Color conversion sheet and backlight unit including same

Abstract

A color conversion sheet, according to one embodiment of the present invention, includes: a substrate layer; a wavelength conversion unit positioned on one surface of the substrate layer and containing organic phosphor and matrix resin; an antistatic layer positioned on the other surface of the substrate layer; and a bead-containing coating layer applied on the antistatic layer, and may further include a light diffusion layer positioned on the surface of the wavelength conversion unit to enhance light diffusion and optical efficiency, wherein the antistatic layer and the bead-containing coating layer, for maintaining antistatic function even during high-temperature operations, are arranged together at the bottommost portion of the color conversion sheet, thereby enabling ease of assembly with an LCD light guide plate and ensuring antistatic performance at high temperatures.

Description

Color conversion sheet and backlight unit including the same

[0001] The present invention relates to a color conversion sheet and a backlight unit including the same, and more specifically, to a color conversion sheet having little color change, excellent reliability, and being able to maintain its function even in a high-temperature drying process, and a backlight unit including the same.

[0002] Most current display devices have evolved from the cathode ray tube (CRT) displays of the past to take the form of liquid crystal displays (LCDs). In particular, most representative display devices, such as TVs, smartphones, and monitors, utilize LCDs. These LCDs are photosensitive displays, meaning they do not emit light themselves and form images; instead, they rely on external light to form images. Therefore, LCDs require a backlight unit (BLU) positioned on the back of the display to emit light.

[0003] In particular, quantum dot technology has been extensively studied and applied recently to realize high-definition liquid crystal displays (LCDs). Quantum dot technology has the advantage of being able to produce a variety of colors simply by adjusting the size of the nano-inorganic particles, and it also boasts excellent stability against light such as UV. However, existing cadmium (Cd)-based nano-inorganic particles have the disadvantage of being environmentally problematic and requiring use with a barrier film due to their vulnerability to moisture, which reduces their price competitiveness. Therefore, recent efforts have been focused on developing organic fluorescent materials that can achieve high color reproducibility and superior luminance characteristics without the inclusion of cadmium-based nano-inorganic particles.

[0004] This type of color conversion sheet has a bead coating on the bottom back surface to facilitate assembly with the LCD light guide plate, and has an antistatic function that can reduce surface resistance, but has the problem of losing its function during the high-temperature drying process that forms the color conversion sheet.

[0005] The present invention has been devised to solve the above problems and to meet the conventional requirements, and the problem to be solved by the present invention is to provide a color conversion sheet formed of an organic material, in which the bead coating and antistatic layer on the lowermost back surface can maintain their functions even during a high-temperature drying process, and in which there is little color change and excellent reliability, and a backlight unit including the same.

[0006] The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

[0007] The above object is achieved by a color conversion sheet including a substrate layer, a wavelength conversion part located on one surface of the substrate layer and including an organic fluorescent substance and a matrix resin, an antistatic layer located on the other surface of the substrate layer, and a bead coating layer formed by being applied on the antistatic layer.

[0008] Preferably, the antistatic composition forming the antistatic layer may include an organic binder resin, a conductive polymer, and a curing agent.

[0009] Preferably, the antistatic composition forming the antistatic layer may include 1 to 30 parts by weight of a conductive polymer per 100 parts by weight of an organic binder resin.

[0010] Preferably, the organic binder resin of the antistatic layer may include at least one resin selected from among acrylic resin, urethane resin and polyester resin, or a mixture of copolymers thereof.

[0011] Preferably, the conductive polymer may include at least one selected from polythiophene, polyaniline, polypyrrole, PEDOT, and PEDOT / PSS.

[0012] Preferably, the color conversion sheet has a surface resistance of 1.0x10 measured on the surface of the bead coating layer. 7 Ω / cm 2 It could be as follows:

[0013] Preferably, the color conversion sheet has a surface resistance of 1.0x10 measured on the surface of the bead coating layer after heat treatment at 170°C for 4 minutes. 7 Ω / cm 2 It could be as follows:

[0014] Preferably, the antistatic layer may have a thickness of 10 to 500 nm.

[0015] Preferably, the bead composition forming the bead coating layer may include an organic binder resin, polymer beads, and a curing agent.

[0016] Preferably, the bead composition forming the bead coating layer may include 0.1 to 0.3 parts by weight of polymer beads per 100 parts by weight of organic binder resin.

[0017] Preferably, the polymer beads may comprise at least one or a mixture of two or more selected from PET, Nylon, polystyrene (PS), polybutyl methacrylate (PBMA), polymethyl methacrylate (PMMA) and melamine.

[0018] Preferably, the organic binder resin of the bead coating layer may include at least one selected from among acrylic resin, urethane resin and polyester resin, or a mixture of copolymers thereof.

[0019] Preferably, the polymer beads may have an average particle diameter of 0.5 to 10 μm.

[0020] Preferably, the thickness of the bead coating layer may be 2 to 7 μm.

[0021] Preferably, it may further include a light diffusion layer positioned on the wavelength conversion unit and increasing light diffusion and light efficiency.

[0022] Preferably, the wavelength conversion unit may be positioned on one surface of the substrate layer and may include a wavelength conversion layer including an organic fluorescent substance and a matrix resin, and a transparent layer positioned on the wavelength conversion layer.

[0023] Preferably, the adhesive strength between the wavelength conversion layer and the transparent layer may be 800 gf / inch or more.

[0024] Preferably, the wavelength conversion unit may be positioned on one surface of the substrate layer and may include a first wavelength conversion layer in which a first organic fluorescent substance is dispersed in a first resin matrix, a transparent layer positioned on the first wavelength conversion layer, and a first wavelength conversion layer in which a second organic fluorescent substance is dispersed in a second resin matrix, the transparent layer being positioned on the first wavelength conversion layer.

[0025] Preferably, the transparent layer may be a polymer film comprising at least one selected from polyethylene terephthalate, polyethylene naphthalate, polyacrylate, polycarbonate, polyetherimide, and polyimide.

[0026] In addition, the above object is achieved by a backlight unit having the above-described color conversion sheet.

