KR102649971B1 - Coma coating apparatus and method for improvement of coating surface uniformity - Google Patents

Abstract

A top cover that covers the top of the coating liquid receiving space through which the base film passes; and a gas injection unit that provides a volatilization-suppressing gas inside the receiving space. A coating device including a comma portion and a coating method using the same are disclosed. In the comma coating device, a cover is installed on the top of the comma portion, and a certain amount of volatilization-inhibiting gas such as nitrogen is injected to compensate for the vapor pressure, thereby suppressing solvent volatilization of the nasal decoction and solving defective problems caused by thickness deviation that occur during coating.

Description

Coma coating apparatus and method for improvement of coating surface uniformity}

This specification relates to a comma coating device and coating method for improving coating surface uniformity.

Recently, with the development of the IT industry and the movement towards miniaturization and precision of products, the level of precision required for IT materials is increasing significantly. Accordingly, more uniformity and precision are required when coating the coating liquid on the surface of the substrate.

In this regard, methods such as comma knife, direct gravure, micro gravure, curtain coating, and slot die coating are usually used to coat coating agents diluted in solvents. The comma knife coating method, which is compatible with various coating materials, is industrially used. It is being used a lot. The reason is that the structure of the comma knife is relatively simple. When coating various materials, the cleaning process before and after coating is easy and the setting is simple, which is advantageous in setting coating conditions.

In the comma coating device, the base film is wound around the back roll unit and passes through the coating unit. The coating portion has an injection portion for injecting the coating liquid, a liquid receiving plate for receiving the coating liquid, and a comma portion, and side dams are provided on both sides of the liquid receiving plate.

However, the comma coater has an open structure in which the injection part must be located outside and the coating liquid must be in contact with air. This implies the possibility of defects such as foreign substances and bubbles being included during coating, and due to the open structure, deterioration or volatilization of the solvent may occur due to air contact, especially in the side section furthest from the injection part, excessive solvent volatilization of the coating agent. The coating line problem caused by this is chronic.

Methods have been proposed to solve this problem.

For example, by increasing the injection part from one to two to shorten the residence time of the coating liquid from the injection part to coating, or by changing the type of diluted solvent to a high boiling point to reduce the amount of solvent volatilized from the coating part, or by reducing the amount of solvent volatilized in the coating part There is a method to reduce air contact by covering the top (Patent Document 1).

However, the method of increasing the injection portion results in the creation of clear coating lines between the injection portions, and the method of reducing volatility by using a high boiling point is initially effective, but as the working time increases, solvent volatilization occurs due to continuous air contact with the surface. As the total amount increases, coating streaks occur again.

In addition, the method of installing a cover on the top of the injection part is effective to some extent in the early stages of work, but fundamentally it cannot suppress the vapor pressure at which the solvent wants to volatilize, so the volatilized solvent escapes into the empty space of the side dam, resulting in the total amount of solvent volatilized. As this increases, thickness deviation occurs.

Patent Document 1: Japanese Patent Application Publication No. 2011-0011192

In exemplary embodiments of the present invention, in one aspect, it is possible to suppress solvent volatilization of the coating liquid, solve defects due to thickness deviation that occurs during coating, and thereby improve the quality of the overall coated surface. A comma coating device and coating method are provided.

In another aspect, exemplary embodiments of the present invention provide a comma coating device and coating method that can be applied to mass production.

In exemplary embodiments of the present invention, a coating device including a comma portion, the top cover covering the top of the coating liquid receiving space through which the base film passes; and a gas injection unit that provides a volatilization-suppressing gas inside the receiving space.

In an exemplary embodiment, the coating device includes a liquid receiving plate, a side dam, and a comma portion, and a top cover that covers the top of the coating liquid receiving space between the liquid receiving plate, the side dam, and the comma portion. It can be included.

