Ultraviolet light emitting element sealant and ultraviolet light emitting device having same

Abstract

To provide an ultraviolet light-emitting element sealant having high ultraviolet light transmittance in ultraviolet wavelength range, especially in the UVC range, high ultraviolet light extraction efficiency from an ultraviolet light-emitting element, excellent UV resistance, and high heat resistance, and an ultraviolet light-emitting device using the ultraviolet light-emitting element sealant.SOLUTION: An ultraviolet light-emitting element sealant 18 contains a condensation polymerized silicone resin and is designed to seal an ultraviolet light-emitting element 13. Among T unit, D unit, M unit, and Q unit, the condensation polymerization silicone resin has at least 90 mol% of the T unit in which molar ratio of number unit to the total number of mono-organosiloxy unit, and is free of hardening catalyst. An ultraviolet light-emitting device 1 has the ultraviolet light-emitting element sealant 18 covering at least a part of an emitting surface of the ultraviolet light-emitting element 13.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an ultraviolet light emitting element sealing material that has high transmittance even in the ultraviolet wavelength region and is excellent in efficiency of extracting ultraviolet light from an ultraviolet light emitting element, and an ultraviolet light emitting device having the same. [Background technology]

[0002] In recent years, ultraviolet light has been utilized in various fields. Ultraviolet LEDs (UV-LEDs) that emit various emission spectra including wavelengths in the ultraviolet region, especially short-wavelength ultraviolet light, have been developed to directly use the high energy of ultraviolet light for sterilization and printing ink curing, or to use it in semiconductor light-emitting devices that use phosphors to convert the wavelength of the irradiated ultraviolet light and adjust the spectral characteristics.

[0003] Generally, ultraviolet rays are divided into three wavelength ranges: UVA (ultraviolet A rays: wavelength 400-315nm), UVB (ultraviolet B rays: wavelength 315-280nm), and UVC (ultraviolet C rays: wavelength 280-100nm). Of the rays from the sun, the highly energetic UVC rays are absorbed by the ozone layer and do not reach the earth's surface, but UVA and UVB rays reach the earth's surface and are useful for activating vitamin D through sunbathing, sterilizing laundry and futons when hanging them out to dry, and photosynthesis, but are also known to cause sunburn, inflammation, age spots, wrinkles, and the development of skin cancer.

[0004] Taking advantage of these characteristics of ultraviolet light, artificial ultraviolet light is used for various industrial and everyday purposes. For example, UVC wavelengths are used in the fields of sterilization, water purification, and air purification, UVB wavelengths are used in the medical and agricultural fields, and UVA wavelengths are used in the fields of resin hardening, adhesion, printing, and painting.

[0005] Mercury-based ultraviolet lamps have traditionally been used as a source of ultraviolet light, but due to environmental concerns and power consumption, there is a shift towards ultraviolet LEDs.

[0006] UV LEDs have a narrower emission wavelength range than UV lamp light sources that irradiate multiple wavelengths, and are highly power efficient at specific wavelengths, contributing to energy savings. They also have a fast lighting speed, no degradation due to switching the power on and off, a long life and low maintenance requirements, making them easy to use, they can be made small, lightweight, and designed freely, and they do not use mercury, so they are environmentally friendly and do not put a burden on the environment. However, they have the disadvantages of having a significantly lower output than UV lamps, and being more expensive per unit of light.

[0007] Conventional light-emitting devices using ultraviolet LEDs did not have a sealant that could protect the ultraviolet LED light-emitting element but transmit ultraviolet light, so they had a fundamental problem in that the extraction efficiency of light such as ultraviolet light emitted from the light-emitting element was reduced due to the difference in refractive index between the light-emitting element and the air layer, and internal reflection within the light-emitting element.

[0008] In view of this, as a curable resin composition for forming an encapsulant having high light transmittance in the ultraviolet wavelength region, high ultraviolet resistance, and high heat resistance, Patent Document 1 discloses a curable resin composition containing an alkoxy oligomer and a curing catalyst, in which the alkoxy oligomer has an organopolysiloxane structure (R 1 R 2 R 3 SiO 1 / 2 ), a structural unit represented by (R 4 R 5 SiO 2 / 2 ), a structural unit represented by (R 6 SiO 3 / 2 ) and (SiO 4 / 2 ) and having one or more structural units selected from structural units represented by (R 7 a (OR 8 ) 3-a SiO 1 / 2 ), a structural unit represented by (R 9 b (OR 10 ) 2-b SiO 2 / 2 ) and ((OR 11 )SiO3 / 2 ), and when all siloxane units constituting the alkoxy oligomer are taken as 100 mol %, these structural units are contained in 90 to 100 mol %, and the atomic ratio of the total amount of O atoms to the total amount of Si atoms contained in the alkoxy oligomer is 2.3 to 3.5, and the curing catalyst is phosphoric acid or an alkoxide of a metal such as B or A.

[0009] Patent Document 2 discloses a semiconductor light emitting device including a package substrate housing a semiconductor light emitting element that emits ultraviolet light with a wavelength of 360 nm or less, a thin film layer of a predetermined thickness formed on the package substrate, and a sealant provided on the thin film layer, formed of silicone resin and having a lens-like shape, for sealing the semiconductor light emitting element, the sealant being formed so as to have a contact angle of 15 degrees or more with the thin film layer. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2016-186063 A [Patent Document 2] JP 2020-174153 A Summary of the Invention [Problem to be solved by the invention]

[0011] However, when used in an ultraviolet LED device equipped with a semiconductor light-emitting element that emits ultraviolet light with a wavelength of 280 nm or less, the light transmittance of the encapsulant is insufficient. If the light transmittance of the encapsulant is low, the efficiency of extracting ultraviolet light from the semiconductor light-emitting element improves, but the encapsulant causes a loss of ultraviolet light, making it difficult to improve the output and radiant flux of the ultraviolet LED device itself.

