Solvent-free thermosetting quantum dot resin composition, quantum dot resin composite produced therefrom, LED package and display device to which this is applied

Abstract

The present invention relates to a solventless thermosetting quantum dot resin composition, a quantum dot resin composite produced therefrom, an LED package to which the same is applied, and a display device. Specifically, the present invention relates to a solventless thermosetting quantum dot resin composition having excellent light characteristic maintaining ability even after long-time driving of a display, a quantum dot resin composite produced therefrom, an LED package to which the same is applied, and a display device.

Description

Technical Field

[0001] The present invention relates to a solvent-free thermosetting quantum dot resin composition, a quantum dot resin composite produced therefrom, an LED package to which the same is applied, and a display device. Specifically, the present invention relates to a solvent-free thermosetting quantum dot resin composition having excellent light property maintaining ability even after long-term driving of a display, a quantum dot resin composite produced therefrom, an LED package to which the same is applied, and a display device.

Background Art

[0002] Quantum dots (QD), also known as semiconductor nanocrystals, can generate light of different wavelengths according to particle size even without a change in the type of substance, and can emit various colors. Since they have advantages such as higher color purity and light stability than conventional light emitters, they have attracted attention as next-generation light-emitting elements.

[0003] Currently, displays using commercially available quantum dots are in a form in which a film containing quantum dots (QD) is manufactured and then the film is incorporated into a TV. When applied in such a film form, there is a drawback that the amount of quantum dots used increases. When switching and applying the above-mentioned film-form quantum dots to an LED package display, not only can the amount of quantum dots used be significantly reduced, but also the depth of the TV is significantly reduced, showing self-luminous characteristics such as an OLED TV.

[0004] However, in the case of an LED package display, there are problems such as a large thermal resistance of the package, resulting in a decrease in lifespan and reliability. Therefore, there is a prior art (Korean Patent Publication No. 10-2018-0061146) that uses organic compounds and inorganic phosphors instead of quantum dots that are vulnerable to heat and moisture to improve color reproducibility and durability. There is also a prior art (Korean Patent Publication No. 10-2018-0097201) that synthesizes quantum dots with a continuous crystal growth structure and forms a metal oxide film on the surface of the quantum dots to improve the thermal stability of the quantum dots, etc.

[0005] However, it is difficult to solve such problems by simply improving heat resistance. In order to apply quantum dots to an LED package display, a quantum dot resin composition and a quantum dot composite with good durability and excellent reliability are required.

Summary of the Invention

Problems to be Solved by the Invention

[0006] As a sealing material for protecting the LED chip, a thermoplastic resin or a thermosetting resin has been used. However, as LEDs have evolved to high power, more thermosetting resins with excellent heat resistance and light resistance have been utilized.

[0007] Conventionally, alicyclic epoxy or polysiloxane has been used as such a thermosetting resin. However, when an LED package display is used for a long time, problems such as a decrease in luminance and a change in chromaticity occur in terms of light characteristics such as luminance and chromaticity. Also, even when an isocyanurate or a nanosilica material is mixed and used to improve the heat resistance of alicyclic epoxy, the problem of light characteristic degradation could not be solved.

[0008] Therefore, the problem to be solved by the present invention is to provide a solvent-free thermosetting quantum dot resin composition with improved photo-stability and reliability, a quantum dot resin composite manufactured therefrom, an LED package to which this is applied, and a display device.

Means for Solving the Problems

[0009] In one embodiment of the present invention for solving the above problems, a solvent-free thermosetting quantum dot resin composition is provided, which contains quantum dots, an epoxy resin, an acid anhydride curing agent, and a curing accelerator. The epoxy resin contains a dicyclopentadiene type epoxy resin, and is characterized in that.

[0010] Preferably, the epoxy resin further contains Triglycidyl Isocyanurate, and is characterized in that a solvent-free thermosetting quantum dot resin composition is provided.

[0011] Preferably, the dicyclopentadiene type epoxy resin contains a (meth)acrylate functional group, and is characterized in that a solvent-free thermosetting quantum dot resin composition is provided.

[0012] Preferably, the epoxy resin and the acid anhydride curing agent are contained in a weight ratio of 1:0.5 to 1:1.4, and is characterized in that a solvent-free thermosetting quantum dot resin composition is provided.

