JP2007320846A - Glass composition and glass spacer using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass composition which hardly undergoes field failure and has good moldability. <P>SOLUTION: The glass composition contains, by mass, 35 to <55% SiO<SB>2</SB>, 0 to 15% Al<SB>2</SB>O<SB>3</SB>, 35 to 58% of (SiO<SB>2</SB>+Al<SB>2</SB>O<SB>3</SB>), 0 to 15% MgO, 10 to 40% CaO, 0 to 30% SrO, 0 to <30% BaO, >0 to 40% of (SrO+BaO), 20 to 50% of (MgO+CaO+SrO+BaO), 0 to <5% ZnO, 0 to <5% Li<SB>2</SB>O, >0 to <5% of (Li<SB>2</SB>O+Na<SB>2</SB>O+K<SB>2</SB>O), 0 to <10% ZrO<SB>2</SB>, 0 to 20% La<SB>2</SB>O<SB>3</SB>, 0 to 20% of (Y<SB>2</SB>O<SB>3</SB>+Nb<SB>2</SB>O<SB>5</SB>+Ta<SB>2</SB>O<SB>5</SB>), and 0 to 15% Fe<SB>2</SB>O<SB>3</SB>, and does not contain B<SB>2</SB>O<SB>3</SB>and TiO<SB>2</SB>substantially. A glass spacer is composed of the glass composition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass composition. Furthermore, it is related with the glass spacer using this glass composition, and it is related with the glass spacer preferably used especially for an electron beam excitation display.

  2. Description of the Related Art A self-luminous electron beam excitation display forms an image by irradiating a fluorescent material with an electron beam emitted from an electron beam source to generate fluorescence, and has recently been widely used as a flat display. The electron beam excitation display has characteristics that a bright image is obtained and a viewing angle is wide as compared with a liquid crystal display device.

A flat electron beam excitation display forms an image by irradiating a phosphor with an electron beam, so that an electron beam source, a phosphor, and other components are incorporated in a vacuum container having a vacuum atmosphere of about 10 ⁻³ Pa or less. For example, a vacuum vessel having an atmospheric pressure resistant structure described in JP-A-7-230776 has been proposed.

  FIG. 2 is a perspective view in which a part of the flat electron beam excitation display is broken. First, the face plate 3 having a fluorescent film 7 and a metal back 8 as an accelerating electrode formed on the inner surface of the glass substrate 6 is disposed at the top. The rear plate 2 is disposed through the support frame 4 so as to face the face plate 3. An electron source 1 in which a plurality of electron-emitting devices 15 are arranged in a matrix is fixed to the rear plate 2. A high voltage is applied between the electron source 1 and the metal back 8 by a power source (not shown). The rear plate 2 and the support frame 4, and the face plate 3 and the support frame 4 are sealed with each other with frit glass or the like to constitute a vacuum container 10.

A columnar glass spacer 5 is provided inside the vacuum vessel 10. In order to make the vacuum vessel 10 an atmospheric pressure resistant structure, the spacer 5 is arranged in a necessary number at a necessary interval.
The glass spacers 5 are each processed into a cylindrical shape having a diameter of 0.1 mm and a height of 1 mm, for example.

  JP-T-2003-526187 discloses a glass spacer.

  Japanese Patent Application Laid-Open No. 2003-217478 describes a field emission display device.

  Japanese Unexamined Patent Publication No. 2003-261352 describes display glass and display glass articles.

In Japanese Patent Laid-Open No. 2000-203857, as a method for producing a glass spacer with high accuracy, a base glass whose cross-sectional shape is substantially similar to a desired cross-sectional shape of the glass spacer is prepared, and the base glass has its viscosity. There method of stretching has been proposed while heating so as to ^{10 5 dPa · sec~10 9 dPa ·} sec (10 5 poise~10 9 poise). This method is also called a redraw method. According to this method, the degree of similarity of the cross-sectional shapes of the base glass and the stretched glass can be improved, and a glass spacer having a desired shape can be easily manufactured.

  In addition, for example, a cylindrical glass spacer can be manufactured with high accuracy by a method in which a glass base melted in a refractory container having a nozzle is drawn from the nozzle. This method can simultaneously produce a large number of glass spacers at the same time, and is preferable as a method for forming cylindrical glass spacers.

  This method is also called a direct spinning method, and the glass temperature is adjusted so that the viscosity of the molten glass during spinning is 100 dPa · sec to 1000 dPa · sec (100 poise to 1000 poise). Therefore, the temperature when the viscosity of the glass is 100 dPa · sec needs to be at least the devitrification temperature. Here, devitrification means producing | generating white turbidity by the crystal | crystallization produced | generated in the molten glass base material and growing. In the glass spacer manufactured from such a molten glass substrate, the produced | generated crystal | crystallization may exist and it is unpreferable on a characteristic and dimensional accuracy. It also adversely affects moldability.

