WO2011135780A1 - Light-emitting device and method for manufacturing the same - Google Patents

Abstract

Disclosed is a light-emitting device in which a core comprising a wiring body provided with a light-emitting element is tightly enclosed within silicone rubber. The core is extruded from a die while the periphery thereof is surrounded by a curable silicone rubber composition, and the core can then be tightly enclosed by curing the curable silicone rubber composition. It is therefore possible to increase the weather resistance of the light-emitting device.

Description

Light emitting device and manufacturing method thereof

The present invention relates to a light emitting device used for outdoor lighting and decoration because of excellent weather resistance, and a manufacturing method capable of long molding.

Conventionally, cable or tape-shaped LED wiring bodies have been proposed for decoration and outdoor lighting (Patent Documents 1 to 3 below). Since these have no function of protecting the substrate, the installation environment is limited.

In other words, restrictions due to physical factors such as external stress, impact and vibration, restrictions due to chemical factors such as moisture, rainwater, cleaning agents, harmful gases and ultraviolet rays, and restrictions due to biological factors such as mold generation and insect attachment However, depending on the usage environment, it may take time to install a protective structure separately.

To prevent this, there has been a proposal to apply a flexible substrate on which a light emitting element is arranged with a silicone tube to be applied to a wide range of environments, but there is no detailed explanation of what kind of silicone is used. (Patent Document 4 below).

As in Patent Document 4, the structure covered with the tube is simple, but a space (gap) is generated between the tube and the light emitter, so that moisture such as water vapor or rainwater may be mixed in, causing internal electrical damage. There was a possibility of waking up. Further, since the optical space repeats birefringence and reflection, it is not desirable in terms of transparency and light transmission, and there is also a problem that the interior is clouded with moisture. If the product is cut and shortened, it may be difficult to cut the tube well, and if it is longer than 5 m, it is difficult to enclose the light emitter in the tube. Inefficient and inferior in productivity.

Patent Document 4 also describes that a flexible substrate on which a light emitting element is arranged is encapsulated in urethane, but urethane is not an optimal material because it easily yellows and changes transmittance, and has low temperature characteristics. Since it is not good, it may be deteriorated due to loss of flexibility when used in a severe low temperature environment.

Japanese Patent No. 4259484 Japanese Patent No. 3596480 JP 2004-247281 A Japanese Patent No. 3916651

The present invention relates to environmental factors, that is, physical factors such as external stress, impact, vibration, etc., chemical factors such as moisture, rainwater, cleaning agents, harmful gases, ultraviolet rays, biological factors such as mold generation and insect adhesion. There is no deterioration due to the cause, moisture such as water vapor or rainwater is not mixed, causing internal electrical damage, excellent transparency and light transmission, no change in transmittance due to yellowing, and excellent low temperature characteristics. It is an object of the present invention to obtain a light emitting device that does not lose flexibility even when used in a severe low temperature environment.

As a result of intensive studies, the present inventors have found that the above-mentioned problem can be solved by tightly encapsulating a core material (hereinafter simply referred to as “core material”) made of a wiring body having a light emitter in silicone rubber. I found that it can be solved.

That is, the present invention relates to a light-emitting device characterized in that a core material made of a wiring body having a light-emitting body is tightly sealed in silicone rubber. The light emitting device of the present invention is formed by extruding from the die while surrounding the core material with the curable silicone rubber composition, thereby bringing the core material and the curable silicone rubber composition into close contact, and then curing. Can be manufactured.

The light emitting device of the present invention is protected from environmental factors because the core material is tightly sealed in the silicone rubber, and it is transparent without causing moisture such as water vapor or rain water to enter the interior and causing electrical damage. It has excellent properties, light transmittance, weather resistance, little change in light transmittance due to yellowing, excellent low temperature characteristics, and does not lose flexibility even when used in severe low temperature environments. Moreover, since silicone rubber is flexible, it is excellent in flexibility. Therefore, there is no restriction on the installation environment, and it can be suitably used for outdoor lighting applications and ornamental applications.

