KR102379839B1 - 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 fired glass frit, paste, and a vacuum glass assembly using the same.
The glass frit according to the present invention has a new component system including at least one of V2O5, TeO2, CuO, BaO, MnO2, FeO3, SnO, MoO3 and ZnO and an inorganic filler in a composition ratio unique to the present invention, and thus a conventional flexible glass composition It has the effect of being able to replace and sinter at a low temperature of 350 ℃ or less.

Description

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 fired glass frit, paste, and a vacuum glass assembly using the same.

In glass windows, home appliances, or electrical and electronic components such as vacuum insulated multilayer glass panels, display panels, and organic EL display panels, sealing or adhesion is performed by a glass frit containing a glass composition and inorganic ceramic particles. Such a 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, dried and then fired to give a sealing function.

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

However, in recent years, the trend of design considering the environment has become stronger worldwide, and safer materials are demanded. For example, in Europe, a directive by the European Union (EU) on the restriction of the use of certain hazardous substances in electronic and electrical equipment (RoHS Directive) came into effect 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 glass composition contains a lot of lead, which is designated as a prohibited substance in the RoHS directive, it is difficult to use it as a sealing glass paste. Accordingly, the development of a novel glass composition that does not contain lead has been required. In addition, in order to reduce thermal damage to various glass sealing parts or electrical and electronic parts and to improve productivity, the development of lead-free glass compositions capable of softening flow at a lower temperature than PbOB ₂ O ₃ glass compositions and having good chemical stability is strongly encouraged. It is being demanded.

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

However, the conventional Ag ₂ OV ₂ O ₅ TeO ₂ glass composition has a problem in that good softening fluidity cannot be obtained due to a high crystallization tendency 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., the thermal expansion coefficient with the tempered glass is not matched, making it difficult to bake at low temperature, so that the tempered glass loosening phenomenon There are problems that may arise.

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

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

In particular, an object of the present invention is to provide a novel lead-free low-temperature-fired glass frit that can be fired at a low temperature and has a low crystallization tendency even during low-temperature firing.

Another object of the present invention is to provide a lead-free low-temperature-fired glass frit with excellent durability without causing peeling or breakage by matching the coefficient of thermal expansion with a glass substrate even if firing at a low temperature is possible.

In order to provide a new glass frit that can be fired at a low temperature as a lead-free glass composition replacing the conventional flexible glass composition, the glass frit according to the present invention contains 30-50 wt% of V ₂ O ₅ and 30-50 wt% of TeO ₂ %, CuO 1-5 wt%, BaO 1-5 wt%, MnO ₂ , FeO ₃ , SnO, MoO ₃ and 1-10 wt% of at least one of ZnO and 5-30 wt% of inorganic fillers.

In addition, in order to provide a glass frit that can be fired at a low temperature and has a low crystallization tendency even when fired at a low temperature, in the glass frit according to the present invention, the content of V ₂ O ₅ and the content of TeO ₂ may satisfy the following relation. .

[Relational Expression]

V ₂ O ₅ (wt. %)/TeO ₂ (wt. %) < 1

In addition, in order to provide a glass frit excellent in durability without delamination or breakage by matching the coefficient of thermal expansion with the glass substrate even if firing at a low temperature is possible, the glass frit according to the present invention preferably contains 10 inorganic fillers. It may be included in an amount of ~20% by weight, and the coefficient of thermal expansion (CTE) after calcination may be in the range of 70 to 90 x 10 ^-7 /°C.

The glass frit according to the present invention has a new compositional system including at least one of V ₂ O ₅ , TeO ₂ , CuO, BaO, MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO and inorganic fillers in a composition ratio unique to the present invention. As a result, it replaces the conventional flexible glass composition and has the effect that it can be fired 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 , not only can it be fired at a low temperature, but also there is an effect that the crystallization tendency is low even during low-temperature firing.

Furthermore, in the glass frit according to the present invention, the inorganic filler may be included in an amount of preferably 10 to 20 wt%, and the coefficient of thermal expansion (CTE) after firing may be in the range of 70 to 90 x 10 ^-7 /°C, so that the glass substrate and The thermal expansion coefficient of the is matched, so that peeling or breakage does not occur and the durability is excellent.

The above-described objects, features, and advantages will be described later in detail, and accordingly, those skilled 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 gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail.

The present invention is not limited to the embodiments disclosed below, but can be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete and to completely convey the scope of the invention to those of ordinary skill in the art. 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 has better 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, since tempered glass used for home appliances may cause annealing of tempered glass when the sealing process is applied at a high temperature, it is necessary to apply the sealing process in the low temperature region (350 ℃ or less). Therefore, the glass frit sealing material used in the sealing process should be capable of firing at a low temperature. In addition, it should be possible to sinter at a low temperature and at the same time satisfy appropriate softening fluidity.

