TW201938277A - Coating apparatus and method for producing coating film - Google Patents

Abstract

Provided is a coating apparatus including a coating part that applies a second coating liquid layer on at least one first coating liquid layer that is previously applied on an object to be coated and is relatively moving along with the object to be coated, the coating apparatus being configured to solidify the first coating liquid layer and the second coating liquid layer to thereby form a coating film, wherein a specific formula is satisfied by a length of a downstream side lip part of the coating part and a non-dimensional velocity that is a moving speed of an interface between the first coating liquid layer and the second coating liquid layer relative to a moving speed of the object to be coated.

Description

Coating device and manufacturing method of coating film

FIELD OF THE INVENTION The present invention relates to a coating device and a method for manufacturing a coating film.

BACKGROUND OF THE INVENTION Conventionally, as one of the coating apparatuses, for example, a mold coater is used. The mold coater sequentially discharges each coating liquid from a plurality of coating sections on a to-be-coated object such as a substrate that is moved relatively to A plurality of coating liquid layers are formed while being continuously laminated.

The mold coater is provided with a plurality of molds along the moving direction of the object to be coated, and the mold is a coating section that discharges the coating liquid and applies the material to the object to be coated. This mold coater is configured to sequentially apply a coating liquid layer to a coating object that is relatively moved by a coating portion on the most upstream side, and sequentially from the next coating portion to the coating portion on the most downstream side. Next, the next coating liquid layer is applied before the previously applied coating liquid layer is cured, and then each coating liquid layer is cured to form a coating film (layered body of each coating film layer) (see Patent Document 1).
Prior art literature patent literature

Patent Document 1: Japanese Patent Laid-Open No. 2000-185254

Summary of the Invention Problems to be Solved by the Invention However, in the coating apparatus as described above, when the next coating liquid layer is coated on the previously-coated coating liquid layer, there is a fear that the first coating liquid may be applied due to the discharge of the next coating liquid The liquid layer may collapse. In addition, there is a possibility that the next coating liquid layer may collapse due to the collapse of the coating liquid layer applied first. In this way, when a failure occurs in which the next coating liquid layer cannot be properly coated on the previously applied coating liquid layer, it becomes impossible to obtain a coating film of a desired quality.

Therefore, it is desirable to appropriately coat the next coating liquid layer on the previously applied coating liquid layer.
On the other hand, in order to apply appropriately, the manufacturing conditions must be set to appropriate conditions, but it is desirable in terms of work efficiency that the manufacturing conditions are in a wide range.

The subject of the present invention is to provide a coating device and a method for manufacturing a coating film in view of the above-mentioned circumstances. The coating device and the method for manufacturing a coating film are provided with a coating that can suppress the collapse of these coating liquid layers in a wide range Under the manufacturing conditions.
Means to solve the problem

The coating device of the present invention includes a coating section. The coating section is configured to firstly discharge one or more first coating liquids onto the object to be coated, and then to move the first coating liquid that has not yet cured and relatively moves with the movement of the object to be coated. On the one or more first coating liquid layers, the next second coating liquid is discharged to apply the second coating liquid layer,
The coating device is configured to cure the first coating liquid layer and the second coating liquid layer to form a coating film,
The coating portion is configured to include an upstream lip portion and a downstream lip portion, and the upstream lip portion and the downstream lip portion are arranged to form slits by being separated from each other in a moving direction of the object to be coated, so as to form a slit from the foregoing The slit discharges the second coating liquid on the first coating liquid layer,
The coating device is configured such that the moving speed of the object to be coated is u _w (m / s), and the moving speed of an interface between the first coating liquid layer and the second coating liquid layer is u _c (m / s), the ratio of u _c to u _w is set to the dimensionless speed (-) represented by the following formula (1), and the length of the downstream lip in the moving direction is set to X (mm) and the dimensionless speed is set to Y, the X and the Y are made to satisfy the following formula (2).
[Number 1]

μ _pre : the smallest viscosity (Pa.s) among the viscosities of the one or more first coating liquids
μ _c : viscosity of the second coating liquid (Pa.s)
h _G : distance between the aforementioned interface and the aforementioned downstream lip (m)
h _pre : the total thickness of the one or more first coating liquid layers (m)
ρ _pre : the largest density (kg / m ³ ) among the densities of the one or more first coating liquids
g: acceleration of gravity (m / s ² )
[Number 2]

Moreover, in the coating apparatus of the said structure,
The X may be 0.1 or more and 4 or less.

The manufacturing method of the coating film of this invention is a manufacturing method of the coating film using the said coating apparatus, and has the following steps:
Firstly, one or more first coating liquids are discharged on the object to be coated, and then the next one or more first coating liquid layers that have not been cured and are relatively moved with the movement of the object to be coated are discharged. Coating the second coating liquid layer with the second coating liquid; and curing the first coating liquid layer and the second coating liquid layer to obtain a coating film.

Embodiment for Carrying Out the Invention First, a coating device according to this embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, FIG. 5, and FIG. 6, the coating device 1 of this embodiment is provided with a coating section 15. The coating section 15 is firstly coated by spraying one or more first coating liquids 33 on the object 31. Then, on the one or more first coating liquid layers 35 that have not cured and relatively moved with the movement of the coating object 31, the next second coating liquid 43 is discharged to apply the second coating liquid layer 45.
The coating device 1 cures the first coating liquid layer 35 and the second coating liquid layer 45 to form a coating film 50,
The application portion 15 is configured to include an upstream lip portion 16a and a downstream lip portion 17a, and the upstream lip portion 16a and the downstream lip portion 17a are arranged to be separated from each other in the moving direction M of the object to be coated 31. Forming a slit 18, and ejecting the second coating liquid 43 from the slit 18 on the first coating liquid layer 35,
The coating device 1 is configured to set the moving speed of the coated object 31 to u _w (m / s), and set the moving speed of the interface 35 b between the first coating liquid layer 35 and the second coating liquid layer 45 to u. _c (m / s), and the ratio of u _c to u _w is set to the dimensionless speed (-) represented by the following formula (1), and further, when the downstream lip portion 17 a is in the moving direction, When the length is set to X (mm) and the dimensionless speed is set to Y, the X and the Y are made to satisfy the following formula (2).
[Number 3]

μ _pre : the smallest viscosity among the viscosities of the one or more first coating solutions 33 (Pa.s)
μ _c : viscosity of the second coating liquid 43 (Pa.s)
h _G : distance (m) between the second interface 35b and the downstream lip 17a
h _pre : total thickness of the one or more first coating liquid layers 35 (m)
ρ _pre : the largest density (kg / m ³ ) among the densities of the one or more first coating liquids 33
g: acceleration of gravity (m / s ² )
[Number 4]

In addition, FIG. 1 illustrates a state where the second coating liquid layer 45 is applied to one first coating liquid layer 35 that is first coated on the object 31 to be coated, but the first coating liquid layer 35 that is applied first is shown in FIG. 1. The number is as described below and is not particularly limited.

The coating device 1 of this embodiment further includes a coating section 5 configured to include an upstream lip 6 a and a downstream lip on the upstream side of the coating section 15 in the moving direction M of the object 31 to be coated. 7a, the upstream lip portion 6a and the downstream lip portion 7a are arranged so as to form the slit 8 by being separated from each other in the moving direction M of the object 31 to be coated, and the slit 8 is formed from the slit before the application portion 15 8 The first coating liquid 33 is discharged onto the object to be coated 31.
Furthermore, in the coating apparatus of the present invention, the coating section 5 is not limited to a configuration capable of performing the slit die coating in this manner. For example, the coating material 5 may be a structure which can perform gravure coating.
Hereinafter, the coating section 5 to which the first coating liquid layer 35 is first applied is referred to as the first coating section 5, and the coating section 15 to which the second coating liquid layer 45 is subsequently applied is referred to as the second coating section 15.

