KR102234679B1 - Lead-free low temperature calcined glass frit suitable for strengthened glass, paste and vacuum glass assembly using the same - Google Patents

Abstract

The present invention relates to a lead-free low-temperature firing glass frit, a paste, and a vacuum glass assembly using the same.
By having a glass composition containing an appropriate amount of V ₂ O ₅ , TeO ₂ , CuO, BaO, ZnO, Ag ₂ O and Bi ₂ O ₃ and a new component system including inorganic fillers, replacing the conventional flexible glass composition and 350 ℃ There is an effect capable of firing at the following low temperature.

Description

Lead-free low temperature firing glass frit suitable for tempered glass, paste, and vacuum glass assembly using the same {LEAD-FREE LOW TEMPERATURE CALCINED GLASS FRIT SUITABLE FOR STRENGTHENED GLASS, PASTE AND VACUUM GLASS ASSEMBLY USING THE SAME}

The present invention relates to a lead-free low-temperature firing glass frit, a paste, and a vacuum glass assembly using the same.

In a glass window, a home appliance, or an electric and electronic component such as a vacuum insulated multilayer glass panel, a display panel, and an organic EL display panel, sealing or bonding is performed by glass frit including a glass composition and inorganic ceramic particles. The sealing glass frit is generally applied in the form of a paste, and the glass paste is applied to glass using a screen printing method or a dispenser method, and then dried and fired to provide a sealing function.

_{Conventionally, a PbOB 2} O ₃ glass composition containing a very large amount of lead oxide has been widely applied. This PbOB ₂ O ₃ -based glass composition had a softening point of approximately 400 to 450°C, exhibiting good softening fluidity and relatively high chemical stability.

However, in recent years, the trend of design considering the environment in the world has become stronger, and safer materials are required. In Europe, for example, a directive by the European Union (RoHS directive) on the restriction of the use of certain hazardous substances in electronic and electrical equipment came into force on July 1, 2006. In the RoHS Directive, a total of six substances, including lead, have been designated as prohibited substances.

Since the PbOB ₂ O ₃ -based glass composition contains a lot of lead, which is designated as a prohibited substance under the RoHS directive, it has become difficult to use it as a sealing glass paste. Accordingly, there has been a demand for the development of a novel glass composition that does not contain lead. In addition, in order to reduce thermal damage and improve productivity of various glass sealing parts or electrical and electronic parts, the development of lead-free glass compositions capable of softening flow at a lower temperature than _{PbOB 2} O _{3 based glass compositions and having good chemical stability is also strongly developed.} The situation is being demanded.

According to the demand for a lead-free glass composition, as a lead-free glass composition that does not contain lead and can be fired at a relatively low temperature, an Ag ₂ OV ₂ O ₅ TeO _{2 lead-free glass composition is known.}

However, the conventional Ag ₂ OV ₂ O ₅ TeO ₂ glass composition has a problem in that a good softening fluidity cannot be obtained due to an increased tendency to crystallize during firing.

In addition, when the conventional Ag ₂ OV ₂ O ₅ TeO ₂ based lead-free glass composition is applied to tempered glass used in home appliances, etc., since the sintering process is performed at a temperature of at least 350° C. or higher, the problem of the tempered glass annealing occurs. have.

In addition, although the conventional Ag ₂ OV ₂ O ₅ TeO ₂ based lead-free glass composition can be fired at a low temperature, the coefficient of thermal expansion with the glass substrate is not matched, so that peeling or breakage may occur.

In addition, the conventional Ag ₂ OV ₂ O ₅ TeO ₂ lead-free glass composition does not use Pb, so chemical durability is weak, and thus there is a problem in that it can easily react with moisture.

An object of the present invention is to provide a new lead-free low-temperature fired glass frit capable of firing at a low temperature as a lead-free glass composition replacing the conventional lead-free glass composition.

In particular, an object of the present invention is to provide a new lead-free low-temperature calcined glass frit having a composition ratio having a low crystallization tendency even at low temperature firing as well as being able to fire at a low temperature.

