JPH01183030A - Manufacture of shadow mask and its device - Google Patents

Abstract

PURPOSE:To make the membrane thickness even and to prevent the surface defect by providing a drying process with the radiant heat from a heat source and a natural exhaust gas or a forcible exhaust gas, and a drying process by utilizing the radiant heat from the heat source and a hot air from a hot air blower, and further with the natural exhaust gas or the forcible exhaust gas. CONSTITUTION:In the first drying furnace A, a continued belt-form thin metal plate 1 is dried by the radiant heat from an extreme infrared ray heater 5 and forcible exhaust units 15 and 16. Then, in the second drying furnace B, it is dried by the radiant heat from the extreme infrared ray heater 5, the hot air from a hot-air blower, and forcible exhaust units 17 to 19. After passing through the drying furnace B, the thin metal plate 1 is cooled in the natural cooling while going down in a duct 6 through rollers 7 and 8. In this case, the hot-air blower can feed the hot air at 40 to 120 deg.C, and can be converted in the distance 30 to 100mm from the thin metal plate 1. And the spraying angles of the hot-air at blowing ports 24 to 26 can be converted from square to 90 deg. upward to the thin metal plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Field of Application) The present invention relates to a method and apparatus for manufacturing a shadow mask used in a color picture tube, and particularly relates to a method for manufacturing a shadow mask used in a color picture tube, and in particular to a method for manufacturing a shadow mask used in a color picture tube. The present invention relates to a method and apparatus for drying a photosensitive resin liquid, which is carried out after both principal surfaces of a thin plate are degreased, washed with water, and coated with a photosensitive resin liquid.

(Prior Art) In general, a shadow mask type color picture tube has a shadow mask in which a large number of beam apertures are arranged at a predetermined pitch and are arranged close to and facing a phosphor screen. This shadow mask concentrates three electron beams corresponding to red, green, and blue from an electron gun near one beam aperture, and displays it on a phosphor screen that is painted to correspond to red, green, and blue. It is one of the most sought-after shrines that has a so-called color selection function that reproduces color images by correct matching.

Such a shadow mask is generally manufactured by photolithography. This photolithography method consists of the steps of applying a photosensitive resin liquid to a continuous strip-shaped metal thin plate that is a material for a shadow mask, drying the photosensitive resin liquid, exposing, developing, burning, and etching.

After degreasing and washing both main surfaces of a continuous strip-shaped thin metal plate with water, applying a photosensitive resin liquid and drying the photosensitive resin liquid, as disclosed in Japanese Patent Application Laid-Open No. 5871207'79, The process of drying the plastic resin liquid includes shielding the radiant heat from the heat source with a radiant heat shielding board □ and drying it with natural or forced exhaust, drying with a combination of a heat source and hot air, and drying with hot or cold air. By comprising at least the step of drying, the film thickness is uniform,
Further, attempts have been made to obtain a photoresist film that is free from surface defects and has uniform sensitivity.

(Problems to be Solved by the Invention) However, in using the above drying method, there were various problems as shown below. That is, as a drying method,
It can be roughly divided into (a) a method of drying using radiant heat called a sheathed heater or infrastein, and (b) a method of drying by blowing warm air, etc. called an atmosphere dryer.

In the former, because the photosensitive film receives rapid radiant heat during the drying process, the photosensitive resin liquid is applied using a dip method, and as it is pulled up, the excess photosensitive resin liquid flows downward, creating a uniform film thickness. However, during this process, a sudden temperature difference occurs between the surface of the photoresist film and the part that is in contact with the continuous thin metal plate that is the internal shadow mask material, causing the photosensitive resin liquid to spread downward evenly. It does not flow down, and a difference occurs, resulting in uneven application.

In addition, when the surface of the photoresist film begins to be fixed and receives sudden radiant heat, air bubbles are generated inside the photoresist film, which burst and form pinholes (portions with a diameter of 10 μm to 1 mm that are not adhered). occurs.

That is, in the past, since this radiant heat was applied rapidly, uneven coating and pinholes were likely to occur due to partial flow of the photosensitive resin liquid. For this reason, the radiant heat was shielded with a radiant heat shielding plate and the radiant heat was converted into convective heat for drying, which resulted in the problem of using more heater power than necessary.

