KR100942472B1 - Lead-free frit composition for plasma display panel exhaust pipe glass sealing, and lead-free paste composition comprising thereof - Google Patents

Abstract

PURPOSE: A lead-free frit composition is provided to ensure reliability and durability of sealing site by mixing components of glass. CONSTITUTION: A lead-free frit composition for sealing plasma display panel vent pipe comprises glass and ceramic filler. The glass contains 74-77 weight% of Bi2O3, 9-10 weight% of B2O3, 10-13 weight% of ZnO, 1.5-2.5 weight% of Na2O, 0.5-1 weight% of SiO2, and 0.5-1 weight% of Al2O3. The ceramic filter is added in 5-30 wt.pt based on 100.0 of glass. The ceramic filler is one or more selected from a group of zircon, eucryptite, alumina, cordierite, and zinc compound.

Description

LEAD-FREE FRIT COMPOSITION FOR PLASMA DISPLAY PANEL EXHAUST PIPE GLASS SEALING, AND LEAD-FREE PASTE COMPOSITION COMPRISING THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to frit compositions used for sealing exhaust pipes, such as electronic components and flat panel displays, and more particularly to lead-free frit compositions used for mutual sealing of plasma display panels and exhaust pipes.

As a sealing material for electronic parts and flat display devices, it has excellent chemical durability and heat resistance as compared with resin-based sealants, and is suitable for securing airtightness such as flat display devices, and includes a mother glass and a ceramic filler. Frit compositions that exist in a glass state after the sealing process are widely used.

The frit composition is basically calcined at a low temperature, that is, low transition point, softening point, etc. to enable low temperature sealing, and excellent fluidity, low temperature crystallization problem and excellent thermal stability at low temperature, reliability, durability and resistance after sealing The basic characteristics are required to have excellent chemical properties.

In particular, when the front substrate and the rear substrate of the plasma display panel which are one of the flat panel display devices are mutually sealed using the frit composition, the temperature of 450 ° C. to 540 ° C., which does not deteriorate the fluorescence characteristics of the phosphor layer provided on the plasma display panel, Low temperature sealing processes should be possible at relatively low firing temperatures. To this end, conventionally, a lead boric acid (PbO-B ₂ O ₃ ) -based frit composition mainly containing lead oxide (PbO) containing a low melting point component as a sealing material has been mainly used.

Recently, however, there has been a movement to regulate a frit composition containing lead due to human hazards and environmental pollution, and accordingly, tin phosphate (P ₂ O ₅ -SnO) -based and zinc boric acid (ZnO) in which lead is removed as a sealing material. A bismuth (Bi ₂ O ₃ ) -based frit composition has been developed and used together with the -B ₂ O ₃ ) system.

Bismuth (Bi ₂ O ₃ ) -based frit composition has better chemical durability than tin phosphate (P ₂ O ₅ -SnO) -based frit composition, weak hygroscopicity, easy mixing and melting, convenient storage, and zinc boric acid (ZnO- Unlike the B ₂ O ₃ ) -based frit composition, it is not necessary to add an additive of a large amount of alkali such as litum (Li), sodium (Na) or potassium (K) in order to lower the firing temperature for sealing, and thus the sealed portion after firing There is an advantage that the yellowing of the glass color of the yellow does not occur.

Such bismuth (Bi ₂ O ₃ ) -based frit composition in Korea Patent No. 10-0653408 is substantially free of lead (Pb) and SiO ₂ components Bi ₂ O ₃ (A) 30 to 45 mol% (mole% ), Consisting of 80 to 95% by weight of the mother glass mainly composed of 13 to 35 mol% of ZnO (B) and 20 to 35 mol% of B ₂ O ₃ (C) and the remaining low-expansion ceramic filler; Satisfies A≥ (B + C) / 2, and the mother glass further comprises 0.3 to 3 mol% of alumina, and the mother glass has at least one member selected from the group consisting of MgO, CaO, BaO and SrO. Disclosed is a frit composition for sealing a panel for a flat panel display having a composition ratio of 3 to 15 mol%.

The frit composition introduced in the patent is used for mutual sealing of the front substrate and the rear substrate of the plasma display panel having the same coefficient of thermal expansion (CTE), and the preparation of Table 1 described in the patent publication. As can be seen from Examples 4, 6 and 7, it is understood that the softening point is 420 to 469 ° C and the thermal expansion coefficient is significant at 78 × 10 ^-7 / ° C to 85 × 10 ^-7 / ° C.

