KR102602002B1 - Coating apparatus and method for producing coating film - Google Patents

Abstract

A coating unit is provided for applying a second coating liquid layer onto one or more first coating liquid layers that are first coated on an object to be coated and are relatively moving together with the object to be coated, wherein the first coating liquid layer and the second coating liquid layer are provided. 2 It is configured to solidify the coating liquid layer to form a coating film, and has a dimensionless speed that is the moving speed of the interface between the first coating liquid layer and the second coating liquid layer relative to the moving speed of the object to be coated, and the downstream of the coating portion A coating device configured such that the length of the side lip satisfies a specific equation.

Description

Coating device and coating film manufacturing method {COATING APPARATUS AND METHOD FOR PRODUCING COATING FILM}

The present invention relates to a coating device and a method of manufacturing a coating film.

Conventionally, as one of the coating devices, a die is used to form a plurality of coating liquid layers in succession by sequentially discharging each coating liquid from a plurality of coating parts onto an object to be coated, such as a relatively moving substrate. A coater is used.

Such a die coater is equipped with a plurality of dies serving as a coating unit that discharges the coating liquid and applies the coating onto the object to be coated along the direction of movement of the object to be coated. This die coater coats the coating liquid layer on the relatively moving workpiece by the most upstream coating section, and then applies the coating layer in order from the next coating section to the most downstream coating section. Before the applied coating liquid layer solidifies, the next coating liquid layer is applied, and then each coating liquid layer is solidified, and a coating film (laminated body of each coating film layer) is formed (see Patent Document 1).

Japanese Patent Publication No. 2000-185254

However, in the above coating device, when applying the next coating liquid layer on the previously applied coating liquid layer, there is a risk that the previously applied coating liquid layer may collapse due to the discharge of the next coating liquid. Additionally, as the coating liquid layer applied first collapses, there is a risk that the subsequent coating liquid layer may also collapse. In this way, if a problem occurs in which the next coating liquid layer cannot be properly applied on the previously applied coating liquid layer, a coating film of the desired quality cannot be obtained.

Therefore, it is desired to appropriately apply the next coating liquid layer on the coating liquid layer applied first.

On the other hand, in order to properly coat, it is necessary to set the manufacturing conditions to appropriate conditions, but it is preferable for the manufacturing conditions to be within a wide range from the viewpoint of work efficiency.

In view of the above circumstances, the present invention provides a coating device and a coating device that enable coating with suppressed collapse of the coating liquid layer when coating the next coating liquid layer on the previously applied coating liquid layer under a wide range of manufacturing conditions. The task is to provide a method for manufacturing a membrane.

The coating device according to the present invention is:

One or more first coating liquids are first discharged and coated on the object to be coated, and on one or more first coating liquid layers that have not yet solidified and are moving relatively with the movement of the object to be coated, then Provided with a coating unit for discharging the second coating liquid to apply the second coating liquid layer,

A coating device configured to solidify the first coating liquid layer and the second coating liquid layer to form a coating film,

The coating portion has an upstream lip portion and a downstream lip portion arranged to form a slot by being spaced apart from each other in the direction of movement of the object to be coated, and discharges the second coating liquid from the slot onto the first coating liquid layer. It is composed,

Let the moving speed of the coated object be u _w (m/s), the moving speed of the interface between the first coating liquid layer and the second coating liquid layer be u _c (m/s), and u for u _w Let the ratio of _c be the dimensionless velocity (-) expressed by the following formula (1), let the length of the downstream lip part in the moving direction be X (mm), and let the dimensionless velocity be Y. , the X and the Y are configured to satisfy the following equation (2).

μ _pre : Among the viscosity of the one or more first coating liquids, the smallest viscosity (Pa·s)

μ _c : Viscosity of the second coating liquid (Pa·s)

h _G : Distance between the interface and the downstream lip (m)

h _pre : Total thickness (m) of the one or more first coating liquid layers

ρ _pre : Among the respective densities of the one or more first coating solutions, the largest density (kg/㎥)

g: acceleration due to gravity (m/s ² )

In addition, in the coating device of the above configuration,

The above X may be 0.1 or more and 4 or less.

The method for producing a coating film according to the present invention is:

A method of manufacturing a coating film using the coating device,

One or more first coating liquids are first discharged and coated on the object to be coated, and on one or more first coating liquid layers that have not yet solidified and are moving relatively with the movement of the object to be coated, then A process of discharging the second coating liquid to apply a second coating liquid layer;

A step of solidifying the first coating liquid layer and the second coating liquid layer to obtain a coating film is provided.

1 is a schematic side view showing a coating device according to one embodiment of the present invention.
Fig. 2 is a schematic side view schematically showing an example of the first and second coating liquid layers coated by the coating device of the present embodiment.
Fig. 3 is a schematic side view schematically showing an example of the first and second coating liquid layers coated by the coating device of the present embodiment.
Fig. 4 is a schematic side view schematically showing an example of the first and second coating liquid layers coated by the coating device of the present embodiment.
FIG. 5 is a schematic side view schematically showing the periphery of the second coating portion in the coating device of FIG. 1 along with the moving speed of the first coating liquid layer.
Fig. 6 is a schematic side view showing an enlarged area S of Fig. 5;
FIG. 7 is a schematic side view schematically showing the force applied to the first coating liquid layer of FIG. 5.
Fig. 8 is a schematic side view schematically showing the periphery of a second coating portion arranged to discharge the second coating liquid vertically downward along with the gravity applied to the first coating liquid layer.
Fig. 9 is a schematic side view schematically showing the periphery of a second coating portion when a second coating liquid layer is applied on a plurality of first coating liquid layers along with the moving speed of the first coating liquid layer.
FIG. 10 is a schematic side view schematically showing the plurality of first coating liquid layers in FIG. 9 as one coating liquid layer as a whole.
Figure 11 is a schematic side view schematically showing a collapsed state of the first coating liquid layer and the second coating liquid layer.
Fig. 12 is a graph showing the relationship between the length (X) of the downstream lip portion of the second coating portion in Test Example 1, the dimensionless speed (Y), and the coating state at each X value and Y value.
FIG. 13 is a graph in which the approximation equation and approximation line calculated from the graph of FIG. 12 are added to the graph of FIG. 12.
FIG. 14 is a graph showing an approximation equation and an approximation line derived from the graph of FIG. 13.
Figure 15 shows the relationship between the distance (gap) between the second interface of the first coating liquid layer and the downstream lip portion, the length of the downstream lip portion, and the bead pressure applied to the first coating liquid layer in Test Example 2. graph.

First, the coating device of this embodiment of the present invention will be described with reference to the drawings.

As shown in FIGS. 1, 5, and 6, the coating device 1 of this embodiment is,

One or more first coating liquids 33 are first discharged and coated on the object to be coated (31), have not yet solidified, and are relatively moving along with the movement of the object to be coated (31). A coating unit 15 is provided for coating the second coating liquid layer 45 by discharging the following second coating liquid 43 on the above first coating liquid layer 35,

A coating device (1) configured to solidify the first coating liquid layer (35) and the second coating liquid layer (45) to form a coating film (50),

The coating portion 15 has an upstream lip portion 16a and a downstream lip portion 17a arranged to form a slot 18 by being spaced apart from each other in the moving direction M of the coated object 31, It is configured to discharge the second coating liquid 43 from the slot 18 onto the first coating liquid layer 35,

The moving speed of the object to be coated 31 is u _w (m/s), and the moving speed of the interface 35b of the first coating liquid layer 35 with the second coating liquid layer 45 is u _c ( m/s), the ratio of u _c to u _w is called the dimensionless speed (-) expressed by the following equation (1), and the length of the downstream lip portion 17a in the moving direction is When X (mm) and the dimensionless velocity are Y, the X and Y are configured to satisfy the following equation (2).

