Light-emitting diode film

Abstract

To provide a light-emitting diode film that protects an LED and an electrode, and is excellent in adhesion reliability, and in re-workability after adhesion.SOLUTION: A light-emitting diode film includes: a substrate; an electrode layer formed on at least a portion of the substrate; solder formed on at least a portion of the electrode layer; a light-emitting diode positioned on the solder and connected to the electrode layer; a molding layer applied to the entire surface of the substrate, the electrode layer, and the light-emitting diode; and a variable adhesive film positioned on the molding layer. The light-emitting diode film satisfies the following Equation 1. The light-emitting diode film protects an LED and the electrode, has excellent adhesion reliability, and excellent re-workability after adhesion.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a light emitting diode film.

Background Art

[0002] With the development of the information society, the requirements for display devices are increasing in various forms. Accordingly, recently, various display devices such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), ELD (Electro Luminescent Display), VFD (Vacuum Fluorescent Display), OLED (Organic Light Emitting Diode), and LED (Light Emitting Diode) have been studied and used. And recent display devices are installed indoors and outdoors and used for purposes such as advertisements. In particular, a transparent LED display can clearly show the object behind the product when the power is off, and when the LED is turned on, it can show various contents like digital signage.

[0003] Among transparent LED displays, a transparent LED film is a display device in which light emitting diodes (hereinafter referred to as "LEDs") are provided as light sources on a thin film. The transparent LED display film can include a plurality of LEDs, and the LEDs can be operated by a driving signal transmitted from the outside to display an intended image. Since such a transparent LED display film is entirely made of a film, it can be thin, light, and have a flexible structure.

[0004] The transparent LED display film can be attached onto an installation target having various surfaces such as a curved surface or a flat surface for various purposes. In order to adhere to various surfaces, the transparent LED display film must have excellent adhesion reliability. Also, during the adhesion process, if the film position of the transparent LED display is set incorrectly or foreign matter is mixed in between the installation targets, peelability for re-peeling the transparent adhesive film from the installation target is required.

[0005] For forming an adhesive layer to attach the transparent LED display film to the adherend surface, the conventional transparent LED display film uses a method of punching out the portion where the LED is located from a sheet having a structure in which a pressure-sensitive adhesive (PSA) and a polyester for molding are laminated, and then attaching it after alignment. This method has the disadvantages of a complicated manufacturing process and a long manufacturing time. Also, since the light source is located in the hole, it is vulnerable to impact, and there is a problem that defects occur when contaminants located in the hole adhere to the metal pad or the light source.

[0006] Patent Document 1 relates to a transparent light-emitting diode film, which includes a base, an electrode layer located on the base and having at least one pattern formed thereon, pads formed on at least a part of the electrode layer, light-emitting diodes located on the pads, and an adhesive layer formed on at least another part of the electrode layer. The adhesive layer is characterized in that an opening is formed in a portion corresponding to the light-emitting diodes (see FIG. 1). Patent Document 1 includes a material with strong heat resistance for the base so that no state change occurs due to temperature when forming the transparent light-emitting diode film.

[0007] However, in Patent Document 1 (Korean Patent Publication No. 2017-0139924 (published on December 20, 2017)), as an optical adhesive layer as an adhesive layer in a transparent light-emitting diode film, as shown in FIG. 1, since the adhesive layer is located in the portion excluding the light-emitting diode, after the lamination of the adhesive layer, in order to mount the light-emitting diode, an opening is formed in the portion corresponding to the light-emitting diode. In the case of the manufacturing process of mounting the light-emitting diode after forming the opening in this way, there is a disadvantage that the cost of the transparent light-emitting diode film is high due to the process stage and the complexity of the light-emitting diode film. In the process of adhering to the adherend surface after removing the protective layer of the transparent light-emitting diode film, impurities easily flow into the opening where the light-emitting diode is mounted. In this case, since the impurities are adsorbed on the metal pad or the light source, product damage and defects may be induced by heating.

[0008] In addition, since there is no adhesive layer at the position of the opening where a light-emitting diode such as an LED chip is mounted, there is a limit in that the adhesion reliability with the adherend surface of the object to be installed is low.

[0009] As shown in FIG. 2, the adhesive layer formed around the opening of the conventional transparent LED display film has a structure in which PSA and PET are laminated. However, after removing the release film, in the process of adhering the adhesive layer to the adherend surface, impurities easily flow into the opening, and there is a problem that there is little adhesive surface where the adhesive layer exists in the opening.

[0010] As part of the efforts to improve the above problems, in Patent Document 2 (Korean Registered Patent Publication No. 10-2425807 (registered on July 22, 2022)), an attempt was made to solve the problem of the inflow of contaminants by covering the light source located in the through-hole with a thermosetting liquid resin. Patent Document 2 includes a substrate having a front surface and a rear surface facing the front surface, an electrode layer formed on the front surface, a light source provided on the front surface and connected to the electrode layer, a first resin layer attached to the front surface of the substrate and having a through-hole that exposes at least a part of the electrode layer and the light source to the outside, and a second resin located in the through-hole and covering a part of the electrode layer exposed to the outside. The resin layer can be formed by injecting a liquid resin into a base. At this time, when most of the liquid resin is a thermosetting resin and shrinks through a thermosetting process, the surface is not flat and bending occurs, or such bending generates a space, reducing the adhesion area between the resin layer and the adherend surface and lowering the bonding force and adhesion. To prevent this, in order to achieve flattening, there were the troublesomeness and disadvantages that uniform pressure must be applied to the entire surface in the presence of a heat source for curing. As an example, there was the disadvantage that the size and weight of the equipment increased to apply a pressure of several hundred Kgf to an area of 1M2, and there was a risk of depth deformation of the film during the curing process.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0012] Accordingly, in order to solve the above problems of the prior art, the present invention provides a light-emitting diode film that protects the LED and the electrodes, has excellent adhesion reliability, and excellent reworkability after adhesion, by applying a molding layer to the entire upper surface of the electrode layer, solder, and light-emitting diode, and laminating a variable adhesive film on the upper surface of the molding layer.

[0013] In addition, by simplifying the structure and manufacturing process of the above excellent light-emitting diode film, it is intended to reduce the manufacturing cost.

Means for Solving the Problems

[0014] The present invention provides a light-emitting diode film including a substrate, an electrode layer formed on at least a part of the substrate, solder formed on at least a part of the electrode layer, a light-emitting diode located on the solder and connected to the electrode layer, a molding layer applied to the entire surface of the substrate, electrode layer, and light-emitting diode, and a variable adhesive film located on the molding layer, and characterized by satisfying the following formula (1).

Number

[0015] In one embodiment of the present invention, the molding layer can have an adhesive force of 100 gf / cm or more with respect to each of the substrate and the variable adhesive film.

[0016] In one embodiment of the present invention, the Young's modulus of the molding layer may be 0.05 to 50 MPa.

[0017] In one embodiment of the present invention, the molding layer may be formed by UV-curing a molding solution.

[0018] In one embodiment of the present invention, the molding solution may have a curing shrinkage rate of 13% or less.

[0019] In one embodiment of the present invention, the viscosity of the molding liquid may be in the range of 100 cps to 2,000 cps.

[0020] In one embodiment of the present invention, the molding liquid may include one or more oligomers, polymers, and / or derivatives thereof selected from silicone acrylate-based, acrylate-based, urethane acrylate-based, urethane-based, butylene-based, isobutylene-based, and rubber, and an oligomer or polymer selected therefrom and a UV initiator and an additive.

