JP2009062257A - Bismuth-base glass composition and bismuth-base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bismuth-base glass composition which can be well softened in heat treatment such as sealing and can crystallize satisfactorily after being softened and which is little re-softened after crystallization in heat treatment such as evacuation. <P>SOLUTION: Disclosed is a bismuth-base glass composition having a composition which comprises by mass 60 to 84% of Bi<SB>2</SB>O<SB>3</SB>, 5.4 to 15% of B<SB>2</SB>O<SB>3</SB>, 10 to 27% of ZnO, 0 to 7% of CuO, 0 to 5% of Fe<SB>2</SB>O<SB>3</SB>, 0 to 10% of BaO+SrO+MgO+CaO and 0 to 5% of SiO<SB>2</SB>+Al<SB>2</SB>O<SB>3</SB>, and being substantially free from PbO. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a flat display device such as a plasma display panel (hereinafter referred to as PDP), various types of field emission displays (hereinafter referred to as FED) having various electron-emitting devices, a fluorescent display tube (hereinafter referred to as VFD), a crystal resonator, and an IC. The present invention relates to a bismuth-based glass composition and a bismuth-based material suitable for sealing electronic components (including electronic component storage containers) such as packages, partition wall formation, side frame formation, and the like.

  Conventionally, glass has been used as a sealing material for flat display devices and the like. Glass is excellent in chemical durability and heat resistance as compared with a resin-based adhesive, and is suitable for ensuring airtight reliability of a flat display device or the like.

  These glasses require various properties such as mechanical strength, fluidity, and electrical insulation depending on the application, but they are used at a temperature that does not deteriorate at least the fluorescence properties of phosphors used in flat display devices. It is required to be possible. Therefore, as a glass that satisfies the above characteristics, lead borate glass (see, for example, Patent Document 1) containing a large amount of PbO that has an extremely large effect of lowering the melting point of the glass has been widely used.

However, recently, environmental problems have been pointed out with respect to PbO contained in lead borate glass, and it is desired to replace lead borate glass with glass that does not substantially contain PbO. Therefore, various low melting glass has been developed as a substitute for lead borate glass. Among them, bismuth-based glass (also referred to as Bi ₂ O ₃ —B ₂ O ₃ -based glass) described in Patent Document 2 and the like is a lead borate based in various properties such as chemical durability and mechanical strength. Since it has the same properties as glass, it is expected as an alternative candidate.

By the way, the glass used for the sealing material is selected to be crystalline or non-crystalline depending on the application. Generally, crystalline glass is selected for applications in which the sealing material should not soften and flow after the sealing step, for example, sealing of exhaust pipes for PDP. In this application, there is a vacuum evacuation process in which the heat treatment temperature is increased to near the softening point, for example, 400 to 420 ° C. after the exhaust pipe sealing process. For this reason, when amorphous glass is used, the glass is re-softened in the evacuation process, and as a result, an airtight leak is likely to occur in a flat display device or the like. Therefore, in order to prevent such a situation, it is considered preferable to select crystalline glass in this application (see, for example, Patent Documents 3 and 4).
Japanese Unexamined Patent Publication No. Sho 63-315536 JP-A-6-24797 JP 2001-122640 A JP 2001-10843 A

The bismuth-based glass described in Patent Document 2 can obtain crystalline glass if the glass composition is selected. However, this crystalline glass contains 13% by mass or more of B ₂ O ₃ which is a glass component (a component which does not constitute a crystal) in the glass composition, and contains ZnO which is a component which constitutes a crystal. Therefore, even if heat treatment is performed, crystals are not sufficiently precipitated, and the glass is easily re-softened in the heat treatment step after crystal precipitation. I could not.

  Furthermore, in general, bismuth-based glass has poor thermal stability compared to lead borate-based glass, that is, it tends to devitrify at high temperatures, and it is difficult to control crystal precipitation. Therefore, if the crystallinity of the bismuth-based glass is to be strengthened, the glass is often crystallized before the glass sufficiently flows in the sealing step, and the function as a sealing material is often not exhibited.

  Therefore, the present invention provides a bismuth-based glass composition that is softened well in a heat treatment step, for example, a sealing step, and that crystals are sufficiently precipitated after softening, and that is not easily re-softened in a heat treatment step after crystal precipitation, for example, a vacuum exhaust step. To obtain a product and a bismuth-based material.

As a result of diligent efforts, the present inventors have set the glass composition range of the bismuth-based glass in terms of mass%, and as the glass composition, mass%, Bi ₂ O ₃ 60 to 84%, B ₂ O ₃ 5.4 to 15 %, ZnO 10-27%, CuO 0-7%, Fe ₂ O ₃ 0-5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5% and substantially containing PbO It is found that the above problem can be solved by not doing so, and is proposed as the present invention. That is, the bismuth-based glass composition of the present invention has, as a glass composition, mass%, Bi ₂ O ₃ 60 to 84%, B ₂ O ₃ 5.4 to 15%, ZnO 10 to 27%, CuO 0 to 7 %, Fe ₂ O ₃ 0-5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, and substantially no PbO. Here, “substantially not containing PbO” in the present invention refers to a case where the content of PbO in the glass composition is 1000 ppm or less.

  Since the glass composition range of the bismuth-based glass composition of the present invention is regulated as described above, the precipitation of crystals (the amount of precipitated crystals, the timing of crystal precipitation, the crystallization temperature, etc.) can be easily controlled. . That is, the bismuth-based glass composition of the present invention exhibits good fluidity at low temperatures and can be well sealed at low temperatures. In addition, since a sufficient amount of crystals are precipitated after the glass is softened, it is difficult for the glass to be resoftened in the heat treatment step after crystallization. For example, the glass is difficult to be softened again in the vacuum exhaust process. Reliability can be ensured.

