KR20170133658A - The manufacturing method of the transparent electromagnetic wave shield film using the copper nano ink and the laser sintering - Google Patents

Abstract

The present invention relates to a method for manufacturing a transparent electromagnetic shielding film, and more particularly, to a method for manufacturing a transparent electromagnetic shielding film by using laser sintering, which comprises: mixing copper formate powder and additives to manufacture copper nano ink; printing the copper nano ink on a substrate; and manufacturing a shielding pattern by selectively sintering by using laser. According to the present invention, dispersion stability and sintering characteristics of the ink is improved while suppressing high oxidation characteristics of copper.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a transparent electromagnetic wave shielding film using a copper nano ink and a laser sintering method,

More particularly, the present invention relates to a method for producing a transparent electromagnetic wave shielding film, and more particularly, to a method for manufacturing a transparent electromagnetic wave shielding film, which comprises the steps of preparing a copper nano ink by mixing a copper foamate powder and an additive, And a method for producing a transparent electromagnetic wave shielding film using laser sintering by producing a shielding pattern.

In the field of printed electronic technology, there is a demand for miniaturization of the pattern on the substrate. In forming the electrode pattern portion on the substrate, a fine metal particle dispersion liquid is used when fine wiring or thin film is formed, and a paste made of a particulate complex containing gold or silver as a main raw material is used.

However, since the particulate complex containing such gold or silver as a main raw material is expensive, it is difficult to widely diffuse it as a general-purpose product because the production cost is high. In the case of producing a paste with a particulate complex using silver as a main raw material The manufacturing cost can be lowered compared with gold. However, when the wiring width and the space between the wirings become narrow, electromigration of electrons causes disconnection.

Accordingly, in order to solve the above problems, use of a paste composed of a particulate complex using copper as a main raw material has been studied. This is because copper not only has high conductivity such as gold or silver but also has excellent ductility, low cost, and very low migration of electrons compared to silver.

In order to obtain the best print pattern, the ink must meet the demanding physico-chemical properties, and in the case of metal ink, the production of uniform and stable metal nanoparticles should be given priority. Therefore, the necessity of copper nanoparticles having low conductivity and relatively high conductivity is being constantly mentioned.

Inks are used in various products such as conductive inks, electromagnetic wave shielding agents, and reflective film forming materials, and in particular, conductive inks are useful when metal patterns are required or when electrodes are to be easily formed. Therefore, printing electronic technology is a technology for printing an electrode pattern on a base material by using conductive ink or paste, and recently it has become a core technology in the development of electronic parts material such as PCB, RFID tag, LCD, LED and touch panel , The application field is gradually expanding.

Conventionally, a photolithography process has been adopted to form a desired pattern on a substrate. The photolithography process repeatedly performs a plurality of process steps such as vacuum deposition, exposure, development, etching, and plating, Higher cost of equipment is required to carry out the steps, which is accompanied by higher manufacturing costs. In addition, the photolithography method has characteristics that it is not suitable for circuit formation of a highly integrated electronic component because it has a configuration difficult to realize a fine pattern, while the printing electronic technology has a feature that a conductive ink or paste is formed on a desired substrate So that it is possible to simplify the process and reduce the cost of the product.

Because of such advantages, printing processes such as ink-jet printing, gravure printing, gravure-offset printing, reverse-offset printing and the like are increasingly attracting attention as processes capable of replacing photolithography. In order to form an electrode pattern through such a printing process, a step of printing a pattern on a substrate using a conductive ink or paste including a metal filler, and a step of providing a connection between the metal fillers, The sintering step is carried out independently, so that there is a limit to quickly form the electrode pattern. In order to solve this problem, a light sintering method using an infrared lamp has been proposed. However, it is possible to perform sintering quickly, but the sintering effect is not excellent.

With the development of semiconductor technology, it has brought about remarkable development of advanced electronic and computer industry, and also the use of electromagnetic wave has increased sharply. Electromagnetic interference is manifested in various ways ranging from malfunctions of computers to accident of factories in factories. As the result of research that negatively affects the human body has been announced continuously, concern and concern about health have been increasing, It is in the process of strengthening regulations and preparing measures. Therefore, electromagnetic shielding technology for various electronic / electric products is emerging as a core technology field of the electronics industry.