The coating device 1 further includes a curing section 27 that cures the first and second coating liquid layers 35 and 45 coated by the first and second coating sections 5 and 15 to form each coating film. Layers 37, 47.

The coating device 1 further includes a support portion 25 that supports the object to be coated 31 on the surface, and makes the object to be coated 31 with respect to the first and second coating units 5 and 2 in the longitudinal direction of the object to be coated 31. 15 moves relatively.

The to-be-coated object 31 is not specifically limited, For example, a belt-shaped sheet | seat member etc. are mentioned.
Examples of the sheet member include a resin film. Examples of the resin film include Lumirror (registered trademark) manufactured by Toray Industries.

The support part 25 is a structure which supports the to-be-coated object 31 which moved to the longitudinal direction from the opposite side of the 1st and 2nd application parts 5 and 15. The first and second coating sections 5 and 15 are coated in this order on the object to be coated 31 supported by the support section 25 and relatively moved with respect to the first coating section 5 and the second coating section 15.
Examples of the supporting portion 25 include a roller and the like.

In the present embodiment, the support portion 25 is formed at a position facing the slit 8 of the first coating portion 5 so that the object 31 to be coated is opposed to the slit 8 from one side (left side in FIG. 1). ) Toward the other side (right of Fig. 1).
In addition, the support portion 25 is formed at a position facing the slit 18 of the second coating portion 15 so that the object 31 to be coated faces the first coating liquid layer 35 from below (bottom in FIG. 1) and upward ( (Top of FIG. 1).

The curing unit 27 is configured to cure the first and second coating liquid layers 35 and 45 to form the respective coating film layers 37 and 47. The cured film 27 is cured to form a coating film 50 that is a laminate of the coating film layer 37 and the coating film layer 47. The curing section 27 is not particularly limited as long as it is a member capable of curing the first and second coating liquid layers 35 and 45. The curing section 27 can be appropriately set in accordance with the types of the first and second coating liquids 33 and 43 and the like.

In this embodiment, as the first coating section 5 and the second coating section 15, a mold having slits 8 and 18 is used. The coating apparatus 1 provided with a mold like this is called a mold coater.

The first coating portion 5 is formed so that the first coating liquid 33 is discharged from the slit 8 before the application of the second coating liquid layer 45, and the first coating is sequentially applied to the object 31 to be moved relatively.液 层 35。 Liquid layer 35.
The first coating section 5 is formed so that the slit 8 is arranged to face upward, and the first coating liquid 33 is discharged to the object 31 to be moved in the left-right direction relative to the slit 8. In the first coating section 5, the first coating solution 33 is formed to be supplied from a storage section (not shown) of the first coating solution 33 through a pipe (not shown) and a pump (not shown).

Specifically, the first coating section 5 includes an upstream-side module 6 and a downstream-side module 7 arranged to face the upstream-side module 6. The first coating section 5 is formed by joining the upstream-side module 6 and the downstream-side module 7. By bringing the two modules 6 and 7 together in this way, a branch pipe 9 and a slit 8 are formed therebetween. The branch pipe 9 is a first coating liquid 33 that is supplied by a pump (not shown). The slit 8 is arranged from the branch pipe 9 toward the leading edge. The gap between the upstream lip 6a, which is the front end edge of the upstream module 6 and the downstream lip 7a, which is the front end edge of the downstream module 7, is the discharge port of the slit 8.

The upstream lip portion 6 a and the downstream lip portion 7 a are arranged on a plane perpendicular to the radial direction of the support portion 25. The slit 8 is arranged parallel to the radial direction of the support portion 25.

The second coating portion 15 is a first coating liquid that is formed to be continuous with the coating of the first coating liquid layer 35, and the next second coating liquid 43 is ejected from the slit 18 and is moved to the object 31 to be moved relatively The second coating liquid layer 45 is sequentially applied on the layer 35.
The second coating portion 15 is formed by arranging the slit 18 so as to face the side, and discharging the second coating liquid 43 on the first coating liquid layer 35 that moves relatively upward and downward with respect to the slit 18. The second coating section 15 is formed to supply the second coating liquid 43 through a pipe (not shown) and a pump (not shown) from a storage section (not shown) of the second coating liquid 43.
The first and second coating sections 5 and 15 may be a slit mold provided with a chamber for decompression.

Specifically, the second coating unit 15 includes an upstream module 16 and a downstream module 17 that is disposed to face the upstream module 16. The second coating section 15 is formed by joining the upstream-side module 16 and the downstream-side module 17. By bringing the two modules 16 and 17 together in this way, a branch pipe 19 and a slit 18 are formed between the two modules. The branch pipe 19 is a second coating liquid 43 which is supplied by a pump (not shown). The slit 18 is arranged from the branch pipe 19 toward the front end edge. The gap between the upstream lip portion 16 a, which is the front end edge of the upstream module 16, and the downstream lip portion 17 a, which is the front end edge of the downstream module 17, is the discharge port of the slit 18.

The upstream lip portion 16 a and the downstream lip portion 17 a are arranged on a plane perpendicular to the radial direction of the support portion 25. The slit 18 is arranged parallel to the radial direction of the support portion 25.

The smaller the length of the downstream-side lip portion 17a, the wider the range of the gap can be, and the second coating liquid layer 45 can be applied without collapse of the first coating liquid layer 35 and the second coating liquid layer 45. In consideration of the above viewpoint, the length of the downstream-side lip portion 17a is preferably 0.1 mm or more and 4 mm or less.

In this embodiment, as shown in FIG. 2, for example, the first coating portion 5 and the second coating portion 5 and the second coating portion 31 may be arranged in a direction (width direction, left-right direction in FIG. 2) perpendicular to the moving direction M of the object 31 to be coated. Each of the coating sections 15 applies a continuous first coating liquid layer 35 and a second coating liquid layer 45.
As shown in FIG. 3, for example, the first coating section 5 may be configured to apply a plurality of first coating liquid layers 35 separated from each other in the width direction (the left-right direction in FIG. 3), and may be configured to The second coating section 15 is configured to apply a plurality of second coating liquid layers 45 corresponding to the respective first coating liquid layers 35 to the respective first coating liquid layers 35.
For example, as shown in FIG. 4, the first coating portion 5 may be a first coating liquid layer 35 that is continuously applied in the width direction (left-right direction in FIG. 4), and may be configured as a second coating portion. 15 On the first coating liquid layer 35, a plurality of second coating liquid layers 45 separated and spaced apart from each other are applied.

The coating device 1 of this embodiment is configured to set the moving speed of the object 31 to be u _w (m / s), and set the moving speed of the interface 45 a between the first coating liquid layer 35 and the second coating liquid layer 45 Let u _c (m / s), and set the ratio of u _c to u _w to the dimensionless speed (-) represented by the above formula (1), and further to the downstream side of the second coating portion 15 When the length of the lip portion 17a is set to X (mm) and the dimensionless speed is set to Y, X and Y are made to satisfy the above formula (2).

Hereinafter, the above-mentioned expressions (1) and (2) will be described.

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

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 coated on the first coating liquid layer 35, the entire first coating liquid layer 35 follows the The object to be coated 31 moves so that the moving speed of the first coating liquid layer 35 is the same as the moving velocity of the object to be coated 31 in the thickness direction as a whole. In other words, the moving speed of the first coating liquid layer is the same as the moving speed of the object 31 in the thickness direction.

