JPH11197569A - Coating method and coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the surface wettability of a base material even in the case unequal coating occurs by coating the surface of the base material with coating materials twice, that is, coating the surface thereof with the coating material of the second layer while the coating material of the first layer applied on the base material maintains fluidity. SOLUTION: A first coating section 13 including a first coating roll 12 for coating the base material 2 with the prescribed coating material as the first layer is disposed on the upstream side in the traveling direction of the base material 2 is such a manner that the base material 2 is guided by plural spreading rolls 6 and are made travelable from the left side toward the right side. Further, a second coating section 15 including the second coating roll 14 for coating the surface of the first layer with the prescribed coating material of the second layer and for regulating the thickness over the entire part to the prescribed thickness while the coating material of the first layer holds the flow property is disposed apart a proper interval on the downstream side of the traveling direction. As a result, the coating quality having excellent surface accuracy free of the unequal coating may be obtd. on the surface of the base material 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating method and a coating apparatus for coating a coating material having a predetermined thickness on a surface of a substrate using a coating roll.

[0002]

2. Description of the Related Art Generally, a coating roll is used to apply various coating agents to a continuous substrate made of resin, paper, cloth, metal such as iron, copper, and the like. Coating equipment is frequently used.

[0003] As an example of such a coating apparatus, a coating apparatus for coating a continuous base material with a coating agent will be described with reference to FIG.

A conventional coating apparatus 1 of this type includes a coating section 3 and a drying section 4 in the running direction of a continuous base material 2 made of a long and wide resin film, paper or cloth. Are arranged so as to apply a desired coating agent. Then, the base material 2 is unwound from the web roll 5 on the left side of FIG.
While being stretched so as to pass through a predetermined path by 6, it is conveyed rightward in the figure, and finally wound up by a take-up roll 7.

[0005] In a coating unit 3 for coating the base material 2 with the coating agent, the base material 2 is coated using various coating rolls 3a such as a simple coating roll, a gravure roll, and a wire bar. The agent is applied. In the drying unit 4 for drying the coating agent applied to the base material 2, the drying air is blown at a predetermined temperature,
The coating agent is dried by spraying under appropriate conditions such as air volume.

[0006]

However, in the above-mentioned conventional coating apparatus 1, when forming a coated product, the number of rotations of the coating roll 3a is reduced or the coating roll 3a is not used.
Even if measures are taken to reduce the contact angle between the substrate and the base material 2, coating unevenness occurs and it is not possible to obtain coating quality with excellent surface accuracy of the coating agent. was there.

[0007] In particular, a coating product which has a problem of reflection of light on the surface of the coating material, for example, a coating material having excellent surface accuracy on the surface of a coating material which surely satisfies the required quality used for displays and the like. There was a problem that it was difficult to obtain quality.

In the conventional coating apparatus 1, when the substrate 2 is made of a fragile material such as tack, polycarbonate, or a vapor-deposited film, coating unevenness is particularly likely to occur, and the surface of the coating agent is hardly affected. There was a problem that it was more difficult to obtain coating quality with excellent accuracy.

Further, in the conventional coating apparatus 1, when the surface of the base material 2 is coated with a very small thickness of submicron, vertical streak-like coating unevenness extending in the traveling direction of the base material 2 occurs. There is a problem that it is difficult to apply a coating having a very small thickness of submicron.

[0010] The present invention has been made in view of these points, and an object of the present invention is to provide a coating method and a coating apparatus capable of obtaining coating quality excellent in surface accuracy of a coating agent. Further, it is another object of the present invention to provide a coating method and a coating apparatus capable of easily coating a very thin submicron coating agent on the surface of a substrate.

[0011]

In order to achieve the above-mentioned object, a feature of the coating method of the present invention described in claim 1 is that a coating agent is applied to a surface of a substrate at least twice. The method is characterized in that the second layer is applied while the second layer is applied to the substrate while the fluidity of the first layer is maintained. And, by adopting such a configuration, when the first coating agent is applied to the surface of the base material, this coating agent is applied to the surface of the base material, and even if coating unevenness occurs. Improves the wettability of the surface of the substrate. Next, the next coating agent is repeatedly applied while the first coating agent applied to the surface of the base material maintains fluidity.
Then, the next coating agent is applied on the base material or the first coating agent in which wettability has been improved by the application of the first coating agent, and the coating unevenness of the first coating agent is reduced. The surface of the next coating agent is formed smoothly while smoothing. In this way,
It is possible to easily and reliably apply a coating agent having a coating quality excellent in surface accuracy without coating unevenness on the surface of the base material. Further, a coating agent having a coating quality excellent in surface accuracy without coating unevenness can be similarly applied to a material which is easily damaged. In addition, as the number of times of applying the coating agent repeatedly,
A configuration in which the number of times is three or more times in a state where the first coating agent maintains fluidity may be adopted.