[0027] According to the color conversion sheet and the backlight unit including the same according to the present invention, by applying an organic fluorescent substance to the color conversion sheet, it is environmentally safe, has excellent color reproducibility and brightness characteristics, has little color change in various environments, and has excellent reliability, and the bead coating and antistatic layer on the lowermost back surface do not lose their functions even in a high-temperature drying process, so that it is easy to combine with an LCD light guide plate, and can maintain low surface resistance.

[0028] However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0029] Figure 1 is a configuration diagram of a color conversion sheet according to one embodiment of the present invention.

[0030] Figure 2 is a configuration diagram of a color conversion sheet according to another embodiment of the present invention.

[0031] FIG. 3 is a schematic diagram of a backlight unit including a color conversion sheet according to one embodiment of the present invention.

[0032] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0033] In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification. In addition, the thickness is shown in the drawings to clearly express various layers and regions. In addition, when it is mentioned in this specification that an element is disposed "on" or "over" another element, the element may be disposed directly on the other element, or there may be elements interposed between the elements. On the other hand, when it is mentioned that an element is disposed "directly on" or "directly above" another element, there may not be interposed elements.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In the event of a conflict, the present specification, including its definitions, will govern. Furthermore, although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

[0035] In this specification, the terms "~-based resin", "~-based polymer", or / and "~-based copolymer" are broad concepts encompassing all of "~ resin", "~ polymer", "~ copolymer", or / and "derivatives of ~ resin, polymer, or copolymer." In addition, in this specification, the term "polymer or copolymer crosslinked with these resins" means "polymer or copolymer crosslinked with the aforementioned resin."

[0036] In this specification, “compound” is a broad concept that includes “monatomic molecules,” “oligomers,” and “polymer compounds including homopolymers and copolymers.”

[0037] The term "including" in this specification means that other components may be included rather than excluding other components unless specifically stated to the contrary.

[0038] The term "combination of these" in this specification means a mixture or combination of one or more of the described components.

[0039] As used herein, the term "and / or" is meant to include any and all combinations of one or more of the items described herein. As used herein, the term "or" means "and / or." The expressions "at least one" or "one or more" preceding elements herein may supplement the entire list of elements and do not imply that they supplement individual elements described above.

[0040] Unless otherwise stated herein, all percentages, parts, ratios, etc. are by weight. Additionally, whenever an amount, concentration, or other value or parameter is given as a range, a preferred range, or a list of upper preferred values ​​and lower preferred values, this should be understood to specifically disclose all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed.

[0041] When a range of numerical values ​​is mentioned in this specification, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range. The scope of the present invention is not intended to be limited to the specific values ​​mentioned when defining the range.

[0042] In this specification, each component is a concept that includes both singular and plural.

[0043] Figure 1 is a configuration diagram of a color conversion sheet according to one embodiment of the present invention.

[0044] Referring to FIG. 1, a color conversion sheet (100) according to an embodiment of the present invention includes a wavelength conversion unit (10), a substrate layer (20), an antistatic layer (30), and a bead coating layer (40), and may further include a light diffusion layer (50). Here, the wavelength conversion unit (10) is located on one surface of the substrate layer (20), the antistatic layer (30) is located on the other surface of the substrate layer (20), and the bead coating layer (40) is formed by being applied on the antistatic layer (30). In addition, the light diffusion layer (50) may be located on the wavelength conversion unit (10). A color conversion sheet (10) according to an embodiment of the present invention having such a structure can convert blue light into white light and emit it.

[0045] In addition, the wavelength conversion unit (10) according to the example illustrated in FIG. 1 includes a wavelength conversion layer (11) and a transparent layer (12). At this time, the wavelength conversion layer (11) is located on one side of the base layer (20) and includes an organic fluorescent substance and a matrix resin, and the transparent layer (12) is located on one side of the wavelength conversion layer (11) (the opposite side of the base layer (20)). Hereinafter, each component will be described in detail.

[0046] The transparent layer (12) according to the present invention is a transparent and flexible polymer film, and preferably includes at least one resin selected from a thermoplastic resin, a thermosetting resin, and a UV-curable resin having a visible light transmittance of 70% or more. More specifically, the transparent layer (12) is preferably a polymer film including at least one selected from polyethylene terephthalate, polyethylene naphthalate, polyacrylate, polycarbonate, polyetherimide, and polyimide.

[0047] In addition, the thickness of the transparent layer (12) is preferably 0.1 to 200 ㎛, and more preferably 1 to 50 ㎛. This is because, when the thickness of the transparent layer (12) is less than 0.1 ㎛, it is difficult to control color changes that may occur due to diffusion or mixing of the organic fluorescent substance (13, 14) or resin matrix (19) depending on temperature, and when it exceeds 200 ㎛, light transmission may be hindered.

[0048] The wavelength conversion layer (11) of the color conversion sheet (100) according to one embodiment of the present invention is positioned between the transparent layer (12) and the substrate layer (20), and may include a green organic fluorescent substance (13) and a red organic fluorescent substance (14) dispersed in a resin matrix (19). In addition, as in the color conversion sheet (200) according to another embodiment of the present invention illustrated in FIG. 2 described below, the first organic fluorescent substance (13), which is a green organic fluorescent substance, and the second organic fluorescent substance (14), which is a red organic fluorescent substance, may be included in separate first wavelength conversion layers (15) and second wavelength conversion layers (16), respectively, and may be separated from each other.

[0049] The resin matrix (19) has the function of fixing the green organic fluorescent substance (13) and the red organic fluorescent substance (14) in the wavelength conversion layer (11) and preventing them from being exposed to moisture or oxygen, thereby preventing the decomposition of the green organic fluorescent substance (13) and the red organic fluorescent substance (14) dispersed in the resin matrix (19).

[0050] It is preferable that the resin matrix (19) include at least one selected from among ester, olefin, acryl, ether, urethane, carbonate, and imide resins.

[0051] In addition, it is preferable that the resin included in the resin matrix (19) has a number average molecular weight (Mn) of 1,000 to 50,000 g / mol or a weight average molecular weight (Mw) of 50,000 to 2,000,000 g / mol. This is because, when the number average molecular weight of the resin included in the resin matrix (19) is less than 1,000 g / mol or the weight average molecular weight is less than 50,000 g / mol, the resin matrix (19) may become sticky, which may cause poor film winding when the color conversion sheet (100) is wound in a roll shape, and when the number average molecular weight exceeds 50,000 g / mol or the weight average molecular weight exceeds 2,000,000 g / mol, the resin matrix (19) has poor solubility in a solvent, which may make it difficult to form a wavelength conversion layer (11).

