WO2015060615A1

WO2015060615A1 - Light-emitting complex, hardened material comprising same, optical sheet, backlight unit, and display device

Info

Publication number: WO2015060615A1
Application number: PCT/KR2014/009879
Authority: WO
Inventors: 최정옥; 권오관; 황준환; 김병철
Original assignee: 주식회사 엘엠에스
Priority date: 2013-10-25
Filing date: 2014-10-21
Publication date: 2015-04-30
Also published as: KR101463416B1

Abstract

A light-emitting complex according to the present invention comprises: at least one quantum dot; and an ionomer for covering the quantum dot. The light-emitting complex has excellent quantum efficiency, a low width of change in a light-emitting peak even when the light-emitting complex is dispersed to a resin, excellent dispersion stability, excellent ultra-violate stability, and excellent heat/moisture stability.

Description

Light emitting composites, cured products including the same, optical sheets, backlight units, and display devices

The present invention relates to a light emitting composite, a composition comprising the same, a cured product, an optical sheet, a backlight unit and a display device, and a light emitting composite having improved dispersibility and luminescence properties, a composition comprising the same, a cured product, an optical sheet, a backlight unit and It relates to a display device.

Quantum dots are materials with crystal structures ranging in size from tens to tens of nanometers and consist of hundreds to thousands of atoms. Quantum dots are very small in size, resulting in quantum confinement effects. The quantum confinement effect refers to a phenomenon in which a band gap of the object becomes large when the object becomes smaller than the nano size. As a result, when light having a wavelength larger than the band gap of the quantum dots is incident on the quantum dots, the quantum dots are excited by absorbing the light and falling 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. Since quantum dots have different light emission characteristics due to quantum confinement effects, they are used in various light emitting devices and electronic devices by controlling them.

In general, when a plurality of quantum dots are dispersed in a solvent or a resin, the quantum dots may be easily aggregated with each other, thereby degrading quantum efficiency. In addition, the quantum dots made of metal are very vulnerable to moisture, so that the quantum efficiency may be lowered by being easily oxidized by moisture in the air. As described above, the quantum dot has a problem in that it is difficult to store because it has low dispersibility in a solvent or resin and low stability in moisture, heat or light.

In addition, even when the optical sheet is manufactured using the quantum dots to improve the color reproducibility of the display device, the quantum dots may be easily damaged as the use time of the optical sheet increases because the quantum dots themselves have low stability against moisture, heat, or light. . As a result, the lifespan of the display device is shortened.

One object of the present invention is to provide a light emitting composite having improved dispersibility and stability against heat, light and moisture as well as quantum efficiency.

Another object of the present invention is to provide a composition and a cured product comprising the light-emitting composite.

Still another object of the present invention is to provide a backlight unit and a display device including the optical sheet made of the composition and the optical sheet made of the composition.

The light emitting composite according to the embodiment of the present invention comprises at least one quantum dot; And an ionomer covering the quantum dots and represented by the structure of Formula 1 below.

[Formula 1]

In Formula 1, x is 20 to 100, y is 1 to 10, M ⁺ is a metal cation, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R _6, and R ₇ are each independently hydrogen. (H) or an alkyl group having 6 or less carbon atoms.

In one embodiment, x may be from 25 to 80 and y may be from 1 to 4, x may be from 30 to 60 and y may be from 1.5 to 2.0.

In one embodiment, the metal cation, at least one monovalent metal ion selected from the group consisting of sodium ions, potassium ions, lithium ions, silver ions and mercury ions; At least one divalent metal ion selected from the group consisting of magnesium ion, calcium ion, strontium ion, barium ion, copper ion, cadmium ion, mercury ion, tin ion, lead ion, iron ion, cobalt ion, nickel ion and zinc ion ; At least one trivalent metal ion selected from the group consisting of aluminum ions, scandium ions, iron ions and yttrium ions; Or at least one tetravalent or higher metal ion selected from the group consisting of titanium ions, zirconium ions, hafnium ions, vanadium ions, tantalum ions, tungsten ions, chromium ions, cerium ions and iron ions.

In one embodiment, the ionomer may be 20 to 100% of the polar group neutralized by the metal cation.

In one embodiment, the ionomer may have a molecular weight of 1,000 or more and 20,000 or less.

In one embodiment, the melting point of the ionomer may be 50 ° C. or more and 150 ° C. or less.

In one embodiment, the ionomer may have a density of 0.85 g / cm ³ or more and 1.05 g / cm ³ or less.

In one embodiment, the ionomer may encapsulate the at least one quantum dot, and two or more quantum dots may be spaced apart from each other in an aggregate formed by the ionomer.

The composition according to an embodiment of the present invention is a resin in a liquid state having a polymerizable functional group (resin); And a light emitting composite dispersed in the resin, wherein the light emitting composite includes at least one quantum dot and an ionomer covering the quantum dot and represented by the structure of Chemical Formula 1.

In addition, the cured product according to an embodiment of the present invention is a cured resin (resin); And a light emitting composite dispersed in the cured resin, wherein the light emitting composite includes at least one quantum dot and an ionomer covering the quantum dot and represented by the structure of Chemical Formula 1.

In one embodiment, the resin may include at least one selected from the group consisting of silicone resins, epoxy resins and acrylic resins. In this case, the resin may be a thermosetting resin or a photocurable resin.

In one embodiment, the composition may further comprise light diffusing beads, the composition may further comprise a blowing agent.

The optical sheet according to an embodiment of the present invention includes a light conversion layer in which at least one quantum dot and the light emitting composite including the ionomer covering the quantum dot and represented by the structure of Formula 1 are dispersed therein.

In one embodiment, the light conversion layer may include at least one cured material selected from the group consisting of silicone resin, epoxy resin and acrylic resin. In this case, the resin may be a thermosetting resin or a photocurable resin.

In one embodiment, the light conversion layer may further include light diffusion beads or voids.

In one embodiment, the optical sheet may further include a barrier layer disposed on one surface of the light conversion layer. The first transparent film may be disposed on the barrier layer. A second transparent film may be disposed between the light conversion layer and the barrier layer.

In one embodiment, the optical sheet may further include a light diffusion layer formed on the barrier layer.

In one embodiment, the optical sheet may further include a light diffusion layer formed on the first transparent film.

In one embodiment, a light diffusion pattern may be formed on the surface of the light diffusion layer.

In one embodiment, the light diffusing layer may include light diffusing beads and may include voids.

In an embodiment, the optical sheet may further include a first barrier layer disposed on an upper surface of the light conversion layer and a second barrier layer disposed on a lower surface of the light conversion layer. In this case, the first transparent film disposed on the first barrier layer and the second transparent film disposed on the second barrier layer may be further included.

In an embodiment, the light emitting layer may further include a third transparent film disposed between the light conversion layer and the first barrier layer and a fourth transparent film disposed between the light conversion layer and the second barrier layer.

In one embodiment, a light diffusion layer may be formed on at least one barrier layer of the first and second barrier layers.

In one embodiment, an optical diffusion layer may be formed on at least one transparent film of the first and second transparent films.

In one embodiment, a light diffusion layer may be formed on at least one of the upper surface and the lower surface of the light conversion layer, in this case, a light diffusion pattern may be formed on the surface of the light diffusion layer, the light diffusion layer is light diffusion It may include beads or voids.

In one embodiment, a light collecting pattern may be formed on one surface of the light conversion layer.

In one embodiment, a backlight unit and a display device include: a light emitting device; A light guide plate receiving light generated by the light emitting device; And an optical sheet disposed on the light guide plate, wherein the optical sheet includes at least one quantum dot and a light emitting composite including an ionomer covering the quantum dot.

In one embodiment, the light emitting device is a blue light emitting device, and the light emitting composite includes a red light emitting composite including only red quantum dots, a green light emitting composite including only green quantum dots, and a multicolor light emitting composite including both the red quantum dots and the green quantum dots. It may include one or more selected from the group consisting of.

According to the present invention, even when a plurality of light emitting composites including quantum dots covered by an ionomer are dispersed in a solvent or a resin, the light emitting composites may be uniformly dispersed in a solvent or a resin without aggregation with each other. In addition, the light emitting composite may be maintained in a uniform dispersed state for a long time.

In addition, since the ionomer protects the quantum dots, the quantum dots can be prevented from being damaged by moisture, light, heat, and the like, and the stability of the light emitting composite with respect to the surrounding environment such as temperature, humidity, and ultraviolet rays can be improved.

Furthermore, one light emitting composite may be configured such that each of the quantum dots may be encapsulated without being aggregated by the ionomer.

Accordingly, the light emitting composite having improved quantum efficiency than the respective quantum dots may be manufactured and used in various fields. In particular, when the light emitting composites according to the present invention are applied to a display device, lifespan may be prevented while improving color reproducibility.

1A is a conceptual diagram illustrating a light emitting composite according to an embodiment of the present invention, FIG. 1B is a view for explaining the quantum dots shown in FIG. 1A, and FIG. 1C is a light emitting composite according to another embodiment of the present invention. It is a conceptual diagram for illustration.

2 is a flowchart illustrating a method of manufacturing a light emitting composite according to an embodiment of the present invention.

3 is a cross-sectional view illustrating an optical sheet according to an embodiment of the present invention.

4A to 4C are partially enlarged cross-sectional views for describing embodiments of the light conversion layer illustrated in FIG. 3.

5A and 5B are partially enlarged cross-sectional views illustrating exemplary embodiments of the first barrier layer illustrated in FIG. 3.

6 to 10 are cross-sectional views for describing an optical sheet according to another exemplary embodiment of the present invention.

11 is a cross-sectional view for describing a backlight unit according to an exemplary embodiment of the present invention.

12 is a cross-sectional view for describing an example of the diffusion sheet illustrated in FIG. 11.

13A to 13C are photographs for explaining an example of a light diffusion pattern formed on the surface of the optical layer of FIG. 12.

13D and 13E are plan views illustrating the divided regions illustrated in FIG. 13C.

14-16 is sectional drawing for demonstrating the Example of the diffusion sheet shown in FIG.

17 is a cross-sectional view for describing a backlight unit according to another exemplary embodiment of the present invention.

18 to 20 are cross-sectional views for describing an embodiment of the first light collecting sheet illustrated in FIG. 17.

21 is a cross-sectional view for describing a backlight unit according to yet another embodiment of the present invention.

22 to 23 are cross-sectional views for describing an embodiment of the inverse prism sheet shown in FIG. 21.

24 is a cross-sectional view for describing a backlight unit according to yet another embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention. As the inventive concept allows for various changes and numerous modifications, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

Terms such as "first and second" may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, step, operation, component, part, or combination thereof described on the specification, and one or more other features or steps. It is to be understood that the present invention does not exclude, in advance, the possibility of the presence or the addition of an operation, a component, a part, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In the present invention, an "ionomer" is a copolymer of an electrically neutral unit and an ionic unit, wherein the polymer has an electrically neutral repeating unit as a main chain and ionized groups are covalently bonded to some main chains as side chains. Means.

In the present invention, "copolymer" is a polymer compound formed by a polymerization reaction between two or more different monomers, and is a statistical copolymer, an optional copolymer, an alternating copolymer, a block copolymer, a graft aerial The concept includes coalescence.

In addition, in the present invention, "luminescent complex" means a complex including an ionomer together with a quantum dot. And "red light emitting complex" means a light emitting complex containing only red quantum dots as quantum dots, "green light emitting complex" means a light emitting complex including only green quantum dots as quantum dots, "multicolor light emitting complex" is a quantum dots as a red quantum dot and It refers to a light emitting complex containing green quantum dots. Here, “red quantum dots” collectively refers to quantum dots having emission peaks in the red wavelength band of about 600 nm to about 660 nm, and “green quantum dots” collectively refers to quantum dots having emission peaks in the green wavelength range of about 520 nm to about 560 nm. do.

On the other hand, light whose peak wavelength in the emission spectrum belongs to the red wavelength band is referred to as "red light", and light belonging to the green wavelength band is referred to as "green light". In addition, the light whose peak wavelength in the emission spectrum belongs to a wavelength band of about 430 nm to about 470 nm is described as "blue light".

1A is a conceptual diagram illustrating a light emitting composite according to an embodiment of the present invention, and FIG. 1B is a view for explaining the quantum dots shown in FIG. 1A.

1A and 1B, the light emitting composite 10a includes a quantum dot 11 and an ionomer 13.

In FIG. 1A and FIG. 1B, two quantum dots 11 are illustrated to describe the relationship between adjacent quantum dots 11, but since the two quantum dots 11 have substantially the same structure, one quantum dot will be described. Duplicate explanations are omitted.

The quantum dot 11 is a particle having a crystal structure of several to tens of nanometers in size, and is composed of hundreds to thousands of atoms. Since the size of the quantum dot 11 is a nano size, a quantum confinement effect appears in the quantum dot 11. The quantum confinement effect refers to a phenomenon in which the band gap of the particle is discontinuously quantized when the particle size is several tens of nanometers or less. The smaller the particle size, the larger the band gap. Therefore, when light having energy greater than the band gap is incident on the quantum dot 11, the quantum dot 11 absorbs the incident light into an excited state, and the quantum dot in the excited state is based It falls to the ground state and emits light of a specific wavelength corresponding to the band gap. The band gap of the quantum dot 11 may be adjusted through the size, composition, etc. of the quantum dot 11 itself.

For example, the quantum dot 11 may include a central particle 1 and a ligand 2 bound to a surface of the central particle 1.