In addition, an object of the present invention is to provide a lead-free low-temperature sintered glass frit having excellent durability without causing peeling or breakage due to matching coefficients of thermal expansion with a glass substrate even if sintering at low temperatures is possible.

Another object of the present invention is to provide a lead-free low-temperature calcined glass frit having excellent chemical durability such as durability against moisture.

In order to provide a new glass frit that can be fired at low temperature as a lead-free glass composition that replaces the conventional lead-free glass composition, the glass frit according to the present invention is V ₂ O ₅ 30-50 wt%, TeO ₂ 35-55 wt. %, CuO 0.5-5% by weight, BaO 1-5% by weight, ZnO 1-10% by weight, and a glass composition comprising 5-20% by weight of at least one of _{Ag 2} O and Bi ₂ O _3; And inorganic fillers.

In addition, in order to provide a glass frit having a low crystallization tendency even when firing at low temperature as well as being possible at low temperature, the glass frit according to the present invention may satisfy the following relational expression in terms of the content of _{V 2} O _{5 and the content of TeO 2.} .

[Relationship]

V ₂ O ₅ (% by weight)/TeO ₂ (% by weight) <1

In addition, in order to prevent the tempered glass loosening of the glass substrate, the glass frit according to the present invention may have a Half Ball temperature of 340° C. or less.

In addition, in order to provide a glass frit in which the glass substrate and the coefficient of thermal expansion are matched, the glass frit according to the present invention may have a coefficient of thermal expansion (CTE) after firing in ^{the range of 70 to 90 x 10 -7} /°C.

In addition, in order to provide a glass frit having excellent chemical durability such as moisture resistance, the glass frit according to the present invention further includes one or more _{of P 2} O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ can do.

The glass frit according to the present invention has _{a glass composition containing an appropriate amount of V 2} O ₅ , TeO ₂ , CuO, BaO, ZnO, Ag ₂ O and Bi ₂ O ₃ and a new component system including an inorganic filler. It replaces the glass composition and has the effect of sintering at a low temperature of 350° C. or less.

In addition, since the glass frit according to the present invention _{can have an optimum ratio of V 2} O ₅ and TeO ₂ , it is possible to sinter at a low temperature and has a low crystallization tendency even at low temperature sintering.

Furthermore, the glass frit according to the present invention may have a half ball temperature of 340° C. or less, thereby preventing the tempered glass from loosening of the glass substrate.

In addition, the glass frit according to the present invention may have a coefficient of thermal expansion (CTE) after firing in ^{the range of 70 to 90 x 10 -7} /°C, so that the coefficient of thermal expansion with the glass substrate is matched, so that peeling or breakage does not occur and durability is improved. It has an excellent effect.

In addition, the glass frit according to the present invention _{may further include one or more of P 2} O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ , and thus has excellent chemical durability such as durability against moisture.

The above-described objects, features, and advantages will be described later in detail, and accordingly, a person of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description will be omitted. Hereinafter, a preferred embodiment according to the present invention will be described in detail.

The present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, only this embodiment is to complete the disclosure of the present invention, and to those of ordinary skill in the entire scope of the invention. It is provided to inform you.

Hereinafter, a lead-free low-temperature fired glass frit, paste, and a vacuum glass assembly using the same according to the present invention will be described in detail.

<Lead-free low temperature firing glass frit>

Glass frit used as a sealing material generally improves fluidity at low temperatures when the temperature of physical properties such as glass transition point and softening point is low. Liquidity may deteriorate.

In addition, tempered glass used in home appliances needs to be applied in a low-temperature region (350° C. or less) because tempered glass unwinding may occur when a sealing process is applied at a high temperature. Therefore, the glass frit sealing material used in the sealing process must be sintered at low temperatures. In addition, it must be possible to sinter at low temperature and satisfy the appropriate softening fluidity.

Accordingly, the present inventors have completed a new glass frit that can be baked at a low temperature and has a low tendency to crystallization so that it can be applied to a sealing process of a tempered glass.

