Transparent nickel complex compound ink composition and its manufacturing method

Abstract

The present invention relates to a transparent nickel complex compound ink composition and a manufacturing method thereof. More specifically, the transparent nickel complex compound ink composition includes a polar portion including nickel and a compound coordinately bonded to the nickel, a solvent, and other additives, and is characterized in that the nickel complex compound ink composition is transparent, particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm.

Description

[Technical field]

[0001] The present invention relates to a transparent nickel complex compound ink composition and a manufacturing method thereof. More specifically, the nickel complex compound ink composition is transparent and particle-free, has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm, and is characterized in that the maximum diameter of nickel particles constituting a thin film formed by applying the composition to a substrate is 150 nm or less, and can be used for forming internal electrodes of multilayer ceramic capacitors (MLCCs), electromagnetic wave shielding, solar cell electrodes, or display panel electrodes. [Background technology]

[0002] Nickel powder is used as a material for capacitors, which are electronic components that make up electronic circuits, in particular as a thick-film conductor material that makes up the internal electrodes of multilayer ceramic components such as multilayer ceramic capacitors (MLCCs) and multilayer ceramic substrates.

[0003] In recent years, as the capacity of multilayer ceramic capacitors has increased, the amount of internal electrode paste used to form thick-film conductors that constitute the internal electrodes of multilayer ceramic capacitors has also increased significantly. Therefore, as metal powder for internal electrode paste, low-cost nonmetals such as nickel are mainly used instead of expensive precious metals.

[0004] The manufacturing process of currently commercialized multilayer ceramic capacitors is simplified as follows. First, an internal electrode paste obtained by kneading nickel powder, a binder resin such as ethyl cellulose, and an organic solvent such as terpineol is screen-printed on a dielectric green sheet. Next, the dielectric green sheets on which the internal electrode paste is printed are laminated so that the internal electrode paste and the dielectric green sheets are alternately overlapped and pressed to obtain a laminate. After that, the obtained laminate is cut to a predetermined size and heated to remove the binder resin (hereinafter referred to as "binder removal process"), and then fired at a high temperature of about 1,300°C to obtain a ceramic molded body. Finally, an external electrode is provided on the obtained ceramic molded body to obtain a multilayer ceramic capacitor.

[0005] In this case, since non-metals such as nickel are used as the metal powder in the internal electrode paste, the binder removal process of the laminate must be carried out in an atmosphere with an extremely low oxygen concentration, such as an inert atmosphere, so as to prevent the non-metals from being oxidized.

[0006] Meanwhile, with the miniaturization and increased capacity of multilayer ceramic capacitors, research and development efforts have been made in recent years to thin the internal electrodes and dielectrics. In particular, in order to achieve a film thickness of 400 nm or less for the internal electrode thin film, the particle size of the nickel powder used in the internal electrode paste has also been made finer, and as a result, nickel powder with an average particle size of 0.5 μm or less is required, and nickel powder with an average particle size of 0.3 μm or less is mainly used.

[0007] In this regard, existing publicly available technologies have disclosed a technology relating to a paste composition that minimizes particle size, such as using an internal electrode paste containing functional particles with a particle size of approximately 50 nm in order to minimize the thickness when forming such an electrode. However, in the end, a problem occurs in that the particle content exceeds 50 parts by weight based on 100 parts by weight of the total composition due to the stability of the composition, and therefore, there is a limit in that the thickness of the internal electrode cannot be reduced to 400 nm or less.

[0008] For this reason, the present inventors have completed the present invention by preparing a transparent, particle-free conductive nickel complex compound ink composition for forming an internal electrode of the multilayer ceramic capacitor (MLCC). The transparent nickel complex compound ink composition is transparent, particle-free, and has the advantage of being able to reduce the metal content compared to existing pastes and inks, making it competitive, and therefore has the advantage of being able to obtain a thin internal electrode thickness.

[0009] In this regard, Japanese Patent Publication No. 2008-127657 discloses a coating liquid for forming a nickel film, a method for producing a nickel film, and a nickel film. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2008-127657 A Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, the present invention has been devised to solve the above-mentioned problems, and one embodiment of the present invention provides a transparent nickel complex compound ink composition and a method for producing the same.

[0012] However, the technical problems that the present invention aims to solve are not limited to the problems described above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present invention pertains from the description below. [Means for solving the problem]

[0013] As a technical means for achieving the above-mentioned technical object, one aspect of the present invention provides a transparent nickel complex compound ink composition comprising nickel and a polar moiety containing a compound represented by the following chemical formula 1 coordinately bonded to the nickel, a solvent, and other additives, wherein the nickel complex compound ink composition is transparent and particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm.

[0014] [ka]

[0015] (In the above chemical formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 5 ~C 20 Alkyl, straight or branched chain C 5 ~C 20 Alkenyl, C 5 ~C 20 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C20 Heteroaryl of C 5 ~C 20 is an alkylcarbonyl of R 1 ~R 3 At least one of the linear or branched chain C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl and straight or branched C 5 ~C 20 Alkyl or C 5 ~C 20 It may be any one selected from the group consisting of alkenyl. In the above chemical formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 8 ~C 18 Alkyl, straight or branched chain C 8 ~C 18 Alkenyl, C 8 ~C 18 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 8 ~C 18 Aryl, linear or branched C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C 8 ~C 18 Heteroaryl, straight or branched C8 ~C 18 or straight or branched chain C 8 ~C 18 It may also be an alkenyl of the formula:

[0016] In the above chemical formula 1, R 1 and R 2 is hydrogen and R 3 is a straight or branched chain C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C substituted with alkyl 8 ~C 18 aryl or heteroaryl, linear or branched C 8 ~C 18 or straight or branched chain C 8 ~C 18 It may also be an alkenyl of the formula:

[0017] The compound represented by Chemical Formula 1 above may be 2-amino-1-methyl-1-propanol, n-hexylamine, hexylamine, cyclohexylamine, n-octylamine, octylamine, dodecylamine, oleylamine, benzylamine, 1-dimethylamino-2-propanol, 2-(diethylamino)ethanol, or diphenylamine.

[0018] The concentration of the polar portion may be 8% by weight to 72% by weight based on the total weight of the transparent nickel complex compound ink composition.

