JP2000288453A - Coating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the sticking of a hardened material on a slit of a die due to the drying up of a coating liquid by mounting a solvent feed pipe for feeding a solvent to be led to a 2nd manifold. SOLUTION: The die is arranged between left and right side plates 9, a solution feed port 6 leading to the 2nd manifold 5 is provided in each side plate 9, the solvent feed port 6 is connected to a solvent feed line 14 through a short pipe 10 and a valve 11. At the time of interrupting the coating, the feed of the coating liquid 7 to a 1st manifold 2 is stopped, the solvent 8 in a solvent tank 13 is sucked by a feed pump 12 through a pipe 10 with a valve 11 opened and supplied to the 2nd manifold 5 through a pipe 10b, a pipe 10a and the solvent feed port 6 and the sticking of the dried hardened material in the slit from the 2nd manifold 5 to a discharge port 4 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus (die coater) provided with a die configured to prevent a cured product from being adhered to a slit formed therein by drying a coating liquid when coating is interrupted.

[0002]

2. Description of the Related Art When performing the work of intermittently applying the same type of coating liquid, a conventional die coater attaches a cover or a tape to the tip of a slit (discharge port) when coating is interrupted to dry the coating liquid. Prevents curing.

[0003]

In the above prior art,
The performance of preventing the coating solution from drying and hardening is insufficient, and the coating solution near the slit tip is dried and hardened. Therefore, at the time of resuming the coating, it is necessary to remove the dried and hardened material inside the slit with a solvent-impregnated film or the like.
Furthermore, when the coating solution is dried and hardened quickly and the die has a very narrow slit, the solvent-impregnated film cannot be inserted, and the dried and hardened material near the slit outlet becomes an obstacle, resulting in ejection unevenness. In addition, there is a problem that streaks and the like are generated on the coated surface.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to prevent adhesion of a cured product due to drying of a coating solution to a slit formed therein when coating is interrupted. An object of the present invention is to provide a coating apparatus (die coater) including a die having a configuration.

[0005]

Means for Solving the Problems In order to achieve the above object, a means provided by the present invention is to form a first manifold and a flat and wide slit from the first manifold to a discharge port in a die, A coating apparatus including a die formed with a second manifold in the slit,
A solvent supply pipe for supplying a solvent for preventing adhesion of a cured product due to drying of the coating liquid is provided so as to be electrically connected to the second manifold.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing one embodiment of a die in the coating apparatus of the present invention, and FIG. 2 is a flow sheet showing a configuration of the coating apparatus of the present invention including a solvent supply pipe.

The die is disposed between the left and right side plates 9, and inside the die 1, the first and second manifolds 2 and a flat and wide slit 3 extending from the first manifold to the discharge port 4, and a second and a third slit in the middle of the slit are provided. This is a configuration in which a manifold 5 is formed.

The side plate 9 is provided with a solution supply port 6 installed so as to be electrically connected to the second manifold 5. The solution supply port 6 (corresponding to a white circle in the second manifold 5 in FIG. 1). ) Indicates the shortest possible pipe 10 and valve 1
1 and connected to the solvent supply system 14. The “solvent supply pipe” of the present invention in the present embodiment includes a solution supply port 6, a pipe 10
(A to c), a valve 11, and a solvent supply system 14.

The shape of the die that can be used in the present invention is not particularly limited as long as it has two manifolds, a first manifold and a second manifold.
Also, the shape of the manifold is not particularly limited as long as the liquid can be uniformly distributed in the lateral direction.

The coating apparatus of the present invention is used as follows. In the case of intermittent application of the same type of coating liquid, when the coating is interrupted, the supply of the coating liquid 7 to the first manifold 2 is stopped, 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, a method may be adopted in which the solvent 8 is supplied to the second manifold 5 by gravity except for the supply pump 12.

With the supplied solvent 8, the coating liquid 7 remaining in the slit 3 from the second manifold 5 to the discharge port 4 is removed, and the portion is filled with the solvent 8.
The adhesion of the dried and cured product in the slit is prevented. Solvent 8
In order to avoid volatilization 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 does not come into contact with the atmosphere.

In the present invention, there are no particular restrictions on the coating liquids and solvents that can be used. Particularly, it is suitable when a coating liquid having a very narrow slit width and a high drying / curing rate is used.

[0013]

The present invention will be described in further detail with reference to examples. When the coating apparatus of the present invention was used to prevent the adhesion of the dried and cured product to the slit formed in the die when coating was interrupted under the following coating conditions, when the coating was resumed (after a 30-minute interruption), No good streaks were generated due to the dried and cured product, and a good coated surface could be obtained. <Example 1> Coating liquid: polyurethane-based resin + curing agent (viscosity: 120c)
ps) Solvent: Ethyl acetate Coating width: 300 mm Slit width: 200 μm <Example 2> Coating liquid: Sol solution obtained by hydrolyzing and dehydrating and condensing a metal alkoxide compound (viscosity: 1 cps) Solvent: isopropyl alcohol Coating width: 300 mm Slit Width: 40 μm

On the other hand, drying prevention (solvent supply) according to the present invention.
If the tip of the discharge port is covered with tape without trying
In the case where no prevention of drying was attempted, the number of streaks generated on the coated surface was visually checked at the time of resuming coating (after interruption for 30 minutes). FIG. 3 shows the comparison result.

FIG. 3 is a graph comparing the number of streaks generated at the start of coating (after a 30-minute interruption) under the following conditions A to C for each of the above Examples. A: No drying prevention B: Discharge port tip covered with tape C: When the dried and cured product is prevented from adhering with the coating device of the present invention

The coating liquid used in Examples 1 and 2 is very easy to dry and harden. Therefore, unless the drying is prevented, the coating liquid is not discharged from the slit.
When the tip of the discharge port is covered with the tape, several lines are generated. On the other hand, in the case where the dried and cured product was prevented from adhering with the coating apparatus of the present invention, no streak was observed and a good coated surface could be obtained.

[0017]

As described above, according to the coating apparatus of the present invention, when the coating is interrupted, the cured product due to the drying of the coating liquid can easily and almost completely adhere to the slit formed inside. This prevents the effect of the dried and cured product of the coating liquid, which causes streaks on the coating surface after the coating is resumed.

[0018]

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one 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 a case where no coating liquid is prevented from being dried at all (A), a case where drying is prevented by the conventional technique (B), and a case where drying is prevented by the present invention (C) when the coating is interrupted.
7 is a graph comparing the number of occurrences of streaks at the time of resuming coating when performing the examples.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Die 2 ... 1st manifold 3 ... Slit 4 ... Discharge port 5 ... 2nd manifold 6 ... Solution supply port 7 ... Coating liquid 8 ... Solvent 9 ... Side plate 10 ... Tube 11 ... Valve 12 ... Supply pump 13 ... Solvent tank 14 ... Solvent supply system

Claims (1)

[Claims] A first manifold and a first manifold inside a die.
In a coating apparatus provided with a die formed with a flat and wide slit extending from a manifold to a discharge port and a second manifold formed in the slit, a solvent for preventing adhesion of a cured product due to drying of a coating liquid is used. A coating apparatus characterized in that a solvent supply pipe to be supplied is installed so as to be electrically connected to a second manifold.