KR102340892B1 - Charged Quantum Dots Microcapsule and Method of Manufacturing the Same - Google Patents

Abstract

The present invention relates to charged quantum dot capsule ink which includes a charged quantum dot capsule, a solvent, a sealing material, and a functional material; a method for manufacturing the same; and manufacture of a color filter and a display by an inkjet printing process using the same, wherein the charged quantum dot capsule has a specific charge on the surface of the capsule, the repulsive force is generated by the coulomb force between adjacent capsules having the same polar charges on the surface, and dispersibility of the capsules is more improved compared to that of non-charged quantum dot capsules.

Description

Charged Quantum Dots Microcapsule and Method of Manufacturing the Same

The present invention relates to an electrically charged quantum dot capsule capable of improving reliability and stability and applicable to inkjet printing and laser printing manufacturing processes, a manufacturing method thereof, and color filter and display manufacturing using the same.

1A and 1B are schematic diagrams illustrating light emission patterns according to a conventional quantum dot structure and crystal size, respectively.

As shown in Figures 1a and 1b, quantum dots (Quantum Dot. QD) or quantum dots are semiconductor crystals with a diameter of several nanometers in diameter consisting of a core 101 and a shell 102, and are discontinuous. As a material that emits light of a specific wavelength depending on the size of the crystal due to the existence of an energy level and a gap, a ligand 103 is attached to the shell surface of the quantum dot to be uniformly dispersed, and the quantum dot R (100) in FIG. 1b ), G(104), and B(105), when the particle size is small, light of a short wavelength is emitted, and as the size of the particle is large, light of a long wavelength is emitted.

Quantum dots can be used in various fields such as displays, solar cells, biosensors, quantum computers, etc. in that they emit various and high-purity light and have excellent chemical properties. In particular, it is possible to implement a display close to natural color due to high color purity and light safety, and thus application and commercialization are being promoted in the display industry.

Quantum dot displays include a fluorescence (photo luminescence, PL) method that emits light through an external light source and an electro luminescence (EL) method that emits light electrically.

As for application fields, QD-LCD, which uses quantum dots as a phosphor to overcome the low color gamut of LCD, is a method of directly depositing quantum dots on LED, which is currently the light source of LCD, a method of placing quantum dots in a tube and placing them on the side of the LED; There are a method of attaching a polymer film in which quantum dots are uniformly dispersed in front of a BLU (back light unit) and a method of applying quantum dots to a color filter or color conversion unit.

In particular, in the case of a color filter or color conversion unit using quantum dots, which has recently attracted attention, a method of converting a white light source to RGB through a color filter containing quantum dots and using blue light with quantum dots activated as a light source to convert blue light as it is A color filter or color conversion unit composed of a transparent subcell passing through and a quantum dot subcell for converting red (R) and green (G) into red (R) and green (G) is being studied.

2 is a step-by-step schematic diagram illustrating a method of manufacturing a color filter using a conventional photolithography process.

As shown in FIG. 2 , as a conventional technique for manufacturing a color filter, a photolithography process using a photoresist is a representative example. However, in the case of the process of FIG. 2 , most of the photoresist and coated quantum dot materials that have not been exposed or developed other than the patterned area are all removed during the cleaning process, so there is a disadvantage in that the amount of material consumed is large.

In the process, a black matrix pattern (Black Matrix) 201 is formed on the substrate 200, a photosensitive composition and a quantum dot material are coated, and a part of the solvent in the coating layer is removed through a vacuum drying process, and a hot plate In addition, the remaining residual solvent is removed. Then, by irradiating light energy through a mask 202 having a desired pattern shape, removing the unexposed part with a developer, and baking using an oven, each pixel, R (203), G (204), B (205) layers can be prepared.

In such a conventional photolithography method, a binder containing an acid group such as a carboxyl group (-COOH) is used in order to make the unexposed part to be easily dissolved in an alkaline developer after the exposure process. Although this conventional method is excellent in terms of precision and reproducibility of a color filter, in order to form a pixel, a process of coating, exposing, developing, and curing each photosensitive composition including pigments of three primary colors is required. As the line becomes too long and there are too many control factors between processes, it is difficult to manage the yield, and the formation of a thick coating layer is required to realize a high color gamut, which exposes various problems in the actual production process.

In order to solve this problem, an inkjet printing method in which a desired pattern is directly formed by printing liquid ink using an inkjet head on a substrate has been proposed. The inkjet method is a method of forming pixels of a desired pattern as an image part in which each ink is colored by spraying ink containing three primary color pigments (R, G, and B) on a substrate. It is self-evident that it can significantly affect the reduction of manufacturing cost by being significantly simplified compared to the lithographic method.

The inkjet method may be divided into a bubble jet method and a piezo method. The bubble jet method applies electricity to an electric hot plate to generate oxygen bubbles, and the oxygen bubbles push the ink, and there is a limit to being applied only to water-based inks. The piezo method uses a ceramic piezoelectric element to push out ink using pressure generated by applying electricity, and unlike the bubble jet method, it has the advantage that it can be applied to both water-based inks and oil-based inks.

On the other hand, with the development of LCD technology, a higher color reproducibility was required, and accordingly, the pigment content in the ink composition for manufacturing a color filter was increased in order to produce a dark color at the same thickness. However, as the pigment content increases, the content of other components, i.e., binder resin, crosslinking agent, etc. is relatively reduced, and due to this content change, sufficient film strength is not realized in the ink film, which may cause printing defects, and chemical resistance There is a problem with degradation. Also, in the case of a color filter, a high contrast ratio is required, and there is a problem in that it is difficult to sufficiently implement such a function. In particular, when the pigment included in the conventional ink composition is a red pigment, the disadvantage of relatively worse chemical resistance compared to pigments of other colors is pointed out. In an effort to solve this technical problem, the quantum dot material is used as a pigment. Studies have been carried out on the use of

3 is a step-by-step schematic diagram illustrating a method for manufacturing a color filter using a conventional inkjet printing process.

The principle of an inkjet printer is a method of discharging ink through a print head in the same way as a general printer used for printing documents.

Referring to FIG. 3 , in the quantum dot color filter process, the quantum dot ink must be uniformly dripped to each subcell. Advantages of the inkjet printing method are that the number of processes is reduced compared to the conventional photolithography method, so that patterning is easy and simple, and the amount of material consumed is small, so it is cost-effective. However, when the inkjet printing method is applied, there is a disadvantage that a separate heat treatment equipment and process are required. Quantum dot ink basically includes quantum dot particles and a solvent necessary to ink them. The solvent is a base material for ink formation and is a kind of impurity. After dropping each color quantum dot ink into a subcell, it is removed through a heat treatment process , because the process of solidifying the ink is required.

Despite the advantages described above, the inkjet printing process has many problems to be solved.

As a representative example of this, the quantum dot ink must be uniformly dropped to each subcell between the black matrix 301 formed on the substrate 300 through the print head 302 . Aggregation between quantum dot particles or compatibility with solvent Due to problems, etc., the print head 302 is clogged or cannot fall on the subcell uniformly, which may cause a problem of forming a non-uniform coating layer. Due to their nature, the development of an additional encapsulation process is a task to be solved in the future.

