JP6989403B2 - Light emitting member - Google Patents

Description

The present invention relates to a light emitting member. More specifically, the present invention relates to a light emitting member having flexibility and waterproofness to which an LED is mounted.

Conventionally, as a light emitting member having flexibility, a band-shaped flexible light emitting body (Patent Document 1) in which an LED is mounted on a circuit formed on a film-shaped flexible substrate is known. However, its flexibility was insufficient due to the use of a film-like base material. Further, since it is necessary to use an adhesive when fixing the light emitting member to the object, there is a problem that the flexibility is further impaired.

Further, when the light emitting member is used in an environment where water is present, the light emitting member is inserted into a transparent resin tube and used, which further impairs flexibility.

JP-A-2017-117516

The present invention provides a light emitting member having flexibility and waterproofness.

As a result of diligent studies, the present inventors have formed a circuit made of a conductive material on the surface of a cloth made of non-conductive fibers, and after forming a light emitting member with LED parts mounted on this circuit, this When the entire light emitting member is coated with the waterproof resin, it has a configuration having a first waterproof resin coating mainly covering the cloth and the circuit portion and a second waterproof resin coating mainly covering the electrodes of the LED parts. By doing so, it was found that a light emitting member having both flexibility and waterproofness can be obtained.

That is, the light emitting member of the present invention is a light emitting member composed of a circuit base cloth in which a circuit made of a conductive member is formed on the surface of a cloth made of non-conductive fibers and an LED component mounted on the circuit. It is a light emitting member having a first waterproof resin layer mainly covering the circuit base cloth and a second waterproof resin layer mainly covering the electrodes of the LED component.

The tensile stress of the first waterproof resin layer at 10% elongation by JIS K7161 is preferably less than 10.0 MPa, and the thickness thereof is preferably 10 μm or more and 200 μm or less. According to this, it is possible to obtain a light emitting member having high flexibility and easy to join by sewing.

The resin material constituting the second waterproof resin layer is preferably a UV curable acrylic resin or an ethylene-vinyl acetate copolymer. Such a resin material can be used in a liquid form of 100% active ingredient. Therefore, it is possible to sufficiently cover the electrode by following the unevenness of the electrode at the time of application. After curing, it is possible to prevent exposure of the electrodes and deformation of the light emitting member due to volume shrinkage. As a curing method, a method of UV irradiation or solidification by cooling, which is completed at a low temperature and in a short time, can be adopted, so that the damage to the circuit base cloth is small and the manufacturing cost can be reduced.

The sheet resistance of the circuit is preferably 0.10Ω / □ (square) or less. It is preferable that the circuit is a metal film containing copper or silver as a main component. It is preferable that the circuit is made of a resin composition containing conductive particles.

According to the present invention, a light emitting member having flexibility and waterproofness can be obtained.

It is a figure which shows an example of the light emitting member of this invention.

Hereinafter, the light emitting member of the present invention will be described with reference to FIG. The light emitting member of the present invention uses cloth 1 made of non-conductive fibers as a base material. Non-conductive fibers include synthetic fibers (polyamide, polyester, polyurethane, polyacrylic, etc.), semi-synthetic fibers (acetate, triacetate, etc.), recycled fibers (rayon, cupra, etc.), and natural fibers (cotton, linen, wool, silk, etc.). Etc.), etc., but are not particularly limited, but synthetic fibers are preferable from the viewpoint of strength and chemical resistance. Particularly preferable synthetic fibers include polyester, polyamide and the like. The form of the fiber may be a monofilament yarn, a multifilament yarn, a spun yarn, a covering yarn or the like. Examples of the form of the cloth 1 include woven fabrics (plain weave, twill weave, satin weave, etc.), knitted fabrics (circular knitting, warp knitting, etc.), and non-woven fabrics, and are not particularly limited.

