JP6773036B2 - Glass substrate suitable for cover glass of mobile display devices, etc. - Google Patents

Description

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

In recent years, in liquid crystal display elements such as mobile devices and touch panels, a cover glass for protecting the surface of the display element is often used. Further, a glass plate having excellent scratch resistance and good visibility is also used in the protective glass of a watch or a camera finder (see Patent Document 1 and Patent Document 2).

The cover glass of such a display element is required to have high hardness and high scratch resistance in order to make it more difficult to break and scratch. However, when a diamond-like carbon (DLC) layer or the like is formed on a glass substrate in order to increase hardness and scratch resistance, it is usually formed on the glass substrate in order to impart slipperiness to the cover glass. There is a problem that the adhesion to the fluorine coating layer formed on the surface is lowered and the slipperiness is remarkably lowered during use (see Patent Document 3).

JP-A-2009-186234 Japanese Unexamined Patent Publication No. 2009-186236 Japanese Unexamined Patent Publication No. 2010-228307

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

As a result of diligent research in view of the above circumstances, the present inventors have completed the following invention.
1. 1. In 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 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 a polysiloxane obtained by polycondensing an alkoxysilane containing the above-mentioned 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 ureido 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 may be substituted with a hydrogen atom or 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, and has 1 to 8 carbon atoms. It is a hydrocarbon group. R ⁴ is an alkyl group having 1 to 5 carbon atoms. N is an integer of 0 to 3.)
2. The alkoxysilane represented by the formula (1) is at least one selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, and γ-ureidopropyltripropoxysilane. The glass substrate described.
3. 3. The glass substrate according to 1 or 2 above, wherein the alkoxysilane represented by the formula (2) is a tetraalkoxysilane in which n is 0 in the formula (2).
4. The glass substrate according to any one of 1 to 3 above, wherein 0.5% or more of the alkoxysilane represented by the formula (1) is contained in the total alkoxysilane.
5. The alkoxysilane represented by the formula (1) is contained in an amount of 0.5 to 60 mol% in the total alkoxysilane, and the alkoxysilane represented by the formula (2) is contained in an amount of 40 to 99.5 mol in the total alkoxysilane. % The glass substrate according to any one of 1 to 4 above.
6. The glass substrate according to any one of 1 to 5 above, wherein the fluorine coating layer is formed from a polycondensation 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 intermediate layer has a thickness of 10 to 500 nm.
8. A display element including the glass substrate according to any one of 1 to 7 above.

According to the present invention, it has high scratch resistance and slipperiness, and has a fluorine coating layer on the surface, a DLC layer on the substrate side, and an intermediate layer of a specific polysiloxane, which is unexpected. In addition, a glass substrate having excellent visibility is provided because the transmittance can be improved and the reflectance is also lowered.
Further, in the glass substrate of the present invention, the intermediate layer of the specific polysiloxane can be cured at a low temperature of 300 ° C. or lower, so that the production efficiency is good, and the thickness on the order of nanometers has sufficient hardness. Since it has high adhesion to the fluorine coating layer and the DLC layer, it does not affect the characteristics of electronic devices and the like, and is particularly preferably used as a cover glass for a liquid crystal display element.

