KR102633247B1 - A glass substrate suitable for cover glass of mobile display devices, etc. - Google Patents

Abstract

Provided is a glass substrate that has high scratch resistance, slipperiness, good visibility, and low reflectivity, and is particularly suitable as a cover glass for mobile display devices. Between the fluorine coating layer on the surface side and the DLC layer on the substrate side, a polysiloxane obtained by polycondensation of an alkoxysilane represented by the following formula (1) and, if necessary, an alkoxysilane containing an alkoxysilane represented by the following formula (2) is contained. A glass substrate having an intermediate layer.
R ¹ ｛Si(OR ² ) ₃ ｝ _P (1)
(R ¹ is a hydrocarbon group having 1 to 12 carbon atoms substituted with a ureide group, R ² is an alkyl group having 1 to 5 carbon atoms, and p represents an integer of 1 or 2)
(R ³ ) _n Si(OR ⁴ ) _4-n (2)
(R ³ is a hydrogen atom, or a heteroatom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, or an acryloxy group, and may be substituted with 1 to 8 carbon atoms. is a hydrocarbon group, R ⁴ is an alkyl group with 1 to 5 carbon atoms, and n represents an integer from 0 to 3.)

Description

A glass substrate suitable for cover glass of mobile display devices, etc.

The present invention relates to a glass substrate having high scratch resistance, slipperiness, good visibility, and low reflectance, particularly a glass substrate suitably used as a cover glass of a mobile display device.

Recently, in liquid crystal display devices such as mobile devices and touch panels, cover glass has been widely used to protect the surface of the display device. Also, in protective glass for watches and camera finders, etc., glass plates with excellent scratch resistance and good visibility are used (see Patent Document 1 and Patent Document 2).

Cover glass for such display elements is required to have high hardness and high scratch resistance in order to be less prone to cracking and scratches. However, when a diamond-like carbon (DLC) layer or the like is formed on a glass substrate to increase hardness and scratch resistance, it is usually formed on the surface formed on the glass substrate because it provides slipperiness to the cover glass. There was a problem that the adhesion with the fluorine coating layer was lowered and the slipperiness was significantly reduced during use (see Patent Document 3).

Japanese Patent Publication No. 2009-186234 Japanese Patent Publication No. 2009-186236 Japanese Patent Publication No. 2010-228307

The object of the present invention is to provide a glass substrate having excellent scratch resistance, corrosion resistance, and good visibility, particularly a glass substrate that is suitably used as a cover glass for display elements such as mobile devices and touch panels.

As a result of intensive research in consideration of the above circumstances, the present inventors have arrived at the completion of the present invention described below.

1. A glass substrate having a fluorine coating layer on the surface side and a diamond-like carbon (DLC) layer on the substrate side, an alkoxysilane containing an alkoxysilane represented by the following formula (1) and an alkoxysilane represented by the following formula (2) A glass substrate characterized by having an intermediate layer made of a film containing polysiloxane obtained by polycondensing silane between the fluorine coating layer and the DLC layer.

R ¹ ｛Si(OR ² ) ₃ ｝ _P (1)

(R ¹ is a hydrocarbon group having 1 to 12 carbon atoms substituted with a ureide group, R ² is an alkyl group having 1 to 5 carbon atoms, and p represents an integer of 1 or 2)

(R ³ ) _n Si(OR ⁴ ) _4-n (2)

(R ³ is a hydrogen atom, or a heteroatom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, or an acryloxy group, and may be substituted with 1 to 8 carbon atoms. is a hydrocarbon group. R ⁴ is an alkyl group with 1 to 5 carbon atoms. n is an integer from 0 to 3.)

2. The alkoxysilane represented by formula (1) is at least one selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, and γ-ureidopropyltripropoxysilane. , the glass substrate described in 1 above.

3. The glass substrate according to 1 or 2 above, wherein the alkoxysilane represented by formula (2) is a tetraalkoxysilane in which n is 0 in formula (2).

4. The glass substrate according to any one of 1 to 3 above, wherein the alkoxysilane represented by formula (1) is contained in an amount of 0.5% or more in the total alkoxysilane.