US 2015027704 A1 (2015.10.01.) US 20090322670 A1 (2009.12.31.) US 20180031910 A1 (2018.02.01.) KR 10-2009-0078099 A1 (2009.07.17.) KR 10-2018-0099991 A1 (2018.09.06.) KR 10-2009-0039178 A1 (2009.04.22.) KR 10-0759838 B1 (2007.09.12.) KR 10-2014-0006310 (2014.01.16.)

The problem to be solved by the present invention is, in manufacturing a color filter or color conversion unit using quantum dots, preventing deterioration of the properties of quantum dots due to penetration of oxygen and moisture, and having compatibility with resin or binder, charged quantum dots An object of the present invention is to provide a capsule, a method for manufacturing the same, and an apparatus using the same.

The problem to be solved by the present invention is to have a positive or negative polarity charge on the surface of the capsule after encapsulating it by mixing it with a material having a charge in the quantum dot material or manufacturing a capsule in powder form, It can be applied to the inkjet printing method for producing a color filter or color conversion part that can be applied or coated uniformly by preventing head clogging by improving the dispersibility, or the laser printing method that can reduce the process speed and reduce manufacturing costs. It is to provide an electrically charged quantum dot capsule and a method for manufacturing the same.

The problem to be solved by the present invention is to include a sealing material inside or outside the quantum dot capsule that is charged, so that the sub-pixel printing and the encapsulation process can be performed in parallel or the encapsulation process can be performed continuously, thereby reducing the color filter manufacturing process and the encapsulation process An object of the present invention is to provide an electrically charged quantum dot capsule capable of simplifying and reducing manufacturing cost, and a method for manufacturing the same.

In the quantum dot capsule having a charge according to the present invention and a method for manufacturing the same, a display layer can be formed by arranging capsules for each color through a laser printing process using a method of applying an electric charge to the surface of the capsule, and color realization For this purpose, it is to provide a reflective display and a transparent display that form a display layer with microcapsules that can implement color without the use of a color filter.

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

The charged quantum dot capsule ink according to an embodiment of the present invention includes a quantum dot capsule having a charge, a solvent, a sealing material and a functional material, wherein the charged quantum dot capsule has a specific charge on the surface of the capsule, Since a repulsive force is generated by Coulomb force between adjacent capsules having the same polarity of charge, dispersibility of the capsules may be further improved compared to quantum dot capsules having no charge.

A red, green, or blue color filter material is additionally coated on the surface of the charged quantum dot capsule, so that the color reproducibility of the quantum dot contained in the capsule can be supplemented.

A method for producing an electrically charged quantum dot capsule ink according to an embodiment of the present invention comprises the steps of encapsulating quantum dots; removing moisture from the surface of the capsule to prepare a powder form; charging the surface of the quantum dot capsule with a positive or negative charge through triboelectrification of the quantum dot capsule and a carrier; And mixing the prepared quantum dot capsule having an electric charge with a sealing material and a functional material that is melted or cured by a solvent, a specific temperature or light in a specific wavelength band; may include

A method for producing an electrically charged quantum dot capsule ink according to an embodiment of the present invention comprises the steps of encapsulating quantum dots; removing moisture from the surface of the capsule to prepare a powder form; charging the surface of the capsule through corona discharge to the quantum dot capsule, or charging the surface of the capsule through mutual collision of the quantum dot capsules by alternately applying a pulse voltage; And mixing the prepared quantum dot capsule having an electric charge with a sealing material and a functional material that is melted or cured by a solvent, a specific temperature or light in a specific wavelength band; may include

A method for producing an electrically charged quantum dot capsule ink according to an embodiment of the present invention comprises the steps of encapsulating quantum dots; applying a charge by coating a charge control agent or an ionic material on the surface of the quantum dot capsule; And mixing the prepared quantum dot capsule having an electric charge with a sealing material and a functional material that is melted or cured by a solvent, a specific temperature or light in a specific wavelength band; may include

A method for producing a charged quantum dot capsule ink according to an embodiment of the present invention comprises the steps of mixing a charge control agent or an ionic material with the quantum dots and then encapsulating to make the entire capsule charge; And mixing the prepared quantum dot capsule having an electric charge with a sealing material and a functional material that is melted or cured by a solvent, a specific temperature or light in a specific wavelength band; may include

According to an embodiment of the present invention, there is provided a method of manufacturing a color filter through an inkjet printing process using a quantum dot capsule ink having a charge, the method comprising: printing a black matrix pattern on a color filter substrate; uniformly spraying red, green, and blue inks including quantum dot capsules having a charge through an inkjet printer head to each sub-pixel between the black matrix patterns; drying the sprayed ink through a heat treatment process; and forming red, green, and blue sub-pixels for color filters, wherein the quantum dot capsule ink having an electric charge includes a sealing material and a functional material, so that red (Red) , Green, and blue subpixels may be formed in parallel with the encapsulation process, or after the subpixels are printed, the encapsulation process may be continuously performed.

An electronic device including a quantum dot capsule ink having a charge according to an embodiment of the present invention is a display device, a lighting device, a backlight unit, a color filter, a color conversion layer, an organic light emitting diode (LED), a surface light emitting device, a magnetic memory or It can be selected from among batteries.

The charged quantum dot capsule and its manufacturing method according to the present invention have the advantage of preventing deterioration of properties for oxygen and moisture permeation from the outside as a color filter is manufactured by encapsulating the quantum dots.

Charged quantum dot capsules and their manufacturing method according to the present invention have the advantage of improving dispersibility without clumping of capsules by the repulsive force between the capsules because the surfaces of the capsules have charges of the same polarity.

The charged quantum dot capsule and its manufacturing method according to the present invention have an advantage in that the nozzle clogging phenomenon can be alleviated when the inkjet printing process is applied.

The charged quantum dot capsule and its manufacturing method according to the present invention can be applied to a laser printing process with a high printing speed because the surface of the capsules are charged, so that a large-area color filter can reduce the process time compared to conventional techniques And it has the advantage of being able to manufacture by reducing the manufacturing cost.

The charged quantum dot capsule and its manufacturing method according to the present invention have the advantage of being able to have effects such as preventing moisture penetration and blocking heat by mixing and encapsulating quantum dots and functional materials together.

In the quantum dot capsule having a charge according to the present invention and a method for manufacturing the same, the quantum dot capsule and the sealing material having an electric charge are mixed together in a solvent used to make ink for inkjet printing, and the subpixel printing and the encapsulation process are performed in parallel or the encapsulation process is performed. Since it can proceed continuously, it has the advantage of simplifying a color filter manufacturing process and an encapsulation process, and reducing manufacturing cost.