[0052] In addition, the acid value of the resin included in the resin matrix (19) is preferably 0 to 20 mgKOH / g, and the hydroxyl value of the resin included in the resin matrix (19) is preferably 0 to 30 mgKOH / g, and more preferably 0 to 20 mgKOH / g. This is because ester, olefin, acryl, ether, urethane, carbonate, and imide resins that can generally be applied as the resin matrix of the wavelength conversion layer included in the color conversion sheet may accelerate the decomposition of an organic fluorescent agent dispersed in the resin matrix due to functional groups such as hydroxyl groups or carboxylic acid groups present in these resins, thereby lowering the reliability of the organic fluorescent agent, so it is preferable to set it within the above range.

[0053] As an example, one of the resins that can be used as the resin matrix (19) is an ester-based resin that preferably includes an ester-based resin polymerized from an aliphatic polyhydric alcohol and an aliphatic or aromatic polyhydric acid. Here, the aliphatic polyhydric alcohol is an aliphatic compound having two or more hydroxyl groups and 2 to 10 carbon atoms, such as at least one of ethylene glycol, propane diol, butane diol, neopentyl glycol, and trimethylol propane. In addition, the aliphatic polyhydric acid is an aliphatic compound having two or more carboxylic acid groups and 2 to 12 carbon atoms, such as at least one of malonic acid, succinic acid, adipic acid, and sebacic acid, and the aromatic polyhydric acid is an aromatic compound having two or more carboxylic acid groups and 1 to 4 aromatic rings, such as at least one of isophthalic acid, phthalic acid, terephthalic acid, and cyclohexyldicarboxylic acid.

[0054] It is preferable that the resin matrix (19) includes at least one of polyester, modified polyester, polyethylene, polycycloolefin, poly(methyl)methacrylate, polyethylene glycol, polyurethane, polycarbonate, polyimide, and block copolymers thereof.

[0055] In addition, the resin matrix (19) may further include a crosslinking agent for chemical crosslinking of the resin matrix (19) as needed. The crosslinking agent may include, but is not limited to, isocyanate, amine, anhydride, thiol, epoxy, etc. crosslinking agents, and various crosslinking agents may be included as needed.

[0056] The green organic fluorescent substance (13) dispersed in the resin matrix (19) of the wavelength conversion layer (11) according to the present invention can absorb blue light and emit green light. Green organic fluorescent substance (13) is a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, triphenylene, perylene, fluoranthene, fluorene, indene, or a derivative thereof (for example, 2-(benzothiazol-2-yl)-9,10-diphenylanthracene or 5,6,11,12-tetraphenylnaphthacene, etc.), furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene, or a compound having a heteroaryl ring such as a borane derivative, distyrylbenzene Aminostyryl derivatives such as derivatives, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, 4,4'-bis(N-(stilben-4-yl)-N-phenylamino)stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, coumarin derivatives such as 2,3,5,6-1H,4H-tetrahydro-9-(2'-benzothiazolyl)quinolizino[9,9a,1-gh]coumarin, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and their metal complexes and aromatic compounds represented by N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine It is preferred to include at least one of the amine derivatives.

[0057] Additionally, the green organic fluorescent substance (13) may include a compound of the following chemical formula 1.

[0058] (Chemical formula 1)

[0059]

[0060] In addition, it is preferable that the green organic fluorescent substance (13) be included in an amount of 0.1 to 5 parts by weight, and more preferably 0.1 to 2 parts by weight, based on 100 parts by weight of the solid content of the resin matrix (19). This is because, if the green organic fluorescent substance (13) is included in an amount of less than 0.1 parts by weight, the effect of converting the color to a desired color through the color conversion sheet (100) may be insufficient, and if it is included in an amount of more than 5 parts by weight, a quenching phenomenon may occur due to interactions such as aggregation of the green organic fluorescent substance (13).

[0061] The wavelength conversion layer (11) according to the present invention may include a red organic fluorescent substance (14) dispersed in a resin matrix (19). The red organic fluorescent substance (14) dispersed in the resin matrix (19) of the wavelength conversion layer (11) absorbs blue light or green light and emits red light.

[0062] Such red organic fluorescent material (14) is a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, triphenylene, perylene, fluoranthene, fluorene, indene, or a derivative thereof (for example, 2-(benzothiazol-2-yl)-9,10-diphenylanthracene or 5,6,11,12-tetraphenylnaphthacene, etc.), a compound having a heteroaryl ring such as furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, pyrrolopyridine, thioxanthene, or a derivative thereof, a borane derivative, Aminostyryl derivatives such as distyrylbenzene derivatives, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, 4,4'-bis(N-(stilben-4-yl)-N-phenylamino)stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, coumarin derivatives such as 2,3,5,6-1H,4H-tetrahydro-9-(2'-benzothiazolyl)quinolizino[9,9a,1-gh]coumarin, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, triazole and metal complexes thereof and N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine It is preferable to include at least one selected from among the representative aromatic amine derivatives.

[0063] In addition, it is preferable that the red organic fluorescent substance (14) includes a compound of the following chemical formula 2.

[0064] (Chemical formula 2)

[0065]

[0066] In addition, it is preferable that the red organic fluorescent substance (14) is included in an amount of 0.1 to 1 part by weight, and more preferably 0.1 to 0.6 parts by weight, based on 100 parts by weight of the solid content of the resin matrix (19). This is because, when the red organic fluorescent substance (14) is included in an amount of less than 0.1 part by weight, the effect of converting the color to a desired color through the color conversion sheet (100) is insufficient, and when it is included in an amount of more than 1 part by weight, a quenching phenomenon may occur due to interactions such as aggregation of the red organic fluorescent substance (14).

[0067] The thickness of the wavelength conversion layer (11) according to the present invention is preferably 1 to 150 µm, and more preferably 5 to 100 µm.