5. The above 1, wherein the alkoxysilane represented by formula (1) is contained in an amount of 0.5 to 60 mol% based on the total alkoxysilanes, and the alkoxysilane represented by the formula (2) is contained in an amount ranging from 40 to 99.5 mol% based on the total alkoxysilanes. The glass substrate according to any one of to 4.

6. The glass substrate according to any one of 1 to 5 above, wherein the fluorine coating layer is formed of a condensation polymer of a silane compound of perfluoroalkyl or perfluoropolyether.

7. The glass substrate according to any one of 1 to 6 above, wherein the fluorine coating layer has a thickness of 1 to 30 nm, the diamond-like carbon layer has a thickness of 50 to 150 nm, and the middle layer has a thickness of 10 to 500 nm.

8. A display element comprising the glass substrate according to any one of 1 to 7 above.

According to the present invention, in addition to having high scratch resistance and slipperiness, the transmittance can be unexpectedly improved by having a fluorine coating layer on the surface and an intermediate layer of a specific polysiloxane in addition to the DLC layer on the substrate side. , Additionally, since the reflectance is also reduced, a glass substrate with excellent visibility is provided.

In addition, the glass substrate of the present invention has good manufacturing efficiency because the specific intermediate layer of polysiloxane can be cured at a low temperature of 300 ° C. or lower, and has sufficient hardness with a thickness of the order of nanometers, and also has a fluorine coating layer and Since it has high adhesion to the DLC layer, it does not affect the characteristics of electronic devices, etc., and is especially preferably used as a cover glass for liquid crystal display elements.

1 is a schematic cross-sectional view showing an example of a glass substrate according to an embodiment of the present invention.

［Glass substrate］

As the glass substrate of the present invention, glass plates made of alkali glass, quartz glass, sapphire glass, alumina silicon glass, etc. can be widely used. The thickness is not particularly limited, but is usually, preferably 0.1 to 2.0 mm, and more preferably 0.2 to 1.3 mm. The glass plate may be chemically strengthened or air-tempered to increase strength. The glass substrate of the present invention has a DLC layer on the substrate side and a fluorine coating layer on the surface side.

［DLC floor］

The DLC layer on the substrate side of the glass substrate is formed to provide high scratch resistance and corrosion resistance. The DLC layer in the present invention is easily obtained using hydrocarbon gas such as acetylene and methane as a raw material by plasma CVD method, sputtering method, ionization vapor deposition method, etc., especially sputtering method. The raw materials may contain hydrogen.

The thickness of the DLC layer in the present invention is preferably 50 to 150 nm, more preferably 70 to 130 nm. In addition, the refractive index is preferably 1.7 or less, more preferably 1.5 or less in order to achieve low reflection. The DLC layer may be porous, and the volume ratio of voids is preferably 40 to 70%, more preferably 45 to 65%.

[Fluorine coating layer]

The fluorine coating layer on the surface side of the glass substrate is formed to increase slipperiness and improve ease of operation, anti-fingerprint adhesion, etc. Glass substrates having a fluorine coating layer on the surface are already known, for example, in International Publication WO2013/115191, Japanese Patent Application Publication No. 2014-218639, etc., and these already known fluorine coating layers can be used in the present invention as well.

The fluorine coating layer in the present invention is, for example, R ^f -Q ¹ -SiX ¹ ₃ (R ^f is perfluoroalkyl having 1 to 6 carbon atoms, and Q ¹ is a fluorine atom having 1 to 10 carbon atoms ^A silane compound containing _a perfluoroalkyl group such _as a divalent organic group that does not _{contain a} divalent organic _{group ,} and O) ₂₀ CF ₂ CF ₂ CH ₂ OCH ₂ CH ₂ CH ₂ SiCl ₃ , CF ₃ CF ₂ CF ₂ O(CF ₂ CF ₂ CF ₂ O) ₂₀ CF ₂ CF 2 CH ₂ OCH ₂ CH ₂ CH _{2 Si} (CH It is formed from a fluorine-containing polymer such as a condensation polymer of a perfluoro(poly)ether group-containing silane compound such as ₂ CH=CH ₂ ) ₃ . A fluorine coating layer is formed by applying a liquid in which these fluorine-containing polymers are dispersed in a medium onto the DLC layer of a glass substrate, drying, and heating.

The thickness of the fluorine coating layer is preferably 1 to 30 nm, more preferably 1 to 15 nm, in terms of optical performance, surface slipperiness, friction durability and antifouling properties.