Quantum dot ink for inkjet printing including a charged capsule capable of performing a sealing process during the printing process of the charged capsule and a method of using the same include quantum dot film, electronic paper, display device, lighting device, backlight unit, color filter , a color conversion layer, a surface light emitting device such as an organic light emitting diode (LED), an electrode, has the advantage of being applicable to electronic devices such as magnetic memory or batteries.

A quantum dot capsule having a charge according to the present invention and a method for manufacturing the same, in a reflective display and a transparent display in which a display layer is formed with a microcapsule, using a method of applying an electric charge to the surface of the capsule, through a laser printing process It is possible to form a display layer by arranging capsules for each color, and has the advantage of being able to implement color without using a color filter for color realization.

1A and 1B are schematic diagrams illustrating light emission patterns according to a conventional quantum dot structure and crystal size, respectively.
2 is a step-by-step schematic diagram illustrating a method of manufacturing a color filter using a conventional photolithography process.
3 is a step-by-step schematic diagram illustrating a method for manufacturing a color filter using a conventional inkjet printing process.
4A and 4B are cross-sectional views illustrating the structure of a quantum dot capsule having an electric charge according to an embodiment of the present invention.
5 is a cross-sectional view illustrating the structure of a quantum dot capsule having an electric charge according to an embodiment of the present invention.
6 is a method of manufacturing a quantum dot capsule having a charge by a charge imparting method, in which the capsule shell region is charged with a positive or negative charge through triboelectrification, according to the embodiment of FIG. 4A. It is a schematic diagram shown.
7 is a cross-sectional view illustrating a manufacturing method of a quantum dot capsule having another charge and the manufactured capsule structure according to an embodiment of the present invention.
8 is a cross-sectional view illustrating a manufacturing method of a quantum dot capsule having another charge and the manufactured capsule structure according to an embodiment of the present invention.
9 is a step-by-step schematic diagram illustrating a method for manufacturing a color filter using an inkjet printing process using a quantum dot capsule having an electric charge.
10 is a cross-sectional view illustrating the structure of an inkjet ink including a quantum dot capsule having an electric charge in parallel to the encapsulation process during the inkjet printing process, according to an embodiment of the present invention.
11 is a schematic diagram of a method of manufacturing a color filter by a laser printing process using an electrically charged quantum dot capsule according to an embodiment of the present invention.
12A and 12B are cross-sectional views illustrating the structure of a quantum dot capsule having an electric charge in another embodiment for paralleling the encapsulation process during the laser printing process, according to an embodiment of the present invention.
13 is a cross-sectional view illustrating a structure of a quantum dot capsule having a charge coated with a color filter material according to an embodiment of the present invention.
14A and 14B are cross-sectional views illustrating structures of a reflective display and a transparent display manufactured using a charged capsule according to an embodiment of the present invention.
15 is a micrograph of a quantum dot capsule having a charge synthesized according to the embodiment of FIG. 5 .
16 is a photograph for comparing and demonstrating the dispersibility of a quantum dot capsule having a charge and a quantum dot capsule having no charge, according to an embodiment of the present invention.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. Effects and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

In the following embodiments, terms such as first, second, etc. are used for the purpose of distinguishing one component from another, not in a limiting sense. Also in the following examples, the singular expression includes the plural expression unless the context clearly dictates otherwise.

In the following embodiments, terms such as include or have means that the features or components described in the specification are present, and the possibility that one or more other features or components will be added is not excluded in advance.

The present invention is technically characterized in that the encapsulation region is charged with a specific charge after encapsulating the quantum dots. The surface of the capsule has the properties of a non-conductor or an insulator, but when it is mixed with a solution, resin, binder, etc., the capsules may be unspecifiedly dispersed or aggregated by the properties of the material to be mixed and the energy administered for mixing. When the exposed surface of the capsule is charged with the same polarity, a repulsive force is generated between adjacent capsules by Coulomb force, and the strength of the repulsive force varies according to the amount of charge the capsules have.

Therefore, if the quantum dot capsules have an equal or similar charge amount, a uniform repulsive force is generated between the capsules to prevent agglomeration of the capsules, and dispersibility can be improved relatively compared to the capsules in a neutral state.

In addition, when the surface of the capsule becomes charged, it can be applied to a laser printing process using an electrostatic image.

4A and 4B are cross-sectional views illustrating the structure of a quantum dot capsule having an electric charge according to an embodiment of the present invention.

Referring to FIG. 4A , the charged quantum dot capsule according to the present invention encapsulates the quantum dot 402, removes moisture from the surface of the capsule 400, and is manufactured in a powder form, and then the capsule is subjected to triboelectrification. It is a capsule structure in which the shell region is charged with a positive or negative charge 401 .

4b, the quantum dot capsule having a charge according to the present invention, after encapsulating the quantum dot 402, the surface of the capsule 400 is coated with a charge control agent (CCA) 403, etc. It is a capsule structure with a positive or negative charge.

The charge control agent may be a positive charge control agent, a negative charge control agent, or a mixture thereof.

The charge control agent is not limited, but may be made of metal soap, OLOA series, Ganex series, or mixtures thereof.

When it is desired to positively control the electrical polarity, the charge control agent is a nigrosine dye, a triphenylmethane compound, the fourth grade ammonium salt--based compound, a polyamine resin (polyamine resin) and an imidazole derivative, or a combination thereof.

In addition, metal oxides such as ultra-fine silica, ultra-fine titanium oxide, and ultra-fine alumina, nitrogen-containing cyclic compounds such as pyridine, derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. can also be used as charge control agents.

In addition, when the electrical polarity is to be negatively controlled, the charge control agent includes a salicylic acid metal complex, a metal containing azo dye, or an oil-soluble dye of metal containing. , the fourth grade ammonium salt based compound, calixarene compound, boron-containing compound such as benzyl acid boron complex and nitroimi It may be a nitroimidazolederivative.

In addition, metal oxides such as ultra-fine silica, ultra-fine titanium oxide, and ultra-fine alumina, nitrogen-containing cyclic compounds such as pyridine, derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. can also be used as charge control agents. However, the types of the above-described charge control agent are exemplary, and the present invention is not limited thereto, and other known suitable materials may be used.

5 is a cross-sectional view illustrating the structure of a quantum dot capsule having an electric charge according to an embodiment of the present invention.

Referring to FIG. 5, to easily charge the surface of the quantum dots 502 capsules 500 or to impart an electric charge to the surface, a Charge Control Agent (CCA) 501, an external additive or an ionic material It can be coated on the surface of the capsules, surface-treated, or synthesized so that the shell region of the capsule has an electric charge.

As a method of electrification of the capsule surface, the uncharged particles may be charged through corona discharge, and the uncharged particles may be charged through mutual collision by alternately applying a pulse voltage.

6 is a method of manufacturing a quantum dot capsule having a charge by a charge imparting method, in which the capsule shell region is charged with a positive or negative charge through triboelectrification according to the embodiment of FIG. 4A. It is a schematic diagram shown.

Referring to FIG. 6 , the quantum dot 602 is encapsulated 600 , and the moisture on the surface of the capsule 600 is removed to prepare a powder form, and then the quantum dot capsule 600 and the carrier 601 friction. Charge may be imparted to the shell region of the surface of the quantum dot capsule 600 through charging.

