WO2014073895A1

WO2014073895A1 - Composite, composition containing same, and apparatus

Info

Publication number: WO2014073895A1
Application number: PCT/KR2013/010094
Authority: WO
Inventors: 권두효; 최정옥; 권오관
Original assignee: 주식회사 엘엠에스
Priority date: 2012-11-09
Filing date: 2013-11-07
Publication date: 2014-05-15

Abstract

The composite comprises at least one quantum dot and a wax-based compound which covers a surface of the quantum dot. The composite has remarkable quantum efficiency, a small change in emission peak even if the composite is dispersed in a resin, and excellent dispersion stability, UV stability and thermal/moisture stability.

Description

Complexes, compositions and devices comprising the same

The present invention relates to a composite, a composition and a device comprising the same, and a composite, a composition and a device comprising the improved dispersibility and luminescent properties.

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 decreasing 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 a light emitting device is manufactured using quantum dots to improve color reproducibility, the quantum dots may be easily damaged as the use time of the light emitting device increases because the quantum dots themselves have low stability against moisture, heat, or light. That is, there is a problem in that the lifetime of the light emitting device is shortened by applying the quantum dots to the light emitting device.

One object of the present invention is to provide a composite with 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 comprising the complex.

Another object of the present invention is to provide a device comprising a coating layer or a film made of the composition.

The composite according to an embodiment of the present invention includes at least one quantum dot and a wax-based compound covering the surface of the quantum dot.

In one embodiment, the wax-based compound may encapsulate the quantum dots. In this case, the wax-based compound may encapsulate one quantum dot. In contrast, the two or more quantum dots may be spaced apart from each other in the aggregate formed by the wax-based compound, so that the quantum dots may be encapsulated by the wax-based compound.

In one embodiment, the molecular weight of the wax-based compound may be 1,000 or more and 20,000 or less.

In one embodiment, the melting point of the wax-based compound may be at least 80 ℃ 200 ℃.

In one embodiment, the wax-based compound may include a polyethylene-based wax, a polypropylene-based wax or an amide-based wax.

In one embodiment, the acid value of the wax-based compound may be 1 mg KOH / g to 200 mg KOH / g.

In one embodiment, the density of the wax-based compound may be 0.95 g / cm ^{3 or} more.

The composition according to the embodiment of the present invention includes a solvent and a complex. The composite includes a wax-based compound dispersed in the solvent and covering at least one quantum dot and the quantum dot.

A composition according to another embodiment of the present invention includes a resin and a composite. The composite includes a wax-based compound dispersed in the resin and covering at least one quantum dot and the quantum dot. In this case, the resin may include a silicone resin, an epoxy resin, or an acrylic resin.

Coating layer or film according to an embodiment of the present invention is prepared using the composition.

According to the present invention, even when a plurality of complexes including quantum dots covered by a wax-based compound are dispersed in a solvent or a resin, the complexes may be uniformly dispersed in a solvent or a resin without aggregation with each other. In addition, the composite can be maintained in a uniform dispersed state for a long time.

In addition, the wax-based compound protects the quantum dots, thereby preventing damage to the quantum dots due to moisture, light, heat, and the like, thereby improving stability of the composite with respect to the surrounding environment such as temperature, humidity, and ultraviolet rays.

Furthermore, the wax-based compound may constitute one complex such that each of the wax-based compounds may be encapsulated without being aggregated with each other.

Accordingly, the composite having improved quantum efficiency than the respective quantum dots can be manufactured and used in various fields. In particular, by using the composites according to the present invention in a light emitting device or an electronic device, it is possible to prevent the lifespan from being reduced while improving color reproducibility, color rendering index, and the like.

1A and 1B are conceptual views illustrating a composite according to an embodiment of the present invention.

Figure 1c is a conceptual diagram for explaining the composite according to another embodiment of the present invention.

Figure 2 is a flow chart for explaining a method for producing a composite and a composition comprising the same according to an embodiment of the present invention.

3 to 5 are cross-sectional views illustrating an apparatus according to 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 embodiments, 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.

1A and 1B, the composite 101 includes a quantum dot 111 and a wax-based compound 130. In the present specification, the "wax-based compound" is defined as a compound having a melting point (Melting point) higher than the room temperature in the solid state at room temperature. That is, in this specification, unless otherwise specified, "wax" refers to a solid state. "Room temperature" is defined as about 15 ° C to about 25 ° C. Melting point of the wax-based compound 130 may be about 80 ℃ to about 200 ℃.

In FIG. 1A and FIG. 1B, two quantum dots 111 are illustrated to describe the relationship between adjacent quantum dots. However, since the two quantum dots 111 are substantially the same, one quantum dot will be described and overlapping descriptions will be omitted. do.

The quantum dot 111 is a particle having a crystal structure of several to several tens of nanometers in size, and is composed of hundreds to thousands of atoms. Since the size of the quantum dot 111 is a nano size, a quantum confinement effect appears in the quantum dot 111. 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 111, the quantum dot 111 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 111 may be adjusted through the size, composition, etc. of the quantum dot 111 itself.

In the present invention, the structure of the quantum dot 111 is not particularly limited. For example, the quantum dot 111 may be a single structure consisting of only a core, a core-single shell structure consisting of a core and a single layer shell, or a core-multishell shell structure consisting of a core and a multilayer shell. Examples of the material forming the core or the shell include II-VI compound semiconductor nanocrystals such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, GaN, GaP, GaAs, InP, InAs, etc. Group III-V compound semiconductor nanocrystal or a mixture thereof is mentioned. For example, the quantum dot 111 may have a CdSe / ZnS (core / shell) structure having a core including CdSe and a shell including ZnS. As another example, the quantum dot 111 may have an InP / ZnS (core / shell) structure having a core including InP and a shell including ZnS.

In this case, the quantum dot 111 may further include a ligand (SC) bonded to the surface of the central particle made of the above-described compounds. The ligand SC may prevent quantum dots 111 adjacent to each other from being aggregated and quenched. The ligand (SC) may include a hydrophobic compound. As an example of the said ligand (SC), the amine compound which has a C6-C30 alkyl group or an alkenyl group, the carboxylic acid compound which has a C6-C30 alkyl group or an alkenyl group, etc. are mentioned. The quantum dot 111 illustrated in FIG. 1A may include the ligand SC.

The wax-based compound 130 covers the quantum dot 111. The wax-based compound 130 may encapsulate the quantum dot 111 by covering the surface of the quantum dot 111 as a whole. In this case, the wax-based compound 130 may form a capsule layer having a predetermined thickness on the surface of the quantum dot 111. By covering the quantum dot 111 with the wax-based compound 130, the quantum dot 111 may be prevented from being damaged by moisture, heat, light, or the like caused by an external environment.