［Middle floor］

The intermediate layer in the present invention is used between the fluorine coating layer and the DLC layer and is characterized by containing polysiloxane having a ureide group as described below. For this reason, it is possible to form a film with sufficient hardness and adhesion even at low temperatures of 100 to 300°C.

That is, the intermediate layer in the present invention contains an alkoxysilane represented by the following formula (1), and, if necessary, a polysiloxane obtained by polycondensing an alkoxysilane containing the alkoxysilane represented by the following formula (2).

R ¹ ｛Si(OR ² ) ₃ ｝ _P (1)

In formula (1), R ¹ is a hydrocarbon group having 1 to 12 carbon atoms and having a ureide group. Among them, R ¹ is preferably a hydrocarbon group of 1 to 7, more preferably 1 to 5 hydrogen atoms, and any hydrogen atom thereof, preferably 3 to 15 hydrogen atoms, particularly preferably 3 to 11 hydrogen atoms. It is a group in which the atom is substituted with a ureide group. The hydrocarbon group is preferably an alkyl group.

R ² is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and more preferably methyl or ethyl group. p represents an integer of 1 or 2.

The alkoxysilane represented by formula (1) is an alkoxysilane represented by formula (1-1) when p is 1.

R ¹ Si(OR ² ) ₃ (1-1)

Moreover, the alkoxysilane represented by formula (1) is an alkoxysilane represented by formula (1-2) when p is 2.

(R ² O) ₃ Si-R ¹ -Si(OR ² ) ₃ (1-2)

Although specific examples of the alkoxysilane represented by formula (1-1) are given, it is not limited to these. For example, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltripropoxysilane, (R)-N-1-phenylethyl-N'-triethyl Toxysilylpropyl urea, (R)-N-1-phenylethyl-N'-trimethoxysilylpropyl urea, etc. are mentioned. Among them, γ-ureidopropyltriethoxysilane or γ-ureidopropyltrimethoxysilane is particularly preferable because it is readily available as a commercial product.

Although specific examples of the alkoxysilane represented by formula (1-2) are given, it is not limited to these. For example, bis[3-(triethoxysilyl)propyl]urea, bis[3-(triethoxysilyl)ethyl]urea, bis[3-(trimethoxysilyl)propyl]urea, bis[3- (Tripropoxysilyl) propyl] urea, etc. are mentioned. Among them, bis[3-(triethoxysilyl)propyl]urea is particularly preferable because it is easy to obtain as a commercial product.

The alkoxysilane represented by formula (1) is preferably 0.5 mol% or more, more preferably 1.0 mol% or more, and even more preferably 2.0 mol% or more in the total alkoxysilanes used to obtain the intermediate layer. In addition, the alkoxysilane represented by formula (1) may be 100 mol% of all alkoxysilanes used to obtain the intermediate layer.

Moreover, as the alkoxysilane for obtaining the intermediate layer, it is preferable to use an alkoxysilane represented by the following formula (2) together with the alkoxysilane represented by the above formula (1).

(R ³ ) _n Si(OR ⁴ ) _4-n (2)

In formula (2), R ³ is carbon which may be substituted with a hydrogen atom, a hetero atom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, or an acryloxy group. It is a hydrocarbon group with 1 to 6 atoms. R ⁴ is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. n is 0 to 3, preferably an integer of 0 to 2.

Examples of R ³ in formula (2) include aliphatic hydrocarbons; Ring structures such as aliphatic rings, aromatic rings, or hetero rings; unsaturated bond; It is an organic group having 1 to 6 carbon atoms, which may contain heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms, and may have a branched structure. Additionally, R ³ may be substituted with a halogen atom, vinyl group, amino group, glycidoxy group, mercapto group, methacryloxy group, isocyanate group, acryloxy group, etc. R ⁴ has the same meaning as R ² described above, and its preferable range is also the same.

Although specific examples of the alkoxysilane represented by formula (2) are given, it is not limited to this. That is, in the alkoxysilane represented by formula (2), specific examples of the alkoxysilane when R ³ is a hydrogen atom include trimethoxysilane, triethoxysilane, tripopoxysilane, and tributoxysilane. I can hear it.