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

Glass frit according to the present invention V ₂ O ₅ 30-50 wt%, TeO ₂ 30-50 wt%, Cu1-5 wt%, BaO 1-5 wt%, MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO Among them, 1 to 10% by weight of at least one kind and 5 to 30% by weight of inorganic fillers are included.

V ₂ O ₅ has the effect of lowering the softening point while increasing the durability of the glass frit, and is contained in the glass frit in an amount of 30 to 50% by weight. When the V ₂ O ₅ content exceeds 50% by weight, there is a problem in that the sintering of the glass frit tends to be difficult. When 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 also there may be a problem in the durability of the glass frit.

TeO ₂ has an effect of increasing the fluidity of the glass frit, and is contained in the glass frit in an amount of 30 to 50 wt%. If TeO ₂ exceeds 50% by weight, it may be difficult to sufficiently lower the softening point, so that firing may not occur. If TeO ₂ is less than 30% by weight, there may be a problem in that it is difficult to vitrify the glass frit depending on the balance relationship with other components.

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

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

The glass frit according to the present invention contains at least one of MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO in an amount of 1 to 10% by weight. When one or more of MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO exceeds 10 wt %, it is difficult to match the thermal expansion coefficient of the glass frit, and problems in durability or fluidity may occur. Similarly, when at least one of MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO is less than 1 wt %, it may be difficult to match the thermal expansion coefficient of the glass frit and a problem in that required physical properties cannot be obtained may occur.

In addition, the glass frit according to the present invention contains 5 to 30% by weight of inorganic filler. More preferably, the inorganic filler may be included in an amount of 10 to 20 wt % in order to provide a glass frit having excellent durability and matching the coefficient of thermal expansion. If the inorganic filler exceeds 30% by weight, the sealing performance of the glass frit may be deteriorated and a problem may occur in water resistance. If the inorganic filler is less than 5% by weight, it may be difficult to match the thermal expansion coefficient of the glass frit, and low-temperature firing may be difficult.

The inorganic filler according to the present invention is a crystalline inorganic particle having a low coefficient of thermal expansion, and specifically, zirconium phosphate, zirconium phosphate tungstate, zirconium, Li ₂ O-Al ₂ O ₃ -SiO ₂ , beta-eucryptite and zirconium tung One or more types of states can be used.

In addition, the glass frit according to the present invention may further include at least one of Ag ₂ O and Bi ₂ O ₃ , and preferably, the Ag ₂ O and Bi ₂ to increase durability of the glass frit and decrease the crystallization tendency. One or more of O ₃ may be included in an amount of 5 to 20% by weight. When at least one of Ag ₂ O and Bi ₂ O ₃ exceeds 20 wt %, the thermal expansion coefficient may be lowered, but a problem in that sealing performance may be deteriorated may occur. When at least one of Ag ₂ O and Bi ₂ O ₃ is less than 5 wt %, it may be difficult to match the coefficient of thermal expansion and difficulty in low-temperature sintering may occur.

In addition, V ₂ O ₅ and TeO ₂ included 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.

[Relational Expression]

V ₂ O ₅ (wt. %)/TeO ₂ (wt. %) < 1

As the content of V ₂ O ₅ increases, the glass transition point of the glass frit may be lowered and the sealing temperature may be lowered, but at the same time, the crystallization tendency _of the glass frit increases. Accordingly, in the glass frit according to the present invention, the ratio of V ₂ O ₅ (wt%) to TeO ₂ (wt%) is preferably less than 1.

In addition, the glass frit according to the present invention preferably has a coefficient of thermal expansion of 70 ~ 90 x 10 ^-7 /℃ in terms of matching the coefficient of thermal expansion with the tempered glass substrate. Since the thermal brim coefficient falls within the range of 70 to 90 x 10 ^-7 /℃, the glass frit according to the present invention can reduce the occurrence of a decrease in adhesion, thereby improving sealing reliability.

<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 the organic vehicle.

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

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

<Vacuum Glass Assembly>

A vacuum glass assembly refers to an assembly comprising two or more glass substrates and a vacuum is maintained between the two or more glass substrates. The vacuum glass assembly can also be used in home appliances such as refrigerators, microwaves, washing machines, or electronic components of various electronic devices.

The glass frit according to the present invention may be used as a sealing material in 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 in that the 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, the sealing process is possible at less than 350° C., which corresponds 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 have a tempered loosening phenomenon.

A vacuum glass assembly according to the present invention comprises: a first glass substrate; a second glass substrate spaced apart from 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, and sealing a space between the first and second glasses, wherein the sealing material includes a sixth The paste according to claim is applied and fired to form.