The central particle (1) may be composed of a II-VI compound, a II-V compound, a III-V compound, a III-IV compound, a III-VI compound, a IV-VI compound, or a mixture thereof. . The "mixture" includes not only a simple mixture of the compounds, but also all three-component compounds, tetracomponent compounds, and dopants doped in these mixtures.

Examples of the II-VI compound include magnesium sulfide (MgS), magnesium selenide (MgSe), magnesium telluride (MgTe), calcium sulfide (CaS), calcium selenide (CaSe), calcium telluride (CaTe), Strontium sulfide (SrS), strontium selenide (SrSe), strontium telluride (SrTe), cadmium sulfide (CdS), cadmium selenide (CdSe), tellurium cadmium (CdTe), zinc sulfide (ZnS), zinc selenide (ZnSe) ), Zinc telluride (ZnTe), mercury sulfide (HgS), mercury selenide (HgSe) or mercury telluride (HgTe).

Examples of the II-V compound include zinc phosphide (Zn ₃ P ₂ ), zinc arsenide (Zn ₃ As ₂ ), cadmium phosphide (Cd ₃ P ₂ ), cadmium arsenide (Cd ₃ As ₂ ), cadmium nitride (Cd ₃ N ₂ ) or zinc nitride (Zn ₃ N ₂ ).

Examples of the Group III-V compounds include boron phosphide (BP), aluminum phosphide (AlP), aluminum arsenide (AlAs), aluminum antimonide (AlSb), gallium nitride (GaN), gallium phosphide (GaP), and ratios. Gallium Dioxide (GaAs), Gallium Antimony (GaSb), Indium Nitride (InN), Indium Phosphide (InP), Indium Bisulfide (InAs), Indium Antimonide (InSb), Aluminum Nitride (AlN) or Boron Nitride ( BN) etc. are mentioned.

Examples of the III-IV compound include boron carbide (B ₄ C), aluminum carbide (Al ₄ C ₃ ), gallium carbide (Ga ₄ C), and the like.

Examples of the III-VI compound include aluminum sulfide (Al ₂ S ₃ ), aluminum selenide (Al ₂ Se ₃ ), aluminum telluride (Al ₂ Te ₃ ), gallium sulfide (Ga ₂ S ₃ ), selenide Gallium (Ga ₂ Se ₃ ), indium sulfide (In ₂ S ₃ ), indium selenide (In ₂ Se ₃ ), gallium telluride (Ga ₂ Te ₃ ), indium telluride (In ₂ Te ₃ ), and the like. have.

Examples of the Group IV-VI compounds include lead sulfide (PbS), lead selenide (PbSe), lead telluride (PbTe), tin sulfide (SnS), tin selenide (SnSe), tin telluride (SnTe), and the like. Can be.

For example, the central particle 1 may have a core / shell structure. Each of the core and the shell of the central particle 1 may be composed of the compounds exemplified above. For example, the above exemplified compounds may form the core or shell, each alone or in combination of two or more. The bandgap of the compound constituting the core may be narrower than the bandgap of the compound constituting the shell, but is not limited thereto. When the central particle 1 has a core / shell structure, the compound constituting the shell may be different from the compound constituting the core. For example, the central particle 1 may have a CdSe / ZnS (core / shell) structure having a core comprising CdSe and a shell comprising ZnS, or an InP / having a core comprising InP and a shell comprising ZnS. It may have a ZnS (core / shell) structure.

As another example, the central particle 1 may have a core / multishell structure having at least two layers of shells. For example, the central particle 1 has a core comprising CdSe, a CdSe / having a first shell surrounding the surface of the core and comprising ZnSe and a second shell surrounding the surface of the first shell and comprising ZnS It may have a ZnSe / ZnS (core / first shell / second shell) structure. Alternatively, the central particle 1 has a core including InP, an ZnSe as a first shell, and an InP / ZnSe / ZnS (core / first shell / second shell) structure including ZnS as a second shell. It can have

As another example, the central particle 1 may be made of only a group II-VI compound or a group III-V compound as a single structure instead of a core / shell structure.

Although not shown in the drawings, the central particle 1 may further include a cluster molecule as a seed. The cluster molecule is a compound that acts as a seed during the process of preparing the central particle 1, and the central particle 1 is formed by growing a compound constituting the central particle 1 from precursors on the cluster molecule. Can be. In this case, examples of the cluster molecule include various compounds disclosed in Korean Laid-Open Publication No. 2007-0064554, but are not limited thereto.

The ligand 2 may prevent the central particles 1 adjacent to each other from aggregation and quenching. The ligand 2 may bind to the central particle 1 and have a hydrophobic property.

As an example of the said ligand (2), the amine compound, carboxylic acid compound, etc. which have a C6-C30 alkyl group are mentioned. Examples of the amine compound having an alkyl group include hexadecylamine, octylamine, and the like. As another example of the said ligand (2), the amine compound, carboxylic acid compound, etc. which have a C6-30 alkenyl group are mentioned. Alternatively, another example of the ligand (2), a phosphine compound including trioctylphosphine, triphenolphosphine, t-butylphosphine, and the like ); Phosphine oxides such as trioctylphosphine oxide; Pyridine; Thiophene, and the like.

Alternatively, the ligand 2 may include a silane compound having one or more functional groups selected from vinyl group, aryl group, acryl group, amine group, methacrylate group, epoxy group and the like.

The type of the ligand 2 is not limited to that illustrated above, and the quantum dot 11 may be composed of the central particle 1 alone without the ligand 2.

The ionomer 13 covers around the quantum dot 11. The ionomer 13 may cover the surface of the quantum dot 11 to encapsulate the quantum dot 11. In this case, the ionomer 13 may form a capsule layer having a predetermined thickness on the surface of the quantum dot 11. Since the ionomer 13 covers the quantum dots 11, the quantum dots 11 can be prevented from being damaged by moisture, heat, light, or the like caused by an external environment.

The molecular weight (MW) of the ionomer 13 may be about 1,000 or more and 20,000 or less. For example, the molecular weight of the ionomer 13 may be 1,000 or more and 10,000 or less, and more preferably 1,000 or more and 6,000 or less. The said molecular weight is a number average molecular weight converted into polystyrene. For example, when the molecular weight of the ionomer 13 is less than about 1,000, since the ionomer 13 cannot exist in a solid state at room temperature, the ionomer 13 hardly encapsulates the quantum dot 11. In addition, when the molecular weight of the ionomer 13 exceeds about 20,000, the solid particle size (average diameter) of the ionomer 13 is several hundred μm or more, so that even if a composite is prepared using the same, it is dispersed in a solvent or a resin. There is a difficult problem. In addition, as an example, the ionomer 13 may be a copolymer of an electrically neutral unit and an ionic unit.

Examples of the electrically neutral unit include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 3 methyl-1-butene, 4-methyl-1-pentene, and the like, each of which is a single compound. Or two or more may be used in combination. For example, ethylene may be used as the neutral unit. The neutral unit may be included in more than about 50% by weight or about 60% by weight or more based on the total weight of the ionomer 13.

Examples of the ionic units include acrylic acid or alkyl acrylic acid, and these may be used alone or in combination of two or more. The alkyl group of the alkyl acrylic acid may include methyl, ethyl, butyl, isobutyl, pentyl, hexyl and the like as a functional group having 20 or less carbon atoms, and these may be included alone or in combination of two or more. Specific examples of the ionic unit may be acrylic acid, methacrylic acid, ethacrylic acid, and the like, and these may be used alone or in combination of two or more. The ionic unit may be included in about 5 to 50% by weight, about 10 to 19% by weight or about 12 to 15% by weight based on the total weight of the ionomer (13).

The ionomer 13 may further include optional co-units in addition to the neutral unit and the ionic unit.

Examples of such selective comonomers include carbon monoxide, sulfur dioxide, acrylonitrile, maleic anhydride, maleic acid diesters, (meth) acrylic acid, maleic acid, maleic acid monoesters, itaconic acid, fumaric acid, fumaric acid monoesters, of these acids Salts, glycidyl acrylate, glycidyl methacrylate, glycidyl ether and the like, and these may be used alone or in combination of two or more. The selective unit may be included in about 35% by weight or less based on the total weight of the ionomer (13).

The polar group of the ionomer 13 may be neutralized with metal ions. As the metal ions, monovalent metal ions, divalent metal ions, trivalent metal ions, polyvalent metal ions, etc. may be used, and these may be used alone or in combination of two or more. Examples of the monovalent metal ions include sodium ions, potassium ions, lithium ions, silver ions, mercury ions, and the like, which may be used alone or in combination of two or more. Examples of the divalent metal ion include magnesium ion, calcium ion, strontium ion, barium ion, copper ion, cadmium ion, mercury ion, tin ion, lead ion, iron ion, cobalt ion, nickel ion, zinc ion, and the like. These may be used alone or in combination of two or more. Examples of the trivalent metal ions include aluminum ions, scandium ions, iron ions, yttrium ions and the like, each of which may be used alone or in combination of two or more. Examples of the polyvalent metal ions include titanium ions, zirconium ions, hafnium ions, vanadium ions, tantalum ions, tungsten ions, chromium ions, cerium ions, iron ions and the like, each of which may be used alone or in combination of two or more. Can be. The ionomer 13 may be neutralized about 20 to 100% of the polar group.

In one embodiment of the present invention, the ionomer 13 may be an ethylene- (meth) acrylic acid copolymer represented by the structure of the following formula (1).

[Formula 1]

In Formula 1, x may be 20 to 100, and y may be 1 to 10. For example, x may be 25 to 80 and y may be 1 to 4. More preferably x may be 30 to 60, y may be about 1.5 to 2.0. And M ⁺ represents at least one selected from the foregoing monovalent metal ions, divalent metal ions, trivalent metal ions and polyvalent metal ions, and R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ and R ₇ independently of each other represents hydrogen (H) or an alkyl group having 6 or less carbon atoms. The alkyl group having 6 or less carbon atoms may be a linear alkyl or branched alkyl group, for example, an ethyl group (* -C ₂ H ₅ ), a propyl group (* -C ₃ H ₇ ), a methyl group (* -CH ₃ ), or the like. It includes.

The ethylene- (meth) acrylic acid copolymer may include an unneutralized polar carboxyl group, and the polar carboxyl group has strong interaction with the metal constituting the quantum dot 11, and thus the ethylene- (meth) The acrylic acid copolymer may stably encapsulate the quantum dots 11.

In one embodiment of the present invention, the ionomer 13 may have an acid value of about 200 mg KOH / g or less.

In the present invention, the "acid value" of the ionomer 13 refers to the number of mg of potassium hydroxide (KOH) required to neutralize 1 g of the ionomer 13. As the acid value of the ionomer 13 has a larger value, it indicates that there are more polar carboxy groups included in the ionomer 13. When the acid value of the ionomer 13 exceeds about 200 mg KOH / g, the ligand 2 may be deteriorated by the carboxy group, so that the surface of the quantum dot 11 may be oxidized. When the surface of the quantum dot 11 is oxidized, the quantum efficiency may be deteriorated even if the quantum dot 11 is encapsulated.

The acid value of the ionomer 13 may be measured according to the ASTM 1386 standard. For example, after weighing about 2 g of the ionomer 13 as a sample, the mixture is put into a Erlenmeyer flask, 40 ml of xylene is heated, and when the sample is a completely colorless transparent solution, 2-3 drops of phenolphthalein solution are added. The acid value can be calculated by titrating with a KOH solution of about 0.1N and using the final point when the color of the solution is maintained for about 10 seconds. The acid value may be calculated by the following Equation 1.

[Equation 1]

Acid value = (A × N × 56.1) / B

In Equation 1, "A" represents the amount of KOH (unit: ml) used for sample titration, "N" represents the normal concentration of KOH (unit: N), and "B" represents the amount of sample (unit) : g) is shown.

Meanwhile, the ionomer 13 may have a density of about 0.85 g / cm ³ or more and about 1.05 g / cm ³ or less. For example, the density of the ionomer 13 may be about 0.85 g / cm ³ or more and about 1.0 g / cm ³ or less, and more preferably about 0.9 g / cm ³ or more and about 1.0 g / cm ³ or less.

The ionomer 13 may have a melting point of about 50 ° C. or more and about 150 ° C. or less. When the melting point of the ionomer 13 is high, the quantum dot 11 may be damaged in the process of liquefying the ionomer 13 to encapsulate the quantum dot 11. For example, the melting point of the ionomer 13 may be about 60 ° C. or more and about 140 ° C. or less, and more preferably about 70 ° C. or more and about 120 ° C. or less.

The diameter d1 of the light emitting composite 10a may be about 10 nm to about 50 μm. The diameter d1 of the light emitting complex 10a is a value measured by a dynamic light scattering method (DLS method) calculated by a Stokes-Einstein equation regarding a diffusion coefficient (hydrodynamic diameter).

1C is a conceptual diagram illustrating a light emitting composite according to another embodiment of the present invention.

Referring to FIG. 1C, the light emitting composite 10b includes at least two

quantum dots

11a and 11b and an ionomer 13.

For convenience, the

quantum dots

11a and 11b included in the light emitting composite 10b will be referred to as "first quantum dots" and reference number "11b" as "second quantum dots". . Since each of the first and second

quantum dots

11a and 11b is substantially the same as the quantum dot 11 described with reference to FIGS. 1A and 1B, detailed descriptions thereof will be omitted.