[0012] The present invention has been made to solve the above-mentioned problems, and aims to provide an ultraviolet light-emitting element sealing material that has higher ultraviolet light transmittance in the ultraviolet wavelength range, particularly in the UVC region, than conventional methods, and has a higher efficiency of extracting ultraviolet light, particularly ultraviolet light in the UVC region, from an ultraviolet light-emitting element, than conventional methods, and that has excellent ultraviolet resistance and high heat resistance, and an ultraviolet light-emitting device in which an ultraviolet light-emitting element is sealed with the ultraviolet light-emitting element sealing material. [Means for solving the problem]

[0013] The ultraviolet light emitting element sealant devised to achieve the above object is an ultraviolet light emitting element sealant containing a condensation polymerization silicone resin for sealing an ultraviolet light emitting element, wherein the condensation polymerization silicone resin contains repeating units consisting of M units which are monoorganosiloxy units, D units which are diorganosiloxy units, T units which are triorganosiloxy units, and Q units which are siloxy units, and the T units account for at least 90 mol % in terms of the molar ratio of the number of units to the total number of the monoorganosiloxy units, and does not contain a curing catalyst. The hardness must be 80 or more on the Shore D scale. It is characterized by:

[0014] In this ultraviolet light emitting device sealing material, for example, the condensation polymerization silicone resin is any three-dimensional crosslinked silicone resin containing T units selected from a T resin consisting of the T units, an MTQ resin having a combination of the M units, the T units, and the Q units, an MDTQ resin having a combination of the M units, the D units, the T units, and the Q units, a DT resin having a combination of the D units and the T units, and a TDQ resin having a combination of the D units, the T units, and the Q units.

[0015] In this ultraviolet light emitting device sealing material, the condensation-polymerized silicone resin preferably has the repeating unit consisting only of the T unit.

[0016] In this ultraviolet light emitting element sealing material, for example, the condensation-polymerized silicone resin is a condensation-polymerized cured product obtained by condensation-polymerizing a composition containing raw material components for the condensation-polymerized silicone resin.

[0017] In the ultraviolet light emitting device sealing material, it is preferable that the condensation polymerization silicone resin raw material component has a hydroxyl group at least at the terminal, and the condensation polymerization occurs via the hydroxyl group.

[0018] It is even more preferable that this ultraviolet light emitting device sealing material is one in which the composition containing the condensation polymerization silicone resin raw material component is solid at room temperature, becomes fluid when heated to a temperature lower than the heat-curing temperature at which the condensation polymerization occurs, and undergoes the condensation polymerization at or above the heat-curing temperature to become the condensation polymerization cured product.

[0019] The ultraviolet light emitting device sealing material may be configured to cover at least a part of the light emitting surface of the ultraviolet light emitting device.

[0020] This ultraviolet light emitting element sealing material covers at least a part of the light emitting surface of the ultraviolet light emitting element. It is something that It may be something like this.

[0021] This ultraviolet light emitting device sealing material may exhibit optical properties such that the average transmittance of light having a wavelength of 200 to 300 nm is 70% or more.

[0022] This ultraviolet light emitting device sealing material may exhibit optical properties such that the transmittance at least at any wavelength between 200 and 250 nm is at least 60%.

[0023] This ultraviolet light emitting device sealing material may have a transmittance of at least 90% at any wavelength of 250 to 280 nm.

[0024] The ultraviolet light emitting device created to solve the above problems comprises an ultraviolet light emitting element mounting base material on which the ultraviolet light emitting element is mounted and connected to wiring, and an ultraviolet light emitting element sealing material which covers at least a portion of the light emitting surface of the ultraviolet light emitting element.

[0025] This ultraviolet light-emitting device has an ultraviolet light extraction rate, calculated as the amount of ultraviolet light emitted from the ultraviolet light-emitting element encapsulant relative to the amount of ultraviolet light irradiated from the ultraviolet light-emitting element, which is 5% or more higher than an ultraviolet light-emitting device that does not have the ultraviolet light-emitting element encapsulant.

[0026] In this ultraviolet light emitting device, it is preferable that the ultraviolet light emitting element sealing material has at least any surface modification treatment surface selected from a corona treatment surface, a plasma treatment surface, an ultraviolet treatment surface, an ozone cleaning treatment surface, and a molecular adhesive treatment surface.

[0027] In this ultraviolet light-emitting device, for example, the ultraviolet light-emitting element sealant may also serve as an adhesive for adhering to a molded optical substrate member selected from an optical cube molded optical member, a rectangular molded optical member, a spherical molded optical member, a hemispherical molded optical member, a prism molded optical member, a spherical lens molded optical member, and an aspherical lens molded optical member, which is made of quartz glass, non-quartz glass, or a transparent resin.

[0028] The ultraviolet light emitting device includes the ultraviolet light emitting element sealing material and ,before At least one of the bonding surfaces between the ultraviolet light-emitting element and the ultraviolet light-emitting element-mounted substrate, and / or at least one of the bonding surfaces between the ultraviolet light-emitting element sealing material and the molded optical substrate member may have a surface-modified surface, such as a corona-treated surface, a plasma-treated surface, an ozone cleaning-treated surface, or a molecular adhesive-treated surface. This ultraviolet light emitting device may be such that at least any one of the bonding surfaces between the ultraviolet light emitting element sealing material and the package molding member constituting the ultraviolet LED device, the ultraviolet light emitting element, and the ultraviolet light emitting element mounting substrate, and / or at least any one of the bonding surfaces between the ultraviolet light emitting element sealing material and the molded optical substrate member has a surface modification treatment surface such as a corona treatment surface, a plasma treatment surface, an ozone cleaning treatment surface, or a molecular adhesive treatment surface. Effect of the Invention

[0029] The ultraviolet light emitting element sealant of the present invention can seal ultraviolet light emitting elements, and can increase ultraviolet light transmittance in the ultraviolet wavelength region of 400 to 100 nm, particularly in the UVC region of 280 to 100 nm, more than conventionally by making T units 90 mol % or more as repeating units of the condensation polymerization silicone resin. As a result, this ultraviolet light emitting element sealant can increase the extraction efficiency of ultraviolet light, particularly ultraviolet light in the UVC region, from the ultraviolet light emitting element more than conventional ultraviolet light emitting devices without a sealant.

[0030] In addition, since the package molding material constituting the ultraviolet LED device is mainly made of ceramic or metal, there is a possibility that the difference in linear expansion coefficient between the sealing material and the sealing material may cause cracks to occur when the sealing material hardens, or the sealing material may peel off from the package molding material. Therefore, by providing a resin buffer layer made of a resin that has rubber elasticity and a linear expansion coefficient close to that of the ultraviolet light emitting element sealing material on a part other than the light emitting surface of the ultraviolet light emitting element, the resin buffer layer can flexibly respond to cracks that occur when the sealing material hardens due to the difference in linear expansion coefficient or shrinkage rate between the package molding material and the like, and therefore cracks can be prevented.

[0031] This ultraviolet light emitting device encapsulant has moldability and an average transmittance of 70% or more, particularly 80% or more, for ultraviolet light having a wavelength of 200 to 300 nm.