Specifically, in one exemplary embodiment, the coating device includes: a comma portion; A coating liquid injection unit that supplies the coating liquid; A back roll unit that runs the base film; a liquid receiving plate that accommodates the coating liquid injected from the coating liquid injection part; A side dam located on the side of the liquid receiving plate and preventing side leakage of the coating liquid; and a top cover covering the top of the coating liquid receiving space between the liquid receiving plate, the side dam, and the comma portion; and a gas injection unit that provides a volatilization-suppressing gas inside the accommodation space.

In an exemplary embodiment, at least one of the coating liquid injection unit and the gas injection unit may be connected to a hole formed in the center of the top cover.

In an exemplary embodiment, at least one of the coating liquid injection unit and the gas injection unit may have a plurality of two or more injection ports, and each injection port may be airtightly connected to the top cover.

In one exemplary embodiment, the top cover may be installed to contact the inner surface of the side dam.

In an exemplary embodiment, the coated base film may have improved thickness uniformity.

In one exemplary embodiment, the thickness deviation (difference between maximum and minimum thickness) of the coating film may be 0 μm. For example, the thickness deviation, which is the difference between the maximum and minimum values of the average values of three measurements each in the operator direction (OS), central part (CE), and equipment drive direction (DS), may be 0㎛.

In one exemplary embodiment, the base film may not be visible during a three-wavelength visual inspection, and may have a coating line level that is visible such that a shadow is not visible or the boundary of the shadow is not recognized when inspecting a lantern shadow.

In exemplary embodiments of the present invention, there is also a method of coating a base film with a coating liquid using a coating device including a comma portion, wherein the base film is coated after passing through a coating liquid receiving space, and the coating liquid receiving space is provided with a volatilization suppressing device. A coating method is provided, characterized in that gas is provided.

Exemplary embodiments of the present invention also provide a method of improving coating thickness uniformity when coating with a coating device including a comma portion, including performing coating with the coating device.

In exemplary embodiments of the present invention, the coating film is a coating film in which a coating liquid is comma-coated on a base film, and the thickness deviation (difference between maximum and minimum thickness) of the coating film is 0㎛ and is not visible during visual inspection at three wavelengths, We provide a coating film that has a visible coating line level so that the shadow is not visible or the boundary line of the shadow is not recognized when inspecting the lantern shadow.

According to exemplary embodiments of the present invention, a cover is installed on the top of the comma portion in the comma coating device, and a certain amount of volatilization-suppressing gas such as nitrogen is injected to compensate for the vapor pressure, thereby suppressing solvent volatilization of the nasal decoction and reducing the volatilization of the solvent generated during coating. It is possible to solve defect problems caused by thickness deviation. In other words, the chronic coating surface thickness deviation that occurs when coating materials with a comma coater can be effectively suppressed and the overall coating surface quality can be improved.

The closed comma coating device and coating method of exemplary embodiments of the present invention and the coated base film obtained thereby can be used in the production of various IT materials such as cell pouches.

1 is a schematic diagram showing the configuration of a comma coating device according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 1 of the present invention.
Figure 3 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 2 of the present invention.
Figure 4 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 3 of the present invention.
Figure 5 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 4 of the present invention.

In this specification, a comma coating device refers to a coating device including a comma portion.

In this specification, comma coating means coating using a coating device including a comma portion.

In this specification, the lantern shadow test refers to a test that determines the appearance condition by looking at the shape of the pattern (shadow) that appears when a xenon lantern or LED lantern is shined on a sample and projected onto a whiteboard.

In this specification, weak recognition when examining a lantern shadow means a case where the boundary line of a pattern (shadow) is not recognized when examining a lantern shadow.

In this specification, strongly recognized when inspecting a lantern shadow means a case where the boundary line of a pattern (shadow) is recognized when inspecting a lantern shadow.

In this specification, the three-wavelength visual inspection refers to an inspection that determines the external condition by shining a three-wavelength lamp on the sample and looking at the shape of the pattern that appears when the light is reflected.

In this specification, volatilization-suppressing gas refers to a gas provided to the coating liquid accommodating part to suppress volatilization of the coating liquid in the coating liquid accommodating part.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram showing the configuration of a comma coating device according to an embodiment of the present invention.

