JP3965517B2 - Intermittent coating apparatus and coating method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reverse coater type intermittent coating apparatus and method for intermittently coating a coating liquid on a long web such as a hoop material, a metal film, a wire mesh, a fabric, and a film.
[0002]
[Prior art]
For mass production of batteries such as spiral electrode type lithium batteries, a copper foil or aluminum foil hoop material used as a battery current collector is used as a web, and a slurry mixture mainly composed of an electrode active material is applied as a coating liquid. Work. In this case, for example, a coating section of a predetermined length is applied to the web so that the coating liquid is applied with a certain thickness to, for example, a 30 cm section of the web and no coating liquid is applied to the subsequent 5 cm section. And uncoated sections are formed alternately.
[0003]
Conventionally, the following invention has been proposed as a reverse coater type intermittent coating apparatus for realizing such intermittent coating (Japanese Patent Publication No. 7-55304).
[0004]
As shown in FIG. 9, the intermittent coating apparatus 100 includes a backing roll (hereinafter referred to as B roll) 102, a coating roll (hereinafter referred to as C roll) 104, and a comma type doctor roll (hereinafter referred to as D roll). ) 106, and a liquid dam 108 is provided between the C roll 104 and the D roll 106 for storing the coating liquid.
[0005]
When the coating section 2 is formed by the intermittent coating apparatus 100, as shown by the solid line in FIG. 9, the web 1 is conveyed by the B roll 102, and the coating liquid is applied to the outer peripheral surface of the C roll 104 by the D roll 106. Is applied, and the coating liquid is transferred to the web 1 at the transfer position where the B roll 102 and the C roll 104 are in contact with each other to form the coating section 2.
[0006]
When the uncoated section 3 is formed, as shown by a dotted line in FIG. 9, the D roll 106 is brought close to the C roll 104 to restrict the coating liquid from coming out of the liquid dam 108, thereby coating the film. After the thickness of the thin coated film is rotated to the transfer position, the B roll 102 is separated from the C roll 104, thereby forming the uncoated section 3. The thin coating film 170 on the surface of the C roll 104 is scraped off by the cleaning blade 110.
[0007]
After the formation of the uncoated section 3, as shown by the solid line in FIG. 9, the B roll 102 is brought close again to the C roll 104, and the D roll 106 is raised to form a gap necessary for coating. . Thereby, the coating section 2 is formed again.
[0008]
By repeating the above operation, the coated section 2 and the uncoated section 3 can be alternately formed on the web 1.
[0009]
[Problems to be solved by the invention]
The intermittent coating apparatus 100 has the following problems.
[0010]
The first problem is that when the uncoated section 3 is formed, the B roll 102 is moved away from the C roll 104. At this time, the coating film on the surface of the C roll 104 is moved to the B roll 102. And the raised portion 150 is generated. Therefore, as shown in FIG. 10, when this raised portion is transferred to the web 1, there is a problem that a part of the coating thickness of the web 1 becomes thick and a raised portion 160 is generated on the coated surface of the web 1.
[0011]
The second problem is that when the uncoated section 3 is formed, the D roll 106 needs to be moved and the B roll 102 needs to be moved, so that the structure of the intermittent coating apparatus 100 becomes large, There is a problem that the uncoated section 3 cannot be formed quickly. That is, if the length of the uncoated section 3 is about 5 cm as described above, the intermittent coating apparatus 100 can form an uncoated section. However, in the recent intermittent coating, The length of the section 3 is required to be about 1 mm to 10 mm, and it is difficult for the intermittent coating apparatus 100 to form such a short uncoated section length.
[0012]
A third problem is that a cleaning blade 110 for scraping off the thin coating film 170 on the surface of the C roll 104 is necessary.
[0013]
Therefore, in view of the above problems, the present invention does not generate a swelled portion in the coating section, and the intermittent coating apparatus capable of reducing the length of the uncoated section with a simple device structure. The construction method is provided.
[0014]
[Means for Solving the Problems]
The invention of claim 1 is a backing roll for transporting a web, a coating roll for contacting the web transported by the backing roll at a transfer position, and a doctor roll for coating a coating liquid on the peripheral surface of the coating roll. And a control device that controls the rotation of the coating roll and the backing roll, and the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll at the transfer position. In the intermittent coating apparatus for transferring to the web, the control device rotates the coating roll and the backing roll in opposite directions at the transfer point when forming a coating section on one side of the web, When forming an uncoated section on one side of the web, the coating roll is stopped and the The coating roll is stopped when the coating roll stops only when the rising portion of the coating liquid generated at the coating position by the previous stop of the coating roll rotates to the transfer position. It is an intermittent coating apparatus characterized by making it carry out.
