JP2000225550A - Method and device for regenerating color cathode-ray tube glass panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for regenerating a color cathode-ray tube glass panel without forming irregularity of a panel inner surface which causes unevenness of interference generated at reuse time. SOLUTION: A panel 5 is fixed with its inner surface facing upward to a base seat 6 movable in the longitudinal direction on the same plane. While a stainless steel felt buff 8 mounted in a tip end of a sander 9 of double action rotating system to have 5 to 20 μm element wire diameter, adjusting a degree of adhesion to the inner surface of the panel 5 by an air cylinder 10, is moved in the right/left directions by a profiling arm 11 formed by copying curvature of the inner surface of the panel 5. Further, a mixed abrasive fluid of prescribed amount containing cerium oxide abrasive powder and a surfactant is supplied by a nozzle to the moving direction side in the vicinity of the felt buff 8, and the inner surface of the panel 5 is polished by this mixed abrasive fluid and the felt buff 8, to completely remove a graphite film and fluorescent film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for regenerating a color CRT glass panel, and more particularly to the removal of a graphite film and a fluorescent film formed on the inner surface of a glass panel.

[0002]

2. Description of the Related Art In general, when a defective tube occurs in the process of manufacturing a color cathode ray tube, the main parts are collected, regenerated and reused because the material cost of the color cathode ray tube is relatively expensive. I have. Defective tubes generated after the frit sealing step of fusing panels and funnels with low melting point powder glass, as well as defective panels and defective funnels generated in the previous steps, are similarly collected and reused. The color CRT glass panel that was determined to be defective in the process before fusing with the funnel, such as the graphite film coating process, the fluorescent film coating process, the aluminum film deposition process, the panel baking process, the internal magnetic shield attaching process, etc. The various coating films formed on the inner surface are removed, and the process is restarted from the first graphite film coating process. Means for removing various coating films include 2 to 10% aqueous caustic soda aqueous solution cleaning, high pressure water jet cleaning, 1 to 10% aqueous hydrofluoric acid solution or aqueous ammonium acid fluoride solution, and rubbing with a sponge. Yes, these washings were performed alone or in combination.

[0003]

However, in a panel regenerated by using the above-described conventional methods for removing various coating films, a defect called "interference unevenness" occurs at the time of re-use, and a high recovery and recovery rate is obtained. There was a problem that can not be obtained. The cause of this "interference unevenness" will be described with reference to FIG.
In the figure, 1 is a graphite film 2 and a fluorescent film 3 on the inner surface.
The glass panel 4 on which is coated and formed shows irregularities formed on the inner surface of the glass panel 1. As a method of regenerating a defective panel, when cleaning is performed with a hydrofluoric acid aqueous solution or an acidic ammonium fluoride aqueous solution that is corrosive to glass, the difference in the adhesive strength between the graphite film 2 and the fluorescent film 3 between the glass panel 1 and the glass film 1. As a result, the graphite film 2 remains as a mask to the end (FIG. 3B), and finally, the irregularities 4 are formed on the inner surface of the glass panel 1 (FIG. 3).
(C)). These irregularities interfere with a graphite film newly applied and formed in the graphite film application step at the time of re-use, causing interference non-uniformity with high frequency. In particular, in the case of a high-definition pitch product having a phosphor screen with a stripe structure, almost all of them are generated, although the degree is different. In addition, this tendency becomes more remarkable by passing through a heat treatment step after the panel baking step, which is one factor that hinders the recovery rate of defective panels generated after the frit sealing step.

In particular, recently, in order to improve the quality of various phosphor screens of a color cathode ray tube, a photosensitive resist used in a graphite film coating step has been changed from PVA (polyvinyl alcohol) to PVP (polyvinylpyrrolidone) or graphite. Due to the ultrafine particles of graphite used to form the film and the increase in the size of the phosphor used to form the fluorescent film, the adhesion between the graphite film and the fluorescent film that is ultimately formed on the inner surface of the glass panel and the inner surface of the glass panel is reduced. There is a tendency to further increase the difference, and there is a concern about an increase in the occurrence rate of interference unevenness. In addition, even when the graphite film and the fluorescent film are completely removed by rubbing with a sponge or the like, various chemicals used for coating and forming the graphite film and the fluorescent film partially react with the glass surface and remain crystallized. This may be lifted up as a trace difference between the graphite film and the fluorescent film by washing with an aqueous solution of hydrofluoric acid or an aqueous solution of acidic ammonium fluoride in the phosphor screen coating step, and may cause interference unevenness.

