JP7780752B2 - Glass material - Google Patents

Description

The present invention relates to glass materials.

In recent years, mobile devices, digital cameras, and touch panel displays have become increasingly popular. Glass substrates used in these applications must be resistant to damage from impacts and scratches.

Traditionally, so-called tempered glass substrates have been used for these applications (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-359504

The production of tempered glass substrates requires a tempering process, such as ion exchange, to strengthen the glass. This tempering process increases the manufacturing cost of the glass.

In light of the above, the present invention aims to provide a glass material that can achieve high strength without undergoing a tempering process.

The glass material of the present invention is characterized by containing, in mol %, more than 15% to 50% of R ₂ O ₃ and more than 0% to 80% of SiO ₂ +B ₂ O ₃ +P ₂ O ₅ +Al ₂ O ₃ , wherein R ₂ O ₃ is at least one selected from Sc ₂ O ₃ , Y ₂ O ₃ , and La ₂ O ₃ .

In the glass material of the present invention, R ₂ O ₃ preferably contains at least Sc ₂ O ₃ .

The glass material of the present invention preferably contains, in mol %, 30 to 50% of R ₂ O ₃ .

The glass material of the present invention preferably contains, in mole percent, more than 0% to 80% of SiO ₂ .

The glass material of the present invention preferably contains, in mole percent, 0 to 80% of B ₂ O ₃ , 0 to 80% of P ₂ O ₅ , and 0 to 80% of Al ₂ O ₃ .

The glass material of the present invention preferably contains, in mole percent, more than 55% but not more than 80% of SiO ₂ +B ₂ O ₃ +P ₂ O ₅ +Al ₂ O ₃ .

The glass material of the present invention preferably has a Vickers hardness of 5.0 GPa or more.

The glass material of the present invention preferably has a Young's modulus of 80 GPa or more.

The present invention provides a glass material that can achieve high strength without undergoing a tempering process.

1 is a schematic cross-sectional view showing one embodiment of an apparatus for producing a glass material of the present invention.

The glass material of the present invention is characterized by containing, in mol%, more than 15% to 50% R ₂ O ₃ and more than 0% to 80% SiO ₂ +B ₂ O ₃ +P ₂ O ₅ +Al _{2 O 3} , where R ₂ O 3 is at least one selected from Sc ₂ O ₃ , Y ₂ O ₃ , and La ₂ O _3. The reasons for specifying the glass composition in this way and the content of each component are explained below. In the following explanation, "%" means "mol%" unless otherwise specified.

R ₂ O ₃ is at least one selected from Sc ₂ O ₃ , Y ₂ O ₃ , and La ₂ O ₃ , and is a component that improves the Vickers hardness and Young's modulus of the glass. The _{R 2} O ₃ content (total amount of Sc ₂ O ₃ , Y ₂ O ₃ , and La ₂ O ₃ ) is more than 15% to 50%, and is preferably 16% to 50%, 17% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 30% to 49%, 30% to 48%, and particularly preferably 30% to 45%. If the _{R 2} O ₃ content is too high, vitrification becomes difficult. If the _{R 2} O ₃ content is too low, the Vickers hardness and Young's modulus tend to decrease. The contents of each component are as follows:

The content of Sc ₂ O ₃ is preferably 0% to 50%, more than 0% to 50%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, more than 15% to 50%, 16% to 50%, 17% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 30% to 49%, 30% to 48%, and particularly preferably 30% to 45%.

The content of Y ₂ O ₃ is preferably 0% to 50%, more than 0% to 50%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, more than 15% to 50%, 16% to 50%, 17% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 30% to 49%, 30% to 48%, and particularly preferably 30% to 45%.

The content of La ₂ O ₃ is preferably 0% to 50%, more than 0% to 50%, 1% to 50%, 2% to 50%, 5% to 50%, 10% to 50%, more than 15% to 50%, 16% to 50%, 17% to 50%, 20% to 50%, 25% to 50%, 30% to 50%, 30% to 49%, 30% to 48%, and particularly preferably 30% to 45%.

It is preferable that R ₂ O ₃ contains at least Sc ₂ O _3. This makes it easier to further increase the Vickers hardness and Young's modulus of the glass material. Furthermore, from the viewpoint of improving the ease of vitrification, it is preferable that Y ₂ O ₃ and/or La ₂ O ₃ be contained. Note that two or more kinds selected from Sc ₂ O ₃ , Y ₂ O ₃ and La ₂ O ₃ may be contained.

