JPS6012983B2 - Sealing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing method using a frit glass mixture for manufacturing color cathode ray tubes, crab light display tubes, and the like.

For example, when manufacturing cathode ray tubes, a funnel and a panel are sealed together using a fritted gas mixer (hereinafter referred to as mixer).

That is, as shown in FIG. 1, a mixture 3 is applied onto a sealed end surface 2 of a funnel 1 serving as one member to be sealed. This mixture 3 is prepared by dissolving one part of nitrocellulose or ethylcellulose in an organic solvent such as aluminum isoacetate or butyl isoacetate or butylcarpitol acetate to form a vehicle, and adding 2000 g of this mixture to the vehicle. Add one piece of frit glass powder that passes through the mesh, and knead well to form a sludge. After applying the mixture 3, it is dried by heating at 13,000 for 5 to 10 minutes, and then the panel 4, which is the other member to be sealed, is sealed to the sealing end surface 2 of the funnel 1. The bridge surface 5 is accurately aligned using a positioning jig or the like, bonded via the mixer 3, and heated at a high temperature of, for example, 4000° for one hour.
In this heating process, first, the nitrocellulose in Mixture 3 is decomposed and evaporated, and then the frit glass is melted and crystallized at 400 to 45 mm, or it is slowly cooled while remaining amorphous. The sealing is completed, and the outer container of the cathode ray tube is formed. Conventionally, in such a manufacturing process, the mixer is made relatively thick, e.g.
．． 5 When applying to the skin, since the specific gravity of Mixture is large, for example, d: 4 to 6, the sealing end surface 2 of the funnel 1
A discharge and fall method is used in which the mixer is turned upward and the mixture discharged from the applicator is dropped. However, according to such a method, a dent is likely to occur in the center of the mixer 3 after drying. If there is such a recess, when the panel 4 is superimposed on the funnel 1, a space will be created in the recess.

Therefore, if the frit glass is melted and sealed in this state, much of the air in the space will escape, but there will be a portion where it cannot escape, forming a cavity in the frit glass layer. In addition, if the tube is sealed while air is escaping, vent holes are formed inside or outside the tube, and further between the inside and outside of the tube.
Not only tubes with ventilation holes inside and outside, but also tubes with ventilation holes on one side, and tubes with no ventilation holes that significantly reduce the effective length of the frit glass layer, Complete vacuum secrecy cannot be maintained due to air leaks. Further, as the withstand voltage decreases, arc heat causes a through hole in the part, which similarly destroys the vacuum seal and destroys the cathode ray tube. As a method for improving such defects, it is conceivable to turn the sealing end surface 2 of the funnel 1 downward and supply and apply the mixture from below.

According to this method, the mixer is on the lower side;
Furthermore, as mentioned above, the specific gravity of Mixture is large and heavy, for example, d: 4 to 6, so the surface has a large degree of curvature, and even after drying, it remains a protruding surface and does not have the above-mentioned dents. However, good results can be obtained. However, even with this method, there are restrictions on the physical characteristics of the mixture used.

For example, if the viscosity of the mixed tea is too low, mountain-shaped protrusions are formed on the surface of the mixed tea 3. In such a state, during sealing, the accuracy of regulating the position with the panel may be hindered, or a portion with a large amount of mixture may protrude in a large amount, and a portion with a small amount of mixture may not be filled, causing vacuum breakdown. The present invention has been made in view of these points, and an object of the present invention is to uniformly apply a mixed layer over the entire surface without creating dents or protrusions on the surface.

Next, an embodiment of the present invention will be explained in the case of manufacturing a cathode ray tube with reference to FIGS. 2 and 3.

11 is a coating device, and this coating device 11 has a container 12 that is long in the horizontal direction.

This container 12 consists of a bottom plate 13, long side plates 14 on the front and rear surfaces, and short end plates 15 on both end surfaces.Furthermore, an upper cover plate 16 is attached to the front and rear of the upper surface, and a closed door is provided between the front and rear upper cover plates 16. 17 is formed. A coating mechanism 21 is provided within the container 12. This application mechanism 21
A rotary shaft 22 is rotatably supported between the end plates 15 at both ends of the container 12, and a roller 23 made of stainless steel, rubber, etc. is fixed to the rotary shaft 22. It protrudes slightly from Sekiguchi 17. A driving gear 24 is fixed to the protrusion at one end of the rotating shaft 22, and a driving device (not shown) is connected to this gear 24, so that the roller 23 is rotated together with the rotating shaft 22. Further, a thickness regulating piece 25 is attached to the inner side of the side plate 14 on the front side of the container 12 so as to be able to freely adjust the advancement limit with respect to the surface of the roller 23 via a support mechanism 26. A scraping piece 27 is attached to the inner side of the cylindrical surface of the roller 23 via a support mechanism 28 so as to be able to freely adjust the advance limit. A transfer device 31 is disposed above the coating device 11.

