KR102186061B1 - Nanophosphor sheet - Google Patents

Abstract

The present invention relates to a nano-phosphor sheet, and more specifically, to a nano-phosphor sheet excellent in moisture resistance, heat resistance and light resistance.
The nano-phosphor sheet according to an embodiment of the present invention may include a polymer resin layer including a nano-phosphor, a light scattering agent, and a polymer resin.
According to the nano-phosphor sheet of the present invention, a nano-phosphor sheet having improved external light extraction efficiency can be provided by manufacturing a single-layered nano-phosphor sheet using a polymer resin having excellent moisture resistance, heat resistance, and light resistance.

Description

Nano phosphor sheet {NANOPHOSPHOR SHEET}

The present invention relates to a nano-phosphor sheet, and more specifically, to a nano-phosphor sheet excellent in moisture resistance, heat resistance and light resistance.

Quantum Dot (QD) is a nano-sized semiconductor particle, and its size is very small, resulting in a quantum confinement effect. Here, the quantum confinement effect means a phenomenon in which the band gap of the object increases when the object becomes smaller than the nano size. Accordingly, when light having a wavelength greater than the band gap of the quantum dot is incident on the quantum dot, the quantum dot absorbs the light and becomes excited, and falls to the ground state while emitting light of a specific wavelength. The wavelength of the emitted light has a value corresponding to the band gap. Quantum dots are widely used in various light-emitting devices and electronic devices by controlling the light-emitting characteristics due to the quantum confinement effect depending on the size and composition.

Quantum dots are used as a phosphor in a display device. In order to optically couple a light source and a quantum dot, a sheet prepared by dispersing the quantum dots in a polymer resin (hereinafter, referred to as a nano phosphor sheet) is used.

The nanophosphor sheet includes a quantum dot, a light scattering agent, a polymer resin, and a barrier layer, and has a structure in which a plurality of quantum dots and a plurality of light scattering agents are dispersed in the polymer resin.

At this time, the polymer resin serves to protect the quantum dots from external impacts and the environment, and to disperse and fix the quantum dots and light scattering agents. Polymer resin is an important factor that determines the reliability, cost, and performance of the nano phosphor sheet. To secure the reliability of the nano phosphor sheet, high refractive index, oxygen and moisture barrier properties, and excellent heat resistance are required. do.

The polymer resin of the conventional nano-phosphor sheet is generally an epoxy resin. Epoxy resin is inexpensive and has excellent properties as a sealing material for optical members, but it has a low barrier of oxygen and moisture, and yellowing occurs at high temperatures, so it is insufficient to be applied to high-efficiency light source devices such as quantum dot liquid crystal displays. There is.

In order to compensate for these shortcomings, the conventional nano-phosphor sheet has a structure further including a pair of barrier layers surrounding the upper and lower portions of the polymer resin. The barrier layer is formed of a material having low oxygen permeability and moisture permeability, and a material having excellent heat resistance to protect the quantum dots vulnerable to oxygen and moisture from the external environment such as heat, oxygen, and moisture, but the external light extraction efficiency is lowered. There was this.

Accordingly, there is a need to develop a single-layered nano-phosphor sheet that does not include a separate barrier layer, and to satisfy this structure, it is necessary to develop a nano-phosphor sheet having excellent oxygen and moisture barrier properties.

1. Korean Patent Publication No. 10-2013-0120486 (Title of invention: 　quantum dot films, lighting devices, and lighting methods)

The present invention was conceived to solve the above problems, and the problem to be solved in the present invention is to provide a nano phosphor sheet capable of implementing a single layer structure by using a polymer resin having excellent moisture resistance, heat resistance and light resistance. have.

The subject of the present invention is not limited to the problems mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

The nano-phosphor sheet according to an embodiment of the present invention for solving the above problem may include a polymer resin layer including a nano-phosphor, a light scattering agent, and a polymer resin.

In addition, according to another feature of the present invention, a film layer disposed on at least one of an upper surface or a lower surface of the polymer resin layer; It may include.