[0021] In one embodiment of the present invention, the molding liquid may additionally include inorganic scattering particles, organic scattering particles, light-absorbing particles, or a combination thereof.

[0022] In one embodiment of the present invention, the molding liquid may be a solvent-free type.

[0023] In one embodiment of the present invention, the variable adhesive film includes a base film and a variable adhesive layer on the base film, and the base film may be directly located on the molding layer.

[0024] In one embodiment of the present invention, the variable adhesive layer can adhere to the adherend surface of the target installation object.

[0025] In one embodiment of the present invention, the variable adhesive layer can have one or more A values as the adhesive force to the adherend surface.

Number

[0026] In one embodiment of the present invention, the adhesive force (A1) of the variable adhesive layer to the adherend surface may be 50 gf / in or less.

[0027] In one embodiment of the present invention, the adhesive force (A2) of the variable adhesive layer to the adherend surface may exceed 50 gf / in.

[0028] In one embodiment of the present invention, the adherend surface may be made of glass or plastic.

[0029] In one embodiment of the present invention, the variable adhesive layer may be a pressure-sensitive adhesive.

[0030] In one embodiment of the present invention, a release film may be included on the variable adhesive layer.

[0031] In one embodiment of the present invention, the thickness of the variable adhesive layer may be 50 to 150 μm.

[0032] In one embodiment of the present invention, the substrate may have a light absorption, light blocking, or light scattering function.

[0033] In one embodiment of the present invention, one or more layers of the base film and the variable adhesive layer in the variable adhesive film may have a light absorption, light blocking, or light scattering function.

[0034] In one embodiment of the present invention, the transmittance of the variable adhesive film may be 30 to 80%.

[0035] In one embodiment of the present invention, a protective film or a protective coating layer may be additionally included under the other surface of the substrate having the electrode layer formed on one surface.

[0036] In one embodiment of the present invention, the protective film includes an adhesive layer, a base material layer, and a protective coating layer. At this time, the adhesive layer may be disposed to face the substrate.

[0037] In one embodiment of the present invention, the protective coating layer may have a light absorption, light blocking, or light scattering function. In one embodiment of the present invention, one or more of the adhesive layer, the base material layer, and the protective coating layer can have a light absorption, light blocking, or light scattering function.

[0038] One embodiment of the present invention provides a light-emitting diode film including a light and dark ratio improvement layer directly below the other surface of the substrate on which the electrode layer is formed.

[0039] In one embodiment of the present invention, the light-emitting diode film can include a construction protective film at the lowermost part of the substrate.

[0040] In one embodiment of the present invention, the light-emitting diode film may have a yellowness (b*) of Δ5 or less after a light resistance test.

Advantages of the Invention

[0041] The present invention can provide a light-emitting diode film that can protect the LED and the electrodes from external forces, has excellent adhesion reliability, excellent reworkability after adhesion, and improved adhesion workability. Further, the present invention can provide a light-emitting diode film that simplifies the manufacturing process of the light-emitting diode film and reduces the manufacturing cost.

Brief Description of the Drawings

[0042]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Best Mode for Carrying Out the Invention

[0043] Hereinafter, with reference to the attached drawings, embodiments of the present application will be described in detail so that those having ordinary knowledge in the technical field to which the present application pertains can easily implement it. However, the present application can be realized in various different forms and is not limited to the embodiments described herein. And, in order to clearly explain the present application in the drawings, parts not related to the explanation are omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0044] Throughout the specification of the present application, when a certain part is said to be "connected", "attached", or "adhered" to another part, this includes not only the case where it is "directly connected", but also the case where it is "electrically connected" with other elements interposed therebetween.

[0045] Throughout the specification of the present application, when a certain member is said to be "above", "on the upper part", "below", or "on the lower part" of another member, this includes not only the case where a certain member is in contact with another member, but also the case where there are still other members between the two members.

[0046] Throughout the specification of the present application, when a certain member is said to be "directly above", "directly on the upper part", "directly at the upper end", "directly below", "directly on the lower part", or "directly at the lower end" of another member, it means that it is in contact with the other member and there are no other members between the two members.

[0047] Throughout the specification of the present application, spatially relative terms such as "below", "beneath", "lower", "above", "upper", etc. can be used to easily describe the correlation with components as shown in the drawings.

[0048] Throughout this specification, the term "light-emitting diode" is used to refer to a basic semiconductor diode structure (i.e., such as an LED). Usually, the terms "light-emitting diode" or "LED" can refer to organic, inorganic, or quantum dot LED chips or devices. In this application, "light-emitting diode", "LED", "LED chip", etc. are used interchangeably with the same meaning.

[0049] Throughout this specification, the "target installation object" means the installation or attachment object and item to which the "light-emitting diode film" of the present invention ultimately adheres. As an example, it is understood that the "target installation object" includes, but is not limited to, the outer wall surface of a building, the indoor ceiling, the indoor wall surface, the side or window of a means of transportation, a curtain, a wallpaper, a flyer, etc. In the present invention, the "target installation object" must be interpreted broadly in consideration of the object, installation position, purpose of use, application, etc. where the "light-emitting diode film" is used / attached or can be used / attached.

[0050] The light-emitting diode film according to the present invention adheres to the "surface to be adhered" or "surface to be adhered to", which is one surface of the target installation object. Throughout this specification, the "surface to be adhered", "surface to be adhered to", "adhesive surface", or "adhesive surface to be adhered to" are used interchangeably with the same meaning.

[0051] Also, as the material of the adhesive surface of the "target installation object", glass or plastic having no unevenness or having a high flatness is included. Plastics include, but are not limited to, plastics such as polymethyl methacrylate (PMMA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyamide (PA), polypropylene (PP), polyethylene (PE), polyvinyl chloride (PVC), etc.

[0052] Throughout this specification, when a part includes a certain component, this means that, unless otherwise stated to the contrary, it does not exclude other components but can further include other components.

[0053] All terms used in this specification (including technical and scientific terms) shall have the same meaning as commonly understood by a normal expert in the technical field to which the present invention pertains, unless otherwise defined. Also, the terms used in this specification shall be construed to have a meaning consistent with the meaning in this specification and the related technical field, and it should be understood that they shall not be construed in an idealized or overly formal sense unless explicitly defined in this specification.

[0054] As shown in FIG. 3, the present invention includes a substrate 100, an electrode layer 110 formed on at least a part of the substrate 100, a solder 120 formed on at least a part of the electrode layer 110, a light-emitting diode 130 located on the solder 120 and connected to the electrode layer 110, a molding layer 140 coated on the entire surfaces of the substrate 100, electrode layer 110, and light-emitting diode 130, and a variable adhesive film located on the molding layer 140, and provides a light-emitting diode 130 film characterized by satisfying the following formula 1.

Number

[0055] In order to ensure excellent adhesion reliability with respect to the adherend surface of the installation target for which the light-emitting diode film 10 according to the present invention is intended, the thickness A of the molding layer 140 must be greater than or equal to the sum of the thickness B of the solder and the thickness C of the light-emitting diode. If the thickness A of the molding layer 140 is less than the thickness of the LED chip, there is a high possibility that bubbles will be generated and trapped during the process of laminating the variable adhesive film 150, and visual distortion will occur during the adhesion construction, resulting in a decline in the aesthetic function. On the other hand, if the thickness A of the molding layer 140 exceeds five times the sum of the thickness B of the solder 120 and the thickness C of the light-emitting diode, the flexibility and stretchability characteristics of the light-emitting diode film 10 will decline, not only increasing the film thickness but also reducing the durability for installation targets having a curved adherend surface. Moreover, when the light-emitting diode film 10 is driven, the light unevenness phenomenon can become severe.