[0015]
According to a second aspect of the present invention, the control device sets the coating roll to a rotational speed VC, the backing roll to the rotational speed VB, and the length on the peripheral surface of the coating roll from the coating position to the transfer position. Is M, and the number of coating sections formed while the coating roll rotates from the coating position to the transfer position is P, and the length of the coating section is L,
VC / VB = M / (P × L)
The intermittent coating apparatus according to claim 1, wherein the coating roll and the backing roll are rotated so that
[0016]
The invention according to claim 3 is the intermittent coating apparatus according to claim 1 or 2, characterized in that the doctor roll has a comma cross-sectional shape.
[0017]
According to a fourth aspect of the present invention, there is provided a backing roll for conveying a web, a coating roll for contacting the web conveyed by the backing roll at a transfer position, and a doctor roll for applying a coating liquid to the peripheral surface of the coating roll. In the coating method of the intermittent coating apparatus for transferring the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll to the web at the transfer position, When forming the coating section on one side of the web, the coating roll and the backing roll are rotated in opposite directions at the transfer point, and when the uncoated section is formed on one side of the web, the coating roll And rotating only the backing roll, the stop position of the coating roll is A coating method for an intermittent coating apparatus, wherein when the rising portion of the coating liquid generated at the coating position due to the previous stop of the coating roll rotates and moves to the transfer position, the coating roll is stopped. .
[0018]
The invention according to claim 5 is a backing roll for transporting a web, a coating roll for contacting the web transported by the backing roll at a transfer position, and a doctor roll for coating a coating liquid on the peripheral surface of the coating roll. And a control device comprising a computer for controlling the rotation of the coating roll and the backing roll, and the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll In the program stored in the control device for realizing the coating method of the intermittent coating apparatus for transferring to the web at the transfer position, the program is configured to form the coating point when forming a coating section on one side of the web. A function of rotating the coating roll and the backing roll in opposite directions, and When the uncoated section is formed on one side of the web, the coating roll is stopped and only the backing roll is rotated. The coating roll is stopped at the coating position by the previous stop of the coating roll. And a function of stopping the coating roll when the raised portion of the generated coating liquid rotates and moves to the transfer position.
[0019]
[Operation]
The case where it coats in the intermittent coating apparatus of this invention is demonstrated.
[0020]
When forming the coating section on one side of the web, the coating roll and the backing roll are rotated in opposite directions at the transfer point.
[0021]
Also, when forming an uncoated section on one side of the web, the coating roll was stopped and only the backing roll was rotated. The coating roll stopped at the coating position due to the previous stop of the coating roll. The coating roll is stopped when the rising portion of the coating liquid rotates and moves to the transfer position.
[0022]
In this intermittent coating apparatus, since the coating roll is only stopped when the uncoated section is formed, the structure becomes simple and a short uncoated section can be formed.
[0023]
In addition, since the coating liquid swells at the start and end positions of the coating section, the coating thickness does not decrease or rise at the start and end of the coating section.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The intermittent coating apparatus 10 of one Example of this invention is demonstrated based on FIGS.
[0025]
(1) Structure of intermittent coating apparatus 10 FIG. 1 is an explanatory diagram of the structure of a reverse coater type intermittent coating apparatus 10.
[0026]
As shown in FIG. 1, the web 1 is conveyed at a speed VB by a backing roll 12 (hereinafter referred to as a B roll) 12 having a diameter dB.
[0027]
A coating roll 14 having a diameter dC (hereinafter referred to as C roll) 14 is disposed on the side of the B roll 12 and is in contact with the B roll 12 via the web 1 at the transfer position F. The rotation direction of the C roll 14 and the rotation direction of the B roll 12 are opposite directions at the transfer position F. In FIG. 1, the C roll 14 rotates in the clockwise direction at the rotation speed VC, and the B roll 12 also rotates in the clockwise direction at the rotation speed VB.
[0028]
Above the C roll 14, a comma-shaped doctor roll (hereinafter referred to as “D roll”) 16 having a cross-sectional shape is disposed, and behind this D roll 16 and the C roll 14, a coating liquid is stored. A liquid dam 18 is arranged. The liquid dam 18 forms a space where the coating liquid is accumulated by the plate 19.