[0012] A feature of the coating method of the present invention described in claim 2 is that, in claim 1, at least the coating of the second layer has a predetermined surface accuracy of 50 mm or less in diameter. In that it is applied by kiss coating using a coating roll. Then, by employing such a configuration, the coating agent is applied to the surface of the base material only by the application roll that comes into contact with the base material with a relatively low contact force without using the pressing roller. In this way, it is possible to more easily and reliably apply a coating agent having a coating quality with excellent surface accuracy without coating unevenness on the surface of the base material. Furthermore, a coating agent having excellent surface accuracy and excellent coating quality without coating unevenness can be more easily and reliably applied even to a material which is easily damaged.
Furthermore, a very thin submicron coating can be easily applied to the surface of the substrate.

A feature of the coating method according to the present invention described in claim 3 is that in claim 2, the coating roll is a gravure roll. And, by adopting such a configuration, the gravure roll accurately controls the amount of the coating agent applied to the base material. In other words, by using a gravure roll, it is possible to accurately control the thickness of the coating agent applied to the base material,
The surface accuracy of the coating agent on the surface of the base material can be further improved, and the application of a very thin submicron coating agent on the surface of the base material can be performed more easily. further,
It is possible to more easily and surely apply a coating agent having excellent coating accuracy with excellent surface accuracy without coating unevenness even on a material which is easily damaged.

[0014] A feature of the coating apparatus of the present invention described in claim 4 is that a first coating roll for coating a coating agent of a first layer on at least the surface of the substrate. And a second coating roll for coating the second layer while the coating agent of the first layer maintains fluidity. And by adopting such a configuration, the coating method according to claim 1, that is, a coating agent is applied to the surface of the base material at least twice and coated in two layers, and the base material is coated. The coating agent of the second layer can be applied while the coating agent of the first layer applied to the first layer maintains fluidity. That is, when the first coating agent is applied to the surface of the base material by the first coating roll, this coating agent is applied to the surface of the base material, and even if coating unevenness occurs, the surface of the base material is Improve the wettability of Next, the next coating agent is repeatedly applied by the second coating roll in a state where the first coating agent applied to the surface of the base material maintains fluidity. Then, the next coating agent is applied by a second coating roll on the base material or the first coating agent in which wettability is improved by the application of the first coating agent. The surface of the coating agent is formed smoothly while unevenness is smoothed. In this way, it is possible to easily and reliably apply a coating agent having a coating quality with excellent surface accuracy without coating unevenness on the surface of the base material. Further, a coating agent having a coating quality excellent in surface accuracy without coating unevenness can be similarly applied to a material which is easily damaged. In addition, it is good also as a structure provided with many application rolls for apply | coating a multilayer coating agent on the surface of a base material.

According to a fifth aspect of the present invention, there is provided a coating apparatus according to the fourth aspect, wherein at least the second coating roll has a predetermined diameter of 50 mm or less for applying a kiss coating. It consists of a coating roller with surface accuracy. By adopting such a configuration, the coating method according to claim 2, that is, at least the coating of the second layer is performed using a coating roll having a predetermined surface accuracy of 50 mm or less in diameter. It can be applied by kiss coating. In other words, the coating agent is applied to the surface of the substrate only by the application roll that contacts the substrate with a relatively low contact force without using the pressing roller. In this way, it is possible to more easily and reliably apply a coating agent having a coating quality with excellent surface accuracy without coating unevenness on the surface of the base material. Furthermore, a coating agent having excellent surface accuracy and excellent coating quality without coating unevenness can be more easily and reliably applied even to a material which is easily damaged. Furthermore, a very thin submicron coating can be easily applied to the surface of the substrate.

