JP2007297265A - Glass for covering electrode, electric wiring-formed glass plate and plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide glass for covering electrodes which can minimize a warpage of e.g. a front substrate of a plasma display device. <P>SOLUTION: The glass for covering electrodes is essentially composed of, by mol, 30-47% B<SB>2</SB>O<SB>3</SB>, 25-42% SiO<SB>2</SB>, 5-17% ZnO and 9-17% of Li<SB>2</SB>O+Na<SB>2</SB>O+K<SB>2</SB>O, with the proviso that one or both of Li<SB>2</SB>O and Na<SB>2</SB>O and K<SB>2</SB>O are contained and Li<SB>2</SB>O is 0-2.5%, and is free from PbO. In the glass for covering electrodes, Na<SB>2</SB>O/K<SB>2</SB>O is <0.25 and Li<SB>2</SB>O is 0.1-2.5%. In the glass for covering electrodes, Na<SB>2</SB>O/K<SB>2</SB>O is 0.25-1 and Li<SB>2</SB>O is 0-1.5%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a glass for electrode coating and an electric wiring suitable for insulatingly coating these electrodes when transparent electrodes such as ITO (indium oxide doped with tin) and tin oxide are formed on a glass substrate. The present invention relates to a formed glass plate and a plasma display device (PDP).

PDP is a typical large-screen full-color display device.
The PDP is manufactured by sealing a front substrate used as a display surface and a rear substrate on which a large number of stripe-shaped or waffle-shaped barrier ribs are formed facing each other, and enclosing a discharge gas between the substrates.

In the front substrate, a plurality of display electrode pairs that generate surface discharge are formed on a front glass substrate, and these electrode pairs are covered with transparent glass.
In the rear substrate, address electrodes orthogonal to the display electrode pair are formed on the rear glass substrate, the address electrodes are covered with glass (usually colored glass), and barrier ribs and phosphor layers are formed thereon. Is.

Electrode coating with glass on the front substrate and the rear substrate is performed by a method of transferring a green sheet containing glass powder onto the electrode and baking it, or applying a paste containing glass powder on the electrode and baking it.
However, such firing may cause warpage of these substrates, and in order to solve this problem, it has been proposed to perform cooling after firing by a special method (see Patent Document 1).

JP 2003-331724 A

The conventional electrode coating glass is considered to be prone to warp as described above, but the warp problem can be solved by adopting the method proposed in Patent Document 1, for example, when manufacturing a PDP. It is thought that.
However, if an electrode coating glass that is less likely to warp is obtained, it is expected that there is no need to take such a special method when manufacturing a PDP.
An object of the present invention is to provide an electrode coating glass, an electrical wiring forming glass plate, and a PDP that can solve such problems.

The present invention is essentially by mole% based on the following _{oxides, B 2 O 3 30~47%,} SiO 2 25~42%, ZnO 5~17%, Li 2 O + Na 2 O + K 2 O 9~17%, from manner becomes, contains either one or both and _{K 2} O of Li ₂ O and Na ₂ O, and the content is 2.5% or less when they contain Li ₂ O, electrodes containing no PbO A glass for coating (the glass of the present invention) is provided.

Further, a glass of the present _invention, Na ₂ O / _K 2 O is less than 0.25, glass for covering electrodes Li ₂ O is 0.1 to 2.5 percent (first glass) provide.
Further, a glass of the present _invention, Na ₂ O / _K 2 O is 0.25 to 1, the glass for covering electrodes content of 1.5% or less (the case containing Li ₂ O 2 glass).
Further, a glass of the present _invention, Na ₂ O / _K 2 O is greater than 1, to provide a glass for covering electrodes containing no Li ₂ O (third glass).

Further, when the glass of the present invention contains Na ₂ O 4-8%, K ₂ O 5-10%, MgO, CaO, SrO or BaO, the total content thereof is 11% or less, When CuO, CeO ₂ or CoO is contained, the total content thereof is 3% or less, B ₂ O ₃ , SiO ₂ , ZnO, Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO Provided is a glass for electrode coating (fourth glass) in which the total content of BaO, CuO, CeO ₂ and CoO is 90% or more.