In addition, according to another feature of the present invention, the partition wall disposed at predetermined intervals on the film layer; It further includes, wherein a plurality of the polymer resin layers may be provided, and the polymer resin layers may be separated by the partition walls.

In addition, according to another feature of the present invention, the partition walls may be disposed at intervals of 10 μm to 100 μm.

In addition, according to another feature of the present invention, the nano-phosphor may be included in an amount of 0.1 to 10% by weight based on the total weight.

In addition, according to another feature of the present invention, the polymer resin is an acrylic binder; Metallic stearate powder; A resin composition containing a monomer and a photoinitiator is cured to form, and the metallic stearate-based powder is zinc stearate, calcium stearate, aluminum stearate, magnesium stearate ( Magnesium Stearate) may include any one or a combination thereof.

In addition, according to another feature of the present invention, the metallic stearate-based powder may be monodispersed at 50°C to 100°C in the acrylic binder.

According to the nano-phosphor sheet of the present invention, a nano-phosphor sheet having improved external light extraction efficiency can be provided by manufacturing a single-layered nano-phosphor sheet using a polymer resin having excellent moisture resistance, heat resistance, and light resistance.

1 is a schematic cross-sectional view of a nano phosphor sheet according to an embodiment of the present invention.
2 is a schematic cross-sectional view of a nano phosphor sheet according to another embodiment of the present invention.
3 is a cross-sectional view schematically illustrating a nano-phosphor sheet in which the film layer of FIG. 2 is formed on the upper and lower surfaces of a polymer resin layer.
4 is a schematic cross-sectional view of a nanophosphor sheet according to another embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

When an element or layer is referred to as “on” another element or layer, it includes all cases where another layer or other element is interposed directly on or in the middle of another element.

Although the first, second, and the like are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are only used to distinguish one component from another component. Therefore, it goes without saying that the first component mentioned below may be the second component within the technical idea of the present invention.

The same reference numerals refer to the same components throughout the specification.

The size and thickness of each component shown in the drawings are illustrated for convenience of description, and the present invention is not limited to the size and thickness of the illustrated component.

Each of the features of the various embodiments of the present invention can be partially or entirely combined or combined with each other, and as those skilled in the art can fully understand, technically various interlocking and driving are possible, and each of the embodiments can be implemented independently of each other It may be possible to do it together in a related relationship.

Hereinafter, a nanophosphor sheet according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

1 is a schematic cross-sectional view of a nano phosphor sheet according to an embodiment of the present invention.

Referring to FIG. 1, the nano phosphor sheet 100 of the present invention includes a polymer resin layer 110.

The polymer resin layer 110 includes a nano phosphor 111, a light scattering agent 112 and a polymer resin 113, and a structure in which the nano phosphor 111 and the light scattering agent 112 are dispersed in the polymer resin 113 Can be formed as Here, the nano-phosphor 111 may be a quantum dot.

Specifically, a quantum dot is a semiconductor having a diameter of several nanometers, and can convert light incident from a light source into light having a desired wavelength. For example, when blue light having a wavelength range between about 430 nm and about 470 nm is incident on a quantum dot, the quantum dots absorb blue light and form a quantum dot 111G that emits green light in a wavelength range between about 520 nm and about 560 nm. In addition, blue light may be converted into green light. In addition, the quantum dot may further include a quantum dot 111R that absorbs blue light and emits red light in a wavelength range of about 610 nm to about 660 nm to convert blue light into red light.

Quantum dots may include a core, a shell surrounding the core, an inorganic ion ligand around the core and the shell, and an alloy type in which the core and the shell are not distinguished.

The core emits light of a specific wavelength at the center of the quantum dot. The shell may be formed by covering the core on the surface of the core to protect the core.

The core-shell and alloy-type quantum dots may be formed of a group II-VI, group III-V, group IV-VI, or group IV semiconductor material or a compound thereof on the periodic table.

