WO2008007596A1

WO2008007596A1 - Lead-free low-melting glass

Info

Publication number: WO2008007596A1
Application number: PCT/JP2007/063418
Authority: WO
Inventors: Nobuyuki Nakai; Taishin Shimooka
Original assignee: Central Glass Company, Limited
Priority date: 2006-07-14
Filing date: 2007-07-05
Publication date: 2008-01-17
Also published as: JP2008019147A

Abstract

Provided is a transparent and insulating SiO2-B2O3-ZnO-R2O-BaO-ZrO2-CuO lead-free low-melting glass. The lead-free low-melting glass includes a SiO2 of 25-40wt%, a B2O3 of 35-55wt%, a ZnO of 5-12wt%, a R2O(Li2O+Na2O+K2O) of 10-18wt%, a BaO of 0.1-3wt%, a ZrO2 of 0.1-7wt%, and a CuO of 0.1-2wt%. Yellowing due to silver reaction can be suppressed and a high visible light transmissivity can be obtained by using the lead-free low-melting glass.

Description

Specification

Lead-free low melting point glass

Technical field

The present invention is for an electronic material substrate typified by a plasma display panel, a liquid crystal display panel, an electo-luminescence panel, a fluorescent display panel, an electo-chromic display panel, a light-emitting diode display panel, a gas discharge display panel, etc. The present invention relates to a low melting glass used as an insulating coating material and a sealing material.

Background of the Invention

[0002] With the recent development of electronic components !, plasma display panels, liquid crystal display panels, electoric luminescence panels, fluorescent display panels, electoric chromic display panels, light emitting diode display panels, gas discharge display panels, etc. Many types of display panels have been developed. Among them, plasma display panels (hereinafter abbreviated as PDPs) are attracting attention as thin and large flat color display devices. In a PDP, there are many cells between a front substrate and a rear substrate used as a display surface, and an image is formed by performing plasma discharge in the cells. This cell is partitioned by partition walls, and an electrode is formed for each pixel unit in order to control the display state of each pixel forming an image.

[0003] An electrode for discharging plasma is formed on the front glass plate of the plasma display panel, and thin linear silver is often used as the electrode. Around the electrode, a highly transparent insulating material is arranged. This insulating material is preferably excellent in plasma durability and transparent. For this reason, dielectric glass is often used as an insulating material. In addition, since this dielectric glass is naturally required to have a lower melting point than that of the glass plate serving as the substrate in the process, a low-melting glass is used.

[0004] However, in the conventional low melting point dielectric glass, the dielectric glass and the silver of the bus electrode react with each other at a low temperature firing of 450 to 600 ° C, and the dielectric glass is colored yellow ( (Yellowing) occurred, and there was a big problem that high transmittance could not be obtained.

[0005] Regarding this yellowing, there are various known methods to be solved by adjusting the glass component. Technology exists. SiO, AlO, etc. are essential components. For example, the content of PbO and CuO

2 2 3

The material for plasma display which tried to prevent diffusion of silver by Cu (for example, see Patent Document 1), and by adding SrO in addition to CuO, the same effect was obtained, and BaO + SrO + MgO Material for plasma display with limited content (for example, see Patent Document 2), Material for plasma display with limited content of BaO + CaO + Bi O (for example,

twenty three

For example, see Patent Document 3), limited content of SiO, B 2 O, ZnO, Bi 2 O, BaO, Al 2 O

2 2 3 2 3 2 3

A material for plasma display (for example, see Patent Document 4) is disclosed.

Patent Document 1: Japanese Patent Laid-Open No. 2001-52621

Patent Document 2: Japanese Patent Laid-Open No. 2001-80934

Patent Document 3: Japanese Patent Laid-Open No. 2001-48577

Patent Document 4: Japanese Patent Laid-Open No. 2003-226549

Summary of the Invention

[0006] A conventional dielectric material (insulating material) has a problem in that the glass layer and the silver electrode react with each other to cause the dielectric layer to be colored yellow (yellowing), resulting in a decrease in visible light transmittance. It is difficult to respond to this yellowing phenomenon, but it has not yet been achieved to the level desired by the market.