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, for an article to which tempered glass is to be applied, the first glass substrate and the second glass substrate may be selected as tempered glass, and ordinary glass may be applied to an article to which ordinary 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 above-mentioned glass frit paste is used as the sealing material.

Hereinafter, specific aspects of the present invention will be described by way of Examples.

<Example>

<Manufacture of glass frit>

Glass frits having the composition ratios shown in Table 1 were prepared. The raw materials of each component were thoroughly mixed for 3 hours in a V-mixer. Here, BaCO ₃ was used as a raw material of BaO, and the same as the components described in Table 1 were used for the remaining components. The mixed materials were sufficiently melted for 1 hour at 800 to 1000° C., and then rapidly cooled on a quenching roller to obtain a glass cullet.

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

The glass cullet obtained as described above and the filler according to the content shown in Table 1 were combined, and then mixed with a ball mill for 2 hours to finally prepare a glass frit.

[Table 1]

<Paste Manufacturing>

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

<Preparation of vacuum glass assembly specimen>

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

<Experimental example>

The glass frits, pastes and specimens prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 2.

1. Glass transition temperature (Tg)

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

3. Haf Ball Temperature

Using a high-temperature microscope, when the glass frit exists in powder form at a temperature increase rate of 10 °C/min, it was observed when the glass frit shrinks the most and takes on the shape of a half ball at each temperature.

4. Water resistance

After the specimen was immersed in a distilled water thermostat at 90° C. and maintained for 48 hours, the color change and weight change of the distilled water were observed. The weight after immersion was measured, and the case where the weight increase/decrease rate was less than 1% was denoted by ○, and the case where the weight was greater than 1% was denoted by Х.

5. Plastic Stability

The glass frit powder was filled and press-molded in a metal mold, and the temperature was raised to 600°C at 10°C/min to observe crystallization after firing. ◎: Crystallization does not occur and gloss is very good, ○: Crystallization does not occur and gloss is good. Х: Crystallization occurs and there is no gloss.

[Table 2]

As shown in Table 2 above, the embodiment according to the present invention has a half ball temperature of 340 ° C. or less, so that not only can it be fired at a low temperature, but also the thermal expansion coefficient corresponds to 80 to 85, which is matched with the tempered glass substrate, and also has water resistance , it can be confirmed that the plastic stability is excellent.

The comparative examples relate to a glass frit having a Ag ₂ OV ₂ O ₅ TeO ₂ component system, and it was confirmed that the softening point was higher as compared to the Examples, and the sealing was not performed properly, so that the water resistance and plastic stability were unsatisfactory.

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

Claims (11)

V ₂ O ₅ 30-50 wt%,
TeO ₂ 30-50% by weight,
1-5 wt% CuO;
1-5% by weight of BaO;
1-10 wt% of at least one of MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO, and
Ag ₂ O contains 5 to 20% by weight,
Further comprising an inorganic filler,
When the coefficient of thermal expansion (CTE) after firing is in the range of 70 ~ 90 x 10 ^-7 /℃
glass frit.
The method of claim 1,
The content of V ₂ O ₅ and the content of TeO ₂ Glass frit, characterized in that it satisfies the following relational expression.

[Relational Expression]
V ₂ O ₅ (wt. %)/TeO ₂ (wt. %) < 1
3. The method according to claim 1 or 2,
the inorganic filler
Glass frit, characterized in that it contains 10 to 20% by weight.
The method of claim 1,
Bi ₂ O ₃ Glass frit, characterized in that it further comprises.
100 parts by weight of the glass frit according to claim 1 and 10 to 100 parts by weight of the organic vehicle
Glass frit paste.
a first glass substrate;
a second glass substrate spaced apart from 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, and sealing the space between the first and second glass;
The sealing material is formed by applying the paste according to claim 5 and firing
vacuum glass assembly. According to claim 1,
The Ag ₂ O is
5 to 10% by weight (not including 10% by weight), characterized in that
glass frit.
The method of claim 1,
1 to 10 wt% of at least one of SnO and MoO ₃
glass frit.
V ₂ O ₅ 30-50 wt%,
TeO ₂ 30-50% by weight,
1-5 wt% CuO;
1-5% by weight of BaO;
1-10 wt% of at least one of MnO ₂ , FeO ₃ , SnO, MoO ₃ and ZnO, and
Ag ₂ O and Bi ₂ O ₃ At least one of more than 10 to 20% by weight,
5 to 30% by weight of inorganic fillers
glass frit.
delete 10. The method of claim 9,
1 to 10 wt% of at least one of SnO and MoO ₃
glass frit.