The ionomer 13 may cover the first and second

quantum dots

11a and 11b to prevent the first and second

quantum dots

11a and 11b from aggregation with each other. That is, the ionomer 13 may make one aggregate so that the first and second

quantum dots

11a and 11b may be encapsulated without being aggregated with each other. The aggregate may be defined as one "light emitting complex 10b". In the light emitting composite 10b, the first and second

quantum dots

11a and 11b are disposed in one aggregate formed by the ionomer 13. The number of quantum dots disposed in the one aggregate may be two or more. For example, the number of quantum dots disposed inside the one aggregate may be several tens to tens of thousands.

The diameter d2 of the light emitting composite 10b may be about 5 nm to about 50 μm, and the diameter d2 of the light emitting composite 10b may be determined in consideration of the dispersibility of a resin, which will be described below. About 0.5 μm to about 10 μm. The diameter d2 of the light emitting composite 10b may vary depending on a cooling rate in the process of manufacturing the light emitting composite 10b.

Since the ionomer 13 is substantially the same as the ionomer described with reference to FIGS. 1A and 1B, detailed descriptions thereof will be omitted.

During the process of encapsulating the

quantum dots

11, 11a, and 11b with the ionomer 13, the light emitting composite 10a described with reference to FIGS. 1A and 1B may be formed, or the light emitting composite 10b described with reference to FIG. 1C may be formed. . In the above process, the light emitting composite 10a described with reference to FIGS. 1A and 1B and the light emitting composite 10b described with reference to FIG. 1C may be simultaneously manufactured.

Hereinafter, with reference to FIG. 2, the manufacturing method of the

light emitting composites

10a and 10b, the composition containing the said

light emitting composites

10a and 10b, and hardened | cured material are demonstrated in detail.

2, the ionomer powder is added to the organic solvent (step S210).

The organic solvent may include toluene. However, according to the characteristics of the ionomer, an appropriate organic solvent may be selectively used.

The ionomer powder is a solid composed of ionomers, and the ionomers constituting the ionomer powder are substantially the same as those described with reference to FIGS. 1A to 1C, and thus detailed descriptions thereof will be omitted.

Subsequently, the ionomer powder is dissolved (step S220).

The ionomer powder can be dissolved by heating the organic solvent. The organic solvent is heated to a temperature above the melting point of the ionomer powder. For example, the organic solvent may be heated to about 50 ℃ to 170 ℃. Accordingly, the ionomer solution in which the ionomer powder is dissolved in the organic solvent may be prepared.

Subsequently, quantum dots are mixed in the ionomer solution (step S230).

When the quantum dots are mixed with the ionomer solution, the quantum dots are dispersed in the ionomer solution. In this case, the quantum dots may be easily dispersed in the ionomer solution without aggregation of each other by the ligand of the quantum dots. Since the quantum dots are substantially the same as the quantum dots described with reference to FIGS. 1A to 1C, detailed descriptions thereof will not be repeated.

Subsequently, the ionomer solution in which the quantum dots are dispersed is cooled (step S240).

The temperature of the ionomer solution in which the quantum dots are dispersed may be cooled to room temperature to solidify the dissolved ionomer. The ionomer solution in which the quantum dots are dispersed may be cooled or quenched by gradually lowering the temperature to room temperature. At this time, when the temperature of the ionomer solution is rapidly lowered, the size of the aggregate formed by the ionomer may be reduced. On the contrary, when the temperature of the ionomer solution is gradually lowered, the size of the aggregate formed by the ionomer may increase. In the present invention, the cooling rate of the ionomer solution may be adjusted so that the diameter of the aggregate is about 5 nm to about 50 μm.

The ionomer aggregate may form a light emitting complex 10a by encapsulating one quantum dot as described with reference to FIGS. 1A and 1B, or form a light emitting complex 10b by encapsulating a plurality of quantum dots as described with reference to FIG. 1C. It may be. Accordingly, the

light emitting composites

10a and 10b according to the present invention can be manufactured.

The

light emitting composites

10a and 10b according to the present invention described above may be stored and used in a powder form by removing the organic solvent. In contrast, the

light emitting composites

10a and 10b may be stored and used in a dispersed state in the organic solvent. In the

light emitting composites

10a and 10b, since the

quantum dots

11, 11a and 11b are encapsulated in powder form by the ionomer 13, they may be stably stored and used without being affected by moisture. In addition, the organic solvent may be uniformly dispersed without aggregation with each other.

In another embodiment, the composition including the

light emitting composites

10a and 10b may include a resin. The resin may be in a liquid state having a polymerizable functional group. The polymerizable functional group may be a vinyl group, an epoxy group or a siloxane group.

In contrast, the resin may be dissolved in a solvent even if the resin itself is a solid phase. In this case, the

light emitting composites

10a and 10b may be dispersed in a solution containing the resin and the solvent.

The composition including the resin may include at least one of the light emitting composite 10a illustrated in FIGS. 1A and 1B and the light emitting composite 10b illustrated in FIG. 1C. As the resin, a silicone resin, an epoxy resin, an acrylic resin, or the like may be used. The resin may be a thermosetting resin or a photocurable resin. Examples of the silicone resins include vinyl siloxane resins, epoxy siloxane resins, polydimethylsiloxane (PDMS), thermoplastic silicone vulcanizate (TPSiV), and thermoplastic silicone polycarbonate-urethane (TSPCU). The composition may further include a crosslinking agent, a catalyst, an initiator, and the like together with the resin.

For example, the composition may include about 0.001 parts by weight to 10 parts by weight of the

light emitting composites

10a and 10b and about 5 parts by weight to about 60 parts by weight of hydride siloxane as the crosslinking agent based on 100 parts by weight of the vinyl siloxane compound as a resin. , About 0.01 parts by weight to about 0.5 parts by weight of the platinum catalyst.

In contrast, the composition including the

light emitting composites

10a and 10b may include at least one monomer and an initiator. The monomer may include an acrylic compound, an epoxy compound, a siloxane compound, and the like. These may be used alone or in combination of two or more, respectively. The composition may include at least one of the light emitting composite 10a illustrated in FIGS. 1A and 1B and the light emitting composite 10b illustrated in FIG. 1C. When the composition includes a monomer, the monomers may be polymerized to form a cured product, and the

light emitting composites

10a and 10b may be dispersed in the cured product.

Meanwhile, the composition may further include diffusion beads in addition to the

light emitting composites

10a and 10b or further include a blowing agent. The present invention provides a cured product formed by curing the composition. The cured product includes, for example, a coating layer or a film. The said hardened | cured material can be formed by crosslinking resin of the said composition, or drying the said composition. For example, the composition may be cured using light or heat, and ultraviolet rays may be used when curing using light. Alternatively, the cured product may be formed by polymerizing monomers of the composition. The method for forming the cured product is not particularly limited. The cured product may have a form in which the

light emitting composites

10a and 10b are dispersed in a matrix structure formed by the resin.

On the other hand, the cured product formed of a composition further comprising a diffusion bead may be in the form of the diffusion beads are dispersed together with the light emitting composite (10a, 10b) in a matrix structure formed by the resin, formed of a composition further comprising a blowing agent The cured product may have a form in which the

light emitting composites

10a and 10b are dispersed in a matrix structure formed by the resin, and voids are formed in the matrix structure.

The present invention also provides a device comprising the cured product. The range of the device is not particularly limited, and may be, for example, a lighting device or a display device.

According to the present invention described above, since the ionomer 13 covers the quantum dots (11, 11a, 11b) to form the light emitting composite (10a, 10b), it is generated when the quantum dots themselves are dispersed in a solvent or resin Agglomeration between the quantum dots and thereby the problem of dispersibility in the solvent or resin can be solved.

In addition, the ionomer 13 protects the

quantum dots

11, 11a and 11b to prevent the quantum dots from being damaged by moisture, light, heat, and the like, thereby improving stability of the

light emitting composites

10a and 10b with respect to the surrounding environment. Can be improved.

Furthermore, the ionomer 13 may constitute one light emitting composite 10b so that each of the

quantum dots

11a and 11b may be encapsulated without being aggregated with each other. Accordingly, the light emitting composite having improved quantum efficiency than the respective quantum dots may be manufactured and used in various fields.

Hereinafter, an optical sheet according to an embodiment of the present invention will be described in detail with reference to FIGS. 3, 4A to 4C, 5A and 5B, and 6 to 10. However, the scope of the present invention is not limited thereto.

3 is a cross-sectional view illustrating an optical sheet according to an exemplary embodiment of the present invention, and FIGS. 4A to 4C are partially enlarged cross-sectional views illustrating embodiments of the light conversion layer illustrated in FIG. 3, and FIGS. 5A and FIG. 5B are partially enlarged cross-sectional views illustrating exemplary embodiments of the first barrier layer illustrated in FIG. 3.

Referring to FIG. 3, the optical sheet 100 includes a light conversion layer 110, a first barrier layer 120a, a second barrier layer 120b, a first transparent film 130a, and a second transparent film 130b. It includes.

The light conversion layer 110 includes a light transmitting resin and a light emitting composite dispersed in the light transmitting resin. The light emitting composite 10a described with reference to FIGS. 1A and 1B or the light emitting composite 10b described with reference to FIG. 1C may be used as the light emitting composite, and thus a detailed description thereof will be omitted.

The light-transmissive resin is a transparent material that transmits light and is cured by light and / or heat to become a substrate for dispersing the light emitting composite. For example, the light transmitting resin may include an acrylic resin, a silicone resin, an epoxy resin, a urethane resin, and the like.

Meanwhile, the light conversion layer 110 may further include diffusion beads in addition to the light emitting composite. The diffusion beads may uniformly diffuse light incident on the optical sheet 100. The diffusion beads may be formed of polycarbonate (PC), polyethylene (PE, PE), polypropylene (PP), methacrylic resin, polyethylene terephtalate (PET), or the like. . These may be used alone or in combination of two or more, respectively. The diameter of each of the diffusion beads may be between about 3 μm and about 30 μm. The diameter of each of the diffusion beads refers to the diameter measured by the Dynamic Light Scattering method (DLS method) calculated by the Stokes-Einstein equation for the diffusion coefficient.

On the other hand, the light conversion layer 110 may further include a void formed inside the light emitting composite. The gap may uniformly diffuse light incident on the optical sheet 100. Each of the pores may have a diameter of about 3 μm to about 30 μm, and may be measured using a scanning electron microscope (SEM).

The light conversion layer 110 may have various structures as shown in FIGS. 4A to 4C.

Referring to FIG. 4A together with FIG. 3, the light conversion layer 110 may have a single layer structure. In the light conversion layer 110 having a single layer structure, at least one selected from a red light emitting composite, a green light emitting composite, and a multicolor light emitting composite including red quantum dots and green quantum dots may be dispersed. For example, a red light emitting composite and a green light emitting composite may be dispersed in the light conversion layer 110 of the single layer structure. As another example, the multicolor light-emitting composite may be dispersed in the light conversion layer 110 of the single layer structure.

Referring to FIG. 4B along with FIG. 3, the light conversion layer 110 may include the first light conversion layer 111 and the first light conversion layer 111 disposed on the first barrier layer 120a. The second light conversion layer 112 may be disposed between the second barrier layers 120b. At least one of the red light emitting composite, the green light emitting composite, and the multicolored light emitting composite may be dispersed in each of the first light conversion layer 111 and the second light conversion layer 112.

For example, a green light emitting composite may be dispersed in the first light conversion layer 111, and a red light emitting composite may be dispersed in the second light conversion layer 112. In this case, the green light generated by the green light-emitting composite dispersed in the first light conversion layer 111 may excite the red light-emitting composite dispersed in the second light conversion layer 112, thereby generating sufficient red light. Can be. In addition, since the green light emitting composite dispersed in the first light conversion layer 111 receives light primarily from the light emitting device, it transmits relatively higher energy than the light emitting composite dispersed in the second light conversion layer 112. As a result, the power density of the light generated by the green light emitting composite dispersed in the first light conversion layer 111 may be maximized. In this case, the multicolor light emitting composite may be further dispersed in one or more of the first light conversion layer 111 and the second light conversion layer 112.

As another example, the green light emitting composite may be dispersed in the first light conversion layer 111, and the multicolor light emitting composite may be dispersed in the second light conversion layer 112.

As another example, the multi-color light emitting composite may be dispersed in the first light conversion layer 111 and the red light emitting composite may be dispersed in the second light conversion layer 112.

As another example, one or more of the red light emitting composite and the multicolored light emitting composite may be dispersed in the first light conversion layer 111, and the green light emitting composite may be dispersed in the second light conversion layer 112. have.

3 and 4C, the light conversion layer 110 may include a first light conversion layer 111, a first light conversion layer 111, and the first light conversion layer 111 disposed on the first barrier layer 120a. And a second light conversion layer 112 disposed between the second barrier layer 120b and an adhesive layer 113 disposed between the first light conversion layer 111 and the second light conversion layer 112. Can be. Since the first light conversion layer 111 and the second light conversion layer 112 are substantially the same as the first light conversion layer 111 and the second light conversion layer 112 described with reference to FIG. The detailed description is omitted.

The adhesive layer 113 serves to bond the first light conversion layer 111 and the second light conversion layer 112. The adhesive layer 113 may be formed of an adhesive compound, and the adhesive compound may be cured to bond the first light conversion layer 111 and the second light conversion layer 112 to each other. The material of the adhesive layer 113 is not particularly limited, and a conventionally known resin may be used without limitation as long as it is a resin that transmits light and has adhesiveness.