Additionally, specific examples of the alkoxysilane represented by formula (2) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, and propyltrimethoxysilane. Ethoxysilane, methyltripropoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, N-2(aminoethyl) ) 3-Aminopropyltrimethoxysilane, 3-(2-aminoethylaminopropyl)trimethoxysilane, 3-(2-aminoethylaminopropyl)triethoxysilane, 2-aminoethylaminomethyltrimethoxysilane , 2-(2-aminoethylthioethyl)triethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, allyltriethoxy Silane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-isocyanate propyltriene Toxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyl diethyl Toxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, etc. I can hear it.

In the alkoxysilane represented by formula (2), the alkoxysilane in which n is 0 is tetraalkoxysilane. Since tetraalkoxysilane is easily condensed with the alkoxysilane represented by formula (1), it is preferable for obtaining the polysiloxane of the present invention. In this formula (2), the alkoxysilane in which n is 0 is more preferably tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, or tetrabutoxysilane, and tetramethoxysilane or tetraethoxysilane is more preferable. Particularly desirable.

When using the alkoxysilane represented by formula (2), the amount used is preferably 40 to 99.5 mol%, more preferably 50 to 99.5 mol%, based on the total alkoxysilane used to obtain the intermediate layer. Preferably it is 60 to 99.5 mol%. In this case, the alkoxysilane represented by formula (1) is preferably 60 mol% or less, more preferably 50 mol% or less, and still more preferably 40 mol% or less, based on the total alkoxysilane used to obtain the intermediate layer. .

The polysiloxane forming the intermediate layer in the present invention is preferably obtained by polycondensation of an alkoxysilane represented by formula (1) and, if necessary, an alkoxysilane containing an alkoxysilane represented by formula (2). The intermediate layer may use multiple types of an alkoxysilane represented by formula (1) and an alkoxysilane represented by formula (2) in combination, as long as the properties are not impaired.

Examples of the polycondensation method in the present invention include hydrolyzing and condensing the alkoxysilane in an organic solvent such as alcohol or glycol. At that time, the hydrolysis/condensation reaction may be either partial hydrolysis or complete hydrolysis. In the case of complete hydrolysis, in theory, 0.5 times the mole of water of all alkoxide groups in the alkoxysilane should be added, but it is usually preferable to add an excess amount of water rather than 0.5 times the mole. The amount of water can be appropriately selected depending on desire, but is preferably 0.5 to 2.5 times the mole of all alkoxy groups in the alkoxysilane.

In the present invention, for the purpose of promoting hydrolysis/condensation reactions, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid, and fumaric acid; Alkalies such as ammonia, methylamine, ethylamine, ethanolamine, and triethylamine; It is preferable to use a catalyst such as a metal salt such as hydrochloric acid, sulfuric acid, or nitric acid. In addition, it is also preferable to further promote the hydrolysis/condensation reaction by heating the solution in which the alkoxysilane is dissolved. At that time, the heating temperature and heating time can be appropriately selected according to desire. For example, a method of heating and stirring at 50°C to reflux for 1 to 24 hours is included.

Another method is to polycondense a mixture of an alkoxysilane, an organic solvent, and an organic acid such as formic acid, oxalic acid, maleic acid, or fumaric acid by heating. For example, a method of polycondensing a mixture of an alkoxysilane, a solvent, and oxalic acid by heating is included. Specifically, this is a method of adding oxalic acid to alcohol in advance to create an alcohol solution of oxalic acid, and then mixing the alkoxysilane while the solution is heated. At that time, the amount of oxalic acid used is preferably 0.2 to 2 moles with respect to 1 mole of all alkoxy groups in the alkoxysilane. Heating in this method can be performed at a liquid temperature of 50 to 180°C. Preferably, it is a method of heating under reflux for tens of minutes to tens of hours to prevent evaporation or volatilization of the liquid.

When obtaining polysiloxane, when using multiple types of alkoxysilanes, the alkoxysilanes may be mixed as a premixed mixture, or the multiple types of alkoxysilanes may be mixed sequentially.