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

In contrast, the interface between the first coating liquid layer 35 and the second coating liquid layer 45 (hereinafter sometimes referred to as the second interface) 35b, after the second coating liquid layer 45 is applied, must follow the surface of the object 31 to be coated. The movement becomes difficult, and the movement is slower than the movement of the coated object 31. According to this, how much the amount of this slowing down makes the moving speed of the second interface 35b of the first coating liquid layer 35 smaller than that before the application of the second coating liquid layer 45, and the first coating liquid layer In the thickness direction of 35, the moving speed of each portion decreases as the first interface 35a is moved toward the second interface 35b. When the moving speed of the second interface 35 b becomes too small, as shown in FIG. 11, the first coating liquid layer 35 will collapse. Along with this, the second coating liquid layer 45 also collapses. The moving speed of the second interface 35 b of the first coating liquid layer 35 is equivalent to the moving speed of the second coating liquid layer 45.

Accordingly, 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 31, the collapse of the first coating liquid layer 35 and the second coating liquid layer 45 can be suppressed.

As shown in FIG. 7, as a main factor that affects a decrease in the moving speed of the second interface 35 b of the first coating liquid layer 35, an application of the liquid bead pressure of the second coating liquid 43 to the first The pressure gradient of the 1 coating liquid layer 35, the gravity applied to the first coating liquid layer 35, and the shearing force applied to the second interface 35b of the first coating liquid layer 35 through the second coating liquid layer 45.

Then, these theoretical and physical mathematical theories are applied to the theoretical formulas of fluid mechanics (Navy Stokes equations). At the time of application, it is assumed that it does not flow in a direction (width direction) perpendicular to the moving direction M of the object to be coated 31. According to this application, the moving speed u _c of the second interface 35 _{b of the} first coating liquid layer 35 can be adjusted to the moving speed u _{w of the} object 31 by using the pressure gradient ∂p / ∂x in the first coating liquid layer 35. The pressure gradient term, gravity term, and shear force term are expressed as the following formula (3). As shown in the following formula (3), the moving speed of the second interface 35b of the first coating liquid layer 35 is obtained by subtracting the pressure gradient term, the gravity term, and the shear force term from the moving speed u _{w of the} object 31. Value.

As shown in the following formula (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 in the first coating liquid layer 35. Requirements such as ∂p / 要 x.
This pressure gradient ∂p / ∂x is the following pressure gradient (that is, pressure distribution) in the moving direction M of the coating object 31: the second coating liquid discharged from the slit 18 of the second coating portion 15 A gradient of the pressure of 43 beads and the pressure applied to the first coating liquid layer 35.
The pressure applied to the first coating liquid layer 35 on the upstream side of the second coating portion 15 (that is, before the second coating liquid 43 is discharged) is 0, and this pressure is equal to the atmospheric pressure. In addition, x is a coordinate in which the moving direction (traveling direction) of the to-be-coated object 31 is made 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, the viscosity μ _{pre of the} first coating liquid 33, and the moving direction of the coated object 31. Elements such as the angle θ formed with respect to the direction of gravity action.

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 interface of the first coating liquid layer 35. Requirements such as the moving speed u _{c of} 35 _b and the distance (gap) h _G between the second interface 35 _b of the first coating liquid layer 35 and the downstream lip portion 17 a.

[Number 5]

μ _pre : viscosity of the first coating solution 33 (Pa.s)
μ _c : viscosity of the second coating liquid 43 (Pa.s)
h _G : distance (m) between the second interface 35b and the downstream lip 17a
h _pre : thickness of the first coating liquid layer (m)
ρ _pre : density of the first coating liquid layer (kg / m ³ )
g: acceleration of gravity (m / s ² )
θ: an angle (°) formed by the moving direction M of the coated object 31 with respect to the direction in which gravity is applied

In addition, if the obtained formula (3) is changed to a ratio (u _c / u _w ) representing the moving speed u _c of the second interface 35 _b of the first coating liquid layer 35 to the moving speed u _w of the object 31 to be coated. In this case, the following formula (4) can be obtained.

[Number 6]

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

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

[Number 7]

As described above, since the moving speed u _c of the second interface 35 _b of the first coating liquid layer 35 is preferably close to the moving speed u _{w of the} object 31, u _c / u _{w is} preferably close to 1.
Here, cosθ is a value from -1 to 1 (-1 ≦ cosθ ≦ 1).
When cos θ = -1 is obtained as shown in FIG. 5 when θ = 180 °, at this time, -ρgcosθ is maximized (-ρ _pre gcosθ = ρ _pre g). According to this, as long as the value other than cos θ is fixed, u _c / u _{w in the} above formula (5) becomes the minimum.
On the other hand, when cos θ = 1 is θ = 0 °, at this time, -ρ _pre gcosθ is minimized (-ρgcosθ = -1). According to this, as long as the value other than cosθ is fixed, u _c / u _w of the above formula (5) of the above formula (5) becomes the maximum (not shown).

In addition, in 0 °>θ> 180 °, u _c / u _w is a value between a value when θ = 0 ° and a value when θ = 180 °.
As shown in FIG. 8, for example, the second coating portion 15 is arranged such that the slit 18 thereof faces downward, and is opposite to the slit 18 from one side (the right side in FIG. 8) to the other side (the left side in the figure). When the second coating liquid 43 is discharged onto the moving first coating liquid layer 35, θ = 90 ° and cosθ = 0. Accordingly, in this case, u _c / u _w is a value between the case where θ = 180 ° and the case where θ = 0 °. In addition, according to cos = 0, the gravity term (gravity term = 0) can be ignored in Equation (3). That is, the gravity applied to the first coating liquid layer 35 is not applied in the direction in which the first coating liquid layer 35 collapses.

Accordingly, the case where θ = 180 ° is the most severe condition for making the u _c / u _w close to 1.
Therefore, when θ = 180 ° is set in the formula (5), the formula (1) can be derived as follows. In the following formula (1), the ratio (u _c / u _w ) of the moving speed is referred to as a dimensionless speed.

[Number 8]

In the above formula (1), when the second coating liquid layer 45 is coated on one of the first coating liquid layers 35 that have been coated on the object 31 to be coated, μ _pre , μ _c , h _G , h _Pre , ρ _pre, and g are as follows.
μ _pre : viscosity of the first coating solution 33 (Pa.s)
μ _c : viscosity of the second coating liquid 43 (Pa.s)
h _G : distance (m) between the second interface 35b and the downstream lip 17a
h _pre : thickness (m) of the first coating liquid layer 35
ρ _pre : density (kg / m ³ ) of the first coating liquid 33
g: acceleration of gravity (m / s ² )

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

As shown in FIG. 9, for example, it is assumed that the coating device 1 includes N-1 from the first to the N-1th from the upstream side toward the downstream side in the moving direction M of the object to be coated 31 (N is 3 or more) (Integer number), the coating portion (the first coating portion) 5 from the first to the N-1th is applied to the coating 31 from the first to the N-1th The first coating liquid layer 35 so far is applied to the next second coating liquid layer 45 (the Nth coating liquid layer) through the Nth coating section (second coating section) 15.