The glass frit according to the present invention is V ₂ O ₅ 30 to 50 wt%, TeO ₂ 35 to 55 wt%, CuO 0.5 to 5 wt%, BaO 1 to 5 wt%, ZnO 1 to 10 wt% and Ag ₂ O and A glass composition containing 5 to 20% by weight of at least one of Bi ₂ O _3; And inorganic fillers.

First, the glass composition contained in the glass frit of the present invention will be described.

V ₂ O ₅ has the effect of lowering the softening point while increasing the durability of the glass frit, so it is contained in the range of 30 to 50% by weight in the glass frit. When the V ₂ O ₅ exceeds 50% by weight, there is a problem in that sintering of the glass frit is liable to be difficult. If V ₂ O ₅ is less than 30% by weight, it is difficult to sufficiently exhibit the effect of lowering the softening point of the glass frit, and a problem may occur in the durability of the glass frit.

TeO ₂ has the effect of increasing the fluidity of the glass frit, and is contained in the range of 35 to 55% by weight in the glass frit. When TeO ₂ exceeds 55% by weight, it is difficult to sufficiently lower the softening point and may not be fired. If TeO ₂ is less than 35% by weight, it may be difficult to vitrify the glass frit according to the balance relationship with other components.

CuO is contained in the range of 1 to 5% by weight in order to match the coefficient of thermal expansion of the glass frit and satisfy the durability. When CuO exceeds 5% by weight, there may be a problem in that the fluidity of the glass frit is lowered. If CuO is less than 0.5% by weight, the required coefficient of thermal expansion of the glass frit may not be obtained.

BaO is contained in the range of 1 to 5% by weight to match the coefficient of thermal expansion of the glass frit and satisfy the durability. When CuO exceeds 5% by weight, there may be a problem in that the fluidity of the glass frit is lowered. If CuO is less than 1% by weight, the required coefficient of thermal expansion of the glass frit may not be obtained.

ZnO is contained in the range of 1 to 10% by weight in order to secure the fluidity of the glass frit and increase the chemical durability. When ZnO exceeds 10% by weight, it is difficult to match the coefficient of thermal expansion of the glass frit, and problems may occur in durability or fluidity. If the ZnO content is less than 1% by weight, it may be difficult to match the coefficient of thermal expansion of the glass frit, and a problem in that required physical properties may not be obtained may occur.

Ag ₂ O and Bi ₂ O ₃ serve to increase the durability of the glass frit and lower the crystallization tendency. The glass frit according to the present invention contains 5 to 20% by weight of at least one of _{Ag 2} O and Bi ₂ O _3. If at least one of Ag ₂ O and Bi ₂ O ₃ exceeds 30% by weight, the coefficient of thermal expansion may be lowered, but the sealing performance may be deteriorated. If at least one of Ag ₂ O and Bi ₂ O ₃ is less than 10% by weight, it may be difficult to match the coefficient of thermal expansion and a problem in that low temperature sintering may be difficult may occur.

In addition, the glass composition included in the glass frit of the present invention may further include one or more _{of P 2} O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO _{3. More preferably, at least one of P 2} O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ is 10 in order to match the thermal expansion coefficient of the glass frit with the thermal expansion coefficient of the glass substrate and increase the chemical durability of the glass frit. It may be included in the glass composition in weight% or less. If at least one of P ₂ O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ exceeds 10% by weight, it is rather difficult to match the coefficient of thermal expansion, and the chemical durability or fluidity of the glass frit may decrease.

Next, an inorganic filler included in the glass frit according to the present invention will be described.

The glass composition according to the present invention described above has a coefficient of thermal expansion of about 120 to 140 10 ^-7 / °C. In order to lower the coefficient of thermal expansion of the glass composition, the glass frit according to the present invention includes an inorganic filler.

