JPH09235136A - Low-melting point class composition and glass ceramics composition for sealing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition not containing lead and suitable for glass ceramics excellent in strength and used for sealing of cathode-ray tubes, plasma display and fluorescent display tubes by controlling ZnO amount in phosphoric acid-tin oxide-based glass composition and amounts of various specific metal oxides other than ZnO. SOLUTION: This glass composition comprises 50-72wt.% of tin oxide expressed in terms of SnO, 0-10w.% of ZnO, 25-40wt.% each of P2 O5 , 0-10wt.% BaO, MgO, CaO and SrO, 0-5wt.% each of CuO, NiO, MnO, CoO, Fe2 O3 , Bi2 O3 , Sb2 O3 , CR2 O3 , TiO2 and ZrO2 and 0.01-10wt.% of BaO+MgO+CaO+SrO+CuO+ NiO+MnO+CoO+Fe2 O3 +Bi2 O3 +Sb2 O3 +Cr2 O3 +TiO2 +ZrO2 , and has low melting point (<=600 deg.C). A cathode-ray tube sealed with glass ceramics composition composed of 60-99wt.% of the glass composition powder and 1-40wt.% of low expandable ceramics filler is excellent in water pressure-resistant strength and heat resistance.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for sealing a cathode ray tube panel and a funnel, which can be sealed by heat treatment at a low temperature, a plasma display panel (PDP), and a fluorescent display tube (VFD). To the composition.

[0002]

2. Description of the Related Art Conventionally, a panel and a funnel of a color cathode ray tube are made of a PbO-B ₂ O ₃ -ZnO-SiO ₂ -based crystalline low melting point glass of the type disclosed in Japanese Patent Publication No. 36-17821 and at 440 ° C. or higher. 3 for temperatures below 450 ° C
It was held for about 0 to 40 minutes and sealed. The thus sealed panel and funnel are exhausted while being heated to 300 to 380 ° C. in order to obtain a high vacuum of 10 ⁻⁶ Torr or more inside.

Further, conventionally, the glass substrate in the PDP or VFD is made of low melting point glass and sealed at 440 to 500 ° C. Thus, the sealed panel is evacuated while being heated to 250 to 380 ° C. in the case of PDP.
A discharge gas such as neon or He-Xe is filled to 0 to 500 Torr, and in the case of VFD, it is heated to 250 to 380 [deg.] C. while being exhausted and sealed to obtain a vacuum.

As the powder glass for sealing used in the past, a glass containing a lead component was used, but recently, a glass containing no lead component has been demanded. In addition, the conventional powdered glass for sealing does not match the coefficient of thermal expansion with the glass substrate, and the panel may crack, or the solder may flow into the glass due to heating during exhaust, foam, or the seal part may crack. Was.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a glass-ceramic composition for use in a cathode ray tube, PDP and VFD for sealing, and a low melting point glass composition which can be used therein, using a glass powder containing no lead component. To do.

[0006]

According to the present invention, tin oxide substantially converted to SnO in terms of mol: 50 to 72%, Z
_{nO: 0~10%, P 2 O} 5: 25~40%, BaO:
0-10%, MgO: 0-10%, CaO: 0-10
%, SrO: 0-10%, CuO: 0-5%, NiO:
0-5%, MnO: 0-5%, CoO: 0-5%, Fe
_{2 O 3: 0~5%, Bi} 2 O 3: 0~5%, Sb 2 O
_{3: 0~5%, Cr 2 O} 3: 0~5%, TiO 2: 0~
_{5%, ZrO 2: 0~5%} , BaO + MgO + CaO +
SrO + CuO + NiO + MnO + CoO + Fe ₂ O ₃
+ Bi ₂ O ₃ + Sb ₂ O ₃ + Cr ₂ O ₃ + TiO ₂ + Z
Provided is a phosphoric acid-tin oxide-based low melting point glass composition characterized by comprising rO ₂ : 0.01 to 10%. The present glass composition is suitable for use as a glass ceramic composition for sealing.

For example, in order to seal the funnel of the cathode ray tube and the panel, the phosphoric acid-tin oxide low melting glass powder 60 to 99% and the low expansion ceramic filler 1 to 40% are used in terms of weight. , The coefficient of thermal expansion from room temperature to 300 ° C after firing is 80 to 110 × 10 ^-7 ° C ^-1
The glass-ceramic composition is preferably Such a composition has a temperature of 400 to 500 ° C.
By holding the temperature of 5 minutes to 1 hour, the panel of the color cathode ray tube and the funnel can be sealed, and
Heating at the time of exhaust at 00 to 380 ° C. does not cause fluidization, foaming, or loss of mechanical strength.