The glass spacer for electron beam excitation display elements includes a flat glass spacer called a rib and a columnar glass spacer called a pillar. In particular, cylindrical glass spacers can be most accurately manufactured by directly spinning molten glass.
JP-A-7-230776 Special table 2003-526187 JP 2003-217478 A JP 2003-261352 A JP 2000-203857 A

  The glass spacer for electron beam excitation display elements keeps the space | interval of both constant between the front plate and back plate of a vacuum vessel. For this reason, the glass spacer is exposed to the electron-emitting device. For this reason, if the glass constituting the glass spacer contains a large amount of alkali metal oxide, there is a problem that electric field breakdown occurs due to uneven distribution of alkali metal ions at the bias voltage. Further, if the alkali metal oxide is contained in a large amount, it becomes impossible to obtain a glass having a high Young's modulus.

  In addition, the conventional glass spacer includes transition metals existing in a plurality of oxidation states, for example, oxides of Ti, V, Cr, Mn, Fe, Ni, Cu, and Nb, in order to impart electron conductivity. It was out. However, when a large amount of these transition metal oxides or the like is contained in the glass, the devitrification temperature of the glass rises, making it difficult to mold the glass spacer.

In the examples of JP-T-2003-526187, a composition containing 10 mol% or more of iron oxide (Fe ₂ O ₃ ) is described. They also contain vanadium pentoxide (V ₂ O ₅ ).

The composition of the glass spacer described in JP-A No. 2003-217478 is such that the total content of alkali metal oxides (Li ₂ O + Na ₂ O + K ₂ O) is 15 mol% or more.

In the examples of JP-A No. 2003-261352, a composition having a total content of alkali metal oxides (Li ₂ O + Na ₂ O + K ₂ O) of 12% by mass or more is described.

  An object of the present invention is to provide a glass composition that is less susceptible to electric field breakdown and has good formability. Furthermore, it is providing the glass spacer which consists of this glass composition.

  In order to achieve the above object, the glass composition of the present invention is less susceptible to electric field breakdown by controlling glass skeleton components, components related to devitrification temperature and viscosity, alkali metal oxides, etc., and formability It is characterized by excellent strength.

That is,
Expressed in mass%,
35 ≦ SiO ₂ <55,
0 ≦ Al ₂ O ₃ ≦ 15,
35 ≦ (SiO ₂ + Al ₂ O ₃ ) ≦ 58,
0 ≦ MgO ≦ 15,
10 ≦ CaO ≦ 40,
0 ≦ SrO ≦ 30,
0 ≦ BaO <30,
0 <(SrO + BaO) ≦ 40,
20 ≦ (MgO + CaO + SrO + BaO) ≦ 50,
0 ≦ ZnO <5,
0 ≦ Li ₂ O <5,
0 <(Li ₂ O + Na ₂ O + K ₂ O) <5,
0 ≦ ZrO ₂ <10,
0 ≦ La ₂ O ₃ ≦ 20,
0 ≦ (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) ≦ 20,
0 ≦ Fe ₂ O ₃ ≦ 15
By weight of component a B ₂ O _3, glass composition characterized by containing no TiO ₂ substantially.

  Furthermore, this invention is a glass spacer which consists of this glass composition.

  The lath composition according to the present invention hardly causes electric field breakdown and has good moldability. Therefore, a glass spacer formed by molding this glass composition is suitable as a spacer for an electron beam excitation display.

Embodiments of the present invention will be described below.
[Glass composition]
The glass composition according to the present invention suitable for a glass spacer will be described in detail below. In addition, the% display in the following is the mass%.

(SiO ₂ )
Silicon dioxide (SiO ₂ ) is an essential main component that forms a glass skeleton. Moreover, it is a component which adjusts the devitrification temperature and viscosity of glass, and also is a component which improves acid resistance especially among chemical durability. When the content of SiO ₂ is less than 35%, the devitrification temperature rises, making it difficult to form a glass spacer. Moreover, the chemical durability of glass deteriorates. On the other hand, if the content is 55% or more, the melting point of the glass becomes high, and it becomes difficult to melt the raw material uniformly. Moreover, since devitrification temperature rises, it becomes difficult to shape | mold as a glass spacer.
Therefore, the lower limit of SiO ₂ is preferably 35% or more, more preferably 38% or more, and further preferably more than 40%. Further, the upper limit of SiO ₂ is preferably less than 55%, more preferably less than 52%, further preferably 50% or less, and most preferably 48% or less.

