CN115448592A

CN115448592A - Glass, cover glass using same, and method for producing glass

Info

Publication number: CN115448592A
Application number: CN202211110212.6A
Authority: CN
Inventors: 村田隆; 齐藤敦己
Original assignee: Nippon Electric Glass Co Ltd
Current assignee: Nippon Electric Glass Co Ltd
Priority date: 2014-04-03
Filing date: 2015-04-01
Publication date: 2022-12-09
Also published as: KR102332532B1; JP2016102045A; KR20240150604A; CN113998884A; KR20160141737A; JP7472925B2; JP6691315B2; CN106132889A; JP2022060313A; KR20230117626A; JP7183108B2; JP2019112303A; KR20210142775A; KR102563271B1; CN115448593A; KR102720090B1; WO2015152342A1; JP2024071784A; CN110194590A

Abstract

The present invention aims to provide a lightweight glass which is less likely to be scratched even without being subjected to ion exchange treatment and has high drop impact strength, and a method for producing the same. The glass of the present invention contains, as a glass composition, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～20％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ O 0～3％、MgO+CaO+SrO+BaO0～12％。

Description

Glass, cover glass using the same, and method for producing glass

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is filed in 2016 under the state of entering China at 09/30/month, and has a national application number of 201580018105.2, entitled "glass, cover glass using the glass, and method for producing glass".

Technical Field

The present invention relates to a glass, a cover glass using the glass, and a method for manufacturing the glass, and more particularly, to a glass suitable for a cover glass of a mobile phone, a digital camera, a PDA (portable terminal), a solar cell, a Chip Size Package (CSP), a Charge Coupled Device (CCD), or a solid-state image sensor (CIS), particularly a cover glass of a touch panel display, and a method for manufacturing the glass.

Background

Devices such as mobile phones, digital cameras, PDAs, etc. are becoming more and more popular. In these applications, the ion-exchanged tempered glass is used as a cover glass for a touch panel display (see patent document 1 and non-patent document 1).

Conventionally, tempered glass is produced by so-called "cutting before strengthening" in which a glass plate is cut into a predetermined shape in advance and then subjected to ion exchange treatment, but in recent years, there has been studied so-called "cutting after strengthening" in which a large-sized glass plate for strengthening is subjected to ion exchange treatment, and then a film such as a touch sensor is formed and cut into a predetermined size. If the cutting is performed after the strengthening, the manufacturing efficiency of the device is dramatically improved.

Documents of the prior art

Patent literature

Patent document 1: japanese patent laid-open publication No. 2006-83045

Non-patent document

Non-patent document 1: broad and full of grains, new glass and its Properties, first edition, institute of Enterprise management System, 20 months 8 and 1984, p.451-498

Disclosure of Invention

Technical problems to be solved by the invention

However, for the cover glass, it is necessary: the (1) scratch is not easy to occur, and (2) the drop impact strength is high. In order to satisfy the above characteristics (1) and (2), a conventional cover glass is subjected to ion exchange treatment to obtain a tempered glass having a compressive stress layer on the surface thereof.

However, the ion exchange treatment increases the manufacturing cost of the cover glass.

In addition, in the case of cutting after strengthening, the tempered glass is easily broken at the time of cutting because a compressive stress layer existing on the surface becomes an obstacle, and the strength of the end face is easily lowered because a region where no compressive stress layer exists is exposed at the end face after cutting. When a film such as a touch sensor is further formed on the surface of the tempered glass, the in-plane strength of the tempered glass tends to decrease.

Further, in recent years, the use of cover glass, in which tempered glass is used, in large-sized televisions is also being studied. However, the conventional tempered glass is not light enough, and does not contribute to weight reduction of large-sized equipment.

The present invention has been made in view of the above circumstances, and a technical object thereof is to provide a lightweight glass which is less likely to cause scratches and has high drop impact strength even without performing an ion exchange treatment, a cover glass using the glass, and a method for producing the cover glass.

Means for solving the problems

The present inventors have repeatedly conducted various experiments and, as a result, have found that the above-described technical problems can be solved by limiting the glass composition range to a predetermined range, and have come to the present invention. That is, the glass of the present invention contains SiO in terms of mass as a glass composition ₂ 50～70％、Al ₂ 3 0～20％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 3 percent of O, and 0 to 12 percent of MgO + CaO + SrO + BaO. Here, li ₂ O+Na ₂ O+K ₂ O means Li ₂ O、Na ₂ O and K ₂ The total amount of O. MgO + CaO + SrO + BaO means the total amount of MgO, caO, srO and BaO.

The glass of the present invention contains B in the glass composition ₂ O ₃ Is 15% by mass or more. This improves scratch resistance and crack resistance. Further, since the young's modulus is decreased, the drop impact property can be improved. Further, the glass of the present invention makes Li in the glass composition ₂ O+Na ₂ O+K ₂ The O content is 3 mass% or less, and the MgO + CaO + SrO + BaO content is 12 mass% or less, preferably 8 mass% or less. As a result, the density is likely to decrease, and as a result, the cover glass is likely to be reduced in weight.

In addition, the glass of the present invention is preferably: the glass composition contains, by mass: siO 2 ₂ 58～70％、Al ₂ O ₃ 7～20％、B ₂ O ₃ 18～30％、Li ₂ O+Na ₂ O+K ₂ O 0～1％、MgO+CaO+SrO+BaO 0～10％。

In addition, the glass of the present invention is preferably: the glass composition contains, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～15％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ O 0～3％、MgO+CaO+SrO+BaO 0～8％。

In addition, the glass of the present invention is preferably: b ₂ O ₃ The content of- (MgO + CaO + SrO + BaO) is 5% by mass or more. Here, "B ₂ O ₃ - (MgO + CaO + SrO + BaO)' means that B is substituted by B ₂ O ₃ The total content of MgO, caO, srO and BaO is subtracted from the content of (A).

For example, in the case of a film-like glass having a thickness of 200 μm or less, it is necessary to be light and bent with a small radius of curvature contributing to winding into a roll. Therefore, if the above-mentioned constitution is adopted, a glass having a low density and a low Young's modulus can be easily obtained, and is suitable as a film-like glass material.