[0032] This ultraviolet light emitting element sealing material transmits ultraviolet light with a wavelength of 200 to 300 nm from the ultraviolet light emitting element with high transmittance, while exhibiting excellent ultraviolet resistance over a long period of time without being deteriorated even by the highly active ultraviolet light irradiated from the ultraviolet light emitting element, and exhibits high heat resistance over a long period of time without being deteriorated by the heat generated by the ultraviolet light emitting element.

[0033] An ultraviolet light-emitting device in which an ultraviolet light-emitting element is sealed with this ultraviolet light-emitting element sealant has higher ultraviolet light transmittance than conventional devices in the ultraviolet wavelength range, particularly in the UVC region, and has a higher efficiency in extracting ultraviolet light, particularly ultraviolet light in the UVC region, from the ultraviolet light-emitting element than conventional devices, as well as excellent ultraviolet resistance and high heat resistance. [Brief description of the drawings]

[0034] [Figure 1] 1 is an exploded cross-sectional view showing a state in which an ultraviolet light emitting element sealing material according to the present invention is used, and an ultraviolet light emitting device using the same. [Diagram 2] FIG. 1 is a diagram showing an example of a combination of an ultraviolet light emitting element sealing material to which the present invention is applied and a molded optical substrate member. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing another embodiment of an ultraviolet light emitting device using the ultraviolet light emitting element sealing material to which the present invention is applied. [Figure 4] 1 is a graph showing the correlation between wavelength and transmittance in an evaluation of light transmittance of a molded sample of an ultraviolet light emitting element encapsulant to which the present invention is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments.

[0036] The ultraviolet light emitting element sealant of the present invention is an optical member made of a condensation-polymerized silicone resin formed as a condensation-polymerized cured product obtained by condensation-polymerizing a composition containing raw material components for a condensation-polymerized silicone resin.

[0037] The ultraviolet light emitting element sealing material contains such a condensation polymerization silicone resin as a base polymer, and the M unit (M unit: monofunctional unit: RSiO 1 / 2 ), D unit (D unit: bifunctional unit: RSiO 2 / 2 unit), T unit (T unit: trifunctional unit: RSiО 3 / 2 unit), and Q unit (Q unit: tetrafunctional unit: SiO4 / 2 ) (in each case, R specifically represents an alkyl group, such as a methyl group, or an aryl group, such as a phenyl group), the resin essentially contains 90 mol % or more of T units relative to the total molar ratio of all T·D·M·Q units. This condensation polymerization silicone resin may contain at least any one of D units, M units, and Q units in addition to T units as repeating units, but by using a condensation polymerization silicone resin in which the main repeating units are 90 mol % or more of T units, and preferably the repeating units are only T structures, the ultraviolet light emitting device encapsulant can have optical properties with a high transmittance of 70% or more at wavelengths of 200 to 300 nm.

[0038] [ka]

[0039] More specifically, the raw material component of the condensation polymerization silicone resin is a polyorganosiloxane (silicone resin) having a siloxane bond of Si-O-Si in the main backbone, which is the main chain, as shown in the following chemical structural formula. In the following chemical structural formula, X is an organic functional group such as a monovalent unsubstituted or substituted hydrocarbon group that does not contain an aliphatic unsaturated group. Examples of X include a hydroxyl group; an alkyl group such as a methyl group, an ethyl group, a propyl group, a pentyl group, a butyl group, a pentyl group, or a hexyl group; an aryl group such as a tolyl group or a xylyl group; and a substituted hydrocarbon group such as a chloromethyl group, a 3-chloropropyl group, or a 3-trifluoropropyl group. In this case, when X is an organic functional group having a conjugated bond of C=C such as a phenyl group, it is preferable to remove the phenyl group in order to reduce the transmittance in the ultraviolet region. X may be one type or multiple types. In addition, it is preferable that most or all of X are methyl groups. OR represents an alkoxysilyl group.

[0040] [ka] [ka] (In the formula, -OR represents an alkoxysilyl group, and -X represents an organic functional group such as a methyl group.)

[0041] As long as the condensation polymerization silicone resin has 90 mol % or more of a T unit repeating structure, it may be a resin mainly composed of a T unit-containing three-dimensional crosslinked silicone resin selected from a T resin consisting of only T units, an MTQ resin having a combination of M units, T units, and Q units, an MDTQ resin having a combination of M units, D units, T units, and Q units, a DT resin having a combination of D units, T units, and Q units, and a TDQ resin having a combination of D units, T units, and Q units, or it may contain a condensation polymerization silicone resin having no T unit repeating structure and having at least any of M units, T units, and Q units as a minor component without a T resin.

[0042] Without a sealant, the extraction rate of ultraviolet light would decrease due to the difference in refractive index between the ultraviolet light-emitting element and the air layer and internal reflection, but this ultraviolet light-emitting element sealant, which is made of a base resin that is a condensation polymerization silicone resin having 90 mol % or more of T units, exists to cover the light-emitting surface of the ultraviolet light-emitting element and reduces the difference in refractive index between the ultraviolet light-emitting element and the air layer, thereby not only improving the extraction rate by 5% or more compared to an ultraviolet light-emitting device without an ultraviolet light-emitting element sealant, but also having excellent moldability because it is formed from a composition containing condensation polymerization silicone resin raw material components.

[0043] On the other hand, an ultraviolet light emitting device encapsulant made of a condensation polymerization silicone resin with less than 90 mol% T units has an average transmittance of 70% or less at wavelengths of 200 to 300 nm, making it difficult to improve the output or radiant flux of the ultraviolet LED device itself, and causing degradation due to ultraviolet light.

[0044] Generally, silicone rubber or silicone resin has low transmittance in the ultraviolet region (particularly UV-B and UV-C), and has not been used as an optical component such as an ultraviolet light emitting element sealant in the past. However, the ultraviolet light emitting element sealant of the present invention uses a condensation polymerization silicone resin having 90 mol% or more of T units, and thus has high ultraviolet light transmittance in the ultraviolet wavelength region, especially in the UVC region, high ultraviolet light extraction efficiency, and excellent ultraviolet resistance and high heat resistance. On the other hand, an ultraviolet light emitting element sealant made of a condensation polymerization silicone resin consisting of only a Q structure is close to a so-called glass structure, and while it has strong mechanical strength, it is difficult to mold it like a resin. In addition, MQ resin formed from M units and Q units is very strong and has good mechanical strength, but the film is brittle, making it difficult to form a three-dimensional shape, let alone a self-supporting film, whereas T resin, MTQ resin, MDTQ resin, DT resin, TQ resin, and TDQ resin are capable of forming a three-dimensional shape compared to MQ resin, and also have the strength derived from resin.