[0056] As shown in FIG. 3, in the present invention, the molding layer 140 is applied so as to cover the entire surface of the substrate 100 on which the electrode layer 110, the solder, and the light-emitting diode are formed. The molding layer 140 is applied on the substrate 100 so as to cover the entire mounted LED chip, protects the LED chip from physical external forces, and prevents impurities from flowing onto the LED chip. Moreover, the manufacturing process of the light-emitting diode film 10 according to the present invention is simple and easy, and manufacturing costs are reduced.

[0057] The variable adhesive film 150 is located on the molding layer 140. The variable adhesive film 150 can include a base film 152 and a variable adhesive layer on the base film 152. At this time, the base film 152 is directly located and adhered on the molding layer 140, and the variable adhesive layer 151 located on the base film 152 adheres to the adherend surface of the intended installation target hereafter. The base film 152 can prevent damage to the electrode layer 110, the solder 120, and the light-emitting diode from external forces, and the variable adhesive layer 151 has excellent adhesion reliability and reworkability (see FIG. 5).

[0058] In the present invention, one surface of the molding layer 140 adheres to the substrate 100, and the other surface adheres to the variable adhesive film 150 located above. The molding layer 140 has an adhesive force of 100 gf / cm or more with respect to each of the substrate 100 and the variable adhesive film 150. By having a high adhesive force, the molding layer 140 protects the LED and the electrodes and has excellent durability.

[0059] The Young's modulus of the molding layer 140 is 0.05 MPa to 50 MPa, preferably 0.05 to 30, and more preferably 0.08 to 20. If the Young's modulus of the molding layer 140 is higher than 50 MPa, the flexibility, stretchability, and adhesion construction characteristics will decrease. If it is lower than 0.05 MPa, physical damage may be caused to the metal wiring, LED, etc. located below the molding layer 140 when exposed to external shocks.

[0060] The molding layer 140 may be formed by UV-curing a molding liquid, and the molding liquid is applied so that the cured molding layer 140 satisfies the following formula (1).

Equation

[0061] Even when having the above thickness range, the molding layer 140 has high transparency and a low curing shrinkage rate, thereby increasing the flattening and the adhesive force to the LED chip, and being excellent in durability and adhesive force even during curved surface adhesion.

[0062] The molding liquid has a curing shrinkage rate of 13% or less, preferably 10% or less during UV curing. If the shrinkage rate of the molding liquid during curing (curing shrinkage rate) is large, it will cause a decrease in adhesion, an appearance distortion phenomenon due to the step between the position of the LED and the empty space, and warping. Therefore, the curing shrinkage rate of the molding liquid is preferably 13% or less. The molding liquid according to the present invention has a low curing shrinkage rate, thereby preventing the occurrence of thickness deviation in the LED light source portion and the peripheral portion, and preventing the occurrence of ring-shaped optical distortion and adhesion lifting failure on the adherend surface when the light-emitting diode film 10 according to the present invention is adhered. In the present invention, the molding liquid provides a molding layer 140 that is excellent in surface flattening of the entire surface of the substrate 100 on which the electrode layer 110, the solder 120, and the light-emitting diode are formed, and has high adhesion reliability.

[0063] The viscosity of the molding liquid is in the range of 100 cps to 2,000 cps at 23°C before curing, preferably 100 to 1500. In this range, the coating film of the molding layer 140 does not become excessively thick and can be controlled to a desired thickness.

[0064] The molding layer 140 may be formed of a transparent material so that light can easily pass through. Preferably, it may be in a transparent state with a transmittance of 80% or more, such as an optically clear resin (OCR). All optically clear resins (OCR) improve visibility by increasing the transmittance due to low reflection characteristics.

[0065] The molding liquid can be manufactured by an optically transparent pressure-sensitive adhesive resin composition for forming an optically transparent resin (OCR). The optically transparent resin pressure-sensitive adhesive composition can include one or more oligomers, polymers, and / or derivatives thereof selected from silicone acrylate-based, acrylate-based, urethane acrylate-based, urethane-based, butylene-based, isobutylene-based, and rubber, an oligomer or polymer selected therefrom, a UV initiator, and an additive. Hereinafter, the components of the molding liquid will be described more specifically, but are not limited thereto, and an optically transparent resin composition widely known for manufacturing an optically transparent resin (OCR) can be used.

[0066] The weight average molecular weight of the oligomer or polymer may be about 5,000 to 300,000 g / mol.

[0067] <Acrylate-based oligomer> The acrylate-based oligomer can include one or more oligomers selected from the group consisting of methyl methacrylate, urethane acrylate, epoxy acrylate, silicone acrylate, ethylhexyl acrylate, butyl acrylate, ethyl acrylate, isobornyl acrylate, cyclohexyl methacrylate, glycidyl methacrylate, glycidyl acrylate, behenyl acrylate, ethyl acrylate, lauryl acrylate, stearyl acrylate, acrylic acid, hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, phenoxy acrylate, methyl acrylate, hexanediol diacrylate, and combinations thereof, but is not limited thereto, and preferably, it may be a urethane acrylate oligomer.

[0068] The acrylate-based resin may be included in an amount of 20 to 80% by weight based on the total weight of the molding liquid. If the weight of the acrylate-based resin is less than 20% by weight, the curing shrinkage rate of the molding layer increases, and if it exceeds 80% by weight, the durability of the molding layer decreases.

[0069] The weight average molecular weight of the acrylate resin may be about 5,000 to 300,000 g / mol.

[0070] <Isobutylene oligomer> Examples of the isobutylene oligomer include a homooligomer of an isobutylene monomer; an oligomer of another monomer copolymerizable with the isobutylene monomer; or a mixture thereof. As an example, the isobutylene oligomer may contain monomers such as 1-butene, 2-butene, isoprene, styrene, or butadiene.

[0071] The cured resin containing the isobutylene oligomer has extremely low polarity, is transparent, and is hardly affected by corrosion, so excellent moisture barrier properties, durability and reliability, and optical properties can be realized. Examples of the isobutylene oligomer may include an oligomer of isobutylene and isoprene, an oligomer of isoprene and styrene, an oligomer of butadiene and styrene, an oligomer of isoprene, butadiene, and styrene, and an oligomer of polyisoprene, polybutadiene, or isoprene and styrene, an oligomer of butadiene and styrene, or an oligomer of isoprene, butadiene, and styrene.

[0072] The isobutylene polymer may be contained in an amount of 10 to 60% by weight based on the total weight of the molding liquid.

[0073] <Rubber> The rubber can have a functional group such as a hydroxyl group or a carboxyl group at its terminal. As an example, as the rubber, a polydiene having a functional group such as a hydroxyl group or a carboxyl group at its terminal can be used. For example, as the rubber, a compound having a polyisoprene skeleton or a polybutadiene skeleton, a styrene-butadiene skeleton, a copolymer of ethylene and propylene (EPM), or a terpolymer of ethylene, propylene, and non-conjugated diene (EPDM) can be used, but is not limited thereto.

[0074] Also, the weight average molecular weight of the rubber can be appropriately selected within a range that does not impair the object of the present application. For example, it may be in the range of about 1,000 to 200,000 g / mol, about 1,000 to 150,000 g / mol, or about 2,000 to 100,000 g / mol.