[0013] Preferably, a solvent-free thermosetting quantum dot resin composition is provided, in which the light property retention rate calculated by the following formula 1 is 80% or more. [Formula 1] Light property retention rate (%) = (Light property after 1000 hours of display driving / Display light property before driving) × 100

[0014] Preferably, the quantum dots are 1 to 30 parts by weight, the epoxy resin is 1 to 50 parts by weight, the acid anhydride curing agent is 1 to 50 parts by weight, the curing accelerator is contained in an amount of 0.05 to 1 part by weight, and is characterized in that a solvent-free thermosetting quantum dot resin composition is provided.

[0015] Preferably, the epoxy resin is an alicyclic epoxy resin, a BPA-PO epoxy resin, a bisphenol A type resin, a bisphenol F type epoxy resin, a novolac type epoxy resin, a nitrogen-containing epoxy resin, a chain aliphatic epoxy resin, or a naphthalene type epoxy resin, and provides a solventless thermosetting quantum dot resin composition characterized by containing any one or more selected from the group consisting of these.

[0016] Preferably, the acid anhydride curing agent is phthalic anhydride, maleic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, glutaric anhydride, dimethyl glutaric anhydride, diethyl glutaric anhydride, methylhexahydrophthalic anhydride, or methyltetrahydrophthalic anhydride, and provides a solventless thermosetting quantum dot resin composition characterized by being any one or more selected from the group consisting of these.

[0017] Preferably, the curing accelerator is a tertiary amine, an imidazole compound, a quaternary phosphonium salt, an organometallic salt, or a phosphorus compound, and provides a solventless thermosetting quantum dot resin composition characterized by being any one or more selected from the group consisting of these.

[0018] Preferably, it further contains an inorganic filler, and the inorganic filler is silica, zinc oxide, alumina, calcium carbonate, barium carbonate, barium sulfate, zinc sulfate, zinc sulfide, magnesium oxide, or antimony oxide, and provides a solventless thermosetting quantum dot resin composition characterized by being any one or more selected from the group consisting of these.

[0019] In another embodiment of the present invention, a quantum dot resin composite produced from the solventless thermosetting quantum dot resin composition is provided.

[0020] In another embodiment of the present invention, there is provided an LED package including an LED chip and a light conversion layer formed on the LED chip and manufactured from the solvent-free thermosetting quantum dot resin composition.

[0021] In still another embodiment of the present invention, there is provided a display device including the LED package.

Advantages of the Invention

[0022] The solvent-free thermosetting quantum dot resin composition according to the present invention and the quantum dot resin composite manufactured therefrom are excellent in durability. Therefore, when applied to an LED package and a display device, the ability to maintain optical properties is excellent even after long-term use.

[0023] In addition, the solvent-free thermosetting quantum dot resin composition according to the present invention has excellent miscibility between quantum dots and resin without containing a solvent, can achieve various viscosities, and can manufacture a display device under various process conditions.

Modes for Carrying Out the Invention

[0024] Hereinafter, the present invention will be described. All terms (including technical and scientific terms) used in this specification can be used in a meaning commonly understood by those skilled in the technical field to which the present invention pertains, unless otherwise defined. Also, terms generally used and defined in a dictionary should not be interpreted ideally or excessively unless specifically defined.

[0025] Also, throughout this specification, when a part is said to "include" a certain component, this means that, unless otherwise stated to the contrary, it does not exclude other components but may further include other components.

[0026] Also, throughout this specification, the optical properties include the luminance (Lv) and chromaticity (Cx, Cy) of the display.

[0027] <Solvent-Free Thermosetting Quantum Dot Resin Composition> The quantum dot resin composition according to an embodiment of the present invention is a solvent-free thermosetting quantum dot resin composition. Specifically, it has excellent miscibility between quantum dots and resin without containing a solvent, can achieve various viscosities, and can manufacture display devices under various process conditions.

[0028] As a specific example, a solvent-free thermosetting quantum dot resin composition is provided, which includes quantum dots, an epoxy resin, an acid anhydride curing agent, and a curing accelerator, and the epoxy resin includes a dicyclopentadiene (DCPD) type epoxy resin.

[0029] When a dicyclopentadiene type epoxy resin is included, it has high durability and excellent light property maintaining ability even after long-term use. Also, even when triglycidyl isocyanurate is further included in the dicyclopentadiene type epoxy resin, the effect of maintaining light property can be obtained after long-term use.