[0068] In a color conversion sheet (100) according to one embodiment of the present invention, it is preferable that the adhesive force between the transparent layer (12) and the wavelength conversion layer (11) be 800 gf / inch or more. This is because, if the adhesive force between the transparent layer (12) and the wavelength conversion layer (11) is less than 800 gf / inch, it is difficult to fix the color conversion sheet (100) to the backlight unit.

[0069] In addition, it is preferable that the wavelength conversion layer (11) and the transparent layer (12) have different refractive indices, and it is preferable that the refractive index of the place where the light finally emitted for the incident light comes out (further away from the light source) is smaller. For example, when the light finally emitted for the incident light comes out through the wavelength conversion layer (11), the refractive index of the transparent layer (12) is larger than that of the wavelength conversion layer (11), and conversely, when the light finally emitted for the incident light comes out through the transparent layer (12), the refractive index of the transparent layer (12) is smaller than that of the wavelength conversion layer (11). That is, as illustrated in FIG. 3, in the color conversion sheet (100) according to one embodiment of the present invention, since the light source (70) is positioned in the direction of the wavelength conversion layer (11), the refractive index of the transparent layer (12) is preferably smaller than that of the wavelength conversion layer (11). This is because the light reflectance of the transparent layer (12) can be increased, so that the color-converted light can be effectively emitted to the outside.

[0070] The substrate layer (20) according to the present invention may be a transparent and flexible polymer film, for example, a polymer film such as polyethylene terephthalate, polyethylene naphtalate, polyacrylate, polycarbonate, polyetherimide, polyimide, etc., but is not limited thereto, and various polymer films may be applied. In addition, the substrate layer (20) may be an optical film such as a diffusion sheet or a prism sheet, but is not limited thereto, and sheets having various functions may be applied.

[0071] The light diffusion layer (50) according to the present invention may be positioned on the wavelength conversion unit (10). That is, the light diffusion layer (50) is positioned on the transparent layer (12) of the wavelength conversion unit (10) and functions to improve light diffusion and light efficiency. It is preferable that the light diffusion layer (50) be a transparent and flexible polymer film, and preferably include at least one selected from polyethylene terephthalate, polyethylene naphtalate, polyacrylate, polycarbonate, polyetherimide, and polyimide. In addition, the light diffusion layer (50) may be an optical film such as a diffusion sheet or a prism sheet, but is not limited thereto, and sheets having various functions may be applied. In addition, the light diffusion layer (50) may be formed of the same material as the base layer (20), or may be composed of different materials.

[0072] The antistatic layer (30) according to the present invention is located on the other surface of the substrate layer (20) (the surface opposite to the surface where the wavelength conversion unit (10) is located). This antistatic layer (30) is formed by applying an antistatic composition containing an organic binder resin, a conductive polymer, and a curing agent to the other surface of the substrate layer (20). More specifically, the antistatic layer (30) is formed by coating an antistatic composition obtained by dispersing an organic binder resin, a conductive polymer, and a curing agent in an organic solvent on the other surface (lower) of the substrate layer (20), drying the coating, and then curing the coating using heat or UV. At this time, the stacking order of the antistatic layer (30) can be either before or after the formation of other functional layers.

[0073] In the present invention, the antistatic composition forming the antistatic layer (30) preferably contains 1 to 30 parts by weight of a conductive polymer and 0.2 to 2.0 parts by weight of a curing agent per 100 parts by weight of an organic binder resin. In particular, the antistatic composition is provided with antistatic properties by a mixed resin between the organic binder resin and the conductive polymer, and preferably contains 1 to 30 parts by weight of the conductive polymer per 100 parts by weight of the organic binder resin. If the content of the conductive polymer in the antistatic composition is less than 1 part by weight per 100 parts by weight of the organic binder resin, the antistatic property is weak, and if it is contained in an excessive amount exceeding 30 parts by weight, the effect of providing antistatic property is improved, but it is uneconomical due to the use of an expensive conductive polymer. Therefore, it is preferable to control the content within the above range so as to achieve a surface resistance within a desired level range.

[0074] In addition, it is preferable that the organic binder resin included in the antistatic composition comprises at least one resin or a mixture of copolymers thereof, wherein the polymer main chain is selected from among acrylic resin, urethane resin, and polyester resin. In the examples described below, a urethane resin having a fluorinated hydrocarbon group side chain and a solids content of 15 wt% is used, but the present invention is not limited thereto.

[0075] In addition, it is preferable to use at least one or more or a mixture thereof selected from polythiophene, polyaniline, polypyrrole, PEDOT (poly 3,4-ethylenedioxythiophene) and PEDOT / PSS (polystyrene sulfonic acid) as the conductive polymer included in the antistatic composition.

[0076] In addition, the curing agent used in the antistatic composition is an additive for forming an antistatic layer, and can be selected from among curing agents that can be typically applied to acrylic resins, urethane resins, and polyester resins. At this time, it is preferable that the antistatic composition contains 0.2 to 2.0 parts by weight of the curing agent per 100 parts by weight of the organic binder resin. If the content of the curing agent is less than 0.2 parts by weight, the adhesive strength between the substrate layer (20) and the antistatic layer (30) is reduced, and if it exceeds 2.0 parts by weight, the problem of reduced miscibility between the constituent materials of the antistatic composition occurs, i.e., the constituent materials are not uniformly decomposed.

[0077] In addition, any solvent used in the antistatic composition can be used as long as it can uniformly dissolve or disperse the above-described mixed resin of the organic binder resin and the conductive polymer, and it is preferable to use a plurality of mixed solvents, and it is most preferable to use a mixed solvent composed of water, ethanol, isopropyl alcohol, and butyl alcohol.

[0078] In addition, the thickness of the antistatic layer (30) is preferably 10 to 500 nm. If the thickness of the antistatic layer (30) is less than 10 nm, there is a problem that the antistatic function is not sufficiently provided, and if it is more than 500 nm, there is a problem that the surface of the antistatic layer is broken and cracks occur.

[0079] The bead coating layer (40) according to the present invention is positioned on one side of the antistatic layer (30) (the side opposite to the side on which the base layer (20) is formed) and includes an organic binder resin and polymer beads. More specifically, the bead coating layer (40) is formed by coating a bead composition obtained by dispersing polymer beads, an organic binder resin, and an optional curing agent in an organic solvent on the lower side of the antistatic layer (30) (the side opposite to the side on which the base layer of the antistatic layer is formed), drying the coating, and then curing the coating using heat or UV. At this time, the lamination order of the bead coating layer (40) can be either before or after the formation of other functional layers.