[0075] The rubber may be contained in an amount of 10 to 60% by weight based on the total weight of the molding liquid.

[0076] <acrylate monomer> The optically transparent resin adhesive composition can additionally contain an acrylate monomer.

[0077] It includes a function of adjusting the viscosity by diluting the oligomer and polymer of the high molecular weight body, and can impart required modulus, adhesiveness, polarity capable of adjusting cloudiness that may occur during high temperature and high humidity evaluation, etc. Monofunctional acrylate and polyfunctional acrylate monomers can be used. The shrinkage rate, curing reaction rate, and durability of the molding layer can be adjusted by utilizing the UV curing reaction.

[0078] The acrylate monomer may be contained in an amount of 20 to 90% by weight based on the total weight of the molding liquid, preferably 20 to 80% by weight, more preferably 30 to 70% by weight. When the content is less than 30% by weight, it is difficult to adjust the viscosity of the composition liquid. When the content is more than 70%, it is difficult to control the curing shrinkage and the curing reaction rate. Any structure may be applied as long as it is compatible with the oligomer or polymer used and satisfies the required physical properties.

[0079] <photoinitiator> When the photoinitiator is irradiated with ultraviolet rays in a specific wavelength region, it generates active radicals, and the generated radicals induce the photopolymerization reaction of the reactive acrylate oligomer or monomer. The photoinitiator may be a ketone-based photoinitiator or a phosphine-based photoinitiator.

[0080] Examples of the ketone-based photoinitiator include, but are not limited to, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), 2-isopropylthioxanthone (ITX), 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, etc.

[0081] The photoinitiator may be contained in an amount of 0.01 to 2% by weight based on the total weight of the molding liquid.

[0082] <Additive> Examples of the additive may include selective ordinary additives such as a reactive diluent, a scattering agent, an adhesion aid, a surfactant, a filler, a coupling agent, a silane, a wetting agent, a plasticizer, a release agent, a crosslinking agent, a catalyst, a curing agent, a wetting agent, a UV stabilizer, a heat stabilizer, and a rust preventive agent. Further, the molding liquid may contain other solvents as an additive, but a solvent-free type is preferred. Each of the reactive diluent and the plasticizer may be contained in an amount of 1 to 10% by weight based on the total amount of the molding liquid. The total amount of other additives excluding the reactive diluent and the plasticizer may be appropriately contained within 0.01 to 5% by weight based on the total amount of the molding liquid.

[0083] Solvents, which are volatile organic compounds, are harmful to the human body and cause environmental pollution problems. Moreover, the conventional process has disadvantages such as a decrease in the productivity of the molding liquid due to the use of a drying oven required for the volatilization of the solvent. However, the solvent-free type molding liquid of the present invention solves the problems of harmfulness and environmental pollution, improves the productivity by omitting the drying process used for the volatilization of the solvent, and at the same time, since shrinkage due to the volatilization of the solvent does not occur, it has the effect of reducing the curing shrinkage rate of the molding layer.

[0084] In one embodiment of the present invention, the molding liquid may include organic and inorganic dyes and pigments for contrast improvement and imparting light characteristics. As the scattering agent, inorganic scattering particles such as SiO2, TiO2, ZrO2, organic scattering particles, light-absorbing particles, or a combination thereof may be included.

[0085] In one embodiment of the present invention, the variable adhesion film 150 located on the molding layer 140 adheres to the adherend surface so as to be provided on an installation target for a light-emitting diode film.

[0086] In one embodiment of the present invention, the variable adhesion film 150 may include a base film 152 and a variable adhesion layer 151 on the base film 152. At this time, the base film 152 is directly located and adhered on the molding layer 140, and the variable adhesion layer 151 located on the base film 152 adheres to the adherend surface of the target installation object hereafter.

[0087] In one embodiment of the present invention, the variable adhesion layer 151 of the variable adhesion film 150 satisfies that the A value according to the following formula 2 is 1 or more with respect to the adherend surface.

Equation

[0088] After the variable adhesion layer 151 adheres to the adherend surface of the target installation object, the adhesive force (A1) with respect to the adherend surface measured 30 minutes later at room temperature is 50 gf / in or less.

[0089] After the variable adhesion layer 151 adheres to the adherend surface of the target installation object, the adhesive force (A2) with respect to the adherend surface measured 1,000 hours later at room temperature exceeds 50 gf / in.

[0090] By satisfying that the value of A according to the above formula (1) is 1 or more, the variable adhesive film 150 has excellent wettability, re - peelability, and adhesion reliability with respect to the adhesive surface of the target installation object. In particular, it can be attached without defects such as bubbles, can be re - peeled from surfaces such as plastic or glass, has excellent peel strength and workability, and can prevent peeling, lifting, etc. after being completely adhered.

[0091] The base film 152 of the variable adhesive film 150 can include, but is not limited to, a polymer resin selected from the group consisting of polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), polyurethane (PU), polyimide (PI), cyclic olefin polymer (COP), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polyamide (PA), polycyclohexylene dimethylene terephthalate (PCT), and polypropylene (PP), or an alloy resin thereof. The thickness of the base film 152 may be 50 μm to 150 μm, preferably 50 μm to 100 μm.

[0092] The variable adhesive layer 151 of the variable adhesive film 150 can be manufactured from a pressure - sensitive adhesive composition, and the pressure - sensitive adhesive composition can include a urethane resin composition containing a urethane - based resin as a main component, an interface conditioner, and an adhesion enhancer.

[0093] In one embodiment of the present invention, the weight ratio (interface conditioner / adhesion enhancer) of the interface conditioner and the adhesion enhancer in the pressure - sensitive adhesive composition may be 0.8 or less. When the above range is satisfied, the variable adhesive film 150 has excellent wettability, re - peelability, and adhesion reliability with respect to the adhesive surface of the target installation object.

[0094] By simultaneously containing the interfacial conditioner and the tackifier, the variable pressure-sensitive adhesive layer 151 has the effect of simultaneously satisfying the releasability and the adhesion stability with respect to an adherend surface such as plastic or glass. The variable pressure-sensitive adhesive layer 151 produced from the pressure-sensitive adhesive composition has a low adhesive force and excellent releasability with respect to the adherend surface because the interfacial conditioner in the variable pressure-sensitive adhesive layer 151 is distributed and present on the adherend surface immediately after adhesion. However, as time passes, while the rearrangement of the interfacial conditioner and the tackifier occurs, the adhesive force increases due to the interaction between the tackifier and the adherend surface, thereby imparting adhesion stability. Ultimately, the present invention can provide a light-emitting diode film 10 having excellent wettability, releasability, and adhesion reliability through the variable pressure-sensitive adhesive layer 151.

[0095] The variable pressure-sensitive adhesive film 150 can include a release film 200 on the variable pressure-sensitive adhesive layer 151 until it adheres to the adherend surface of the target installation object.

[0096] The release film 200 exhibits hydrophobicity in order to have release properties with respect to the variable pressure-sensitive adhesive layer 151, while an adherend surface such as plastic or glass exhibits hydrophilic properties compared to the release film 200. Therefore, when the release film 200 on the variable pressure-sensitive adhesive layer 151 is removed and the variable pressure-sensitive adhesive layer 151 is adhered to the adherend surface of the target installation object, the hydrophobic group of the interfacial conditioner present in the variable pressure-sensitive adhesive layer 151 is oriented on the adherend surface immediately after adhesion and has a low adhesive force. However, as time passes, rearrangement occurs to balance the hydrophobic group and the hydrophilic group of the interfacial conditioner in the variable pressure-sensitive adhesive layer 151 with respect to the adherend surface such as plastic or glass, which is relatively more hydrophilic than the release film 200. Eventually, the tackifier reacts with the adherend surface and the adhesive force increases.

