KR101704636B1 - Ink-coating device for preventing contamination of coating head, and apparatus for coating conductive film including the device - Google Patents

Abstract

The present invention provides an ink-coating device for coating conductive metal precursor ink on a flexible substrate by a roll-to-roll process. According to the present invention, a coating head can be prevented from contamination. The ink-coating device according to the present invention comprises: a heating roller which supports and heats a flexible substrate coated with a catalyst layer; a first guide roller which is disposed in parallel to and at a certain distance from the heating roller so as to support the flexible substrate; a coating head which is disposed offset at a certain distance from the heating roller to the guide roller, and which applies metal precursor ink on the flexible substrate; and an ink-impermeable heat-resistant film which is wound from the upper portion of the guide roller to the upper portion of the heating roller. According to the present invention, in the flexible substrate transfer zone from the upper portion of the guide roller to the heating roller, the metal precursor ink can be applied on the flexible substrate in a state in which the flexible substrate has been stacked on the heat-resistant film.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink coating apparatus capable of preventing contamination of a coating head and a conductive film coating apparatus including the same,

The present invention relates to a conductive film coating apparatus, and more particularly, to an ink coating unit for coating a conductive film on a flexible substrate using a heating roller and a conductive film coating apparatus including the same.

Recently, aluminum electrodes have been utilized in various technical fields such as solar cells and organic light emitting devices (OLED). Aluminum electrodes are used as core electrode materials for various electronic, electric, energy and environmental devices because they are excellent in electric conductivity and economical in price.

Patent Document 1 discloses a method of using a catalyst and an aluminum precursor ink to form an aluminum thin film (film) on a substrate. According to this method, an aluminum precursor ink is coated on a substrate, and the substrate is heated to a temperature of 90 to 150 DEG C under a metal precursor decomposition activation catalyst atmosphere to facilitate aluminum film formation. Whereby the aluminum precursor in the precursor ink composition is decomposed by the metal precursor decomposition activation catalyst to form an aluminum thin film on the surface of the substrate.

Patent Document 2 discloses an apparatus for forming the above-described aluminum film by a roll-to-roll method. In this connection, Fig. 1 of the present specification schematically shows an aluminum film coating apparatus of the above-mentioned Patent Document 2. Fig. 1, a conventional conductive metal film coating apparatus includes a supply roll 100 for supplying a roll-shaped flexible substrate, a recovery roll 200 for recovering a coated flexible substrate in a roll form, and a metal film A slot die 310 for forming a catalyst layer, a first drier 320, a slot die 330 for forming a conductor layer, and a second drier (not shown) for forming a conductor layer are formed in the chamber 10, 340).

The slot die 400 for forming a catalyst layer is coated with a catalyst layer on a flexible substrate, and the first drier 320 irradiates the coated catalyst layer with NIR. The slot die 330 for forming a conductive layer coatings the metal precursor solution on the catalyst layer and the second drier 340 dries the coated flexible substrate.

Generally, when a metal film is formed by reacting a catalyst with a metal precursor as disclosed in Patent Document 1, it is necessary to heat the flexible substrate at a temperature suitable for the reaction between the catalyst and the precursor (for example, 90 to 150 ° C). However, in this conventional technique, when a substrate is heated by placing a drying device (dryer) in front of the slot die for heating the flexible substrate, the temperature of the flexible substrate is lowered again before the flexible substrate passes through the drying device and reaches the slot die there is a problem.

In general, when the flexible substrate is heated by irradiating hot air or infrared rays toward the flexible substrate, the heat energy is not concentrated on the flexible substrate but is heated to the ambient air, so that the thermal energy is diffused to the surroundings and the temperature of the entire chamber 300 is unnecessarily There is a problem that heat energy can not be used efficiently.

Patent Document 1: Korean Patent No. 10-1124620 (issued on February 29, 2012) Patent Document 2: Korean Patent No. 10-1501240 (issued on March 12, 2015)

According to an embodiment of the present invention, there is provided an ink coating unit and a conductive metal film coating apparatus including the same that can prevent a coating head from being contaminated by arranging a coating head between a heating roller and a guide roller.

According to an embodiment of the present invention, a heat-resistant film is wound around a heating roller and a guide roller, and a flexible substrate is laminated on the heat-resistant film so as to prevent contamination of the heating roller. An ink coating unit capable of obtaining a flexible substrate having excellent electrical conductivity and a conductive metal film coating apparatus including the ink coating unit are provided.

According to an embodiment of the present invention, since the heating roller includes both the preheating section and the reaction and drying sections, it is possible to perform the preheating, the reaction, and the drying process all at once while the flexible substrate is wound around the heating roller An ink coating unit and a conductive metal film coating apparatus including the same are provided.