In the bismuth-based glass composition of the present invention, the Bi ₂ O ₃ content is regulated to 60 to 84% by mass. If the content of Bi ₂ O ₃ is 60% by mass or more, the glass has a low melting point and is easy to seal at low temperatures. On the other hand, if the content of Bi ₂ O ₃ is 84% by mass or less, it is possible to suppress a situation where crystals are precipitated before the glass is softened, and it becomes easy to secure desired fluidity in the sealing step. .

In the bismuth-based glass composition of the present invention, the content of B ₂ O ₃ is regulated to 5.4 to 15% by mass. If the content of B ₂ O ₃ is 5.4% by mass or more, it is possible to suppress a situation in which crystals are precipitated before the glass is softened, and it becomes easy to secure desired fluidity in the sealing step. . On the other hand, if the content of B ₂ O ₃ is 15% by mass or less, the precipitation of crystals can be easily controlled, and a sufficient amount of crystals can be easily precipitated particularly in the heat treatment step.

  In the bismuth-based glass composition of the present invention, the content of ZnO is regulated to 10 to 27% by mass. If the content of ZnO is 10% by mass or more, the precipitation of crystals can be easily controlled, and in particular, a low-expansion crystal can be precipitated to increase the crystallinity of the glass. On the other hand, if the content of ZnO is set to 27% by mass or less, the crystal precipitation time can be delayed, so that it becomes easy to precipitate crystals on the glass after ensuring the desired fluidity in the sealing step.

Further, in the bismuth-based glass composition of the present invention, the crystals to be precipitated are Bi ₂ O ₃ —B ₂ O ₃ —ZnO-based crystals, and these crystals have low expansion. The coefficient of thermal expansion of the glass is difficult to change, and undue stress is hardly left on the object to be sealed after the sealing process, so that airtight reliability of a flat display device or the like can be ensured. Moreover, since the bismuth-type glass composition of this invention has controlled content of ZnO to 10 mass% or more, these crystals can be precipitated preferentially.

  Furthermore, the bismuth-type glass composition of this invention does not contain PbO substantially in a glass composition. In this way, it is possible to accurately meet recent environmental demands.

Secondly, the bismuth-based glass composition of the present invention has, as a glass composition, mass%, Bi ₂ O ₃ 60 to 79.9%, B ₂ O ₃ 5.4 to 15%, ZnO 15 to 27%, _{CuO 0~5%, Fe 2 O 3} 0~5%, BaO + SrO + MgO + CaO 0~10%, SiO 2 + Al 2 O 3 0~5%, MoO 3 + WO 3 0~5%, Sb 2 O 3 0~5%, It is characterized by containing 0 to 5% of In ₂ O ₃ + Ga ₂ O ₃ and substantially not containing PbO.

Third, the bismuth-based glass composition of the present invention has a glass composition of mass%, Bi ₂ O ₃ 67-79.9%, B ₂ O ₃ 5.6-15%, ZnO 15-27%, _{CuO 0~5%, Fe 2 O 3} 0~5%, BaO + SrO + MgO + CaO 0~10%, SiO 2 + Al 2 O 3 0~5%, MoO 3 + WO 3 0~5%, Sb 2 O 3 0~5%, It is characterized by containing 0 to 5% of In ₂ O ₃ + Ga ₂ O ₃ and substantially not containing PbO.

Fourth, the bismuth-based glass composition of the present invention has, as a glass composition, mass%, Bi ₂ O ₃ 60 to less than 77%, B ₂ O ₃ 5.4 to 10%, ZnO less than 10 to 15%, _{CuO 0~7%, Fe 2 O 3} 0~5%, BaO + SrO + MgO + CaO 0~10%, SiO 2 + Al 2 O 3 containing 0 to 5%, and substantially characterized in that it does not contain the PbO.

  Fifth, the bismuth-based material of the present invention contains 40 to 100% glass powder and 0 to 60% refractory filler powder composed of the above-mentioned bismuth-based glass composition, and is crystalline. Characterized by In addition, the bismuth-type material of this invention may be comprised only with glass powder, without adding a refractory filler powder. The “crystallinity” as used in the present invention is 600 ° C., preferably 570 ° C., more preferably measured by a differential thermal analysis (DTA) apparatus (in the atmosphere, the temperature rising rate is 10 ° C./min, starting from room temperature). Means a crystallizing peak that develops at 550 ° C., more preferably 530 ° C.

  Sixth, the bismuth-based material of the present invention is characterized by a crystallization temperature of 490 to 570 ° C. In addition, the “crystallization temperature” in the present invention refers to a temperature at which a crystallization peak appears in the measurement with a DTA apparatus (in the atmosphere, the temperature rising rate is 10 ° C./min, measurement starts from room temperature).

  Seventh, the bismuth-based material of the present invention is characterized in that the refractory filler powder is a ZnO-containing refractory filler powder.

Eighth, the bismuth-based material of the present invention is characterized in that the refractory filler powder is one or more selected from the group of willemite, zinc oxide, garnite, ZnO.Al ₂ O ₃ .SiO _2. Attached.

  Ninth, the bismuth-based material of the present invention is characterized by being used for sealing.

  Tenth, the bismuth-based material of the present invention is characterized in that it is used for a partition wall of a flat display device or an electronic component.

  Eleventh, the bismuth-based material of the present invention is characterized by being used for a flat display device or a side frame of an electronic component.

  12thly, the tablet of this invention is the tablet which sintered the bismuth type material to the predetermined shape, Comprising: This bismuth type material is characterized by being said bismuth type material. In addition, the shape of the tablet of the present invention is not particularly limited, but it is preferable to have a ring shape when fixing the exhaust pipe is assumed.

  Thirteenth, the tablet-integrated exhaust pipe of the present invention is characterized in that the above-mentioned tablet is attached to the distal end portion of the expanded exhaust pipe. Here, in the present invention, the “tip portion of the exhaust pipe” refers to the surface portion of the exhaust pipe having an enlarged diameter, and the exhaust pipe bottom surface or the exhaust pipe outer peripheral side surface on the side in contact with the panel in the enlarged diameter portion Point to. Further, the tablet includes not only an aspect in which the tablet is adhered only to the distal end portion of the exhaust pipe but also an aspect in which the tablet is adhered to a part of the distal end portion of the exhaust pipe.

