JPH09253555A - Coating applicator and coating method and apparatus for production of color filter and production method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to stably form coating films of a uniform thickness on the surface of a member to be coated. SOLUTION: The coating applicator for executing the coating method to be used for production of color filters is formed of a slit die 40 for holding a shim 62 between a front lip 58 and a rear lip 60, a manifold 68 for a coating liquid formed within this slit die 40 and the shim 62 formed between the front and rear lips 58 and 60. The device has a slit which communicates with this manifold 68 and is regulated with the bottom end opening as a discharge port. The spacing between lip wetting surfaces 76 forming the front and rear lips 58 and 60 covers the entire area of the lip wetting surfaces 76 and is confined within 4% of the deviation from the reference value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method for discharging a coating liquid onto a surface of a member to be coated such as a flat sheet member to form a coating film of the coating liquid, and a coating apparatus and coating. The present invention relates to an apparatus and method for manufacturing a color filter for a color liquid crystal display using the method.

[0002]

Related Background Art A color filter for a color liquid crystal display has a fine grid pattern of three primary colors on a glass substrate as a member to be coated, and such a grid pattern is a black coating on the glass substrate. After the film is formed, the glass substrate is further coated with the three primary colors of red, blue and green.

Therefore, in order to manufacture a color filter, a coating step of sequentially coating a glass substrate with black, red, blue and green coating liquids to form respective coating films is essential. Conventionally, spinners, bar coaters or roll coaters have been used as coating devices in this type of coating process, but in recent years, in order to reduce the consumption of the coating liquid and improve the physical properties of the coating film, Use of a die coater is being considered.

The die coater is provided with an applicator for discharging a coating solution, a so-called slit die, and this type of slit die is disclosed, for example, in JP-A-2-207865 and JP-A-5-205.
Each is disclosed in Japanese Patent No. 104054. These known slit dies discharge the coating liquid from its discharge port,
A coating film of the coating liquid is formed on the surface of the web which is the member to be coated.

[0005]

Since all of the above-mentioned known slit dies form a coating film on the surface of a continuously running web, coating on a hard single-wafer member such as a glass substrate is required. It cannot be applied as it is to the formation of a film. Further, in order to obtain a uniform coating film, various contrivances have been adopted in the shape near the discharge port of the known slit die, but no consideration is given to the supply route of the coating liquid to the discharge port. Absent. Therefore, in the known slit die, the coating liquid cannot be satisfactorily guided over the entire area of the discharge port in the longitudinal direction, and uniform and stable coating film formation cannot be ensured.

The present invention has been made based on the above-mentioned circumstances, and its object is to form a uniform and stable coating film by which the coating liquid can be uniformly guided to the discharge port of the coating device. It is an object of the present invention to provide a coating apparatus and a coating method capable of performing the above, and a manufacturing apparatus and a manufacturing method of a color filter using the coating apparatus and the coating method.

[0007]

The above object is achieved by the present invention, and a coating apparatus according to claim 1 is a one-way type which receives a supply means for supplying a coating liquid and a supply of the coating liquid from the supplying means. The applicator capable of ejecting the coating liquid from the ejection port extending to and the at least one of the applicator and the member to be coated are relatively moved to form a coating film of the coating liquid on the surface of the member to be coated. A moving means, the applicator, a front lip and a rear lip coupled to the front and rear when viewed in the relative traveling direction of the member to be coated, and a slit formed between these lips, for guiding the coating liquid to the discharge port, The front and rear lip liquid contact surfaces that form the slits are provided, and the gap between the lip liquid contact surfaces of these lips has a deviation from the set value of 4% or less over the entire lip liquid contact surface. Fit in range It is.

According to the coating apparatus of the first aspect, the gap between the front and rear lips, that is, the gap between the liquid contact surfaces of the lips is maintained substantially uniform over the entire area of the liquid contact surfaces of the lips. It smoothly flows through the slit, and is uniformly discharged from the entire longitudinal direction of the discharge port. The coating device according to claim 2, wherein the front and rear lips are connected to the liquid contact surface of the lip and have opposite lip tip surfaces of the member to be coated, and the radius of curvature of the corner connecting the lip tip surface and the liquid contact surface of the lip. Is set in the range of 0.1 μm to 10 μm. According to the coating apparatus of the second aspect, the gap between the lip and liquid contact surfaces of the front and rear lips, that is, the slit gap can be made uniform over the entire area in the longitudinal direction of the ejection port.

According to a third aspect of the present invention, the flatness of the liquid contact surface of the lip is in the range of 0.01 μm to 5 μm, and the maximum height of the surface roughness is set in the range of 0.001 μm to 0.2 μm. There is. In the case of the coating device according to claim 3, since the lip-wetted surface has sufficient smoothness, the paint particles in the coating liquid do not aggregate to form a lump on the lip-wetted surface,
The coating liquid is smoothly guided to the discharge port through the slit.

