JPH11106971A - Metal sheet cleaning method and cleaning device - Google Patents

Abstract

(57) [Problem] To provide a cleaning method in which oil is almost completely removed from the surface of a metal thin plate so that no oil remains on the surface of the metal thin plate sent to an application step. SOLUTION: In the step of removing the oil attached to the main surface of the metal sheet 1, the oil concentration in the degreasing liquid 14 in the degreasing tank 10 in which the metal sheet is immersed is maintained at 2,000 ppm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an etching product such as a shadow mask for a color CRT, an aperture grill for a Trinitron (registered trademark) tube, and a lead frame for a semiconductor device by a photo-etching method. Prior to a coating step of applying a water-soluble photosensitive resist to a main surface of a metal sheet, a method of cleaning the metal sheet to remove oil attached to the main surface of the metal sheet, and a method for performing the method. The present invention relates to an apparatus for cleaning thin metal sheets.

[0002]

2. Description of the Related Art In general, a shadow mask, an aperture grill, a lead frame, etc. are transported in a longitudinal direction by using a photo-etching method while a long metal sheet is transported in the longitudinal direction. It is manufactured by sequentially performing processing. For example, a series of manufacturing processes of a shadow mask will be described.
A long metal sheet of about 3 mm is degreased and washed with water to remove oil and the like adhering to the main surface of the metal sheet (washing step). Next, a resist having photosensitivity on both main surfaces of the metal thin plate, for example, a water-soluble photosensitive resist containing milk casein and ammonium bichromate is applied and dried, so that both main surfaces of the metal thin plate are coated. A resist film having a thickness of about several μm is formed (coating step). Subsequently, a mask material having a predetermined pattern is brought into close contact with the surface of each of the resist films formed on both main surfaces of the metal thin plate, and is exposed, so that images of a large number of hole patterns corresponding to the electron beam passage holes are formed. Is baked on a resist film (baking step). Next, by spraying a developing solution onto both main surfaces of the metal thin plate, a predetermined pattern that is formed into a latent image on the resist film is developed (developing step). Next, the metal sheet is immersed in a hardening solution, and then heated (burning) is applied to the metal sheet to dry and harden the resist film, so that the metal sheet has an etching resistance having a predetermined pattern on both main surfaces. Is formed (hardening step). Next, an etching solution is sprayed on the metal sheet on which the resist film is formed, and the etched surface of the main surface of the metal sheet on which the resist film is not adhered is etched to form an electron beam passage hole in the metal sheet. A large number of through holes are formed (etching step). Then, the resist film adhered to the metal sheet is peeled off from both main surfaces of the metal sheet (peeling step). Finally, a long metal thin plate is cut to obtain a large number of single-wafer-shaped shadow masks (shearing step).

[0003] In the above-described shadow mask manufacturing process, in the cleaning step, in order to remove cold rolling oil, rust-preventive oil, contaminants, and the like attached to the metal sheet, an alkaline solution containing a surfactant is used. A degreasing treatment of immersing the metal sheet in a degreasing liquid is performed. FIG. 4 is a schematic diagram showing a schematic configuration of a conventional metal sheet cleaning apparatus.

[0004] This cleaning apparatus includes a degreasing tank 10 and a water washing tank 12. A degreasing liquid 14 is accommodated in the degreasing tank 10, and a spray pipe 18 having a number of spray nozzles 16 is disposed inside the washing tank 12.
Then, the metal thin plate 1 as the shadow mask material is continuously conveyed in the longitudinal direction by a plurality of conveying rollers 20, immersed in the degreasing liquid 14 in the degreasing tank 10, degreased, and then washed with water. While being sent into the washing tank 12 and passing through the washing tank 12, water is sprayed from a spray nozzle 16 of a spray pipe 18 to be washed. Degreasing tank 1
A pair of drainage rollers 22 and 22 are provided at the outlet of 0, and by the pair of drainage rollers 22 and 22,
The degreasing liquid attached to the metal sheet 1 carried out of the degreasing tank 10 is squeezed to prevent the degreasing liquid from being taken out of the degreasing tank 10. The metal sheet 1 that has been rinsed in the rinsing tank 12 is sent to a resist coating device (not shown) installed on the downstream side of the rinsing tank 12.