The method for manufacturing a light-emitting device of the present invention is extremely useful in that the light-emitting device can be continuously formed into a long shape, and there is little internal damage during manufacture.

It is a fragmentary perspective view of an example of the core material used for the light-emitting device of this invention. It is a fragmentary perspective view of an example of the light-emitting device of this invention. It is a schematic explanatory drawing of an example of the manufacturing method of this invention. It is explanatory drawing which shows the state in the in-die of FIG. It is explanatory drawing which shows the molding state in the out die | dye of FIG.

In the present invention, for example, an LED can be used as the light emitter. The LED may use the LED element as it is, or may be used in the form of an LED module. For example, a flexible printed wiring board or a cable such as a flat cable can be used as the wiring body. A module that controls light emission of a light emitter such as an LED may be mounted on the core material. The core material of the present invention may be generally used, and may be one described in the above prior art document.

The present invention is characterized in that the core material is tightly sealed in silicone rubber. Thereby, the core material can be protected from environmental factors, and moisture can be prevented from entering from the outside. Silicone rubber is light-transmitting, has little temperature dependence, and can be suitably used in harsh environments, and can be used for a long time because it has weather resistance.

The silicone rubber can be obtained by curing a curable silicone rubber composition. As the curable silicone rubber composition, those containing the following (A) and (B) can be suitably used, and the following (C ) Is preferable for increasing the strength.
(A) The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
(Wherein, ^{R 1} is identical or different unsubstituted or substituted monovalent hydrocarbon group with one another, a is a number that satisfies 1.5 <a <2.8, in total ^{R 1,} 0.001 ~ 20 mol% is an alkenyl group and / or a cycloalkenyl group.)
Organopolysiloxane (B) Curing agent (C) Reinforcing filler having an average degree of polymerization of 100 or more

The component (A) preferably has an average degree of polymerization of 100 or more from the viewpoint of moldability. More preferably, it is 3000 to 100,000. Further, R ¹ preferably has 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms. Specific examples of R ¹ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, nonyl group, Alkyl group such as decyl group, vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, hexenyl group, alkenyl group such as octenyl group, cycloalkenyl group such as cyclohexenyl group, phenyl group, tolyl Group, aryl group such as xylyl group, naphthyl group, aralkyl group such as benzyl group, phenylethyl group, phenylpropyl group, chloromethyl group, bromoethyl group, 3,3,3-trifluoropropyl group, 3-chloropropyl group Halogen substitution such as cyanoethyl group, cyano group-substituted hydrocarbon group, etc. It is.

Each R ¹ group may be different or the same, but preferably has at least two alkenyl groups and / or cycloalkenyl groups in the molecule. The content of the alkenyl group and / or cycloalkenyl group is preferably 0.001 mol% or more and 20 mol% or less in the total R ¹ . When the content is less than 0.001 mol%, the curability is inferior, and when it exceeds 20 mol%, the cured rubber becomes brittle and the mechanical strength is lowered. A preferable lower limit is 0.01 mol%, and a more preferable upper limit is 10 mol%.

Examples of the organopolysiloxane include those in which a group other than the alkenyl group and / or cycloalkenyl group in R ¹ is a methyl group, or a part of the methyl group of such an organopolysiloxane is a phenyl group, trifluoropropyl. Those substituted with a group or the like are preferred.

Further, the molecular chain terminal of the component (A) is preferably blocked with a triorganosilyl group or a hydroxyl group. Examples of the triorganosilyl group include a trimethylsilyl group, a dimethylvinylsilyl group, and a trivinylsilyl group. Is done.

A is preferably a number satisfying 1.5 <a <2.8 from the viewpoint of rubber physical properties after curing. By setting it as this range, the silicone rubber suitable for the use of the present invention in which hardness, elongation, and mechanical strength are balanced can be obtained. A more preferable value of a is in the range of 1.8 to 2.5, and more preferably 1.98 to 2.02.