[0007] Conventionally, lead-based glass has been employed for low-melting glass, for example, low-melting glass for substrate coating. Although the lead component is an important component for lowering the melting point of glass, it has a tendency to avoid its adoption in recent years because it has a great negative impact on the human body and the environment. Lead-free electronic materials such as PDP are being studied. Being sung.

[0008] That is, JP 2001-52121 A, JP 2001-80934 A, and JP 20

The 01-48577 gazette has the basic problem of containing lead, which is a significant improvement against yellowing. Furthermore, Japanese Patent Application Laid-Open No. 2003-226549 does not contain lead, and a considerable improvement against yellowing is recognized. However, as with lead, it contains bismuth that tends to be avoided from an environmental point of view. RU

[0009] According to the present invention, 25 to 40 weight SiO ^_0/0, BO 35 to 55 weight ^_0/0, ZnO 5-12

2 2 3

Wt%, R 2 O (Li 2 O + Na 2 O + K 2 O) 10-18 wt%, BaO 0.1-3 wt%, ZrO

2 2 2 2

Transparent insulating SiO—B 2 O—ZnO containing 0.1 to 7% by weight and 0.1 to 2% by weight of CuO

2 2 2 3

— R 2 O—BaO 2 —ZrO—CuO-based lead-free low melting glass is provided. [0010] The lead-free low-melting glass can be used as an insulating coating material and a sealing material for an electronic material substrate or a PDP panel.

Detailed description

[0011] Insulation for electronic material substrates typified by plasma display panels, liquid crystal display panels, electoric luminescence panels, fluorescent display panels, electoric chromic display panels, light emitting diode display panels, gas discharge display panels, etc. A low melting point glass used as a coating material and a sealing material can reduce the phenomenon that the dielectric layer is colored yellow (yellowing) by the reaction between the glass and the silver electrode. .

[0012] The lead-free low-melting glass of the present invention is illustratively described in detail below.

[0013] SiO is a glass-forming component and coexists with another glass-forming component, B 2 O.

2 2 3

It can form a more stable glass, and is contained in an amount of 25% (wt% or less). If it exceeds 40%, the soft softness point of the glass will rise, making formability and workability difficult. More preferably, it is 26 to 38% of range.

[0014] B 2 O is a glass forming component similar to SiO, facilitating glass melting, and thermal expansion of glass

2 3 2

An excessive increase in the coefficient is suppressed, and an appropriate fluidity is imparted to the glass during baking, and the dielectric constant of the glass is lowered together with SiO. Contained in glass at 35-55%

2

Is preferred. If it is less than 35%, the flowability of the glass becomes insufficient and the sinterability is impaired. On the other hand, if it exceeds 55%, the stability of the glass is lowered. More preferably, it is 38 to 52% of range.

[0015] ZnO lowers the soft spot of the glass and adjusts the thermal expansion coefficient to an appropriate range, and is preferably contained in the glass in a range of 5 to 12%. If it is less than 5%, the above-mentioned action cannot be exhibited. On the other hand, if it exceeds 12%, the glass becomes unstable and devitrification tends to occur. More preferably, it is in the range of 6 to 11%.

[0016] R 2 O (Li 0, Na 0, K 2 O) lowers the soft softness point of glass, gives moderate fluidity, and thermal expansion

2 2 2 2

The coefficient is adjusted to an appropriate range, and it is preferably contained in the range of 10 to 18%. If it is less than 10%, the above-mentioned action cannot be exerted. On the other hand, if it exceeds 18%, the thermal expansion coefficient is excessively increased. More preferably, it is 11 to 17% of range.

[0017] BaO has an effect of imparting moderate fluidity to glass and increasing transparency, and has a content of 0.1 to 3%. It is contained in a box. If it exceeds 3%, the above effect cannot be exhibited. More preferably, it is in the range of 1 to 2%.

[0018] ZrO has the effect of increasing the water resistance of the glass, and is contained in the range of 0.1 to 7%. Than

2

Preferably, it is in the range of 1% to 6%.

[0019] CuO has the effect of mitigating the coloration of silver colloid (yellowing) due to the reaction between the silver electrode used as the bus electrode wire and the dielectric layer, and the diffusion of silver into the dielectric layer. It is preferably contained in the range of ˜2%. If the content is less than 1%, the above-mentioned effect cannot be exhibited. If the content exceeds 2%, the glass is colored and the transparency is lowered. More preferably, it is in the range of 0.1 to 1%.