μ _pre : Among the viscosity of the one or more first coating liquids 33, the smallest viscosity (Pa·s)

μ _c : Viscosity (Pa·s) of the second coating liquid 43

h _G : Distance (m) between the second interface 35b and the downstream lip portion 17a

h _pre : Total thickness (m) of the one or more first coating liquid layers (35)

ρ _pre : Among the respective densities of the one or more first coating liquids 33, the largest density (kg/㎥)

g: acceleration due to gravity (m/s ² )

In addition, Figure 1 illustrates an aspect in which the second coating liquid layer 45 is applied on one first coating liquid layer 35 that is applied first on the object to be coated 31, but the first coating liquid layer (45) is applied first. The quantity of 35) is not particularly limited as will be described later.

The coating device 1 of the present embodiment is further provided on the upstream side of the coating portion 15 in the moving direction M of the coated object 31 and on the upstream side of the coated object 31 in the moving direction M. It has an upstream lip portion 6a and a downstream lip portion 7a arranged to form a slot 8 by being spaced apart, and flows from the slot 8 onto the coated object 31 before the coating portion 15. It is provided with a coating portion 5 configured to discharge the first coating liquid 33.

In addition, in the coating device of the present invention, the coating unit 5 is not limited to being configured to enable slot die coating as described above. For example, the coated object 5 may be configured to enable gravure coating.

Hereinafter, the coating unit 5 that first applies the first coating liquid layer 35 is referred to as the first coating unit 5, and the coating unit 15 that subsequently applies the second coating liquid layer 45 is referred to as the second coating unit. It is said to be (15).

The coating device 1 further solidifies the first and second coating liquid layers 35 and 45 applied by the first and second coating units 5 and 15, respectively, to form the respective coating film layers 37 and 47. It is provided with a solidification part 27 that forms.

The coating device 1 further supports the object to be coated 31 on the surface and is applied to the first coating portion 5 and the second coating portion 15 in the longitudinal direction of the object to be coated 31. It is provided with a support part 25 that moves relatively.

The object to be coated 31 is not particularly limited, but examples include a strip-shaped sheet member.

Examples of such sheet members include resin films. In addition, examples of the resin film include Lumiror (registered trademark) manufactured by Toray Industries, Ltd., etc.

The support portion 25 supports the coated object 31 moving in the longitudinal direction from the side opposite to the first and second coated portions 5 and 15. The first and second coating parts 5 and 15 are attached to the object to be coated 31, which is supported on the support part 25 and moves relative to the first coating part 5 and the second coating part 15. Pottery in order.

Examples of such support portion 25 include rollers and the like.

In this embodiment, the support portion 25 is located at a position opposite to the slot 8 of the first coating portion 5, and the object to be coated 31 is positioned on one side (relative to the slot 8). It is designed to move from the left direction in FIG. 1 to the other side (right direction in FIG. 1).

In addition, the support portion 25 is located at a position opposite to the slot 18 of the second coating portion 15, and supports the object to be coated 31 together with the first coating liquid layer 35 in a relatively downward direction (see Figure 1). It is designed to move from downward) to upward (upward in Figure 1).

The solidification unit 27 is configured to solidify the first and second coating liquid layers 35 and 45 to form the respective coating film layers 37 and 47. By being solidified by this solidification unit 27, the coating film 50, which is a laminate of the coating film layer 37 and the coating film layer 47, is formed. The solidification portion 27 is not particularly limited as long as it can solidify the first and second coating liquid layers 35 and 45. This solidification portion 27 is appropriately set depending on the types of the first and second coating liquids 33 and 43, etc.

In this embodiment, dies having slots 8 and 18 are employed as the first coating portion 5 and the second coating portion 15. The coating device 1 equipped with a die in this way is called a die coater.

Prior to application of the second coating liquid layer 45, the first coating unit 5 discharges the preceding first coating liquid 33 from the slot 8 and applies it onto the relatively moving object 31. The first coating liquid layer 35 is sequentially applied.

The first coating portion 5 is arranged so that the slot 8 faces upward, and applies the first coating liquid 33 to the object to be coated 31 moving in the left and right directions relative to the slot 8. It is designed to be discharged. The first coating liquid 33 is supplied to the first coating part 5 from a receiving part (not shown) of the first coating liquid 33 through a pipe (not shown) and a pump (not shown). It is done.

Specifically, the first coating portion 5 is provided with an upstream dive lock 6 and a downstream dive lock 7 disposed opposite to the upstream dive lock 6. The first coating portion 5 is formed by joining the upstream dive lock 6 and the downstream dive lock 7. By combining both dive locks 6 and 7 in this way, a manifold 9 in which the first coating liquid 33 supplied by a pump (not shown) is stored between them, and the manifold 9 A slot 8 is formed disposed toward the leading edge. In addition, the gap between the upstream lip portion 6a, which is the leading edge of the upstream dive lock 6, and the downstream lip portion 7a, which is the leading edge of the downstream dive lock 7, is connected to the discharge port of the slot 8. It is done.

The upstream lip portion 6a and the downstream lip portion 7a are arranged so as to be located on a plane perpendicular to the radial direction of the support portion 25. The slots 8 are arranged parallel to the radial direction of the support portion 25.

Following the application of the first coating liquid layer 35, the second coating unit 15 discharges the next second coating liquid 43 from the slot 18 and applies it to the relatively moving object 31. The second coating liquid layer 45 is sequentially applied to the first coating liquid layer 35.

The second coating portion 15 is arranged so that the slot 18 faces the side, and the second coating liquid 43 is applied on the first coating liquid layer 35 moving in an upward and downward direction relative to the slot 18. ) is designed to discharge. The second coating liquid 43 is supplied to the second coating part 15 from a receiving part (not shown) of the second coating liquid 43 through a pipe (not shown) and a pump (not shown). It is done.

Additionally, the first and second coating portions 5 and 15 may be slot dies provided with a chamber for decompression.

Specifically, the second coating portion 15 is provided with an upstream dive lock 16 and a downstream dive lock 17 disposed opposite to the upstream dive lock 16. The second coating portion 15 is formed by joining the upstream dive lock 16 and the downstream dive lock 17. By joining both dive locks 16 and 17 in this way, a manifold 19 in which the second coating liquid 43 supplied by a pump (not shown) is stored between them, and the manifold 19 A slot 18 is formed disposed toward the leading edge. In addition, the gap between the upstream lip portion 16a, which is the leading edge of the upstream dive lock 16, and the downstream lip portion 17a, which is the leading edge of the downstream dive lock 17, is the discharge port of the slot 18. It is written as .

The upstream lip portion 16a and the downstream lip portion 17a are arranged so as to be located on a plane perpendicular to the radial direction of the support portion 25. The slots 18 are arranged parallel to the radial direction of the support portion 25.

The smaller the length of the downstream lip portion 17a, the wider the range of the gap over which the second coating liquid layer 45 can be applied without the first coating liquid layer 35 and the second coating liquid layer 45 collapsing. can do. Considering this viewpoint, it is preferable that the length of the downstream lip portion 17a is 0.1 mm or more and 4 mm or less.

In this embodiment, for example, as shown in FIG. 2, in the direction perpendicular to the moving direction M of the object to be coated 31 (width direction, left and right direction in FIG. 2), the first coating portion ( 5) and the second coating portion 15 may be configured to coat one continuous first coating liquid layer 35 and a second coating liquid layer 45, respectively.

For example, as shown in FIG. 3, in the width direction (left and right directions in FIG. 3), the first coating portion 5 includes a plurality of first coating liquid layers 35 spaced apart from each other at intervals. It is configured to coat, and the second coating unit 15 is configured to apply a plurality of second coating liquid layers 45 corresponding to each first coating liquid layer 35, respectively, on each first coating liquid layer 35. You can stay.