According to an embodiment of the present invention, there is provided an ink coating apparatus for coating a conductive metal precursor ink on a flexible substrate in a roll-to-roll manner, comprising: a heating roller for supporting and heating a flexible substrate coated with a catalyst layer; A first guide roller disposed in parallel with the heating roller at a predetermined interval and supporting the flexible substrate; A coating head disposed on the heating roller so as to be offset from the guide roller side by a predetermined distance and coating the metal precursor ink on the flexible substrate; And an ink-impermeable heat-resistant film wound on at least the upper portion of the guide roller and the upper portion of the heating roller, wherein, in a conveying section of the flexible substrate from the upper portion of the guide roller to the heating roller, Wherein the metal substrate ink is coated on the flexible substrate in a state where the flexible substrate is laminated on the heat resistant film.

According to an embodiment of the present invention, there is provided an ink coating apparatus for coating a conductive metal precursor ink on a flexible substrate in a roll-to-roll manner, comprising: a heating roller for supporting and heating a flexible substrate coated with a catalyst layer; A first guide roller disposed in parallel with the heating roller at a predetermined interval and supporting the flexible substrate; And a coating head which is disposed offset from the heating roller by a predetermined distance toward the guide roller side and coating the metal precursor ink on the flexible substrate, wherein the flexible substrate contacts the first portion of the outer circumferential surface of the heating roller The heating roller and the heating roller are moved such that the first and second sections contact the second section of the outer circumferential surface of the heating roller and the third section, Wherein the guide member is wound on a guide roller.

According to an embodiment of the present invention, there is provided an apparatus for coating a conductive metal film on a flexible substrate in a roll-to-roll manner, comprising: a chamber filled with an inert gas; A catalyst coating device, disposed in the chamber, for coating a first surface of the flexible substrate with a catalyst; And an ink coating apparatus as described above which is disposed in the chamber, coating the conductive metal precursor ink on the catalyst coat layer of the flexible substrate and producing a conductive metal film by reaction of the catalyst and the conductive metal precursor A conductive metal film coating apparatus is provided.

According to an embodiment of the present invention, the coating head is disposed between the heating roller and the guide roller to prevent the coating head from being contaminated.

According to an embodiment of the present invention, a heat-resistant film is wound around a heating roller and a guide roller, and a flexible substrate is laminated on the heat-resistant film, thereby preventing contamination of the heating roller and obtaining a flexible substrate having excellent electric conductivity .

According to an embodiment of the present invention, the heating roller includes both the preheating section and the reaction and drying sections, so that the preheating, the reaction, and the drying process can be performed at one time while the flexible substrate is wound around the heating roller It is possible to obtain a flexible substrate having an electrically conductive metal film of excellent quality and to miniaturize the size of the ink coating unit.

1 is a block diagram for explaining a conventional conductive film coating apparatus;
2 is a block diagram of a conductive film coating apparatus according to an embodiment of the present invention;
3 is a view for explaining a catalyst coating unit according to one embodiment,
4 is a view for explaining the ink coating unit according to the first embodiment,
5 is a view for explaining the effect of the ink coating according to the first embodiment,
6 (a) is a view for explaining the temperature gradients of the heating roller, the flexible substrate, the catalyst layer, and the precursor ink layer according to the prior art,
6 (b) is a view for explaining a temperature gradient of the heating roller, the heat-resistant film, the flexible substrate, the catalyst layer, and the precursor ink layer according to the embodiment of the present invention,
7 is a view for explaining the ink coating unit according to the second embodiment,
8 is a view for explaining the ink coating unit according to the third embodiment,
9 is a view for explaining the ink coating unit according to the fourth embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features, and advantages of the present invention will become more readily apparent from the following description of preferred embodiments with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Where the terms first, second, etc. are used herein to describe components, these components should not be limited by such terms. These terms have only been used to distinguish one component from another. The embodiments described and exemplified herein also include their complementary embodiments.

In the present specification, the singular form includes plural forms unless otherwise specified in the specification. The terms "comprise" and / or "comprising" used in the specification do not exclude the presence or addition of one or more other elements.

Hereinafter, the present invention will be described in detail with reference to the drawings. In describing the specific embodiments below, various specific details have been set forth in order to explain the invention in greater detail and to assist in understanding it. However, it will be appreciated by those skilled in the art that the present invention may be understood by those skilled in the art without departing from such specific details. In some cases, it should be mentioned in advance that it is common knowledge in describing an invention that parts not significantly related to the invention are not described in order to avoid confusion in explaining the present invention.

2 is a block diagram of a conductive film coating apparatus according to an embodiment of the present invention.

Referring to the drawings, a conductive film coating apparatus according to an embodiment includes a chamber 10, a supply roll 20, a catalyst coating unit 30, an ink coating unit 40, a position control unit 50, 60, and a gas purification unit 70.

The chamber 10 receives the components described below which constitute a conductive film coating apparatus and can block the air inside the chamber from the outside to form a gas atmosphere suitable for film coating. In one embodiment, the chamber 10 may be filled with an inert gas such as argon (Ar), and it is desirable to remove moisture and oxygen within the chamber 10.

The conductive film coating apparatus of the illustrated embodiment is a device for coating a conductive film on a flexible substrate in a roll-to-roll manner, and the flexible substrate 5 is wound in a roll form. The supply roll 20 un-winds the flexible substrate 5 in the form of a roll and supplies it to the catalyst coating unit 30. [ The flexible substrate 5 on which the conductive metal film is formed while passing through the catalyst coating unit 30 and the ink coating unit 40 is wound again in the form of a roll in the recovery roll 60. Depending on the specific embodiment, at least one of the feed roll 20 and the recovery roll 60 may be disposed outside the chamber 10.

