Color conversion pixel, composition for color conversion pixel, and display device including the same

Abstract

Provided are a color conversion pixel including quantum dots and a color material, a composition for the color conversion pixel, and a display device including the color conversion pixel.

Description

Technical Field

[0001] The present invention relates to a color conversion pixel comprising quantum dots and color materials, a composition for the color conversion pixel, and a display device comprising the color conversion pixel. Background Technology

[0002] Recent display devices include liquid crystal displays (LCDs) and organic light-emitting diode (OLEDs). These differ in how each pixel is driven. To display dynamic images, LCDs use a material called liquid crystal to control the color represented by each pixel, while OLEDs achieve dynamic images by applying an electric current to each pixel to generate light, thus displaying the colors within each pixel over time, creating multiple frames. Furthermore, existing LCDs may differ depending on whether the light source is a CCFL (cold cathode fluorescent lamp) or an LED (light-emitting diode), and OLEDs can be categorized into RGB OLEDs, where each pixel independently generates color, and WOLEDs (white OLEDs), which combine with a color filter (CF).

[0003] To achieve the desired color, a light source and a suitable color filter are required. Currently, methods using pigments, dyes, and other colorants are commonly employed. In existing technologies, colorants used in displays utilize the transmission and absorption characteristics of specific wavelengths. For example, Pigment Red 254, a colorant for red, has absorption characteristics in the blue and green regions and transmission characteristics in the red region, thus it may be perceived as red in the general visible light region (wavelength range: 380 to 780 nm). However, using pigments alone makes it difficult to meet high-quality requirements such as high brightness, high contrast, and high definition, and using dyes alone results in reduced heat resistance and lightfastness.

[0004] On the other hand, quantum dots, which have been extensively studied recently, are particles with unique properties due to their small size, down to a few nanometers. In addition to exhibiting photoluminescence (PL) properties, which allow them to receive light and emit it at longer wavelengths, they have also been studied for their electrical conductivity (EL) properties, which allow them to generate light through electrical injection. Due to these properties, numerous studies have been conducted to utilize quantum dots as display materials. Early research involved developing sheets incorporating quantum dots and investigating structures that used existing color filters to convert blue light sources into white light sources. More recently, the color conversion characteristics of each pixel have been studied. For example, Korean Patent Application Publication No. 10-2018-0030353, which relates to a photoresist composition and a color filter using that composition, investigated a method where a blue pixel renders the blue light source as is, a green quantum dot pixel renders the blue light source as a green light source, and a red quantum dot pixel renders the blue light source as a red light source.

[0005] However, if the known color-conversion pixels lack partitions, the blue light from the backlight unit will leak into adjacent pixels, emitting blue light that has leaked from the red pixels, or generating light that has been converted to red due to the leakage of blue light encountering red quantum dots. Even within blue pixels, blue light generated for green quantum dots leaks from green pixels into adjacent blue pixels and out of the pixel. Therefore, even with existing color-conversion pixels, there is a problem of light leakage into adjacent pixels. Thus, to prevent interference from these adjacent pixels, partitions must be formed between each pixel to prevent color mixing caused by light leakage. Since the partitions used in the prior art are necessary to prevent light leakage, they are usually black, but it is difficult to fabricate thick patterns of black partitions. Furthermore, the formation of partitions inevitably reduces the pixel aperture ratio due to the area of ​​the partitions. Therefore, to improve the performance of each color-conversion pixel, it is necessary to develop a high-purity pixel that minimizes interference between pixels and does not cause color mixing, even without partitions. Summary of the Invention

[0006] Technical issues

[0007] The present invention aims to improve upon the problems of the prior art described above, and its object is to provide a color conversion pixel that minimizes interference between pixels and does not cause color mixing even in the absence of adjacent pixels, and presents color purity, a composition for manufacturing the color conversion pixel, and a display device including the color conversion pixel.

[0008] Technical solution

[0009] To achieve the above objectives, the present invention provides a color conversion pixel comprising quantum dots and color materials.

[0010] Furthermore, the present invention provides a composition for color conversion pixels, comprising: quantum dots; a colorant having a transmittance of more than 50% in at least two wavelength regions of 450 nm, 540 nm and 640 nm; a monomer; a binder; an initiator; and additives.

[0011] Furthermore, the present invention provides a display device including color conversion pixels.

[0012] Invention Effects

[0013] The color conversion pixel of this invention comprises quantum dots and a color material with high transmittance to a specific wavelength region, thereby providing the following effects: minimizing light interference between each pixel, preventing color mixing even in the absence of interlayers, and improving color purity.