FIG. 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, a glass plate made of alkali glass, quartz glass, sapphire glass, alumina silicon glass or the like can be widely used. The thickness is not particularly limited, but is usually preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.3 mm. The glass plate may be chemically strengthened or air-cooled strengthened in order to increase the 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 layer]
The DLC layer on the substrate side of the glass substrate is formed to impart high scratch resistance and corrosion resistance. The DLC layer in the present invention uses a hydrocarbon gas such as acetylene or methane as a raw material, and can be easily obtained by a plasma CVD method, a sputtering method, an ionization vapor deposition method, or the like, preferably by a sputtering method. The raw material may also contain hydrogen.
The thickness of the DLC layer in the present invention is preferably 50 to 150 nm, more preferably 70 to 130 nm. 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 fraction of the pores 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 improve slipperiness, ease of operation, fingerprint adhesion prevention, and the like. A glass substrate having a fluorine coating layer on its surface is known from, for example, International Publication WO2013 / 115191, JP-A-2014-218369, and the like, and these known fluorine coating layers can be used in the present invention.
The fluorine coating layer in the present invention is, for example, R ^f- Q ^1- SiX ¹ ₃ (R ^f is a perfluoroalkyl having 1 to 6 carbon atoms, and Q ¹ contains fluorine atoms having 1 to 10 carbon atoms. It is a divalent organic group, and X ¹ is a hydrolyzable group such as a halogen atom or an alkoxy group.) A silane compound having a perfluoroalkyl group, 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 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 It is formed from a fluorine-containing polymer such as a hydrolyzate of a perfluoro (poly) ether group-containing silane compound such as Si (CH ₂ CH = CH ₂ ) ₃ . A fluorine-coated 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 from the viewpoint of optical performance, surface slipperiness, friction durability and antifouling property.

[Middle layer]
The intermediate layer in the present invention is used between the fluorine coating layer and the DLC layer, and is characterized by containing a polysiloxane having a ureido group as described below. This makes it possible to form a film having sufficient hardness and adhesion even at a low temperature of 100 to 300 ° C.
That is, the intermediate layer in the present invention is a poly obtained by polycondensing an alkoxysilane represented by the following formula (1) and, if necessary, an alkoxysilane containing an alkoxysilane represented by the following formula (2). Contains siloxane.

R ¹ {Si (OR ² ) ₃ } _P (1)
In the formula (1), R ¹ is a hydrocarbon group having a ureido group and having 1 to 12 carbon atoms. Among them, R ¹ is preferably a hydrocarbon group of 1 to 7, more preferably 1 to 5, and any hydrogen atom thereof, preferably 3 to 15 hydrogen atoms, particularly preferably 3 to 11 hydrogen atoms. It is a group substituted with a hydrocarbon 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 a methyl group or an ethyl group. p represents an integer of 1 or 2.

The alkoxysilane represented by the formula (1) is an alkoxysilane represented by the formula (1-1) when p is 1.
R ¹ Si (OR ² ) ₃ (1-1)
The alkoxysilane represented by the formula (1) is an alkoxysilane represented by the formula (1-2) when p is 2.
(R ² O) ₃ Si-R ^1- Si (OR ² ) ₃ (1-2)

Specific examples of the alkoxysilane represented by the formula (1-1) will be given, but the present invention is not limited thereto. For example, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltripropoxysilane, (R) -N-1-phenylethyl-N'-triethoxysilylpropylurea, (R)-. Examples thereof include N-1-phenylethyl-N'-trimethoxysilylpropyl urea. Of these, γ-ureidopropyltriethoxysilane or γ-ureidopropyltrimethoxysilane is particularly preferable because it is easily available as a commercially available product.

Specific examples of the alkoxysilane represented by the formula (1-2) will be given, but the present invention is not limited thereto. For example, bis [3- (triethoxysilyl) propyl] urea, bis [3- (triethoxysilyl) ethyl] urea, bis [3- (trimethoxysilyl) propyl] urea, bis [3- (tripropoxysilyl) Propyl] Urea and the like. Among them, bis [3- (triethoxysilyl) propyl] urea is particularly preferable because it is easily available as a commercially available product.

The alkoxysilane represented by the formula (1) is preferably 0.5 mol% or more, more preferably 1.0 mol% or more, still more preferably 2 in the total alkoxysilane used for obtaining the intermediate layer. It is 0.0 mol% or more. The alkoxysilane represented by the formula (1) may be 100 mol% of the total alkoxysilane used to obtain the intermediate layer.

Further, as the alkoxysilane for obtaining the intermediate layer, it is preferable to use the 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 a hydrogen atom or a carbon atom which may be substituted with 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 of numbers 1-6. R ⁴ is an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms. n represents an integer of 0 to 3, preferably 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 bonds; hetero atoms such as oxygen atoms, nitrogen atoms and sulfur atoms. It is an organic group having 1 to 6 carbon atoms, which may contain such substances and may have a branched structure. In addition, R ³ may be substituted with a halogen atom, a vinyl group, an amino group, a glycidoxy group, a mercapto group, a metharoxy group, an isocyanate group, an acryloxy group and the like. R ⁴ has the same meaning as R ² described above, and the preferred range is also the same.