[0045] The ultraviolet light emitting device sealing material is made of a cured silicone resin, which is a condensation polymerization silicone resin, as a base material, has a branched structure (T unit) of 90 mol % or more, and has a Shore D hardness after curing of 40 to 95, preferably 45 to 90, and more preferably 50 to 85, thereby exhibiting the above-mentioned specific optical properties.

[0046] The ratio of T units in the condensation polymerization silicone resin of the ultraviolet light emitting device sealing material is not particularly limited as long as it is 90 mol % or more, but is preferably 90% to 100%, more preferably 95% to 100%, and even more preferably 97% to 100%.

[0047] In particular, when the condensation polymerization silicone resin of the ultraviolet light emitting element sealant is molded using a condensation polymerization silicone resin with a high ratio of T units, such as 90 mol % or more of T units, it can achieve both high transmittance in the ultraviolet region and moldability compared to optical members molded with other silicone rubbers or silicone resins, such as addition polymerization silicone resins or addition polymerization silicone rubbers, or radical polymerization silicone resins or radical polymerization silicone rubbers. Thus, one of the factors that causes the ultraviolet light emitting element sealant to exhibit the above-mentioned specific optical properties is that the condensation polymerization silicone resin of the ultraviolet light emitting element sealant has a structure of T units as its main structure.

[0048] The condensation-polymerized silicone resin of the ultraviolet light emitting device sealing material is formed by condensation polymerization of hydroxyl groups at one or both ends, preferably at both ends, of a condensation-polymerized silicone resin raw material component through dehydration to harden into a condensation-polymerized silicone resin.

[0049] The mass average molecular weight of the condensation-polymerized silicone resin used in the ultraviolet light emitting element sealing material is not particularly limited and may be appropriately selected depending on the intended use. For example, the mass average molecular weight of the condensation-polymerized silicone resin is preferably 2,000 to 7,000, more preferably 2,500 to 6,000, and even more preferably 3,000 to 5,000.

[0050] Condensation polymerization silicone resin raw material components that form the condensation polymerization silicone resin of the ultraviolet light emitting device encapsulant include YR3370, a condensation polymerization silicone resin manufactured by Momentive Performance Materials Japan, LLC, and KR-200, KR-220LP, KR-242A, KR-255, and KR-282, which are condensation polymerization silicone resins manufactured by Shin-Etsu Chemical Co., Ltd. In particular, it is advisable to select a condensation polymerization silicone resin that does not contain organic solvents, has an active ingredient content of 90% or more, and has a low volatile ingredient content of 10% or less.

[0051] The condensation polymerization silicone resin used in the ultraviolet light emitting device sealing material is a composition containing condensation polymerization silicone resin raw material components that is a solid that does not exhibit fluidity at room temperature, and when heated below the heat-curing temperature at which condensation polymerization occurs, it becomes liquid and exhibits fluidity although it has some viscosity; when heated to a temperature above the heat-curing temperature, for example 150°C or higher, and condensation polymerization is performed, a condensation polymerization cured product is obtained.

[0052] In this ultraviolet emitting element sealant, the composition containing the condensation polymerization silicone resin raw material component does not preferably contain organic and / or inorganic catalysts, such as platinum-containing catalysts, lead-containing catalysts, titanium-containing catalysts, aluminum-containing catalysts, zinc-based catalysts, iron-based catalysts, metal catalysts, phosphoric acid catalysts, amine-based catalysts, and curing catalysts made of organic compounds. Since the composition containing the condensation polymerization silicone resin raw material component does not contain a catalyst, the ultraviolet emitting element sealant also does not contain a catalyst, and therefore the ultraviolet emitting element sealant can reduce or eliminate the factors that cause the curing catalyst to absorb ultraviolet light, thereby increasing the average transmittance of ultraviolet light with a wavelength of 200 to 300 nm.

[0053] The composition containing a condensation-polymerizable silicone resin raw material component used to form an ultraviolet light-emitting device sealant preferably contains a condensation-polymerizable silicone resin raw material component that can be condensed and cured, from the viewpoint of eliminating factors that absorb ultraviolet light, such as C—C bonds and C=C bonds, as seen in the structural formula of addition-polymerized silicone.

[0054] It is preferable that such an ultraviolet emitting element sealant made of a condensation polymerization silicone resin has a corona irradiation treatment surface, a plasma irradiation treatment surface, or an ultraviolet ray irradiation treatment surface. As a result, organic functional groups such as some alkyl groups or phenyl groups bonded to T units that become Si-C bonds are eliminated by energy irradiation treatment or the like, and have a Q structure and / or a glass structure (Si=O structure or Si-OH structure), and as a result, the Si group is inorganicized, and it is presumed that high transmittance can be achieved even in the ultraviolet ray region by modifying, removing, or reducing the Si-C bonds that are considered to be factors in absorbing wavelengths in the ultraviolet ray region. As a result, it is possible to obtain an ultraviolet emitting element sealant with stable characteristics while maintaining the transmittance in the visible region and maintaining the high transmittance in the ultraviolet ray region. Thus, one of the factors that causes the ultraviolet emitting element sealant to exhibit the above-mentioned specific optical characteristics is that the ultraviolet emitting element sealant is preferably made of a condensation polymerization silicone resin that does not have an addition-polymerizable functional group such as a vinyl group.

[0055] The ultraviolet light emitting device sealing material may be configured to cover at least a part of the light emitting surface of the ultraviolet light emitting device.

[0056] This ultraviolet light emitting device sealing material may have a Shore D hardness of 40 to 95, preferably 45 to 90, and more preferably 50 to 85 after curing.

[0057] The linear expansion coefficient of the condensation-polymerized silicone resin used in the ultraviolet light emitting device sealing material may be 100-500, preferably 100-400, and more preferably 100-300.

[0058] The refractive index of the condensation polymerization silicone resin used in the ultraviolet light emitting device sealing material in the ultraviolet region of 300 nm or less is 1.30 to 1.60, preferably 1.40 to 1.50, which improves the reduction in the ultraviolet light extraction efficiency caused by internal reflection, etc., which occurs due to the difference in refractive index between the ultraviolet light emitting device's refractive index in the ultraviolet region of 300 nm or less, which is 1.70 to 2.00, and the air's refractive index in the ultraviolet region of 300 nm or less, which is 0.90 to 1.10.