[0014] Furthermore, since there is no need to form partitions, the manufacturing process of color filters is simplified, thereby increasing the aperture ratio of pixels and enabling the production of pixels. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the color conversion pixel according to the present invention.

[0016] Figure 2 This is a graph showing the transmittance of a color material included in a color conversion pixel according to an embodiment of the present invention, based on wavelength.

[0017] Figure 3 The transmission spectra of common blue, green, and red pigments are shown. Detailed Implementation

[0018] The best embodiment of the present invention

[0019] This invention relates to a color conversion pixel comprising quantum dots and color materials, a color filter comprising the color conversion pixel, and a display device comprising the color filter. The color conversion pixel of this invention may refer to a blue pixel, a green pixel, or a red pixel of the color filter.

[0020] The color conversion pixel of the present invention comprises quantum dots and a color material with high transmittance to a specific wavelength region, thereby providing the following effects: minimizing light interference between each pixel, preventing color mixing even in the absence of interlayers, and improving color purity.

[0021] Furthermore, the color filter including the color conversion pixel of the present invention does not require the formation of partitions between each pixel, thus simplifying the process. This allows for an increase in the pixel aperture ratio, and by suppressing the emission of quantum dots from an external light source, it is possible to manufacture pixels that convert colors into high-purity colors, and to manufacture display devices that include such color conversion pixels.

[0022] Color materials exhibit transmission and absorption properties at specific wavelengths. For example, red color materials are transmissive in the red region (above 600 nm) and can therefore be identified in the general visible light region (wavelength range: 380 to 780 nm), but exhibit absorption properties in other wavelength ranges. Similarly, green color materials are transmissive in the green region (500 to 560 nm) and can therefore be identified as green in the visible light region, but exhibit absorption properties in other wavelength regions.

[0023] On the other hand, quantum dots convert blue light into light of a specific wavelength (converting short-wavelength light into long-wavelength light), red quantum dots are used to absorb blue light from red pixels and convert it into red light, and green quantum dots absorb blue light from green pixels and convert it into green light.

[0024] When common colorants are introduced to improve the color purity performance of pixels including quantum dots, for example, when red quantum dots and red colorants are used simultaneously to manufacture pixels, the red colorant, as described above, has absorption properties for both blue and green light. Therefore, the red colorant absorbs and hinders the absorption of blue light by the red quantum dots, thus degrading the pixel's performance. Therefore, using colorants typically used in red or green pixels together with quantum dots as a composition for manufacturing color-conversion pixels is not preferred.

[0025] Therefore, the color conversion pixel of the present invention includes a color conversion pixel comprising quantum dots and a color material, and specifically includes a color conversion pixel comprising quantum dots and a color material capable of preventing color mixing between pixels, and more specifically includes a color conversion pixel comprising quantum dots and a color material having high transmittance to two specific wavelength regions. Therefore, even without partitions, the color purity of each pixel can be improved, and the effect of preventing color mixing can be obtained. By using such a color conversion pixel, a display device with improved color can be provided.

[0026] <Color to Pixel Conversion>

[0027] The color conversion pixel of the present invention includes a color conversion pixel comprising quantum dots and a color material, and preferably includes quantum dots and a color material having high transmittance to two specific wavelength regions.

[0028] quantum dots

[0029] The color conversion pixels of this invention include quantum dots.

[0030] The quantum dots of this invention are not particularly limited to any quantum dot particle capable of emitting light upon stimulation by light or electricity. For example, they can be selected from the group consisting of: group II-VI semiconductor compounds; group III-V semiconductor compounds; group IV-VI semiconductor compounds; group IV elements or compounds containing such elements; and combinations thereof, which can be used alone or in combination of two or more.

[0031] For example, II-VI semiconductor compounds may include: binary compounds selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; and ternary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, and CdZnS. e, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe and mixtures thereof; and quaternary compounds selected from, but not limited to, the group consisting of CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0032] III-V semiconductor compounds may include: 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, GaAlNP, and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof, but are not limited thereto.

[0033] IV-VI semiconductor compounds may include: 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, but are not limited thereto.

[0034] Although not limited to this, Group IV elements or compounds containing such elements may be selected from the group consisting of: elements selected from the group consisting of Si, Ge and mixtures thereof; and binary compounds selected from the group consisting of SiC, SiGe and mixtures thereof.

[0035] Quantum dots can have a uniform single structure; a core-shell structure, a gradient structure, or a hybrid structure thereof; and in this invention, quantum dots are not particularly limited as long as they can emit light upon stimulation by light.