The adhesive layer 113 may include a moisture absorbent. The moisture absorbent may absorb and remove moisture introduced into each of the first light conversion layer 111 and the second light conversion layer 112. Examples of the moisture absorbent include metals such as calcium oxide, barium oxide, strontium oxide, magnesium oxide, calcium carbonate, magnesium sulfate, and the like. Organometallic compounds such as oxides, aluminum oxide acylate, aluminum oxide alkoxide, aluminum oxide alylate, zeolites, and the like, and the like, each of which may be used alone. Or two or more may be mixed and used.

Meanwhile, in FIG. 4C, although the adhesive layer 113 is disposed between the first light conversion layer 111 and the second light conversion layer 112, the adhesive layer 113 is formed on the first barrier. The layer 120a may be disposed between the first photoconversion layer 111 or the second barrier layer 120b and the second photoconversion layer 112. Alternatively, the light conversion layer 110 may additionally include the first barrier layer 120a and the agent in addition to the adhesive layer 113 disposed between the first light conversion layer 111 and the second light conversion layer 112. One or more of an adhesive layer disposed between the first light conversion layer 111 and an adhesive layer disposed between the second barrier layer 120b and the second light conversion layer 112 may be further included.

Referring to FIG. 3 again, the first barrier layer 120a is disposed under the light conversion layer 110. The first barrier layer 120a may protect the light emitting composite dispersed in the light conversion layer 110 from heat, light, moisture, and the like. In particular, the first barrier layer 120a may prevent moisture caused by an external environment from penetrating into the light conversion layer 110. The first barrier layer 120a may have a thickness of about 5 nm to about 40 μm.

The first barrier layer 120a may have various structures as shown in FIGS. 5A and 5B. However, the structure of the first barrier layer 120a is not limited to FIGS. 5A and 5B and may have various structures.

Referring to FIGS. 5A and 5B together with FIG. 3, the first barrier layer 120a may have a single layer structure or a stacked structure in which a plurality of layers are stacked.

The first barrier layer 120a may include an inorganic film made of an inorganic material. Examples of the inorganic material constituting the inorganic layer include silicon oxide, silicon nitride, silicon oxynitride, silicon oxycarbide, metal oxide, and metal nitride ( metal nitride, metal oxynitride, metal oxycarbide, and the like. These may be used alone or in combination of two or more, respectively. In this case, the metal in the metal oxide, metal nitride, metal oxynitride or metal oxide carbide may include aluminum, titanium, indium, tin, tantalum, zirconium, niobium, and the like, and these metals may be each alone or two or more. May be used in combination.

The inorganic film may be a physical vapor deposition method such as sputtering deposition, thermal evaporation, electron beam evaporation, plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (atomic layer). It can be formed using a chemical vapor deposition method such as deposition, ALD).

In an embodiment, the first barrier layer 120a may have a single layer structure composed of one inorganic layer, as shown in FIG. 5A. In this case, the first barrier layer 120a may have a thickness of about 5 nm to about 10 μm.

In another embodiment, the first barrier layer 120a may have a structure in which two or more inorganic films are stacked as shown in FIG. 5B, or a structure in which an organic film made of an inorganic film and an organic material is stacked.

For example, the first barrier layer 120a may include a first layer 121a and a second layer 122a. The first layer 121a may be formed on the first transparent film 130a, and the second layer 122a may be formed between the first layer 121a and the light conversion layer 110. .

For example, each of the first layer 121a and the second layer 122a may be an inorganic layer formed of different inorganic materials. In detail, the first layer 121a may be an inorganic film formed of silicon nitride, and the second layer 122a may be an inorganic film formed of silicon oxide. Alternatively, the first layer 121a may be an inorganic film formed of silicon oxide, and the second layer 122a may be an inorganic film formed of silicon nitride. Meanwhile, the first barrier layer 120a is disposed between the second layer 122a and the light conversion layer 110 and is formed of an inorganic material that is different from the inorganic material forming the second layer 122a. Three layers (not shown) may be further included. In this case, the third layer may be formed of an inorganic material substantially the same as the first layer 121a, or may be formed of an inorganic material different from the first layer 121a.

As another example, the first layer 121a may be an inorganic layer, and the second layer 122a may be an organic layer formed of an organic material. In this case, the thickness of the first barrier layer 120a may be about 5 nm to about 40 μm. When the second layer 122a, which is an organic film, is bonded to the light conversion layer 110, the second layer 122a may be disposed between the first barrier layer 120a and the light conversion layer 110. Adhesion can be improved. The second layer 122a, which is an organic layer, may be formed to a thickness of about 0.5 μm to about 30 μm to assist the barrier function of the first barrier layer 120a. Alternatively, the second layer 122a, which is an organic layer, may be formed to a thickness of about 0.5 μm or less in order to simply increase the adhesive force between the first layer 121a and the light conversion layer 110.

Examples of the organic material constituting the organic film may include acrylic polymer resin, epoxy polymer resin, silicone polymer resin, urethane polymer resin, parylene, polyethylene terephthalate (PET), polymethylmethacrylate (polymethylmethacrylate, PMMA), polyethersulfone (PES), polycarbonate (PC), polyethylenenaphthalate (PEN), polyimide (PI), polyarylate, cyclic olefin polymer (cyclic olefin polymers (COP), cyclic olefin copolymers (cyclic olefic copolymers (COC)), polyethylene (polyethylene, PE), polypropylene (polypropylene, PP), methacryl (methacrylic) and the like.

The organic film may be formed by applying a curable resin to a substrate through a printing process or a coating process, and curing it using heat and / or light. The curable resin may include a photocuring agent or a catalyst together with a curable monomer or a polymer (copolymer). In this case, the curable resin may be a printing process such as ink-jetting, pad printing, screen printing, spin-coating, tape casting, slot-die, or the like. ) Can be applied to the substrate through a coating process such as coating, gravure coating, offset coating, spray coating and the like. Alternatively, the organic film may be formed by applying to the substrate and curing the PECVD or PVD method. Alternatively, the organic layer may be attached to the inorganic layer in the form of a transparent film.

When the first layer 121a is an inorganic film and the second layer 122a is an organic film, the first barrier layer 120a is disposed between the second layer 122a and the light conversion layer 110. It may further comprise a third layer (not shown) disposed and formed of an inorganic material. The third layer may be formed of an inorganic material substantially the same as the first layer 121a, or may be formed of another inorganic material.

As another example, the first layer 121a may be an organic layer, and the second layer 122a may be an inorganic layer. For example, the first layer 121a may include an acrylic polymer resin, and the second layer 122a may include aluminum oxide, for example, alumina. Alternatively, the first layer 121a may include hexamethyldisiloxane or parylene, and the second layer 122a may include aluminum oxide.

When the first layer 121a is an organic layer and the second layer 122a is an inorganic layer, the first barrier layer 120a is disposed between the second layer 122a and the light conversion layer 110. It may further include a third layer (not shown) disposed and formed of an organic material. The third layer may be formed of an organic material substantially the same as the first layer 121a, or may be formed of another kind of organic material.

As another example, the first barrier layer 120a may have a structure in which these units are repeatedly stacked by using a combination of the first layer 121a and the second layer 122a described above as a unit. In this case, the first barrier layer 120a is disposed between the repeating stacked structure and the light conversion layer 110 and corresponds to a combination of the first and

second layers

121a and 122a described above. It may further include.

Referring to FIG. 3 again, the second barrier layer 120b is disposed on the light conversion layer 110. That is, the light conversion layer 110 is disposed between the first barrier layer 120a and the second barrier layer 120b. Since the second barrier layer 120b may have the same structure as one of the structures of the first barrier layer 120a described above, detailed descriptions thereof will be omitted. However, the second barrier layer 120b may have the same structure as the first barrier layer 120a or may have different structures.

The first transparent film 130a is disposed below the first barrier layer 120a and is formed of a transparent material. The first transparent film 130a may have a transmittance of about 60% or more with respect to light in the visible light region. For example, the first transparent film 130a may have a transmittance of about 90% or more with respect to light in the visible light region. Specifically, it is preferable to have an average transmittance of 80% or more for blue light of 430 nm to 470 nm. It is also desirable to have a transmittance of at least 90% for light of 450 nm. In addition, the first transparent film 130a preferably has a moisture transmittance of 0.01 g / m ² · day or less. Moisture permeability is the amount of water transmitted in 24 g for a sample having an area of 1 m ² , and the smaller the value, the better the moisture blocking.

The first transparent film 130a may be formed of an organic material having flexibility. Examples of the organic material for forming the first transparent film 130a may include polymethylmethacrylate (PMMA), polyethylene terephthalate (PET), polyethersulfone (PES), and polycarbonate. , PC), polyethylenenaphthalate (PEN), polyimide (PI), polyarylate, cyclic olefin polymer (COP), cyclic olefic copolymer (cyclic olefic copolymer, COC), polyethylene (PE), polypropylene (PP), methacryl (methacrylic), polyurethane (ployurethane) and the like. On the other hand, the first transparent film 130a may be formed of an epoxy resin.

The second transparent film 130b may be disposed on the second barrier layer 120b and may be formed of a transparent material. The second transparent film 130b may have substantially the same optical characteristics as the first transparent film 130a. For example, the first transparent film 130a may be formed of substantially the same material. Therefore, duplicated detailed description of the second transparent film 130b will be omitted.

6 is a cross-sectional view for describing an optical sheet according to another exemplary embodiment of the present invention.

Referring to FIG. 6, the optical sheet 200 includes a light conversion layer 210, a first transparent film 230a, a second transparent film 230b, a first barrier layer 220a, and a second barrier layer 220b. It includes.

Since the light conversion layer 210 is substantially the same as the light conversion layer 110 described with reference to FIGS. 3 and 4A to 4C, detailed descriptions thereof will be omitted.

The first transparent film 230a is disposed below the light conversion layer 210, and the second transparent film 230b is disposed above the light conversion layer 210. In addition, the first barrier layer 220a is disposed below the first transparent film 230a, and the second barrier layer 220b is disposed above the second transparent film 230b. That is, in the present exemplary embodiment, the first and second

transparent films

230a and 230b are disposed between the first barrier layer 220a and the second barrier layer 220b and the light conversion layer 210. It is disposed between the first transparent film 230a and the second transparent film 230b.

Except for such a positional relationship, the first transparent film 230a, the second transparent film 230b, the first barrier layer 220a and the second barrier layer 220b are illustrated in FIGS. Since the first transparent film 130a, the second transparent film 130b, the first barrier layer 120a, and the second barrier layer 120b described above with reference to FIG. 5B are substantially the same, detailed descriptions thereof will be omitted. .

7 is a cross-sectional view for describing an optical sheet according to still another embodiment of the present invention.

Referring to FIG. 7, the optical sheet 300 includes a light conversion layer 310, a first transparent film 330a, a second transparent film 330b, a first barrier layer 320a, and a second barrier layer 320b. And a third transparent film 340a and a fourth transparent film 340b.

The optical sheet 300 according to the present embodiment is substantially the same as the optical sheet 200 described with reference to FIG. 6 except that the optical sheet 300 further includes the third transparent film 340a and the fourth transparent film 340b. Since the same, duplicate description is omitted.

The third transparent film 340a is disposed below the first barrier layer, and the fourth transparent film 340b is disposed above the second barrier layer 320b. That is, the first barrier layer 320a is disposed between the first transparent film 330a and the third transparent film 340a, and the second barrier layer 320b is the second transparent film 330b. And the fourth transparent film 340b.

Since the third transparent film 340a and the fourth transparent film 340b are formed of substantially the same material as the first transparent film 330a or the second transparent film 330b, detailed descriptions thereof will not be repeated. do.

The third transparent film 340a may block moisture penetrating from the lower side of the optical sheet 300 together with the first barrier layer 320a and the first transparent film 330a, and the fourth transparent film. The 340b may block moisture penetrating from the upper side of the optical sheet 300 together with the second barrier layer 320b and the second transparent film 340b.

8, 9 and 10 are cross-sectional views illustrating optical sheets according to still another embodiment of the present invention.

Referring to FIG. 8, the optical sheet 400 may include a transparent film 430, a first light conversion layer 410a, and a second light conversion layer 410b.

The transparent film 430 may be formed of substantially the same material as the first transparent film 130a illustrated in FIG. 3. Therefore, redundant descriptions are omitted.

The first light conversion layer 410a is disposed below the transparent film 430, and the second light conversion layer 410b is disposed above the transparent film 430. Each of the first light conversion layer 410a and the second light conversion layer 410b may include a light transmitting resin and a light emitting composite dispersed in the light transmitting resin. The first light conversion layer 410a and the second light conversion layer 410b are the first light conversion layer 111 and the second light conversion layer 112 shown in FIGS. 4B and 4C except for the arrangement position. Duplicate detailed description is omitted since it is substantially the same as).

Referring to FIG. 9, the optical sheet 500 includes a light conversion layer 510 including a transparent film 530 and a light emitting composite disposed under the transparent film 530 and dispersed in a light transmissive resin and the light transmissive resin. Equipped. Since the transparent film 530 is substantially the same as the transparent film 430 illustrated in FIG. 8, detailed descriptions thereof will be omitted.

For example, the light conversion layer 510 may have a single layer structure. In this case, since the light conversion layer 510 is substantially the same as the light conversion layer 110 shown in FIG. 4A, detailed descriptions thereof will be omitted.

