WO2024004707A1 - Film-attached glass substrate, and method for producing same - Google Patents

Abstract

Provided is a film-attached glass substrate, which can achieve a high level of anti-glare and of scratch resistance.　A film-attached glass substrate 1 comprises: a glass substrate 2; and an anti-glare film 3, which is provided on a main surface 2a of the glass substrate 2 and comprises silicon oxide as a primary component. The arithmetic mean height Sa of a surface 3a of the anti-glare film 3 is 0.3 µm or more. In a pencil hardness test specified in JIS K5600-5-4: 1999, when the presence or absence of scratches on the surface 3a of the anti-glare film 3 is assessed by observing the surface 3a of the anti-glare film 3 using a metal microscope at a magnification of 100 times, the pencil hardness is 7H or higher.

Description

Glass substrate with film and method for manufacturing the same

The present invention relates to a film-coated glass substrate having an anti-glare film and a method for manufacturing the film-coated glass substrate.

Conventionally, in displays such as mobile phones, tablet terminals, televisions, and digital signage, visibility deteriorates due to reflected images reflected on the display surface due to indoor lighting (fluorescent lights, etc.) or external light such as sunlight. Sometimes. Anti-glare treatment and anti-reflection treatment are known as treatments for suppressing reflections caused by external light.

Patent Document 1 below discloses a cover glass that includes a glass plate and an anti-glare layer provided on the glass plate. In Patent Document 1, an anti-glare layer is formed by applying an inorganic paint onto a glass plate by a spray coating method, thereby imparting an anti-glare effect to the cover glass. As the main components of the above-mentioned inorganic paint, a silica precursor, an alumina precursor, a zirconia precursor, a titania precursor, etc. are used.

International Publication No. 2020/218056

In recent years, film-coated glass substrates such as those disclosed in Patent Document 1 are required to have higher anti-glare properties. At this time, in order to improve anti-glare properties, a method of increasing the thickness of the anti-glare film can be considered. However, increasing the thickness of the anti-glare film may reduce the scratch resistance. As a result, there is a problem in that many scratches occur on the anti-glare film due to long-term use.

An object of the present invention is to provide a film-coated glass substrate and a method for manufacturing the film-coated glass substrate, which can achieve both high levels of anti-glare properties and scratch resistance.

Each aspect of a film-coated glass substrate and a method for manufacturing the film-coated glass substrate that solves the above problems will be described.

A film-coated glass substrate according to aspect 1 of the present invention includes a glass substrate and an anti-glare film, which is provided on the main surface of the glass substrate and has silicon oxide as a main component, and has a surface of the anti-glare film. The arithmetic mean height Sa is 0.3 μm or more, and in the pencil hardness test of JIS K5600-5-4:1999, the presence or absence of scratches on the surface of the anti-glare film is determined using a metallurgical microscope at a magnification of 100 times. The anti-glare film is characterized by having a pencil hardness of 7H or higher, as determined by observing the surface of the anti-glare film.

In the film-coated glass substrate according to Aspect 2, in Aspect 1, it is preferable that the haze of the film-coated glass substrate measured in accordance with JIS K7136:2000 is 30% or more.

In the film-coated glass substrate according to Aspect 3, in Aspect 1 or 2, it is preferable that the strain point of the glass substrate is 550° C. or higher.

In the film-coated glass substrate according to Aspect 4, in any one of Aspects 1 to 3, the ratio between the root mean square height Sq and the minimum autocorrelation length Sal at the surface of the anti-glare film (Sq/Sal) is preferably 0.05 or more.

A method for producing a film-coated glass substrate according to aspect 5 of the present invention includes the steps of: forming a coating film having unevenness by applying a coating liquid containing a silica precursor on a glass substrate by a spray coating method; forming an anti-glare film by baking the coating film at a temperature of 500° C. or higher, and forming the anti-glare film so that the arithmetic mean height Sa on the surface of the anti-glare film is 0.3 μm or higher. It is characterized by the formation of

In the method for manufacturing a glass substrate with a film according to Aspect 6, in Aspect 5, when firing the coating film, it is preferable that the coating film is fired at a temperature equal to or lower than the strain point of the glass substrate.

In the method for manufacturing a glass substrate with a film according to Aspect 7, in Aspect 5 or 6, it is preferable that the strain point of the glass substrate is 550° C. or higher.

In the method for producing a glass substrate with a film according to aspect 8, in any one of aspects 5 to 7, the silica precursor is an N-functional silicon alkoxide (N=2, 3, 4) and the N-functional silicon alkoxide. It is preferable that at least one of the hydrolyzed condensates of silicon alkoxides is included.

According to the present invention, it is possible to provide a film-coated glass substrate and a method for manufacturing the film-coated glass substrate, which can achieve both high levels of anti-glare properties and scratch resistance.

FIG. 1 is a schematic cross-sectional view showing a film-coated glass substrate according to a first embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a film-coated glass substrate according to a second embodiment of the present invention.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely illustrative, and the present invention is not limited to the following embodiments.

[First embodiment]
(Glass substrate with film)
FIG. 1 is a schematic cross-sectional view showing a film-coated glass substrate according to a first embodiment of the present invention. As shown in FIG. 1, the film-coated glass substrate 1 includes a glass substrate 2 and an anti-glare film 3. An anti-glare film 3 is provided on a glass substrate 2.

In this embodiment, the glass substrate 2 has a substantially rectangular plate shape. However, the glass substrate 2 may have a substantially disk-like shape, for example, and its shape is not particularly limited.

It is preferable that the glass substrate 2 is a glass substrate that transmits at least part of light in the wavelength range of 450 nm to 700 nm. It is preferable that the glass substrate 2 is a transparent glass substrate. In this specification, "transparent" means that the light transmittance in the visible wavelength range of 450 nm to 700 nm is 70% or more.