The degreasing tank 10 is refilled with a fresh degreasing solution prepared in the preparation tank 24 from the preparation tank 24. On the other hand, a part of the degreasing liquid containing the oil used in the degreasing treatment of the metal sheet 1 and removed from the metal sheet 1 overflows from the degreasing tank 10, and a receiving tank 26 for receiving the overflowed degreasing liquid is provided. . The oil-containing degreasing liquid 28 that has flowed into the receiving tank 26 is allowed to stand in the receiving tank 26 for a long time, and the oil content is separated by a difference in specific gravity. The oil that has floated due to the specific gravity difference in the receiving tank 26 overflows from the receiving tank 26, and an oil tank 30 for receiving the overflowed oil is connected to the receiving tank 26. The oil component 32 flowing into the oil tank 30 was collected in the drum 34, and the used degreasing solution from which the oil component was separated in the receiving tank 26 was sent to the water purification plant through the drain pipe 60.

[0006]

However, in a system in which the oil-containing degreasing liquid 28 overflowing from the degreasing tank 10 is allowed to stand for a long time in the receiving tank 26 to separate the oil component by the difference in specific gravity as in the conventional cleaning apparatus, The capacity of the receiving tank 26 and the length of the separation time limit the processing capacity of the receiving tank 26. For this reason, the amount of the degreasing liquid overflowing from the degreasing tank 10 cannot be increased to a certain degree or more, and accordingly, the amount of the degreasing liquid replenished from the blending tank 24 to the degreasing tank 10 also increases to a certain degree or more. Can not be much. As a result, in the conventional cleaning device, the degreasing liquid 1 in the degreasing tank 10 is removed.
The oil concentration in No. 4 had increased to about 5,000 ppm.

However, the degreasing liquid 14 in the degreasing tank 10
When the oil concentration in the metal sheet rises to about 5,000 ppm, the degreasing property of the metal sheet 1 becomes very poor, and foreign matters such as oil droplets containing metal powder remain on the surface of the metal sheet after the washing step. Become. As a result, spot rust occurs on the surface of the metal sheet due to, for example, a potential difference between the different poles between the surface of the metal sheet and the residual foreign matter, and the shadow mask product has a transparency called “black pin” or “white pin”. This may cause poor shape of the hole. Further, in a coating step performed after the cleaning step, for example, when a water-soluble photosensitive resist composed of milk casein and ammonium dichromate is coated on the surface of a thin metal plate, residual oil repels the resist into a circular shape. hand,
A coating defect called “repelling” occurs in which the resist is not applied to the surface of the metal sheet only in the circular portion. Further, the oil contained in the degreasing tank 10 at a high concentration in the residual oil on the metal sheet or in the degreasing liquid adhering to the surface of the metal sheet.
When taken out of the oil, especially oil in the emulsion state,
It is difficult to remove the metal sheet from the surface of the metal sheet even by the water washing treatment in the water washing tank 12, and it is carried into the resist tank of the resist coating apparatus as it is, which causes contamination of the resist.

In the oil separation method based on the difference in specific gravity in the receiving tank 26, oil in which mineral oil or the like is in an emulsion state or oil such as dissolved animal and vegetable oils or ester oil can be separated from the degreasing solution. It is difficult, and the degreasing solution containing these oils flows through the drain pipe 60 to the water purification plant.
Further, when the degreasing liquid exceeding the capacity of the receiving tank 26 flows from the degreasing tank 10 into the receiving tank 26, the oil is not sufficiently separated in the receiving tank 26, and the degreasing liquid from the receiving tank 26 has a large amount of oil. It flows to the water purification plant as it is. For this reason, in the water purification plant, it was necessary to perform the neutralization treatment with the neutralizing agent and the microorganism treatment with the activated sludge on a daily basis.

The present invention has been made in view of the above circumstances, and the degreasing property of the degreasing liquid in the degreasing tank is sufficiently maintained, and rust spots on the surface of the metal sheet after the cleaning step. There is no foreign matter that may be caused on the surface of the metal sheet, and the coating process that follows the cleaning process may cause poor coating of the water-soluble photosensitive resist, such as “repelling”. The oil that causes the generation does not remain on the surface of the metal sheet, and furthermore, the residual oil on the metal sheet or the surface of the metal sheet that may cause contamination of the resist in the resist tank of the resist coating device. It is an object of the present invention to provide a method for cleaning a thin metal sheet in which the oil content contained in the adhered degreasing liquid is not taken out of the degreasing tank, and which is capable of suitably performing such a cleaning method. Providing a purification apparatus, and,
The above-described cleaning method can be suitably performed, and furthermore, a metal sheet that can eliminate or reduce the amount of waste liquid discharged from the apparatus, thereby eliminating the need for wastewater treatment in a water purification plant or reducing its load. It is an object of the present invention to provide a cleaning device.