Moreover, the electrical wiring pattern is formed on the glass plate, The electrical wiring formation glass plate with which the electrical wiring pattern is coat | covered with the said glass for electrode coating is provided.
A PDP in which cells are defined by a front glass substrate, a rear glass substrate, and partition walls used as a display surface, wherein a transparent electrode on the front glass substrate is coated with the electrode coating glass. provide.

The present inventor _has, B 2 _{O 3} and 30 to 47 mol%, a SiO ₂ 30 to 42 mol%, glass for PDP unleaded glass of various compositions containing ZnO 5 to 17 mol% and _{K 2} O, respectively When the warpage of the substrate on which the glass layer was formed was measured by the method described later, the warpage was negative when the substrate surface on which the glass layer was not formed became concave, and the substrate surface was When warping is positive, warping is positive, and those containing neither Li ₂ O nor Na ₂ O are found to have large warping, and when the content of Li ₂ O is increased, the warping increases. The present invention has been reached.

Further, with respect to the glass not containing Li ₂ O, the warpage is changed from a negative value to a positive value as the molar ratio of Na ₂ O to K ₂ O (Na ₂ O / K ₂ O) increases from 0 to 1. It increased monotonously, and when Na ₂ O / K ₂ O exceeded 1, the increase rate was found to be small, and the preferred embodiment of the present invention was achieved.

  By performing electrode coating of the PDP front substrate using the glass of the present invention, the warpage of the front substrate can be reduced.

The glass of the present invention is usually powdered and used for electrode coating. In addition, powdering is normally performed by classifying glass after pulverization.
When electrode coating is performed using a glass paste, the powdered glass of the present invention (hereinafter referred to as the glass powder of the present invention) is kneaded with a vehicle to form a glass paste. This glass paste is applied and baked on a glass substrate on which an electrode such as a transparent electrode is formed, for example, to form a glass layer covering the electrode. In the production of the PDP front substrate, firing is typically performed at a temperature of 600 ° C. or lower.
When electrode coating is performed using a green sheet, the glass powder of the present invention is kneaded with a resin, and the obtained kneaded product is coated on a support film such as a polyethylene film to form a green sheet. This green sheet is transferred onto an electrode formed on a glass substrate, for example, and then baked to form a glass layer covering the electrode.

The glass powder of the present invention preferably has a mass average particle diameter (D ₅₀ ) of 0.5 μm or more. If it is less than 0.5 μm, the time required for pulverization may be too long. More preferably, it is 0.7 μm or more. The mass average particle diameter is preferably 4 μm or less. More preferably, it is 3 μm or less.
The maximum particle size of the glass powder of the present invention is preferably 20 μm or less. If it exceeds 20 μm, if it is used to form an electrode-covered glass layer of PDP that is usually required to have a thickness of 30 μm or less, irregularities are generated on the surface of the glass layer, and the image of PDP may be distorted. More preferably, it is 10 μm or less.

The average linear expansion coefficient (α) of the glass of the present invention at 50 to 350 ° C. is preferably 65 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C., typically 65 × 10 ^{−7 to} 85 × 10. ^-7 / ° C.
The glass of the present invention preferably has a softening point (Ts) of 630 ° C. or lower. If it exceeds 630 ° C., it may be difficult to obtain a dense fired layer (glass layer) by firing at a temperature of 600 ° C. or lower. More preferably, it is 600 degrees C or less.

  The glass of the present invention is suitable when it is desired to lower its relative dielectric constant (ε) at 1 MHz, for example, less than 8, and the ε is typically 6 to 7.

  The warp (W) obtained by measuring the substrate on which the glass layer made of the glass of the present invention is formed by the method described later is preferably in the range of −50 to 50 μm, more preferably −30 to 30 μm. . In the following, the term “warp” is used when, as a general rule, it does not matter whether the warp is concave or convex, but the magnitude (the absolute value of W).