[0036] According to one embodiment, the quantum dot has a core-shell structure, and the core may include at least one selected from the group consisting of InP, InZnP, InGaP, CdSe, CdS, CdTe, ZnS, ZnSe, ZnTe, CdSeTe, CdZnS, CdSeS, PbSe, PbS, PbTe, AgInZnS, HgS, HgSe, HgTe, GaN, GaP, GaAs, InGaN, InAs, and ZnO, and the core may include ZnS, ZnSe, ZnT At least one of the following groups: e, ZnO, CdS, CdSe, CdTe, CdO, InP, InS, GaP, GaN, GaO, InZnP, InGaP, InGaN, InZnSCdSe, PbS, TiO, SrSe, and HgSe, preferably including at least one of the following groups: InP / ZnS, InP / ZnSe, InP / GaP / ZnS, InP / ZnSe / ZnS, InP / ZnSeTe / ZnS, and InP / MnSe / ZnS.

[0037] Quantum dots can typically be fabricated using wet chemical processes, metal-organic chemical vapor deposition (MOCVD), or molecular beam epitaxy (MBE).

[0038] Wet chemistry is a method of growing particles by placing precursor materials in an organic solvent. When the crystal grows, the organic solvent is naturally coordinated on the surface of the quantum dot crystal, acting as a dispersant to control the growth of the crystal. Therefore, the size growth of quantum dot particles can be controlled more easily and cheaper than vapor deposition methods such as organometallic chemical vapor deposition or molecular beam epitaxy.

[0039] Depending on the manufacturing purpose of the green, red, and blue pixels, green quantum dots, red quantum dots, and blue quantum dots can be used respectively.

[0040] Specifically, the quantum dot can be a green quantum dot, which refers to a material that absorbs blue light and converts it into green light. Generally, any quantum dot material used to manufacture green pixels can be used without restriction. For example, the center wavelength of the green quantum dot can be 500 to 560 nm, preferably 520 nm to 550 nm, and most preferably about 540 nm.

[0041] Furthermore, the quantum dot can be a red quantum dot, which refers to a substance that absorbs blue light and converts it into red light. Generally, any quantum dot material used to manufacture red pixels can be used without restriction. For example, the center wavelength of the red quantum dot can be above 600 nm, preferably 600 nm to 700 nm, and most preferably about 640 nm.

[0042] Furthermore, the quantum dot can be a blue quantum dot, which refers to a material that emits blue light. Generally, any quantum dot material used to manufacture blue pixels can be used without restriction. For example, the center wavelength of the blue quantum dot can be below 500 nm, preferably 400 nm to 500 nm, and most preferably about 450 nm.

[0043] color material

[0044] The color conversion pixel of the present invention includes a color material.

[0045] The colorant preferably has a transmittance of 50% or more in at least two wavelength regions of 450nm, 540nm, and 640nm, more preferably 60% or more, and most preferably 70% or more. Furthermore, the colorant has a transmittance of 50% or less in at least one region of 450nm, 540nm, and 640nm, preferably 30% or less, and most preferably 5% or less.

[0046] The colorant of the present invention has a transmittance of more than 50% in at least two wavelength regions of 450nm, 540nm, and 640nm, more preferably more than 60%, and most preferably more than 70%, and a transmittance of less than 50% in one region, preferably less than 30%, and most preferably less than 5%.

[0047] The colorant has a transmittance of more than 50% in the wavelength regions of 450nm and 540nm, more preferably more than 60%, and most preferably more than 70%, and a transmittance of more than 50% in the wavelength regions of 450nm and 640nm, more preferably more than 60%, and most preferably more than 70%.

[0048] The transmittance of the colorant according to wavelength according to an embodiment of the present invention is as follows: Figure 2 As shown.

[0049] Specifically, when the quantum dot is a green quantum dot, the color material can have a transmittance of more than 50% in the wavelength regions of 450nm and 540nm, and a transmittance of less than 50% in the wavelength region of 640nm. Preferably, it is a cyan color material. In this case, the color conversion pixel of the present invention can be a green pixel. The cyan color material can be used without restriction as long as it is a known color material that is identified as cyan in the visible light region, and includes cyan pigments and cyan dyes. For example, the cyan dye can be Acid Blue 90, Acid Blue G 4061 (Sinochem Tianjin Imp Exp Corp), Acid Blue GN (Jagson Colorchem Ltd), Acid Brilliant Blue G (Sinochem Ningbo Imp & Exp Corp), Acid Brilliant Blue G (Nanjing Chemicals Import and Export Corp), Brighten Colorchem BV, etc., and the cyan pigment can be Polar Blue G (Ciba Specialty Chemicals Inc), Polar Blue G-Ol (Ciba Specialty Chemicals Inc), Ricolan Cyanine G (Rite Industries Inc.), Sandolan Cyanine NG (Clariant GmbH), etc.