In addition, the glass of the present invention is preferably: (SrO + BaO)/(MgO + CaO) is 1 or less in mass ratio. Here, (SrO + BaO)/(MgO + CaO) means a value obtained by dividing the total content of SrO and BaO by the total content of MgO and CaO.

With the above configuration, a low-density glass can be easily obtained, and is suitable as a film-like glass material.

In addition, the glass of the present invention is preferably: based on the quality standard, B ₂ O ₃ Content ratio of (A) to (B) of Al ₂ O ₃ Is large (i.e., B) ₂ O ₃ －Al ₂ O ₃ More than 0 mass%).

With the above configuration, glass having a low Young's modulus can be easily obtained, and is suitable as a film-like glass material.

In addition, the glass of the present invention is preferably: liquid phase viscosity of 10 ^5.0 dPas or more. Here, the "liquidus viscosity" refers to a value obtained by measuring the viscosity of glass at a liquidus temperature by the platinum ball pulling method. The "liquidus temperature" is a value obtained by measuring the temperature at which crystals are precipitated, by placing a glass powder which passes through a standard sieve of 30 mesh (500 μm) but remains in a glass powder of 50 mesh (300 μm) in a platinum boat, holding the boat in a temperature gradient furnace for 24 hours.

In addition, the glass of the present invention is preferably: the density was 2.40g/cm ³ The following (particularly 2.30 g/cm) ³ Below) and a coefficient of thermal expansion in a temperature range of 30 to 380 ℃ of 25 to 40 x 10 ^-7 The strain point is 610 ℃ or lower, and the Young's modulus is 66GPa or lower (particularly 65GPa or lower). Here, "density" can be measured by a known archimedes method. "coefficient of thermal expansion in the temperature range of 30 to 380 ℃ means an average value measured by using an dilatometer. "strain point" refers to a value determined according to the method of ASTM C336. "Young's modulus" is a value measured by a well-known resonance method.

In addition, the glass of the present invention is preferably: formed by an overflow downdraw process. Here, the "overflow downdraw method" is a method of producing a glass plate by overflowing molten glass from both sides of a heat-resistant water-guiding tubular structure, merging the overflowing molten glass at the lower end of the water-guiding tubular structure, and extending and molding the merged molten glass downward.

In addition, the glass of the present invention is preferably: the glass is used for protective glass.

In addition, the glass of the present invention is preferably: no ion exchange treatment was performed. Thus, the manufacturing cost of the cover glass can be reduced.

However, when the glass of the present invention is used as a cover glass or the like, stains caused by adhesion of fingerprints or the like are not likely to be a problem. In this case, it is preferable that the photocatalyst particles are supported on the glass surface.

With such a configuration, stains such as fingerprints attached to the surface can be decomposed and removed by the action of the photocatalyst particles.

In addition, contains a large amount of B ₂ O ₃ The glass (2) has a strong tendency to phase separate, and in particular, the surface of the glass may be phase-separated even without heat treatment. When such a glass is subjected to an acid treatment, the surface portion becomes porous, and a glass having a large specific surface area can be easily obtained.

In addition, the glass of the present invention is preferably: the glass surface is porous. Here, "the surface is porous" means that only the surface is porous, in other words, the entire particle is not a porous body. The term "porous" refers to a state in which a large number of pores are present, but the pores do not necessarily need to be in communication with each other.

With the above configuration, a large amount of photocatalyst particles can be supported on the surface of the glass, and a large amount of organic matter can be adsorbed on the surface of the photocatalyst, so that the photocatalytic function can be greatly improved.

In addition, the glass of the present invention is preferably: the photocatalyst particles are titanium dioxide particles.

With the above configuration, when light including ultraviolet light such as sunlight is irradiated, organic matter such as stains and bacteria is rapidly decomposed, and excellent effects such as antifouling, antibacterial, and antifungal effects can be obtained.

The cover glass of the present invention comprises the above-described glass of the present invention.

The cover glass of the present invention is preferably: the glass surface is porous and supports photocatalyst particles.

The cover glass having the above-described structure can easily maintain a clean state by decomposing and removing stains such as fingerprints attached to the surface by the action of the photocatalyst particles.

The method for producing glass of the present invention is a method for producing glass comprising, as a glass composition, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～20％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 3 percent of O and 0 to 12 percent of MgO + CaO + SrO + BaO. More preferably, it is prepared to contain, by mass: siO 2 ₂ 58～70％、Al ₂ O ₃ 7～20％、B ₂ O ₃ 18～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 1% of O, 0 to 10% of MgO + CaO + SrO + BaO, or a glass containing, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～15％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 3 percent of O and 0 to 8 percent of MgO + CaO + SrO + BaO.

In addition, the production method of the present invention is preferably: further, a solution containing a photocatalyst component is applied to the surface of the glass, and then, heat treatment is performed to support photocatalyst particles on the surface of the glass.

With the above configuration, the photocatalyst particles can be easily supported on the glass surface.

In addition, the production method of the present invention is preferably: after the glass surface is subjected to acid treatment, a solution containing a photocatalyst component is applied.

With the above configuration, the surface of the glass as the substrate is porous, and the specific surface area can be increased, so that a large amount of photocatalyst particles can be supported.

In addition, the production method of the present invention is preferably: as the solution containing the photocatalyst component, a solution in which titanium dioxide particles are dispersed is used.

With the above configuration, titanium dioxide particles capable of quickly decomposing organic substances such as stains and bacteria can be easily applied to the glass surface.

Effects of the invention

According to the present invention, as described above, by defining the glass composition in a specific range, even without performing ion exchange treatment, it is possible to provide a light-weight glass which is less likely to be scratched and has high drop impact strength, a cover glass using the glass, and a method for producing the cover glass.

Detailed Description

The reason why the content of each component in the glass of the present invention is limited as described above is as follows. The following% means mass% unless otherwise specified.

