JPH09166879A - Method for applying coating liquid to band-shaped metallic sheet and coating applicator therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating applying method which eliminates the trouble in terms of safety of work and management of the device and obviates the occurrence of with clouding of a coating liquid by heating the squeeze rollers themselves and heating the coating liquid before supply onto a metallic sheet, thereby specifying the viscosity of the coating liquid at the time of the coating liquid is packed into the recessed parts of the metallic sheet surfaces. SOLUTION: The squeeze rollers 24, 26, back up rollers 18, 20, 22 and supply pipes 28, 30 are respectively heated, by which the UV resins on the metallic sheet 1 are heated. Then, the UV resins on the metallic sheet 1 are heated to a prescribed temp. by controlling the respective calorific values of the heater 46 and the heater 48, by which the viscosity of the UV resins is controlled to the extent of obviating the occurrence of the white clouding. The temp. of the UV resins is so controlled that the viscosity of the UV resins supplied onto the metallic sheet 1 at the time the UV resins are packed into the recessed parts of the metallic sheet surfaces attains a range of 15 to 60cps.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a color CRT, for example.
In the manufacturing process of shadow masks for semiconductors and lead frames for semiconductor manufacturing, a squeegee roller is used to apply the coating liquid on the surface of a thin metal plate, and an etching resistance layer is formed (backed) on one side of the thin metal plate. The present invention relates to a method for applying a coating liquid to a thin metal plate, and a device for applying the coating liquid to a strip-shaped thin metal plate used for carrying out the method.

[0002]

2. Description of the Related Art In recent years, a color CRT has been widely used as a display device such as a computer and a monitor in addition to a general color television picture tube for receiving television broadcasting. With such diversification of applications, there is an increasing demand for extremely high-definition image quality for color CRTs. Further, a shadow mask, which is one of the components of the color CRT, is required to have fine through holes that are uniform in size and shape. Particularly in a shadow mask for a high resolution color CRT, the diameter of the through hole is often smaller than the thickness of the shadow mask plate material (thin metal plate). If it is attempted to form such a through hole of the shadow mask by one etching, it is extremely difficult to form the through hole into a desired shape as designed, and only a shadow mask that cannot be practically used can be obtained. It is known empirically.

As one of the countermeasures against this, for example, USP.
No. 3,679,500 and Japanese Patent Publication No. 57-26345, etc., the etching process is divided into two steps and performed stepwise.
A step etching method is disclosed. In this two-step etching method, first, an etching solution is sprayed onto both sides or one side of a metal thin plate from a spray nozzle to a metal thin plate on which a resist film having a desired pattern image is formed on both main surfaces. Etching is performed, the etching is temporarily stopped before the through holes are formed in the metal thin plate, and the metal thin plate is washed with water and dried to form fine recesses on both sides or one side of the metal thin plate. Then, when both surfaces are etched, one of the surfaces is etched, and when one surface is etched, the etched surface is covered with an etching resistance layer. Next, the metal thin plate is sprayed with an etching solution from a spray nozzle onto the surface not covered with the etching resistance layer to perform the second etching,
The minute recessed portion formed on the one surface side and the minute recessed portion formed on the other surface side are communicated with each other. After completion of the etching, the etching resistance layer and the resist film are respectively peeled off from the surface of the metal thin plate, washed with water, and dried to obtain a metal thin plate having fine through-holes formed on both sides.

In the above-described two-step etching method, in order to form an etching resistant layer by a squeegee coating method using a solventless type coating solution having a high viscosity, for example, as disclosed in Japanese Utility Model Publication No. 6-33150. A coating device is used.