In the coating device of claim 4, the straightness of the lip tip surface is in the range of 0.01 μm to 10 μm, and the maximum height Rmax of the surface roughness is set in the range of 0.001 μ to 0.2 μm. There is. According to the coating apparatus of claim 4, the clearance between the lip tip surface and the member to be coated is uniform over the entire longitudinal direction of the discharge port, and the lip tip surface is smooth and the wettability of the coating liquid is excellent. The meniscus of the coating liquid in the clearance is stably maintained, and a coating film having a uniform film thickness is formed on the surface of the member to be coated.

An applicator of a coating device according to a fifth aspect of the present invention includes a manifold formed between the front and rear lips, for supplying the coating liquid to the slit, and the length of the lip contact surface from the manifold to the discharge port. In (H), the central portion is constant when viewed in the longitudinal direction of the ejection port, and the end portions of the ejection port are shortened toward the end of the ejection port. According to the coating apparatus of claim 5, the flow path resistance of the coating liquid in the slit of the applicator is smaller on both end sides of the discharge port than on the central side thereof, whereby the entire discharge port in the longitudinal direction. The pressure in the slit becomes uniform, and the coating liquid is uniformly discharged from the discharge port.

In the applicator of the sixth aspect, the slit of the applicator is formed by a shim sandwiched between the front and rear lips, and in this case, the slit can be easily obtained. In the coating apparatus according to the seventh aspect, the inner width of the manifold formed by the shim is gradually reduced toward the lip tip surface when viewed in the longitudinal direction of the discharge port. In this case, the flow path of the coating liquid is narrowed toward the discharge port in the slit, and as a result, the pressure in the slit becomes uniform over the entire longitudinal direction of the discharge port, and the coating liquid is uniformly discharged from the discharge port. It

In the coating apparatus of claim 8, the lip contact surface is H
It has a Rockwell hardness in the range of RC30 to HRC70. In this case, the lip liquid contact surface is not easily scratched, and the slit gap formed between the lip liquid contact surfaces is stably maintained. In the coating device according to claim 9, the slit gap is 0.05 mm.
From 0.3 mm to 0.3 mm.In this case, the slit gap is optimal considering the thickness required for the color filter coating film and the processing and assembling properties of the applicator itself. .

A color filter manufacturing apparatus according to a tenth aspect includes the coating apparatus according to any one of the first to eighth aspects, and the color filter manufacturing apparatus discharges the coating liquid from the coating device. A predetermined coating film is sequentially formed on a transparent substrate such as a glass substrate to manufacture a color filter. The coating method according to claim 11 uses the coating device according to any one of claims 1 to 9 to relatively move at least one of an applicator and a member to be coated to apply a coating liquid to the surface of the member to be coated. To form a coating film. According to the coating method of claim 11,
Similar effects of the coating device according to the first to ninth aspects are exhibited.

According to a twelfth aspect of the method of manufacturing a color filter, a predetermined coating film is sequentially formed on a transparent substrate such as a glass substrate by using the coating method according to the eleventh aspect.
Manufacture color filters.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, there is shown a so-called die coater applied to the manufacture of a color filter, and the die coater includes a base 2. Base 2
A pair of guide groove rails 4 is provided on the upper side, and a stage 6 is disposed on these guide groove rails 4, and the upper surface of the stage 6 is configured as a suction surface. The stage 6 is reciprocally movable in the horizontal direction on the guide groove rail 4 via a pair of slide legs 8.

A casing 12 extending along the guide groove rail 14 is arranged between the pair of guide groove rails 4, and the casing 12 has a built-in feed mechanism.
The feed mechanism has a feed screw 14 composed of a ball screw as shown in FIG. 2, and the feed screw 14 is screwed into a nut-like connector 16 fixed to the lower surface of the stage 6. Extends through it. Both ends of the feed screw 14 are rotatably supported by bearings (not shown), and an AC servo motor 18 is connected to one end thereof. Although an opening is formed on the upper surface or side surface of the casing 12 to allow the connector 16 to move, the opening is omitted in FIG.

Although the stage 6 is configured to reciprocate here, the slit die 40 described later may be configured to reciprocate with respect to the stage 6 as well. The point is that at least one of the stage 6 and the slit die 40 should reciprocate. An inverted L-shaped sensor column 20 is arranged on one end of the upper surface of the base 2. The sensor column 20 has a tip extending above one of the guide groove rails 4, and an electric lifting actuator 21 is attached to the tip. A thickness sensor 22 is attached downward to the lift actuator 21, and a laser displacement meter, an electronic micro displacement meter, an ultrasonic thickness meter, or the like can be used as the thickness sensor 22.

Further, the sensor column 20 is provided on the upper surface of the base 2.
A die support 24 having an inverted L-shape is arranged on the center side of the base 2. The tip of the die post 24 is located above the pair of guide groove rails 4, that is, above the reciprocating path of the stage 6, and a lifting mechanism 26 is attached to the tip. Although not shown in detail in FIG. 1, the elevating mechanism 26 includes an elevating bracket,
This elevating bracket is attached to a pair of guide rods so as to be able to move up and down. A feed screw composed of a ball screw is arranged between the guide rods, and the feed screw is screwed into a nut portion of the lifting bracket and extends through the nut portion. An AC servomotor 30 is installed on the upper end of the feed screw.
The AC servomotor 30 is attached to the upper surface of the casing 28. The guide rod and the feed screw described above are the casing 2
8 and is rotatably supported via bearings.