The circuit base cloth 3 of the present invention is obtained by forming the circuit 2 made of a conductive material on the surface of the cloth 1 made of non-conductive fibers. Examples of the conductive material forming the circuit 2 include carbon and the like in addition to various metals. The circuit 2 is preferably made of a metal film having a metal content of 95% or more. Examples of the method for forming such a circuit 2 include a metal plating method and the like. Examples of the metal species used include gold, silver, copper, nickel, tin, zinc and the like.

The circuit 2 formed on the surface of the cloth 1 may be a resin composition containing conductive particles. Examples of the conductive particles used include carbon particles, carbon nanotubes, and the like, in addition to particles made of metal particles, metal oxides, conductive polymers, and the like. The particle size of the conductive particles is preferably 0.01 to 10 μm.

Resin components used in the resin composition containing conductive particles include synthetic resins such as acrylic resin, urethane resin, polyester resin, silicone resin, epoxy resin, melamine resin, and polyamine resin, natural rubber, dammar, mastic, and the like. Natural resin can be mentioned. The content of the conductive material in the resin composition is preferably 20% by mass to 95% by mass. Various printing methods are adopted as a method for forming the circuit 2 using the resin composition containing the conductive particles, and drying is performed after printing if necessary.

Circuits 2 may be superposed in the thickness direction to form a multi-layer circuit. The component mounting density can be increased by forming the circuit 2 in multiple layers.

The LED component 4 is mounted on the circuit 2 of the circuit base cloth 3 having the above configuration via the joining member 8. Examples of the joining member 8 include a resin composition containing conductive particles, solder, and the like.

As a method of joining using a resin composition containing conductive particles, (1) a resin composition containing conductive particles is applied to a circuit side electrode, and (2) an LED component 4 side electrode and a circuit side electrode are applied. The LED component 4 is placed on the circuit 2 so that the resin composition containing the conductive particles applied to the above is combined, and (3) the resin composition containing the conductive particles is dried, heat-cured as necessary, and UV. Hardens. Examples of the coating method (1) include screen printing and a dispenser. The composition of the resin composition containing the conductive particles is the same as that for the circuit.

The above steps (1) and (2) may be reversed. In the opposite case, (1) the LED component 4 is placed on the circuit 2 so that the LED component side electrode and the circuit side electrode are aligned, and (2) the conductive particles are connected so that the LED component side electrode and the circuit side electrode are connected. (3) The resin composition containing the conductive particles is dried, and if necessary, heat-cured and UV-cured. In this case, a dispenser or the like can be mentioned as the coating method of (2).

As a method of joining using solder, after printing cream solder on the circuit side electrode, heat it to the melting point of the solder or higher to reflow the solder and join it, or wire-shaped solder and a soldering iron. A method of soldering a circuit-side electrode and a component-side electrode using the method can be mentioned.

The light emitting member of the present invention has a first waterproof resin layer 9 that mainly covers the circuit base cloth 3. Examples of the resin component constituting the first waterproof resin layer 9 include polyurethane elastomers, polyester elastomers, ethylene-vinyl acetate copolymers and the like. The first waterproof resin layer 9 is required to have high flexibility as well as waterproofness. Therefore, it is preferable that the first waterproof resin layer 9 has a tensile stress of less than 10.0 MPa at 10% elongation according to JIS K7161 and a thickness of 10 μm or more and 200 μm or less. When the tensile stress and the thickness at the time of 10% elongation are within this range, a light emitting member having sufficient flexibility in actual use can be obtained.

The waterproofness of the first waterproof resin layer 9 is as follows: a circuit base cloth 3 (width 10 mm, length 120 mm) in which the first waterproof resin layer 9 is formed on the front and back, and a brass plate (width 60 mm, length) as a counter electrode. 120 mm) is immersed in an acidic artificial sweat solution specified in JIS L0848: 2004 at an interval of 60 mm and an immersion depth of 100 mm for 72 hours, and a DC power supply and an ammeter are connected in series between the circuit base cloth 3 and the metal plate. The amount of current flowing when a DC voltage of 10 V was applied for 90 seconds was used as an index for evaluation. A resin having a current amount of less than 1 mA can be used in the present invention as a waterproof resin.