(Al ₂ O ₃ )
Aluminum oxide (Al ₂ O ₃ ) is a component that forms a glass skeleton, and is also a component that adjusts the devitrification temperature and viscosity of the glass. Moreover, it is also a component which improves water resistance especially among chemical durability. On the other hand, Al ₂ O ₃ is a component that deteriorates acid resistance among chemical durability. If the Al ₂ O ₃ content exceeds 15%, the melting point of the glass becomes high and it becomes difficult to melt the raw material uniformly. Moreover, since devitrification temperature rises, it becomes difficult to shape | mold as a glass spacer.
Therefore, the upper limit of Al ₂ O ₃ is preferably 15% or less, more preferably 12% or less, and even more preferably less than 10%. Al ₂ O ₃ may not be contained, but is preferably contained, and the lower limit thereof is preferably 3% or more, more preferably 5% or more, and further preferably 7% or more.

(SiO ₂ + Al ₂ O ₃ )
The total content of SiO ₂ and Al ₂ O ₃ (SiO ₂ + Al ₂ O ₃ ), which is a component that forms a glass skeleton, is important for the moldability of the glass.
When (SiO ₂ + Al ₂ O ₃ ) is less than 35%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer. Moreover, the chemical durability of glass deteriorates. On the other hand, if it exceeds 58%, the melting point of the glass becomes high and it is difficult to melt the raw material uniformly. Moreover, since devitrification temperature rises, it becomes difficult to shape | mold as a glass spacer.
Therefore, the lower limit of (SiO ₂ + Al ₂ O ₃ ) is preferably 35% or more, more preferably 38% or more, further preferably more than 40%, and more preferably 45% or more. Most preferred. The upper limit of (SiO ₂ + Al ₂ O ₃ ) is preferably 58% or less, more preferably 56% or less, and even more preferably 55% or less.

(MgO, CaO, SrO, BaO)
Alkaline earth oxides (MgO, CaO, SrO, BaO) are components that adjust the devitrification temperature and viscosity of glass, and are components that improve the Young's modulus of glass. In particular, strontium oxide (SrO) and barium oxide (BaO) are effective in reducing the devitrification temperature of glass.

When the content of magnesium oxide (MgO) exceeds 15% by mass, the devitrification temperature rises, so that it becomes difficult to form the glass spacer.
Therefore, the upper limit of MgO is preferably 15% or less, more preferably 10% or less, further preferably 8% or less, and most preferably 6% or less. MgO may not be contained, but is preferably contained, and the lower limit thereof is preferably 2% or more, and more preferably 3% or more.

When the content of calcium oxide (CaO) is 10% or less, it is not possible to obtain an effect sufficient to adjust the devitrification temperature and the viscosity. On the other hand, if it exceeds 40%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the lower limit of CaO is more than 10%, preferably 12% or more. The upper limit of CaO is preferably 40% or less, more preferably less than 30%, further preferably 25% or less, and most preferably 20% or less.

When the content of strontium oxide (SrO) exceeds 30%, the devitrification temperature rises, so that it is difficult to form a glass spacer.
Therefore, the upper limit of SrO is preferably 30% or less, more preferably 25% or less, further preferably 20% or less, and most preferably 15% or less. SrO may not be contained, but it is preferably contained, and the lower limit thereof is preferably 5% or more, and more preferably 10% or more.

When the content rate of barium oxide (BaO) is 30% or more, the devitrification temperature rises, so that it becomes difficult to form the glass spacer.
Therefore, BaO may not be contained, but the upper limit in the case of inclusion is preferably less than 30%, more preferably 20% or less, and even more preferably 15% or less.

(SrO + BaO)
The total content of SrO and BaO (SrO + BaO), which is a component for adjusting the devitrification temperature and viscosity of the glass, is important for the moldability of the glass.
When SrO and BaO are not contained at all, the devitrification temperature and viscosity cannot be adjusted sufficiently. On the other hand, if (SrO + BaO) exceeds 40%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the lower limit of (SrO + BaO) necessarily includes any of them, more preferably 5% or more, and even more preferably 10% or more. The upper limit of (SrO + BaO) is preferably 40% or less, more preferably 30% or less, further preferably less than 25%, and most preferably 20% or less.

(MgO + CaO + SrO + BaO)
When the total content (MgO + CaO + SrO + BaO) of alkaline earth oxides (MgO, CaO, SrO, BaO) is less than 20%, the devitrification temperature and viscosity cannot be adjusted sufficiently. On the other hand, if (MgO + CaO + SrO + BaO) exceeds 50%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the lower limit of (MgO + CaO + SrO + BaO) is preferably 20% or more, more preferably 25% or more, and further preferably 30% or more. The upper limit of (MgO + CaO + SrO + BaO) is preferably 50% or less, more preferably 45% or less, further preferably 40% or less, and most preferably 35% or less.

