JP2011105596A - Glass tablet, method for producing the same, and glass tablet-integrated exhaust pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass tablet having high fluidity, a method for producing the glass tablet, and a glass tablet-integrated exhaust pipe. <P>SOLUTION: The glass tablet is a ring-like glass tablet comprising a glass powder and a filler powder, and do not substantially contain PbO. The method for producing the glass tablet includes steps of: uniformly mixing a glass powder containing substantially no PbO with a filler power; adding a vehicle having good thermal decomposition property to the mixture powder to prepare granules; press-forming the granules; and calcining the product. The tablet-integrated exhaust pipe is obtained by sticking the glass tablet comprising the glass powder and the filler powder containing substantially no PbO to the outer peripheral face at the tip end of the exhaust pipe made of glass. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a glass tablet and a glass tablet integrated exhaust pipe used for display tubes such as a plasma display panel (PDP), a surface electric field display (SED), a field emission display (FED), and a fluorescent display tube (VFD). is there.

  In recent years, development of flat panel displays (FPDs) such as liquid crystal displays (LCDs), PDPs, and SEDs has been rapidly progressing as large-sized flat TVs and wall-mounted TVs.

  For example, in a PDP, minute cells are regularly formed between a front plate and a back plate in the vertical and horizontal directions. When discharge occurs inside the cell, ultraviolet light is emitted from a rare gas enclosed in the cell, and the fluorescent light that has absorbed the ultraviolet light is emitted. The body emits visible light fluorescence to display characters and images.

  For the purpose of exhausting the inside of the panel (between the front plate and the back plate) or filling the inside of the panel with a predetermined gas in the FPD such as PDP, FED, SED, plasma addressed liquid crystal display (PALC), VFD, etc. A glass tube called an exhaust pipe is attached.

  In order to seal the gas, the front plate and the back plate are made by adding a vehicle to a mixture of low-melting glass powder and filler powder (sealing powder) and kneading the mixture uniformly. Wear tightly around the circumference.

  In order to exhaust the gas inside the panel or inject a rare gas into the panel, an exhaust port having a diameter of several millimeters is provided in the non-display portion of the back plate, and the center of the exhaust port and the axis of the exhaust pipe are concentric. It arrange | positions so that it may become.

  In order to join the exhaust pipe to the back plate, the inclination of the exhaust pipe should be as small as possible so that the connection with the exhaust device can be easily automated, and the air tightness of the joint part should be kept so as not to reduce the light emitting capacity of the display. Desired.

  When joining the exhaust pipe to the back plate, a method is widely adopted in which a slurry containing a low-melting glass powder and a solvent is applied to the end face of the exhaust pipe, and the exhaust pipe is baked and joined to the back plate while standing on the back plate. .

  If this method is used, the inside of the panel may be contaminated by the solvent evaporated during firing. In order to prevent contamination inside the panel, a method is used in which the exhaust pipe is heated in advance to remove (debinder) the organic components of the slurry coating layer.

  In this method, when the organic component of the slurry coating layer is removed, the flatness of the remaining low-melting glass layer may be poor. If the flatness is poor, a tilt occurs when the exhaust pipe is stood on the back plate, and there is a problem of joining in that state. In addition, a gap is generated between the low-melting glass layer and the panel, resulting in a problem that airtightness cannot be maintained.

  Therefore, there is a glass tablet integrated exhaust pipe that integrates the glass tablet and the glass tablet and the exhaust pipe so that the sealing material is molded into a flat surface so that the exhaust pipe is not tilted and is joined with high airtightness. Suggested and used.

  Generally, a glass tablet is produced as follows.

  First, glass powder and filler powder are uniformly mixed, and then a vehicle containing a resin such as methylcellulose and nitrocellulose and a solvent such as α-terpineol and amyl acetate is added to produce granules having a particle size of about 100 μm. .

  Next, the granule is filled in a mold and press-molded to prepare a glass tablet precursor.

  Finally, the glass tablet precursor is temporarily fired at about 200 to 350 ° C., whereby the resin component is volatilized and burned, and sintered at 330 to 430 ° C. to produce a glass tablet. In general, the glass tablet has an annular shape, and its cross section has a shape such as a circle, a rectangle, and an L shape.

  The glass tablet integrated exhaust pipe is generally manufactured as follows.

  First, a glass tube produced by a known method such as the Danner method, downdraw method, updraw method or the like is cut into a predetermined length to produce an exhaust pipe. The exhaust pipe is used by expanding the tip of the exhaust pipe into a flare shape, a flange shape, or a cylindrical shape as necessary.

  Next, a glass tablet is fixed to the outer peripheral surface of the tip of the exhaust pipe obtained on the enlarged diameter side. At this time, the exhaust pipe and the glass tablet are aligned so that the holes are concentric. As a fixing method, a method in which the exhaust pipe and the glass tablet are heated in contact with each other and the glass tablet is fused to the outer peripheral surface of the exhaust pipe, or a method in which both are bonded using an adhesive is used. The

  In addition, although heating for removing a binder from a glass tablet may be performed before adhering to a glass tube, you may heat in order to fuse | melt a glass tablet and an exhaust pipe.