[0030] Preferably, when a (meth)acrylate functional group is further included in the dicyclopentadiene type epoxy resin, it has high adhesiveness and excellent barrier properties (moisture absorption resistance), better durability, and thus the light properties are well maintained even after long-term use. Also, it can have low viscosity characteristics, and uniform dispersion of quantum dots is possible without containing a solvent, enabling realization of various viscosities.

[0031] The quantum dot resin composition according to an embodiment of the present invention may further include an inorganic filler to impart thixotropy.

[0032] The quantum dot resin composition according to an embodiment of the present invention may be included with 1 to 30 parts by weight of quantum dots, 1 to 50 parts by weight of epoxy resin, 1 to 50 parts by weight of acid anhydride curing agent, and 0.05 to 1 part by weight of curing accelerator.

[0033] The quantum dot resin composition according to one embodiment of the present invention may contain 1 to 30 parts by weight of quantum dots, 1 to 50 parts by weight of an epoxy resin, 1 to 50 parts by weight of an acid anhydride curing agent, 0.05 to 1 part by weight of a curing accelerator, and 0.1 to 20 parts by weight of an inorganic filler.

[0034] Hereinafter, the composition of the solvent-free thermosetting quantum dot resin composition of the present invention will be specifically described.

[0035] Epoxy resin The epoxy resin in the present invention preferably essentially contains a dicyclopentadiene (DCPD) type epoxy resin and may further contain triglycidyl isocyanurate (TGIC). Further, the dicyclopentadiene (DCPD) type epoxy resin may contain a (meth) acrylate functional group. "(Meth) acrylate" means acrylate and methacrylate.

[0036] The DCPD type epoxy resin is an epoxy resin derived from dicyclopentadiene and means an epoxy resin having two or more epoxy groups per molecule.

[0037] When the DCPD type epoxy resin is included, the adhesion is good and the barrier properties are excellent, preventing external air and moisture from penetrating into the quantum dot resin composition, and improving the durability and light property retention rate of the quantum dot resin composition. Further, when a DCPD type epoxy resin containing one or more (meth) acrylate functional groups is used, the adhesion and barrier properties are further improved, thereby greatly improving the light property retention rate. This is presumably because in addition to the curing between the epoxy group and the curing agent, curing by the (meth) acrylate functional group is added, achieving a more complex and dense three-dimensional network structure.

[0038] Triglycidyl Isocyanurate (TGIC) can be cured in three directions, has excellent mechanical strength and heat resistance, and excellent adhesion and high-temperature performance. Therefore, when used in combination with DCPD-type epoxy resin, it is considered to be helpful for improving adhesion and barrier properties and has the effect of improving the light property retention rate. Although not described as a comparative example in this specification, compared with adding bisphenol A-type epoxy or alicyclic epoxy to DCPD-type epoxy resin, relatively excellent light stability was achieved when TGIC epoxy was applied.

[0039] In addition, according to the required physical properties such as heat resistance and chemical resistance, it can further contain any one or more selected from the group consisting of alicyclic epoxy resin, BPA-PO epoxy resin, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, novolac-type epoxy resin, nitrogen-containing epoxy resin, chain aliphatic epoxy resin, and naphthalene-type epoxy resin. For example, in order to enhance chemical resistance and heat resistance, bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, or novolac-type epoxy resin can be added, and in order to enhance weather resistance and tracking resistance, alicyclic epoxy resin can be added. BPA-PO epoxy resin can be used for the flexibility of the cured product, and chain aliphatic epoxy resin can be used to enhance mobility because it can achieve low viscosity, and naphthalene-type epoxy resin can be used to enhance low thermal expansion characteristics and moisture absorption resistance.

[0040] In the quantum dot resin composition, the total content of epoxy resin is 1 to 50 parts by weight, preferably 20 to 50 parts by weight, and more preferably 35 to 45 parts by weight. If the content of epoxy resin is less than 1 part by weight, the mechanical properties of the cured product may decrease, and if it exceeds 50 parts by weight, the light properties of the display may decrease.

[0041] The epoxy resin and the acid anhydride curing agent are contained in a weight ratio of 1:0.5 to 1:1.4, preferably 1:0.75 to 1:1.2, and more preferably 1:0.9 to 1:1.0. When the epoxy resin and the acid anhydride curing agent are contained in the above weight ratio, the light characteristic retention rate is improved, and particularly the luminance (Lv) retention rate is significantly improved.