The molecular weight (MW) of the wax-based compound 130 may be about 1,000 to 20,000. The said molecular weight is a number average molecular weight converted into polystyrene. For example, when the molecular weight of the wax-based compound 130 is less than about 1,000, the wax-based compound 130 cannot encapsulate the quantum dots 111 because the wax-based compound 130 may not have a property of a wax present in a solid state at room temperature. It is difficult. In addition, when the molecular weight of the wax-based compound 130 exceeds about 20,000, the size (average diameter) of the recrystallization of the wax-based compound 130 is several hundred μm or more, so that even if a composite is prepared using the solvent or There is a problem that is difficult to disperse in the resin. In addition, when the molecular weight of the wax-based compound 130 exceeds about 20,000, the wax-based compound 130 may be in a liquid phase at a temperature exceeding about 200 ℃ in the process of encapsulating the quantum dot 111 The quantum dot 111 may be damaged.

Synthetic wax may be used as the wax-based compound 130. The wax-based compound 130 may be a polymer, a copolymer or an oligomer. The wax-based compound 130 may include a polyethylene-based wax, a polypropylene-based wax, or an amide-based wax.

When the wax compound 130 is the ethylene wax or the polypropylene wax, the wax compound 130 may include at least one of units represented by the following Chemical Formulas 1 to 7.

In

Chemical Formulas

1, 2, 3, 4, 5, 6, and 7, R ₁ , R ₃ , R _5, and R ₇ each independently represent a single bond or an alkylene group having 1 to 10 carbon atoms (*-(CH ₂ )). _x- *, x represents an integer of 1 to 10), R ₂ , R ₄ , R ₆ and R ₈ each independently represent hydrogen or an alkyl group having 1 to 10 carbon atoms, R _a , R _b , R _c , R _d , R _e , R _f and R _g each independently represent hydrogen or an alkyl group having 1 to 3 carbon atoms.

Specifically, when R ₂ of Formula 1 includes hydrogen, the unit of Formula 1 includes a carboxyl group. On the contrary, when R ₂ in Formula 1 represents an alkyl group having 1 to 10 carbon atoms, the unit of Formula 1 includes an ester group.

When R ₄ of Formula 2 includes hydrogen, the unit of Formula 2 includes an aldehyde group. On the contrary, when R ₄ in Formula 2 represents an alkyl group having 1 to 10 carbon atoms, the unit of Formula 2 includes a ketone group.

When R ₆ of Formula 3 includes hydrogen, the unit of Formula 3 includes a hydroxy group. On the contrary, when R _{6 in} Formula 3 represents an alkyl group having 1 to 10 carbon atoms, the unit of Formula 3 includes an ether group.

When R _a , R _b , R _c , R _d , R _e , R _f and R _g of Formulas 1 to 7 each independently represent hydrogen, the polyethylene wax may be defined. For example, the polyethylene wax includes a polyethylene wax (PE wax) including only a unit in which R _g of Formula 7 is hydrogen. In addition, the polyethylene wax is selected from units in which R _g of Formula 7 is hydrogen, and units in which R _a , R _b , R _c , R _d , R _e and R _f of Formulas 1 to 6 are hydrogen. At least one oxygen-containing unit may be included at the same time. Examples of the polyethylene wax containing at least one oxygen-containing unit include oxidized polyethylene wax (PE wax), an ethylene-acrylic acid copolymer, and ethylene-vinyl acetate, which are oxides of polyethylene. Ethylene-vinyl acetate copolymer Ethylene-maleic anhydride copolymer etc. are mentioned.

In addition, when R _a , R _b , R _c , R _d , R _e , R _f and R _g of Formulas 1 to 7 each independently represent a methyl group having 1 carbon number, the polypropylene wax may be defined. have. For example, the polypropylene wax includes a polypropylene wax (PP wax) including only a unit in which R _g of Formula 7 is a methyl group. In addition, the polypropylene wax is a unit in which R _g of Formula 7 is a methyl group, and units of R _a , R _b , R _c , R _d , R _e and R _f of Formulas 1 to 6 are hydrogen. At least one oxygen-containing unit selected may be included at the same time. As an example of the polypropylene wax containing an oxygen containing unit, a propylene-maleic anhydride copolymer etc. are mentioned.

The amide wax has a main chain including an amide bond (-CONH-). That is, the amide wax may be a polymer, copolymer or oligomer including a unit containing an amide bond. The unit of the amide wax may have 1 to 10 carbon atoms. The amide wax may further include one or more kinds of oxygen-containing units represented by Formulas 1 to 6.

When the wax-based compound 130 includes at least one oxygen-containing unit among units represented by Chemical Formulas 1 to 6, the quantum dot 111 may be stably compared with the case where only the unit represented by Chemical Formula 7 is included. It can be encapsulated. That is, the PE wax or the PP wax encapsulates the surface of the quantum dot 111 at random, while the wax-based compound 130 and the quantum dot 111 are formed by the polarity of oxygen included in the oxygen-containing unit. The interaction with the metal constituting the is strong. Therefore, when the wax-based compound 130 includes at least one oxygen-containing unit among the units represented by Chemical Formulas 1 to 6, the wax-based compound 130 may stably encapsulate the quantum dots 111. have. Among the oxygen-containing units, the unit represented by Chemical Formula 1, particularly a carboxyl group, is most advantageous for encapsulating the quantum dots 111 because the wax-based compound 130 has a strong interaction with the quantum dots 111. Therefore, the wax compound 130 according to the present invention preferably includes at least a carboxy group as a substituent.

In addition, in the case of using the wax-based compound 130 including at least one oxygen-containing unit of the units represented by Formulas 1 to 6, a plurality of quantum dots 111 in the process of manufacturing the composite 101 When reacting with the solution in which the wax compound 130 is dissolved, the wax compound 130 may encapsulate a maximum amount of the quantum dots 111. That is, when the amount of the quantum dot 111 added to the solution in which PE wax, PP wax or the like is dissolved is "1" and the amount of the encapsulated quantum dot 111 is "A", "A" is not 0. It can have a value greater than 1 and less than 1. In contrast, when the amount of the quantum dot 111 added to the solution in which the wax-based compound 130 containing the oxygen-containing unit is dissolved is "1", the amount of the quantum dot 111 encapsulated thereby (B) ) Has a larger value than A.

An oxygen-containing wax-based compound, which is a wax-based compound 130 including oxygen-containing units represented by Chemical Formulas 1 to 6, may be prepared by oxidizing polyethylene or polypropylene as a base material. Alternatively, the oxygen-containing wax-based compound may be prepared by polymerizing single monomers or copolymerizing two or more different monomers.

For example, since the recrystallization formed when the PE wax containing ethylene as a unit is recrystallized, it can be easily used without difficulty in encapsulating the quantum dots 111, but the wax-based compound 130 In consideration of the interaction between the quantum dot 111 and the oxygen-based PE wax, the quantum dot 111 can be encapsulated relatively more stably than the PE wax.