  When the tablet-integrated exhaust pipe manufactured in this way is attached to a flat display tube or the like, the panel is placed with the tablet portion down so that the center of the exhaust port provided on the back plate and the axis of the exhaust pipe are concentric. What is necessary is just to hold | maintain in the state stood up and to bake.

Until now, lead glass has been used as the low melting point glass powder for the sealing material, but it does not contain lead due to environmental problems due to toxicity of lead, for example, SnO—P ₂ O ₅ based low Melting glass (for example, refer to Patent Documents 1 and ₂ ) and Bi ₂ O ₃ —B ₂ O ₃ based low melting point glass (for example, refer to Patent Documents 3 and 4) have been developed.
JP-A-9-227154 Japanese Patent Laid-Open No. 9-235136 JP-A-6-24797 JP 2000-241143 A

By the way, when a glass tablet is produced by using lead-free glass, for example, SnO—P ₂ O ₅ low melting glass instead of lead glass, the glass is oxidized and reduced at the time of preliminary firing. In addition, when a glass tablet is produced using a Bi ₂ O ₃ —B ₂ O ₃ low melting point glass, it is crystallized inside the glass at the time of pre-firing and actually sealed. Has a problem that it cannot be used as a sealing material due to low fluidity.

  An object of the present invention is to provide a glass tablet having high fluidity, substantially free of PbO and containing glass powder and filler powder, a method for producing the same, and a glass tablet integrated exhaust pipe.

  The present inventors obtained fluidity because the glass (resin binder, solvent, etc.) and glass react with each other through oxygen during calcination to promote redox and crystallization of glass. In addition to finding out that it has disappeared, the present inventors have found that the above-mentioned problems can be solved by using a vehicle having good thermal decomposability, and propose the present invention.

  That is, the glass tablet of the present invention is characterized by containing glass powder and filler powder and substantially not containing PbO.

  Moreover, the manufacturing method of the glass tablet of this invention is the process which mixes the glass powder and filler powder which do not contain PbO substantially, and adds the vehicle with favorable thermal decomposition property to the said mixed powder, and is set as a granule. The method includes a step, a step of press-molding the granule, and a step of pre-baking.

  Furthermore, the tablet-integrated exhaust pipe of the present invention is formed by adhering a glass tablet containing glass powder and filler powder and substantially free of PbO to the outer peripheral surface of the tip of the exhaust pipe made of glass. It is characterized by.

  When the method for producing a glass tablet of the present invention is used, even if PbO is not substantially contained, the glass powder is not crystallized or oxidized / reduced, so it has excellent fluidity and sealing properties. Glass tablets can be made.

  Hereinafter, a method for producing a glass tablet will be described.

  First, lead-free glass powder and lead-free filler powder are mixed uniformly.

  Next, a vehicle having a good thermal decomposability is added to the mixed powder to produce granules having a particle size of about 100 μm.

  Subsequently, the granules are filled in a mold and press-molded to prepare a glass tablet precursor.

  Finally, the glass tablet precursor is temporarily fired at about 200 to 350 ° C., whereby the vehicle components are volatilized and burned, and sintered at 330 to 430 ° C. to produce a glass tablet.

  Since the glass tablet of this invention does not contain PbO substantially, it can reduce environmental impact.

  The glass tablet of the present invention has excellent fluidity and sealing property because the flow diameter of the button test at 410 to 500 ° C. is 19 to 30 mm. If the flow diameter is smaller than 19 mm, the fluidity is poor, so the sealing strength is low. If the flow diameter is larger than 30 mm, the fluidity is too high, and the sealing material leaking from the sealed part has an adverse effect on other parts. May cause effects.

  The button test was evaluated by measuring the diameter of a button when a cylindrical preliminarily fired button having a diameter of 20 mm and a height of 10 mm was heated at a temperature higher than the softening point for 10 minutes and then left at room temperature. The temperature was raised and lowered at 10 ° C./min.

When the glass tablet of the present invention has a thermal expansion coefficient smaller than that to be sealed (glass substrate) by 5 to 20 × 10 ⁻⁷ / ° C., it is preferable that the sealing is difficult to peel off because compressive strain is applied to the glass tablet after sealing. If it is less than 5 × 10 ⁻⁷ / ° C., it is difficult to obtain sufficient compression strain, and if it is greater than 20 × 10 ⁻⁷ / ° C., cracks due to the difference in thermal expansion coefficient may occur in the glass tablet or glass substrate. Because there is. A difference of 8 to 15 × 10 ⁻⁷ / ° C. is more preferable.