  Fourteenth, in the tablet-integrated exhaust pipe of the present invention, the tablet and the high melting point tablet are attached to the tip of the expanded exhaust pipe, and the tablet is expanded in diameter. It is attached to the front-end | tip part side of an exhaust pipe, It is characterized by the high melting point tablet being attached to the back end part side rather than said tablet. Here, the “high melting point tablet” referred to in the present invention refers to a tablet that is not softened and deformed at less than 520 ° C. For example, in the case of a glass tablet, it refers to a tablet having a softening point measured by a DTA apparatus of 520 ° C. or higher.

  The reason for limiting the glass composition range as described above in the bismuth-based glass composition of the present invention is as follows. In addition, the following% display points out the mass% except the case where there is particular notice.

Bi ₂ O ₃ is a main component for lowering the softening point of the glass, and is a component that becomes a crystal component of the precipitated crystal. The content is 60 to 84%, preferably 65.1 to 79.9%, more preferably 67 to 79.3%, still more preferably 72 to 77%, and particularly preferably 75 to 77%. When the content of Bi ₂ O ₃ is less than 60%, the softening point increases and it becomes difficult to seal at a temperature of 500 ° C. or lower. When the content of Bi ₂ O ₃ is more than 84%, the devitrification resistance of the glass deteriorates, and before it softens in the sealing process, crystals are deposited on the glass and the function as a sealing material is exhibited. It becomes difficult.

B ₂ O ₃ is an essential component for constituting a glass network of bismuth-based glass. The content is 5.4 to 15%, preferably 5.6 to 11%, more preferably 6.5 to 10%, still more preferably 7 to 9%. When the content of B ₂ O ₃ is less than 5.4%, the devitrification resistance of the glass deteriorates, and before the glass softens in the sealing process, crystals are precipitated on the glass, It becomes difficult to demonstrate the function. When the content of B ₂ O ₃ is more than 15%, it becomes difficult to control the precipitation of crystals, and it becomes difficult to deposit a sufficient amount of crystals particularly in the heat treatment step.

ZnO has an effect of suppressing devitrification of the glass during melting, and is an essential component for increasing the crystallinity of the glass by precipitating low expansion crystals. Its content is 10 to 27%, preferably 12 to 24%, more preferably 12 to 22%. When the content of ZnO is less than 10%, it is difficult to deposit low expansion crystals on the glass in the heat treatment step. When the content of ZnO is more than 27%, the crystal precipitation time is advanced, and it becomes difficult to secure desired fluidity in the sealing step. Furthermore, when the content of Bi ₂ O ₃ is less than 60 to 77%, the content of ZnO is more preferably less than 10 to 15%, particularly preferably less than 12 to 15%, and most preferably less than 13.5 to 15%. preferable.

  CuO is a component that suppresses devitrification during glass melting, and its content is 0 to 7%, preferably 0 to 5%, more preferably 0 to 3%, and still more preferably 0.1 to 2%. is there. If the CuO content is more than 7%, the glass composition is not balanced and the glass tends to devitrify when melted.

Fe ₂ O ₃ is a component that suppresses the devitrification of the glass during melting, and its content is 0 to 5%, preferably 0 to 3%, more preferably 0.1 to 3%. If the content of Fe ₂ O ₃ is more than 5%, the glass becomes thermally unstable.

  BaO, SrO, MgO and CaO have an effect of suppressing devitrification at the time of melting of the glass, and the content thereof is 0 to 10% in total amount (BaO + SrO + MgO + CaO), preferably 0 to 7%, more preferably 0. .1-5%. When the total amount of these components is more than 10%, the softening point of the glass rises and it becomes difficult to seal at a low temperature of 500 ° C. or lower.

SiO ₂ and Al ₂ O ₃ have the effect of enhancing the weather resistance of the glass, and the content thereof is 0 to 5%, preferably 0 to 3%, more preferably 0 in terms of the total amount (SiO ₂ + Al ₂ O ₃ ). ~ 1%. When the total amount of these components is more than 5%, the softening point of the glass becomes high and sealing becomes difficult at a low temperature of 500 ° C. or lower.

  The bismuth-type glass composition of this invention can contain the following components other than the said component, for example.

MoO ₃ and WO ₃ are components that make it easy to control the precipitation time of crystals, and the total content (MoO ₃ + WO ₃ ) is 0 to 5%, preferably 0 to 3%, more preferably 0 to 0%. 1%. When the total amount of these components is more than 5%, the balance of the glass composition is lacking, and the thermal stability of the glass tends to deteriorate, and conversely, it becomes difficult to control the time of crystal precipitation.

Sb ₂ O ₃ is a component that makes it easy to control the precipitation time of crystals, and its content is 0 to 5%, preferably 0 to 3%, more preferably 0.1 to 1%. When the content of Sb ₂ O ₃ is more than 5%, the glass composition is not balanced and the glass tends to be devitrified, and conversely, it is difficult to control the crystal precipitation time.

In ₂ O ₃ and Ga ₂ O ₃ are components that make it easy to control the time of crystal precipitation, and the content thereof is 0 to 5%, preferably 0 to 0 in terms of the total amount (In ₂ O ₃ + Ga ₂ O ₃ ). 3%, more preferably 0 to 1%. When the total amount of these components is more than 5%, the balance of the glass composition is lost, and the glass tends to be devitrified, and conversely, it is difficult to control the crystal precipitation time.