For example, as shown in FIG. 4, in the width direction (left and right directions in FIG. 4), the first coating portion 5 is configured to apply one continuous first coating liquid layer 35. , the second coating unit 15 may be configured to coat a plurality of second coating liquid layers 45 spaced apart from each other on the first coating liquid layer 35 .

The coating device 1 of the present embodiment sets the moving speed of the object to be coated 31 to u _w (m/s), the interface 45a of the first coating liquid layer 35 with the second coating liquid layer 45. The moving speed is called u _c (m/s), the ratio of u _c to u _w is called the dimensionless speed (-) expressed by the above equation (1), and the downstream of the second coating portion 15 When the length of the side lip 17a is X (mm) and the dimensionless speed is Y, X and Y are configured to satisfy the above equation (2).

The above formula (1) and formula (2) are explained below.

First, as shown in FIGS. 1, 5, and 6, one coating liquid layer 35 is applied on the object 31, and the next coating liquid layer is applied on this one coating liquid layer 35. The mechanism for suppressing collapse of the first coating liquid layer 35 and the second coating liquid layer 45 in the case of coating (45) and the derivation of equation (1) will be explained.

In FIG. 1, between the first coating portion 5 and the second coating portion 15, that is, before the second coating liquid layer 45 is applied on the first coating liquid layer 35, the first coating liquid layer Since the entire body 35 moves in accordance with the object to be coated 31, the moving speed of the first coating liquid layer 35 is the same as the moving speed of the object to be coated 31 in the entire thickness direction. That is, the moving speed is the same as the moving speed of the coated object 31 in any part of the thickness direction of the preceding coating liquid layer.

From this state, as shown in FIG. 5, even if the second coating liquid layer 45 is applied on the first coating liquid layer 35, the interface of the first coating liquid layer 35 with the object to be coated 31 ( (hereinafter sometimes referred to as the first interface) 35a follows the movement of the object to be coated 31 as before the second coating liquid layer 45 is applied. Accordingly, the moving speed of the first interface 35a of the first coating liquid layer 35 is equal to the moving speed of the object to be coated 31.

In contrast, the interface 35b of the first coating liquid layer 35 with the second coating liquid layer 45 (hereinafter sometimes referred to as the second interface) is coated when the second coating liquid layer 45 is applied. It becomes difficult to follow the movement of the workpiece 31, and it lags behind the movement of the workpiece 31 to be coated. Therefore, by the amount of this delay, the moving speed of the second interface 35b of the first coating liquid layer 35 becomes smaller than before the second coating liquid layer 45 is applied, and also the movement speed of the second interface 35b of the first coating liquid layer 35 becomes smaller than before the second coating liquid layer 45 is applied, and In , the moving speed of each part decreases as it moves from the first interface 35a to the second interface 35b. If the moving speed of the second interface 35b becomes too small, the first coating liquid layer 35 collapses, as shown in FIG. 11. Along with this, the second coating liquid layer 45 also collapses. Additionally, the moving speed of the second interface 35b of the first coating liquid layer 35 is equal to the moving speed of the second coating liquid layer 45.

Therefore, by making the moving speed of the second interface 35b of the first coating liquid layer 35 close to the moving speed of the object to be coated 31, the first coating liquid layer 35 and the second coating liquid layer 45 collapse. Losing can be prevented.

As shown in FIG. 7, factors affecting the decrease in the moving speed of the second interface 35b of the first coating liquid layer 35 include the bead pressure of the second coating liquid 43 causing the first coating liquid layer to The pressure gradient applied to (35), the gravity applied to the first coating liquid layer 35, and the shear force applied to the second interface 35b of the first coating liquid layer 35 by the second coating liquid layer 45. can be mentioned.

So, these are applied to the theoretical equations of fluid mechanics (Navier-Stokes' equations) based on physical and mathematical theories. In application, it is assumed that the material to be coated 31 does not flow in a direction perpendicular to the moving direction M (width direction). By this application, the moving speed u _c of the second interface 35b of the first coating liquid layer 35 is the moving speed u _w of the object to be coated 31 and the pressure gradient ∂ in the first coating liquid layer 35. The pressure gradient term, gravity term, and shear force term using p/∂x are expressed as shown in Equation (3) below. As shown in the following equation (3), the moving speed of the second interface 35b of the first coating liquid layer 35 is calculated by dividing the pressure gradient term, gravity term, and shear force term from the moving speed u _w of the coated object 31. It becomes subtracted.

As shown in the following equation (3), the pressure gradient term includes the thickness h _pre of the first coating liquid layer 35, the viscosity μ _pre of the first coating liquid 33, and the pressure gradient within the first coating liquid layer 35. Elements such as ∂p/∂x are included.

This pressure gradient ∂p/∂x is the pressure applied to the first coating liquid layer 35 by the bead pressure of the second coating liquid 43 discharged from the slot 18 of the second coating portion 15. It is a gradient (that is, pressure distribution) in the moving direction M of the coated object 31.

Additionally, on the upstream side of the second coating portion 15 (i.e., before the second coating liquid 43 is discharged), the pressure applied to the first coating liquid layer 35 is 0, and this pressure is Equivalent to atmospheric pressure. In addition, x is a coordinate with the moving direction (progress direction) of the coated object 31 as positive.

The gravity term includes the density ρ _pre of the first coating liquid layer, the gravitational acceleration g, the thickness h _pre of the first coating liquid layer 35, and the viscosity μ _pre of the first coating liquid 33, and the blood pressure in the direction in which gravity acts. Factors such as the angle θ formed by the moving direction of the tribute 31 are included.

The shear force term includes the thickness h _pre of the first coating liquid layer 35, the viscosity μ _pre of the first coating liquid 33, the viscosity μ _c of the second coating liquid 43, and the second coating liquid layer 35. Factors such as the moving speed u _c of the interface 35b and the distance (gap) h _G between the second interface 35b of the first coating liquid layer 35 and the downstream lip portion 17a are included.

μ _pre : Viscosity (Pa·s) of the first coating liquid 33

μ _c : Viscosity (Pa·s) of the second coating liquid 43

h _G : Distance (m) between the second interface 35b and the downstream lip portion 17a

h _pre : Thickness (m) of the first coating liquid layer

ρ _pre : Density of the first coating liquid layer (kg/㎥)

g: acceleration due to gravity (m/s ² )

θ: Angle (°) formed by the moving direction M of the coated object 31 with respect to the direction in which gravity is applied.

In addition, the obtained equation (3) is calculated as the ratio of the moving speed u _c of the second interface 35b of the first coating liquid layer 35 to the moving speed u _w of the coated object 31 (u _c /u _w ). By modifying to represent , the following equation (4) is obtained.

Here, the pressure gradient ∂p/∂x in the first coating liquid layer 35 is influenced by the length of the downstream lip portion 17a of the second coating portion 15.

Therefore, the pressure gradient ∂p/∂x is separately considered as the length of the downstream lip portion 17a, and instead, the pressure gradient is set to 0 (zero) in the above equation (4) (∂p/ ∂x＝0). By this, the following equation (5) is obtained.

As described above, since it is better for the moving speed u _c of the second interface 35b of the first coating liquid layer 35 to be closer to the moving speed u _w of the coated object 31, u _c /u _w is equal to 1. Closer is better.

Here, cosθ takes a value between -1 and 1 (-1≤cosθ≤1).

cosθ=-1 occurs when θ=180° as shown in FIG. 5, and at this time, -ρgcosθ becomes the maximum (-ρ _pre gcosθ=ρ _pre g). Therefore, if values other than cosθ are constant, u _c /u _w in equation (5) becomes minimum.