SiO ₂ The content of (B) is 50 to 70%, preferably 53 to 70%, 55 to 70%, 58 to 70%, 60 to 70%, 62 to 69%, particularly preferably 62 to 67%. If SiO is present ₂ When the content of (b) is too small, the density tends to be high. On the other hand, if SiO ₂ When the content (c) is too large, the high-temperature viscosity increases, the meltability decreases, and defects such as devitrification crystals (cristobalite) are likely to occur in the glass.

Al ₂ O ₃ Is an optional component, but if the content is too small, the scratch resistance, crack resistance, and heat resistance tend to decrease. In addition, the transmittance is easily decreased by phase separation. Thus, al ₂ O ₃ The lower limit of (b) is 0% or more, preferably 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, and particularly preferably 9% or more. On the other hand, al ₂ O ₃ Although the Young's modulus can be improved, if the content is too large, the Young's modulus becomes too high, and the impact strength tends to be lowered. In addition, in the case of film-like glass, it is difficult to reduce the radius of curvature. And, if Al ₂ O ₃ When the content (c) is too large, the liquid phase temperature increases and the devitrification resistance is liable to decrease. Thus, al ₂ O ₃ The upper limit range of (A) is 20% or less, preferably 19% or less, 18% or less, 17% or less, 15% or less, less than 13% or 12% or less, particularly preferablyLess than 11%.

B ₂ O ₃ Is a component for improving scratch resistance and crack resistance, and is a component for lowering Young's modulus. Or a component that decreases the density. Further, the dielectric loss and the vibration loss are reduced. Further, the components are easily induced to phase separate. When phase separation occurs in the glass, the surface of the glass is easily modified into a porous state by acid treatment, and photocatalyst particles are supported, whereby a high photocatalytic activity function can be obtained. B is ₂ O ₃ The content of (B) is 15-30%. If B is ₂ O ₃ When the content of (b) is too small, scratch resistance and crack resistance are liable to be lowered, and further, young's modulus is high and impact resistance is liable to be lowered. In addition, in the case of film-like glass, it is difficult to reduce the radius of curvature. Further, the flux has insufficient ability to act as a flux, and the high-temperature viscosity increases, so that the foam quality tends to deteriorate. It is difficult to achieve further low density. Thus, B ₂ O ₃ The lower limit of (b) is 15% or more, preferably 18% or more, 20% or more, more than 20%, 22% or more, 24% or more, particularly 25% or more. On the other hand, if B ₂ O ₃ When the content of (b) is too large, heat resistance and chemical durability tend to be deteriorated, and transmittance tends to be deteriorated due to phase separation. Thus, B ₂ O ₃ The upper limit range of (b) is 30% or less, preferably 28% or less and 27% or less.

B ₂ O ₃ －Al ₂ O ₃ Preferably more than 0%, more preferably 1% or more, 2% or more, 3% or more, 4% or more, 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, and particularly preferably 10% or more. The larger the value, the more likely the Young's modulus is to be lowered, and therefore the drop impact strength is likely to be improved. In the case of film-like glass, the radius of curvature is easily reduced. In addition, "B" is ₂ O ₃ －Al ₂ O ₃ "means from B ₂ O ₃ Less Al than the content of ₂ O ₃ Amount after the content of (c).

The alkali metal oxide is a component for improving the fusibility and moldability, but if the content is too large, the density increases, the water resistance decreases, and the thermal expansion decreasesThe coefficient of expansion becomes excessively high, the thermal shock resistance is lowered, and the coefficient of expansion is hardly matched with the coefficient of thermal expansion of the surrounding material. In addition, when photocatalyst particles are supported on the surface of the alkali metal oxide, the photocatalytic activity function is lowered. Thus, li ₂ O+Na ₂ O+K ₂ The content of O is 0 to 3%, preferably 0 to 2%, 0 to 1%, 0 to 0.5%, 0 to 0.2%, 0 to 0.1%, particularly preferably 0 to less than 0.1%. Li ₂ O、Na ₂ O and K ₂ The respective contents of O are preferably 0 to 3%, 0 to 2%, 0 to 1%, 0 to 0.5%, 0 to 0.2%, 0 to 0.1%, and particularly preferably 0 to less than 0.1%. If the content of the alkali metal oxide is small, siO is not necessary ₂ Alkaline barrier films such as films.

The alkaline earth metal oxide is a component that lowers the liquidus temperature and makes it difficult for crystalline foreign matter to be generated in the glass, and is also a component that improves the meltability and moldability. The content of MgO + CaO + SrO + BaO is 0 to 12%, preferably 0 to 10%, 0 to 8%, 0 to 7%, 1 to 7%, 2 to 7%, 3 to 9%, particularly preferably 3 to 6%. If the content of MgO + CaO + SrO + BaO is too small, the flux performance is not sufficiently exhibited, the meltability is lowered, and the devitrification resistance is liable to be lowered. On the other hand, if the content of MgO + CaO + SrO + BaO is too large, the density increases, making it difficult to reduce the weight of the glass, and the thermal expansion coefficient increases excessively, so that the thermal shock resistance tends to decrease. In addition, the phase separation of the glass is deteriorated. Further, the young's modulus becomes high, and it is difficult to reduce the radius of curvature in the case of a film-like glass.

If the mass ratio is (MgO + CaO + SrO + BaO)/Al ₂ O ₃ If the amount is too small, the devitrification resistance is lowered, and it becomes difficult to form a glass sheet by the overflow down-draw method. On the other hand, if the mass ratio (MgO + CaO + SrO + BaO)/Al is ₂ O ₃ If it is too large, the density and the thermal expansion coefficient may be excessively increased. Therefore, the mass ratio of (MgO + CaO + SrO + BaO)/Al ₂ O ₃ Preferably 0.1 to 1.2, 0.2 to 1.2, 0.3 to 1.2, 0.4 to 1.1, and particularly preferably 0.5 to 1.0. In addition, (MgO + CaO + SrO + BaO)/Al ₂ O ₃ Means that the content of MgO + CaO + SrO + BaO is divided by Al ₂ O ₃ Obtained byThe value is obtained.