The wax-based compound 130 may have an acid value of about 1 mg KOH / g to about 200 mg KOH / g. In the present invention, the "acid value" of the wax-based compound 130 refers to the number of mg of potassium hydroxide (KOH) required to neutralize 1 g of the wax-based compound 130. When the wax-based compound 130 includes a carboxyl group, the wax-based compound 130 may have an acid value of about 1 mg KOH / g or more. That is, the larger the acid value, the more carboxyl groups included in the wax-based compound 130. However, when the acid value of the wax-based compound 130 is less than about 1 mg KOH / g, the amount of the carboxyl group interacting with the quantum dot 111 is very small, so that the wax-based compound 130 and the quantum dot ( 111) the interactions between them are almost the same as with PE wax or PP wax. In addition, when the acid value of the wax-based compound 130 exceeds about 200 mg KOH / g, the ligand (SC) rather than by the carboxy group may be deteriorated to oxidize the surface of the quantum dot (111). Even if the quantum dot 111 is encapsulated due to oxidation of the quantum dot 111, a problem occurs that quantum efficiency is lowered. Therefore, the wax-based compound 130 preferably has an acid value of about 1 mg KOH / g to about 200 mg KOH / g. More preferably, the wax-based compound 130 may have an acid value of about 5 mg KOH / g to about 50 mg KOH / g.

The acid value of the wax-based compound 130 may be measured according to the ASTM 1386 standard. For example, after quantifying about 2 g of the wax-based compound 130 as a sample, the mixture is put into a Erlenmeyer flask, and 40 ml of xylene is heated to raise the temperature. When the sample becomes a completely colorless transparent solution, 2-3 drops of phenolphthalein solution are added. The acid value can be calculated by adding a titration with a KOH solution of about 0.1 N and maintaining the color of the solution 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.

On the other hand, the wax-based compound 130 may have a high density of about 0.95 g / cm ³ or more. When the wax-based compound 130 has a high density, the melting point of the composite 101 including the wax-based compound 130 is higher than that of the low-density wax having a low density of less than about 0.95 g / cm ³ . Heat resistance can be improved. In addition, when the wax-based compound 130 has a high density, since the crystallinity of recrystallization of the wax-based compound 130 is superior to that of the low-density wax, the quantum dot 111 may be stably encapsulated.

For example, PE wax may be classified into high density PE wax (HDPE wax) and low density PE wax (LDPE wax) according to the above criteria. That is, HDPE wax has a density of at least about 0.95 g / cm ³ . In this case, the density of the HDPE wax may be about 1.20 g / cm ³ or less. The HDPE wax may have a melting point of about 120 ° C. to about 200 ° C. LDPE wax may have a density of less than about 0.95 g / cm ³ . The melting point of the LDPE wax may be about 80 ° C to about 110 ° C. Therefore, when using the PE wax as the wax-based compound 130, encapsulating the quantum dots 111 with HDPE wax rather than LDPE wax can encapsulate the quantum dots 111 more uniformly.

The content of the units represented by Formulas 1 to 7 included in the wax-based compound 130 may vary depending on the molecular weight of the wax-based compound 130 and the acid value of the wax-based compound 130.

Referring back to FIGS. 1A and 1B, the diameter d1 of the composite 101 may be about 10 nm to 50 nm. The diameter d1 of the composite 101 is a value measured by a dynamic light scattering method (DLS method) calculated by a Stokes-Einstein equation for a diffusion coefficient (hydrodynamic diameter). Can be defined as

Referring to FIG. 1C, the composite 102 includes at least two or more

quantum dots

112 and 114 and a wax-based compound 130.

The

quantum dots

112 and 114 included in the complex 102 are described for convenience by referring to reference numeral 112 as a “first quantum dot” and referring to reference numeral 114 as a “second quantum dot”. Since each of the first and second

quantum dots

112 and 114 is substantially the same as the quantum dot 111 described with reference to FIGS. 1A and 1B, detailed descriptions thereof will be omitted.

The wax-based compound 130 may cover the first and second

quantum dots

112 and 114 to prevent the first and second

quantum dots

112 and 114 from aggregation with each other. That is, the wax-based compound 130 may make one aggregate so that the first and second

quantum dots

112 and 114 may be encapsulated without being aggregated with each other. The aggregate may be defined as one "composite 102". In the composite 102, the first and second

quantum dots

112 and 114 are disposed in an aggregate formed by the wax-based compound 130. The number of quantum dots disposed in the aggregate may be several tens to tens of millions.

The diameter (d2) of the composite (102) may be about 5 nm to about 50 μm, and the diameter (d2) of the composite (102) is about 0.5 in view of the dispersibility for the resin described below. μm to about 10 μm. The diameter d2 of the composite 102 may vary depending on the recrystallization rate (cooling rate) in the process of manufacturing the composite 102.

Since the wax-based compound 130 is substantially the same as the wax-based compound described with reference to FIGS. 1A and 1B, detailed descriptions thereof will be omitted.

In the process of manufacturing the quantum dots covered with the wax-based compound 130, the composite 101 described with reference to FIGS. 1A and 1B may be formed, or the complex 102 described with reference to FIG. 1C may be formed. In the above process, the composite 101 described with reference to FIGS. 1A and 1B and the composite 102 described with reference to FIG. 1C may be simultaneously manufactured.

Hereinafter, a method of manufacturing the

composites

101 and 102 and a composition including the

composites

101 and 102 according to the present invention will be described in detail with reference to FIG. 2.

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

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

The organic solvent may include toluene. The wax powder is a solid made of a wax-based compound, and the wax-based compound constituting the wax powder is substantially the same as that described in FIGS. 1A to 1C, and thus detailed descriptions thereof will be omitted. Instead of the wax powder, solid wax pellets may be added to the organic solvent.

Then, the wax powder is dissolved (step S220).

The wax powder or the wax pellet can be dissolved by heating the organic solvent. The organic solvent is heated to a temperature above the melting point of the wax powder. For example, the organic solvent may be heated to about 200 ℃ to 220 ℃. Accordingly, it is possible to prepare a wax solution in which the wax powder is dissolved in the organic solvent.

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

When the quantum dots are mixed with the wax solution, the quantum dots are dispersed in the wax solution. In this case, the ligands of the quantum dots may be easily dispersed in the wax solution without aggregation with each other. 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 wax solution in which the quantum dots are dispersed is cooled (step S240).

By cooling the temperature of the wax solution in which the quantum dots are dispersed to room temperature, the dissolved wax compound may be recrystallized. The wax solution in which the quantum dots are dispersed may be slowly cooled to room temperature and cooled or quenched to control the recrystallization rate (cooling rate). In this case, when the recrystallization rate is high, that is, when the temperature of the wax solution is drastically lowered, the size of the aggregate formed by the wax-based compound may be reduced. On the contrary, when the temperature of the wax solution is gradually lowered, the size of the aggregate can be increased.