Next, the composition of the glass of the present invention will be described. Hereinafter, mol% is simply expressed as%.
B ₂ O ₃ is a component that stabilizes the glass or lowers Ts and is essential. If it is less than 30%, vitrification becomes difficult. Preferably it is 32% or more. If it exceeds 47%, Ts becomes rather high, or phase separation tends to occur. It is preferably 45% or less, more preferably 42% or less, and typically 40% or less.
SiO ₂ is a component constituting a glass skeleton and is essential. If it is less than 25%, it becomes difficult to vitrify. Preferably it is 30% or more, more preferably 32% or more. If it exceeds 42%, Ts becomes too high. Preferably it is 40% or less, More preferably, it is 38% or less.

  ZnO is a component that lowers Ts or reduces α, and is essential. If it is less than 5%, Ts becomes high. Preferably it is 10% or more. If it exceeds 17%, crystals tend to precipitate during firing. It is preferably 15% or less, and is typically 12% or less when it is desired to lower Ts.

Li ₂ O, Na ₂ O, and K ₂ O are components that facilitate vitrification or lower Ts, and must contain one or both of Li ₂ O and Na ₂ O and K ₂ O.
When the total R ₂ O content of these three components is less than 9%, Ts becomes high. Typically 10% or more. When R ₂ O exceeds 17%, α increases. Typically 15% or less.
If neither Li ₂ O nor Na ₂ O is contained, or K ₂ O is not contained, warpage increases.
When Li ₂ O is contained, if its content exceeds 2.5%, the warpage becomes large.
The total content of Na ₂ O and K ₂ O is typically 10.5% or more.

The glass of the present invention consists essentially of the above components, but may contain other components as long as the object of the present invention is not impaired. In this case, the total content of components other than the above components is preferably 12% or less, more preferably 10% or less, and typically 5% or less.
For example, there are cases where MgO, CaO, SrO or BaO may be contained within a range where the total RO of these four components is 11% or less in order to lower Ts or reduce α. If it exceeds 11%, vitrification may be difficult. RO is typically 7% or less.

In addition, when it is desired to suppress the phenomenon that carbon is left in the glass after baking due to insufficient binder removal at the time of baking, the total content of these three components is CuO, CeO ₂ or CoO. It may be contained up to 3%. If the total exceeds 3%, the coloring of the glass becomes rather remarkable. Typically, it is 1.5% or less.
When one of these three components is contained, it is typical that CuO is contained in a range of 1.5% or less.

In addition, Bi ₂ O ₃ may be contained up to 5% for improving the sinterability, but Bi ₂ O ₃ does not contain Bi ₂ O ₃ from this point of view because there are resource problems and the like. It is preferable that
In addition, components such as Al ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , and MnO ₂ are exemplified. These components are usually added for the purposes of adjusting α, Ts, chemical durability, glass stability, transmittance of the glass coating layer, and suppressing silver coloring phenomenon.
The glass of the present invention does not contain PbO.

The first glass has Na ₂ O / K ₂ O of less than 0.25 and contains 0.1 to 2.5% of Li ₂ O, so that the absolute value of W is set to 40 μm or less, for example. It is.
When Na ₂ O / K ₂ O is 0, that is, when Na ₂ O is not contained, Li ₂ O is preferably 1 to 2%, and typically 1.3 to 1.7. The same applies when Na ₂ O / K ₂ O is more than 0 and 0.04 or less.

When Na ₂ O / K ₂ O is more than 0.04 and 0.2 or less, Li ₂ O is typically 0.5 to 1.5%.
When Na ₂ O / K ₂ O is more than 0.2 and less than 0.25, Li ₂ O is typically 0.1 to 1.3%.

