KR20160035653A - Sealeant for vacuum window with excellent sealing performance and durability and vacuum window including the same - Google Patents

Abstract

The present invention discloses a lead-free sealant for a vacuum window having excellent sealing property and durability which causes no environmental contamination by virtue of the lack of lead (Pb), is used as a sealing finishing material for a vacuum widow with a dispensing process and prevents a sucking phenomenon by virtue of high viscosity at high temperature during vacuum molding, as well as a vacuum window using the same. The vacuum window having excellent sealing property and durability includes: a first vacuum glass sheet having a vacuum vent penetrating through the edge at one side; a second vacuum glass sheet spaced apart from the first vacuum glass sheet to face each other; a spacer interposed between the first and the second glass sheets to maintain the space therebetween; a cap sealing material for sealing the vacuum vent of the first vacuum glass sheet; and a lead-free sealant sealed along the outermost edges of the first or second vacuum glass sheet through a dispensing process so that the first and the second vacuum glass sheets may be laminated with each other. The lead-free sealant comprises 70-80 wt% of Bi_2O_3, 5-10 wt% of B_2O_3, 0.1-5.0 wt% of ZnO and 5-10 wt% of BaO.

Description

TECHNICAL FIELD [0001] The present invention relates to a lead-free sealant for a vacuum window having excellent sealability and durability, and a vacuum window for the vacuum window,

The present invention relates to a lead-free sealant for a vacuum window, and more particularly to a lead-free sealant for a vacuum window, which does not contain lead (Pb) and is free from environmental pollution, To a lead-free sealant for a vacuum window, which is excellent in sealing property and durability, which can prevent the phenomenon of sucking due to high viscosity at the time of vacuum formation.

In buildings, mining and vista are basic requirements to be involved in human happiness, but among the various materials of window architecture, more than 35% of the total energy loss of the house is occupied in terms of energy saving, and more than 60% is occupied in some buildings.

Especially, in recent years, efforts are being made to reduce the amount of freon gas, carbon dioxide, and the like worldwide, and various environmental regulations and energy saving are becoming more important.

In most countries of Europe, the heat transfer rate of windows is controlled by a much stronger standard than that of Korea due to the relatively low thermal insulation performance and the disadvantage of the cooling load due to the nature of the transparent material compared to the airtight wall. In this case, countries that rely on imports for more than 98% of their total energy can save a national budget of more than $ 5 billion a year, saving only 10% of energy, saving 7% can do.

Thus, for typical building windows, building energy can be saved by approximately 20-30% even if the heat conduction rate is reduced from approximately 3.0W / ㎡ · k to 1.5W / ㎡ · k only.

FIG. 1 is a view for explaining a sealant fading phenomenon of a vacuum window according to the related art, and FIG. 2 is a photograph of the sealant of FIG. 1 taken by a scanning electron microscope.

Referring to FIGS. 1 and 2, in the case of the conventional vacuum window 1, the use of a sealant containing lead (Pb), which is an environmentally harmful substance, is constrained in use. Accordingly, efforts have been actively made to replace the lead-free sealant 30 that does not contain lead (Pb), and the lead-free sealant 30 is used in manufacturing a panel of a flat panel display.

In recent years, attempts have been made to fabricate the vacuum window 1 by using the lead-free sealant 30 used in manufacturing the panel of the flat panel display. The conventional vacuum window 1 is formed by applying a lead-free sealant 30 along the outermost edges of the upper and lower vacuum glasses 10 and 20 and then sealing the upper and lower vacuum glasses 10 and 20 by vacuum firing, Respectively.

However, since the lead-free sealant 30 used in the manufacture of the flat panel display panel as in the prior art is not easy for high vacuum, when the vacuum window 1 is applied, the lead-free sealant 30 sucked into the vacuum- In addition, in the case of a severe case, a channel is formed due to bubbles due to external bubbles, so that a vacuum window can not be performed. do.

A related prior art is Korean Patent Laid-Open Publication No. 10-2009-0036709 (published on Apr. 15, 2009), which discloses a vacuum window glass and a manufacturing method thereof.