  The low-melting glass used for the glass tablet of the present invention is preferably made of a low-melting glass having a sealing temperature of 550 ° C. or lower. Since the exhaust pipe is made of glass with relatively low heat resistance so that the exhaust pipe can be sealed with a burner after the inside of the panel is exhausted, the low temperature glass with a sealing temperature exceeding 550 ° C. is heated during firing. This is because there is a risk of deformation.

  The glass tablet of the present invention may have any shape, but an annular shape is preferable because the exhaust pipe can be easily sealed. In particular, it is preferable that the cross-sectional shape is circular, square, or L-shaped because of good adhesion to the exhaust pipe.

The glass tablet of the present invention includes Bi ₂ O ₃ —B ₂ O ₃ glass, SnO—P ₂ O ₅ glass, P ₂ O ₅ —Ag ₂ O glass, and P ₂ O ₅ —CuO glass as glass powder. Alternatively, V ₂ O ₅ —BaO-based glass can be used. These glasses are preferable because they have a low melting point of 500 ° C. or lower. In particular, Bi ₂ O ₃ —B ₂ O ₃ based glass and SnO—P ₂ O ₅ based glass are preferable because of excellent weather resistance and fluidity.

First, it describes _SnO-P 2 _{O 5} based glass.

The composition of SnO—P ₂ O ₅ glass powder is expressed in mol%, SnO 35-60%, P ₂ O ₅ 18-45%, ZnO 0-20%, B ₂ O ₃ 0-30%, SiO ₂ 0. _{~15%, Al 2 O 3 0~10} %, R 2 O 0~10% (R is Li, Na, K and Cs) preferably contains a.

The reason why the SnO—P ₂ O ₅ glass is limited to the above composition range is shown below.

  SnO is a component that lowers the melting point of glass. If the SnO content is less than 35%, the viscosity of the glass increases and the sealing temperature tends to increase, and if it exceeds 60%, vitrification becomes difficult. In addition, since it will become easy to devitrify at the time of sealing when there is much SnO, it is preferable that it is 55% or less. Moreover, if it is 40% or more, since it is excellent in fluidity | liquidity and high airtightness is obtained, it is preferable.

P ₂ O ₅ is a glass forming oxide. If the P ₂ O ₅ content is less than 18%, it is difficult to obtain sufficient glass stability. If it is in the range of 18 to 45%, sufficient stability can be obtained for the glass, but if it exceeds 45%, the moisture resistance tends to deteriorate. It if P ₂ O ₅ is more than 20%, a glass is further stabilized, so appears a tendency that weather resistance of the sealing glass exceeds 35% is slightly deteriorated, it is 20 to 35% Is more preferable.

  ZnO is an intermediate oxide. ZnO is not an essential component, but is desirably 4% or more because it has a great effect of stabilizing the glass. However, if ZnO exceeds 20%, devitrification tends to occur on the glass surface during sealing. The ZnO content is desirably 5 to 15%.

B ₂ O ₃ is a glass forming oxide. B ₂ O ₃ is not an essential component, but has an effect of stabilizing the glass. However, if it exceeds 30%, the viscosity of the glass becomes too high, the fluidity at the time of sealing is remarkably deteriorated, and the airtightness of the sealing part tends to be impaired. A preferable range of B ₂ O ₃ is 0 to 25%.

SiO ₂ is a glass forming oxide. Although SiO ₂ is not an essential component, it is desirable to contain it because it has an effect of suppressing devitrification, and it is particularly preferred to contain 6% or more. If it exceeds 15%, the softening temperature rises and the sealing temperature tends to increase.

Al ₂ O ₃ is an intermediate oxide. Al ₂ O ₃ is not an essential component, but it has an effect of stabilizing the glass and also has an effect of lowering the thermal expansion coefficient. However, if it exceeds 10%, the softening temperature rises and the sealing temperature tends to increase. In addition, when the stability of glass, a thermal expansion coefficient, fluidity | liquidity, etc. are considered, the range of 0.5 to 5% is more preferable.

R ₂ O (R is Li, Na, K, and Cs) is not an essential component, but there is a tendency that the adhesive force is improved by adding at least one of the R ₂ O components to the composition. However, if the total amount exceeds 10%, devitrification tends to occur during sealing. Further, among R ₂ O, Li ₂ O is most likely to improve the adhesive force.

In addition to the above, the SnO—P ₂ O ₅ glass may contain the following components.

Although lanthanoid oxides such as La ₂ O ₃ and CeO ₂ are not essential components, the weather resistance of the glass tends to be improved by containing 0.1% or more in total in the glass component.

In addition to the lanthanoid oxide, the use of other rare earths such as Y ₂ O ₃ is effective for improving the weather resistance of the glass. The amount of rare earth added excluding the lanthanoid oxide is preferably 0 to 5%.

  R′O (R ′ is Mg, Ca, Sr, and Ba) is not an essential component, but is useful as a component that stabilizes the glass. If the total amount of R'O exceeds 15%, devitrification tends to occur. Therefore, the content of R′O is desirably 15% or less, more preferably 10% or less.