[0019] The solvent may be terpineol, alpha-terpineol, dihydro-terpineol, terpinyl acetate, dihydro terpinyl acetate, isobornyl acetate, isobornyl propionate, isobornyl isobutyrate, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dipropylene glycol monomethyl ether, ethylene glycol phenyl ether, propylene ... The alcohol may include a material selected from the group consisting of ethylene glycol monobutyl ether acetate, dipropylene glycol methyl ether acetate, ethanol, propanol, isopropyl alcohol, butanol, isooctyl alcohol, diacetone alcohol, 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, and combinations thereof.

[0020] The other additives may include a material selected from the group consisting of binder resins, plasticizers, stabilizers, dispersants, release agents, reducing agents, surfactants, wetting agents, thixotropic agents, leveling agents, and combinations thereof.

[0021] The binder resin may include a material selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl pyrrolidone, acryl, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and combinations thereof.

[0022] The maximum diameter of nickel particles in a thin film formed by applying the transparent nickel complex compound ink composition to a substrate may be 150 nm or less.

[0023] The transparent nickel complex compound ink composition may be characterized as being a transparent nickel complex compound ink composition for forming an internal electrode of a multilayer ceramic capacitor (MLCC), for electromagnetic wave shielding, for forming a solar cell electrode, or for forming a display panel electrode.

[0024] Another aspect of the present invention provides a method for producing a transparent nickel complex compound ink composition, the method including the steps of: mixing a nickel precursor and a compound represented by the following chemical formula 1 to prepare a nickel complex compound; mixing the nickel complex compound with a solvent; heating the nickel complex compound mixed with the solvent; and heating a binder resin together in the heating step, wherein the nickel complex compound ink composition is transparent and particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm.

[0025] [ka]

[0026] (In the above chemical formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 5 ~C 20 Alkyl, straight or branched chain C 5 ~C 20 Alkenyl, C 5 ~C 20 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl of C 5 ~C 20 is an alkylcarbonyl of R 1 ~R 3 At least one of the linear or branched chain C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl and straight or branched C 5 ~C 20 Alkyl or C 5 ~C 20 It may be any one selected from the group consisting of alkenyl. The nickel complex compound ink composition may be transparent, particle-free, and have an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm.

[0027] The heating may be carried out at less than 115°C. Effect of the Invention

[0028] According to one aspect of the present invention, the transparent nickel complex compound ink composition is transparent and particle-free, and therefore it is possible to form a thinner coating than with conventional paste compositions, thereby making it possible to form a thin film.

[0029] In addition, the maximum diameter of the nickel particles constituting the thin film formed by applying the nickel complex compound ink composition to a substrate is very small, at 150 nm or less, so the roughness of the nickel internal electrodes is low. This leads to the advantage of high adhesion when the internal electrodes of the MLCC and the dielectric green sheets are laminated and pressed together in an alternating manner, and as a result, the number of thin films within an MLCC of the same volume can be increased to improve performance.

[0030] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the present invention or the claims. [Brief description of the drawings]

[0031] [Figure 1a] 4A and 4B are photographs showing transparent nickel complex compound ink compositions for forming internal electrodes of MLCCs manufactured according to an embodiment and a comparative example of the present invention. [Figure 1b] As described with respect to Figure 1a. [Figure 2a] Graphs a to g show the absorbance of transparent nickel complex compound ink compositions prepared according to an example of the present invention and a comparative example. [Figure 2b]As explained with respect to Figure 2a. [Figure 2c] As explained with respect to Figure 2a. [Figure 2d] As explained with respect to Figure 2a. [Figure 2e] As explained with respect to Figure 2a. [Figure 2f] As explained with respect to Figure 2a. [Figure 2g] As explained with respect to Figure 2a. [Figure 3a] 4A and 4B are photographs showing thin films of nickel internal electrodes manufactured according to an embodiment and a comparative example of the present invention. [Figure 3b] As explained with respect to Figure 3a. [Figure 4a] 4A to 4G are scanning electron microscope (SEM) photographs showing nickel internal electrode thin films produced according to an embodiment of the present invention and a comparative example, respectively. [Figure 4b] As explained with respect to Figure 4a. [Figure 4c] As explained with respect to Figure 4a. [Figure 4d] As explained with respect to Figure 4a. [Figure 4e] As explained with respect to Figure 4a. [Figure 4f] As explained with respect to Figure 4a. [Figure 4g] As explained with respect to Figure 4a. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The present invention may, however, be embodied in many different forms and, therefore, should not be construed as limited to the embodiments set forth herein, but rather as defined only by the claims.

[0033] Incidentally, the terms used in this specification are merely used to describe a particular embodiment and are not intended to limit the present invention. A singular expression includes plural expressions unless otherwise clearly indicated in the context. Throughout the specification of this disclosure, when a certain component is referred to as "including" or "comprising" a certain component, this does not mean that other components are excluded, and means that other components may be further included, unless otherwise specified.

[0034] First, the transparent nickel complex compound ink composition according to one embodiment of the present invention can be used for electrodes of a wide variety of electronic devices and semiconductors containing nickel, or can be used for electromagnetic wave shielding (EMI Shielding). For example, the transparent nickel complex compound ink composition can be used for forming an internal electrode of an MLCC, for electromagnetic wave shielding, for forming a solar cell electrode, or for forming an electrode of a display panel, and preferably, the transparent nickel complex compound ink composition can be used for forming an internal electrode of an MLCC or for electromagnetic wave shielding.

[0035] MLCC(Multilayer Ceramic Capacitor) MLCC is an abbreviation for Multilayer Ceramic Capacitor, and is known as a multilayer ceramic capacitor.

[0036] MLCCs are capacitors with a fixed value, in which a ceramic material acts as the dielectric, and are essentially composed of two or more ceramic layers and metal layers acting as electrodes. The composition of the ceramic material determines the electrical behavior of the MLCC and therefore the range of applications.