For example, the II-VI group semiconductor compound may be a binary compound of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, or a combination thereof. The III-V group semiconductor compound may be a binary compound of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, or a combination thereof. The IV-VI semiconductor compound may be a binary compound of SnS, SnSe, SnTe, PbS, PbSe, PbTe, or a combination thereof. The group IV element or compound may be Si, Ge, SiC, SiGe, or a combination thereof. In addition, the semiconductor compound may be a ternary element compound or a quaternary element compound including a group II-VI, III-V, IV-VI, or IV element on the periodic table. Furthermore, the semiconductor material or compound is not limited to those described above, and may be any semiconductor material or compound known to those skilled in the art.

The inorganic ionic ligand includes a halogen group or a chalcogen group element. These elements may be in the form of a monoatomic ion or a polyatomic ion including these elements.

Meanwhile, the nanophosphor 111 may be included in an amount of 0.1 to 10% by weight based on the total weight of the nanophosphor sheet 100.

Further, the polymer resin layer 110 may include a light scattering agent 112.

The light scattering agent 112 is formed so that the surface has a predetermined curvature, so that the light incident into the polymer resin layer 110 is dispersed in various directions. Accordingly, an area where light incident in the polymer resin layer 110 and the quantum dot meet may be increased.

The light scattering agent 112 may be formed of metal oxide particles, air bubbles, glass beads, or polymer beads, and may be formed of a mixture of selected materials. The light scattering agent 112 is not limited to the above-described materials and may be formed of any material known to those skilled in the art.

The light scattering agent 112 formed of these materials may have a relatively high or low refractive index with respect to the polymer resin 113 to be described later. For example, the ratio of the refractive index of the light scattering agent 112 and the polymer resin 113 may be in the range of about 0.3 to 2.0. Accordingly, the light scattering agent 112 may change a path of light incident on the polymer resin layer 110 and diffuse outgoing light.

It is preferable that the light scattering agent 112 has a shape of a sphere as a whole, but may have an elliptical shape, a distorted shape, or any other unintended shape when actually manufactured.

Further, the polymer resin layer 110 includes a polymer resin 113.

The polymer resin 113 is fixed by uniformly dispersing and fixing the nano phosphor 111 and the light scattering agent 112 inside the polymer resin layer 110, and enclosing the nano phosphor 111 to prevent external impacts and environments. The phosphor 111 can be protected.

The polymer resin 113 preferably has an average distance between atoms of 0.2 nm to 3.0 nm, and more preferably 0.3 nm to 1.0 nm. In general, the oxygen molecule diameter is 0.32 nm and the water molecule diameter is 0.33 nm, so by forming the average distance between atoms of the polymer resin 113 smaller than the diameter of the oxygen molecule and the water molecule, the oxygen molecule and the water molecule It is possible to prevent penetration into the stratum 110.

The polymer resin layer 110 may be formed by curing a resin composition including an acrylic binder, a metallic stearate powder, a monomer, and a photoinitiator.

The type of the acrylic binder is not particularly limited as long as it has an acrylate functional group. For example, an acrylate monomer, an acrylate oligomer, or a mixture thereof may be used. At this time, it is preferable that the acrylate monomer or acrylate oligomer contains at least one or more acrylate functional groups capable of participating in the curing reaction.

The acrylate oligomer may be a urethane acrylate oligomer, an epoxy acrylate oligomer, a polyester acrylate, a polyether acrylate, or a mixture thereof. In addition, acrylate monomers are dipentaerythritol hexaacrylate, dipentaerythritol hydroxy pentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylene propyl triacrylate, propoxylated glycerol triacrylate , Trimethyllopropane ethoxy triacrylate, 1,6-hexanediol diacrylate, propoxylated glycero triacrylate, tripropylene glycol diacrylate, ethylene glycol diacrylate, or a mixture thereof, etc. may be used. have. In addition, the acrylic binder may be a copolymer of two or more compounds containing an acrylate functional group.

Meanwhile, the acrylic binder may further include a functional group having polarity capable of ionic bonding with water molecules at the terminal. When a functional group having a polarity is further included in the acrylic binder, the moisture penetration prevention performance may be further improved due to surface adsorption of moisture. The polar functional group may include a hydroxy group or an acrylic group, but is not limited thereto.