The principle is as follows. If there is a difference between the work function of the quantum dot capsule 600 or the surface-treated capsule (the minimum work or energy required to pull out one electron in the material) and the work function of the carrier 601, the two objects When they rub against each other, the movement of electrons becomes active due to thermal energy from frictional heat, and according to the difference in work function, the two objects have different affinity for electrons, so a material that relatively likes electrons can attract electrons. Therefore, an object that has relatively lost electrons has a positive charge due to lack of electrons, and an object that has gained electrons has a negative charge. Using these characteristics, it is possible to set the surface of the quantum dot capsule to have a charge of a specific sign.

7 is a cross-sectional view illustrating a manufacturing method of a quantum dot capsule having another charge and the manufactured capsule structure according to an embodiment of the present invention.

Referring to FIG. 7 , as another method of manufacturing a quantum dot capsule 702 having a charge, a material, particle or chemical 701 having a relatively very small size compared to the quantum dot capsule 700 is used as a quantum dot. Through the capsule and mixing process, the capsule surface area 703 may be directly injected so that the capsule surface may be set to be charged.

8 is a cross-sectional view illustrating a manufacturing method of a quantum dot capsule having another charge and the manufactured capsule structure according to an embodiment of the present invention.

Referring to FIG. 8 , a material (charge control agent or ionic material), particles or chemical material 801 having a relatively very small size compared to the quantum dot capsule is mixed with the quantum dot 802 and then encapsulated to charge the entire It is possible to manufacture a quantum dot capsule 800 that stands out.

However, in the case of the quantum dot capsule 800 that is electrically charged as a whole, the dispersibility may be lower compared to the method in which the charge is displayed on the surface of the quantum dot capsule. A charged material with this must be applied.

9 is a step-by-step schematic diagram illustrating a method for manufacturing a color filter using an inkjet printing process using a quantum dot capsule having an electric charge.

Referring to FIG. 9 , a color filter may be manufactured by applying the charged quantum dot capsule according to the present invention to the inkjet printing process shown in FIG. 3 .

Referring to FIG. 9 , the color filter pattern may be formed by spraying each of the RGB sub-pixels and the black matrix forming the color filter pattern by an inkjet printing method.

A color filter is a major component used to express color in a liquid crystal display (LCD) panel. The pixel unit of the color filter consists of three sub-pixels of RGB, and the LCD color filter A black matrix (B/M) is formed between the RGB of , which is located between color sub-pixels to prevent light leakage and photoelectric conversion in TFT (Thin Film Transistor). The black matrix material is placed in an optically inactive area of the transparent substrate to prevent light leakage and provides a light shield to the amorphous silicon transistor. The black mask material should have low reflectivity for optimal contrast ratio, and may be organic or inorganic, but chromium (Cr) is the most common inorganic material.

Charged quantum dot capsules are mixed with a solvent or curable resin required for ink formation. In the case of using a curable resin, there is an advantage in that it can solve the problem of solvent reaction and the deterioration of visibility during the drying process.

Quantum dots in capsules used for inkjet printing for color filter manufacturing are group II-VI compound semiconductor nanocrystals, group III-V compound semiconductor nanocrystals, group IV-VI compound semiconductor nanocrystals, group IV compound semiconductor nanocrystals, and their It may be selected from the group consisting of mixtures.

The group II-VI compound semiconductor nanocrystals include a binary compound including CdSe, CdTe, ZnS, ZnSe, and ZnTe; ternary compounds including CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, CdZnS, CdZnSe, CdZnTe; and CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and a quaternary compound including HgZnSTe, wherein the group III-V compound semiconductor nanocrystals are GaN, GaP, GaAs, GaSb, InP , InAs, a binary compound including InSb; ternary compounds including GaNP, GaNAs, GaNSb, GaPAs, GaPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP; And GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, selected from the group consisting of quaternary compounds comprising InAlPSb, the IV-VI compound semiconductor nanocrystals silver is a binary compound including PbS, PbSe, and PbTe; ternary compounds including PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, and SnPbTe; and SnPbSSe, SnPbSeTe, and a quaternary compound including SnPbSTe, wherein the group IV compound semiconductor nanocrystal includes a single element compound including Si and Ge; It may be selected from the group consisting of a binary compound including SiC and SiGe.

The solvent is selected from the group consisting of chloroform, chlorobenzene, cyclohexane, hexane, heptane, octane, hexadecane, undecane, decane, dodecane, xylene, toluene, benzene, octadecane, tetradecane, butyl ether and ethanol. There may be more than one type.

When the curable resin includes a photocurable functional group, curing process after printing becomes smoother because it can be cured by photocuring. Curable ink is different from general liquid ink, which is liquid at room temperature using a solvent, as a curable resin, which uses a monomer that is solid at room temperature and has a lower viscosity at high temperature. It is a solid-like ink. It is also expressed In the case of using liquid ink used in general inkjet printing, there is a problem in that the solvent contained in the ink production process reacts with the upper part of the light emitting layer to cause deterioration of quality, and in the process of drying the liquid ink, there is a problem There may be a problem of deteriorating visibility (coffee ring phenomenon) by forming a surface. The curable resin is those that are cured without a solvent drying process, and for example, a material that is heat-cured at 80° C. or less among acrylic monomers showing a viscosity of 10 cp or less at a high temperature of about 100° C. is used or A material capable of UV curing may be used. Of course, it is not limited to these conditions, and the temperature at which the viscosity of the curable resin is lowered, the viscosity, and the curing temperature may be adjusted according to the specific form of applying the solvent-free curable ink. In the inkjet printing process, the temperature of the printhead is raised to lower the viscosity of the monomer contained in the curable ink to perform inkjet printing, and the color conversion layer is formed by lowering the temperature or curing the monomer by irradiating UV. In addition, in the case of the curable ink in the present invention, it is not limited to not using a solvent at all, and a small amount of solvent may be added. In the present invention, the problem of quality deterioration in the drying process does not occur by including the solvent only to the extent necessary for the minimum drying process in which the above-described drying process problem does not occur. The curable resin constituting the curable ink can be an organic monomer, and in particular, the acrylic monomer exhibits a viscosity of 10 cp or less at a temperature near 100 ° C.

Using Dimatix's DMP2831 as an inkjet printer, a black matrix pattern 901 is printed on the color filter substrate 900, and quantum dot capsule ink is charged through the print head 902 Red (Red) 903, green (Green) 904 and blue (Blue) 905 are uniformly sprayed on each sub-pixel between the black matrix patterns 901 formed on the substrate 900 to dry and remove the solvent through a heat treatment process. Red 906, green 907, and blue 908 subpixels for filters may be formed.

Compared with the method of performing the inkjet printing process by directly mixing quantum dots with a solvent in the conventional inkjet printing process shown in FIG. As it is added dropwise in the form of ink, it is possible to prevent uneven coating and aggregation of quantum dot particles due to impact even after the ink is dropped on the subcell. It can alleviate the phenomenon and has the advantage of being relatively less affected by moisture and heat during the heat treatment process to remove the solvent.

