JP4374647B2 - Coating device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating apparatus (die coater) provided with a die configured to prevent adhesion of a cured product due to drying of a coating liquid in a slit formed inside when coating is interrupted.
[0002]
[Prior art]
When performing the operation of intermittently applying the same type of coating solution, the conventional die coater attaches a cover or tape to the slit tip (discharge port) when coating is interrupted to prevent drying and hardening of the coating solution. ing.
[0003]
[Problems to be solved by the invention]
In the above-described prior art, the performance of the coating solution for preventing drying and curing is insufficient, and the coating solution near the slit tip is dried and cured.
Therefore, when the coating is resumed, the dried and hardened material inside the slit must be removed with a film impregnated with a solvent.
Furthermore, when the coating solution is fast and hard to dry, and the die has a very narrow slit, a film impregnated with a solvent cannot be inserted, and the dried and hardened product near the slit exit becomes an obstacle, resulting in discharge unevenness. In addition, there is a problem that streaks are generated on the coating surface.
[0004]
The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to provide a die having a configuration in which adhesion of a cured product due to drying of a coating liquid is prevented in a slit formed inside when coating is interrupted. Providing a coating apparatus (die coater) comprising:
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the means provided by the present invention includes:
A coating device in which a flat and wide slit extending from the first manifold and the first manifold to the discharge port is formed inside the die , and a die formed by forming a second manifold in the slit is disposed between the left and right side plates. In
A solvent supply pipe that supplies a solvent for preventing adhesion of a cured product due to drying of the coating solution is installed so as to be electrically connected to the second manifold through a solution supply port provided in one side plate .
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a sectional view showing an embodiment of a die in the coating apparatus of the present invention, and FIG. 2 is a flow sheet showing the configuration of the coating apparatus of the present invention including a solvent supply pipe.
[0007]
The die is arranged between the left and right side plates 9. Inside the die 1, a flat and wide slit 3 extending from the first manifold 2 to the discharge port 4 and a second manifold 5 in the middle of the slit are arranged. It is the formed structure.
[0008]
The side plate 9 is provided with a solution supply port 6 installed so as to conduct to the second manifold 5, and the solution supply port 6 (corresponding to a white circle in the second manifold 5 in FIG. 1) It is connected to the solvent supply system 14 through the pipe 10 and the valve 11 which are as short as possible.
The “solvent supply pipe” of the present invention in this embodiment includes a solution supply port 6, pipes 10 (a to c), a valve 11, and a solvent supply system 14.
[0009]
The shape of the die that can be used in the present invention is not particularly limited as long as it has two manifolds of a first manifold and a second manifold.
Further, the shape of the manifold is not particularly limited as long as the liquid can be uniformly distributed in the lateral direction.
[0010]
The coating apparatus of the present invention is used as follows.
In the case where the same kind of coating liquid is applied intermittently, the supply of the coating liquid 7 to the first manifold 2 is stopped when the coating is interrupted, the valve 11 is opened, and the solvent 8 in the solvent tank 13 is removed. The liquid is sucked up by the supply pump 12 through the pipe 10 (c) and supplied to the second manifold 5 through the pipe 10 (b), the pipe 10 (a), and the solvent supply port 6.
Alternatively, the system may be such that the solvent 8 is supplied to the second manifold 5 by gravity except for the supply pump 12.
[0011]
The supplied solvent 8 removes the coating liquid 7 remaining in the slit 3 from the second manifold 5 to the discharge port 4, and fills the portion with the solvent 8, thereby adhering the dried cured product in the slit. Is prevented.
In order to avoid volatilization of the solvent 8 and maintain the filled state, it is preferable to supply the solvent 8 little by little after filling the solvent 8 so that the slit 3 is not exposed to the atmosphere.
[0012]
In the present invention, there are no particular limitations on the coating solution and solvent that can be used. It is particularly suitable when using a coating solution having a very narrow slit width and a fast drying and curing rate.
[0013]
【Example】
The present invention will be described in more detail based on examples.
Using the coating apparatus of the present invention when coating was interrupted under the coating conditions exemplified below, an attempt was made to prevent adhesion of a dried cured product to the slit formed in the die. No streaks were observed due to the dried cured product, and a good coating surface could be obtained.
<Example 1>
Coating liquid: polyurethane resin + curing agent (viscosity: 120 cps)
Solvent: Ethyl acetate Application width: 300mm
Slit width: 200 μm
<Example 2>
Coating solution: Sol solution (viscosity: 1 cps) obtained by hydrolyzing and dehydrating and condensing metal alkoxide compounds
Solvent: Isopropyl alcohol Application width: 300mm
Slit width: 40 μm
[0014]
On the other hand, in the case where the tip of the discharge port is covered with tape without trying to prevent drying (solvent supply) according to the present invention, and in the case where drying prevention is not attempted at all, streaks on the coating surface are resumed when coating is resumed (after 30 minutes of interruption) The number of generations was confirmed by visual confirmation. The comparison result is shown in FIG.
[0015]
FIG. 3 is a graph comparing the number of streaks generated at the start of coating (after interruption for 30 minutes) under the following conditions A to C for each of the above examples.
A: No drying prevention B: Covering the tip of the discharge port with a tape C: In the case of preventing adhesion of a dry cured product in the coating apparatus of the present invention.
Since the coating liquid used in Example 1 and Example 2 is very easy to dry and cure, the result is that the coating liquid is not discharged from the slit unless drying is prevented. There are several occurrences.
On the other hand, when the dried and cured product was prevented from adhering with the coating apparatus of the present invention, no streaking was observed and a good coating surface could be obtained.
[0017]
【The invention's effect】
As described above, according to the coating apparatus of the present invention, when coating is interrupted, it is easy and almost completely prevented that a cured product due to drying of the coating liquid adheres to the slit formed inside. Thus, after restarting the coating, the influence of the dried and hardened product of the coating solution that causes streaks on the coating surface is avoided.
[0018]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of a die in a coating apparatus of the present invention.
FIG. 2 is a flow sheet showing a configuration of a coating apparatus of the present invention including a solvent supply pipe.
FIG. 3 shows two examples of a case where the coating solution is not dried at all when the coating is interrupted (A), a case where drying is prevented according to the prior art (B), and a case where drying is prevented according to the present invention (C). Is a graph comparing the number of streaks when coating is resumed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Die 2 ... 1st manifold 3 ... Slit 4 ... Discharge port 5 ... 2nd manifold 6 ... Solution supply port 7 ... Application liquid 8 ... Solvent 9 ... Side plate 10 ... Pipe 11 ... Valve 12 ... Supply pump 13 ... Solvent tank 14 ... Solvent supply system

Claims (1)

A coating device in which a flat and wide slit extending from the first manifold and the first manifold to the discharge port is formed inside the die , and a die formed by forming a second manifold in the slit is disposed between the left and right side plates. In
A coating apparatus characterized in that a solvent supply pipe for supplying a solvent for preventing adhesion of a cured product due to drying of the coating liquid is installed so as to conduct to the second manifold through a solution supply port provided in one side plate. .

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