JPH0859292A - Crystallizing sealant glass and production of information display apparatus using the same - Google Patents

Abstract

PURPOSE: To carry out sealing of high strength in a short time by including crystallizing glass powder capable of depositing plural crystalline phases mutually different in depositing time and crystalline nuclei including a crystal phase secondarily depositing into a crystallizing glass in a larger amount than primarily depositing crystal phase. CONSTITUTION: This crystallizing sealant glass has a composition composed of 60-85wt.% of PbO, 5-15wt.% of B2 O3 , 8-18wt.% of ZnO, 0-5wt.% of SiO2 and 0-5wt.% of BaO, and a crystalline phase secondarily depositing into crystallizing glass is 4PbO.B2 O3 and the crystalline phase contains 1-6000ppm crystalline nuclei, and the crystalline nuclei contain 4PbO.B2 O3 crystalline phase in a larger amount than a crystalline phase primarily depositing into the crystallizing glass. A cathode-ray tube using the crystallizing sealant glass is produced as follows. Sealant glass is mixed with vehicle according to ordinary method to prepare slurry. The slurry is applied to a face to be bonded by funnel glass and then a panel glass to which fluorescent substance is applied is brought into contact with the face to be bonded, and heated and baked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystalline sealant glass and a method for manufacturing an information display device such as a cathode ray tube or a plasma display using the same.

[0002]

2. Description of the Related Art A crystalline sealant glass that precipitates a crystalline phase in glass by firing is used for various sealings such as sealing between a panel glass and a funnel glass in manufacturing a cathode ray tube.

The process of crystallizing glass is divided into a process of generating nuclei in the glass and a process of growing crystals centering on the nuclei. Usually, in the case of producing crystallized glass, as a means for promoting the precipitation of a crystal phase, 1) a nucleating substance is put in advance in the melting process of glass, 2) glass is powdered and the surface thereof is used as a nucleus. It is known to use it. For crystalline sealant glass,
The method 2) is generally used.

Particularly in a crystalline sealant glass for assembling a high vacuum container such as a cathode ray tube or an intermediate vacuum container such as a plasma display, a large tensile stress is always applied to the sealing region, Sufficient strength is required for the sealant glass fired body to withstand it. Therefore, generally, a crystalline sealant glass that precipitates two or more kinds of crystalline phases by firing is used,
The interaction of the crystal phases ensures the strength of the fired body.

As such a crystalline sealant glass, there is a PbO-B ₂ O ₃ -SiO ₂ -ZnO-BaO type glass, and a glass containing a small amount of zircon. Such crystalline sealant glass, _{fired, 2PbO · ZnO · B 2 O} 3 crystal phase precipitates to a first, 4PbO · B ₂ O ₃ crystal phase is deposited on the second.

FIG. 1 shows the DTA characteristics of such a crystalline sealant glass. The left vertical axis represents the calorific value (or heat absorption amount) of the glass, the right vertical axis represents the firing temperature of the glass, and the horizontal axis represents the time.
The temperature was raised from room temperature to 440 ° C at 10 ° C / min and the holding temperature was 44
The temperature was maintained at 0 ° C. and baking was performed. In FIG. 1, the crystalline glass softens in the region a, flows in the region b, and the crystalline phase precipitates in the region c. One th peak C ₁ is the exothermic peak of the crystal phase 2PbO · ZnO · B ₂ O ₃ precipitated to a first, a second peak C ₂ crystalline phase 4PbO · B ₂ O ₃ precipitated Second It is an exothermic peak.

However, in such a crystalline sealant glass, a plurality of crystalline phases are sequentially deposited as shown in FIG. 1. Therefore, by the time these depositions are completed, a crystalline sealant glass having only a single crystalline phase is obtained. In comparison, it was unsatisfactory in that it took a long time and productivity was poor.

In order to secure the strength of the sealed portion,
Not only the strength as a fired body of the crystalline sealant glass, the mutual mutual diffusion of the elements constituting the crystalline sealant glass and the adherend glass is sufficiently adhered to each other firmly, and the crystalline sealant glass and the adherend glass It is essential that the wetting stress concentration does not occur sufficiently at the interface of.

Therefore, since the powdery or paste-like crystalline sealant glass is once softened by firing, sufficient interdiffusion and sufficient flow occur until the initiation of precipitation of the crystalline phase, and ideal wetting can be secured. Is required, and when these times are added together, it becomes a relatively long time.