On the other hand, cosθ = 1 when θ = 0°, and at this time, -ρ _pre gcosθ becomes the minimum (-ρgcosθ = -1). Therefore, if values other than cosθ are constant, u _c /u _w in equation (5) becomes the maximum (not shown).

Additionally, when 0°<θ<180°, u _c /u _w becomes a value between the value when θ=0° and the value when θ=180°.

For example, as shown in FIG. 8, the second coating portion 15 is arranged so that the slot 18 faces downward, and is positioned on one side relative to the slot 18 (in FIG. 8). When discharging the second coating liquid 43 on the first coating liquid layer 35 moving from the right side to the other side (left side in FIG. 8), θ = 90° and cosθ = 0. Therefore, in this case, u _c /u _w becomes a value between the case of θ = 180° and the case of θ = 0°. Additionally, because cos = 0, the gravity term can be ignored in equation (3) (gravity term = 0). That is, the gravity applied to the first coating liquid layer 35 is not applied in the direction of collapsing the first coating liquid layer 35.

Therefore, the case where θ = 180° is the most stringent condition for u _c /u _w to approach 1.

Therefore, if θ = 180° in the above equation (5), equation (1) is derived as follows. In addition, in the following equation (1), the ratio (u _c /u _w ) of the moving speed is called a dimensionless speed.

In the above formula (1), when the second coating liquid layer 45 is applied to one first coating liquid layer 35 coated on the object to be coated 31, μ _pre , μ _c , h _G , h _pre , ρ _pre and g are as follows.

μ _pre : Viscosity (Pa·s) of the first coating liquid 33

μ _c : Viscosity (Pa·s) of the second coating liquid 43

h _G : Distance (m) between the second interface 35b and the downstream lip portion 17a

h _pre : Thickness (m) of the first coating liquid layer 35

ρ _pre : Density of the first coating liquid 33 (kg/㎥)

g: acceleration due to gravity (m/s ² )

Next, as shown in FIG. 9, a plurality of first coating liquid layers 35 are applied on the object to be coated 31, and the following second coating liquid layers are applied on the plurality of first coating liquid layers 35. The mechanism for suppressing collapse of the first coating liquid layer 35 and the second coating liquid layer 45 in the case of coating (45) and the derivation of equation (1) will be explained.

As shown in FIG. 9, for example, the coating device 1 applies N-1 pieces from the 1st to the N-1th from the upstream side to the downstream side in the moving direction M of the coated object 31 ( N is an integer of 3 or more) of coating portions, of which the 1st to N-1 coating portions (first coating portions) 5 are used to form coatings from the 1st to the N-1 on the object 31. The first coating liquid layer 35 up to the first is applied first, and the next second coating liquid layer 45 (N-th coating liquid layer) is applied by the N-th coating part (second coating part) 15. It is assumed to be potted.

In this case, when the second coating liquid layer 45 is applied on the outermost (N-1st) first coating liquid layer 35, the outermost coating layer 45 is applied from the innermost (1st) first coating liquid layer 35. Up to the first coating liquid layer 35, the moving speed of each first coating liquid layer 35 gradually decreases. In addition, also in each first coating liquid layer 35, the moving speed gradually decreases from the side of the coated object 31 to the second coating liquid layer 45 side. In addition, the moving speed of the interface of the first coating liquid layer 35 with the coated object 31 is equal to the moving speed of the coated object 31, u _w , while the N-1st 1 The moving speed of the interface of the coating liquid layer 35 with the second coating liquid layer 45 is equal to the moving speed of the second coating liquid layer 45, and becomes u _c .

In this way, as a whole of the plurality of first coating liquid layers 35, from the interface of the first first coating liquid layer 35 with the object to be coated 31, the N-1th first coating liquid layer 35 The moving speed decreases toward the interface with the second coating liquid layer 45.

And, if the moving speed of the interface of the N-1th first coating liquid layer 35 with the second coating liquid layer 45 becomes too small, the plurality of first coating liquid layers 35 collapse, and accordingly, the first coating liquid layer 35 collapses. 2 The coating liquid layer 45 collapses.

Therefore, by making the moving speed of the N-1th first coating liquid layer 35 close to the moving speed of the object to be coated 31, collapse of the plurality of first coating liquid layers 35 and the second coating liquid layer is suppressed. can do.

In this way, if the entire plurality of first coating liquid layers 35 are regarded as one first coating liquid layer 35, it is seen that one coating liquid layer 35 and the second coating liquid layer 45 as a whole collapse. The suppressing mechanism is the same as in the case of coating the second coating liquid layer 45 on the one coating liquid layer 35 described above (see FIG. 5).

In addition, as a factor affecting the decrease in the movement speed from the first interface 35a to the second interface 35b, as in the above (see FIG. 7), pressure gradient, gravity, and shear force are applied to the plurality of first coaters. It is applied to the entire liquid layer (35).

Therefore, even in the case where the second coating liquid layer 45 is applied on the plurality of first coating liquid layers 35, the plurality of first coating liquid layers 35 are regarded as one first coating liquid layer 35 as a whole. By doing so, the above formula (1) is applied.

In other words, the above equation (1) applies not only to the case of coating the next second coating liquid layer 45 on the first coating liquid layer 35 previously coated on the object 31 (two-layer coating) , even in the case of coating the next second coating liquid layer 45 on the two or more first coating liquid layers 35 previously coated on the object 31 (coating three or more layers), the two or more first coating liquid layers 35 applied previously By taking the first coating liquid layer 35 as a whole and considering it as one first coating liquid layer 35, equation (1) is applied as in the above two-layer coating.

In this case, in equation (1), the interface of the outermost (N-1st) first coating liquid layer 35 with the second coating liquid layer 45 and its moving speed are expressed as a plurality of first coating liquid layers ( This is the second interface 35b and its moving speed in 35).

The thickness of the first coating liquid layer 35 becomes all the thicknesses of the first coating liquid layer 35 from the 1st to the N-1th.

On the other hand, in equation (1), the smaller μ _pre is, the smaller u _c /u _w becomes, so the condition becomes more stringent. Therefore, among the viscosity of the plurality of first coating liquids 33, the smallest viscosity is adopted as a representative value.

Additionally, in equation (1), the larger ρ _pre is, the smaller u _c /u _w becomes, so the condition becomes more stringent. Therefore, among the respective viscosity of the plurality of first coating liquids 33, the largest viscosity is adopted as a representative value.

Therefore, in equation (1), when the second coating liquid layer 45 is applied to the plurality of first coating liquid layers 35 coated on the object to be coated 31, μ _pre , μ _c , h _G , h _pre , ρ _pre and g are as follows.

μ _pre : Among the viscosity of the plurality of first coating liquids 33, the smallest viscosity (Pa·s)

μ _c : Viscosity of the second coating liquid (Pa·s)

h _G : Distance (m) between the second interface 35b and the downstream lip portion 17a

h _pre : Total thickness (m) of the plurality of first coating liquid layers 35

ρ _pre : Among the respective densities of the plurality of first coating liquids 33, the largest density (kg/㎥)

g: acceleration due to gravity (m/s ² )

And, as shown below, these are combined with the case where there is only one first coating liquid layer 35 described above.

μ _pre : Among the viscosity of the one or more first coating liquids 33, the smallest viscosity (Pa·s)

μ _c : Viscosity of the second coating liquid (Pa·s)

h _G : Distance (m) between the second interface 35b and the downstream lip portion 17a

h _pre : Total thickness (m) of the one or more first coating liquid layers (35)

ρ _pre : Among the respective densities of the one or more first coating liquids 33, the largest density (kg/㎥)

g: acceleration due to gravity (m/s ² )

In this way, the above equation (1) is derived.