The solvent used when polycondensing an alkoxysilane (hereinafter also referred to as a polymerization solvent) is not particularly limited as long as it dissolves the alkoxysilane. Moreover, even if the alkoxysilane does not dissolve, it is sufficient as long as it dissolves with the progress of the polycondensation reaction of the alkoxysilane. Generally, since alcohol is produced by the polycondensation reaction of an alkoxysilane, alcohols, glycols, glycol ethers, or organic solvents with good compatibility with alcohols are used.

Specific examples of organic solvents in the condensation reaction include alcohols such as methanol, ethanol, propanol, butanol, and diacetone alcohol: ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexylene glycol, 1, 3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, Glycols such as 1,5-pentanediol, 2,4-pentanediol, 2,3-pentanediol, and 1,6-hexanediol: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, Ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dipropyl ether, ethylene glycol dibutyl ether, Diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, Diethylene glycol monopropyl ether, Diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl Glycol ethers such as ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, and propylene glycol dibutyl ether, N-methyl-2-pyrrolidone, N, N- Dimethylformamide, N,N-dimethylacetamide, γ-butyrolactone, dimethyl sulfoxide, tetramethyl urea, hexamethylphosphotriamide, m-cresol, etc. are mentioned. You may use a mixture of multiple types of said organic solvent.

The polysiloxane polymerization solution (hereinafter also referred to as polymerization solution) obtained by the above method has a concentration calculated by converting the silicon atoms of all alkoxysilanes injected as raw materials into SiO ₂ (hereinafter referred to as SiO ₂ conversion concentration) of 20% by mass. It is desirable to set it to the following. By selecting an arbitrary concentration within this concentration range, gel formation can be suppressed and a homogeneous solution can be obtained.

In the present invention, the polymerization solution of polysiloxane obtained above may be used as is to form an intermediate layer, or, if necessary, the polymerization solution may be concentrated, diluted by adding a solvent, or replaced with another solvent.

At that time, the solvent used (hereinafter also referred to as an addition solvent) may be the same as the polymerization solvent, or may be a different solvent. This addition solvent is not particularly limited as long as the polysiloxane is dissolved uniformly, and may be one type or multiple types, and can be selected and used arbitrarily.

Specific examples of such an addition solvent include, in addition to the solvents mentioned above as examples of polymerization solvents, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; Ester, such as methyl acetate, ethyl acetate, and ethyl lactate, etc. are mentioned. Liquids whose viscosity has been adjusted using these solvents can be applied to a substrate by spin coating, flexographic printing, inkjet, slit coating, etc. to improve applicability when forming an intermediate layer.

In the present invention, the coating liquid for forming the intermediate layer contains other components other than the polysiloxane, such as inorganic fine particles, metaloxane oligomers, metaloxane polymers, leveling agents, and even surfactants. It may be contained.

As inorganic fine particles, fine particles such as silica fine particles, alumina fine particles, titania fine particles, or magnesium fluoride fine particles are preferable, and those in a colloidal solution state are particularly preferable. By containing inorganic fine particles in the coating liquid for forming the intermediate layer, it becomes possible to adjust the surface shape and refractive index of the formed cured film and provide other functions. As for the inorganic fine particles, the average particle diameter (D50) is preferably 0.001 to 0.2 μm, and more preferably 0.001 to 0.1 μm. When the average particle diameter exceeds 0.2 μm, the transparency of the formed intermediate layer may decrease.

Dispersion media for inorganic fine particles include water and organic solvents. As a colloidal solution, pH or pKa is preferably 1 to 10, and more preferably 2 to 7, from the viewpoint of stability of the polysiloxane solution.

Organic solvents used in the dispersion medium of colloidal solutions include alcohols such as methanol, propanol, butanol, ethylene glycol, propylene glycol, butanediol, pentanediol, hexylene glycol, diethylene glycol, dipropylene glycol, and ethylene glycol monopropyl ether. ; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Aromatic hydrocarbons such as toluene and xylene; Amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; Ester such as ethyl acetate, butyl acetate, and γ-butyrolactone; and ethers such as tetrahydrofuran and 1,4-dioxane. Among these, alcohols and ketones are preferred. Organic solvents can be used individually or in combination of two or more.

As the metaloxane oligomer and metaloxane polymer, single or complex oxide precursors of silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium, zinc, etc. are used. The metaloxane oligomer and metaloxane polymer may be obtained by hydrolysis or the like from monomers such as metal alkoxide, nitrate, hydrochloride, or carboxylate.

