JP3203764B2 - Coating method and applicator using bar coater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is applied to the non-continuity of the substrate
Applying liquid using a bar coater
The present invention relates to a method and a coating device. More specifically, the present invention provides a coating method and a coating apparatus which are optimal as a method for coating a color filter material used for a liquid crystal color television or the like.

[0002]

2. Description of the Related Art A coating method using a bar coater is a general method for uniformly coating a flexible continuous film (web). Figure 3 is a schematic diagram of a case of applying the coating apparatus of the conventional bar coater discontinuity of the substrate. As a non-continuity of <br/> substrate, where a glass substrate is used. FIG.
(a), the bar coater 1 is rotating immersed partially into the coating solution pan 3 that the coating liquid 2 was accumulated. Bar coater 1
As shown in FIG. 3 (b) , a thin metal wire 5 is densely wound around a metal round bar 4 as shown in FIG. With the rotation of the bar coater 1 , the coating liquid 2 in the coating liquid pan 3 is picked up and applied to the glass substrate 6 running in the direction A to form a coating film 7. At this time, the coating liquid 2 is measured at the contact portion between the glass substrate 6 and the bar coater 1, and only a desired amount of coating is applied to the glass substrate 6 . Others form a liquid pool 8 together with the newly supplied coating liquid 2 , and the coating liquid 2 is applied to the glass substrate 6 via the liquid pool 8 in a steady state.

[0003]

[0007] However, gas with viscous with puddle content of the coating liquid 2 during the coating end
The film tended to adhere to the final end of the lath substrate 6 and become thick.

[0004] When the coating film becomes thicker, the ratio of the flat portion of the film thickness decreases, and the utilization rate of the glass substrate deteriorates. Further, when the coating film is patterned by photolithography, a portion having a large film thickness is difficult to remove by development and often remains.

In order to improve this, when the final end of the substrate approaches 10 to 20 mm , the rotation of the bar coater 1 is stopped, the pickup of a new coating liquid 2 is eliminated, and the coating of the final part of the substrate is performed by the liquid pool. It is thought to do. However, even in this case, the thick coating of the coating film is not significantly improved.

The present invention relates to such a conventional bar coater.
The problem was solved in that the coating method, for the purpose of improving the uniformity of the coating thickness of the discontinuity of the substrate.

[0007]

In order to achieve the above object, the technical means of the present invention is to provide a method for coating a final end of a non-continuous substrate by applying a coating liquid in a coating pan in which a bar coater is dipped.
To lower the liquid level of the cloth liquid with respect to the bar coater .

[0008]

According to the above construction, when the liquid level of the coating liquid drops, the liquid pool is pulled down due to the viscosity, and the substrate and the bar are pulled down.
The liquid pool at the contact portion with the coater is reduced, the amount of the coating liquid adhering to the final end of the substrate is reduced, the increase in the film thickness at the substrate end is small, and the uniformity of the film thickness is improved.

[0009]

EXAMPLES Hereinafter, a bar coater to an embodiment of the present invention in FIG. 1
Will be described based on a schematic diagram of a coating apparatus according to the present invention. Fig. 1 (a),
In (b) , the bar coater 11 is partially immersed in a coating liquid pan 13 in which a coating liquid 12 is stored and rotates. The coating liquid pan 13 is in communication with the auxiliary tank 19 via a pipe 20, and the coating liquid 12 can move between the coating liquid pan 13 and the auxiliary tank 19. The auxiliary tank 19 has a pressure adjusting device 21
Is connected to the piston wall 22 in the auxiliary tank 19 .
Can be moved left and right to adjust the pressure of the auxiliary chamber 23. Although not shown, a coating liquid supply device is separately provided so as to detect the liquid level of the coating liquid pan 13 before starting the coating on the glass substrate 16 and keep the liquid level at a predetermined value. I have.

[0010] With the rotation of the bar coater 11, the coating liquid 12 in the coating liquid pan 13 is picked up and applied to a glass substrate 16 running in the B direction to form a coating film 17.
The coating liquid is measured at the contact portion between the glass substrate 16 and the bar coater 11, and a liquid reservoir 18 is formed by the remaining coating liquid and the newly picked-up coating liquid.