[0050] For example, in a green pixel of one embodiment, the color material absorbs red light, transmits blue and green light, and converts the blue light transmitted through the green quantum dots into green light, thereby improving the color purity of the green pixel.

[0051] Furthermore, when the quantum dots are red quantum dots, the color material can have a transmittance of more than 50% in the wavelength regions of 450nm and 640nm, and a transmittance of less than 50% in the wavelength region of 540nm. Preferably, it is a magenta color material. In this case, the color conversion pixel of the present invention can be a red pixel. The magenta color material can be used without restriction as long as it is a known color material that is identified as magenta in the visible light region. The magenta color material includes magenta dyes and magenta pigments. For example, the magenta dyes can include Acid Magenta IIS (British Dyestuffs Corporation, BDC), Magenta S (Interessen Gemeinschaft Farbenindustrie AG, IG), etc., and the magenta pigments can be Diamond Magenta I, Magenta A pdr, Magenta AB pdr (Interessen Gemeinschaft Farbenindustrie AG), etc.

[0052] For example, in a red pixel of one embodiment, the color material absorbs green light, transmits blue and red light, and converts the blue light transmitted through the red quantum dot into red light, thereby improving the color purity of the red pixel.

[0053] <The composition of color conversion pixels>

[0054] The color conversion pixel of the present invention can be prepared from a composition for color conversion pixels comprising quantum dots and color materials, and the composition for color conversion pixels of the present invention may also include one or more of monomers, binders, initiators, additives and solvents in addition to quantum dots and color materials.

[0055] quantum dots

[0056] The description of the quantum dots in the color conversion pixel also applies to the composition used for the color conversion pixel.

[0057] The quantum dot content can be 5 to 40% by weight, preferably 10 to 30% by weight, relative to the solid components in the composition used for color conversion pixels.

[0058] color material

[0059] The description of the colorant used in the color conversion pixel can also be applied to the composition used in the color conversion pixel.

[0060] The colorant content may be 1 to 20% by weight, preferably 1.5 to 10% by weight, relative to the solid components in the composition used for color conversion pixels.

[0061] monomer

[0062] The color conversion pixel according to embodiments of the present invention may further comprise monomers. The monomers impart suitable viscosity characteristics to the composition, and free radicals generated by the initiator described later form the structure through the monomers.

[0063] The monomer is selected from at least one of the following substances: trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethoxylated dipentaerythritol hexa(meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, and dipentaerythritol (poly)acrylate, preferably, dipentaerythritol hexaacrylate.

[0064] The content of the monomer can be 20 to 60% by weight, preferably 25 to 50% by weight, relative to the solid components in the composition used for color conversion pixels.

[0065] adhesives

[0066] The color conversion pixel according to an embodiment of the present invention may further include an adhesive.

[0067] The adhesive may include acrylic adhesive resins, cardo-based adhesive resins, epoxy resins, or combinations thereof, for example, preferably using a resin having a structure represented by the following chemical formula 1, but not limited thereto.

[0068] [Chemical Formula 1]

[0069]

[0070] In the above chemical formula 1, p is an integer from 3 to 15, and * represents a bonding bond.

[0071] The content of the adhesive can be 20 to 60% by weight, preferably 25 to 50% by weight, relative to the solid components in the composition used for color conversion pixels.

[0072] Initiator

[0073] The color conversion pixel according to an embodiment of the present invention may further include an initiator.

[0074] In one embodiment of the invention, the initiator can be used without particular limitation on its type, as long as it is a monomer capable of polymerization. Specifically, considering factors such as polymerization characteristics, initiation efficiency, absorption wavelength, availability, and price, the initiator is preferably at least one compound selected from the group consisting of acetophenone compounds, benzophenone compounds, triazine compounds, biimidazole compounds, oxime compounds, and thioxanone compounds.

[0075] The initiator content can be 1 to 10% by weight, preferably 1.5 to 5% by weight, relative to the total content of the composition used for color conversion pixels.

[0076] additive

[0077] The color conversion pixels according to embodiments of the present invention may further include additives.

[0078] The additive may include at least one selected from the group consisting of other polymers, epoxy additives (curing agents), and leveling agents.

[0079] Specific examples of the other polymer compounds mentioned above include curable resins such as epoxy resins and maleimide resins; thermoplastic resins such as polyvinyl alcohol, polyacrylic acid, polyethylene glycol monoalkyl ethers, polyfluoroalkyl acrylates, polyesters, and polyurethanes.