In this equation (1), the dimensionless speed is an index indicating the extent to which the movement of the second interface 35b of the first coating liquid layer 35 follows the movement of the object to be coated 31. That is, as the moving speed of the second interface 35b of the first coating liquid layer 35 approaches the moving speed of the coated object 31, the dimensionless speed approaches 1, and becomes 1 when they match. Additionally, as the dimensionless speed approaches 1, the first coating liquid layer 35 and the second coating liquid layer 45 become easier to be coated without further collapsing.

Conversely, as the moving speed of the second interface 35b of the first coating liquid layer 35 becomes farther (smaller) from the moving speed of the coated object 31, the dimensionless speed moves away from 1 and decreases toward 0. , the first and second coating liquid layers 35 and 45 become prone to collapse.

In addition, in equation (1), the dimensionless speed is changed by changing each element (each manufacturing condition) except the pressure gradient ∂p/∂x among the elements included in the pressure gradient term, gravity term, and shear force term. You can do it. Therefore, the width of the numerical range that the dimensionless velocity can take is equivalent to the width of the numerical range that can be taken by each element except the pressure gradient ∂p/∂x, that is, the width of the manufacturing conditions.

Next, the derivation of the above equation (2) will be explained.

As described above, the pressure gradient ∂p/∂x in the first coating liquid layer 35 when the second coating liquid layer 45 is applied is determined by the length of the downstream lip portion 17a of the second coating portion 15. are affected accordingly.

Therefore, the length of the downstream lip portion 17a affects the collapse of the first coating liquid layer 35 when applying the second coating liquid layer 45.

On the other hand, the above-mentioned non-dimensional speed also affects the collapse of the first coating liquid layer 35 when coating the second coating liquid layer 45.

In this way, depending on the numerical value of the dimensionless speed, the numerical range of the length of the downstream lip portion of the second coating portion that can be coated widens or narrows. Conversely, depending on the length of the downstream lip portion 17a, the numerical range of the dimensionless speed that can be coated widens or narrows.

However, as shown in the examples described later, when the length 2 It becomes possible to coat the second coating liquid layer 45 without the coating liquid layer 45 collapsing, and both the numerical range of X and the numerical range of Y can be widened. In addition, in the embodiment described later, the second coating liquid layer 45 is applied on the first coating liquid layer 35 while varying the length of the downstream lip portion 17a and varying the dimensionless speed. coating, and whether the second coating liquid layer 45 can be applied without the first coating liquid layer 35 collapsing under each condition, that is, the desired first and second coating liquid layers 35 and 45 are obtained. Whether it is possible or not is explained.

In addition, as shown in the examples described later, each non-dimensional velocity is referred to as the y-axis, and the length of the downstream lip portion 17a is referred to as the x-axis, and each non-dimensional velocity and the downstream lip portion ( 17a) is plotted together with whether the coating condition is good or not to create a graph, and in the obtained graph, for each downstream lip portion 17a, a plot is closest to the plot with a poor coating condition and a plot with a good coating condition is selected. By selecting each and approximating the selected plot group with a quadratic equation, equation (2) as an approximation equation is obtained.

In this way, equation (2) is derived.

According to the above equations (1) and (2), when applying the second coating liquid layer 45, the coating is applied so as to satisfy the above equation (2) in the relationship with the first coating liquid layer 35 applied previously. The coating conditions of the device 1 can be determined.

The thickness of each first coating liquid layer 35 and the second coating liquid layer 45 can be appropriately set to satisfy the above equations (1) and (2). These thicknesses are, for example, depending on the viscosity of each of the first coating liquid 33 and the second coating liquid 43, the first and second coating liquids ( It can be adjusted by adjusting at least one of the discharge amount of 33, 43) and the moving speed of the object to be coated 31.

For example, if the thickness of the first coating liquid layer 35 and the second coating liquid layer 45 is too small, it becomes difficult to coat the entire desired area, and if it is too large, the thickness sags under its own weight, making coating difficult. It tends to break down.

Therefore, considering this viewpoint, for example, the thickness of the first coating liquid layer 35 is preferably 0.01 μm or more and 1000 μm or less, and more preferably 0.1 μm or more and 500 μm or less.

For example, the thickness of the second coating liquid layer 45 is preferably 0.01 μm or more and 1000 μm or less, and more preferably 0.1 μm or more and 500 μm or less.

Each first coating liquid 33 contains a solidifying component, is applied onto the object 31 to be coated, and is solidified on the object 31 to be coated.

The second coating liquid 43 contains a solidifying component, is applied on the first coating liquid layer 35, and is solidified on the first coating liquid layer 35.

The types of the first and second coating liquids 33 and 43 can be appropriately set to satisfy the above equations (1) and (2).

Examples of the first and second coating liquids 33 and 43 include polymer solutions, and materials used as the solidification component include thermosetting materials, ultraviolet curing materials, and electron beam curing materials.

Examples of the first coating liquid 33 include primers, adhesives such as ultraviolet curing adhesives, adhesives, and liquid crystals.

By using these, there is an advantage that the adhesive strength between the second coating liquid layer 45 and the object to be coated 31 is increased.

The viscosity of the first coating liquid 33 is preferably 0.0005 Pa·s or more and 30 Pa·s or less, and more preferably 0.001 Pa·s or more and 20 Pa·s or less. This viscosity is a value measured by the measurement method described in the Examples described later.

When the viscosity of the first coating liquid 33 is 0.0005 Pa·s or more, there is an advantage that coating can be easily performed using a conventionally known coating method.

When the viscosity of the first coating liquid 33 is 30 Pa·s or less, there is an advantage that the liquid can be easily supplied to the coating portion 5 by a conventionally known liquid supply means such as a pump.

The density ρ _pre of the first coating liquid 33 is preferably 600 to 1,400 kg/m 3 , and more preferably 700 to 1,300 kg/m 3 . This density is a value measured by the measurement method described in the Examples described later.

The thickness of the first coating liquid layer 35 (when there are two first coating liquid layers 35, the thickness of each coating liquid layer 35) is preferably 0.1 to 1000 μm, and more preferably 1 to 500 μm. This thickness is a value measured by the measurement method described in the Examples described later.

Examples of the second coating liquid 43 include adhesives such as ultraviolet curing adhesives, adhesives, and liquid crystals.

The viscosity of the second coating liquid 43 is preferably 0.0005 Pa·s or more and 30 Pa·s or less, and more preferably 0.001 Pa·s or more and 20 Pa·s or less. This viscosity is a value measured by the measurement method described in the Examples described later.

When the viscosity of the second coating liquid 43 is 0.0005 Pa·s or more, there is an advantage that coating can be easily performed using a conventionally known coating method.

When the viscosity of the second coating liquid 43 is 30 Pa·s or less, there is an advantage that the liquid can be easily supplied to the coating portion 15 by a conventionally known liquid supply means such as a pump.

The density ρ _pre of the second coating liquid 43 is preferably 600 to 1,400 kg/m 3 , and more preferably 700 to 1,300 kg/m 3 . This density is a value measured by the measurement method described in the Examples described later.

The thickness of the second coating liquid layer 45 is preferably 0.1 to 1000 μm, and more preferably 1 to 500 μm. This thickness is a value measured by the measurement method described in the Examples described later.

The first and second coating solutions 33 and 43 may be of the same type or may be of different types.

When the first and second coating liquids 33 and 43 are of different types, it is preferable that the first coating liquid 33 has a higher viscosity than the second coating liquid 43.

The discharge amount of the first coating liquid 33 from the slot 8 of the first coating portion 5 can be appropriately set to satisfy equations (1) and (2).

This discharge amount can be, for example, 0.01 to 50 L/min.