In this case, when the second coating liquid layer 45 is coated on the outermost (N-1th) first coating liquid layer 35, it is from the first innermost (first) first coating liquid layer 35 to Up to the outermost first coating liquid layer 35, the moving speed of each first coating liquid layer 35 gradually decreases. In each of the first coating liquid layers 35, the moving speed gradually decreases from the object to be coated 31 side to the second coating liquid layer 45 side. In addition, the moving speed of the interface between the first first coating liquid layer 35 and the object to be coated 31 is equivalent to the moving speed of the coating object 31 and becomes u _w . On the other hand, the N-1th first coating liquid The moving speed of the interface between the layer 35 and the second coating liquid layer 45 is equivalent to the moving speed of the second coating liquid layer 45 and becomes u _c .

In this way, as the entirety of the plurality of first coating liquid layers 35, the interface from the first first coating liquid layer 35 to the object 31 is directed toward the first N-1th coating liquid layer 35 and the first coating liquid layer 35. The moving speed of the interface of the 2 coating liquid layer 45 becomes smaller.

In addition, when the moving speed of the interface between the N-1th first coating liquid layer 35 and the second coating liquid layer 45 becomes too small, a situation may occur in which the plurality of first coating liquid layers 35 collapse, As a result, the second coating liquid layer 45 is collapsed.
This makes it possible to suppress the collapse of the plurality of first coating liquid layers 35 and the second coating liquid layer by making the moving speed of the N-1th first coating liquid layer 35 close to the moving speed of the object 31.

In this way, when the entirety of the plurality of first coating liquid layers 35 is regarded as one first coating liquid layer 35, it is a mechanism for suppressing the collapse of the first coating liquid layer 35 and the second coating liquid layer 45 as a whole. This is the same as the case where the second coating liquid layer 45 is coated on one coating liquid layer 35 (see FIG. 5).

In addition, as a main factor that affects the decrease in the moving speed from the first interface 35a to the second interface 35b, it is formed as described above (see FIG. 7) to apply a pressure gradient, gravity, and a shear force. In the case of the entirety of the plurality of first coating liquid layers 35.

Therefore, even when the second coating liquid layer 45 is coated on the plurality of first coating liquid layers 35, the plurality of first coating liquid layers 35 can be regarded as one first coating liquid layer as a whole. 35, and the above formula (1) applies.

That is, the above-mentioned formula (1) is not only the case where the next second coating liquid layer 45 is applied to one first coating liquid layer 35 that has been previously applied to the object to be coated 31 (two-layer coating), Even in the case where the next second coating liquid layer 45 is applied to two or more first coating liquid layers 35 that have been previously applied to the object 31 (application of three or more layers), the first application The two or more first coating liquid layers 35 as a whole are regarded as one first coating liquid layer 35, and Equation (1) can be applied in the same manner as in the above two-layer coating.

In this case, in Equation (1), the interface between the first coating liquid layer 35 and the second coating liquid layer 45 on the outermost side (the N-1th) and the moving speed thereof are a plurality of firsts. The second interface 35b in the coating liquid layer 35 and its moving speed.
The thickness of the first coating liquid layer 35 is the entire thickness of the first coating liquid layer 35 from the first to the N-1th.

On the other hand, in Equation (1), the smaller u _{pre is, the} smaller u _c / u _w becomes, so it becomes a stricter condition. Accordingly, among the viscosities of the plurality of first coating liquids 33, the smallest viscosity is adopted as a representative value.

In Equation (1), the larger ρ _pre is, the smaller u _c / u _w becomes, so it becomes a stricter condition. Accordingly, among the viscosities of the plurality of first coating liquids 33, the maximum viscosity is adopted as a representative value.

Accordingly, in the formula (1), when the second coating liquid layer 45 is applied to the plurality of first coating liquid layers 35 that have been coated on the object 31, μ _pre , μ _c , h _G , h _pre , ρ _pre and g are as follows.
μ _pre : the smallest viscosity (Pa.s) among the viscosities of the plurality of first coating liquids 33
μ _c : viscosity of the second coating liquid (Pa.s)
h _G : distance (m) between the second interface 35b and the downstream lip 17a
h _pre : total thickness (m) of the plurality of first coating liquid layers 35
ρ _pre : the largest density (kg / m ³ ) among the densities of the plurality of first coating liquids 33
g: acceleration of gravity (m / s ² )

Then, these are combined with the case where there is one first coating liquid layer 35 as described below.
μ _pre : the smallest viscosity among the viscosities of the one or more first coating solutions 33 (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 17a
h _pre : total thickness of the one or more first coating liquid layers 35 (m)
ρ _pre : the largest density (kg / m ³ ) among the densities of the one or more first coating liquids 33
g: acceleration of gravity (m / s ² )

This is done to derive the above formula (1).

In this formula (1), the dimensionless speed is an index showing the degree to which the movement of the second interface 35b of the first coating liquid layer 35 follows the movement of the object 31 to be coated. In other words, the closer the moving speed of the second interface 35b of the first coating liquid layer 35 to the moving speed of the object 31 is, the closer the dimensionless speed is to 1, and it becomes 1 when they match. Moreover, the closer the dimensionless speed is to 1, the easier the first coating liquid layer 35 and the second coating liquid layer 45 can be applied without further collapse.
Conversely, as the moving speed of the second 35b of the first coating liquid layer 35 deviates from the moving speed of the coated object 31 (the smaller it becomes), the dimensionless speed deviates from 1 and becomes smaller toward 0, and the first And the second coating liquid layers 35 and 45 become more likely to collapse.

In addition, in the formula (1), among the requirements included in the pressure gradient term, the gravity term, and the shear force term, each requirement (except the manufacturing conditions) ) To make the dimensionless speed change. According to this, the magnitude of the numerical range that can be obtained by the dimensionless velocity is equivalent to the magnitude of the numerical range that can be obtained by each element except the pressure gradient ∂p / ∂x, that is, the width of the manufacturing conditions.

Next, the derivation of the above formula (2) will be described.

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 affected by the length of the downstream-side lip portion 17 a of the second coating portion 15.
Accordingly, the length of the downstream lip portion 17 a affects the collapse of the first coating liquid layer 35 when the second coating liquid layer 45 is applied.

On the other hand, the dimensionless speed also affects the collapse of the first coating liquid layer 35 when the second coating liquid layer 45 is applied.

In this way, depending on the magnitude of the dimensionless speed, the numerical range of the length of the downstream lip portion of the second coatable portion that can be applied is widened or narrowed. Conversely, depending on the degree of the length of the downstream-side lip portion 17a, the value range of the dimensionless speed that can be applied is widened or narrowed.

However, as shown in the example described later, when the length X and the dimensionless speed Y of the downstream-side lip portion 17a satisfy the ranges shown in the following formula (2), it becomes possible to prevent the first coating When the liquid layer 35 and the second coating liquid layer 45 collapse, the second coating liquid layer 45 is applied, and both the numerical range of X and the numerical range of Y can be widened. In the embodiment described later, the first coating liquid layer 35 is coated while variously changing the length of the downstream-side lip portion 17a and variously changing the dimensionless speed. Whether the second coating liquid layer 45 can be applied under various conditions without collapsing the first coating liquid layer 35, that is, whether the desired first and second coating liquid layers can be obtained 35, 45.

As shown in the examples described later, each dimensionless speed is set to the y-axis, the length of the downstream side lip portion 17a is set to the x-axis, and each dimensionless speed and the dimension corresponding to each dimensionless speed are set. The downstream lip portion 17a is plotted together with whether the coating state is good to make a chart. In the obtained chart, for each downstream lip portion 17a, the plot closest to the poor coating state is selected and is The plot in a good coating state, and by approximating the selected plot group with a quadratic equation, Equation (2) is obtained as an approximate equation.

[Number 9]

This is done to derive Equation (2).