As used herein, the term "flexible substrate" may refer to one of plastic films, fibers, paper, flexible glass, and woven fabrics and includes, but is not limited to, ) May include any flexible material.

The catalyst coating apparatus 30 is disposed in the chamber 10 and forms a catalyst layer by coating a catalyst on one surface of the flexible substrate 5 transferred from the supply roll 20. The catalyst used may vary depending on the type of the conductive metal to be coated on the flexible substrate 5. In one embodiment, when aluminum (Al) is used as the conductive metal, the catalyst is selected from the group consisting of titanium isopropoxide (Ti (Oi-Pr) 4), titanium chloride (TiCl4), platinum Catalyst, a nickel (Ni) catalyst, a manganese (Mn) catalyst, a zinc (Zn) catalyst or a combination thereof. In one embodiment, the catalyst may be coated by a microgravure coating method. However, the manner of coating the catalyst is not limited to a specific method, and one of known methods such as slot die coating, dip coating, roll coating and the like can be used.

The ink coating unit 40 is disposed in the chamber 10 at the rear end of the catalyst coating apparatus 40 in the traveling direction of the flexible substrate and the catalyst coated flexible substrate 5 in the catalyst coating unit 30 is guided by one or more guides And guided by the rollers to be transported to the ink coating unit 40.

The ink coating unit 40 coats a conductive metal precursor ink on the catalyst coating layer of the flexible substrate. The coated metal precursor reacts with the catalyst under suitable temperature conditions to form a conductive metal film. In one embodiment, the conductive metal to be coated on the flexible substrate is selected from the group consisting of Al, Li, Na, K, Rb, Cs, Ber, (Mg), calcium (Ca), or a combination thereof.

The metal precursor ink is composed of a metal precursor and a solvent, and may further include a solution stabilizer if necessary. The metal precursor may be, for example, a metal hydride, a complex of a metal hydride and an ether or amine-based material, or a combination thereof. The solvent may be, for example, water, tetrahydrofuran (THF), alcohol solvent, ether solvent, sulfide solvent, toluene solvent, xylene solvent Based solvent, an alkane-based solvent, an oxane-based solvent, an amine-based solvent, a polyol-based solvent, or a combination thereof.

In one embodiment, the metal precursor ink is stored in the ink reservoir 85 and then injected into the ink head 42 of Fig. 5 of the ink coating unit 40, do. The coating method by the ink head can be coated in at least one of, for example, slot die coating, slide coating, curtain coating, and spray coating, and other known methods can be used.

When the conductive metal film is formed on the flexible substrate, the flexible substrate is then transferred to the recovery roll 60 through the position control unit 50. [ The position control unit 50 can detect and adjust the edge position of the flexible substrate so that the flexible substrate is uniformly wound on the recovery roll.

In one embodiment, the conductive film coating apparatus may further comprise a gas purifier 70 for purifying the gas in the chamber 10. In one embodiment, the gas purifier 70 may include means for removing solvent (solvent) and moisture from the air in the chamber, and blowing means for blowing the purified air into the chamber 10. . For example, the gas purification unit 70 can include a heat exchanger, and when the air containing the solvent passes through the heat exchanger, the water vapor and the solvent condense, and the condensed water vapor and the solvent are discharged in separate paths have.

In an alternative embodiment, it may comprise an adsorbent layer composed of carbon or zeolite for solvent removal, and as the air passes through the adsorbent layer, the solvent adsorbs on the adsorbent surface to remove the solvent from the air. In addition, any known method of removing the solvent and water vapor, respectively, may be used, and the present invention is not limited to any particular method.

3 is a view for explaining a catalyst coating unit according to one embodiment.

In the illustrated embodiment, it is assumed that the catalyst coating unit 30 is coated with a catalyst by a microgravure method. In this case, the catalyst coating unit 30 comprises a microgravure coating roll 31, at least one pressure roller 32, a pneumatic cylinder 33, a reservoir 34 for storing the catalyst solution, a drying section 37, And may include a guide roller 39.

As shown in the figure, a part of the microgravure coating roll 31 is immersed in a storage tank 34 storing the catalyst solution, and the flexible substrate 5 is transported while contacting the top of the coating roll 31. The catalyst solution is coated on the flexible substrate in contact with the coating roll 31 as the coating roll 31 rotates after the catalyst solution is absorbed on the surface of the coating roll 31 immersed in the reservoir 34. At this time, one or more guide rollers 39 guide the conveyance path of the flexible substrate, and one or more pressure rollers 32 provided on the pneumatic cylinder 33 can press the flexible substrate against the coating roll 31. [ Further, although not shown, a doctor blade for removing the catalyst solution that is unnecessarily deposited on the surface of the coating roll 31 may be arranged in contact with the coating roll 31. [

The drying unit 37 heats and softens the flexible substrate 5 to evaporate the solvent of the catalyst solution. For example, an infrared (IR) drying method may be used for drying the flexible substrate 5, or alternatively, a hot air dryer may be used.