The discharge amount of the second coating liquid 43 from the slot 18 of the second coating portion 15 can be appropriately set to satisfy equations (1) and (2).

This discharge amount can be, for example, 0.01 to 50 L/min.

The thickness of the coated object 31 is not particularly limited, but is preferably, for example, 20 to 100 μm.

In FIG. 1, an embodiment in which the object to be coated 31 is flexible and has a long shape is shown; however, an embodiment in which the object to be coated 31 is a single plate or an inflexible embodiment may also be adopted. there is.

The moving speed of the coated object 31 can be adjusted, for example, by adjusting the rotational speed of the support portion 25. This moving speed is preferably 1 to 300 m/min, and more preferably 5 to 50 m/min.

When the moving speed of the coated object 31 is 1 m/min or more, the coated object can be moved more stably. For example, because the support portion 25 can be rotated more stably, the workpiece 31 can be moved more stably.

By setting the moving speed of the object to be coated 31 to 300 m/min or less, the oscillation and meandering of the object to be coated 31 can be suppressed as it moves.

In this way, in the coating device 1 of this embodiment, the first coating liquid 33 has a viscosity of 0.0005 to 30 Pa·s, and the second coating liquid 43 has a viscosity of 0.0005 to 30 Pa·s. It is suitable that the moving speed of the coated object 31 is 1 to 300 m/min.

Next, the manufacturing method of the coating film 50 of this embodiment will be described.

The method for manufacturing the coating film 50 of this embodiment uses the coating device 1 described above.

In this manufacturing method, one or more first coating liquids 33 are first discharged and coated on the object to be coated (31), have not yet solidified, and are relatively coated with the movement of the object to be coated (31). A process of coating the second coating liquid layer 45 by discharging the next second coating liquid 43 from the second coating portion 15 on one or more moving first coating liquid layers 35 (the following coating liquid) process) and,

A process of solidifying the first coating liquid layer 35 and the second coating liquid layer 45 to obtain a coating film 50 is provided.

Additionally, in this embodiment, one or more first coating liquid layers (here, one first coating liquid layer) are first applied on the object to be coated 31 by one or more first coating portions 5 (here, one first coating portion 5). A process of coating one coating liquid layer 35 (previous coating process) is further provided.

Specifically, in the method of manufacturing the coating film 50 of the present embodiment, first, the length

In setting the dimensionless speed The viscosity μ _pre of the first coating liquid 33, the viscosity μ _c of the second coating liquid 43, the total thickness h _pre of the first coating liquid layer 35, and each density ρ _pre of the first coating liquid layer are set. Additionally, by setting the arrangement of the second coating portion 15, the distance h _G between the second interface 35b of the first coating liquid layer 35 and the downstream lip portion 17a is set. Also, the gravitational acceleration g is constant.

The length X of the downstream lip portion 17a of the second coating portion 15 can be set when manufacturing the downstream dive lock 17.

Then, under set conditions, the first coating liquid 33 is discharged from the one or more first coating portions 5 on the object 31 to apply one or more first coating liquid layers 35, and the corresponding coating liquid layer 35 is applied. 1 The second coating liquid 43 is discharged from the second coating portion 15 on the coating liquid layer 35 to coat the second coating liquid layer 45 . Subsequently, each of the first and second coating liquid layers 35 and 45 coated on the object 31 is solidified by the solidification unit 27, and one or more of the first coating layer 37 and the second coating layer are solidified. The film layer 47 (coated film 50 as a laminate of these) is obtained.

In addition, when applying three or more coating liquid layers on the object 31, in coating each coating liquid layer from the second to the Nth, first, to satisfy the above equations (1) and (2) You may apply the next coating liquid layer on the coated coating liquid layer. Specifically, when applying a plurality of (N-1) first coating liquid layers 35 on the object to be coated 31, each of the first coating liquid layers 35 from the 2nd to the N-1th When coating is performed sequentially to satisfy the above equations (1) and (2), and then the second coating liquid layer 45 is applied on the N-1th first coating liquid layer 35, the second Coating of the coating liquid layer 45 may be performed so as to satisfy the above equations (1) and (2).

According to the coating device 1 and the manufacturing method of the coating film 50 of the present embodiment described above, the length X of the downstream lip portion 7a of the second coating portion 15 and the By coating the second coating liquid layer 45 so that the relationship between the dimensional speed Y is in a range that satisfies equation (2), the movement speed of the object to be coated 31 during coating of the second coating liquid layer 45, Since the difference in movement speed between the second interface 35b of the first coating liquid layer 35 becomes small, it becomes possible for the movement of the second interface 35b to sufficiently follow the movement of the coated object 31. Therefore, it becomes possible to apply the second coating liquid layer 45 without the first and second coating liquid layers 35 and 45 collapsing.

In addition, it becomes possible to widen the range of coating conditions that allow coating without collapse.

Therefore, when applying the next second coating liquid layer 45 on the first coating liquid layer 35 applied previously, the coating in which collapse of these coating liquid layers 35 and 45 is suppressed can be applied under a wide range of coating conditions. It becomes possible in

The manufacturing method of the coating device 1 and the coating film 50 of this embodiment is applicable to, for example, a process material for forming a semiconductor chip.

In this case, the first coating layer 37 can be a die attach film, and the second coating layer 47 can be a dicing tape. The laminate (coating film) 50 in which these first and second coating film layers 37 and 47 are laminated is stacked on a semiconductor chip so that the first coating film layer 37 is on the semiconductor wafer side, and the semiconductor chip is formed as desired. After cutting to obtain semiconductor chip pieces of the same size and quantity, the second coating film layer 47 can be removed, and the exposed first coating film layer 37 can be laminated on a separate semiconductor chip.

Since the coating device and the coating film manufacturing method of this embodiment are configured as described above, they have the following advantages.

The present inventors conducted extensive research and discovered the following findings.

That is, when the next coating liquid layer is discharged on the previously applied coating liquid layer that has not yet solidified, the interface (first interface) of the previously applied coating liquid layer with the object to be coated follows the movement of the object to be coated. Therefore, the moving speed is equal to the moving speed of the object to be coated. In contrast, the interface (second interface) of the previous coating liquid layer with the next coating liquid layer becomes difficult to follow the movement of the object to be coated due to contact with the next coating liquid layer, and its moving speed is determined by the coating liquid layer. It is lower than the movement speed of the tribute. And, if the movement speed of the second interface of the previously formed coating liquid layer is too low than the movement speed of the object to be coated, this second interface will not be able to follow the movement of the object to be coated. As a result, it was discovered that the coating liquid layer applied earlier collapsed.

In addition, not only in the case of applying the next coating liquid layer on one coating liquid layer applied first on the object to be coated in this way (two-layer coating), but also in the case of applying the next coating liquid layer on two or more coating liquid layers previously applied on the object to be coated. Even in the case of applying a coating liquid layer (coating three or more layers), by considering the two or more coating liquid layers applied first as a whole and considering it as one coating liquid layer, the coating liquid layer that was applied first collapses in the same mechanism as the above-mentioned single-layer coating. I also found something to throw away.

Therefore, the present inventors focused on the movement speed of the object to be coated and the movement speed of the interface (second interface) of the second coating liquid layer of one or more first coating liquid layers coated previously, and determined the relationship between these through physical and Based on mathematical theory, extensive research was conducted to apply it to the theoretical equation of fluid dynamics (Navier-Stokes' equation).

As a result, when applying the next second coating liquid layer to one or more first coating liquid layers coated previously, the moving speed of the second interface of the first coating liquid layer is the moving speed of the object to be coated and the first coating liquid layer. Due to the pressure gradient term resulting from the pressure gradient generated by the second coating liquid layer within the liquid layer, the gravity term resulting from the gravity applied to the first coating liquid layer, and the moving speed of the second interface of the first coating liquid layer. It was found that the shear stress term is expressed as a formula.