In addition, as many electronic devices including displays are evolving into a transparent wearable form, various functional materials in a transparent form are expected to be required.

In this connection, Korean Patent Laid-Open No. 10-2014-0044743 (entitled "Conductive hybrid copper ink and a light sintering method using the same, hereinafter referred to as Prior art 1") discloses a copper precursor, a metal having a particle diameter of 5 to 500 nm Nanoparticles, a conductive hybrid copper ink having a solubility of 1 to 70 g, a metal precursor / a metal precursor other than copper as a solvent of 100 g, or a mixture thereof, and a polymeric binder resin is photo-sintered at room temperature / Reducing and sintering the conductive hybrid copper ink and a method of sintering using the conductive hybrid copper ink.

Korean Patent Laid-Open No. 10-2013-0014929 (entitled "Electric Sintering Method of Metal Nanoparticle Pattern Using Heat Treatment", hereinafter referred to as "Prior Art 2") is a pattern for printing a pattern with a metal nano- A heat treatment step of heating the metal nanoparticles so as to connect the metal nanoparticles, and an electric sintering step of applying a voltage to the heat-treated pattern to perform electrical sintering.

In the prior art 1, a conductive hybrid copper ink including a copper precursor and a metal nanoparticle, a metal precursor other than copper or a mixture thereof and a polymeric binder resin is photo-sintered to form a pattern electrode, The copper ink of the present invention does not contain a constitution for suppressing the high oxidation resistance of the copper particles and may contain a binder resin which is insoluble in the ink composition in a predetermined ratio, thereby increasing resistance due to oxidation of the copper particles. The light sintering method according to the prior art 1 can be sintered faster than the thermal sintering method, but provides insufficient energy for suppressing oxidization of the copper particles reduced by the irradiated light to produce a high quality pattern electrode There is a problem.

In the conventional art 2, a pattern is printed on a substrate, heat treatment is performed so that the conductive particles are connected to each other, and the electrode is subjected to electric sintering. The pattern electrode manufactured by the electric sintering method may cause a difference in physical properties .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art, and it is an object of the present invention to provide a copper nano- And an object of the present invention is to produce transparent electromagnetic wave shielding film by sintering with a laser beam.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise form disclosed. There will be.

According to an aspect of the present invention, there is provided a method of manufacturing a transparent electromagnetic wave shielding film, comprising the steps of: preparing a copper nano ink by mixing a copper formate powder and an additive; There is provided a method for producing a transparent electromagnetic wave shielding film using laser sintering by printing and then selectively sintering using a laser to produce a shielding pattern.

In an embodiment of the present invention, there is provided a method of manufacturing a transparent electromagnetic wave shielding film using laser sintering, comprising the steps of: (i) mixing a solvent with 20 to 50 wt% of copper formate (II) powder to prepare a first solution; (ii) 0.3 to 5 parts by weight of a surfactant is mixed with 100 parts by weight of the first solution to prepare a second solution, (iii) 0.3 to 3 parts by weight of a dispersant is added to 100 parts by weight of the first solution, (Iv) 1 to 8 parts by weight of a carboxylic acid-amine salt is added to 100 parts by weight of the first solution to prepare a fourth solution, (v) 100 parts by weight of the first solution (Vi) printing a copper nano ink onto a substrate to form a printing layer, and (vii) irradiating the printing layer with a laser beam The copper layer in the portion of the print layer irradiated with the laser beam No part that ink is sintered, the sintering will not be removed may be a step in which a shielding pattern having a predetermined pattern is formed, may be that the reduced copper in the copper nano ink by irradiating a laser beam.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a line width of 5 to 50 mu m.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a thickness of 2 to 30 탆.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a line spacing of 50 to 300 mu m.

In an embodiment of the present invention, the volume resistivity of the transparent electromagnetic wave shielding film may be 10 to 90 mu OMEGA cm.

In the embodiment of the present invention, the electromagnetic wave shielding factor of the transparent electromagnetic wave shielding film may be 30 to 70 dB, and the sheet resistance value may be 10 to 200 mΩ / □.

In the embodiment of the present invention, the transmittance of the transparent electromagnetic wave shielding film may be 80 to 90%.

In the embodiment of the present invention, in the step (vii), a laser beam of a nanosecond pulse may be irradiated.