(ZnO)
Zinc oxide (ZnO) is a component that adjusts the devitrification temperature and viscosity of the glass. When the content ratio of ZnO is 5% or more, the devitrification temperature rises, so that it is difficult to form the glass spacer.
Therefore, ZnO may not be contained, but the upper limit in the case of inclusion is preferably less than 5%, and more preferably 3% or less.

(Li ₂ O, Na ₂ O, K ₂ O)
Alkali metal oxides (Li ₂ O, Na ₂ O, K ₂ O) are components that adjust the devitrification temperature and viscosity of the glass, and are components that adjust the coefficient of thermal expansion of the glass.

Lithium oxide (Li ₂ O) is a component that improves the Young's modulus of glass. When the content of lithium oxide (Li ₂ O) is 5% or more, electric field breakdown may occur in the electron beam excited display. Moreover, since the viscosity of glass falls too much, the heat resistance of glass will worsen and chemical durability will also deteriorate.
Therefore, the upper limit of Li ₂ O is preferably less than 5%, and more preferably 4% or less. Li ₂ O may not be contained, but is preferably contained, and the lower limit thereof is preferably 1% or more, and more preferably 2% or more.

When the content of sodium oxide (Na ₂ O) is 5% or more, electric field breakdown may occur in the electron beam excitation display. Moreover, since the viscosity of glass falls too much, the heat resistance of glass will worsen and chemical durability will also deteriorate.
Therefore, Na ₂ O may not be contained, but the upper limit when it is contained is preferably less than 5%, more preferably 3% or less, and further preferably 2% or less.

When the content of potassium oxide (K ₂ O) is 5% or more, electric field breakdown may occur in the electron beam excited display. Moreover, since the viscosity of glass falls too much, the heat resistance of glass will worsen and chemical durability will also deteriorate.
Therefore, K ₂ O may not be contained, but the upper limit when it is contained is preferably less than 5%, more preferably 3% or less, and further preferably 2% or less.

(Li ₂ O + Na ₂ O + K ₂ O)
The total content of alkali metal oxides (Li ₂ O, Na ₂ O, K ₂ O) (Li ₂ O + Na ₂ O + K ₂ O) is important for the glass formability.
When no alkali metal oxide is contained, since the melting point of the glass is high, it becomes difficult to uniformly melt the raw material and it is difficult to form the glass spacer. On the other hand, when the total content of alkali metal oxides is 5% or more, electric field breakdown may occur in the electron beam excitation display. Moreover, since the viscosity of glass falls too much, the heat resistance of glass will worsen and chemical durability will also deteriorate.
Accordingly, the lower limit of (Li ₂ O + Na ₂ O + K ₂ O) necessarily includes any of them, more preferably 1% or more, still more preferably 2% or more, and most preferably more than 3%. preferable. The upper limit of (Li ₂ O + Na ₂ O + K ₂ O) is preferably less than 5%.

(ZrO ₂₎
Zirconium oxide (ZrO ₂ ) improves the chemical durability of the glass. It also improves the heat resistance of the glass. However, when the content ratio of ZrO ₂ is 10% or more, the devitrification temperature of the glass rises, so that it becomes difficult to form the glass spacer.
Therefore, the upper limit of ZrO ₂ is preferably less than 10%, more preferably 5% or less, and even more preferably 4% or less. ZrO ₂ may not be contained, but is preferably contained, and the lower limit thereof is preferably 2% or more.

(La ₂ O ₃ )
Lanthanum oxide (La ₂ O ₃ ) is a component that adjusts the devitrification temperature and viscosity of the glass, and is a component that improves the Young's modulus of the glass. If the content of La ₂ O ₃ exceeds 20%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, La ₂ O ₃ may not be contained, but the upper limit in the case of inclusion is preferably 20% or less, more preferably 15% or less, and further preferably 10% or less.

(Y ₂ O ₃ )
Yttrium oxide (Y ₂ O ₃ ) is a component that adjusts the devitrification temperature and viscosity of the glass, and is a component that improves the Young's modulus of the glass. If the content of Y ₂ O ₃ exceeds 20%, the devitrification temperature rises, making it difficult to form a glass spacer.
Therefore, the upper limit of Y ₂ O ₃ is preferably 20% or less, more preferably 15% or less, further preferably 10% or less, and most preferably 8% or less. Y ₂ O ₃ may not be included, but is preferably included.