In the latter case, there are problems in the method of controlling the blowing position when blowing hot air, and when strong wind hits the coated surface, it causes uneven coating, making it impossible to obtain a uniform film formation, and it is difficult to prevent dust. There is a point.

This invention solves the above-mentioned conventional problems, and achieves uniform film thickness and no surface defects in the drying process of the photosensitive resin liquid applied to the continuous strip-shaped thin metal plate that is the shadow mask material.
Furthermore, it is an object of the present invention to provide a method and apparatus for manufacturing a shadow mask with improved uniformity of sensitivity.

[Structure of the Invention] ′ (Means for Solving the Problems) This invention provides a method of degreasing both main surfaces of a continuous strip-shaped thin metal plate, washing them with water,
In a method for manufacturing a shadow mask comprising at least a first step of applying a photosensitive resin liquid and a second step of drying the photosensitive resin liquid, the second step at least applies radiant heat from a heat source. A method for producing a shadow mask, which comprises the following steps: drying by natural exhaust or forced exhaust; and drying by natural exhaust or forced exhaust using radiant heat from a heat source and hot air from a hot air blower. It is.

Further, the present invention comprises a first drying oven and a second drying oven for drying the photosensitive resin liquid of a continuous strip-shaped thin metal plate coated with a photosensitive resin liquid after degreasing and washing both main surfaces with water, 1st
The drying oven has a heat source and a mechanism that can perform natural exhaust or forced exhaust, and the second drying oven has a heat source and a mechanism that supplies radiant heat from the heat source and hot air in the range of 40 to 120 ° C. Furthermore, this mechanism can vary the distance from 30 to 100 mm from the continuous strip-shaped thin metal plate, and the angle at which the hot air is blown can also be varied from perpendicular to the continuous strip-shaped thin metal plate up to 90 degrees upward. This is a shadow mask manufacturing apparatus characterized in that it is possible to produce a shadow mask.

(Function) According to the present invention, in the first drying step, drying is performed by heat radiation from the heat source and natural exhaust or forced exhaust, that is, by removing the radiant heat shield plate and lowering the temperature of the heater of the heat source, the Coating unevenness due to run-off of the photosensitive film,
This prevents the formation of pinholes and further reduces the temperature, resulting in energy savings.

Next, in a second drying step, hot air is blown upward toward the surface of the continuous strip-shaped thin metal plate from a distance of about 30 to 100 mm at an angle close to parallel to 45°, thereby drying the surface of the continuous strip-shaped thin metal plate. It is possible to destroy the atmosphere where the temperature is high and the drying efficiency is improved. To solve the problem of uneven coating caused by strong wind hitting the coated surface, the surface of the photosensitive film is dried and fixed in the first drying process, and the hot air outlet is used to dry and fix the surface of the photosensitive film in the width direction of the continuous strip metal sheet. The problem was solved by blowing air evenly.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

The apparatus used in the method of manufacturing a shadow mask according to the present invention is constructed as shown in FIG. 1, and includes a first drying oven A and a second drying oven B.

The first drying oven A is equipped with a far-infrared heater (such as Infrastein) 5 serving as a heat source and forced exhaust devices 15 and 16. Further, the second drying oven B includes a far-infrared heater (such as Infrastein) 5 serving as a heat source and a forced exhaust device 17.1.
8.19 and a hot air blower. This hot air blower includes air outlets 24 to 24 provided in the second drying oven B.
26, a play filter 20, a fan 21, a heater 22, and a filter 23 to which each of the air outlets 24 to 26 is connected. Each of the forced exhaust devices 15 to 19 is connected to a fan 27.

Furthermore, since the oven length is long, each of the drying ovens A and B is divided into a plurality of zones by partition plates 9 to 14, and the oven temperature in the drying ovens A and B is controlled for each zone. The partition plates 9 to 14 are opened at a distance of 30 to 70 mm through which the continuous strip metal thin plate 1 that is the shadow mask material can pass, and the air is exhausted from the lower part of the partition plates 9 to 14 by forced exhaust devices 15 to 19, respectively. .