Moreover, the bismuth-type glass composition of this invention can add a various component further as an arbitrary component. For example, Li ₂ O, Na ₂ O, K ₂ O, Cs ₂ O, La ₂ O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ , CeO _{2 and the} like can be added up to 10%. Alkali metal oxides such as Li ₂ O, Na ₂ O, K ₂ O and Cs ₂ O are components that lower the softening point of glass. However, since the alkali metal oxide has an action of promoting devitrification of the glass, the addition amount is preferably limited to 2% or less in total. Rare earth oxides such as La ₂ O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ and CeO ₂ are components that thermally stabilize the glass, but when the total amount of these components is more than 5%, The softening point of glass becomes high and it becomes difficult to seal at a low temperature of 500 ° C. or lower.

A suitable content range of each component can be appropriately selected to obtain a preferable glass composition range. Among these, as a more preferable glass composition range,
(1) By mass%, Bi ₂ O ₃ 60-79.9%, B ₂ O ₃ 5.4-15%, ZnO 15-27%, CuO 0-5%, Fe ₂ O ₃ 0-5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, MoO ₃ + WO ₃ 0-5%, Sb ₂ O ₃ 0-5%, In ₂ O ₃ + Ga ₂ O ₃ 0-5%, And substantially free of PbO,
(2) By mass%, Bi ₂ O ₃ 67-79.9%, B ₂ O ₃ 5.6-15%, ZnO 15-27%, CuO 0-5%, Fe ₂ O ₃ 0-5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, MoO ₃ + WO ₃ 0-5%, Sb ₂ O ₃ 0-5%, In ₂ O ₃ + Ga ₂ O ₃ 0-5%, And substantially free of PbO,
(3) By mass%, Bi ₂ O ₃ 60 to less than 77%, B ₂ O ₃ 5.4 to 10%, ZnO less than 10 to 15%, CuO 0 to 7%, Fe ₂ O ₃ 0 to 5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, and substantially no PbO,
(4) By mass%, Bi ₂ O ₃ 71-79.9%, B ₂ O ₃ 5.4-11%, ZnO 15-22%, CuO 0-5%, Fe ₂ O ₃ 0-5%, BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, MoO ₃ + WO ₃ 0-5%, Sb ₂ O ₃ 0-5%, In ₂ O ₃ + Ga ₂ O ₃ 0-5%, And substantially free of PbO,
(5) By mass%, Bi ₂ O ₃ 67 to less than 77%, B ₂ O ₃ 6.5 to 10%, ZnO 12 to less than 15%, CuO 0 to 7%, Fe ₂ O ₃ 0 to 5%, Examples of the glass include BaO + SrO + MgO + CaO 0 to 10%, SiO ₂ + Al ₂ O ₃ 0 to 5%, and substantially no PbO.

If the glass composition range is regulated within the above range, Bi ₂ O ₃ —B ₂ O ₃ —ZnO-based crystals can be sufficiently precipitated after the glass has been softened and flowed. It is difficult for the thermal expansion coefficient to fluctuate, and undue stress does not easily remain on the object to be sealed after the sealing process, which makes it easier to ensure the airtight reliability of the flat display device or the like.

The bismuth-based glass composition having the above glass composition exhibits good fluidity at 500 ° C. or lower, and has a thermal expansion coefficient of about 90 to 110 × 10 ⁻⁷ / ° C. in a temperature range of 30 to 300 ° C.

The bismuth-based glass composition of the present invention can adjust the crystallization temperature by adjusting the particle size, and can correspond to a two-stage heat treatment process (when the heat treatment process is performed twice). For example, in the primary heat treatment performed at a low temperature of about 460 ° C., in order to complete the crystallization of the glass while ensuring fluidity, the particle size may be reduced. For example, the average particle diameter D ₅₀ is 0.1 to 15 μm, Preferably, it may be less than 0.2 to 10 μm. In addition, when the glass crystallization is completed while fusing to the material to be sealed by the primary heat treatment and then sealing to the other material to be sealed by the secondary heat treatment, conversely, the bismuth glass composition may be increased particle size of the glass powder, for example, an average particle diameter D ₅₀ 10 super ～100Myuemu, preferably may be set to 15～70Myuemu. Here, “average particle diameter D ₅₀ ” refers to a value measured by a laser diffraction method.

The bismuth-based glass composition of the present invention can be crystallized even with a glass powder alone, and Bi ₂ O ₃ —B ₂ O ₃ —ZnO-based crystals are precipitated, so that the thermal expansion coefficient of the glass is ensured. Can be lowered. Therefore, the bismuth-based glass composition of the present invention can be suitably used as a sealing material with glass powder alone. Moreover, the bismuth-type glass composition of this invention can also be used as a partition wall formation material, a side frame formation material, etc. by glass powder alone, when the difference in thermal expansion coefficient with a glass substrate is appropriate.

  When the thermal expansion coefficient of the material to be sealed is low, it is preferable to add a refractory filler powder to the glass powder made of the bismuth glass composition of the present invention to obtain a composite material. The mixing ratio of the bismuth glass powder and the refractory filler powder is preferably 40 to 99.9% by volume of the bismuth glass powder, 0.1 to 60% by volume of the refractory filler powder, more preferably 40 to 99. Volume%, refractory filler powder 1 to 60 volume%, more preferably bismuth glass powder 50 to 95 volume%, refractory filler powder 5 to 45 volume%, particularly preferably bismuth glass powder 60 volume% or more and 90 volume% Less than 10% by volume and 40% by volume or less of the refractory filler powder. If the content of the refractory filler powder is less than 0.1% by volume, the effect of adding the refractory filler powder becomes poor. When the content of the refractory filler powder is more than 60% by volume, the content of the glass powder is relatively decreased, and the fluidity of the bismuth-based material tends to be impaired.

  In the bismuth-based material of the present invention, as the refractory filler powder, mayemite, β-eucryptite, zircon, tin oxide, mullite, quartz glass, alumina and the like can be used singly or in combination.