However, the frit composition may not only seal the front substrate and the rear substrate of the plasma display panel but also provide an exhaust pipe, which is a glass product, for injecting and discharging the discharge gas into the space between the two substrates after the mutual sealing of the two substrates. It can also be used to seal the back substrate to cover the exhaust holes formed in the back substrate.

However, the frit composition of the registered patent is a sealing material for sealing the front substrate and the rear substrate of the plasma display panel having the same thermal expansion coefficient, and when used as it is for sealing the rear substrate and the exhaust pipe having different thermal expansion coefficient, the thermal stability is lowered. Due to the deterioration of the sealing strength and the cold heat strength occurs a problem that the durability falls.

Therefore, when the conventional frit composition including the registered patent used for sealing the front substrate and the rear substrate of the plasma display panel having the same thermal expansion coefficient is used for the sealing of the rear substrate and the exhaust pipe of the plasma display panel as it is, Even though the frit composition basically has the characteristics that must be provided, such as sealing requirements, it does not satisfy the thermal stability requirements at the same time, the sealing strength is reduced, there is a problem that the reliability and durability of the sealing portion after sealing is inferior.

Accordingly, the technical problem to be achieved by the present invention is to solve the above problems, and to have low transition point, softening point and the like so as to enable low temperature sealing without containing lead components harmful to the environment and human body, and excellent in fluidity, crystallization at low temperature, etc. Lead-free frit composition for sealing a plasma display panel exhaust pipe, which is a bismuth (Bi ₂ O ₃ ) -based sealing material having excellent thermal strength and excellent sealing strength and excellent reliability and durability of the sealing portion after sealing the exhaust pipe, and lead-free containing the same. It is to provide a paste composition.

Technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

The lead-free frit composition for sealing a plasma display panel exhaust pipe according to the present invention for solving the above problems is Bi ₂ O ₃ 60 to 80 wt%, B ₂ O ₃ 5 to 20 wt%, ZnO 5 to 17 wt%, Na ₂ O 1 to 3 wt%, SiO ₂ 0.5 to 2.5 wt% and Al ₂ O ₃ A mother glass comprising 0.5 to 5% by weight, and ceramic filler added in an amount of 5 to 30 parts by weight based on 100 parts by weight of the mother glass.

The ceramic filler is selected from the group consisting of zircon (ZrO ₂ · SiO ₂ ), eucryptite, alumina (Al ₂ O ₃ ), cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ ), zinc compounds It may be one or more selected.

It is preferable that the lead-free frit composition has an average thermal expansion coefficient of 60 × 10 ⁻⁷ / ° C. to 75 × 10 ⁻⁷ / ° C. at 50 ° C. to 300 ° C. after firing.

The thermal expansion coefficient of the lead-free frit composition is preferably 8 × 10 ⁻⁷ / ° C. to 20 × 10 ⁻⁷ / ° C. smaller than the thermal expansion coefficient of the plasma display panel as the encapsulated material.

The transition point of the lead-free frit composition is preferably 340 to 440 ° C, and the softening point is 400 to 480 ° C.

The lead-free paste composition for sealing a plasma display panel exhaust pipe according to the present invention for solving the above problems is added to 1 to 20 parts by weight based on the lead-free frit composition for plasma display panel exhaust pipe sealing, and 100 parts by weight of the lead-free frit composition And a vehicle in which an organic binder and a solvent are mixed.

The organic binder is an acrylic resin-based polymer, the organic binder is 15 to 20% by weight, the solvent is preferably 80 to 85% by weight.

The solvent is preferably at least one selected from the group consisting of butyl carbitol acetate (Buthyl Carbitol Acetate) and alpha terpineol (α-Terpineol).

The lead-free paste composition for sealing the plasma display panel exhaust pipe further includes at least one pigment selected from the group consisting of P-4300 and P-433, wherein the pigment is 0.1 part by weight of 100 parts by weight of the lead-free frit composition for sealing the plasma display panel exhaust pipe. It is preferable that it is 4 weight part.