The coating device disclosed in Japanese Utility Model Laid-Open No. 6-33150 has a front side in the transport direction of the strip-shaped metal thin plate 1 as shown in FIG. 3 which is a perspective view of a main part and FIG. 4 which is a schematic side view. First squeegee roller 50 including a smooth roller
The second squeegee roller 52, which is a grooved roller, is arranged on the front side in the transport direction on the upper surface side of the thin metal plate 1. Further, a first backup roller 54 is provided on the front side of the first squeegee roller 50 in the transport direction of the thin metal plate 1, and a second backup roller 56 is provided between the first squeegee roller 50 and the second squeegee roller 52. , And a third backup roller 58 is arranged on the front side of the second squeegee roller 52 and on the lower surface side of the thin metal plate 1. Further, the first squeegee roller 50 and the second
A first supply pipe 60 and a second supply pipe 62 for supplying the coating liquid 64 onto the metal thin plate 1 are respectively arranged on the front side of the squeegee roller 52 in the transport direction of the metal thin plate 1. ing. The upper surfaces of the first, second and third backup rollers 54, 56 and 58 are respectively located above a horizontal plane including both lower surfaces of the first squeegee roller 50 and the second squeegee roller 52. The thin metal plate 1 is conveyed such that it is slightly downward and upward with respect to the horizontal plane.

The outer peripheral surface of the first squeegee roller 50 is
Depending on the viscosity of the coating liquid and the state of the surface of the thin metal plate 1, a smooth surface having a required surface roughness can be obtained.
The width of the groove cut on the outer peripheral surface of the squeegee roller 52 is
An appropriate setting is selected so that an etching resistance layer having a required film thickness is deposited and formed on the thin metal plate 1. Then, the metal thin plate 1 passes through the position while contacting the first squeegee roller 50, whereby the coating liquid 64 supplied onto the metal thin plate 1 from the first supply pipe 60 is applied to the surface of the metal thin plate 1. The large number of minute recesses formed are completely filled, and then the metal thin plate 1 passes through the position of the second squeegee roller 52 while contacting the second squeegee roller 52. The coating solution 64 supplied onto the metal sheet 1 is further applied to form an etching resistance layer having a desired thickness on the metal thin plate 1. As the coating liquid for forming the etching resistance layer, for example, UV resin (ultraviolet curable resin), paraffin, asphalt, lacquer or the like is used. In FIG. 3, reference numeral 66 is a flow guide plate for the coating liquid 64, and reference numeral 68 is a resist film that covers the image portion. Further, in FIG. 4, reference numeral 70 denotes an initial charging bucket, but the initial charging bucket 70 may not be provided.

When the coating liquid is applied to the surface of a thin metal plate by using the coating apparatus shown in FIGS. 3 and 4, and a large number of fine recesses formed on the surface of the thin metal plate are filled,
The filling property of the coating liquid into the fine recesses is improved, and the coating film having a sufficient thickness is deposited and formed on the surface of the metal thin plate.

By the way, when the metal thin plate 1 moves while contacting the first squeegee roller 50, a fine recess on the surface of the metal thin plate 1 is coated with the coating liquid, for example, the UV resin 64, supplied onto the metal thin plate 1. When the portion is filled with holes, as shown in FIG. 5A, the fine recessed portion 7 on the surface of the thin metal plate 1 is formed.
The air pool 74 inside 2 is extruded from the inside of the recess 72 by the UV resin 64 and replaces the UV resin 64, but the air extruded from the inside of the recess 72 becomes fine bubbles 76 and becomes a thin metal plate. Mix into the UV resin 64 on 1. At this time, if the viscosity of the UV resin 64 is appropriately low, as shown in FIG. 5B, the air bubbles 76 mixed in the UV resin 64 on the thin metal plate 1 are directed to the surface of the UV resin 64 toward the surface thereof. Moves, diffuses from the surface of the UV resin 64 into the air, and disappears from the UV resin 64 on the thin metal plate 1. However, if the temperature of the UV resin 64 is low and its viscosity is high,
The bubbles 76 remain confined in the UV resin 64 on the thin metal plate 1, and a large number of bubbles 76 are mixed in the UV resin 64, so that the UV resin 64 becomes clouded. Then, as shown in FIG. 5C, the concave portion 72 on the surface of the thin metal plate 1 is filled with the UV resin 64 in a state where the air bubbles 76 are still trapped. When the second etching is performed in this state, the trapped bubbles 7
6 causes the recess 72 to be etched, resulting in a so-called “white pin” in which the hole diameter size of the fine through hole becomes larger than the desired size.