In addition, the acrylic binder may be included in an amount of 10% to 60% by weight of the polymer resin 113. When the content of the acrylic binder is less than 10% by weight, photocuring may not sufficiently occur, and when it is more than 60% by weight, fairness may be deteriorated or physical properties of the cured polymer resin 113 may be deteriorated.

Further, the polymer resin 113 may contain metallic stearate-based powder.

The metallic stearate-based powder is monodisperse in the acrylic binder, and by narrowing the average distance between atoms of the photo-cured polymer resin 113, penetration of oxygen and moisture can be prevented. At this time, the metallic stearate-based powder may be dispersed at 50°C to 100°C, more preferably at 70°C to 80°C.

The metallic stearate-based powder may include any one of zinc stearate, calcium stearate, aluminum stearate, and magnesium stearate, or a combination thereof.

In addition, the polymer resin 113 may contain a monomer.

The monomer may be a polyfunctional monomer. The polyfunctional monomer may impart photopolymerization to the photocurable resin composition, or impart dispersion stability of the quantum dots and light scattering agent 112, and may impart an appropriate viscosity.

The polyfunctional monomer is a compound that can be photocured together with the above-described acrylic binder or metallic stearate powder, and may include a compound having 3 to 15 functional acrylate groups.

The polyfunctional monomer is a hydroxy group-containing acrylate compound such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, pentaerythritol triacrylate or dipentaerythritol pentaacrylate, polyethylene glycol diacrylate or poly. Water-soluble acrylate compounds such as propylene glycol diacrylate, polyfunctional polyester acrylate compounds of polyhydric alcohols such as trimethylolpropane triacrylate, pentaerythritol tetraacrylate or dipentaerythritol hexaacrylate, trimethyl Isocyanate modification of acrylate compounds of polyfunctional alcohols such as allpropane and hydrogenated bisphenol A or ethylene oxide adducts of polyphenols such as bisphenol A and biphenols and/or propylene oxide adducts, and acrylate compounds containing hydroxy groups Polyfunctional or monofunctional polyurethane acrylate as water, bisphenol A diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, or epoxy acrylate compound that is a (meth)acrylic acid adduct of phenol novolac epoxy resin, modified caprolactone It may be a caprolactone-modified acrylate compound compound such as ditrimethylolpropane tetraacrylate, ε-caprolactone-modified dipentaerythritol acrylate, and caprolactone-modified hydroxypivalsan neopentyl glycol ester diacrylate. , One or two or more selected from these may be used in combination.

In particular, pentaerythritol triacrylate, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, caprolactone-modified ditrimethylolpropane tetraacrylate, and the like can be used.

In addition, the polymer resin 113 may contain a photoinitiator.

The photoinitiator may be selected without limitation as long as it is an ultraviolet curable initiator that is commonly used. For example, the photoinitiator consists of 1-hydroxy cyclohexylphenyl ketone, benzyl dimethyl ketal, hydroxydimethylacetophenone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin butyl ether. It may include one or more selected from the group.

On the other hand, the polymer resin 113 may contain one or more solvents to impart an appropriate solubility and viscosity. The type of organic solvent that is commonly used is not limited, but benzene, toluene, methyl ethyl ketone, methyl isobutyl ketone, acetone, ethanol, tetrahydrofurfuryl alcohol, propyl alcohol, propylene carbonate, N-methyl pyrrolidine, N-vinyl pyrrolidine, N-acetyl pyrrolidine, N-hydroxy methyl pyrrolidine, N-butyl pyrrolidine, N-ethylpyrrolidinone, N-(N-octyl)pyrrolidine, N- (N-dodecyl)pyrrolidinone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methyl cyclohexanone, ethyl acetate, butyl acetate, tetrahydrofuran, methanol, amylpropionate, methyl pro In the group consisting of cypionate, propylene glycol methyl ether, diethylene glycol monobutyl ether, dimethyl sulfoxide, dimethyl formamide, ethylene glycol, hexafluoroantimonate, monoalkyl ether of ethylene glycol and dialkyl ether of ethylene glycol It may include at least one selected.

In addition, the polymer resin 113 may further include other additives capable of removing air bubbles or dissipating electric charges.