[0080] In the present invention, the bead composition constituting the bead coating layer (40) may include 0.1 to 0.3 parts by weight of polymer beads and 0.01 to 0.2 parts by weight of a curing agent, relative to 100 parts by weight of an organic binder resin. In particular, the bead composition facilitates bonding with a light guide plate by a mixed resin between the organic binder resin and the polymer beads, thereby imparting the characteristic of ease of processability, and it is preferable to include 0.1 to 0.3 parts by weight of polymer beads, relative to 100 parts by weight of the organic binder resin. At this time, if the polymer beads are contained in an amount less than 0.1 parts by weight relative to 100 parts by weight of the organic binder resin in the bead composition, the ease of assembly with the light guide plate is reduced, and if they are contained in an excessive amount exceeding 0.3 parts by weight, particle dispersion is difficult, and it is difficult for the organic binder resin to sufficiently cover the polymer beads and coat them as a single layer, resulting in poor appearance. Therefore, it is preferable to set it within the above range.

[0081] In addition, it is preferable that the organic binder resin included in the bead composition includes a polymer main chain including at least one selected from among acrylic resin, urethane resin, and polyester resin, or a mixture of copolymers thereof.

[0082] In addition, it is preferable that the polymer beads included in the bead composition include at least one or a mixture of two or more selected from PET, nylon, polystyrene (PS), polybutyl methacrylate (PBMA), polymethyl methacrylate (PMMA), and melamine.

[0083] In addition, the curing agent included in the bead composition is an additive for forming the bead coating layer (40), and it is preferable to select and use among curing agents that can be commonly applied to acrylic resin, urethane resin, and polyester resin. In addition, it is preferable that the bead composition includes 0.01 to 0.2 parts by weight of the curing agent per 100 parts by weight of the organic binder resin. If the content of the curing agent in the bead composition is less than 0.01 parts by weight, the organic binder resin is not sufficiently cured, resulting in a decrease in the adhesive strength between the bead coating layer (40) and the antistatic layer (30), and if it exceeds 0.2 parts by weight, there is a problem in that the miscibility of the bead composition is reduced.

[0084] In addition, the average particle diameter of the polymer beads contained in the bead composition is preferably 0.5 to 10 ㎛, and more preferably 4 to 8 ㎛. If the average particle diameter of the polymer beads is less than 0.5 ㎛, the polymer beads are not easily dispersed within the bead composition, and if the average particle diameter exceeds 10 ㎛, the polymer beads protrude outside the bead coating layer (40) and fall off.

[0085] In addition, the thickness of the bead coating layer (40) is preferably 2 to 7 μm, and more preferably 3 to 5 μm. When the thickness of the bead coating layer is less than 2 μm, the polymer beads may not be sufficiently covered with the organic binder resin, so that the particles may protrude or not be uniformly coated, and when the thickness exceeds 7 μm, it is disadvantageous for sheet thinning. In particular, in the present invention, the purpose of forming the bead coating layer (40) is to improve the ease of process by solving the problem that the color conversion sheets, which are finished products, do not easily separate from each other due to static electricity generated between them. However, when the thickness of the bead coating layer (40) exceeds 7 μm, the disadvantages in sheet thinning are greater than the advantages in terms of ease of process.

[0086] Additionally, the solvent used in the bead composition forming the bead coating layer (40) may be any solvent capable of uniformly dissolving or dispersing the organic binder resin and polymer bead mixture resin contained in the bead composition. For example, the solvent used in the bead composition may be water, alcohol, or ether-based solvents, but is not limited thereto, and various solvents may be used.

[0087] The surface resistance of the color conversion sheet according to one embodiment of the present invention, i.e., the surface resistance measured on the surface of the bead coating layer (40), is 1.0x10 7 Ω / cm 2 It is desirable that the surface resistance is 1.0x10 7 Ω / cm 2 If it exceeds this, the antistatic effect is minimal due to high surface resistance.

[0088] In addition, the color conversion sheet according to one embodiment of the present invention has a surface resistance of 1.0x10 measured on the surface of the bead coating layer (40) after performing heat treatment at 170°C for 4 minutes. 7 Ω / cm 2 It is desirable that the surface resistance after heat treatment is 1.0x10 7 Ω / cm 2 If it exceeds, the antistatic performance of the antistatic layer (30) is deteriorated during the process of manufacturing the color conversion sheet (100) or the process of manufacturing the backlight unit thereafter.

[0089] As described above, the color conversion sheet (100) according to one embodiment of the present invention comprises an antistatic layer (30) that maintains an antistatic function even at high temperatures on the lowermost rear surface, and a bead coating layer (40) is laminated on the surface of the antistatic layer (30) to ensure ease of assembly with the light guide plate and an antistatic function.

[0090] Figure 2 is a configuration diagram of a color conversion sheet according to another embodiment of the present invention.

[0091] Referring to FIG. 2, a color conversion sheet (200) according to another embodiment of the present invention includes a wavelength conversion part (17) including a first wavelength conversion layer (15), a transparent layer (12), and a second wavelength conversion layer (16). The color conversion sheet (100) illustrated in FIG. 1 has a structure in which one wavelength conversion layer (11) includes both a green organic phosphor (13) and a red organic phosphor (14), whereas the color conversion sheet (200) illustrated in FIG. 2 has a structure in which the first organic phosphor (13), which is a green organic phosphor, and the second organic phosphor (14), which is a red organic phosphor, are separated and positioned in separate first wavelength conversion layers (15) and second wavelength conversion layers (16), respectively. Hereinafter, a detailed configuration of such a color conversion sheet (200) will be described. However, overlapping descriptions of the same configuration and structure as the color conversion sheet (100) of FIG. 1 are omitted.