Other methods for removing various coating films for reproducing defective panels include, for example, JP-A-7-37509.
Japanese Patent Application Publication No. JP-A-2005-64103 discloses a method of removing a fluorescent film and a carbon film (graphite film) by injecting a liquid that does not invade the panel at a high pressure onto the inner surface of the panel. It is very difficult to remove them, and it is obvious that the trace difference is raised for the above-mentioned reason, and there is a possibility that high-pressure water may cause defects such as new pits on the inner surface of the panel. Further, in a cathode ray tube polishing apparatus disclosed in Japanese Patent Application Laid-Open No. 5-28920, as shown in FIG. 4, a stainless steel in which a glass panel 15 surface of a cathode ray tube is held upward and an aqueous solution of an abrasive for optical glass is impregnated. The polishing buff 13 made of felt is made to adhere to the surface of the glass panel 15 by the joint mechanism 14 while the rotary polishing jig 16 is rotated so that the polishing buff 13 is impregnated with the abrasive. In the polishing means, "burn-in" of the polishing buff 13 is performed.
In addition, with the method in which the polishing buff 13 is pressed against the face surface by the joint mechanism 14, it is difficult to uniformly polish the entire surface of the curved panel, and polishing unevenness may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a method and apparatus for reproducing a glass panel in which irregularities on the inner surface of the glass panel which cause interference unevenness at the time of reuse are not formed. To improve the recovery and recovery rate of defective panels.

[0007]

A method for regenerating a color CRT glass panel according to the present invention is a method for regenerating a color CRT glass panel having an inner surface coated with a graphite film and a fluorescent film, wherein at least the inner surface of the panel is formed. The regenerating process includes a process of removing the graphite film and the fluorescent film by polishing with a mixed polishing liquid containing cerium oxide polishing powder and a polishing tool. Further, the mixed polishing liquid contains a surfactant. Further, the mixed polishing liquid was prepared by adding water 5 to 100 parts by weight of the cerium oxide polishing powder.
It is blended in a mixing ratio of 0 to 300 parts by weight and 0 to 30 parts by weight of a surfactant. In addition, 5-2 as a polishing tool
A disk-shaped web buff or felt buff made of one or more of stainless steel fiber, nylon fiber, polyester fiber and polyaramid fiber having a wire diameter of 0 μm is used.

Further, the color CRT glass panel reproducing apparatus according to the present invention holds a color CRT glass panel having a graphite film and a fluorescent film applied on the inner surface thereof, and is capable of moving back and forth or left and right on the same plane. And its moving speed adjustment mechanism, a disk-shaped polishing buff made of web or felt is attached to the tip,
A sander that presses and rotates a polishing buff on the surface to be cleaned of the panel and a pressure adjusting mechanism thereof, and is formed to imitate the curvature of the surface to be cleaned of the panel, and the sander can be moved left and right or back and forth along the surface to be cleaned of the panel. Arm and a moving speed adjusting mechanism for moving the same in a direction, and a polishing liquid supply mechanism for supplying a predetermined amount of mixed polishing liquid to a moving direction side near a polishing buff that moves while rotating on the surface to be cleaned of the panel. It is a thing.
The sander rotates (revolves) the polishing buff concentrically around its center (rotation), and further rotates (revolves) over a wide range around other locations.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2
1 is a front view and a top view showing a color CRT glass panel reproducing apparatus according to Embodiment 1 of the present invention. In the drawing, reference numeral 5 denotes a color CRT glass panel (hereinafter abbreviated as a panel) in which a graphite film and a fluorescent film are applied and formed on the inner surface, and 6 holds the panel 5 and is on the same plane in the front-rear direction (in FIG. A pedestal movable in the vertical direction), 7 is a moving speed adjusting mechanism of the pedestal 6, 8 is a stainless steel fiber felt buff (hereinafter abbreviated as felt buff) which is a disk-shaped polishing buff made of web or felt,
Reference numeral 9 denotes a sander to which the felt buff 8 is attached at the tip, which presses and rotates the felt buff 8 on the surface to be cleaned of the panel 5, 10 denotes an air cylinder which is a pressure adjusting mechanism of the sander 9, and 11 denotes the curvature of the surface of the panel 5 to be cleaned And a copying speed adjusting mechanism 12 for moving the sander 9 in the left-right direction along the surface to be cleaned of the panel 5. The present apparatus is provided with a polishing liquid supply mechanism (not shown) for supplying a predetermined amount of mixed polishing liquid to the side in the moving direction near the felt buff 8 that moves while rotating on the surface to be cleaned of the panel.