As described above, the lead-free frit composition for sealing the plasma display panel exhaust pipe and the paste composition including the same according to the present invention have a low transition point, a softening point, and the like so that low temperature sealing is possible without containing lead components harmful to the environment and human body. Plasma Display Panel Exhaust Pipe Bar is a bismuth (Bi ₂ O ₃ ) -based sealing material that is excellent in fluidity, has no problems such as crystallization even at low temperatures, and has excellent thermal stability and excellent sealing strength and excellent reliability and durability of the sealing portion after sealing the exhaust pipe. Wearable lead-free frit compositions and lead-free paste compositions comprising the same are provided.

Other specific details of the present invention are included in the detailed description and drawings.

Advantages and features of the present invention, methods of achieving them, and the like will become apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims.

Embodiments described herein will be described with reference to the accompanying tables and drawings for the purpose of explanation of the invention.

Hereinafter, a lead-free frit composition for sealing a plasma display panel exhaust pipe and a paste composition including the same according to various embodiments of the present invention will be described with reference to the accompanying table and drawings.

The lead-free frit composition for sealing a plasma display panel exhaust pipe according to the present invention for solving the above problems is Bi ₂ O ₃ 60 to 80 wt%, B ₂ O ₃ 5 to 20 wt%, ZnO 5 to 17 wt%, Na ₂ O 1 to 3 wt%, SiO ₂ 0.5 to 2.5 wt% and Al ₂ O ₃ A mother glass comprising 0.5 to 5% by weight, and ceramic filler added in an amount of 5 to 30 parts by weight based on 100 parts by weight of the mother glass.

The thermal expansion coefficient of the rear substrate of the glass plasma display panel which is generally manufactured and sold is 80 × 10 ⁻⁷ / ° C. to 83 × 10 ⁻⁷ / ° C., and the thermal expansion coefficient of the exhaust pipe is higher than that of the rear substrate of the plasma display panel. usually 86 × 10 ^-7 / ℃ to a 88 × 10 ^-7 / ℃ degree. The reason why the thermal expansion coefficients of the rear substrate and the exhaust pipe are different is that the specifications, specifications, and features required by the products are different from each other. Therefore, it is very difficult to make the same coefficients of thermal expansion of the two products.

When a material having a small coefficient of thermal expansion and a large material are encapsulated with each other, a thermal stress is generated. More specifically, a material having a small coefficient of thermal expansion is pulled by a material having a large coefficient of thermal expansion, that is, a tensile force, and conversely, a coefficient of thermal expansion. Larger materials have a holding force, or compressive force, that prevents them from being stretched by smaller materials.

Based on the above principle, in order to increase the sealing strength by reducing the thermal stress by increasing the thermal stability by interposing the frit composition between the rear substrate and the exhaust pipe of the plasma display panel as the sealing material, theoretically, the exhaust pipe, the lead-free frit composition and the plasma display panel It is believed that it is desirable to have the coefficients of thermal expansion of each of the rear substrates of the substrate have similar values. That is, when the lead-free frit composition has a thermal expansion coefficient of about 84 × 10 ⁻⁷ / ° C. to 85 × 10 ⁻⁷ / ° C., which is less than the thermal expansion coefficient of the exhaust pipe and larger than the thermal expansion coefficient of the rear substrate of the plasma display panel, the exhaust pipe and the plasma Since the thermal expansion coefficients of the rear substrate of the display panel and the lead-free frit composition become similar to each other, thermal stress is not generated or is weakly generated, which is considered to be advantageous in thermal stability.

The reason is that when the stress distribution between the back substrate, the lead-free frit composition, and the exhaust pipe of the plasma display panel is considered, there is a weak tensile force between the back substrate of the plasma display panel and the back substrate of the plasma display panel. A weak compressive force acts on the lead-free frit composition in contact with the surface, and a weak tensile force acts on the lead-free frit composition in contact with the exhaust pipe between the lead-free frit composition and the exhaust pipe, and a weak compressive force on the exhaust pipe. This is because it is considered advantageous to design such that there is minimal stress between the back substrate of the panel, the lead-free frit composition, and the exhaust pipe.

However, as a result of actual experiments, unlike the above theoretical predictions, the thermal expansion coefficient of the lead-free frit composition, which is a sealing material, is smaller than the tubular exhaust pipe as well as the rear substrate of the plate-shaped plasma display panel. It was found that the sealing strength of the sealing portion was high.