[0092] The color conversion sheet (200) illustrated in FIG. 2 has a wavelength conversion part (17) in which a first wavelength conversion layer (15), a transparent layer (12), and a second wavelength conversion layer (16) are sequentially laminated on a base layer (20), and a light diffusion layer (50) is positioned on the second wavelength conversion layer (16) of the wavelength conversion part (17). That is, a first wavelength conversion layer (15) including a first resin matrix (19a) containing a first organic fluorescent substance (13) and a second wavelength conversion layer (16) including a second resin matrix (19b) containing a second organic fluorescent substance (14) form multiple layers.

[0093] At this time, the closer the distance between the second organic phosphor (14), which is a red organic phosphor, and the first organic phosphor (13), which is a green organic phosphor, is, the easier it is to absorb green light, so that the red light emission efficiency can increase. Therefore, even in a color conversion sheet including the same content of organic phosphors (13, 14), it is possible to implement various white lights by adjusting the distance between these organic phosphors (13, 14). Here, when the green organic phosphor (13) and the red organic phosphor (14) are included together in a resin matrix formed of a single layer, the distance between the green organic phosphor (13) and the red organic phosphor (14) may be relatively close, but may be affected by the surrounding environment, for example, a high temperature or high humidity environment, so that the distance between them may change relatively greatly. This may change the emission efficiency of the red organic phosphor (14), which may ultimately change the color coordinates of the white light that can be converted by the color conversion sheet or reduce the reliability. Meanwhile, in the case where a resin matrix layer containing a green organic fluorescent substance (13) and a resin matrix layer containing a red organic fluorescent substance (14) are in contact with each other to form multiple layers, the green or red organic fluorescent substance present at the interface of each layer may diffuse to the interface of the other layer over time, and as a result, the distance between the red organic fluorescent substance (14) and the green organic fluorescent substance (13) may become closer, thereby changing the luminous efficiency of the red organic fluorescent substance (14), which may change the color coordinates of white light or reduce reliability.

[0094] Accordingly, in the present invention, as illustrated in FIG. 2, the color conversion sheet (200) is configured to completely separate the first and second wavelength conversion layers (15, 16) by arranging a transparent layer (12) between a first wavelength conversion layer (15) including a green (first) organic fluorescent substance (13) and a second wavelength conversion layer (16) including a red (second) organic fluorescent substance (14), thereby maintaining a constant distance between the green organic fluorescent substance (13) and the red organic fluorescent substance (14), thereby maintaining the luminous efficiency of the red organic fluorescent substance (14) constant, and thereby preventing a decrease in the color coordinates and reliability of white light emitted by the color conversion sheet (200).

[0095] That is, the color conversion sheet (200) according to another embodiment of the present invention can have a technical effect of being able to implement high color uniformity and uniform brightness even in a high temperature and high humidity environment by disposing a transparent layer (12) between the first wavelength conversion layer (15) and the second wavelength conversion layer (16), thereby preventing the green and red organic fluorescent substances (13, 14) and the first / second resin matrix (19a, 19b) included in the first and second wavelength conversion layers (15, 16) from diffusing or mixing with each other.

[0096] The thickness of the first wavelength conversion layer (15) and the second wavelength conversion layer (16) according to the present invention is preferably 1 to 150 µm, and more preferably 5 to 100 µm.

[0097] In addition, in the wavelength conversion unit (17), it is preferable that the wavelength conversion layer at the location where light is finally emitted for incident light (the wavelength conversion layer furthest from the light source) has a lower refractive index than the transparent layer (12). For example, when light finally emitted for incident light comes through the first wavelength conversion layer (15), the refractive index of the transparent layer (12) is higher than the refractive index of the first wavelength conversion layer (15), and conversely, when light finally emitted for incident light comes through the second wavelength conversion layer (16), the refractive index of the transparent layer (12) is preferably higher than the refractive index of the second wavelength conversion layer (16). That is, in the case of the color conversion sheet (200) illustrated in FIG. 2, when applied to the backlight unit of FIG. 3, light is emitted through the second wavelength conversion layer (16), and therefore, the refractive index of the second wavelength conversion layer (16) may be lower than the refractive index of the transparent layer (12). This is because the light reflectance of the transparent layer (12) can be increased, so that the color-converted light can be effectively emitted to the outside.

[0098] Next, a backlight unit (900) including a color conversion sheet according to an embodiment of the present invention will be described with reference to FIG. 3, which is a schematic diagram of a backlight unit including a color conversion sheet according to an embodiment of the present invention.

[0099] A backlight unit (900) according to one embodiment of the present invention may include a light source (700), a reflector (500) that can increase light efficiency by reflecting light emitted from the light source (700), a light guide plate (300) positioned above the reflector (500) and that serves to evenly spread light emitted from the light source (700), and a color conversion sheet (100, 200) positioned above the light guide plate (300).

[0100] Here, the color conversion sheet (100, 200) is the same color conversion sheet as that described in the embodiment shown in FIG. 1 or FIG. 2 described above, and thus, redundant descriptions are omitted. In addition, the upper portion of the color conversion sheet (100) may further include at least one optical sheet, for example, a diffusion sheet, a prism sheet, a brightness enhancement film (DBEF), etc.

[0101] Hereinafter, the composition and resulting effects of the present invention will be described in more detail through examples and comparative examples. However, these examples are intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these examples.

[0102] [Example]

[0103] [Example 1]

[0104] (Step 1) Formation of antistatic layer and bead coating layer

[0105] An antistatic composition was prepared by dispersing 1 g of PEDOT / PSS (Baytron PH, manufactured by Bayer), 133.3 g of a urethane resin (manufactured by Dainichi Seika Co., Ltd.) having a fluorinated hydrocarbon side chain with a solid content of 15 wt%, and 0.4 g of an aziridine curing agent (manufactured by DOORICHEM) in 100 g of a mixed solvent containing water, ethanol, isopropyl alcohol, and butyl alcohol (weight ratio of 20 / 55 / 20 / 5), and then applying the antistatic composition to the lower part of a polyester film (TAK, XG7PH8) having a thickness of 100 μm and drying to form an antistatic layer having a thickness of 50 nm after drying.

[0106] Next, 80 g of acrylic resin (Samwon, AT-2100) containing 0.1 g of PBMA particles with an average particle size of 6 μm and 0.024 g of a curing agent (Samhwa, SC70I) was dispersed in 100 g of ethyl acetate solvent to prepare a bead composition. The bead composition was then applied onto an antistatic layer and dried to form a bead coating layer with a thickness of 5 μm after drying. Thereafter, a wavelength conversion section as shown below was formed on the opposite side of the polyester film on which the antistatic layer was formed.