In addition, for example, a component that stabilizes glass such as Nb ₂ O ₅ , TiO ₂ , ZrO ₂ , CuO, MnO, and In ₂ O ₃ can be contained up to 20% in total. In addition, when content of these stabilization components exceeds 20%, glass will become unstable and it will become difficult to manufacture. In order to obtain a more stable glass, the content is preferably 15% or less.

The contents of Nb ₂ O ₅ , TiO ₂ , and ZrO ₂ are all 0 to 15%, particularly preferably 0 to 10%. If the content of any component exceeds 15%, the glass tends to be unstable.

  The contents of CuO and MnO are both 0 to 10%, particularly preferably 0 to 5%. If the content of any component exceeds 10%, the glass tends to be unstable.

In ₂ O ₃ can be used for the purpose of obtaining high weather resistance. The content of In ₂ O ₃ is preferably 0 to 5%.

  Further, it is preferable that halogens such as F and Cl are not substantially contained since there is a risk of lowering the display luminance.

The glass tablet of the present invention contains SnO—P ₂ O ₅ glass powder and filler powder, and is represented by volume%, SnO—P ₂ O ₅ glass powder is 55 to 90%, and filler powder is 10 to 45. % Is preferable because of excellent fluidity and sealing properties. Moreover, since desired mechanical strength and a thermal expansion coefficient are easy to be obtained, it is preferable.

Filler powders include KZr ₂ (PO ₄ ) ₃ (hereinafter referred to as KZP), LiZr ₂ (PO ₄ ) ₃ (hereinafter referred to as LZP), NbZr (PO ₄ ) ₃ (hereinafter referred to as NZP), NaZr. ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NaSn (PO ₄ ) ₃ (hereinafter referred to as NSP), Ca _0.25 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ (Hereinafter referred to as CNZP), Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Mg _0.25 Nb _{0 .5} Zr _1.5 (PO ₄ ) ₃ , (ZrO) ₂ P ₂ O ₇ (hereinafter referred to as ZP), Mg _0.5 Zr ₂ (PO ₄ ) ₃ , Zr ₂ WO ₄ (PO ₄ ) ₂ , From cordierite, tin oxide and niobium oxide It can be used as a mixture of two or more members selected from the group that.

  In addition to the filler powder, one or more selected from the group consisting of willemite, alumina, zircon, β-eucryptite and zirconia may be added up to a total volume of 5% by volume.

  The filler powder described above may be coated with alumina, silica, zircon, titania, zirconia or the like in a thickness of 0.1 to 1.0 μm in order to reduce the reactivity with glass. If the coating thickness is thinner than 0.1 μm, the effect of coating is difficult to obtain, and if it is thicker than 1.0 μm, the coating tends to peel off due to the difference in thermal expansion coefficient, which is not preferable. The coating is performed on filler powders of different materials.

_Next, described Bi ₂ O 3 _-B 2 _{O 3} based glass.

The Bi ₂ O ₃ -B ₂ O ₃ based glass, by _mol%, containing _{Bi 2 O 3 30~50%, B} 2 O 3 10~40%, BaO + SrO 1~10%, a 0 to 35% ZnO It is preferable.

The reason why the Bi ₂ O ₃ —B ₂ O ₃ -based glass is limited to the above composition range will be described below.

Bi ₂ O ₃ is a main component for lowering the softening point of the glass, and its content is 30 to 50%, preferably 35 to 45%. If the content of Bi ₂ O ₃ is less than 30%, the softening point tends to be high and the fluidity tends to be poor, and if it exceeds 50%, a stable glass tends to be difficult to obtain.

B ₂ O ₃ is essential as a glass forming component, and its content is 10 to 40%, preferably 18 to 40%. If the content of B ₂ O ₃ is less than 10%, the glass becomes unstable and tends to devitrify. Even when devitrification does not occur, the crystal deposition rate is extremely high at the time of firing, and the fluidity necessary for operations such as adhesion, sealing, and coating cannot be obtained. On the other hand, if B ₂ O ₃ exceeds 40%, the viscosity of the glass becomes too high and firing at a temperature of 500 ° C. or less becomes difficult.

  BaO and SrO have a great effect on the stabilization of the glass, and contain them in a total amount of 1 to 10%, preferably 2 to 9%. If the total amount of these components is less than 1%, the effect is not obtained, while if it exceeds 10%, the transition point becomes high. The BaO content is preferably 0 to 10%, particularly preferably 2 to 9%, and the SrO content is preferably 0 to 5%, particularly preferably 0 to 3%.

  ZnO has a great effect on stabilizing the glass, and its content is 0 to 30%, preferably 5 to 25%. When the content exceeds 30%, the glass is easily crystallized and the fluidity is deteriorated.

In the Bi ₂ O—B ₂ O ₃ based glass, components other than those described above will be described.