As another example, the light conversion layer 510 may have a structure in which two layers are stacked. In this case, since the light conversion layer 510 is substantially the same as the light conversion layer 110 shown in FIG. 4B, detailed descriptions thereof will be omitted.

Referring to FIG. 10, the optical sheet 600 includes a light conversion layer 610 including a transparent film 630 and a light emitting composite disposed on the transparent film 630 and dispersed in a light transmissive resin and the light transmissive resin. Equipped. Since the optical sheet 600 according to the present exemplary embodiment is substantially the same as the optical sheet 500 illustrated in FIG. 9 except that the light conversion layer 610 is disposed on the transparent film 630, detailed descriptions thereof will be repeated. Is omitted.

Hereinafter, a backlight unit according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 11 to 23. However, the scope of the present invention is not limited thereto.

Referring to FIG. 11, the backlight unit 1000 may include a light emitting device 1100, a light guide plate 1200, a reflecting plate 1300, a diffusion sheet 1400, a first light collecting sheet 1500, and a second light collecting sheet 1600. Include.

The light emitting device 1100 generates light and emits the light toward the light guide plate 1200.

As an example, the light emitting device 1100 may be a white light emitting device that emits white light. The white light emitting device may include a blue light emitting chip that generates blue light, and a light conversion layer covering the blue light emitting chip. The light conversion layer absorbs a part of the blue light generated by the blue light emitting chip and converts the light into red light and green light so that the white light emitting device finally emits white light. The light conversion layer may include a phosphor including a Yttrium aluminum garnet (YAG). In contrast, the light conversion layer may include a quantum dot or the like.

As another example, the light emitting device 1100 may be a blue light emitting device emitting blue light. The blue light emitting device may include a blue light emitting chip that generates blue light, and blue light generated by the blue light emitting chip may be emitted to the outside of the light emitting device 1100 to provide blue light to the light guide plate 1200.

The blue light emitting chip of the light emitting device 1100 includes a light emitting diode that generates blue light. The light emitting diode may include a nitride compound. The nitride compound may include at least one nitride selected from indium (In), gallium (Ga), and aluminum (Al). For example, the nitride compound may be represented by "In _i Ga _j Al _k N", where 0≤i, 0≤j, 0≤k, and i + j + k = 1.

For example, the light emitting diode may have a stacked structure of an n-type semiconductor layer, an active layer, and a p-type semiconductor layer, each including the nitride compound. The n-type semiconductor layer may be doped with n-type impurities, the p-type semiconductor layer may be doped with p-type impurities, and the active layer may be an undoped layer. As a specific example, the light emitting diode is an n-type semiconductor layer having a GaN / AlGaN double layer structure doped with n-type impurities, an active layer composed of InGaN, and a p-type semiconductor layer having a double layer structure of GaN / AlGaN doped with p-type impurities. It may have a stacked structure.

The emission spectrum of the blue light generated by the light emitting diode may have a half width (FWHM) of about 50 nm or less. Preferably, the emission spectrum of the blue light may have a half width of about 30 nm or less.

As another example, the light emitting device 1100 may include the blue light emitting chip and a green light emitting layer covering an upper portion of the blue light emitting chip. The green light emitting layer may include green particles, green dyes, or pigments that absorb blue light provided from the blue light emitting chip to emit green light. The green particles may include one or more selected from green quantum dots, green light emitting composites, green phosphors, and green fluorescent complexes. As the green dye or pigment, a conventionally known compound may be used. As the green quantum dot and the green light emitting composite,

light emitting composites

10a and 10b including the quantum dots 11 described with reference to FIGS. 1A to 1C, known quantum dots, or a composite including the same may be used without limitation. As the green phosphor and the green fluorescent complex, a known phosphor or a complex including the same may be used without limitation, and thus detailed description thereof will be omitted.

The light guide plate 1200 is disposed adjacent to the light emitting device 1100. Light generated by the light emitting device 1100 may be incident to the light guide plate 1200, and light emitted from the light guide plate 1200 may be incident to the diffusion sheet 1400.

The reflective plate 1300 is disposed under the light guide plate 1200. The reflective plate 1300 may increase light utilization efficiency by reflecting light leaking to the lower portion of the light guide plate 1200 back to the light guide plate 1200.

The diffusion sheet 1400 may be disposed on the light guide plate 1200 to diffuse light emitted from the light guide plate 1200. The diffusion sheet 1400 will be described later in detail with reference to FIGS. 12 to 16.

The first light collecting sheet 1500 is disposed on the diffusion sheet 1400, and a first light collecting pattern including a plurality of protrusions is formed on a surface of the first light collecting sheet 1500. The first condensing pattern faces the second condensing sheet 1600. The second light collecting sheet 1600 is disposed on the first light collecting sheet 1500 and has a shape substantially the same as a protrusion formed on the first light collecting sheet 1500 on the surface of the second light collecting sheet 1600. A second condensing pattern including a plurality of protrusions having is formed. The second condensing pattern faces the display panel on the backlight unit 1000. The length direction of the protrusion of the first condensing pattern and the length direction of the protrusion of the second condensing pattern may cross each other. In this case, an angle at which the protrusions cross in the longitudinal direction may be about 90 degrees.

Hereinafter, the diffusion sheet 1400 described with reference to FIG. 11 will be described in detail with reference to FIGS. 12 to 16.

FIG. 12 is a cross-sectional view for describing an exemplary embodiment of the diffusion sheet 1400 illustrated in FIG. 11. FIG. 13A is a photograph for describing a light diffusing pattern in the form of a fine protrusion, which is an example of the light diffusion pattern formed on the surface of the optical layer of FIG. 12, and FIG. 13B is a fine groove as an example of the light diffusion pattern formed on the surface of the optical layer of FIG. 12. It is a photograph for demonstrating the light-diffusion pattern of a form. FIG. 13C is a photograph for describing a light diffusion pattern in the form of a convex division, which is an example of the light diffusion pattern formed on the surface of the optical layer of FIG. 12, and FIGS. 13D and 13E are plan views illustrating the division regions shown in FIG. 13C. admit.

Referring to FIG. 11 along with FIG. 11, the diffusion sheet 1400A includes a base sheet 1400a ′ and an optical layer 1450a.

The base sheet 1400a ′ has the same structure as the selected one of the

optical sheets

100, 200, 300, 400, 500, and 600 described with reference to FIGS. 3 to 10. Therefore, redundant descriptions are omitted.

The optical layer 1450a is disposed on one surface of the base sheet 1400a 'and includes a light diffusion pattern 1451a formed on the surface. In this case, the optical layer 1450a may have a non-flat surface to have a cross-sectional shape having a random thickness. The average thickness of the optical layer 1450a may be about 1 μm to 15 μm.

For example, a planar projection shape may be formed on the surface of the optical layer 1450a, and a light diffusion pattern having a plurality of fine protrusions may be formed as illustrated in FIG. 13A. Protruding height of the fine protrusions may be about 1 ㎛ to 20 ㎛. The protruding height of the fine protrusions may be defined as a height difference between a region where the fine protrusions are not formed and a vertex of the fine protrusions. In addition, the size of the fine protrusions may be about 1 ㎛ to 40 ㎛. The size of the fine protrusions may be defined as the maximum value of the distance between two points on the edge in the planar projection shape of the fine protrusions.

As another example, a light diffusion pattern in the form of a plurality of fine grooves may be formed on the surface of the optical layer 1450a as shown in FIG. 13B. The depth of the fine groove may be about 1 ㎛ to 20 ㎛. The depth of the microgroove may be defined as a height difference between a region where the microgroove is not formed and the lowest point of the microgroove. In addition, the size of the fine groove may be about 1 ㎛ to 40 ㎛. The size of the microgroove may be defined as a maximum value of the distance between two points on an edge in the planar projection shape of the microgroove.

The planar projection shape of the micro-projections and the micro-grooves may have various shapes such as circular, elliptical, polygonal, and irregular shapes, and each of the micro-projections or each of the micro-grooves may have a different shape and size. The spacing between the fine protrusions and the fine grooves may be irregular, and some fine protrusions or grooves may be formed to be connected to each other.

As another example, the light diffusion pattern 1451a formed on the surface of the optical layer 1450a may include both the minute protrusions and the minute grooves.

As another example, the surface of the optical layer 1450a may be formed to have a periodic continuous wave shape or as shown in FIG. 13C to have a plurality of convex divided regions. When the surface of the optical layer 1450a is formed in a wave shape, the pitch of the wave shape may be about 10 μm to 150 μm. For example, the wave shape amplitude may be about 1 μm to 20 μm. When the surface of the optical layer 1450a is formed to have a convex divided region, the width of the divided region may be about 10 μm to 100 μm, and the height may be about 0.5 μm to 5 μm. Each of the divided regions protrudes outward to have a convex shape, and the boundary between the divided regions has a relatively concave shape due to the convex shape. The pitch of the wave shape may be defined as the distance between the peaks of the convex portion or the distance between the valleys of the concave portion in the regularly repeated wave shape, and the amplitude of the wave shape is between the highest point and the lowest point on the surface on which the wave shape is formed. Can be defined as the height difference. The width of the divided area may be defined as the maximum value of the distances between two points on the edge of each divided area in the plane projection, and the height may be defined as the height difference between the highest point and the lowest point on the surface where the divided area is formed.

The divided regions may be formed in various shapes as shown in FIGS. 13D and 13E. Specifically, the planar projection shape of each partition may have various shapes such as circular, elliptical, rhombus, polygonal, indefinite, etc., and the width and height of each partition may be different from each other, and the boundary of adjacent partitions is a straight line. Or curved. In addition, such a partition is not limited in size or shape.

The height of the fine protrusions formed in the optical layer 1450a, the depth of the fine grooves, the amplitude and pitch of the wave shape, the width and height of the divided regions, the density of the fine protrusions and the grooves, etc. are appropriately adjusted according to the degree of required light diffusion. Can be.

As another example, although not shown in the drawing, the light diffusion pattern 1451a may be a continuous pattern having a shape in which a plurality of recesses are continuously connected. Each of the recesses is recessed in a direction from the surface of the diffusion sheet 1400A toward the inside of the diffusion sheet 1400A. The depth or width of the recesses may be appropriately adjusted as needed and the depth or width of each of the recesses may have an irregular value. In contrast, the light diffusion pattern 1451a may have a shape in which concave portions and convex portions are continuously combined, or may be embossed patterns.

As another example, although not shown in the drawing, the light diffusion pattern 1451a may be a discontinuous pattern. In the discontinuous pattern, the convex portions may have a form in which they are spaced apart from each other, or the concave portions may have a form in which they are disposed apart from each other. The convex portion or the concave portion constituting the discontinuous pattern may have a dot shape when viewed in a plan view. The height, depth, and width of each of the convex portions or the concave portions may have different irregular values.

Although not shown in the drawings, the surface of the optical layer 1450a may be a planarized surface. In this case, the optical layer 1450a may include light diffusion beads dispersed therein or voids formed therein to diffuse light. The diffusion beads are formed of polycarbonate (PC) resin, polyethylene (PE) resin, polypropylene (PP) resin, methacryl (metacrylic) resin, polyethylene terephtalate (PET) resin, or the like. These may be used alone or in combination of two or more. Each of the diffusion beads may have a diameter of about 3 μm to about 30 μm. The diameter of each of the diffusion beads may be defined as a value measured by a dynamic light scattering method (DLS method). Each of the pores may have a diameter of about 3 μm to about 30 μm, and may be measured using a scanning electron microscope (SEM).

The diffusion sheet 1400A may be disposed on the light guide plate 1200 so that the optical layer 1450a faces the first light collecting sheet 1500. On the contrary, the diffusion sheet 1400A may be disposed such that the optical layer 1450a faces the light guide plate 1200. 14 is a cross-sectional view for describing another example of the diffusion sheet illustrated in FIG. 11.

Referring to FIG. 11 along with FIG. 11, the diffusion sheet 1400B includes a base sheet 1400b ′, a first optical layer 1450b, and a second optical layer 1460b.

The base sheet 1400b ′ has the same structure as the selected one of the

optical sheets

The first optical layer 1450b is disposed on a lower surface of the base sheet 1400b 'and includes a light diffusion pattern 1451b formed on a surface thereof. The second optical layer 1460b is disposed on an upper surface of the base sheet 1400b 'and includes a light diffusion pattern 1541b formed on a surface thereof. Since each of the first optical layer 1450b and the second optical layer 1460b has a structure substantially the same as that of the optical layer 1450a illustrated in FIG. 12, detailed descriptions thereof will be omitted. However, the light diffusion pattern 1451b formed on the surface of the first optical layer 1450b may be the same as or different from the light diffusion pattern 1541b formed on the surface of the second optical layer 1460b. 15 is a cross-sectional view for describing still another example of the diffusion sheet illustrated in FIG. 11.

Referring to FIG. 11 along with FIG. 11, the diffusion sheet 1400C includes a transparent film 1430c, a first optical layer 1450c, and a second optical layer 1460c.

Since the transparent film 1430c is substantially the same as the first transparent film 130a illustrated in FIG. 3, detailed descriptions thereof will be omitted.

The first optical layer 1450c is disposed on a lower surface of the transparent film 1430c, includes a light diffusion pattern 1451c formed on a surface thereof, and includes a light emitting composite 10 dispersed therein. The second optical layer 1460c is disposed on an upper surface of the transparent film 1430c, includes a light diffusion pattern 1541c formed on a surface thereof, and includes a light emitting composite 10 dispersed therein. The first optical layer 1450b and the second optical layer shown in FIG. 14 except that the first optical layer 1450c and the second optical layer 1460c include a light emitting composite 10 dispersed therein. Since it is substantially the same as the layer 1460b, the overlapping detailed description is omitted.