Further, the feature of the coating apparatus of the present invention described in claim 6 is that in claim 5,
The second coating roll is a gravure roll.
And by adopting such a configuration, the coating method according to claim 3, that is, the coating agent for the second layer can be coated by a gravure roll. In other words, by using a gravure roll, it is possible to accurately control the thickness of the coating agent applied to the base material,
The surface accuracy of the coating agent on the surface of the base material can be further improved, and the application of a very thin submicron coating agent on the surface of the base material can be performed more easily. further,
It is possible to more easily and surely apply a coating agent having excellent coating accuracy with excellent surface accuracy without coating unevenness even on a material which is easily damaged.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings. The same or corresponding components as those of the above-described conventional device are denoted by the same reference numerals in the drawings.

FIGS. 1 to 3 show a first embodiment of a coating apparatus according to the present invention using the coating method according to the present invention. FIG. 1 is a block diagram, and FIG. Sectional view showing, FIG.
FIG. 3 is a sectional view taken along line BB of FIG. 2.

As shown in FIG. 1, in the coating apparatus 11 of the present embodiment, the substrate 2 is guided by a plurality of stretching rolls 6, 6 and can travel from left to right in FIG. On the upstream side of the traveling direction of the substrate 2 shown on the left side of FIG. 1, a first coating of a predetermined coating agent on the substrate 2 as a first layer is performed.
A first coating unit 13 having a coating roll 12 is provided, and a predetermined coating agent of a second layer is coated on the first layer on the downstream side in the traveling direction shown on the right in FIG. A second coating unit 15 including a second coating roll 14 for coating and for setting the entire thickness to a predetermined thickness is provided at appropriate intervals.

The first coating section 13 will be further described with reference to FIGS.

The first coating roll 12 of the first coating unit 13
Is formed to have a relatively small diameter of about 20 to 50 mm. As shown in FIG. 2, the lower surface, which is one surface of the base material 2, is subjected to kiss coating, specifically, a coating method called microgravure coating. The first layer of coating is applied. That is, the first coating roll 12 uses a so-called microgravure roll made of a gravure rule having a diameter of 50 mm or less, and the outer peripheral surface of the first coating roll 12 has a base material as shown in FIG. An engraving portion 16 having a width smaller than the entire width of No. 2 is engraved over the entire circumference. The pattern of the engraved portion 16 is a pattern in which oblique line groove patterns, pyramid-shaped recesses, or truncated pyramid-shaped recesses are arranged in a grid pattern according to the design concept and the thickness of the coating agent applied to the base material 2. And so on.

The first coating roll 12 has a pair of support members 18, 18 erected on a base 17 which is moved up and down by a known suitable lifting drive mechanism (not shown). 19 is rotatably supported. Rotational force is transmitted to the first coating roll 12 from a drive motor via a coupling (both not shown). Then, in the present embodiment, the first coating roll 12 is rotated in the opposite direction (the counterclockwise direction in FIG. 2) at the contact portion with the traveling direction of the substrate 2. An overflow receiver 20 is fixed on a base 17 below the first coating roll 12 by a tightening bolt 21. A coating agent supply nozzle 22 for supplying a predetermined coating agent to the first coating roll 12 is fixed on the overflow receiver 20. As shown in FIG. 3, the coating agent supply nozzle 22 is formed to have the same width as the engraved portion 16 of the first coating roll 12. As shown in FIG. 2, the coating material supply nozzle 22 is integrally formed by interlocking two split nozzle pieces 22a and 22b in the lower half with a thin sandwiching material 23 therebetween. Have been. Further, a coating agent storage section 24 having a circular section that is long in the width direction and temporarily stores the coating agent supplied from the outside is formed on the upper portion of the thin sandwiched object 23. An elongated communication groove 25 is formed in the upper portion of the coating agent storage section 24 by not interposing the thin interposed member 23. Then, the coating agent supply nozzle 22
At the upper end of the first coating roll 12, the coating agent supplied from the coating agent storage unit 24 through the communication groove 25 is stored.
A long and narrow nozzle portion 26 which is opened upward to be applied to the engraving portion 16 is formed. The length of the nozzle portion 26 is the first
It is formed to have the same width as the width of the engraving part 16 of the coating roll 12, and at both ends in the width direction of the coating agent supply nozzle 22, the width regulating closing members 2 for closing both ends of the nozzle part 26 respectively.
7, 27 are fixed. Also, the first coating roll 12
Immediately before the engraving portion 16 applies the coating agent stored in the nozzle portion 26 to the lower surface of the base material 2, a doctor blade 28 for wiping excess coating agent applied to the engraving portion 17 is provided. ing. The doctor blade 28 is mounted on a holder 27 rotatably supported on a pivot 29 parallel to the first coating roll 12. The doctor blade 28 applies an appropriate amount of the coating agent over the entire width in the engraving portion 16 of the first coating roll 12, and applies the coating agent on the outer portion from both ends of the engraving portion 16. Also works to scrape.