[0080] The curing agent is used for deep curing and improving mechanical strength, and specific examples include epoxy compounds, polyfunctional isocyanate compounds, melamine compounds, and oxetane compounds.

[0081] Specific examples of epoxy compounds in the curing agent include bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol F epoxy resin, phenolic varnish epoxy resin, other aromatic epoxy resins, alicyclic epoxy resins, glycidyl ester-based resins, glycidyl amino-based resins, or brominated derivatives of these epoxy resins, aliphatic, alicyclic, or aromatic epoxy compounds other than epoxy resins and their brominated derivatives, butadiene (co)polymer epoxides, isoprene (co)polymer epoxides, (meth)acrylate glycidyl ester (co)polymers, triglycidyl isocyanurate, etc.

[0082] The curing agent can be used in conjunction with a curing aid compound capable of ring-opening polymerization of the epoxy groups of epoxy compounds and the oxetane skeleton of oxetane compounds. The curing aid compound includes, for example, polycarboxylic acids, polycarboxylic anhydrides, and acid-producing agents. Commercially available polycarboxylic anhydrides can be used as epoxy resin curing agents. Specific examples of epoxy resin curing agents include trade names (Adecahadona EH-700) (manufactured by Adeka Kogyo Co., Ltd.), (Rikasiddo HH) (manufactured by Shin Nippon Ewha Co., Ltd.), and (MH-700) (manufactured by Shin Nippon Ewha Co., Ltd.). The curing agents exemplified above can be used alone or in combination of two or more.

[0083] As the leveling agent, commercially available surfactants can be used to further improve the film-forming properties of the black photosensitive resin composition. Examples include silicone, fluorinated, ester, cationic, anionic, nonionic, and amphoteric surfactants, which can be used individually or in combination of two or more.

[0084] Those skilled in the art can appropriately add and use the additives without affecting the effects of the present invention. For example, the content of the additives may be 0.1 to 3% by weight, preferably 0.2 to 1% by weight, relative to the solid components in the composition for color conversion pixels.

[0085] solvent

[0086] The color conversion pixel according to an embodiment of the present invention may further include a solvent.

[0087] Solvents commonly used in the art can be used without particular limitation, provided that the solvent is effective in dissolving other components contained in the composition used for color conversion pixels. Specific examples of solvents may be selected from, but are not limited to, one or more of ethers, acetates, aromatics, ketones, alcohols, esters, and amides.

[0088] Specific examples of the ether solvents mentioned include: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, and other ethylene glycol monoalkyl ethers; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether, and other propylene glycol monoalkyl ethers; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, and other diethylene glycol dialkyl ethers, etc.

[0089] Specific examples of the acetate solvents mentioned include: methyl cellolytic acetate, ethyl cellolytic acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and other alkylene glycol alkyl ether acetates; methoxybutyl acetate, methoxypentyl acetate, n-pentyl acetate, and other alkoxyalkyl acetates, etc.

[0090] Examples of aromatic solvents include benzene, toluene, xylene, and mesitylene.

[0091] Specific examples of ketone solvents include: methyl ethyl ketone, acetone, methyl pentyl ketone, methyl isobutyl ketone, and cyclohexanone.

[0092] Specific examples of alcohol solvents include ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, and glycerol.

[0093] Specific examples of ester solvents include: cyclic esters such as γ-butyrolactone; ethyl 3-ethoxypropionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, etc.

[0094] Specific examples of amide solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0095] The solvent is preferably propylene glycol monomethyl ether acetate, but is not limited thereto.

[0096] The solvent content can be 100 to 400% by weight, preferably 150 to 300% by weight, relative to the solid components in the composition used for color conversion pixels.

[0097] Color filters and display devices

[0098] This invention relates to a color filter including the aforementioned color conversion pixel and a display device including the color filter. Furthermore, the display device and color filter of this invention are applicable to all the above-described contents regarding the color conversion pixel; although repeated detailed descriptions are omitted, the same description applies even if the description is omitted.

[0099] refer to Figure 1 The color filter included in the display device of the present invention includes a first pixel 21, a second pixel 22, and a third pixel 23 for forming different colors on a substrate 10, and at least one of the first to third pixels can be a color conversion pixel according to the present invention. For example, when light (e.g., blue light) 30 from the outside is incident on the color filter, red light, green light, and blue light can be emitted from the first pixel region, the second pixel region, and the third pixel region, respectively.