At least one selected from among a red light emitting composite, a green light emitting composite, and a multicolor light emitting composite including red quantum dots and green quantum dots may be dispersed in the first optical layer 1450c and the second optical layer 1460c. Since the red light emitting composite, the green light emitting composite, and the multicolored light emitting composite have the same structure as the

light emitting composites

10a and 10b described with reference to FIGS. 1A to 1C, detailed descriptions thereof will not be repeated.

For example, a green light emitting composite may be dispersed in the first optical layer 1450c, and a red light emitting composite may be dispersed in the second optical layer 1460c. In this case, the green light generated by the green light emitting composite dispersed in the first optical layer 1450c may excite the red light emitting composite dispersed in the second optical layer 1460c, thereby generating sufficient red light. . In addition, since the green light emitting composite dispersed in the first optical layer 1450c receives light primarily from the light emitting device 1100, the green light emitting composite has relatively higher energy than the light emitting composite dispersed in the second optical layer 1460c. As a result, the power density of the light generated by the green light emitting composite dispersed in the first optical layer 1450c may be maximized. In this case, the multicolor light-emitting composite may be further dispersed in at least one of the first optical layer 1450c and the second optical layer 1460c.

As another example, the green light emitting composite may be dispersed in the first optical layer 1450c, and the multicolor light emitting composite may be dispersed in the second optical layer 1460c.

As another example, the multi-color light emitting composite may be dispersed in the first optical layer 1450c, and the red light emitting composite may be dispersed in the second optical layer 1460c.

As another example, one or more of the red light emitting composite and the multicolored light emitting composite may be dispersed in the first optical layer 1450c, and the green light emitting composite may be dispersed in the second optical layer 1460c. FIG. 16 is a cross-sectional view for describing another example of the diffusion sheet 1400 illustrated in FIG. 11.

Referring to FIG. 11 along with FIG. 11, the diffusion sheet 1400D includes a transparent film 1430d and an optical layer 1460d. Since the transparent film 1430d is substantially the same as the transparent film 1430c illustrated in FIG. 15, detailed descriptions thereof will be omitted. Since the optical layer 1460d is substantially the same as the optical layer 1450a illustrated in FIG. 12 except that the optical layer 1460d includes the light emitting composite 10 dispersed therein, the detailed description thereof will be omitted.

In the optical layer 1460d, at least one selected from among a red light emitting composite, a green light emitting composite, and a multicolor light emitting composite including red quantum dots and green quantum dots may be dispersed. For example, a red light emitting composite and a green light emitting composite may be dispersed in the optical layer 1460d. As another example, the multicolor light-emitting composite may be dispersed in the optical layer 1460d.

The backlight unit described above may widen the color reproduction region of the display device by using the diffusion sheet including the light conversion layer and improve color purity and color reproducibility of colors displayed by the display device.

Referring to FIG. 17, the backlight unit 2000 may include a light emitting device 2100, a light guide plate 2200, a reflecting plate 2300, a diffusion sheet 2400, a first light collecting sheet 2500, and a second light collecting sheet 2600. Include. Except for the diffusion sheet 2400 and the first light collecting sheet 2500, since the backlight unit 1000 is substantially the same as the backlight unit 1000 illustrated in FIG. 11, detailed descriptions thereof will be omitted.

The diffusion sheet 2400 includes a transparent film and a light diffusion layer, and is a conventional diffusion sheet containing no quantum dots. The light diffusion layer may be formed on one surface of the transparent film, or formed on both surfaces thereof. The light diffusion layer may include a light diffusion pattern formed on a surface thereof, and the light diffusion pattern may be substantially the same as the light diffusion pattern 1451a of the optical layer 1450a described with reference to FIGS. 12 and 13A to 13E. Alternatively, the light diffusion layer may include diffusion beads or pores. When the light diffusing layer includes the diffusion beads or the pores, the surface of the light diffusing layer may be a planarized surface.

The first light collecting sheet 2500 is disposed on the diffusion sheet 2400. Hereinafter, the first light collecting sheet 2500 will be described in detail with reference to FIG. 18.

FIG. 18 is a cross-sectional view for describing an exemplary embodiment of the first light collecting sheet 2500 illustrated in FIG. 17.

Referring to FIG. 17 along with FIG. 17, the first light collecting sheet 2500A includes a base sheet 2500a 'and an optical layer 2560a.

The base sheet 2500a ′ has the same structure as the selected one of the

optical sheets

The optical layer 2560a is disposed on an upper surface of the base sheet 2500a 'and includes a light converging pattern 2601 formed on a surface thereof. Since the condensing pattern 2601 is substantially the same as the condensing pattern formed on the surface of the first condensing sheet 1500 described with reference to FIG. 11, detailed description thereof will be omitted.

19 is a cross-sectional view for describing another exemplary embodiment of the first light collecting sheet 2500 illustrated in FIG. 17.

Referring to FIG. 19 along with FIG. 17, the first light collecting sheet 2500B includes a base sheet 2500b ', a first optical layer 2550b, and a second optical layer 2560b.

The base sheet 2500b ′ has the same structure as the selected one of the

optical sheets

The first optical layer 2550b is disposed on a bottom surface of the base sheet 2500b 'and includes a light diffusion pattern 2551b formed on a surface thereof. Since the first optical layer 2550b is substantially the same as the first optical layer 1450b described with reference to FIG. 14, detailed descriptions thereof will be omitted.

The second optical layer 2560b is disposed on an upper surface of the base sheet 2500b 'and includes a light converging pattern 2601b formed on a surface thereof. Since the second optical layer 2560b is substantially the same as the optical layer 2560a described with reference to FIG. 18, detailed descriptions thereof will be omitted.

20 is a cross-sectional view for describing another example of the first light collecting sheet 2500 illustrated in FIG. 17.

Referring to FIG. 17 together with FIG. 17, the first light collecting sheet 2500C includes a transparent film 2530c, a first optical layer 2550c, and a second optical layer 2560c.

The first optical layer 2550c is disposed on a lower surface of the transparent film 2530c and includes a light diffusion pattern 2551c formed on a surface thereof, and the light emitting composite 10 is dispersed therein. The second optical layer 2560c is disposed on an upper surface of the transparent film 2530c and includes a light collecting pattern 2601c formed on a surface thereof. The transparent film 2530c and the first optical layer 2550c are substantially the same as the transparent film 1430c and the first optical layer 1450c shown in FIG. 15, and the second optical layer 2560c is illustrated in FIG. Since it is substantially the same as the 2nd optical layer 2560b shown in 19, the overlapping detailed description is abbreviate | omitted.

In the above, examples in which the first light collecting sheet 2500 illustrated in FIG. 17 include the light emitting composite 10 or the light conversion layer having the light emitting composite as in the case of FIGS. 18 to 20 have been described. As a 2500, a conventional light collecting sheet, that is, a light collecting sheet or a light collecting sheet not including a light conversion layer including the light emitting composite, is used, and the second light collecting sheet 2600 has the structure described with reference to FIGS. 18 to 20. The backlight unit may be configured to form a backlight unit.

Referring to FIG. 21, the backlight unit 3000 may include a light emitting device 3100, a light guide plate 3200, a reflecting plate 3300, and an inverse prism sheet 3500. The light emitting device 3100, the light guide plate 3200, and the reflecting plate 3300 are substantially the same as the light emitting device 1100, the light guide plate 1200, and the reflecting plate 1300 of the backlight unit 1000 illustrated in FIG. 11. The detailed description is omitted.

The reverse prism sheet 3500 is disposed on the light guide plate 3200. Hereinafter, the reverse prism sheet 3500 will be described in detail with reference to FIG. 22.

FIG. 22 is a cross-sectional view for describing an exemplary embodiment of the inverse prism sheet 3500 illustrated in FIG. 21.

Referring to FIG. 22 along with FIG. 21, the inverse prism sheet 3500A includes a base sheet 3500a ', a first optical layer 3550a, and a second optical layer 3560a.

The base sheet 3500a ′ has the same structure as the selected one of the

optical sheets

The first optical layer 3550a is disposed on a bottom surface of the base sheet 3500a 'and includes a light collecting pattern 3551a formed on a surface thereof. That is, the first optical layer 3550a is disposed on the bottom surface of the base sheet 3500a 'to face the light guide plate 3200. The condensing pattern 3551a formed on the surface of the first optical layer 3550a is substantially the same as the condensing pattern 2601c formed on the surface of the second optical layer 2560c shown in FIG. do.

The second optical layer 3560a is disposed on an upper surface of the base sheet 3500a 'and includes a light diffusion pattern 3501a formed on a surface thereof. Since the second optical layer 3560a is substantially the same as the second optical layer 1460b illustrated in FIG. 14, detailed descriptions thereof will be omitted.

FIG. 23 is a cross-sectional view for describing another example of the inverse prism sheet 3500 shown in FIG. 21.

Referring to FIG. 23 along with FIG. 21, the inverse prism sheet 3500B includes a base sheet 3500b 'and an optical layer 3550b.

The base sheet 3500b 'has the same structure as the selected one of the

optical sheets

The optical layer 3550b is disposed on a lower surface of the base sheet 3500b 'and includes a light collecting pattern formed on a surface thereof. That is, the reverse prism sheet 3500B is disposed on the light guide plate 3200 such that the optical layer 3550b faces the light guide plate 3200. Since the optical layer 3550b is substantially the same as the first optical layer 3550a illustrated in FIG. 22, detailed descriptions thereof will be omitted.

By using the inverse prism sheets described with reference to FIGS. 22 and 23, the luminance can be maximized while minimizing the number of optical sheets required for the configuration of the backlight unit. At the same time, by applying the light emitting composite to the inverted prism sheet, the color purity of the color that the light provided by the backlight unit passes through the color filter of the display panel may be improved.

Referring to FIG. 24, the backlight unit 4000 may include a light emitting device 4100, a light guide plate 4200, a reflecting plate 4300, an inverted prism sheet 4500, and a protective sheet 4600. Since the reverse prism sheet 4500 and the protective sheet 4600 are substantially the same as the backlight unit 3000 illustrated in FIG. 21, detailed descriptions thereof will be omitted.

The reverse prism sheet 4500 is disposed on the light guide plate 4200 and includes a light collecting pattern protruding toward the light guide plate 4200.

The protective sheet 4600 is disposed between the light guide plate 4200 and the reverse prism sheet 4500 to prevent damage to a light converging pattern formed on the surface of the reverse prism sheet 4500 and exit from the light guide plate 4200. The light is uniformly diffused and transferred to the anti-prism sheet 4500. The protective sheet 4600 includes a base sheet 4600 ′, a first optical layer 4650, and a second optical layer 4660.

The base sheet 4600 ′ has the same structure as the selected one of the

optical sheets

The first optical layer 4650 is located on the bottom surface of the base sheet 4600 ', and the second optical layer 4660 is located on the top surface of the base sheet 4600'. Light diffusion patterns 4471 and 4661 may be formed on surfaces of each of the first and second

optical layers

4650 and 4660. Each of the first and second

optical layers

4650 and 4660 may be formed to have an average thickness of about 1 μm to 15 μm.

Meanwhile, although FIG. 24 illustrates that the protective sheet 4600 includes both the first and second

optical layers

4650 and 4660, the protective sheet 4600 protects the light collecting pattern of the anti-prism sheet 4500. In order to reduce optical defects such as wet-out by reducing the contact area of the converging pattern formed on the anti-prism sheet 4500 and the protective sheet 4600, the protective sheet 4600 may be formed of the first sheet. It may include only two optical layers 4660.

발광 복합체의 제조Preparation of Luminescent Composites

[실시예 1]Example 1

The ionomer solution was prepared by dissolving the ionomer by mixing 20 mg of ionomer in 1 ml of toluene and raising the temperature to about 110 ° C. To the ionomer solution, about 20 mg of CdSe-based red quantum dot Nanodot-HE-615 (trade name, QD solution, Korea) was mixed in 1 ml of toluene, and then cooled to room temperature. Thereafter, toluene was removed using an evaporator, and a light emitting composite according to Example 1 of the present invention in a powder state was prepared.

As the ionomer, Aclyn 201A (trade name, Honeywell, USA) having a melting point of about 102 ° C. was obtained by partially replacing a copolymer of ethylene and acrylic acid with Ca ²⁺ ions.

[실시예 2]Example 2

Except for the type of ionomer and the dissolution temperature for preparing the ionomer solution, the light emitting composite according to Example 2 was prepared in the same manner as the method for preparing the light emitting composite in Example 1. In preparing the light emitting composite according to Example 2, Aclyn 285A (trade name, Honeywell, USA) having a melting point of about 82 ° C with an ionomer partially substituted with Na ⁺ ions was used at about 90 ° C.

[실시예 3]Example 3

Except for the type of ionomer and the dissolution temperature for preparing the ionomer solution, the light emitting composite according to Example 3 of the present invention was prepared in the same manner as the method for preparing the light emitting composite in Example 1. For preparing the light emitting composite according to Example 3, Aclyn 295A (trade name, Honeywell, USA) having a melting point of about 99 ° C with an ionomer partially substituted with Zn ²⁺ ions was used at about 110 ° C. It was.

