JP3475913B2 - Separation method of glass panel and funnel - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for separating a glass panel and a funnel.

[0002]

2. Description of the Related Art Generally, in a cathode ray tube, a glass panel and a funnel are joined by frit glass, and when a defective product is produced in the manufacturing process, the glass panel and the funnel are separated and recycled. .

Conventionally, as a method for separating a glass panel and a funnel, a Braun tube is immersed in a nitric acid solution to dissolve a part of the frit glass, and then hot water and cold water are applied to the outer surface of the glass panel 8 as shown in FIG. A method is known in which the glass panel 8 and the funnel 9 are separated by alternately pouring water and applying thermal stress to the frit glass 4.

In FIG. 4, 10 indicates a nozzle.

By the way, as the cathode ray tube, as shown in FIG. 5, a glass panel 8 of a normal type in which the thickness is substantially uniform in the central portion and the edge portion, and as shown in FIG. There is a flat type in which the central portion and the edge portion have different wall thicknesses.

The wall thickness ratio B ₁ / A ₁ between the central portion and the edge portion of the glass panel 8 of the ordinary cathode ray tube (the ratio of the wall thickness B _{1 at} the edge portion to the wall thickness A _{1 at the} central portion in FIG. 5) is It is almost 1.
Further, (6, the ratio of the thickness B ₂ of the edge relative to the thickness A ₂ of the central portion) wall thickness ratio B ₂ / A ₂ between the central portion and the edge portion of the flat type cathode ray tube of the glass panel 11 is substantially It is 2.

[0007]

However, in such a conventional method for separating a glass panel and a funnel, such a glass panel 11 has a wall thickness at the central portion and at the edge portion, especially when it is used for a flat cathode ray tube. Because of the large difference, when the thermal stress is applied to the frit glass 4, the distribution of the thermal stress applied to the glass panel 4 becomes non-uniform, and as a result, the glass panel 11 is broken.

The present invention has been made to solve such a problem, and is a method for separating a glass panel and a funnel which can prevent the glass panel from cracking when thermal stress is applied to the frit glass. The purpose is to provide.

[0009]

A method for separating a glass panel and a funnel according to the present invention is a method for separating a CRT in which a glass panel and a funnel are joined by frit glass into the glass panel and the funnel. And immersing the CRT in an organic acid solution
And a melting step of melting a part of the frit glass,
A warm bath warming step of warming the cathode ray tube with a warm bath, and a thermal stress is applied to the frit glass by alternately pouring hot water and cold water on the outer surface of the funnel, and a separation step of separating the glass panel and the funnel. Is used sequentially.

By using this method, the thermal stress applied to the glass panel can be reduced and the distribution of the thermal stress can be made uniform.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

In the method of separating the glass panel and the funnel according to the embodiment of the present invention, a melting step, a warm bath keeping step and a separating step, which will be described later, are performed in this order.

First, the structure of the cathode ray tube before reproduction will be described.

As shown in FIG. 2, in the cathode ray tube 1, a glass panel 2 and a funnel 3 are joined by a frit glass 4.

The funnel 3 has a neck portion 3a in which an electron gun (not shown) is housed, and a high voltage necessary for operating the cathode ray tube 1 is provided with an internal duck (which is formed on the inner surface of the funnel 3). And an anode contact button 3b made of stainless steel for applying to the electron gun via a not shown).

Next, each step will be described.

In the melting step, the cathode ray tube 1 is placed at 35 ° C. to 4 ° C.
It is immersed in an organic acid solution of glycolic acid or the like at 5 ° C. for 3 to 5 minutes while applying ultrasonic vibration, and a part of the frit glass 4 is dissolved by the organic acid solution. By applying ultrasonic vibration to the organic acid solution in this way, the dissolution of the frit glass 4 can be promoted.

Then, in the warm bath warming step, as shown in FIG. 2, the cathode ray tube 1 in which a part of the frit glass 4 is melted with the funnel 3 positioned above the glass panel 2 is placed from the glass panel 2 side. A warm bath is kept warm by immersing in warm water 5 at 45 ° C to 55 ° C for 4 to 6 minutes. At the time of keeping the temperature in the hot bath, the funnel 3 is immersed in the frit glass 4 by 20 mm or more (hereinafter referred to as immersion depth D (mm)).