[0020] MnO reacts with a silver electrode used as a bus electrode wire and a dielectric layer, and in the dielectric layer

2

It has the effect of mitigating silver diffusion and color development (yellowing) of silver colloid, and it is preferably contained in the range of 0 to 2%. If it exceeds 2%, the glass is colored and the transparency is lowered. More preferably, it is in the range of 0 to 1%.

[0021] RO (MgO + CaO + SrO) imparts moderate fluidity to glass and adjusts the thermal expansion coefficient to an appropriate range, and is contained in the range of 0 to 10%. If it exceeds 10%, the thermal expansion coefficient will rise excessively. More preferably, it is in the range of 0 to 6%.

[0022] The lead-free low-melting glass described above, wherein the weight ratio of B 2 O 3 ZZnO is 3 or more and 7 or less. 3 not yet

twenty three

If it is full, yellowing will be prominent, and if it exceeds 7, the stability will deteriorate. More preferably, it is the range of 4-6.

[0023] In addition, In O, TiO, SnO, TeO and the like represented by general oxides may be added!

2 3 2 2 2

[0024] By substantially not containing PbO, it is possible to eliminate the influence on the human body and the environment. Here, “substantially free of PbO” means that PbO may be contained up to an amount enough to be mixed as an impurity in the glass raw material. For example, if it is in the range of 0.3 wt% or less in the low-melting glass, the above-mentioned adverse effects, that is, the influence on the human body and the environment, the influence on the insulation characteristics, etc., are hardly affected by PbO. It becomes.

[0025] lead-free low-melting-point glass of the present invention, the thermal expansion coefficient of 65 at 30 ° C~300 ° C X 10 " V ° C~95 X 10- 7 Z ° C, further軟I匕点is 500 ° It may be C or more and 630 ° C or less. If the tension coefficient is out of this range, problems such as film peeling and substrate warping may occur during thick film formation. Preferably, in the range of ^{75 X 10- 7 Z ° C~85 X} 10- 7 Z ° C. In addition, if the soft spot exceeds 630 ° C, problems such as soft deformation of the substrate may occur. The temperature is preferably 500 ° C or higher and 590 ° C or lower.

Furthermore, the lead-free low melting point glass of the present invention can be used as an insulating coating material and a sealing material for a substrate for electronic materials. Thereby, it can be set as the board | substrate for electronic materials by which yellowing was suppressed.

Furthermore, the lead-free low-melting glass of the present invention can be used as an insulating coating material and a sealing material for PDP panels. As a result, a PDP panel in which yellowing is suppressed can be obtained.

[0028] The present invention is a disclosure of a low-melting-point glass corresponding to a yellowing phenomenon caused by a reaction with silver, and the object is not limited to a silver electrode.

[0029] It should be noted that the lead-free low melting point glass of the present invention can be used for, for example, both the front plate and the back plate of PDP glass. When used as a back plate, it is often used as a sealing material or covering material, and is used in powder form. This powdered glass is mixed with a low-expansion ceramics filler such as muraite or alumina, heat-resistant pigments, etc., if necessary, at a ratio of 0.6 {glass Z (glass + filler) weight ratio} or more. Then, it is generally kneaded with organic oil to form a paste.

[0030] The glass substrate is a transparent glass substrate, particularly soda-lime-silica glass, or similar glass (high strain point glass), or an alumino-lime borosilicate-based glass with little (or little) alkalinity. Glass is frequently used.

Hereinafter, the present invention will be described based on examples. However, the present invention is not limited to the examples.

[Examples 1 to 7 and Comparative Examples 1 to 4]

(Preparation of low melting point glass mixed paste) Fine silica sand as SiO source and BO source

2 2 3

Acid, zinc white as ZnO source, lithium carbonate as Li O source, sodium carbonate as Na O source

twenty two

, Potassium carbonate as the K 2 O source, cupric oxide as the CuO source, and 2 as the MnO source

twenty two

Manganese oxide, magnesium carbonate as MgO source, calcium carbonate as CaO source Strontium carbonate was required as the SrO source, and barium carbonate was required as the BaO source. After mixing these materials to the desired low melting point glass composition, they were put into a platinum crucible and heated and melted in an electric heating furnace at 1000 to 1300 ° C for 1 to 2 hours. Examples 1 to 7 in Table 1 The glasses having the compositions shown in Comparative Examples 1 to 4 in Table 2 were obtained.