In the embodiment of the present invention, the laser beam irradiated in the step (vii) may have a wavelength of 300 to 1100 nm and an intensity of 10 ³ to 10 ⁷ W / cm ² .

In an embodiment of the present invention, the diameter of the laser beam irradiated in the step (vii) may be 5 to 500 mu m.

In an embodiment of the present invention, after the step (vii), the step of removing the area of the print layer where the laser beam is not irradiated may be removed using a cleaning solvent.

In an embodiment of the present invention, the carboxylic acid-amine salt may be composed of a carboxylic acid having 1 to 10 carbon atoms and an amine having 1 to 10 carbon atoms.

In the embodiment of the present invention, in the step (vi), the copper nano ink produced in the step (v) may be printed on a substrate by a roll-to-roll method.

In an embodiment of the present invention, the method may further include milling the third solution for a predetermined time period between steps (iii) and (iv).

In order to accomplish the above object, another embodiment of the present invention provides a transparent electromagnetic wave shielding film having a shielding pattern manufactured by the above method.

In the embodiment of the present invention, the electromagnetic wave shielding factor of the transparent electromagnetic wave shielding film may be 30 to 70 dB and the sheet resistance value may be 10 to 200 m? / ?.

According to the embodiment of the present invention, the first effect that the cost of the metal ink can be reduced by using the copper fine particle complex (copper foil) as the conductive filler instead of the silver particles used as the conventional metal filler, The second effect that the oxidation stability can be secured and the dispersibility to the solvent can be increased. The copper nano ink of the present invention has properties suitable for the roll-to-roll printing process by mixing the dispersant, the surfactant and the additives at a predetermined mixing ratio The third effect that the fine pattern can be easily implemented is that the copper complex is reduced and sintered by selectively printing a laser beam after printing the copper nano ink on the substrate, and at the same time, the pattern can be formed into a predetermined shape, A fifth effect that a film having high transparency can be produced, and a fourth effect that a film having excellent electromagnetic wave shielding function can be produced It has the effect of claim 6.

It should be understood that the effects of the present invention are not limited to the effects described above, but include all effects that can be deduced from the description of the present invention or the composition of the invention described in the claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" (connected, connected, coupled) with another part, it is not only the case where it is "directly connected" "Is included. Also, when an element is referred to as "comprising ", it means that it can include other elements, not excluding other elements unless specifically stated otherwise.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

A method for producing a transparent electromagnetic wave shielding film using laser sintering in an embodiment of the present invention, includes the steps of: (i) mixing a solvent with 20 to 50 wt% of copper formate (II) powder to prepare a first solution; ) 0.3 to 5 parts by weight of a surfactant is mixed with 100 parts by weight of the first solution to prepare a second solution, (iii) 0.3 to 3 parts by weight of a dispersant is added to 100 parts by weight of the first solution, (Iv) 1 to 8 parts by weight of a carboxylic acid-amine salt is added to 100 parts by weight of the first solution to prepare a fourth solution, (v) 100 parts by weight of the first solution (Vi) forming a printing layer on the substrate by printing the copper nano ink on the substrate, and (vii) forming a printing layer on the printing layer, Irradiating a laser beam, The copper nano ink in the portion irradiated with the laser beam may be sintered, and the portion not sintered may be removed to form a shielding pattern having a predetermined pattern. By irradiating the laser beam, copper in the copper nano ink It can be reduced.

The copper formate (II) powder of the present invention is a filler that provides conductivity to the conductive ink. In general, pure copper nanoparticles are easily oxidized with a small amount of oxygen to form an oxide film. Copper particles having an oxide coating significantly lower the electrical conductivity and increase the sintering temperature to form electrodes using conductive ink There was a problem that it was difficult. Therefore, in order to produce a conductive ink using copper particles having a low specific resistance and low cost, it is preferable to form a passive layer as a material which can prevent oxidation on the surface of copper particles and can be easily pyrolyzed at low temperature to lower the interfacial resistance between copper particles It may be preferable to ensure electrical conductivity and printability. For this reason, in the present invention, a copper foamate powder in which copper particles and a formate salt are combined is selected as a conductive filler. The copper formate powder is excellent in dispersibility with respect to a solvent and has an advantage of being able to be fired at a low temperature of 100 to 300 DEG C and is excellent in oxidation stability to form a high conductivity copper thin film.