A support shaft (not shown) is provided on the lifting bracket.
A U-shaped die holder 32 is rotatably mounted in a vertical plane via the guide groove rails 4 above the pair of guide groove rails 4.
It extends horizontally across the space. Further, a horizontal bar 36 is fixed to the lifting bracket above the die holder 32, and the horizontal bar 36 extends along the die holder 32. Pneumatic adjustment actuators 38 are attached to both ends of the horizontal bar 36, respectively. These adjustment actuators 38 have extendable and contractible rods that project from the lower surface of the horizontal bar 36, and the lower ends of these extendable and retractable rods are in contact with both ends of the die holder 32, respectively.

A slit die 40 as an applicator is mounted in the die holder 32. As shown in FIG. 2, the supply hose 4 for the coating liquid is supplied from the slit die 40.
2 extends, and the tip of the supply hose 42 is connected to the supply port of the electromagnetic switching valve 46 in the syringe pump 44. A suction hose 48 extends from a suction port of the electromagnetic switching valve 46, and the tip of the suction hose 48 is inserted into a tank 50 that stores a coating liquid.

The pump body 52 of the syringe pump 44 is
It is possible to selectively connect to one of the supply hose 42 and the suction hose 48 by the switching operation of the electromagnetic switching valve 46. The electromagnetic switching valve 46 and the pump main body 52 are electrically connected to a computer 54, and their operations are controlled by receiving a control signal from the computer 54. Computer 5
4, the lifting actuator 21 and the thickness sensor 22 described above are also electrically connected.

A sequencer 56 is also electrically connected to the computer 54 to control the operation of the syringe pump 44. The sequencer 56 includes an AC servomotor 18 of the feed screw 14 on the stage 6 side and an elevating mechanism 26,
Of the AC servomotors 18 and 30, the signal from the position sensor 59 for detecting the moving position of the stage 6, and the slit. A signal from a sensor (not shown) that detects the operating state of the die 40 is input, while the sequencer 56 outputs a signal indicating a sequence operation to the computer 54. Instead of using the position sensor 59, it is also possible to incorporate an encoder in the AC servo motor 18 and detect the position of the stage 6 by the sequencer 56 based on the pulse signal output from this encoder. It is also possible to incorporate control by the computer 54 into the sequencer 56.

Although not shown in the figure, the die coater has a loader for supplying a single-wafer member as a member to be coated on the stage 6, that is, a glass substrate A for a color filter, and the glass substrate A is removed from the stage 6. Unloaders are provided for these, and a cylindrical coordinate system industrial robot, for example, can be used for the main components of these loaders and unloaders.

As is apparent from FIG. 1, the slit die 40 described above has a direction orthogonal to the reciprocating direction of the stage 6,
That is, it extends horizontally in the width direction of the stage 6, and both ends thereof are supported by the die holder 32. Here, the horizontal adjustment of the slit die 40 can be performed by extending and retracting the extensible rods of the adjustment actuator 38 provided at both ends of the horizontal bar 36, and rotating the die holder 32 around its support axis.

Referring to FIGS. 3 and 4, details of the slit die 40 of the first embodiment are shown. This slit die 40 has a front lip 58 which is a long block.
And a rear lip 60. The front and rear lips 58, 60 are connected to each other via shims 62 in the front-rear direction of the stage 6 and are integrally connected to each other by a plurality of connecting bolts 64. The front lip 58 is arranged on the front side in the forward direction of the stage 6, and the rear lip 60 is arranged on the rear side.

More specifically, on the lower surface of the front lip 58, the portion close to the rear lip 60 further projects downward, while the rear lower portion of the rear lip 60 extends downward so as to be continuous with the lower surface of the front lip 58. An inclined surface is formed. Thus, a nozzle portion 66 extending in the width direction is formed at the center of the lower surface of the slit die 40.

As is apparent from FIG. 4, a manifold 68 is formed on the inner surface of the rear lip 60 at the center thereof. The manifold 68 is formed of a groove, and the groove extends horizontally in the width direction of the slit die 40. The groove wall located on the upper side of the manifold 68 inclines slightly downward from the center toward the left and right, and the groove wall on the lower side is not horizontal and inclines downward toward the shim 62 side. Has been done.

The manifold 68 is always connected to the above-mentioned coating liquid supply hose 42 via an internal passage 70, and the internal passage 70 is positioned at the upper center of the manifold 68. The shim 62 has a thin plate shape,
The manifold 68 itself and a portion corresponding to the lower portion of the manifold 68 are cut out. Therefore, the shim 62 has a vertical slit 72 (see FIG. 3) that connects to the manifold 68 between the front lip 58 and the rear lip 60.
The lower end opening of the slit 72 serves as a discharge port 74 that opens to the lower surface of the nozzle portion 66, that is, the lip lower surface 66a. Like the manifold 68, the discharge port 74 also extends in the direction orthogonal to the reciprocating direction of the stage 6, that is, in the width direction of the stage 6.