4 is a view for explaining the ink coating unit according to the first embodiment of the present invention.

Referring to the drawings, the ink coating unit 40 according to the first embodiment includes a heating roller 41, a first guide roller 42, and a coating head 43, And may further include a roller (44).

The heating roller 41 can support and heat the flexible substrate 5 coated with the catalyst layer. The heating roller 41 is heated by any heating means disposed inside the heating roller. For this, the main body of the heating roller 41 is preferably made of a material having excellent thermal conductivity.

The heating means for heating the heating roller 41 is not limited to a specific means. In one embodiment, the heating roller 41 may be heated by an induction heating type or a heat pipe may be used to heat the heating roller. Alternatively, an IR heater may be used. In this case, the IR heater may be disposed adjacent to the outside of the heating roller 41, and the heating roller may be heated by irradiating IR onto the heating roller 41. When the heating roller 41 is heated by the heating means, thermal energy of the heating roller 41 is transferred to the surface of the heating roller by heat conduction, thereby heating the flexible substrate 5 in contact with the surface of the heating roller.

When the induction heating type or the heat pipe is used as the heating means, the heating means can be disposed inside the heating roller 41, so that the volume of the device can be reduced. In addition, thermal energy due to heating is transmitted only to the inside of the heating roller 41 without being diffused to the outside of the heating roller 41, so that the thermal energy is not diffused to other places in the chamber 10 as compared with the hot air drying or IR drying method. There is an advantage that energy efficiency is improved.

The heating roller 41 may have a function of inducing a reaction between the catalyst and the metal precursor and drying the catalyst. 4, when the flexible substrate 5 is conveyed while wrapping the heating roller 41 in half, the flexible substrate 5 is brought into contact with the heating roller 41 at a contact start point (i.e., (that is, the point (b)) at which the flexible substrate is separated from the heating roller 41 from the heating roller 41 in the path approximately 1/2 of the circumference of the heating roller. In this specification, the section from the contact start point at which the flexible substrate 5 begins to be wound around the heating roller to the separation start point at which the flexible substrate starts to be separated from the heating roller 41 is referred to as "reaction and drying section" do.

In this reaction and drying period, the reaction of the catalyst with the metal precursor is caused and a drying reaction takes place, whereby a conductive metal film can be formed on the flexible substrate 5. In one embodiment, the reaction and drying periods may be between about 1/4 and 3/4 of the circumference of the heating roller 41, and the reaction rate of the catalyst and the ink, the rotational speed of the heating roller 41, ), The length of the reaction and drying section may be varied depending on the specific operating conditions.

The first guide roller 42 is arranged side by side with the heating roller 41 at a predetermined interval from the heating roller 41. [ In an embodiment, the upper end of the heating roller 41 and the upper end of the first guide roller 42 may be disposed at the same height. Therefore, when the flexible substrate 5 is conveyed while covering at least the upper portion of the heating roller 41 and the first guide roller 42 as shown in the figure, the conveyance interval between the heating roller 41 and the first guide roller 42 The flexible substrate 5 can be transported horizontally.

Since the first guide roller 42 does not include a separate heating means, the first guide roller 42 may be smaller than the heating roller 41. However, in an alternative embodiment, the first guide roller 42 may be configured to function as a heating roller, in which case the heating roller 41 and the first guide roller 42 may, for example, ≪ / RTI >

The coating head 43 is disposed adjacent to the outer circumferential surface of the heating roller 41 and coats the metal precursor ink on the catalyst layer of the flexible substrate 5 wound around the heating roller 41. Although the coating head 43 in the illustrated embodiment is shown coating the metal precursor ink in a slot die fashion, the coating head 43 may be one of a variety of known coating methods such as, for example, slide coating, curtain coating, and spray coating It may be an applied device.

In one preferred embodiment, the coating head 43 is located at the top of the heating roller 41, that is, not vertically above the central axis of the heating roller 41, but offset from it by a predetermined distance. In the illustrated embodiment, the coating head 43 is offset from the heating roller 41 by a predetermined distance toward the first guide roller 42 side. Therefore, various byproducts such as smoke generated when the metal precursor ink reacts with the catalyst do not reach the coating head 43, so that contamination of the nozzle of the coating head 43 and clogging of the nozzle can be prevented.

The mounting position of the coating head 43, that is, the distance by which the coating head 43 is offset from the top end of the heating roller 41, may be varied according to the specific embodiment. For example, it may be preferable that the metal precursor ink is transferred to the heating roller 41 within 1 to 2 seconds immediately after the ink of the metal precursor is sprayed on the portion of the flexible substrate 5 immediately below the coating head 43. For this, The offset distance of the coating head 43 can be set in consideration of other factors such as the feed speed of the heating roller 5 (i.e., the rotation speed of the heating roller 41).