When the amount of the copper formate powder is less than 20 wt%, the amount of the copper particles providing conductivity is insufficient, and the desired electrical conductivity can not be realized. When the copper formate powder exceeds 50 wt%, the copper formate powder The dispersibility may be deteriorated.

The average particle diameter of the copper formate powder is 0.2 to 2 占 퐉, more preferably 0.5 to 1 占 퐉. As the average particle diameter of the copper formate is smaller, the contact point between the copper particles is increased to form a copper thin film having a high electrical conductivity. However, when the particle size is less than 0.2 μm, the cohesion between the copper formate particles increases, Can be degraded. When the average particle diameter of the copper formate particles exceeds 2 탆, the contact point between the copper particles decreases, so that the interfacial resistance between the copper particles increases, and the electrical conductivity deteriorates.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a line width of 5 to 50 탆.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a thickness of 2 to 30 탆.

In the embodiment of the present invention, the shielding pattern formed in the step (vii) may have a line spacing of 50 to 300 mu m.

In the embodiment of the present invention, the volume resistivity of the transparent electromagnetic wave shielding film may be 10 to 90 mu OMEGA cm.

The shielding pattern of the present invention may have a line width of 5 to 50 탆, a puncture of 2 to 30 탆, and a line spacing of 50 to 300 탆. The shielding pattern according to the present invention can be realized with a wide line width, but it is preferable that the shielding pattern has a line width and a line width in the same range as that for the transparent electromagnetic wave shielding film. When the line width and the line-to-line distance are out of the above ranges, the transparency is low and it is not suitable for producing a film having excellent transparency and may not be suitable for producing a film having excellent electromagnetic shielding due to low electromagnetic wave shielding ratio. It is also preferable that the volume resistivity of the shielding pattern is in the range of 10 to 90 mu OMEGA cm. In order to have such a resistance value, it is preferable that the shielding pattern is controlled to 2 to 30 mu m.

In the embodiment of the present invention, the electromagnetic wave shielding factor of the transparent electromagnetic wave shielding film may be 30 to 70 dB and the sheet resistance value may be 10 to 200 m? / ?.

In the embodiment of the present invention, the transparency of the transparent electromagnetic wave shielding film may be 80 to 90%.

In the embodiment of the present invention, in the step (vii), the laser beam of the nanosecond pulse may be irradiated.

In the embodiment of the present invention, the laser beam irradiated in the step (vii) may have a wavelength of 300 to 1100 nm and an intensity of 10 ³ to 10 ⁷ W / cm ² . The intensity of the laser beam is defined as the light energy per unit area (W / cm ² ). The light energy is determined according to the power of the laser beam to be irradiated, and the unit area can be determined according to the diameter of the laser beam to be irradiated. Further, when the lens is used to concentrate the beam, the diameter of the laser beam can be determined by the distance from the lens to the substrate on which the copper nano ink is printed. That is, in order to control the intensity of the laser beam, the output power of the laser beam and the separation distance from the lens to the substrate on which the copper nano ink is printed can be considered.

Also, it is preferable that the intensity of the laser beam irradiated in consideration of the above conditions is 10 ³ to 10 ⁷ W / cm ^{2. If} the intensity of the laser beam is excessive, the light energy per unit area increases, The copper complex can be reduced and sintered within a short period of time. However, the high energy may cause deformation of the substrate, in particular, deformation of the polymer substrate, which is vulnerable to high temperatures. When the intensity of the laser beam is less than the lower limit of the above range , The reduction and sintering time may be prolonged and the process efficiency may be lowered.

In the embodiment of the present invention, the diameter of the laser beam irradiated in the step (vii) may be 5 to 500 mu m. The laser beam can realize a fine line width in a desired shape by controlling the movement while forming a copper coating film by reducing and sintering the copper complex in the copper nano ink to copper particles. Therefore, the line width of the shielding pattern can be determined according to the diameter of the laser beam. When the shielding pattern is required to be finer, the diameter of the laser beam is controlled to be small and the laser beam must be scanned for a short time. If the diameter of the laser beam exceeds a certain size, it may be difficult to realize a line width suitable for the shielding pattern because the laser beam is irradiated relatively relatively. The laser beam having an excessively small diameter is caused by the diffraction limit of light It may be preferable to irradiate a laser beam having a diameter in the above range.