Mass ratio (SrO + BaO)/B ₂ O ₃ Preferably 0.1 or less, 0.05 or less, 0.03 or less, and particularly preferably 0.02 or less. This makes it easy to improve scratch resistance and crack resistance. Here, srO + BaO means the total amount of SrO and BaO. In addition, (SrO + BaO)/B ₂ O ₃ Refers to the SrO + BaO content divided by B ₂ O ₃ The value obtained by (a).

In addition, the mass ratio B ₂ O ₃ The value of (SrO + BaO) is preferably 10 or more, 20 or more, 30 or more, 40 or more, and particularly preferably 50 or more. This makes it easy to improve the scratch resistance and crack resistance. In addition, B is ₂ O ₃ /(SrO + BaO) means that the content of SrO + BaO is divided by B ₂ O ₃ The value obtained by (a).

B ₂ O ₃ The content of- (MgO + CaO + SrO + BaO) is preferably 5% or more, 6% or more, 7% or more, 8% or more, 9% or more, 10% or more, 11% or more, and particularly preferably 12% or more. Thus, the density is easily decreased, and therefore, the weight reduction of the apparatus is easily achieved. In addition, the young's modulus becomes small.

MgO is a component that reduces the high-temperature viscosity without lowering the strain point and improves the meltability, and is the most effective component for reducing the density among alkaline earth metal oxides. Or a component that improves crack resistance. In addition, the component is also a component that easily induces phase separation. When phase separation occurs in the glass, the surface of the glass is easily modified into a porous state by acid treatment, and photocatalyst particles are supported, whereby a high photocatalytic activity function can be obtained. The content of MgO is preferably 0 to 12%, 0 to 10%, 0 to 8%, 0.1 to 6%, 0.5 to 3%, particularly preferably 1 to 2%. However, if the content of MgO is too large, the liquidus temperature rises and the devitrification resistance is liable to decrease. In addition, glass is likely to cause phase separation, and transparency is likely to be lowered.

CaO is a component that remarkably improves the meltability by reducing the high-temperature viscosity without lowering the strain point, and is a component that has a large effect of improving the devitrification resistance in the glass composition system of the present invention. Therefore, a suitable lower limit range of CaO is 0% or more, 0.1% or more, 1% or more, 2% or more, 3% or more, and particularly 4% or more. On the other hand, if the content of CaO is too large, the thermal expansion coefficient and the density are excessively increased, the compositional balance of the glass composition is deteriorated, and the devitrification resistance is easily lowered. Therefore, a suitable upper limit range of CaO is 12% or less, 10% or less, 8% or less, 7% or less, 6% or less, and particularly 5% or less.

SrO is a component that reduces high-temperature viscosity and improves meltability without lowering strain point, but if the content of SrO is increased, scratch resistance and crack resistance tend to be lowered. Therefore, the content of SrO is preferably 0 to 3%, 0 to 2%, 0 to 1.5%, 0 to 1%, 0 to 0.5%, and particularly preferably 0 to 0.1%.

BaO is a component that reduces the high-temperature viscosity and improves the meltability without lowering the strain point, but if the content of BaO is increased, the scratch resistance and the crack resistance are liable to be lowered. Therefore, the content of BaO is preferably 0 to 3%, 0 to 2%, 0 to 1.5%, 0 to 1%, 0 to 0.5%, particularly preferably 0 to less than 0.1%.

The mass ratio (SrO + BaO)/(MgO + CaO) is preferably 1 or less, 0.8 or less, 0.5 or less, and particularly preferably 0.3 or less. If the mass ratio (SrO + BaO)/(MgO + CaO) is too large, the density of the glass becomes too large.

In addition to the above components, the following components may be incorporated into the glass composition.

ZnO is a component for improving meltability, but if a large amount of ZnO is contained in the glass composition, the glass is easily devitrified, and the density is also easily increased. Therefore, the content of ZnO is preferably 0 to 5%, 0 to 3%, 0 to 0.5%, 0 to 0.3%, and particularly preferably 0 to 0.1%.

ZrO ₂ Is a component for improving the Young's modulus. ZrO (ZrO) ₂ The content of (b) is preferably 0 to 5%, 0 to 3%, 0 to 0.5%, 0 to 0.2%, particularly preferably 0 to 0.02%. If ZrO ₂ If the content of (b) is too large, the liquid phase temperature rises, and devitrified zircon crystals are likely to precipitate.

TiO ₂ The component is a component for reducing the high-temperature viscosity and improving the meltability, and the component for suppressing the overexposure, but if the glass composition contains a large amount, the glass is colored, and the transmittance is liable to decrease. Thus, tiO ₂ The content of (b) is preferably 0 to 5%0 to 3%, 0 to 1%, 0 to 0.1%, particularly preferably 0 to 0.02%.

P ₂ O ₅ Is a component for improving the devitrification resistance, but if a large amount is contained in the glass composition, the glass tends to separate phases and turn milky white, and there is a fear that the water resistance is remarkably lowered. Thus, P ₂ O ₅ The content of (b) is preferably 0 to 5%, 0 to 1%, 0 to 0.5%, particularly preferably 0 to 0.1%.

SnO ₂ Is a component having a good clarifying action in a high-temperature region, and is a component that lowers the high-temperature viscosity. SnO ₂ The content of (B) is preferably 0 to 1%, 0.01 to 0.5%, 0.05 to 0.3, particularly preferably 0.1 to 0.3%. If SnO ₂ When the content of (B) is too large, snO ₂ The devitrified crystals of (2) are easily precipitated in the glass.

As described above, snO is added to the glass of the present invention ₂ As the fining agent, it is preferable, but as long as the glass characteristics are not impaired, ceO may be added in an amount of up to 1% ₂ 、SO ₃ C, metal powder (e.g., al, si, etc.).

As ₂ O ₃ 、Sb ₂ O ₃ F, cl also function effectively as a fining agent, and the glass of the present invention does not exclude the inclusion of these components, but the content of these components is preferably less than 0.1%, particularly preferably less than 0.05%, respectively, from the environmental viewpoint.