The inorganic filler according to the present invention is a crystalline inorganic particle having a low coefficient of thermal expansion, specifically zirconium phosphate tungstate (Zr ₂ (WO ₄ ) (PO ₄ ) ₂ ), zirconium phosphate tungstate containing trace amounts of iron tungstate, In zirconium phosphate, quartz glass (Quartz glass SiO ₂ ), mullite (3Al ₂ O ₃ 2SiO ₂ ), zirconium silicate (ZrSiO ₄ ), zirconium, Li ₂ O-Al ₂ O ₃ -SiO ₂ and beta-eucryptite More than one type can be used. From the viewpoint of lowering the coefficient of thermal expansion of the glass composition according to the present invention, the inorganic filler is among zirconium phosphate tungstate (Zr ₂ (WO ₄ ) (PO ₄ ) ₂ ), zirconium phosphate tungstate and zirconium phosphate containing trace amounts of iron tungstate. It is preferable to use one or more.

In addition, in order to provide a glass frit having excellent thermal expansion coefficient matching and durability, the mixing ratio of the glass composition and the inorganic filler is preferably 9:1 to 7:3. When the ratio of the inorganic filler exceeds 30% of the total glass frit, the sealing performance of the glass frit may deteriorate, and a problem may occur in water resistance. On the other hand, if the ratio of the inorganic filler is less than 10% of the total glass frit, it may be difficult to match the coefficient of thermal expansion of the glass frit and low temperature firing may be difficult. As a most preferred embodiment, when the blending ratio of the glass composition and the inorganic filler is in the range of 8.5:1.5 to 7.5:2.5, the adhesive strength between the glass frit and the glass substrate is the most excellent.

_{In addition, V 2} O ₅ and TeO ₂ contained in the glass frit according to the present invention are preferably contained so as to satisfy the following relational expression in terms of plasticity stability related to crystallization tendency.

[Relationship]

V ₂ O ₅ (% by weight)/TeO ₂ (% by weight) <1

As _{the content of V 2} O ₅ increases, the glass transition point of the glass frit decreases, so that the sealing temperature may decrease, but at the same time, the crystallization tendency of the glass frit increases. Therefore, it is preferable to have an optimum ratio in relation to _{TeO 2.} Accordingly, the glass frit according to the present invention preferably has a ratio of _{V 2} O _{5 (% by weight) to TeO 2} (% by weight) is less than 1.

In addition, it is preferable that the glass frit according to the present invention has a coefficient of thermal expansion of 70 to 90 x 10 ^-7 /°C, particularly in terms of matching the coefficient of thermal expansion with the tempered glass substrate. Since the thermal window coefficient ^{falls within the range of 70 to 90 x 10 -7} /°C, the glass frit according to the present invention can reduce the occurrence of a decrease in adhesion, thereby improving sealing reliability.

In addition, it is preferable that the glass frit according to the present invention has a half ball temperature of 340° C. or less in order to prevent the tempered loosening of the glass substrate. The half ball temperature refers to the temperature at which the glass frit contracts to the maximum when heated at a heating rate of 10 °C/min and has a half ball shape. If the half ball temperature of the glass frit exceeds 340 °C, the glass frit must be fired at a temperature exceeding at least 350 °C, which may cause reinforcement annealing in the glass substrate.

<Glass frit paste>

Next, the glass frit paste according to the present invention includes 100 parts by weight of the aforementioned glass frit and 10 to 100 parts by weight of an organic vehicle.

When the organic vehicle is less than 20 parts by weight or exceeds 100 parts by weight, the viscosity of the paste may be too high or too low, making the application process difficult.

The organic vehicle may include an organic solvent and an organic binder. As the organic solvent, a solvent such as α-terpineol or butyl carbitol may be used, and ethyl cellulose may be used as the organic binder, but is not limited thereto.

<Vacuum glass assembly>

The vacuum glass assembly includes two or more glass substrates and means an assembly in which a vacuum is maintained between the two or more glass substrates. The vacuum glass assembly may be used in home appliances such as refrigerators, microwave ovens, washing machines, or electronic components of various electronic devices.

The glass frit according to the present invention may be used as a sealing material for the vacuum glass assembly.

In particular, the glass frit according to the present invention is preferably used in a vacuum glass assembly to which tempered glass is applied.