[0097] Hereinafter, the following substances can be used as the urethane resin composition, the interfacial conditioner, and the tackifier contained in the variable pressure-sensitive adhesive layer 151, but are not limited thereto.

[0098] <Urethane resin composition> The urethane resin composition is mainly composed of a urethane resin obtained by curing a urethane prepolymer formed by reacting a polyol and a polyfunctional isocyanate compound in the presence of a catalyst.

[0099] The polyol may contain one type of polyol, and more preferably, may contain two or more types of polyols. At this time, one of the two or more types of polyols includes a polyol having three or more OH groups. As an example, it can be selectively used from the group consisting of polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, and castor oil-based polyol. Such a polyol component can exhibit excellent properties such as excellent reworkability for residue reduction.

[0100] The polyester polyol can be obtained by an esterification reaction between a polyol component and an acid component. As an example of the polyol component, it can be selectively used from the group consisting of ethylene glycol, diethylene glycol, 1,3 - butanediol, 1,4 - butanediol, neopentyl glycol, 3 - methyl - 1,5 - pentanediol, 2 - butyl - 2 - ethyl - 1,3 - propanediol, 2,4 - diethyl - 1,5 - pentanediol, 1,2 - hexanediol, 1,6 - hexanediol, 1,8 - octanediol, 1,9 - nonanediol, 2 - methyl - 1,8 - octanediol, 1,8 - decanediol, octadecanedecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol. As an example of the acid component, succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12 - dodecanedioic acid, 1,14 - tetradecanedioic acid, dimer acid, 2 - methyl - 1,4 - cyclohexanedicarboxylic acid, 2 - ethyl - 1,4 - cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 1,4 - naphthalenedicarboxylic acid, 4,4’ - biphenylcarboxylic acid, and their acid anhydrides can be used.

[0101] In addition, the polyether polyol can be obtained by addition polymerization of an alkylene oxide selected from ethylene oxide, propylene oxide or butylene oxide using water, low molecular weight polyols (such as propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (such as bisphenol A, etc.), dihydroxybenzene (such as catechol, resorcinol, hydroquinone, etc.) as initiators. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc.

[0102] The polycaprolactone polyol is a caprolactone-based polyester diol obtained by ring-opening polymerization of a cyclic ester monomer such as ε-caprolactone or σ-valerolactone. As an example thereof, there are a polycarbonate polyol obtained by polycondensation reaction of the polyol component and phosgene, a polycarbonate polyol obtained by transesterification and condensation of the polyol component and a diester such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethyl butyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate or dibenzyl carbonate, a copolymer polycarbonate polyol obtained by using two or more of the polyol components in combination, a polycarbonate polyol obtained by esterification reaction of the various polycarbonate polyols and a carboxyl group-containing compound, a polycarbonate polyol obtained by etherification reaction of the various polycarbonate polyols and a hydroxyl group-containing compound; a polycarbonate polyol obtained by transesterification reaction of the various polycarbonate polyols and an ester compound; a polycarbonate polyol obtained by transesterification reaction of the various polycarbonate polyols and a hydroxyl group-containing compound; a polyester-based polycarbonate polyol obtained by polycondensation reaction of the various polycarbonate polyols and a dicarboxylic acid compound; and a copolymer polyether-based polycarbonate polyol obtained by copolymerizing the various polycarbonate polyols and an alkylene oxide.

[0103] The castor oil-based polyol is a castor oil-based polyol obtained by reacting castor oil fatty acid with the polyol component.

[0104] As other components for producing the urethane resin, the polyfunctional isocyanate compound can be used alone or in a mixed form selected from a polyfunctional aliphatic isocyanate compound, a polyfunctional alicyclic isocyanate compound, a polyfunctional aromatic diisocyanate compound or a trimer having an isocyanurate ring.

[0105] As a preferable example of the polyfunctional aliphatic isocyanate compound, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate can be selectively used from the group consisting of them.

[0106] Examples of the polyfunctional alicyclic isocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate. The polyfunctional aromatic diisocyanate compound can be selectively used from the group consisting of phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.

[0107] The polyol and the polyfunctional isocyanate compound are reacted in the presence of a catalyst to produce in the form of a urethane prepolymer having a hydroxy group terminal, and then a three-dimensional network structure can be formed by using a polyfunctional isocyanate having two or more functional groups as a curing agent.

[0108] As other examples of the polyfunctional isocyanate compound, trimethylolpropane adducts of the various polyfunctional isocyanate compounds described above, biurets obtained by reacting with water, and trimers having an isocyanurate ring can be used, and these may be used in combination.

[0109] As described above, the urethane resin is obtained by curing a composition containing a polyol and a polyfunctional isocyanate compound. Such a composition may contain an antistatic agent, a catalyst, resin components other than the urethane resin, a tackifier, an inorganic filler, an organic filler, a metal powder, a pigment, a softening agent, a plasticizer, an antioxidant, a conductive agent, an antioxidant, a UV absorber, a light stabilizer, a surface lubricant, a leveling agent, a corrosion inhibitor, a heat stabilizer, a polymerization inhibitor, a lubricant, a solvent, etc., within a range that does not impair the effects of the present invention. More preferably, it may contain a deterioration inhibitor such as an antistatic agent, an antioxidant, a UV absorber or a light stabilizer.

[0110] <Interface modifier> The interface modifier is a compound having both hydrophilicity that is easily soluble in water and hydrophobicity that is easily soluble in oil within one molecule. Hydrophilicity means the property of easily binding to water molecules. Conversely, the property of having weak affinity for water is called hydrophobicity.

[0111] In the present invention, as the interface modifier, a silicone-based nonionic interface modifier can be used.

[0112] The silicone-based nonionic surface conditioner may be a single one or one or more selected from, but not limited to, modified polydimethylsiloxane (e.g., alkyl-modified, phenyl-modified, amino-modified, polyether-modified, and polyoxyalkylene-modified polydimethylsiloxane, etc.), organosilicone, polyalkylene modified heptamethyl trisiloxane, polyalkyleneoxide modified dimethylpolysiloxane, polyalkyleneoxide modified heptamethyl trisiloxane, polyalkyleneoxide modified heptamethylsiloxane, polyether-polymethylsiloxane-copolymer, polyethoxlated dimethyl siloxanes, Polymethylsiloxane copolymer, polyoxpropylene-polyoxyethylene block copolymers, siliconepolyether copolymer. In a preferred embodiment, the silicone-based nonionic surface conditioner is a polyalkyleneoxide modified silicone in which a polyethylene oxide / polypropylene oxide polar block is grafted to a silicone backbone, and may be polyethylene oxide modified dimethylpolysiloxane or polypropylene oxide modified dimethylpolysiloxane.Alternatively, it may preferably be a polyalkylene oxide-modified silicone containing polyethylene oxide and polypropylene oxide. At this time, the ends of the polyethylene oxide and polypropylene oxide may be capped with an alkyl group such as a methyl group or a butyl group. If the ends of the polyethylene oxide and polypropylene oxide are not capped with an alkyl group, the hydroxy generated by the reaction can chemically react with the urethane resin of the adhesive, preventing the rearrangement of the interface conditioner on the adherend surface.