[0010]

The invention according to claim 1 is
Prior to a coating step of applying a water-soluble photosensitive resist to the main surface of the metal sheet, the metal sheet is immersed in a degreasing solution to remove the oil attached to the main surface of the metal sheet. 2,000p oil concentration in the degreasing solution
pm or less.

According to a second aspect of the present invention, in the cleaning method of the first aspect, the temperature of the degreasing solution is adjusted within a range of 50 ° C. to 65 ° C.

According to a third aspect of the present invention, in the cleaning method according to the first or second aspect, the time for immersing the thin metal plate in the degreasing solution is within a range of 60 seconds to 120 seconds. .

According to a fourth aspect of the present invention, in the cleaning method according to any one of the first to third aspects, the metal sheet is washed with water after the metal sheet is immersed in a degreasing solution.

According to a fifth aspect of the present invention, in the cleaning method according to any one of the first to fourth aspects, the metal sheet is dipped in hot water before the metal sheet is dipped in the degreasing solution. And

According to a sixth aspect of the present invention, there is provided a degreasing tank in which a degreasing liquid is stored, and prior to a coating step of applying a water-soluble photosensitive resist to a main surface of the metal thin plate, the metal thin plate is placed in the degreasing tank. In a cleaning apparatus for a thin metal sheet, which is immersed in a degreasing liquid of the above, to remove oil attached to the main surface of the thin metal sheet, the oil concentration in the degreasing liquid in the degreasing tank is maintained at 2,000 ppm or less. It is characterized in that oil concentration adjusting means for adjusting is provided.

According to a seventh aspect of the present invention, in the cleaning apparatus according to the sixth aspect, a part of the degreasing liquid stored in the degreasing tank is caused to flow out of the degreasing tank, and the discharged degreasing liquid is again degreasing tank. An oil / water separator is provided in the middle of the circulation path for removing oil in the degreasing liquid flowing out of the degreasing tank, and the oil separated from the degreasing liquid by the oil / water separator is provided in the circulation path. Characterized in that an oil collecting means for collecting oil is provided to constitute the oil concentration adjusting means described above.

The invention according to claim 8 is a cleaning apparatus according to claim 6 or 7, wherein the temperature of the degreasing liquid stored in the degreasing tank is adjusted within a range of 50 ° C to 65 ° C. Is provided.

According to a ninth aspect of the present invention, in the cleaning apparatus according to any one of the sixth to eighth aspects, the time for immersing the metal sheet in the degreasing solution in the degreasing tank is set to 60 seconds to 12 hours.
An immersion time control means for controlling the immersion time within a range of 0 seconds is provided.

According to a tenth aspect of the present invention, in the cleaning apparatus according to any one of the sixth to ninth aspects, a water washing means for washing the metal sheet after being immersed in the degreasing liquid in the degreasing tank. Is provided.

According to an eleventh aspect of the present invention, in the cleaning apparatus according to any one of the sixth to tenth aspects, a hot water tank in which hot water is stored is provided, and the hot water in the hot water tank includes:
It is characterized in that the metal sheet before being immersed in the degreasing solution in the degreasing tank is immersed.

According to the method for cleaning a metal sheet according to the first aspect of the present invention, since the degreasing property of the degreasing liquid in the degreasing tank is sufficiently maintained, the metal sheet is immersed in the degreasing liquid in the degreasing tank and subjected to degreasing treatment. The oil content is almost completely removed from the surface of the thin metal sheet, so that no oil remains on the surface of the thin metal sheet sent to the coating step.

In the cleaning method according to the second aspect of the present invention, the degreasing property of the degreasing liquid in the degreasing tank is further improved, and the efficiency of the degreasing treatment of the metal sheet is improved.

In the cleaning method according to the third aspect of the present invention, the thin metal sheet is degreased satisfactorily, and the oil is sufficiently removed from the surface of the thin metal sheet.

[0024] In the cleaning method according to the fourth aspect of the present invention, contaminants adhering to the surface of the metal sheet carried out of the degreasing tank are removed from the surface of the metal sheet.