When used for sealing for PDP or VFD, 50 to 98% by weight of low-melting glass powder of phosphoric acid-tin series and low expansion ceramic filler 2 are used.
It is preferable that the glass-ceramic composition has a thermal expansion coefficient of 60 to 90 × 10 ⁻⁷ ° C. ⁻¹ from room temperature to 250 ° C. after firing. The composition for sealing has a temperature of 400 to 500 ° C. for 5 minutes or more.
The glass substrate for PDP or the fluorescent display tube can be sealed by heating for about 1 hour, and it may flow, foam, or lose mechanical strength due to heating at 280 to 380 ° C. after exhaustion. Absent.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, that the glass composition has a low melting point means that the softening point is 600 ° C. or lower. In addition, the low expansion ceramics filler,
Average thermal expansion coefficient from room temperature to 300 ° C is 70 × 10
A ceramic filler whose temperature is ^-7 ° C ^-1 or less.

The composition range of the phosphoric acid-tin oxide low melting point glass in the present invention will be described. In the present invention, a relatively low temperature of 400 to 500 ° C. and a short time (5
The low melting point glass has the following composition range in terms of mol% so that it can be sufficiently flowed in a minute to 1 hour) and sealed.

Tin oxide converted to SnO 50 to 72%, ZnO 0 to 10%, P ₂ O ₅ 25 to 40%, BaO 0 to 10%, MgO 0 to 10%, CaO 0 to 10%, SrO 0 -10%, CuO 0-5%, NiO 0-5%, MnO 0-5%, CoO 0-5%, Fe ₂ O ₃ 0-5%, Bi ₂ O ₃ 0-5%, Sb ₂ O _{3 0~ 5%, Cr 2 O 3} 0~ 5%, TiO 2 0~ 5%, ZrO 2 0~ 5%, BaO + MgO + CaO + SrO + CuO + NiO + M
nO + CoO + Fe ₂ O ₃ + Bi ₂ O ₃ + Sb ₂ O ₃ +
_{Cr 2 O 3 + TiO 2 +} ZrO 2 0.01~10%.

The content of tin oxide converted to SnO is 5
If it is less than 0 mol%, the softening point becomes too high, the fluidity is poor, and the strength and airtightness of the sealed portion are impaired, and the softening point is 400 to 50
It cannot be sealed at 0 ° C. If the content exceeds 72 mol%, glass becomes difficult. More preferable range is 52 to 7
0 mol%.

The inclusion of ZnO can lower the expansion coefficient of the sealed product, but if the content exceeds 10 mol%, the softening point becomes too high and sealing cannot be carried out at 400 to 500 ° C. A more preferable range is 0 to 8 mol%.

If the content of P ₂ O ₅ is less than 25 mol%, vitrification becomes difficult, and if it exceeds 40 mol%, the water resistance of the sealed product is deteriorated, which is not preferable. . A more preferable range is 27 to 38 mol%.

BaO, MgO, CaO, SrO, Cu
O, NiO, MnO, CoO, Fe ₂ O ₃ , Bi ₂ O
By containing at least one of ₃ , Sb ₂ O ₃ , Cr ₂ O ₃ , TiO ₂ , and ZrO ₂ , the adhesion between the adherend glass and the sealing composition can be improved. The total amount is 0.
01 mol% or more is required. Poor adhesion strength results in poor water pressure resistance.

If the total amount of BaO, MgO, CaO and SrO exceeds 10 mol%, the softening point is too high, which is not preferable.
More preferably, the total amount is 5 mol% or less.

CuO, NiO, MnO, CoO, Fe ₂
O ₃ , Bi ₂ O ₃ , Sb ₂ O ₃ , Cr ₂ O ₃ , TiO
_{If the} total amount of ₂ and ZrO ₂ exceeds 5 mol%, the coefficient of thermal expansion increases excessively, which is not preferable. More desirably, the total amount is 3 mol%
It is as follows.

The total amount is more preferably 0.05 to 5 mol%. Further, the more desirable component among the above components is B
aO, MgO, CaO, SrO, CuO, Fe ₂ O ₃ ,
Bi ₂ O ₃ .