By modifying this formula, it can be expressed as a ratio of the moving speed of the second interface of the first coating liquid layer to the moving speed of the coated object.

Here, the present inventors have further studied carefully and found that the pressure gradient generated within the first coating liquid layer is influenced by the length of the downstream lip portion of the coating portion that discharges the second coating liquid (length in the moving direction of the coated object). found to receive

Therefore, the pressure gradient is separately considered as the length of the downstream lip portion, and instead, the equation is completed by setting the pressure gradient to 0 (zero) in the equation representing the ratio of the moving speeds. In addition, in this formula, the ratio of the moving speeds is referred to as a dimensionless speed.

In this formula, the dimensionless speed is an index indicating the degree to which the second interface of the first coating liquid layer follows the movement of the object to be coated.

In addition, in this formula, the width of the numerical range that can be taken by the dimensionless speed corresponds to the width of the numerical range that can take each element (each manufacturing condition) excluding the pressure gradient, and therefore the width of the manufacturing conditions that can be coated Equivalent to

Meanwhile, in consideration of the length of the lip portion on the downstream side of the coating portion described above, the present inventors variously changed the length and variously changed the dimensionless speed to form a second coating liquid layer on the first coating liquid layer. was applied, and it was examined whether the desired first and second coating liquid layers could be obtained without the first coating liquid layer collapsing under each condition.

As a result, the range of the downstream lip portion and the dimensionless speed at which the desired first coating liquid layer and the second coating liquid layer are obtained can be expressed by a specific relational expression, and by setting each manufacturing condition to satisfy this relational expression, coating After discovering that possible manufacturing conditions were broadened, this embodiment was completed.

That is, the coating device 1 of this embodiment:

One or more first coating liquids 33 are first discharged and coated on the object to be coated (31), have not yet solidified, and are relatively moving along with the movement of the object to be coated (31). A coating unit 15 is provided for coating the second coating liquid layer 45 by discharging the following second coating liquid 43 on the above first coating liquid layer 35,

A coating device (1) configured to solidify the first coating liquid layer (35) and the second coating liquid layer (45) to form a coating film (50),

The coating portion 15 has an upstream lip portion 16a and a downstream lip portion 17a arranged to form a slot 18 by being spaced apart from each other in the moving direction M of the coated object 13, It is configured to discharge the second coating liquid 43 from the slot 18 onto the first coating liquid layer 35,

The moving speed of the object to be coated 31 is u _w (m/s), and the moving speed of the interface 35b of the first coating liquid layer 35 with the second coating liquid layer 45 is u _c ( m/s), the ratio of u _c to u _w is called the dimensionless speed (-) expressed by the following equation (1), and the length of the downstream lip portion 17a in the moving direction is When X (mm) and the dimensionless velocity are Y, the X and Y are configured to satisfy the following equation (2).

μ _pre : Among the viscosity of the one or more first coating liquids 33, the smallest viscosity (Pa·s)

μ _c : Viscosity (Pa·s) of the second coating liquid 43

h _G : Distance (m) between the interface 35b and the downstream lip portion 17a

h _pre : Total thickness (m) of the one or more first coating liquid layers (35)

ρ _pre : Among the respective densities of the one or more first coating liquids 33, the largest density (kg/㎥)

g: acceleration due to gravity (m/s ² )

According to this configuration, the relationship between the length By applying the second coating liquid layer 45, when coating the second coating liquid layer 45, the movement speed of the object 31 and the second coating liquid layer 45 of the first coating liquid layer 35 are Since the difference in movement speed of the interface 35b becomes small, it becomes possible for the movement of the interface 35b to sufficiently follow the movement of the object to be coated 31. Therefore, it becomes possible to apply the second coating liquid layer 45 without the first and second coating liquid layers 35 and 45 collapsing.

In addition, it becomes possible to widen the range of manufacturing conditions that can be coated without collapse.

Therefore, when coating the next second coating liquid layer 45 on the first coating liquid layer 35 coated previously, coating with the collapse of these coating liquid layers suppressed becomes possible under a wide range of manufacturing conditions.

In addition, in the coating device 1 of the above configuration, the above X may be 0.1 or more and 4 or less.

According to this structure, it becomes possible to apply the second coating liquid layer 45 more reliably without the first coating liquid layer 35 and the second coating liquid layer 45 collapsing.

The method for producing a coating film according to the present invention is:

A method of manufacturing a coating film using the coating device (1),

One or more first coating liquids 33 are first discharged and coated on the object to be coated (31), have not yet solidified, and are relatively moving along with the movement of the object to be coated (31). A process of discharging the following second coating liquid (43) on the above-mentioned first coating liquid layer (35) to apply a second coating liquid layer (45);

A process of solidifying the first coating liquid layer 35 and the second coating liquid layer 45 to obtain a coating film 50 is provided.

According to this configuration, the second coating liquid layer 45 can be coated on the first coating liquid layer 35 using the coating device 1, so that the first coating liquid layer 35 coated first as described above can be applied. ), coating with suppressed collapse of the coating liquid layer 45 becomes possible under a wide range of manufacturing conditions.

As described above, according to the present embodiment, when applying the next coating liquid layer on the previously applied coating liquid layer, a coating device that enables coating with suppressed collapse of these coating liquid layers under a wide range of manufacturing conditions; and A method for manufacturing a coating film is provided.

The coating device of this embodiment and the manufacturing method of the coating film are the same as above, but the present invention is not limited to the above embodiment, and appropriate design changes can be made within the scope intended by the present invention.

[Example]

Next, the present invention will be described in more detail using test examples, but the present invention is not limited to these.

Test example 1

(Materials used)

· Coated object: PET (polyethylene terephthalate) film (Product name: Diafoil, manufactured by Mitsubishi Chemical Corporation)

· First coating solution: Acrylic polymer (Product name: Paracron, manufactured by Negami Kogyo Co., Ltd.)

Density and Viscosity: As listed in Table 1

・Second coating solution: Acrylic polymer (Product name: ART CURE, manufactured by Negami Kogyo Co., Ltd.)

Density and Viscosity: As listed in Table 1

In addition, density and viscosity were measured using the following measurement method.

(Method of measuring density)

The densities of the first and second coating liquids were measured by putting constant weights of the first and second coating liquids into measuring cylinders and measuring their respective volumes.

(Method for measuring viscosity)

Using a rheometer (type RS1, manufactured by HAAKE) equipped with a jig (a cone plate with a cone diameter of 25 to 50 mm and a cone angle of 0.5 to 2°), the shear rate was measured under temperature conditions of 21 to 25°C. Under the condition of 100 (1/s), the viscosity of each first and second coating liquid is measured.

(Coating of first and second coating liquid layers)

Using the coating device as shown in FIG. 1, coating of the first coating liquid layer and coating of the second coating liquid layer were performed under the conditions shown in Table 1, and the coating conditions of the first coating liquid layer and the second coating liquid layer were evaluated. .

The thicknesses of the first coating liquid layer and the second coating liquid layer, and the distance between the second interface of the first coating liquid layer and the downstream lip of the second coating portion were measured by the following method.

The coating condition was evaluated by the following method. Additionally, equation (2) was derived as follows.

The results are shown in Table 1 and Figures 12 to 14. In addition, in Figure 12, the length In FIG. 13, an approximate line representing the range of the plot group that is closest to the coating defect and has good coating (i.e., the boundary between the coating defect and the coating defect in the good coating range) calculated in FIG. 12 is shown in the graph of FIG. 12. Show a graph. FIG. 14 shows a graph derived from only the approximate lines from FIG. 13.