[0037] Recently, the demand for MLCCs in smartphones, portable personal computers (PCs), and the automotive industry has increased dramatically, and the shortage of MLCCs has become a major issue around the world. Electronic devices that we use every day, such as smartphones, PCs, light-emitting diodes (LEDs), and TVs, are equipped with more than 1,000 MLCCs. Electric vehicles require more than 10,000 MLCCs to realize electronic control and automation systems. MLCCs are installed in electronic devices to distribute and adjust the amount of current flowing through the circuit, remove noise, and prevent electronic device malfunctions. Furthermore, these electronic devices with high performance, multifunctionality, and high integration require many high-capacity MLCCs. Combined with this trend, the internal space of electronic devices is limited by batteries and integrated circuits, so miniaturization of high-capacity MLCCs is a major issue.

[0038] Key factors for the development of MLCCs with high volumetric efficiency and high capacitance include 1) the use of dielectric materials with high dielectric constants, 2) stacking of a greater number of internal electrodes and dielectric layers, 3) increasing the area of ​​overlapping internal electrodes, and 4) reducing the thickness of the internal electrodes and dielectric layers. For high capacitance and volumetric efficiency, next-generation MLCCs must have many stacked dielectric layers with thicknesses of less than 1 μm. In particular, the internal electrodes require many stacked layers with thicknesses of 400 nm or less.

[0039] Basic Principles of MLCC The basic principle of MLCCs' electricity storage is based on the polarization phenomenon of dielectrics. In the absence of an external electric field, the electric dipoles inside the dielectric are randomly distributed, exhibiting the characteristics of an insulator. However, when a voltage is applied to the electrodes at both ends to generate an electric field in the dielectric film, the dipoles are aligned in the direction of the magnetic field, and positive and negative charges are concentrated at the positive electrodes, making it possible to store electricity.

[0040] MLCCs are the core components of passive devices that have the function of temporarily charging the electricity stored in this way, and have the characteristic of passing AC current, blocking DC current, and constantly discharging current. MLCCs with even higher capacitance are required as passive devices for next-generation electronic devices that are smaller and have higher capacity.

[0041] MLCCs are made up of many dielectric layers and internal electrodes stacked in parallel and crossed fashion. The internal electrodes are connected to external terminations for surface mounting. The capacitance of an MLCC is written as follows:

[0042]

number

[0043] ε r is the relative dielectric constant, ε 0 is the vacuum dielectric constant, n is the number of laminated internal electrodes, S is the area of ​​the internal electrodes, and T is the thickness of the internal electrodes. In order to realize a high-capacity MLCC, the thickness of the dielectric layer and the number of layers are the main factors in determining the chip size. That is, to increase the capacitance of the MLCC to achieve high capacity, the surface area of ​​the internal electrodes must be maximized, and the thickness of the dielectric thin film and the internal electrodes must be minimized. However, with the need for ultra-miniaturization of elements, it is impossible to increase the area, so the thickness of the internal electrodes must be minimized and the internal electrodes and dielectric thin films in the same volume must be laminated to obtain high capacitance.

[0044] Below, various aspects of the present invention that enable the formation of thin films to minimize the thickness of the internal electrodes of MLCCs are described in detail.

[0045] A first aspect of the present invention provides a transparent nickel complex compound ink composition comprising nickel, a polar moiety comprising a compound represented by the following chemical formula 1 coordinately bonded to the nickel, a solvent, and other additives, wherein the nickel complex compound ink composition is transparent and particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm.

[0046] [ka]

[0047] (In the above chemical formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 5 ~C 20 Alkyl, straight or branched chain C 5 ~C 20 Alkenyl, C 5 ~C 20 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl of C 5 ~C 20 is an alkylcarbonyl of R 1 ~R 3 At least one of the linear or branched chain C 1 ~C 5 or straight or branched chain C 8 ~C 18C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl and straight or branched C 5 ~C 20 Alkyl or C 5 ~C 20 It may be any one selected from the group consisting of alkenyl. Hereinafter, the transparent nickel complex compound ink composition according to the first aspect of the present invention and the thin film formed by applying the nickel complex compound ink composition to a substrate will be described in detail.

[0048] In one embodiment of the present invention, the transparent nickel complex compound ink composition may be characterized by being transparent and particle-free. That is, in the case of an internal electrode paste, which can be said to be a conventional nickel ink composition, functional nickel particles having a particle size of about 50 nm are contained in a particle content of 50 parts by weight or more based on 100 parts by weight of the total composition for the stability of the composition, so that there is a limitation that the thickness of the internal electrode cannot be reduced to 400 nm or less. However, the transparent nickel complex compound ink composition according to the present invention is characterized by being particle-free, and does not cause the above problem, so that it is possible to achieve a thin internal electrode. As a result, the internal electrode manufactured using the transparent nickel complex compound ink composition can realize a larger number of internal electrode stacks, and thus it is possible to achieve a miniaturization and a large capacity of a multilayer ceramic capacitor equipped with the same.

[0049] In one embodiment of the present invention, preferably, in the above formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 8 ~C 18Alkyl, straight or branched chain C 8 ~C 18 Alkenyl, C 8 ~C 18 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 8 ~C 18 Aryl, linear or branched C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C 8 ~C 18 Heteroaryl, straight or branched C 8 ~C 18 or straight or branched chain C 8 ~C 18 and more preferably, R 1 and R 2 is hydrogen and R 3 is a straight or branched chain C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C substituted with alkyl 8 ~C 18 aryl or heteroaryl, linear or branched C 8 ~C 18 or straight or branched chain C 8 ~C 18 It may also be an alkenyl of the formula:

[0050] In one embodiment of the present invention, the compound represented by the above formula 1 may be 2-amino-1-methyl-1-propanol, n-hexylamine, hexylamine, cyclohexylamine, n-octylamine, octylamine, dodecylamine, oleylamine, benzylamine, 1-dimethylamino-2-propanol, 2-(diethylamino)ethanol, or diphenylamine. That is, the unshared electron pair of nitrogen contained in the above formula 1 may form a coordinate bond with nickel to form a polar portion.

[0051] In one embodiment of the present invention, the concentration of the polar moiety may be 8% by weight to 72% by weight, preferably 8% by weight to 64% by weight, and more preferably 8% by weight to 56% by weight, based on the total weight of the nickel complex compound ink composition. If the concentration of the polar moiety is less than 8% by weight, based on the total weight of the conductive nickel complex compound ink composition, the content of the solvent is relatively high, which may make it difficult to form a uniform thin film when forming a nickel internal electrode by applying the transparent nickel complex compound ink composition to a substrate, and if the concentration exceeds 72% by weight, the content of the solvent is relatively low, which may make it difficult to mix the polar moiety and the solvent uniformly.