Conventionally, as a method for shortening the crystal phase precipitation time, it has been known to increase the amount of oxide having a relatively low melting point in the composition of the crystalline sealant glass, but generally, the precipitation of the crystal phase is performed. And the flow time from the melting to the start of precipitation of the crystal phase is shortened, and sufficient wettability cannot be secured.

As another method, it is also known to pulverize a sealant glass in which a crystal phase is precipitated and use the particles as crystal nuclei (JP-A-62-226828). However, even in this method, the main component of the crystal nuclei is the crystal phase that precipitates first, so if the amount required to obtain a shortening of the precipitation time of the second and subsequent crystal phases is added, the above-mentioned flow time also increases. It is shortened and causes the same problem.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a crystal that does not cause a decrease in strength, shortens the time required for sealing, and improves productivity. A sealant glass and an information display device using the same are provided.

[0013]

The present invention comprises a crystalline glass powder which precipitates a plurality of crystalline phases having different precipitation times and a crystal nucleus, and the crystal nucleus is precipitated in the crystalline glass after the second. The present invention relates to a crystalline sealant glass containing a larger amount of crystalline phase than the crystalline phase that precipitates first, and a method for manufacturing a cathode ray tube and a plasma display using the crystalline sealant glass.

In the present invention, the precipitation time of the crystalline phase of the crystalline glass is the time from the time when the glass reaches the holding temperature during firing to the time when the exothermic peak due to the precipitation of the crystalline phase occurs on the DTA curve of the glass. Say.

The crystalline glass powder in the present invention, upon firing, deposits a plurality of crystal phases having different deposition times. This crystalline glass powder is preferably one in which the difference between the precipitation time of the first crystalline phase and the precipitation time of the second and subsequent crystalline phases is as small as possible.

The type of the crystal phase and the composition of the glass powder are not particularly limited as long as they satisfy the manufacturing process of the molded body to be sealed and various characteristics required for the molded body. Examples of such glass powder include the following.

PbO-B ₂ O ₃ --SiO ₂ --BaO, P
_{bO-TiO 2 -SiO 2, SiO} 2 -ZnO-BaO
_{-Al 2 O 3, TiO 2 -SiO} 2 -ZnO-CaO-
_{Al 2 O 3, PbO-SiO} 2 -Al 2 O 3, PbO-
_{ZnO-B 2 O 3, P} 2 O 5 -ZnO-Li 2 O-Na
₂ O-K ₂ O.

On the other hand, the crystal nuclei contain more crystal phases that precipitate after the second firing of the crystalline glass powder than crystal phases that precipitate first. In this crystal nucleus, when the content of the crystal phase that precipitates after the second crystal is less than the content of the crystal phase that precipitates first, the firing time of the crystal phase that precipitates after the glass in the glass becomes longer. At the same time, the wettability is lowered and the object of the present invention cannot be achieved.

The content of the second and subsequent crystal phases precipitated in the crystal nuclei is preferably 10% (% by weight, the same applies hereinafter) or more. If this content is less than 10%, the properties of the sealant glass may be impaired, which is not preferable. On the other hand, the content of the crystal phase that precipitates first in the crystal nuclei is a range that adjusts the precipitation time when the fluidity is sufficiently secured and the precipitation time of the crystal phase that precipitates first is too long. It is preferable that it is small.

The content of the crystal nuclei is such that the crystal phase precipitated after the second in the crystalline glass is 1 to 20000 ppm by weight (weight pp) with respect to the crystalline sealant glass.
m, the same applies hereinafter). When the content of the crystal phase that precipitates after the second is less than 1 ppm, the precipitation time of the crystal phase that precipitates after the second becomes long, which is not preferable, and when it exceeds 20,000 ppm, the fluidity at the time of sealing is deteriorated, which is not preferable. The content of the crystal phase precipitated after the second is particularly preferably an amount of 1 to 6000 ppm in the above range.

When a panel glass and a funnel glass are sealed in the production of a cathode ray tube, it is preferable to use the following crystalline sealant glass because sealing at a low temperature and a high strength can be achieved in a short time.