The strain point of the glass substrate 2 is not particularly limited, but is preferably 500°C or higher, more preferably 550°C or higher, even more preferably 560°C or higher, even more preferably 570°C or higher, even more preferably 580°C or higher, and More preferably 590°C or higher, even more preferably 600°C or higher, even more preferably 610°C or higher, even more preferably 620°C or higher, even more preferably 630°C or higher, even more preferably 640°C or higher, even more preferably is 650°C or higher, even more preferably 660°C or higher, particularly preferably 670°C or higher, and most preferably 680°C or higher. In this case, even when the glass substrate 2 is fired at a high temperature in the manufacturing process described later, distortion in the glass substrate 2 is less likely to remain, and deformation of the film-covered glass substrate 1 can be further suppressed. Therefore, when the film-coated glass substrate 1 is used for a display or the like, visibility can be further improved. Note that the upper limit of the strain point of the glass substrate 2 is not particularly limited, but may be, for example, 1000°C.

The strain point of the glass substrate 2 can be measured in accordance with ASTM C336. In addition, the strain point of the glass substrate 2 can be determined by a known method (for example, JP-A No. 2002-308643, JP-A No. 2012-041217, JP-A No. 2002-029776, JP-A No. 2006-252828, JP-A No. 2006-252828, 2022-008627, JP-A-08-295530, etc.). In particular, alkali-free glass that does not substantially contain alkali metal oxides (for example, 0.1% or less) tends to have a high strain point, and is also difficult to improve scratch resistance and chemical resistance. preferable.

The glass used for the glass substrate 2 is not particularly limited, and for example, borosilicate glass, aluminosilicate glass, quartz glass, crystallized glass, etc. can be used. Note that the glass used for the glass substrate 2 is desirably not chemically strengthened glass, since there is a risk that the chemical strengthening will deteriorate if it is fired at a high temperature in the manufacturing process described below.

The glass used for the glass substrate 2 can contain, for example, SiO ₂ , Al ₂ O ₃ , B ₂ O ₃ , alkaline earth metal oxides, alkali metal oxides, SnO ₂ and the like.

SiO ₂ is a component that forms a glass network former (network-forming oxide). The content of SiO ₂ can be, for example, 50% to 75% in mass percentage. When the content of SiO ₂ is at least the above lower limit, the strain point of the glass can be further improved. On the other hand, when the content of SiO ₂ is below the above upper limit, the high temperature viscosity can be lowered, and the meltability of the glass can be further improved.

The content of Al ₂ O ₃ can be, for example, 8% to 25% in mass percentage. When the content of Al ₂ O ₃ is at least the above lower limit, the strain point of the glass can be further improved. Further, it is possible to make the glass difficult to undergo phase separation. On the other hand, when the content of Al ₂ O ₃ is below the above upper limit, the liquidus temperature of the glass is unlikely to become high.

B ₂ O ₃ is a component that lowers the high temperature viscosity of glass and improves its meltability. The content of B ₂ O ₃ can be, for example, 0.01% to 15% in mass percentage. When the content of B ₂ O ₃ is at least the above lower limit, the meltability of the glass can be further improved. On the other hand, when the content of B ₂ O ₃ is below the above upper limit, the strain point of the glass can be further improved.

Alkaline earth metal oxides are components that lower the high temperature viscosity of glass and increase its meltability. Examples of alkaline earth metal oxides include MgO, CaO, SrO, BaO, and the like. These may be used alone or in combination. The content of alkaline earth metal oxides (total amount if multiple types are included) is, for example, 0.1% to 20%, 1% to 20%, 5% to 20%, 10% to mass percentage. It is 20%. When the content of the alkaline earth metal oxide is at least the above lower limit, the meltability of the glass can be further improved. On the other hand, when the content of the alkaline earth metal oxide is below the above upper limit, the strain point of the glass can be further improved. Moreover, the component balance of the glass composition can be made difficult to collapse, and devitrification crystals can be made difficult to precipitate.

Alkali metal oxides are components that improve the meltability of glass. Examples of the alkali metal oxide include Li ₂ O, Na ₂ O, K ₂ O, and the like. These may be used alone or in combination. The content of alkali metal oxides (total amount when multiple types are included) is preferably 0.01% or more, more preferably 0.02% or more, and even more preferably 0.05% or more in mass percentage. , preferably 24% or less, more preferably 20% or less, even more preferably 10% or less, even more preferably 5% or less, even more preferably 3% or less, even more preferably 1% or less, even more preferably 0 .5% or less, even more preferably 0.3% or less, particularly preferably 0.1% or less. When the content of the alkali metal oxide is at least the above lower limit, the meltability of the glass can be further improved. On the other hand, when the content of the alkali metal oxide is below the above upper limit, the strain point of the glass can be further improved.

SnO ₂ is a component that has a good fining effect in a high temperature range and increases the strain point of glass. The content of SnO ₂ can be, for example, 0% to 1% in mass percentage. When the content of SnO ₂ is at least the above lower limit, the strain point of the glass can be further improved. On the other hand, when the content of SnO ₂ is below the above upper limit, devitrification of the glass can be made more difficult to occur.

In addition to the above-mentioned components, the glass used for the glass substrate 2 contains other components such as ZnO, P ₂ O ₅ , TiO ₂ , Y ₂ O ₃ , Nb ₂ O ₅ , and La ₂ O ₃ . It's okay. One type of other components may be used alone, or a plurality of types may be used in combination. In addition, other components can be contained within a range that does not impede the effects of the present invention, and from the viewpoint of raw material cost, the content of other components (total amount if multiple types are included) in mass percentage, Preferably it is 10% or less, more preferably 5% or less.