That is, it was confirmed that controlling the thermal expansion coefficient of the lead-free frit composition so that the compressive force acts on the rear substrate and the exhaust pipe, and the tensile force acts on the lead-free frit composition at the sealed portion can increase the sealing strength most. Experimental results show that the thermal expansion coefficient of the lead-free frit composition is approximately 8 × 10 ⁻⁷ / ° C. to 20 × 10 ⁻⁷ / ° C. than the thermal expansion coefficient of 80 × 10 ⁻⁷ / ° C. to 83 × 10 ⁻⁷ / ° C. of the rear substrate of the plasma display panel. It is preferable that the degree is as small as 60 × 10 ⁻⁷ / ° C. to 75 × 10 ⁻⁷ / ° C., and considering the transition point and softening point requirements for low temperature sealing at the same time, 9 × 10 ⁻⁷ / ° C. to 11 × 10 ⁻⁷ / It was confirmed that it is more preferable that they are ^{69x10 <-7>} / ^degreeC- 74x10 <^-7> / ^{degreeC for} small degrees.

If the thermal expansion coefficient of the lead-free frit composition is less than 60 × 10 ⁻⁷ / ° C., the difference between the thermal expansion coefficients of the rear substrate of the exhaust pipe and the plasma display panel becomes too large, and the thermal stability is lowered. It will decrease drastically, and in severe cases cracks can occur.

On the contrary, when the coefficient of thermal expansion of the lead-free frit composition is greater than 75 × 10 ⁻⁷ / ° C., a weak compressive force is generated on the rear substrate of the plasma display panel, and a weak tensile force is generated on the lead-free frit composition in contact with the rear substrate. In addition, a relatively strong compressive force is generated in the exhaust pipe compared to the rear substrate of the plasma display panel, and a relatively strong tensile force is generated in the lead-free frit composition in contact with the exhaust pipe. As a result, a stress difference between the lead-free frit composition in contact with the rear substrate and the rear substrate and the lead-free frit composition in contact with the exhaust pipe and the exhaust pipe is severely generated to increase the stress imbalance. As a result, the thermal stability is deteriorated, and thus the sealing strength of the sealing portion is drastically reduced after the sealing process, and in severe cases, cracks may occur in the lead-free frit composition which is in contact with the exhaust pipe having a relatively high tensile force when heat shock is applied from the outside. Can be.

As described above, the thermal expansion coefficient of the rear substrate of the plasma display panel as the encapsulated product is 80 × 10 ⁻⁷ / ° C. to 83 × 10 ⁻⁷ / ° C., and the thermal expansion coefficient of the lead-free frit composition is appropriate for the thermal expansion of the rear substrate of the plasma display panel. Considering that it is preferable that the coefficient is 8 × 10 ^-7 / ℃ to 20 × 10 ^-7 / ℃ smaller than the coefficient, the lead-free frit composition has an average coefficient of thermal expansion of 60 × 10 ^-7 / ℃ to 50 ℃ to 300 ℃ after firing It is preferable that it is ^{75x10 <-7>} / ^degreeC .

In addition, the lead-free frit composition satisfies the above coefficient of thermal expansion, while the transition point is preferably 340 to 440 ° C and the softening point is 400 to 480 ° C for low temperature sealing.

The lead-free frit composition of the present invention that meets these requirements is described below with reference to FIGS. 1 and 2.

1 is a graph showing the thermal expansion coefficient analysis results of the lead-free frit composition according to Example 5 of the present invention, Figure 2 is a graph showing the XRD analysis of the ceramic filler of the lead-free frit composition according to Example 5 of the present invention.

First, the composition, composition ratio, and its characteristics of a mother glass are demonstrated.

Bi ₂ O ₃ acts as a glass former in the lead-free frit composition of the present invention to stabilize the glass, lower the softening point of the glass and increase the dielectric constant and coefficient of thermal expansion. Increasing the content of Bi ₂ O ₃ may lower the softening point to lower the firing temperature in the sealing process, but if the amount is large, 60 to 80% by weight should be taken into account to increase the coefficient of thermal expansion of the glass.

