydrogen silsesquioxane having one or more alkoxy groups is represented by the following general formula (2), and the hydrogen polysiloxane having one or more alkoxy groups is represented by the following general formula (3): ((HO)SiO ３／２ ) ａ ((HO)Si(OR)O ２／２ ) ｂ ((HO) ２ SiO ２／２ ) ｃ ((HO)Si(OR) ２ O １／２ ) ｄ ((HO) ２ Si(OR)O １／２ ) ｅ ((HO) ３ SiO １／２ ) ｆ (1) (In the general formula (1), -OR is an alkoxy group, a, b, c, d, e, and f are each independently an integer of 0 or more, and b + d + e is an integer of 1 or more.) (HSiO ３／２ ) ｇ (HSi(OR)O ２／２ ) ｈ (HSi(OH)O ２／２ ) ｉ (HSi(OR) ２ O １／２ ) ｊ (HSi(OR)(OH)O １／２ )ｋ (HSi(OH) ２ O １／２ ) ｌ (2) (In the general formula (2), -OR is an alkoxy group, g, h, i, j, k, and l are each independently an integer of 0 or more, and h+j+k is an integer of 1 or more.) (HSiO ３／２ ) ｍ (HSi(OR)O ２／２ ) ｎ (HSi(OH)O ２／２ ) ｏ (HSi(OR) ２ O １／２ ) ｐ (HSi(OR)(OH)O １／２ ) ｑ (HSi(OH) ２ O １／２ ) ｒ (Si(OR １ ) ｓ O （４－ｓ）／２ ) ｔ (3) (In the general formula (3), —OR is an alkoxy group, and —OR １ represents an alkoxy group or a hydroxy group, m, n, o, p, q, and r each independently represent an integer of 0 or greater, n + p + q represents an integer of 1 or greater, s represents an integer of 0 or greater and 3 or less, and t represents an integer of 1 or greater.) [Appendix 3] The curable composition according to Appendices 1 or 2, wherein the metal element is at least one selected from zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel. [Appendix 4] The curable composition according to any one of Appendices 1 to 3, wherein the metal element is at least one selected from zirconium, zinc, iron, and cobalt. [Appendix 5] The curable composition according to any one of Appendices 1 to 4, which is in the form of a film. [Appendix 6] The curable composition according to Appendices 5, wherein the average thickness is 3 μm or less. [Appendix 7] The curable composition according to any one of Appendices 1 to 6, wherein the content of the metal element is 0.0001% by mass or more and 0.5% by mass or less relative to the total amount of solids in the curable composition. [Appendix 8] The curable composition according to any one of Appendices 1 to 6, comprising a polysiloxane component and a metal element, －１ More than 1200cm －１When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１ [Supplementary Note 9] A polysiloxane film having a maximum absorbance of 0.1 or less at 1000 cm in an infrared absorption spectrum. －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 2800 cm －１ More than 3000cm －１ The polysiloxane film according to Appendix 8, having a maximum absorbance of 0.04 or less in the following measurement. [Appendix 10] The polysiloxane film according to Appendix 8 or 9, wherein the metal element is at least one selected from zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel. [Appendix 11] The polysiloxane film according to claim 8, wherein the metal element is at least one selected from zirconium, zinc, iron, and cobalt. [Appendix 12] The polysiloxane film according to any one of Appendixes 8 to 11, having a content of the metal element of 0.0001% by mass or more and 0.5% by mass or less. [Appendix 13] The polysiloxane film according to any one of Appendixes 8 to 12, having an average thickness of 3 μm or less. [Appendix 14] An optical element comprising: a light-transmitting member having a light incident surface and a light exit surface; and the curable composition according to any one of Appendices 1 to 7 or the polysiloxane film according to any one of Appendices 8 to 13, provided on the light incident surface. [Appendix 15] An ultraviolet light-emitting device comprising: a light-emitting element that emits ultraviolet light; and the polysiloxane film according to any one of Appendices 8 to 13. [Appendix 16] The ultraviolet light-emitting device according to Appendices 15, wherein the polysiloxane film is provided on the light exit surface of the light-emitting element. [Appendix 17] The ultraviolet light-emitting device according to Appendices 16, further comprising a light-transmitting member having a light incident surface and a light exit surface, wherein the polysiloxane film is provided between the light exit surface of the light-emitting element and the light incident surface of the light-transmitting member.