When the glass composition of the present invention is used for a glass ceramic composition for sealing a Braun tube, the content of the low melting point glass powder is 60 with respect to the total amount of the low melting point glass powder and the low expansion ceramic filler. ~ 99% by weight
Is preferred. If it exceeds 99% by weight, the amount of the low-expansion ceramics filler is small, so that the coefficient of thermal expansion becomes too large, the average coefficient of thermal expansion does not match that of the panel and the funnel, and cracking easily occurs. If the content is less than 60% by weight,
The glass content is small and the fluidity deteriorates, and the airtightness of the sealed portion is impaired. For the above reasons, more preferably 65 to 9
9% by weight, particularly preferably 70 to 99% by weight.

On the other hand, the content of the low expansion ceramics filler is preferably in the range of 1 to 40% by weight based on the total amount of the low melting point glass powder and the low expansion ceramics filler. Total content of low expansion ceramics filler is 40% by weight
If it exceeds 5, the fluidity at the time of sealing will be poor. Content is 1% by weight
If it is less than 100%, it is difficult to match the average coefficient of thermal expansion to the valve, and the strength becomes weak. For the above reasons, it is more preferably 1 to 35% by weight, particularly preferably 1 to 30% by weight.

As such a low expansion ceramics filler, zircon, cordierite, aluminum titanate, alumina, mullite, silica, β-eucryptite, β-spodumene and β-quartz solid solution are preferable in terms of handling, and these are used alone. Or used in combination of two or more.

The low-expansion ceramics filler is preferably 9% or less by weight of the total amount of alumina and zircon relative to the amount of the glass-ceramic composition for sealing. Alumina has a coefficient of thermal expansion of 65 to 75 × 10 ^-7 ° C ^-1 (50 to
350 ° C.), zircon has a coefficient of thermal expansion of 42 to 48 × 10
^{It is −7} ° C. ⁻¹ (50 to 350 ° C.), and the coefficient of thermal expansion is relatively large, and the effect of adjusting the coefficient of thermal expansion even when mixed with glass is smaller than that of other low expansion ceramic fillers. When the content of the low-expansion ceramics filler is within the above-mentioned preferred range, a desired coefficient of thermal expansion can be obtained without significantly reducing the amount of the glass component, which is effective in improving the compressive strength.

For reference, other thermal expansion coefficients (50 to 350)
(° C, unit: × 10 ^-7 / ° C) is as shown below. Cordierite 10 to 20, aluminum titanate 10 to 20, mullite 50 to 60, silica 5 to 6, β-eucryptite -60 to -80, β-spodumene 8 to 15, β-quartz solid solution -10 to +10.

From the above viewpoint, it is more preferable that the total amount of the low expansion ceramic filler other than alumina and zircon is 16 to 40% by weight based on the amount of the glass ceramic composition for sealing.

In the glass-ceramic composition for sealing a cathode ray tube, the average thermal expansion coefficient of the sealing composition at room temperature to 300 ° C. after firing is preferably in the range of 80 to 110 × 10 ⁻⁷ ° C. ⁻¹ . If the average coefficient of thermal expansion is out of this range, a strong tensile stress acts on the panel glass, the funnel glass, or the sealing portion, and the pressure resistance of the bulb decreases.

When the glass composition of the present invention is used as a glass ceramic composition for sealing PDP or VFD, the content of the low melting point glass powder is 50 with respect to the total amount of the glass ceramic composition for sealing. It is preferably in the range of to 98% by weight. If it exceeds 98% by weight, the amount of the low melting point filler is small, so that the coefficient of thermal expansion becomes too large and the coefficient of thermal expansion does not match the coefficient of thermal expansion of the substrate glass, and after sealing, the tensile strength is strong in the seal frit portion and cracking easily occurs. If it is less than 50% by weight, the glass content is small and the fluidity is deteriorated, and the airtightness of the sealed portion is impaired. For the above reason, it is more preferably 55 to 98% by weight, particularly preferably 60 to 98% by weight.

On the other hand, the content of the low expansion ceramics filler in this case is preferably 2 to 50% by weight. More preferably 2 to 45% by weight, particularly preferably 2
４０40% by weight.

As the low-expansion ceramics filler, zircon, cordierite, alumina, aluminum titanate, mullite, the same as in the sealing composition for cathode ray tubes.
At least one selected from silica, β-eucryptite, β-spodumene and β-quartz solid solution is preferable. Among such ceramic fillers, cordierite and zircon are preferable from the viewpoint of improving the sealing strength.