According to the above formulae (1) and (2), when the second coating liquid layer 45 is applied, the coating conditions of the coating device 1 can be determined to satisfy the above-mentioned values in a relationship with the first coating liquid layer 35 that is applied first. Equation (2).

The thickness of each of the first coating liquid layer 35 and the second coating liquid layer 45 can be appropriately set so as to satisfy the above-mentioned expressions (1) and (2). These thicknesses can be adjusted, for example, by adjusting the first and second coating liquids from the first and second coating portions 5, 15 in accordance with the viscosity of each of the first coating liquid 33 and the second coating liquid 43. At least one of the discharge amount of 33 and 43 and the moving speed of the to-be-coated object 31.
For example, if the thickness of the first coating liquid layer 35 and the second coating liquid layer 45 is too small, it will be difficult to apply the coating covering the entire desired area. If the thickness is too large, it will cause depression due to its own weight. Therefore, application tends to be difficult.
Therefore, when considering the above point, for example, the thickness of the first coating liquid layer 35 is preferably 0.01 μm or more and 1000 μm or less, and 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 of the first coating liquids 33 includes a curing component, and can be applied to the object to be coated 31 and cured on the object to be coated 31.
Each of the second coating liquids 43 has a structure that contains a curing component and can be applied to the first coating liquid layer 35 to be cured on the first coating liquid layer 35.

The types of the first and second coating liquids 33 and 43 can be appropriately set so as to satisfy the above-mentioned formulas (1) and (2).

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

Examples of the first coating liquid 33 include a primer, an adhesive such as an ultraviolet curing adhesive, an adhesive, and a liquid crystal.
By using these, there is an advantage that the adhesion between the second coating liquid layer 45 and the object 31 can be improved.

The viscosity of the first coating liquid 33 is preferably 0.0005 Pa. s or more and 30Pa. Below s, more preferably 0.001Pa. s or more and 20Pa. s or less. The viscosity is a value measured by a measurement method described in Examples described later.
The viscosity of the first coating solution 33 was 0.0005 Pa. In the case of s or more, there is an advantage that it can be easily applied by a conventionally known coating method.
The viscosity of the first coating solution 33 was 30 Pa. In the case of s or less, there is an advantage that the liquid can be easily supplied to the coating unit 5 by a conventionally known liquid supply mechanism such as a pump.

The density ρ _{pre of the} first coating liquid 33 is preferably 600 to 1400 kg / m ³ , and more preferably 700 to 1300 kg / m ³ . The density is a value measured by a measurement method described in Examples described later.

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

Examples of the second coating liquid 43 include an adhesive such as an ultraviolet curing adhesive, an adhesive, and a liquid crystal.

The viscosity of the second coating liquid 43 is preferably 0.0005 Pa. s or more and 30Pa. Below s, more preferably 0.001Pa. s or more and 20Pa. s or less. The viscosity is a value measured by a measurement method described in Examples described later.
The viscosity of the second coating liquid 43 was 0.0005 Pa. In the case of s or more, there is an advantage that it can be easily applied by a conventionally known coating method.
The viscosity of the second coating liquid 43 was 30 Pa. In the case of s or less, there is an advantage that the liquid can be easily supplied to the coating unit 15 by a conventionally known liquid supply mechanism such as a pump.

The density ρ _{pre of} the second coating liquid 43 is preferably 600 to 1400 kg / m ³ , and more preferably 700 to 1300 kg / m ³ . The density is a value measured by a measurement method described in 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. The thickness is a value measured by a measurement method described in Examples described later.

The first and second coating liquids 33 and 43 may be the same type or different types.
When the first and second coating liquids 33 and 43 are 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 slit 8 of the first coating section 5 can be appropriately set so as to satisfy the expressions (1) and (2).
The discharge amount can be set to, for example, 0.01 to 50 L / min.

The discharge amount of the second coating liquid 43 from the slit 18 of the second coating portion 15 can be appropriately set so as to satisfy the expressions (1) and (2).
The discharge amount can be set to, for example, 0.01 to 50 L / min.

Although the thickness of the to-be-coated object 31 is not specifically limited, For example, it is preferable that the thickness is 20-100 micrometers.
In FIG. 1, although the coated object 31 is shown to have a flexible and strip-like configuration, in addition, the coated object 31 may have a veneer-like configuration or be non-flexible. Like this.

The moving speed of the coated object 31 can be adjusted by, for example, adjusting the rotation speed of the support portion 25. The moving speed is preferably 1 to 300 m / min, and more preferably 5 to 50 m / min.
By making the moving speed of the to-be-coated object 31 1 m / min or more, a to-be-coated object can be moved more stably. For example, since the support portion 25 can be rotated more stably, the object to be coated 31 can be moved more stably.
By setting the moving speed of the coated object 31 to be 300 m / min or less, it is possible to suppress rattling or meandering when the coated object 31 moves.

As described above, in the coating device 1 of this embodiment, it is preferable that the first coating liquid 33 has 0.0005 to 30 Pa. The viscosity of s and the second coating liquid 43 are 0.0005 to 30 Pa. The viscosity of s and the moving speed of the coating object 31 are 1 to 300 m / min.

Next, the manufacturing method of the coating film 50 of this embodiment is demonstrated.

The manufacturing method of the coating film 50 of this embodiment uses the coating device 1 mentioned above.
The manufacturing method has the following steps:
Firstly, one or more first coating liquids 33 are discharged onto the coated object 31 for coating, and then on the one or more first coating liquid layers 35 that have not been cured and are relatively moved with the movement of the coated object 31. Discharging the next second coating liquid 43 from the second coating portion 15 to apply the second coating liquid layer 45 (the next coating step); and curing the first coating liquid layer 35 and the second coating liquid layer 45 To obtain a coating film 50.

Further, in this embodiment, it is further provided that one or more first coating sections 5 (here, one first coating section 5) are first coated on the object 31 to be coated with one or more first coating sections 5. 1 coating liquid layer (here, one coating liquid layer) 35 step (previous coating step).

Specifically, in the manufacturing method of the coating film 50 of this embodiment, first, the length X and the dimensionless speed Y of the downstream-side lip portion 17a are set to satisfy the above-mentioned formula (2).
In the setting of the dimensionless speed X, the first and second coating liquids 33 and 43 are adjusted by adjusting the types and concentrations of the first and second coating liquids 33 and 43, the moving speed of the object to be coated 31, and the discharge amount from the first coating portion 5. The viscosity μ _{pre of the} 1 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 the respective density ρ _{pre of the} first coating liquid layer. Further, by setting the arrangement of the second coating portion 15, the distance h _G between the second interface 35 b of the first coating liquid layer 35 and the downstream lip portion 17 a is set. The gravitational acceleration g is constant.
The length X of the downstream-side lip portion 17 a of the second application portion 15 can be set when the downstream-side module 17 is produced.

Then, under the set conditions, the first coating liquid 33 is discharged from the one or more first coating portions 5 on the object 31 to apply the one or more first coating liquid layers 35, and the first coating is applied to the first coating liquid layer 35. The second coating liquid 43 is discharged from the second coating portion 15 on the liquid layer 35 to apply the second coating liquid layer 45. Next, each of the first and second coating liquid layers 35 and 45 that have been applied to the object 31 is cured by the curing unit 27 to obtain one or more first coating film layers 37 and second coating film layers 47. (The coating film 50 which is a laminated body of these).