[0100] In one embodiment, such as Figure 1As shown, the color filter is formed with blue pixel 21, green pixel 22 and red pixel 23. Preferably, green pixel 22 and / or red pixel 23 are color conversion pixels according to the present invention, and both green pixel 22 and red pixel 23 are color conversion pixels according to the present invention.

[0101] In one embodiment, the color filter is formed with blue pixel 21, green pixel 22 and red pixel 23. Preferably, the blue pixel 21, green pixel 22 and / or red pixel 23 are color conversion pixels according to the present invention, and all of the blue pixel 21, green pixel 22 and red pixel 23 are color conversion pixels according to the present invention.

[0102] Since the color filter of the present invention includes the color conversion pixel according to the present invention, it may not include: the partition between the first pixel 21, the second pixel 22 and the third pixel 23 for dividing them, and the substrate 10 is preferably a transparent substrate such as glass.

[0103] In one embodiment, such as Figure 1 As shown, the color filter may not include: the partitions used to divide the blue pixel 21, green pixel 22 and red pixel 23.

[0104] Furthermore, the present invention provides a display device including the aforementioned color filter. The display device according to the present invention can utilize all structures known in the prior art, except for the color filter according to the present invention.

[0105] In one embodiment, the display device of the present invention includes a liquid crystal panel having a lower substrate, an upper substrate, and a liquid crystal layer disposed between the lower substrate and the upper substrate facing each other, and a backlight device for providing light. An image is formed onto the liquid crystal panel and a color filter, the color filter converting the wavelength of light emitted from the backlight device and transmitted through the liquid crystal panel to form color. Furthermore, the backlight device may include a light source 30 that emits blue light to provide blue light to the liquid crystal panel.

[0106] Embodiments of the present invention

[0107] In the following description, preferred embodiments, comparative examples, and experimental examples are presented to aid in understanding the invention. However, these embodiments, comparative examples, and experimental examples are for illustrative purposes only and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments, comparative examples, and experimental examples within the scope and spirit of the invention, and such changes and modifications obviously fall within the scope of the appended claims.

[0108] Preparation Examples 1 to 9: Preparation of Compositions for Color Conversion Pixels

[0109] The compositions prepared according to the compositions of Preparation Examples 1 to 9 were added sequentially according to the contents in Table 1, and the solvent, colorant, quantum dot, monomer, binder, initiator, epoxy resin and additive were mixed by rotating at 300 rpm for 30 minutes to prepare a composition for color conversion pixels.

[0110] In this preparation example, in order to prepare a composition for blue conversion pixels, the following were prepared: a white photosensitive resin composition using TiO2 as a scatterer (Preparation Example 1); a blue-white photosensitive resin composition using TiO2 as a scatterer and containing a blue pigment (Preparation Example 2); and a transparent organic composition of Preparation Example 3.

[0111] Table 1

[0112]

[0113]

[0114] White pigment: Pigment White 6 (DuPont TR-88) Blue pigment: Pigment Blue 15:6, Xcolor Pigment Company

[0115] Cyan pigment: a product of BCG.

[0116] Green pigment: Pigment Green 58

[0117] Magenta dye: Saujanya Dyestuff

[0118] Red pigment: Pigment Red 254

[0119] Green quantum dots (GQD): Nanolumi quantum dots, center wavelength 530nm, FWHM 30nm.

[0120] Red quantum dot (RQD): Nanolumi quantum dot, center wavelength 640nm, FWHM 38nm.

[0121] Monomer: Dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.)

[0122] Adhesive: Adhesive of Chemical Formula 2 in Synthesis Example 1

[0123] Initiator: Irgacure OXE03 (BASF)

[0124] Epoxy resin: Diethylene glycol diglycidyl ether (Daicel)

[0125] Additives: Leveling agent (F475, DIC Company)

[0126] Solvent: Propylene glycol monomethyl ether acetate (PGMEA)

[0127] Synthesis Example 1: Synthesis of Adhesive Resin of Chemical Formula 2

[0128] Place the white solid powder of the following chemical formula 1-1 into a three-necked flask, add 27g of thiophenol and 32g of ethanol, and stir.

[0129] [Chemical Formula 1-1]

[0130]

[0131] 16.3 g of trimethylamine was slowly added dropwise to the reaction solution. After the reaction was complete, ethanol was removed by vacuum distillation, and the organic matter was dissolved in dichloromethane. After washing with water, dichloromethane was removed by vacuum distillation. An equal volume of PGMEA solvent was added to a three-necked flask to prepare a 50% solution, and then the temperature was raised to 115 °C. 31.1 g of 3,3',4,4'-biphenyltetracarboxylic acid dianhydride was added dropwise at 115 °C, and the mixture was stirred for 6 hours while maintaining the temperature at 118 °C. 7.35 g of phthalic anhydride was added, and the reaction was terminated after stirring for another 2 hours. After cooling, a resin of formula 1 with a weight average molecular weight of 4,300 g / mol was obtained.