[0052] In one embodiment of the present invention, the transparent nickel complex compound ink composition contains, as a solvent, terpineol, alpha-terpineol, dihydro-terpineol, terpinyl acetate, dihydro terpinyl acetate, isobornyl acetate, isobornyl propionate, isobornyl isobutyrate, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dipropylene glycol monomethyl ether, ethylene glycol phenyl ether, propylene ... The transparent nickel complex compound ink composition may include a material selected from the group consisting of ethylene glycol monobutyl ether acetate, dipropylene glycol methyl ether acetate, ethanol, propanol, isopropyl alcohol, butanol, isooctyl alcohol, diacetone alcohol, 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, and combinations thereof. That is, the solvent is well mixed with the polar portion and exhibits excellent wettability to the substrate, particularly the surface of glass, so that when the transparent nickel complex compound ink composition including the same is applied to the substrate, a thin thickness can be formed and the coating flatness is also excellent.Furthermore, in the case of a solvent with a low vapor pressure such as dipropylene glycol monomethyl ether, the number of vaporized molecules is smaller than that of a normal solvent, so that even if only a small amount of heat is applied, the molecules in the liquid state can be quickly changed to a gaseous state. When such a solvent is used in combination with a solvent having approximately the same polarity, the molecules in the liquid state can be gasified together with the surrounding solvent molecules when vaporized. Therefore, in the drying and sintering process after coating, the solvent is generally quickly vaporized while maintaining excellent wettability over the entire surface of the coating area, so that the coating flatness after the drying and sintering process is also excellent. Therefore, when this is applied to a substrate, a thin thickness can be formed, and the coating flatness is also excellent. Therefore, when this is applied to an internal electrode of a multilayer ceramic capacitor (MLCC), the wettability to the dielectric green sheet, which is the substrate of the internal electrode, is also excellent, so that the internal electrode can be made thin. Meanwhile, the content of the solvent may be 12% by weight to 86% by weight based on the total weight of the conductive nickel complex compound ink composition.

[0053] In one embodiment of the present invention, the other additives may include a material selected from the group consisting of a binder resin, a plasticizer, a stabilizer, a dispersant, a release agent, a reducing agent, a surfactant, a wetting agent, a thixotropic agent, a leveling agent, and combinations thereof.

[0054] The binder resin may include a material selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl pyrrolidone, acryl, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and combinations thereof. In one embodiment of the present invention, the humectant may be a polyol such as 1,2-hexanediol, 1,6-hexanediol, glycerin, polyethylene glycol, sorbitol, or trehalose, an amino acid, a natural humectant factor (NMF) such as urea, lactate, or PCA-Na (sodium pyrrolidone carboxylate), or a polymer humectant such as hyaluronate, chondroitin sulfate, or hydrolyzed collagen.

[0055] In one embodiment of the present invention, the leveling agent is an additive having a smoothing (leveling) effect, and a compound containing nitrogen, such as polyamine, can be used.

[0056] In one embodiment of the present invention, the transparent nickel complex ink composition may have an absorbance (ABS) of 1.0 or more in a wavelength band of 600 nm to 650 nm. The reason why the peak of the absorbance (ABS) of the nickel complex ink composition in the wavelength band of 600 nm to 650 nm is observed is that when the unshared electron pair of nitrogen contained in the above chemical formula 1 forms a coordinate bond with nickel to form a polar part, an energy level difference occurs in the d orbital function of nickel, and it is measured that the d orbital electrons of the low energy level of nickel absorb light of a specific wavelength in the wavelength band of 600 nm to 650 nm and move to the d orbital function of a high energy level. On the other hand, the value of the absorbance (ABS) may mean a value when the concentration of the polar part is 8% by weight to 72% by weight based on the total weight of the conductive nickel complex ink composition.

[0057] The second aspect of the present invention provides a thin film formed by applying the transparent nickel complex compound ink composition to a substrate. In this case, various types of substrates can be applied, for example, glass, and preferably a dielectric green sheet serving as a substrate for an internal electrode of a multilayer ceramic capacitor (MLCC). Meanwhile, the transparent nickel complex compound ink composition for the internal electrode of the MLCC contains a solvent that is well mixed with the polar part and has a low vapor pressure, and therefore has excellent wettability with the substrate as described above. In the drying and sintering processes after coating, the solvent generally evaporates quickly while maintaining excellent wettability over the entire surface of the coating area, so that the coating flatness after the drying and sintering processes is also excellent. Therefore, when this is applied to a substrate, a thin thickness can be formed, and the coating flatness is also excellent.

[0058] Detailed explanations of parts that overlap with the first aspect of the present invention have been omitted, but the contents explained with respect to the first aspect of the present invention are similarly applicable even if the explanation is omitted in the second aspect.

[0059] In one embodiment of the present invention, the maximum diameter of nickel particles in the thin film containing the transparent nickel complex compound ink composition may be 150 nm or less. In this way, the average diameter of the nickel particles is very small, and the roughness of the nickel internal electrode can be reduced. This leads to the advantage that the internal electrodes of the MLCC and the dielectric green sheets are highly adhesive when stacked and pressed together, and as a result, the number of thin films in the MLCC with the same volume can be increased to improve performance.

[0060] A third aspect of the present invention provides a method for producing a transparent nickel complex compound ink composition, the method including the steps of: mixing a nickel precursor and a compound represented by the following Chemical Formula 1 to prepare a nickel complex compound; mixing the nickel complex compound with a solvent; heating the nickel complex compound mixed with the solvent; and heating a binder resin together in the heating step.

[0061] [ka]

[0062] (In the above chemical formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 5 ~C 20 Alkyl, straight or branched chain C 5 ~C 20 Alkenyl, C 5 ~C 20 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18C 6 ~C 20 Heteroaryl of C 5 ~C 20 is an alkylcarbonyl of R 1 ~R 3 At least one of the linear or branched chain C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Aryl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 6 ~C 20 Heteroaryl and straight or branched C 5 ~C 20 Alkyl or C 5 ~C 20 It may be any one selected from the group consisting of alkenyl. Detailed explanations of parts that overlap with the first aspect of the present invention have been omitted, but the contents explained with respect to the first aspect of the present invention are similarly applicable even if the explanation is omitted in the third aspect.