In the cleaning method according to the fifth aspect of the present invention, the metal sheet is immersed in hot water to remove oil and contaminants which are relatively easy to remove from the surface of the metal sheet. When immersed in a degreasing solution,
The amount of oil to be removed from the surface of the metal sheet by the degreasing liquid is reduced, and the degree of increase in the oil concentration in the degreasing liquid is reduced. Therefore, the oil concentration in the degreasing liquid is reduced to 2,000 pp.
m or less.

When the apparatus for cleaning a metal sheet according to claim 6 is used, the oil concentration adjusting means adjusts the oil concentration in the degreasing solution in the degreasing tank so as to be maintained at 2,000 ppm or less. The degreasing properties of the degreasing liquid in the degreasing tank are sufficiently maintained, and therefore, the metal sheet immersed in the degreasing liquid in the degreasing tank and subjected to the degreasing treatment is almost completely free of oil from its surface. The oil does not remain on the surface of the metal sheet sent to the coating step.

[0027] In the cleaning apparatus according to the seventh aspect of the present invention, the degreasing liquid in the degreasing tank is circulated through the circulation path, and the oil component is removed by oil-water separation means provided in the middle of the circulation path. After being returned to the degreasing tank after
The oil concentration is maintained at 2,000 ppm or less. And in this cleaning device, since the degreasing solution is used in circulation,
It is not necessary to flow waste liquid from the washing device to the water purification plant.

In the cleaning apparatus according to the eighth aspect of the present invention, the temperature of the degreasing solution in the degreasing tank is adjusted to 50 ° C. to 6 ° C. by the temperature adjusting means.
Since the temperature is adjusted within the range of 5 ° C., the degreasing property of the degreasing liquid in the degreasing tank is further increased, and the efficiency of the degreasing treatment of the metal sheet is improved.

In the cleaning apparatus according to the ninth aspect of the present invention, the time for immersing the thin metal plate in the degreasing solution in the degreasing tank is controlled within the range of 60 seconds to 120 seconds by the immersion time control means. The thin plate is satisfactorily degreased, and the oil is sufficiently removed from the surface of the thin metal plate.

In the cleaning apparatus according to the tenth aspect of the present invention, the metal sheet is washed by the water washing means, whereby contaminants adhering to the surface of the metal sheet carried out of the degreasing tank are removed from the metal sheet surface.

In the cleaning apparatus according to the eleventh aspect of the present invention, since the metal sheet is immersed in hot water in a hot water tank, oil and contaminants which are relatively easy to remove from the surface of the metal sheet are removed. Then, when the metal sheet is immersed in the degreasing liquid, the amount of oil to be removed from the surface of the metal sheet by the degreasing liquid decreases, and the degree of increase in the oil concentration in the degreasing liquid decreases. In addition, it becomes easier to maintain the oil concentration in the degreasing liquid at 2,000 ppm or less by the oil concentration adjusting means.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic diagram showing a schematic configuration of a cleaning apparatus used to carry out the method for cleaning a metal sheet according to the present invention. In FIG. 1, the same components as those of the conventional cleaning apparatus shown in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted.

The washing apparatus shown in FIG. 1 is provided with an oil / water separator 36, which is connected to the receiving tank 26 for storing the oil-containing degreasing liquid 28 overflowing from the degreasing tank 10. ing. Then, after a part of the oil component is separated in the receiving tank 26 due to a difference in specific gravity, the degreasing liquid still containing the oil component is sent from the receiving tank 26 to the oil / water separator 36 by a pump (not shown). I have. The oil that has floated in the receiving tank 26 due to the specific gravity difference overflows from the receiving tank 26 and flows into the oil tank 30 in the same manner as in the conventional apparatus. Oil / water separator 3 from receiving tank 26
The degreasing liquid containing oil sent to 6 is supplied to an oil / water separator 36.
Thus, the oil is separated into a regenerated liquid from which the oil has been removed.
The oil-water separator 36 is connected to the oil tank 30 and the degreasing tank 10 by piping. The oil separated from the degreasing liquid in the oil / water separator 36 is sent from the oil / water separator 36 into the oil tank 30 by a pump (not shown), and the regenerated liquid from which the oil has been removed is separated from the oil / water. The water is sent from the device 36 into the degreasing tank 10 by the pump 38. The oil component 32 that overflowed from the receiving tank 26 and flowed into the oil tank 30 and the oil component 32 that was sent from the oil-water separator 36 and flowed into the oil tank 30.
Is collected in the drum 34 as in the conventional apparatus.