[0059] This ultraviolet light emitting element sealing material may be a condensation polymerization silicone resin having a high ratio of T units, such as 90 mol % or more of T units, and thus exhibits optical properties such as an average transmittance of 70% or more, more preferably 80% or more, at a wavelength of 200 to 300 nm.

[0060] This ultraviolet light emitting device sealing material may be a condensation polymerization silicone resin having a high ratio of T units, such as 90 mol % or more of T units, and thus exhibits optical properties such as a transmittance of at least 60%, more preferably 65%, and even more preferably 70%, at least any wavelength in the range of 200 to 250 nm.

[0061] This ultraviolet light emitting device sealing material may be a condensation polymerization silicone resin having a high ratio of T units, such as 90 mol % or more of T units, so that the transmittance is at least 90% at any wavelength of 250 to 280 nm.

[0062] As shown in FIG. 1, this ultraviolet light-emitting device 1 includes, as an example, an ultraviolet light-emitting element mounting base material 20 formed by mounting a light-emitting diode as an ultraviolet light-emitting element 13 and connecting it to wiring patterns 15a, 15b made of copper foil via wiring 14a, 14b, and comprising an insulating reflector 17a and a substrate 16, a package case as reflector 17b surrounding the ultraviolet light-emitting element 13 in a recess 11, a package molding member 10 made of a reflector 12, for example a metal film and ceramic, and an ultraviolet light-emitting element sealant 18 that seals the recess 11 together with the ultraviolet light-emitting element 13.

[0063] In this ultraviolet light-emitting device 1, the ultraviolet light-emitting element sealing material 18 may be a condensation polymerization silicone resin having a high ratio of T units, such as 90 mol % or more of T units, so that the ultraviolet light-emitting element sealing material 18 also serves as an adhesive to adhere to the ultraviolet light-emitting element 13.

[0064] This ultraviolet light-emitting device 1 has a configuration of ultraviolet light-emitting element encapsulant 18, and therefore the ultraviolet light extraction rate, calculated as the amount of ultraviolet light emitted from the ultraviolet light-emitting element encapsulant 18 to the outside relative to the amount of ultraviolet light irradiated from the ultraviolet light-emitting element 13, is at least 5%, preferably 10% or more, and more preferably 15% or more, compared to an ultraviolet light-emitting device that does not have an ultraviolet light-emitting element encapsulant.

[0065] As shown in FIG. 1 and FIGS. 2(a) to (d), this ultraviolet light-emitting device 1 may be configured such that, for example, the ultraviolet light-emitting element sealant 18 also serves as an adhesive for adhering to a molded optical substrate member 30 selected from an optical cube molded optical member, a rectangular parallelepiped molded optical member, a spherical molded optical member, a hemispherical molded optical member, a prism molded optical member, a spherical lens molded optical member, and an aspherical lens molded optical member, which is made of quartz glass, non-quartz glass, or a transparent resin, or the same or a different resin as the condensation polymerization silicone resin.

[0066] The shape of the molded optical substrate member 30 of such an ultraviolet light emitting device 1 is not particularly limited. The molded optical substrate member 30 of the ultraviolet light emitting device 1 may be, for example, as shown in Fig. 2(a) and (b), a lens, for example, a convex lens such as a biconvex lens, a plano-convex lens (see Fig. 2(a)), or a convex meniscus lens; a concave lens such as a biconcave lens, a plano-concave lens, or a concave meniscus lens; an aspheric lens; a cylindrical lens (see Fig. 2(b)); a toroidal lens; a Fresnel lens; a lens sheet in a sheet-like shape having such a shape; a lens array in which a large number of such lenses are arranged; a film; or a light guide plate. Note that the ultraviolet light emitting element, the ultraviolet light emitting element mounting substrate, etc. are omitted in the drawings.

[0067] The ultraviolet light-emitting device 1 is configured such that the ultraviolet light-emitting element sealant 18 has been subjected to a surface modification treatment, such as corona treatment, plasma treatment, or a molecular adhesive, or can be adhered to the ultraviolet light-emitting element 13, the ultraviolet light-emitting element mounting substrate 20, the package molding member 10, and the molded optical substrate member 30 used as needed, etc., by an adhesive.

[0068] In the ultraviolet light emitting device 1, since the molded optical substrate member 30 is a lens, it is possible to collect, diffuse, scatter, or guide the light from the ultraviolet light emitting element 13, improve the light extraction efficiency from the ultraviolet light emitting element 13 and / or the ultraviolet light emitting element sealant 18, and adjust the light intensity and the light irradiation area at the irradiation destination. In this case, the light from the ultraviolet light emitting element 13 may have a peak wavelength of 100 to 360 nm, preferably 100 to 280 nm, and more preferably 250 to 280 nm.

[0069] In addition, the ultraviolet light-emitting device 1 may be one in which the ultraviolet light-emitting element sealant 18 is covered with a molded optical substrate 30 made of the same or a different type of resin as the condensation polymerization silicone resin or made of quartz glass, or the molded optical substrate 30 may be a hybrid lens covered with a coating or covering member made of various silicone resins, such as a coating layer or a matte coating layer, or a light-collecting or light-diffusing covering member.

[0070] In other words, the ultraviolet light-emitting device 1 can be used in combination with a molded optical substrate 30 having a three-dimensional or plate-like support member such as quartz glass that has high transmittance even in the ultraviolet region, by bonding or laminating an optical element made of organic resin with an optical element made of quartz glass, coating quartz glass with an organic resin and molding it, or molecularly bonding an optical element made of organic resin with quartz glass.

[0071] As long as the ultraviolet light emitting device 1 satisfies the required transmittance, the ultraviolet light emitting element sealing material 18 may contain an organic or inorganic filler having light diffusing properties, wavelength converting properties, or thermal conductivity, or may be provided with a separate layer.

[0072] As shown in Figures 3(1a) to (1e), the ultraviolet light-emitting device 1 may be one in which the ultraviolet light-emitting element sealing material 18 seals the entire ultraviolet light-emitting element 13, or it may be one that covers only the light-emitting surface of the ultraviolet light-emitting element 13.

[0073] Specifically, as shown in FIG. 3(1a), the ultraviolet light-emitting device 1 may not have a package molding material, and the entire ultraviolet light-emitting element 13 on the ultraviolet light-emitting element mounting substrate 20 may be sealed with an ultraviolet light-emitting element sealing material 18.