Each of SiO ₂ and Al ₂ O ₃ is a component to be contained for further stabilizing the glass, and the total amount is 5% or less, preferably 2% or less. If these components exceed the above range, the viscosity of the glass becomes too high, which is not preferable. Incidentally, it is preferable that the content of SiO ₂ and _Al 2 _{O 3} is 0-2%, respectively.

  CuO is a component for stabilizing the glass, and its content is 0 to 20%, preferably 0 to 15%. If CuO exceeds 20%, the precipitation rate of crystals tends to be extremely high and the fluidity tends to deteriorate, which is not preferable.

Fe ₂ O ₃ is a component for stabilizing the glass, and its content is 0 to 5%, preferably 0 to 2%. If Fe ₂ O ₃ exceeds 5%, the glass becomes unstable.

Cs ₂ O and F ₂ are components that lower the viscosity of the glass, and the content of Cs ₂ O is 0 to 5%, preferably 0 to 3%, and the content of F ₂ is 0 to 20%, preferably 0 to 10%. When these components exceed the above range, the chemical durability of the glass is lowered.

In addition to the above components, MgO, La ₂ O ₃ , TiO ₂ , ZrO ₂ , V ₂ O ₅ , Nb ₂ O ₅ , MoO ₃ , WO ₃ , TeO ₂ , Ag ₂ O, Na ₂ O, K ₂ O, Li ₂ O, or the like can be added at 5% or less.

The glass tablet of the present invention contains Bi ₂ O ₃ —B ₂ O ₃ -based glass powder and filler powder, and is represented by volume%, Bi ₂ O ₃ —B ₂ O ₃ -based glass powder is 55 to 90%, The filler powder content of 10 to 45% is preferable because of excellent fluidity and sealing property. Moreover, since desired mechanical strength and a thermal expansion coefficient are easy to be obtained, it is preferable.

  As the filler powder, one or two or more selected from the group consisting of willemite, cordierite, zircon, tin oxide and alumina can be mixed and used.

In addition to the filler powder, KZP, LZP, NZP, NaZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NSP, CNZP, Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Mg _0.25 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , ZP, Mg _0.5 Zr ₂ One or two or more selected from the group consisting of (PO ₄ ) ₃ and Zr ₂ WO ₄ (PO ₄ ) ₂ , β-eucryptite and zirconia may be added up to 5% by volume.

  The filler powder described above may be coated with alumina, silica, zircon, titania, zirconia or the like in a thickness of 0.1 to 1.0 μm in order to reduce the reactivity with glass. If the coating thickness is thinner than 0.1 μm, the effect of coating is difficult to obtain, and if it is thicker than 1.0 μm, the coating tends to peel off due to the difference in thermal expansion coefficient, which is not preferable. The coating is performed on filler powders of different materials.

  Vehicles having good thermal decomposability include resins such as polyethylene glycol derivatives, polymethylstyrene (PMS), polyethylene carbonate, N, N′-dimethylformamide (DMF), γ-butyrolactone, tetralin, butyl carbitol acetate, Ethyl acetate, isoamyl acetate, dimethyl sulfoxide (DMSO), propylene carbonate, 2,4-diethyl-1,5-pentanediol, N-methyl-2-pyrrolidone, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, benzyl alcohol, Toluene, 3-methoxy-3-methylbutanol, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether Le, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, n- hex tridecyl alcohol (n-HDA) solvents such as the can be used alone or confused with. Since these vehicles decompose, burn, and volatilize at a temperature of 300 ° C. or less, they tend to hardly change the quality of the glass.

  Hereinafter, a method for producing a glass tablet integrated exhaust pipe will be described.

  First, an exhaust pipe having a predetermined length and a glass tablet made of the above-described material are prepared. When one end of the exhaust pipe is expanded in a flare shape, flange shape, cylindrical shape, etc., when sealing the panel and the exhaust pipe, it is easy to seal so as to cover the exhaust hole and prevent tilting This is preferable because it can be performed.

  The exhaust pipe whose diameter has been enlarged is a flare shape as shown in FIG. 1, a flange shape as shown in FIGS. 2 and 3, or a shape in which the flare portion and the flange portion are combined as shown in FIG. This refers to a machined one end of the exhaust pipe.

  Next, the glass tablet is fixed to one end of the exhaust pipe using a jig.

  Finally, it is heated at a temperature 10 to 40 ° C. higher than the softening point of the glass tablet to integrate the exhaust pipe and the glass tablet to produce a glass tablet integrated exhaust pipe.

If the thermal expansion coefficient of the glass tablet integrated exhaust pipe of the present invention is 5 to 20 × 10 ⁻⁷ / ° C. smaller than that of the exhaust pipe, it is preferable that the sealing is difficult to peel off because compression distortion is applied to the glass tablet after sealing. If it is less than 5 × 10 ⁻⁷ / ° C., it is difficult to obtain sufficient compressive strain, and if it is greater than 20 × 10 ⁻⁷ / ° C., cracks due to the difference in thermal expansion coefficient may occur in the glass tablet or the exhaust pipe. Because there is.