[0093] The disclosure of Japanese Patent Application No. 2024-105339, filed on June 28, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

[0094] DESCRIPTION OF REFERENCE NUMERALS 2 Light-emitting element 21 Light-emitting surface (first interface) 3 Lens (light-transmitting member) 31 Opposing surface (second interface) 5 Polysiloxane film 6 Curable composition film 10 Optical member 100, 200, 300 Ultraviolet light-emitting device

Claims

1. A curable composition comprising at least one of polysilanol having an alkoxy group, hydrogen silsesquioxane having an alkoxy group, and hydrogen polysiloxane having an alkoxy group, and a metal element.

2. The curable composition according to claim 1, wherein the polysilanol having an alkoxy group is represented by the following general formula (1), the hydrogen silsesquioxane having an alkoxy group is represented by the following general formula (2), and the hydrogen polysiloxane having an alkoxy group is represented by the following general formula (3): ((HO)SiO ３／２ ) ａ ((HO)Si(OR)O ２／２ ) ｂ ((HO) ２ SiO ２／２ ) ｃ ((HO)Si(OR) ２ O １／２ ) ｄ ((HO) ２ Si(OR)O １／２ ) ｅ ((HO) ３ SiO １／２ ) ｆ (1) (In the general formula (1), -OR is an alkoxy group, a, b, c, d, e, and f are each independently an integer of 0 or more, and b + d + e is an integer of 1 or more.) (HSiO ３／２ ) ｇ (HSi(OR)O ２／２ ) ｈ (HSi(OH)O ２／２ ) ｉ (HSi(OR) ２ O １／２ ) ｊ (HSi(OR)(OH)O １／２ ) ｋ (HSi(OH) ２ O １／２ ) ｌ (2) (In the general formula (2), -OR is an alkoxy group, g, h, i, j, k, and l are each independently an integer of 0 or more, and h+j+k is an integer of 1 or more.) (HSiO ３／２ ) ｍ (HSi(OR)O ２／２ ) ｎ (HSi(OH)O ２／２ ) ｏ (HSi(OR) ２ O １／２ ) ｐ (HSi(OR)(OH)O １／２ ) ｑ (HSi(OH) ２ O １／２ ) ｒ (Si(OR １ ) ｓ O （４－ｓ）／２ ) ｔ (3) (In the general formula (3), —OR is an alkoxy group, and —OR １ represents an alkoxy group or a hydroxy group, m, n, o, p, q, and r each independently represent an integer of 0 or greater, n+p+q represents an integer of 1 or greater, s represents an integer of 0 or greater and 3 or less, and t represents an integer of 1 or greater.

3. The curable composition according to claim 1, wherein the metal element is at least one selected from the group consisting of zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel.

4. The curable composition according to claim 1, wherein the metal element is at least one selected from the group consisting of zirconium, zinc, iron, and cobalt.

5. The curable composition according to claim 1, which is in the form of a film.

6. The curable composition according to claim 5, having an average thickness of 3 μm or less.

7. The curable composition according to claim 1, wherein the content of the metal element is 0.0001 mass % or more and 0.5 mass % or less relative to the total amount of solids in the curable composition.

8. A compound containing polysiloxane and a metal element, which has an infrared absorption spectrum of 1000 cm －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 1250 cm －１ More than 1300cm －１ Below cm －１ A polysiloxane film having a maximum absorbance of 0.1 or less at 1000 nm.

9. 1000 cm in infrared absorption spectrum －１ More than 1200cm －１ When the maximum absorbance value below is set to reference value 1, 2800 cm －１ More than 3000cm －１ The polysiloxane film according to claim 8, wherein the maximum absorbance at the following temperature is 0.04 or less.

10. The polysiloxane film according to claim 8, wherein the metal element is at least one selected from the group consisting of zirconium, titanium, tin, aluminum, zinc, manganese, iron, cobalt, and nickel.

11. The polysiloxane film according to claim 8, wherein the metal element is at least one selected from the group consisting of zirconium, zinc, iron, and cobalt.

12. The polysiloxane film according to claim 8, wherein the content of the metal element is 0.0001% by mass or more and 0.5% by mass or less.

13. The polysiloxane film according to claim 8, having an average thickness of 3 μm or less.

14. An optical component comprising: a light-transmitting member having a light incident surface and a light exit surface; and a curable composition according to any one of claims 1 to 7 or a polysiloxane film according to any one of claims 8 to 13 provided on the light incident surface.

15. An ultraviolet light emitting device comprising: a light emitting element that emits ultraviolet light; and the polysiloxane film according to any one of claims 8 to 13.

16. The ultraviolet light emitting device according to claim 15, wherein the polysiloxane film is provided on the light emitting surface of the light emitting element.

17. The ultraviolet light emitting device according to claim 16, further comprising a light-transmitting member having a light incident surface and a light emitting surface, the polysiloxane film being provided between the light emitting surface of the light emitting element and the light incident surface of the light-transmitting member.

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