The charged quantum dot capsule can also be used to manufacture the color conversion part of the organic light emitting diode using the inkjet printing process.

The color conversion unit includes a red conversion unit and a green conversion unit respectively formed in a red area and a green area of the sub-pixel area, and the red conversion unit includes a quantum dot material that converts blue light emitted from the blue organic light emitting diode layer into red. It is formed by printing a curable ink composed of a charged capsule and a curable resin, and the green conversion unit is a charged capsule containing a quantum dot material that converts blue light emitted from the blue organic light emitting diode layer into green and a curable resin. It may be formed by printing the configured curable ink.

When the red conversion unit and the green conversion unit further include particles having color filter characteristics, color purity may be increased. The color filter is a part that converts the light emitted from the rear light source so that color can be realized in the liquid crystal display, and commercial particles used in the color filter may be applied or particles having the same characteristics may be applied.

Color purity can be increased by mixing and using particles having color filter characteristics with a charged capsule containing a quantum dot material. Commercially available colorants generally used in color filters are pigments, and both dye particles having color filter characteristics or nanostructured particles having color filter characteristics can be used.

Particles exhibiting color filter properties applicable to the green conversion part include metallophthalocyanine, and particles exhibiting color filter properties applicable to the red conversion part include diketopyrrolopyrrole and Pigment Red 254. There is this.

10 is a cross-sectional view illustrating the structure of an inkjet ink including a quantum dot capsule having an electric charge in parallel to the encapsulation process during the inkjet printing process, according to an embodiment of the present invention.

Referring to FIG. 10 , for the manufacture of the encapsulation ink 1004 used in the inkjet printing process, it is melted by light in a specific temperature or a specific wavelength band in a solvent 1003 used together with the quantum dot capsule 1000 having an electric charge. It is possible to manufacture by mixing the sealing material 1001 and the functional material 1002 that are cured or cured. When the encapsulation ink is used, red (Red) 906, green (907), and blue (908) sub-pixel printing for color filters during the inkjet printing process of the color filter in FIG. 9 together with sub-pixel printing Since the encapsulation process can be performed in parallel or the encapsulation process can be performed continuously after sub-pixel printing, the color filter manufacturing process can be simplified and the required process time can be shortened.

The sealing material 1001 and the functional material 1002 may be used without limitation as long as they are a sealing material for sealing an organic electronic device or a display device applicable to an inkjet process or a functional material for sealing.

The charged quantum dot capsule contained in the inkjet ink including the charged quantum dot capsule is preferably 10 to 80% by volume in the ink. In the case of including more than 80% of the quantum dot capsule in the volume ratio, the printing process may not be performed smoothly, but since the dispersibility is higher than when using the quantum dot capsule that does not show an electric charge, a larger amount can be added . The sealing material contained in the inkjet ink including the quantum dot capsule having a charge is preferably 0.05 to 50% by volume, and the ratio of the functional material may be adjusted within the range of 0.01 to 20% depending on the type or function.

The sealing material composition may include a curable compound having at least one curable functional group. The curable functional group may be, for example, at least one selected from an oxetane group, a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, an amide group, an epoxide group, a sulfide group, an acetal group, and a lactone group.

The curable compound may include a curable compound having a cyclic structure in a molecular structure and having at least two or more curable functional groups. The compound having a cyclic structure in the molecular structure may have 3 to 10, 4 to 8, or 5 to 7 of cyclic atoms in the molecular structure, and 1 or 2 or more and 10 or less cyclic structures may exist in the compound.

The curable compound may include a monofunctional curable compound. The monofunctional curable compound may have one curable functional group. The monofunctional curable compound is 65 to 165 parts by weight, 68 to 162 parts by weight, 73 to 160 parts by weight, 78 to 159 parts by weight, 85 to 158 parts by weight, or It may be included in the range of 90 to 157 parts by weight.

The curable compound may further include a linear or branched aliphatic curable compound. The aliphatic curable compound may have at least two or more curable functional groups. In addition, the linear or branched aliphatic compound is 20 parts by weight or more, less than 205 parts by weight, 23 parts by weight to 204 parts by weight, 30 parts by weight to 203 parts by weight, 34 parts by weight based on 100 parts by weight of the compound having a cyclic structure. It may be included in the range of parts by weight to 202 parts by weight, 40 parts by weight to 201 parts by weight, 60 parts by weight to 200 parts by weight, or 100 parts by weight to 173 parts by weight.

By controlling the content ratio of the curable compound having the cyclic structure and the aliphatic curable compound, the occurrence of haze due to unreacted or over-curing is prevented to realize optical properties and to prevent damage to the device due to the nature of the organic layer composition directly applied to the organic electronic device and , it is possible to control the physical properties of the device so that it can be applied to the inkjet method.

As a functional material 1002 for sealing using the sealing material 1001, a photoinitiator, a surfactant, a photosensitizer, a titanium-based coupling agent, an aluminum-based coupling agent, or a silane coupling agent, a moisture absorbent, an inorganic filler, an antifoaming agent, A tackifier, a UV stabilizer, or an antioxidant may be included in an appropriate range according to the desired physical properties.

The quantum dot ink for inkjet printing according to FIGS. 9 and 10 is a quantum dot film, an electronic paper, a display device, a lighting device, a backlight unit, a color filter, a color conversion layer, a surface light emitting device, an electrode, a magnetic memory or an electronic device such as a battery. application is possible.

11 is a schematic diagram of a method of manufacturing a color filter by a laser printing process using an electrically charged quantum dot capsule according to an embodiment of the present invention.

11, since the quantum dot capsules according to the present invention have a positive or negative charge, a color filter or a color conversion unit can be manufactured by applying a laser printing process capable of printing on a large area at a faster speed compared to the conventional inkjet printing process. .

The laser printing process may consist of charging->exposure->development->drying->settlement_>cleaning. The laser printing method includes the steps of preparing red (1100R), green (1100G), and blue (1100B) color quantum dot capsules having a negatively charged surface; setting the surface of the drum 1106, which is a photoreducer, to be negatively charged through a charger; Quantum dot capsules ((1100R), (1100G), (1100B)) that are charged through the developing roller (or developer) 1104 are printed positions i.e. quantum dot capsules ((1100R), (1100G), (1100B)) irradiating the laser beam 1103 to the drum 1106 through the reflection mirror 1105 by reflecting the laser beam 1103 from the optical unit only on the information part to selectively arrange or arrange; The reflected laser beam removes negative charges formed on the surface of the drum 1106 and creates a latent image; When the negatively charged quantum dot capsules ((1100R), (1100G), (1100B)) attached to the developing roller (or developing device) 1104 move to the surface of the drum 1106 irradiated with the laser beam 1103, the drum The step of attaching the quantum dot capsule ((1100R), (1100G), (1100B)) having negative charge only to the portion not having a negative charge of (1106); allowing the back surface of the substrate 1101 to be positively charged through the transfer roller (or transfer machine) 1102; The negatively charged quantum dot capsules ((1100R), (1100G), (1100B)) attached to the surface of the drum 1106 are pulled toward the substrate 1101 by attractive force and arranged at a set position of the substrate 1101 ; discharging all the surfaces of the drum 1106 using the discharge lamp 1108 after the quantum dot capsules ((1100R), (1100G), and (1100B) are moved to the substrate 1101; And the quantum dot capsules ((1100R), (1100G), (1100B) of different colors are all arranged on the substrate 1101, and then pass through the heating roller 1109 and receive heat and pressure to attach to the substrate 1101. is comprised of