The low-expansion ceramics filler is preferably 9% or less in terms of weight of the total amount of alumina and zircon with respect to the amount of the glass-ceramic composition for sealing. This is because alumina and zircon have a relatively large thermal expansion coefficient as described above, and the effect of adjusting the thermal expansion coefficient even when mixed with glass is smaller than that of other low expansion fillers. When the content of the low-expansion ceramics filler is within the above-mentioned preferred range, a desired coefficient of thermal expansion can be obtained without significantly reducing the amount of the glass component, which is effective in improving the compressive strength. From the above viewpoint, the total amount of the low expansion ceramics filler other than alumina and zircon is more preferably 16 to 50% by weight based on the amount of the glass ceramics composition for sealing.

The glass-ceramic composition for PDP and VFD sealing preferably has a coefficient of thermal expansion of 60 to 90 × 10 ⁻⁷ ° C. ⁻¹ after firing at room temperature to 250 ° C. If the coefficient of thermal expansion is out of this range, tensile stress acts strongly on the substrate glass or the sealing material, and the pressure resistance decreases.

A pigment may be added to the composition for coloring and used.

[0032]

EXAMPLE A raw material slurry obtained by dropping 85% orthophosphoric acid into a solid raw material excluding the P ₂ O ₅ component of the glass component was well mixed and then dried at 120 ° C. to obtain a powder batch. It was created. This raw material was put into a quartz crucible, covered with a lid, melted at 1000 to 1100 ° C., and then broken into water or passed through a roller to give a glass in the form of flakes. Then, this was crushed for a predetermined time in a ball mill to produce low melting point glass powders having the compositions shown in Tables 1 and 2.

These low-melting glass powders and low-expansion ceramics fillers were mixed in the weight ratios shown in the upper columns of Tables 3 and 4 to prepare a sealing composition. Examples 1 to 10
Is an example, and Examples 11 to 13 are comparative examples. The results of measuring the flow button diameter, the residual adhesive strain, and the average coefficient of thermal expansion of this sealing composition are shown in Tables 3 and 4.

Flow button diameter: Shows the fluidity of the composition at the time of sealing. The sample powder of the sealing composition is 5.5 g for cathode ray tubes, 3.5 g for PDP and 3.5 g for VFD.
Was pressed into a cylindrical shape having a diameter of 12.7 mm, and then held at the firing temperature (unit: ° C) described in Tables 3 and 4 for 30 minutes, the diameter (unit: mm) at which the sealing composition flowed. ). This flow button diameter is 2 for CRT applications.
6.5 mm or more, 20 for PDP and VFD applications.
0 mm or more is desirable.

Adhesive residual strain: The sealing composition and a vehicle (solution of 1.2% nitrocellulose dissolved in isoamyl acetate) were mixed at a weight ratio of 6.5: 1 to form a paste. This paste is applied on a funnel glass piece for sealing a cathode ray tube, and on a substrate glass piece for PDP and VFD, and after firing under the same conditions as for the flow button diameter, the glass piece and the sealing composition The residual strain (unit: nm / cm) generated between the product and the product was measured using a polarimeter. "+" Indicates that the sealing composition is subjected to compressive strain,
"-" Indicates the case where the sealing composition is subjected to tensile strain. This residual strain is desirably in the range of -100 to +500 nm / cm.

Average coefficient of thermal expansion: The composition for sealing is baked under the same conditions as those for the flow button diameter, and then polished to a predetermined size,
The amount of elongation is measured by a thermal expansion measuring device at a temperature rising rate of 10 ° C / min, and an average coefficient of thermal expansion from room temperature to 300 ° C (for cathode ray tubes) or room temperature to 250 ° C (for PDP and VFD) (unit: × 10 ^-7 ° C ^-1 ) was calculated. In the use of CRT glass, the average coefficient of thermal expansion is preferably in the range of 80 to 110 × 10 ⁻⁷ ° C. ⁻¹ in consideration of matching of coefficients of thermal expansion. In PDP and VFD applications, the average coefficient of thermal expansion is 60 to 90 ×, considering the matching of the coefficient of thermal expansion with the substrate glass for PDP and the substrate glass for VFD.
The range of 10 ^-7 ° C ^-1 is desirable.