[0042] Anhydride curing agent In the present invention, the acid anhydride curing agent reacts with the epoxy resin to form a three-dimensional network structure, improving the mechanical properties of the cured product. Just as the properties of the epoxy resin affect the properties of the composition and the final cured product, the properties of the curing agent used also affect the properties of the composition and the final cured product. However, when using an acid anhydride curing agent that is not an amine-based curing agent such as aliphatic diamine, polyamine, and aromatic diamine, the heat resistance is excellent.

[0043] In the present invention, the acid anhydride curing agent is any one or more selected from the group consisting of phthalic anhydride, maleic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, glutaric anhydride, dimethylglutaric anhydride, diethylglutaric anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride.

[0044] The content of the acid anhydride curing agent in the quantum dot resin composition is 1 to 50 parts by weight, preferably 20 to 50 parts by weight, and more preferably 35 to 45 parts by weight. If the content of the acid anhydride curing agent is less than 1 part by weight, the curing of the epoxy resin may be delayed or may not be cured sufficiently. If it exceeds 50 parts by weight, not only is there no benefit due to the excessive content, but the light characteristics of the display may deteriorate.

[0045] Curing accelerator The curing accelerator of the present invention plays a role in promoting the curing reaction between the epoxy resin and the acid anhydride curing agent. Specifically, any one or more selected from the group consisting of tertiary amines, imidazole compounds, quaternary phosphonium salts, organometallic salts, and phosphorus compounds are used.

[0046] The curing accelerator in the quantum dot resin composition has a content of 0.05 to 1.0 parts by weight, preferably 0.05 to 0.5 parts by weight, and more preferably 0.08 to 0.2 parts by weight. If the content of the curing accelerator is less than 0.05 parts by weight, a sufficient curing acceleration effect cannot be obtained, and if it exceeds 1.0 parts by weight, the cured product may discolor.

[0047] Quantum dot Quantum Dots (QD) are nano-sized semiconductor materials and have different energy band gaps depending on their size and composition, so they emit light of various emission wavelengths.

[0048] This quantum dot can be a homogeneous monolayer structure; a multi-layer structure such as a core-shell form or a gradient structure; or a mixed structure thereof. When the shell has a plurality of layers, each layer can contain different components, for example, (quasi) metal oxides.

[0049] The quantum dots (QD) are freely selected from II-VI group compounds, III-V group compounds, IV-VI group compounds, group IV elements, group IV compounds, and combinations thereof. When the quantum dot is in the form of a core-shell, the core and the shell can be freely composed of the following exemplary components respectively.

[0050] As an example, the II-VI group compounds can be selected from the group consisting of binary compounds selected from the group consisting of CdO, CdS, CdSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; ternary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof; and quaternary compounds selected from the group consisting of CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and mixtures thereof.

[0051] As another example, the III-V group compounds can be selected from the group consisting of binary compounds selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb and mixtures thereof; ternary compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlSb, InAlPAs, InAlPsb, and mixtures thereof.

[0052] As another example, the group-IV-VI compounds can be selected from the group consisting of binary compounds selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

[0053] As another example, the group-IV elements can be selected from the group consisting of Si, Ge, and mixtures thereof. The group-IV compounds can be binary compounds selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0054] The aforementioned binary, ternary, or quaternary compounds may be present in the particles at a uniform concentration or may be present in the same particles in a state where the concentration distribution is partially different. Also, one quantum dot may have a core / shell structure surrounding the other quantum dot. The interface between the core and the shell can have a concentration gradient in which the concentration of the elements present in the shell decreases towards the center.

[0055] The form of the quantum dots is not particularly limited as long as it is a form commonly used in the art. As an example, those in the form of spherical, rod-shaped, pyramid-shaped, disc-shaped, multi-arm-shaped, or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplates, etc. can be used.