The object of the present invention is to provide a method for manufacturing a vacuum window which is free of lead (Pb) and which is free from environmental pollution and is used as a sealing finish of a vacuum window by applying a dispensing method, The present invention also provides a lead-free sealant for a vacuum window which is excellent in sealing properties and durability that can be prevented from being deteriorated.

In order to achieve the above object, the lead-free sealant for a vacuum window according to the present invention has excellent sealing and durability, comprising 70 to 80 wt% of Bi ₂ O ₃ , 5 to 10 wt% of B ₂ O ₃ , 0.1 to 5.0 wt% of ZnO, wt% and BaO: 5 to 10 wt%.

According to an aspect of the present invention, there is provided a vacuum window having an excellent sealing performance and durability, including: a first vacuum glass having a vacuum outlet passing through one side edge; A second vacuum glass spaced apart from the first vacuum glass so as to face the first vacuum glass; A spacer inserted in a spaced-apart space between the first and second vacuum glasses to maintain a gap between the first and second vacuum glasses; A cap encapsulant for sealing the vacuum exhaust port of the first vacuum glass; And a lead-free sealing material sealed by a dispensing method along an outermost edge of the first or second vacuum glass to adhere the first and second vacuum glass, wherein the lead-free sealing material comprises Bi ₂ O ₃ : , B ₂ O ₃ : 5 to 10 wt%, ZnO: 0.1 to 5.0 wt%, and BaO: 5 to 10 wt%.

The lead-free sealant for vacuum window liners and its vacuum windows, which are excellent in sealing properties and durability according to the present invention, are designed not to add lead (Pb), which is an environmental regulating material, but to design an optimum component system mainly composed of Bi ₂ O ₃ , There is no fear of contamination, and as a sealing finish material of a vacuum window by applying a dispensing method, a high temperature viscosity is high when vacuum firing is performed, so that the sealing phenomenon can be suppressed and the sealing property and durability can be improved.

1 is a view for explaining a sealant abatement phenomenon of a vacuum window according to a related art.
Fig. 2 is a photograph of the sealant of Fig. 1 taken by a scanning electron microscope.
3 is a cross-sectional view illustrating a vacuum window according to an embodiment of the present invention.
4 is a view for explaining a process of manufacturing the lead-free sealant of FIG. 3 by the dispensing method.
5 is a photograph showing a crystallization image after the first firing and the second firing according to Example 1. Fig.
Fig. 6 is a photograph of a flow butt after the first predetermined and second firing according to Example 1. Fig.
7 is a graph showing the temperature-shrinkage ratio relationship for Examples 1 and 2 and Comparative Examples 1 to 4;
8 is a graph showing the temperature-viscosity relationship for Example 1 and Comparative Example 2. Fig.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lead-free sealant and a vacuum window for a vacuum window according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Lead-free sealant for vacuum windows

Since lead-free sealant for vacuum window according to the embodiment of the present invention is free from lead (Pb), there is no fear of environmental pollution, and it is utilized as a sealing finish material of vacuum window by applying dispensing method, It is possible to prevent the phenomenon of sucking due to high viscosity.

For this purpose, the lead-free solder for vacuum window according to the embodiment of the present invention may contain 70 to 80 wt% of Bi ₂ O ₃ , 5 to 10 wt% of B ₂ O ₃ , 0.1 to 5.0 wt% of ZnO and 5 to 10 wt% of BaO, .

Bi ₂ O ₃ is preferably added in an amount of 70 to 80 wt% of the total weight of the lead-free sealant for vacuum window according to the present invention. If the addition amount of Bi ₂ O ₃ is less than 70 wt%, the softening temperature becomes 500 ° C or higher, and it can not serve as a sealing material. On the other hand, when the addition amount of Bi ₂ O ₃ exceeds 80 wt%, the coefficient of thermal expansion becomes high and sealing becomes difficult.

B ₂ O ₃ is preferably added in an amount of 5 to 10 wt% of the total weight of the lead-free sealant for vacuum window according to the present invention. If the addition amount of B ₂ O ₃ is less than 5 wt%, there is a high possibility that the crystal phase will be precipitated. On the other hand, when the addition amount of B ₂ O ₃ is more than 10 wt%, the softening temperature exceeds 500 ° C, which makes it difficult to carry out low temperature sealing.