That is, the composition of the crystalline glass powder is P
_{bO 60~85%, B 2 O 3} 5~15%, ZnO 8
~18%, SiO ₂ 0~5%, the range of BaO 0 to 5%, the crystalline phase precipitated in second in the crystalline glass 4
A PbO · B ₂ O _3, and containing an amount of crystal nuclei content of 4PbO · B ₂ O ₃ crystal phase is 1～6000Ppm, crystal nuclei crystallizable glass in 4PbO · B ₂ O ₃ crystalline phase It contains more than the crystal phase that precipitates first.

The reasons for limiting the composition of the crystalline glass powder are as follows.

If the content of PbO is less than 60%, the viscosity becomes large and the sealing temperature must be raised, which may significantly impair the properties of the components in the container. If it exceeds 85%, the devitrification becomes strong. Stable sealing is not possible.

When the content of B ₂ O ₃ is less than 5%, the softening point becomes high and the fluidity is impaired, and when it exceeds 15%, the chemical durability is deteriorated.

If the content of ZnO is less than 8%, the softening point becomes too high and it is difficult to crystallize. If it exceeds 18%, devitrification is likely to occur during the production of crystalline glass.

By containing SiO ₂ , the water resistance can be improved. If the content exceeds 5%, the viscosity increases and the sealing temperature rises.

By containing BaO, the solubility of the crystalline glass is improved. If the content exceeds 5%, the coefficient of thermal expansion becomes too large.

The more preferable crystalline sealant glass used for sealing the panel glass and the funnel glass is as follows.

That is, the composition of the crystalline glass powder is P
_{bO 70~81%, B 2 O 3} 7~10%, ZnO 1
The range of 0 to 14%, SiO _{2 to} 1 to 3%, and BaO to 1 to 3%, and the second crystal phase to be precipitated in the crystalline glass is 4PbO · B ₂ O ₃ and 4PbO · B ₂ O ₃ Of the crystal phase, the content of the crystal phase is 1 to 5000 ppm, alumina 0 to 10%, zircon 0.05 to 5%, the balance crystalline glass powder, the crystal nucleus is 4PbO · B ₂ O ₃ crystal phase Is contained in the crystalline glass in an amount larger than that of the crystal phase that precipitates first.

By containing alumina, the strength of the fired body of the crystalline sealant glass can be improved. If its content exceeds 10%, the fluidity becomes poor, which is not preferable.

Zircon is a component that shortens the precipitation time of the first crystal phase (2PbO.ZnO.B ₂ O ₃ ) that precipitates in the crystalline glass. The content of zircon is 0.
If it is less than 05%, that effect is not obtained, and if it exceeds 10%, the precipitation time of the first crystal phase to be precipitated becomes too short and the wetting becomes insufficient and the airtightness decreases, which is not preferable.

A Braun tube using such a crystalline sealant glass can be manufactured as follows.

A crystalline sealant glass and a vehicle are mixed according to a conventional method to prepare a slurry. As this vehicle, various ones such as one having nitrocellulose dissolved in amyl acetate can be used. This slurry is applied to the adhesive surface of the funnel glass. Next, the panel glass on which the fluorescent substance or the like is previously mounted is placed on the funnel glass such that the adhesive surface of the panel glass comes into contact with the adhesive surface of the funnel glass. This is then heated to 5-25 at 420-460 ° C.
Bake for minutes.

By this firing, the crystalline glass powder is first softened and then fluidized to sufficiently wet the adhesive surfaces of the panel glass and the funnel glass. Then, in the crystalline glass, 2PbO.ZnO.B ₂ O was used as the first crystal phase.
₃ precipitates and then 4PbO.B as the second crystal phase
₂ O ₃ is deposited and high strength sealing is performed.

When a plasma display panel is manufactured, the following crystalline sealant glass is preferably used for sealing two substrate glasses.

That is, the composition of the crystalline glass powder is P
_{bO 70~81%, B 2 O 3} 7~10%, ZnO 1
The range of 0 to 14%, SiO _{2 to} 1 to 3%, and BaO to 1 to 3%, and the second crystal phase to be precipitated in the crystalline glass is 4PbO · B ₂ O ₃ and 4PbO · B ₂ O ₃ Of the crystal phase, the content of the crystal phase is 1 to 5000 ppm, low expansion filler 2 to 30%, zircon 0.05 to 5%, the balance crystalline glass powder, low expansion filler lead titanate, cordier At least one selected from light, β-eucryptite, β-spodumene, β-quartz solid solution, and silica, and the crystal nucleus of 4PbO · B ₂ O ₃ crystal phase is first deposited in crystalline glass. It contains more than the crystalline phase.