The first waterproof resin layer 9 mainly covers the circuit base cloth 3. As a method for forming the first waterproof resin layer 9, a liquid waterproof resin is applied by a dipping method, a coating method, a spray method, a printing method, or the like, and then dried, heat-cured, UV-cured, and cooled if necessary. Is solidified by. When a sheet-shaped waterproof resin layer is laminated in advance, heat fusion, pressure bonding with an adhesive, or the like is performed. The step of forming the first waterproof resin layer 9 may be performed before mounting the LED component 4 or may be performed after mounting the LED component 4. From the viewpoint of controlling the thickness of the first waterproof resin layer 9 to be thin to obtain a more flexible light emitting member, it is preferable to form the first waterproof resin layer 9 before mounting the LED component 4.

The second waterproof resin layer 10 mainly covers the LED component 4. Examples of the resin component constituting the second waterproof resin layer 10 include a UV curable acrylic resin or an ethylene-vinyl acetate copolymer. According to this, it can be used in a liquid form of 100% active ingredient. It is possible to sufficiently cover the electrode 7 by following the unevenness of the electrode 7 at the time of application, and after curing, exposure of the electrode 7 and deformation of the light emitting member due to volume shrinkage are unlikely to occur. Further, as a curing method, solidification by UV irradiation or cooling, which is completed at a low temperature and in a short time, can be used, so that the circuit base cloth 3 is less damaged and the manufacturing cost can be reduced. In addition to the above, epoxy resin, silicone resin, and the like can be considered as the liquid resin having 100% active ingredient, but the epoxy resin has a high thermosetting temperature and a relatively long curing time. The silicone resin has poor adhesion to the circuit base cloth 3.

For the waterproofness of the second waterproof resin layer 10, a part of the circuit base cloth 3 is exposed, the LED component 4 is mounted, and the conductive portion of the circuit base cloth 3 and the LED component 4 is formed by the second waterproof resin layer 10. The evaluation method and evaluation criteria of the first waterproof resin layer 9 are the same except that they are coated.

In the case of a UV-curable acrylic resin, the second waterproof resin layer 10 is applied by a dispenser, a brush, a brush, or the like, and then cured by UV irradiation. When the second waterproof resin layer 10 is formed of an ethylene-vinyl acetate copolymer, the ethylene-vinyl acetate copolymer is solid at room temperature, so that it is melted by heating and then applied with a glue gun, a dispenser, or the like. Allow to cool and solidify. It is also possible to place a solid piece on the part, heat it to melt it, make it flow, and then cool it to solidify it. When forming the second waterproof resin layer 10, it is important to completely cover the conductive portion of the light emitting member. It is desirable to take care so that there is no gap at the boundary with the first waterproof resin layer 9. The second waterproof resin layer 10 needs to cover at least the electrode 7 of the LED component 4, but may cover the entire LED component 4.

The present invention will be described below by way of examples, but the present invention is not limited by these examples.

[Example 1]
<Making conductive fabric>
Niei Kako on one side of the fabric (polyester woven fabric, warp: polyester processed yarn (33dtex), weft: polyester processed yarn (69dtex), plain weave (weaving density: warp 189 / 2.54 cm, weft 120 / 2.54 cm)) A protective film PET75-RC611 manufactured by Co., Ltd. was attached to protect one side of the fabric. The cloth is immersed in an aqueous solution containing 0.3 g / L of palladium chloride, 30 g / L of stannous chloride, and 300 mL / L of 36% hydrochloric acid at room temperature for 30 seconds, and then washed thoroughly with water to remove palladium chloride on the surface of the cloth. Granted. Next, the palladium chloride was reduced by immersing it in an aqueous solution of borohydrofluoric acid having an acid concentration of 0.1 N at 40 ° C. for 1 minute and then washing it thoroughly with water. Next, PET75-RC611 was peeled off, and cupric chloride 9 g / L, 37% formalin 9 mL / L, 32% sodium hydroxide 40 mL / L, N, N, N', N'-tetrakis (2-hydroxypropyl). A copper film was formed on the cloth by immersing it in an aqueous solution containing 20 g / L of ethylenediamine and a stabilizer at 40 ° C. for 15 minutes and then washing it thoroughly with water. Finally, the obtained copper-coated fabric was immersed in an electrolytic silver-plated bath Dine Silver GPE-ST15 manufactured by Daiwa Kasei Co., Ltd., and was energized at a current density of 2 A / dm ² at room temperature for 1.5 minutes and washed thoroughly with water. A conductive cloth having a silver coating formed on a copper coating was obtained. The metal coating amount of the obtained conductive fabric by atomic absorption spectroscopy was copper: 30 g / m ² and silver: 5 g / m ² . The sheet resistance value by the resistivity meter Loresta MCP-T360 manufactured by Mitsubishi Chemical Analytech was 0.017Ω / □ (square).