Front lip 58 and rear lip 60
In the inner surface of the, the portions that define the slits 72 are the lip liquid contact surfaces 76, and the gap between these lip liquid contact surfaces 76 (the gap between the slits 72) is the slit 72.
5% in the vertical direction (arrow B direction in FIG. 5) and the longitudinal direction of the discharge port 74 (E direction in FIG. 5), that is, the entire lip contact surface 76, the deviation from the reference value is 4%. It is contained within. Here, the gap of the slit 72, that is, its reference value is determined by the thickness of the shim 62,
The gap is set in the range of 0.05 mm to 0.3 mm, for example.

As shown in FIGS. 5 and 6, the discharge width of the discharge port 74 along the width direction of the stage 6 is the length between both ends of the manifold 68 (see FIG. 5). ), That is, the distance between the legs 62a of the shim 62 (see FIG. 6),
The ejection width is indicated by reference numeral W in FIGS.
In addition, in FIG. 6, the shim 62 is shown by hatching.

In order to give the above-mentioned precision to the gap of the slit 72, the flatness of the lip contact surfaces 76 of the front lip 58 and the rear lip 60 is in the range of 0.01 μm to 5 μm, and the surface roughness thereof is 0.001 μm. It is processed to fit within the range of 0.2 μm. Further, the nozzle portion 66
The lower surface 66a of the lip is horizontally arranged, and the straightness of the lower surface 66a of the lip to the liquid contact surface 76 of the lip is 0.01 μ.
The maximum height R of the surface roughness in the range from m to 10 μm
It is machined so that max falls within the range of 0.001 μm to 0.2 μm.

Furthermore, as is apparent from the enlarged cross section of FIG. 7, the front and rear lips 58 and 60 respectively have their liquid contact surface 76 and the lower lip surface 66a.
The corner portion connecting with and is set within the range of the radius of curvature R of 0.1 μm to 10 μm. Here, the maximum height Rmax of the surface roughness defined in the present invention is a numerical value measured according to JIS B 0601 (1982). That is, the maximum height Rmax
When sandwiching the extracted part with two straight lines parallel to the average line of the part extracted by the reference length from the sectional curve, the interval between these two straight lines is measured in the direction of the longitudinal magnification of the sectional curve and this value is It is expressed in meters (μm). Also,
The flatness and straightness defined in the present invention refer to JIS B 0621 (198
It is defined according to 2). That is, flatness refers to the amount of deviation from the geometrically correct plane of the planar feature, and straightness refers to the deviation from the geometrically correct line of the linear feature.

Next, the connecting structure of the front lip 58 and the rear lip 60 will be described in detail. Front lip 5
8 has a plurality of insertion holes 78 for connecting bolts 64.
And the through holes 78 are formed in the manifold 6
8 are arranged at equal intervals in the longitudinal direction. Also,
Insertion holes 80 for the connecting bolts 65 are also formed in the lower portions of both ends of the front lip 58 one by one. The shim 62 and the rear lip 60 have a front lip 58.
Through holes 82 and screw holes 84 are formed corresponding to the insertion holes 78 and 80, respectively. Therefore, the shim 62 is sandwiched between the front lip 58 and the rear lip 60, and the connecting bolts 64 and 65 are inserted into the through holes 78 and 80 of the front lip 58.
By screwing 5 into the screw hole 84 of the rear lip 60 through the through hole 82 of the shim 62, the front lip 58 and the rear lip 60 can be integrally connected via the shim 62.

Here, the connection bolt 64 is screwed, that is, tightened, by screwing the screw hole 8 of the rear lip 60 in FIG.
It is carried out in the order of the numbers # 1 to # 12 attached to No. 4. That is, first, the connecting bolts 64 screwed into the two screw holes 84 on both sides of the internal passage 70 of the rear lip 60 are sequentially tightened. After this, the connecting bolts 64 adjacent to both sides of the tightened connecting bolt 64 are alternately tightened left and right, and finally, the lower connecting bolt 65 is tightened.

When the connecting bolts 64 are tightened in this order, the central portion of the shim 62 is not bent, and the gap between the slits 72 can be obtained with high precision. In the drawing, the insertion hole 7 of the front lip 58 is shown.
8, the through hole 82 of the shim 62 and the threaded hole 84 of the rear lip 60 are shown only in FIGS. 4, 5 and 8.
Further, in FIG. 4, only a part of the insertion hole 78 and the through hole 82 is shown, and further, the screw hole 84 of FIG. 5 and FIG.
2 are different from each other, but this is merely for convenience of drawing and is not limited to the number of connecting bolts 64.

The slit 72 of the slit die 40 has a narrow gap. Therefore, in order to maintain the gap of the slit 72 with high accuracy, the hardness of the lip wetted surfaces 76 of the front lip 58 and the rear lip 60 is increased to increase the hardness of the lip. Scratches on the wetted surface 76 should be prevented. However, considering the processing of the insertion holes 78 and 80 and the screw holes 84 described above, the hardness of the liquid contact surface 76 of the lip is preferably in the range of HRC30 or more and HRC70 or less in terms of Rockwell hardness.