[0132] [Chemical Formula 1]

[0133]

[0134] Examples and Comparative Examples: Fabrication of Color Conversion Pixels

[0135] By using the composition prepared in the above preparation example, a pattern was formed by photolithography, as shown in Table 2 below, to manufacture color conversion pixels including blue pixels, green pixels, and red pixels respectively.

[0136] In the photolithography process, the surface of the glass substrate (Eagle 2000, manufactured by Corning Corporation) was sequentially washed with a neutral detergent, water, and alcohol. Using a coating machine (Mikasa Corporation, Opticoat MS-A150), the glass substrate was coated with the structures constructed in Examples 1 to 7 and Comparative Examples 1 to 4 in Table 2 below at a speed that allows each composition to have a certain thickness. After coating, the substrate was pre-baked on a hot plate at 90°C for 1 to 10 minutes to form a coating film.

[0137] Then, after inserting a mask for pattern formation onto the coating, an exposure machine (Ushio Corporation, HB-50110AA) is used at 200 mJ / cm². 2Under the specified exposure conditions (using a 365nm sensor), pattern exposure was performed simultaneously with UV irradiation. After the exposure, unwanted portions were dissolved and removed using a developer solution, leaving only the exposed areas to form the pattern. The pattern was then heat-cured in a convection oven at 130°C for 60 minutes, thus completing the sample fabrication. Within the pixels, the substrate was fabricated in the order of forming blue pixels, red pixels, and green pixels without forming partitions. A schematic diagram of the resulting structure is shown below. Figure 1 As shown.

[0138] Table 2

[0139]

[0140]

[0141] Typical quantum dot pixels are used to absorb light generated from a blue light source to produce long-wavelength light. For example, in Comparative Examples 1 and 2, the photosensitive resin composition is prepared in the following manner: the green pixel uses quantum dots that absorb light generated from a blue light source to produce green wavelength light, and the red pixel uses quantum dots that absorb light generated from a blue light source to produce red wavelength light.

[0142] <Experimental Example>

[0143] For the color conversion pixels prepared according to the examples and comparative examples, the performance was evaluated as follows, and the results are shown in Table 3.

[0144] Experimental Example 1: Brightness Assessment

[0145] The light intensity was driven from green (green brightness) to red (red brightness), and the spectrum of the substrate was measured on the upper part of the substrate using a CAS 140CT device. The wavelength of the desired color was calculated as the area ratio, and the results of comparative examples 1 to 4 and examples 1 to 7 were measured according to the following classification and are shown in Table 3.

[0146] ◎: When the brightness of green to red is above 80% compared to blue.

[0147] ○: When the brightness of green to red is above 60% compared to blue.

[0148] △: When the brightness of green to red is above 40% compared to blue.

[0149] ×: When the brightness of green to red is below 25% compared to blue.

[0150] Experimental Example 2: Color Purity Evaluation

[0151] The spectrum of the substrate was measured on the upper part of the substrate using a CAS 140CT instrument, with green (green purity) being driven to red (red purity). The wavelengths other than the wavelength of the desired color were calculated as area ratios, and the results of comparative examples 1 to 4 and examples 1 to 7 were measured according to the following classification and are shown in Table 3.

[0152] ◎: When the wavelength other than the desired color is below 0.1%.

[0153] ○: When the wavelength other than the desired color is greater than 0.1% but less than 1%.

[0154] △: When the wavelength other than the desired color is greater than 1% but less than 3%.

[0155] ×: When the wavelength other than the desired color is greater than 3%.

[0156] Experiment 3: Sharpness Assessment

[0157] To assess the sharpness between pixels, a specific pixel is driven, and the sharpness is evaluated by assessing the intensity of light generated from neighboring pixels. The results are shown in Table 3.

[0158] Green / red sharpness is evaluated by the light intensity produced by the adjacent red pixel after driving the green pixel, and green / blue sharpness is evaluated by the light intensity produced by the adjacent blue pixel after driving the green pixel. The evaluation criteria are as follows.

[0159] ◎: When the intensity produced is less than 0.1% compared to the intensity of green light.

[0160] ○: When the intensity produced is greater than 0.1% but less than 1% compared to the intensity of green light.

[0161] △: When the intensity produced is greater than 1% but less than 3% compared to the intensity of green light.