Reference numeral 6 indicates a weight.

The surface temperature of the glass panel 2 after the warm bath is kept at 38 ° C. to 43 ° C. and the surface temperature of the funnel 3 is 20 ° C.
The temperature was between 30 ° C and 30 ° C. It is preferable that the surface temperature of the funnel 3 after the warm bath is kept at 20 ° C. or higher because a crack in the glass panel 2 occurs if the temperature difference between the funnel 3 and the hot water poured into the funnel 3 is large in the separation step described later.

Next, after taking out the cathode ray tube 1 from the hot water, in the separation step, as shown in FIG. 1, from the upper part of the funnel 3 to the part around the central axis X (see FIGS. 1 and 3) of the funnel 3. Towards the entire outer surface of the funnel 3 (excluding the neck portion 3a), hot water (first stage) and cold water (2
Thermal stress is applied to the frit glass 4 by pouring water in 3 steps for 20 seconds to 60 seconds in the order of step) and warm water (3 step), and the glass panel 2 and the funnel 3 are separated.

The temperature difference T between hot water and cold water is preferably 30 ° C. or higher. For example, the temperature of hot water is preferably 40 ° C. to 60 ° C., and the temperature of cold water is preferably 10 ° C. to 20 ° C.

As shown in FIGS. 1 and 3, four nozzles 7 (only two are shown in FIG. 1) for pouring hot water and cold water are provided above the funnel 3 and the funnel 3.
Are arranged so as to surround the central axis X and face each other across the central axis X.

A separation method for separating the CRT 1 in which the glass panel 2 and the funnel 3 are joined by the frit glass 4 as described above into the glass panel 2 and the funnel 3, and a part of the frit glass 4 is separated. A melting process of melting, a warm bath warming process of warming the cathode ray tube 1 and a hot bath warming process by alternately pouring hot water and cold water onto the outer surface of the funnel 3 to apply heat stress to the frit glass 4 and the glass panel 2 and the funnel 3. By sequentially including the separation step of separating the heat stress, the heat stress applied to the glass panel 2 can be reduced, and the distribution of the heat stress can be made uniform. Therefore, when the heat stress is applied to the frit glass 4, It is possible to prevent the glass panel 2 from breaking.

In the melting step, when the cathode ray tube 1 is dipped in an organic acid solution to dissolve a part of the frit glass 4, a conventional nitric acid is used to dissolve the frit glass 4. In comparison, it has no effect on the environment and the human body, is easy to handle, and can prevent corrosion of the anode contact button 3b used in the cathode ray tube 1 and equipment of the melting process. Since it is possible to prevent corrosion of the equipment and the like, it is possible to reduce equipment costs and maintenance costs.

Further, in the separation step, hot water and cold water are poured from above the funnel 3 toward a portion around the central axis X of the funnel 3, so that the distribution of the thermal stress applied to the glass panel 2 is more uniform. Therefore, it is possible to further prevent the glass panel 2 from being broken when a thermal stress is applied to the frit glass 4.

Next, experimental examples will be described in order to confirm the effects of the present invention.

100 cathode ray tubes 1 were produced by a usual method, and the produced cathode ray tube 1 was tried to be regenerated by the following method, and the presence or absence of cracks in the glass panel 2 was examined.

36-inch flat type CRT 1 (thickness 15 mm at the center and thickness 38 mm at the edge) is 4
While applying ultrasonic vibration to glycolic acid solution at 0 ° C, 5
It was immersed for a minute to melt a part of the frit glass 4. Then, the cathode ray tube 1 was immersed in warm water 5 at 50 ° C. for 5 minutes to keep it warm in a warm bath. When the warm bath was kept warm, the immersion depth D of the funnel 3 was set to 50 mm. The surface temperature of the glass panel 2 after the warm bath was 41 ° C., and the surface temperature of the funnel 3 was 25 ° C.

Next, hot water at 55 ° C., cold water at 15 ° C., 55
Heat stress is applied to the frit glass 4 by pouring hot water of ℃ from the upper part of the funnel 3 toward the peripheral part of the central axis X of the funnel for 30 seconds in each of three stages, so that the glass panel 2 and the funnel 3 are separated from each other. separated.