Next, a method of regenerating a panel 5 having a graphite film and a fluorescent film coated on the inner surface thereof will be described with reference to a defective tube generated after a frit sealing step of fusing the panel 5 and a funnel with a low melting point powder glass. This will be described in detail below. In addition,
An anti-reflection film or an anti-static film is formed on the outer surface of the panel 5, and the anti-reflection film or the anti-static film is removed by the same method, but the description is omitted here. First, after melting the low melting point frit glass on the outside of the glass bulb by 0.5 mm to 2 mm with about 10% hot nitric acid aqueous solution,
Apply heat shock with hot and cold water to divide into panel 5 and funnel, remove shadow mask and internal magnetic shield built in panel 5, and remove remaining low melting point frit glass on glass panel sealing surface. After dissolving / removing with a 10% aqueous nitric acid aqueous solution, it is washed with water.

Next, the separated panel 5 is shown in FIGS.
Is fixed to the pedestal 6 of the glass panel reproducing apparatus shown in FIG. The pedestal 6 allows the panel 5 to move in the front-rear direction on the same plane. On the other hand, the felt buff 8 attached to the tip of the sander 9 has the degree of pressure bonding to the inner surface of the panel 5 adjusted by the air cylinder 10, and the copying arm 11 formed by imitating the curvature of the inner surface of the panel 5.
The moving speed is arbitrarily adjusted by the moving speed adjusting mechanism 12. In the present embodiment, a double-action rotation method (rotation / revolution method) in which the felt buff 8 is rotated (revolved) concentrically around its center and further rotated (revolved) over a wider range around other points. Thunder 9 (for example, "Orbital Maiton (Nitto Koki)", "Dynorbital Supreme (DYNA
BRADE-Inc: USA) ”). Further, in the present embodiment, the felt buff 8 made of stainless steel fiber is used, but the polishing buff is not limited to this.
A disk-shaped web buff or felt buff made of any one or more of stainless steel fibers, nylon fibers, polyester fibers, and polyaramid fibers having a strand diameter of 5 to 20 μm can be used.

Further, at least a cerium oxide polishing powder is contained in a moving direction side near the felt buff 8 which moves while rotating on the inner surface of the panel 5 from a nozzle (not shown) of a polishing liquid supply mechanism. In the method, a predetermined amount of the mixed polishing liquid containing a surfactant is supplied. Thus, the inner surface of the panel 5 is polished with the mixed polishing liquid containing at least cerium oxide polishing powder and the felt buff 8 to remove the graphite film and the fluorescent film applied to the inner surface of the panel 5. In the present embodiment, 150 parts by weight of water and 1 part by weight of surfactant
A mixed polishing liquid mixed at a mixing ratio of 0 parts by weight was used.
After polishing for a predetermined time to completely remove the graphite film and the fluorescent film, the panel 5 is washed with water.

In the present embodiment, the main component of the cerium oxide polishing powder used for the mixed abrasive is CeO ₂ (about 40%).
A 45% content), but contains _{La 2 O 3, Nd 2 O} 3 rare earth oxides such as such as the other, and contained some organic substances depending on those production locations and production process, This organic component may remain fixed on the surface of the panel 5 during polishing of the panel 5. In particular, in the recent color cathode ray tube manufacturing process, after assembling the mask, there is a tendency to omit a bake oven treatment for removing the assembling (welding) distortion of the mask. When washing with a hydrofluoric acid solution or an aqueous solution of acidic ammonium fluoride in the above, there is a possibility that uneven cleaning may occur. In order to prevent the organic components from sticking, it is effective to add a surfactant to the mixed abrasive. The mixing ratio is desirably 50 to 300 parts by weight of water and 0 to 30 parts by weight of a surfactant based on 100 parts by weight of the cerium oxide polishing powder.

In the following, when the mixing ratio (weight ratio) of the mixed polishing liquid composed of cerium oxide polishing powder, water, and a surfactant is changed, the influence on the cleaning unevenness due to the presence or absence of the pair bake furnace treatment and the fluorescent screen Table 1 shows the results of an experiment on the effect of washing with a hydrofluoric acid aqueous solution or an acidic ammonium fluoride aqueous solution in the coating step on erosion unevenness. As a polishing buff, nylon fiber 50%, stainless steel fiber 5
A disc-shaped web buff having a diameter of 120 mm and consisting of 0% was used, and the other polishing conditions were the same. As shown in Table 1, the effect on the cleaning unevenness was affected by the presence or absence of the surfactant when the pear baking furnace treatment was not performed, and the cleaning unevenness did not occur when the surfactant was added ( B,
C). In the case where the bake oven treatment was performed, no cleaning unevenness occurred regardless of the presence or absence of the surfactant.
On the other hand, the influence on the erosion unevenness depends on the mixing ratio of the cerium oxide polishing powder and water (D). However, in this experiment, there was no erosion unevenness that could not be reused,
Good results were obtained.