[0107] (Step 2) Formation of wavelength conversion layer

[0108] An organic fluorescent substance solution was prepared by dissolving the same weight of a green organic fluorescent substance according to Chemical Formula 1 and a red organic fluorescent substance according to Chemical Formula 2 in ethyl acetate, then mixing a polyester resin (Toyobo, Vylon630) into the organic fluorescent substance solution, adding ethyl acetate so that the viscosity became 150 cps, and stirring at 150 rpm for 30 minutes to prepare a wavelength conversion layer composition. At this time, the total content of the organic fluorescent substance (red organic fluorescent substance and green organic fluorescent substance) was set to 0.72 parts by weight per 100 parts by weight of the polyester resin solid content.

[0109] Next, the manufactured wavelength conversion layer composition was bar-coated on the opposite side of the surface of the polyester film on which the antistatic layer was formed, and then dried at 170°C for 4 minutes to form a wavelength conversion layer having a thickness of 10 μm after drying.

[0110] (Step 3) Formation of transparent layer

[0111] Next, 80 parts by weight of toluene was added to 100 parts by weight of silicone resin (DOW, 7904), stirred for 2 hours, 0.05 parts by weight of platinum catalyst (DOW, SYL-OFF 4000 CATALYST) was added, and stirred for an additional 30 minutes to prepare a transparent layer composition. The prepared transparent layer composition was applied to the opposite side of the diffusion layer of a diffusion film (TFN, TDV10F), and dried at 170°C for 2 minutes to form a transparent layer having a thickness of 24 μm after drying.

[0112] (Step 4) Manufacturing the color conversion sheet

[0113] Next, the wavelength conversion layer and transparent layer manufactured as described above were laminated so as to be in contact with each other, and then a color conversion sheet was manufactured using a roll laminate (GMP, EXCELAM Ⅱ-355Q).

[0114] [Example 2]

[0115] A color conversion sheet was manufactured in the same manner as in Example 1, except that 6 g of PEDOT / PSS (Baytron PH, manufactured by Bayer) was used in the antistatic layer.

[0116] [Example 3]

[0117] A color conversion sheet was manufactured in the same manner as in Example 1, except that 0.2 g of PEDOT / PSS (Baytron PH, manufactured by Bayer) was used in the antistatic layer and 0.24 g of PBMA particles were used in the bead coating layer.

[0118] [Comparative example]

[0119] [Comparative Example 1]

[0120] A color conversion sheet was manufactured in the same manner as in Example 1, except that the antistatic layer was not formed.

[0121] [Comparative Example 2]

[0122] A color conversion sheet was manufactured in the same manner as in Example 1, except that 7 g of PEDOT / PSS (Baytron PH, manufactured by Bayer) was used.

[0123] [Comparative Example 3]

[0124] A color conversion sheet was manufactured in the same manner as in Example 1, except that 0.1 g of PEDOT / PSS (Baytron PH, manufactured by Bayer) was used.

[0125] [Comparative Example 4]

[0126] A color conversion sheet was manufactured in the same manner as in Example 1, except that 0.3 g of PBMA particles were used in the bead coating layer.

[0127] [Comparative Example 5]

[0128] A color conversion sheet was manufactured in the same manner as in Example 1, except that 0.07 g of PBMA particles were used in the bead coating layer.

[0129] The physical properties were measured using the color conversion sheets according to Examples 1 to 3 and Comparative Examples 1 to 5 through the following experimental examples, and the results are shown in Table 1 below.

[0130] [Experimental Example]

[0131] (1) Color coordinate measurement

[0132] The color coordinate (x, y) values ​​of the color conversion sheet according to the examples and comparative examples were measured using a spectroradiometer (KONICA MINOLTA, CA-S20W).

[0133] (2) Adhesion measurement

[0134] In order to measure the adhesive strength between the transparent layer and the wavelength conversion layer, in the examples and comparative examples, without forming the antistatic layer and the bead coating layer, one side of the polyester film laminated on the wavelength conversion layer was attached to a SUS plate and fixed, and then, using a tensile tester (LLOYD, L / F Plus), the diffusion film laminated on the transparent layer was peeled off from the polyester film at a peeling speed of 300 mm / min and 180 degrees at room temperature (25°C), and the adhesive strength between the transparent layer and the wavelength conversion layer was measured.

[0135] (3) Surface resistance measurement

[0136] For the examples and comparative examples, (Step 2) the surface resistance was measured on the surface of the bead coating layer using a surface resistance meter (Advantest, R8340A). At this time, the surface resistance measured immediately after forming the antistatic layer and the bead coating layer in Step 1 was taken as the surface resistance before heat treatment (initial surface resistance), and the surface resistance (final surface resistance) was measured after manufacturing the final color conversion sheet through the coating, drying, and laminating processes in Step 2. For reference, it was confirmed that (Step 3) the formation of a transparent layer did not affect the surface resistance.

[0137] (4) Check the appearance of the seat

[0138] The appearance of the color conversion sheets for the examples and comparative examples was evaluated by visually observing them. At this time, if no particles or stains were visible to the naked eye, it was marked as "O", and if aggregated particles were visible or surface stains appeared, it was marked as "X".

[0139] (5) Anti-blocking property evaluation

[0140] After placing two sheets of the color conversion sheet of the examples and comparative examples, 1 kg / cm 2 After leaving the sheets under pressure for 24 hours, the occurrence of adhesion was evaluated when separating the two sheets. If the two sheets were immediately separated by their own weight, it was marked as "O", and if they were not immediately separated by their own weight, it was marked as "X".

[0141] The results of the experiment performed on the color conversion sheet according to the experimental example described above are as shown in Table 1.

