JP2006314995A - Knife coating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a knife coating apparatus capable of coating of a thin film even with a high-viscosity coating liquid. <P>SOLUTION: The apparatus has (1) a backup roll in which parts of the peripheral surface coming in contact with a substrate to be carried are composed of an elastic material and (2) a coating knife which forms a liquid-supplying section along the transverse direction of the substrate on the substrate carrying path, has a wedge shape so as for the liquid-supplying section to decrease in the volume of the liquid pool from the inlet to the outlet for the liquid and can increase the spacing between the backup roll and the tip of the liquid outlet of the knife or decrease the spacing relative to the backup roll having a surface of an elastic material so as to adjust the elastic backup roll through pressurization through the coating substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a knife coating apparatus for uniformly forming a coating liquid on a surface of a base material supported on an outer peripheral surface of a backup roll and forming a thin film.

In this type of conventional knife coating equipment, the backup roll is made of a rigid body such as steel, the backup roll is polished with high precision, the back surface of the substrate to be conveyed is supported, and the distance from the knife tip is used as a reference. It was. In addition, these rigid back-up rolls have run out of the outer peripheral surface of about 1 μm regardless of how accurately they are polished, and the bearing that supports the roll has also experienced several μm of runout. . For this reason, with these conventional knife coating apparatuses, it was difficult to set the distance between the knife tip and the substrate to 1 μm or less.

Problems to be solved by the invention

As described above, in a conventional knife coating apparatus using a backup roll, a limit is mainly imposed on the swing of the backup roll. Therefore, the distance between the knife tip and the substrate surface cannot be made minute, and as a result, the minimum coating is performed. The work thickness was 3 μm or more, and there was a problem that thin film coating of about 1 μm could not be performed.

Means to solve the problem

The present invention forms a liquid supply part along the transverse direction of the base material on the back-up roll in which the contact surface with the base material for transporting the base material on the outer peripheral surface is made of an elastic body, and the base material transport path In addition, the liquid supply portion has a wedge shape so that the volume of the liquid reservoir decreases from the liquid inlet toward the outlet, and the interval between the backup roll and the knife liquid outlet tip increases, and the surface is elastic. It is characterized in that there is provided a coating knife that can be adjusted to a minus interval with respect to the backup roll as a body and can pressurize and adjust the elastic backup roll via a coating substrate.

By using an elastic body on the surface of the backup roller and the base material contact area and using a knife with a wedge-shaped liquid reservoir, the tip of the knife and the elastic body can be backed up without being affected by minute vibrations of the backup roller. The distance from the substrate surface supported by the roll can be reduced.

Specifically, the coating liquid pressurized from the outside is supplied to the liquid reservoir formed by the wedge-shaped liquid reservoir of the knife and the backup roll, the backup roll is rotated, and the base supported by the backup roll is supplied. While the material is being conveyed, the tip of the knife is moved so that the space between the surface of the substrate and the tip of the knife is brought into close contact via the substrate supported by the backup roll, and the pressure is applied using a pressurizing device equipped on the knife. The interval is made negative by pressing.

The backup roll is elastically deformed to the state where the pressure applied to the knife tip is balanced by the elastic action, and as a result, the knife tip and the substrate surface are in close contact with each other, but from the knife liquid reservoir to the knife tip. A minute coating liquid film is formed between the tip of the knife and the substrate surface by the pressure of the coating liquid supplied under pressure from a wedge-shaped knife liquid reservoir whose volume gradually decreases. This film thickness varies depending on the pressure of the coating liquid supplied under pressure, the pressure applied to press the knife tip in the direction of the backup roll, and the elastic coefficient of the backup roll. It becomes a constant relationship. As a result, thin film coating by knife coating with a coating film thickness of about 1 μm, which was impossible with the conventional method, became possible.

Since it is difficult to change the elastic modulus of the backup roll, it is necessary to adjust the film thickness as a certain value, specifically by adjusting the knife pressure and the coating liquid supply pressure. I can do it.

FIG. 1 shows an example of an embodiment of the knife coating apparatus of the present invention. In this embodiment, a lever-type pressurizing device is used as the knife pressurizing device. This is because the knife tip can be finely adjusted compared to a direct-acting pressure device, and when the unexpected force applied to the knife tip is applied, the knife tip can be directly adjusted by the effect of the lever ratio. Although it is used because it is easier to move than the dynamic type, the pressure method of the knife is not limited to the lever type.

In an example of thin film coating using a conventional backup roll type knife coating apparatus, the test result with a steel backup roll of φ120 using a coating liquid with a viscosity of 3000 mPa · s was that the limit of the minimum thin film was 3 μm. . Although the run-out of the backup roll in this test was 1 μm or less, it was difficult to apply a thin film of 3 μm or less. However, in the coating test using the elastic body backup roll of the present invention, the same viscosity liquid was used, and in the backup roll diameter φ120 test, thin film coating up to 1 μm was possible.

The invention's effect

As described in the examples, knife coating using a rigid backup roll is affected by the viscosity of the coating solution, particularly when the film coating is from several hundred mPa · s to several thousand mPa · s. 5 μm was the mechanical limit. However, in the knife coating apparatus according to the present invention, a coating of 1 μm can be realized with a coating liquid having a relatively high viscosity of 3000 mPa · s, exceeding the limit of conventional thin film coating.

It is an example of embodiment in the knife coating apparatus which concerns on this invention, and is a cross-sectional view which shows the relationship between a back roller, a knife, and a pressurization apparatus. 1 shows an example of an embodiment in a knife coating apparatus according to the present invention, and shows a state in which a knife is pressed by a pressurizing device and is pressure-bonded to a backup roll. 1 shows an example of an embodiment in a knife coating apparatus according to the present invention, and shows a state where a knife is spaced between a backup roll and a knife by a knife opening operation of a pressurizing device. The knife coating apparatus which concerns on this invention shows an example of embodiment, a knife is pressurized with a pressurization apparatus, the backup roll which is an elastic body elastically deforms, and a coating liquid is supplied from a coating liquid supply port The pressure is supplied, guided to the liquid reservoir at the tip of the knife, and is further pressurized from the inlet to the tip of the liquid reservoir to be coated on the substrate.

Explanation of symbols

1. 1. Backup roll 2. Coating knife 3. Pneumatic cylinder for knife pressurization 4. Knife fixing and moving lever 5. Lever fulcrum Base material 7. Guide roll8. 8. Coating liquid supply port 9. Liquid reservoir portion for uniform coating liquid 10. Knife tip portion liquid reservoir portion Coating liquid reservoir member A, knife tip liquid reservoir inlet part B, knife tip liquid reservoir outlet part

Claims (1)

  The contact surface with the base material for transporting the base material on the outer peripheral surface forms a liquid supply portion along the transverse direction of the base material on the base material transport path, and a backup roll made of an elastic body, The liquid supply part has a wedge shape so that the volume of the liquid reservoir decreases from the liquid inlet toward the outlet, the distance between the backup roll and the knife liquid outlet tip increases, and the surface is an elastic body. A knife coating apparatus comprising a coating knife that can be adjusted to a negative interval with respect to a backup roll and pressurize and adjust the elastic backup roll via a coating substrate.

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