Among these, if the ZnO-containing refractory filler powder is added, the crystallinity can be increased without changing the crystal seed of the bismuth-based material. As the ZnO-containing refractory filler, for example, willemite (2ZnO · SiO ₂ ), garnite (ZnO · Al ₂ O ₃ ), zinc oxide (ZnO), ZnO · Al ₂ O ₃ · SiO _{2 and the} like are used alone or in combination. Can be used. In particular, willemite is preferable because it has a small coefficient of thermal expansion and the above effects are remarkable. In the case of adding a ZnO-containing refractory filler powder, the glass powder, but the content of B ₂ O ₃ in the glass composition is 6.5% or more preferred. If the content of B ₂ O ₃ is less than 6.5%, the crystallization temperature tends to shift to the low temperature side, and it tends to be difficult to ensure the desired fluidity.

If a small amount (for example, 0.1 to 2%) of a refractory filler powder that acts as a crystal nucleus, such as titanium oxide or iron oxide, is added, the crystallinity of the bismuth glass can be increased. In addition to the above refractory filler powder, it is possible to add a refractory filler powder such as silica or zirconia in order to adjust the thermal expansion coefficient of the bismuth-based material, adjust the fluidity and improve the mechanical strength. it can. In the case of adding a refractory filler powder, which acts as a crystal nucleus, the glass powder, the content of B ₂ O ₃ in the glass composition preferably 6.5% or more. When the content of B ₂ O ₃ is less than 6.5%, the crystallization temperature is excessively shifted to the low temperature side, and it becomes difficult to ensure desired fluidity.

  In the bismuth-based material of the present invention, the crystallization temperature is preferably 490 to 570 ° C, more preferably 500 to 540 ° C, and still more preferably 510 to 530 ° C. When the crystallization temperature is lower than 490 ° C., the crystal deposition time becomes too early, and it becomes difficult to secure desired fluidity in the sealing step. When the crystallization temperature is higher than 570 ° C., it becomes difficult to deposit a sufficient amount of crystals in the sealing process, and the glass is easily re-softened in a heat treatment process after crystal deposition, for example, a vacuum evacuation process. It becomes difficult to ensure airtight reliability.

It is important that the thermal expansion coefficient of the bismuth-based material is designed to be about 5 to 30 × 10 ⁻⁷ / ° C., preferably about ^{7 to} 20 × 10 ⁻⁷ / ° C. lower than the material to be sealed. This is to prevent the sealing layer from being broken by setting the strain applied to the sealing layer after the sealing step to the compression side. In particular, in the case of a high strain point glass substrate for PDP (thermal expansion coefficient 75 to 90 × 10 ⁻⁷ / ° C.), a suitable thermal expansion coefficient of the sealing material is 55 to 80 × 10 ⁻⁷ / ° C. Further, in the case of a soda glass substrate for VFD (thermal expansion coefficient 85 to 100 × 10 ⁻⁷ / ° C.), a suitable thermal expansion coefficient of the sealing material is 70 to 90 × 10 ⁻⁷ / ° C.

  The bismuth-based material may be used as a powder, but it is easy to handle when it is kneaded uniformly with a vehicle and used as a paste. The vehicle is mainly composed of an organic solvent and a resin, and the resin is added for the purpose of adjusting the viscosity of the paste. Moreover, surfactant, a thickener, etc. can also be added as needed. The produced paste is applied using an applicator such as a dispenser or a screen printer.

  As the resin, acrylic acid ester (acrylic resin), ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethylstyrene, polyethylene carbonate, methacrylic acid ester and the like can be used. In particular, acrylic acid esters and nitrocellulose are preferable because they have good thermal decomposability.

  As organic solvents, N, N′-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyllactone (γ-BL), tetralin, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether , Diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy-3-methylbutanol, water, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl Ether, tripropylene glycol monobutyl ether, propylene carbonate, dimethyl sulfoxide (DMSO) N- methyl-2-pyrrolidone and the like can be used. In particular, α-terpineol is preferable because it is highly viscous and has good solubility in resins and the like.

  The bismuth-based material of the present invention is preferably sintered into a predetermined shape to form a tablet. In a flat display device such as a PDP, a tablet (also referred to as a press frit, a glass sintered body, a glass molded body, etc.) molded into a ring shape is used to seal the exhaust pipe to the panel. . The tablet has an insertion hole for inserting the exhaust pipe. The exhaust pipe is inserted into the insertion hole, and the tip of the exhaust pipe is aligned with the position of the exhaust hole of the panel and fixed with a clip or the like. . Thereafter, heat treatment is performed at the sealing temperature of the tablet to soften the tablet, whereby the exhaust pipe is attached to the panel. If the bismuth-based material of the present invention is processed into a tablet, the exhaust pipe can be easily connected to the exhaust equipment and the inclination of the exhaust pipe can be reduced with respect to the panel. It can be mounted vertically, and further, it can be mounted so that airtight reliability is maintained while maintaining the light emission capability of the flat display device. In particular, the tablet of the present invention is suitable for fixing an exhaust pipe of a PDP because desired fluidity can be ensured in the sealing step and heat resistance after crystallization is good.

  The tablet of the present invention is produced through a plurality of independent heating processes as follows. First, a binder or solvent is added to a bismuth-based material to form a slurry. Thereafter, this slurry is put into a granulator such as a spray dryer to produce granules. At that time, the granules are heat-treated at a temperature at which the solvent volatilizes (about 100 to 200 ° C.). Furthermore, the produced granule is put into a mold designed to have a predetermined size and is dry press-molded into a ring shape to produce a pressed body. Next, the binder remaining in the press body is decomposed and volatilized in a heat treatment furnace such as a belt furnace, and sintered at a temperature about the softening point of the bismuth glass to produce a tablet. Further, the sintering in the heat treatment furnace may be performed a plurality of times. When the sintering is performed a plurality of times, the strength of the tablet is improved, and the tablet can be effectively prevented from being broken or broken.