[0015]

[Table 1]

Next, Table 2 shows the results of experiments on the grindability, seizure of the buff, and the abrasion resistance of a web buff or a felt buff having a diameter of 120 mm depending on the combination of each fiber type and element diameter. Table 1 shows the mixed polishing liquid.
A was used, and the other polishing conditions were the same. As shown in Table 2, with respect to the grindability and abrasion resistance, 100% stainless steel (E) or a 50% blend with other fibers (J) is good, but the strand diameter of the stainless steel is good. Is 25 to 30 [mu] m (K), fine scratches occur and the recycled glass panel cannot be reused. On the other hand, when the element wire diameter is as small as 1 to 3 μm or less (G), the average particle diameter of the cerium oxide powder of the mixed polishing liquid is generally 3 to 5 μm.
Since it is m, it is difficult to enter the gaps between the fibers, and the buffing tends to occur. Further, the wear resistance of the buff increases, and the wear resistance also decreases. As a result, it is desirable that the size of the strand diameter of the fiber constituting the buff is in the range of about 5 to 20 μm. Although the results of comparison between the web buff and the felt buff are not shown in Table 2, the web buff is hard to cause seizure, but is slightly inferior in grindability to the felt buff, and the felt buff is excellent in grindability, but seizure occurs. Either of them may be used because each of them has a feature that it is easy to perform, and each has advantages and disadvantages.

[0017]

[Table 2]

As described above, according to the glass panel reproducing apparatus in the present embodiment, the copying travel of the felt buff 8 by the copying arm 11 formed by imitating the curvature of the surface to be cleaned (in this case, the inner surface) of the panel 5. Since the method is adopted, the entire surface of the panel 5 can be polished uniformly, and polishing unevenness does not occur. Further, since the traveling speed of the pedestal 6 holding the panel 5 and the traveling speed of the felt buff 8 are both adjustable, the polishing time can be arbitrarily adjusted, and the conditions can be easily optimized. In the present embodiment, the pedestal 6 is configured to move in the front-rear direction and the felt buff 8 is moved in the left-right direction. However, the pedestal 6 may be moved in the left-right direction and the felt buff 8 may be moved in the front-rear direction. Is obtained. Further, by supplying a predetermined amount of the mixed polishing liquid to the moving direction side in the vicinity of the felt buff 8, the reduction in image sticking can be completely prevented. As a result, according to the present embodiment, the unevenness of the inner surface of the glass panel, which causes interference unevenness at the time of reuse, is not formed, and the recovery and recovery rate of the defective panel is significantly improved.

[0019]

[Embodiment 1] Hereinafter, the glass panel recycling method according to the first embodiment of the present invention will be described with reference to a CRT glass panel for 41 cm (17 inches) as an example. In addition,
In this embodiment, the glass panel is regenerated by removing various coating films by using the glass panel regenerating apparatus (FIG. 1) described in Embodiment 1 above. The description is omitted because it is similar to the first embodiment.

In this embodiment, a disc-shaped felt buff 8 having a diameter of 120 mm and made of 100% stainless steel fiber having a strand diameter of 6 to 10 μm was used as a polishing buff. The pressure (pressing force) applied to the inner surface of the panel 5 is adjusted to 1.5 kg / cm ² by increasing or decreasing the pressure of the air cylinder 10, and the moving speed of the pedestal 6 holding the panel 5 in the front-rear direction is reduced to 30 kg / cm ^2.
The movement pitch of the felt buff 8 in the left-right direction along the copying arm 11 was 50 mm / sec. As the mixed polishing liquid, a mixture prepared by mixing 150 parts by weight of water and 10 parts by weight of a surfactant with respect to 100 parts by weight of the cerium oxide polishing powder was used, and the mixed polishing liquid was moved near the felt buff 8. It was supplied at a constant rate to the direction side. Under these conditions, after approximately two reciprocations of polishing for about 5 minutes, the inner and outer surfaces of the panel 5 were washed with water. The panel 5 regenerated by the above method was washed with an aqueous solution of hydrofluoric acid or an aqueous solution of ammonium ammonium fluoride, and then subjected to a graphite coating step. As a result, interference unevenness, which had conventionally been a problem, did not occur.