The glass of the present invention preferably has the following characteristics.

The density is preferably 2.40g/cm ³ 2.35g/cm or less ³ Hereinafter, 2.30g/cm is particularly preferable ³ The following. If the density is too high, it is difficult to achieve weight reduction of the glass.

The thermal expansion coefficient in the temperature range of 30-380 ℃ is preferably 25-40 x 10 ^-7 /℃、30～38×10 ^-7 Per DEG C, particularly preferably from 32 to 36X 10 ^-7 /. Degree.C.. If the coefficient of thermal expansion is too low, it is difficult to match the coefficients of thermal expansion of the various peripheral materials, and the glass sheet is likely to warp. On the other hand, if the thermal expansion coefficient is too high, the thermal shock resistance is liable to decrease.

The strain point is preferably 610 ℃ or lower, 600 ℃ or lower, 590 ℃ or lower, 580 ℃ or lower, and particularly preferably 570 ℃ or lower. When an object falling from a high place hits the glass, the glass is easily deformed to relax the collision stress and the falling impact if the viscosity, particularly the strain point of the glass is low.

10 ^2.5 The temperature at dPa · s is preferably 1650 ℃ or lower, 1620 ℃ or lower, 1600 ℃ or lower, and particularly preferably 1580 ℃ or lower. Bubble quality affects not only glass yield, but also touch sensor yield. Therefore, it is important to reduce the high-temperature viscosity and improve the foam quality. Here, "10 ^2.5 The "temperature at dPa · s" is a value measured by a platinum ball pulling method.

The Young's modulus is preferably 66GPa or less, 65GPa or less, 63GPa or less, 61GPa or less, and particularly preferably 60GPa or less. If the Young's modulus is reduced, the stress generated per a certain amount of deformation can be reduced. In addition, when an object falling from a high place collides with the glass, the glass is easily elastically deformed, and thus the impact of the falling is easily relaxed. As a result, the amount of deformation suitable for glass is limited to a small range of applications, and is particularly suitable for cover glass. In the case of forming the glass into a film, the lower the young's modulus, the smaller the curvature radius, the more the glass can be rolled into a roll.

The liquid phase temperature is preferably 1180 ℃ or lower, 1150 ℃ or lower, 1130 ℃ or lower, 1110 ℃ or lower, or 1090 ℃ or lower, and particularly preferably 1070 ℃ or lower. The liquid phase viscosity is preferably 10 ^5.0 10 dPas or more ^5.2 10 dPas or more ^5.3 10 dPas or more ^5.5 dPa · s or more, particularly preferably 10 ^5.7 dPa · s or more. Thus, devitrification is less likely to occur during molding, and therefore, a glass sheet is easily molded by an overflow down-draw method or the like, and the surface quality of the glass sheet is improved.

The scratch resistance is preferably 5N or more, 7N or more, 10N or more, 12N or more, or 15N or more. If the scratch resistance is low, the trace of the crack hardly enters the glass. Here, the "scratch resistance" refers to a load of generating a crack having a length of 15% or more of the total scratch length and a width of 2 times or more of the scratch width in a direction perpendicular to the scratching direction after the surface of the glass is scratched with a knoop indenter at a speed of 0.4 mm/s. The scratch test was carried out in a constant temperature and humidity chamber which holds 30% of humidity and 25% of temperature, using a Bruker friction abrasion tester UMT-2.

The cracking resistance is preferably 200gf or more, 500gf or more, 700gf or more, 900gf or more, 1200gf or more, 1500gf or more, 2000gf or more, 2500gf or more, 3000gf or more, and particularly preferably 35000gf or more. If the cracking resistance is low, the glass is likely to be scratched. Here, "crack resistance" refers to a load at which the crack generation rate reaches 50%. The "crack occurrence rate" is a value measured as follows. First, in a constant temperature and humidity chamber which holds a humidity of 30% and a temperature of 25 ℃, a vickers indenter set to a predetermined load was driven into the glass surface (optical polished surface) for 15 seconds, and the number of cracks generated from 4 corners of the indentation after the 15 seconds was counted (maximum 4 for 1 indentation). The indenter was driven 50 times in this way, and after the total number of cracks generated was determined, the total number of cracks generated was determined by the equation of 200 × 100 (%).

The dielectric loss tangent at a frequency of 1MHz is preferably 0.01 or less and 0.05 or less, and particularly preferably 0.001 or less.

The internal friction is preferably 0.01 or less, 0.002 or less, 0.001 or less, and particularly preferably 0.0008 or less.

The glass of the present invention can be produced by charging a glass batch prepared to have a predetermined glass composition into a continuous glass melting furnace, melting the glass batch by heating, clarifying the obtained molten glass, supplying the clarified glass to a forming apparatus, and forming the clarified glass into a flat plate shape or the like.

The glass of the present invention is preferably formed by the overflow downdraw process. Thus, a glass plate having good surface quality without polishing can be obtained. In the case of the overflow down-draw method, the surface of the glass sheet to be the surface is formed in a free surface state without contacting the tubular (Japanese patent: 27147shaped) refractory, and therefore, the surface quality of the glass sheet can be improved. The glass of the present invention has excellent devitrification resistance and viscosity characteristics suitable for molding, and therefore, a glass sheet can be efficiently molded by the overflow down-draw method.

In addition to the overflow downdraw method, various forming methods can be used for the glass of the present invention. For example, a forming method such as a slobbering down (slobbering down) method, a float method, a roll out (roll out) method, or the like can be used.

The glass of the present invention preferably has a flat plate shape, that is, a glass plate, and the plate thickness thereof is preferably 0.6mm or less, 0.5mm or less, 0.4mm or less, and particularly preferably 0.05 to 0.3mm. If it is in the shape of a flat plate, it can be easily applied to a cover glass. Further, the smaller the thickness of the glass sheet, the easier the weight of the glass sheet is reduced, and the lighter the weight of the apparatus is.