Specific examples of the alkoxysilane represented by the formula (2) will be given, but the present invention is not limited thereto. That is, in the alkoxysilane represented by the formula (2), specific examples of the alkoxysilane when R ³ is a hydrogen atom include trimethoxysilane, triethoxysilane, tripropoxysilane, tributoxysilane and the like. ..

Specific examples of the alkoxysilanes represented by the other formulas (2) and (2) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and propyltrimethoxysilane. Propyltriethoxysilane, 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-amino Ethylthioethyl) triethoxysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, allyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxy Propyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-isocyanaxpropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-Methoxypropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethylethoxy Examples thereof include silane, trimethylethoxysilane, and trimethylmethoxysilane.

In the alkoxysilane represented by the formula (2), the alkoxysilane in which n is 0 is a tetraalkoxysilane. Tetraalkoxysilane is preferable for obtaining the polysiloxane of the present invention because it easily condenses with the alkoxysilane represented by the formula (1). As the alkoxysilane in which n is 0 in the formula (2), tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane or tetrabutoxysilane is more preferable, and tetramethoxysilane or tetraethoxysilane is particularly preferable.

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

The polysiloxane forming the intermediate layer in the present invention is preferably polycondensed with an alkoxysilane represented by the formula (1) and, if necessary, an alkoxysilane containing the alkoxysilane represented by the formula (2). Can be obtained. In the intermediate layer, a plurality of types of alkoxysilane represented by the formula (1) and alkoxysilane represented by the formula (2) may be used in combination as long as the characteristics are not impaired.

Examples of the polycondensation method in the present invention include a method of 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, theoretically, 0.5 times by mole of water of all alkoxide groups in the alkoxysilane may be added, but usually, it is preferable to add an excess amount of water by more than 0.5 times by mole. The amount of water can be appropriately selected as desired, but is preferably 0.5 to 2.5 times the molar amount of all alkoxy groups in the alkoxysilane.

In the present invention, for the purpose of promoting the hydrolysis / condensation reaction, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, oxalic acid, maleic acid and fumaric acid; alkalis 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. 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 the heating time can be appropriately selected as desired. For example, a method such as heating and stirring at 50 ° C. to reflux for 1 to 24 hours can be mentioned.

As another method, there is a method of heating and polycondensing a mixture of an alkoxysilane, an organic solvent, and an organic acid such as formic acid, oxalic acid, maleic acid, and fumaric acid. For example, a method of heating a mixture of alkoxysilane, a solvent and oxalic acid to polycondensate it. Specifically, it is a method in which oxalic acid is added to alcohol in advance to prepare an alcohol solution of oxalic acid, and then the alkoxysilane is mixed in a heated state of the solution. At that time, the amount of oxalic acid used is preferably 0.2 to 2 mol with respect to 1 mol of all the alkoxy groups contained 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 several tens of minutes to ten and several hours so that evaporation and volatilization of the liquid do not occur.

When a plurality of types of alkoxysilanes are used in obtaining the polysiloxane, the alkoxysilanes may be mixed as a premixed mixture, or the plurality of types of alkoxysilanes may be sequentially mixed.
The solvent used for polycondensing the alkoxysilane (hereinafter, also referred to as a polymerization solvent) is not particularly limited as long as it dissolves the alkoxysilane. Even if the alkoxysilane is not dissolved, it may be dissolved as the polycondensation reaction of the alkoxysilane progresses. Generally, since alcohol is produced by the polycondensation reaction of alkoxysilane, alcohols, glycols, glycol ethers, or an organic solvent having good compatibility with alcohols is used.