As a result, the number of cracks in the glass panel 2 was 0 out of 100. In addition, when the edge surface of the separated frit glass 4 was visually observed, the surface was very smooth.

For comparison, a conventional method as shown in FIG. 4, that is, the Braun tube 1 is immersed in a nitric acid solution at 40 ° C. for 10 minutes to dissolve a part of the frit glass 4, and then the Braun tube 1 is used. 60 ° C. hot water and 12 ° C. cold water were sequentially poured onto the glass panel 2 for 20 seconds to 30 seconds to apply thermal stress to the frit glass 4 to separate the glass panel 2 and the funnel 3.

As a result, the glass panel 2 has 10 cracks.
50 out of 0 occurred. Further, when the edge surface of the separated frit glass 4 was visually observed, irregularities were found on the surface.

As described above, it was confirmed that the glass panel 2 can be prevented from cracking when the thermal stress is applied to the frit glass 4 by the method for regenerating a cathode ray tube according to the present invention.

Here, various conditions in the warm bath heat retaining step were examined.

In the warm bath warming step, the immersion depth D (mm) of the funnel 3, the temperature of the warm water 5 (° C.), and the warm water 5
When the presence or absence of cracks in the glass panel 2 when various immersion times (minutes) were changed was examined, the results shown in Table 1 were obtained.

However, in the dissolving step, glycolic acid at 40 ° C. was used as the organic acid solution, and the immersion time was 5 minutes. In addition, in the separation step, warm water at 55 ° C and 1
Three-stage water injection was performed using 5 ° C. cold water, and hot water and cold water were injected for 30 seconds each.

In Table 1, "○" means good.
“X” indicates each defect.

[0039]

[Table 1]

As is clear from Table 1, in the warm bath heat-retaining step, the funnel 2 has an immersion depth D of 20 mm or more, the hot water 5 has a temperature of 45 ° C. to 55 ° C., and the hot water 5 has an immersion time of 4 to 6 minutes. It can be understood that the glass panel 2 can be prevented from being broken by defining the respective ranges.

Therefore, in the warm bath warming step, the immersion depth D of the funnel 2 should be 20 mm or more, the temperature of the hot water 5 should be 45 to 55 ° C., and the immersion time of the hot water 5 should be 4 to 6 minutes. Is preferred.

Next, various conditions in the separation process were examined.

In the separation step, when the temperature difference T (° C.) between the hot water and the cold water and the pouring time (seconds) of the hot water and the cold water were variously changed, the presence or absence of cracks in the glass panel 2 was examined. The results shown in Table 2 were obtained.

However, in the dissolving step, glycolic acid at 40 ° C. was used as the organic acid solution, and the immersion time was 5 minutes. Also, in the warm bath insulation process, funnel 3
The immersion depth D was 50 mm, the temperature of the hot water 5 was 50 ° C., and the immersion time of the hot water 5 was 30 seconds.

In Table 2, "○" means good,
“X” indicates each defect.

[0046]

[Table 2]

As is apparent from Table 2, in the separation step, the temperature difference T between the hot water and the cold water is set to 30 ° C. or more, and the hot water and cold water pouring time is set to 20 seconds or more, respectively. It can be seen that cracking can be prevented. However, if each of the hot water and cold water pouring times exceeds 60 seconds, the pouring time becomes too long and the production efficiency is considerably lowered, which is not practical.

Therefore, in order to prevent the glass panel from cracking and to suppress the deterioration of the production efficiency, the temperature difference T between the hot water and the cold water is 30 ° C. or more, and the pouring time of the hot water and the cold water is respectively set. It is preferable to define each in the range of 20 seconds to 60 seconds.

In the above embodiment, the case where glycolic acid is used as the organic acid solution has been described, but not limited to this, maleic acid, malic acid, formic acid, lactic acid, acetic acid,
Even when an organic acid solution such as dichloroacetic acid and pyruvic acid is used, the same effect as above can be obtained.