[실시예 4]Example 4

Except for the type of ionomer and the dissolution temperature for preparing the ionomer solution, the light emitting composite according to Example 4 of the present invention was prepared in the same manner as the method for preparing the light emitting composite in Example 1. In preparing the light emitting composite according to Example 4, Aclyn 246A (trade name, Honeywell, USA) having a melting point of about 95 ° C with an ionomer partially substituted with Mg ²⁺ ions was used at about 105 ° C. It was.

[실시예 5]Example 5

(1) Preparation of Ionomer (Production Example 1)

A polymer solution was prepared by mixing 2.0 g of polyethylene-acrylic acid copolymer polymer having a melting point of about 70 ° C. under nitrogen atmosphere with 10 ml of toluene and stirring at about 70 ° C. for 1 hour. Thereafter, 100 ml of a solution in which zinc acetate (Zn (Et) ₂ ) was dissolved in toluene at a concentration of 0.3 M was added to the prepared polymer solution, and reacted for 1 hour to obtain an ionomer partially substituted with Zn ²⁺ ions. Melting point of the prepared ionomer is about 52 ℃.

(2) Preparation of Light Emitting Composite

Except for the type of ionomer and the dissolution temperature for preparing the ionomer solution, the light emitting composite according to Example 5 was prepared in the same manner as the method for preparing the light emitting composite in Example 1. In the preparation of the light-emitting composite according to Example 5, the melting point produced in Preparation Example 1 was about 52 ° C, and the ionomer partially substituted with Zn ²⁺ ions was used after being dissolved at about 60 ° C.

[실시예 6] Example 6

(1) Preparation of Ionomer (Production Example 2)

2.0 g of polyethylene-acrylic acid copolymer polymer having a melting point of 160 ° C. under nitrogen atmosphere was mixed with 10 ml of toluene and stirred at 70 ° C. for 1 hour to prepare a polymer solution. Thereafter, 100 ml of a solution in which zinc acetate (Zn (Et) ₂ ) was dissolved in toluene at a concentration of 0.3 M was added to the prepared polymer solution, and reacted for 1 hour to obtain an ionomer partially substituted with Zn ²⁺ ions. The melting point of the prepared ionomer is about 148 ° C.

(2) Preparation of Light Emitting Composite

After mixing 20 mg of the ionomer of Preparation Example 2 in 1 ml of dimethylformamide, the ionomer of Preparation Example 2 was dissolved by raising the temperature to about 160 ° C., thereby preparing an ionomer solution. To the ionomer solution, about 20 mg of CdSe-based red quantum dot Nanodot-HE-615 (trade name, QD solution, Korea) was mixed in 1 ml of toluene, and then cooled to room temperature. Thereafter, dimethylformamide and toluene were removed using an evaporator to prepare a light emitting composite according to Example 1 of the present invention in powder form.

[비교예 1]Comparative Example 1

Nanodot-HE-615 (trade name, QD solution, Korea), which is a CdSe-based red quantum dot, was prepared.

발광 복합체의 특성 평가Characterization of Luminescent Composites

[실험예 1] - 양자효율 평가 (1)Experimental Example 1-Quantum Efficiency Evaluation (1)

Measurement samples 1 to 6 were prepared by mixing toluene with each of the light emitting composites according to Examples 1 to 6 of the present invention. Meanwhile, Comparative Sample 1 was prepared by mixing quantum dots according to Comparative Example 1 with toluene.

Quantum efficiency (Quantum Yield, QY) and emission wavelength of the light emitting composite according to Example 1 of the present invention were measured using the measurement sample 1. The measurement was carried out using an absolute quantum efficiency measuring device C11347-11 (trade name, HAMAMATSU, Japan).

In the same manner, using the measurement samples 2 to 6 to measure the quantum efficiency and emission wavelength of the light emitting composite according to Examples 2 to 6 of the present invention. The results are shown in Table 1.

In addition, using Comparative Sample 1, the quantum efficiency and emission wavelength of the quantum dots according to Comparative Example 1 were measured. The results are shown in Table 1.

Table 1

In toluene	Quantum Efficiency (QY,%)	Emission wavelength (nm)
Measurement sample 1	93.9	615.2
Measurement sample 2	93.5	614.6
Measurement sample 3	94.5	614.4
Measurement sample 4	93.9	614.4
Measurement sample 5	90.1	614.9
Measurement sample 6	85.7	619.2
Comparison sample 1	90.3	614.2

Referring to the measurement results of Table 1, it can be seen that the quantum efficiencies when the light emitting composites of Examples 1 to 5 of the present invention are dispersed in toluene are 93.9%, 93.5%, 94.5%, 93.9%, and 90.1%, respectively. On the other hand, it can be seen that the quantum efficiency when the quantum dot according to Comparative Example 1 is dispersed in toluene is 90.3%. Accordingly, it can be seen that the light emitting composites according to Examples 1 to 5 of the present invention have a higher or at least similar quantum efficiency than that of the quantum dots according to Comparative Example 1.

On the other hand, when the light emitting composite according to Example 6 of the present invention is dispersed in toluene, it can be seen that the quantum efficiency is 85.7%, which is lower than that of the quantum dot according to Comparative Example 1.

When the light emitting complexes of Examples 1 to 5 of the present invention are dispersed in toluene, the emission wavelengths are 615.2 nm, 614.6 nm, 614.4 nm, 614.4 nm, and 614.9 nm, respectively, and the emission wavelengths of the quantum dots according to Comparative Example 1 are 614.2 nm. It can be seen that. Accordingly, the difference between the light emission wavelength of the light emitting composite encapsulated by the ionomer having a melting point of about 140 ° C. or less and the light emission wavelength of the quantum dot according to Comparative Example 1 is less than about 1 nm, as in Examples 1 to 5 of the present invention. The same can be said.

On the other hand, the light emission wavelength of the light emitting composite according to Example 6 of the present invention is 619.2 nm, showing a difference of 5 nm from the light emission wavelength of the quantum dot according to Comparative Example 1 and the light emitting composite according to Examples 1 to 5 of the present invention It can be seen that the difference between 4 nm and 4.8 nm.

As described above, the light emitting composite according to the sixth embodiment of the present invention is compared with the light emitting composites according to Examples 1 to 5 and the quantum dot according to Comparative Example 1, the quantum efficiency is lowered and the emission wavelength is also changed significantly. Can be. That is, when manufacturing a light emitting composite using an ionomer having a melting point of more than about 140 ℃ as in Example 6, the quantum dot is damaged by the high temperature applied to dissolve the ionomer, the quantum efficiency of the light emitting composite is lowered and light emission It can be seen that the wavelength is changed.

[실험예 2] - 양자효율 평가 (2)Experimental Example 2-Quantum Efficiency Evaluation (2)

Each of the light emitting composites according to Examples 1 to 6 of the present invention has a B kit and an optical density (OD) value of 0.1 in an OE-6630 A / B kit (trade name, Dow Corning Silicon, USA), which is a siloxane resin. Measurement samples 7-12 were prepared by mixing to phosphorus concentration.

Further, Comparative Sample 2 was prepared by mixing quantum dots according to Comparative Example 1 with OE-6630 and an OD value of 0.1.

For each of the measurement samples 7 to 12 and the comparative sample 2, the quantum efficiency and the emission wavelength were measured using C11347-11 (trade name, HAMAMATSU, Japan) which is an absolute quantum efficiency meter. The results are shown in Table 2.

TABLE 2

Classification (in OE-6630)	Quantum Efficiency (%)	Emission wavelength (nm)
Measurement sample 7	93.7	621.4
Measurement Sample 8	93.2	622.1
Measurement Sample 9	94.1	620.9
Measurement sample 10	93.6	621.6
Measurement Sample 11	80.9	626.9
Measurement Sample 12	76.3	630.6
Comparison sample 2	81.0	627.1

Referring to the measurement results of Table 2, when dispersed in the siloxane resin as in the measurement samples 7 to 12, the quantum efficiency of the light emitting composite according to Examples 1 to 4 of the present invention is 93.7%, 93.2%, 94.1%, And 93.6%, the light emitting composite quantum efficiencies according to Examples 5 and 6 are 80.9% and 76.3%, respectively. Example 5 has a quantum efficiency of at least 12.3% less than that of Examples 1 to 4, It can be seen that 6 is reduced by more than 16.9%.

On the other hand, as in Comparative Sample 2, it can be seen that when the quantum dots are dispersed in the siloxane resin, the quantum efficiency is 81.0%. Therefore, in the process of preparing a light emitting composite by encapsulating the quantum dots with an ionomer, an ionomer having a melting point of less than about 60 ° C. is used as in Example 5, or an ionomer having a melting point of more than about 140 ° C. is used as in Example 6. It can be seen that when the light emitting composite is dispersed in the siloxane resin, the quantum efficiency is reduced to a level similar to that when only the quantum dots are dispersed. In this case, it can be seen that the case of the sixth embodiment has a greater reduction in quantum efficiency than the case of the fifth embodiment.

In the case of the light emission wavelength, the light emission wavelengths of the measurement samples 7 to 10 in the case where the light emitting composite according to Examples 1 to 4 of the present invention were dispersed in the siloxane resin were 621.4 nm, 622.1 nm, 620.9 nm and 621.6 nm. I can see it.

On the other hand, it can be seen that the emission wavelengths of the measurement samples 11 and 12 when the light emitting composites according to Examples 5 and 6 are dispersed in the siloxane resin are 626.9 nm and 630.6 nm, respectively. Thus, when dispersed in the siloxane resin, the light emitting composite of Example 5 changed the emission wavelength by 4.8 nm or more compared with the light emitting composite of Examples 1 to 4. In the light emitting composite of Example 6, it can be seen that the light emission wavelength of 8.5 nm or more is changed compared with those of Examples 1 to 4. It can be seen that the variation of the emission wavelength is relatively larger in Example 6.

On the other hand, the emission wavelength when the quantum dots according to Comparative Example 1 is dispersed in the siloxane resin is 627.1 nm, it can be seen that the emission wavelength is changed to a level between the change in the emission wavelength of Example 5 and Example 6.

As described above, in Example 5 and Example 6, the decrease in the quantum efficiency and the change in the emission wavelength were generated more rapidly than in the case of Examples 1 to 4.

In Example 5, the temperature was raised to about 60 ° C. in order to dissolve the ionomer having a melting point of less than 60 ° C. Therefore, the dissolution temperature for dissolving the ionomer is lower than that of the other embodiments, and the time required for cooling to room temperature is relatively short. As a result, it can be seen that when the quantum dots are not sufficiently encapsulated by the ionomer and dispersed in the siloxane resin, the quantum efficiency is lowered and the emission wavelength is also changed.

In Example 6, in order to dissolve the ionomer having a melting point exceeding 140 ° C., the temperature was raised to about 160 ° C. In this process, the quantum dots were damaged and the change in quantum efficiency and emission wavelength was relatively large. .

[실험예 3] - 분산 안정성의 평가Experimental Example 3-Evaluation of Dispersion Stability

For the measurement samples 7 to 12 and the comparative sample 2, the transmittance (transmittance immediately after dispersion) immediately after the preparation of the samples was measured using the Cary-4000 (trade name, Agilent, USA) which is a transmittance measuring device. After 1 month elapsed, their permeability (permeability after 1 month) was measured again to calculate dispersion stability. The results are shown in Table 3.

TABLE 3

Classification (in OE-6630)	Dispersion stability (%)
Measurement sample 7	2
Measurement Sample 8	3
Measurement Sample 9	2
Measurement sample 10	3
Measurement Sample 11	8
Measurement Sample 12	7
Comparison sample 2	15

The "transmission immediately after dispersion" is a value (unit:%) obtained by taking an arithmetic mean for transmittance within the visible light range of about 400 nm to about 700 nm as transmittance immediately after preparing the measurement samples or the comparative sample. In addition, "permeability after 1 month" is a value obtained by taking the arithmetic mean by measuring the permeability in the same manner at the time when 1 month elapses while leaving the samples measured "permeability immediately after dispersion" at room temperature (unit: %).

Dispersion stability (%) of Table 3 means the difference value between "permeability immediately after dispersion" and "permeability after 1 month." As the sample having poor dispersion stability increases precipitation over time, the transmittance of visible light increases, and as a result, the difference between "permeability immediately after dispersion" and "permeability after 1 month" becomes large. Therefore, the dispersion stability (%) has a larger value as the dispersion stability of the sample is not good.

Referring to Table 3, it can be seen that the dispersion stability of the measurement samples 7 to 12 are 2%, 3%, 2%, 3%, 8% and 7%, respectively. On the other hand, it can be seen that the dispersion stability of Comparative Sample 2 is 15%. That is, it can be seen that the dispersion stability of the light emitting composite according to the embodiments of the present invention is much superior to Comparative Sample 2. It can be seen that even if time elapses, precipitation does not occur and the dispersed state is stably maintained in the siloxane resin. However, it is understood that measurement samples 11 and 12 have better dispersion stability than Comparative Sample 2, but the dispersion stability is poor compared to Measurement samples 7 to 10.