As shown schematically in FIGS. 3 and 4, a groove 86 is formed in the lower portion of the outer surface of the front lip 58, and the groove 86 is formed in the manifold 6.
8 extends parallel to 8 to form a neck portion 88 that divides the front lip 58 into an upper portion and a lower portion. The upper and lower portions of the front lip 58 are provided with a plurality of differential screws 90 arranged at equal intervals in the longitudinal direction of the manifold 68.
These differential screws 90 are arranged so as to avoid the connecting bolts 64 described above. By the tightening or loosening operation of each differential screw 90, the neck portion 88 of the front lip 58 can be elastically bent, whereby the gap of the slit 72, that is, the discharge port 74 can be finely adjusted.

Next, one process relating to the production of the color filter, that is, a coating method performed by using the above-mentioned die coater will be described. First, when the origin of each of the operating parts of the die coater is returned, the stage 6 detects the thickness sensor 22.
Of the slit die 40 through the suction hose 48 and the supply hose 42 from the tank 50.
The coating liquid fills the passage extending to the inside of the manifold 68 and the slit 72. Further, as a coating preparation operation, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump main body 52 and the suction hose 48 to the pump main body 52, and the coating liquid in the tank 50 is passed through the suction hose 48 to the pump main body 52. Perform suction operation. When a predetermined amount of the coating liquid is sucked into the syringe pump 44, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 and the supply hose 42.

In this state, the glass substrate A is supplied onto the stage 6 from a loader (not shown), and the glass substrate A is held on the stage 6 under suction pressure. Here, the glass substrate A has a width dimension wider than the discharge width W of the discharge port 74 in the slit die 40. When the loading of the glass substrate A is completed in this way, the thickness sensor 22 is lowered to a predetermined position, and the glass substrate A
Is measured by the thickness sensor 22. After the measurement, the thickness sensor 22 is raised to the original position.

When the loading of the glass substrate A is completed, the stage 6 is moved forward toward the slit die 40,
It stops just before the slit die 40. Thereafter, the slit die 40 is lowered, and the slit die 40, that is,
A predetermined clearance between the lower surface of the nozzle portion 66 and the upper surface of the glass substrate A, that is, several times the thickness T of the coating film to be formed, for example, a clearance H of 0.1 mm (see FIG. 7). ) Is secured. The clearance H takes the thickness of the glass substrate A measured by the thickness sensor 22 into consideration and is based on an output signal from a distance sensor (not shown) that measures the distance between the stage 6 and the slit die 40. It is set accurately by positioning the descending position of.

Next, the stage 6 is further moved forward, and at the time when the start line on the upper surface of the glass substrate A where the coating film formation should be started is positioned directly below the discharge port 74 of the slit die 40, Stop 6 once. Substantially simultaneously with the temporary stop of the stage 6, the syringe pump 44 starts the discharge operation of the coating liquid and supplies the coating liquid toward the slit die 40. Therefore, the coating liquid L is discharged onto the glass substrate A from the discharge port 74 of the slit die 40. Here, since the gap of the ejection port 74 is constant along the longitudinal direction of the slit die 40, that is, the reciprocating direction of the stage 6, the ejection port 74 is uniformly distributed along the start line of the glass substrate A. The coating liquid L is discharged, and as a result, a liquid pool C called a meniscus (see FIG. 7) is formed along the start line between the slit die 40 and the glass substrate A.

When the stage 6 is advanced in the forward direction at a constant speed while continuously discharging the coating liquid L from the discharge port 74 simultaneously with the formation of the liquid pool C as described above, FIGS. Apply the coating liquid L on the upper surface of the glass substrate A
The coating film D is continuously formed. In forming the coating film D, the start line of the glass substrate A is moved to the slit die 40 without temporarily stopping the forward movement of the stage 6.
The coating liquid L may be discharged from the discharge port 74 at the timing of passing through the discharge port 74.

As the stage 6 advances, when the finish line on the glass substrate A where the formation of the coating film D should be finished reaches the position immediately before the ejection port 74 of the slit die 40,
At this point, the discharge operation of the syringe pump 44 is stopped. In this way, even if the discharge of the coating liquid L from the discharge port 74 of the slit die 40 is stopped, the coating liquid D is consumed (squeegee) while the coating liquid in the liquid pool C on the glass substrate A is consumed (squeegee).
Formation continues until the finish line. The finish line on the glass substrate A is the slit die 40.
The discharge operation of the syringe pump 44 may be stopped at the time when the syringe pump 44 has passed through the discharge port 74.