B ₂ O ₃ acts as a glass former which is an essential component for constituting glass in the composition of the present invention, but the softening point of the glass is increased due to the addition. In other words, when the addition ratio is too low, glass may not be formed. On the contrary, when the addition ratio is too high, the glass melting point may be increased, and thus the gelation may occur. It is desirable to be.

ZnO acts as a free modifier. In other words, the glass is produced based on irregularly three-dimensionally expanded mesh-like skeletal structure. ZnO does not form a mesh alone, but as a component of glass, it enters a mesh made by a mesh forming oxide (glass former). It acts as a glass modifier that can affect the glass properties and stabilizes the glass chemically and lowers the softening point, dielectric constant and coefficient of thermal expansion of the glass. Therefore, in order to smoothly perform the function as a glass modifier, the addition ratio should be increased, but when the addition ratio is too high, it is difficult to vitrify, so it is preferably added at 5 to 17 wt%.

Na ₂ O acts as a glass modifier and can control the firing temperature by lowering the transition point of the glass, increasing the dielectric constant and increasing the coefficient of thermal expansion. However, if the addition ratio is too high, the glass transition temperature may be drastically lowered, and the thermal expansion coefficient may increase, which may hinder stability, so it is preferably added at 1 to 3% by weight.

SiO ₂ acts as a glass former and is excellent in many respects such as increasing chemical durability, heat resistance and thermal shock resistance and decreasing thermal expansion coefficient as SiO ₂ is added, but as the addition ratio increases, the glass transition point increases proportionally. It is preferable to add 0.5 to 2.5% by weight since it is difficult to fire at low temperature.

Al ₂ O ₃ has the effect of widening the range of vitrification and enhancing the chemical stability of the glass. When the addition ratio is low, Al ₂ O ₃ crystallization occurs due to a decrease in glass stability, and when the ratio is high, the Al ₂ O ₃ is preferably 0.5 to 5% by weight because it lowers the coefficient of thermal expansion.

It is preferable that the softening point of a mother glass is 440 degreeC or less. If the softening point of the mother glass is high, low temperature sealing is difficult. Furthermore, when the ceramic filler is added, the transition point and softening point of the entire lead-free frit composition are increased, so that the transition point of the mother glass is preferably 340 to 410 ° C, and the softening point is 360 to 440 ° C.

Next, the composition, composition ratio, and the characteristics of the ceramic filler will be described.

The ceramic filler is used together with the mother glass to increase the thermal stability effect of the bismuth (Bi ₂ O ₃ ) -based sealing material because the coefficient of thermal expansion is small in the range of 10 to 30 × 10 ^-7 / ℃ at room temperature to 350 ℃, 5-30 parts by weight based on 100 parts by weight of the mother glass is added. If the ceramic filler is less than 5 parts by weight with respect to 100 parts by weight of the mother glass, the coefficient of thermal expansion is high, and cracks may occur in the sealing part when a strong thermal shock is applied. It is because when it is higher than 30 weight part, fluidity | liquidity may fall and the airtightness of the sealing part at the time of sealing may fall.

Ceramic fillers include zircon (ZrO ₂ · SiO ₂ ), eucryptite, alumina (Al ₂ O ₃ ), cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ , Cordierite ), At least one selected from the group consisting of zinc compounds.

Particularly, crystals containing cordierite as the main crystal have a good affinity with bismuth (Bi ₂ O ₃ ) -based glass, so that the ceramic filler is dissolved in the glass in the sealing process, and bismuth (Bi ₂ O ₃₎ It is suitable because not only the effect of improving the thermal stability of the) -based sealing material is large, but also crystals containing Bi ₂ O ₃ as components in the sealing step are not precipitated.

On the other hand, the lead-free paste composition for sealing the plasma display panel exhaust pipe according to the present invention for solving the above problems is added in an amount of 1 to 20 parts by weight based on 100 parts by weight of the lead-free frit composition for sealing the plasma display panel exhaust pipe, It includes a vehicle in which a solvent is mixed. Here, the vehicle refers to a mixture of an organic binder for binding a lead-free frit and a solvent for dispersing the organic binder.