[table 1]

ο

100 100 100 100 100 100 100

[Table 2]

Zr0 ₂

Mn0 ₂

RO (MgO + CaO + SrO) 6.

wt% B2O3 ZnO 1.0 0.9 1.5 0.7

Softening point ( ^D c) 570 550 655 483

Thermal expansion coefficient (X 10-7Z ° C) 72 74 63 98

Suppression of yellowing X X Note 1) Note 1)

Note 1) Not implemented due to physical property value failure.

100.0 100.0 100.0 100.0

[0033] A part of the glass was poured into a mold and made into a block shape for use in measuring thermal properties (thermal expansion coefficient, softening point). The remaining glass was flaked with a rapid cooling twin roll molding machine and sized with a pulverizer into a powder with an average particle size of 1 to 3 μm and a maximum particle size of less than 10 μm.

[0034] Next! /, A paste oil composed of α-terpineol and butyl carbitol acetate is mixed with ethylcellulose as a binder and the above glass powder, and the viscosity is 300 ± 50 parts. A paste of the same size was prepared.

[0035] (Formation of insulating coating) Apply the above paste using an applicator to a soda-lime glass substrate with a thickness of 2 to 3 mm and a size of 100 mm square, taking into consideration that the film thickness after baking should be about 30 m. Then, a coating layer was formed. Next, after drying, a clear dielectric layer was formed by firing at 550 ° C. or lower for 10 to 60 minutes below the soft spot.

[0036] The obtained sample was observed with the naked eye and a microscope, and it was judged that the yellowing phenomenon was markedly suppressed as compared with the conventional sample, and the others were marked X.

[0037] The softening point was the temperature at which the viscosity coefficient r? = 10 ⁷ · ⁶ was reached using a Littleton viscometer. The thermal expansion coefficient was determined from the amount of elongation at 30 to 300 ° C when the temperature was raised at 5 ° C / min using a thermal dilatometer.

(Results) Tables 1 and 2 show the low melting point glass composition and various test results.

[0039] As shown in Examples 1 to 7 in Table 1, in the composition range of the present invention, the occurrence of yellowing was remarkably suppressed as compared with the conventional case.

[0040] On the other hand, Comparative Examples 1 to 4 in Table 2 outside the composition range of the present invention, as in the prior art, show significant yellowing, or do not show favorable physical properties, and are suitable for coating substrates such as PDP Cannot be applied as low melting point glass.

Claims

The scope of the claims

[1] SiO the 25 to 40 weight ^_0/0, BO 35 to 55 weight ^_0/0, ZnO 5-12 wt ^_0/0, RO (Li O

2 2 3 2 2

+ Na O + K Ο) 10-18%, BaO 0.1-3%, ZrO 0.1-7%

2 2 2

The CuO comprises 0.1 to 2 wt ^_0/0, the transparent insulating SiO- BO- ZnO- RO- BaO- Z

2 2 3 2

rO CuO lead-free low melting point glass.

2

[2] The lead-free low melting point glass according to claim 1, wherein the weight ratio of B 2 O 3 ZZnO is in the range of 3 to 7.

twenty three

[3] The lead-free low melting point glass according to claim 1 or 2, comprising 0 to 2% by weight of MnO.

2

[4] The lead-free low-melting glass according to any one of claims 1 to 3, comprising 0 to 10% by weight of RO (MgO + CaO + SrO).

[5] 30 ° C~300 ° C coefficient of thermal expansion is ^{65 X 10- 7 Z ° C~95 X} 10 "V ° C, softening point 50

The lead-free low-melting glass according to any one of claims 1 to 4, wherein the glass is 0 ° C or higher and 630 ° C or lower.

[6] A substrate for electronic materials comprising the lead-free low melting point glass according to any one of claims 1 to 5 as an insulating coating material and a sealing material.

[7] A PDP panel comprising the lead-free low melting point glass according to any one of claims 1 to 5 as an insulating coating material and a sealing material.