KR20060093506A - Lead-free low-melting glass frit - Google Patents

Abstract

A lead-free low melting glass composition for use in a plasma display panel that does not contain lead that is harmful to humans and the environment is disclosed. The lead-free low melting glass composition of the present invention contains BaO 5-25% by weight, B ₂ O ₃ 10-30% by weight, ZnO 30-60% by weight, SiO ₂ , Al ₂ O ₃ , CaO, P ₂ O ₅ At least one selected from Bi ₂ O ₃ , Li ₂ O, Na ₂ O, Fe ₂ O ₃ , Cu ₂ O, CeO ₂ , and CoO, and does not contain lead that is harmful to the environment and human body. It can be used at the firing temperature of 580 ℃, excellent etching characteristics can be used as the barrier material for the etching method, and since the color does not change after firing can realize a color close to white.

Glass, Plasma Display Panel, Lead Free, Plasticity

Description

Lead-free Low-melting Glass Frit

The present invention relates to lead-free low melting glass, and more particularly to lead-free low melting glass used in a plasma display panel containing no lead harmful to humans and the environment.

A flat panel display (FPD) device is a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), a vacuum fluorescent device ( Vacuum Fluorescent Dispaly (VFD), etc., is being spotlighted as an information transmission medium in the 21st century society during the age of low noise and low power.

The PDP is composed of an upper panel on which a transparent conductive film (ITO) electrode, a bus electrode, a dielectric layer, a magnesium oxide (MgO) protective layer, etc. are formed, and a bottom plate on which an addressing electrode, a reflective film, a partition wall, and a fluorescent film are formed. It consists of a lower panel, and plasma gas is injected into the inner space between the upper and lower plates.

In the case of the glass powder applied to such a PDP, it should be possible to fire at a relatively low firing temperature of 540 to 580 ° C. In the past, PbO-B ₂ O ₃ containing PbO-B ₂ O ₃ having a low melting point as a main component for glass properties melting at low temperatures System glass compositions are mainly used.

However, in recent years, it is required to remove lead components from glass materials from the viewpoint of environmental problems, and in response to these requirements, tin phosphate (P ₂ O ₅ -SnO), bismuth (Bi ₂ O ₃ ), and zinc boric acid It has been developed, such as the glass composition (ZnO-B ₂ O ₃₎ based.

However, tin phosphate-based glass contains P ₂ O ₅ having high hygroscopicity, which causes problems in mixing and melting raw materials during glass production, and is prone to deterioration during storage as glass powder, and thus may not maintain initial characteristics.

In addition, bismuth-based glass is used more than 50% Bi ₂ O ₃ as the main component, because the price of Bi ₂ O ₃ is very expensive, the price of glass powder is inevitably increased, Bi ₂ O ₃ is more than 50% If contained, there is a problem that the weak acid is not etched, which is not suitable for the PDP etching partition material.

In addition, zinc boric acid-based glass has a limit in lowering the firing temperature, there is no choice but to use an alkali component in the composition, the use of the alkali component has a problem that a yellowing phenomenon of the color changes after the partition wall firing occurs.

The present invention has been made to solve the above problems, the lead-free low melting point does not contain the lead (PbO) harmful to the environment and human body, and the yellowing phenomenon does not occur after the partition wall firing It is an object to provide a glass composition.

In order to achieve the above object, the lead-free low melting glass composition of the present invention comprises 5 to 25% by weight of BaO, 10 to 30% by weight of Bi ₂ O ₃ , ZnO 30 to 60% by weight, SiO ₂ , Al ₂ O ₃ At least one selected from CaO, P ₂ O ₅ , Bi ₂ O ₃ , Li ₂ O, Na ₂ O, Fe ₂ O ₃ , Cu ₂ O, CeO ₂ , CoO.

In the glass composition, the ratio of BaO is preferably 5 to 25% by weight. If the ratio is lower than 5% by weight, the etching properties of the weak acid are poor, which is unsuitable as a barrier material for PDP etching, and the ratio is higher than 25% by weight. The coefficient of thermal expansion is excessively increased.

In the glass composition, the ratio of B ₂ O ₃ is preferably 10 to 30% by weight, and when the ratio is lower than 10% by weight, glass may not be formed. When the ratio is higher than 30% by weight, the melting point of the glass is increased and acid is increased. Etching characteristics of the PDP etch becomes poor, making the PDP etching barrier material unsuitable.

In the glass composition, the ratio of ZnO is preferably 30 to 60% by weight. If the ratio is lower than 30% by weight, the etching property against the weak acid is deteriorated.

SiO ₂ increases the mechanical strength of the glass and lowers the coefficient of thermal expansion. The content of SiO ₂ is preferably 1 to 15% by weight. If the ratio is higher than 15% by weight, the melting point of the glass is increased and the etching characteristics are deteriorated.

While Al ₂ O ₃ lowers the coefficient of thermal expansion of the glass, when it is contained in a large amount, it is difficult to form the glass and the etching characteristics deteriorate.