The organopolysiloxane of the above formula (1) may have a linear molecular structure or a branched structure containing R ¹ SiO _3/2 units or SiO _4/2 units. Linear diorgano, in which the chain portion is basically composed of repeating R ¹ ₂ SiO _2/2 diorganosiloxane units and both ends of the molecular chain are blocked with R ¹ ₃ SiO _1/2 triorganosiloxy units Polysiloxanes can generally be used. Further, the alkenyl group and / or cycloalkenyl group in the molecule may be bonded to either the molecular chain terminal or the silicon atom in the middle of the molecular chain, or may be bonded to both, but it is curable. From the viewpoint of the physical properties of the cured product, it is preferable that it has an alkenyl group and / or a cycloalkenyl group bonded to at least silicon atoms at both ends of the molecular chain.

The curing agent for component (B) can be appropriately selected from known curing agents that are usually used for curing silicone rubber. Examples of these curing agents include di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, dicumyl peroxide and the like used in radical reactions. When the organic peroxide or organopolysiloxane of component (A) has two or more alkenyl groups and / or cycloalkenyl groups in one molecule, one molecule of hydrogen atom bonded to a silicon atom is used as an addition reaction curing agent. Two or more organohydrogenpolysiloxanes and platinum-based catalysts can be used. In the present invention, it is preferable to cure by radical reaction and / or addition reaction.

Examples of the organohydrogenpolysiloxane include tris (dimethylhydrogensiloxy) methylsilane, tris (dimethylhydrogensiloxy) phenylsilane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetra. Methylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, both ends trimethylsiloxy group-blocked methylhydrogenpolysiloxane, both ends trimethylsiloxy group-blocked dimethylsiloxane / methylhydrogensiloxane Polymer, both ends dimethylhydrogensiloxy-blocked dimethylpolysiloxane, both ends dimethylhydrogensiloxy-blocked dimethylsiloxane methylhydrogen Hexane copolymers, both end trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane copolymers, both end trimethylsiloxy-blocked methylhydrogensiloxane-diphenylsiloxane-dimethylsiloxane _{copolymer, (CH 3) 2 HSiO 1} / _A copolymer comprising ₂ units and SiO _4/2 units, a copolymer comprising (CH ₃ ) ₂ HSiO _1/2 units, SiO _4/2 units and (C ₆ H ₅ ) SiO _3/2 units, and the like In these exemplified compounds, a part or all of the methyl group may be another alkyl group such as an ethyl group or a propyl group, an aryl group such as a phenyl group, or a halogen-substituted alkyl group such as a 3,3,3-trifluoropropyl group. And the like substituted with.

The molecular structure of the organohydrogenpolysiloxane may be any of linear, cyclic, branched, and three-dimensional network structures, but the number of silicon atoms in one molecule, that is, the degree of polymerization is 2 to 1,000. Preferably, those having about 3 to 500, particularly preferably about 3 to 300 can be used.

The compounding amount of the organohydrogenpolysiloxane is preferably 0.1 to 50 parts by mass, particularly 0.3 to 30 parts by mass with respect to 100 parts by mass of the organopolysiloxane as the component (A).

The addition amount of these curing agents may be the same as in the case of ordinary silicone rubber, and may be an effective curing amount. However, in the case of radical reaction, the organic peroxide is added to 100 parts by mass of component (A). It is preferable to use 0.1 to 10 parts by mass with respect to the addition reaction. In the addition reaction, the SiH group of the organohydrogenpolysiloxane is 0 with respect to 1 mol of the alkenyl group and / or cycloalkenyl group of the component (A). .5 to 5 mol and platinum black, platinous chloride, reaction product of chloroplatinic acid and monohydric alcohol, complex of chloroplatinic acid and olefins, platinum-based catalyst such as platinum bisacetoacetate, palladium It is preferable to use an amount such that the catalyst such as a rhodium-based catalyst or a rhodium-based catalyst is 1 to 2,000 ppm of the curable silicone rubber composition.