The metaloxane oligomer and metaloxane polymer may be commercially available products. Examples include Methyl Silicate 51, Methyl Silicate 53A, Ethyl Silicate 40, Ethyl Silicate 48, EMS-485, and SS-101 manufactured by Colcoat Co., Ltd.; and titanium oxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical Co., Ltd. These may be used individually or in combination of two or more.

In addition, as the leveling agent and surfactant, known ones, especially commercial products, can be used. Moreover, the method of mixing the other components mentioned above with polysiloxane may be done simultaneously with polysiloxane, or may be done after, and is not specifically limited.

The intermediate layer can be obtained by applying the polysiloxane solution of the present invention on the DLC layer of a glass substrate and heat curing. For application of the polysiloxane solution, a known or well-known method can be employed. For example, dip method, flow coat method, spray method, bar coat method, gravure coat method, roll coat method, blade coat method, air knife coat method, flexo printing method, inkjet method, slit coat method, etc. can be adopted. there is. Among them, a good coating film can be formed in the flexo printing method, slit coating method, inkjet method, spray coating method, and gravure coating method.

The polysiloxane solution is preferably filtered using a filter or the like before application. The formed coating film is preferably dried at room temperature to 120°C, more preferably 50 to 100°C, and then heat-cured at preferably 100 to 600°C, more preferably 150°C or higher. The time required for drying is preferably 1 minute to 30 minutes, more preferably 1 minute to 10 minutes. The heat curing time is preferably 10 minutes to 24 hours, more preferably 30 minutes to 24 hours.

The intermediate layer used in the glass substrate of the present invention can obtain a cured film with sufficient hardness even at a curing temperature exceeding 180°C. The thickness of the intermediate layer in the present invention is preferably 10 to 500 nm, more preferably 30 to 300 nm.

Additionally, prior to thermal curing, it is also effective to irradiate energy rays (such as ultraviolet rays) using a mercury lamp, metal halide lamp, xenon lamp, or excimer lamp. By irradiating energy rays to the dried coating film, the curing temperature can be further lowered or the hardness of the film can be increased. The irradiation amount of the energy ray can be appropriately selected as needed, but is usually preferably from hundreds to thousands of mJ/cm2.

In the present invention, a fluorine coating layer is formed on the surface of the intermediate layer obtained as described above. This fluorine coating layer is already known, as described above, and is formed by a known method.

1 is a schematic cross-sectional view showing an example of a glass substrate according to an embodiment of the present invention. The cover glass (1) has a fluorine coating layer (2), an intermediate layer (3), a DLC layer (4), and a glass substrate (5). The intermediate layer 3 is an intermediate layer formed on the DLC layer. The fluorine coating layer is formed by applying a liquid containing the above-described fluorine-containing polymer and baking it. The glass substrate of the present invention is obtained by using a glass substrate having a DLC layer, forming an intermediate layer on the DLC layer, and then forming a fluorine coating layer on the intermediate layer.

Example

Below, examples of the present invention will be shown and the present invention will be described in detail, but the present invention is not to be construed as being limited to the following examples. The meanings of the abbreviations and measurement methods below are as follows.

TEOS: Tetraethoxysilane

UPS: 3-Ureidopropyltriethoxysilane

MeOH: methanol

EtOH: Ethanol

IPA: Isopropyl alcohol

PGME: propylene glycol monomethyl ether

HG: hexylene glycol

BCS: Ethylene glycol monobutyl ether

AF: manufactured by FT-Net, “Fluomat P-5425”

［Method for measuring residual alkoxysilane monomer］

The remaining alkoxysilane monomer in the polysiloxane solution was measured by gas chromatography (hereinafter referred to as GC). GC measurement was performed using Shimadzu GC-14B (manufactured by Shimadzu Corporation) under the following conditions.

Column: Capillary column CBP1-W25-100 (length 25 mm, diameter 0.53 mm, thickness 1 ㎛)

Column temperature: From the starting temperature of 50°C, the temperature was raised at 15°C/min to reach an ultimate temperature of 290°C (holding time: 3 minutes).

Sample injection volume: 1 μL, injection temperature: 240 ℃, detector temperature: 290 ℃, carrier gas: nitrogen (flow rate 30 ml/min), detection method: FID method.