When the vacuum glass assembly to which the tempered glass is applied is exposed to a high-temperature heat treatment process such as a sealing process, tempered annealing may occur in the tempered glass. Accordingly, the vacuum glass assembly to which the tempered glass is applied has a problem that a heat treatment process cannot be applied at a high temperature.

However, when the glass frit paste according to the present invention is applied as a sealing material, a sealing process is possible at less than 350° C. corresponding to a low temperature. Therefore, when the glass frit paste according to the present invention is applied as a sealing material, the tempered glass applied to the vacuum glass assembly does not undergo a tempered loosening phenomenon.

The vacuum glass assembly according to the present invention comprises: a first glass substrate; A second glass substrate spaced apart from each other to face the first glass substrate; And a sealing material arranged along an edge of the first or second glass substrate, bonding the first and second glass substrates to each other, and sealing a space between the first and second glasses, wherein the sealing material is a sixth It is formed by applying and firing the paste described in section.

The first glass substrate and the second glass substrate of the present invention may be selected according to the requirements of the article to which the vacuum glass assembly is applied. For example, a first glass substrate and a second glass substrate may be selected as tempered glass for an article to which tempered glass is to be applied, and a general glass may be applied to an article to which a general glass is to be applied.

As mentioned above, since the sealing material according to the present invention can be fired at a low temperature so that it can be applied to tempered glass, the first glass substrate and the second glass substrate are preferably tempered glass.

In addition, the glass frit paste mentioned above is used as the sealing material.

Hereinafter, specific aspects of the present invention will be described through examples.

< Example >

<glass Frit Manufacturing>

A glass frit having a composition ratio shown in Table 1 was prepared. The raw materials of each component were thoroughly mixed for 3 hours in a V-mixer. Here, BaO's raw material was BaCO ₃ , P ₂ O ₅ 's raw material was NH ₄ H ₂ PO ₄ , and the rest of the ingredients were the same as those in Table 1. The mixed material was sufficiently melted for 1 hour at 800-1000°C, and then quenched with a quenching roller to obtain a glass cullet (glass composition).

After controlling the initial particle size of the glass cullet obtained by the above process with a ball mill, the particle size was controlled so that the glass powder that did not pass through the 325 mesh sieve (ASTM C285-88) after pulverizing for about 1 hour remains within 1 g using a jet mill .

After mixing the glass cullet obtained as above with the inorganic filler in the mixing ratio shown in Table 2 below, it was mixed with a ball mill for 2 hours to finally prepare a glass frit.

Inorganic filler 1: zirconium phosphate tungstate (Zr ₂ (WO ₄ )(PO ₄ ) ₂ )

Inorganic filler 2: zirconium phosphate tungstate containing a trace amount of iron tungstate

Inorganic filler 3: zirconium phosphate

[Table 1]

[Table 2]

< Paste Manufacturing>

After preparing an organic vehicle by mixing α-terpineol and ethyl cellulose in an appropriate ratio, a paste was prepared by mixing it with the glass frit prepared as above in an appropriate ratio. A three roll mill was used for uniform mixing.

<Manufacture of vacuum glass assembly specimen>

Two tempered glasses were prepared, and the pastes according to Examples 1 to 5 and Comparative Examples 1 and 2 were applied to the outer periphery of each tempered glass to prepare a total of 7 glass assembly specimens. Vacuum evacuation and sealing processes were performed at 350° C. for these glass assemblies. Accordingly, a total of 7 glass assembly specimens were completed.

< Experimental example >

The glass frit, paste, and specimen prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 3.

1. Glass transition temperature (Tg)

The glass transition point was measured at a heating rate of 10° C./min using a TMA instrument (TMA-Q400 TA instrument).

2. Coefficient of thermal expansion (CTE(x10 ^-7 /℃))

The coefficient of thermal expansion was measured at a heating rate of 10 °C/min using a TMA instrument (TMA-Q400 TA instrument).

3. Haf Ball temperature

Using a high-temperature microscope, when the glass frit was present in powder form at a heating rate of 10 ℃/min, it was observed when the glass frit contracted to the maximum and became a half ball form.