Further, the laser beam normally irradiated from the light source has a Gaussian distribution in intensity, and there exists a local intensity difference between the center portion and the outer portion of the laser beam. Due to the local intensity difference of the laser beam, sintering characteristics of the center portion and the outer portion of the shielding pattern formed by irradiating the laser beam can be changed. Particularly, when the intensity difference between the center portion and the outer portion of the laser beam is excessively large, the center portion of the shielding pattern may be etched while excess energy is applied. Therefore, in the step of irradiating the laser beam, it may be more preferable to simultaneously consider the diameter of the laser beam and the local intensity difference.

The laser beam can be irradiated to one site until the copper nano ink printed on the substrate is sintered. Further, it is necessary to determine the scan speed of the laser beam after grasping the time for irradiating the laser beam in consideration of the wavelength and diameter of the laser beam.

In the shielding pattern of the present invention, copper nano ink having high dispersion stability is printed on a substrate, and then the irradiation condition of the laser beam is controlled to reduce and sinter the copper complex in the copper nano ink to copper particles to form a copper film, So that it is easy to realize a fine line width in a desired shape.

The pattern formation can be performed by printing a copper nano ink on the entire surface of the substrate, controlling the movement path of the laser beam, and selectively irradiating the laser beam. The pattern formation can be performed by inkjet printing, gravure printing, gravure offset printing, reverse- When a printing process such as roll-to-roll printing is performed, a copper nano ink may be printed in a desired shape, and then a laser beam may be selectively irradiated to a region where the copper nano ink is printed.

The method may further include, between the step (vi) and the step (vii), drying the substrate on which the copper nano ink is printed at a predetermined temperature. The laser beam may react explosively when the organic volatile substance is injected at a position where there is an excessive amount of organic volatiles, which may make it difficult to realize a desired line width, and may cause a problem that the electrical resistance is locally increased. Therefore, it may be preferable to further include forming the copper nano ink film by drying the substrate on which the copper nano ink is printed, before irradiating the laser beam. The substrate on which the copper nano ink is printed may be dried at room temperature or may be dried faster by applying a separate drying means (such as a heat dryer or a vacuum dryer) to form a copper nano ink film.

In the embodiment of the present invention, after the step (vii), the step of removing the laser beam from the printing layer using the cleaning solvent may further comprise removing the laser beam. When a copper nano ink is printed on the entire surface of a substrate and then a laser beam is selectively irradiated to sinter a part of the area to form a pattern, a cleaning step for removing the area not irradiated with the laser beam by using a cleaning solvent is further performed . In one embodiment of the present invention, the cleaning solvent may be but is not limited to isopropyl alcohol (IPA), and it does not react with the area reduced to copper (sintered part) by the laser beam, Any solvent capable of removing copper nanoinks may be possible. Further, it is apparent that, even when copper nano ink is printed in a predetermined shape and laser sintering is performed, the step of cleaning may be further performed using a cleaning solvent.

In the embodiment of the present invention, the copper nano ink may be fired in a temperature range of 100 to 300 ° C.

In an embodiment of the present invention, the solvent may be selected from the group consisting of isopropyl alcohol, isobutyl alcohol, ethanol, butanol, pentanol, hexanol, octyl alcohol, 1,4-butanediol, cyclohexanol, octyl alcohol, benzyl alcohol, , Diethylene glycol, terpineol, eugenol, and the like, but it should not be construed as being limited thereto.

In order to facilitate the roll-to-roll process, the copper nanoink of the present invention contains 50 to 80 wt% of a solvent, and more preferably 65 to 80 wt% of a solvent. In the case of printing the copper nano ink of the present invention by the roll-to-roll method, the solvent should consider the change in the weight due to the contact angle and the solvent absorption of the blanket, especially the blanket of the PDMS rubber material, in order to increase the printability. When the above-mentioned solvents are applied to the PDMS rubber material, the contact angle may be 10 ° to 80 °, and more preferably, the contact angle may be 10 ° to 30 °. When the contact angle exceeds 80 °, it is difficult to coat the copper nano ink on the blanket. When the contact angle is less than 10 °, the affinity between the blanket and the solvent is large, so it may be difficult to pattern the copper nano ink printed on the blanket. When the solvent is selected, the absorbency of the blanket to the solvent must be considered. If the blanket is excessively absorbed by the solvent, the life of the blanket may significantly decrease, and the desired pattern may not be realized have. The solvent may be one kind of solvent selected from among the above-mentioned materials, and one or more kinds of solvents may be mixed in consideration of the contact angle with respect to the blanket and the weight change due to absorption of the solvent. .