[0056] Also, the size of the quantum dots is not particularly limited and can be appropriately adjusted within the normal range known in the art. In one example, the average particle size D of the quantum dots 50It can be about 2 to 10 nm. When the particle size of the quantum dots is controlled within the range of about 2 to 10 nm in this way, light of a desired color can be emitted. For example, when the particle size of the quantum dot core / shell containing InP is about 5 to 6 nm, light with a wavelength of about 520 to 550 nm is emitted, while when the particle size of the quantum dot core / shell containing InP is about 7 to 8 nm, light with a wavelength of about 620 to 640 is emitted. For example, as blue light-emitting QDs (Quantum dots), non-cadmium (Cd)-based group III-V QDs (e.g., InP, InGaP, InZnP, GaN, GaAs, GaP) can be used.

[0057] In this specification, the quantum dots can include any one or more selected from the group consisting of the aforementioned quantum dot nanoparticles, quantum dot-containing particles, primary particles formed by joining a plurality of quantum dot particles, and quantum dot composite particles.

[0058] In a specific example, the quantum dot-containing particles are particles containing at least one quantum dot, and specifically, can be in a form including at least one quantum dot particle bound to the surface of an inorganic core particle or a polymer core particle.

[0059] In another embodiment, the primary particles can be particles in which a plurality of quantum dots are aggregated, or particles in a form in which a plurality of quantum dots are embedded in a matrix. Such a matrix can be a normal inorganic or organic substance known in the art.

[0060] The primary particles can further include normal thermally conductive inorganic particles known in the art. Since such inorganic particles have excellent thermal conductivity, they play a role in releasing the self-heat of the quantum dots to the outside.

[0061] Non-limiting examples of thermally conductive inorganic particles that can be used include aluminum oxide, silicon oxide, titanium dioxide, aluminum nitride, boron nitride, silicon nitride, silicon carbide, aluminum oxide, or a mixture of two or more.

[0062] The average particle size (D 50 ) of the thermally conductive inorganic particles is not particularly limited and can be appropriately adjusted within the range known in the art. As an example, the average particle size of the thermally conductive inorganic particles is 1 to 100 μm, specifically 1 to 50 μm. At this time, two or more kinds of thermally conductive inorganic particles having different average particle sizes or different components can also be mixed and used.

[0063] The content of such thermally conductive inorganic particles is not particularly limited and can be appropriately adjusted in consideration of the heat generation characteristics.

[0064] As an example, the content of the thermally conductive inorganic particles is 0.1 to 99.9 parts by weight, specifically 0.5 to 99.5 parts by weight, based on the total weight of the primary particles (for example, 100 parts by weight). Further, the thermally conductive inorganic particles are 1 to 100,000 parts by weight, specifically 100 to 100,000 parts by weight, based on 100 parts by weight of the quantum dots to be mixed.

[0065] The quantum dot composite particles may include a surface treatment layer containing at least one of a halide and an oxyhalide between the quantum dots and the polymer coating layer. Specifically, it may be one in which quantum dots; the (oxy)halide surface treatment layer bonded to the surface of the quantum dots; and the (meth)acrylic polymer coating layer are sequentially formed.

[0066] The surface treatment layer can contain, without limitation, halogen (X = F, Cl, Br, I)-containing substances known in the art. As an example, it can be at least one halogen salt of fluoride, chloride, bromide, and iodide. Specifically, it can include organic halides, inorganic halides, inorganic oxyhalides, or combinations thereof.

[0067] Non-limiting examples of halogen-containing substances that can be used include, for example, tetrabutylammonium bromide, cetyltrimethylammonium bromide, cetylammonium bromide (CTAB: Cetyl Ammonium Bromide), ammonium chloride, ammonium bromide, ammonium iodide, ammonium fluoride, potassium chloride, potassium bromide, potassium iodide, sodium chloride, sodium bromide, sodium iodide, indium chloride, indium bromide, indium iodide, and the like. These components can be used alone or in combination of two or more.

[0068] As the polymer, ordinary acrylic or methacrylic polymers known in the art can be used without limitation. Specifically, it is preferable to use a (meth)acrylic polymer containing polar functional groups in the molecule within a predetermined range.

[0069] As a specific example, the (meth)acrylic polymer is a polymer of a (meth)acrylic monomer or a (meth)acrylic resin in which the content of at least one polar functional group selected from carboxyl groups and hydroxyl groups in the molecule is 1 part by weight or more, specifically 1 to 50 parts by weight, and the molecular weight (Mw) is 5,000 g / mol or more, specifically 10,000 to 500,000 g / mol.