In addition, when three or more coating liquid layers are coated on the object to be coated 31, the coating liquid layers from the second to the Nth coating may be coated on the coating liquid layer that was previously coated. One coating liquid layer is applied so as to satisfy the above formulas (1) and (2). Specifically, when applying a plurality of (N-1) first coating liquid layers 35 to the object 31, each of the first coating liquid layers from the second to the N-1 may be applied. The application of 35 is performed in order to satisfy the above formulas (1) and (2). Next, when the second application liquid layer 45 is applied to the N-1th first application liquid layer 35, the second application is applied. The application of the liquid layer 45 is performed so as to satisfy the above formulas (1) and (2).

According to the manufacturing method of the coating device 1 and the coating film 50 of the present embodiment described above, the second coating liquid layer 45 can be coated so that the length X of the downstream lip portion 7a of the second coating portion 15 and the number The relationship between the dimensionless speed Y represented by the formula (1) is a range satisfying the formula (2), and when the second coating liquid layer 45 is applied, the moving speed of the object 31 and the first coating liquid layer 35 are adjusted. The difference in the moving speed of the second interface 35b becomes smaller, so that the movement of the second interface 35b can sufficiently follow the movement of the object to be coated 31. This makes it possible to apply the second coating liquid layer 45 without collapsing the first and second coating liquid layers 35 and 45.
In addition, it becomes possible to widen the range of application conditions that can be applied without collapsing.
Therefore, when it becomes possible to apply the next second coating liquid layer 45 on the first coating liquid layer 35 that was previously applied, the coating that can suppress the collapse of these coating liquid layers 35 and 45 is applied in a wide range. The coating conditions were performed.

The manufacturing method of the coating device 1 and the coating film 50 of this embodiment can be applied to, for example, a process material for forming a semiconductor wafer.
In this case, the first coating film layer 37 may be a sticky crystal film, and the second coating film layer 47 may be a dicing tape. A laminated body (coating film) 50 laminated on these first and second coating film layers 37 and 47 can be laminated on a semiconductor wafer such that the first coating film layer 37 becomes a semiconductor wafer side, and the semiconductor wafer can be laminated in a After the semiconductor wafer is cut to obtain a desired size and number, the second coating film layer 47 is removed, and the exposed first coating film layer 37 is laminated on another semiconductor wafer.

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

The inventors of this case devoted themselves to research, and found the following knowledge.
In other words, when the next coating liquid layer is discharged on the previously-coated and uncured coating liquid layer, the interface (first interface) between the first coating liquid layer and the object to be coated will follow the object to be coated. The movement speed is equivalent to the movement speed of the coated object. On the other hand, the interface (second interface) between the previous coating liquid layer and the next coating liquid layer is caused by contact with the next coating liquid layer, and it becomes difficult to follow the movement of the object to be coated, and the movement thereof The speed will be lower than the moving speed of the coated object. In addition, when the moving speed of the second interface of the coating liquid layer formed earlier becomes too low compared with the moving speed of the object to be coated, the second interface may become unable to follow the movement of the object to be coated. As a result, it was found that the coating liquid layer applied first collapsed.

In addition, it has been found that the following case is not only the case where the next coating liquid layer is coated on one of the coating liquid layers previously coated on the object to be coated (two-layer coating), In the case where the next coating liquid layer is applied to two or more coating liquid layers on the object to be coated (coating of three or more layers), the two or more coating liquid layers applied first can be considered as a whole. One coating liquid layer has the same mechanism as the single-layer coating described above, which causes the first coating liquid layer to collapse.

Therefore, the inventors of the present invention have paid attention to the moving speed of the object to be coated and the moving speed of the interface (second interface) between the first coating liquid layer and the second coating liquid layer that are applied first or more. The relationship is based on physics and mathematics theory and is applied to the theoretical formula of fluid mechanics (Navy Stokes equation).

As a result, it was found that when one or more of the first coating liquid layers applied first are coated with the next second coating liquid layer, the moving speed of the second interface of the first coating liquid layer can be determined by the following The term is expressed as a formula: the moving speed of the object to be coated, a pressure gradient term due to a pressure gradient generated by the second coating liquid layer in the first coating liquid layer, and a gravity due to the gravity applied to the first coating liquid layer. Gravity term and a shear stress term due to the moving speed of the second interface of the first coating liquid layer.

When this formula is deformed, it can be expressed as an expression of the ratio of the moving speed of the second interface of the first coating liquid layer to the moving speed of the object to be coated.

Here, after the inventors of the present case studied more earnestly, it was found that the pressure gradient generated in the first coating liquid layer was discharged from the downstream side lip of the coating portion of the second coating liquid Length in the direction of movement).

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

In this formula, the dimensionless speed is an index showing how much the second interface of the first coating liquid layer follows the movement of the object to be coated.
In this formula, the magnitude of the range of values that can be obtained by dimensionless speed is equivalent to the magnitude of the range of values that can be obtained by each element (each manufacturing condition) except the pressure gradient, and accordingly, it corresponds to the coatable The magnitude of the manufacturing conditions.

On the other hand, in consideration of the length of the downstream lip portion of the aforementioned coating portion, the inventors of the present application reviewed the following: while making various changes to the length and variously changing the dimensionless speed described above, Is it possible to obtain the desired first and second coating liquid layers by applying the second coating liquid layer to the first coating liquid layer under various conditions without collapsing the first coating liquid layer.

As a result, it was found that the range of the downstream-side lip and the dimensionless speed at which the desired first coating liquid layer and the second coating liquid layer can be obtained can be expressed by a specific relational expression, and each of them can be further manufactured. The conditions are set so as to satisfy this relational expression, so that the manufacturing conditions that can be applied are widened, and finally this embodiment is completed.

In other words, the coating device 1 of this embodiment is provided with a coating section 15. The coating section 15 firstly sprays one or more first coating liquids 33 on the object to be coated 31, and then coats the uncured and following One or more first coating liquid layers 35 which are relatively moved by the movement of the object to be coated 31, and the next second coating liquid 43 is discharged to apply the second coating liquid layer 45.
The coating device 1 is configured to cure the first coating liquid layer 35 and the second coating liquid layer 45 to form a coating film 50,
The coating portion 15 is configured to include an upstream lip 16a and a downstream lip 17a, and the upstream lip 16a and the downstream lip 17a are arranged to be separated from each other in the moving direction M of the object 13 to be coated. Forming a slit 18, and ejecting the second coating liquid 43 from the slit 18 on the first coating liquid layer 35,
The coating device 1 is configured to set the moving speed of the coated object 31 to u _w (m / s), and set the moving speed of the interface 35 b between the first coating liquid layer 35 and the second coating liquid layer 45 to u. _c (m / s), and the ratio of u _c to u _w is set to the dimensionless speed (-) represented by the following formula (1), and further, when the downstream lip portion 17 a is in the moving direction, When the length is set to X (mm) and the dimensionless speed is set to Y, the X and the Y are made to satisfy the following formula (2).
[Number 10]

μ _pre : the smallest viscosity among the viscosities of the one or more first coating solutions 33 (Pa.s)
μ _c : viscosity of the second coating liquid 43 (Pa.s)
h _G : distance (m) between the aforementioned interface 35b and the aforementioned downstream lip 17a
h _pre : total thickness of the one or more first coating liquid layers 35 (m)
ρ _pre : the largest density (kg / m ³ ) among the densities of the one or more first coating liquids 33
g: acceleration of gravity (m / s ² )
[Number 11]

According to the configuration, the second coating liquid layer 45 can be applied so that the length X of the downstream lip portion 17a of the coating portion 15 and the dimensionless speed Y expressed by the above formula (1) can be applied. The relationship is in a range satisfying the above formula (2), and when the second coating liquid layer 45 is applied, the moving speed of the object 31 and the interface 35b between the first coating liquid layer 35 and the second coating liquid layer 45 are adjusted. The difference in the moving speed becomes smaller, so that the movement of the interface 35b can sufficiently follow the movement of the object to be coated 31. This makes it possible to apply the second coating liquid layer 45 without collapsing the first and second coating liquid layers 35 and 45.
Furthermore, it becomes possible to widen the range of application conditions for manufacturing conditions without collapsing.
Therefore, when it becomes possible to apply the next second coating liquid layer 45 on the first coating liquid layer 35 applied first, the coating which can suppress the collapse of these coating liquid layers is applied under a wide range of manufacturing conditions. get on.