[0063] Hereinafter, the method for producing the transparent nickel complex compound ink composition according to the third aspect of the present invention will be described in detail step by step.

[0064] First, in one aspect of the present invention, a method for preparing the transparent nickel complex compound ink composition includes a step of preparing a nickel complex compound by mixing a nickel precursor and a compound represented by the following Chemical Formula 1:

[0065] In one embodiment of the present invention, the nickel precursor is nickel formate (C 2 H 2 NiO 4), nickel acetate (Ni(CH 3 CO 2 ) 2 ), Nickel chloride (NiCl 2 ), Nickel sulfate (NiSO 4 ), nickel acetylacetonate (Ni(C 5 H 7 O 2 ) 2 ), Nickel Carbonate (NiCO 3 ), nickel cyclohexanebutyrate ([C 6 H 11 (CH 2 ) 3 CO 2 ] 2 Ni, Nickel Nitrate (Ni(NO 3 ) 2 ), Nickel oxalate (NiC 2 O 4 ), Nickel stearate (Ni(H 3 C(CH 2 ) 16 CO 2 ) 2 , nickel octanonate ([CH 3 (CH 2 ) 6 CO 2 ] 2 In this case, the carboxyl group contained in the nickel precursor may be converted to CO in the subsequent binder removal step. 2 The composition may be evaporated and removed as a result, and the final composition may contain only the polar portion including the compound represented by Chemical Formula 1 coordinated to the nickel particles and the solvent.

[0066] In one embodiment of the present invention, preferably, in the above formula 1, R 1 ~R 3 are each independently hydrogen, straight or branched chain C 8 ~C 18 Alkyl, straight or branched chain C 8 ~C 18 Alkenyl, C8 ~C 18 Cycloalkyl, linear or branched C 1 ~C 5 or straight or branched chain C 8 ~C 18 C 8 ~C 18 Aryl, linear or branched C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C 8 ~C 18 Heteroaryl, straight or branched C 8 ~C 18 or straight or branched chain C 8 ~C 18 and more preferably, R 1 and R 2 is hydrogen and R 3 is a straight or branched chain C 1 ~C 5 Alkyl, straight or branched chain C 8 ~C 18 C substituted with alkyl 8 ~C 18 aryl or heteroaryl, linear or branched C 8 ~C 18 or straight or branched chain C 8 ~C 18 It may also be an alkenyl of the formula:

[0067] Most preferably, in one embodiment of the present invention, the compound represented by the above formula 1 may be 2-amino-1-methyl-1-propanol, n-hexylamine, hexylamine, cyclohexylamine, n-octylamine, octylamine, dodecylamine, oleylamine, benzylamine, 1-dimethylamino-2-propanol, 2-(diethylamino)ethanol, or diphenylamine. That is, the unshared electron pair of nitrogen contained in the above formula 1 may form a coordinate bond with nickel to form a polar portion.

[0068] In one embodiment of the present invention, the molar number of the compound represented by the above chemical formula 1, which forms a coordinate bond with the nickel precursor, may be 2 to 6 times, preferably 4 times, the molar number of the nickel precursor. That is, the nickel precursor and the compound represented by the above chemical formula 1 may form a polar part by forming a coordinate bond. In this case, if the molar number of the compound represented by the above chemical formula 1 is less than twice the molar number of the nickel precursor, the polar part may not be formed, and if it exceeds 6 times, the compound represented by the above chemical formula 1 that remains without forming a complex compound may cause a large amount of bubbles during the subsequent binder removal treatment, which may cause a problem of voids being generated in the thin film of the internal electrode, resulting in a decrease in conductivity.

[0069] Then, in one aspect of the present invention, a method for producing the transparent nickel complex ink composition includes a step of mixing the nickel complex with a solvent.

[0070] In one aspect of the present invention, the content of the mixed solvent may be 12% by weight to 86% by weight, preferably 20% by weight to 82% by weight, based on the total weight of the conductive nickel complex compound ink composition. If the content of the solvent is less than 12% by weight, the dispersion stability of the transparent nickel complex compound ink composition may be reduced, and if it exceeds 86% by weight, the content of the solvent is too high compared to the nickel complex compound, making it difficult to form a uniform thin film of the nickel internal electrode formed by coating on the substrate. Meanwhile, the specific type of the solvent has been described in the first aspect of the present invention, and therefore the description thereof will be omitted in the third aspect of the present invention.

[0071] Next, in one aspect of the present invention, the method for producing the transparent nickel complex compound ink composition for forming a thin film includes a step of heating the nickel complex compound mixed with the solvent.

[0072] In one embodiment of the present invention, the heating may be performed at a temperature below 115° C., through which hydrates contained in the nickel precursor may be evaporated and removed.

[0073] In one aspect of the present invention, the method for producing the transparent nickel complex compound ink composition for forming a thin film may include a step of heating a binder resin together with the nickel complex compound mixed with the solvent in the step of heating the nickel complex compound.

[0074] In one embodiment of the present invention, the transparent nickel complex ink composition may have an absorbance (ABS) of 1.0 or more in a wavelength band of 600 nm to 650 nm. The reason why the peak of the absorbance (ABS) of the nickel complex ink composition in the wavelength band of 600 nm to 650 nm is observed is that when the unshared electron pair of nitrogen contained in the above chemical formula 1 forms a coordinate bond with nickel to form a polar part, an energy level difference occurs in the d orbital function of nickel, and it is measured that the d orbital electrons of the low energy level of nickel absorb light of a specific wavelength in the wavelength band of 600 nm to 650 nm and move to the d orbital function of a high energy level. On the other hand, the value of the absorbance (ABS) may mean a value when the concentration of the polar part is 8% by weight to 72% by weight based on the total weight of the conductive nickel complex ink composition.

[0075] The present invention will now be described in detail with reference to examples so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

[0076] Example 1: Preparation of nickel internal electrodes Step 1: Preparation of transparent nickel complex ink composition Nickel acetate and benzylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 21.4 wt% of the polar part was mixed with 73.6 wt% of diacetone alcohol as a solvent. The transparent nickel complex compound ink was mixed with 5 wt% of PVB (polyvinyl butyral) as a binder and stirred at 100°C to prepare a transparent nickel complex compound ink composition.