The reinforcing filler of component (C) may be any substance as long as it is used as a silicone rubber reinforcing material. The reinforcing silica fine powder is preferably used, and those used in the conventional silicone rubber composition can be used, and in particular, the reinforcing silica fine powder having a specific surface area of 50 m ² / g or more is used. In particular, 50 to 800 m ² / g of precipitated silica, fumed silica, calcined silica and the like are preferably used. Fumed silica is suitable for improving rubber strength.

The reinforcing silica fine powder may be a surface-treated silica fine powder. In that case, these silica fine powders may be directly embedded in a powder state in advance. It can be processed by a generally known technique as a normal processing method. For example, the untreated silica fine powder and the processing agent are put in a mechanical kneading apparatus or fluidized bed sealed at normal pressure, and an inert gas is present if necessary. Under the mixing treatment at room temperature or heat treatment. In some cases, a catalyst may be used to facilitate the treatment. After kneading, the treated silica fine powder can be produced by drying.

The blending amount of the treatment agent may be more than the amount calculated from the coating area of the treatment agent. Treatment agents are silazanes such as hexamethyldisilazane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane Silane coupling agents such as trimethylmethoxysilane, triethylmethoxysilane, vinyltris (methoxyethoxy) silane, trimethylchlorosilane, dimethyldichlorosilane, divinyldimethoxysilane and chloropropyltrimethoxysilane, polymethylsiloxane, organohydrogenpolysiloxane, etc. Organosilicon compounds are mentioned, and these are surface-treated and used as hydrophobic silica fine powder. As the treating agent, silane coupling agents or silazanes are particularly preferable.

When the specific surface area is less than 50 m ² / g, the reinforcing effect cannot be sufficiently obtained.
The addition amount can be added within the range that can maintain light transmittance. The amount is preferably 1 to 50 parts by mass with respect to 100 parts by mass of component (A). When it exceeds 50 parts by mass, the transparency is lost and the effects of the present invention cannot be obtained. The amount is preferably 1 to 30 parts by mass.

In addition, to the curable silicone rubber composition, color adjusting agents such as various inorganic substances and organic substances can be added as necessary to adjust transparency and optical characteristics. The color tone adjusting agent is added for the purpose of diffusing light and is not particularly limited as long as it achieves the purpose, but preferably a metal, a metal oxide, a metal nitride, a metal carbide, etc. Examples thereof include light diffusing fillers, organic or inorganic pigments, and dyes.

The addition amount of the color tone adjusting agent is not particularly limited as long as the transparency is not impaired. An appropriate amount can be used as long as the light transmittance does not become 50% or less. Preferably, 0.01 to 50% by mass of pigment, dye or light diffusion filler is added to the curable silicone rubber composition. When the color tone adjusting agent is added, the light transmittance of the 2 mm optical path length of the silicone rubber is preferably 50 to 99.9%.

Although the manufacturing method of a curable silicone rubber composition is not specifically limited, It can obtain by knead | mixing the predetermined amount of the component mentioned above with 2 rolls, a kneader, a Banbury mixer, etc. If necessary, kneading may be performed under heating. Specifically, the method of adding component (B) after kneading component (A) and component (C), kneading component (A), component (C) and other additives under heating, then ( Examples thereof include a method of adding the component B). The heating temperature and heating time are not particularly limited, but for example, heat treatment is performed at 100 to 200 ° C. for 30 minutes to 5 hours.

The curing conditions of the curable silicone rubber composition are not particularly limited, but are generally cured by heat curing at 80 to 250 ° C., particularly 120 to 200 ° C. for 5 seconds to 1 hour, particularly 30 seconds to 30 minutes. A molded product can be obtained. Further, post-curing may be performed at 100 to 200 ° C. for about 10 minutes to 10 hours.