  It is preferable that the tablet of the present invention is used as a tablet-integrated exhaust pipe by being attached to the distal end portion of the expanded exhaust pipe. With the above configuration, it is not necessary to simultaneously align the three parts of the panel, the tablet, and the exhaust pipe in the exhaust hole, and the exhaust pipe installation work can be simplified. In order to manufacture such a tablet-integrated exhaust pipe, it is necessary to heat-treat the tablet in contact with one end of the exhaust pipe and adhere the tablet to the tip of the exhaust pipe. In such a case, it is generally possible to employ a method of fixing the exhaust pipe with a jig and inserting a tablet into the exhaust pipe in this state to perform heat treatment. The jig for fixing the exhaust pipe is preferably made of a material to which the tablet is not fused, and for example, a carbon jig or the like can be used. Moreover, what is necessary is just to perform adhesion | attachment of an exhaust pipe and a tablet for a short time of about 5 to 10 minutes near the softening point of bismuth-type glass. Furthermore, the tablet of this invention can ensure desired fluidity | liquidity at a sealing process, and the sealing strength of a to-be-sealed thing and a tablet is favorable. Furthermore, since a sufficient amount of crystals precipitates after the tablet flows in the sealing process, the tablet is hardly re-softened in the subsequent heat treatment process, and airtight reliability of a flat display device or the like can be ensured.

As the exhaust pipe, SiO ₂ —Al ₂ O ₃ —B ₂ O ₃ glass containing a predetermined amount of an alkali metal oxide is suitable, but in particular, product grade “FE-2” manufactured by Nippon Electric Glass Co., Ltd. Is preferred. This exhaust pipe has a thermal expansion coefficient of 85 × 10 ⁻⁷ / ° C., a heat resistant temperature of 550 ° C., and has dimensions of, for example, an outer diameter of 5 mm and an inner diameter of 3.5 mm. Moreover, it is preferable to enlarge the diameter of the tip of the exhaust pipe, and it is preferable to form a flare or flange at the tip. Various methods can be adopted as a method of expanding the tip portion of the exhaust pipe. In particular, a method of heating using a gas burner while rotating the tip of the exhaust pipe and processing it into a predetermined shape using several kinds of jigs is preferable because it is excellent in mass productivity.

  An example of the tablet-integrated exhaust pipe having such a configuration is shown in FIG. FIG. 1 is a cross-sectional view of a tablet-integrated exhaust pipe, where the tip of the exhaust pipe 1 is enlarged in diameter, and the tablet 2 is bonded to the tip of the exhaust pipe on the panel side.

  In the tablet-integrated exhaust pipe of the present invention, the tablet and the high melting point tablet are attached to the distal end portion of the expanded exhaust pipe, and the tablet is attached to the distal end side of the expanded exhaust pipe, It is preferable to attach the high melting point tablet to the rear end side of the tablet. If the tablet-integrated exhaust pipe is configured in this way, the tablet is attached to the tip of the exhaust pipe, so when attaching the exhaust pipe to the panel, the area that contacts the panel etc. It becomes wider than the case, and the exhaust pipe can be made to stand on a panel or the like stably, and it becomes easy to attach vertically without tilting to the panel or the like. If the tablet-integrated exhaust pipe is configured as described above, in the process of manufacturing the tablet-integrated exhaust pipe, when the tablet is fixed to the exhaust pipe, a high melting point tablet is placed between the jig and the tablet. Thus, the tablet-integrated exhaust pipe can be manufactured, that is, it is not necessary to use a special jig in manufacturing the tablet-integrated exhaust pipe, and the manufacturing process can be simplified.

  In the tablet-integrated exhaust pipe having the above-described configuration, the tablet is preferably fixed to the outer peripheral surface of the front end portion of the glass tube, more preferably fixed only to the outer peripheral surface of the front end portion of the glass tube, and the front end surface of the front end portion of the glass tube That is, it is not fixed to the surface bonded to the panel or the like. In this way, it is possible to easily prevent the glass from flowing into the exhaust holes formed in the panel or the like. In addition, if the high melting point tablet is not directly bonded to the exhaust pipe, but is fixed to the exhaust pipe through the tablet, the exhaust pipe can be pressure sealed with the high melting point tablet part fixed with a clip in the sealing process. ,preferable.

  As the high melting point tablet, it is preferable to use product grades “ST-4” and “FN-13” manufactured by Nippon Electric Glass Co., Ltd. as materials. The high melting point tablet can be produced by the above method. Moreover, ceramics, metal, etc. can also be used as a material of the high melting point tablet.

  FIG. 2 shows an example of the tablet-integrated exhaust pipe having such a configuration. FIG. 2 is a cross-sectional view of the tablet-integrated exhaust pipe, where the tip of the exhaust pipe 1 has an enlarged diameter, and the tablet 2 is bonded to the tip of the exhaust pipe 1 on the outer peripheral surface side of the flange portion 1a. . On the other hand, the high melting point tablet 3 is not bonded to the outer peripheral surface side of the exhaust pipe 1. The tablet 2 is attached to the front end side of the flange portion 1 a, and the high melting point tablet 3 is attached to the rear end portion side of the flange portion 1 a than the tablet 2.

  The bismuth-based material of the present invention is preferably used as a sealing material. In that case, since the bismuth-based material of the present invention can be sealed at a low temperature, it can be sealed without deteriorating the characteristics of a member having poor heat resistance. The bismuth-based material of the present invention is preferably used for sealing a flat display device or an electronic component. As long as the flat display device can be sealed at a low temperature, the manufacturing efficiency can be improved, and the deterioration of characteristics of other members such as a phosphor can be prevented. On the other hand, an electronic component may use a member whose characteristics deteriorate at a high temperature (for example, a conductive adhesive for a crystal resonator package). Therefore, the bismuth-based material of the present invention can be sealed at a low temperature and is suitable for these applications.