As the first coating roll 12, a simple gravure roll or a plain roll may be used.

The second coating roll 14 is also a microgravure roll like the first coating roll 12, and the configuration of the second coating section 15 is the same as that of the first coating section 13. Since it is formed, its description is omitted. The second
It is important to use a microgravure roll as the coating roll 14.

That is, in the present embodiment, two microgravure coating type coating sections are provided.

The surface accuracy of the engraved portion 16 of the second coating roll 14 is such that coating unevenness when the substrate 2 is made of a fragile material such as tack, polycarbonate, or a vapor-deposited film can be prevented. Coating products where the reflection of light on the surface of the coating agent poses a problem, for example, coating quality with excellent surface accuracy of the coating agent surface that reliably satisfies the required quality used for displays, etc. In order to obtain a very thin coating of micron thickness, the surface roughness must be Rmax
= 0.4 to 6.3S.
When the surface roughness falls below this range, coating unevenness tends to occur, and when the surface roughness exceeds this range, the surface accuracy of the coating agent decreases.

The other configuration is the same as that of the above-described conventional coating apparatus 1, and the description thereof is omitted.

In this embodiment, the first coating roll 12 and the second coating roll 14 are used to apply the coating material to the base material 2 in two layers. If necessary, use three or more coating rolls for the substrate 2
It is good also as a structure which apply | coats a coating agent to three or more layers. However, in this case as well, it is important to form the third layer or more of the uppermost coating agent in a state where the coating agent of the first layer has fluidity. .

Next, the operation of the present embodiment having the above-described configuration will be described.

Using the coating apparatus 11 of the present embodiment, the substrate 2
When the coating agent is applied to the surface of the base material, the base material 2 is run at a predetermined speed in FIG. The coating of this first layer
For example, the first coating roll 12 is formed to have a diameter of about 30 mm, the engraved portion 16 on the outer peripheral surface is formed as a diagonal groove pattern of 100 mesh / inch, and is rotated at 50 to 100 rpm in a direction opposite to the running direction of the substrate 2. At the same time, the coating agent supplied to the nozzle portion 26 of the coating agent supply nozzle 22 is wound up by the first coating roll 12, and the excess coating agent is discharged from the outer peripheral surface of the first coating roll 12 by the doctor blade 28. The scraping is performed by guiding a predetermined amount of the coating agent accurately measured by the engraving unit 16 to the coating unit on the lower surface of the substrate 2. At this time, the first layer may be simply applied to the substrate 2. Also, when the first coating agent is applied to the surface of the substrate 2, this coating agent is applied to the surface of the substrate 2,
Even if coating unevenness occurs, the wettability of the surface of the substrate 2 can be easily improved.

The substrate 2 coated with the first layer as described above
While the coating agent of the first layer maintains the fluidity, the coating agent of the second layer is coated on the first layer by the second coating roll 14, and the two layers are combined. Thus, a coating agent is applied to a predetermined thickness.

That is, the second layer is formed by forming the second coating roll 14 into a diagonal groove pattern of, for example, a diameter of about 30 mm and the engraved portion 16 on the outer peripheral surface at a mesh of 120 mesh / inch at 150 to 200 rpm. While rotating in the direction opposite to the running direction of the base material 2 in the same manner as in the first layer, the coating agent supplied to the nozzle portion 26 of the coating agent supply nozzle 22 is wound up by the second coating roll 14, Excess coating agent 10 is scraped off from the outer peripheral surface of second coating roll 14 by doctor blade 28, and the coating agent accurately measured by engraving section 16 is guided to the coating section on the lower surface of substrate 2. This is done by:

The coating apparatus 1 according to the present embodiment having the above-described configuration.
According to 1, the coating agent is applied to the substrate 2 at least twice,
In order to apply the second layer by the second coating roll 14 where the coating agent of the first layer applied to the base material 2 has fluidity, the first layer is applied. Is integrated with the second-layer coating agent applied later to form a coating layer having a uniform thickness and a uniform thickness as a whole.