If the vehicle has an addition ratio of more than 20 parts by weight with respect to 100 parts by weight of the lead-free frit composition, the coating height of the lead-free frit composition, which is an encapsulation material that is changed to glass upon plasticization due to increased fluidity, is lowered, resulting in a decrease in airtightness and lead-free paste in the exhaust pipe. When dispensing the composition (dispensing) the shape does not come out properly, the workability may be lowered, if lower than 1 part by weight, the stability of the entire lead-free paste composition is lowered, difficult to quantitative discharge by the dispensing method is difficult to seal Can be.

The organic binder serves to disperse and bind the lead-free frit composition in a powder state and to adjust viscosity.

 The organic binder is 15 to 20% by weight, preferably 18% by weight, and the solvent is 80 to 85% by weight and preferably 82% by weight. The reason is that the organic binder does not properly function as the vehicle because the organic binder does not have the properties of the vehicle itself that can maintain the lead-free paste composition in a uniform shape if the weight is less than 15% by weight. This is because when the content is more than% by weight, many organic binders are present in the lead-free paste composition, and therefore, even after calcination, a small amount of the organic binder may be present in the lead-free paste composition, which may cause contamination in the plasma display panel manufacturing process.

The organic binder is an acrylic resin-based polymer, and if the viscosity is too low (less than 500 cps), the binder polymer content in the sealing paste composition should be adjusted to control the flow characteristics. If the viscosity is too high (3000 cps), bubbles are generated on the sealing surface. Alternatively, since the amount of gas in the binder polymer is increased after the calcination process, a problem may occur in the degassing gas during the exhaust process, it is preferable to have a viscosity in the range of 500 to 3000 cps in consideration of various physical properties such as thermal stability and bubble generation. Do.

The solvent serves to dissolve the binder polymer to maintain a paste state of a certain viscosity. Preferred examples of the solvent are butyl carbitol acetate (Buthyl Carbitol Acetate), it is preferably at least one selected from the group consisting of alpha terpineol (α-Terpineol).

The lead-free paste composition for sealing the plasma display panel exhaust pipe may further include at least one pigment selected from the group consisting of P-4300 and P-433 (trade names of Shinceramics Co., Ltd.) for coloring the sealing portion. May be 0.1 to 4 parts by weight based on 100 parts by weight of the lead-free frit composition.

Since the pigment serves to attract oil, it should be added within a range that does not affect the physical properties of the lead-free paste composition itself. The reason is that if the pigment is less than 0.1 parts by weight with respect to 100 parts by weight of the lead-free frit composition, the color is too light and the color change is severe even with slight changes of the lead-free paste composition. If it is more than 4 parts by weight, the physical properties of the lead-free paste composition itself are affected. Because it is going crazy.

Hereinafter, the present invention through the preferred embodiment of the present invention will be described in more detail through [Table 1]. However, the following examples are merely to help the understanding of the present invention, the scope of the present invention is not limited only to the following examples.

Table 1, are compared to the embodiment of the lead-free frit compositions in accordance with the invention examples.

Classification (wt%) Example Comparative Example One 2 3 4 5 6 One 2 3 4 5 Parent glass (wt%) Bi ₂ O ₃ 60 65 70 74 77 80 44.4 41.5 30 8.7 38.5 B ₂ O ₃ 20 15 12 10 9 5 20.4 17 13.8 18.4 23 ZnO 15 17 15 13 10 5 33.4 36 38.5 36.6 27.5 BaO 0.5 5 11.9 19.3 2 CaO 3.4 Fe ₂ O ₃ One 0.7 Cu ₂ O 0.5 5 Na ₂ O 3 One One 2 2 2.5 3.9 SiO ₂ One One One 0.5 One 2.5 2.4 10.6 3.3 Al ₂ O ₃ One One One 0.5 One 5 1.2 0.5 Filler (wt%) Cordie-rite 11 11 11 11 11 11 10 30 Transition point 438 427 407 381 384 376 440 456 450 Softening point 472 464 437 419 417 410 420 562 445 CTE (× 10 ^-7 / ℃) 62.8 64.9 65.5 71.6 70.8 74.2 85 73 78 68.9

Comparative Example 1 is a registered Patent No. 10-0653408 described in the background art, Comparative Example 2 is a registered Patent 10-0782160, Comparative Example 3 is a Patent Publication 10-2008-0003676, Comparative Example 4 is a Patent Publication 10-06. 2006-0093506, and Comparative Example 5 are published Patent Publication No. 10-2008-0085070.