[0074] Specifically, the ultraviolet light-emitting device 1 may be configured such that only the light-emitting surface of the ultraviolet light-emitting element 13 arranged in the center of the package molded member 10 is covered with ultraviolet light-emitting element sealing material 18 on the ultraviolet light-emitting element mounting substrate 20, as shown in FIG. 1b, or the upper end of the package molded member 10 may be covered with a molded optical substrate member 30 which is a quartz glass plate, as shown in FIG. 1c.

[0075] Alternatively, the ultraviolet light-emitting device 1 may be one in which only the upper light-emitting surface of the ultraviolet light-emitting element 13 is sealed by a lens-shaped ultraviolet light-emitting element sealing material 18 on the light-emitting surface of the ultraviolet light-emitting element 13 arranged in the center of the package molded member 10 on an ultraviolet light-emitting element mounting substrate 20, as shown in FIG. 1(1d), or one in which the upper end of the package molded member 10 is covered by a molded optical substrate member 30 which is a quartz glass plate, as shown in FIG. 1(1e).

[0076] Alternatively, the ultraviolet light emitting device 1 may be configured to have a resin buffer layer 40 made of an organic resin that covers all but the light emitting surface of the ultraviolet light emitting element 13 and is filled in the package molding material or molded separately, as shown in Figures 3(2a) to (2f).

[0077] Specifically, as shown in Figure 3 (2a), the ultraviolet light-emitting device 1 may be configured such that only the light-emitting surface of the ultraviolet light-emitting element 13 arranged in the center of the package molding member 10 on the ultraviolet light-emitting element mounting substrate 20 is covered with a lens-shaped ultraviolet light-emitting element sealing material 18 of the same diameter, and the same height surrounding the ultraviolet light-emitting element 13 is filled with a resin buffer layer 40, or as shown in Figure 3 (2b), the entire light-emitting surface of the ultraviolet light-emitting element 13 and part of the resin buffer layer 40 may be covered with a wide range of ultraviolet light-emitting element sealing material 18.

[0078] Alternatively, as shown in FIG. 2c, the ultraviolet light-emitting device 1 may be configured such that only the light-emitting surface of the ultraviolet light-emitting element 13 arranged in the center of the package molding member 10 on the ultraviolet light-emitting element mounting substrate 20 is covered with a lens-shaped ultraviolet light-emitting element sealing material 18 of the same diameter, and the ultraviolet light-emitting element 13 and the ultraviolet light-emitting element sealing material 18 are surrounded by a resin buffer layer 40 so that the convex lens shape is not buried.

[0079] Alternatively, as shown in the same figure (2d), the ultraviolet light-emitting device 1 may be configured such that it is covered on an ultraviolet light-emitting element mounting substrate 20 with a lens-shaped ultraviolet light-emitting element sealing material 18 that is wider and expands upward than the light-emitting surface of the ultraviolet light-emitting element 13 located in the center of the package molding member 10, and the ultraviolet light-emitting element 13 and the ultraviolet light-emitting element sealing material 18 are filled with a resin buffer layer 40 so that they fit snugly around them.

[0080] Alternatively, as shown in the same figure (2e), the ultraviolet light-emitting device 1 may be configured such that the ultraviolet light-emitting element 13 arranged in the center of the package molding member 10 is surrounded by a resin buffer layer 40 of the same height on the ultraviolet light-emitting element mounting substrate 20, and the ultraviolet light-emitting element 13 and the resin buffer layer 40 are covered with a plate-shaped ultraviolet light-emitting element sealing material 18 of the same diameter as the hollow in the package molding member 10, so that the periphery and top surface of the ultraviolet light-emitting element 13 are covered with the ultraviolet light-emitting element sealing material 18 and the periphery thereof is filled with the resin buffer layer 40.

[0081] This resin buffer layer 40 has rubber elasticity and is made of a layer of resin with a linear expansion coefficient close to that of the ultraviolet light emitting element sealing material 18, thereby making it possible to prevent cracks and the like that occur when the sealing material 18 hardens due to differences in the linear expansion coefficient or shrinkage rate of the package molding member 10, etc.

[0082] This resin buffer layer 40 may be a layer made of an organic resin, and in this case, examples of the organic resin include a silicone resin having a low hardness. The hardness of the organic resin after curing is 10 to 80, preferably 10 to 70, and more preferably 10 to 60 Shore A, so that even if a difference occurs in the linear expansion coefficient or shrinkage rate of the package molding member 10, etc., the organic resin can follow the difference and protect the ultraviolet light emitting element encapsulant 18.

[0083] The resin buffer layer 40 may be formed from a silicone resin. Such a silicone resin is preferably a silicone resin that is liquid before curing, and examples of such a silicone resin include LSR7010, LSR7020, LSR7030, LSR7040, LSR7050, LSR7060, LSR7070, LSR7080, and LSR7090 manufactured by Momentive Performance Materials Japan, LLC, and MS-1001, MS-1002, and MS-1003 manufactured by Dow Toray Co., Ltd.

[0084] Metal fillers such as alumina, aluminum nitride, aluminum, silver, and titanium, and inorganic fillers such as titanium oxide and magnesium hydroxide may be added to the silicone resin forming the resin buffer layer 40 in order to improve heat transfer and UV light reflection properties, and to provide UV protection to the light emitting element.

[0085] Referring to Fig. 1, the ultraviolet light emitting device 1 is produced as follows. An ultraviolet light emitting device mounting substrate 20, on which a light emitting diode, which is an ultraviolet light emitting device 13, is mounted and connected to copper foils 15a and 15b, which are wiring patterns, is joined to a package molding member 10, which is a package case surrounding the ultraviolet light emitting device 13 in a recess 11, with an adhesive. Next, a composition containing a condensation polymerization silicone resin raw material component is heated to a heat curing temperature or lower, for example, 100°C or lower, to give it fluidity, and filled into the recess. The composition is then heated to a heat curing temperature, for example, 150°C, to form an ultraviolet light emitting device encapsulant 18 made of a cured product cured into a condensation polymerization silicone resin. At this time, as shown in Figs. 2 and 3, the ultraviolet light emitting device 1 may be obtained by covering and adhering the ultraviolet light emitting device encapsulant 18 to the molded optical substrate 30 before or after curing as necessary, or a resin buffer layer 40 may be provided to obtain the ultraviolet light emitting device 1. EXAMPLES

[0086] Hereinafter, examples to which the present invention is applied and comparative examples to which the present invention is not applied will be described.

[0087] (Preparation of ultraviolet light emitting element encapsulant: Preparation of composition containing condensation polymerization silicone resin raw material component) As shown in Table 1 below, compositions containing condensation polymerization silicone resin raw material components of Example 1 and Comparative Examples 1 to 3 were prepared.