As described above, the case where the silicone rubber is produced by curing the curable silicone rubber composition containing the component (A) and the component (B) has been described, but the curable silicone rubber composition that can be used is not limited thereto. . For example, (D) a curing agent comprising an organopolysiloxane containing two or more silanol groups and (E) an organosilicon compound having two or more hydrolyzable groups such as alkoxy groups, acetoxy groups, ketoxime groups, and propenoxy groups. Condensation reaction type curable silicone rubber compositions containing

In these cases as well, if necessary, (C) a reinforcing filler, a color tone adjusting agent and other additives are blended as in the case of the curable silicone rubber composition containing the components (A) and (B). can do.

As the core material, a commercially available one, for example, a core material in which LED elements are arranged in series at a fixed interval on a flexible printed wiring board, or a core material connected with a cable such as a flat cable can be used. .

FIG. 1 shows an example of a core material in the present invention in which LED elements 2 are arranged in series at a constant interval on a flexible printed wiring board 1. FIG. 2 shows an example of the light emitting device of the present invention in which the core material is tightly sealed in the silicone rubber 3.

The manufacturing method of the light emitting device of the present invention is such that the core material comprising the wiring body provided with the light emitter is surrounded by the curable silicone rubber composition and extruded from the die to bring the core material and the curable silicone rubber composition into close contact with each other. And then cured.

FIG. 3 shows a schematic explanatory diagram of an example of the production method of the present invention. The out die in FIG. 3 corresponds to the die referred to in the manufacturing method of the present invention. As shown in FIG. 3, the indie 7 is disposed so as to be surrounded by the outdie 8. The core material 4 is drawn out from the core material wound body 10 and introduced into the indie 7. The state in the in-die 7 is shown in FIG. On the other hand, the curable silicone rubber composition is introduced into the out die 8 while surrounding the outer periphery of the in die 7 by the extrusion screw 5. In the process of passing through the out die 8, the core material 4 and the curable silicone rubber composition 6 are in close contact and integrated into an uncured molded product 9. The molding state of the out die 7 is shown in FIG.

FIG. 5 shows a case where the cross-sectional shape of the uncured molded product 9 is a semicircular shape, but the shape can be any shape such as an ellipse or a rectangle according to the outlet shape of the out die 8. The extrusion molding apparatus needs to be designed so that bubbles and the like are not mixed inside the uncured molded product 9.

The speed at which the uncured molded product 9 is extruded may be in the range of 0.1 to 5 m / min, and preferably about 0.5 to 3 m / min. In addition, when it is less than 0.1 m / min, productivity will worsen and cost will become high, and when it exceeds 5 m / min, hardening will become inadequate.
Next, the uncured molded product 9 is cured to obtain the light emitting device of the present invention.
The curing device may be any device that is continuously connected to the extruder, and may be a vertical type or a horizontal type.

The curing temperature is preferably in the range of 80 ° C. to 250 ° C., but a more preferable curing temperature is 120 to 200 ° C. The curing time is 1 to 60 minutes, preferably 3 to 30 minutes. If the temperature is less than 100 ° C, curing is insufficient, and if it exceeds 250 ° C, the cured product is deteriorated, which is not preferable. If the curing time is less than 1 minute, curing is insufficient, and if it exceeds 60 minutes, it is uneconomical and causes internal deterioration.

By the production method of the present invention, a core material having a length of several meters to several hundred meters or more can be tightly sealed in silicone rubber.
The manufactured light emitting device can be cut into a desired dimension such as 5 m or less. Since the wiring of the wiring body is exposed by cutting, a conductive wire may be joined to the exposed wiring and connected to an external power source.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.
The materials used in the examples are as follows.