In the illustrated embodiment, the ink coating unit 40 further includes the heat resistant film 4. [ The heat resistant film 4 may be wound around the heating roller 41 and the first guide roller 42 to form a menopause path and may be wound around the heating roller 41 from the top of the first guide roller 42, The heat-resistant film and the flexible substrate can be integrally transferred in a state where the flexible substrate 5 is laminated on the heat-resistant film 4 in the conveying section of the flexible substrate before being separated from the heat-

Specifically, when the flexible substrate 5 is wound on the first guide roller 42, the flexible substrate 5 is stacked on the heat resistant film 4 and transported toward the heating roller 41. The metal precursor ink is sprayed onto the flexible substrate 5 by the coating head 43 immediately before the heating roller 41 and heated by being wound on the heating roller 41 and heated by the reaction of the ink and the catalyst, The heat resistant film 4 and the flexible substrate 5 are transported together while being laminated. The heat resistant film 4 is separated from the flexible substrate 5 so that the heat resistant film 4 is transported toward the first guide roller 42 and the flexible substrate 5 is transported to at least the second guide roller 44 And can be transported out of the ink coating unit 40 through one guide roller.

In one embodiment, the heat-resistant film 4 can be made of an ink-impermeable heat-resistant film that is not permeable to ink. Further, since the heat energy from the heating roller 41 must pass through the heat-resistant film 4 and be transferred to the flexible substrate 5, it is preferable that the heat-resistant film 4 has a thickness as thin as possible. In one embodiment, the heat resistant film 4 may be composed of a film of polyimide (PI) having a thickness of 25 micrometers.

On the other hand, as shown in Fig. 4, in an alternative embodiment, it may further comprise one or more pressure rollers 46,47. In the illustrated embodiment, the first pressure roller 46 is arranged to face the first guide roller 42 with the laminated structure of the heat resistant film 4 and the flexible substrate 5 interposed therebetween. The second pressing roller 47 is located at a position where the heat resistant film 4 and the flexible substrate 5 are separated from each other immediately before the laminated structure of the heat resistant film 4 and the flexible substrate 5 is separated from the heating roller 41 .

The first pressure roller 46 applies a predetermined pressure toward the center of the first guide roller 42 and the second pressure roller 47 applies a predetermined pressure toward the center of the heating roller 41 Thus, the heat-resistant film 4 and the flexible substrate 5 are stacked, and thereafter, no slip occurs between the heat-resistant film 4 and the flexible substrate 5 until they are separated from each other by the heating roller 41.

The number and position of the pressure rollers are not particularly limited. For example, in another alternative embodiment, one or more pressure rollers may be further provided within the section from the contact starting point to the separation point (i.e., the section from (a) to (b) of Figure 4).

As described above, according to the first embodiment of the present invention, the heat resistant film 4 is wound around the heating roller 41 and the first guide roller 42 in a closed loop and rotated, and the flexible substrate 5 is placed on the heat resistant film 4 The heating roller 41 and the coating head 43 can be stacked and transported so that the flexible substrate 5 can perform both the reaction and the drying process while passing through one heating roller. ), And clogging of nozzles can be solved.

The technical effect according to the embodiment of the present invention will be described in more detail as follows.

First, contamination of the coating head 43 and clogging of the nozzle during ink coating can be prevented.

When the coating head 43 is disposed on the uppermost position of the heating roller 41, when the ink is sprayed directly below the coating head 43, the reaction between the catalyst and the ink causes by-products resulting from the reaction, And reaction by-products such as aluminum oxide (Al 2 O 3) are generated, which causes the coating head 43 to become contaminated with reaction by-products, and in particular, the nozzle of the coating head is clogged.

In order to solve this problem, there is a method in which the coating head 43 is slightly moved to the right or left side rather than the uppermost part of the heating roller 41. However, when the coating head 43 is installed on the heating roller 41, There is also a problem of flowing down along the inclined surface of the substrate.

However, according to the embodiment of the present invention, the first guide roller 42 is provided in parallel to the heating roller 41 so that the flexible substrate 5 is horizontally fed from the guide roller 42 toward the heating roller 41 The coating head 43 is arranged not in a vertical upper portion of the heating roller 41 but in a horizontal region between the heating roller 41 and the first guide roller 42. According to this configuration, Can be prevented from being contaminated or clogged with the nozzles and the coating liquid sprayed on the heating roller 41 can be prevented from flowing down along the surface of the heating roller do.

Secondly, it is also possible to prevent the surface of the heating roller 41 from being contaminated by the ink.

According to the embodiment of the present invention, the ink-impermeable heat-resistant film 4 is configured to be wound around the heating roller 41 and the first guide roller 42 in a closed loop to rotate, During the drying process, the flexible substrate 5 is laminated on the heat-resistant film 4 so that the heat-resistant film and the flexible substrate are integrally transferred.

Therefore, even if a part of the ejected ink leaks under the flexible substrate 5, the heat resistant film 4 prevents it, so that the surface of the heating roller 41 can be prevented from being contaminated by the ink. Generally, when the heating roller is contaminated and replaced, it is difficult in terms of difficulty and cost of replacing. However, since only the heat resistant film 4 needs to be replaced in the present invention, it is advantageous in that the operation is easier and the maintenance can be performed at a lower cost have.