SiO ₂ , B ₂ O ₃ , P ₂ O ₅ and Al ₂ O ₃ are components that form the glass skeleton. The content of _{SiO 2} + B ₂ O ₃ + P ₂ O ₅ + Al ₂ O ₃ (total amount of SiO ₂ , B ₂ O ₃ , P ₂ O ₅ and Al ₂ O ₃ ) is greater than 0% and less than 80%, and is preferably 1% to 80%, 2% to 80%, 5% to 80%, 10% to 80%, 20% to 80%, 30% to 80%, 40% to 80%, 45% to 80%, 50% to 80%, 55% to 80%, greater than 55% to 80%, greater than 55% to 79%, greater than 55% to 78%, greater than 55% to 77%, and particularly preferably greater than 55% to 75%. _If the content _{of SiO2} + _B2O3 + _P2O5 + _{Al2O3 is} too low, vitrification becomes difficult. If the content _{of SiO2} + _B2O3 + _P2O5 + _Al2O3 is too high, the Vickers _hardness and Young's modulus tend to decrease. The contents of each component are as follows _.

The SiO ₂ content is preferably 0% to 80%, more than 0% to 80%, 1% to 80%, 2% to 80%, 5% to 80%, 10% to 80%, 20% to 80%, 30% to 80%, 40% to 80%, 45% to 80%, 50% to 80%, 55% to 80%, more than 55% to 80%, more than 55% to 79%, more than 55% to 78%, more than 55% to 77%, and particularly preferably more than 55% to 75%.

The content of B ₂ O ₃ is preferably 0% to 80%, more than 0% to 80%, 1% to 80%, 2% to 80%, 5% to 80%, 10% to 80%, 20% to 80%, 30% to 80%, 40% to 80%, 45% to 80%, 50% to 80%, 55% to 80%, more than 55% to 80%, more than 55% to 79%, more than 55% to 78%, more than 55% to 77%, and particularly preferably more than 55% to 75%.

The P ₂ O ₅ content is preferably 0% to 80%, more than 0% to 80%, 1% to 80%, 2% to 80%, 5% to 80%, 10% to 80%, 20% to 80%, 30% to 80%, 40% to 80%, 45% to 80%, 50% to 80%, 55% to 80%, more than 55% to 80%, more than 55% to 79%, more than 55% to 78%, more than 55% to 77%, and particularly preferably more than 55% to 75%.

The content of Al ₂ O ₃ is preferably 0% to 80%, more than 0% to 80%, 1% to 80%, 2% to 80%, 5% to 80%, 10% to 80%, 20% to 80%, 30% to 80%, 40% to 80%, 45% to 80%, 50% to 80%, 55% to 80%, more than 55% to 80%, more than 55% to 79%, more than 55% to 78%, more than 55% to 77%, and particularly preferably more than 55% to 75%.

Of SiO ₂ , B ₂ O ₃ , P ₂ O ₅ and Al ₂ O ₃ , it is preferable that at least SiO ₂ or B ₂ O ₃ is contained, and it is more preferable that at least SiO ₂ is contained.

_The content of _R2O3 + _SiO2 + _B2O3 + _P2O5 + _{Al2O3 (} total amount of _R2O3 , _SiO2 , _B2O3 , _P2O5 , _{and Al2O3} ) is preferably 80% _or more, 90% or more, ₉₅ % _or more, or ₉₈ % or _more , particularly preferably 99% or more. The upper limit may be 100%.

By having the above composition, the glass material of the present invention can achieve high Vickers hardness and high Young's modulus. Specifically, the Vickers hardness is preferably 5.0 GPa or more, 5.5 GPa or more, 6.0 GPa or more, 6.2 GPa or more, and particularly 6.5 GPa or more. Furthermore, the Young's modulus is preferably 80 GPa or more, 90 GPa or more, 100 GPa or more, 110 GPa or more, and particularly 120 GPa or more.

The glass material of the present invention can be produced, for example, by a containerless levitation method. Figure 1 is a schematic cross-sectional view showing one embodiment of an apparatus for producing the glass material of the present invention. The method for producing the glass material of the present invention will be described below with reference to Figure 1.

The glass material manufacturing apparatus 1 has a molding die 10. The molding die 10 has a molding surface 10a and a plurality of gas outlet holes 10b opening into the molding surface 10a. The gas outlet holes 10b are connected to a gas supply mechanism 11 such as a gas cylinder. Gas is supplied from the gas supply mechanism 11 to the molding surface 10a via the gas outlet holes 10b. The type of gas is not particularly limited, and may be, for example, air or oxygen, or a reducing gas containing nitrogen gas, argon gas, helium gas, carbon monoxide gas, carbon dioxide gas, or hydrogen.

First, raw material ingot 12 is placed on molding surface 10a. Examples of raw material ingot 12 include raw material powder integrated by press molding or the like, a sintered body obtained by integrating raw material powder by press molding or the like and then sintering, and an aggregate of crystals having a composition equivalent to the target glass composition.