As shown in Figure 1, the comma coating device of one embodiment of the present invention includes a comma portion; A coating liquid injection unit that supplies the coating liquid; A back roll unit that runs the base film; a liquid receiving plate that accommodates the coating liquid injected from the coating liquid injection part; A side dam located on the side of the liquid receiving plate and preventing side leakage of the coating liquid; and a top cover located between the comma portion and the liquid receiving plate, and a hose capable of injecting nitrogen is additionally installed on the top cover.

As described above, in the above comma coater structure, the back roll unit transfers the base film and continuously moves during work, but the comma unit, side dam, liquid receiving plate, injection unit, etc. are fixed and do not move even during work. A fixed top cover is completed by manufacturing and inserting a top cover of the correct size between the comma part and the liquid receiving plate and connecting the air injection part to the center of the top cover. At this time, if nitrogen is injected through the air injection unit, the vapor pressure of the volatile solvent generated from the coating liquid is compensated and the generation of volatile solvent is significantly reduced, which has the effect of improving the uniformity of the coating thickness.

In an exemplary embodiment, the back roll unit moves the base film constantly while allowing the base film to pass through the coating liquid receiving unit.

In an exemplary embodiment, the comma portion can control the coating thickness and surface condition when coating is performed as the base film passes through the coating liquid receiving portion.

In one exemplary embodiment, the injection unit constantly supplies the coating liquid to the coating liquid receiving unit at the rear side of the comma portion. The injection unit may have two or more injection ports.

In one exemplary embodiment, the coating liquid receiving part is provided with a liquid receiving plate to prevent the coating liquid supplied from the injection unit from flowing down. Additionally, side dams are installed on the sides of the liquid receiving plate to prevent side leakage of the coating liquid.

In one exemplary embodiment, the top cover is located between the comma portion and the liquid receiving plate to suppress solvent volatilization to some extent. However, in exemplary embodiments of the present invention, instead of sealing the coating liquid receiving portion, a certain amount of gas such as nitrogen is injected to compensate for the vapor pressure, thereby suppressing solvent volatilization of the coating liquid and preventing defects due to thickness deviation that occurs during coating. Let's solve it.

In one exemplary embodiment, the gas is an inert gas, such as nitrogen.

In an exemplary embodiment, it is desirable to provide gas so that the vapor pressure in the coating liquid receiving portion is in the range of 0.01Mpa to 0.1Mpa.

In one exemplary embodiment, the top cover may be installed to contact the inner surface of the side dam.

In an exemplary embodiment, at least one of the coating liquid injection unit and the gas injection unit may be connected to a hole formed in the center of the top cover.

In an exemplary embodiment, at least one of the coating liquid injection unit and the gas injection unit may have a plurality of two or more injection ports, and each injection port may be airtightly connected to the top cover.

In the above comma coater structure, the back roll unit transports the base film and continuously moves during work, but the comma unit, side dam, liquid receiving plate, injection unit, and top cover are fixed and do not move even during work.

When coating materials using the comma coaters of these exemplary embodiments of the present invention, the uniformity and quality of the overall coating surface that occurs can be improved, and mass production is facilitated. In general, in order to maintain consistent quality during mass production, expensive equipment such as a sealed coating device, for example, a slot die, is applied, but the problem is that working conditions cannot be established for the production of products that are difficult to apply to the coating conditions of the slot die. This is a situation that happens frequently. On the other hand, the comma coating device and the comma coating method of exemplary embodiments of the present invention can set mass production working conditions with a simple structure, thereby not only reducing defective production but also reducing facility investment costs.

In an exemplary embodiment, the coated base film obtained by the manufacturing method of the present invention may have improved thickness uniformity.

In one exemplary embodiment, the thickness deviation (difference between maximum and minimum thickness) may be 0 μm. For example, the difference between the maximum and minimum values of the average values measured three times each in the operator direction (OS), center (CE), and equipment drive direction (DS) may be 0㎛.