[0088] Example 1 100 g of YR3370 (manufactured by Momentive Performance Materials Japan, LLC, product name: methyl-based silicone resin), which is solid at room temperature, was weighed out, transferred to a syringe and placed in an oven set to 80°C, where the YR3370 was heated and melted into a flowable liquid.

[0089] Comparative Example 1 25 g of YR3370, which is a solid at room temperature, 75 g of X-40-9225 (manufactured by Shin-Etsu Chemical Co., Ltd., product name: T-unit-based condensation polymerization silicone resin), which is liquid at room temperature for adding the curing catalyst, and 1 g of D-15 (manufactured by Shin-Etsu Chemical Co., Ltd., product name: zinc-based curing catalyst), were weighed out, stirred to disperse uniformly, transferred to a syringe and placed in an oven set to 80°C, where they were heated and melted into a flowable liquid.

[0090] Comparative Example 2 25 g of YR3370, which is a solid at room temperature, 75 g of X-40-9225 (manufactured by Shin-Etsu Chemical Co., Ltd., product name: T-unit-based condensation polymerization silicone resin), which is liquid at room temperature for adding the curing catalyst, and 3 g of D-15 (manufactured by Shin-Etsu Chemical Co., Ltd., product name: zinc-based curing catalyst), were weighed out, stirred to disperse uniformly, transferred to a syringe and placed in an oven set at 80°C, where they were heated and melted into a flowable liquid.

[0091] Comparative Example 3 100 g of MS-1003 (product name: addition type silicone resin, manufactured by Dow Toray Industries, Inc.), which is liquid at room temperature, was weighed out and transferred into a syringe.

[0092] [Table 1]

[0093] (Preparation of molded sample of ultraviolet light emitting device encapsulant and evaluation of its appearance) The compositions containing the condensation polymerization silicone resin raw material components for the flowable ultraviolet light emitting device sealant of Example 1 and Comparative Examples 1 to 3 were poured into a mold and heated at 150°C or higher to prepare flat plate samples with a thickness of 1 mm, and the samples were evaluated for cracks, etc. Samples without abnormalities in appearance were evaluated as passing (◯), and samples with abnormalities were evaluated as failing (×). The results are summarized in Table 2.

[0094] [Table 2]

[0095] As is clear from Table 2, there were no abnormalities in the appearance of the samples derived from the compositions containing the condensation polymerization silicone resin raw material components of Example 1 and Comparative Example 3. The samples derived from the compositions containing the condensation polymerization silicone resin raw material components of Comparative Examples 1 and 2 had layer separation, were abnormal in appearance, and the upper resin layer was brittle.

[0096] (Preparation of molded samples of ultraviolet light emitting device encapsulant and evaluation of their light transmittance) The compositions containing the condensation polymerization silicone resin raw material components for ultraviolet light emitting device sealing material having flowability of Example 1 and Comparative Examples 1 to 3 were poured into a mold, heated to 150°C, and flat plate samples with a thickness of 1 mm were prepared, and the light transmittance in the wavelength range of 200 to 500 nm was evaluated using a spectrophotometer UV-3600Plus (product name, manufactured by Shimadzu Corporation). The results are summarized in Figure 4. Table 3 shows details of the transmittance in each wavelength range for Example 1 and Comparative Example 3, which were free of any particular abnormality in appearance.

[0097] [Table 3]

[0098] As is clear from FIG. 4 and Table 3, the molded sample derived from the composition containing the condensation polymerization silicone resin raw material components of Example 1 exhibited high transmittance over the entire wavelength range from 200 to 500 nm, whereas the molded sample derived from the composition containing the condensation polymerization silicone resin raw material components of Comparative Examples 1 to 3 exhibited relatively low transmittance over the entire wavelength range from 200 to 500 nm, particularly low transmittance in the 200 to 360 nm range, and particularly low transmittance in the UVC wavelength range.

[0099] (Production of ultraviolet light emitting device and evaluation of its ultraviolet resistance and ultraviolet light emission intensity) Example 2 An NCSU334B (manufactured by Nichia Corporation, product name: emission peak wavelength 280 nm) with the quartz glass window removed was prepared as an ultraviolet light-emitting device, and the condensation polymerization silicone resin raw material component-containing composition for the flowable ultraviolet light-emitting device encapsulant of Example 1 and Comparative Example 3 was poured into the recess so as to cover the top surface, which would be the light-emitting surface of the ultraviolet light-emitting device, and cured by heating at 150°C or higher to produce an ultraviolet light-emitting device having a cured ultraviolet light-emitting device encapsulant.

[0100] Example 3 As another example, NCSU334B (manufactured by Nichia Corporation, product name: emission peak wavelength 280 nm) with the quartz glass window removed was prepared as an ultraviolet light-emitting device, and MS-1003 (manufactured by Dow-Toray Industries, product name: addition type silicone resin), which is liquid at room temperature, was poured into the recess so as not to cover the top surface which becomes the light-emitting surface of the ultraviolet light-emitting element, and this was heated and cured at 150°C to form a resin buffer layer. After that, the flowable ultraviolet light-emitting element sealing material of Example 1 was poured in so as to cover the top surface which becomes the light-emitting surface of the ultraviolet light-emitting element, to produce an ultraviolet light-emitting device having a resin buffer layer and cured ultraviolet light-emitting element sealing material.

[0101] (UV resistance evaluation test and UV light emission intensity evaluation test) To evaluate the emission intensity of ultraviolet light, an ultraviolet integrating light meter UIT-250 and a separate type receiver for ultraviolet integrating light meter UVD-S254 (both product names manufactured by Ushio Inc.) were used to measure the peak illuminance [P.mW / cm2] of the ultraviolet light emitted from the ultraviolet light emitter. A current value of 350 mA was applied to the NCSU334B with the quartz glass window removed to cause it to emit light, a separate receiver UVD-S254 was placed on the top surface of the ultraviolet light emitter, and the peak illuminance was measured without any ultraviolet light emitting element sealant. Then, the peak illuminance was measured for the ultraviolet light emitter having the cured ultraviolet light emitting element sealant of Example 2, and the ultraviolet light emitter having the resin buffer layer and the cured ultraviolet light emitting element sealant of Example 3. The results are shown in Table 4.