Third, it is possible to form a flexible substrate having excellent electric conductivity by spraying a sufficient amount of ink.

When a conductive metal layer is formed on a flexible substrate by ink coating, generally, the more conductive ink is applied to the flexible substrate, the higher the electrical conductivity. However, if a large amount of ink is sprayed onto the flexible substrate 5 such as a fiber, the rest of the ink leaks to the bottom of the flexible substrate except for the ink penetrating into the flexible substrate. Therefore, Electrical conductivity is no longer improved.

However, according to the embodiment of the present invention, since the ink is jetted in the laminated state of the heat resistant film 4 and the flexible substrate 5, the heat resistant film 4 functions to confine the ink even when an excessive amount of ink is injected, It is possible to prevent the metal substrate from leaking under the flexible substrate 5 and to react with the catalyst with sufficient ink so that a metal film layer having better electric conductivity than the conventional one can be formed.

Fourth, a flexible substrate having excellent electrical conductivity can be obtained by heating and coating the flexible substrate from below to above using a heating roller.

When the heating roller 41 is used, the coating environment of the conductive metal is formed from the bottom to the top so that a flexible substrate having excellent electrical conductivity can be obtained. The reason for the improvement of the coating quality will be briefly described with reference to FIGS. 5 and 6. FIG.

Fig. 5 is an enlarged view of the upper part of the heating roller 41 and the coating head 43 of Fig. 4 and showing a state in which the flexible substrate 5 having the catalyst layer 6 is separated from the first guide roller 42 to the heating roller 6 (a) and 6 (b) schematically show the temperature gradients of the heating roller and the flexible substrate stack according to the prior art and one embodiment of the present invention, respectively have.

5, the heating roller 41 is rotated in the counterclockwise direction in the drawing, and the catalyst layer 6 is formed on the laminated structure of the heat-resistant film 4 and the flexible substrate 5 on the right side of the coating head 43 And the precursor ink layer 7 is formed on the catalyst layer 6 by spraying the precursor ink at the coating head 43. [

When the precursor ink layer 7 is coated on the catalyst layer 6 by the coating head 43, the metal precursor solution seeps into the catalyst layer 6 to be mixed and reaction occurs. In this case, the region where the reaction actually occurs between the catalyst and the metal precursor is the region where the impregnated metal precursor meets the catalyst, that is, the catalyst layer 6. Therefore, in order to form a fast, efficient and high-quality metal film, it is important that the temperature of the catalyst layer 6 is preheated to a temperature suitable for the reaction.

However, when the flexible substrate is heated by irradiating hot air or IR toward the flexible substrate as in the prior art shown in FIG. 1, the upper surface of the flexible substrate, that is, the precursor ink layer 7, And then heated. Therefore, when the hot air reaches the metal precursor coating layer 7, the thermal energy is firstly taken away in evaporating the solvent of the metal precursor solution. Therefore, thermal energy is not efficiently transferred to the catalyst layer 6, It is slowly rising.

That is, even if the temperature of the precursor ink layer 7 is high as shown in FIG. 6 (a), thermal energy can not be transmitted downward, and thus the reaction between the intended catalyst and the metal precursor does not occur immediately, The conversion efficiency of the optical fiber is reduced. In order to solve this problem, if the temperature of the hot air is further raised to blow the hot air toward the precursor coating layer 7, the solvent of the precursor solution evaporates and the reaction efficiency may be lowered.

However, when the heating roller 41 is used as in the embodiment of the present invention, thermal energy is transferred from the center of the heating roller 41 to the surface side by heat conduction as indicated by arrows in FIG. 5, In the heating roll system in which heat is supplied from the side of the heating roller 41 to the flexible substrate 5, the temperature rises from the lowermost end of the precursor ink at the portion contacting the catalyst, the heat is transferred by the heat conduction method, so that the heat transfer efficiency is high and the heat dispersion is small. Therefore, even if the heat is transferred from the flexible substrate 5 to the catalyst layer 6, Relatively small, and therefore the efficiency with which the precursor ink is converted into the metal film is good and is suitable to cause the reaction before the evaporation of the solvent, An electrically conductive metal layer can be formed.

Various modifications according to the structure in which the heat resistant film 4 and the flexible substrate 5 are wound around the heating roller 41 and the first guide roller 42 will be described below with reference to FIGS. 7 to 9 .

Fig. 7 shows an ink coating unit according to the second embodiment.

The ink coating unit 40 according to the illustrated second embodiment includes a heating roller 41, a first guide roller 42, a coating head 43 and a second guide roller 44, 4 have the same or similar structures and functions as the corresponding components of the first embodiment of FIG.

The heat resistant film 4 is configured to be wound around the supply roll 411 and the recovery roll 412 in the second embodiment of Fig. 7 as compared with the first embodiment. That is, the heat-resistant film 4 does not form a closed loop while wrapping the heating roller 41 and the first guide roller 42, but the heat-resistant film 4 wound on the supply roll 411 is first wound 1 guide roller 42 and the heating roller 41, and then wound on the recovery roll 412 again.