[0142] Color coordinate x Color coordinate y Adhesion (gf / inch) Surface resistance (Ω / cm) 2 ) Blocking performance evaluation appearance initial final implementation example 10.1950.1619341.3x10 5 2.0x10 5 OO Example 20.1950.1598931.7x10 5 2.4x10 5 OO Example 30.1940.1589174.1x10 5 2.2x10 6OO Comparison Example 10.1930.16416002.0x10 11 1.0x10 13 OO Comparative Example 20.1950.1629011.7x10 5 2.3x10 5 OX Comparative Example 30.1940.1609487.9x10 6 1.5x10 7 OO Comparative Example 40.1950.1608711.7x10 5 2.3x10 5 OX Comparative Example 50.1940.1619471.4x10 5 2.1x10 5 XO

[0143] As shown in Table 1, Examples 1 to 3 showed that the surface resistance of the bead coating layer, which is the lowest cross-section, was 1.0x10 even after the initial and completion of the color conversion sheet. 7 Ω / cm 2 The following is well maintained, and in particular, the surface resistance required by the present invention is exhibited even when heat treatment is performed at 170°C for 4 minutes during the manufacturing process. In addition, it was confirmed that the color conversion sheet was stably manufactured in Examples 1 to 3 with an adhesive strength of 800 gf / inch or more between the wavelength conversion layer and the transparent layer, and that there was no problem in the ease of assembly with the light guide plate.

[0144] On the other hand, Comparative Example 1 has a surface resistance value of 1.0x10 from the beginning. 7 Ω / cm 2 , and after the high temperature (170℃) drying process, 1.0x10 13 Ω / cm 2 It can be seen that the anti-static function is completely lost with the surface resistance value above.

[0145] In addition, it can be seen that Comparative Example 2 had poor appearance due to excessive conductive polymer content, and Comparative Example 3 had a surface resistance of 1.0x10 after heat treatment at 170°C for 4 minutes due to insufficient conductive polymer content. 7 Ω / cm 2It can be seen that the anti-static function is deteriorated when exceeded.

[0146] In addition, it can be seen that Comparative Example 4, which contained an excessive amount of polymer beads, had poor appearance due to difficulty in dispersing the polymer beads particles.

[0147] And it was confirmed that Comparative Example 5, which had an insufficient content of polymer beads, had poor ease of assembly with the light guide plate. More specifically, when the content of polymer beads is less than 0.1 part by weight as in Comparative Example 5, due to the insufficient particles, an air layer is not formed between different color conversion sheets when they come into contact with each other, resulting in poor anti-blocking properties, and the sheets become attached to each other due to static electricity generated between them, making it difficult to separate them due to their own weight during assembly.

[0148] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention.

Claims

1. Base layer; A wavelength conversion part located on one side of the above substrate layer and including an organic fluorescent substance and a matrix resin; An antistatic layer located on the other surface of the above-mentioned substrate layer; A bead coating layer formed by applying it on the above antistatic layer; Color conversion sheet including.

2. In paragraph 1, A color conversion sheet, wherein the antistatic composition forming the antistatic layer comprises an organic binder resin, a conductive polymer, and a curing agent.

3. In paragraph 2, A color conversion sheet, wherein the antistatic composition forming the antistatic layer comprises 1 to 30 parts by weight of a conductive polymer for 100 parts by weight of an organic binder resin.

4. In paragraph 2, A color conversion sheet, wherein the organic binder resin of the antistatic layer comprises at least one resin selected from among acrylic resin, urethane resin and polyester resin, or a mixture of copolymers thereof.

5. In paragraph 2, A color conversion sheet, wherein the conductive polymer comprises at least one selected from polythiophene, polyaniline, polypyrrole, PEDOT, and PEDOT / PSS.

6. In paragraph 1, The above color conversion sheet has a surface resistance of 1.0x10 measured on the surface of the bead coating layer. 7 Ω / cm 2 Below, color conversion sheet.

7. In paragraph 1, The above color conversion sheet was heat treated at 170℃ for 4 minutes and the surface resistance measured on the surface of the bead coating layer was 1.0x10 7 Ω / cm 2 Below, color conversion sheet.

8. In paragraph 1, A color conversion sheet wherein the anti-static layer has a thickness of 10 to 500 nm.

9. In paragraph 1, A color conversion sheet comprising a bead composition forming the above bead coating layer, comprising an organic binder resin, polymer beads, and a curing agent.

10. In paragraph 9, A color conversion sheet, wherein the bead composition forming the above bead coating layer comprises 0.1 to 0.3 parts by weight of polymer beads per 100 parts by weight of organic binder resin.

11. In paragraph 9, A color conversion sheet, wherein the polymer beads comprise at least one or a mixture of two or more selected from PET, nylon, polystyrene (PS), polybutyl methacrylate (PBMA), polymethyl methacrylate (PMMA), and melamine.

12. In paragraph 9, A color conversion sheet, wherein the organic binder resin of the bead coating layer comprises at least one selected from acrylic resin, urethane resin and polyester resin, or a mixture of copolymers thereof.

13. In paragraph 9, The above polymer beads are a color conversion sheet having an average particle diameter of 0.5 to 10㎛.

14. In paragraph 1, A color conversion sheet, wherein the thickness of the above bead coating layer is 2 to 7㎛.

15. In paragraph 1, A light diffusion layer positioned on the wavelength conversion section and increasing light diffusion and light efficiency; A color conversion sheet that further includes:

16. In paragraph 1, The above wavelength conversion unit is, A wavelength conversion layer located on one side of the above substrate layer and including an organic fluorescent substance and a matrix resin; and A transparent layer positioned on the wavelength conversion layer; Color conversion sheet including.

17. In paragraph 16, A color conversion sheet having an adhesive strength between the wavelength conversion layer and the transparent layer of 800 gf / inch or more.

18. In paragraph 1, The above wavelength conversion unit is, A first wavelength conversion layer located on one surface of the above-mentioned substrate layer, wherein a first organic fluorescent substance is dispersed in a first resin matrix; A transparent layer positioned on the first wavelength conversion layer; A first wavelength conversion layer positioned on the transparent layer, wherein a second organic fluorescent substance is dispersed in a second resin matrix; Color conversion sheet including.

19. In paragraph 16 or 18, A color conversion sheet, wherein the transparent layer is a polymer film comprising at least one selected from polyethylene terephthalate, polyethylene naphthalate, polyacrylate, polycarbonate, polyetherimide, and polyimide.

20. A backlight unit having a color conversion sheet according to Article 1.

Images