ZnO is preferably added in an amount of 0.1 to 5.0 wt% of the total weight of the lead-free sealant for vacuum window according to the present invention. When the addition amount of ZnO is less than 0.1 wt%, there is a problem that the thermal expansion coefficient increases and sealing becomes difficult. On the other hand, when the addition amount of ZnO is more than 5.0 wt%, there is a problem that the crystal phase precipitates and sealing becomes difficult, and the sealing and durability of the vacuum window deteriorate.

BaO is preferably added in an amount of 5 to 10 wt% of the total weight of the lead-free sealant for vacuum window according to the present invention. When the addition amount of BaO is less than 5 wt%, it may be difficult to properly exhibit the glass stabilizing function. On the other hand, when the addition amount of BaO exceeds 10 wt%, the crystal phase precipitates and the glass transition temperature and softening point increase.

Further, the lead-free sealant for vacuum window according to the embodiment of the present invention may further include at least one of CO ₃ O ₄ , NiO, CuO, CeO ₂ , Fe ₂ O ₃ and ZrO ₂ , It is preferably added in an amount of 0.1 to 5 wt% of the total weight of the lead-free lead-free sealant. These metal oxides are added for the purpose of lowering the softening point and improving the stability of the glass. If the addition amount is less than 0.1 wt%, the above-mentioned effect of addition can not be exhibited properly. On the contrary, if the addition amount exceeds 5 wt% , Crystallization is induced and the function of the sealing material can not be exhibited.

The lead-free sealant for vacuum window according to the embodiment of the present invention may further include a ceramic filler. At this time, the ceramic filler is selected from among cordierite, eucryptite, aluminum titanate, zircon, spodumene, willemite and mulite. Or more species.

Particularly, the lead-free solder for vacuum window according to the embodiment of the present invention has a softening point (Ts) of 500 ° C or less, and when the softening point of the lead-free sealant exceeds 500 ° C, the low temperature sealing is practically difficult. Of course, the filler can be added to allow low-temperature sealing, but if the filler is put in an excessive amount, the fluidity of the sealant becomes poor, and there is a high possibility that the sealability and durability of the vacuum window after sealing are lowered. The softening point is preferably 500 캜 or lower.

The lead-free solder for vacuum window according to the embodiment of the present invention preferably has a viscosity of at least 6 g / cm.sup.2 at a temperature of 500.degree. C. or less. This is because the air is drawn from the inside of the vacuum window using a dispensing technique, The high temperature viscosity of the lead-free sealant should be high enough to prevent the lead-free sealant from being sucked in.

Vacuum window

FIG. 3 is a cross-sectional view illustrating a vacuum window according to an embodiment of the present invention, and FIG. 4 is a view illustrating a process of manufacturing the lead-free sealant of FIG. 3 by a dispensing method.

3 and 4, the vacuum window 100 having excellent sealing property and durability according to the embodiment of the present invention includes a first vacuum glass 110, a second vacuum glass 120, a spacer 130, A cap sealing material 140, and a lead-free sealing material 150.

The first vacuum glass 110 has a vacuum exhaust port passing through one side edge thereof and the second vacuum glass 120 is disposed so as to face the first vacuum glass 110. The first and second vacuum glasses 110 and 120 may have a plate shape and may be designed to have the same area, but the present invention is not limited thereto, and the shapes and areas of the first and second vacuum glasses 110 and 120 may be different from each other Do. Preferably, the first vacuum glass 110 has a vacuum degree of 5.0 x 10 ^-4 torr to 6.0 x 10 ^-4 torr, and the second vacuum glass 120 uses a low-E glass Is preferably used.

The spacers 130 are inserted into spaces between the first and second vacuum glasses 110 and 120 to maintain a gap between the first and second vacuum glasses 110 and 120. At this time, it is preferable that the spacers 130 are arranged in a matrix arrangement in a plan view. This is because the thickness deviation of the first and second vacuum glasses 110 and 120 at the edge portion and the central portion is It is to minimize.

The cap sealing material 140 is formed for sealing the vacuum exhaust port of the first vacuum glass 110. The cap sealing material 140 is formed so as to cover the vacuum exhaust port, thereby sealing the vacuum exhaust port of the first vacuum glass 110. At this time, the vacuum exhaust port is formed for the purpose of extracting air so that the empty space between the first and second vacuum glasses 110 and 120 is vacuumed by the first and second vacuum glasses 110 and 120 being attached to each other And may be mounted on one side edge of the first vacuum glass 110, but the present invention is not limited thereto.