Compared to Examples 1 to 6 and Comparative Examples of the present invention, Examples 1 to 6 are all lower or similar to the comparative examples at 340 to 440 ° C and 400 to 480 ° C, respectively, of the transition point and softening point of the lead-free frit composition. It can be seen that low temperature sealing is possible. Further, in Examples 1 to 6, the thermal expansion coefficient of the lead-free frit composition is about 8 × 10 ⁻⁷ / ° C. to 20 × than the thermal expansion coefficient of the rear substrate of the plasma display panel from 80 × 10 ⁻⁷ / ° C. to 83 × 10 ⁻⁷ / ° C. 10 ^-7 / ℃ small 60 × 10 ^-7 / ℃ to 75 × 10 ^-7 / ℃, but to find out the condition satisfaction range, in Comparative examples are Comparative example 3 (Comparative example 3 but the low-temperature sealing requirements are so high that the softening point Except that the thermal expansion coefficient condition is not satisfied.

Particularly, Examples 4 to 6 were prepared because the transition point and softening point of the mother glass were 376 to 384 ° C. and 410 to 419 ° C., respectively, which are much lower than those of the comparative examples, thus enabling low temperature sealing at a lower temperature. In addition to good efficiency, the coefficient of thermal expansion of the lead-free frit composition is more preferably from about 9 × 10 ⁻⁷ / ° C. to about 80 × 10 ⁻⁷ / ° C. to 83 × 10 ⁻⁷ / ° C. of the rear substrate of the plasma display panel. It can be seen that it is 11 × 10 ⁻⁷ / ° C., which is 69 × 10 ⁻⁷ / ° C. to 74 × 10 ⁻⁷ / ° C.

Hereinafter, the drawings that are not mentioned in the accompanying drawings will be described.

Figure 3 is a photograph of the sealing of the two exhaust pipes using the lead-free frit composition according to Example 5 of the present invention to measure the tensile strength of the sealing portion, Figure 4 is a tensile test report of the sealing portion of FIG.

As can be seen from the tensile test report, the tensile breakdown load of the seal portion or the bond portion is 181 N, which is clearly understood by those skilled in the art that it is superior to other third-party products using conventional lead-free frit compositions in the market. That's a number.

FIG. 5 is a photograph of a portion of an actual plasma display panel and an exhaust pipe that are mutually sealed using the lead-free frit composition according to the fifth embodiment of the present invention to measure the tensile strength of the sealing portion, and FIG. 6 is a tensile force of the sealing portion of FIG. 5. It is a photograph showing the fracture surface after the test, Figure 7 is a tensile test report of the sealing portion of Figs.

As can be seen from the tensile test report, the tensile breakdown load of the seal portion or the bond portion is 176 N, which is clearly understood by those skilled in the art that it is superior to other third-party products using conventional lead-free frit compositions on the market. That's a number.

FIG. 8 is a photograph of a portion of an actual plasma display panel and an exhaust pipe immersed in 4 ° C. ice water by using a lead-free frit composition according to a fifth embodiment of the present invention in order to perform a cold test of the sealing portion, and FIG. 9. A portion of the actual plasma display panel and the exhaust pipe which are sealed to each other by using the lead-free frit composition according to the fifth embodiment of the present invention in order to perform a negative cooling test are photographs immersed in 100 ° C water. As a result after the cold heat test of FIG. 9, a portion of the actual plasma display panel and the exhaust pipe which were mutually sealed using the lead-free frit composition according to Example 5 of the present invention were separated between 4 ° C. ice water of FIG. 8 and 100 ° C. breaking water of FIG. 9. Is a photograph showing that no cracks occurred in the sealing part even after immersion 10 times for 30 seconds.

As described above, the lead-free frit composition according to the embodiments of the present invention has a low transition point, a softening point, and the like so as to enable low temperature sealing without containing lead components harmful to the environment and the human body, and has excellent fluidity and problems such as crystallization even at low temperatures. It can be seen that the bismuth (Bi ₂ O ₃ ) -based sealing material having excellent thermal stability and excellent sealing strength and excellent reliability and durability after sealing the exhaust pipe.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a graph showing a thermal expansion coefficient analysis results of the lead-free frit composition according to Example 5 of the present invention,

Figure 2 is a graph showing the XRD analysis of the ceramic filler of the lead-free frit composition according to Example 5 of the present invention,

FIG. 3 is a photograph of mutual sealing of two exhaust pipes using a lead-free frit composition according to Example 5 of the present invention to measure the tensile strength of the sealing portion;

4 is a tensile test report of the sealing portion of FIG.