A typical content in the case of containing Na ₂ O is 3.5% or less.
The typical content of K ₂ O is 9 to 14%.
The first glass is a suitable mode when it is desired to improve the transparency of the glass layer by increasing the sinterability.

The second glass has Na ₂ O / K ₂ O of 0.25 to 1, and when Li ₂ O is contained, the absolute value of W is, for example, 40 μm or less by setting the content to 1.5% or less. It is something to try.
When Na ₂ O / K ₂ O is 0.25 or more and less than 0.4, it is preferable to contain Li ₂ O in order to make the absolute value of W smaller, and the typical content thereof is 0.1 ~ 1.3%.

When Na ₂ O / K ₂ O is 0.4 or more and 1 or less, Li ₂ O is preferably not contained, and even if it is contained, it is preferably 0.5% or less.

The typical content of Na ₂ O is 2-8% and the typical content of K ₂ O is 5-13%.
The second glass is a mode suitable for the case where it is desired to suppress so-called silver color development at the time of firing, which is likely to occur when used for silver electrode coating.

The third glass has Na ₂ O / K ₂ O of more than 1 and does not contain Li ₂ O, so that the absolute value of W is set to 50 μm or less, for example. Na ₂ O / K ₂ O is typically 2 or less.
Typical content of Na ₂ O is from 5 to 10%.

The fourth glass contains components other than B ₂ O ₃ , SiO ₂ , ZnO, Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO, BaO, CuO, CeO ₂ and CoO. In the range not impairing the object of the present invention, the total content may be 10% or less, and preferably the total is 5% or less.
The fourth glass typically does not contain Li ₂ O.

As described above, the glass of the present invention is suitable when ε is lowered to make ε 6-7, for example, but when ε is not desired to be so low, glass (glass a), i.e., by mol% based on the following _{oxides, B 2 O 3 33~42%,} SiO 2 5~12%, ZnO 28~45%, Li 2 O + Na 2 O + K 2 O 3~8 %, Li ₂ O 0-4%, MgO + CaO + SrO + BaO 5-20%, BaO 5-15%, CuO + CeO ₂ + CoO 0-3%, and a glass containing no PbO is a preferred embodiment, and its ε Is typically 8-9.

Hereinafter, the composition of the glass A will be described.
B ₂ O ₃ is a component that stabilizes the glass or lowers Ts and is essential. If it is less than 33%, vitrification becomes difficult, or Ts becomes high. Typically, it is 34% or more. If it exceeds 42%, vitrification becomes rather difficult. Preferably it is 42% or less, typically 40% or less.
SiO ₂ is a component constituting a glass skeleton and is essential. If it is less than 5%, vitrification becomes difficult. Typically 7% or more. If it exceeds 12%, Ts becomes too high. Typically 11% or less.

  ZnO is a component that lowers Ts or reduces α, and is essential. If it is less than 28%, Ts becomes high. If it exceeds 45%, vitrification becomes difficult, or crystals tend to precipitate during firing. Preferably it is 42% or less. ZnO is typically 30-40%.

Li ₂ O, Na ₂ O, and K ₂ O are components that have the effect of facilitating vitrification or lowering Ts, and must contain at least one of them. If the total R ₂ O content of these three components is less than 3%, the effect is small. Typically 4% or more. If R ₂ O exceeds 8%, α increases.
When Li ₂ O is contained, if its content exceeds 4%, the warp becomes large. Typically 3% or less.
When Na ₂ O is contained, its content is typically 4% or less.
It is preferable to contain 2% or more of K ₂ O. If it is less than 2%, warping may increase. In this case, the content of K ₂ O is typically 6% or less.

BaO is a component that lowers Ts and is essential. If it is less than 5%, Ts becomes high. Typically 6% or more. If it exceeds 15%, α becomes large. Typically 13% or less.
When it is desired to reduce the warp, it is preferable that B ₂ O ₃ is 38% or less, ZnO is 32% or more, and BaO is 11% or less.