[0102] [Table 4]

[0103] As is clear from Table 4, the peak illuminance of the ultraviolet light emitting device of Examples 2 and 3 having the ultraviolet light emitting element encapsulant is improved compared to the ultraviolet light emitting device without the ultraviolet light emitting element encapsulant, and no deterioration of the ultraviolet light emitting element encapsulant due to ultraviolet light irradiation by turning on the ultraviolet light emitting device is observed. Furthermore, the ultraviolet light emitting device having the resin buffer layer and the cured ultraviolet light emitting element encapsulant of Examples 2 and 3 can stably cure the ultraviolet light emitting element encapsulant, and no cracks or the like were observed due to heat generation by turning on the ultraviolet light emitting device. [Industrial Applicability]

[0104] The ultraviolet light emitting element encapsulant of the present invention can be used as an optical component in the fields of sterilization and disinfection, water purification, and air purification, which require high transmittance even in the ultraviolet wavelength region, especially in the deep ultraviolet region, and / or as an encapsulant in the optical field for collecting, diffusing, diffusing, or guiding ultraviolet wavelengths, especially in the deep ultraviolet region, and improving the light extraction efficiency of light emitting elements. In addition, an ultraviolet light emitting element encapsulant can be obtained that has good moldability, is inexpensive, and has high transmittance even in the ultraviolet region, like quartz glass. [Explanation of symbols]

[0105] Reference numeral 1 denotes an ultraviolet light-emitting device, 10 denotes a package molding member, 11 denotes a recess, 12 denotes a reflector, 13 denotes an ultraviolet light-emitting element, 14a and 14b denote wiring, 15a and 15b denote wiring patterns, 16 denotes a substrate, 17a denotes an insulating reflector, 17b denotes a reflector, 18 denotes an ultraviolet light-emitting element sealing material, 20 denotes an ultraviolet light-emitting element mounting substrate, 30 denotes a molded optical substrate member, and 40 denotes a resin buffer layer.

Claims

1. The ultraviolet light emitting device sealant contains a condensation polymerization silicone resin and is used to seal an ultraviolet light emitting device, the condensation polymerization silicone resin having repeating units of monoorganosiloxy units, namely M units, diorganosiloxy units, T units, triorganosiloxy units, and Q units, the T units being at least 90 mol % in terms of the molar ratio of the number of units to the total number of the monoorganosiloxy units, the ultraviolet light emitting device sealant being free of a curing catalyst, and having a Shore D hardness of 80 or more.

2. The ultraviolet light emitting element sealing material according to claim 1, characterized in that the condensation polymerization silicone resin is any one of a T unit-containing three-dimensional crosslinked silicone resins selected from a T resin consisting of the T units, an MTQ resin having a combination of the M units, the T units, and the Q units, an MDTQ resin having a combination of the M units, the D units, the T units, and the Q units, a DT resin having a combination of the D units and the T units, and a TDQ resin having a combination of the D units, the T units, and the Q units.

3. 2. The ultraviolet emitting element sealing material according to claim 1, wherein the condensation-polymerized silicone resin has the repeating unit consisting only of the T unit.

4. 4. The ultraviolet emitting element sealant according to claim 1, wherein the condensation-polymerized silicone resin is a condensation-polymerized cured product obtained by condensation-polymerizing a composition containing raw material components for the condensation-polymerized silicone resin.

5. 5. The ultraviolet emitting element sealing material according to claim 4, wherein the raw material component for condensation polymerization of silicone resin has at least a hydroxyl group at a terminal thereof and undergoes the condensation polymerization via the hydroxyl group.

6. The ultraviolet light emitting element sealing material according to claim 4, characterized in that the composition containing the condensation polymerization silicone resin raw material component is solid at room temperature, becomes fluid when heated to a temperature lower than the heat-curing temperature at which the condensation polymerization is carried out, and undergoes the condensation polymerization at a temperature equal to or higher than the heat-curing temperature to become the condensation polymerization cured product.

7. 7. The ultraviolet emitting element encapsulant according to claim 1, which is intended to cover at least a part of the light emitting surface of an ultraviolet emitting element.

8. 8. The ultraviolet emitting element encapsulant according to claim 1, wherein the encapsulant covers at least a part of the light emitting surface of the ultraviolet emitting element.

9. 9. The ultraviolet emitting device encapsulant according to claim 1, which has optical properties such that the average transmittance at wavelengths of 200 to 300 nm is 70% or more.

10. 10. The ultraviolet emitting element encapsulant according to claim 1, which exhibits optical properties such that the transmittance at least in any one of wavelengths from 200 to 250 nm is at least 60%.

11. 11. The ultraviolet emitting element sealing material according to claim 1, wherein the transmittance is at least 90% at any wavelength of 250 to 280 nm.

12. An ultraviolet light-emitting device comprising: an ultraviolet light-emitting element mounting base material on which the ultraviolet light-emitting element is mounted and connected to wiring; and an ultraviolet light-emitting element sealing material according to any one of claims 1 to 11, which covers at least a portion of the light-emitting surface of the ultraviolet light-emitting element.

13. The ultraviolet light-emitting device described in claim 12, characterized in that the ultraviolet light extraction efficiency, calculated as the amount of ultraviolet light emitted from the ultraviolet light-emitting element encapsulant relative to the amount of ultraviolet light irradiated from the ultraviolet light-emitting element, is 5% or more higher than that of an ultraviolet light-emitting device without the ultraviolet light-emitting element encapsulant.

14. The ultraviolet light emitting device according to any one of claims 12 to 13, characterized in that the ultraviolet light emitting element sealing material has at least one surface modification treatment surface selected from a corona treatment surface, a plasma treatment surface, an ultraviolet treatment surface, an ozone cleaning treatment surface, and a molecular adhesive treatment surface.

15. The ultraviolet light emitting device according to any one of claims 12 to 14, characterized in that the ultraviolet light emitting element sealing material also serves as an adhesive for adhering to a molded optical substrate member selected from an optical cube molded optical member, a rectangular molded optical member, a spherical molded optical member, a hemispherical molded optical member, a prism molded optical member, a spherical lens molded optical member, and an aspherical lens molded optical member, which is made of quartz glass, non-quartz glass, or a transparent resin.

16. The ultraviolet light-emitting device described in claim 15, characterized in that at least one of the bonding surfaces between the ultraviolet light-emitting element sealing material and the ultraviolet light-emitting element and the ultraviolet light-emitting element mounting substrate, and / or at least one of the bonding surfaces between the ultraviolet light-emitting element sealing material and the molded optical substrate member has at least one surface modification treatment surface selected from a corona treatment surface, a plasma treatment surface, an ozone cleaning treatment surface, and a molecular adhesive treatment surface.

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