At the time when the finish line on the glass substrate A passes through the discharge port 74 or at the time when the finish line passes, the suction operation of the syringe pump 44 is slightly performed, which causes the coating liquid L in the slit 72 of the slit die 40. Is sucked toward the manifold 68 side. At the same time, the slit die 40 is raised to the original position, and the process of discharging the coating liquid L from the slit die 40 is completed. Next, syringe pump 4
4 is given a discharge operation by the same amount as the suction operation to prevent air from remaining in the slit 72 of the slit die 40, and then the electromagnetic switching valve 46 of the syringe pump 44 connects the pump body 52 and the suction hose 48. The switching operation is performed accordingly, and the pump body 52 is caused to perform a suction operation of sucking the coating liquid in the tank 50 through the suction hose 48. When a predetermined amount of coating liquid is sucked into the syringe pump 44, the electromagnetic switching valve 46 of the syringe pump 44 is switched to connect the pump body 52 and the supply hose 42. The coating liquid L attached to the lower end surface of the slit die 40 is wiped off by a cleaner (not shown) at the raised position.

On the other hand, the forward movement of the stage 6 is continued even after the discharging step of the coating liquid L is completed, and when the stage 6 reaches the end of the guide groove rail 4, the forward movement is stopped. . In this state, the glass substrate A on which the coating film D is formed
Is removed from the stage 6 by an unloader after the suction by the suction is released. After this, the stage 6 is moved back and returned to the initial position shown in FIG. 1 to complete the series of coating steps. At the initial position, the stage 6 waits until a new glass substrate is loaded.

Regarding the formation of the coating film D on the above-mentioned glass substrate A, the lip liquid contact surfaces 76 of the front lip 58 and the rear lip 60 are mirror-finished such that their flatness and surface roughness have the processing accuracy in the above-mentioned range. And again,
The slit 72 in the slit die 40 has a gap of 4 from the reference value over the entire area of the lip wetted surface 76.
It is kept within%. Therefore, the manifold 68
The coating liquid L guided from the slit 72 to the slit 7
2 can be smoothly flowed in the entire area of the ejection port 74 in the longitudinal direction, and the ejection port 74 uniformly ejects it onto the glass substrate A. As a result, the film thickness T of the coating film D on the glass substrate A is also uniform in the width direction thereof, and defects such as vertical stripes due to the partial lack of the film thickness T do not occur in the coating film D. .

Further, since the lip wetted surface 76 is mirror-finished, the particles of the coating material in the coating liquid L do not stick to the lip wetted surface 76 and grow into lumps. Since the surface 76 has sufficient hardness, the lip-wetted surface 76 is not scratched. Therefore, the gap between the slits 72 can be maintained for a long period of time.

Since the flatness and surface roughness of the liquid contact surface 76 of the lip are within the above-mentioned range, the labor and cost required for processing them do not become excessive. On the other hand, since the lip lower surface 66a of the nozzle portion 66 is straight with respect to the lip liquid contact surface 76, the clearance H secured between the ejection port 74 and the glass substrate A is the ejection port 74.
Is uniform over the longitudinal direction of the
Since “a” also has a mirror-finished surface similar to the liquid contact surface 76 of the lip, the wettability with respect to the coating liquid L is excellent. Therefore, the meniscus C is easily formed between the lip lower surface 66a and the glass substrate A, the meniscus C becomes uniform in the longitudinal direction of the ejection port 74, and
Stable and maintained. Such a stable meniscus C
Contributes greatly to making the film thickness T of the coating film D uniform.

Further, the lip lower surface 66a and the lip liquid contact surface 7
Since the radius of curvature R of the corner portion between 6 and 6 is restricted to the above range, the corner portion becomes an acute angle, which also greatly contributes to the stability of the meniscus C. Further, also on the rear lip 60 side, since the corner between the lip lower surface 66a and the lip contact surface 76 is an acute angle, the liquid separation of the coating liquid L from the corner is stable, and this is also the coating film D. It is very useful in making the film thickness T of the film uniform.

Furthermore, as described above, when the opening edge of the discharge port 74 has an acute angle, the gap of the discharge port 74 can be easily measured, and the gap is accurately set to a constant value within the range of 0.05 to 0.3 mm. Can be set to. Here, if the gap is secured to be 0.05 mm or more, the gap can be easily adjusted, whereas if the gap exceeds 0.3 mm, the coating liquid in the slit 72 and the manifold 68 is discharged. It becomes difficult to hold the pressure sufficiently, and it becomes impossible to uniformly discharge the coating liquid L from the discharge port 74.

Next, referring to FIG. 9, there is shown a rear lip 61 applied to the slit die 40 of the second embodiment. Compared to the rear lip 60 described above, the rear lip 61 has a triangular slope 92 at the lower ends of both ends of the manifold 68.
Differs only in that it is provided. Each triangular slope 92
Is formed over the range of X from the end of the manifold 68, and the boundary with the above-mentioned lip liquid contact surface 76 is inclined downward toward the end of the manifold 68. Therefore,
In the lip liquid contact surface 76, the vertical length defined between the upper edge and the lower edge of the lip liquid contact surface 76 is such that both end portions of the discharge port 74 in the longitudinal direction gradually decrease toward the end.

The above-mentioned triangular slope 9 is formed on the rear lip 61.
When 2 is formed, the volume of the both ends of the manifold 68 is gradually increased toward the end by the amount of the triangular slope 92, so that the manifold 68 is supplied into the manifold 68 through the internal passage 70. When viewed in the width direction of the slit 72, the coating liquid L is actively guided to both side portions thereof, and the flow path resistance of the slit 72 becomes small at both end portions thereof. Therefore, when the coating liquid L is discharged from the discharge port 74, even if the discharge pressure is low, the discharge port 7
4, the discharge amount of the coating liquid L from both ends of the coating film 4 does not decrease as compared with the discharge amount from the center thereof, and the film thickness T on both sides of the coating film D is smaller than that in the center. Does not become thin.