[0029]
The edge 20 of the comma-shaped D-roll 16 is positioned with respect to the B-roll 12 through a predetermined gap, and a shear pressure is applied to the edge 20, and is stored in the liquid dam 18 with respect to the rotating C-roll 14. The coating liquid is applied to the surface of the C roll 14 with a predetermined thickness. Hereinafter, the position of the C roll 14 to which the coating liquid is applied by the edge 20 is referred to as a coating position G. The D roll 16 is in a state where the edge 20 is fixed at a position away from the C roll 14 by the coating thickness, and does not move or rotate during coating.
[0030]
Next, terms that appear in the following explanation are defined.
[0031]
As shown in FIG. 1, the angle between the coating position G and the transfer position F on the C roll 14, that is, the angle between the transfer position F and the center point O of the C roll 14 and the coating position G is present. The distance along the circumferential surface of the C roll 14 with respect to the coating liquid existence angle θ is referred to as an angle θ (°), and is referred to as a coating liquid existence distance M. That is,
M = π × dC × θ / 360 (1)
There is a relationship.
[0032]
(2) Structure of the control system of the intermittent coating apparatus 10 FIG. 2 is a block diagram showing the structure of the control system of the intermittent coating apparatus 10.
[0033]
As shown in FIG. 2, a B roll motor 22 that rotates the B roll 12 and a C roll motor 24 that rotates the C roll 14 are connected to a control unit 26, and an operation unit 28 is provided in the control unit 26. Yes.
[0034]
The control unit 26 includes a computer such as a personal computer, and the operation unit 28 corresponds to a keyboard, a mouse, or the like. This control part 26 is comprised from CPU, memory, a hard disk, etc., and the control method of the intermittent coating apparatus 10 demonstrated by (4) is realizable with the program memorize | stored in the control part 26 which consists of this computer. .
[0035]
(3) Description of Comparative Example of Intermittent Coating Apparatus 10 In the intermittent coating apparatus 10 of the present embodiment, when a coating section 2 having a coating length L is formed on one side of the web 1 as shown in FIG. The B roll 12 and the C roll 14 are rotated together, and when the uncoated section 3 having an uncoated length N is formed, only the B roll 12 is rotated and the C roll 14 is stopped.
[0036]
However, the uncoated section 3 is not formed by simply stopping the C roll 14, but the uncoated section 3 is formed by performing the control shown in (4). Hereinafter, the reason will be described using a comparative example shown in FIG.
[0037]
FIG. 5 is an enlarged view of the transfer position F in the comparative example.
[0038]
As shown in FIG. 5A, when the coating section 2 is formed, the coating liquid coated on the surface of the C roll 14 is transferred to the web 1 conveyed by the B roll 12 and is predetermined. The coating layer is formed with a thickness of.
[0039]
By the way, when the C roll 14 is stopped, a raised portion 6 is generated at the coating position G of the D roll 16, and this raised portion 6 is directly transferred to the surface of the web 1 as shown in FIG. Therefore, as shown in FIG. 5C, there is a problem that a raised portion 82 occurs in a part of the coating section 2.
[0040]
Here, the reason why the rising portion 6 occurs at the coating position G of the D roll 16 when the C roll 14 is stopped will be described. While the C roll 14 is rotating, the coating liquid is uniformly applied to the surface of the web 1. However, when the C roll 14 stops and starts to rotate again, the swelled portion 6 occurs due to the fluidity and fluid pressure of the coating liquid in the vicinity of the edge 20.
[0041]
And as shown in FIG.5 (d), when forming the uncoated area | region 3, in order to stop only the C roll 14, the position of the terminal of the coating area 2 of the web 1 is the position of the C roll 14. There is a problem that the shape of the terminal end of the coating section 2 becomes a slope 84 due to the wipe effect that is in a state of rubbing the surface.
[0042]
In addition, since the surface of the C roll 14 is rubbed, the thickness of the coating solution applied to the C roll 14 is also reduced to form the slope 88, so that the position of the starting end of the coating section 2 is also illustrated in FIG. As shown in FIG. 5 (e), there is a problem that the slope 86 is formed.
[0043]
Because of the above problems, the coating section 2 having a uniform coating thickness cannot be formed simply by stopping the C roll 14 when forming the uncoated section 3.
[0044]
Therefore, the present applicant performs the following control method in order to solve these three problems.
[0045]
(4) Control method of the present embodiment of the intermittent coating apparatus 10 Hereinafter, the control method of the present embodiment will be described with reference to FIGS.
[0046]
As described above, the control method will be briefly described based on the flowchart of FIG.
[0047]
In step S1, when forming the coating section 2 having the coating length L on one side of the web 1, both the B roll 12 and the C roll 14 are rotated.
[0048]
In step S2, only the B roll 12 is rotated to form the uncoated section 3 having an uncoated length N, and the C roll 14 is stopped for tC seconds.