[0113] The silicone-based nonionic interface conditioner is preferably used in a content of 0.01 to 5 parts by weight based on 100 parts by weight of the urethane resin. When the silicone-based nonionic interface conditioner is contained in less than 0.01 part by weight, the amount of the interface conditioner is insufficient at the interface of the adhesive in contact with the release film 200 of the adhesive, resulting in high adhesive strength and problems in reworkability. When it is contained in more than 5 parts by weight, the amount of the interface conditioner is large at the interface of the adhesive, and it takes time for the rearrangement to reach equilibrium, resulting in no increase in adhesive strength and vulnerable adhesion reliability.

[0114] The silicone-based nonionic interface conditioner has a hydrophilic-lipophilic balance (HLB) value of 4 to 8. When the HLB value of the silicone-based nonionic interface conditioner is 4 to 8, it has been found that after the adhesive is attached to the adherend surface, as time passes, the hydrophilic groups of the interface conditioner are oriented toward the adherend surface side, so that the adhesive strength gradually increases. On the other hand, if the HLB value is less than 4, it is close to hydrophobicity (lipophilicity), and rearrangement does not occur on the adherend surface side in the adhesive, making it difficult to increase the adhesive strength. If the HBL value exceeds 8, it is close to hydrophilicity, and rearrangement does not occur in the adhesive, resulting in no increase in adhesive strength and vulnerable adhesion reliability.

[0115] <Adhesion enhancer> In the present invention, as the tackifier, a silane coupling agent can be used. As one embodiment, as the tackifier, vinyltrimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-ethoxycyclohexyl)ethyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, etc. can be used.

[0116] The tackifier is preferably used in a content of 0.1 to 10 parts by weight based on 100 parts by weight of the urethane resin. When the tackifier is contained in less than 0.1 part by weight, after adhesion to the adherend surface, the adhesive strength does not increase, and the adhesion reliability is fragile. When it exceeds 10 parts by weight and peeling is required after a certain period of time, there are problems such as destruction of the adherend and generation of adhesive residues.

[0117] In one embodiment of the present invention, in the adhesive composition, the weight ratio (a / b) of the interfacial conditioner (a) to the tackifier (b) is 0.8 or less. The weight ratio (a / b) of the interfacial conditioner (a) to the tackifier (b) is preferably 0.7 or less, and more preferably 0.5 or less. When the weight ratio (a / b) of the interfacial conditioner (a) to the tackifier (b) exceeds 0.8, the adhesive strength does not increase with the passage of time, and the adhesion reliability is very low.

[0118] As an embodiment of the present invention, the light-emitting diode film 10 includes a substrate 100, an electrode layer 110 formed on at least a part of the substrate 100, a solder 120 formed on at least a part of the electrode layer 110, a light-emitting diode located on the solder 120 and connected to the electrode layer 110, a molding layer 140 applied to cover the entire surfaces of the substrate 100, the electrode layer 110, and the light-emitting diode, and a variable adhesive film 150 located on the molding layer 140. Further, a protective film 170 may be additionally included at the lower part of the other surface of the substrate 100 having the electrode layer 110 formed on one side (see FIG. 4). The protective film has a function of preventing physical damage to the light-emitting diode film 10 from external impacts.

[0119] The protective film 170 is located at the lower part of the other surface of the substrate 100 on which the electrode layer 110 is formed. As an example, the protective film 170 may be directly located at the lower part of the substrate 100, or other members may exist between the substrate 100 and the protective film 170.

[0120] In an embodiment of the present invention, the protective film 170 can include an adhesive layer 171, a base material layer 172, and a protective coating layer 173. In this case, the adhesive layer 171 is disposed to face the substrate, and the protective coating layer 173 is disposed to be located at the outermost lower corner of the substrate in the light-emitting diode film 10 of the final product.

[0121] In an embodiment of the present invention, only the protective coating layer 173 can be attached to the lower part of the other surface of the substrate having the electrode layer formed on one side. The protective coating layer 173 may be directly located at the lower part of the substrate 100, or other members may exist between the substrate 100 and the protective coating layer 173.

[0122] In one embodiment of the present invention, the adhesive layer 171 and the protective coating layer 173 can be manufactured using an adhesive composition prepared with a suitable base resin such as an acrylic resin, an epoxy resin, a urethane resin, an ester resin, etc., but are not limited thereto, and may be manufactured with a commonly used adhesive composition.

[0123] One or more of the adhesive layer 171, the base material layer 172, and the protective coating layer 173 in the protective film 170 can contain commonly used additives in addition to the base resin. As an example, by including light absorption, light blocking, and light scattering substances, it can include light absorption, light blocking, or light scattering functions.

[0124] The protective coating layer 173 can contain commonly added additives in addition to the above-mentioned resins as long as the effects of the present invention are not inhibited. As an example, by including light absorption, light blocking, and / or light scattering substances, it can include light absorption, light blocking, and / or light scattering functions.

[0125] In another embodiment of the present invention, the substrate 100 can have a light absorption, light blocking, or light scattering function, and / or one or more of the base film 152 and the variable adhesive layer 151 in the variable adhesive film 150 can have a light absorption, light blocking, or light scattering function. At this time, the transmittance of the variable adhesive film may be 30 to 80%. In the present invention, when one or more layers included in the light-emitting diode film 10 have a light absorption, light blocking, or light scattering function, light absorption, light blocking, or light scattering substances commonly used in one or more layers may be included.

[0126] In one embodiment of the present invention, in order to improve the contrast ratio of the light-emitting diode film 10, the contrast ratio improvement layer 190 may be directly located below the other surface of the substrate 100 on which the electrode layer 110 is formed. The contrast ratio improvement layer 190 may be formed by applying and drying a black resin composition containing a light-absorbing material such as carbon black on the substrate, or may exist in the form of a sheet, plate, film, or the like. As the light-absorbing material, carbon black, titanium black such as lower-order titanium oxide or titanium oxynitride, metal oxides such as iron oxide, and other organic pigment mixed color systems can be used.

[0127] The contrast ratio improvement layer 190 has an opaque or translucent optical property by exhibiting a black or colored color. Further, the contrast ratio improvement layer 190 can provide a light-emitting diode with improved optical characteristics by having a pattern according to the transmittance. As an example, the black resin composition can be applied and dried on the substrate to form a black film, and photolithography can be used to provide fine patterning of the contrast ratio improvement layer 190.

[0128] As shown in FIG. 4, in one embodiment of the present invention, by including the construction protection film 180 at the lowermost part of the substrate 100, damage to the product during the process can be prevented, and the construction protection film 180 is removed after the manufacturing process.

[0129] The light-emitting diode film 10 according to the present invention has a yellowness (b*) after the light resistance test of 5 or less. If the yellowness of the light-emitting diode film 10 exceeds 5, the transparency of the entire film decreases, so the yellowness (b*) after the light resistance test must satisfy 5 or less. Therefore, the light-emitting diode film 10 can simultaneously achieve high transparency and visible light transmittance and excellent light resistance with a desired neutral color.

Example

[0130] Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, the following embodiments are for the purpose of understanding the present invention, and the scope of the present invention is not limited to the following embodiments.

[0131] Manufacture of Light-Emitting Diode Film After printing solder paste on the terminal portion of a mesh-type transparent electrode substrate formed of a Ni-Cu laminated structure on 188-μm PET, an LED was mounted using a chip mounter, and after passing through reflow so that the peak temperature became 180°C, a film-type LED substrate was prepared.