The glass of the present invention is preferably in the form of a film. In this case, the thickness is preferably 200 μm or less, 100 μm or less, 50 μm or less, and particularly preferably 30 μm or less.

The glass of the present invention preferably has various functional films on the surface. As the functional film, for example, a transparent conductive film for imparting conductivity, an antireflection film for reducing reflectance, an antiglare film (antiglare film) for imparting an antiglare function, improving visibility, and improving writing feeling of a touch pen or the like, an antifouling film for preventing adhesion of a fingerprint, and imparting water repellency and oil repellency, and the like are preferable. The transparent conductive film functions as an electrode for a touch sensor, and is preferably formed on a surface to be a display device side, for example. As the transparent conductive film, for example, tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), or the like is used. In particular, ITO is preferable because of its low resistance. The ITO can be formed by, for example, a sputtering method. The FTO and ATO can be formed by a CVD (Chemical Vapor Deposition) method. The antireflection film is formed on the surface to be the observer side. In addition, when there is a gap between the touch panel and the cover glass, it is preferable to form an antireflection film also on the surface to be the back surface side of the cover glass (the side opposite to the display device side). The antireflection film is preferably a multilayer dielectric film in which, for example, a low refractive index layer having a relatively low refractive index and a high refractive index layer having a relatively high refractive index are alternately laminated. The antireflection film can be formed by, for example, sputtering or CVD. When used as a cover glass, the antiglare film is formed to be an observerA surface of the side. The antiglare film preferably has a substantially convex-concave structure. The structure may be an island-like structure partially covering the surface of the glass. Further, the structure is preferably not substantially regular. Based on this, the anti-glare function can be improved. The antiglare film can be coated with SiO by spraying, for example ₂ And drying the light-transmitting material. When used as a cover glass, the antifouling film is formed on the surface to be the viewer side. The antifouling film preferably comprises a fluorine-containing polymer containing silicon in the main chain. The fluorine-containing polymer is preferably a polymer having an-O-Si-O-unit in the main chain and a fluorine-containing water-repellent functional group in the side chain. The fluoropolymer can be synthesized, for example, by dehydrating and condensing silanol. When the antireflection film and the antifouling film are formed, the antifouling film is preferably formed on the antireflection film. In the case of further forming the anti-glare film, it is preferable to first form the anti-glare film, and form the anti-reflection film and/or the anti-smudge film thereon.

The glass of the present invention or the cover glass using the glass of the present invention preferably has photocatalyst particles supported on the surface. The photocatalyst particles may use particles containing various materials. For example, titanium dioxide particles, tungsten oxide particles, and the like can be used. Particular preference is given to titanium dioxide particles in the anatase form. The reason why anatase type titanium dioxide is preferred is that the titanium dioxide has higher reactivity as a photocatalyst than rutile type or brookite type titanium dioxide. The average particle diameter of the photocatalyst particles is preferably 1nm or more and 2nm or more, particularly preferably 3nm or more, and is preferably 200nm or less, 100nm or less, 50nm or less, 30nm or less, 20nm or less, particularly preferably 10nm or less.

In addition to the ultraviolet-responsive photocatalyst, visible-light-responsive photocatalysts such as nitrogen-doped titanium dioxide particles, copper oxide-doped titanium dioxide particles, and copper oxide-doped tungsten oxide particles may be used. If this type of photocatalyst is employed, the indoor environment can also obtain the effect of the photocatalyst. In addition, if used in a field environment, there is an advantage in that more light energy can be used than the ultraviolet-responsive type.

In order to support a large number of photocatalyst particles on the surface, the glass surface is preferably porous. As a method for making the surface porous, a method of subjecting the glass surface to acid treatment can be employed. That is, the glass composition according to the present invention has a property of easily separating phases, and in many cases, surface phase separation occurs. Therefore, if the surface is subjected to acid treatment, a phase having low acid resistance, which contains a large amount of boric acid, is melted out, and a phase having high acid resistance, which contains a large amount of silicon, remains on the surface. As a result, the glass surface becomes porous, and the specific surface area increases significantly. Since the phase separation is not easily caused in the glass, the glass surface is only porous even by the acid treatment. The thickness (depth) of the porous surface (porous layer) is preferably 10 μm or less. If the thickness of the porous surface is too small, the effect of increasing the specific surface area is small. If the surface thickness is too large, organic substances and the like may accumulate inside, and the function as a photocatalyst may be deteriorated.

Next, a method of supporting the photocatalyst particles on the glass will be described.

First, a glass having the above composition is prepared. For the prepared glass, phase separation is important. The size of the phase separation particles contained in the glass is preferably 1nm or more, 2nm or more, 3nm or more, 5nm or more, particularly preferably 10nm or more, and further preferably 100nm or less, 80nm or less, particularly preferably 60nm or less. Such glass can be made using an overflow downdraw method. The characteristics such as the composition and properties of the glass are as described above, and the description thereof is omitted here.

As the pretreatment, it is preferable that the surface of the glass is subjected to an acid treatment. By performing the acid treatment on the surface in advance, the surface of the glass can be modified to be porous, and the specific surface area can be increased. As a method of the acid treatment, for example, immersion of the glass in an acid solution can be employed. Alternatively, the acid solution may be sprayed on the glass. As the acid, for example, hydrochloric acid, nitric acid, sulfuric acid, or the like can be used.

Next, a solution containing photocatalyst particles was applied to the surface of the glass. The coating method is not limited. For example, a method of dispersing photocatalyst particles and immersing glass in a solution can be used. Alternatively, a solution containing photocatalyst particles may be sprayed onto the glass surface.

Subsequently, the glass is heat-treated. The photocatalyst particles can be fixed to the glass surface by heat treatment. The heating temperature is preferably 250 ℃ or higher, 410 ℃ or higher, and particularly preferably 420 ℃ or higher. The higher the heating temperature, the more firmly the photocatalyst particles can be fixed on the glass surface. If the heating temperature is too high, the glass may soften, and the pores may be clogged, resulting in a decrease in the surface area. Therefore, the heating temperature is preferably 650 ℃ or lower.