[0070] The quantum dots used in the present invention can refer to Korean Patent Publication No. 10-2021-0033160 within the scope not conflicting with this specification.

[0071] The content of the quantum dots in the quantum dot resin composition is 1 to 30 parts by weight, preferably 5 to 25 parts by weight, and more preferably 10 to 20 parts by weight. If the content of the quantum dots exceeds 30 parts by weight, the coating properties and optical properties may deteriorate.

[0072] Arming filler The inorganic filler in the present invention is used together with an epoxy resin and an acid anhydride curing agent, and can improve mechanical properties such as reducing the thermal expansion coefficient and the curing shrinkage rate of the composition and the final cured product, improve adhesion, and impart thixotropy to the composition.

[0073] In the present invention, the inorganic filler can be selectively used according to the required process. Specifically, for applying the quantum dot resin composition according to the present invention in a dome shape on an LED chip, it can be used for the purpose of imparting thixotropy to the composition.

[0074] The inorganic filler that can be used can be any one or more selected from the group consisting of silica, zinc oxide, alumina, calcium carbonate, barium carbonate, barium sulfate, zinc sulfate, zinc sulfide, magnesium oxide, and antimony oxide.

[0075] When the quantum dot resin composition contains an inorganic filler, its content is 0.1 to 20 parts by weight, preferably 0.1 to 15 parts by weight, and more preferably 0.1 to 10 parts by weight. If the content of the inorganic filler exceeds 20 parts by weight, the coating properties may deteriorate.

[0076] Physical properties The quantum dot resin composition according to the present invention has a light property maintenance rate of 80% or more, preferably 90% or more, in terms of light properties such as luminance (Lv) and color coordinates (Cx, Cy). The light property maintenance rate is calculated by the following formula 1.

[0077] Formula 1 Light property maintenance rate (%) = (Light properties after 1000 hours of display driving / Display light properties before driving) × 100

[0078] Method for producing a quantum dot resin composition The quantum dot resin composition according to the present invention can be produced by mixing an epoxy resin, an acid anhydride curing agent, a curing accelerator, and quantum dots at room temperature. In order to impart thixotropy, an inorganic filler can be further mixed and produced together.

[0079] <Quantum Dot Resin Composite, LED Package, and Display Device> On the other hand, the present invention provides a quantum dot resin composite produced from the above-described solventless thermosetting quantum dot resin composition.

[0080] Further, the present invention provides an LED package including an LED chip and a light conversion layer formed on the LED chip and produced from the above-described solventless thermosetting quantum dot resin composition.

[0081] Furthermore, the present invention provides a display device including the above-described LED package.

[0082] Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited by the examples.

[0083] <Example 1> Epoxy resin 1 (EP-4088S, ADEKA), acid anhydride curing agent (methylhexahydrophthalic anhydride, MH-700G, Shin-Nippon Rika), curing accelerator (quaternary phosphonium salt), inorganic filler (SiO2, EVONIK), and quantum dot composite particles surface-treated with chloride (according to Example 1 of Korean Patent Publication No. 10-2021-0033160) were mixed to produce a solventless thermosetting quantum dot resin composition. Epoxy resin 1 is a DCPD-type epoxy resin and contains a methacrylate functional group. The composition ratios are shown in Table 1 below.

[0084] <Examples 2 and 3> They were produced in the same manner as in Example 1, except that the contents of epoxy resin 1 and the acid anhydride curing agent were changed.

[0085] <Examples 4 and 5> They were produced in the same manner as in Example 1, except that epoxy resin 1 and epoxy resin 2 (TGIC, TEPIC-S, Nissan Chemical) were mixed and used with different composition ratios, respectively.

[0086] <Comparative Example 1 and Comparative Example 2> Epoxy resin 2 and epoxy resin 3 (C-2021P, Daicel Corporation) were produced in the same manner as in Example 1, except that they were mixed and used with different composition ratios. Epoxy resin 3 is one of the alicyclic epoxies and is 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate.

[0087]

Table 1

[0088] <Evaluation of the ability to maintain optical properties (Lv, Cx, Cy)> After applying the quantum dot resin compositions produced in Examples 1 to 5 and Comparative Examples 1 and 2 to the LED chips on the PCB substrate, they were cured at about 190°C for about 5 minutes to fabricate display devices. The initial optical property values (Lv, Cx, Cy) before driving and the optical property values after driving for 1,000 hours of the fabricated display devices were measured using an optical property measuring device (CA410), and the optical property retention rate was calculated by the following formula 1. The results are shown in Table 2.