(Method for measuring the thickness of the first coating layer and the second coating layer)

The first coating liquid layer and the second coating liquid layer are applied so that the width of the first coating liquid layer (length in the direction perpendicular to the direction of movement of the object to be coated; hereinafter the same) is larger than the width of the second coating liquid layer. , and solidified by drying, thereby forming the first coating film layer and the second coating film layer. The thickness of only the formed first coating layer was measured using a linear gauge (D-10HS, manufactured by Ozaki Seisakusho). Meanwhile, the thickness of the area where the first coating film layer and the second coating film layer overlap is measured with the linear gauge, and the thickness of the first coating film layer is calculated by subtracting the thickness of only the first coating film layer from the measured thickness. did. In this way, the thicknesses of the first coating film layer and the second coating film layer were measured, respectively.

(Method for measuring the distance (gap) between the second interface of the first coating liquid layer and the downstream lip portion)

The distance between the coated object 31 and the downstream lip portion was measured using a taper gauge, and the distance (gap) was measured by subtracting the thickness of the first coating liquid layer from the measured distance. In addition, the thickness of the first coating liquid layer was calculated from the measured value of the first coating film layer and the volume concentration of the first coating liquid.

(Evaluation method of potter’s condition)

The coating condition was evaluated as follows.

The coating conditions of the first coating liquid layer and the second coating liquid layer were evaluated.

The coated first and second coating liquid layers are obtained, and when the obtained first and second coating liquid layers are visually observed, there are no apparent defects, and the case where the desired first and second coating liquid layers are obtained is very good. This is indicated by “○”.

When the coated first and second coating liquid layers are obtained and the obtained first and second coating liquid layers are observed with the naked eye, stripes are observed, and the case where the desired first and second coating liquid layers are obtained is approximately good. This is indicated by “△”.

As shown in FIG. 12, the first coating liquid layer collapses due to the discharge of the second coating liquid layer, and the second coating liquid layer also collapses along with this, and the desired first and second coating liquid layers are not obtained. , is said to be defective and is indicated by “×”.

(How to derive equation (2))

The results in Table 1 were substituted into the above equation (1), and each dimensionless speed was calculated.

The obtained non-dimensional velocity is set to the y-axis and the length of the downstream lip is to the Thus, the graph in FIG. 12 is obtained.

12, in each downstream lip portion, the plot (indicated by "bold line ○") is closest to the plot indicating that the coating condition is defective (plot indicated by " By selecting each plot) and approximating the selected plot group with a quadratic equation, equation (2) as an approximation equation was obtained, as shown in FIGS. 13 and 14.

From the graphs shown in FIGS. 12 to 14, it can be seen that the coating condition becomes good by coating in the range of there was.

Moreover, even in the case where a plurality of first coating liquid layers are applied first, the coating condition of the first coating liquid layer and the second coating liquid layer becomes good by coating so that X and Y satisfy the equation (2).

Test example 2

The effect of the length of the downstream lip portion of the coated portion on the bead pressure was investigated by applying one layer of coating liquid to the object to be coated.

(Materials used)

· Coated object: PET (polyethylene terephthalate) film (Product name: Diafoil, manufactured by Mitsubishi Chemical Corporation)

· Coating solution: Acrylic polymer (Product name: ART CURE, manufactured by Negami Kogyo Co., Ltd.)

Weight concentration: 50wt%

Density: 960㎏/㎥

Viscosity: 1.22 Pa·s

Additionally, density and viscosity were measured using the above-mentioned measurement method.

(Coating of coating liquid layer)

Using a coating device as shown in FIG. 1, coating was performed directly on the object to be coated only from the second coating portion. Specifically, under the following conditions, in each case where the length of the downstream lip portion of the second coated portion is 0.2 mm and 3 mm, the distance (gap) between the object to be coated and the downstream lip portion of the second coated portion is 50 to 250. One layer of the coating liquid layer was applied onto the object to be coated, varying from ㎛ to ㎛, and the bead pressure of the coating liquid at the time of coating was measured and the coating state of the coating liquid layer was evaluated.

Movement speed of coated object: 10m/min

Thickness of coating liquid layer: 70㎛,

The bead pressure of the coating liquid was measured by the following method. Additionally, the coating state was evaluated by the above-described method.

The results are shown in Figure 15.

(Method of measuring bead pressure)

With the gap sufficiently large so that the coating liquid discharged from the second coating part does not reach the object to be coated, the coating liquid is discharged from the second coating part (the coating liquid does not reach the object to be coated). flowing), the pressure P ₀ of the coating liquid supplied to the second coating portion at that time was measured. On the other hand, in the state where each gap is adjusted as described above, the coating liquid is discharged from the second coating portion to the object to be coated (it reaches the object to be coated, and the coating liquid is applied to the object to be coated), and at that time, the first 2 The pressure P ₁ of the coating liquid supplied to the coating part was measured. Then, the bead pressure (P ₁ -P ₀ ) of the coating liquid was measured by subtracting the pressure P ₀ from the pressure P ₁ .

As shown in Fig. 15, the smaller the length of the downstream lip portion of the second coating portion, the larger the range of the gap that can be coated.

Therefore, it was found that the smaller the length of the downstream lip portion of the second coating portion, the wider the range of coating conditions under which coating can be applied.

Although the embodiments and examples of the present invention have been described as above, it is also planned from the beginning to appropriately combine the characteristics of each embodiment and examples. In addition, the embodiments and examples disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above-described embodiments and examples, and is intended to include all changes within the meaning and scope equivalent to the claims.

1: Pottering device
5: 1st Pottery Department
7a: Downstream lip part
8: slot
15: 2nd Pottery Department
17a: Downstream lip part
18: slot
27: Solidification department
31: Tribute
33: First coating amount
35: first coating liquid layer
37: first coating film layer
43: Second coating solution
45: second coating liquid layer
47: second coating film layer
50: coating film

Claims (3)

One or more first coating liquids are first discharged and coated on the object to be coated, and on one or more first coating liquid layers that have not yet solidified and are moving relatively with the movement of the object to be coated, then Provided with a coating unit for discharging the second coating liquid to apply the second coating liquid layer,
A coating device configured to solidify the first coating liquid layer and the second coating liquid layer to form a coating film,
The coating portion has an upstream lip portion and a downstream lip portion arranged to form a slot by being spaced apart from each other in the direction of movement of the object to be coated, and discharges the second coating liquid from the slot onto the first coating liquid layer. It is composed of
Let the moving speed of the coated object be u _w (m/s), the moving speed of the interface between the first coating liquid layer and the second coating liquid layer be u _c (m/s), and u _c for u _w Let the ratio be the dimensionless speed (-) expressed by the following equation (1), and let the length of the downstream lip part in the moving direction be A coating device configured so that the above X and the above Y satisfy the following formula (2).

μ _pre : Among the viscosity of the one or more first coating liquids, the smallest viscosity (Pa·s)
μ _c : Viscosity of the second coating liquid (Pa·s)
h _G : Distance between the interface and the downstream lip (m)
h _pre : Total thickness (m) of the one or more first coating liquid layers
ρ _pre : Among the respective densities of the one or more first coating solutions, the largest density (kg/㎥)
g: acceleration due to gravity (m/s ² )
The coating device according to claim 1, wherein X is 0.1 or more and 4 or less. A method for producing a coating film using the coating device according to claim 1 or 2,
One or more first coating liquids are first discharged and coated on the object to be coated, and on one or more first coating liquid layers that have not yet solidified and are moving relatively with the movement of the object to be coated, then A process of discharging the second coating liquid to apply a second coating liquid layer;
A method for producing a coating film, comprising a step of solidifying the first coating liquid layer and the second coating liquid layer to obtain a coating film.