In this transfer device 31, suspension devices 33 are movably provided on a rail 32 at predetermined intervals. Further, a support stand 34 is provided below the seal 32 up to the coating device 11 section. Then, the mixture 3 is injected and stored in the container 12 of the coating device 11 so that the lower part of the roller 23 is submerged in contact with the container 12 . Then, when the roller 23 is rotated in the direction of the arrow, the mixture 3 adheres to the roller 23, is drawn up, and rises.

This is scraped off at the tip of the thickness regulating piece 25 so that the mixed tea film 3a has a desired thickness, thereby regulating the amount of the mixed tea film 3a that adheres to the roller 23 and moves up. On the other hand, one of the funnels 1 serving as a sealing section is held between the necks of each suspension device 33 of the transfer device 31 and suspended with the sealed end surface 2 facing downward.
is placed on the support stand 34 and moved along the rail 32 in the direction of the arrow. Then, the funnel 1 is the mixture membrane 3a.
When the sealed end surface 2 comes onto the roller 23 coated with
is attached to the sealed end surface 2. In this case, it is preferable to set the sealing end surface 2 of the funnel 1 at a position slightly above the upper outer circumferential surface of the roller 23 so that it bites into the mixture film 3a by about 0.05 to 0.5 degrees. Furthermore, the rotational speed of the roller 23 can be adjusted by setting its peripheral speed, more precisely, the peripheral speed of the mixer at the position corresponding to the sealed end surface 2 of the funnel 1, to be the same as the feeding speed of the funnel 1. The thickness of the mixture applied to the sealed end surface 2 can be made most uniform. Then, as the roller 23 rotates, the excess mixed flour 3 adhering to the roller 23 is removed by the residual liquid scraping piece 27, merges with the mixed flour 3 in the container 12, and moves up again by the roller 23.

In this way, after applying the mixcha 3 with the sealing end surface 2 of the funnel 1 facing downward, the funnel 1 is turned over and the sealing end surface 2 is facing upward within the time that the applied mixcha 3 does not dry. . As a result, the protrusions that appear in the downward state of the Mixture 3 tend to fall due to their own weight and surface tension, sink into the nearby Mixture layer, and become flat, but as shown in Figure 4. Minor unevenness remains. Immediately after the funnel 1 is inverted, a vibrating body 41 consisting of a mechanical pipelator, an ultrasonic vibrator, or the like is applied to the funnel 1 to give vibration to the funnel 1.

This vibration reduces the viscosity of the mixed cha 3, and the unevenness on its surface is absorbed into the mixed cha layer, making it smooth as shown in Figure 5, and the surface of the frit glass after drying has less curvedness and is flat. It becomes close to. After applying the mixed cha 3, it is dried in the same manner as before, and then a panel 4, which is the other member to be sealed, is placed on the sealed end face 2 of the funnel 1, and the sealed end face 5 is attached to the sealed end face 2 of the funnel 1. 3, heated and sealed, and then subjected to a cooling process to form the outer envelope of a cathode ray tube.

In the above method, it is best to invert the funnel mixture relatively early after application, but the time until inversion starts is determined by the physical characteristics of the mixture, its thickness, the width of the application area, etc. .

That is, the time from when the mixed tea is applied until the beginning of the inversion is preferably carried out when the mixed tea has stopped dripping.

If the viscosity of the mixed tea is low, some of the mixed tea will drip like rain immediately after application, and if the viscosity is high, it will drip while pulling strings, and if you turn it over in this condition, the mixed tea will drip inside and outside the funnel. . For example, it consists of 0.066% nitrocellulose, 7.33% butyl acetate and 92.6% fritted glass powder, and has a viscosity of 70%.
For a mixture of 0.00 centipoise, approximately 5 seconds after application is appropriate. In addition, when using a mixer that uses ethyl acetate etc. and has a high drying speed, if it takes a long time to turn over,
As the surface layer of the mixture continues to dry, even if it is inverted, the effect of absorbing the protrusions will be small, so it is better to invert it a little further away.
Also, the faster the funnel is turned, the better; however, if it is too far, the centrifugal force during reversal may cause the mixer to be blown away or become lopsided, so it should be determined based on the shape of the funnel, the characteristics of the mixer, etc. .

