WO2008032622A1

WO2008032622A1 - Lead-free low-melting-point glass

Info

Publication number: WO2008032622A1
Application number: PCT/JP2007/067296
Authority: WO
Inventors: Taishin Shimooka; Nobuyuki Nakai
Original assignee: Central Glass Company, Limited
Priority date: 2006-09-13
Filing date: 2007-09-05
Publication date: 2008-03-20
Also published as: JP2008069032A

Abstract

[PROBLEMS] A lead-free low-melting-point glass of high visible light transmission that inhibits yellowing by silver reaction is demanded in the development of electronic material substrate represented by a plasma display panel. [MEANS FOR SOLVING PROBLEMS] There is provided a SiO2-B2O3-ZnO-R2O-BaO-ZrO2 based lead-free low-melting-point glass characterized by containing, by weight, 5 to 11% SiO2, 45 to 65% B2O3, 20 to 30% ZnO, 10 to 18% R2O(Li2O+Na2O+K2O), 0.1 to 3% BaO, 0.1 to 7% ZrO2, 0 to 2% CeO2, 0 to 2% CoO and 0 to 2% CuO wherein the weight ratio of B2O3/ZnO is in the range of 1.5 to 3. The glass is characterized by having a thermal expansion coefficient of (65 to 95)x10-7/°C at a temperature of from 30° to 300°C and a softening point of 500° to 630°C.

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 electoluminescence panel, a fluorescent display panel, an electochromic display panel, a light emitting diode display panel, a gas discharge display panel, and the like. The present invention relates to a low-melting glass used as an insulating coating material.

Background art

[0002] With the development of electronic components in recent years, there are many such as plasma display panels, liquid crystal display panels, electoric luminescence panels, fluorescent display panels, electoric chromic display panels, light emitting diode display panels, and gas discharge display panels. Different 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, an insulating coating material having high transparency is arranged. This insulating coating material is excellent in plasma durability and is preferably transparent. For this reason, dielectric glass is often used as the insulating coating material. In addition, since the dielectric glass is naturally required to have a lower melting point than 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, at 450 to 600 ° C! /, The low temperature firing, the dielectric glass reacts with the silver of the bus electrode, and the dielectric glass is colored yellow (yellow The phenomenon of changing) occurred, and high transmittance was not obtained!

[0005] Regarding this yellowing, there are various known methods to be solved by adjusting the glass component. Technology exists. Si_〇 and _2, Al ₂ 〇 ₃ such as essential components, for example, PbO and limit the content of CuO, for plasma display materials tries to prevent diffusion of the silver by Cu (for example, see Patent Document 1), The same effect can be obtained by adding SrO in addition to CuO. Material for plasma display with limited content of BaO + SrO + MgO (see, for example, Patent Document 2) Content of BaO + CaO + BiO Materials for plasma displays with limited content (eg, see Patent Document 3), materials for plasma displays with limited content of Si〇, B〇, Zn〇, BiO, Ba〇, AlO (for example, Patent Document 4) Reference).

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 Unexamined Patent Publication No. 2003-226549

Disclosure of the invention

Problems to be solved by the invention

[0006] In a low-melting-point dielectric glass, which is a conventional insulating coating material, a phenomenon occurs in which the dielectric layer (glass) is colored yellow (yellowing) due to the reaction between the glass and the silver electrode, and the visible light transmittance is reduced. There is a problem of decline. 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 glass has been adopted as the low-melting glass. Although lead is an important component for making glass have a low melting point, 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, and lead-free electronic materials such as PDP are being investigated. ing.

[0008] That is, JP-A-2001-52621, JP-A-2001-80934, and JP-A-2001-48577 show considerable improvement against yellowing, but contain lead. There is a basic problem. Furthermore, JP 2003-226549 A contains bismuth, which does not contain lead and has a tendency to be avoided from the environmental point of view, as well as lead, which can be considerably improved against yellowing! /

Means for solving the problem

[0009] According to the present invention, by weight, SiO is 5 to 5; 11, BO is 45 to 65, ZnO is 20 to 30, R 0 (Li 2 O + Na O + KO) 10 ~; 18, BaO 0.1 ~ 3, ZrO 0.1 ~ 7, CeO 0 ~ 2, CoO 0 ~ 2, CuO 0 ~ 2 transparent insulation Si ○ ₂ — BO —ZnO—R O—BaO—ZrO 2 is a lead-free low melting glass.

[0010] The lead-free low-melting glass described above, wherein the weight ratio of B 2 O 3 / ZnO is 1.5 or more and 3 or less.

[0011] Further, the lead-free low-melting glass as described above, which contains 0 to 2 MnO by weight%

[0012] Further, the lead-free low-melting glass as described above, wherein the glass contains RO (MgO + CaO + SrO) in an amount of 0 to 10% by weight.