  Therefore, it is preferable that the difference in thermal expansion coefficient between the object to be sealed (glass substrate) and the exhaust pipe is small. More preferably, the thermal expansion coefficients are equal.

  When the exhaust pipe to which the glass tablet is fixed is baked, stress concentrates on the outer peripheral surface of the exhaust pipe that comes into contact with the glass tablet. However, the smaller the height of the enlarged diameter portion, the easier it is to break. Therefore, in the present invention, the tip of the glass tube is expanded, and the tablet is fixed to the outer peripheral surface portion where the tube diameter is the largest, thereby increasing the portion where the stress is concentrated, and breakage of the glass tube generated in the subsequent process. Can be greatly reduced.

  The glass tablet integrated exhaust pipe of the present invention has a glass tablet firmly attached to the outer peripheral surface of the distal end portion of the exhaust pipe made of an enlarged glass pipe. Because it is protected, it is hard to break. Further, since the glass tablet is in contact with the outer peripheral surface of the exhaust pipe, when it is disposed on the back plate, the glass tablet is in contact with the back plate on a surface wider than the enlarged diameter portion of the exhaust pipe, so that the stability is high.

  The present invention will be described in detail with reference to examples.

  Tables 1 and 2 show glass compositions, Tables 3 and 4 show filler powders, and Table 5 shows resins. Tables 6 and 7 show glass tablets. Further, Table 8 shows the configuration of the tablet-integrated exhaust pipe, and Table 9 shows the evaluation results.

  Samples A to L described in Tables 1 and 2 were prepared as follows.

  First, glass raw materials were prepared so as to have the composition shown in Table 1 or 2, and put into a quartz crucible, and melted at the temperature and atmosphere described in the table for 2 hours with the quartz crucible covered.

  Subsequently, the molten glass was formed into a thin plate shape through two water-cooled rollers positioned in parallel, and pulverized using a ball mill to prepare each sample having an average particle diameter of 5 μm.

  Samples A to L were evaluated for glass transition point, softening point, and thermal expansion coefficient.

  The glass transition point was determined by a differential thermal analyzer (DTA).

  The softening point was measured by a macro type differential thermal analysis (DTA) apparatus (manufactured by Rigaku).

  The thermal expansion coefficient was determined by a push rod type thermal expansion measuring device.

  The filler powder and vehicle used in Tables 3, 4 and 5 were shown as Samples a to h and Samples α to δ, respectively.

  Samples 1 to 18 described in Tables 6 and 7 were produced as follows.

  First, a predetermined amount of vehicle (samples α to δ) is added to 100 parts by mass of a mixture of glass powder (samples A to L) and filler powder (samples a to h) at a ratio described in the table, and mixed uniformly. Thus, granules having a particle size of approximately 100 μm were prepared. In addition, 20 mass parts was used for samples AH, and 10 mass parts was used for samples IL.

  Next, after filling the granule into a mold, a glass tablet precursor (diameter 20 mm, height 10 mm) was produced by press molding.

  Finally, after pre-baking the glass tablet precursor at 300 ° C., each sample was prepared by sintering for 10 minutes at the softening point.

  Samples 1 to 18 were measured for thermal expansion coefficient, softening point, and flow diameter.

  As is clear from Tables 6 and 7, the thermal expansion coefficient was 57.5 to 75.0, and the flow diameter was 19.5 to 22.0 mm.

  Next, an exhaust pipe integrated with a glass tablet was prepared and evaluated.

First, in terms of mass%, SiO ₂ 63.7%, Al ₂ O ₃ 9.7%, B ₂ O ₃ 12.4%, ZnO 2.1%, Li ₂ O 3.5%, Na ₂ O 5 Glass (glass A) having a composition of 0.3%, K ₂ O 3.0%, Sb ₂ O ₃ 0.3%, SiO ₂ 64.7%, Al ₂ O ₃ 6.0%, B ₂ O ₃ 10.4%, ZnO 2.1%, Li ₂ O 4.2%, Na ₂ O 7.3%, K ₂ O 5.0%, Sb ₂ O ₃ 0.3% glass ( Exhaust pipes described in FIGS. 1 to 4 were produced using glass B). Glass A had a thermal expansion coefficient of 85 × 10 ⁻⁷ / ° C., and glass B had a thermal expansion coefficient of 70 × 10 ⁻⁷ / ° C.

  A manufacturing process of the glass tablet integrated exhaust pipe will be described with reference to FIG.

  Next, as shown in FIG. 5A, a jig 2 in which a hole 2 a into which the cylindrical portion of the exhaust pipe 1 is fitted is prepared, and the diameter-expanded portion 1 a of the exhaust pipe 1 is turned up. Then, the cylindrical portion of the exhaust pipe 1 is inserted into the hole 2 a of the jig 2. Since the diameter of the enlarged portion 1 a is increased, the exhaust pipe 1 is suspended by the pedestal 2 b of the jig 2.