[실험예 4] - 자외선 안정성 및 열/수분 안정성의 평가 -1Experimental Example 4-Evaluation of UV Stability and Heat / Moisture Stability -1

The light emitting composite according to Example 1 in powder form was prepared and the first quantum efficiency (QYT1, unit:%) was measured using an absolute quantum efficiency measuring device C11347-11 (trade name, HAMAMATSU, Japan). Subsequently, after irradiating ultraviolet (UV) light having a wavelength of 365 nm for 150 hours at a radiation intensity of about 1 mW / cm ² for a severe condition of about 540 J / cm ² , the second quantum efficiency (QYT2, unit:%) Was measured. The difference between the first quantum efficiency and the second quantum efficiency (ΔQY1 = QYT1-QYT2, unit:%) was calculated to evaluate ultraviolet stability of the light emitting composite according to Example 1. The results are shown in Table 4.

Prepare the light emitting composites according to Examples 2 to 6 in the powder form and the quantum dots according to Comparative Example 1, and powdered in substantially the same manner as the experimental method for the light emitting composite according to Example 1 in powder form for each UV stability of each of the light emitting composites according to Examples 2 to 6 and the quantum dots according to Comparative Example 1 was evaluated. The results are shown in Table 4.

In addition, for the light emitting composites according to Examples 1 to 6 and the quantum dots according to Comparative Example 1 in a powder state, after measuring the first quantum efficiency (QYT1, unit:%), the temperature and the humidity 85 ° C and relative humidity 85 It was left for 240 hours under severe conditions of%. Subsequently, third quantum efficiency (QYT3, unit:%) was measured for the light emitting composites according to Examples 1 to 6 and the quantum dots according to Comparative Example 1. The difference between the first quantum efficiency and the third quantum efficiency (ΔQY2 = QYT1-QYT3, unit:%) is calculated to provide heat / moisture for the light emitting composites according to Examples 1 to 6 and the quantum dots according to Comparative Example 1. The stability was evaluated. The results are shown in Table 4.

Table 4

division	UV stability (△ QY1,%)	Heat / moisture stability (△ QY2,%)
Example 1	14	17
Example 2	17	20
Example 3	20	22
Example 4	18	23
Example 5	34	45
Example 6	22	32
Comparative Example 1	49	57

Referring to Table 4, the ultraviolet stability of the light emitting composites according to Examples 1 to 6 were 14%, 17%, 20%, 18%, 34% and 22%, respectively, whereas the ultraviolet stability of the quantum dots according to Comparative Example 1 was It can be seen that 49%. The better the stability to ultraviolet rays, the smaller the change in the quantum efficiency under the harsh conditions of the ultraviolet rays (irradiation amount of about 540 J / cm ² ), the smaller the ultraviolet stability. That is, it can be seen that the ultraviolet stability of the light emitting composite according to Examples 1 to 6 of the present invention is superior to the quantum dots according to Comparative Example 1. Among the light emitting composites according to Examples 1 to 6, it can be seen that the ultraviolet light stability of the light emitting composites according to Examples 1 to 4 is superior to the ultraviolet light stability of the light emitting composites according to Examples 5 and 6.

In addition, the thermal / moisture stability of the light emitting composites according to Examples 1 to 6 was 17%, 20%, 22%, 23%, 45%, and 32%, respectively, whereas the thermal / moisture stability of the quantum dots according to Comparative Example 1 was It can be seen that 57%. The greater the stability to temperature and humidity, the smaller the change in quantum efficiency under the harsh conditions of high temperature and high humidity (temperature 85 ° C and relative humidity 85%), so that the heat / moisture stability has a smaller value. That is, it can be seen that the thermal / moisture stability of the light emitting composites according to Examples 1 to 6 of the present invention is superior to the quantum dots according to Comparative Example 1. Among the light emitting composites according to Examples 1 to 6, it can be seen that the heat / moisture stability of the light emitting composites according to Examples 1 to 4 is superior to that of the light emitting composites according to Examples 5 and 6.

[실험예 5] - 자외선 안정성 및 열/수분 안정성의 평가 -2 Experimental Example 5-Evaluation of UV Stability and Heat / Moisture Stability -2

Among the OE-6630 A / B kit (trade name, Dow Corning Silicon, USA), the luminescent composite according to Example 1 was dispersed in the OE-6630 B kit, and OE-6630 A kit and 1: 4 (A kit: B kit) And a heat treatment in an oven at about 150 ° C. for about 2 hours to prepare a first film sample having a thickness of about 200 μm.

The second to sixth film samples were prepared by substantially the same process as the process for preparing the first film sample using the light emitting composite according to Examples 2 to 6. In addition, the first comparative film sample was manufactured through a process substantially the same as the process of preparing the first film sample using the quantum dot according to Comparative Example 1.

Ultraviolet stability and heat / moisture stability were evaluated for each of the first to sixth film samples and the first comparative film sample in substantially the same manner as in the evaluation method of Experimental Example 4. The results are shown in Table 5.

Table 5

division	UV stability (△ QY1,%)	Heat / moisture stability (△ QY2,%)
First film sample	3	5
Second film sample	5	6
Third film sample	2	4
Fourth film sample	5	7
5th film sample	17	20
Sixth film sample	12	16
First Comparative Film Sample	38	40

Referring to Table 5, it can be seen that UV stability of the film samples including the light emitting composite according to Examples 1 to 6 of the present invention is superior to that of the first comparative film sample including the quantum dots.

Among the first to sixth film samples, it can be seen that the ultraviolet stability of the fifth and sixth film samples is not as good as that of the first to fourth film samples. That is, it can be seen that the ultraviolet stability of the first to fourth film samples is very good at a level of about 5% or less.

In addition, when comparing the heat / moisture stability of the first to sixth film samples with the heat / moisture stability of the first comparative film sample, the heat / moisture of the film samples including the light emitting composite according to Examples 1 to 6 of the present invention. It can be seen that the stability is superior to that of the first comparative film sample.

Among the first to sixth film samples, the heat / moisture stability of the fifth and sixth film samples is better than that of the first comparative film sample, but not as good as the first to fourth film samples. have. That is, it can be seen that the heat / moisture stability of the first to fourth film samples is very good at a level of about 7% or less.

As described above, even when the cured product is manufactured using the siloxane-based resin, it can be seen that the ultraviolet light stability and the heat / moisture stability of the light emitting composite according to the present invention are superior to those using the quantum dots as they are.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims

At least one quantum dot; And

A light emitting composite comprising the ionomer covering the quantum dot and represented by the structure of Formula 1 below:

[Formula 1]

In Formula 1, x is 20 to 100, y is 1 to 10, M + is a metal cation, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6, and R 7 are each independently hydrogen. (H) or an alkyl group having 6 or less carbon atoms.
The method of claim 1,

x is 25 to 80, y is 1 to 4, characterized in that the light-emitting composite.
The method of claim 2,

x is 30 to 60, y is 1.5 to 2.0, the light emitting composite.
The method of claim 1, wherein the metal cation,

At least one monovalent metal ion selected from the group consisting of sodium ions, potassium ions, lithium ions, silver ions and mercury ions;

At least one divalent metal ion selected from the group consisting of magnesium ion, calcium ion, strontium ion, barium ion, copper ion, cadmium ion, mercury ion, tin ion, lead ion, iron ion, cobalt ion, nickel ion and zinc ion ;

At least one trivalent metal ion selected from the group consisting of aluminum ions, scandium ions, iron ions and yttrium ions; or

A light emitting composite comprising at least one tetravalent metal ion selected from the group consisting of titanium ions, zirconium ions, hafnium ions, vanadium ions, tantalum ions, tungsten ions, chromium ions, cerium ions and iron ions.
The method of claim 1,

The ionomer is a light emitting composite, characterized in that 20 to 100% of the polar group is neutralized by the metal cation.
The method of claim 1,

The ionomer has a molecular weight of 1,000 to 20,000, the light emitting composite, characterized in that.
The method of claim 1,

Melting point (melting point) of the ionomer is a light emitting composite, characterized in that more than 50 ℃ 150 ℃.
The method of claim 1,

The ionomer has a density of 0.85 g / cm 3 or more and 1.05 g / cm 3 or less.
The method of claim 1,

And the ionomer encapsulates the at least one quantum dot.
The method of claim 1,

The light emitting composite, characterized in that two or more quantum dots are spaced apart from each other in the aggregate formed by the ionomer.
Resin in a liquid state having a polymerizable functional group; And

It includes a light emitting composite dispersed in the resin,

The light emitting composite comprises at least one quantum dot and an ionomer covering the quantum dot and represented by the structure of Formula 1 below:

[Formula 1]

In Formula 1, x is 20 to 100, y is 1 to 10, M + is a metal cation, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6, and R 7 are each independently hydrogen. (H) or an alkyl group having 6 or less carbon atoms.
The method of claim 11,

The resin is a composition, characterized in that it comprises at least one selected from the group consisting of a silicone resin, an epoxy resin and an acrylic resin.
The method of claim 12,

The resin is a composition, characterized in that the thermosetting resin or photo-curable resin.
The method of claim 11,

The composition further comprises light diffusing beads.
The method of claim 11,

The resin composition, characterized in that it further comprises a blowing agent.
Cured resins; And

It includes a light emitting composite dispersed in the cured resin,

The light-emitting composite includes at least one quantum dot and a cured product comprising an ionomer covering the quantum dot and represented by the structure of Formula 1 below:

[Formula 1]

In Formula 1, x is 20 to 100, y is 1 to 10, M + is a metal cation, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6, and R 7 are each independently hydrogen. (H) or an alkyl group having 6 or less carbon atoms.
The method of claim 16,

The resin is a cured product comprising at least one selected from the group consisting of silicone resins, epoxy resins and acrylic resins.
The method of claim 17,

The said resin is thermosetting resin or photocurable resin, The hardened | cured material characterized by the above-mentioned.
The method of claim 16,

Hardened | cured material further containing a light-diffusion bead.
The method of claim 16,

Hardened | cured material further containing a space | gap.
An optical sheet comprising at least one quantum dot and a light conversion layer covering the quantum dots and including a light emitting composite including an ionomer represented by the structure of Formula 1 below:

[Formula 1]

In Formula 1, x is 20 to 100, y is 1 to 10, M + is a metal cation, and R 1 , R 2 , R 3 , R 4 , R 5 , R 6, and R 7 are each independently hydrogen. (H) or an alkyl group having 6 or less carbon atoms.
The method of claim 21,

The optical conversion layer is at least one cured product selected from the group consisting of a silicone resin, an epoxy resin and an acrylic resin.
The method of claim 22,

The resin is an optical sheet, characterized in that the thermosetting resin or photo-curable resin.
The method of claim 21,

The optical conversion layer further comprises a light diffusion bead.
The method of claim 21,

The optical conversion layer further comprises a void.
The method of claim 21,

The optical sheet further comprises a barrier layer disposed on one surface of the light conversion layer.
The method of claim 26,

The optical sheet further comprises a first transparent film disposed on the barrier layer.
The method of claim 26,

The optical sheet further comprises a second transparent film disposed between the light conversion layer and the barrier layer.
The method of claim 26,

The optical sheet further comprises a light diffusion layer formed on the barrier layer.
The method of claim 27,

The optical sheet further comprises a light diffusion layer formed on the first transparent film.
The method of claim 29 or 30,

An optical sheet, characterized in that a light diffusion pattern is formed on the surface of the light diffusion layer.
The method of claim 29 or 30,

And the light diffusing layer comprises light diffusing beads.
The method of claim 29 or 30,

And the light diffusing layer comprises a void.
The method of claim 21,

And a first barrier layer disposed on the top surface of the light conversion layer and a second barrier layer disposed on the bottom surface of the light conversion layer.
The method of claim 34, wherein

The optical sheet further comprises a first transparent film disposed on the first barrier layer and a second transparent film disposed on the second barrier layer.
36. The method of claim 35 wherein

The optical sheet further comprises a third transparent film disposed between the light conversion layer and the first barrier layer and a fourth transparent film disposed between the light conversion layer and the second barrier layer.
The method of claim 34, wherein

And a light diffusing layer formed on at least one barrier layer of the first and second barrier layers.
36. The method of claim 35 wherein

The optical sheet further comprises a light diffusion layer formed on at least one transparent film of the first and second transparent film.
The method of claim 37 or 38,

An optical sheet, characterized in that a light diffusion pattern is formed on the surface of the light diffusion layer.
The method of claim 37 or 38,

And the light diffusing layer comprises light diffusing beads.
The method of claim 37 or 38,

And the light diffusing layer comprises a void.
The method of claim 21,

And an optical diffusion layer formed on at least one of an upper surface and a lower surface of the light conversion layer.
The method of claim 42, wherein

An optical sheet, characterized in that a light diffusion pattern is formed on the surface of the light diffusion layer.
The method of claim 42, wherein

And the light diffusing layer comprises light diffusing beads.
The method of claim 42, wherein

And the light diffusing layer comprises a void.
The method of claim 21,

Optical sheet comprising a light collecting pattern formed on one surface of the light conversion layer.
Light emitting element;

A light guide plate receiving light generated by the light emitting device; And

An optical sheet disposed on the light guide plate;

And the optical sheet comprises a light emitting composite comprising at least one quantum dot and an ionomer covering the quantum dots.
The method of claim 47,

The light emitting device is a blue light emitting device,

The light emitting composite may include at least one selected from the group consisting of a red light emitting composite including only red quantum dots, a green light emitting composite including only green quantum dots, and a multicolor light emitting composite including both the red quantum dots and the green quantum dots. Backlight unit.
Light emitting element;

A light guide plate receiving light generated by the light emitting device; And

An optical sheet disposed on the light guide plate; And

A display panel disposed on the optical sheet;

And the optical sheet comprises a light emitting composite comprising at least one quantum dot and an ionomer covering the quantum dots.