The low expansion filler acts to reduce the thermal expansion of the fired body of the crystalline sealant glass and to match the thermal expansion of the substrate glass. The content of low expansion filler is 2
If it is less than%, such an effect is not sufficient, there is residual stress in the sealing portion, and the strength is reduced, so it is not preferable. It is not preferable because the strength is lowered.

A plasma display using such a crystalline sealant glass can be manufactured as follows.

A crystalline sealant glass and a vehicle are mixed to form a slurry. As this vehicle, the one described in the manufacture of the cathode ray tube is used. Next, this slurry is applied to the peripheral edge of the substrate glass on which electrodes and the like have been previously formed. Then, another substrate glass is placed on this, heated, and baked at 420 to 500 ° C. for 5 to 40 minutes.

By this firing, the crystalline glass powder is first softened and then flows to sufficiently wet the adhesive surface of the substrate glass. Next, in the crystalline glass, 2Pb
O ・ ZnO ・ B ₂ O ₃ crystal phase precipitates, and secondly 4Pb
O.B ₂ O ₃ crystal phase is precipitated and the sealing with excellent strength is completed.

[0042]

EXAMPLES PbO 75%, B ₂ O ₃ 9
%, ZnO 12%, SiO ₂ 2%, BaO 2% crystalline glass powder.

[0043] Upon firing 35 minutes the crystalline glass powder at 440 ° C., the crystalline phase of 2PbO · ZnO · B ₂ O ₃ is deposited to a first crystalline phase of 4PbO · B ₂ O ₃ is deposited on the second This was confirmed using an X-ray diffractometer.

This fired body was photographed by an electron microscope, and the image was processed to obtain the area ratio of crystal phases and the like. As a result, 2PbO.ZnO.B ₂ O ₃ crystal phase and 4PbO.
The ratio of the B ₂ O ₃ crystal phase to the glass was approximately 5: 3: 2.

Next, the raw material prepared so that PbO: B ₂ O ₃ = 4: 1 (molar ratio) was heated to melt and vitrify. Next, this was made into flakes and reheated to be crystallized to synthesize a crystal nucleus of 4PbO.B ₂ O ₃ .

The crystalline glass powder, alumina, zircon and crystal nuclei were mixed in a weight ratio shown in Table 1 (the content of the crystalline glass powder is the balance), and 9 kinds of crystalline sealant glass (Example: Example 1) were mixed. ~ 5, Comparative Example: Examples 6-9) were obtained.

DT for this crystalline sealant glass
A characteristic (temperature rising from room temperature to 440 ° C. at 10 ° C./min and holding temperature at 440 ° C.) was measured, and flow time t _b (region b in FIG. 1, from end of heat absorption to start of heat generation). Time), and the precipitation time t _c of the second crystal phase was determined.

Separately from this, the flow button diameter was measured as an index of fluidity and wettability. For the flow button diameter, 10 g of crystalline sealant glass was pressure-molded into a cylindrical shape having a diameter of 12.7 mm, and this molded body was molded on a glass substrate at 440 ° C. for 10 minutes.
It is obtained by calcining for minutes and determining the diameter of the calcined body. When the panel glass and the funnel glass are sealed, the flow button diameter is preferably 26 mm or more.
5 mm or more is particularly preferable.

The above crystalline glass powder, lead titanate, zircon, and crystal nuclei (4PbO.B ₂ O ₃ ) were mixed in the weight ratio shown in Table 1 (the content of the crystalline glass powder is the balance), and 5
Types of crystalline sealant glasses (Examples: Examples 10-1)
2, comparative example: Examples 13-14) were obtained.

Regarding this crystalline sealant glass, D
TA characteristics (temperature rising from room temperature to 470 ° C. at 10 ° C./min and holding temperature at a holding temperature of 470 ° C.) were measured, and a flow time t _b ,
The precipitation time t _c of the second crystal phase was determined.

The flow button diameter was also measured for this crystalline sealant glass. Flow button diameter is 1 at 470 ℃
It is measured by holding for 0 minutes. When sealing the substrate glass of the plasma display, the flow button diameter is 2
It is preferably 4.5 mm or more, and particularly preferably 25 mm or more.