MgO, CaO and SrO are not essential, but may be contained until the total RO of the contents of these three components and BaO reaches 20% in order to lower Ts or reduce α. . If it exceeds 20%, vitrification may be difficult. RO is typically 8-18%.
When CaO is contained, the content is preferably 5% or less. If it exceeds 5%, crystals tend to precipitate during firing.

CuO, CeO _2, and CoO are not essential, but any one is used to suppress the phenomenon that the binder is not enough during firing and carbon remains in the fired glass and the glass is colored. It is preferable to contain at least seeds in a range where the total content of these three components is 3% or less. If the total exceeds 3%, the coloring of the glass becomes rather remarkable. Typically, it is 1.5% or less.
When it contains any of these three components, it is typical to contain CuO in a range of 1.5% or less, and a range of 0.3 to 1% is exemplified.

Glass A substantially consists of the above components, but may contain other components as long as the object of the present invention is not impaired. In this case, the total content of components other than the above components is preferably 10% or less, and typically 5% or less.
Examples of such components include Al ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , MnO _{2 and the} like. These components are usually added for the purpose of adjusting α, Ts, chemical durability, glass stability, the transmittance of the glass coating layer, and suppressing the silver coloring phenomenon.
PbO is not contained.
Bi ₂ O ₃ may be contained in an amount of 5% or less in order to improve the sinterability, but it is more preferable not to contain Bi ₂ O ₃ because there are resource problems and the like.

The electric wiring forming glass plate of the present invention is typically a PDP front substrate, and the electric wiring in this case is constituted by a display electrode pair or the like.
The maximum diameter of the portion covered with the electrode coating glass in the electric wiring forming glass plate of the present invention is typically 14 cm or more, and in such a case, the effect of warpage suppression is often significant. The maximum diameter means, for example, when the portion is rectangular, the longer of the two diagonals, and is 106 cm or more when used for a 42-inch or larger PDP.

  The PDP of the present invention can be produced by a known method except that the glass of the present invention is used as the electrode coating glass.

The raw materials were prepared and mixed so as to have a composition represented by mol% in the column from B ₂ O ₃ to CoO or CuO in the table. This was heated to 1250 ° C. using a platinum crucible and melted for 60 minutes.
Examples 1-9 are examples of the first glass, Examples 10-36 are examples of the second glass, Examples 37-40 are examples of the third glass, Examples 41-48 are comparative examples, Examples A1- A6 is an example of glass A, and example A7 is a comparative example of glass A. In Examples 8, 9, 32-36, 39, and 40, melting as described above was not performed, and the values of Ts, α, ε, and W were estimated from the composition.

A portion of the molten glass obtained as described above was poured into a stainless steel mold and gradually cooled. The slowly cooled glass was processed into a cylindrical shape having a length of 20 mm and a diameter of 5 mm, and α was measured using this as a sample using a horizontal differential detection type thermal expansion meter TD5010SA-N manufactured by Bruker AXS. The results are shown in the table (unit: 10 ⁻⁷ / ° C.).

A part of the remaining molten glass was poured into a stainless steel roller to be flaked. The obtained after the glass flakes 16 hours dry grinding in an alumina ball mill, subjected to an air classifier, to prepare a glass powder D ₅₀ is 2-4 [mu] m.
Using the glass powder as a sample, Ts was measured using a differential thermal analyzer (DTA). The results are shown in the table (unit: ° C).

  The remainder of the molten glass was poured into a stainless steel mold and slowly cooled. Samples obtained by processing slowly cooled glass into a disk shape having a diameter of 40 mm and a thickness of 3 mm and depositing aluminum as electrodes on both sides thereof are used as samples, and the ε is measured by an electrode contact method using an LCR meter 4192A manufactured by Yokogawa Hewlett-Packard Company. It was measured. The results are shown in the table.