In an exemplary embodiment, it may not be recognized during a three-wavelength visual inspection, and the shadow may not be recognized during a lantern shadow inspection, or the boundary line of the shadow may not be recognized.

Exemplary embodiments of the present invention are explained in more detail through the following examples. The embodiments disclosed herein are illustrated for illustrative purposes only, and the embodiments of the present invention may be implemented in various forms and should not be construed as limited to the embodiments described herein.

[Example]

In the example, as shown in FIG. 1 above, the top cover and gas injection part were connected between the comma part, the liquid receiving plate, and the side dam, and nitrogen was injected.

[Comparative Example 1]

Comparison 1 is a schematic diagram showing the configuration of a general comma coating device as shown in FIG. 2 described above. In contrast to Comparative Example 2 below, the comma coating device shown in FIG. 2 has one injection unit.

[Comparative Example 2]

Figure 3 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 2 of the present invention.

As shown in Figure 3, in Comparative Example 2, the number of injection parts was increased from one to two so that the coating solution was injected into both sides of the base film.

[Comparative Example 3]

Figure 4 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 3 of the present invention.

As shown in Figure 4, in Comparative Example 3, the type of diluted solvent was changed to a high boiling point (EA 35% and toluene 40%) to reduce the amount of solvent volatilized from the coating portion.

[Comparative Example 4]

Figure 5 is a schematic diagram showing the configuration of the comma coating device in Comparative Example 4 of the present invention.

As shown in Figure 5, in Comparative Example 4, only the top cover was installed on the upper side of the comma portion to suppress solvent volatilization and reduce air contact.

Table 1 shows the results of external inspection for the effectiveness and coating quality of the methods of each Example and Comparative Example.

In the lantern shadow test during the exterior inspection, the brightness of the lantern is more than 500 lux, the distance between the whiteboard and the sample is 50cm, and the distance between the whiteboard and the lantern is 100cm.

In the three-wavelength visual inspection, the brightness of the three-wavelength lamp is more than 1000 lux, the distance between the three-wavelength lamp and the sample is 90cm, and the distance between the observer's eyes observing the sample and the sample is 50cm.

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example structure
How to improve 1 inlet 2 injection ports
installation high point
Solvent use Top cover installed top cover and
nitrogen purging Coating information
(Acrylic adhesive) SOKEN DYNE
2094R SOKEN DYNE
2094R SOKEN DYNE
2094R SOKEN DYNE
2094R SOKEN DYNE
2094R solid content 25% 25% 25% 25% 25% Diluent solvent type and ratio Ethyl Acetate 75% Ethyl Acetate 75% Ethyl Acetate 35%
Toluene 40% Ethyl Acetate 75% Ethyl Acetate 75% Fabric width
/coating width 1080mm/1040mm 1080mm/1040mm 1080mm/1040mm 1080mm/1040mm 1080mm/1040mm Coating thickness
(Wet) 100㎛ 100㎛ 100㎛ 100㎛ 100㎛ Thickness measurement
(OS) 29㎛ 25㎛ 28㎛ 27㎛ 25㎛ Thickness measurement
(CE) 25㎛ 26㎛ 25㎛ 25㎛ 25㎛ Thickness measurement
(DS) 29㎛ 25㎛ 28㎛ 27㎛ 25㎛ Thickness deviation (maximum-minimum) 4㎛ 1㎛ 3㎛ 2㎛ 0㎛ Appearance inspection results Good central part
Coated file (steel) Good Good Good Judgment Thickness NG
(Not Good) Appearance NG
(Not Good) Thickness NG
(Not Good) Thickness NG
(Not Good) Thickness OK

*Standard for external inspection

In the above external inspection results, “good” means that the coating line is at the level of the coating line below or that the coating line is not visible (not visible during the lantern shadow test and three-wavelength visual inspection).