Although the glass used for the glass substrate 2 is not limited to these, for example, as a glass composition, in mass %, SiO ₂ 58% to 70%, Al ₂ O ₃ 10% to 19%, B ₂ O ₃ 6.5% to 15%, MgO 0% to 2%, CaO 3% to 12%, BaO 0.1% to 5%, SrO 0% to 4%, BaO + SrO 0.1% to 6%, ZnO 0 % ~ 5%, MgO + CaO + BaO + SrO + ZnO 5% ~ 15%, Li ₂ O + Na ₂ O + K ₂ O 0% ~ 0.5%, ZrO 5% ~ 20%, TiO ₂ 0% ~ 5%, P ₂ O ₅ 0% ~ 5 % composition, or glass composition, in mass %, SiO ₂ 55% to 70%, Al ₂ O ₃ 10% to 20%, B ₂ O ₃ 0.1% to 4.5%, MgO 0 % to 1%, CaO 5% to 15%, SrO 0.5% to 5%, BaO 5% to 15%, Li ₂ O + Na ₂ O + K ₂ O 0% to 0.5%. can.

The thickness of the glass substrate 2 is not particularly limited. The thickness of the glass substrate 2 can be, for example, about 0.1 mm to 5 mm.

The glass substrate 2 has a first main surface 2a and a second main surface 2b. The first main surface 2a and the second main surface 2b are opposed to each other. An anti-glare film 3 is provided on the first main surface 2a of the glass substrate 2.

The anti-glare film 3 has an uneven structure. The anti-glare film 3 is provided to provide a so-called anti-glare effect that suppresses the reflection of external light. The anti-glare film 3 is a film whose main component is silicon oxide.

In addition, in this specification, the above-mentioned "consisting as a main component" means that the component is contained in the film in an amount of 50% by mass or more, preferably 80% by mass or more, and 90% by mass or more. % or more is more preferable. Naturally, the component may be contained in the film in an amount of 100% by mass.

The arithmetic mean height Sa at the surface 3a of the anti-glare film 3 is 0.3 μm or more. The arithmetic mean height Sa can be measured in accordance with ISO 25178 using, for example, an optical interference microscope or a laser microscope. Note that the arithmetic mean height Sa of the anti-glare film 3 can be increased by increasing the thickness of the anti-glare film 3.

Furthermore, the pencil hardness of the anti-glare film 3 is 7H or higher. Pencil hardness can be evaluated using principles, devices, instruments, and procedures based on the pencil hardness test of JIS K5600-5-4:1999. Specifically, using a pencil "UNI" (manufactured by Mitsubishi Pencil Co., Ltd.), the scratching distance was set to 10 mm, and the presence or absence of scratches of 1 mm or more on the surface 3a of the anti-glare film 3 was determined using a metallurgical microscope at a magnification of 100. This can be done by observing the surface 3a of the anti-glare film 3 with epi-illumination at a magnification of .

Since the film-coated glass substrate 1 of the present embodiment has the above configuration, it can achieve both high levels of anti-glare properties and scratch resistance. Therefore, the film-coated glass substrate 1 of this embodiment can be suitably used as a cover glass in a display such as a mobile phone, a tablet terminal, a television, or a digital signage.

In this embodiment, the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 is 0.3 μm or more, preferably 0.32 μm or more, more preferably 0.33 μm or more, and preferably 0.7 μm or less, more preferably is 0.5 μm or less, more preferably 0.45 μm or less. When the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 is greater than or equal to the above lower limit, the anti-glare properties of the film-coated glass substrate 1 can be further improved. Further, when the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 is equal to or less than the above upper limit value, peeling of the anti-glare film 3 from the glass substrate 2 can be made even less likely to occur.

Further, the pencil hardness of the anti-glare film 3 is 7H or more, preferably 8H or more, and more preferably 9H or more. When the pencil hardness of the anti-glare film 3 is greater than or equal to the above lower limit, the scratch resistance of the film-coated glass substrate 1 can be further improved. Note that the upper limit of the pencil hardness of the anti-glare film 3 is not particularly limited, but may be, for example, 10H.

Furthermore, the pencil hardness of the anti-glare film 3 can be determined by a method based on the principles, equipment, instruments, and procedures described in the above-mentioned JIS K5600-5-4:1999. The pencil hardness can be set to the maximum hardness at which the incidence of scratches is 30% or less when scratched with a pencil of the same hardness 10 times or more. Note that a plurality of film-coated glass substrates prepared under the same conditions are prepared and the pencil hardness of each is evaluated, and if the obtained pencil hardnesses are different, the median value can be taken as the pencil hardness.

In this embodiment, the root mean square height Sq at the surface 3a of the anti-glare film 3 is preferably 0.30 μm or more, more preferably 0.35 μm or more, still more preferably 0.40 μm or more, and preferably 0.80 μm. The thickness is more preferably 0.60 μm or less, and even more preferably 0.56 μm or less. When the root mean square height Sq on the surface 3a of the anti-glare film 3 is greater than or equal to the above lower limit, the anti-glare properties of the film-coated glass substrate 1 can be further improved. Moreover, when the root mean square height Sq of the surface 3a of the anti-glare film 3 is equal to or less than the above upper limit value, peeling of the anti-glare film 3 from the glass substrate 2 can be made even less likely to occur.