CaO has the effect of lowering the melting point of glass and making the color clear, but when it contains a large amount, the coefficient of thermal expansion of glass becomes high.

P ₂ O ₅ lowers the melting point of the glass and prevents devitrification, but when contained in a large amount, the coefficient of thermal expansion of the glass is increased, and the hygroscopicity of the glass powder is increased, which may cause deterioration of initial characteristics.

Bi ₂ O ₃ lowers the melting point of the glass, but when contained in a large amount, the coefficient of thermal expansion of the glass increases, the etching characteristics deteriorate, and the color appears to be brown.

Li ₂ O has an excellent effect of lowering the melting point of the glass, but when contained in a large amount, the coefficient of thermal expansion increases and devitrification easily occurs.

Na ₂ O lowers the melting point of the glass, but when it is contained in a large amount, the coefficient of thermal expansion is increased, and the color changes to a yellow color system when applied and baked on the PDP electrode and the dielectric.

Fe ₂ O ₃ and CeO ₂ has the effect of making the color of the glass yellow when contained in a small amount, Cu ₂ O and CoO has the effect of making the color of the glass blue and ultramarine blue when contained in a small amount. Therefore, when Fe ₂ O, CeO ₂ , Cu ₂ O, CoO is added by mixing the appropriate amount of glass color can be made from blue to green system. Green is a complementary color to compensate for the yellow color of the glass due to yellowing, and when yellowing occurs, the color may cancel each other and appear as a white system.

The above-described glass composition is lead-free low melting point glass can be used at a firing temperature of 530 ~ 580 ℃, excellent etching characteristics and can be applied as a barrier material for the etching method. In addition, there is no color change after firing, thereby achieving a color close to white.

Hereinafter, preferred embodiments of the present invention will be described in detail.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 BaO B2O3 ZnO SiO2 CaO P2O5 Bi2O3 Li2O Na2O Fe2O3 Cu2O CeO2 CoO 19.3 18.4 36.6 10.6--8.7 1 3.9 1 0.5-- 13.5 16.4 43.5 8.7--11.6-4.8-0.5 1- 12.4 16.3 46.9 6.7--10.5-4.8--1.9 0.5 11.5 16.2 47.8 7.6--9.6-4.8-0.3 1.9 0.3 10.6 16.3 47.2 7.7--11.5-4.8 1.4--0.5 6.7 21.8 48.6 4.8--9.5-5.7 1.9 0.5 0.5- Sum 100 100 100 100 100 100 Tg (℃) 450 462 456 457 458 460 CTE (10-7 / ° C) 78 75 75 77 73 72 Etch Rate (μm / min) 12 14 14 11 12 13

Referring to Table 1, in Examples 1 to 6 of the present invention, BaO 5-20 wt%, B ₂ O ₃ 15-25 wt%, ZnO 35-50 wt%, SiO ₂ 3-12 wt%, Bi ₂ O ₃ 7 to 13% by weight, Na ₂ O 3 to 7% by weight based on the glass composition, Li ₂ O 0-2% by weight, FeO ₃ 0-2% by weight, Cu ₂ O 0-1% by weight, CeO _The etch rate for the transition point, the coefficient of thermal expansion, and the 1% nitric acid solution was measured, including at least one of ₂ 0-2 wt% and 0-1 wt% CoO.

As a result of the measurement of the glass having the composition of Examples 1 to 6, the transition point was 440 to 470 ° C, the coefficient of thermal expansion (CTE) was 70 to 80 x 10 ^-7 / ° C, The etching rate showed 11-15 micrometers / min.

Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 BaO B2O3 ZnO SiO2 CaO P2O5 Bi2O3 Li2O Na2O Fe2O3 Cu2O CeO2 CoO 9.7 23.1 55.1 4.8----5.8 1 0.5-- 9.7 23.2 53.1 4.8----7.7-0.5 1- 9.4 22.6 51.9 5.2----8.5--1.9 0.5 13.4 22.9 50.7 4.8----5.7-0.3 1.9 0.3 15.4 25 50 2.9----4.8 1.4--0.5 12.5 26.9 49 2.9----5.8 1.9 0.5 0.5- Sum 100 100 100 100 100 100 Tg (℃) 464 448 442 460 460 471 CTE (10 ^-7 / ℃) 71 75 76 72 68 70 Etch Rate (μm / min) 18 17 18 18 17 17

Referring to Table 2, in Examples 7 to 12 of the present invention, BaO 5-20 wt%, B ₂ O ₃ 20-30 wt%, ZnO 45-55 wt%, SiO ₂ 2-6 wt%, Na ₂ O 3-9% by weight was based on the glass composition, at least one of Fe ₂ O ₃ 0-2%, Cu ₂ O 0-1%, CeO ₂ 0-2%, CoO 0-1% Including the transition point, the coefficient of thermal expansion (CTE), and the etching rate for 1% nitric acid solution was measured.

The transition point was 430-475 ° C., the thermal expansion coefficient was 65-80 × 10 ⁻⁷ / ° C., and the etching rate for the 1% nitric acid solution was measured. 16-20 micrometer / min was shown.

Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 BaO B2O3 ZnO SiO2 Al2O3 CaO P2O5 Bi2O3 Li2O Na2O Fe2O3 Cu2O CeO2 CoO 17.4 18.6 47.3-2.9-7.7--4.6 1 0.5-- 17.4 19.3 46.6-3.4-7.2--4.6-0.5 1- 10.5 14.4 49.3 5.7--6.2 6.7-4.8--1.9 0.5 11.5 15.2 47.3 5.3--6.7 6.7-4.8-0.3 1.9 0.3 13.9 15.4 45.3 4.3--7.7 6.7-4.8 1.4--0.5 19.5 15.2 44.8 3.3--9.5--4.8 1.9 0.5 0.5- 13.5 13.5 37.5 2.9-1.9-28.8----1.9- 15.4 13.5 37.5 2.9---28.8--1.4 0.5-- 11.6 15.4 40.6 1.9---29--1--0.5 Sum 100 100 100 100 100 100 100 100 100 Tg (℃) 462 462 456 464 464 456 465 465 467 CTE (10-7 / ° C) 73 76 74 74 76 79 74 70 68 Etch Rate (μm / min) 15 16 15 14 15 15 11 12 11

Referring to Table 3, in Examples 13 to 21 of the present invention, BaO 8-25 wt%, B ₂ O ₃ 10-25 wt%, ZnO 35-55 wt% were based on the glass composition, SiO ₂ 0 ~ 8 wt%, Al ₂ O 3 0-5 wt%, CaO 0-5 wt%, P ₂ O ₅ 0-15 wt%, Bi ₂ O ₃ 0-35 wt%, Na ₂ O 0-6 wt%, Fe ₂ O ₃ 0 ~ _2% by weight, Cu ₂ O 0 ~ 1% by weight, CeO ₂ 0 ~ _2% by weight, including any one or more of the weight percent CoO 0 ~ 1 transition point, thermal expansion coefficient, and nitric acid 1% solution The etch rate for was measured.

The transition point was 440-475 ° C., the coefficient of thermal expansion (CTE) was 65-80 × 10 ⁻⁷ / ° C., and the 1% nitric acid solution was measured. Etching rate showed 10-17 micrometer / min.

When the above-mentioned embodiment is put together and a preferable composition range is set and put together in a table | surface, it is as following Table 4.

ingredient Weight percent range BaO 5-25 B ₂ O ₃ 10-30 ZnO 35-55 SiO ₂ 12 or less Al ₂ O ₃ 5 or less CaO 5 or less P ₂ O ₅ 15 or less Bi ₂ O ₃ 35 or less Li ₂ O 2 or less Na ₂ O 9 or less Fe ₂ O ₃ 2 or less Cu ₂ O 1 or less CeO ₂ 2 or less CoO 1 or less

The glass composition having such a composition can be applied not only to PDP partition material but also for dielectric and sealing.

The present invention described above is not limited to the above-described embodiments, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be clear to those who have it.

The present invention made as described above can produce a lead-free glass containing no lead harmful to the environment and human body.

In addition, it can be used at a firing temperature of 530 ~ 580 ℃, it is excellent in etching characteristics can be used as a partition material for the etching method.

In addition, there is no color change after firing, thereby achieving a color close to white.

Claims (5)

BaO 5 to 25% by weight, B ₂ O ₃ 10 to 30% by weight, ZnO 30 to 60% by weight, containing SiO ₂ , Al ₂ O ₃ , CaO, P ₂ O ₅ , Bi ₂ O ₃ , Li ₂ O A low melting glass composition comprising at least one selected from Na ₂ O, Fe ₂ O ₃ , Cu ₂ O, CeO ₂ , and CoO. The method of claim 1, SiO ₂ is a low melting point glass composition, characterized in that 1 to 12% by weight. The method of claim 2, The Al ₂ O ₃ is 5% by weight or less, CaO is 5% by weight or less, P ₂ O ₅ is 15% by weight or less, Bi ₂ O ₃ is 35% by weight or less, Li ₂ O is 2% by weight or less, Na ₂ O Is 9 wt% or less, Fe ₂ O ₃ is 2 wt% or less, Cu ₂ O is 1 wt% or less, CeO ₂ is 2 wt% or less, and CoO is 1 wt% or less. BaO 5-20 wt%, B ₂ O ₃ 15-25 wt%, ZnO 35-50 wt%, SiO ₂ 3-12 wt%, Bi ₂ O ₃ 7-13 wt%, Na ₂ O 3-7 wt% And a low melting point glass composition comprising at least one selected from Li ₂ O, FeO ₃ , Cu ₂ O, CeO ₂ , and CoO. BaO 5-20 wt%, B ₂ O ₃ 20-30 wt%, ZnO 45-55 wt%, SiO ₂ 2-6 wt%, Na ₂ O 3-9 wt%, Fe ₂ O ₃ , Cu A low melting glass composition comprising at least one selected from ₂ O, CeO ₂ , and CoO.