[0013] Further, 30 ° C~300 thermal expansion coefficient in ° C is ^{(65~95) X 10- 7 / °} C, softening point 500

It is the above lead-free low melting point glass having a temperature of from ° C to 630 ° C.

[0014] Furthermore, the present invention is an electronic material substrate using the above lead-free low-melting glass as an insulating coating material.

[0015] Furthermore, the present invention is a PDP panel using the above lead-free low melting point glass as an insulating coating material!

The invention's effect

[0016] A low-melting-point dielectric glass, which is a conventional insulating coating material, has become a problem! / In addition, a glass that reduces the phenomenon of yellowing (yellowing) due to the reaction between the glass and the silver electrode. Obtainable.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] The present invention relates to a transparent insulating lead-free low melting point glass in which SiO is 5 to 5% by weight, 11, BO is 45 to 65, ZnO is 20 to 30, R 0 (Li O + Na O + KO) 18--, BaO 0.1--3, ZrO 0-!-7, CeO 0-2, CoO 0-2, CuO 0-2 SiO-BO —ZnO—RO—BaO—ZrO lead-free low melting point glass.

[0018] Si_〇 ₂ is a glass forming component, more coexist with a another glass forming component BO, those capable of forming a stable glass, 5% (wt%, the true in the following It is contained. If it exceeds 11%, the softening point of the glass will rise, making formability and workability difficult. More preferably, it is in the range of 6 to 10%. [0019] B is ₂ 〇 ₃ is a glass forming component Si_〇 ₂ Similarly, the glass melt is facilitated, suppresses an excessive increase in the thermal expansion coefficient of the glass, and, given an appropriate fluidity to the glass upon baking, Together with SiO, it decreases the dielectric constant of the glass. It is preferably contained in the glass at 45 to 65%. If it is less than 45%, the fluidity of the glass becomes insufficient, and the sinterability is impaired. On the other hand, if it exceeds 65%, the stability of the glass is lowered. More preferably, it is in the range of 48-60%.

ZnO lowers the softening point of the glass and adjusts the thermal expansion coefficient to an appropriate range, and is preferably contained in the glass in a range of 20 to 30%. If it is less than 20%, the above-mentioned action cannot be exhibited. On the other hand, if it exceeds 30%, the glass becomes unstable and devitrification tends to occur. More preferably, it is 22 to 29% of range.

[0021] RO (Li 0, Na 0, KO) lowers the softening point of glass, imparts moderate fluidity, and adjusts the coefficient of thermal expansion to an appropriate range, and is contained in the range of 10 to 18%. It is preferable to let them. 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%.

[0022] BaO has an effect of imparting moderate fluidity to glass and increasing transparency, and is contained in a range of 0.;! To 3%. If it exceeds 3%, the above effect cannot be exhibited. More preferably, it is in the range of !! to 2%.

[0023] ZrO has the effect of increasing the water resistance of the glass, and is contained in the range of 0.;! To 7%. More preferably, it is in the range of 1% to 6%.

[0024] CeO 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 a range of ˜2%. If it exceeds 2%, the glass is colored and the transparency is lowered. More preferably, the range is 0.;! ~ 1%.

[0025] CoO 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 a range of ˜2%. If it exceeds 2%, the glass is colored and the transparency is lowered. More preferably, the range is 0.;! ~ 1%.

[0026] CuO reacts with a silver electrode used as a bus electrode wire and a dielectric layer, and silver is contained in the dielectric layer. Is effective to alleviate silver colloid coloration (yellowing) due to diffusion, and 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, the range is 0.;! ~ 1%.

[0027] MnO has an effect of mitigating 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 to cause silver colloid coloration (yellowing). It is preferably contained in the range of ˜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%.

[0028] Since CeO, CoO, CuO, and MnO have the same effect as described above, there is a desirable range of the total, which is less than 3%. If it exceeds 3%, the glass is colored and the transparency is lowered. More preferably, it is 0.3 to 2% of range.

[0029] RO (MgO + CaO + SrO) imparts moderate fluidity to the 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%.

[0030] The lead-free low-melting glass described above, wherein the weight ratio of B 2 O 3 / ZnO is 1.5 or more and 3 or less. 1.

If it is less than 5, yellowing becomes prominent, and if it exceeds 3, stability deteriorates. More preferably, it is in the range of 1.8 to 2.5.

[0031] In addition, In O, TiO, SnO, TeO and the like represented by general oxides may be added.

Yes

[0032] 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 is mixed in as an impurity in the glass raw material. For example, within the range of 0.3 wt% or less in low-melting glass, the above-mentioned adverse effects, that is, the effects on the human body and the environment, the influence on the insulation characteristics, etc., are hardly affected by PbO. become.