[0077] Step 2: Fabrication of nickel internal electrodes The transparent nickel complex compound ink composition prepared in step 1 was printed on glass with a doctor blade using a 30 μm applicator and dried at 600° C. to prepare a nickel internal electrode.

[0078] Example 2: Preparation of nickel internal electrodes In step 1 of Example 1, nickel acetate and cyclohexylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 20.6 wt% of the polar part was mixed with 74.4 wt% of diacetone alcohol as a solvent. A nickel internal electrode was manufactured in the same manner as in Example 1, except that.

[0079] Example 3: Preparation of nickel internal electrodes In step 1 of Example 1, nickel acetate and n-octylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 23.5 wt % of the polar part was mixed with 71.5 wt % of diacetone alcohol as a solvent. A nickel internal electrode was manufactured in the same manner as in Example 1.

[0080] Example 4: Preparation of nickel internal electrodes In step 1 of Example 1, nickel acetate and n-octylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 13.4 wt% of the polar part was mixed with 81.6 wt% of diacetone alcohol as a solvent. A nickel internal electrode was manufactured in the same manner as in Example 1.

[0081] Comparative Example 1: Manufacture of nickel internal electrodes Step 1: Preparation of transparent nickel complex ink composition Nickel acetate and ethylene diamine were mixed in a molar ratio of 1:2 to form a nickel polar part, and 13.0 wt% of the polar part was mixed with 82.0 wt% of diacetone alcohol as a solvent. The transparent nickel complex compound ink was mixed with 5 wt% of PVB (polyvinyl butyral) as a binder and reacted at 100°C to prepare a transparent nickel complex compound ink composition.

[0082] Step 2: Fabrication of nickel internal electrodes The transparent nickel complex compound ink composition prepared in step 1 was printed on glass with a doctor blade using a 30 μm applicator and dried at 600° C. to prepare a nickel internal electrode.

[0083] Comparative Example 2: Manufacture of nickel internal electrodes In step 1 of Comparative Example 1, nickel acetate and n-octylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 7.2 wt% of the polar part was mixed with 87.8 wt% of diacetone alcohol as a solvent. A nickel internal electrode was manufactured in the same manner as in Comparative Example 1, except that

[0084] Comparative Example 3: Manufacture of nickel internal electrodes In step 1 of Comparative Example 1, nickel acetate and n-octylamine were mixed in a molar ratio of 1:4 to form a nickel polar part, and 3.7 wt% of the polar part was mixed with 91.3 wt% of diacetone alcohol as a solvent. A nickel internal electrode was manufactured in the same manner as in Comparative Example 1, except that

[0085] Experimental Example 1. Comparison of the appearance of transparent nickel complex ink compositions for the internal electrodes of MLCCs Experimental Example 1-1. Comparison of appearance depending on the type of ammonium ligand In order to compare the appearance of the transparent nickel complex compound ink compositions according to the type of ammonium ligand, photographs of the transparent nickel complex compound ink compositions prepared in step 1 of Examples 1 to 3 and the transparent nickel complex compound ink composition prepared in step 1 of Comparative Example 1 are shown in Fig. 1a. First, as shown in Fig. 1a, the transparent nickel complex compound ink compositions prepared in step 1 of Examples 1 to 3 of the present invention were transparent and did not form precipitates, so it was confirmed that they were in a particle-free state not containing nickel particles.

[0086] Furthermore, the transparent nickel complex compound ink composition produced in step 1 of Comparative Example 1 was also transparent and no precipitate was formed, confirming that it was in a particle-free state that did not contain nickel particles. From this, it was found that the transparent nickel complex compound ink composition only differs in color depending on the type of ammonium ligand, and that it is transparent and no precipitate is formed regardless of whether the ammonium ligand is monovalent or divalent or higher, and therefore it can be in a particle-free state that does not contain nickel particles.

[0087] Experimental Example 1-2. Comparison of appearance by polar part concentration It was confirmed that the concentration of the transparent nickel complex compound ink composition became thinner as the content of the polar moiety decreased and the content of the solvent increased, as seen in the transparent nickel complex compound ink composition prepared in step 1 of Example 3 shown in FIG. 1a, the transparent nickel complex compound ink composition prepared in step 1 of Example 4 shown in FIG. 1b, and the transparent nickel complex compound ink compositions prepared in step 1 of Comparative Examples 2 and 3 shown in FIG. 1b.

[0088] Experimental Example 2. Measurement of absorbance of transparent nickel complex ink composition Experimental Example 2-1. Comparison of absorbance according to the type of ammonium ligand A spectrophotometer BioMate (trade name) 160 manufactured by Thermo Fisher Scientific was used to measure the absorbance of the transparent nickel complex compound ink compositions produced in step 1 of Examples 1 to 3 and the transparent nickel complex compound ink composition produced in step 1 of Comparative Example 1. The absorbance was measured in the wavelength range of 200 nm to 900 nm using this, and the results are shown in Figures 2a to 2c and 2d, respectively. Figures 2a to 2c are graphs showing the absorbance of the transparent nickel complex compound ink compositions produced in step 1 of Examples 1 to 3, and Figure 2d is a graph showing the absorbance of the transparent nickel complex compound ink composition produced in step 1 of Comparative Example 1.

[0089] As shown in Figs. 2a to 2c, it was confirmed that the transparent nickel complex compound ink compositions produced in step 1 of Examples 1 to 3 have absorbance for light in the wavelength band of about 600 nm to 750 nm. Specifically, it was confirmed that the absorbance (ABS) for light in the wavelength band of 650 nm was 1.5 or more. In contrast, in the case of the transparent nickel complex compound ink composition produced in step 1 of Comparative Example 1 shown in Fig. 2d, it was confirmed that the transparent nickel complex compound ink composition produced in step 1 of Examples 1 to 3 shown in Figs. 2a to 2c had absorbance for light in the wavelength band of 500 nm to 650 nm. Specifically, it was confirmed that the transparent nickel complex compound ink compositions produced in step 1 of Examples 1 to 3 had absorbances (ABS) for light in the wavelength band of 650 nm of 2.3 or more, 1.5 or more, and 2.3 or more, respectively, and the transparent nickel complex compound ink composition produced in step 1 of Comparative Example 1 had a value of 1.0 or more.