The area around the outlet holes 24 to 26 of the hot air blower is the second
It is configured as shown in the figure, and air outlets 24 to 26 are fixed to the partition plates 11 to 3, respectively (Figure 2 shows the vicinity of the partition plate 11 and the air outlets 24 for convenience).
. During operation, the play filter 20, fan 21, heater 22, and filter 23 send clean hot air controlled at approximately 100°C into the furnace, with the temperature and humidity conditioned. Air is blown into the furnace from The hot air blowing position is the second drying oven B.
The continuous strip metal thin plate 1 is sandwiched between the lower side of the zone, that is, the upper side of the partition plates 9 to 14, and slit-shaped air outlets 24 to 26 with a width of about 600 mm and an interval of 5 mm are directed toward the continuous strip metal thin plate 1 from both sides. 45 upwards from a distance of about 75mm
It is installed at an angle of °.

Now, a method of drying the continuous strip-shaped thin metal plate 1 using the above-mentioned apparatus will be explained.

First, the continuous strip metal thin plate 1 undergoes degreasing, water washing, acid treatment, and water washing processes on both main surfaces in the previous process, and then is transferred to the photosensitive resin liquid coating device 4 at the entrance of the drying oven via rollers 2.3. pass through. At this time, the photosensitive resin liquid is made of, for example, casein and ammonium dichromate, and is applied to both sides of the continuous strip metal sheet 1 while being pulled up by a dip-type coating device 4, and then transferred to the first drying oven A. to go into.

In the first drying oven A, the continuous strip metal sheet 1 is dried by radiant heat from the far-infrared heater 5 and forced exhaust devices 15 and 16.

Next, the continuous strip metal sheet 1 passed through the first drying oven A.
enters the second drying oven B, where it is dried by radiant heat from the far-infrared heater 5, hot air from the hot air blower, and forced exhaust bag placement 17, 18, 19.

After passing through the second drying oven B, it is naturally cooled while descending inside the duct 6 via rollers 7.8.
- In the above case, the hot air blower is capable of supplying hot air in the range of 40 to 120°C, and can be varied at a distance of 30 to 100 mm from the continuous strip metal thin plate 1. or,
The angle at which the hot air is blown from the outlets 24 to 26 can also be varied from perpendicular to the continuous strip-shaped thin metal plate 1 to an upward angle of 90°.

[Effects of the Invention] According to the present invention, in the process of drying the photosensitive resin liquid applied to both sides of a continuous strip-shaped thin metal plate, there are two steps: drying by radiant heat from the heat source and natural or forced exhaust; By using radiant heat and hot air from a hot air blower, and further including a step of drying by natural exhaust or forced exhaust, the occurrence of pinholes and coating unevenness can be suppressed. As a result, it is possible to obtain a shadow mask material coated with an extremely high-quality photoresist film having a uniform film thickness and no surface defects, and the use of hot air improves drying efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a shadow mask manufacturing apparatus according to an embodiment of the invention, and FIG. 2 is a perspective view showing the vicinity of the outlet of a hot air blower in the shadow mask manufacturing apparatus of the invention. A...first drying oven, B...second drying oven, 1...
- Continuous strip metal thin plate, 4... Photosensitive resin liquid coating device, 5... Far infrared heater (heat source), 6... Duct, 9-14... Partition plate, 15-19... Forced exhaust device, 20... Play filter, 21... Fan, 22... Heater, 23... Filter, 24
~26...Blowout port of hot air blower, 27...Fan. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) Production of a shadow mask comprising at least a first step of applying a photosensitive resin liquid after degreasing and washing both main surfaces of a continuous strip-shaped thin metal plate, and a second step of drying the photosensitive resin liquid. In the method, the second step includes at least a step of drying by radiant heat from the heat source and natural exhaust or forced exhaust, and a step of drying by using radiant heat from the heat source and hot air from the hot air blower, and further by natural exhaust or forced exhaust. A method for producing a shadow mask, comprising a step of drying. (2) Consisting of a first drying oven and a second drying oven for drying the photosensitive resin liquid of the continuous strip-shaped thin metal plate coated with the photosensitive resin liquid after degreasing and washing both main surfaces with water; The drying oven has a heat source and a mechanism that can perform natural exhaust or forced exhaust, and the second drying oven has a heat source and a mechanism that supplies radiant heat from the heat source and hot air in the range of 40 to 120 ° C. Furthermore, this mechanism is made of 30~
It can be varied by a distance of 100 mm, and the angle at which the hot air is blown can vary from perpendicular to the continuous strip-shaped thin metal plate to upward.
A shadow mask manufacturing device characterized by being variable in angle up to 0°.