In the above embodiment, the case of pouring hot water, cold water, and hot water in three steps in the order of separation has been described, but even if thermal stress is applied to the frit glass 4 by pouring water in three steps. , If the glass panel 2 and the funnel 3 are not separated, for example, hot water (first stage),
Thermal stress is applied to the frit glass 4 by pouring cold water (second step), hot water (third step), cold water (fourth step), and hot water (fifth step) in five steps in this order, and the glass panel 2
And the funnel 3 may be separated.

In the above embodiment, the case where the flat type cathode ray tube is regenerated has been described as an example, but the present invention can be applied to the regeneration of the ordinary type cathode ray tube.

Further, the present invention is not only used as a method for separating the glass panel 2 and the funnel 3 when regenerating the cathode ray tube 1, but also when the cathode ray tube 1 is discarded and the like. And the funnel 3 can be separated from each other.

[0053]

As described above, according to the present invention, the thermal stress applied to the glass panel can be reduced and the distribution of the thermal stress can be made uniform, so that the glass panel can be prevented from cracking. It is possible to provide a method of separating the glass panel and the funnel which can be performed.

[Brief description of drawings]

FIG. 1 is a front view schematically showing a separation step in a method for separating a glass panel and a funnel which is an embodiment of the present invention.

FIG. 2 is a front view that also schematically shows the warm bath insulation process.

FIG. 3 is a plan view that also schematically shows the separation step.

FIG. 4 is a diagram schematically showing a conventional method for separating a glass panel and a funnel.

FIG. 5 is a front cross-sectional view of a glass panel of an ordinary CRT.

FIG. 6 is a front cross-sectional view of a flat type CRT glass panel.

[Explanation of symbols]

1 CRT 2 glass panels 3 funnel 3a neck part 3b Anode contact button 4 frit glass 5 hot water 6 weights 7 nozzles

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidefumi Okada 1-1, Sachimachi, Takatsuki, Osaka Prefecture Matsushita Electronics Industrial Co., Ltd. (72) Hideaki Tokian 1-1, Sachimachi, Takatsuki, Osaka Matsushita (56) Reference JP 62-200638 (JP, A) JP 1-194239 (JP, A) JP 3-156830 (JP, A) JP 8-310838 (JP, A) JP 2001-297701 (JP, A) Japanese Patent Publication No. 3-79812 (JP, B2) Patent 2710071 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 9/50

Claims (6)

(57) [Claims] 1. A separation method for separating a CRT in which a glass panel and a funnel are joined by frit glass into the glass panel and the funnel, wherein the CRT is dipped in an organic acid solution to form the frit. A melting step of melting a part of the glass, a warm bath warming step of warming the cathode ray tube, and a thermal stress is applied to the frit glass by alternately pouring hot water and cold water onto the outer surface of the funnel to apply the thermal stress to the glass. A method of separating a glass panel and a funnel, which comprises sequentially separating a panel and the funnel. 2. In the dissolving step, the Braun tube is immersed in an organic acid solution at 35 ° C. to 45 ° C. for 3 minutes to 5 minutes, and ultrasonic vibration is applied to the organic acid solution. 1 Symbol placing a glass panel and a funnel with separation methods. 3. In the warm bath heat retaining step, the Braun tube is immersed in hot water at 45 ° C. to 55 ° C. from the glass panel side with the glass panel of the Braun tube positioned below and the funnel positioned above. be those, wherein CRT is the while immersed warm water to the frit glass 20mm or more 45 ° C. to 55 ° C., according to claim 1 or <br/> claims, characterized in that warm bath kept 4 minutes to 6 minutes Item 3. A method for separating a glass panel and a funnel according to item 2 . 4. In the separating step, hot water, cold water, and hot water are poured into the outer surface of the funnel in three steps in this order to apply thermal stress to the frit glass to separate the glass panel and the funnel. The method for separating a glass panel and a funnel according to any one of claims 1 to 3 , characterized in that. 5. A temperature difference T between the hot water and the cold water in the separating step is 30 ° C. or more, and a pouring time of the hot water and the cold water is each 20 seconds to 60 seconds. A method for separating the glass panel and the funnel according to any one of claims 1 to 4 . 6. The separation step, any one of claims 1 to 5, characterized in that the water injection toward the hot and the cold water from above of the funnel to the surrounding portion of the central axis of the funnel The method for separating the glass panel and funnel described in.