[0089] Formula 1 Optical property retention rate (%) = (Optical property after 1000 hours of display driving / Display optical property before driving) × 100

[0090]

Table 2

[0091] When Examples 1 to 5 were compared with the Comparative Examples, in all the light characteristics (Lv, Cx, Cy), the light characteristic retention rates of the Comparative Examples were not as good as those of Examples 1 to 5. Particularly in the items of Lv and Cy, the physical properties were not significantly good. On the other hand, Examples 1 to 5 all showed a retention rate of 80% or more in all items, and most of the Examples showed an excellent retention rate of 90% or more.

[0092] In Examples 1 to 5, the higher the ratio of the DCPD type epoxy resin, the more excellent the light characteristic retention rate. When only the DCPD type epoxy resin was used as in Examples 1 to 3, the Lv retention rate was 99% or more.

[0093] In Examples 1 to 3, when the weight ratio of the epoxy resin to the curing agent was about 1:0.94 (Example 1), the retention rate was more excellent in all items.

[0094] It is obvious to those skilled in the technical field to which the present invention pertains that the present invention is not limited to the above Examples, and various changes or modifications can be made within the scope not exceeding the technical gist of the present invention.

Claims

1. A solvent-free thermosetting quantum dot resin composition comprising a quantum dot, an epoxy resin, an acid anhydride curing agent, and a curing accelerator, wherein the epoxy resin comprises a dicyclopentadiene type epoxy resin.

2. The solvent-free thermosetting quantum dot resin composition according to claim 1, wherein the epoxy resin further comprises triglycidyl isocyanurate.

3. The solvent-free thermosetting quantum dot resin composition according to claim 1, wherein the dicyclopentadiene type epoxy resin comprises a (meth)acrylate functional group.

4. The solvent-free thermosetting quantum dot resin composition according to claim 1, wherein the epoxy resin and the acid anhydride curing agent are contained in a weight ratio of 1:0.5 to 1:1.

4.

5. The solvent-free thermosetting quantum dot resin composition according to claim 1, wherein the light property retention rate calculated by the following formula 1 is 80% or more. [Formula 1] Light property retention rate (%) = (Light property after 1000 hours of display driving / Display light property before driving) × 100

6. The quantum dot is 1 to 30 parts by weight, the epoxy resin is 1 to 50 parts by weight, the acid anhydride curing agent is 1 to 50 parts by weight, The solvent-free thermosetting quantum dot resin composition according to claim 1, wherein the curing accelerator is 0.05 to 1 part by weight.

7. The epoxy resin is Further comprising any one or more selected from the group consisting of alicyclic epoxy resins, BPA-PO epoxy resins, bisphenol A-type resins, bisphenol F-type epoxy resins, novolac-type epoxy resins, nitrogen-containing epoxy resins, chain aliphatic epoxy resins, and naphthalene-type epoxy resins. The solventless thermosetting quantum dot resin composition according to claim 1.

8. The acid anhydride curing agent is Any one or more selected from the group consisting of phthalic anhydride, maleic anhydride, trimellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, glutaric anhydride, dimethyl glutaric anhydride, diethyl glutaric anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. The solventless thermosetting quantum dot resin composition according to claim 1.

9. The curing accelerator is Any one or more selected from the group consisting of tertiary amines, imidazole compounds, quaternary phosphonium salts, organometallic salts, and phosphorus compounds. The solventless thermosetting quantum dot resin composition according to claim 1.

10. Further comprising an inorganic filler, The inorganic filler is any one or more selected from the group consisting of silica, zinc oxide, alumina, calcium carbonate, barium carbonate, barium sulfate, zinc sulfate, zinc sulfide, magnesium oxide, and antimony oxide. The solventless thermosetting quantum dot resin composition according to claim 1.

11. A quantum dot resin composite produced from the solventless thermosetting quantum dot resin composition according to any one of claims 1 to 10.

12. An LED chip; and An LED package comprising: a light conversion layer formed on the LED chip and manufactured from the solventless thermosetting quantum dot resin composition according to any one of claims 1 to 10.

13. A display device comprising the LED package according to claim 12.

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