[0011] from the substrate rear end is about 20mm, barcode
Rotation of the motor 11 is stopped, further work is pressure regulator 21, the piston wall 22 is moved to the left in the auxiliary tank 19,
The pressure in the auxiliary chamber 23 is reduced to a negative pressure. Since the coating liquid 12 in the coating liquid pan 13 is exposed to the atmosphere, the coating liquid pan 1
The third coating liquid 12 flows into the auxiliary tank 19 . Therefore, the liquid level in the portion of the coating liquid pan 13 where the bar coater 11 is immersed drops rapidly. At this time, apply the coating liquid in the liquid pool
Viscosity by flow down with decreasing liquid surface with the liquid, the coating amount of the coating is reduced in the final end, the thickness increase can be suppressed.

FIG. 2 shows the film thickness distribution of the coating film at the rear end of the substrate when the coating method of the present invention is used. Compared with the conventional coating method, the increase in the film thickness at the rear end portion is suppressed to be low, and the range of the flat portion of the film thickness is widened.

Here, the higher the speed at which the liquid level of the coating liquid pan 13 drops, the more easily the coating liquid in the liquid pool portion flows down. Therefore, the smaller the flow resistance of the path from the coating liquid pan 13 to the pipe 20, the smaller the flow resistance. Great effect.

However, when the liquid level of the coating liquid pan 13 falls, it is necessary to stop the function of the coating liquid supply device and not to supply a new coating liquid .

When the coating of the substrate is completed, the bar coater 11 is rotated again , and the coating liquid in the auxiliary tank 19 is transferred to the coating liquid pan.
The liquid level is maintained at a predetermined value before the next substrate is coated by operating the coating liquid supply device while moving to the position 13 . Many
When applying to several substrates continuously, apply the liquid level many times.
It will be lowered temporarily.

[0016]

As is apparent from the above description, according to the present invention, it is possible to obtain a coated substrate excellent in film thickness flatness without increasing the coated film thickness at the final end of the substrate. Therefore, using a wider range of non-continuity of the substrate as an active surface.
As a result, if the method of the present invention is used for forming pixels such as color filters of a color liquid crystal television , a uniform image can be obtained over the entire screen.

[Brief description of the drawings]

FIG. 1A shows a bar coater implemented by using the present invention .
Schematic cross-sectional view in schematic cross-sectional view (b) the rear stage in the stage prior to that coating apparatus

Shows the distribution of the coating thickness of the substrate rear end of the case of using the case and the coating method according to a conventional bar coater with a coating method according to a bar coater of the invention; FIG

FIG. 3 (a) Outline of a conventional coating apparatus using a bar coater
Sectional view (b) Cross section of both ends of bar coater

[Description of Signs ] 11 Bar coater 12 Coating liquid 13 Coating liquid pan 16 Glass substrate (non-continuous substrate) 19 Auxiliary tank 20 Piping 21 Pressure adjusting device

Continuation of the front page (56) References JP-U 4-99263 (JP, U) JP-B 50-3095 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B05C 1 / 02 102 B05D 1/28 G02B 5/20 101 G02F 1/1335 505

Claims (2)

(57) [Claims] 1. A bar immersed partially in the coating liquid in the coating liquid pan
Bar of applying the coating solution to the discontinuity of the substrate using a Kota
In the coating method using a coater, at the end of coating on the substrate, the level of the coating liquid in the portion where the bar coater is immersed is adjusted.
A bar characterized by being applied to a bar coater by lowering it.
-Coating method using a coater. 2. A bar immersed partially in the coating liquid in the coating liquid pan
Bar of applying the coating solution to the discontinuity of the substrate using a Kota
In a coating apparatus using a coater , a coating liquid
Detects coating liquid level in coating liquid pan before starting coating
A coating liquid supply device for maintaining the liquid level at a predetermined value by
The coating liquid can be alternately circulated through the piping to and from the cloth liquid pan.
An auxiliary tank, and the bar at the end of coating of the substrate.
A bar coater comprising: means for stopping the rotation of the coater; and a pressure adjusting device for lowering the pressure in the auxiliary tank to lower the liquid level of the coating liquid in the coating liquid pan .
That the coating apparatus.