In this way, glass having a photocatalyst body supported on the surface thereof can be obtained.

Next, preferred embodiments of the glass of the present invention are illustrated.

(1) A glass comprising, as a glass composition, by mass: siO 2 ₂ 55～70％、Al ₂ O ₃ 3～15％、B ₂ O ₃ 18～30％、Li ₂ O+Na ₂ O+K ₂ O 0～1％、MgO+CaO+SrO+BaO 0～7％。

(2) A glass comprising, as a glass composition, by mass: siO 2 ₂ 55～70％、Al ₂ O ₃ 3～12％、B ₂ O ₃ 20～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 0.5 percent of O, 0 to 6 percent of MgO + CaO + SrO + BaO and the density of the mixture is 2.28g/cm ³ The strain point is 610 ℃ or lower, and the Young's modulus is 66GPa or lower.

(3) A glass comprising, as a glass composition, by mass: siO 2 ₂ 58～70％、Al ₂ O ₃ 7～20％、B ₂ O ₃ 18～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 1% of O, 0 to 6% of MgO + CaO + SrO + BaO, and a Young's modulus of 63GPa or less.

(4) A glass with a density of 2.40g/cm ³ The thermal expansion coefficient in the temperature range of 30-380 ℃ is 36 x 10 ^-7 /° C or less, a strain point of 610 ℃ or less, and a Young's modulus of63GPa or less.

(5) A glass with a density of 2.30g/cm ³ Hereinafter, the coefficient of thermal expansion in the temperature range of 30 to 380 ℃ is 25 to 36X 10 ^-7 /° C, a strain point of 610 ℃ or less, and a Young's modulus of 63GPa or less.

(6) A glass with a density of 2.30g/cm ³ The thermal expansion coefficient in the temperature range of 30-380 ℃ is 25-40 multiplied by 10 ^-7 /° C, a strain point of 610 ℃ or less, and a Young's modulus of 65GPa or less.

Example 1

The present invention will be described in detail below with reference to examples. It should be noted that the following embodiments are merely examples. The present invention is not limited in any way by the following examples.

Tables 1 to 6 show examples of the present invention (sample Nos. 1 to 42). In the table, [ none ] indicates no measurement.

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

[ Table 5]

[ Table 6]

Samples Nos. 1 to 42 were produced as follows. First, a glass raw material prepared to have a glass composition shown in the table was put into a platinum crucible, melted at 1600 ℃ for 24 hours, and then flowed out onto a carbon plate to be formed into a flat plate. Next, the obtained samples were evaluated for density ρ, coefficient of thermal expansion α, strain point Ps, annealing point Ta, softening points Ts, 10 ⁴ Temperature at dPa · s, 10 ³ Temperature at dPa · s, 10 ^2.5 Temperature at dPa · s, young's modulus E, liquidus temperature TL, liquidus viscosity log η TL, scratch resistance (scratch resistance), and crack resistance (crack resistance). In this example, snO was used as a fining agent ₂ However, snO may also be used ₂ Other clarifying agents. In addition, if the defoaming is good by adjusting the melting conditions and compounding ingredients, the clarifying agent may not be used.

The density ρ is a value measured by a known archimedes method.

The thermal expansion coefficient α is a value measured by using an dilatometer, and is an average value in a temperature range of 30 to 380 ℃.

The strain point Ps, annealing point Ta and softening point Ts are values measured according to the methods of ASTM C336, C338.

10 ^4.0 Temperature at dPa · s, 10 ^3.0 Temperature at dPa · s and 10 ^2.5 The temperature at dPa · s is a value measured by a platinum ball pulling method.

The young's modulus E is a value measured by a resonance method. The larger the Young's modulus, the larger the specific Young's modulus (Young's modulus/density), and in the case of a flat plate shape, the glass is difficult to bend due to its own weight.

The liquidus temperature TL was a value obtained by measuring the temperature at which crystals were precipitated, by placing a glass powder which passed through a standard sieve 30 mesh (500 μm) but remained in a sieve 50 mesh (300 μm) in a platinum boat, holding the boat in a temperature gradient furnace for 24 hours.

The liquidus viscosity log η TL is a value obtained by measuring the viscosity of the glass at the liquidus temperature TL by the platinum ball pulling method.

With respect to scratch resistance (scratch resistance), when the glass surface was scratched with a knoop indenter at a speed of 0.4mm/s, a load at which a crack having a length of 15% or more of the total scratch length and a width of 2 times or more of the scratch was generated in a direction perpendicular to the scratching direction was measured, and a case where the load was 10N or more was evaluated as "a", and a case where the load was less than 10N was evaluated as "B". The scratch test was carried out in a constant temperature and humidity chamber maintained at 30% humidity and 25% temperature by using a friction and abrasion tester UMT-2 of Bruker.

The cracking resistance (cracking resistance) is a value obtained by measuring a load at which the crack generation rate reaches 50%. The crack generation rate was measured as follows. First, in a constant temperature and humidity chamber maintained at a humidity of 30% and a temperature of 25 ℃, a vickers indenter set to a predetermined load was driven into the glass surface (optical polished surface) for 15 seconds, and the number of cracks generated from 4 corners of the indentation after the 15 seconds was counted (maximum 4 for 1 indentation). The indenter was driven 50 times in this way, and after the total number of cracks generated was determined, the total number of cracks generated was determined by the equation of 200 × 100 (%).

The dielectric loss tangent at a frequency of 1MHz was measured under the conditions of 1MHz and 25 ℃ by a known parallel plate capacitor method.

The internal friction was measured using a known half-width method (half 20385method).