In order to prevent the clouding phenomenon of the UV resin 64 described above, the viscosity of the UV resin 64 may be lowered by raising the temperature of the UV resin 64 on the metal thin plate 1. Therefore, conventionally, hot air is blown into the coating booth from a drying device disposed adjacent to the upstream side of the coating booth where the UV resin coating process is performed on the surface of the thin metal plate, so that the atmosphere inside the coating booth is increased. By raising the temperature, the squeegee roller, backup roller,
The entire coating apparatus including the coating liquid supply pipe and the initial charging bucket was heated.

[0010]

However, in the method of raising the ambient temperature in the coating booth to heat the entire coating apparatus, even an unnecessary portion is heated. Therefore, the ultrasonic sensor incorporated in the coating apparatus is used. However, this may lead to malfunction of precision equipment such as an air cylinder, and may bring about an adverse effect in terms of work safety and apparatus management because the entire coating booth becomes hot. In addition, the squeegee roller and the like cannot be sufficiently heated only by the hot air sent from the drying device into the coating booth, and the squeegee roller is heated by the upstream drying device to the thin metal plate that has been conveyed to the coating position. Only when they come into contact with each other and receive heat from the thin metal sheet, the metal sheet is heated to a required temperature. Therefore, the temperature of the squeegee roller and the UV resin in contact therewith does not rise so much for several tens of minutes immediately after the start of operation of the apparatus, so that the above-mentioned problem of the clouding phenomenon of the UV resin occurs.

The present invention has been made in view of the above circumstances, and promptly warms only a necessary portion of the coating apparatus, which may cause malfunction of precision equipment incorporated in the coating apparatus. To provide a coating method that does not cause a negative effect on safety of work and management of the device and does not cause a clouding phenomenon of the coating liquid when the coating liquid is applied to a thin metal plate by a squeegee roller, and It is an object of the present invention to provide a coating apparatus capable of suitably carrying out the coating method.

[0012]

According to the first aspect of the present invention,
The method of applying the coating liquid to the strip-shaped thin metal plate is a strip-shaped thin metal plate having a large number of fine recesses formed on the surface thereof, and a plurality of backup rollers arranged on the lower surface side thereof at a distance from each other. While supporting and transporting in the longitudinal direction, the coating liquid is supplied onto the thin metal plate, and the coating liquid is spread and spread on the surface of the thin metal plate by the squeegee roller arranged on the upper surface side of the thin metal plate. In the coating method for filling the concave portion formed on the metal thin plate, the squeegee roller itself is heated and the coating liquid before being supplied onto the thin metal plate is heated to form the concave portion on the surface of the thin metal plate. It is characterized in that the viscosity of the coating liquid at the time of filling the part is set to 15 to 60 cps.

According to a second aspect of the present invention, in a coating apparatus, three backup rollers are provided on the lower surface side of a strip-shaped metal thin plate having a large number of fine recesses formed on the surface thereof and spaced from each other. , Two squeegee rollers arranged on the upper surface side of the metal thin plate so as to be respectively located between the backup rollers, and the squeegee roller on the front side in the transport direction of the metal thin plate. An outer peripheral surface of the squeegee roller of the other of the squeegee rollers, the outer peripheral surface of the squeegee roller on the front side in the conveying direction of the thin metal plate being a smooth surface, and the outer periphery of the other squeegee roller. In a coating device having a large number of grooves formed on its surface, a roller heating means for heating the squeegee roller is provided, and a coating liquid supply pipe of the coating liquid supply means is heated. Characterized in that a heating means.