[0090] In other words, as is clear from the above Experimental Example 1-1, in the case of a transparent nickel complex compound ink composition, when a monovalent ammonium ligand is used among the types of ammonium ligand, it was confirmed that the absorbance (ABS) value for light in the 650 nm wavelength band is 1.0 or more.

[0091] Experimental Example 2-2. Comparison of absorbance according to the concentration of polar parts A spectrophotometer BioMate (trade name) 160 manufactured by Thermo Fisher Scientific was used to measure the absorbance of the transparent nickel complex compound ink composition prepared in step 1 of Examples 3 and 4 and the transparent nickel complex compound ink composition prepared in step 1 of Comparative Examples 2 and 3. The absorbance was measured in a wavelength range of 200 nm to 900 nm using this, and the results are shown in Fig. 2e, Fig. 2f, and Fig. 2g, respectively. Fig. 2c is a graph showing the absorbance of the transparent nickel complex compound ink composition prepared in step 1 of Example 3, Fig. 2e is a graph showing the absorbance of the transparent nickel complex compound ink composition prepared in step 1 of Example 4, and Figs. 2f and 2g are graphs showing the absorbance of the transparent nickel complex compound ink composition prepared in step 1 of Comparative Examples 2 and 3, respectively.

[0092] As shown in FIG. 2c, it was confirmed that the transparent nickel complex compound ink composition prepared in step 1 of Example 3 had absorbance for light in the wavelength band of about 600 nm to 750 nm. Specifically, it was confirmed that the absorbance (ABS) for light in the wavelength band of 650 nm was 2.3 or more. In addition, in the case of the transparent nickel complex compound ink composition prepared in step 1 of Example 4 shown in FIG. 2e and the transparent nickel complex compound ink compositions prepared in step 1 of Comparative Examples 2 and 3 shown in FIG. 2f and FIG. 2g, it was confirmed that the transparent nickel complex compound ink composition prepared in step 1 of Example 3 shown in FIG. 2c had absorbance for light in the wavelength band of 600 nm to 750 nm. In contrast, specifically, it was confirmed that the absorbance (ABS) for light in the 650 nm wavelength band was 1.4 or more for the transparent nickel complex compound ink composition produced in Step 1 of Example 4, and 0.7 or more and 0.3 or more for the transparent nickel complex compound ink compositions produced in Step 1 of Comparative Examples 2 and 3, respectively.

[0093] That is, as is evident from Experimental Example 1-2, it was confirmed through the absorbance (ABS) value that the concentration of the transparent nickel complex compound ink composition becomes thinner as the polar part content decreases and the solvent content increases.

[0094] Experimental Example 3: Observation of nickel internal electrodes Experimental Example 3-1. Comparison of nickel internal electrodes according to the type of ammonium ligand Fig. 3a shows a photograph of the nickel internal electrode manufactured in step 2 of Examples 1 to 3 and the nickel internal electrode manufactured in step 2 of Comparative Example 1. In addition, scanning electron microscope (SEM) photographs were taken to observe the shape of the thin film of the nickel internal electrode manufactured in step 2 of Examples 1 to 3 and the nickel internal electrode manufactured in step 2 of Comparative Example 1, and the results are shown in Figs. 4a to 4d, respectively.

[0095] As shown in Fig. 3a, in the case of the nickel internal electrode manufactured in step 2 of Examples 1 to 3 and the nickel internal electrode manufactured in step 2 of Comparative Example 1, regardless of whether the ammonium ligand is monovalent or divalent or higher, there appears to be no visible difference. However, as shown in Figs. 4a to 4d, it was confirmed that the maximum diameter of the nickel particles constituting the thin film of the nickel internal electrode manufactured in step 2 of Comparative Example 1 using a divalent ammonium ligand is larger than the maximum diameter of the nickel particles constituting the thin film of the nickel internal electrode manufactured in step 2 of Examples 1 to 3 using a monovalent ammonium ligand. In particular, in the case of the nickel particles constituting the thin film of the nickel internal electrode manufactured in step 2 of Example 3 using normal octylamine (n-octylamine) as a monovalent ammonium ligand as shown in Fig. 4c, the average diameter is very small, whereas it was confirmed that the maximum diameter of the nickel particles constituting the thin film of the nickel internal electrode manufactured in step 2 of Comparative Example 1 using ethylenediamine (ethylenediamine) as a divalent ammonium ligand as shown in Fig. 4d is close to 150 nm. In addition, it was confirmed that the nickel internal electrode manufactured in step 2 of Example 3 had smaller roughness than the nickel internal electrode manufactured in step 2 of Comparative Example 1.

[0096] This leads to the advantage of high adhesion when the internal electrodes of the MLCC and the dielectric green sheets are stacked alternately and compressed together, making it possible to increase the number of thin films within an MLCC of the same volume and improve performance.

[0097] Experimental Example 3-2. Comparison of nickel internal electrodes according to the concentration of the polarity part Fig. 3b shows a photograph of the nickel internal electrode prepared in step 2 of Example 4 and the nickel internal electrode prepared in step 2 of Comparative Examples 2 and 3. In addition, SEM photographs were taken to observe the shape of the thin film of the nickel internal electrode prepared in step 2 of Example 4 and the nickel internal electrode prepared in step 2 of Comparative Examples 2 and 3, and the results are shown in Figs. 4e to 4g, respectively.

[0098] As shown in FIG. 4e, unlike the nickel internal electrode manufactured in step 2 of Example 4, in the case of the nickel internal electrode manufactured in step 2 of Comparative Examples 2-3, it was confirmed that a uniform thin film was not formed, and therefore the nickel internal electrode was in the form of a lump. This was confirmed through the fact that, while it can be confirmed that a uniform thin film is formed in the case of the nickel internal electrode manufactured in step 2 of Example 4 as shown in FIG. 4e, the thin film of the nickel internal electrode manufactured in step 2 of Comparative Example 2 shown in FIG. 4f is interrupted, and the thin film of the nickel internal electrode manufactured in step 2 of Comparative Example 3 shown in FIG. 4g is not observed. This suggests that it may be difficult to form a uniform thin film as the content of the polar part decreases and the content of the solvent increases.