Example 2

The materials of samples No.4 and 5 shown in Table 1 were melted in a test melting furnace to obtain molten glass, and then a glass plate having a thickness of 0.3mm was formed by the overflow down-draw method. As a result, the glass plate had a warp of 0.075% or less, a Warp (WCA) of 0.15 μm or less (cut fh:0.8mm, fl:8 mm) and a surface roughness (Ry)

Hereinafter (cut. Lamda.c: 9 μm). In the molding, the surface quality of the glass sheet is adjusted by appropriately adjusting the speed of the pulling roll, the speed of the cooling roll, the temperature of the heating device, the temperature of the molten glass, the flow rate of the molten glass, the sheet pulling speed, the rotational speed of the stirrer, and the like. The "warpage" refers to a value measured by placing a glass plate on an optical plate and using a gap measuring instrument described in JIS B-7524. "warp" refers to a value obtained by measuring the WCA (filter center line warp) described in JIS B-0610 using a stylus-type surface shape measuring apparatus, and this measurement method for measuring the surface warp of the fpd glass substrate mounted with SEMI STD D15-1296 ". "average surface roughness (Ry)" means a value measured according to SEMI D7-94 "method for measuring surface roughness of FPD glass substrate".

Example 3

The glass No.5 prepared in example 2 was processed into a size of 100 mm. Times.100 mm. Times.0.3 mm, to prepare a glass sample. The glass sample was immersed in 80-5 wt% HCl for 10 minutes to modify the surface to be porous. Next, the acid-treated glass sample was immersed in an aqueous ethanol solution for 10 minutes and washed.

Subsequently, titanium dioxide (anatase type) particles having an average particle diameter of 5nm were dispersed in a 2-propanol solution at 2wt%, and the glass sample was immersed in the obtained solution for 5 minutes to attach the titanium particles to the surface of the glass sample.

Then, the glass sample was placed in an annealing furnace (annealer) maintained at 500 ℃ and, after heat treatment for 2 hours, taken out, thereby obtaining a glass sample having titania particles supported on the surface thereof. The sample thus obtained is irradiated with ultraviolet rays, and then the organic matter can be decomposed by the photocatalytic function of the titanium dioxide particles.

Example 4

The material of sample No.19 shown in Table 3 was melted in a test melting furnace to obtain molten glass, and then film-like glass having a thickness of 100 μm was formed by the overflow downdraw method. The film-like glass can be wound in a roll shape having a curvature radius of 60 mm.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

It should be noted that the present application is based on and requires the priority and benefit of japanese patent application laid out on 4/3/2014 (japanese patent application 2014-076596), japanese patent application laid out on 4/22/2014 (japanese patent application 2014-087828), japanese patent application laid out on 5/23/2014 (japanese patent application 2014-106847), japanese patent application laid out on 10/23/2014 (japanese patent application 2014-216332), and japanese patent application laid out on 11/13/2014 (japanese patent application 2014-230599), the entire contents of which are incorporated by reference. The entire contents of which are hereby incorporated by reference.

Industrial applicability

The glass of the present invention is suitable as a cover glass, but in addition to this, it is also suitable as a substrate for flat panel displays such as liquid crystal displays and organic EL displays, a substrate for image sensors such as CSP, CCD and CIS, and a substrate for touch sensors. In addition, when the photocatalyst particles are supported on the surface, the antifouling function can be maintained for a long time, and therefore, the photocatalyst particles can be used for applications other than the above-mentioned applications, for example, as architectural glass.

Claims

1. A glass is characterized in that the glass is characterized in that,

the glass composition contains, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～20％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ O 0～3％、MgO+CaO+SrO+BaO 0～12％。

2. The glass according to claim 1,

the glass composition contains, by mass: siO 2 ₂ 58～70％、Al ₂ O ₃ 7～20％、B ₂ O ₃ 18～30％、Li ₂ O+Na ₂ O+K ₂ O 0～1％、MgO+CaO+SrO+BaO 0～10％。

3. The glass according to claim 1,

the glass composition contains, by mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～15％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ O 0～3％、MgO+CaO+SrO+BaO 0～8％。

4. The glass according to any one of claims 1 to 3,

B ₂ O ₃ the content of- (MgO + CaO + SrO + BaO) is 5% by mass or more.

5. The glass according to any one of claims 1 to 4,

(SrO + BaO)/(MgO + CaO) is 1 or less in mass ratio.

6. The glass according to any one of claims 1 to 5,

based on the quality standard, B ₂ O ₃ Content ratio of (A) to (B) Al ₂ O ₃ The content of (A) is large.

7. The glass according to any one of claims 1 to 6,

the density of the glass is 2.40g/cm ³ The thermal expansion coefficient in the temperature range of 30-380 ℃ is 25-40 multiplied by 10 ^-7 /° C, the strain point is 610 ℃ or less, and the Young's modulus is 66GPa or less.

8. The glass according to any one of claims 1 to 7,

viscosity of liquid phase is 10 ^5.0 dPas or more.

9. The glass according to any one of claims 1 to 8,

the glass is formed by an overflow downdraw process.

10. The glass according to any one of claims 1 to 9,

the glass is used as a cover glass.

11. The glass according to any one of claims 1 to 10,

the glass was not subjected to ion exchange treatment.

12. The glass according to any one of claims 1 to 11,

photocatalyst particles are supported on the surface of the glass.

13. The glass according to claim 12,

the glass surface is porous.

14. The glass according to claim 12 or 13,

the photocatalyst particles are titanium dioxide particles.

15. A protective glass is characterized in that the protective glass is provided with a glass body,

the glass according to any one of claims 1 to 14 is used.

16. A method for producing glass, characterized in that,

the glass composition comprises the following components in mass: siO 2 ₂ 50～70％、Al ₂ O ₃ 0～20％、B ₂ O ₃ 15～30％、Li ₂ O+Na ₂ O+K ₂ 0 to 3 percent of O and 0 to 12 percent of MgO + CaO + SrO + BaO.

17. The method for producing glass according to claim 16,

further, a solution containing a photocatalyst component is applied to the surface of the glass, and then, heat treatment is performed to support photocatalyst particles on the surface of the glass.

18. The method for producing glass according to claim 17,

after the glass surface is subjected to acid treatment, a solution containing a photocatalyst component is applied.

19. The method for producing glass according to claim 17 or 18,

as the solution containing the photocatalyst component, a solution in which titanium dioxide particles are dispersed is used.