The length of the heat resistant film 4 is limited in the first embodiment of FIG. 4, so that the replacement cycle for replacing the heat resistant film due to ink contamination is relatively short. However, according to the second embodiment of FIG. 7, Since the length of the heat-resistant film 4 wound on the heat-resistant film 4 is much longer, the replacement period of the heat-resistant film can be increased.

On the other hand, in the illustrated second embodiment, one or more pressure rollers 46, 47, 48 may be additionally arranged as required. Although three pressure rollers 46, 47 and 48 are shown in the figure, one or two pressure rollers may be omitted, for example, in accordance with a specific embodiment, and the reaction and drying periods (i.e., It is needless to say that one or more pressure rollers may be additionally provided.

8 shows an ink coating unit according to the third embodiment.

The illustrated ink coating unit according to the third embodiment includes a heating roller 41, a first guide roller 42, a coating head 43, a second guide roller 44, and a third guide roller 45 And the remaining components except for the third guide roller 45 have the same or similar structure and function as those of the corresponding components of the first embodiment of FIG. 4, and a description thereof will be omitted.

The heat-resistant film 4 is wound around the heating roller 41 and the first guide roller 42 to rotate in the closed loop in the third embodiment of Fig. 8 as compared with the first embodiment. However, in the first embodiment, the flexible substrate 5 is conveyed to the heating roller 41 through the first guide roller 42, but in the third embodiment of FIG. 8, the flexible substrate 5 is conveyed to the third guide roller 45 And the heating roller 41 and is conveyed.

Therefore, in this embodiment, the flexible substrate 5 has a first section (i.e., a section from (a) to (b) in FIG. 8) in contact with a part of the outer circumferential surface of the heating roller 41, (That is, a section that partially winds the first guide roller 42) and a third section that comes into contact with another portion of the outer circumferential surface of the heating roller 41 c) to (d)) sequentially.

According to the configuration of the third embodiment, the heating roller 41 may also have a preheating function for preheating the flexible substrate. That is, the separation start point (i.e., b (a)) at which the flexible substrate is separated from the heating roller 41 from the contact start point (i.e., point (a)) at which the flexible substrate 5 first starts to contact the heating roller 41 (Hereinafter referred to as "preheating zone "), the flexible substrate 5 is preheated before the flexible substrate 5 is coated by the coating head 43 .

In the illustrated embodiment, the preheating period corresponds to about 1/8 of the circumference of the heating roller 41 from the point (a) to the point (b), and the reaction and drying period corresponds approximately to the point (c) Of the circumference of the circle. Preferably, for the preheating required for the reaction, the length of the preheating zone may be between 1/8 and 1/2 of the circumference of the heating roller 41, and the length of the reaction and drying zone for sufficient reaction and drying is < To about 1/8 to 1/2 of the circumference of the circumferential surface of the base material. However, it goes without saying that the preheating period and the length of the reaction and drying sections may vary depending on various conditions such as the size (radius) of the heating roller, the feeding speed of the flexible substrate, the heating temperature of the heating roller, .

According to the third embodiment, since the flexible substrate 5 is subjected to the preheating, the reaction, and the drying process while passing through the single heating roller 41, the ink coating apparatus can be miniaturized and the apparatus efficiency can be improved.

Fig. 9 shows an ink coating unit according to the fourth embodiment.

The ink coating unit according to the fourth embodiment includes a first guide roller 42, a coating head 43, a second guide roller 44, and a third guide roller 45, The description will be omitted because it has the same or similar structure and function as the corresponding components of the third embodiment of FIG.

9, the heat-resistant film 4 is configured to be wound around the supply roll 411 and the recovery roll 412. In the fourth embodiment shown in Fig. The heat resistant film 4 wound on the supply roll 411 is wound and transported along a path partially wrapping the first guide roller 42 and the heating roller 41 so that the heat resistant film 4 is wound again on the recovery roll 412 . Therefore, the replacement period of the heat-resistant film 4 can be increased as compared with the third embodiment.

Although the embodiments of the present invention have been described with reference to the drawings, various modifications may be made in addition to those described above. For example, in the illustrated embodiments, the heat-resistant film 4 is included as a component of the invention, but the heat-resistant film 4 may be omitted in the alternative embodiment. For example, the heat-resistant film 4 may be omitted in the embodiment of Figs. 8 and 9, and in this case also, the prevention of contamination of the coating head 43 and the preheating of the flexible substrate by using one heating roller 41, Reaction, and drying process can be performed.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

4: Heat-resistant film
5: Flexible substrate
10: chamber
20: Supply roll
30: catalyst coating unit
40: Ink coating unit
50: Position control unit
60: Recovery roll

Claims (19)