<Making circuit fabric>
A urethane-based hot melt sheet (trade name: Eceran SHM-101PUR) manufactured by Seadam Co., Ltd. is laminated on the non-metal coated surface of the conductive fabric, and 130 with the air-driven fully automatic transfer press HP-4536A-12 manufactured by Hashima Co., Ltd. It was hot-pressed at ° C., 0.5 MPa for 30 seconds and bonded. Next, a circuit fabric with an adhesive layer was obtained by cutting out a circuit pattern with a laser cutting machine LS900 manufactured by Gravotech. The circuit patterns are a linear pattern with a width of 2 mm and a length of 300 mm for a power supply, a linear pattern with a width of 1 mm and a length of 300 mm for a signal, and a linear pattern with a width of 2 mm and a length of 300 mm for a signal for power supply / signal. They were arranged in the order of / GND so as to be parallel with an interval of 1 mm.

<Formation of the first waterproof resin layer>
The tensile stress at 10% elongation by JIS K7161 as the first waterproof resin layer for covering the non-metal coated surface of the circuit fabric on the polyester organgie KK2040 manufactured by Uni Textile Co., Ltd. as the base fabric is 0.76 MPa. , A laminated product of a polyurethane sheet manufactured by Seadam Co., Ltd. (trade name: Higres DUS202, thickness 100 μm) having a thickness of 170 μm and a urethane-based hot melt sheet manufactured by Seadam Co., Ltd. (trade name: Eceran SHM101PUR, thickness 70 μm) is further laminated. A laminated product of the first waterproof resin layer Higres DUS202 (thickness 100 μm) / Eceran SHM101PUR (thickness 70 μm) for covering a metal-coated surface having an opening for mounting components on which a circuit cloth is layered. A circuit base that forms the first waterproof resin layer by stacking and hot-pressing HP-4536A-12, an air-driven fully automatic transfer press manufactured by Hashima Co., Ltd., at 130 ° C. for 0.5 MPa for 30 seconds. I got a cloth. The opening for mounting components was formed so that a 5050 size serial full-color LED chip and a 3216 size chip capacitor could be mounted every 30 mm in the extension direction of the circuit.

<Mounting of parts>
A silver paste PE873 manufactured by DuPont Electronics Materials Co., Ltd. is applied as a joining member to the metal coating surface exposed in the opening for mounting parts of the circuit base cloth using a dispenser, and a 5050 size World Semi serial product is further applied thereto. A full-color LED chip WS2812B and a 3216 size 0.1 μF chip capacitor are installed, and by heating at 80 ° C for 30 minutes in a hot air circulation drying furnace, the solvent contained in the silver paste is removed, and the parts and circuit base are electrically connected. Joined to.

<Formation of a second waterproof resin layer>
A UV curable acrylic resin composition was obtained by mixing 95 parts by mass of a urethane acrylate oligomer CN981 manufactured by SARTOMER and 5 parts by mass of a photopolymerization initiator IRGACURE184 manufactured by BASF. Next, the UV curable resin composition was applied using a dispenser so that the conductive portion of the circuit base cloth and the component (LED chip and chip capacitor) was completely covered. Next, a second waterproof resin layer was formed by irradiating with a UV LED light having a wavelength of 365 nm and curing it by irradiating it with an integrated light amount of 10,000 mJ / cm ^2.