[0049]
Then, steps 1 and 2 are repeated.
[0050]
However, as described above, when the C roll 14 is stopped, a raised portion is generated at the coating position G. Further, in the coating section 2, an inclined surface is generated at the start and end.
[0051]
Therefore, the present invention pays attention to these two points so that the swelled portion 6 generated at the coating position G is positioned at the end 4 and the start end 5 of the coating section 2, and as shown in FIG. The raised portion 6 is coated on the inclined surfaces at the end 4 and the start end 5 of the section 22 so that the positions of the end 4 and the start end 5 of the coating section 2 are substantially so-called cliffs.
[0052]
By doing in this way, the inclined surface and the rising part in the edge part of the coating area 2 do not generate | occur | produce.
[0053]
In order to specifically realize this control method, that is, in order for the raised portion 6 generated at the coating position G to come to the positions of the end 4 and the start 5 of the coating section 2, the control unit 26 is Then, control is performed so as to satisfy the following expression (2).
[0054]
VC / VB = M / (P × L) (2)
However, VC refers to the rotational speed of the C roll 14, VB refers to the rotational speed of the B roll 12, and P represents the coating section 2 formed while the C roll 14 rotates from the coating position G to the transfer position F. M represents the coating liquid existing distance, and L represents the coating length of the coating section 2.
[0055]
A state near the transfer point F when the control unit 26 controls the rotation of the C roll 14 and the B roll 12 so as to satisfy the expression (2) will be described with reference to FIG.
[0056]
First, while the C roll 14 and the B roll 12 are rotating, as shown in FIG. 7A, the coating section 2 having a uniform coating thickness is formed by the uniform coating thickness portion of the C roll 14. Is formed.
[0057]
Next, immediately before the C roll 14 stops, as shown in FIG. 7B, the raised portion 6 of the C roll 14 approaches the transfer point F, and the raised portion is at the end 4 that is about to become a slope due to the wipe effect. 6 is transferred.
[0058]
When the C roll 14 stops, only the B roll 12 rotates, and therefore, as shown in FIG. 7C, the end of the coating section 2 is transferred to the swelled portion 6 to form a cliff shape, and thereafter The surface of the web 1 hits the C roll 14 and the uncoated section 3 is formed. The uncoated length N of the uncoated section 3 is determined by the stop time tC (seconds) of the C roll 14, and if the stop time tC (seconds) is shortened, the uncoated length N of the uncoated section 3 is determined. Thus, an uncoated section 3 of 10 mm or less, which could not be realized conventionally, can be formed. That is,
N = tC × VB (3)
Because there is a relationship.
[0059]
On the other hand, the end of the coating layer of the C roll 14 is stopped with the raised portion 6 still remaining.
[0060]
When the C roll 14 starts to rotate again, as shown in FIG. 7 (d), at the position of the start end 5 of the coating section 2, the raised portion 6 is applied to the slope of the wipe effect by the C roll 14, and the cliff It becomes a shape.
[0061]
When both the C roll 14 and the B roll 12 are rotating, the coating section 2 is formed by the uniform coating thickness portion of the C roll 14 as shown in FIG. The coating length L of the coating section 2 can be set by the rotation time of the C roll 14.
[0062]
The table shown in FIG. 8 is a result of an experiment performed by the control method of the present example, and the numerical values in this table are the coating length L of the coating section 2 and the uncoated length of the uncoated section 3 from the left side. N, rotation speed of B roll 12 and C roll 14, stop time tC of C roll 14, diameter dC of C roll 14, coating length angle θ, coating distance M, number of patterns P, C roll 14 and B roll The ratio of the rotational speed of 12, the diameter dB of the B roll 12, and the traveling angle γ at which the B roll 12 rotates while the C roll 14 is stopped are shown. According to this table, the uncoated length N is 2 mm, and the length of the uncoated section 3 that could not be realized conventionally can be realized.
[0063]
In addition, although an experimental result is not shown, when uncoated length N forms 1-10 mm, as diameter dB of B roll 12, it can implement to about 50-300 mm, and diameter dC of C roll 14 Even so, it can be carried out up to about 50 to 300 mm. Further, the rotation speed (web conveyance speed) VB can be implemented from a low speed of 0.1 m / min to a high speed of 50 m / min.
[0064]
As described above, unlike the intermittent coating apparatus 100 of the prior art, the intermittent coating apparatus 10 of the present embodiment has a structure that stops only the C roll 14, so the control unit 26 rotates the C roll 14. The stop time can be shortened, whereby the uncoated length N of the uncoated section 3 can be shortened, for example, from 1 mm to 10 mm. Also, the coating speed can be increased.