The lead-free sealing material 150 is sealed by the dispensing method along the outermost edges of the first vacuum glass 110 or the second vacuum glass 120 to thereby adhere the first and second vacuum glasses 110 and 120 . At this time, since the lead (Pb) is not added to the lead-free sealing material 150, as described above, there is no fear of environmental pollution, and the lead-free sealing material 150 is applied to the sealing finish material of the vacuum window 100 The high temperature viscosity at the time of vacuum firing is high, so that the fading phenomenon can be prevented in advance.

To this end, the lead-free sealing material 150 may include 70 to 80 wt% of Bi ₂ O ₃ , 5 to 10 wt% of B ₂ O ₃ , 0.1 to 5.0 wt% of ZnO, and 5 to 10 wt% of BaO.

At this time, the lead-free sealing material having the above composition is coated on the second vacuum glass 120 by the dispensing method using the dispenser 200 by a scanning method and then cured, 1 and the second vacuum glass 110, 120, respectively. As described above, when the lead-free sealant composition 150a is applied by the dispensing method, not only the time and cost can be shortened, but also it becomes possible to perform the process in an automated manner.

The lead-free sealant composition (150a) having the above composition does not contain lead (Pb) and has a high high-temperature viscosity and low temperature shrinkage ratio. Therefore, no bubbles are generated even after vacuum firing, The phenomenon of being sucked into the inside of the two vacuum glasses 110 and 120 is suppressed, and the sealing property and the durability are improved.

At this time, the lead-free sealing material 150 preferably has a softening point Ts of 500 ° C or less. If the softening point of the lead-free sealing material 150 exceeds 500 ° C, the low temperature sealing is practically difficult. Of course, the filler may be added to allow low-temperature sealing. However, if the filler is put in an excessive amount, the fluidity of the lead-free sealing material 150 becomes poor, and there is a high possibility that the sealing and durability of the vacuum window after sealing are lowered. The softening point of the lead-free sealing material 150 is preferably 500 ° C or less. The lead-free sealing material 150 preferably has a viscosity of not less than 6 g / cm <"> s at 500 DEG C or less. When the air is drawn from the inside of the vacuum window 100 using a dispensing technique, This is because the high temperature viscosity of the sealing material 150 can prevent the phenomenon that the lead-free sealing material 150 is sucked into the inside.

The vacuum window having excellent sealing and durability according to the embodiment of the present invention described above is designed not to add lead (Pb) which is an environmental regulation material, but to design an optimum component system using Bi ₂ O ₃ as a main component, It is possible to improve the sealing property and durability by suppressing the sucking phenomenon due to high viscosity at the time of vacuum firing by applying the dispensing method as a sealing finishing material of vacuum window.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail with reference to preferred embodiments of the present invention. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

The contents not described here are sufficiently technically inferior to those skilled in the art, and a description thereof will be omitted.

1. Manufacture of lead-free sealant

Weighed to have the composition shown in Table 1, put in an alumina crucible, melted in an electric furnace and quenched to prepare a lead-free sealant according to Examples 1 to 2 and Comparative Examples 1 to 4. Then, the glass transition temperature, softening point and thermal expansion coefficient were measured by differential thermal analysis (DTA) measurement of the lead-free sealant according to Examples 1 to 2 and Comparative Examples 1 to 4.

[Table 1] (% by weight)

2. Property evaluation

Table 2 shows the results of physical property evaluation for lead-free sealant according to Examples 1 to 2 and Comparative Examples 1 to 4. 5 is a photograph showing a crystallization image after primary firing and secondary firing according to Example 1, and Fig. 6 is a photograph showing a flow butt after primary firing and secondary firing according to Example 1. Fig.

[Table 2]

As shown in Tables 1 and 2, it can be seen that the glass transition temperature and softening point of Examples 1 and 2 were lower than those of Comparative Examples 1 to 4. Further, in Examples 1 and 2, the thermal expansion coefficient was measured to be 78.37 x 10 ^-7 / K and 79.26 x 10 ^-7 / K, respectively, which are lower than those of Comparative Examples 1 to 4.