That is, the coating agent for forming the second layer is applied by the first first coating roll 12 onto the substrate 2 or the first layer coating agent in which wettability is improved. First
The surface of the next coating agent of the second layer is formed smoothly while smoothing the coating unevenness of the coating agent of the layer.

Therefore, according to the coating apparatus 11 of the present embodiment, the first layer only needs to be simply applied to the base material 2, and the coating agent for the second layer is applied to the first layer. The coating agent of the second layer is applied on the coating agent of the first layer in a state in which the wettability is improved by applying the coating agent, and the coating unevenness of the first layer is smoothed. Since the surface can be formed smoothly, the number of rotations of the coating roll 3a, which has been performed when coating a conventional easily fragile material, can be reduced, or the contact angle between the coating roll 3a and the base material 2 can be reduced. Even if no countermeasure is taken, coating quality excellent in surface accuracy without coating unevenness on the surface of the base material 2 made of a material that is easily damaged can be reliably obtained.

Further, since the coating agent is applied to the surface of the substrate 2 only by the second coating roll 14 which contacts the substrate 2 with a relatively low contact force without using the pressing roller, 2. It is possible to more easily and reliably apply a coating agent having a coating quality excellent in surface accuracy without coating unevenness on the surface of No. 2, and
It is possible to more easily and reliably apply a coating agent having excellent surface accuracy and coating quality without coating unevenness even on the easily susceptible material 2, and a submicron surface Thin coating can be easily performed.

Further, the second coating roll 14 composed of a microgravure roll having a diameter of 50 mm or less, preferably about 20 to 50 mm, can accurately control the amount of the coating agent applied to the substrate 2. I can do it. The thickness of the coating agent applied to the substrate 2 can be accurately controlled, and as a result, the surface accuracy of the coating agent on the surface of the substrate 2 can be further improved, and Sub-micron very thin coating agent can be applied to the surface more easily,
It is possible to more easily and surely apply a coating agent having excellent coating accuracy with excellent surface accuracy without coating unevenness even on a material which is easily damaged.

The first layer may be simply applied to the substrate 2. That is, since there may be coating unevenness, the first coating unit 13 can be selected from various coating methods according to the design concept and the like as needed.

Further, according to the coating apparatus 11 of the present embodiment, the coating agent is applied to the surface of the
Conventionally, the second layer coating agent is applied while the first layer coating agent applied to the base material 2 retains fluidity while the layer is coated. Can be applied even with high-viscosity coating agents such as UV coating agents, EB coating agents, hot melt coating agents, and two-component reactive coating agents that did not use solvents It is also possible to prevent environmental destruction by a coating agent using a solvent.

Further, the thickness of the second layer coating agent by the second coating roll 14 can be easily made smaller than the thickness of the first layer coating agent by the first coating roll 12. In other words, by controlling only the thickness of the coating agent of the second layer by the second coating roll 14, the thickness of the coating layer as a whole can be easily controlled.

Further, according to the coating apparatus 11 of the present embodiment, the first coating section 13 and the second coating section 15 which are independent of each other.
Therefore, different coating agents can be applied to the first layer and the second layer.

FIG. 4 shows a second embodiment of a coating apparatus according to the present invention using the coating method according to the present invention. In the coating apparatus 11A of this embodiment, the same overflow receiver is used. A first coating roll 12 and a second coating roll 14 are provided side by side in 20. That is, in the present embodiment, the first coating roll 12 and the second coating roll 14 are provided in one coating unit 31, and the second coating roll 12 located on the downstream side in the traveling direction of the substrate 2 is provided. The doctor blade 28 is provided only on the work roll 14.

The other structure is the same as that of the first embodiment.

With this configuration, the present embodiment provides the same effects as those of the first embodiment described above, and the first coating roll 12 and the second coating roll 1
4, the coating apparatus 11A is downsized,
It is possible to easily reduce the installation space, shorten the cleaning time, and the like.

FIG. 5 shows a third embodiment of the coating apparatus according to the present invention using the coating method according to the present invention. In the coating apparatus 11B of this embodiment, one coating unit is provided. 3
1, a first coating roll 12 and a second coating roll 14 are provided, and the first coating roll 12 is formed so as to rotate in the same direction with respect to the traveling direction of the substrate 2. I have.