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

According to the configuration described above, it is possible to more reliably apply the second coating liquid layer 45 without collapsing the first coating liquid layer 35 and the second coating liquid layer 45.

The manufacturing method of the coating film of this invention is the manufacturing method of the coating film using the said coating apparatus 1, and has the following steps:
Firstly, one or more first coating liquids 33 are discharged onto the coated object 31 for coating, and then on the one or more first coating liquid layers 35 that have not been cured and are relatively moved with the movement of the coated object 31. Then, the next second coating liquid 43 is discharged to apply the second coating liquid layer 45; and the first coating liquid layer 35 and the second coating liquid layer 45 are cured to obtain a coating film 50.

According to the configuration, since the second coating liquid layer 45 can be coated on the first coating liquid layer 35 using the coating apparatus 1 described above, it becomes possible to apply the first coating liquid layer 35 to be coated as described above. In the case of one second coating liquid layer 45, the coating can suppress the collapse of these coating liquid layers, and is performed under a wide range of manufacturing conditions.

As described above, according to this embodiment, a coating device and a method for manufacturing a coating film can be provided. The coating device and the method for manufacturing a coating film can coat the next coating liquid layer on the previously applied coating liquid layer. The coating for suppressing the collapse of these coating liquid layers can be performed under a wide range of manufacturing conditions.

Although the coating device and the method for manufacturing a coating film according to this embodiment are as described above, the present invention is not limited to the above embodiment, and design changes can be appropriately made within the scope of the present invention.
Examples

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

Test example 1
(Materials used)
・ Coated object: PET (polyethylene terephthalate) film (brand name: DIAFOIL, manufactured by Mitsubishi Chemical Corporation)
・ First coating liquid: acrylic polymer (brand name: PARACRON, manufactured by Negami Industries, Ltd.)
Density and viscosity: as described in Table 1. Second coating liquid: acrylic polymer (trade name: ART CURE, manufactured by Genjo Industrial Co., Ltd.)
Density and viscosity: As described in Table 1, the density and viscosity are measured by the following measurement methods.

(Density measurement method)
Each of the first and second coating liquids having a fixed weight was put into a graduated cylinder, and the respective volumes were measured, whereby the densities of the first and second coating liquids were measured.

(Measurement method of viscosity)
Use a rheometer (type RS1, manufactured by HAAKE) equipped with a jig (cone plate with a cone diameter of 25 to 50 mm and a cone angle of 0.5 to 2 °) at a temperature of 21 to 25 ° C. The viscosity of each of the first and second coating liquids was measured at a shear rate of 100 (1 / s).

(Coating of the first and second coating liquid layers)
Using the coating device shown in FIG. 1, the coating of the first coating liquid layer and the coating of the second coating liquid layer were performed under the conditions described in Table 1. The coating state was 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 lip portion on the downstream side of the second coating portion were measured by the following methods.
The coating state was evaluated by the following method. The derivation of equation (2) is performed as follows.
The results are shown in Table 1, and Figs. 12 to 14. In FIG. 12, the length X of the downstream lip portion of the second coating portion is set to the x-axis, the dimensionless speed Y is set to the y-axis, and the lengths X and dimensionless speed Y The coating state at the time is shown on the graph. In FIG. 13, the range that is calculated in FIG. 12 is the closest to the poorly coated and well-coated plot group (that is, the boundary with the poorly-coated range in the well-coated range). The approximate lines are described in the graph on the graph in FIG. 12. FIG. 14 is a graph showing only an approximate line extracted from FIG. 13.

(Method for measuring thickness of first coating film layer and second coating film layer)
The first coating liquid layer and the second coating liquid are applied such that the width of the first coating liquid layer (the length in a direction perpendicular to the moving direction of the object to be coated is the same below) is larger than the width of the second coating liquid layer. Layer, and cured by drying, thereby forming a first coating film layer and a second coating film layer. Only the thickness of the formed first coating film layer was measured with a linear gauge (D-10HS, manufactured by Ozaki Corporation). On the other hand, the thickness of the area where the first coating film layer and the second coating film layer overlap is measured by the above-mentioned linear gauge, and only the thickness of the first coating film layer is subtracted from the measured thickness. This calculates the thickness of the second coating film layer. In this way, the thicknesses of the first coating film layer and the second coating film layer were measured.

(Method for measuring the distance (gap) between the second interface of the first coating liquid layer and the downstream lip)
The distance (gap) is measured by measuring the distance between the object to be coated 31 and the downstream lip with a taper gage, and subtracting the thickness of the first coating liquid layer from the measured distance. The thickness of the first coating liquid layer is calculated from the measured value of the first coating liquid layer and the volume concentration of the first coating liquid layer.

(Evaluation method of coating state)
The coating state was evaluated as described below.
The coating states of the first coating liquid layer and the second coating liquid layer were evaluated.
When the applied first coating liquid layer and the second coating liquid layer are obtained, and the obtained first and second coating liquid layers are visually observed, there are no defects in appearance and the desired first and second coatings can be obtained. In the case of a liquid layer, it was set to be very good, and was shown as "○".
When the applied first coating liquid layer and the second coating liquid layer are obtained, and the obtained first and second coating liquid layers are visually observed, streaks can be observed, and approximately first and second desired liquids can be obtained. In the case of the coating liquid layer, it was considered to be generally good and was expressed as "Δ".
As shown in FIG. 12, the first coating liquid layer is collapsed due to the ejection of the second coating liquid layer, and the second coating liquid layer is also collapsed along with this, so that the desired first and second coatings cannot be obtained. In the case of a liquid layer, it was set as "bad" and indicated by "x".

(Derivation method of equation (2))
The results of Table 1 are brought into the above-mentioned formula (1), and each dimensionless velocity is calculated.
Let the obtained dimensionless speed be the y-axis and the length of the downstream lip portion be the x-axis. The length of each dimensionless speed and the length of the downstream side lip corresponding to each dimensionless speed are marked with The results of the coating state are plotted and plotted to obtain the graph of FIG. 12.
Then, in FIG. 12, in each of the downstream-side lip portions, the plot closest to the indication that the coating state is bad (the plot indicated by “×”) and the plot that indicates that the coating state is good (by the “ "Bold line ○" is plotted), and the selected plot group is approximated by a quadratic equation. As a result, as shown in Figs. 13 and 14, a formula (2 ).

[Table 1]

From the graphs shown in FIGS. 12 to 14, it can be seen that the coating state can be changed by changing the range of X and Y above the approximate formula by Y, that is, coating and forming to satisfy X and Y of the formula (2). Well.
In addition, even in the case where a plurality of first coating liquid layers are first applied, the first coating liquid layer and the second coating liquid layer can be made by coating so that X and Y satisfy the formula (2). The coating state becomes good.