As shown in FIGS. 5 and 6, a flow button test was conducted. As a result, in Example 1, And it was confirmed that no crystal precipitation occurred at 500 ° C after the first and second firing.

7 is a graph showing the temperature-shrinkage ratio relationships for Examples 1 and 2 and Comparative Examples 1 to 4.

7, in the case of Comparative Examples 1 to 4 {(c), (d), (e) and (f)}, the shrinkage rate decreases linearly up to a temperature of 350 to 450 ° C., Lt; RTI ID = 0.0 > C, < / RTI > On the other hand, in the case of Examples 1 and 2 {(a) and (b)}, compared with Comparative Examples 1 to 4 {(c), (d), (e) It can be confirmed that the shrinkage ratio is not greatly changed.

Therefore, in Examples 1 and 2 {(a) and (b)}, the shrinkage rate is low even in the temperature range of about 450 to 500 ° C. Thus, it is believed that the vacuum phenomenon do.

8 is a graph showing the temperature-viscosity relationship for Example 1 and Comparative Example 2. Fig.

As shown in FIG. 8, in the case of Example 1 and Comparative Example 2, the viscosity decreases linearly as the temperature increases. However, the viscosity curve of Example 1 is higher than that of Comparative Example 2, . In particular, it was confirmed that the overall viscosity curve was upward as the thermal characteristic Ts of the Example 1 was increased by about 5 占 폚 as compared with the Comparative Example 2.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. These changes and modifications may be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

100: vacuum window 110: first vacuum glass
120: second vacuum glass 130: spacer
140: cap sealing agent 150: lead-free sealing material
200: Dispenser

Claims (10)

Bi ₂ O ₃ : 70 to 80 wt%
B ₂ O ₃ : 5 to 10 wt%
0.1 to 5.0 wt% of ZnO and
And BaO: 5 to 10 wt% based on the total weight of the unvulcanized sealant.
The method according to claim 1,
The lead-
Wherein at least one of CO ₃ O ₄ , NiO, CuO, CeO ₂ , Fe ₂ O ₃ and ZrO ₂ is further added in an amount of 0.1 to 5 wt%.
The method according to claim 1,
The lead-
A ceramic filler is further added,
The ceramic filler is selected from the group consisting of cordierite, eucryptite, aluminum titanate, zircon, spodumene, willemite and mulite. Or more of the total weight of the unvulcanized sealant for vacuum window.
The method according to claim 1,
The lead-
And has a softening point (Ts) of 500 DEG C or less, which is excellent in sealing property and durability.
The method according to claim 1,
The lead-
And has a viscosity of at least 6 g / cm.sup.2 at 500.degree. C. or lower.
A first vacuum glass having a vacuum outlet through one side edge thereof;
A second vacuum glass spaced apart from the first vacuum glass so as to face the first vacuum glass;
A spacer inserted in a spaced-apart space between the first and second vacuum glasses to maintain a gap between the first and second vacuum glasses;
A cap encapsulant for sealing the vacuum exhaust port of the first vacuum glass; And
And a lead-free sealing material sealed along a outermost edge of the first or second vacuum glass for dispensing the first and second vacuum glasses,
Wherein the lead-free sealing material comprises 70 to 80 wt% of Bi ₂ O ₃ , 5 to 10 wt% of B ₂ O ₃ , 0.1 to 5.0 wt% of ZnO, and 5 to 10 wt% of BaO. Excellent vacuum window.
The method according to claim 6,
The first vacuum glass
And a vacuum degree of 5.0 × 10 ^-4 torr to 6.0 × 10 ^-4 torr, which is excellent in sealing property and durability.
The method according to claim 6,
The second vacuum glass
And a low-E glass. The vacuum window is excellent in sealing property and durability.
The method according to claim 6,
The lead-
A vacuum window excellent in sealing property and durability, characterized in that a lead-free sealing material composition is applied by a dispensing method using a dispenser and then sealed by curing.
The method according to claim 6,
The lead-
And has a softening point (Ts) of 500 deg. C or lower and a viscosity of 6 g / cm.sup.2 or higher at 500 deg. C or lower.

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