・ Organopolysiloxane:
(A-1) Methylvinyl consisting of 99.85 mol% of dimethylsiloxane units and 0.15 mol% of methylvinylsiloxane units, having an average degree of polymerization of 8,000, and having both molecular chain ends blocked with dimethylvinylsiloxy groups Polysiloxane (a-2) comprising 99.5 mol% of dimethylsiloxane units and 0.5 mol% of methylvinylsiloxane units, having an average degree of polymerization of 8,000, and both ends of the molecular chain blocked with dimethylvinylsiloxy groups Methyl vinyl polysiloxane

・ Curing agent:
(B-1) Vinylsiloxane complex of chloroplatinic acid (platinum content 1% by mass)
(B-2) Methyl hydrogen polysiloxane represented by the following formula (2)

・ Reinforcing silica fine powder:
(C-1) Reinforcing silica fine powder having a BET specific surface area of 300 m ² / g (trade name: Aerosil 300, manufactured by Nippon Aerosil Co., Ltd.)

・ Other ingredients:
(F-1) Hexamethyldisilazane

[Example 1]
100 parts by weight of (a-1), 15 parts by weight of (c-1), 4.5 parts by weight of (f-1) as a surface treating agent for (c-1) and 1 part by weight of ion-exchanged water, The mixture was mixed and kneaded while heating at 170 ° C. for 2 hours to homogenize to prepare an unvulcanized silicone compound A.

100% by mass of unvulcanized silicone compound A and 0.2 parts by mass of vinyl siloxane complex of chloroplatinic acid (b-1), 0.7 parts by mass of curing agent (b-2), and ethynyl as a control agent for (b-1) A silicone composition A was obtained by kneading 0.2 parts by mass of cyclohexanol with a two roll.

As shown in FIG. 3, a silicone material A and a core material formed by connecting a plurality of LED elements to a flexible wiring board are simultaneously inserted through separate insertion ports and extruded at a speed of 1 m / min. Then, it was cured at 130 ° C. for 10 minutes to obtain a molded product having an elliptical cross section having a length of 50 m, a thickness of 2 mm, and a width of 15 mm. The following evaluation was performed about what was obtained.

[Example 2]
Molded product in the same manner as in Example 1 except that 100 parts by mass of the silicone composition A of Example 1 was further mixed with 3 parts by mass of titanium oxide (color tone adjusting agent) having an average particle diameter of 3 μm to obtain a silicone composition B. Got. The following evaluation was performed about what was obtained.

[Example 3]
(A-2) 100 parts by mass, (c-1) 10 parts by mass, (c-1) (f-1) 4.5 parts by mass and ion-exchanged water 1 part by mass with a kneader. The mixture was blended and kneaded while heating at 170 ° C. for 2 hours to homogenize to prepare an unvulcanized silicone compound B.

A molded product was obtained in the same manner as in Example 2 except that unvulcanized silicone compound B was used instead of unvulcanized silicone compound A. The following evaluation was performed about what was obtained.

[Comparative Example 1]
A core material having a length of 1 m formed by connecting a plurality of LED elements to a flexible wiring board is previously placed in a mold, and a transparent liquid urethane resin RU-841A-CLR (manufactured by Nissin Resin Co., Ltd.) is poured over the core material. After removing the bubbles, it was cured and taken out at 80 ° C. for 1 hour to obtain a molded product having a length of 1 m, a thickness of 2 mm, and a width of 15 mm and an elliptical cross section. The following evaluation was performed about what was obtained.

[Comparative Example 2]
A transparent urethane resin used in Comparative Example 1 is injected into a transparent cured tube-shaped urethane resin tube after a core material having a length of 50 cm formed by connecting a plurality of LED elements to a flexible wiring board is inserted. Then, the core is covered and the opening is hermetically sealed with heat, then cured at 80 ° C. for 1 hour, and encapsulated in an elliptical urethane resin having a length of 50 cm, a thickness of 2 mm, and a width of 15 mm. A molded product was obtained. The following evaluation was performed about what was obtained.

The following performance evaluation was performed on the molded products of Examples and Comparative Examples, and the results are shown in Table 1.
[Performance evaluation method]

-Molded product internal state The presence or absence of air bubbles inside the molded product was observed.

-Continuous productivity The state of the molded product when 50 m was continuously produced was observed.

-Internal breakability The presence or absence of internal disconnection was confirmed by conducting and observing the presence or absence of light emission of the LED.