Claims

1. A polar portion including nickel and a compound represented by the following formula 1 coordinated to the nickel; A solvent; Other additives, A transparent nickel complex compound ink composition comprising: The nickel complex compound ink composition is transparent, particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength band of 600 nm to 650 nm, A transparent nickel complex ink composition, wherein the concentration of the polar moiety is 13.4% by weight to 23.5% by weight based on the total weight of the transparent nickel complex ink composition. 【Chemistry 1】 (In the above chemical formula 1, R １ ~R ３ are each independently hydrogen, a straight or branched chain C ５ ~C ２０ Alkyl, straight or branched C ５ ~C ２０ Alkenyl of C ５ ~C ２０ cycloalkyl, straight or branched C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ aryl of straight or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ Heteroaryl of ５ ~C ２０ is an alkylcarbonyl of R １ ~R ３ At least one of the linear or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ aryl of straight or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ Heteroaryl and straight or branched C ５ ~C ２０ Alkyl or C ５ ~C ２０ is any one selected from the group consisting of alkenyl.

2. In the above formula 1, R １ ~R ３ are each independently hydrogen, a straight or branched chain C ８ ~C １８ Alkyl, straight or branched C ８ ~C １８ Alkenyl of C ８ ~C １８ cycloalkyl, straight or branched C １ ~C ５ or straight or branched chain C ８ ~C １８ C ８ ~C １８ aryl of straight or branched chain C １ ~C ５ Alkyl, straight or branched C ８ ~C １８ C ８ ~C １８ Heteroaryl of the formula: ８ ~C １８ or straight or branched chain C ８ ~C １８ 2. The transparent nickel complex compound ink composition according to claim 1, wherein the alkenyl group is one of the formulas represented by the formula:

3. In the above formula 1, R １ and R ２ is hydrogen, R ３ is a straight or branched chain C １ ~C ５ Alkyl, straight or branched C ８ ~C １８ C substituted with alkyl ８ ~C １８ aryl or heteroaryl of straight or branched chain C ８ ~C １８ or straight or branched chain C ８ ~C １８ 2. The transparent nickel complex compound ink composition according to claim 1, wherein the alkenyl group is one of the formulas represented by the formula:

4. The compound represented by the above Chemical Formula 1 includes 2-amino-1-methyl-1-propanol, n-hexylamine, hexylamine, cyclohexylamine, n-octylamine, octylamine, dodecylamine, and the like.

2. The transparent nickel complex compound ink composition according to claim 1, wherein the nickel complex compound is selected from the group consisting of 1-(2-(dimethylamino)ethanol, 1-(2-(diethylamino)ethanol, and 1-(2-(diethylamino)ethanol).

5. 2. The transparent nickel complex ink composition according to claim 1, wherein the content of the solvent is 71.5% by weight to 81.6% by weight based on the total weight of the transparent nickel complex ink composition.

6. The solvent may be terpineol, alpha-terpineol, dihydro-terpineol, terpinyl acetate, dihydroterpinyl acetate, isobornyl acetate, isobornyl propionate, isobornyl isobutyrate, ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, glycol, dipropylene glycol, dipropylene glycol monomethyl ether, ethylene glycol phenyl ether, propylene glycol phenyl ether, ethylene glycol monobutyl ether acetate, dipropylene glycol methyl ether acetate, ethanol, propanol, isopropyl alcohol, isooctyl alcohol, butanol, diacetone alcohol 2. The transparent nickel complex ink composition of claim 1, comprising a material selected from the group consisting of 1,2-pentanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,5-pentanediol, and combinations thereof.

7. 2. The transparent nickel complex compound ink composition according to claim 1, wherein the other additives include a material selected from the group consisting of a binder resin, a plasticizer, a stabilizer, a dispersant, a release agent, a reducing agent, a surfactant, a wetting agent, a thixotropic agent, a leveling agent, and combinations thereof.

8. 8. The transparent nickel complex compound ink composition according to claim 7, wherein the binder resin comprises a material selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl pyrrolidone, acrylic, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and combinations thereof.

9. 8. The transparent nickel complex compound ink composition according to claim 7, wherein the binder resin comprises a material selected from the group consisting of polyvinyl butyral, ethyl cellulose, polyvinyl pyrrolidone, acrylic, polyvinyl acetal, polyvinyl alcohol, polyolefin, polyurethane, polystyrene, and combinations thereof.

10. 2. The transparent nickel complex compound ink composition according to claim 1, which is a transparent nickel complex compound ink composition for forming an internal electrode of a multilayer ceramic capacitor (MLCC), for electromagnetic wave shielding, for forming a solar cell electrode, or for forming a display panel electrode.

11. A method for preparing a nickel complex compound by mixing a nickel precursor and a compound represented by the following Chemical Formula 1: mixing the nickel complex with a solvent; heating the nickel complex mixed with the solvent; heating a binder resin together in the heating step; A method for producing a transparent nickel complex compound ink composition comprising the steps of: 【Chemistry 2】 (In the above chemical formula 1, R １ ~R ３ are each independently hydrogen, a straight or branched chain C ５ ~C ２０ Alkyl, straight or branched C ５ ~C ２０ Alkenyl of C ５ ~C ２０ cycloalkyl, straight or branched C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ aryl of straight or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ Heteroaryl of ５ ~C ２０ is an alkylcarbonyl of R １ ~R ３ At least one of the linear or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ aryl of straight or branched chain C １ ~C ５ or straight or branched chain C ８ ~C １８ C ６ ~C ２０ Heteroaryl and straight or branched C ５ ~C ２０ Alkyl or C ５ ~C ２０ is any one selected from the group consisting of alkenyl.

12. The method for producing a transparent nickel complex compound ink composition according to claim 11, wherein the nickel complex compound ink composition is transparent, particle-free, and has an absorbance (ABS) value of 1.0 or more in a wavelength range of 600 nm to 650 nm.

13. The method for producing a transparent nickel complex compound ink composition according to claim 11, wherein the heating is carried out at a temperature of less than 115°C.

Images