Here, most of the alkaline components in the degreasing solution treated by the oil / water separator 36 migrate into the regenerating solution, and the regenerating solution is sent to the degreasing tank 10 for reuse as described above. In some cases, the surfactant component in the degreasing liquid is used for degreasing and is separated from the degreasing liquid together with the oil and sent to the oil tank 30. For this reason, if the degreasing liquid is circulated and used through the oil-water separator 36, the concentration of the surfactant in the degreasing liquid 14 in the degreasing tank 10 will be reduced. Liquid 1
In order to always maintain the surfactant concentration in Example 4 at the same level, in the preparation tank 24, a new degreasing solution is prepared so that only the surfactant component in the degreasing solution has a higher concentration than the conventional one. To be. On the other hand, since the regenerated liquid is supplied from the oil-water separator 36 into the degreasing tank 10, the amount of the new degreasing liquid supplied from the blending tank 24 into the degreasing tank 10 is greatly reduced as compared with the conventional one. Is less than one third of the supply amount.

The degreasing property is improved by setting the temperature of the degreasing liquid 14 in the degreasing tank 10 within the range of 50 ° C. to 65 ° C. For this reason, a temperature controller 40 may be provided, and the temperature of the degreasing liquid 14 in the degreasing tank 10 may be adjusted by the temperature controller 40 so as to be within the above range. The time for immersing the thin metal sheet 1 in the degreasing liquid 14 in the degreasing tank 10 to perform the degreasing treatment is preferably in the range of 60 seconds to 120 seconds, and therefore, a controller (not shown)
Thus, the transport speed of the metal sheet 1 by the transport roller 20 may be appropriately controlled. Although not shown, an electrolytic degreasing device may be added to the degreasing tank 10.

In the cleaning apparatus having the above-described structure,
The supply amount of the new degreasing solution from the mixing tank 24 into the degreasing tank 10,
By appropriately setting the amount of the degreasing liquid circulated through the oil / water separator 36, the oil concentration in the degreasing liquid 14 in the degreasing tank 10 is always maintained at 2,000 ppm or less, and the degreasing of the metal sheet 1 is performed. Perform processing. As described above, the oil concentration in the degreasing liquid 14 in the degreasing tank 10 is 2,000 ppm.
The degreasing solution 1 in the degreasing tank 10 is maintained
4 sufficiently retains the degreasing property for the metal sheet 1. Therefore, when the metal sheet 1 immersed in the degreasing liquid 14 in the degreasing tank 10 and subjected to the degreasing treatment is carried out from the degreasing tank 10, foreign substances that may cause rust spots on its surface. It is possible to prevent oil remaining which remains or causes a coating failure called "repelling" in the coating process. Further, oil remains on the surface of the metal sheet 1 and the residual oil is taken out of the degreasing tank 10 or a degreasing liquid containing a high concentration of oil adheres to the surface of the metal sheet 1 and the oil is taken out of the degreasing tank 10. Therefore, there is no need to worry that oil is brought into the resist tank of the resist coating apparatus via the thin metal plate 1 and contaminates the resist.

Incidentally, as shown in FIG.
Is installed, and the degreasing solution 14 in the degreasing tank 10 is sampled and sent to an oil concentration meter 42 by a pump (not shown), and the oil concentration in the degreasing solution is continuously or intermittently measured by the oil concentration meter 42. Alternatively, the oil concentration in the degreasing liquid 14 in the degreasing tank 10 may be constantly monitored. Then, a measurement signal is sent from the oil concentration meter 42 to the controller 44, and a control signal is sent from the controller 44 to the pump 38 so that the oil concentration in the degreasing liquid 14 in the degreasing tank 10 becomes 2,000 ppm or less. The circulation amount of the liquid (the supply amount of the regenerating liquid into the degreasing tank 10) is controlled. Although not shown, the supply amount of the fresh degreasing liquid supplied from the mixing tank 24 into the degreasing tank 10 may be controlled based on the measured concentration of the oil concentration meter 42.

In this cleaning device, the oil-water separation device 3
According to 6, oils such as mineral oils and the like in an emulsion state and oils such as dissolved animal and vegetable oils and ester oils can also be separated from the degreasing solution. It does not contain those oils. As described above, since the regenerated liquid sent out from the oil-water separator 36 does not contain oil, the degreasing liquid is not circulated and used as in the washing apparatus shown in FIG. In the case of discharging all or part of the regenerated solution sent out of the washing device, there is no need to neutralize the waste solution with a neutralizing agent or to treat the microorganism with activated sludge. It can be discharged after a simple purification process. When the degreasing solution is completely circulated and used as in the cleaning device shown in FIG. 1,
It is not necessary to flow waste liquid from the washing device to the water purification plant.