Recrystallized wax-based compound can encapsulate quantum dots. In this case, according to the recrystallization rate, as described in Figure 1a and 1b, the wax-based compound can encapsulate one quantum dot to form a composite 101, as described in Figure 1c Multiple quantum dots can be encapsulated to form a composite 102.

Accordingly,

composites

101 and 102 according to the present invention can be manufactured.

Composites

101 and 102 according to the present invention described above may be stored and used in powder form by removing the organic solvent. Alternatively, the

complexes

101 and 102 may be stored and used in a dispersed state in the organic solvent. The

composites

101 and 102 may be stably stored and used by the wax-based compound 130 encapsulating the

quantum dots

111, 112 and 114 in a powder form with little effect on moisture. The organic solvent may be uniformly dispersed and stored in the organic solvent without aggregation of the

composites

101 and 102.

In another embodiment, the composition comprising the

composites

101 and 102 may include a resin. The resin may itself be a liquid phase. Alternatively, the resin may be dissolved in a solvent even if the resin itself is a solid phase, and the

composites

101 and 102 may be dispersed in a solution containing the resin and the solvent. The composition including the resin may include at least one of the composite 101 illustrated in FIGS. 1A and 1B and the composite 102 illustrated in FIG. 1C. Specific examples of the resin include vinyl siloxane resins, epoxy siloxane resins, polydimethylsiloxane (PDMS), thermoplastic silicone vulcanizate (TPSiV), thermoplastic silicone polycarbonate-urethane (TSPCU), and the like. The composition may further include a crosslinking agent, a catalyst, an initiator, and the like together with the resin.

In one example, the composition is about 0.001 to 10 parts by weight of the composite (101, 102) 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.

Alternatively, the composition comprising the

complexes

101 and 102 may include at least one monomer and an initiator. The monomer may include an acrylate compound, an epoxy compound, a siloxane compound, or the like. These may be used alone or in combination of two or more, respectively. The composition may include at least one of the composite 101 shown in FIGS. 1A and 1B and the complex 102 shown in FIG. 1C. When the composition includes a monomer, the monomers may be polymerized to form a cured product, and the

composites

101 and 102 may be dispersed in the cured product.

The present invention provides a coating layer or film formed of the composition. The coating layer or film may be formed by crosslinking the resin of the composition or by drying the composition. For example, the composition may be cured using light or heat, and ultraviolet rays may be used when photocuring. Alternatively, the coating layer or film may be formed by polymerizing monomers of the composition. The method for forming the coating layer or film is not particularly limited.

The coating layer or the film may have a form in which the

composites

101 and 102 are dispersed in a matrix structure formed by the resin.

The present invention also provides a device comprising the coating layer or film. 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, even if a plurality of complexes (101, 102) including the quantum dots (111, 112, 114) covered by the wax-based compound 130 is dispersed in a solvent or a resin, the composite The

fields

101 and 102 may be uniformly dispersed in a solvent or a resin without aggregation with each other. In addition, the

composites

101 and 102 may be maintained in a uniform dispersed state for a long time.

In addition, the wax-based compound 130 protects the quantum dots (111, 112, 114) to prevent damage to the quantum dots due to moisture, light, heat, etc., so that the stability of the composite (101, 102) to the surrounding environment Can improve.

Furthermore, the wax-based compound 130 may constitute one

composite

101 and 102 such that each of the quantum dots 111 may be encapsulated without being aggregated with each other. Accordingly, the composite having improved quantum efficiency than the respective quantum dots can be manufactured and used in various fields.

[실시예 1]Example 1

After mixing 20 mg of the wax compound in 1 ml of toluene, the wax compound was dissolved by raising the temperature to about 130 ° C. to prepare a wax solution. The wax solution was mixed with a solution of Nanodot-HE-606 (trade name, QD solution, Korea), which was about 20 mg of CdSe-based red quantum dots in 1 ml of toluene, was cooled to room temperature. Then, after removing toluene using an evaporator, a composite according to Example 1 of the present invention in a powder state was prepared.

As the wax-based compound, Licowax PED 136 wax (trade name, Clariant, Switzerland) having an acid value of about 50 mg KOH / g was used as an oxidized high density polyethylene wax (Oxidized HDPE Wax).

[실시예 2]Example 2

Except for the kind of the wax-based compound, a composite according to Example 2 of the present invention was prepared in substantially the same manner as the composite was prepared in Example 1. In preparing the composite according to Example 2, Licowax PED 191 wax (trade name, Clariant, Switzerland) was used as Oxidized High Density Polyethylene Wax (Oxidized HDPE Wax) having an Acid value of about 7 mg KOH / g.

[실시예 3]Example 3

Except for the kind of the wax-based compound, a composite according to Example 3 of the present invention was prepared in substantially the same manner as the composite was prepared in Example 1. In the preparation of the composite according to Example 3, L-C 301E wax (trade name, Lion Chemtech Co., Korea) was used as an oxidized low density polyethylene wax (Oxidized LDPE Wax) having an acid value of about 16 mg KOH / g.

[실시예 4]Example 4

Except for the type of wax-based compound, the composite according to Example 4 of the present invention was prepared in substantially the same manner as the composite was prepared in Example 1. In preparation of the composite according to Example 4, Escor ^™ 5000 ExCo wax (trade name, ExxonMobil Chemical, USA) is an ethylene acrylic acid copolymer having an acid value of about 75 mg KOH / g (Ethylene-Acrylic Acid Copolymer). Was used.

[실시예 5]Example 5

Except for the kind of the wax-based compound, a composite according to Example 5 of the present invention was prepared in substantially the same manner as the composite was prepared in Example 1. In preparing the composite according to Example 5, an EVATANE 18-150 wax (trade name, ARKEMA, France), which was an ethylene vinyl acetate copolymer, was used.

[실시예 6]Example 6

Except for the kind of the wax compound, the composite according to Example 6 of the present invention was prepared in substantially the same manner as the composite according to Example 1. In the preparation of the composite according to Example 6, Licomont AR 504 wax (trade name, Clariant, Switzerland) is a polypropylene wax having an acid value of about 40 mg KOH / g to about 45 mg KOH / g. ) Was used.

[실시예 7]Example 7

Except for the kind of the wax compound, the composite according to Example 7 was prepared in substantially the same manner as the composite according to Example 1 was prepared. In preparing the composite according to Example 7, LC 104N wax (Non-Oxidized HDPE Wax) having an acid value of 0 mg KOH / g (trade name, Lion Chemtech Co., Korea) was used. .