The other structure is the same as that of the second embodiment.

With this configuration, the present embodiment provides the same effects as the above-described second embodiment, and also provides the first embodiment.
By rotating the coating roll 12 in the same direction as the traveling direction of the substrate 2, it is possible to more reliably prevent the substrate 12 from being damaged.

When the coating agent is applied to the base material 2 by the first coating roll 12, if the back surface of the coating agent occurs due to the absence of the doctor blade 28, the first coating agent may be used. It is preferable that a portion of the outer peripheral surface of the work roll 12 other than the engraved portion 16 has a stepped shape with a small diameter. In addition, the back side of the coating agent means that the area in the axial direction of the coating agent supplied to the outer peripheral surface of the first coating roll 12 exceeds the width of the base material 2, and as a result, the width of the base material 2 is reduced. This means that the coating agent located at the portion that has exceeded the base material penetrates into the surface of the substrate 2 opposite to the coating surface from both ends in the width direction of the substrate.

FIG. 6 shows a fourth embodiment of the coating apparatus according to the present invention using the coating method according to the present invention. In the coating apparatus 11C of this embodiment, one coating unit is provided. 3
1, a first coating roll 12 and a second coating roll 14 are provided, and a doctor blade 28 is provided on both the first coating roll 12 and the second coating roll 14. .

The other structure is the same as that of the second embodiment.

With this configuration, the present embodiment provides the same effects as the above-described second embodiment, and also provides the first embodiment.
In order to apply a doctor blade 28 to the coating roll 12 and accurately measure and apply the first layer, the second coating roll 14
, The final finishing of the coating thickness can be performed with higher accuracy.

Further, since the doctor blade is disposed on the first coating roll 12, the coating agent for applying the coating agent to the base material 2 by the first coating roll 12 is used. Can be reliably prevented.

The present invention is not limited to the above embodiments, but can be variously modified as needed.

[0054]

As described above, according to the coating method and the coating apparatus of the present invention, it is possible to obtain coating quality excellent in surface accuracy without coating unevenness on the surface of a substrate made of a material which is easily damaged. And an extremely excellent effect that coating of a very small thickness of submicron can be easily performed on the surface of the base material.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a main part of a first embodiment of a coating apparatus according to the present invention using a coating method according to the present invention.

FIG. 2 is a cross-sectional view showing a coating unit in FIG.

FIG. 3 is a sectional view taken along the line BB of FIG. 2;

FIG. 4 is a view similar to FIG. 1, showing a main part of a second embodiment of the coating apparatus according to the present invention using the coating method according to the present invention;

FIG. 5 is a view similar to FIG. 1 showing a main part of a third embodiment of a coating apparatus according to the present invention using a coating method according to the present invention;

FIG. 6 is a view similar to FIG. 1, showing a main part of a fourth embodiment of a coating apparatus according to the present invention using a coating method according to the present invention;

FIG. 7 is a configuration diagram showing a conventional coating apparatus.

[Explanation of symbols]

 2 Base material 11, 11A, 11B, 11C Coating device 12 First coating roll 13 First coating unit 14 Second coating roll 15 Second coating unit 16 Engraving unit 31 Coating unit

Claims (6)

[Claims] 1. A coating method in which a coating agent having a predetermined thickness is applied to a surface of a running continuous base material by using a coating roll. The coating agent is applied at least twice and coated in two layers, and the second layer coating agent is coated while the first layer coating agent applied to the base material maintains fluidity. Coating method characterized by performing. 2. The method according to claim 1, wherein at least the second layer is applied by kiss coating using an application roll having a predetermined surface accuracy of 50 mm or less in diameter.
Coating method described in 1. 3. The coating method according to claim 2, wherein the coating roll is a gravure roll. 4. A coating apparatus for applying a coating agent having a predetermined thickness to a surface of a running continuous base material using a coating roll, wherein at least a surface of the base material is coated A first coating roll for applying a one-layer coating agent, and a second coating roll for applying the second layer while the first-layer coating agent maintains fluidity. A coating apparatus comprising: 5. The coating apparatus according to claim 4, wherein at least the second coating roll is a coating roll having a predetermined surface accuracy of 50 mm or less for applying a kiss coating. 6. The coating apparatus according to claim 5, wherein the second coating roll is a gravure roll.