Next, referring to FIG. 10, a shim 63 applied to the slit die 40 of the third embodiment is shown. The shim 63 is provided on the manifold 6 of both legs 62a.
The triangular protrusions 94 are provided below 8 and the triangular protrusions 94 gradually reduce the shim interval Y defining the width of the slit 72 from the upper edge to the lower edge. In this case, the ejection width W of the ejection port 74 is defined between the triangular protrusions 94.

By using the above-mentioned shim 63, when the coating liquid L is introduced from the manifold 68 into the slit 72,
Even if the discharge pressure is low, the coating liquid L flows toward the discharge port 74 so as to be narrowed, so that the discharge amount of the coating liquid L from both ends of the discharge port 74 is smaller than the discharge amount from the central portion. It does not decrease and the same advantages as in the case of the second embodiment can be obtained.

In the slit die 40 of the third embodiment as well, the rear lip 61 of the second embodiment is attached to the rear lip thereof.
Of course, can be used.

[0057]

[Examples and Comparative Examples] As described above, the high precision coating device, particularly the coating device of the color filter coating device, has a uniform coating thickness accuracy in the width direction of the coating device, and has a surface defect of the coating film. Two things that are not important are important. In Table 1, the width of the applicator varies from 280 mm to 400 mm, but the accuracy of the flatness, surface roughness, radius of curvature R, etc. of this applicator, and the accuracy of coating thickness when using this applicator And the relationship with surface defects.

[0058]

[Table 1]

As a result, it was found that the accuracy of coating thickness depends particularly on the lip gap. That is, it was found that the coating thickness accuracy was not satisfactory unless the deviation from the set value was within 4% over the entire area of the lip contact surface. To maintain this accuracy, the flatness of the lip contact surface should be 5 μm.
The following accuracy is required. On the other hand, if the precision is too high, the processing cost will increase, so the limit is 0.01 μm.

Next, it has been found that the surface defect depends on the surface roughness of the liquid contact surface of the lip and the radius of curvature R of the corner connecting the lip tip surface and the liquid contact surface of the lip. That is, if the surface roughness is poor, the coating liquid enters the gaps of the roughness, and the coating liquid aggregates to form foreign matter, which serves as nuclei to generate streaks, and sometimes the aggregates flow out, which becomes a foreign matter defect. .
JP-A-2-207865 and JP-A-7-256189 specify the centerline average roughness as the surface roughness in the applicator described in JP-A-7-256189, but in the ultra-precision coating such as a color filter, the lip contact surface It was not good because streaks were generated due to the slight scratches. After various evaluations, it was found that the maximum height of surface roughness should be controlled. As a result, it was found that the maximum height Rmax of the surface roughness is preferably 0.2 μm or less. On the other hand, if it is too good, the processing cost will increase, so 0.001 μm is the limit.

Further, the radius of curvature R of the corner portion is free of defects,
If it is uniform in the width direction of the applicator, it may be 10 μm or more. However, the larger the size, the more difficult it is to finish the width direction uniformly. Therefore, on the contrary, it was found that the variation in the smaller one or in the width direction was smaller. Therefore, the curvature radius R is optimally 0.1 to 10 μm. It goes without saying that it is satisfactory if it has the three features of flatness, maximum height of surface roughness, and radius of curvature of corners.

Here, as described above, the maximum height RMax of the surface roughness specified in the present invention is a numerical value measured according to JIS B 0621 (1982). That is, the maximum height R
Max is a value obtained by measuring the distance between these two straight lines in the direction of the longitudinal magnification of the section curve when sandwiching the section extracted by two straight lines parallel to the average line of the section extracted by the reference length from the section curve. It is expressed in meters (μm). The flatness and straightness defined in the present invention are JIS B 0621 (198
It is defined according to 4). That is, the flatness means the deviation from the geometrically correct plane of the planar body, and the straightness means the deviation from the geometrically correct straight line of the linear body.

On the other hand, as shown in Table 2 below, the conventional 30 μm
By improving the straightness that was, to 10 μm,
Thickness accuracy is improved. Therefore, it was found that the straightness of the lip tip surface is preferably in the range of 0.01 μm to 10 μm, and the maximum height Rmax of the surface roughness thereof is preferably in the range of 0.001 μm to 0.2 μm.

[0064]

[Table 2]

[0065]

As described above, according to the coating device and the coating method of claims 1 and 11 of the present invention, the gap between the slits of the applicator is made uniform over the entire area of the lip contact surface. Thus, the coating liquid is smoothly guided to the ejection port through the slit, and is evenly ejected from the ejection port. As a result, a coating film having a uniform film thickness can be formed on the surface of the member to be coated.