FIG. 5 is a photograph of a portion of an actual plasma display panel and an exhaust pipe sealed together using a lead-free frit composition according to Embodiment 5 of the present invention to measure the tensile strength of the sealed portion;

Figure 6 is a photograph showing the fracture surface after the tensile force test for the sealing of Figure 5,

7 is a tensile test report of the sealing portion of Figure 5 and 6,

FIG. 8 is a photograph of a portion of an actual plasma display panel and an exhaust pipe immersed in 4 ° C. ice water by using a lead-free frit composition according to Example 5 of the present invention to perform a cold test of the sealed portion.

9 is a photograph of a portion of an actual plasma display panel and an exhaust pipe immersed in 100 ° C. water, which are sealed to each other by using the lead-free frit composition according to Example 5 of the present invention to perform a cold test of the sealing portion, and

FIG. 10 shows a part of an actual plasma display panel and an exhaust pipe which are sealed to each other by using the lead-free frit composition according to the fifth embodiment of the present invention as a result of the cold heat test of FIGS. 8 and 9. The photograph shows that no cracks occurred in the sealing part even after reciprocating immersion 10 times for 30 seconds between 100 ℃ of the water.

Claims (9)

74 to 77 wt% Bi ₂ O ₃ , 9 to 10 wt% B ₂ O ₃ , 10 to 13 wt% ZnO, 1.5 to 2.5 wt% Na ₂ O, 0.5 to 1 wt% SiO _{2 and} 0.5 to Al ₂ O ₃ Mother glass comprising 1% by weight, and 5 to 30 parts by weight of a ceramic filler added to 100 parts by weight of the mother glass Lead-free frit composition for sealing the plasma display panel exhaust pipe comprising a. In claim 1, The ceramic filler is selected from the group consisting of zircon (ZrO ₂ · SiO ₂ ), eucryptite (Eucryptite), alumina (Al ₂ O ₃ ), cordierite (2MgO · 2Al ₂ O ₃ · 5SiO ₂ ), zinc compounds Lead-free frit composition for sealing at least one plasma display panel exhaust pipe. In claim 1, The lead-free frit composition is a lead-free frit composition for sealing a plasma display panel exhaust pipe having an average thermal expansion coefficient of 60 × 10 ^-7 / ℃ to 75 × 10 ^-7 / ℃ at 50 ℃ to 300 ℃ after firing. In claim 1, The thermal expansion coefficient of the lead-free frit composition is 8 × 10 ^-7 / ℃ to 20 × 10 ^-7 / ℃ smaller than the thermal expansion coefficient of the plasma display panel is a sealed lead-free frit composition for sealing the exhaust pipe. In claim 1, The transition point of the lead-free frit composition is 340 to 440 ℃, the softening point is 400 to 480 ℃ lead-free frit composition for sealing the plasma display panel exhaust pipe. A lead-free frit composition for sealing the plasma display panel exhaust pipe of any one of claims 1 to 5, and A vehicle in which 1 to 20 parts by weight is added to 100 parts by weight of the lead-free frit composition, and an organic binder and a solvent are mixed. Lead-free paste composition for sealing a plasma display panel exhaust pipe comprising a. In claim 6, The organic binder is an acrylic resin polymer, The organic binder is 15 to 20% by weight, the solvent is 80 to 85% by weight lead-free paste composition for sealing a plasma display panel exhaust pipe. In claim 6, The solvent is butyl carbitol acetate (Buthyl Carbitol Acetate), alpha terpineol (α-Terpineol) lead-free paste composition for sealing a plasma display panel exhaust pipe is at least one selected from the group consisting of. In claim 6, The lead-free paste composition for sealing the plasma display panel exhaust pipe Lead-free paste composition for sealing the plasma display panel exhaust pipe further comprises a pigment added in 0.1 to 4 parts by weight based on 100 parts by weight of the lead-free frit composition for sealing the plasma display panel exhaust pipe.

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