  The bismuth-based material of the present invention is preferably used for sealing PDP. In the PDP, after the sealing step, the inside of the PDP is evacuated through an exhaust pipe, and then a necessary amount of rare gas is injected to seal the exhaust pipe. This evacuation process is preferably performed at as high a temperature as possible in order to increase the exhaust efficiency. In this respect, the bismuth-based material of the present invention has a large amount of crystals deposited after the glass has flowed. Therefore, it is difficult to re-soften in the subsequent vacuum evacuation step, and the exhaust temperature can be raised. For the same reason, the bismuth-based material of the present invention is also suitable as a sealing material for the front glass substrate and the back glass substrate.

  The bismuth-based material of the present invention is preferably used as a partition wall forming material for flat display devices or electronic parts. In addition to being sinterable at a low temperature, the bismuth-based material of the present invention precipitates a sufficient amount of crystals after sintering, so that a dimensional change hardly occurs in the subsequent heat treatment step. Furthermore, if a certain amount of refractory filler powder is contained, the mechanical strength and dimensional stability of the partition walls can be further improved. The bismuth-based material of the present invention can be sintered at a low temperature and has excellent heat resistance after crystallization. Therefore, the bismuth-based material is used for the purpose of forming a part of the partition wall, that is, for repairing the defect part of the partition wall. You can also

  The bismuth-based material of the present invention is preferably used as a material for forming a side frame (support frame, side spacer) of a flat display device or electronic component. Since the bismuth-based material of the present invention regulates the glass composition of the bismuth-based glass composition within the above range, crystals are precipitated after the side frame sintering process, and the side frame is stabilized during the formation of the side frame. And the dimensional accuracy of the side frame can be easily improved. Furthermore, if the refractory filler powder is added to the bismuth-based glass powder, the thermal expansion coefficient of the side frame can be easily adjusted, and the mechanical strength of the side frame can be easily increased. As a result, the inside of the flat display device can be reliably supported even when the inside of the flat display device is in a vacuum state, and even if a mechanical shock is applied to the flat display device, a crack is generated from the side frame. It becomes difficult. Moreover, since the glass composition range is regulated as described above, the bismuth-based material of the present invention is densely sintered at a temperature lower than the strain point of the high strain point glass substrate (for example, 570 ° C. or lower), The side frame can be formed at a temperature below the strain point of the high strain point glass substrate.

  In particular, the bismuth-based material of the present invention is preferably used for a side frame of an FED. Since the bismuth-based material of the present invention can easily control the precipitation of crystals, the dimensional accuracy of the side frame can be easily improved. As a result, the distance between the front glass substrate and the rear glass substrate can be made uniform, the acceleration voltage applied between the front plate and the back plate inside the FED apparatus varies, and the velocity of electrons that collide with the phosphor. It is difficult to cause a situation in which the luminance characteristics of the FED are adversely affected.

  Hereinafter, the present invention will be described in detail based on examples.

  Tables 1 to 4 show examples (samples a to t) of the present invention, and Table 5 shows comparative examples (samples u to x) of the present invention.

  Each sample described in Tables 1 to 5 was prepared as follows.

First, a glass batch in which raw materials such as various oxides and carbonates were prepared so as to have the glass composition shown in the table was prepared, and this was put in a platinum crucible and melted at 900 to 1200 ° C. for 1 to 2 hours. Next, a part of the molten glass was poured into a stainless steel mold as a sample for measuring the thermal expansion coefficient, and the other molten glass was formed into a thin piece by a water-cooled roller. Finally, the flaky glass was pulverized with a ball mill and then passed through a sieve having an opening of 200 mesh to obtain each sample having an average particle diameter D ₅₀ of 10 μm.

  Each sample was evaluated for glass transition point, softening point, thermal expansion coefficient, crystallization temperature and crystallinity.

  The glass transition point and the thermal expansion coefficient were determined by a push rod type thermal expansion coefficient measurement (TMA) apparatus.

  The softening point was determined with a DTA apparatus. The measurement was performed in the atmosphere at a temperature rising rate of 10 ° C./min, and the measurement was started from room temperature.

  The crystallization temperature was measured with a DTA apparatus. The measurement was performed in the atmosphere at a temperature rising rate of 10 ° C./min, and the measurement was started from room temperature. Moreover, the presence or absence of a glass transition point and a thermal expansion coefficient in a temperature range of 500 ° C. or lower were measured with a TMA apparatus using a fired body heat-treated at a temperature 20 ° C. lower than the crystallization temperature as a sample.

  The crystallinity is evaluated with a DTA apparatus, where a crystallization peak appears at a temperature of 570 ° C. or lower and heat treatment is performed at a temperature 20 ° C. lower than the crystallization temperature, and then measured with a TMA apparatus. Samples that did not show a glass transition point or yield point in the region were marked with “◯”, and other samples were marked with “X”.

  Tables 6 to 9 show examples (samples Nos. 1 to 20) of the present invention, and Table 10 shows comparative examples (samples Nos. 21 to 24) of the present invention.

  Glass powder and refractory filler powder were mixed at the ratios shown in Tables 6 to 10 to prepare bismuth-based materials (sample Nos. 1 to 24).

Willemite and tin dioxide (tin stone) were used as the refractory filler. The average particle diameter D ₅₀ of willemite was 11 μm, and the average particle diameter D ₅₀ of tin dioxide was 8 μm.

  Using the above samples, the softening point, crystallization temperature, thermal expansion coefficient, glass transition point, flow diameter, and surface state were evaluated.

  The softening point was measured with a DTA apparatus. The measurement was performed in the atmosphere at a temperature rising rate of 10 ° C./min, and the measurement was started from room temperature. The crystallization temperature was measured with a DTA apparatus. The measurement was performed in the atmosphere at a temperature rising rate of 10 ° C./min, and the measurement was started from room temperature.