[0033] is 30 ° C~300 thermal expansion coefficient (65 to 95) in ^{° C X 10- 7 / ° C} , softening point 500 ° C or more on the 630 ° above lead-free low-melting-point glass is C or less . Thermal expansion coefficient ^{(65~95) X 10 - 7 /} ° C outside the thick film formation at the time of peeling of the coating, and problems such as warpage of the substrate occurs. Preferred details, in the range of ^{(75~85) X 10- 7 / °} C. In addition, if the softening point exceeds 630 ° C, problems such as softening deformation of the substrate occur. Preferably, it is 500 ° C or higher and 590 ° C or lower. [0034] Furthermore, the present invention is a substrate for an electronic material using the above low-melting glass as an insulating coating material. By using the above-mentioned low-melting glass, it is possible to obtain a substrate for electronic materials in which yellowing is suppressed.

[0035] Further, the present invention is a panel for PDP using the above-mentioned low melting point glass as an insulating coating material. By using the above-mentioned low melting point glass, it is possible to obtain a PDP panel in which yellowing is suppressed with the force S.

[0036] The present invention is a disclosure of a low-melting-point glass corresponding to the yellowing phenomenon due to the reaction with silver, and its object is limited to a silver electrode!

[0037] The glass substrate is a transparent glass substrate, in particular, soda-lime-silica glass, or similar glass (high strain point glass), or an alumino-lime borosilicate system with little (or almost no) alkali content. Glass is used a lot!

Example 1

Hereinafter, description will be made based on examples.

(Preparation of low melting point glass mixed paste) Fine silica sand as SiO source, boric acid as BO source, zinc white as ZnO source, lithium carbonate as Li O source, sodium carbonate as Na O source Potassium carbonate as KO source, Cerium carbonate as CeO, Connole oxide as CoO, Cupric oxide as CuO source, Manganese dioxide as MnO source, Magnesium carbonate as MgO source, CaO source as CaO source Calcium carbonate was required, strontium carbonate as the SrO source, and barium carbonate as the BaO source. These are prepared to have a desired low melting point glass composition, and then put into a platinum crucible and heated and melted in an electric heating furnace at 1000 to 1300 ° C for! To 2 hours. ! ~ 4, Comparative Example in Table 2; Glasses having compositions shown in! ~ 4 were obtained.

[0040] [Table 1]

[Table 2]

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 m.

Subsequently, ethyl cellulose as a binder and the above glass powder were mixed with paste oil consisting of terbinol and butyl carbitol acetate to prepare a paste having a viscosity of about 300 ± 50 poise. [0043] (Formation of insulating coating) Apply the above paste to a soda-lime glass substrate with a thickness of 2 to 3 mm and a size of 100 mm square using an applicator, taking into consideration that the film thickness after baking should be about 30 πι. Then, a coating layer was formed. Next, after drying, a clear dielectric layer was formed by firing at 630 ° C. or lower for 10 to 60 minutes.

[0044] The obtained samples were observed with the naked eye and a microscope, and A was determined for those in which the yellowing phenomenon was judged to be significantly suppressed as compared with the conventional sample, and B was set for the others.

[0045] The softening point was the temperature at which the viscosity coefficient 7] = 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) The low melting point glass composition and various test results are shown in the table.

[0047] As shown in Examples in Table 1;! To 4, within the composition range of the present invention, the occurrence of yellowing was remarkably suppressed as compared with the prior art.

[0048] 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, are markedly yellowed or do not show favorable physical properties and are used for coating substrates such as PDP. It can not be applied as low melting point glass.

Claims

The scope of the claims

[1] Si_〇 of the transparent insulating ₂ - B ₂ 〇 ₃ - ZnO - RO- BaO- Zr_〇 shall apply in _2-based lead-free low-melting-point glass, 5 to SiO by weight%; 11, BO 45 to 65, ZnO 20 ~ 30, R 0 (Li O + Na O + K Ο) 10 ~; 18, BaO 0.1 ~ 3, ZrO 0.1 ~ 7, CeO 0 ~ 2, CoO 0 ~ 2. Contains 0-2 CuO.

[2] The lead-free low-melting glass according to claim 1, wherein the weight ratio of B 2 O 3 / ZnO is 1.5 or more and 3 or less.

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

2 included.

[4] A lead-free low-melting glass according to any one of claims 1 to 3, wherein the glass is RO (Mg

O + CaO + SrO) 0-;

[5] A lead-free low-melting-point glass according to any one of claims 1 to 4, 30 ° C~300 Contact Keru thermal expansion coefficient ° C is ^{(65~95) X 10- 7 / °} C, softening The point is between 500 ° C and 630 ° C.

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

[7] A panel for PDP using the lead / low melting point glass of any one of claims 1 to 6 as an insulating coating material.