Test example 2
The effect of the length of the lip portion downstream of the coating portion on the liquid bead pressure was investigated by coating a coating liquid layer on the object to be coated.
(Materials used)
・ Coated object: PET (polyethylene terephthalate) film (brand name: DIAFOIL, manufactured by Mitsubishi Chemical Corporation)
・ Coating liquid: acrylic polymer (trade name: ART CURE, manufactured by Negami Industry Co., Ltd.)
Weight concentration: 50wt%
Density: 960kg / m ³
Viscosity: 1.22Pa. s
The density and viscosity are measured by the above-mentioned measurement method.

(Coating of the coating liquid layer)
Using the coating apparatus shown in FIG. 1, the object to be coated was directly coated from only the second coating section. Specifically, the distance (gap) between the object to be coated and the downstream lip portion of the second coating portion in each of the cases where the length of the downstream lip portion of the second coating portion is 0.2 mm and 3 mm under the following conditions ) Perform various changes between 50 and 250 μm to perform coating of a single coating liquid layer on the object to be coated, measure the bead pressure of the coating liquid during coating, and evaluate the coating state of the coating liquid layer.
Moving speed of coated object: 10m / min
Coating liquid layer thickness: 70 μm

The bead pressure of the coating liquid was measured by the following method. The coating state was evaluated by the method described above.
The results are shown in FIG. 15.

(Method for measuring liquid bead pressure)
The coating liquid is discharged from the second coating portion while the gap is sufficiently set so that the coating liquid discharged from the second coating portion does not reach the object to be coated. Is discharged in the case of an object), and the pressure P ₀ of the coating liquid supplied to the second coating section at this time is measured. On the other hand, in a state where the gaps are adjusted as described above, the coating liquid is discharged from the second coating section toward the object to be coated (arrives to the object to be coated, and the coating liquid is applied to the object to be coated). The pressure P ₁ of the coating liquid supplied to the second coating section was measured. Then, the pressure P _{0 is} subtracted from the pressure P ₁ to measure the bead pressure (P ₁ -P ₀ ) of the coating liquid.

As shown in FIG. 15, the smaller the length of the downstream lip portion of the second application portion, the larger the range of the gap that can be applied.
Therefore, it can be seen that the smaller the length of the downstream lip portion of the second application portion, the wider the range of application conditions that can be applied.

Although the embodiments and examples of the present invention have been described as above, the features of the respective embodiments and examples may be appropriately combined from the beginning. In addition, the embodiments and examples disclosed this time are illustrative in all points and should not be considered as limiting structures. The scope of the present invention is not the above-mentioned embodiments and examples, but is expressed by the scope of patent application, and is intended to include all meanings and changes within the scope equivalent to the scope of patent application.

1‧‧‧ coating device

5‧‧‧The first coating section (coating section)

6, 16‧‧‧ upstream module

7, 17‧‧‧ downstream module

6a, 16a ‧‧‧ upstream side lip

7a, 17a ‧‧‧ downstream side lip

8, 18‧‧‧ slit

9, 19‧‧‧ branch

15‧‧‧Second coating section (coating section)

25‧‧‧ support

27‧‧‧Cure Department

31‧‧‧ Coated

33‧‧‧The first coating liquid

35‧‧‧The first coating liquid layer

35a, 35b‧‧‧ interface

37‧‧‧The first coating film layer

43‧‧‧Second coating liquid

45‧‧‧Second coating liquid layer

47‧‧‧The second coating film layer

50‧‧‧ coated film

S‧‧‧ area

M‧‧‧ direction of movement

X‧‧‧ length

Y‧‧‧Dimensionless speed

FIG. 1 is a schematic side view showing a coating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side view schematically showing an example of the first and second coating liquid layers applied by the coating apparatus of the embodiment.

FIG. 3 is a schematic side view schematically showing an example of the first and second coating liquid layers applied by the coating apparatus of the embodiment.

FIG. 4 is a schematic side view schematically showing an example of the first and second coating liquid layers applied by the coating apparatus of the embodiment.

FIG. 5 is a schematic side view schematically showing the periphery of the second coating section in the coating apparatus of FIG. 1 together with the moving speed of the first coating liquid layer.

FIG. 6 is a schematic side view showing an enlarged region S of FIG. 5.

FIG. 7 is a schematic side view schematically showing a force applied to the first coating liquid layer of FIG. 5.

FIG. 8 is a schematic side view schematically showing the periphery of the second coating portion arranged to discharge the second coating liquid downward in the vertical direction together with the gravity applied to the first coating liquid layer.

FIG. 9 is a schematic side view schematically showing the periphery of the second application portion when the second application liquid layer is applied to the plurality of first application liquid layers, together with the moving speed of the first application liquid layer.

FIG. 10 is a schematic side view schematically showing the plurality of first coating liquid layers of FIG. 9 as one coating liquid layer as a whole.

11 is a schematic side view schematically showing a state where the first coating liquid layer and the second coating liquid layer have collapsed.

12 is a graph showing the relationship between the length (X), the dimensionless speed (Y), and the coating state at each X value and the Y value of the downstream lip portion of the second coating portion in Test Example 1. FIG.

FIG. 13 is a graph obtained by adding an approximate expression and an approximate line calculated from the graph of FIG. 12 to the graph of FIG. 12.

FIG. 14 is a graph in which an approximate expression and an approximate line are extracted from the graph of FIG. 13 and displayed.

FIG. 15 shows the distance (gap) between the second interface of the first coating liquid layer and the downstream lip, the length of the downstream lip, and the beads applied to the first coating liquid layer in Test Example 2. ) A graph of the relationship of stress.

Claims (3)

A coating device includes a coating section, wherein the coating section firstly spit out one or more first coating liquids on a coating object to be coated, and then moves one of the first coating liquid which has not yet cured and moves relatively with the movement of the coating object. The second coating liquid layer is discharged onto the more than one first coating liquid layer to apply the second coating liquid layer, and the coating device is configured to cure the first coating liquid layer and the second coating liquid layer to form a coating film. The coating portion is configured to have an upstream lip portion and a downstream lip portion, and the upstream lip portion and the downstream lip portion are arranged to form slits by being separated from each other in the moving direction of the object to be coated, so that The slit discharges the second coating liquid on the first coating liquid layer, and the coating device is configured to set the moving speed of the object to be coated to u _w (m / s), and the sum of the first coating liquid layer and The moving speed at the interface of the second coating liquid layer is set to u _c (m / s), and the ratio of u _c to u _w is set to the dimensionless speed (-) represented by the following formula (1). Further, the length of the downstream lip in the moving direction is set X (mm), and the speed the dimensionless is Y, so that the X and the Y satisfy the following equation (2): [Formula 1] μ _pre : the smallest viscosity (Pa.s) among the viscosities of the one or more first coating liquids μ _c : the viscosity (Pa.s) of the second coating liquid h _G : the interface and the downstream lip Distance (m) h _pre : the total thickness of the one or more first coating liquid layers (m) ρ _pre : the largest density (kg / m ³ ) among the densities of the one or more first coating liquids g : Acceleration of gravity (m / s ² ) [number 2] . The coating device according to claim 1, wherein X is 0.1 or more and 4 or less. A method for manufacturing a coating film is a method for manufacturing a coating film using a coating device such as the item 1 or 2 and has the following steps: Firstly, one or more first coating liquids are discharged on the object to be coated, and then the next one or more first coating liquid layers that have not been cured and are relatively moved with the movement of the object to be coated are discharged. A second coating liquid to coat the second coating liquid layer; and The first coating liquid layer and the second coating liquid layer are cured to obtain a coating film.