A coating apparatus according to a third aspect of the present invention is the coating apparatus according to the second aspect, further comprising roller heating means for heating the backup roller.

According to the coating method of the first aspect of the invention having the above-mentioned structure, the squeegee roller itself is heated and the coating liquid is supplied onto the thin metal plate in a heated state. Then, the coating liquid having a low viscosity of 15 to 60 cps is spread and spread on the surface of the metal thin plate by the squeegee roller, and is filled in the concave portion formed on the surface of the metal thin plate. Therefore, when the concave portion on the surface of the metal thin plate is filled with the coating liquid supplied onto the metal thin plate, the air is displaced by the coating liquid and pushed out from the concave portion to form fine air bubbles on the metal thin plate. Even if mixed in the coating liquid, the viscosity of the coating liquid is low, so that the bubbles mixed in the coating liquid diffuse from the coating liquid into the air and disappear. For this reason, the coating liquid on the thin metal plate does not have a clouding phenomenon.

When the coating apparatus according to the second aspect of the present invention having the above structure is used, the squeegee roller itself is heated by the roller heating means, and the coating liquid supply pipe is heated by the pipe heating means, so that the coating liquid is heated. Is
It is heated while passing through the coating liquid supply pipe, and is supplied onto the metal thin plate in a heated state. Therefore, the coating liquid whose temperature has risen and whose viscosity has become low is spread and spread on the surface of the metal thin plate by the squeegee roller, and is filled in the concave portions formed on the surface of the metal thin plate. For this reason, when the coating liquid supplied onto the thin metal plate fills the concave portion on the surface of the thin metal plate, air in the concave portion becomes fine bubbles and is mixed in the coating liquid on the thin metal plate. Since the air bubbles mixed in the coating liquid diffuse into the air from the coating liquid and disappear, it is possible to prevent the clouding phenomenon from occurring in the coating liquid on the thin metal plate.

In the coating apparatus according to the third aspect of the present invention, since the backup roller is further heated by the roller heating means, heat is not taken away by the metal thin plate coming into contact with the backup roller, and the metal thin plate is backed up. It is supplementarily heated by the rollers. Therefore, the coating liquid on the thin metal plate is heated more effectively, and the viscosity thereof is lowered.

[0018]

Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic front view showing an example of the structure of a coating device used for carrying out the coating method according to the present invention, showing the coating device together with a drying device, and a part of the coating device is shown in section. It is the represented figure.

In FIG. 1, the coating device 10 is arranged adjacent to the downstream side of the drying device 12 in the conveying direction of the strip-shaped metal thin plate 1. While passing through the drying device 12, the thin metal plate 1 is heated by blowing hot air onto the front and back surfaces from a plurality of blowing nozzles 14 provided on each of the upper and lower sides, and is heated to a certain temperature. The loaded state is carried into the coating booth 16 of the coating apparatus 10. The thin metal plate 1 carried into the coating booth 16 has a large number of fine recesses formed on its upper surface. On the lower surface side of the metal thin plate 1, three backup rollers 18, 20, 22 are arranged at a distance from each other in the transport direction of the metal thin plate 1, and the metal thin plate 1 has these backup rollers 18, 20. ,
It is supported by 22 and conveyed in the coating booth 16 in the longitudinal direction. Further, on the upper surface side of the metal thin plate 1, the first backup roller 18 on the front side in the transport direction of the metal thin plate 1 is provided.
The first squeegee roller 24, which is a smooth roller, is disposed between the second backup roller 20 and the second backup roller 20 in the center, and the second backup roller 20 in the center and the third backup roller in the front side in the transport direction. A second squeegee roller 26, which is a grooved roller, is disposed between the second squeegee roller 26 and the squeegee roller 22. Further, on the front side of the first squeegee roller 24 and the second squeegee roller 26 in the transport direction of the metal thin plate 1, a first supply pipe 28 for supplying a coating liquid, for example, a UV resin, onto the metal thin plate 1 and Second supply pipe 30
Each of the discharge ports is provided. Each of the supply pipes 28 and 30 is connected to a UV resin storage tank 32 by a flow path. Since these configurations are the same as those of the conventional coating apparatus described above with reference to FIGS. 3 and 4, further description will be omitted.