Next, gas is ejected from the gas ejection holes 10b to levitate the raw material lump 12 above the molding surface 10a. In other words, the raw material lump 12 is held in a state where it is not in contact with the molding surface 10a. In this state, laser light is irradiated onto the raw material lump 12 from the laser light irradiation device 13. This heats and melts the raw material lump 12, vitrifying it to obtain molten glass. The molten glass is then cooled to obtain a glass material. During the process of heating and melting the raw material lump 12 and the process of cooling the molten glass and further the glass material until their temperatures are at least below their softening points, it is preferable to continue ejecting gas at least to prevent contact between the raw material lump 12, the molten glass, and further the glass material and the molding surface 10a. In addition to laser light irradiation, radiant heating may also be used to heat and melt the raw material lump 12. If necessary, the glass material may be processed into the desired shape by cutting, polishing, pressing, etc.

The present invention will be described below based on examples, but the present invention is not limited to these examples.

Table 1 shows Examples 1 to 5 of the present invention and Comparative Example 6.

Each sample was prepared as follows. First, raw materials were mixed to produce the glass composition shown in Table 1, and a raw material batch was prepared. The raw material batch was heat-treated at a temperature of 1050°C and sintered to obtain a glass raw material lump.

Next, glass material (approximately 2 mm in diameter) was produced by the containerless levitation method using an apparatus similar to that shown in Figure 1. A 100 W CO2 _laser oscillator was used as the heat source. _O2 gas was used as the gas for levitating the glass raw material mass in the air, and the supply flow rate was 0.1 L/min to 30 L/min. The obtained glass material was annealed in air near the glass transition point for 1 hour, and then the following measurements were performed. The results are shown in Table 1.

Vickers hardness was calculated from the area of the indentation by pressing a Vickers indenter with a load of 0.98 N onto the surface of optically polished glass material for 5 seconds in a thermo-hygrostat chamber at a temperature of 25°C and a humidity of 60%.

Young's modulus was measured using the ultrasonic pulse method after the glass material was processed to have parallel planes and optically polished.

As shown in Table 1, the glass materials of Examples 1 to 5 had a Vickers hardness of 6.7 GPa to 9.5 GPa. They also had a Young's modulus of 103 GPa to 137 GPa.

On the other hand, the glass material of Comparative Example 6 had a Vickers hardness of 6.1 GPa and a Young's modulus of 74 GPa.

The glass material of the present invention can be suitably used for applications requiring high strength, such as semiconductor elements, cover members for optical equipment, and optical elements.

1 Manufacturing apparatus 10 Mold 10a Mold surface 10b Gas ejection hole 11 Gas supply mechanism 12 Raw material lump 13 Laser light irradiation device

Claims (8)

The composition contains, in mole percent, 30 % to 50% of R ₂ O ₃ , more than 0% to 70 % of SiO ₂ , and 40% to 70 % of SiO ₂ +B ₂ O ₃ +P ₂ O ₅ +Al ₂ O ₃ ,
The R ₂ O ₃ is at least one selected from Sc ₂ O ₃ , Y ₂ O ₃ and La ₂ O ₃ ;
A glass material containing, in mole percent, at least more than 15% of Sc ₂ O ₃ . 2. The glass material according to claim 1 , containing, in mole percent, from 0% to less than 70 % of B ₂ O ₃ , from 50% to less than 70 % of P ₂ O ₅ , and from 0% to less than 70 % of Al ₂ O ₃ . _3. The glass material according to claim 1, containing, in mole percent, from 30% to less than 45% of R ₂ O ₃ , and from 55% to 70 % of SiO ₂ +B ₂ O ₃ +P ₂ O _{5 +} Al 2 O 3 . 4. The glass material according to claim 1 , which contains, in mole percent, 40 to 70 % of SiO ₂ . In mole percent, R ₂ O ₃ 30% to 50%, SiO ₂ 40% to 70%, SiO ₂ +B ₂ O ₃ +P ₂ O ₅ +Al ₂ O ₃ Contains 40% to 70%
The R ₂ O ₃ But Sc ₂ O ₃ , Y ₂ O ₃ and La ₂ O ₃ At least one selected from
In mole percent, at least Sc ₂ O ₃ A glass material containing more than 15% of In mole percent, B ₂ O ₃ 0% to 30%, P ₂ O ₅ 0% to 30%, Al ₂ O ₃ The glass material according to claim 5, containing 0% to 30%. 7. The glass material according to claim 1 , having a Vickers hardness of 5.0 GPa or more. 8. The glass material according to claim 1 , having a Young's modulus of 80 GPa or more.