[실시예 8]Example 8

Except for the type of wax-based compound, the composite according to Example 8 was prepared in substantially the same manner as the composite according to Example 1. For the preparation of the composite according to Example 8, Escor ^™ 5100 ExCo wax (trade name, ExxonMobil Chemical, USA) is an ethylene acrylic acid copolymer having an acid value of about 180 mg KOH / g. Was used.

[비교예 1]Comparative Example 1

Nanodot-HE-606 (trade name, QD solution, Korea), which is a CdSe-based red quantum dot, was prepared.

[실험예 1] - 복합체의 특성 평가 1Experimental Example 1-Characterization of the composite 1

Measurement samples 1 to 8 were prepared by mixing toluene with each of the composites according to Examples 1 to 8 of the present invention.

For the measurement sample 1, the quantum efficiency (Quantum Yield, QY) and the emission wavelength of the composite according to Example 1 of the present invention were measured using C9920-02 (trade name, HAMAMATSU, Japan) as an absolute quantum efficiency meter. .

In the same manner, for the measurement samples 2 to 8, the quantum efficiency and emission wavelength of the composite according to Examples 2 to 8 of the present invention were measured. The results are shown in Table 1.

In addition, Comparative Sample 1 was prepared by mixing quantum dots according to Comparative Example 1 with toluene. Quantum efficiency and emission wavelength of the quantum dots according to Comparative Example 1 were measured using Comparative Sample 1. The results are shown in Table 1.

Table 1

In toluene	Quantum Efficiency (QY,%)	Emission wavelength (nm)
Measurement sample 1	83.8	606.4
Measurement sample 2	83.1	606.7
Measurement sample 3	83.0	606.5
Measurement sample 4	82.7	606.3
Measurement sample 5	82.9	606.1
Measurement sample 6	82.6	606.9
Measurement sample 7	82.9	606.3
Measurement Sample 8	82.5	606.8
Comparison sample 1	82.3	606.0

Referring to the results of measurement samples 1 to 6 of Table 1, the quantum efficiencies of the composites according to Examples 1 to 6 in the state dispersed in toluene are 83.8%, 83.1%, 83.0%, 82.7%, 82.9% and 82.6%. Able to know. In addition, as in the results of measurement samples 7 and 8, it can be seen that the quantum efficiencies of the composites according to Examples 7 and 8 in the state dispersed in toluene are 82.9% and 82.5%, respectively.

On the other hand, it can be seen that the quantum efficiency of the quantum dot according to Comparative Example 1 in a state dispersed in toluene is 82.3%.

According to the quantum efficiency results according to Examples 1 to 8 and Comparative Example 1 of the present invention, the quantum efficiency of the composite according to Examples 1 to 8 of the present invention in the state dispersed in toluene is the same as that of Comparative Example 1 It can be seen that higher than the quantum efficiency. That is, even when the composite is manufactured using the quantum dots, it can be seen that the quantum efficiency of the composite is not lower than the quantum efficiency of the quantum dots themselves.

Further, in the state of being dispersed in toluene as in Measurement Samples 1 to 6, the emission wavelengths of the composites according to Examples 1 to 6 were 606.4 nm, 606.7 nm, 606.5 nm, 606.3 nm, 606.1 nm and 606.9 nm, and Example 7 And it can be seen that the emission wavelength of each of the composites according to 8 are 606.3 nm and 606.8 nm.

On the other hand, it can be seen that the emission wavelength of the quantum dot according to Comparative Example 1 is 606.0 nm.

According to this, when encapsulated by the wax-based compound as in Examples 1 to 8 of the present invention, it can be seen that the emission wavelength of the composite dispersed in toluene is longer than the emission wavelength of the quantum dot itself. However, since the emission wavelength of the composite according to the present invention is longer than the emission wavelength of the quantum dot itself, but the difference is less than about 1 nm, the emission wavelength of the composite in the state dispersed in toluene is substantially the same as the emission wavelength of the quantum dot itself. The same can be said. That is, even when the quantum dot is encapsulated with a wax-based compound, it can be seen that there is almost no shift in the emission wavelength compared to the emission wavelength of the quantum dot itself.

[실험예 2] - 복합체 특성 평가 2Experimental Example 2-Evaluation of Composite Properties 2

Each of the composites according to Examples 1 to 8 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. Mixtures at concentrations produced measurement samples 9-16.

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 9 to 16 and the comparative sample 2, quantum efficiency and emission wavelength were measured using C9920-02 (trade name, HAMAMATSU, Japan) as 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 9	87.3	609.5
Measurement sample 10	86.5	609.7
Measurement Sample 11	84.9	610.6
Measurement Sample 12	85.7	610.3
Measurement Sample 13	83.5	611.1
Measurement Sample 14	82.9	612.4
Measurement Sample 15	75.0	614.3
Measurement Sample 16	74.6	612.6
Comparison sample 2	73.2	614.5

Referring to Table 2, in the state dispersed in the siloxane resin as in the measurement samples 9 to 16, the quantum efficiencies of the composites according to Examples 1 to 6 were 87.3%, 86.5%, 84.9%, 85.7%, 83.5%, and 82.9. %, And the quantum efficiencies of the composites according to Examples 7 and 8 are 75.0% and 74.6%, respectively.

Referring to the result of Comparative Sample 2, it can be seen that the quantum efficiency of the quantum dot according to Comparative Example 1 in the state dispersed in the siloxane resin is 73.2%.

According to this, as in Examples 1 to 8 of the present invention, the composite including the quantum dots encapsulated by the wax-based compound shows a high quantum efficiency compared to the quantum dots dispersed in the siloxane resin, even in the state dispersed in the siloxane resin. It can be seen.

Comparing Table 2 with the data in Table 1, the quantum efficiency of measurement sample 9 in which the composite was dispersed in siloxane resin was 87.3%, which is different from the quantum efficiency of 83.8% of measurement sample 1 in which the composite was dispersed in toluene. It can be seen that + 3.5%. In addition, the quantum efficiency of measurement sample 10 is 86.5%, and it can be seen that the difference from 83.1%, which is the quantum efficiency of measurement sample 2, is + 3.4%. It can be seen that the quantum efficiencies of each of the measurement samples 11 to 14 are + 1.9%, + 3%, + 0.6%, and + 0.3% from the quantum efficiency of each of the measurement samples 3 to 6.

On the other hand, when comparing the data of Comparative Sample 2 representing the quantum efficiency of the quantum dots dispersed in the siloxane resin with the quantum efficiency of Comparative Sample 1, it can be seen that the difference in the quantum efficiency is -9.1% as the quantum dots are dispersed in the siloxane resin. In other words, it can be seen that when the quantum dots are dispersed in the siloxane resin, the quantum efficiency is lower than when the quantum dots are dispersed in toluene.