Referring to Figure 11, since the quantum dot capsules ((1100R), (1100G), (1100B)) having different colors in the present invention must be selectively disposed on the substrate 1101, the drum 1106 by the number corresponding to each color ), a developing roller (or developing device) 1104, a discharge lamp 1108, a laser beam 1103, a reflective mirror 1105, and the like should be added to sequentially perform the series of process steps described above. Quantum dot capsules ((1100R), (1100G), and (1100B) of different colors are all arranged on the substrate 1101 and finally passed through the heating roller 1109 and subjected to appropriate heat and pressure when completely applied to the substrate 1101. can be attached.

The manufacturing method is equally applicable to color quantum dot capsules having a positive charge.

12(a)(b) is a cross-sectional view illustrating the structure of a quantum dot capsule having an electric charge in another embodiment for paralleling the encapsulation process during the laser printing process, according to an embodiment of the present invention.

Referring to FIG. 12 ( a ), the sealing material 1201 or functional material 1203 that is melted, cured, or dried by light of a specific temperature or a specific wavelength band together with the quantum dots 1202 during the laser printing process according to FIG. 11 . It can be encapsulated by mixing them, and the surface of the capsule 1200 can be set to have a specific charge.

The charged quantum dots contained in the charged quantum dot capsule for the laser printing process are preferably 10 to 80% by volume in the ink. It is preferable that the sealing material has a volume ratio of 0.05 to 50%, and the ratio of the functional material may be adjusted within the range of 0.01 to 20% depending on the type or function.

Alternatively, referring to FIG. 12(b), using the quantum dot capsules coated with the sealing material 1201 on the surface of the quantum dot 1202 capsule 1200 having a specific charge, manufactured according to the embodiment of FIGS. 4 to 8, In the laser printing process as shown in FIG. 11, the encapsulation process can be performed in parallel with the color filter manufacturing or the encapsulation process can be performed continuously with the color filter manufacturing, thereby simplifying the manufacturing process and reducing the required process time. have

11 and 12, the charged quantum dot capsule used in the laser printing process is a quantum dot film, electronic paper, display device, lighting device, backlight unit, color filter, color conversion layer, surface light emitting device, electrode, magnetic It can be applied to electronic devices such as memories or batteries.

13 is a cross-sectional view illustrating a structure of a quantum dot capsule having a charge coated with a color filter material according to an embodiment of the present invention.

Referring to FIG. 13, the color filter material on the surface of the quantum dots 1302 capsules 1300 that are charged according to the embodiment of FIGS. 4 to 8 or 12, Red (Red) 1301R, Green (Green) ) 1301G and blue (Blue) 1301B can be coated to complement the color reproducibility of the quantum dots 1302 .

As the color filter material, commercially available particles used in color filters may be applied, or particles having the same characteristics may be applied. Commercially available colorants generally used in color filters are pigments, and both dye particles having color filter characteristics or nanostructured particles having color filter characteristics can be used. Particles exhibiting color filter properties applicable to green conversion include metallophthalocyanine, and particles exhibiting color filter properties applicable to red conversion include diketopyrrolopyrrole and Pigment Red 254. .

14 is a cross-sectional view illustrating a structure of a reflective display and a transparent display manufactured using a charged capsule according to an embodiment of the present invention.

14(a) (b), the laser printing process according to FIG. 11 using a quantum dot capsule having a charge or a microcapsule for electrophoresis having a charge, prepared according to the embodiment of FIGS. 4 to 8 Through this, microcapsule reflective displays and transparent displays that can be printed on a large area at high speed can be manufactured.

The surface of the capsule has the properties of a non-conductor or an insulator, but when it is mixed with a solution, resin, binder, etc., the capsules may be unspecifiedly dispersed or aggregated by the properties of the material to be mixed and the energy administered for mixing.

When the exposed surface of the capsule is charged with the same polarity, a repulsive force is generated between adjacent capsules by Coulomb force, and the strength of the repulsive force varies according to the amount of charge the capsules have.

Therefore, if the quantum dot capsules have an equal or similar charge, a uniform repulsive force is generated between the capsules to prevent agglomeration of the capsules, and when compared to the capsules in a neutral state, the dispersibility can be improved relatively, and the capsule When the surface becomes charged, it can be applied to a laser printing process using an electrostatic image.

Referring to FIG. 14( a ), charged quantum dot capsules or charged electrophoresis microcapsules ( 1400B , 1400R , 1400Y ) containing two different color particles are produced through the laser printing process according to FIG. 11 , It is possible to form a display layer between the upper electrode 1402 formed on the upper substrate 1401 and the lower electrode 1403 formed on the lower substrate 1404 by arranging on the lower electrode 1403 patterned for each capsule. At this time, if a capsule coated with a sealing material on the surface of the capsule having a specific charge in FIG. 12(b) is used, the capsules 1400B, 1400R, and 1400Y in the display layer are fixed by the sealing material serving as the binder 1406 . This can be used to fabricate microcapsule reflective displays.

Referring to FIG. 14( b ), charged quantum dot capsules or electrophoretic microcapsules ( 1405B, 1405R, 1405Y ) containing one color particle are charged through the laser printing process according to FIG. 11 , color capsules It is possible to form a display layer between the upper electrode 1402 formed on the upper substrate 1401 and the lower electrode 1403 formed on the lower substrate 1404 by arranging on the lower electrode 1403 patterned separately. At this time, if a capsule coated with a sealing material on the surface of the capsule having a specific charge in FIG. 12(b) is used, the capsules 1400B, 1400R, and 1400Y in the display layer are fixed by the sealing material serving as the binder 1406 . A transparent display can be produced.

Microcapsules may be soft capsules or hard capsules, and may be prepared by in-situ polymerization, coacervation approach, or interfacial polymerization.

In the production of microcapsules, a polar or non-polar dispersion medium may be used as the fluid. For example, water, methanol, ethanol, propanol, butanol, propylene carbonate, toluene, benzene, chloroform, hexane, cyclohexane, dodecane, perchlorethylene, trichloroethylene, isopar-G, a type of isoparaffin oil Any one or more of -M and isopar-H may be used. Dyes or pigments may be added to the fluid.