Subsequently, as shown in FIG. 5 (b), an annular refractory glass tablet 3 (manufactured by Nippon Electric Glass Co., Ltd .: FN) is formed on the pedestal 2b on the outer peripheral surface of the expanded diameter portion 1a of the exhaust pipe 1. −13, coefficient of thermal expansion of 76 × 10 ⁻⁷ , heat resistant temperature of 600 ° C.) as necessary (when the exhaust pipe of FIG. 4 is used). Since the inner diameter of the high melting point glass tablet 3 is larger than the outer diameter of the pedestal portion 2 b, a gap is formed between the pedestal portion 2 b and the refractory glass tablet 3.

  Finally, as shown in FIG. 5C, the glass tablet 4 is placed on the high melting point tablet 3. At this time, the inner diameter of the glass tablet 2 is slightly larger than the outer diameter of the enlarged portion 1a (preferably about 0.1 to 0.4 mm). The outer peripheral surface of the enlarged portion 1a and the glass tablet 4 There is no gap between them. In this state, the glass tablet 4 is bonded to the outer peripheral surface of the expanded diameter portion 1a by placing the glass tablet 4 in an electric furnace or the like and softening the glass tablet 4 without significant deformation.

  In the state shown in FIG. 5C, it is preferable that the front end surface 4 a of the glass tablet 4 is substantially at the same position as the front end surface 1 a of the exhaust pipe 1 in a state after the glass tablet 4 is bonded. Further, when the glass tablet 4 is baked to adhere to the enlarged diameter portion 1a of the exhaust pipe 1, the glass tablet 4 and the high melting point tablet 3 are simultaneously bonded.

  Therefore, the glass tablet 2 and the high melting point tablet 3 are integrated with the exhaust pipe 1. After the glass tablet 4 and the high melting point tablet 3 are integrated with the exhaust pipe 1 as described above, the exhaust pipe 1 is taken out from the jig 2.

  According to the above manufacturing method, since the high melting point tablet 3 exists between the glass tablet 4 and the pedestal 2b of the jig 2, the glass tablet 2 is baked to be attached to the glass tube 1. At this time, the glass tablet 2 does not adhere to the jig 4. For this reason, it is not necessary to use a material that does not adhere to the glass tablet 4 as the material of the jig 2. Moreover, when the material of the jig | tool 4 is a material which is easy to adhere | attach with the glass tablet 4, a mold release agent is apply | coated between these, or the glass tablet 2 is fusion-bonded material (for example, to a jig | tool) Carbon) must be used.

  Samples <1> to <8> were prepared using such a method.

  Subsequently, samples <1> to <8> shown in Table 8 were erected on the window glass with the tablet side facing down, and baked for 10 minutes at the sealing temperature of the low-melting glass material shown in Table 1. Samples <1> to <8> were fired while applying a load of 400 g to the glass tube. About the glass tube joined in this way, the inclination of the glass tube, the airtightness of the joint part, and the mechanical strength were evaluated.

  The inclination of the glass tube was measured using a projector, and the portion having the maximum oblique angle was measured. If all 30 inclinations were within 3 °, the result was “good”, and the other cases were “bad”.

The airtightness of the joint is such that the opening of the exhaust pipe is connected to a helium leak detector, and helium gas is blown onto the joint with the window glass, and all 30 samples are 1 × 10 ⁻⁷ atm · cc / sec or less. If it was a leak rate, it was determined as “good”.

  The mechanical strength is that the window glass is held upright so that the exhaust pipe is horizontal, and then the glass tube part 40 mm away from the window glass with the window glass fixed is autographed at a speed of 2 mm / min. The load required for breaking was calculated, and the average value was shown as the mechanical strength.

  As is apparent from Table 9, Samples <1> to <8> had a small inclination of the exhaust pipe and good airtightness at the joint. Further, the mechanical strength was 4.5 kg or more. When the fractured portion was observed, cracks occurred in both the glass tablet portion and the expanded diameter portion of the exhaust pipe, and it is considered that both were firmly joined.

  Since the glass tablet of the present invention does not substantially contain PbO and is excellent in fluidity and sealing properties, PDP, surface electric field display (SED), field emission display (FED), plasma addressed liquid crystal display (PALC), It is suitable as a sealing material for display tubes such as VFD.

It is sectional drawing which shows 1st embodiment of an exhaust pipe. It is sectional drawing which shows 2nd embodiment of an exhaust pipe. It is sectional drawing which shows 3rd embodiment of an exhaust pipe. It is sectional drawing which shows 4th embodiment of an exhaust pipe. It is sectional drawing which shows an example of the production method of a glass tablet integrated exhaust pipe, (a) is sectional drawing which shows the fixing method of an exhaust pipe, (b) is sectional drawing which shows the arrangement method of a glass tablet. (C) is sectional drawing which shows the integration method of an exhaust pipe integrated with a glass tablet. It is sectional drawing which shows 1st embodiment of a glass tablet integrated exhaust pipe. It is sectional drawing which shows 2nd embodiment of a glass tablet integrated exhaust pipe. It is sectional drawing which shows 3rd embodiment of a glass tablet integrated exhaust pipe. It is sectional drawing which shows 4th embodiment of a glass tablet integrated exhaust pipe.