According to the coating apparatus of the second to fourth aspects, the flatness and surface roughness of the liquid contact surface of the lip and the straightness of the tip surface of the lip are regulated, so that the labor and cost required for the processing are excessive. It is possible to easily give a desired accuracy to the gap between the slits. According to the coating apparatus of the fifth aspect, even if the discharge pressure of the coating liquid is low, the flow path resistance at both ends of the slit is smaller than that at the center thereof, so that the coating liquid can be uniformly discharged from the discharge port. it can.

According to the coating apparatus of the sixth aspect, the slit can be obtained simply by inserting the shim between the front lip and the rear lip. According to the coating device of the seventh aspect, the same effect as that of the fourth aspect can be obtained by gradually reducing the interval between the shims defining the width of the slit toward the ejection port.

According to the coating apparatus of the eighth aspect, since the lip-wetted surfaces of the front and rear lips are made hard, it is possible to prevent the lip-wetted surfaces from being scratched and maintain the slit gap with high accuracy. According to the coating apparatus of the ninth aspect, the opening degree of the discharge port of the coating device can be suppressed within an appropriate range. According to the color filter manufacturing apparatus and manufacturing method of the tenth and twelfth aspects, it is possible to manufacture a high-quality color filter.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a die coater.

FIG. 2 is a schematic configuration diagram showing the die coater of FIG. 1 including a coating liquid supply system.

FIG. 3 is a side view showing a slit die partially broken away.

FIG. 4 is an exploded perspective view showing the slit die of the first embodiment.

FIG. 5 is an enlarged view of the rear lip shown in FIG.

FIG. 6 is a diagram illustrating a relationship between a rear lip and a shim.

FIG. 7 is an enlarged cross-sectional view of a slit die in a VII part in FIG.

FIG. 8 is a view for explaining the order of fastening the connecting bolts when assembling the slit die.

FIG. 9 is a perspective view of a rear lip of the second embodiment.

FIG. 10 is a perspective view showing a shim of a third embodiment together with a rear lip.

[Explanation of symbols]

 6 stage 14 feed screw 40 slit die (applicator) 44 syringe pump (supplying means) 50 tank 58 front lip 60 rear lip 62 shim 66a lip lower surface 68 manifold 72 slit 74 discharge port 92 triangular slope 94 triangular protrusion 76 lip wetted surface A Glass substrate (coated material)

Claims (12)

[Claims] 1. A supply means for supplying a coating liquid, an applicator capable of receiving the supply of the coating liquid from the supplying means and discharging the coating liquid from a discharge port extending in one direction, the coating device and a member to be coated. And a moving means for forming a coating film of the coating liquid on the surface of the member to be coated by relatively moving at least one of the coating device and the coating device, A front lip and a rear lip that are joined to each other in the front-back direction when viewed in a general advancing direction, a slit that is formed between the lips and that guides the coating liquid to the discharge port, and a lip liquid contact surface of the front and rear lips that forms the slit The coating liquid is characterized in that the gap between the lip liquid contact surfaces of each lip is within a range of 4% or less from the set value over the entire area of the lip liquid contact surfaces. Location. 2. The front and rear lips have a lip tip surface that is continuous with the lip liquid contact surface and faces the member to be coated, and a corner connecting the lip tip surface and the lip liquid contact surface is from 0.1 μm. The coating device according to claim 1, wherein the coating device has a radius of curvature in the range of 10 μm. 3. The flatness of the liquid contact surface of the lip is 0.01.
The coating apparatus according to claim 1 or 2, wherein the maximum height Rmax of the surface roughness is in the range of 0.001 µm to 0.2 µm, and the surface roughness is in the range of 5 µm to 5 µm. 4. The straightness of the lip tip surface is 0.01.
The coating apparatus according to any one of claims 1 to 3, characterized in that the maximum height Rmax of the surface roughness is in the range of 0.001 µm to 0.2 µm in the range of µm to 10 µm. . 5. Between the front and rear lips,
A manifold for supplying a coating liquid is formed in the slit, and a length (H) of the lip contact surface from the manifold to the discharge port is constant in a central portion when viewed in the longitudinal direction of the discharge port, The coating device according to any one of claims 1 to 4, wherein both end portions of the ejection port are set to be shorter toward the end of the ejection port. 6. The coating apparatus according to claim 1, wherein the slit is formed by a shim sandwiched between the front and rear lips. 7. The inner width of the manifold formed by the shim as seen in the longitudinal direction of the discharge port is gradually reduced toward the lip tip surface, according to claim 6. Coating equipment. 8. The coating apparatus according to claim 1, wherein the lip-wetted surface has a Rockwell hardness in the range of HRC30 to HRC70. 9. The gap between the slits is 0.05 mm to 0.3 mm.
It is set in the range of
8. The coating apparatus according to any one of 8. 10. A color filter manufacturing apparatus including the coating apparatus according to claim 1. 11. The coating apparatus according to claim 1, wherein at least one of the applicator and the member to be coated is relatively moved to coat the surface of the member to be coated with the coating liquid. A coating method comprising forming a film. 12. A method for manufacturing a color filter, which comprises manufacturing a color filter by using the coating method according to claim 11.