As the dye or pigment, azo dye, anthraquinone dye, carbonium dye, indigo dye, sulfide dye, phthalocyanine dye, etc. may be used, and as the pigment, titanium dioxide, zinc oxide, Lithopon, Zinc sulfonate, Carbon black, Graphite, Chrome yellow, Zinc chromate, Redoxide of iron, Red lead , Cardmium red, Molybdate chrome orange, Milori blue, pressian blue, iron blue, Cobalt blue, chrome green, Viridian, zinc Inorganic pigments such as zinc green, silver powder, bronze powder, fluorescent pigment and pearl pigment, or insoluble azo, soluble azo, phthalocyanine, quinacridone, dioxazine, isoindole Organic pigments such as non-based, vat dye-based, phyllocholine-based, fluorine-based, quinophthalone-based, and metal complex can be used.

As the surfactant, an anionic surfactant, a cationic surfactant or an amphoteric surfactant can be used. The hydrophilic group of the anionic surfactant includes carboxylic acid (-COOH), sulfuric ester (-OSO ₃ H), and sulfonic acid (-SO ₃ H), and as a hydrophobic group, an alkyl group, an isoalkyl group, a benzene ring, or a hydrocarbon such as a naphthalene ring includes the group. Medialan A, naphthenic acid soap, rosin, CMC, Emulphor STH, Mersolate, Aerosol, Igepon T, ABS, Nekal A, BX, Gardinol, Turkey red oil, Arctic Syntex, Vel, Igepon B, Gardinol GY, Tergitol P, etc. can

Most of the hydrophilic groups of cationic surfactants are simple amine salts and quaternary ammonium salts containing primary to tertiary amines obtained through salt formation, and very few phosphonium salts and sulfonium salts are included. have. Among these, quaternary ammonium salts are the most important, and as the five N types, not only those bonded to chain alkyls, but also cyclic nitrogen compounds, such as pyridinium salts or quinolinium salts, especially heterocyclic compounds such as imidazolinium salts. do. Primary, secondary, tertiary amine salts, Sapamin CH, Aquard, Decamine, Sapamin MS, Benzalkonium chloride, Hyamine, Repellat, Emcol E-607, Zelan A, Velan PF, Isotan Q-16, Myxal, etc. may be used. .

The amphoteric surfactant contains -COOH group, -SO ₃ H group, -OSO ₃ H group as an anion in the molecule, and a type of soap containing only an amine, particularly a nitrogen group in the form of quaternary ammonium as a cation can be used. .

According to the in-situ polymerization method, microcapsules can be prepared through a reaction process of forming an emulsion and structuring it in a core-shell form.

First, particles are dispersed in a fluid to prepare a core material. At this time, the particles may be dispersed in a ratio of 0.1 to 25 wt% with respect to the fluid, but may be dispersed in a larger amount if necessary. The dispersion of the core material may be dispersed using an ultrasonic disperser or a homogenizer.

Next, a prepolymer is prepared by mixing the polymer to form the shell of the microcapsule by adjusting the acidity. This process may be performed simultaneously with the process of preparing the dispersion of the core material.

As the polymer for forming the shell, a polymer precursor capable of exhibiting low elasticity and hard properties may be used, and copolymers such as urea-formaldehyde, melamine-formaldehyde, methylvinyl ether comaleic anhydride, gelatin, polyvinyl Polymers such as alcohol, polyvinyl acetate, cellulosic derivatives, acacia, carrageenan, carboxymethylrelulose, hydrolyzed styrene anhydride copolymer, agar, alginate, casein, albumin, cellulose phthalate, etc. can be used, and the hydrophilicity of these polymers By controlling the hydrophobicity and surrounding the core material, a shell can be formed. In addition, the prepolymer may be dispersed in a fluid like particles to prepare a dispersion.

Forming an emulsion may be performed by mixing and stirring the prepared dispersion of the core material and the prepolymer dispersion of the shell material. As a condition for forming such an emulsion, it is necessary to optimize the ratio of particles and prepolymer, and the two dispersions may be mixed in a volume ratio of 1:5 to 1:12. In addition, a stabilizer may be added to improve dispersibility. In the emulsion the particles may be in the dispersed phase and the shell material may be in the continuous phase.

In this case, additives may be added to increase the stability of the emulsion. Such additives may be organic polymers with high wettability and high viscosity after dissolution in aqueous phase. Specifically, gelatin, polyvinyl alcohol, sodium carboxymethyl cellulose, starch, hydroxyethyl cellulose, polyvinylpyrrolidone, alginate At least one of them may be used.

The core material dispersion can be microencapsulated by controlling the pH and temperature of the emulsion formed so that the continuous phase shell material dispersion is deposited around the dispersed phase particles to form a shell of microcapsules.

In this case, the process of adding an additive to increase the hardness of the shell by reducing elasticity by configuring the microcapsule shell more densely may be included. The type of additive to be added may be an ionic or polar substance that is easily soluble in an aqueous phase. For example, at least one of ammonium chloride, resorcinol, hydroquinone, and catechol as a curing catalyst may be used.

In the case of the coacervation method, it is possible to use oil/water emulsions of the inner and outer phases. The dispersion of the core material is coacervated (agglomerated) out of the aqueous outer phase, and is granulated by forming a shell on the oily droplets of the inner phase by controlling the temperature, pH, relative concentration, etc.

In the case of coacervation, as a shell material, urea-formaldehyde, melamine-formaldehyde, gelatin, or arabic rubber, etc. can be used.

In the case of the interfacial polymerization method, the lipophilic monomer in the inner phase is present as an emulsion in the aqueous outer phase. The monomer in the inner phase liquid crystal reacts with the monomer introduced into the aqueous outer phase, polymerization reaction occurs at the interface between the droplets of the inner phase and the surrounding aqueous outer phase, and a shell of particles is formed around the droplets. The formed shell is relatively thin and permeable, but unlike other manufacturing methods, heating is not required, so there is an advantage that various dielectric fluids can be applied.

<Example>

FIG. 15 is a photomicrograph of the charged quantum dot microcapsules synthesized according to the embodiment of FIG. 5 .

Referring to Figure 15 (a), quantum dots were microencapsulated using melamine and urea as wall materials, and referring to Figure 15 (b), the surface of quantum dot microcapsule 1500 was coated with tetraethoxysilane ( It was confirmed that the quantum dot microcapsule 1502 having a charge in which a charge control agent coating shell was formed in the outer region of the surface of the microcapsule by coating with TEOS) 1501 was synthesized.

Example 1: Method for preparing quantum dot microcapsules of FIG. 15 (a)

Melamine-formaldehyde prepolymer was prepared as a transparent solution by mixing 7.62 g of melamine and 13.78 g of formaldehyde, raising the temperature to 70° C., and maintaining it for 30 minutes. After the solution was cooled to 25° C. and maintained at the same temperature, 1.22 g of urea, 60 g of a 5% solution of PVA (MW: 85,000-146,000) used as a stabilizer, and 60 g of a 1% solution of surfactant SDS were added to the solution. Melamine and urea were used as wall materials and formaldehyde as hardener. While stirring the solution, 60 ml of quantum dot ink was put into the reactor solution, and emulsification was carried out for 10 minutes at 6000 rpm with a high-speed homogenizer. After confirming the state of the emulsion with a microscope, the reaction was carried out by setting the circulator temperature to 86°C and the time to 6 hours. After completion of the reaction, the quantum dot microcapsules were collected in a centrifuge at 10000 rpm and then redispersed in ethanol.