The minimum autocorrelation length Sal on the surface 3a of the anti-glare film 3 is preferably 1.5 μm or more, more preferably 3 μm or more, even more preferably 5 μm or more, and preferably 30 μm or less, more preferably 20 μm or less, even more preferably It is 8 μm or less. When the minimum autocorrelation length Sal on the surface 3a of the anti-glare film 3 is greater than or equal to the above lower limit, the anti-glare properties of the film-coated glass substrate 1 can be further improved. Further, when the minimum autocorrelation length Sal on the surface 3a of the anti-glare film 3 is equal to or less than the above upper limit value, glare called sparkle can be further suppressed.

Further, the ratio (Sq/Sal) between the root mean square height Sq and the minimum autocorrelation length Sal on the surface 3a of the anti-glare film 3 is preferably 0.03 or more, more preferably 0.05 or more, and even more preferably It is 0.06 or more, preferably 0.10 or less, more preferably 0.08 or less, and still more preferably 0.07 or less. When the ratio (Sq/Sal) is greater than or equal to the above lower limit, the antiglare properties of the film-coated glass substrate 1 can be further improved. Moreover, when the ratio (Sq/Sal) is below the above upper limit value, it is possible to more reliably prevent the haze from becoming too high.

Note that the root mean square height Sq and the minimum autocorrelation length Sal can be measured in accordance with ISO 25178, for example. Furthermore, the ratio (Sq/Sal) can be increased by increasing the thickness of the anti-glare film 3.

The average thickness of the anti-glare film 3 is not particularly limited, but is preferably 430 nm or more, more preferably 500 nm or more, even more preferably 700 nm or more, preferably 2000 nm or less, more preferably 1500 nm or less, and still more preferably 1000 nm or less. can be designed. Note that the average film thickness of the anti-glare film 3 can be estimated from coating amount per unit area×liquid coating efficiency×concentration in terms of solid content/density of the film.

In this embodiment, the haze of the film-coated glass substrate 1 is preferably 30% or more, more preferably 40% or more, preferably 80% or less, and more preferably 60% or less. When the haze of the film-coated glass substrate 1 is greater than or equal to the above lower limit, the anti-glare properties of the film-coated glass substrate 1 can be further improved. Moreover, when the haze of the film-coated glass substrate 1 is below the above-mentioned upper limit value, the visibility of the display surface can be further improved when used for a display or the like.

The haze of the film-coated glass substrate 1 can be measured, for example, in accordance with JIS K7136:2000. Note that the haze of the film-coated glass substrate 1 can be increased, for example, by increasing the thickness of the anti-glare film 3.

Hereinafter, an example of the method for manufacturing a film-coated glass substrate of the present invention will be described.

(Method for manufacturing glass substrate with film)
In the method for manufacturing the film-covered glass substrate 1 of this embodiment, first, the glass substrate 2 is prepared. As the glass substrate 2, those mentioned above can be used. Further, the glass substrate 2 may have a functional layer on the surface of the substrate body. Examples of the functional layer include an undercoat layer, an adhesion improving layer, a protective layer, and a colored layer.

Next, a coating film having irregularities is formed by applying a coating liquid onto the prepared glass substrate 2 by a spray coating method.

The coating liquid contains a silica precursor. The silica precursor can be used, for example, as a matrix forming component when forming an anti-glare film by a spray coating method. By containing the silica precursor in the coating liquid, the adhesion to the glass substrate 2 can be improved, and the refractive index can be matched with that of the glass substrate 2.

Examples of the silica precursor include siloxane polymers. As the siloxane polymer, it is preferable to use silicon alkoxide or a hydrolyzed condensate thereof. Moreover, it is preferable that the silicon alkoxide contains at least one of an N-functional silicon alkoxide (N=2, 3, 4) and a hydrolyzed condensate thereof. Examples of such silicon alkoxides include tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane, which are tetrafunctional silicon alkoxides.

Furthermore, the silicon alkoxide may be a trifunctional silicon alkoxide or a bifunctional silicon alkoxide having an organic substituent such as an alkyl group, a vinyl group, a phenyl group, or an epoxy group. Examples of silicon alkoxides having an organic substituent include trifunctional silicon alkoxides such as methyltriethoxysilane, methyltrimethoxysilane, vinyltriethoxysilane, and phenyltriethoxysilane, and dimethyl silicone alkoxides. Examples include diethoxysilane and dimethyldimethoxysilane. When such an organic substituent is present, the stress of the coating film to be formed can be reduced, and the occurrence of cracks during the heating process during firing can be further suppressed.

These silicon alkoxides may be used alone or in a mixture of multiple types.

The size of the siloxane polymer can be grown by proceeding with the hydrolytic condensation reaction. The size of the siloxane polymer can be, for example, 2 nm to 30 nm in volume average.

The content of the silica precursor is, for example, 50% or more, preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, particularly preferably It is 90% or more.

The coating liquid may contain an alumina precursor, a zirconia precursor, a titania precursor, or an yttria precursor. These may be used alone or in combination. When the coating liquid contains an alumina precursor, a zirconia precursor, a titania precursor, or an yttria precursor, the durability of the film (coating film) can be further improved, and the refractive index of the film (coating film) can be further improved. The refractive index matching between the glass substrate 2 and the glass substrate 2 can be further improved.

The content of the alumina precursor, zirconia precursor, titania precursor, or yttria precursor (total amount if multiple types are included) is the mass percentage of the solid content in terms of alumina, zirconia, titania, or yttria, for example. , 0% to 30%.

Examples of the alumina precursor include aluminum alkoxides, hydrolyzed condensates of aluminum alkoxides, water-soluble aluminum salts, and aluminum chelates. Examples of water-soluble aluminum salts include aluminum nitrate, aluminum chloride, aluminum sulfate, aluminum acetate, aluminum formoacetate, aluminum acetylacetate, and the like.