An ink coating apparatus for coating a conductive metal precursor ink on a flexible substrate in a roll-to-roll manner,
A heating roller 41 for supporting and heating the flexible substrate coated with the catalyst layer;
A first guide roller (42) arranged side by side with the heating roller at a predetermined interval and supporting the flexible substrate;
A coating head 43 disposed offset from the heating roller 41 by a predetermined distance toward the guide roller 42 and coating the metal precursor ink on the flexible substrate; And
And an ink-impermeable heat-resistant film (4) wound at least from the top of the guide roller to the top of the heating roller,
Wherein a metal precursor ink is coated on the flexible substrate in a state in which the flexible substrate is laminated on the heat resistant film in a transfer section of the flexible substrate from the upper portion of the guide roller until the flexible substrate is separated from the heating roller Device. The method according to claim 1,
The heating roller causes a reaction between the catalyst and the metal precursor from a contact starting point at which the flexible substrate starts to contact the heating roller to a separation starting point at which the flexible substrate starts to be separated from the heating roller, And a reaction and drying section. 3. The method of claim 2,
Wherein thermal energy in the heating roller is transferred to the flexible substrate by thermal conduction so that thermal energy is transferred from the flexible substrate toward the catalyst layer to promote the reaction between the catalyst and the metal precursor in the reaction and drying sections. Coating apparatus. 3. The method of claim 2,
Wherein a length of a path from the contact start point to the separation starting point along the outer circumferential surface of the heating roller is between 1/4 and 3/4 of the circumference of the heating roller. The method according to claim 1,
Wherein the heat resistant film is wound around the guide roller and the heating roller to form a menopause path. The method according to claim 1,
Wherein the heat resistant film is wound in a roll-to-roll manner at least from the top of the guide roller to the top of the heating roller. An ink coating apparatus for coating a conductive metal precursor ink on a flexible substrate in a roll-to-roll manner,
A heating roller 41 for supporting and heating the flexible substrate coated with the catalyst layer;
A first guide roller (42) arranged side by side with the heating roller at a predetermined interval and supporting the flexible substrate; And
And a coating head (43) disposed offset from the heating roller (41) toward the guide roller (42) by a predetermined distance and coating the metal precursor ink on the flexible substrate,
A first section in which the flexible substrate contacts the first portion of the outer circumferential surface of the heating roller, a second section in contact with a portion of the outer circumferential surface of the guide roller, and a third section in contact with the second portion of the outer circumferential surface of the heating roller Wherein the flexible substrate is wound on the heating roller and the guide roller so that the flexible substrate is sequentially passed through the heating roller and the guide roller. 8. The method of claim 7,
The first section includes a preheating section for heating the flexible substrate from a first contact starting point at which the flexible substrate starts to contact the heating roller to a first separation starting point at which the flexible substrate starts to be separated from the heating roller and,
The third section causes a reaction of the catalyst with the metal precursor from a second contact starting point at which the flexible substrate begins to contact the heating roller to a second separation starting point at which the flexible substrate begins to separate from the heating roller And a reaction and drying section for drying the flexible substrate. 9. The method of claim 8,
Wherein the path length from the first contact starting point to the first separation starting point of the preheating section along the outer circumferential surface of the heating roller is between 1/8 and 1/2 of the circumference of the heating roller. 9. The method of claim 8,
Wherein the path length along the outer circumferential surface of the heating roller from the second contact starting point to the second separation starting point of the reaction and drying section is between 1/8 and 1/2 of the circumference of the heating roller. 8. The method of claim 7,
The rotational speed and the heating temperature of the heating roller are set so as to heat the flexible substrate to a temperature range suitable for causing a reaction between the catalyst and the metal precursor while the flexible substrate passes through the first section of the heating roller Wherein the ink coating apparatus comprises: 9. The method of claim 8,
Wherein thermal energy in the heating roller is transferred to the flexible substrate by thermal conduction so that thermal energy is transferred from the flexible substrate toward the catalyst layer to promote the reaction between the catalyst and the metal precursor in the reaction and drying sections. Coating apparatus. 8. The method of claim 7,
Further comprising an ink-impermeable heat-resistant film (4) wound on the heating roller and the guide roller at least in a path from the first section to the third section. 14. The method of claim 13,
Wherein the metal precursor ink is coated on the flexible substrate in a state where the flexible substrate is laminated on the heat resistant film. 14. The method of claim 13,
Wherein the heat resistant film is wound around the guide roller and the heating roller to form a menopause path. 14. The method of claim 13,
Wherein the heat resistant film is wound on the guide roller and the heating roller at least from the first section to the third section by a roll-to-roll method. An apparatus for coating a conductive metal film on a flexible substrate by a roll-to-roll method,
A chamber (10) filled with an inert gas;
A catalyst coating apparatus (30) disposed in the chamber and coating a catalyst on a first surface of the flexible substrate; And
17. A method according to any one of claims 1 to 16, wherein the conductive metal precursor ink is coated on the catalyst coat layer of the flexible substrate and the conductive metal precursor is reacted with the catalyst to form a conductive metal film. And an ink coating apparatus (40). 18. The method of claim 17,
A feed roll (20) disposed in the chamber, for feeding the flexible substrate to the catalyst coating apparatus; And
And a recovery roll (60) disposed in the chamber, for recovering the flexible substrate from which the conductive metal film is produced, and winding the same in a roll form. 18. The apparatus according to claim 17,
A microgravure coating roll for coating a catalyst solution on the flexible substrate; And
And a drying unit for heating and drying the flexible substrate coated with the catalyst solution.

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