  Further, 100 g of the glass powder was kneaded with 25 g of an organic vehicle in which 10% by mass of ethyl cellulose was dissolved in α-terpineol or the like to prepare a paste ink (glass paste) having a size of 100 mm × 100 mm (maximum diameter: 141 mm), On a glass substrate (PD200 manufactured by Asahi Glass Co., Ltd.) having a thickness of 1.8 mm, screen printing was performed uniformly so that the film thickness after firing was 20 μm, and dried at 120 ° C. for 10 minutes. Then, this glass substrate was heated up to 570 ° C. at a temperature rising rate of 10 ° C. per minute, held at that temperature for 30 minutes, and baked to form a glass layer on the glass substrate.

  The warpage of the portion of the glass substrate with a glass layer having a length of 100 mm on the diagonal line was measured using a surface roughness meter. The results are shown in the table (unit: μm). This warp (W) is preferably within ± 50 μm. In addition, the value of W of Examples 28-31 and 38 is an estimated value from a composition.

  It can be used as glass for covering a PDP transparent electrode or the like.

Claims (20)

In mole% based on the following _{oxides, B 2 O 3 30~47%,} SiO 2 25~42%, ZnO 5~17%, Li 2 O + Na 2 O + K 2 O 9~17%, consisting essentially, contains a Li ₂ O and Na ₂ either O or both _{K 2} O, it is in its content when they contain Li ₂ O is 2.5% or less, glass for covering electrodes containing no PbO. The glass for electrode coating according to claim 1, wherein Na ₂ O / K ₂ O is less than 0.25 and Li ₂ O is 0.1 to 2.5%. The glass for electrode coating according to claim 2, wherein K ₂ O is 9 to 14%. The glass for electrode coating according to claim 2, wherein Na ₂ O is 0 to 3.5%. Does not contain Na ₂ O, claim 1 or 3 glass for covering electrodes Li ₂ O is 1-2%. The glass for electrode coating according to claim 1, wherein Na ₂ O / K ₂ O is 0.25 to 1, and when Li ₂ O is contained, the content is 1.5% or less. The glass for electrode coating according to claim 6, wherein K ₂ O is 5 to 13%. The glass for electrode coating according to claim 6, wherein Na ₂ O is 2 to 8%. The glass for electrode coating according to claim 6, wherein Na ₂ O / K ₂ O is 0.4 or more and Li ₂ O is not contained. The glass for electrode coating according to claim 1, wherein Na ₂ O / K ₂ O is more than 1, and Li ₂ O is not contained. The glass for electrode coating according to claim 10, wherein Na ₂ O is 5 to 10%. The glass for electrode coating according to claim 10, wherein Na ₂ O / K ₂ O is 2 or less. When Na ₂ O contains 4 to 8%, K ₂ O contains 5 to 10%, MgO, CaO, SrO or BaO contains 11% or less, and contains CuO, CeO ₂ or CoO their total content is not more than _{3%, B 2 O 3,} SiO 2, ZnO, Li 2 O, Na 2 O, K 2 O, MgO, CaO, SrO, BaO, CuO, of CeO ₂ and CoO The glass for electrode coating according to claim 1, wherein the total content is 90% or more. Glass for covering electrodes according to claim 13 containing no li ₂ O. Any glass for covering electrodes according to Claim 1~14 Na ₂ O + _{K 2} O is at least 10.5%. Any glass for covering electrodes according to claim 15 containing no Bi ₂ O _3. The average linear expansion coefficient of ^{65 × 10 -7 ~90 × 10 -7} / ℃ any glass for covering electrodes according to claim 1 to 16 is at 50 to 350 ° C..   The glass for electrode coating according to any one of claims 1 to 17, which has a softening point of 630 ° C or lower.   An electrical wiring forming glass plate, wherein an electrical wiring pattern is formed on a glass plate, and the electrical wiring pattern is covered with the electrode coating glass according to claim 1.   A plasma display device in which cells are defined by a front glass substrate, a rear glass substrate, and partition walls used as a display surface, wherein the transparent electrode on the front glass substrate is for covering an electrode according to claim 1. Plasma display device covered with glass.