<Evaluation of flexibility of light emitting member>
The light emitting member was cut out with a width of 10 mm (margin width 1.5 mm / power supply circuit width 2 mm / space width 1 mm / signal circuit width 1 mm / space width 1 mm / GND circuit width 2 mm / margin width 1.5 mm) and a length of 300 mm. Next, the cut-out light emitting member was attached to a tensile tester EZtestCE manufactured by Shimadzu Corporation, and the stress when compressing by 50 mm in the circuit extension direction was measured and used as an index of flexibility. The evaluation criteria were: ◯: less than 0.1N, ×: 0.1N or more. The results are shown in Table 1.

<Evaluation of waterproofness of light emitting members>
The waterproofness of the light emitting member was evaluated according to the method for evaluating the waterproofness of the first waterproof resin layer and the second waterproof resin layer. The evaluation criteria were as follows: ◯: current amount was less than 1 mA, ×: current amount was 1 mA or more. The results are shown in Table 1.

[Example 2]
A light emitting member was produced by the same method as in Example 1 except that the method for forming the second waterproof resin layer was changed to the method using an ethylene-vinyl acetate copolymer shown below, and the flexibility and waterproofness were evaluated.

<Formation of a second waterproof resin layer>
A rod-shaped molded product (trade name: Hot Stick HB-40S) of an ethylene-vinyl acetate copolymer manufactured by Taiyo Denki Sangyo Co., Ltd. is applied by heating and melting with a glue gun so that the circuit fabric and the conductive parts of the parts are completely covered. did. Next, it was allowed to cool to room temperature to be solidified to form a second waterproof resin layer.

[Example 3]
<Making circuit fabric>
A polyurethane sheet manufactured by Seadam Co., Ltd. (trade name: Higres DUS202, thickness 100 μm) having a tensile stress of 0.76 MPa and a thickness of 170 μm at 10% elongation by JIS K7161 which is the first waterproof resin layer and Seadam Co., Ltd. A silver paste (product number TR70901) manufactured by Taiyo Ink Mfg. Co., Ltd. was screen-printed on a laminated product of a urethane-based hot melt sheet (trade name: Eceran SHM101PUR, thickness 70 μm) with an emulsion thickness of 15 μm, stainless steel 150 mesh, and a wire diameter of 60 μm. .. Then, the circuit pattern was formed by drying in a hot air circulation drying oven at 130 ° C. for 30 minutes. The obtained circuit pattern was superposed on the polyester organdy KK2040 manufactured by Uni Textile Co., Ltd., which is the base cloth, and the air-driven fully automatic transfer press HP-4536A-12 manufactured by Hashima Co., Ltd. was used at 130 ° C., 0.5 MPa, 30 ° C. A circuit base cloth was obtained by hot pressing for a second and bonding.

<Formation of the first waterproof resin layer>
A laminated product of the first waterproof resin layer Higres DUS202 (thickness 100 μm) / Eceran SHM101PUR (thickness 70 μm) for covering the metal-coated surface provided with an opening for mounting parts on the obtained circuit base cloth was laminated and stocked. A circuit base fabric on which the first waterproof resin layer was formed was obtained by hot-pressing at 130 ° C. for 0.5 MPa for 30 seconds with an air-driven fully automatic transfer press HP-4536A-12 manufactured by Hashima Co., Ltd. .. The opening for mounting components was formed so that a 5050 size serial full-color LED chip and a 3216 size chip capacitor could be mounted every 30 mm in the extension direction of the circuit.