In an embodiment of the present invention, the dispersing agent is at least one compound selected from phosphoric acid ester or polyetherester, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, polysiloxane, polyethyleneimine, polyacrylic acid, But may be, but is not limited to, copolymers.

The copper nanoink according to the present invention contains 0.3 to 3 parts by weight of a dispersing agent based on 100 parts by weight of copper formate and a solvent in order to increase the dispersibility of the copper formate powder to produce an electrode having uniform physical properties. When the dispersant is contained in an amount of less than 0.3 part by weight, the dispersibility may not be sufficiently secured. When the amount of the dispersant is more than 3 parts by weight, the effect of increasing the dispersibility by the addition of the dispersant is limited, There may be a problem.

A commercially available product may also be used as a dispersant. Examples thereof include Disperbyk 111, Disperbyk 110, Disperbyk 106, Disperbyk 140, Disperbyk 108, Disperbyk 174, Disperbyk 180, Disperbyk 183, Disperbyk 184, Disperbyk 190 or Tego 652 or Triton X- Triton X-45, Triton QS-15, and the like.

In an embodiment of the present invention, the surfactant may be a silicone surfactant. The copper nanoink of the present invention contains 0.3 to 5 parts by weight of a surfactant in order to increase the wettability with respect to the blanket of the roll-to-roll process. When the amount of the surfactant is less than 0.3 part by weight, the effect of increasing the wettability to the blanket can not be sufficiently secured. When the amount of the surfactant is more than 5 parts by weight, And the purity of the ink may be lowered.

In an embodiment of the present invention, the silicone surfactant may have a molecular weight of 600 to 6,000. When the molecular weight is less than 600, the wettability with respect to the blanket may decrease, which may not be suitable for the roll-to-roll process. When the molecular weight exceeds 6,000, the viscosity of the silicone- So that there is a problem that the printing property is lowered.

In an embodiment of the present invention, the carboxylic acid-amine salt may be composed of a carboxylic acid having 1 to 10 carbon atoms and an amine having 1 to 10 carbon atoms.

The copper nanoink of the present invention comprises 1 to 8 parts by weight of a carboxylic acid-amine salt. The carboxylic acid-amine salt can disperse the copper formate evenly in the solvent to increase the dispersibility and can be easily pyrolyzed at low temperature to promote sintering of the copper nano ink. The powder and additives contained in the copper nano ink may have a problem of dispersion stability and settlement over time. In the present invention, the carboxylic acid-amine salt capable of increasing the dispersion stability is added at a predetermined ratio, The same problem can be solved. When the copper nano-ink contains less than 1 part by weight of the carboxylic acid-amine salt, the effect obtained by adding the carboxylic acid-amine salt described above is insufficient. When the amount exceeds 8 parts by weight, The purity of the ink can be lowered.

The carboxylic acid-amine salt is bonded at a molar ratio of carboxylic acid and amine of 1: 1, and may be added thereto to increase the dispersion stability of the copper formate powder. When the dispersion stability of the copper formate powder is increased, it is possible to form a denser copper thin film than when the copper nano ink is sintered, thereby reducing the resistance of the thin film.

The copper nanoink of the present invention is characterized by containing less than 3 parts by weight of an epoxy binder. The epoxy-based binder is added in order to increase the coating property of the conductive filler by providing the adhesive property with the substrate in the process of printing and coating the copper nano ink on the substrate. The epoxy-based binder is advantageous in that it has a low unit cost, is easily controlled in physical properties, and has excellent coating properties. Thus, an epoxy-based binder is selected in the present invention. However, the present invention is not limited to this, and it is specified that a binder commonly used in the art such as a urethane resin, an acrylic resin, or the like may be used or a mixture thereof may be used. On the other hand, when the epoxy-based binder is contained in an amount of more than 3 parts by weight, the viscosity is excessively increased to have a physical property not suitable for the roll-to-roll printing process and is limited as described above. However, it may vary depending on the molecular weight of the epoxy- .