FIG. 2 is a schematic view showing another example of the structure of the apparatus for cleaning a thin metal plate. In this cleaning apparatus, the degreasing liquid 14 in the degreasing tank 46 overflows from the degreasing tank 46, and is introduced into the oil / water separator 36 through the receiving tank 26.
The oil is supplied from the degreasing tank 46 directly to the oil / water separator 36. With such a configuration, the circulation efficiency of the degreasing liquid is improved, and the oil concentration in the degreasing liquid 14 in the degreasing tank 46 can be further reduced. Further, in this cleaning device, the inside of the degreasing tank 46 is divided into a plurality of tanks (two tanks in the illustrated example) by a partition wall 48. And
The degreasing liquid from the mixing tank 24 and the regenerating liquid from the oil / water separator 36 are supplied into the second tank 52, and the degreasing liquid overflowing from the second tank 52 flows into the receiving tank 26, The thin plate 1 is first introduced into the first tank 50, then guided into the second tank 52, and then carried out of the degreasing tank 46. With such a configuration, most of the oil adhering to the surface of the metal sheet 1 is removed from the surface of the metal sheet 1 while being immersed in the degreasing liquid 14 in the first tank 50, and the second tank 52 The degreasing solution 14 contains almost no oil in the form of an emulsion, and the second tank 52
Inside, the cleanliness of the degreasing liquid 14 increases. As a result, the degreasing liquid adhered to the surface of the metal sheet 1 and taken out of the degreasing tank 10 is in a clean state, so that the water washing treatment in the washing tank 12 is facilitated, and as a result, the metal sheet 1 is used as a medium. This prevents oil from being brought into the resist tank of the resist coating apparatus and contaminating the resist.

FIG. 3 is a schematic view showing still another example of the configuration of the apparatus for cleaning a thin metal plate. This cleaning device includes:
A hot water tank 56 in which hot water 54 adjusted to a temperature of about 60 ° C. to 80 ° C. is stored is provided in front of the degreasing tank 46. Then, the metal sheet 1 is guided to the hot water tank 56 by the transport roller 20, is immersed in the hot water 54 in the hot water tank 56, is then transported to the degreasing tank 46, and is in the degreasing liquid 14 in the degreasing tank 46. It is soaked and degreased. With such a configuration, the hot water tank 5
Oil and contaminants which are relatively easy to remove are removed from the surface of the metal sheet 1 immersed in the hot water 54 in 6, and then the metal sheet 1 is immersed in the degreasing liquid 14 in the degreasing tank 46. The amount of oil to be removed from the surface of the metal sheet 1 by the degreasing liquid 14 in the degreasing tank 46 decreases, and the degree of increase in the oil concentration in the degreasing liquid 14 decreases. For this reason, the burden on the oil-water separator 36 is reduced, and it becomes easier to maintain the oil concentration in the degreasing liquid in the degreasing tank 46 at 2,000 ppm or less. The oil that floats due to the difference in specific gravity in the hot water tank 56 overflows from the hot water tank 56 and flows into the oil tank 30.

[0042]

Next, a method for cleaning a metal sheet according to the present invention will be described with reference to specific examples.

As the thin metal plate 1, a shadow mask made of a long aluminum-killed low-carbon steel plate having a width of 637 mm and a thickness of 0.216 mm is used, and the thin metal plate 1 is formed by using a cleaning apparatus having the structure shown in FIG. After degreasing and washing with water, a water-soluble photosensitive resist containing milk casein and ammonium dichromate is applied to both main surfaces of the metal sheet 1 by a dipping and pulling-up method, and the metal coated with the photosensitive resist is coated. The thin plate 1 was passed through a drying furnace at a temperature of 60 ° C. to 100 ° C. to form a resist film having a thickness of about 8 μm on both main surfaces of the thin metal plate 1.

As the oil / water separator 36, EUF-5 manufactured by Zeotech Co., Ltd. was used. In addition, in the mixing tank 24, “Lyomix M-50” manufactured by Lion Corporation
Asahi Chemical Co., Ltd.
1/4 of Asahi Cleaner EN4
In addition, a fresh defatted solution was prepared. The temperature of the degreasing solution 14 in the degreasing tank 10 was adjusted to 60 ° C.