(Nb ₂ O ₅ )
Niobium pentoxide (Nb ₂ O ₅ ) is a component that adjusts the devitrification temperature and viscosity of the glass, and is a component that improves the Young's modulus of the glass. Furthermore, the electrical properties of the glass can be adjusted. When the content of Nb ₂ O ₅ exceeds 20%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the upper limit of Nb ₂ O ₅ is preferably 20% or less, more preferably 15% or less, still more preferably less than 10%, and most preferably 8% or less. Nb ₂ O ₅ may not be included, but is preferably included.

(Ta ₂ O ₅ )
Tantalum pentoxide (Ta ₂ O ₅ ) is a component that adjusts the devitrification temperature and viscosity of the glass, and is a component that improves the Young's modulus of the glass. Furthermore, the electrical properties of the glass can be adjusted. If the content of Ta ₂ O ₅ exceeds 20%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the upper limit of Ta ₂ O ₅ is preferably 20% or less, more preferably 15% or less, still more preferably less than 10%, and most preferably 8% or less. Ta ₂ O ₅ may not be included, but is preferably included.

(Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ )
The total content of Y ₂ O ₃ , Nb ₂ O ₅ and Ta ₂ O ₅ (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) is important for the glass formability.
If (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) exceeds 20%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the upper limit of (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) is preferably 20% or less, more preferably 15% or less, still more preferably 10% or less, % Is most preferred. (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) may not be included, but is preferably included.

(Fe ₂ O ₃ )
Usually, iron (Fe) in glass is a component that adjusts the electrical characteristics of the glass, and is also a component that adjusts the devitrification temperature and viscosity of the glass. When the content of Fe converted to Fe ₂ O ₃ exceeds 15%, the devitrification temperature of the glass rises, so that it becomes difficult to form the glass spacer.
Therefore, the upper limit of the iron content (Fe) is preferably 15% or less, more preferably 12% or less, further preferably less than 10%, more preferably 5% in terms of Fe ₂ O _3. Most preferably: Further, Fe ₂ O ₃ may not be contained, but is preferably contained.

(Fe ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ )
The total content of Fe ₂ O ₃ , Nb ₂ O ₅ and Ta ₂ O ₅ (Fe ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) is important for the glass formability.
If (Fe ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) exceeds 15%, the devitrification temperature rises, so that it becomes difficult to form a glass spacer.
Therefore, the upper limit of (Fe ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) is preferably 15% or less, more preferably 12% or less, still more preferably less than 10%, % Is most preferred. Further, (Fe ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) may not be included, but is preferably included.

(B ₂ O ₃ )
Boron trioxide (B ₂ O ₃ ) is liable to volatilize and may be scattered during melting. Therefore, it is preferable that B ₂ O ₃ is not substantially contained.

(TiO ₂ )
When titanium oxide (TiO ₂ ) is contained in the glass, the devitrification temperature of the glass rises, so that it becomes difficult to form the glass spacer. Therefore, it is preferable that TiO ₂ is not substantially contained.

(V ₂ O ₅ )
Furthermore, some raw materials for vanadium pentoxide (V ₂ O ₅ ) require careful handling. It is preferable that V ₂ O ₅ is not substantially contained.

(MnO)
Furthermore, some raw materials for manganese oxide (MnO) require careful handling. It is preferable that MnO is not substantially contained.

(F, P ₂ O ₅ )
Fluorine (F) and phosphorus pentoxide (P ₂ O ₅ ) are liable to volatilize and thus may be scattered during melting. In this invention, it is preferable not to contain substantially.

(SnO ₂ )
If tin oxide (SnO ₂ ) is contained in the glass, the devitrification temperature of the glass rises, making it difficult to form a glass spacer. Therefore, it is preferable not to contain SnO ₂ substantially.

(PbO)
Furthermore, some lead oxide (PbO) raw materials require careful handling. It is preferable that PbO is not substantially contained.

  In the present invention, substantially not containing a substance means that the substance is not intentionally included unless it is inevitably mixed with an industrial raw material. Specifically, the content is less than 0.1%. Preferably, it is less than 0.05%. More preferably, it is less than 0.03%.

[Physical properties of glass spacer]
Each physical property of the glass spacer according to the present invention will be described in detail below.

(Temperature characteristics)
If the temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass is 100 dPa · sec is 0 ° C or more, devitrification is less likely to occur during glass molding, and a high yield of homogeneous glass spacers is achieved. Can be manufactured with. The temperature difference is more preferably 15 ° C. or higher, further preferably 30 ° C. or higher, and most preferably 45 ° C. or higher.