Example 2: Method for preparing quantum dot microcapsules having an electric charge of FIG. 15(b)

Example 1 In order to bind tetraethoxysilane (TEOS) 1501, which imparts electric charge to the quantum dot microcapsules after the process, first, -OH groups must be coated on the surface of the microcapsules. 100w% of the microcapsule weight was added, and a 28w% ammonia solution was added so that the pH became 11.6, followed by stirring at 50° C. for 5 hours to coat the surface of the microcapsule with silica. After silica coating, after washing at 10000rpm in a centrifuge, the charged quantum dot microcapsules were redispersed in ethanol.

16 is a photograph comparing and demonstrating dispersibility of quantum dot microcapsules with charge and quantum dot microcapsules with no charge, according to an embodiment of the present invention.

Referring to FIG. 16 , after microencapsulating quantum dots, the microcapsules surface-treated to show an electric charge and the quantum dot microcapsules that do not show an electric charge are each shaken for 10 minutes using a vortex mixer equipment. Acid properties were compared.

Referring to Figure 16 (a), when the surface of the quantum dot microcapsule does not show an electric charge, the microcapsules irregularly aggregation phenomenon appears due to energy such as vibration and friction applied to a vortex mixer. Able to know.

Referring to FIG. 16(b), in the case of microcapsules coated so that the surface of the quantum dot microcapsule is negatively charged, after application to a vortex mixer, the surface of the quantum dot microcapsule is relatively non-charged compared to the case As a result, it was confirmed that the flowability was good and the dispersibility was very good because the capsules did not aggregate due to the repulsive force between the microcapsules.

Example 3: Manufacturing method of quantum dot microcapsules without charge of FIG. 16 (a)

Melamine-formaldehyde prepolymer was prepared as a transparent solution by mixing 7.62 g of melamine and 13.78 g of formaldehyde, raising the temperature to 70° C., and maintaining it for 30 minutes. After the solution was cooled to 25° C. and maintained at the same temperature, 1.22 g of urea, 60 g of a 5% solution of PVA (MW: 85,000-146,000) used as a stabilizer, and 60 g of a 1% solution of surfactant SDS were added to the solution. Melamine and urea were used as wall materials and formaldehyde as hardener. While stirring the solution, 60 ml of quantum dot ink was put into the reactor solution, and emulsification was carried out for 10 minutes at 6000 rpm with a high-speed homogenizer. After confirming the state of the emulsion with a microscope, the reaction was carried out by setting the circulator temperature to 86°C and the time to 6 hours. After completion of the reaction, the quantum dot microcapsules were collected in a centrifuge at 10000rpm, washed and dried in an oven at 90°C.

Example 4: Manufacturing method of quantum dot microcapsules having a charge of FIG. 16(b)

Example 3 After the process, 28w% ammonia aqueous solution was added to the redispersed quantum dot microcapsule slurry to coat the -OH group on the surface of the quantum dot microcapsule so that the pH became 11.6, and then tetraethoxysilane (TEOS) was added 100w relative to the capsule weight. % was added and stirred at 50° C. for 8 hours to coat the surface of the microcapsule with silica. After silica coating, it was washed three times at 10000rpm in a centrifuge and dried in an oven at 90°C.

Claims (8)

Including charged quantum dot microcapsules, solvents, sealing materials and functional materials for sealing display devices,
The charged quantum dot microcapsule is microencapsulated by including a plurality of quantum dots inside, and the surface of the microcapsule has a specific charge, and Klong's force ( Charged quantum dot microcapsule ink, characterized in that the dispersibility of microcapsules is further improved compared to quantum dot microcapsules that do not show an electric charge by arranging the microcapsules by generating a repulsive force by Coulomb force.
According to claim 1,
A red, green or blue color filter material is additionally coated on the surface of the charged quantum dot microcapsule, so as to complement the color reproducibility of the quantum dot contained in the microcapsule. Quantum dot microcapsule ink with an electric charge.
A method for producing the quantum dot microcapsule ink having the charge of claim 1 or 2,
microencapsulating a plurality of quantum dots;
removing moisture from the surface of the microcapsule to prepare it in a powder form;
charging the surface of the quantum dot microcapsule with a positive or negative charge through triboelectrification of the quantum dot microcapsule and a carrier; and
Mixing the prepared quantum dot microcapsules having an electric charge with a sealing material and a functional material that are melted or cured by a solvent, a specific temperature or light in a specific wavelength band;
A method for producing an electrically charged quantum dot microcapsule ink comprising a.
A method for producing the quantum dot microcapsule ink having the charge of claim 1 or 2,
microencapsulating a plurality of quantum dots;
removing moisture from the surface of the microcapsule to prepare it in a powder form;
charging the quantum dot microcapsules to the surface of the microcapsule through corona discharge, or alternately applying a pulse voltage to charge the surface of the microcapsule through the mutual collision of the quantum dot microcapsules; and
Mixing the prepared quantum dot microcapsules having a charge with a solvent, a sealing material and a functional material that are melted or cured by light of a specific temperature or a specific wavelength band; manufacturing method.
A method for producing the quantum dot microcapsule ink having the charge of claim 1 or 2,
microencapsulating the quantum dots;
applying a charge by coating a charge control agent or an ionic material on the surface of the quantum dot microcapsule; and
Mixing the prepared quantum dot microcapsules having an electric charge with a sealing material and a functional material that are melted or cured by a solvent, a specific temperature or light in a specific wavelength band;
A method for producing an electrically charged quantum dot microcapsule ink comprising a.
delete A method of manufacturing a color filter through an inkjet printing process using the quantum dot microcapsule ink having a charge according to claim 1 or 2,
printing a black matrix pattern on a color filter substrate;
uniformly spraying red, green, and blue ink containing quantum dot microcapsules that are charged through an inkjet printer head between the black matrix patterns to each sub-pixel;
drying the sprayed ink through a heat treatment process; and
forming red, green, and blue sub-pixels for color filters;
including,
Since the charged quantum dot microcapsule ink includes a sealing material and a functional material,
When the red, green, and blue subpixels are formed, the encapsulation process is performed in parallel, or
After the sub-pixel printing, the encapsulation process is continuously performed.
A method of manufacturing a color filter by an inkjet printing process.
An electronic device comprising the quantum dot microcapsule ink charged according to claim 1 or 2, wherein the electronic device includes a display device, a lighting device, a backlight unit, a color filter, a color conversion layer, an organic light emitting diode (LED), An electronic device comprising an electrically charged quantum dot microcapsule ink, characterized in that it is a surface light emitting device, a magnetic memory, or a battery.

Images