The occurrence of rust on the surface of the thin metal plate 1 is monitored for about three months in units of coils for the case where the oil-water separator 36 is operated and the case where the operation is stopped. The number of coils where occurred was checked every day. As a result, the number of rust spots was an average of several days a day when the conventional cleaning method without operating the oil / water separator 36 was used, but when the degreasing was performed by operating the oil / water separator 36. Is almost gone.

Furthermore, the number of occurrences of “repelling” in the resist film was also 2 months on average when the conventional cleaning method was used.
There were no coils during the monitoring period.

[0047]

According to the method for cleaning a metal sheet according to the first aspect of the present invention, the degreasing property of the degreasing liquid in the degreasing tank is sufficiently maintained, and the degreasing liquid is immersed in the degreasing liquid in the degreasing tank to perform the degreasing treatment. Oil is almost completely removed from the surface of the thin metal sheet, and no oil remains on the surface of the thin metal sheet sent to the coating process, causing rust spots due to foreign matter remaining on the surface of the thin metal sheet. In addition, shadow mask products do not suffer from defects in the shape of through-holes called “black pins” or “white pins”. In addition, coating defects called “repelling” of water-soluble photosensitive resist during the coating process are eliminated. It does not occur. Furthermore, the residual oil on the metal sheet or the oil contained at a high concentration in the degreasing liquid adhering to the surface of the metal sheet is taken out of the degreasing tank and taken into the resist tank of the resist coating device to contaminate the resist. No more.

In the cleaning method according to the second aspect of the present invention, the degreasing property of the degreasing solution in the degreasing tank is further improved, and the efficiency of the degreasing treatment of the metal sheet is further improved.

In the cleaning method according to the third aspect of the present invention, the metal sheet is degreased well, and the oil is sufficiently removed from the surface of the metal sheet.

In the cleaning method according to the fourth aspect of the present invention, contaminants adhering to the surface of the metal sheet carried out of the degreasing tank are removed from the surface of the metal sheet, and the surface of the metal sheet sent to the coating step is cleaned. Become.

In the cleaning method according to the fifth aspect of the present invention, after the metal sheet is immersed in hot water to remove oil and contaminants which are relatively easy to remove from the surface of the metal sheet, the metal sheet is removed from the degreasing liquid. Since the amount of oil to be removed from the surface of the metal sheet by the degreasing liquid decreases because the oil is immersed in the degreasing liquid, the degree of increase in the oil concentration in the degreasing liquid decreases, so that the oil concentration in the degreasing liquid is 2,000 ppm. It is easier to maintain:

When the apparatus for cleaning a thin metal plate according to the sixth aspect of the present invention is used, the cleaning method according to the first aspect of the present invention can be suitably carried out. Therefore, the degreasing property of the degreasing liquid in the degreasing tank is sufficiently improved. Maintained, oil is almost completely removed from the surface of the degreased metal sheet immersed in the degreasing solution in the degreasing tank, and no oil remains on the surface of the metal sheet sent to the coating process . Therefore, foreign matter remaining on the surface of the thin metal plate causes rust, which causes shadow mask products to have defects in the shape of through-holes called “black pins” or “white pins”, or water-soluble in the coating process. Poor coating called "repelling" of the photosensitive resist occurs, and the residual oil on the metal sheet and the oil contained in the degreasing solution attached to the surface of the metal sheet at a high concentration are taken out of the degreasing tank and the resist is removed. It is possible to prevent the resist from being brought into the resist tank of the coating apparatus and contaminating the resist.

In the cleaning device according to the seventh aspect of the present invention, since the degreasing solution is circulated and used, it is not necessary to flow the waste liquid from the cleaning device to the water purification plant, or the amount thereof can be reduced. Wastewater treatment is unnecessary or the load can be reduced.

In the cleaning device according to the eighth aspect of the present invention, the degreasing property of the degreasing liquid in the degreasing tank is further improved, and the efficiency of the degreasing treatment of the metal sheet is further improved.

In the cleaning apparatus according to the ninth aspect of the present invention, the thin metal plate is satisfactorily degreased and the oil is sufficiently removed from the surface of the thin metal plate.

In the cleaning apparatus according to the tenth aspect of the present invention, contaminants adhering to the surface of the metal sheet carried out of the degreasing tank are removed from the surface of the metal sheet, and the surface of the metal sheet sent to the coating step is cleaned. Become.