For example, when the viscosity of the mixture is 7,000 centipoise, the thickness is 0.8cm, and the application width is 8cm, and the rotation radius of the rotating mixcha part is 40mm or less, 0.5~
1.9 degrees is appropriate. In addition, in order to avoid applying large acceleration to the mixed gear, it is preferable to set the speed at the beginning and end of the rotation to be low, and to set the speed at the middle to high speed. and,
It is preferable to set the center of rotation at the time of reversal toward the mixer, that is, toward the sealed end surface of the funnel. In addition, when the funnel is vibrated, in addition to directly applying vibration to the funnel immediately after reversing as described above, vibration may also be applied to the chuck supporting the funnel immediately after reversing. As shown, the funnel 1 may be inverted and placed on the frame 42, and the frame 42 may be vibrated by the diaphragm 43 to indirectly vibrate the funnel 1.

In addition, the magnitude and time of vibration by the vibrating body can be selected depending on the viscosity of the mixture, the amount of application, the degree of dripping, and the shape and size of the funnel.
As for the direction of vibration, horizontal vibration has a large effect, and even vertical vibration has a sufficient effect if it is large.In practice, vibration may be applied from an oblique direction to act as component forces in the horizontal and vertical directions.

In addition, in the implementation, even if the thickness regulating piece 25 in the coating mechanism 21 is not used, the viscosity of the mixture and the roller 2
Although it is possible to pump up a certain amount of mixture by regulating the outer diameter, rotation speed, etc. of 3, it is possible to make it more uniform by using the thickness regulating piece 25.

Furthermore, although it is possible to apply the coating without using the scraping piece 27, if the operation is continued for a long period of time, a layer of the mixed mixture that moves and thickens will remain on the surface of the roller 23, and the sealing end surface 2 of the funnel 1 will be coated. Its use is desirable because it reduces the amount of mixture applied and causes local variations in thickness.

moreover,. By providing an angle at the opposite end in contact with the roller 23, that is, at the end where the mixer falls, the air bubbles can be pushed out and defoamed there. In the above embodiment, the case where the funnel and panel of a cathode ray tube are sealed with a mixture was explained, but for example, the base glass and cover glass of a flat light display tube may be sealed with a mixture. It can be widely used in the production of articles such as glass tubes.

According to the present invention, a mixture is supplied and applied from below to the sealing end surface of one of the sealed members such as a funnel, and before the applied mixture dries, one of the sealed members is coated. By inverting the parts so that the sealed end face, that is, the coated mixture char faces upward, and applying vibration to one of the sealed members, the weight and surface tension of the mixture char, as well as the viscosity caused by the vibration, are reduced. By lowering, the protrusions of the mixer can be absorbed and the mixer can be coated uniformly and flatly, which is particularly effective when using a high-viscosity mixer to increase the coating thickness. Therefore, the sealing with the other sealed part can be performed reliably.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the funnel and panel of a cathode ray tube, FIG. 2 is a cross-sectional view of the device showing one embodiment of the present invention, and FIG.
The figure is a partially cut away perspective view, FIGS. 4 and 5 are cross-sectional views showing the coating state according to the method of the present invention, and FIG. 6 is a side view of another embodiment in a vibrating state. 1. ．．・・・・Funnel as one of the attached villages,
2... Sealed end face, 3... Frit glass mixture, 4... Panel as the other member to be sealed, 5... Sealed end face. Figure 4, son-in-law, figure 5, figure 6, figure 2, figure 2, figure 3, figure 3.

Claims (1)

[Claims] 1. Apply a frit gas mixture from below to the sealed end surface of one of the members to be sealed with the sealed end surface facing downward, and apply the frit gas mixture to one of the members within the time that the applied frit gas mixture does not dry. While inverting the sealing member so that its sealed end face faces upward, vibration is applied to one of the members to be sealed, and then the sealing end face of the one member to be sealed is applied to the sealed end face of the other member to be sealed. A sealing method characterized by joining and sealing the bonded end surfaces.