Specific examples of the organic solvent 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, and 1,3-propanediol. , 1,2-Butandiol, 1,3-Butandiol, 1,4-Butandiol, 2,3-Butandiol, 1,2-Pentanediol, 1,3-Pentanediol, 1,4-Pentanediol, Glycos such as 1,5-pentanediol, 2,4-pentanediol, 2,3-pentanediol, 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 ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, etc. Glycol ethers, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ-butyrolactone, dimethylsulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol and the like. Be done. A plurality of kinds of the above organic solvents may be mixed and used.

The polysiloxane polymerization solution obtained by the above method (hereinafter, also referred to as a polymerization solution) has a concentration obtained by converting the silicon atom of all alkoxysilanes charged as a raw material into SiO ₂ (hereinafter referred to as a SiO ₂ conversion concentration). ) Is preferably 20% by mass or less. By selecting an arbitrary concentration in this concentration range, gel formation can be suppressed and a homogeneous solution can be obtained.
In the present invention, the polymerization solution of the polysiloxane obtained above may be used as it is for forming the intermediate layer, or if necessary, the above polymerization solution may be concentrated or a solvent may be added. It may be diluted 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 another solvent. The additive solvent is not particularly limited as long as the polysiloxane is uniformly dissolved, and any one or a plurality of types can be arbitrarily selected and used.

Specific examples of such an added solvent include ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; and esters such as methyl acetate, ethyl acetate and ethyl lactate, in addition to the solvents mentioned as examples of the above-mentioned polymerization solvent. Be done. It is possible to improve the coatability when a liquid whose viscosity is adjusted by these solvents is applied onto a substrate by spin coating, flexographic printing, inkjet, slit coating or the like to form an intermediate layer.

In the present invention, the coating liquid for forming the intermediate layer contains components other than the above polysiloxane, such as inorganic fine particles, metalloxane oligomers, metalloxane polymers, leveling agents, and surfactants. May be included.
As the inorganic fine particles, fine particles such as silica fine particles, alumina fine particles, titania fine particles, and magnesium fluoride fine particles are preferable, and those in a colloidal solution state are particularly preferable. By containing the inorganic fine particles in the coating liquid when forming the intermediate layer, it is possible to adjust the surface shape and refractive index of the cured film to be formed, and to impart other functions. The average particle size (D50) of the inorganic fine particles is preferably 0.001 to 0.2 μm, more preferably 0.001 to 0.1 μm. If the average particle size exceeds 0.2 μm, the transparency of the formed intermediate layer may decrease.

Examples of the dispersion medium of the inorganic fine particles include water and an organic solvent. The colloidal solution preferably has a pH or pKa of 1 to 10 from the viewpoint of stability of the polysiloxane solution. 2 to 7 are more preferable.

Examples of the organic solvent used as the dispersion medium of the colloidal solution 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; esters such as ethyl acetate, butyl acetate and γ-butyrolactone; Esters such as tetrahydrofuran and 1,4-dioxane can be mentioned. Of these, alcohols and ketones are preferred. The organic solvent can be used alone or in combination of two or more.

As the metalloxane oligomer and metalloxane polymer, single or composite oxide precursors such as silicon, titanium, aluminum, tantalum, antimony, bismuth, tin, indium, and zinc are used. The metalloxane oligomer and metalloxane polymer may be obtained by hydrolysis or the like from monomers such as metal alkoxides, nitrates, hydrochlorides and carboxylates.

The metalloxane oligomer and metalloxane polymer may be commercially available products. Examples thereof include methyl silicate 51, methyl silicate 53A, ethyl silicate 40, ethyl silicate 48, EMS-485, SS-101, etc. manufactured by Corcote; and titanoxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical Co., Inc. Can be mentioned. These may be used alone or in combination of two or more.

Further, as the leveling agent, the surfactant and the like, known ones, particularly commercially available products can be used. Further, the method of mixing the above-mentioned other components with the polysiloxane may be simultaneous with or after the polysiloxane, and is not particularly limited.