In this coating apparatus, three backup rollers 18, 20, 22 and two squeegee rollers 24,
Roller heating means for heating the respective 26 are provided. That is, as shown in FIG.
4 and 26 are formed so that the inside thereof is hollow, and axial ventilation passages 38, 38, 40 and 40 are formed in the support shafts 34, 34, 36 and 36 at both ends, respectively. The ventilation passage 3 of the support shafts 34, 36 at one end
8 and 40 are connected to the heated air supply pipe 42, respectively, and the ventilation paths 38 and 40 of the support shafts 34 and 36 at the other ends are connected to the exhaust pipe 44, respectively. The heating air supply pipe 42 is connected to the compressed air source by a flow path, and a heater 46 is inserted and connected in the middle of the pipe. The compressed air supplied from the compressed air source is heated by passing through the heater 46, and the heated air is supplied to the hollow portions of the squeegee rollers 24, 26 through the heated air supply pipe 42. Squeegee roller 2
The squeegee rollers 24 and 26 are heated by flowing heated air through the hollow portions 4 and 26. Although not shown in FIG. 2, the backup rollers 18, 20, 22 also have the same structure, and are heated by the heated air flowing through the hollow portions inside them. There is.

Further, in this coating apparatus, as shown in FIG. 1, each supply pipe 2 for supplying the UV resin onto the thin metal plate 1.
Pipe heating means for heating 8, 30 is provided.
That is, the heater 48 is provided so as to cover the supply pipes 28 and 30, and the heater 48 heats the supply pipes 28 and 30 to heat the UV resin flowing in the pipes. doing. In addition, in the method of adjusting the temperature of the UV resin stored in the storage tank 32, since the UV resin is stored in the storage tank 32 at a high temperature for a long time, the composition of the UV resin is changed and the performance is improved. Is deteriorated, which is not preferable.

As described above, in this coating device, the squeegee rollers 24 and 26 and the backup rollers 18 and 2 are used.
Nos. 0 and 22 and supply pipes 28 and 30 are respectively heated, so that the UV resin on the thin metal plate 1 is heated. Therefore, the heater 46 and the supply pipes 28, 30 which are connected to the heating air supply pipe 42 by insertion are connected.
The UV resin on the thin metal plate 1 is heated to a predetermined temperature by adjusting the amount of heat generated by the heater 48 provided so as to cover the UV resin, and the viscosity of the UV resin is adjusted to the extent that the clouding phenomenon does not occur. can do. In the coating method according to the present invention, the viscosity of the UV resin is 15 to 6 when the UV resin is supplied onto the metal thin plate 1 and filled in the recesses on the surface of the metal thin plate.
The temperature of the UV resin is adjusted so as to be in the range of 0 cps.

Using the coating apparatus shown in FIG. 1, the UV resin is heated to various temperatures to form an etching resistance layer (backing) on the thin metal plate in each case, and the viscosity and coating performance of the UV resin are set. Table 1 shows the experimental results for examining the relationship with. In Table 1, ⊚ indicates that the UV resin on the metal thin plate was not surely clouded, ○ indicates that the UV resin on the metal thin plate was not clouded by any means, and × is on the metal thin plate. It shows that the UV resin became cloudy.

[0025]

[Table 1]

As can be seen from the results shown in Table 1, the viscosity of the UV resin is 60 cps for both resins A and B.
When the UV resin is heated to the temperature as shown below, the clouding phenomenon does not occur in the UV resin on the thin metal plate. Further, when the viscosity of the UV resin is lower than 15 cps, liquid leaks from the flow guide plate (shown by reference numeral 66 in FIG. 3) and the etching resistance layer cannot be properly formed on the thin metal plate.