As described above, the composites according to Examples 1 to 6 of the present invention maintain or increase quantum efficiency even when dispersed in the siloxane resin, whereas the quantum dot is significantly reduced when dispersed in the siloxane resin. Able to know. However, when comparing each of the quantum efficiencies of the measurement samples 7 and 8 with the quantum efficiencies of the measurement samples 15 and 16, the quantum dots are encapsulated when the wax-based compound is an oxygen-free wax or a wax having an acid value of about 180 mg KOH / g. If the quantum dot itself is improved than the quantum efficiency itself, it can be seen that the quantum efficiency may be lowered when mixed with the siloxane resin.

Referring back to Table 2, in the state dispersed in the siloxane resin, the emission wavelength of the composite according to Examples 1 to 6 is 609.5 nm, 609.7 nm, 610.6 nm, 610.3 nm, 611.6 nm and 612.4 nm, and Example 7 and It can be seen that the emission wavelength of each of the composites according to 8 is 614.3 nm and 612.6 nm. It can be seen that the emission wavelength of the quantum dot according to Comparative Example 1 is 614.5 nm. According to this, both of the composites according to Examples 1 to 8 of the present invention and the quantum dots according to Comparative Example 1 have a longer emission wavelength when dispersed in the siloxane resin than 606.0 nm, which is the emission wavelength of the quantum dots themselves dispersed in toluene. Able to know.

Comparing with the data of Table 1, it can be seen that the emission wavelength of Measurement Sample 9 is longer by 3.1 nm than the emission wavelength of Measurement Sample 1. It can be seen that the emission wavelength of each of the measurement samples 10 to 14 increases by 3.0 nm, 4.1 nm, 4.0 nm, 5.0 nm and 5.5 nm compared to the emission wavelength of each of the measurement samples 2 to 6. It can be seen that the emission wavelength of each of the measurement samples 15 and 16 increases by 8 nm and 5.8 nm compared to the emission wavelength of the measurement samples 7 and 8 respectively.

On the other hand, comparing the emission wavelength of Comparative Sample 2 with Comparative Sample 1, it can be seen that the emission wavelength increases by 8.5 nm as the quantum dots are dispersed in the siloxane resin.

As described above, even when dispersed in the siloxane resin, it can be seen that the change in the emission wavelength of the composites according to Examples 1 to 6 of the present invention is smaller than the change in the emission wavelength of the quantum dot according to Comparative Example 1. That is, in the process of dispersing the composite or the quantum dots in the siloxane resin, the composite or the quantum dots are aggregated (aggregation), the phenomenon that the emission wavelength is relatively longer when dispersed in the siloxane resin than the emission wavelength in toluene, which is a simple dispersion solvent This happens. Nevertheless, when the composites according to the present invention are dispersed in the siloxane resin, it can be seen that the change in the emission wavelength is relatively small compared to the case where the quantum dots are dispersed in the siloxane resin as it is.

However, since the quantum dot is encapsulated to some extent by the wax-based compound, the composite according to Example 7 shows quantum efficiency at a level similar to that of the measurement samples 1 to 6 in the state dispersed in toluene. However, since the wax-based compound constituting the composite according to Example 7 does not contain oxygen, the encapsulation effect of the quantum dots is low, so that when dispersed in the siloxane resin, although the quantum efficiency is higher than that of the quantum dots according to Comparative Example 1, the examples 1 to It can be seen that the quantum efficiency is lower than the composite according to 6. In addition, when the composite according to Example 7 was dispersed in siloxane resin (measurement sample 15), it was found that the change in emission wavelength was large when compared with the case where the emission wavelength was dispersed in toluene (measurement sample 7).

In addition, in the composite according to Example 8, since the quantum dots are encapsulated by the wax-based compound, the quantum efficiency is shown to be similar to those of the measurement samples 1 to 6 in the state dispersed in toluene. However, when the ligand of the surface of the quantum dot is destroyed by the compound constituting the complex according to Example 8 and dispersed in the siloxane resin by oxidizing the quantum dot, the quantum efficiency is higher than that of the quantum dot according to Comparative Example 1, It can be seen that the quantum efficiency is lower than the resulting composite.

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

Permeability immediately after the measurement samples 9 to 16 and Comparative Sample 2 were prepared using Cary-4000 (trade name, Agilent, USA), which is a transmittance measuring device, Permeability immediately after dispersion) was measured. 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 9	2
Measurement sample 10	4
Measurement Sample 11	3
Measurement Sample 12	5
Measurement Sample 13	6
Measurement Sample 14	6
Measurement Sample 15	13
Measurement Sample 16	14
Comparison sample 2	18

In Experimental Example 3, "transmittance immediately after dispersion" is a value calculated from an arithmetic mean of a transmittance within a range of about 400 nm to about 700 nm, which is a visible light region measured by a transmittance measuring device immediately after the measurement sample or the comparative sample is prepared. :%)to be. In addition, "transmittance measured after one month" refers to a transmittance within a range of about 400 nm to about 700 nm, which is a visible light region measured by a transmittance measuring device at a point in which one month has elapsed after the measurement sample or the comparative sample is manufactured. , Calculated as the arithmetic mean (%). Dispersion stability of Table 3 is computed by calculating the transmittance | permeability (%) just after dispersion | distribution of a quantum dot, and the value (%) of the difference (%) after 1 month. The lower the permeability measured after 1 month, the smaller the dispersion stability, and the higher the permeability measured after 1 month, the larger the dispersion stability. That is, when the dispersion stability of the measurement sample or the comparative sample is not good, precipitation occurs and the permeability increases with time, and as a result, the dispersion stability value has a large value.

Referring to Table 3, it can be seen that the dispersion stability of measurement samples 9 to 16 is 2%, 4%, 3%, 5%, 6%, 6%, 13% and 14%, respectively. On the other hand, it can be seen that the dispersion stability of Comparative Sample 2 is 18%. That is, it can be seen that the dispersion stability of the measurement samples 9 to 16 including the composite according to the embodiments of the present invention is relatively superior to the comparative sample 2. It can be seen that even after time, no precipitation occurs and the state remains dispersed in the siloxane resin. In particular, in the case of measurement samples 15 and 16, although dispersion stability is good compared with the comparative sample 2, it turns out that dispersion stability is not good compared with the measurement samples 9-14.

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

The composite according to Example 1 in powder form was prepared and the first quantum efficiency (QYT1, unit:%) was measured using C9920-02 (trade name, HAMAMATSU, Japan) as an absolute quantum efficiency meter. 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 for the composite according to Example 1. The results are shown in Table 4.

Prepare the composites according to Examples 2 to 8 in the powder state and the quantum dots according to Comparative Example 1, and for each of the powder state in the substantially same manner as the experimental method for the composite according to Example 1 in the powder state Ultraviolet stability for each of the composites according to Examples 2 to 8 and the quantum dots according to Comparative Example 1 was evaluated. The results are shown in Table 4.