An 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 it. A known or well-known method can be adopted for applying the polysiloxane solution. For example, a dip method, a flow coating method, a spray method, a bar coating method, a gravure coating method, a roll coating method, a blade coating method, an air knife coating method, a flexographic printing method, an inkjet method, a slit coating method and the like can be adopted. Above all, a good coating film can be formed by the flexographic printing method, the slit coating method, the inkjet method, the spray coating method, and the gravure coating method.

The polysiloxane solution is preferably filtered using a filter or the like before coating. The formed coating film is preferably dried at room temperature to 120 ° C., more preferably 50 to 100 ° C., and then thermoset 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 thermosetting time is preferably 10 minutes to 24 hours, more preferably 30 minutes to 24 hours.

The intermediate layer used for the glass substrate of the present invention can obtain a cured film having 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.

It is also effective to irradiate energy rays (ultraviolet rays, etc.) with a mercury lamp, a metal halide lamp, a xenon lamp, an excimer lamp, or the like prior to thermal curing. By irradiating the dried coating film with energy rays, the curing temperature can be further lowered and the hardness of the coating film can be increased. The irradiation amount of the energy ray can be appropriately selected as needed, but is usually preferably several hundred to several thousand mJ / cm ² .

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

FIG. 1 is a schematic cross-sectional view showing an example of a glass substrate according to an embodiment of the present invention. The glass 1 includes 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 the above-mentioned fluorine-containing polymer-containing liquid and firing it. The glass base plate of the present invention can be 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.

Hereinafter, examples of the present invention will be shown and the present invention will be specifically described, but the present invention is not construed as being limited to the following examples. The meanings of the abbreviations and the measurement methods in the following 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: FT-Net, " Fluoromart P-5425 "

[Measurement method for residual alkoxysilane monomer]
The residual alkoxysilane monomer in the polysiloxane solution was measured by gas chromatography (hereinafter referred to as GC). The 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, wall thickness 1 μm)
Column temperature: The temperature was raised from a starting temperature of 50 ° C. to 15 ° C./min to an ultimate temperature of 290 ° C. (holding time: 3 minutes).
Sample injection amount: 1 μL, injection temperature: 240 ° C., detector temperature: 290 ° C., carrier gas: nitrogen (flow rate 30 mL / min), detection method: FID method.

[Steel wool scratch resistance]
Using a steel wool scratch resistance tester (manufactured by Daiei Seiki Co., Ltd.) and Bonstar commercial use (pound winding) # 0000 (bonster sales company), speed: 25 round trips / minute, distance: 6 cm, area: 2 cm x 2 cm, load: After rubbing steel wool on the substrate at 1 kg, the water contact angle was measured.

[Water contact angle]
Using a contact angle meter DM-701 (manufactured by Kyowa Surface Chemistry Co., Ltd.), 3 μm (liter) of water was dropped onto the steel wool scratch resistance test site on the substrate, and the water contact angle was measured.

[Average transmittance]
The glass substrates of Samples 1 to 3 obtained in Examples and Comparative Examples were subjected to a transmittance spectrum at a visible light wavelength (380 to 780 nm) using an ultraviolet visible spectrophotometer UV-3600 (product name of Shimadzu Corporation). Then, the value obtained by multiplying the daylight spectrum and the valence coefficient obtained from the wavelength distribution of the luminosity function and weight averaging was used as the average transmittance. Table 1 shows the results of measurement according to JIS R3106 (1998).
[Average reflectance]
The glass substrates of Samples 1 to 3 obtained in Examples and Comparative Examples were used with an ultraviolet-visible spectrophotometer UV-3600 (product name of Shimadzu Corporation), an absolute specular reflectance measuring device ASR3145, and a multipurpose large sample chamber MPC-3100. The value obtained by multiplying the reflectance spectrum at the visual light wavelength (380 to 780 nm) by the weight coefficient obtained from the daylight spectrum and the wavelength distribution of the relative luminosity and weighting and averaging the 45 ° reflectance used. The average reflectance was used. Table 1 shows the results of measurement according to JIS R3106 (1998). The results are shown in Table 1.