［Steel wool scratch resistance］

Using steel wool scratch resistance tester (manufactured by Tai-A Jeonggi Co., Ltd.), Bonestar business use (pound note (卷)) #0000 (Bonestar sales company), speed: 25 round trip/min, distance: 6 cm, area: 2 cm × 2 cm, load: 1 kg, steel wool was rubbed on the substrate, and then the water contact angle was measured.

[Water contact angle]

Using a contact angle meter DM-701 (manufactured by Kyowa Interface Chemicals), 3 μm (liter) of water was dropped onto a steel wool scratch resistance test spot on the substrate to measure the water contact angle.

[Average transmittance]

The glass substrates of Samples 1 to 3 obtained in Examples and Comparative Examples were analyzed for transmittance spectra in the visible wavelength (380 to 780 nm) using an ultraviolet-visible spectrophotometer UV-3600 (Shimadzu Corporation product name). The value obtained by multiplying the weighted coefficient obtained from the brightness spectrum and the wavelength distribution of specific visibility and performing a weighted average was taken as the average transmittance. Table 1 shows the results of measurement in accordance with JIS R3106 (1998).

［Average reflectance］

The glass substrates of Samples 1 to 3 obtained in Examples and Comparative Examples were measured for 45 hours using an ultraviolet-visible spectrophotometer UV-3600 (product name of Shimadzu Corporation), an absolute specular reflectance measurement device ASR3145, and a multi-purpose large sample room MPC-3100. ° The value obtained by multiplying the reflectance spectrum in the visible light wavelength (380 to 780 nm) by the weighted coefficient obtained from the wavelength distribution of the daylight spectrum and the specific visibility, and weighted averaging, was used as the average reflectance. Table 1 shows the results of measurement in accordance with JIS R3106 (1998). The results are shown in Table 1.

[Production Example 1]

Into a 4-opening reaction flask equipped with a reflux tube, MeOH (27.25 g) as a solvent and TEOS (32.98 g) as an alkoxysilane were added and stirred.

Next, a mixture of MeOH (11.23 g) as a solvent, a 6% nitric acid solution (8.75 g) as an acid, and water (15.0 g) was added dropwise, and stirred for 30 minutes. After stirring, the mixture was refluxed for 2 hours, then 92% UPS (2.39 g) and MeOH (2.39 g) as alkoxysilane were added, the mixture was refluxed for another 30 minutes, and allowed to cool to room temperature. After standing to cool, MeOH (70.67 g) was added as a solvent to prepare a polysiloxane solution (A).

When this polysiloxane solution was measured by GC, no alkoxysilane monomer was detected.

[Comparative Manufacturing Example 1]

Into a four-opening reaction flask equipped with a reflux tube, MeOH (27.92 g) as a solvent and TEOS (34.72 g) as an alkoxysilane were added and stirred.

Next, a mixture of MeOH (13.96 g) as a solvent, a 6% nitric acid solution (8.75 g) as an acid, and water (14.65 g) was added dropwise, and stirred for 30 minutes. After stirring, the mixture was refluxed for 2 hours and 30 minutes and left to cool to room temperature. After standing to cool, MeOH (70.67 g) was added as a solvent to prepare a polysiloxane solution (B).

When this polysiloxane solution was measured by GC, no alkoxysilane monomer was detected.

[Example 1]

The polysiloxane solution (A) (50 g) obtained in Production Example 1 was diluted with PGME (30 g), HG (10 g), BCS (5 g), and PB (5 g) to obtain a coating liquid for film formation ( A1) was set.

The coating liquid for film formation (A1) was applied using a spin coater on the DLC layer of a glass substrate (thickness: 0.7 mm) on which a DLC layer with a thickness of 100 nm was formed by a sputtering method to form a coating film. Next, the glass plate on which the coating film was formed was dried on a hot plate at 80°C for 3 minutes, and then cured in a clean oven at 300°C for 30 minutes to obtain a glass substrate with a film (middle layer) with a thickness of 100 nm.

On the intermediate layer of this glass substrate, AF was applied with a spin coater to form a fluorine coating layer with a thickness of about 10 nm so that the contact angle was about 113°. Next, the glass substrate of Sample 1 (Example 1) was obtained by drying at 80°C for 3 minutes on a hot plate and then curing at 170°C for 20 minutes in a clean oven.