Coated line weak level: slightly visible when inspecting a lantern shadow (visible so that the boundary of the shadow cannot be identified), not visible when visually inspecting three wavelengths

Coated line medium level: strongly visible when inspecting lantern shadow, weakly visible when inspecting three wavelengths visually

Coated line Kang Soo-jun: Strongly recognized when inspecting lantern shadow, strongly recognized during visual inspection of three wavelengths

*Thickness measurement standard

Measured 3 times each in the worker direction (OS), center (CE), and equipment drive direction (DS) and averaged

Thickness measuring instrument: Magnescale Model name: LT-30

When two injection parts are installed as in Comparative Example 2 above, good results are obtained in terms of coating thickness uniformity, but there is a problem in that one strong coating streak occurs in the central area due to unevenness at the point where the coating liquid from the two injection parts meet. It is difficult to say that it has improved.

In addition, even when solvent volatilization is suppressed by applying a significant amount of toluene, a high boiling point solvent, as in Comparative Example 3, only a slight improvement is achieved compared to Comparative Example 1, and it is not a fundamental solution.

In addition, when the top cover is manufactured and covered as in Comparative Example 4, solvent volatilization can be suppressed to some extent, but the vapor pressure caused by solvent volatility cannot be fundamentally prevented, so solvent volatilization occurs through the side portion, etc., resulting in a slight improvement compared to Comparative Example 1. This is not a fundamental solution at this level.

On the other hand, when a top cover is manufactured between the comma portion and the liquid receiving plate as in Example 1, as well as a separate air injection part is manufactured and installed and nitrogen (N2) gas is supplied, the coating thickness is measured to be the same throughout, resulting in effective improvement. By being able to confirm what has been done, a certain quality level of the coated product can be maintained.

Although non-limiting and exemplary embodiments of the present invention have been described above, the technical idea of the present invention is not limited to the accompanying drawings or the above description. It is obvious to those skilled in the art that various forms of modification are possible without departing from the technical spirit of the present invention, and such types of modifications will fall within the scope of the patent claims of the present invention.

Claims (11)

A coating device including a liquid receiving plate, a side dam, and a comma portion,
A top cover that covers the top of the coating liquid receiving space between the liquid receiving plate, side dam, and comma portion through which the base film passes; and
It includes a gas injection unit that provides gas that compensates for vapor pressure to suppress volatilization of the coating liquid inside the receiving space from the top cover side,
A coating device including a comma portion, wherein the gas injection portion is connected to a hole formed in the top cover.
delete The method of claim 1, wherein the coating device,
comma part;
An injection unit for supplying a coating liquid;
A back roll unit that runs the base film;
a liquid receiving plate that accommodates the coating liquid injected from the injection unit;
A side dam located on the side of the liquid receiving plate and preventing side leakage of the coating liquid;
a top cover covering the top of the coating liquid receiving space between the liquid receiving plate, the side dam, and the comma portion; and
The gas injection unit providing gas to suppress volatilization of the coating liquid inside the receiving space.
According to claim 3,
A coating device including a comma portion, wherein at least one of the coating liquid injection portion and the gas injection portion includes a comma portion connected to a hole formed in the center of the top cover.
According to claim 4,
A coating device including a comma portion, wherein at least one of the coating liquid injection portion and the gas injection portion has a plurality of two or more injection ports, and each injection port is airtightly connected to the top cover.
According to claim 3,
A coating device including a comma portion, wherein the top cover is installed to contact the inner surface of the side dam.
A method of coating a base film with a coating solution using a coating device including the comma portion of any one of claims 1 and 3 to 6,
A coating method wherein a base film is coated after passing through a coating liquid receiving space, and gas is provided to the coating liquid receiving space to suppress volatilization of the coating liquid.
According to claim 7,
A coating method, characterized in that the gas is an inert gas.
According to claim 7,
A coating method characterized in that the coating thickness uniformity of the coated base film is improved.
A method of improving coating thickness uniformity when coating with a coating device including a comma, comprising the step of performing coating with the coating device of any one of claims 1 and 3 to 6. How to improve uniformity. delete