[0027]

When the coating solution is applied to the strip-shaped metal thin plate by the coating method according to the first aspect of the present invention, only a necessary portion of the coating device is quickly warmed and the precision equipment incorporated in the coating device is applied. It does not cause any malfunction of the equipment or the like and does not cause any adverse effects on work safety or equipment management, and does not cause cloudiness of the coating liquid on the thin metal plate immediately after the equipment starts operating. The etching resistance layer can be formed (backed) on the thin metal plate.

When the coating liquid is applied to the strip-shaped metal thin plate by using the coating device of the invention according to claim 2, it becomes possible to quickly heat only a necessary portion of the coating device. It is possible to achieve the above effects of the invention according to item 1.

In the coating apparatus according to the third aspect of the present invention, the temperature of the metal thin plate is prevented from lowering until the metal thin plate is conveyed to the coating position, and the metal thin plate is supplementarily heated. It becomes possible to more effectively heat the coating liquid on the thin metal plate and reduce its viscosity.

[Brief description of the drawings]

FIG. 1 is a schematic front view showing an example of the configuration of a coating device used for carrying out a coating method according to the present invention, showing the coating device together with a drying device, and a part of which is shown in section. Is.

FIG. 2 is a perspective view showing a schematic configuration of a squeegee roller of the coating device shown in FIG.

FIG. 3 is a perspective view of a main part showing an example of a configuration of a conventional coating device.

4 is a schematic side view of the coating device shown in FIG.

FIG. 5 is a partial enlarged side sectional view for explaining a problem in a case where a coating solution is applied to a metal thin plate to form an etching resistance layer on the metal thin plate by a conventional coating method.

[Explanation of symbols]

 10 Coating Device 18, 20, 22 Backup Roller 24, 26 Squeegee Roller 28, 30 Coating Liquid Supply Pipe 42 Heated Air Supply Pipe 46 Compressed Air Heating Heater 48 Supply Pipe Heating Heater

Claims (3)

[Claims] 1. A belt-shaped metal thin plate having a large number of minute recesses formed on the surface thereof is supported by a plurality of backup rollers arranged on the lower surface side thereof at a distance from each other and conveyed in the longitudinal direction. However, the coating liquid is supplied onto the thin metal plate, and the coating liquid is spread on the surface of the thin metal plate by the squeegee roller arranged on the upper surface side of the thin metal plate to form the recesses formed on the surface of the thin metal plate. In a method of applying a coating liquid to a strip-shaped metal thin plate, the squeegee roller itself is heated, and the coating liquid before being supplied onto the metal thin plate is heated to fill the part of the metal thin plate surface. The viscosity of the coating liquid when it is filled in the recess is 15 to 60
A method for applying a coating solution to a strip-shaped thin metal plate, which is characterized in that it is set to cps. 2. Three backup rollers arranged at a distance from each other on the lower surface side of a strip-shaped metal thin plate having a large number of fine recesses formed on the surface thereof, and each of the backup rollers on the upper surface side of the metal thin plate. Two squeegee rollers arranged so as to be respectively positioned between the backup rollers, and a coating liquid which is arranged on the front side of the squeegee roller in the transport direction of the metal thin plate and supplies the coating liquid onto the metal thin plate. A supply means is provided, and of the squeegee rollers, the outer peripheral surface of the squeegee roller on the front side in the transport direction of the metal thin plate is formed as a smooth surface, and a large number of grooves are formed on the outer peripheral surface of the other squeegee roller, In a device for applying a coating liquid to a strip-shaped thin metal plate, a roller heating means for heating the squeegee roller is provided, and a pipe for heating a coating liquid supply pipe of the coating liquid supply means. Characterized in that a thermal means, the coating solution of a coating apparatus to strip sheet metal. 3. An apparatus for applying a coating liquid to a strip-shaped thin metal plate according to claim 2, further comprising roller heating means for heating the backup roller.