In the cleaning apparatus according to the eleventh aspect of the present invention, the metal sheet is immersed in hot water in a hot water tank to remove oil and contaminants which are relatively easy to remove from the surface of the metal sheet. Is immersed in the degreasing liquid in the degreasing tank, the amount of oil to be removed from the surface of the metal sheet by the degreasing liquid decreases, and the degree of increase in the oil concentration in the degreasing liquid decreases. The adjusting means makes it easier to maintain the oil concentration in the degreasing liquid in the degreasing tank at 2,000 ppm or less.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of a cleaning apparatus used to carry out a method for cleaning a metal sheet according to the present invention.

FIG. 2 is a schematic view showing another example of the configuration of the apparatus for cleaning a thin metal plate.

FIG. 3 is a schematic view showing still another example of the configuration of the apparatus for cleaning a thin metal plate.

FIG. 4 is a schematic view showing a schematic configuration of a conventional thin metal plate cleaning apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal thin plate 10, 46 Degreasing tank 12 Rinse tank 14 Degreasing liquid 24 Mixing tank 26 Receiving tank 28 Oil-containing degreasing liquid 30 Oil tank 32 Oil 36 Oil-water separator 38 Pump 40 Temperature controller 42 Oil concentration meter 44 Controller 48 Partition wall 50 1st tank 52 Second tank 54 Hot water 56 Hot water tank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01J 9/14 H01J 9/14 H

Claims (11)

[Claims] 1. A metal sheet for immersing a metal sheet in a degreasing solution to remove oil attached to the main surface of the metal sheet prior to a coating step of applying a water-soluble photosensitive resist to the main surface of the metal sheet. The method for cleaning a thin metal plate according to claim 1, wherein the oil concentration in the degreasing solution is maintained at 2,000 ppm or less. 2. The method for cleaning a metal sheet according to claim 1, wherein the temperature of the degreasing solution is adjusted within a range of 50 ° C. to 65 ° C. 3. The method for cleaning a metal sheet according to claim 1, wherein the time for immersing the metal sheet in the degreasing solution is within a range of 60 seconds to 120 seconds. 4. After immersing the metal sheet in a degreasing solution,
The method for cleaning a metal sheet according to any one of claims 1 to 3, wherein the metal sheet is washed with water. 5. Before immersing the metal sheet in the degreasing solution,
5. The method for cleaning a metal sheet according to claim 1, wherein the metal sheet is immersed in hot water. 6. A degreasing tank having a degreasing liquid stored therein, and the metal sheet is immersed in a degreasing liquid in the degreasing tank prior to a coating step of applying a water-soluble photosensitive resist to a main surface of the metal sheet. In the metal sheet cleaning device for removing the oil attached to the main surface of the metal sheet, the oil concentration in the degreasing liquid in the degreasing tank is 2,000 ppm.
An apparatus for cleaning a thin metal plate, comprising an oil concentration adjusting means for adjusting the oil content to be maintained as follows. 7. A circulation path in which the oil concentration adjusting means causes a part of the degreasing liquid stored in the degreasing tank to flow out of the degreasing tank, and returns the discharged degreasing liquid to the degreasing tank again. An oil / water separating means interposed in the middle of the path for removing oil in the degreasing liquid flowing out of the degreasing tank, and an oil collecting means for collecting the oil separated from the degreasing liquid by the oil / water separating means. The apparatus for cleaning a thin metal sheet according to claim 6, wherein the apparatus is configured. 8. The temperature of the degreasing liquid stored in the degreasing tank is set at 5
The apparatus for cleaning a thin metal sheet according to claim 6 or 7, further comprising a temperature adjusting means for adjusting the temperature within a range of 0 ° C to 65 ° C. 9. An immersion time control means for controlling a time for immersing a thin metal plate in a degreasing solution in a degreasing tank within a range of 60 seconds to 120 seconds. An apparatus for cleaning a thin metal sheet as described in the above. 10. A rinsing means for rinsing a metal sheet after being immersed in a degreasing solution in a degreasing tank.
An apparatus for cleaning a metal sheet according to any one of claims 9 to 9. 11. The hot water tank according to claim 6, wherein hot water is stored, and a hot water tank for immersing the thin metal sheet in the hot water before being immersed in the degreasing liquid in the degreasing tank is provided. Equipment for cleaning thin metal sheets.