<Mounting of parts>
Dupont Electronics Material's silver paste PE873 is applied as a bonding member to the component mounting electrode of the circuit base cloth using a dispenser, and 5050 size World Semi's serial full-color LED chip WS2812B and 3216 size 0 are further applied. A 1 μF chip capacitor was installed and heated at 80 ° C. for 30 minutes in a hot air circulation drying furnace to remove the solvent contained in the silver paste, and the parts and the circuit base cloth were electrically bonded.

<Formation of a second waterproof resin layer>
A UV curable acrylic resin composition was obtained by mixing 95 parts by mass of a urethane acrylate oligomer CN981 manufactured by SARTOMER and 5 parts by mass of a photopolymerization initiator IRGACURE184 manufactured by BASF. Next, the UV curable resin composition was applied using a dispenser so that the circuit base cloth and the conductive portion of the component were completely covered. Next, a second waterproof resin layer was formed by irradiating with a UV LED light having a wavelength of 365 nm and irradiating with an integrated light amount of 10,000 mJ / cm2 to cure the mixture.

[Example 4]
A light emitting member was produced by the same method as in Example 1 except that the method of mounting the components was changed to the solder joining shown below, and the flexibility and waterproofness were evaluated.

<Mounting of parts>
Solder paste SB6-HLGQ-20 manufactured by Nihon Genma Co., Ltd. is printed on a component mounting electrode of the circuit base cloth with a stencil having a thickness of 100 μm, and 5050 size World Semi serial full-color LED chips WS2812B and 3216 are printed on the solder paste SB6-HLGQ-20. A 0.1 μF chip capacitor of a size was installed, placed on a hot plate heated to 160 ° C., heated, and the solder paste was reflowed to electrically bond the component and the circuit base cloth.

[Comparative Example 1]
The flexibility and waterproofness of a commercially available strip-shaped flexible light emitting member (NeoPixel RGB TAPE 1907-04 manufactured by Peace Corporation) in which a serial full-color LED was mounted on a two-layer flexible substrate having a width of 10 mm and a length of 300 mm were evaluated.

[Comparative Example 2]
A light emitting member in which a commercially available strip-shaped flexible light emitter with a width of 10 mm, a length of 300 mm, and a serial full-color LED mounted on a double-layer flexible substrate is inserted into a silicone rubber tube (Silicon waterproof NeoPixel RGB TAPE 9769-02 manufactured by Peace Corporation). We evaluated the flexibility and waterproofness of the.

Since the light emitting member of the present invention has flexibility and waterproofness, it can be easily joined to clothing, interior goods, and the like. Since the circuit base cloth is a cloth, it can be sewn to textile products such as clothing and curtains by a normal sewing method. Since it is waterproof, there is no risk of electric leakage even if it gets wet with sweat or rain.

1: Cloth 2: Circuit 3: Circuit base Cloth 4: LED component 5: LED chip 6: Substrate 7: Electrode 8: Joining member 9: First waterproof resin layer 10: Second waterproof resin layer

Claims (6)

It is a light emitting member composed of a circuit base cloth in which a circuit made of a conductive member is formed on the surface of a cloth made of non-conductive fibers and an LED component mounted on the circuit, and covers the circuit base cloth. A light emitting member having a first waterproof resin layer and a second waterproof resin layer that covers the electrodes of the LED component. The light emitting member according to claim 1, wherein the tensile stress of the first waterproof resin layer at 10% elongation by JIS K7161 is less than 10.0 MPa, and the thickness of the first waterproof resin layer is 10 μm or more and 200 μm or less. .. The light emitting member according to claim 1 or 2, wherein the second waterproof resin layer is made of a UV curable acrylic resin or an ethylene-vinyl acetate copolymer. The light emitting member according to any one of claims 1 to 3, wherein the sheet resistance of the circuit in the circuit base cloth is 0.10 Ω / □ (square) or less. The light emitting member according to any one of claims 1 to 4, wherein the circuit in the circuit base cloth is a metal film containing copper or silver as a main component. The light emitting member according to any one of claims 1 to 4, wherein the circuit in the circuit base cloth is made of a resin composition containing conductive particles.

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