  The thermal expansion coefficient and the presence or absence of a glass transition point in a temperature range of 500 ° C. or less were measured with a TMA apparatus using samples heat-treated under the heat treatment conditions shown in Tables 6 to 10.

  The flow diameter is a powder having a mass corresponding to the true specific gravity of the bismuth-based material, pressed into a button shape having an outer diameter of 20 mm by a mold, and then placed on a high strain point glass substrate. The temperature was raised at 10 ° C./min in an electric furnace, held at the heat treatment temperature shown in Tables 6 to 10 for 10 minutes, the temperature was lowered at a rate of 10 ° C./min, and the diameter of the obtained button sample was measured with a digital caliper. And evaluated.

  The surface state was observed with a microscope and evaluated as “◯” when crystals were deposited on the entire button surface, and “X” when crystals were not deposited on the entire button surface.

  As is clear from Tables 6 to 9, sample No. Nos. 1 to 20 have a thermal expansion coefficient at 30 to 300 ° C. matched with a soda glass substrate, a high strain point glass substrate, and the like, and are considered to be suitable as a sealing material. Sample No. Nos. 1 to 20 show a flow diameter of 18 mm or more under the heat treatment conditions shown in the table, have good fluidity, and crystallize after the glass is softened. The sealing performance was also excellent. Furthermore, sample no. Nos. 1 to 20 use willemite or tin dioxide as the refractory filler powder, the surface of the button after heat treatment is sufficiently crystallized, and the glass transition point, which is a characteristic characteristic of non-crystalline glass, is 500 ° C. It was not observed in the following temperature range. Therefore, sample no. 1 to 20 are considered to be crystallized at high density (high crystallinity).

  On the other hand, Sample No. No. 21 uses willemite as a refractory filler powder, and the button surface was in a matte state, but the glass transition point could be confirmed at a temperature below the softening point and crystallized at a low density (low crystallinity). it is conceivable that. Sample No. Nos. 22 to 24 use willemite as a refractory filler powder and have a flow diameter of 20 mm or more and good fluidity, but the button surface is glossy and the button surface is crystallized. It wasn't.

  The bismuth-based material of the present invention includes PDP, FED, VFD and cathode ray tube (CRT) sealing materials, PDP partition wall forming materials, PDP, FED and VFD side frame forming materials, crystal resonators, IC packages, etc. It is suitable as a sealing material for parts, a magnetic head-core or between core and slider.

It is sectional drawing which shows the tablet integrated exhaust pipe of this invention. It is sectional drawing which shows the tablet integrated exhaust pipe of this invention.

Explanation of symbols

1 Exhaust pipe 2 Tablet 3 High melting point tablet

Claims (14)

As a glass composition, in _{mass%, Bi 2 O 3 60~84%} , B 2 O 3 5.4~15%, ZnO 10~27%, CuO 0~7%, Fe 2 O 3 0~5%, BaO + SrO + MgO + CaO A bismuth-based glass composition containing 0 to 10%, SiO ₂ + Al ₂ O ₃ 0 to 5%, and substantially free of PbO. As a glass composition, in _{mass%, Bi 2 O 3 60~79.9%} , B 2 O 3 5.4~15%, ZnO 15~27%, 0~5% CuO, Fe 2 O 3 0~5% BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, MoO ₃ + WO ₃ 0-5%, Sb ₂ O ₃ 0-5%, In ₂ O ₃ + Ga ₂ O ₃ 0-5% And the bismuth-type glass composition characterized by not containing PbO substantially. As a glass composition, in _{mass%, Bi 2 O 3 67~79.9%} , B 2 O 3 5.6~15%, ZnO 15~27%, 0~5% CuO, Fe 2 O 3 0~5% BaO + SrO + MgO + CaO 0-10%, SiO ₂ + Al ₂ O ₃ 0-5%, MoO ₃ + WO ₃ 0-5%, Sb ₂ O ₃ 0-5%, In ₂ O ₃ + Ga ₂ O ₃ 0-5% And the bismuth-type glass composition of Claim 2 which does not contain PbO substantially. As a glass composition, in mass%, Bi less than _{2 O 3 60~77%, B 2} O 3 5.4~10%, ZnO less than 10~15%, CuO 0~7%, Fe 2 O 3 0~5% BaO + SrO + MgO + CaO 0 to 10%, SiO ₂ + Al ₂ O ₃ 0 to 5%, and substantially free of PbO.   It contains the glass powder 40-100% which consists of the bismuth-type glass composition in any one of Claims 1-4 by volume% display, and 0-60% of refractory filler powders, and is crystalline. Characteristic bismuth-based material.   The bismuth-based material according to claim 5, wherein the crystallization temperature is 490 to 570 ° C.   The bismuth-based material according to claim 5 or 6, wherein the refractory filler powder is a ZnO-containing refractory filler powder. Refractory filler powder, willemite, zinc oxide, gahnite, according to any one of claims 5-7, characterized in that it _{ZnO · Al 2 O 3 · SiO} 2 than selected one or two or more groups Bismuth material.   The bismuth-based material according to any one of claims 5 to 8, which is used for sealing.   The bismuth-based material according to claim 5, wherein the bismuth-based material is used for a partition wall of a flat display device or an electronic component.   The bismuth-based material according to claim 5, wherein the bismuth-based material is used for a flat display device or a side frame of an electronic component.   A tablet obtained by sintering a bismuth-based material into a predetermined shape, wherein the bismuth-based material is the bismuth-based material according to any one of claims 5 to 11.   A tablet-integrated exhaust pipe, wherein the tablet according to claim 12 is attached to a distal end portion of the exhaust pipe having an enlarged diameter.   The tablet according to claim 12 and a high melting point tablet are attached to a distal end portion of an exhaust pipe having an enlarged diameter, and the tablet is attached to a distal end portion side of the exhaust pipe having an enlarged diameter. A tablet-integrated exhaust pipe, wherein the tablet is attached to the rear end side of the tablet.

Images