4. Water resistance

The specimen was immersed in a distilled water thermostat at 90° C. and maintained for 48 hours, and then color change and weight change of the distilled water were observed. The weight after immersion was measured, and the increase/decrease rate of the weight was less than 1%, and the case of 1% or more was expressed as Х.

5. Plasticity stability

Glass frit powder was filled into a metal mold and then subjected to pressure molding, and the temperature was raised to 600°C at 10°C/min, and crystallization was observed after firing. ◎: crystallization does not occur and glossiness is very good, ○: crystallization does not occur and glossiness is also good. Х: Crystallization occurs and there is no gloss.

6. Adhesive strength

The glass frit prepared in Examples and Comparative Examples was prepared and placed in a pellet shape on a 100mmx25mmx5mm glass plate, covered with a glass plate of the same size, sealed at 350°C, and measured strength using MTS (measurement equipment: R&B company RB301).

◎: The adhesive strength measurement result exceeds the commercial level and is judged to be a very good level.

○: The adhesive strength measurement result is judged to be a commercial level

X: It is judged that the adhesive strength measurement result does not reach the commercial level

[Table 3]

As shown in Table 3 above, the embodiment according to the present invention has a half ball temperature of 340° C. or less so that not only can be fired at a low temperature, but also has a coefficient of thermal expansion of 80 to 85, so that it is matched with a tempered glass substrate, and also has water resistance. , It can be seen that the plastic stability is excellent. In particular, it was confirmed that Examples 2, 4, and 5 had the most excellent adhesive strength.

The comparative examples were _{for a glass frit having an Ag 2} OV ₂ O ₅ TeO ₂ component system, and compared to the examples, the softening point was high, and the sealing was not properly performed, so that water resistance and plastic stability were found to be unsatisfactory.

Although the present invention has been described above, the present invention is not limited by the embodiments disclosed in the present specification, and it is obvious that various modifications may be made by a person skilled in the art within the scope of the technical idea of the present invention. In addition, even if not explicitly described and described the effects of the configuration of the present invention while describing the embodiments of the present invention, it is natural that the predictable effects of the configuration should also be recognized.

Claims (9)

V ₂ O ₅ 30-50% by weight,
TeO ₂ 35-55% by weight,
0.5-5% by weight of CuO,
BaO 1-5% by weight,
ZnO 1-10% by weight and
A glass composition comprising 5 to 20% by weight of at least one of Ag ₂ O and Bi ₂ O _3; And
Inorganic filler; includes,
It is fired at at least one temperature of 350 ℃ or lower and functions as a sealing material.
Glass frit.
The method of claim 1,
In the above glass composition,
The content of the V ₂ O _{5 and} the content of TeO ₂ is a glass frit, characterized in that satisfying the following relational formula.

[Relationship]
V ₂ O ₅ (% by weight)/TeO ₂ (% by weight) <1
The method of claim 1,
The glass composition is
P ₂ O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ Glass frit, characterized in that it further comprises at least one of.
The method of claim 3,
The glass composition is
P ₂ O ₅ , MnO ₂ , Fe ₂ O ₃ , SnO and MoO ₃ Glass frit, characterized in that it comprises 10% by weight or less of at least one of.
The method of claim 1,
Glass frit, characterized in that the blending ratio of the glass composition and the weight of the inorganic filler is 9:1 ~ 7:3.
The method of claim 1,
The glass frit is
Glass frit, characterized in that the coefficient of thermal expansion (CTE) after firing is in ^{the range of 70 ~ 90 x 10 -7 / ℃.}
The method of claim 1,
The glass frit is
Glass frit, characterized in that the half ball temperature is 340 ℃ or less.
Including 100 parts by weight of the glass frit according to any one of claims 1 to 7 and 10 to 100 parts by weight of an organic vehicle
Glass frit paste.
A first glass substrate;
A second glass substrate spaced apart from each other to face the first glass substrate; And
Includes; a sealing material arranged along the edge of the first or second glass substrate, bonding the first and second glass substrates to each other, and sealing a space between the first and second glasses,
The sealing material is formed by applying the paste according to claim 8 and firing.
Vacuum glass assembly.