In addition, for the composites according to Examples 1 to 8 in powder form and the quantum dots according to Comparative Example 1, after measuring the first quantum efficiency (QYT1, unit:%), a temperature of 85 ° C. and a relative humidity of 85% in a thermo-hygrostat It was left under the harsh conditions of. Subsequently, a third quantum efficiency (QYT3, unit:%) was measured for the composites according to Examples 1 to 8 and the quantum dots according to Comparative Example 1. Calculate the difference between the first quantum efficiency and the third quantum efficiency (ΔQY2 = QYT1-QYT3, unit:%) to obtain heat / moisture stability for the composites according to Examples 1 to 8 and the quantum dots according to Comparative Example 1. Was evaluated. The results are shown in Table 4.

Table 4

division	UV stability (△ QY1,%)	Heat / moisture stability (△ QY2,%)
Example 1	15	16
Example 2	19	18
Example 3	21	21
Example 4	19	21
Example 5	22	24
Example 6	21	25
Example 7	29	41
Example 8	30	42
Comparative Example 1	52	55

Referring to Table 4, the ultraviolet stability of the composite according to Examples 1 to 8 is 15%, 19%, 21%, 19%, 22%, 21%, 29% and 30%, respectively, according to Comparative Example 1 It can be seen that the UV stability of the quantum dot is 52%. 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 composite according to Examples 1 to 8 of the present invention is superior to the quantum dots according to Comparative Example 1. Among the composites according to Examples 1 to 8, it can be seen that the ultraviolet stability of the composite according to Examples 1 to 6 is superior to the ultraviolet stability of the composite according to Examples 7 and 8.

In addition, the thermal / moisture stability of the composites according to Examples 1 to 8 were 16%, 18%, 21%, 21%, 24%, 25%, 41% and 42%, respectively, whereas the quantum dots according to Comparative Example 1 It can be seen that the heat / moisture stability is 55%. The greater the stability to temperature and humidity, the smaller the change in quantum efficiency under high temperature and high humidity (temperature 85 ° C. and relative humidity 85%), and therefore the smaller the heat / moisture stability. That is, it can be seen that the thermal / moisture stability of the composites according to Examples 1 to 8 of the present invention is superior to the quantum dots according to Comparative Example 1. Among the composites according to Examples 1 to 8, it can be seen that the thermal / moisture stability of the composites according to Examples 1 to 6 is superior to that of the composites according to Examples 7 and 8.

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

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

Using the composite according to Examples 2 to 8, the second to eighth film samples were prepared through a process substantially the same as that of preparing the first film sample. 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.

UV stability and heat / moisture stability were evaluated for each of the first to eighth 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	4
Second film sample	4	7
Third film sample	4	6
Fourth film sample	5	10
5th film sample	5	9
Sixth film sample	6	11
Seventh film sample	21	30
Eighth film sample	28	32
First Comparative Film Sample	38	40

Referring to Table 5, when the ultraviolet stability of the first to eighth film samples is compared with the ultraviolet stability of the first comparative film sample, the ultraviolet stability of the film samples including the composite according to Examples 1 to 8 of the present invention is quantum dots It can be seen that it is superior to the first comparative film sample including the.

Among the first to eighth film samples, the ultraviolet stability of the seventh and eighth film samples is better than that of the first comparative film sample, but it is not good compared to the first to sixth film samples. That is, it can be seen that the ultraviolet stability of the first to sixth film samples is very excellent at a level of about 6% or less.

Further, comparing the heat / moisture stability of the first to eighth film samples with the heat / moisture stability of the first comparative film sample, the heat / moisture stability of the film samples comprising the composite according to Examples 1 to 8 of the present invention. It turns out that it is excellent compared with this 1st comparative film sample.

Among the first to eighth film samples, the heat / moisture stability of the seventh and eighth film samples is better than that of the first comparative film sample, but not as good as the first to sixth film samples. have. That is, it can be seen that the heat / moisture stability of the first to sixth film samples is very good at a level of about 11% or less.

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

[실험예 6] - 자외선 안정성 및 열/수분 안정성의 평가 -3Experimental Example 6-Evaluation of UV Stability and Heat / Moisture Stability -3

After dissolving MB2478 (trade name, Mitsubishi Rayon, Japan) in toluene, the composite according to Example 1 was dispersed and dried at about 80 ° C. to prepare a ninth film sample having a thickness of about 200 μm.

The tenth to sixteenth film samples were prepared by substantially the same process as the process for preparing the ninth film sample using the composite according to Examples 2 to 8. In addition, the second comparative film sample was manufactured by substantially the same process as the process of manufacturing the ninth film sample using the quantum dot according to Comparative Example 1.

The UV stability and the heat / moisture stability of each of the ninth through sixteenth film samples and the second comparative film sample were evaluated in substantially the same manner as in the evaluation method of Experimental Example 4. The results are shown in Table 6.

Table 6

division	UV stability (△ QY1,%)	Heat / moisture stability (△ QY2,%)
Ninth film sample	8	5
10th film sample	9	7
11th film sample	11	7
12th film sample	14	13
Film film	13	10
Fourteenth film sample	16	12
15th film sample	27	32
16th film sample	35	34
Second Comparative Film Sample	48	43

Referring to Table 6, comparing the ultraviolet stability of the ninth to sixteenth film samples with the ultraviolet stability of the second comparative film sample, the ultraviolet stability of the film samples including the composite according to Examples 1 to 8 of the present invention, respectively 8%, 9%, 11%, 14%, 13%, 16%, 27% and 35%, the UV stability of the second comparative film sample containing quantum dots is excellent when compared to 48%. .

Among the ninth to sixteenth film samples, the ultraviolet stability of the fifteenth and sixteenth film samples is better than that of the second comparative film sample, but it is not good compared to the ninth to fourteenth film samples. That is, it can be seen that the ultraviolet stability of the ninth to fourteenth film samples is excellent at a level of about 16% or less.

In addition, when comparing the heat / moisture stability of the ninth to sixteenth film samples with the heat / moisture stability of the second comparative film sample, the heat / moisture stability of the film samples including the composite according to Examples 1 to 8 of the present invention. As 5%, 7%, 7%, 13%, 10%, 12%, 32% and 34%, it can be seen that the heat / moisture stability of the first comparative film sample is superior to that of 43%.

Among the ninth to sixteenth film samples, the heat / moisture stability of the fifteenth and sixteenth film samples is better than that of the second comparative film sample, but not as good as the ninth to fourteenth film samples. have. That is, it can be seen that the heat / moisture stability of the ninth to fourteenth film samples is very good at a level of about 13% or less.

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

Hereinafter, the apparatus according to the present invention will be described in more detail with reference to FIGS. 3 to 5. However, the scope of the present invention is not limited thereto.