[Comparative Example 1]

In Example 1, the fluorine coating layer was formed by directly applying the AF coating film on the DLC layer of the glass substrate without using the polysiloxane solution (A) obtained in Production Example 1, without forming an intermediate layer. , By carrying out the same procedure as Example 1, a glass substrate of Sample 2 (Comparative Example 1) was obtained.

[Comparative Example 2]

Sample 3 (Comparative Example 2) was carried out in the same manner as in Example 1, except that the polysiloxane solution (B) obtained in Comparative Production Example 1 was used instead of the polysiloxane solution (A) obtained in Production Example 1. ) A glass substrate was obtained.

For each of Sample 1 (Example 1), Sample 2 (Comparative Example 1), and Sample 3 (Comparative Example 2) obtained above, the water contact angle, average transmittance, and average reflectance after the steel wool scratch resistance test were measured. , the results are shown in Table 1 and Table 2. In addition, in the table, “-” means not measured.

As shown in Tables 1 and 2, in the examples, even if the steel wool scratch resistance test was repeated 9000 times, the water contact angle was 90 ° or more and the transmittance was high at 94% or more, and the average reflectance was low at 6% or less. It has been done.

On the other hand, in Comparative Examples 1 and 2, the steel wool scratch resistance test was less than 5000 reciprocations, and although the water contact angle was 90 ° or less in all cases, and the scratch resistance was low, the average transmittance was 94% or less, a lower value compared to the examples. and the average reflectance was 6% or more, a high value compared to the Example.

The glass substrate of the present invention is widely used as a cover glass for display elements such as mobile devices and touch panels.

In addition, the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2015-152008 filed on July 31, 2015 are hereby cited and accepted as disclosure of the specification of the present invention.

1: Cover glass
2: Fluorine coating layer
3: Middle layer
4: DLC layer
5: Glass substrate

Claims (8)

A glass substrate having a fluorine coating layer on the surface side and a diamond-like carbon (DLC) layer on the substrate side, comprising polysiloxane obtained by polycondensation of an alkoxysilane represented by the formula (1) below, or an alkoxysilane represented by the formula (1) below, and A glass substrate characterized by having an intermediate layer containing polysiloxane obtained by polycondensing an alkoxysilane containing an alkoxysilane represented by formula (2) between the fluorine coating layer and the DLC layer.
R ¹ ｛Si(OR ² ) ₃ ｝ _P (1)
(R ¹ is a hydrocarbon group having 1 to 12 carbon atoms substituted with a ureide group, R ² is an alkyl group having 1 to 5 carbon atoms, and p represents an integer of 1 or 2)
(R ³ ) _n Si(OR ⁴ ) _4-n (2)
(R ³ is a hydrogen atom, or a heteroatom, a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a methacryloxy group, an isocyanate group, or an acryloxy group, and may be substituted with 1 to 8 carbon atoms. is a hydrocarbon group. R ⁴ is an alkyl group with 1 to 5 carbon atoms. n is an integer from 0 to 3.) According to claim 1,
A glass wherein the alkoxysilane represented by formula (1) is at least one selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, and γ-ureidopropyltripropoxysilane. Board. According to claim 1,
A glass substrate wherein the alkoxysilane represented by formula (2) is a tetraalkoxysilane in which n is 0 in formula (2). According to claim 1,
A glass substrate containing 0.5 mol% or more of the alkoxysilane represented by Formula (1) in all alkoxysilanes. According to claim 1,
A glass substrate in which the alkoxysilane represented by formula (1) is contained in an amount of 0.5 to 60 mol% based on all alkoxysilanes, and the alkoxysilane represented by formula (2) is contained in an amount ranging from 40 to 99.5 mol% in all alkoxysilanes. According to claim 1,
A glass substrate in which the fluorine coating layer is formed from a condensation polymer of a silane compound of perfluoroalkyl or perfluoropolyether. According to claim 1,
A glass substrate wherein the fluorine coating layer has a thickness of 1 to 30 nm, the diamond-like carbon layer has a thickness of 50 to 150 nm, and the middle layer has a thickness of 10 to 500 nm. A display element comprising the glass substrate according to any one of claims 1 to 7.

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