Examples of the zirconia precursor include zirconium alkoxide, a hydrolyzed condensate of zirconium alkoxide, and the like. Examples of the titania precursor include titanium alkoxide, a hydrolyzed condensate of titanium alkoxide, and the like.

The coating liquid contains a solvent. The solvent is not particularly limited, and includes water, alcohols, ketones, ethers, cellosolves, esters, glycol ethers, and the like. These solvents may be used alone or in combination.

Water can be used in the hydrolysis reaction of silicon alkoxide and the like. However, if the water content is too large, the coating film will be more likely to crack due to the high surface tension. Therefore, the water content can be, for example, 3 to 6 in molar ratio to Si atoms.

Furthermore, from the viewpoint of making the coating liquid easier to dry, it is preferable that the coating liquid contains a solvent having a boiling point of less than 90°C. Examples of the solvent having a boiling point of less than 90°C include methanol, ethanol, isopropyl alcohol, tetrahydrofuran, hexane, and the like. The content of the solvent having a boiling point of less than 90° C. (the total amount if multiple types are included) can be, for example, 30% or more and 90% or less in mass percentage of the entire coating liquid.

The coating liquid may contain metal oxide nanoparticles.

The solid content (heated residue) in the coating liquid can be, for example, 1% by mass to 5% by mass.

When applying the coating liquid, the coating liquid is sprayed onto the glass substrate 2 by a spray coating method. Examples of the nozzle used in the spray coating method include a two-fluid nozzle and a one-fluid nozzle, but a two-fluid spray gun using a two-fluid nozzle is preferable. In this case, even if the coating liquid does not contain oxide fine particles, the unevenness of the anti-glare film 3 can be formed even more efficiently. Furthermore, the adhesion between the glass substrate 2 and the anti-glare film 3 can be further improved.

The particle size of the coating liquid droplets discharged from the nozzle is usually 0.1 μm to 100 μm, preferably 1 μm to 50 μm. When the particle size of the droplets is equal to or larger than the above lower limit, it is possible to form irregularities that provide a sufficient anti-glare effect in a much shorter time. When the particle size of the droplets is less than or equal to the above upper limit, it is possible to further facilitate the formation of appropriate irregularities that provide sufficient anti-glare effect. Note that the particle size of the droplets of the coating liquid can be adjusted as appropriate depending on the type of nozzle, air flow rate, discharge amount, etc. For example, in a two-fluid nozzle, the higher the air flow rate, the smaller the droplets, and the higher the ejection amount, the larger the droplets. Note that the particle size of the droplet refers to the median diameter on a volume basis measured by a laser diffraction particle size distribution meter. The air flow rate can be, for example, 50 L/min to 300 L/min. Further, the air pressure can be, for example, 0.1 MPa to 0.6 MPa.

The gun distance can be, for example, 20 mm or more and 300 mm or less. Note that the gun distance refers to the distance from the gun to the glass substrate 2 that is the object of film formation.

The amount of coating liquid applied per unit area is, for example, 50 g/m ² or more, 80 g/m ² or more, 100 g/m ² or more, 200 g/m ² or less, 180 g/m ² or less, 160 g/m ² or less. be able to. Although it depends on the solid content concentration of the coating liquid, when the coating amount of the coating liquid per unit area is large, the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 tends to become large. Furthermore, the thickness of the anti-glare film 3 tends to increase. On the other hand, when the coating amount of the coating liquid per unit area is small, the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 tends to become small. Furthermore, the thickness of the anti-glare film tends to become thinner.

The application temperature of the coating liquid can be, for example, 10°C or higher and 80°C or lower.

Furthermore, it is preferable that the surface temperature of the glass substrate 2 when applying the coating liquid is, for example, 15° C. to 75° C. Further, the humidity when applying the coating liquid is, for example, 20% to 80%, preferably 50% or more.

The drying temperature of the coating liquid is not particularly limited, but can be, for example, 25°C or higher, 100°C or higher, or 450°C or lower, or 400°C or lower. The drying time can be, for example, 10 minutes or more and 600 minutes or less.

Next, the coating film is fired at a temperature of 500°C or higher. Thereby, the anti-glare film 3 can be formed on the glass substrate 2, and the glass substrate 1 with the film can be obtained.

In the method for manufacturing the film-coated glass substrate 1 of the present embodiment, the anti-glare film 3 is formed by baking the coating film applied by the spray coating method at a temperature of 500°C or higher, so the resulting film-coated glass substrate 1 It is possible to achieve both high levels of anti-glare properties and scratch resistance.

Conventionally, when increasing the thickness of an anti-glare film with the aim of increasing anti-glare properties, scratch resistance has sometimes been reduced. As a result, there has been a problem in that the anti-glare film has many scratches due to long-term use.

In contrast, the present inventor has proposed that even when the thickness of the anti-glare film 3 is increased, the coating film applied by the spray coating method can be manufactured using a method of baking at a temperature of 500°C or higher. It has been found that the scratch resistance of the glass substrate 1 can be improved and that both anti-glare properties and scratch resistance can be achieved at a high level.

In this embodiment, the firing temperature of the coating film is 500°C or higher, preferably 510°C or higher, more preferably 520°C or higher, even more preferably 530°C or higher, even more preferably 540°C or higher, and even more preferably 550°C. Above, even more preferably 560°C or higher, even more preferably 570°C or higher, even more preferably 580°C or higher, even more preferably 590°C or higher, even more preferably 600°C or higher, even more preferably 610°C or higher, Still more preferably 620°C or higher, even more preferably 630°C or higher, even more preferably 640°C or higher, particularly preferably 650°C or higher. In order to evaporate and burn the organic components remaining in the coating film (residual solvent, alkoxy groups, alkyl groups, vinyl groups, epoxy groups, etc. contained in the silica precursor) and make the coating film dense, the firing temperature must be set. The higher the value, the better. It is preferable that the coating film after firing consists of only inorganic components. When the firing temperature of the coating film is equal to or higher than the above lower limit, the scratch resistance of the film-coated glass substrate 1 can be further improved.