Referring to FIG. 3, a light emitting device 501 is formed on a light emitting diode (LED) element portion 10 and the LED element portion 10 and includes a first composite including the composite according to the present invention as described above. The cured product layer 310 and the second cured product layer 320 are included. The LED element part 10 includes a base part 2 and an LED chip 1 formed in a groove part of the base part 2.

The first cured product layer 310 includes a green composite 311 dispersed in a matrix structure formed by the curable resin. The green composite 311 includes green quantum dots, and the green quantum dots are encapsulated by a wax-based compound. The "matrix structure" means the internal structure of the cured product formed by the curable resin of the composition used to form the first cured product layer 310 by chemical reaction. Since the wax-based compound is substantially the same as described with reference to FIGS. 1A, 1B, and 1C, detailed descriptions thereof will not be repeated.

The second cured product layer 320 includes an encapsulated red composite material 321 dispersed in a matrix structure formed by the curable resin. The red complex 321 includes red quantum dots, and the red quantum dots are encapsulated by a wax-based compound. The wax compound encapsulating the red quantum dots may be the same as or different from the wax compound encapsulating the green quantum dots.

The green composite 311 may have a light emission peak at about 520 nm to about 570 nm, which is a green wavelength region. In addition, the red complex 321 may have a light emission peak at about 600 nm to about 680 nm, which is a red wavelength region. For example, the red wavelength region may be about 620 nm to about 670 nm.

The LED chip 1 generates blue light. The blue light may have a wavelength of about 400 nm to about 480 nm. For example, the blue wavelength region may be about 400 nm to about 450 nm.

Unlike the stacked structure illustrated in FIG. 3, the first cured material layer 310 may include a red composite 321, and the second cured material layer 320 may include a green composite 311.

Although not illustrated in the drawings, unlike the laminated structure illustrated in FIG. 3, the light emitting device includes a green composite 311 and a red composite 321, and includes a cured product layer covering the LED chip 1. May have

Referring to FIG. 4, the light emitting device 502 includes a phosphor layer 410 including an LED element unit 10, a first cured product layer 310, a second cured product layer 320, and a phosphor 411. Include. The light emitting device 502 is substantially the same as the light emitting device 501 described with reference to FIG. 3 except for the fluorescent layer 410. Therefore, redundant descriptions are omitted.

The fluorescent layer 410 may compensate for light emission of the green composite 311 of the first cured product layer 310 and / or the red composite 321 of the second cured material layer 320. The phosphor 411 may have a light emission peak at, for example, about 520 nm to about 570 nm in a green region and / or about 600 nm to about 680 nm in a red region. In contrast, the phosphor 411 may have a light emission peak at about 580 nm to about 600 nm, which is a yellow region.

Referring to FIG. 5, the light emitting device 503 includes an LED element unit 10 and a cured product layer ML. The cured product layer ML may include all of the green composite 311, the red composite 321, and the phosphor 411 dispersed in a matrix structure formed by the curable resin.

Although not shown in the drawings, the light emitting device includes a first layer including two compounds of the green complex 311, the red complex 321, and the phosphor 411, and a second layer including the remaining one compound. It may include.

In contrast, when the LED chip is a light emitting chip that generates UV light, the light emitting device includes a first layer including a blue composite, a second layer including a green composite, and a third layer including a red composite on the light emitting chip. It may have a laminated structure. At this time, each of the red, green and blue composites includes a quantum dot encapsulated with a wax-based compound according to the present invention. The stacking order of the first to third layers may be variously changed.

In the above-described light emitting devices having various structures, deterioration of the light emitting device can be minimized by using the composite according to the present invention having good UV stability and heat / moisture stability, and the life of the light emitting device can be shortened due to damage of the quantum dots. You can prevent it. In addition, when the composite according to the present invention is dispersed in a resin to form a cured product layer, shift of emission peaks can be minimized. Accordingly, the light emitting device or the display device can be easily controlled to have the color characteristics (spectrum) required by the user, and color reproducibility can be improved.

As such, by using the composite according to the present invention in a light emitting device, a light emitting device that satisfies both color reproducibility and lifespan characteristics can be manufactured.

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

Composite comprising a wax-based compound covering the surface of the quantum dot.
The method of claim 1,

The wax-based compound is characterized in that the encapsulation of the quantum dot.
The method of claim 1,

The wax-based compound is characterized in that the encapsulation of one quantum dot.
The composite according to claim 1, wherein two or more quantum dots are spaced apart from each other in the aggregate formed by the wax-based compound.
The method of claim 1,

The wax-based compound has a molecular weight of 1,000 to 20,000 or less composite.
The method of claim 1,

Melting point (melting point) of the wax-based compound is a composite, characterized in that more than 80 ℃ 200 ℃.
The method of claim 1,

The wax-based compound is a composite comprising a polyethylene-based wax (polyethylene-based wax), polypropylene-based wax (Polypropylene-based wax) or amide-based wax (Amide-based wax).
The method of claim 7, wherein

The wax-based compound is a complex, characterized in that it comprises at least one of the units represented by the formula 1 to 7;

<Formula 1>

<Formula 2>

<Formula 3>

<Formula 4>

<Formula 5>

<Formula 6>

<Formula 7>

In Chemical Formulas 1, 2, 3, 4, 5, 6, and 7, R 1 , R 3 , R 5, and R 7 each independently represent a single bond or an alkylene group having 1 to 10 carbon atoms (*-(CH 2 )). x- *, x represents an integer of 1 to 10), R 2 , R 4 , R 6 and R 8 each independently represent hydrogen or an alkyl group having 1 to 10 carbon atoms, R a , R b , R c , R d , R e , R f and R g each independently represent hydrogen or an alkyl group having 1 to 3 carbon atoms.
The method of claim 1,

The acid value of the wax-based compound (complex), characterized in that 1 mg KOH / g to 200 mg KOH / g.
The method of claim 9,

The wax compound is a composite, characterized in that it comprises a polyethylene wax.
The method of claim 1,

The wax-based compound has a density of 0.95 g / cm 3 or more composite.
The method of claim 11,

The wax compound is a composite, characterized in that it comprises a polyethylene wax.
The method of claim 12,

The acid value of the polyethylene wax is a complex, characterized in that 1 mg KOH / g to 200 mg KOH / g.
menstruum; And

A composition comprising a composite dispersed in the solvent and comprising at least one quantum dot and a wax-based compound covering the quantum dot.
Resins; And

A composition comprising a wax-based compound dispersed in the resin and covering at least one or more quantum dots and the quantum dots.
The method of claim 15,

The resin is a composition, characterized in that it comprises at least one of a silicone resin, an epoxy resin and an acrylic resin.
Device comprising a coating layer or film formed of the composition according to claim 14.
18. The device of claim 17, wherein the device is an illumination or display device.