In the embodiment of the present invention, in the step (vi), the copper nanoink produced in the step (v) may be printed on the substrate by a roll-to-roll method. The roll-to-roll method includes a gravure printing method, a gravure offset printing method, and a reverse offset printing method. A detailed description of a method for manufacturing a fine pattern electrode using a gravure offset and a reverse offset printing method, .

First, a method of manufacturing a fine pattern electrode using a reverse offset printing method is a method in which a copper nano ink is printed on a blanket of a PDMS rubber material and then patterned in such a manner as to be printed on a cliche provided with an inverted pattern of patterns, . The step of printing the copper nano ink in the manufacturing step may be performed by using a slit die nozzle or by a doctor blade method, but the present invention is not limited thereto and any printing method that is conventionally practiced in the art can be used.

Next, a method of manufacturing fine pattern electrodes using the gravure offset printing method is a method in which a copper nano ink is printed on a gravure roll, the pattern is patterned on a blanket roll, the blanket roll is rotated on the substrate, And a step of calcining the mixture.

It should be noted that the manufacturing method of the fine pattern electrode using the reverse offset and gravure offset printing method is not limited to the above-mentioned step, and that the manufacturing step may be changed as much as possible.

In the embodiment of the present invention, the third solution may be milled for a predetermined time period between steps (iii) and (iv). The reason for performing the milling is to more uniformly mix the copper formate, the surfactant and the dispersant contained in the third solution and to crush the copper formate particles. When the copper formate particles are finely pulverized, sintering can be promoted and a denser copper thin film can be formed. Since the surfactant or dispersant is a substance having a relatively high molecular weight, it may be preferable to increase the viscosity of the solution so that it is difficult to uniformly mix the solution and it may take a long time to perform the milling treatment for a predetermined period of time . The milling time is not particularly limited, but it may be preferable to perform for 1 to 25 hours. More preferably, the milling time can be from 1 to 10 hours. When the milling time is less than 1 hour, the uniform mixing and pulverizing effect is not sufficient. If the milling time is more than 25 hours, the coagulation phenomenon of the copper formate powder may be increased due to excessive pulverization.

In order to accomplish the above object, another embodiment of the present invention provides a transparent electromagnetic wave shielding film having a shielding pattern manufactured by the above method.

In the embodiment of the present invention, the electromagnetic wave shielding factor of the transparent electromagnetic wave shielding film may be 30 to 70 dB and the sheet resistance value may be 10 to 200 m? / ?.

Hereinafter, the effects of the present invention will be described in detail with reference to experimental examples and examples of the present invention.

[Example 1]

One. Copper nano ink  Manufacturing stage

23.5 wt% of copper formate powder, 76 wt% of IPA as a solvent, 0.5 wt% of a phosphate ester as a dispersant, and polysiloxane (molecular weight: 3,000) as a surfactant were mixed in this order and milled for 5 hours using a monomill. Next, a copper nano ink was prepared by mixing 5 wt% of carboxylic acid-amine salt (I). (Carboxylic acid-amine salt (I); Carboxylic acid (Carbon chain; C <6) + Amine (carbon chain; 5 <C <10)

2. Copper nano ink  Printing step

The copper nano ink prepared by the above method was printed on a PET substrate by a reverse offset printing method.

3. Fabrication of transparent electromagnetic wave shielding film by laser sintering

A PET substrate (type: IF70, thickness: 50 mu m, SKC Inc.) on which copper nano ink was printed was dried in a drying oven at 70 DEG C for 10 minutes.

After the drying was completed, a nanosecond pulse ultraviolet laser apparatus (Coherent, AVIA 355-5 model; wavelength = 355 nm, pulse width = <20 ns, repetition rate = 30 kHz, max. Power = 4.2 W, unfocused laser beam diameter = mm) was used to sinter the copper nano ink.

Specifically, after the dried substrate was placed on the automatic transfer stage, the surface of the dried ink was scanned line by line by irradiating a laser beam (diameter = 2.85 mm) not focused on the surface of the dried ink. At this time, the output of the laser beam was 1.8 W and the scan speed was 3 mm / s. Nitrogen gas was supplied through the gas gun to prevent oxidation while the laser beam was irradiated.