On the other hand, the upper limit of the firing temperature of the coating film is not particularly limited, but it is preferable that the firing temperature is equal to or lower than the strain point of the glass substrate 2. If the firing temperature exceeds the strain point of the glass substrate 2, distortion will remain in the glass substrate 2 unless it is appropriately annealed, which is undesirable from the viewpoint of manufacturing costs. Therefore, from the viewpoint of further improving manufacturing costs and productivity, the firing temperature of the coating film is preferably below the strain point of the glass substrate 2, more preferably (the strain point of the glass substrate 2 -5°C). Hereinafter, more preferably (strain point of glass substrate 2 -10°C) or less, still more preferably (strain point of glass substrate 2 -20°C) or less, still more preferably (strain point of glass substrate 2 -30°C) Below, even more preferably (strain point of glass substrate 2 -40°C) or lower, still more preferably (strain point of glass substrate 2 -50°C) or lower, even more preferably (strain point of glass substrate 2 -60°C) ) or less, still more preferably (strain point of glass substrate 2 -70°C) or less, particularly preferably (strain point of glass substrate 2 -80°C) or less.

The baking time of the coating film is not particularly limited, but is preferably 10 minutes or more, more preferably 30 minutes or more, and preferably 300 minutes or less, more preferably 200 minutes or less.

The coating film can be baked using, for example, a hot air heating device, a contact heating device, or a far infrared heating device.

[Second embodiment]
FIG. 2 is a schematic cross-sectional view showing a film-coated glass substrate according to a second embodiment of the present invention. The film-coated glass substrate 21 further includes an anti-reflection film 24 on the anti-glare film 3.

Preferably, the antireflection film 24 is a dielectric multilayer film. In this case, when the film-covered glass substrate 21 is used for a display or the like, image clarity can be further improved. In this embodiment, the antireflection film 24 is a dielectric multilayer in which a high refractive index film 25 having a relatively high refractive index and a low refractive index film 26 having a relatively low refractive index are alternately laminated in this order. It is a membrane. The antireflection film 24 is a dielectric multilayer film in which a low refractive index film 26 having a relatively low refractive index and a high refractive index film 25 having a relatively high refractive index are alternately laminated in this order. It's okay. Note that the high refractive index film 25 and the low refractive index film 26 are preferably sputtered films. With such a configuration, the adhesion between the high refractive index film 25 and the low refractive index film 26 can be improved.

Examples of the material for the high refractive index film 25 include niobium oxide, titanium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silicon nitride, aluminum oxide, and aluminum nitride.

Examples of the material for the low refractive index film 26 include silicon oxide, aluminum oxide, magnesium fluoride, and the like.

The thickness of each layer constituting the antireflection film 24 is preferably 1 nm or more and 500 nm or less, more preferably 2 nm or more and 300 nm or less, and even more preferably 5 nm or more and 200 nm or less.

In this embodiment, the total number of layers constituting the antireflection film 24 is six. However, in the present invention, the total number of layers constituting the antireflection film 24 is not particularly limited. The total number of layers constituting the antireflection film 24 is preferably two or more layers, and preferably seven layers or less. By keeping it within this range, it is possible to obtain a film that is effective and can be easily formed.

The total thickness of the antireflection film 24 is preferably 50 nm or more and 1000 nm or less, more preferably 75 nm or more and 750 nm or less, and even more preferably 100 nm or more and 500 nm or less.

The antireflection film 24 can be formed by, for example, a sputtering method, a CVD method, a vacuum evaporation method, or the like. Note that the antireflection film 24 is preferably provided after baking the coating film.

Other points are similar to the first embodiment.

Also in the film-covered glass substrate 21 of this embodiment, the arithmetic mean height Sa at the surface 3a of the anti-glare film 3 is 0.3 μm or more, and the pencil hardness of the anti-glare film 3 is 7H or more. Therefore, the film-covered glass substrate 21 can achieve both high levels of anti-glare properties and scratch resistance.

Note that in the first and second embodiments, the anti-glare film 3 was provided only on the first main surface 2a side of the glass substrate 2; The anti-glare film 3 may be provided on both sides of the main surface 2b.

Further, in the second embodiment, the anti-reflection film 24 was provided on the anti-glare film 3, but the anti-reflection film 24 may be provided between the glass substrate 2 and the anti-glare film 3. Further, the antireflection film 24 may also be provided on both the first main surface 2a side and the second main surface 2b side of the glass substrate 2.

Furthermore, a functional layer may be provided on either or both of the first main surface 2a side and the second main surface 2b side of the glass substrate 2 of the film-coated glass substrates 1 and 21. Examples of the functional layer include an antifouling layer, a protective layer, a colored layer, a light-shielding layer, and a decorative layer. Note that these functional layers are preferably provided after firing the coating film.

Furthermore, an antifouling layer may be provided on the outermost layer of the film-coated glass substrates 1 and 21.

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples in any way, and can be implemented with appropriate modifications within the scope of the gist.

Preparation of glass substrate A;
As a glass composition, glass raw materials are prepared and melted so that the content of alkali metal oxides is 0.1% or less by mass percentage, and the glass is formed into a plate shape using an overflow down-draw method to a thickness of 0.5 mm. A glass substrate A was obtained. The strain point of the obtained glass substrate A was 685°C.