  Furthermore, the higher the glass transition point, the higher the heat resistance of the glass spacer, and the glass spacer is less likely to be deformed with respect to processing involving high temperature heating. If a glass transition point is 550 degreeC or more, a shape will not change by the high temperature heating in the manufacturing process of display glass. Therefore, the glass transition point of the glass composition is preferably 550 ° C. or higher, and more preferably 580 ° C. or higher. Moreover, it is more preferable that it is 600 degreeC or more.

The glass spacer is less likely to be peeled off from the display substrate as the difference between the average linear expansion coefficient and the thermal expansion coefficient of the display glass substrate is smaller. In general, the average linear expansion coefficient of the display glass substrate at 50 to 350 ° C. is 80 to 90 × 10 ⁻⁷ / ° C.

Therefore, the average linear expansion coefficient of the glass spacer at 50 to 350 ° C. is preferably more than 70 × 10 ⁻⁷ / ° C., more preferably more than 75 × 10 ⁻⁷ / ° C., and more preferably 80 × 10 ^−7. More preferably, the temperature is at least / ° C. The average linear expansion coefficient is preferably 100 × 10 ⁻⁷ / ° C. or less, more preferably 95 × 10 ⁻⁷ / ° C. or less, and further preferably 90 × 10 ⁻⁷ / ° C. or less. .

(Young's modulus)
Moreover, the glass spacer can give sufficient mechanical strength to an electron beam excitation display, so that the Young's modulus is high. The Young's modulus of the glass composition is preferably more than 86 GPa, more preferably 90 GPa or more. Moreover, it is more preferable that it is 95 GPa or more. Most preferably, it is 100 GPa or more.

(Volume resistivity)
Furthermore, when the volume resistivity of the glass spacer is too low, electrons flow too much. If the volume resistivity is too high, the glass spacer is easily charged. The volume resistivity of the glass spacer is preferably 10 ¹³ Ω · cm or more at 25 ° C., more preferably 10 ¹⁴ Ω · cm or more.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

[Glass composition]
(Examples 1 to 22, Comparative Examples 1 to 19)
Batches were prepared for each of Examples and Comparative Examples by blending ordinary glass raw materials such as silica sand so as to have the compositions shown in Table 1A, Table 2A, Table 3A, Table 4A, and Table 5A, respectively. This batch was heated to 1200-1500 ° C. in an electric furnace, melted, and maintained for about 4 hours until the composition became uniform. Thereafter, the melted glass was poured out on an iron plate and slowly cooled to normal temperature in an electric furnace to obtain a glass sample. In addition, all the glass compositions in a table | surface are the values displayed by the mass%.

  Moreover, in Table 1B, Table 2B, Table 3B, Table 4B, and Table 5B, mol% was displayed about each composition of Examples 1-22 and Comparative Examples 1-19. These examples are considered based on the composition expressed in mol%. However, in the prior literature, since many glass compositions are displayed in mass% (weight%), in consideration of the ease of comparison with this, the present specification is based on mass% display. is there. According to the composition expressed in mol%, the intention of these examples can be easily understood.

About the glass produced in this way, an average linear expansion coefficient and a glass transition temperature were determined from a thermal expansion curve. The Young's modulus was obtained from the longitudinal and transverse wave velocities propagating through the glass by the single-around method and the density of the glass measured by the Archimedes method. Furthermore, the relationship between the viscosity and the temperature was examined by a normal platinum ball pulling method, and the temperature when the viscosity of the glass was 100 dPa · sec was obtained from the result. Then, glass crushed to a particle size of 1.0 mm to 2.8 mm is placed in a platinum boat and heated in an electric furnace with a temperature gradient (900 ° C. to 1400 ° C.) for 2 hours, and electricity corresponding to the appearance position of the crystal. The devitrification temperature was determined from the maximum temperature of the furnace. The volume resistivity was determined by a three-terminal method based on JIS C 2141 (1992).
These measurement results are also shown in Table 1A, Table 2A, Table 3A, Table 4A, and Table 5A.

The glass produced in Example 1 contains SiO ₂ and Al ₂ O ₃ as glass skeleton components, contains MgO, CaO, and SrO as alkaline earth metal oxides, and Li ₂ O, Na as alkali metal oxides. _It has a composition containing ₂ O and further containing ZrO ₂ .

  The glass produced in Examples 2-6 is the composition which adjusted the alkaline earth metal oxide of the glass in Example 1, and the content rate of an alkali metal oxide.

The glass produced in Example 7 has a composition in which La ₂ O ₃ is added to the glass of Example 1.

The glass produced in Example 8 has a composition in which Y ₂ O ₃ is contained in the glass of Example 1. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was 77 ° C., and the Young's modulus was 105 GPa. This shows that the inclusion of Y ₂ O ₃ increases the temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass is 100 dPa · sec, and the Young's modulus also increases. .