[0132] Thereafter, a molding liquid manufactured in the following examples and comparative examples was applied onto a previously prepared film-type LED substrate. Except for Comparative Example 7, after the variable adhesion layer of a variable adhesion film manufactured by the following method was brought into contact with and adhered to the applied molding layer so as to face the molding layer, the molding layer was cured by UV irradiation to obtain a light-emitting diode film.

[0133] <Manufacture of variable adhesion film> To 100 parts by weight of a hydroxy group-containing urethane prepolymer (weight average molecular weight 80,000) at the terminal, 6 parts by weight of a polyfunctional hexamethylene diisocyanate crosslinking agent was blended, 0.01 part by weight of a catalyst dibutyltin dilaurate (DBTDL), 0.3 part by weight of a polypropylene oxide / polyethylene oxide (20 / 80) polydimethylsiloxane with an HBL of 7, and 2 parts by weight of 3-methacryloylpropyltrimethoxysilane were added, and it was diluted with methyl ethyl ketone (MEK) so that the solid content became 50% by weight, and mixed and defoamed to manufacture a variable adhesion agent composition. The manufactured variable adhesion agent composition was applied onto a PET base material film and dried in an oven at 120°C for 3 minutes to coat it so that the thickness of the adhesion layer became 100 μm.

[0134] <Manufacture of molding liquid> Example 1: 30 g of urethane acrylate oligomer SC2404 (Miwon), 20 g of isobornyl acrylate, 40 g of ethylhexyl acrylate, 10 g of trimethylolpropane triacrylate, and 1 g of Irgacure 651 were homogenized to produce a molding solution. Using the produced molding solution, a light-emitting diode film was obtained by the method described above. In this example, a light-emitting diode film with a thickness A of the molding layer 140 being 1.5 times the total height of the thickness B of the solder and the thickness C of the LED was obtained.

[0135] Example 2: A light-emitting diode film was obtained by the method of Example 1, except that 20 g of polyisobutylene BASF OPPANOL B15N, 50 g of isobornyl acrylate, 15 g of ethylhexyl acrylate, 15 g of tricyclodecane dimethanol diacrylate, and 1 g of Irgacure 651 were homogenized to produce a molding solution.

[0136] Example 3: Using a basket mill, 3 g of zirconia (ZrO 2 ) having an average particle size of 1 μm was dispersed in the molding solution of Example 1 so that a light-scattering agent was included, and a light-emitting diode film was obtained by the method of Example 1.

[0137] Example 4: Using a basket mill, 0.5 g of carbon black having an average particle size of 25 nm was dispersed in the molding solution of Example 1 so that particles capable of adjusting the transmittance were included, and a light-emitting diode film was obtained by the method of Example 1.

[0138] Comparative Example 1: A light-emitting diode film was obtained by the method of Example 1, except that the thickness A of the molding layer was set to 0.8 times the total height of the thickness B of the solder and the thickness C of the LED.

[0139] Comparative Example 2: A light-emitting diode film was obtained by the method of Example 1, except that the thickness A of the molding layer was made 5.2 times the total height of the thickness B of the solder and the thickness C of the LED.

[0140] Comparative Example 3: 10 g of urethane acrylate oligomer SC2404 (Miwon), 10 g of isobornyl acrylate, 75 g of ethylhexyl acrylate, 5 g of trimethylolpropane triacrylate, and 1 g of Irgacure 651 were homogenized to produce a molding solution. Using the produced molding solution, a light-emitting diode film was obtained by the method described above. In this example, a light-emitting diode film having a molding layer thickness A of 0.8 times the total height of the solder thickness B and the LED thickness C was obtained.

[0141] Comparative Example 4: A light-emitting diode film was obtained by the method of Comparative Example 3, except that the thickness A of the molding layer was 5.2 times the total height of the thickness B of the solder and the thickness C of the LED.

[0142] Comparative Example 5: 40 g of acrylic urethane oligomer SC2404 (Miwon), 30 g of isobornyl acrylate, 10 g of ethylhexyl acrylate, 20 g of trimethylolpropane triacrylate, and 1 g of Irgacure 651 were homogenized to produce a molding solution. Using the produced molding solution, a light-emitting diode film was obtained by the method described above. In this example, a light-emitting diode film having a molding layer thickness A of 0.8 times the total height of the solder thickness B and the LED thickness C was obtained.

[0143] Comparative Example 6: A light-emitting diode film was obtained by the method of Comparative Example 5, except that the thickness A of the molding layer was 5.2 times the total height of the thickness B of the solder and the thickness C of the LED.

[0144] Comparative Example 7: A light-emitting diode film was obtained by the method of Example 1, except that the molding solution of Example 1 was used and a PET material release film was attached onto the molding layer instead of the variable adhesion film.

[0145] Experimental Example: Performance Evaluation of Light-Emitting Diode Film The performance of the transparent LED film panels manufactured in the above Examples and Comparative Examples was evaluated by the following method.

[0146] 1. Measurement of Shrinkage Rate of Molding Layer After applying the molding liquids of the Examples and Comparative Examples and before UV curing, the density of the molding liquid (liquid state) and the density of the molding layer (solid state) after UV curing were measured and substituted into the following formula to calculate the shrinkage rate. Shrinkage rate of molding liquid = (1 / density after curing - 1 / density before curing) / (1 / density before curing) * 100

[0147] 2. Tensile Strength (Young's Modulus and Elongation Rate) The molding liquids prepared in the Examples and Comparative Examples were applied and cured to obtain a molding layer with a thickness of 1.3 mm, and the molding layer samples were cut to a length of 60 mm and a width of 15 mm. After fixing the cut test pieces to the upper and lower jigs of a UTM (universal testing machine) so that the distance was 25 mm, while pulling the test pieces at a speed of 100 mm / min, the stress corresponding to the strain until the test pieces were cut was measured to calculate the Young's modulus value.

[0148] - Young's modulus (Young’s modulus (E’)): The value of the ratio of stress / strain in the range of strain from 0.3% to 1%

Equation

[0149] 3. Measurement of Total Light Transmittance and Haze Value The total light transmittance in the range of 380 to 760 nm of the molding layers manufactured in the above Examples and Comparative Examples was measured according to the JIS K 7105 standard, and the haze was measured using an NDH-7000 (manufactured by Nippon Denshoku).

[0150] 4. Push Test The variable adhesive films of the light-emitting diode films prepared in Examples 1 to 4 and Comparative Examples 1 to 6 were attached to a glass or SUS plate so that the transparent substrate was positioned in the upper layer. In the case of Comparative Example 7, the molding layer of the branched light-emitting diode film was attached to a glass or SUS plate so that the transparent substrate was positioned in the upper layer. At this time, after driving the light-emitting diode film to emit light from the LED, pressure was applied with a Push Pull Gage using a probe with a diameter of 5 mm at the point of the LED, and the falling force of the LED was measured. The acceptable criterion was set at 3 Kgf.

[0151] 5. Adhesion Workability The light-emitting diode films manufactured in the Examples and Comparative Examples were prepared in a size of 430×600 mm, and using a wool spatula, the molding layer or variable adhesive film of the light-emitting diode film was attached to the adherend surface of the glass material without generating bubbles. The adhesion workability of each of the Examples and Comparative Examples was judged according to the following criteria.