Preparation of glass substrate B;
As glass substrate B, commercially available soda lime glass (strain point: 500°C) was used.

Preparation of coating liquid A;
For 1 part by mass of tetraethoxysilane (TEOS), 0.4 parts by mass of water, 7.2 parts by mass of denatured ethanol (contains 85.5% by mass of ethanol as a main component, and also includes methanol, etc.), and nitric acid. The siloxane polymer was mixed and stirred to advance the hydrolysis and condensation reaction of TEOS to grow the size of the siloxane polymer, and the volume average of the size of the siloxane polymer measured by dynamic light scattering measurement was 4.0 nm. A coating liquid A was obtained. Note that nitric acid was adjusted and mixed so that the pH was 4. The solid content (heated residue) concentration of the obtained coating liquid A was 3.2% by mass in terms of silica. In addition, when measuring the scattered light intensity by the dynamic light scattering method, a product manufactured by Malvern Panalytical, product number "Zetasizer Nano S" was used.

Preparation of coating liquid B;
After aging, 0.055 parts by mass of aluminum nitrate nonahydrate was added to coating liquid A and stirred to obtain coating liquid B. The total solid content (heated residue) concentration of the obtained coating liquid B in terms of silica and alumina was 3.4% by mass. Moreover, the proportion of solid content in terms of silica was 95% by mass, and the proportion in terms of alumina was 5% by mass.

Preparation of coating liquid C;
1 part by mass of tetraethoxysilane (TEOS), 0.4 parts by mass of water, 8.1 parts by mass of isopropyl alcohol, and nitric acid are mixed and stirred to advance the hydrolysis and condensation reaction of TEOS, The size of the siloxane polymer was grown to obtain a coating liquid C in which the volume average size of the siloxane polymer measured by dynamic light scattering measurement was 3.9 nm. Note that nitric acid was adjusted and mixed so that the pH was 4. The solid content (heated residue) concentration of the obtained coating liquid C in terms of silica was 2.9% by mass.

Preparation of coating liquid D;
For 1 part by mass of tetraethoxysilane (TEOS), 0.064 parts by mass of methyltriethoxysilane, 0.47 parts by mass of water, denatured ethanol (contains 85.5% by mass of ethanol as the main component, and other parts such as methanol etc.) 8.0 parts by mass (including 1-butanol), 0.93 parts by mass of 1-butanol, and nitric acid are mixed and stirred to proceed with the hydrolysis and condensation reaction of TEOS and methyltriethoxysilane to form a siloxane polymer. A coating liquid D was obtained in which the volume average size of the siloxane polymer measured by dynamic light scattering measurement was 3.9 nm. Note that nitric acid was adjusted and mixed so that the pH was 4. The solid content (heated residue) concentration of the obtained coating liquid D was 2.8% by mass in terms of silica.

Preparation of coating liquid E;
For 1 part by mass of tetraethoxysilane (TEOS), 0.095 parts by mass of methyltriethoxysilane, 0.48 parts by mass of water, denatured ethanol (contains 85.5% by mass of ethanol as the main component, and other parts such as methanol etc.) 8.5 parts by mass (including 1-butanol), 0.96 parts by mass of 1-butanol, and nitric acid are mixed and stirred to proceed with the hydrolysis and condensation reaction of TEOS and methyltriethoxysilane to form a siloxane polymer. A coating solution E was obtained in which the volume average size of the siloxane polymer measured by dynamic light scattering measurement was 3.9 nm. Note that nitric acid was adjusted and mixed so that the pH was 4. The solid content (heated residue) concentration of the obtained coating liquid E was 2.8% by mass in terms of silica.

(Example 1)
A coating film was formed by spray coating coating liquid A on glass substrate A. The coating amount during spray coating was 116 g/m ² per unit area. Further, a two-fluid spray gun was used, and the gun distance was 96 mm. The air pressure was 0.16 MPa, and the liquid discharge rate was 0.2 kg/hour.

Next, the obtained glass substrate with the coating film was placed in a hot air heating furnace, and the temperature was raised from room temperature to 600°C over 1 hour, and then held at 600°C for 30 minutes. Thereafter, the temperature was lowered to room temperature over 2 hours. Thereby, a film-coated glass substrate having an anti-glare film formed on the glass substrate was obtained.

(Examples 2 to 9 and Comparative Examples 1 to 5)
A glass substrate with a film was prepared in the same manner as in Example 1, except that the types of glass substrate and coating liquid, spray coating conditions (coating amount, air pressure, gun distance), and firing temperature were changed as shown in Table 1 below. I got it.

[evaluation]
(Evaluation of gloss, haze, and sparkle)
The film-coated glass substrates obtained in Examples 1 to 9 and Comparative Examples 1 to 5 were measured for gloss, which is an indicator of glossiness, haze, which is an indicator of white turbidity, and sparkle, which is an indicator of glare. The gloss was measured based on JIS Z 8741:1997 using Microgloss (60°) (manufactured by BYK) at an incident angle of 60° on a glass substrate with a film. Haze was measured using NDH-5000 (manufactured by Nippon Denshoku Co., Ltd.) based on JIS K 7136:2000. Sparkle was measured using SMS-1000 (manufactured by Display-Messtechnik & System) in sparkle measurement mode.

(Evaluation of reflection)
Regarding the film-coated glass substrates obtained in Examples 1 to 9 and Comparative Examples 1 to 5, the reflection brightness angle distribution of a line light source was measured in the reflection measurement mode of SMS-1000 (manufactured by Display-Messtechnik & System). From the measured distribution, read the specular reflection brightness Rs, the reflection brightness R(1) and R(-1) that are 0.1° and -0.1° deviated from the specular reflection angle, and calculate Rs/[R(1) and R (-1)] was calculated as the reflection value. The smaller this value, the less reflection and the higher the anti-glare performance. Further, the above measurements were performed at a working distance of 410 mm using a lens with a focal length of 16 mm.