[0162] ×: When the intensity produced is greater than 3% compared to the green light intensity

[0163] Table 3

[0164]

[0165] When the blue light source behind the green pixel is driven to achieve green, a blue light source is generated in the backlight unit (BLU). The blue light source is converted to green in the green pixel to display green. However, when the color conversion pixel is constructed as in Comparative Examples 1 and 2 without forming a partition, the blue light from the backlight unit flows out to the adjacent pixel to emit blue light from the red pixel or is converted to red light by encountering the red quantum dot. In addition, even in the blue pixel, the blue light generated in the green pixel will leak into the adjacent blue pixel. Referring to Table 3, it can be confirmed that in Comparative Examples 1 and 2, where only quantum dots are introduced in the green and red pixels, the color quality deteriorates and the sharpness between pixels is reduced due to the above problems.

[0166] Furthermore, when color material is introduced into quantum dots, such as in Comparative Examples 3 and 4, to construct color conversion pixels using the same color material as each pixel, the efficiency of the quantum dots decreases because the color material absorbs the blue light that should have been absorbed by the quantum dots. As a result, the brightness of green and even red pixels decreases. Figure 3 ).

[0167] Conversely, in Example 1, where cyan and magenta color materials are introduced into the green and red pixels, it can be confirmed that the color purity and sharpness are excellent even without partitions. Examples 2 to 7, where color material is introduced only in one of the green and red pixels, show improved color purity and sharpness without partitions.

Claims

1. A color filter comprising color conversion pixels formed on a substrate, wherein, The color conversion pixel is formed from a composition for color conversion pixels comprising quantum dots, color materials, monomers, binders, initiators, and additives, wherein the binder comprises a structure represented by the following chemical formula 1: [Chemical Formula 1] ， In the chemical formula 1, p is an integer from 3 to 15, and * represents a bonding bond. The colorant is selected from one or more of the following: cyan pigment having a transmittance of more than 50% in the wavelength regions of 450nm and 640nm, and magenta dye having a transmittance of more than 50% in the wavelength regions of 450nm and 540nm. The color filter has no partitions between the individual color conversion pixels.

2. The color filter according to claim 1, wherein, The cyan pigment, which has a transmittance of more than 50% in the wavelength regions of 450 nm and 640 nm, has a transmittance of less than 50% in the wavelength region of 540 nm. The magenta dye having a transmittance of more than 50% in the wavelength regions of 450 nm and 540 nm has a transmittance of less than 50% in the wavelength region of 640 nm.

3. The color filter according to claim 1, wherein, The quantum dots are either green or red.

4. The color filter according to claim 1, wherein, Relative to the total weight of the solid components in the composition used for color conversion pixels, The content of the quantum dots is 5 to 40% by weight; The content of the colorant is 1 to 20% by weight; The content of the monomer is 20 to 60% by weight; The adhesive content is 20 to 60% by weight; The initiator content is 1 to 10% by weight; and The additive content is 0.1 to 3% by weight.

5. A display device comprising a color filter according to any one of claims 1 to 3.

6. A color filter comprising color conversion pixels formed on a substrate, in, The color conversion pixel is formed from a composition for color conversion pixels comprising quantum dots, color materials, monomers, binders, initiators, and additives, and includes: Red conversion pixels, which include red quantum dots and magenta pigments; and Green conversion pixels, which include green quantum dots and cyan pigments, The adhesive described herein comprises a structure represented by the following chemical formula 1: [Chemical Formula 1] ， In the chemical formula 1, p is an integer from 3 to 15, and * represents a bonding bond. The magenta pigment has a transmittance of over 50% in the 450nm and 640nm wavelength regions, and a transmittance of less than 50% in the 540nm wavelength region. The cyan pigment has a transmittance of over 50% in the 450nm and 540nm wavelength regions, and a transmittance of less than 50% in the 640nm wavelength region. The color filter uses blue light as its light source, and there are no partitions between the individual color conversion pixels.

7. A color filter without partitions, comprising color conversion pixels formed on a substrate, wherein the color conversion pixels are formed from a composition for color conversion pixels, the composition comprising: Red quantum dots or green quantum dots; A colorant having a transmittance of more than 50% in two wavelength regions of 450nm, 540nm and 640nm and a transmittance of less than 50% in one region; Monomers; binders; initiators; and additives, The adhesive described herein comprises a structure represented by the following chemical formula 1: [Chemical Formula 1] ， In the chemical formula 1, p is an integer from 3 to 15, and * represents a bonding bond. When the quantum dot is a red quantum dot, the colorant is a magenta colorant. When the quantum dot is a green quantum dot, the colorant is a cyan colorant.

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