-Low temperature flexibility A bending test was conducted at 40 ° C. below freezing point, and a product bent at 90 ° or more was considered acceptable.

-Light transmittance The silicone composition used in the examples was subjected to heat compression molding (170 ° C. × 10 minutes, 10 MPa) to prepare a sheet of length: width: thickness = 170 mm: 150 mm: 2 mm. Light was passed in the thickness direction of this sheet, and the light transmittance at an optical path length of 2 mm was measured. A spectrophotometer U3310 type (manufactured by Hitachi, Ltd.) was used as a measuring device, and parallel light having a wavelength of 600 nm was used as light, and measurement was performed at a temperature of 25 ° C.
Moreover, the sheet | seat of the length: width: thickness = 170mm: 150mm: 2mm which consists of a hardened | cured material of the transparent urethane resin used in the comparative example 1 was created, and the light transmittance was measured similarly to the above. The measured values are shown in the column of Comparative Example 1 in Table 1.

-Light diffusivity The silicone composition used in the Examples was pressure-heated and molded (170 ° C. × 10 minutes, 10 MPa) to prepare a sheet of length: width: thickness = 170 mm: 150 mm: 2 mm.
A He-Ne laser beam (Neoarc's wavelength 632.8 nm, oscillation output 0.6 mW, beam diameter 0.8 mmφ) is vertically incident on the surface of the sheet 30 cm away, and the laser beam spot spreads red on the back of the sheet The diameter was measured. When the spot diameter was 0.8 mm to 1.0 mm, x was marked, and when it exceeded 1.0 mm, it was marked.
Moreover, the light diffusivity was measured similarly to the above using the sheet | seat which consists of the hardened | cured material of the urethane resin of the length: width: thickness = 170mm: 150mm: 2mm used by the measurement of light transmittance. The measurement results are shown in the column of Comparative Example 1 in Table 1.

-Water resistance The molded product was immersed in warm water at 80 ° C, and the internal state and performance change after 1000 hours were observed.

・ Ultraviolet light degradation test Leave a 2 mm thick sheet used for light transmittance measurement for 24 hours in EYE SUPER UV TESTER SUV-W151 (Iwasaki Electric Co., Ltd., illuminance 100 mW, temperature 50 ° C., humidity 30%). The appearance and discoloration were evaluated with a color difference meter. The measurement results when using a sheet made of a cured urethane resin are shown in the column of Comparative Example 1 in Table 1.

Claims (6)

A light emitting device comprising: a core material comprising a wiring body provided with a light emitter, which is tightly sealed in silicone rubber.
The light emitting device according to claim 1, wherein the light emitter is an LED, and the wiring body is a flexible printed wiring board.
The silicone rubber is
(A) The following average composition formula (1)
R ¹ _a SiO _{(4-a) / 2} (1)
(Wherein, ^{R 1} is identical or different unsubstituted or substituted monovalent hydrocarbon group with one another, a is a number that satisfies 1.5 <a <2.8, in total ^{R 1,} 0.001 ~ 20 mol% is an alkenyl group and / or a cycloalkenyl group.)
2. A product obtained by curing a curable silicone rubber composition containing an organopolysiloxane having an average degree of polymerization of 100 or more and (B) a curing agent. Or the light-emitting device of Claim 2.
The light-emitting device according to claim 3, wherein the curable silicone rubber composition contains (C) a reinforcing filler.
The curable silicone rubber composition contains 0.01% to 50% by weight of any one of pigments, dyes, and light diffusing fillers as a color tone adjusting agent, and has a 2 mm optical path length of the cured silicone rubber. 5. The light emitting device according to claim 3, wherein the light transmittance is 50% to 99.9%.
The core material composed of the wiring body including the light emitter is extruded from a die while surrounding the core material with the curable silicone rubber composition, thereby bringing the core material and the curable silicone rubber composition into close contact with each other. 6. The method for manufacturing a light-emitting device according to claim 1, wherein the light-emitting device is cured and then cured.

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