(Evaluation of pencil hardness)
The film-coated glass substrates obtained in Examples 1 to 9 and Comparative Examples 1 to 5 were evaluated for pencil hardness. Specifically, after scratching a distance of 10 mm with a pencil with a hardness of 7H (manufactured by Mitsubishi Pencil Co., Ltd., "Uni") at the load and speed of the pencil hardness test described in JIS K5600-5-4:1999, I wiped off the powder. The presence or absence of scratches was determined by observing the indentation under epi-illumination of a metallurgical microscope at a magnification of 100 times, and checking whether scratches of 1 mm or more had occurred. Scratching was repeated 10 times, and the evaluation was made as ``Good'' when the scratch incidence rate was 30% or less, and as × when the scratch incidence rate was greater than 30%. Similar tests were also conducted using pencils with other hardnesses, and the maximum hardness at which the scratch rate was 30% or less was defined as the pencil hardness. Each time the pencil was scratched, it was sharpened using abrasive paper according to the procedure described in JIS K5600-5-4:1999, and used for evaluation.

(Evaluation of surface roughness)
The surface roughness of the film-coated glass substrates obtained in Examples 1 to 9 and Comparative Examples 1 to 5 was evaluated in accordance with ISO 25178.

Specifically, an optical interference microscope (manufactured by Ryoka System Co., Ltd., "VertScan R5300", version: VS-Measure Version 5.05.0001, CCD camera: SONY HR-571/2, objective lens: 20X, lens barrel : 1XBody, wavelength filter: 530 white, measurement mode: Wave, visual field size: 316.77 μm x 237.72 μm, resolution: 640 x 480) to measure the surface height distribution. In addition, from the measured height distribution, after interpolating BadPixel using analysis software VS-Viewer Version 5.05.0001, linear surface correction is performed, and arithmetic mean height Sa, root mean square height Sq, and minimum self The correlation length Sal (distance at which the autocorrelation function attenuates to 0.2) was calculated. In order to facilitate the measurement, a 100 nm thick aluminum film was formed on the sample surface before the measurement. Film formation was performed by sputtering.

The results are shown in Tables 1 and 2 below.

(Evaluation of image distortion)
Line-shaped lighting such as a fluorescent lamp was reflected on the surface opposite to the surface on which the anti-glare film was formed, and the image was observed. In Examples 1 to 6, 8, and 9 and Comparative Examples 1 to 5, no image distortion was observed on the entire surface of the film-coated glass substrate, but in Example 7, image distortion was observed on the film-coated glass substrate. There were some places you could see. In Examples 1 to 6, 8, and 9 and Comparative Examples 1 to 5, it is considered that residual strain was small because the strain point of substrate A was higher than the firing temperature.

(Evaluation of cracks)
When the surface of the anti-glare film was observed under epi-illumination of a metallurgical microscope at a magnification of 100 times, cracks were observed in some parts in Examples 2, 3, and 6. On the other hand, in Examples 1, 4, 5, and 7 where the coating amount was smaller than these, Comparative Examples 1 to 5 where the firing temperature was low, and Examples 8 and 9 where methyltriethoxysilane was used, cracks were not observed. The occurrence of was suppressed. In particular, in Examples 8 and 9, the occurrence of cracks was suppressed despite the large coating amount and high firing temperature, and it can be said that both reflection and hardness were achieved at a higher level.

1, 21...Glass substrate with film 2... Glass substrate 2a, 2b...First and second main surfaces 3...Anti-glare film 3a...Surface 24...Anti-reflection film 25...High refractive index film 26...Low refractive index film

Claims (8)

1. a glass substrate;
   an anti-glare film provided on the main surface of the glass substrate and containing silicon oxide as a main component;
   Equipped with
   The arithmetic mean height Sa on the surface of the anti-glare film is 0.3 μm or more,
   In the JIS K5600-5-4: 1999 pencil hardness test, the presence or absence of scratches on the surface of the anti-glare film was determined by observing the surface of the anti-glare film at 100x magnification using a metallurgical microscope. A glass substrate with a film having a pencil hardness of 7H or more.
2. The film-coated glass substrate according to claim 1, wherein the haze measured in accordance with JIS K7136:2000 is 30% or more.
3. The film-coated glass substrate according to claim 1 or 2, wherein the glass substrate has a strain point of 550°C or higher.
4. The film-coated glass substrate according to claim 1 or 2, wherein the ratio (Sq/Sal) between the root mean square height Sq and the minimum autocorrelation length Sal on the surface of the anti-glare film is 0.05 or more.
5. forming a coating film having unevenness by applying a coating liquid containing a silica precursor on a glass substrate by a spray coating method;
   forming an anti-glare film by baking the coating film at a temperature of 500°C or higher;
   Equipped with
   A method for manufacturing a glass substrate with a film, comprising forming the anti-glare film so that the arithmetic mean height Sa on the surface of the anti-glare film is 0.3 μm or more.
6. The method for manufacturing a glass substrate with a film according to claim 5, wherein when firing the coating film, the coating film is fired at a temperature equal to or lower than the strain point of the glass substrate.
7. The method for manufacturing a film-coated glass substrate according to claim 5 or 6, wherein the glass substrate has a strain point of 550°C or higher.
8. The film-coated glass according to claim 5 or 6, wherein the silica precursor contains at least one of an N-functional silicon alkoxide (N=2, 3, 4) and a hydrolyzed condensate of the N-functional silicon alkoxide. Substrate manufacturing method.

Images