1, 11, 21, 31, 41 Exhaust pipe 1a Expanded part 2 Jig 2a Hole 2b Base part 3, 43 High melting point glass tablet 4, 12, 22, 32, 42 Glass tablet 10, 20, 30, 40 Glass Tablet-integrated exhaust pipe 11a Flare portion 21a, 41a Flange portion 31a First flange portion 31b Second flange portion

Claims (17)

  A glass tablet comprising glass powder and filler powder and substantially free of PbO.   The glass tablet according to claim 1, wherein the glass tablet is used for sealing an exhaust pipe for a flat display tube.   The glass tablet according to claim 1 or 2, wherein the flow diameter of the button test at 410 to 500 ° C is 19 to 30 mm. It contains SnO—P ₂ O ₅ glass powder and filler powder, and is characterized in that SnO—P ₂ O ₅ glass powder is 55 to 90% and filler powder is 10 to 45% in terms of volume%. The glass tablet according to claim 3. KZr ₂ (PO ₄ ) ₃ , LiZr ₂ (PO ₄ ) ₃ , NbZr (PO ₄ ) ₃ , NaZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NaSn (PO ₄ ) ₃ , Ca _0.25 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Na _0.5 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , Mg _0.25 Nb _0.5 Zr _1.5 (PO ₄ ) ₃ , (ZrO) ₂ P ₂ O ₇ , Mg _0.5 Zr ₂ (PO ₄ ) ₃ , Zr ₂ WO ₄ (PO _{4 2} , 2 or more filler powder selected from the group consisting of cordierite, tin oxide and niobium oxide is contained, The glass tablet according to claim 4. The composition of SnO—P ₂ O ₅ glass powder is expressed in mol%, SnO 35-60%, P ₂ O ₅ 18-45%, ZnO 0-20%, B ₂ O ₃ 0-30%, SiO ₂ 0. _{~15%, Al 2 O 3 0~10} %, glass tablet according to claim 4 or 5 R 2 O 0~10% (R is Li, Na, K and Cs), characterized by containing. Bi ₂ O ₃ —B ₂ O ₃ -based glass powder and filler powder are contained, and by volume%, Bi ₂ O ₃ —B ₂ O ₃ -based glass powder is 55 to 90%, and filler powder is 10 to 45%. The glass tablet according to claim 3, wherein   8. The glass tablet according to claim 7, comprising one or more filler powders selected from the group consisting of willemite, cordierite, zircon, tin oxide and alumina. The composition of Bi ₂ O ₃ —B ₂ O ₃ glass powder is expressed in mol%, Bi ₂ O ₃ 30-50%, B ₂ O ₃ 10-40%, BaO + SrO 1-10%, ZnO 0-30%. It contains, The glass tablet of Claim 7 or 8 characterized by the above-mentioned.   A step of uniformly mixing a glass powder and a filler powder substantially free of PbO, a step of adding a vehicle having good thermal decomposability to the mixed powder to form granules, a step of pressing the granules, and The manufacturing method of the glass tablet characterized by including the process of pre-baking.   A tablet-integrated exhaust pipe, wherein the glass tablet according to any one of claims 1 to 9 is fixed to an outer peripheral surface of a tip portion of an exhaust pipe made of glass. The tablet-integrated exhaust pipe according to claim 11, wherein the thermal expansion coefficient of the glass tablet is smaller by 5 to 20 × 10 ⁻⁷ / ° C. than the thermal expansion coefficient of the exhaust pipe.   13. The tablet-integrated exhaust pipe according to claim 11 or 12, wherein one end of the exhaust pipe made of glass has an enlarged diameter, and a glass tablet is disposed on the outer peripheral surface of the tip portion.   14. The tablet-integrated exhaust pipe according to claim 13, wherein one end of the exhaust pipe made of glass has a flared diameter, and a glass tablet is disposed on the outer peripheral surface of the tip portion.   14. The tablet-integrated exhaust pipe according to claim 13, wherein one end of the exhaust pipe made of glass is enlarged in a flange shape, and a glass tablet is disposed on the outer peripheral surface of the tip portion thereof.   14. The tablet-integrated exhaust pipe according to claim 13, wherein one end of the exhaust pipe made of glass is expanded in a cylindrical shape, and a glass tablet is disposed on the outer peripheral surface of the tip portion thereof.   An annular glass tablet and an annular high lead glass tablet having a melting point higher than that of the glass tablet are provided at the tip of the exhaust pipe made of glass. The tablet-integrated exhaust pipe according to claim 13, wherein the tablet-integrated exhaust pipe is attached to the outer peripheral surface, and the high melting point glass tablet is attached to the outer peripheral surface of the rear end portion of the glass tablet.