The glass produced in Examples 9 to 12 has a composition in which the content of SiO ₂ , Al ₂ O ₃ and alkaline earth metal oxide in the glass in Example 8 is adjusted.

  The glass produced in Example 13 has a composition in which ZnO is contained in the glass of Example 8.

The glass produced in Example 14 has a composition in which Nb ₂ O ₅ is contained in the glass of Example 1. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was 72 ° C. This indicates that the inclusion of Nb ₂ O ₅ increases the temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass is 100 dPa · sec.

The glass produced in Example 15 has a composition in which the contents of SiO ₂ and Al ₂ O ₃ in the glass in Example 14 are adjusted.

The glass produced in Example 16 has a composition in which Ta ₂ O ₅ is contained in the glass of Example 1. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was 45 ° C. This shows that the inclusion of Ta ₂ O ₅ increases the temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass is 100 dPa · sec.

Glass produced in Example 17 to 20, SiO ₂ in Example 16, and an alkali metal oxide, a composition obtained by adjusting the content of ZrO _2.

The glass produced in Examples 21 and 22 has a composition in which Fe ₂ O ₃ is contained in the glass of Example 1. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was 35 to 53 ° C. This indicates that the inclusion of Fe ₂ O ₃ increases the temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass is 100 dPa · sec. The volume resistivity of Example 22 was 3.6 × 10 ¹⁴ Ω · cm at 25 ° C. It can be seen that the volume resistivity is reduced by containing Fe ₂ O ₃ .

The glass produced in Comparative Example 1 is obtained by removing V ₂ O ₅ from the glass composition described in Example 3 of JP-T-2003-526187, and the viscosity of the glass is 100 dPa · sec. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature was -95 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is small.

  The glass produced in Comparative Example 2 has the glass composition described in Example 1 of JP-A-2003-217478, and is a glass composition outside the scope of the present invention. The Young's modulus was 85 GPa. This shows that the Young's modulus is small as compared with the example of the present invention. The glass transition temperature was 472 ° C. This shows that the glass transition temperature is low when compared with the examples of the present invention.

  The glass produced in Comparative Example 3 has a glass composition described in Example 13 of JP-A-2003-261352, and is a glass composition outside the scope of the present invention. The Young's modulus was 82 GPa. This shows that the Young's modulus is small as compared with the example of the present invention. Moreover, the glass transition temperature was 520 degreeC. This shows that the glass transition temperature is low when compared with the examples of the present invention.

In Comparative Example 4, SiO ₂ , (SiO ₂ + Al ₂ O ₃ ), and (MgO + CaO + SrO + BaO) were composed of compositions outside the range of the present invention, but were not vitrified because they were devitrified during molding of the molten glass.

The glass produced in Comparative Example 5 has a composition in which (SiO ₂ + Al ₂ O ₃ ) and (SrO + BaO) are outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −56 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

The glass produced in Comparative Example 6 has SiO ₂ , (SiO ₂ + Al ₂ O ₃ ), (SrO + BaO), and (MgO + CaO + SrO + BaO) having a composition outside the scope of the present invention. The average linear expansion coefficient was 62 × 10 ⁻⁷ / ° C. This shows that the average linear expansion coefficient is small when compared with the examples of the present invention.

The glass produced in Comparative Example 7 has a composition in which Al ₂ O ₃ is outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −19 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

In the glass produced in Comparative Example 8, (SiO ₂ + Al ₂ O ₃ ), MgO and CaO are composed of compositions outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −187 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

  The glass produced in Comparative Example 9 has CaO and SrO having a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −101 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

  The glass produced in Comparative Example 10 has BaO having a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −2 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

  The glass produced in Comparative Example 11 has ZnO having a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −7 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

In Comparative Example 12, LiO ₂ and (Li ₂ O + Na ₂ O + K ₂ O) have a composition outside the scope of the present invention. The glass transition temperature was 525 ° C. This shows that the glass transition temperature is low when compared with the examples of the present invention.

In Comparative Example 13, ZrO ₂ has a composition outside the range of the present invention, but a homogeneous glass could not be obtained due to devitrification.

In Comparative Example 14, SiO ₂ and La ₂ O ₃ consisted of compositions outside the scope of the present invention, but were not vitrified due to devitrification.

In Comparative Example 15, (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) was composed of a composition outside the range of the present invention, but was not vitrified due to devitrification.