The crystal nuclei in Example 9 (comparative example) and Example 14 (comparative example) were 2PbO.ZnO.B ₂ O ₃ crystal phase, 4PbO.B ₂ O ₃ crystal phase, and glass 5: 3: It was contained in a weight ratio of 2.

As is clear from Table 1, the crystalline sealant glass of the present invention has a relatively long flow time t _{b, a} large flow button diameter, and a short precipitation time t _c of the second crystal phase. .

[0054]

[Table 1]

[0055]

The crystalline sealant glass of the present invention enables high strength sealing in a short time. Such a crystalline sealant glass is particularly suitable for manufacturing a cathode ray tube for sealing a panel glass and a funnel glass, and for manufacturing a plasma display for sealing two substrate glasses.

[Brief description of drawings]

FIG. 1 is a graph showing DTA characteristics of crystalline glass.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Ryuichi Tanabe 1150, Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Asahi Glass Co., Ltd. Central Research Laboratory (72) Inventor Setsuro Ito 1150, Hazawa-machi, Kanagawa-ku, Yokohama Asahi Glass Co., Ltd. In the Central Research Laboratory (72) Akira Nakamura Ichiro Glass Co., Ltd. 1-50-1 Gyoda, Funabashi City, Chiba Prefecture (72) Inventor Noboru Nakamura 1-50-1 Gyoda, Funabashi, Chiba Iwaki Glass Co., Ltd. Within

Claims (6)

[Claims] 1. A crystalline glass powder for precipitating a plurality of crystal phases having different precipitation times, and a crystal nucleus, the crystal nucleus precipitating a crystal phase that precipitates second or later in the crystalline glass first. A crystalline sealant glass that contains more than the crystalline phase. 2. The composition of the crystalline glass powder is PbO 60-
85% by weight, B ₂ O ₃ 5 to 15% by weight, ZnO 8 to 1
8% by weight, SiO ₂ 0 to 5% by weight, BaO 0 to 5% by weight, and the second crystal phase precipitated in the crystalline glass is 4PbO.B ₂ O ₃ and 4PbO.B ₂ O. ₃
The crystalline sealant glass according to claim 1, which contains an amount of crystal nuclei such that the content of the crystal phase is 1 to 6000 ppm by weight. 3. The composition of the crystalline glass powder is PbO 70-
81 wt%, B ₂ O ₃ 7~10 wt%, ZnO. 10 to
14% by weight, SiO ₂ 1-3% by weight, BaO 1-3% by weight, and the second crystal phase to be precipitated in the crystalline glass is 4PbO.B ₂ O ₃ and 4PbO.B ₂ O. ₃
Crystal nucleus in an amount such that the content of the crystal phase is 1 to 6000 ppm by weight, alumina 0 to 10% by weight, zircon 0.05 to
The crystalline sealant glass according to claim 1, comprising 5% by weight and the balance crystalline glass powder. 4. The composition of the crystalline glass powder is PbO 70-
81 wt%, B ₂ O ₃ 7~10 wt%, ZnO. 10 to
14% by weight, SiO ₂ 1-3% by weight, BaO 1-3% by weight, and the second crystal phase to be precipitated in the crystalline glass is 4PbO.B ₂ O ₃ and 4PbO.B ₂ O. ₃
Crystal nuclei in an amount such that the content of the crystal phase is 1 to 6000 ppm by weight, low expansion filler 2 to 30% by weight, zircon 0.
05 to 5% by weight and the balance crystalline glass powder, and the low expansion filler is at least one selected from lead titanate, cordierite, β-eucryptite, β-spodumene, β-quartz solid solution and silica. The crystalline sealant glass according to claim 1. 5. The crystalline sealant glass according to claim 1, 2 or 3 is interposed in the sealing portion between the panel glass and the funnel glass and fired at 420 to 460 ° C. for 5 to 25 minutes to obtain the panel glass and the funnel glass. A method for manufacturing a cathode ray tube for sealing. 6. The crystalline sealant glass according to claim 1 or 4 is provided in a sealing area between two substrate glasses, and the temperature is 420 to 500 ° C.
A method for manufacturing a plasma display, which comprises firing for 5 to 40 minutes and sealing two substrate glasses.