A substrate on which copper nano ink is printed is placed on an automatic transfer stage, and then a laser beam is selectively irradiated to form a pattern. Then, the non-sintered region is removed using isopropyl alcohol to form a transparent electromagnetic wave shielding film having a shielding pattern .

[Experimental Example 1]

Transparent electromagnetic wave Of shielding film  Analysis of electromagnetic wave shielding rate

In order to analyze the electromagnetic wave shielding effect of the transparent electromagnetic wave shielding film, the electromagnetic wave shielding ratio was measured at a measurement frequency range of 30 MHz to 1 GHz. As a result of repeating the experiment five times, it was confirmed that the average shielding rate was 55.7dB.

[Experimental Example 2]

Transparency analysis of transparent electromagnetic wave shielding film

The transmittance of the transparent electromagnetic wave shielding film was measured to be 86%.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (16)

(i) mixing a solvent with 20 to 50 wt% of copper formate (II) powder to prepare a first solution;
(ii) 0.3 to 5 parts by weight of a surfactant is mixed with 100 parts by weight of the first solution to prepare a second solution;
(iii) 0.3 to 3 parts by weight of a dispersing agent is added to 100 parts by weight of the first solution to prepare a third solution;
(iv) adding 1 to 8 parts by weight of a carboxylic acid-amine salt to 100 parts by weight of the first solution to prepare a fourth solution;
(v) adding an epoxy-based binder to the first solution in an amount of more than 0 and less than 5 parts by weight based on 100 parts by weight of the first solution;
(vi) printing the copper nanoink on a substrate to form a print layer; And
(vii) a step of irradiating the printing layer with a laser beam to sinter the copper nano ink of the portion of the printing layer irradiated with the laser beam, and removing the non-sintered portion to form a shielding pattern having a predetermined pattern ; Lt; / RTI &gt;
Wherein the copper in the copper nano ink is reduced by irradiating the laser beam. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt;
The method according to claim 1,
Wherein the shielding pattern formed in the step (vii) has a line width of 5 to 50 mu m.
The method according to claim 1,
Wherein the shielding pattern formed in the step (vii) has a haze of 2 to 30 占 퐉.
The method according to claim 1,
Wherein the shielding pattern formed in the step (vii) has a line spacing of 50 to 300 mu m.
The method according to claim 1,
Wherein the volume resistivity of the transparent electromagnetic wave shielding film is 10 to 90 mu OMEGA cm.
The method according to claim 1,
Wherein the electromagnetic wave shielding film of the transparent electromagnetic wave shielding film has an electromagnetic shielding ratio of 30 to 70 dB and a surface resistance value of 10 to 200 mQ / □.
The method according to claim 1,
Wherein the transparent electromagnetic wave shielding film has a transmittance of 80 to 90%.
The method according to claim 1,
Wherein the laser beam is irradiated with a nanosecond pulse in the step (vii).
The method according to claim 1,
Wherein the laser beam irradiated in the step (vii) has a wavelength of 300 to 1100 nm and an intensity of 10 ³ to 10 ⁷ W / cm ² .
The method according to claim 1,
Wherein the diameter of the laser beam irradiated in the step (vii) is 5 to 500 mu m.
The method according to claim 1,
After the step (vii)
Removing an area of the print layer where the laser beam is not irradiated using a cleaning solvent; The method of manufacturing a transparent electromagnetic wave shielding film using laser-sintering according to claim 1,
The method according to claim 1,
Wherein the carboxylic acid-amine salt comprises a carboxylic acid having 1 to 10 carbon atoms and an amine having 1 to 10 carbon atoms.
The method according to claim 1,
In the step (vi), the copper nano ink produced in the step (v)
Wherein the transparent conductive film is printed on the substrate by a roll-to-roll method.
The method according to claim 1,
Milling the third solution for a predetermined time between steps (iii) and (iv); The method of manufacturing a transparent electromagnetic wave shielding film using laser-sintering according to claim 1,
A transparent electromagnetic wave shielding film produced by the manufacturing method according to any one of claims 1 to 14.
16. The method of claim 15,
Wherein the electromagnetic wave shielding film of the transparent electromagnetic wave shielding film has a shielding ratio of 30 to 70 dB and a surface resistance value of 10 to 200 mQ / □.