In this embodiment, the wire diameter is 6 to 10 μm.
Although a felt buff made of 100% stainless steel fiber and having a diameter of 120 mm was used, a disc-shaped web buff made of a similar material may be used. In addition, wire diameter 10
50% of stainless steel fiber of ~ 15 µm, strand diameter of 10-1
Almost the same results were obtained using a buff made of 50% nylon fiber of 5 μm.

[0022]

As described above, according to the present invention, the inner surface of the color CRT glass panel having the inner surface coated with the graphite film and the fluorescent film is coated with a mixed polishing liquid containing at least cerium oxide polishing powder by 5 to 20 μm. By polishing with a disc-shaped web buff or felt buff made of one or more of any one of stainless steel fiber, nylon fiber, polyester fiber or polyaramid fiber having a wire diameter of, removing the graphite film and the fluorescent film, the glass Since no irregularities are formed on the inner surface of the panel,
The glass panel can be regenerated so as not to cause interference unevenness at the time of re-use, and the recovery and recovery rate of the defective panel is significantly improved.

In addition, by mixing a surfactant with a mixed polishing solution containing at least cerium oxide polishing powder, unevenness in cleaning caused by the organic components contained in the cerium oxide polishing powder remaining fixed on the glass panel surface is eliminated. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view showing a color CRT glass panel reproducing apparatus according to a first embodiment of the present invention.

FIG. 2 is a top view illustrating a color CRT glass panel reproducing apparatus according to the first embodiment of the present invention.

FIG. 3 is a partially enlarged cross-sectional view of the inner surface of a glass panel for explaining a cause of interference unevenness that occurs when a conventional defective panel is reused.

FIG. 4 is a front view and a side view showing a conventional CRT polishing apparatus.

[Explanation of symbols]

1, 5, 15 glass panel, 2 graphite film, 3
Fluorescent film, 4 irregularities, 6 pedestals, 7 moving speed adjusting mechanism, 8 stainless steel fiber felt buff, 9 sander, 10 air cylinder, 11 copying arm, 12 moving speed adjusting mechanism, 13 polishing buff, 14 joint mechanism, 16 rotary polishing jig.

Continued on the front page. (72) Inventor Akito Yamamoto 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Inventor Naoki Masae 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Incorporated F term (reference) 3C049 AA06 AA07 AA09 AC04 CA01 CA06 CB03 5C012 AA02

Claims (6)

[Claims] 1. A method for regenerating a color CRT glass panel having an inner surface coated with a graphite film and a fluorescent film, wherein the inner surface of the panel is polished with a mixed polishing solution containing at least cerium oxide polishing powder and a polishing tool, A method for regenerating a color CRT glass panel, comprising a step of removing the graphite film and the fluorescent film. 2. The method for regenerating a color CRT glass panel according to claim 1, wherein the mixed polishing liquid contains a surfactant. 3. The mixed polishing liquid is cerium oxide polishing powder 10.
The color CRT glass panel according to claim 1 or 2, wherein the mixing ratio is 50 to 300 parts by weight of water and 0 to 30 parts by weight of a surfactant with respect to 0 parts by weight. Method. 4. A disk-shaped web buff or felt buff made of one or more of stainless steel fiber, nylon fiber, polyester fiber and polyaramid fiber having an element diameter of 5 to 20 μm as a polishing tool. The method for regenerating a color CRT glass panel according to any one of claims 1 to 3, characterized in that: 5. A pedestal holding a color CRT glass panel having an inner surface coated with a graphite film and a fluorescent film and movable in the front-back or left-right direction on the same plane, and a moving speed adjusting mechanism thereof, and a disk made of web or felt A polishing buff of a shape is attached to the tip, a sander that presses and rotates the polishing buff on the surface to be cleaned of the panel and a pressure adjusting mechanism thereof, formed to imitate the curvature of the surface to be cleaned of the panel, A copying arm for moving the sander in the left-right or front-rear direction along the surface to be cleaned of the panel and a moving speed adjusting mechanism thereof, and a moving direction side near the polishing buff that moves while rotating on the surface to be cleaned of the panel. And a polishing liquid supply mechanism for supplying a predetermined amount of the mixed polishing liquid to the glass panel. 6. The sander according to claim 5, wherein the polishing buff rotates (revolves) concentrically around its center and further rotates (revolves) over a wide range around other parts. A reproducing apparatus for the color CRT glass panel described in the above.