Meanwhile, the nano phosphor sheet 100 of the present invention may be formed in a single layer structure.

Referring to FIG. 1, the nano phosphor sheet 100 may be formed in a single-layer structure composed of a polymer resin layer 110. Specifically, the polymer resin layer 110 of the present invention includes a polymer resin 113 including a metallic stearate powder, and thus has excellent moisture resistance, heat resistance, and light resistance, and does not include a separate barrier film. It can be used in a single layer structure without the need. Accordingly, by allowing the nanophosphor sheet 100 to be used as a light conversion sheet or plate, external light extraction efficiency can be improved.

The nanophosphor sheet 100 formed in such a structure has the physical properties shown in [Table 1] below.

- Initial value 72hr Lv 100% 99.1% Color coordinates Δx 0 0.002 Δy 0 -0.003 Dark Spot - None

Table 1 is a blue light test result of the nano-phosphor sheet 100 of the present invention.

Referring to Table 1, after 72 hours, the nano-phosphor sheet 100 was measured to have a luminance of 99.1% and a color deviation of CIE (0.002, -0.003), and a dark spot was not found, It shows excellent physical properties.

In addition, the nanophosphor sheet 101 may include a film layer 120 disposed on at least one of an upper surface or a lower surface of the polymer resin layer 110.

2 is a cross-sectional view schematically showing a nano-phosphor sheet according to another embodiment of the present invention, and FIG. 3 is a cross-sectional view schematically showing a nano-phosphor sheet in which the film layer of FIG. 2 is formed on the upper and lower surfaces of a polymer resin layer to be.

Referring to FIG. 2, the nano phosphor sheet 101 may be formed in a two-layer structure by coating a polymer resin layer 110 on the upper surface of the film layer 120. At this time, the polymer resin layer 110 is preferably coated to a thickness of 1㎛ to 30㎛. And, the film layer 120 may be composed of one selected from a base film (Base film) or a functional film.

The base film may be formed in a thin plate or film shape having a predetermined thickness. And, it is preferable that the base film is formed of a transparent material through which light can be transmitted. For example, the base film may be formed of one selected from polyethylene terephthalate film (PET Film), polycarbonate (PC), and polyethylene terephthalate copolymer (Co-Polyethylene Terephthalate; CoPET). .

The functional film may be a photofunctional film. The photofunctional film may function to condense, diffuse, transmit, refract or reflect light. Accordingly, the photofunctional film may serve as a prism sheet, a diffusion sheet, and a light guide plate. In addition, the photofunctional film may include optical patterns of various shapes to perform this function, and the present invention is not limited thereto.

The nanophosphor sheet 101 formed in such a structure has the physical properties shown in [Table 2] below.

Example Condition Initial value 48hr 72hr 240hr 480hr 1,000hr Luminance CIE x CIE y One 85℃ 100% 99.18 99.02 99.16 98.95 99.21 99.28 0.0004 0.0010 2 60℃/RH95% 100% 100.21 100.16 100.08 100.25 100.29 100.31 -0.0006 -0.0008

Referring to Example 1 of Table 2, the nanophosphor sheet 101 was measured to have a luminance retention of 99.28% and a color deviation of CIE (0.0004, 0.0010) after 1,000 hours in a high temperature environment of 85°C.

Further, referring to Example 2 of Table 2, the nanophosphor sheet 101 has a luminance retention of 100.31% and a color deviation of CIE (-0.0006, 0.0008) after 1,000 hours in an environment at a temperature of 60°C and a relative humidity of 95%. ), and exhibits excellent physical properties.

In addition, the nanophosphor sheet 102 may be formed in a multilayer structure.

Referring to FIG. 3, the nanophosphor sheet 102 may be formed in a three-layer structure by disposing a film layer 120 on the upper and lower surfaces of the polymer resin layer 110.

Specifically, the film layer 120 disposed on the upper and lower surfaces of the polymer resin layer 110 may be a base film. At this time, the polymer resin layer 110 is preferably formed to a thickness of 1㎛ to 100㎛. In addition, a separate diffusion sheet (not shown) may be disposed between the polymer resin layer 110 and the film layer 120. Here, since the diffusion sheet has the same configuration and function as the known diffusion sheet, a detailed description will be omitted.