The sealing composition is interposed between a 25-inch funnel and a panel, and the composition is heated to 400 to 500 ° C. for 30 hours.
The valve was manufactured by sealing the funnel and the panel after holding for a minute. In addition, the sealing composition is interposed between the end portions of the PDP substrate on which electrodes and partition ribs are formed in advance.
PDP was manufactured by holding at 0 to 500 ° C. for 30 minutes and sealing. A VDF panel was manufactured by placing a grid between the end portions of the glass substrate on which the electrodes and the like were placed, and interposing the grid and holding it at 400 to 500 ° C. for 30 minutes to seal the glass substrates together. Tables 3 and 4 show the results of measuring the water pressure resistance and heat resistance of these valves and panels. Each measuring method is as follows.

Hydrostatic strength: A pressure difference was measured when a pressure difference due to water was applied to the inside or outside of the valve or panel to measure the pressure difference (unit: kg / cm ² , an average value of 5 pieces). In order to guarantee the strength as a valve or panel, it is usually desirable that the water pressure resistance strength is 3 kg / cm ² or more.

Heat resistance: The temperature difference between water and hot water was applied to the inside or outside of the valve or panel to measure the temperature difference (unit: ° C, average of 5 pieces). CRT, PD
Considering the thermal stress generated in the heat treatment process for manufacturing P and VFD, it is usually desirable that the heat resistance strength be 45 ° C. or higher.

From the table, it can be seen that the sealing composition according to the present invention has the properties superior to those of the conventional products. In particular, in Examples 2 to 5 and Examples 8 to 10, the total amount of alumina and zircon contained as the low expansion ceramics filler was set to 9% by weight or less with respect to the amount of the glass ceramics composition for sealing. High water pressure resistance is obtained.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[0045]

The cathode ray tube, PDP, and VFD sealed by using the sealing composition containing no lead according to the present invention have excellent water pressure resistance and heat resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuneo Manabe 1150, Hazawa-machi, Kanagawa-ku, Kanagawa Prefecture Asahi Glass Co., Ltd. Central Research Laboratory (72) Inventor Setsuro Ito 1150, Hazawa-machi, Kanagawa-ku, Yokohama Asahi Glass Co., Ltd. Central Research Center

Claims (5)

[Claims] 1. Substantially in molar terms, tin oxide converted to SnO 50 to 72%, ZnO 0 to 10%, P ₂ O ₅ 25 to 40%, BaO 0 to 10%, MgO 0 to 10%. , CaO 0-10%, SrO 0-10%, CuO 0-5%, NiO 0-5%, MnO 0-5%, CoO 0-5%, Fe ₂ O ₃ 0-5%, Bi ₂ O ₃ 0 to 5%, Sb ₂ O ₃ 0 to 5%, Cr ₂ O ₃ 0 to 5%, TiO ₂ 0 to 5%, ZrO ₂ 0 to 5%, BaO + MgO + CaO + SrO + CuO + NiO + M
nO + CoO + Fe ₂ O ₃ + Bi ₂ O ₃ + Sb ₂ O ₃ +
_{Cr 2 O 3 + TiO 2 +} ZrO 2 0.01~10%, phosphoric acid, characterized by comprising - tin oxide-based low-melting-point glass composition. 2. A phosphorous-tin oxide low melting point glass composition powder of 60 to 99% and a low expansion ceramics filler of 1 to 40% by weight, which are from room temperature to 300 ° C. after firing. Coefficient of thermal expansion is 80 ~ 110 × 10 ^-7 ℃ ^-1
A glass-ceramic composition for sealing for sealing a panel of a cathode ray tube and a funnel. 3. A phosphorous-tin oxide low melting point glass composition powder of 50 to 98% and a low expansion ceramics filler of 2 to 50% by weight, which is from room temperature after firing to 250 ° C. A glass-ceramic composition for sealing a plasma display panel or a fluorescent display tube, which has a thermal expansion coefficient of 60 to 90 × 10 ^-7 ° C ^-1 . 4. The low expansion ceramics filler is selected from the group consisting of zircon, cordierite, aluminum titanate, alumina, mullite, silica, β-eucryptite, β-spodumene, and β-quartz solid solution.
The glass-ceramic composition for sealing according to claim 2 or 3, which is one or more kinds. 5. The sealing glass-ceramic composition according to claim 2, 3 or 4, wherein the low-expansion ceramics filler has a total amount of alumina and zircon of 9% or less based on the weight of the sealing glass-ceramic composition in terms of weight. Stuff.