[0065]
In addition, since the B roll 12 remains in contact with the C roll 14, the liquid that has not been transferred, which has been generated conventionally, does not remain on the C roll 14, and a cleaning blade is also unnecessary.
[0066]
Further, since the B roll 12 is not moved, there is no fluctuation in the tension with respect to the web 1, and the web 1 can be stably run.
[0067]
【The invention's effect】
As described above, according to the present invention, since only the C roll is stopped, the structure of the intermittent coating apparatus can be simplified.
[0068]
In addition, the length of the uncoated section can be shortened.
[0069]
Furthermore, the rising part in a coating area is prevented, and an edge becomes a cliff shape.
[Brief description of the drawings]
FIG. 1 is an explanatory view of an intermittent coating apparatus showing an embodiment of the present invention.
FIG. 2 is a block diagram of the electric system.
FIG. 3 is a side view when intermittent coating is performed on a web.
4 is an enlarged view of FIG. 3. FIG.
FIG. 5 is an enlarged view of a transfer position F in a comparative example.
FIG. 6 is a flowchart of a control method according to the present embodiment.
FIG. 7 is an enlarged view of a transfer position F in the present embodiment.
FIG. 8 is a table showing experimental results in this example.
FIG. 9 is an explanatory diagram of a conventional intermittent coating apparatus.
FIG. 10 is an enlarged view when intermittent coating is performed in a conventional intermittent coating apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Intermittent coating apparatus 12 B roll 14 C roll 16 D roll 18 Liquid dam 20 Edge 22 B roll motor 24 C roll motor 26 Control part 28 Operation part

Claims (5)

A backing roll for conveying the web;
A coating roll contacting the web conveyed by the backing roll at a transfer position;
A doctor roll for applying a coating liquid to the peripheral surface of the coating roll;
A control device for controlling the rotation of the coating roll and the backing roll;
Have
In the intermittent coating apparatus for transferring the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll to the web at the transfer position,
The controller is
When forming a coating section on one side of the web, rotate the coating roll and the backing roll in opposite directions at the transfer point,
When forming an uncoated section on one side of the web, the coating roll is stopped and only the backing roll is rotated, and the coating roll is stopped by the previous stop of the coating roll. The intermittent coating apparatus is characterized in that the coating roll is stopped when a rising portion of the coating liquid generated in the rotation rotates to the transfer position. The controller is
The coating roll is set to a rotation speed VC, the backing roll is set to a rotation speed VB, the length on the peripheral surface of the coating roll from the coating position to the transfer position is set to M, and the transfer position to the transfer position is set to M. When the number of coating sections formed during the rotation of the coating roll is P and the length of the coating section is L,
VC / VB = M / (P × L)
The intermittent coating apparatus according to claim 1, wherein the coating roll and the backing roll are rotated so that The intermittent coating apparatus according to claim 1 or 2, wherein the doctor roll has a comma cross-sectional shape. A backing roll for conveying the web;
A coating roll contacting the web conveyed by the backing roll at a transfer position;
A doctor roll for applying a coating liquid to the peripheral surface of the coating roll;
Have
In the coating method of the intermittent coating apparatus for transferring the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll to the web at the transfer position,
When forming a coating section on one side of the web, rotate the coating roll and the backing roll in opposite directions at the transfer point,
When forming an uncoated section on one side of the web, the coating roll is stopped and only the backing roll is rotated, and the coating roll is stopped by the previous stop of the coating roll. A coating method for an intermittent coating apparatus, comprising: stopping the coating roll when a rising portion of the coating liquid generated in the step rotates and moves to the transfer position. A backing roll for conveying the web;
A coating roll contacting the web conveyed by the backing roll at a transfer position;
A doctor roll for applying a coating liquid to the peripheral surface of the coating roll;
A control device comprising a computer for controlling the rotation of the coating roll and the backing roll;
Have
Stored in the control device that realizes a coating method of an intermittent coating device that transfers the coating liquid applied to the coating position on the peripheral surface of the coating roll by the doctor roll to the web at the transfer position. Program
The program is
When forming a coating section on one side of the web, a function of rotating the coating roll and the backing roll in opposite directions at the transfer point;
When forming an uncoated section on one side of the web, the coating roll is stopped and only the backing roll is rotated, and the coating roll is stopped by the previous stop of the coating roll. A function of stopping the coating roll when the swelled portion of the coating liquid generated is rotated to the transfer position;
A program characterized by realizing.

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