[Manufacturing Example 1]
MeOH (27.25 g) as a solvent and TEOS (32.98 g) as an alkoxysilane were put into a four-necked reaction flask equipped with a reflux tube, and the mixture was stirred.
Then, 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 the mixture was stirred for 30 minutes. After stirring, the mixture was refluxed for 2 hours, then 92% UPS (2.39 g) and MeOH (2.39 g) were added as alkoxysilane, and the mixture was further refluxed for 30 minutes and allowed to cool to room temperature. After allowing to cool, MeOH (70.67 g) was added as a solvent to prepare a polysiloxane solution (A).
When the solution of this polysiloxane was measured by GC, no alkoxysilane monomer was detected.

[Comparative Manufacturing Example 1]
MeOH (27.92 g) as a solvent and TEOS (34.72 g) as an alkoxysilane were put into a four-necked reaction flask equipped with a reflux tube, and the mixture was stirred.
Then, 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 the mixture was stirred for 30 minutes. After stirring, the mixture was refluxed for 2 hours and 30 minutes and allowed to cool to room temperature. After allowing to cool, MeOH (70.67 g) was added as a solvent to prepare a polysiloxane solution (B).
When the solution of this polysiloxane 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 form a coating solution (A1). And said.
A coating film-forming coating solution (A1) was applied to the DLC layer of a glass substrate (thickness: 0.7 mm) on which a DLC layer having a thickness of 100 nm was formed by a sputtering method with a spin coater 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 form a glass substrate having a coating film (intermediate layer) having a thickness of 100 nm. Got
AF was applied on the intermediate layer of the glass substrate with a spin coater to form a coating film of a fluorine coating layer having 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 on a hot plate at 80 ° C. for 3 minutes and then curing at 170 ° C. for 20 minutes in a clean oven.

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

[Comparative Example 2]
In Example 1, the same procedure as in Example 1 is carried out 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. As a result, the glass substrate of Sample 3 (Comparative Example 2) 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 transmittance after the steel wool scratch resistance test. The average reflectance was measured and the results are shown in Tables 1 and 2. In the table, "-" means unmeasured.

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 as high as 94% or more, and the average reflectance was 6 The result was as low as% or less.
On the other hand, in Comparative Examples 1 and 2, the steel wool scratch resistance test was 5000 reciprocations or less, and the average transmittance was 94% or less even though the scratch resistance was low with a water contact angle of 90 ° or less. The average reflectance was 6% or more, which was higher than that of the examples.

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

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

1: Cover glass 2: Fluorine coating layer 3: Intermediate 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, which is represented by the alkoxysilane represented by the following formula (1) and, if necessary, represented by the following formula (2). A glass substrate characterized by having an intermediate layer containing a polysiloxane obtained by polycondensing an alkoxysilane containing an alkoxysilane to be formed 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 ureido 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 may be substituted with a hydrogen atom or 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, and has 1 to 8 carbon atoms. It is a hydrocarbon group. R ⁴ is an alkyl group having 1 to 5 carbon atoms. N is an integer of 0 to 3.) Claim 1 that the alkoxysilane represented by the formula (1) is at least one selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane and γ-ureidopropyltripropoxysilane. The glass substrate described in. The glass substrate according to claim 1 or 2, wherein the alkoxysilane represented by the formula (2) is a tetraalkoxysilane in which n is 0 in the formula (2). The glass substrate according to any one of claims 1 to 3, wherein the alkoxysilane represented by the formula (1) is contained in an amount of 0.5% or more in the total alkoxysilane. The alkoxysilane represented by the formula (1) is contained in an amount of 0.5 to 60 mol% in the total alkoxysilane, and the alkoxysilane represented by the formula (2) is contained in an amount of 40 to 99.5 mol in the total alkoxysilane. % The glass substrate according to any one of claims 1 to 4. The glass substrate according to any one of claims 1 to 5, wherein the fluorine coating layer is formed from a polycondensation polymer of a silane compound of perfluoroalkyl or perfluoropolyether. The glass substrate according to any one of claims 1 to 6, 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 intermediate layer has a thickness of 10 to 500 nm. A display element including the glass substrate according to any one of claims 1 to 7.

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