In the glass produced in Comparative Example 16, (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) has a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −82 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

In the glass produced in Comparative Example 17, (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) has a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −80 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

The glass produced in Comparative Example 18 has TiO ₂ having a composition outside the scope of the present invention. The temperature difference obtained by subtracting the devitrification temperature of the glass from the temperature when the viscosity of the glass was 100 dPa · sec was −21 ° C. Compared with the Example of this invention, this shows that the temperature difference which subtracted the devitrification temperature of glass from the temperature when the viscosity of glass is 100 dPa * sec is low.

The glass produced in Comparative Example 19 was composed of Fe ₂ O ₃ having a composition outside the range of the present invention. However, since the glass was devitrified during molding of the molten glass, a homogeneous glass could not be obtained.

[Glass spacer manufacturing method]
The base material used for the glass spacer is preferably manufactured by a method in which a glass base melted in a refractory container having a nozzle is directly drawn from the nozzle. The base material thus manufactured is precisely cut into a predetermined length to obtain a glass spacer.

[Glass spacer shape]
The glass spacer according to the present invention preferably has a cylindrical shape (see FIG. 1A).

A method for manufacturing the glass spacer will be described with reference to FIG.
The glass composition obtained in the above-described Examples was melted by the above-described method, and then formed into pellets while being cooled. This pellet was put into the manufacturing apparatus 100 to produce a glass spacer. As a manufacturing apparatus, a manufacturing apparatus 100 as shown in FIG. 1 was used.

  The pellet fireproof kiln 20 is put into the manufacturing apparatus 100 of FIG. 1B and heated and melted by the heater 30 to obtain a glass substrate 40. The glass substrate 40 is drawn from a nozzle 21 attached to the lower part of the refractory kiln 20 and formed into a fibrous base material 50. This base material was cut into a predetermined length to produce a cylindrical glass spacer.

It is a schematic diagram explaining the glass spacer by this invention, and its manufacturing apparatus. It is the perspective view which fractured | ruptured a part of flat type electron beam excitation display.

Explanation of symbols

5: Glass spacer 100: Glass spacer manufacturing apparatus 20: Refractory kiln 21: Nozzle 30: Heater 40: Glass base 50: Fibrous base material 10: Vacuum container 1: Electron source 2: Rear plate 3: Face plate 4 : Support frame 6: Glass substrate 7: Fluorescent film 8: Metal back 15: Electron emitting device

Claims (10)

Expressed in mass%,
35 ≦ SiO ₂ <55,
0 ≦ Al ₂ O ₃ ≦ 15,
35 ≦ (SiO ₂ + Al ₂ O ₃ ) ≦ 58,
0 ≦ MgO ≦ 15,
10 ≦ CaO ≦ 40,
0 ≦ SrO ≦ 30,
0 ≦ BaO <30,
0 <(SrO + BaO) ≦ 40,
20 ≦ (MgO + CaO + SrO + BaO) ≦ 50,
0 ≦ ZnO <5,
0 ≦ Li ₂ O <5,
0 <(Li ₂ O + Na ₂ O + K ₂ O) <5,
0 ≦ ZrO ₂ <10,
0 ≦ La ₂ O ₃ ≦ 20,
0 ≦ (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) ≦ 20,
0 ≦ Fe ₂ O ₃ ≦ 15
Containing components, B ₂ O _3, glass composition characterized by containing no TiO ₂ substantially. The (Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) in the composition is expressed by mass%,
0 <(Y ₂ O ₃ + Nb ₂ O ₅ + Ta ₂ O ₅ ) ≦ 20
The glass composition according to claim 1. The Y ₂ O ₃ in the composition is represented by mass%,
0 <Y ₂ O ₃ ≦ 20
The glass composition according to claim 1 or 2. The Nb ₂ O ₅ in the composition is represented by mass%,
0 <Nb ₂ O ₅ ≦ 20
The glass composition according to claim 1 or 2. The Ta ₂ O ₅ in the composition is expressed by mass%,
0 <Ta ₂ O ₅ ≦ 20
The glass composition according to claim 1 or 2. The glass composition according to any one of claims 1 to 5, wherein an average linear expansion coefficient at 50 to 350 ° C of the composition is more than 70 × 10 ^-7 / ° C and not more than 100 × 10 ^-7 / ° C. object.   The glass composition according to claim 1, wherein the Young's modulus of the composition is more than 86 GPa.   The glass composition according to claim 1, wherein a temperature difference obtained by subtracting a devitrification temperature of the composition from a temperature when the viscosity of the composition is 100 dPa · sec is 0 ° C. or more. object.   A glass spacer comprising the glass composition according to claim 1. A vacuum vessel, and an electron-emitting device and a glass spacer disposed inside the vacuum vessel,
The electron beam excitation display in which the said glass spacer consists of a glass composition of any one of Claims 1-8.

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