The nanophosphor sheet 102 formed in such a structure has the physical properties shown in [Table 3] below.

Example Condition Initial value 48hr 72hr 240hr 480hr 1,000hr Luminance CIE x CIE y One 85℃ 100% 99.54 99.76 99.59 98.98 100.29 100.67 -0.0016 -0.0033 2 60℃/RH95% 100% 99.89 99.88 99.88 99.85 99.86 99.87 -0.0016 -0.0034

Referring to Example 1 of Table 3, the nanophosphor sheet 102 was measured to have a luminance retention of 100.67% and a color deviation of CIE (-0.0016, -0.0033) after 1,000 hours in a high temperature environment of 85°C.

In addition, referring to Example 2 of Table 3, the nanophosphor sheet 102 has a luminance retention of 99.87% and a color deviation of CIE (-0.0016, 0.0034) after 1,000 hours in an environment at a temperature of 60° C. and 95% relative humidity ), and shows excellent physical properties.

Meanwhile, the film layer 120 disposed on the upper and lower surfaces of the polymer resin layer 110 may be a functional film. At this time, the polymer resin layer 110 is preferably formed to a thickness of 1㎛ to 100㎛.

In addition, the nanophosphor sheet 104 may further include barrier ribs 130 disposed on the film layer 120 at predetermined intervals.

4 is a schematic cross-sectional view of a nanophosphor sheet according to another embodiment of the present invention.

Specifically, the partition wall 130 may be formed of a transparent resin, applied on the upper surface of the film layer 120 disposed under the polymer resin layer 110, and cured. The partition walls 130 are preferably disposed at intervals of 10 μm to 100 μm, but may be disposed at intervals of 100 μm to 1 cm.

In addition, after the partition wall 130 is disposed, the polymer resin layer 110 may be formed. A plurality of polymer resin layers 110 are provided, and each of the polymer resin layers 110 may be separated by a partition wall 130. At this time, the polymer resin layer 110 is preferably formed to a thickness of 1㎛ to 100㎛.

On the other hand, the nanophosphor sheet 104 including the partition wall 130 may be manufactured using a gap roll, a slot die, or a patterning method. It is preferable to use a patterning method.

Although embodiments of the present invention have been described with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention You can understand. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting.

100, 101, 102, 103 ... Nano phosphor sheet
110… Polymer resin layer
111 ... Nano phosphor
112… Light scattering agent
113 ... Polymer resin
120… Film layer
130… septum

Claims (7)

Including a polymer resin layer comprising a nano phosphor, a light scattering agent and a polymer resin,
The polymer resin is an acrylic binder; Metallic stearate-based powder monodispersed at 50°C to 100°C in the acrylic binder; A resin composition containing a monomer and a photoinitiator is cured to form,
The metallic stearate-based powder monodispersed in the acrylic binder narrows the average distance between atoms of the cured polymer resin to prevent the penetration of oxygen and moisture,
The polymer resin has an average distance between atoms of 0.2 nm to 3.0 nm, a nano phosphor sheet. The method of claim 1,
A film layer disposed on at least one of an upper surface or a lower surface of the polymer resin layer; Containing, nano phosphor sheet. The method of claim 2,
Barrier ribs disposed on the film layer at predetermined intervals; It further includes,
The polymer resin layer is provided in plurality,
The nano-phosphor sheet between the polymer resin layers and separated by the partition walls. The method of claim 3,
The barrier ribs are disposed at intervals of 10 μm to 100 μm. The method of claim 1,
The nano phosphor is,
Included in an amount of 0.1 to 10% by weight based on the total weight of the nano phosphor sheet, nano phosphor sheet. The method of claim 1,
The metallic stearate-based powder,
Zinc stearate (Zinc Stearate), calcium stearate (Calcium Stearate), aluminum stearate (Aluminium Stearate), magnesium stearate (Magnesium Stearate) any one or a combination of these, a nano phosphor sheet comprising. delete

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