[0152] Good O: No trapped bubbles generated, no side spreading phenomenon after adhesion - Exhibits excellent performance in the process of re-peeling and re-attaching for re-explanation of the position after adhesion Defective X: - Confirmation of bubble generation and trapping phenomenon - Poor re-peeling and re-adhesion properties for re-explanation of the position after adhesion

[0153] [Table 1]

[0154] As described in Table 1 above, Examples 1 to 4 all showed good adhesion workability and durability.

[0155] In contrast, Comparative Examples 1 to 6 did not satisfy the formula 1 (1*(B + C) ≤ A ≤ 5*(B + C), where A is the height of the molding layer measured from the substrate, B is the thickness of the solder, and C is the thickness of the light-emitting diode).

[0156] As a result, in the case of Comparative Example 1, bubbles were trapped during the lamination process of the variable adhesive film, causing lifting. The thickness uniformity and flatness of the molding layer and the variable adhesive film corresponding to the site where the LED chip was located were not good. As a result, the adhesion workability was not good, causing the durability of the light-emitting diode. In the case of Comparative Example 2, since the molding layer did not satisfy the formula 1 (1*(B + C) ≤ A ≤ 5*(B + C), where A is the height of the molding layer measured from the substrate, B is the thickness of the solder, and C is the thickness of the light-emitting diode), wiring cracks occurred even with a low force of 2.5 in the push test, and torsion of the molding layer occurred, resulting in poor adhesion workability due to the lifting phenomenon. Also, it was confirmed that the result value of the push test was 3 Kgf or less and the durability was not sufficient.

[0157] In the cases of Comparative Examples 3 and 4, the adhesion workability was not good, and the Young's modulus of the molding layer was measured to be 0.03, which is lower than 0.05. In particular, in the case of Comparative Example 4, the result value of the push test was measured to be a very low value of 1.1 Kf, and the wiring, solder cracks, LEDs, etc. were damaged by the impact, pressing, and bending deformation forces applied from the outside, and the durability was not good.

[0158] In the cases of Comparative Examples 5 and 6, the shrinkage rate of the molding layer was as high as 15%, and the Young's modulus was measured to be 120 MPa, confirming that the flexibility, stretchability, and adhesive properties decreased. When having a high Young's modulus as in Comparative Examples 5 and 6, the shrinkage rate of the molding layer exceeds 10 - 13%. In this case, even if a slight curl is formed during adhesion to the adherend surface of the light-emitting diode film, lifting occurs and the adhesion workability decreases.

[0159] In the case of Comparative Example 7 that does not include a variable adhesive film, the re-adhesion adhesive force and the adhesion workability thereby were not good.

Explanation of Signs

[0160] 10: Light-emitting diode film, 20: Target installation object 100: Substrate, 110: Electrode layer, 120: Solder 130: Light-emitting diode, 140: Molding layer, 150: Variable adhesive film 151: Variable adhesive layer, 152: Base film, 200: Release film 170: Protective film, 171: Adhesive layer, 172: Base material layer 173: Protective coating layer, 180: Protective film for construction, 190: Brightness contrast improvement layer A: Height of the molding layer, B: Height of the solder, C: Thickness of the light-emitting diode

Claims

1. A substrate; an electrode layer formed on at least a portion of the substrate; a solder formed on at least a portion of the electrode layer; a light emitting diode located on the solder and connected to the electrode layer; a molding layer applied to the entire surface of the substrate, the electrode layer and the light emitting diode; a variable adhesive film positioned on the molding layer; A light-emitting diode film characterized by satisfying the following formula 1: [0010]

2. The light emitting diode film according to claim 1 , wherein the molding layer has an adhesive strength of 100 gf / cm or more to the substrate and the variable adhesive film, respectively.

3. 2. The light-emitting diode film as claimed in claim 1, wherein the molding layer has a Young's modulus of 0.05 to 50 MPa.

4. The light emitting diode film according to claim 1 , wherein the molding layer is formed by UV curing a molding liquid.

5. The light-emitting diode film according to claim 4 , wherein the molding liquid has a cure shrinkage rate of 13% or less.

6. 5. The light-emitting diode film as claimed in claim 4, wherein the viscosity of the molding liquid ranges from 100 cps to 2,000 cps.

7. 5. The light-emitting diode film according to claim 4, wherein the molding liquid comprises an oligomer or polymer selected from one or more oligomers, polymers and / or derivatives thereof selected from silicone acrylates, acrylates, urethane acrylates, urethanes, butylenes, isobutylenes and rubbers, and a UV initiator and an additive.

8. 8. The light-emitting diode film as claimed in claim 7, wherein the molding liquid additionally comprises inorganic scattering particles, organic scattering particles, light absorbing particles, or a combination thereof.

9. 8. The light-emitting diode film as claimed in claim 7, wherein the molding liquid is solvent-free.

10. The variable adhesive film includes a base film and a variable adhesive layer on the base film, The light-emitting diode film according to claim 1 , wherein the substrate film is located directly on the molding layer.

11. 11. The light emitting diode film according to claim 10, wherein the variable adhesion layer adheres to a target surface of the object.

12. The light-emitting diode film according to claim 10 , wherein the variable adhesion layer has an A value of 1 or more as an adhesion strength to the adhered surface. [0025]

13. 13. The light emitting diode film of claim 12, wherein the adhesive strength (A1) of the variable adhesive layer to the adhered surface is 50 gf / in or less.

14. 13. The light emitting diode film of claim 12, wherein the adhesive strength (A2) of the variable adhesive layer to the adhered surface is greater than 50 gf / in.

15. The light emitting diode film according to claim 12, wherein the surface to be adhered is made of a glass or plastic material.

16. 11. The light emitting diode film of claim 10, wherein the variable adhesive layer is a pressure sensitive adhesive.

17. 11. The light emitting diode film of claim 10, further comprising a release film on the variable adhesive layer.

18. 11. The light-emitting diode film according to claim 10, wherein the thickness of the variable adhesive layer is 50 to 150 μm.

19. The light-emitting diode film according to any one of claims 1 to 18, wherein the substrate has a light-absorbing, light-blocking or light-scattering function.

20. The light-emitting diode film according to any one of claims 10 to 18, wherein one or more layers of the base film and the variable adhesive layer in the variable adhesive film have a light-absorbing, light-blocking or light-scattering function.

21. 21. The light emitting diode film according to claim 20, wherein the transmittance of the variable adhesive film is 30-80%.

22. The light emitting diode film according to any one of claims 1 to 18, further comprising a protective film or protective coating layer on a lower portion of the other surface of the substrate having the electrode layer formed on one surface thereof.

23. The light emitting diode film of claim 22, wherein the protective film comprises an adhesive layer, a base layer, and a protective coating layer, and the adhesive layer is disposed opposite the substrate.

24. 23. The light-emitting diode film as claimed in claim 22, wherein the protective coating layer has a light-absorbing, light-blocking or light-scattering function.

25. 24. The light-emitting diode film as claimed in claim 23, wherein one or more of the adhesive layer, the substrate layer and the protective coating layer have a light-absorbing, light-blocking or light-scattering function.

26. 19. The light emitting diode film according to claim 1, further comprising a brightness-dark ratio improving layer directly provided on a lower portion of the other surface of the substrate on which the electrode layer is formed.

27. The light-emitting diode film according to any one of claims 1 to 18, further comprising a protective film for installation on the bottom of the substrate.

28. 19. The light-emitting diode film according to claim 1, wherein the yellowness index (b*) after a light resistance test is Δ5 or less.

Images