WO2017022638A1

WO2017022638A1 - Glass substrate suitable for cover glass, etc., of mobile display device

Info

Publication number: WO2017022638A1
Application number: PCT/JP2016/072214
Authority: WO
Inventors: 政太郎大田; 洋介飯沼; 和輝江口
Original assignee: 日産化学工業株式会社
Priority date: 2015-07-31
Filing date: 2016-07-28
Publication date: 2017-02-09
Also published as: TW201718259A; JP6773036B2; CN108139506B; JPWO2017022638A1; KR20180036762A; KR102633247B1; CN108139506A; TWI704050B

Abstract

Provided is a glass substrate suitable particularly as a cover glass or the like for a mobile display device, the glass substrate having high scratch resistance and smoothness, good visibility, and low reflectance. A glass substrate having, between a fluorine coating layer on a front surface side and a DLC layer on a substrate side, an intermediate layer containing a polysiloxane obtained by polycondensation of an alkoxy silane including an alkoxy silane represented by formula (1) and, as needed, an alkoxy silane represented by formula (2). (1): R¹[Si(OR²)₃]_P (In formula (1), R¹ represents a C1-12 hydrocarbon group substituted by a ureido group, R² represents a C1-5 alkyl group, and p represents an integer of 1 or 2.) (2): (R³)_nSi(OR⁴)_4-n (In formula (2), R³ represents a hydrogen atom or a C1-8 hydrocarbon group which may be substituted by 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, R⁴ represents a C1-5 alkyl group, and n represents an integer of 0-3.)

Description

Glass substrate suitable for cover glass of mobile display devices

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

In recent years, cover glass for protecting the surface of a display element is often used in liquid crystal display elements such as mobile devices and touch panels. Further, glass plates having excellent scratch resistance and good visibility are used in protective glasses such as watches and camera viewfinders (see Patent Documents 1 and 2).

The cover glass in such a display element is required to have a high hardness and a high scratch resistance so that it is 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 the slip property of the cover glass. There was a problem that the adhesion with the fluorine coating layer formed on the surface was lowered, and the slipping property was remarkably lowered during use (see Patent Document 3).

JP 2009-186234 A JP 2009-186236 A JP 2010-228307 A

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 of a display device such as a mobile device or a touch panel. It is in.

As a result of intensive studies in view of the above situation, the present inventors have completed the present invention described below.
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), an alkoxysilane represented by the following formula (2), A glass substrate comprising an intermediate layer made of a polysiloxane-containing film obtained by polycondensation of an alkoxysilane containing benzene 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 is 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 having 1 to 8 carbon atoms. A hydrocarbon group, R ⁴ is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 0 to 3.)
2. In the above 1, 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 as described.
3. The glass substrate of said 1 or 2 whose alkoxysilane represented by Formula (2) is tetraalkoxysilane whose n is 0 in Formula (2).
4). 4. The glass substrate according to any one of 1 to 3 above, wherein the alkoxysilane represented by the formula (1) is contained in an amount of 0.5% or more 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) in the total alkoxysilane is 40 to 99.5 mol. 5. The glass substrate according to any one of 1 to 4 above, which is contained in an amount of 1%.
6. The glass substrate according to any one of 1 to 5 above, wherein the fluorine coating layer is formed from a polycondensate of a silane compound of perfluoroalkyl or perfluoropolyether.
7). 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). 8. A display device comprising the glass substrate according to any one of 1 to 7 above.

According to the present invention, it has high scratch resistance and slippage, and it is unexpected by having a specific polysiloxane intermediate layer in addition to the fluorine coating layer on the surface and the DLC layer on the substrate side. Further, since the transmittance can be improved and the reflectance is also lowered, a glass substrate having excellent visibility is provided.
In the glass substrate of the present invention, the intermediate layer of the above specific polysiloxane can be cured at a low temperature of 300 ° C. or less, so that the production efficiency is good, and the thickness of the nanometer order has sufficient hardness, and In addition, 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 suitably used as a cover glass for liquid crystal display elements.

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 in order to impart high scratch resistance and corrosion resistance. The DLC layer in the present invention is easily obtained by a sputtering method using a hydrocarbon gas such as acetylene or methane as a raw material, preferably a plasma CVD method, a sputtering method, an ionization vapor deposition method, among others. The raw material can also contain hydrogen.
The DLC layer in the present invention has a thickness of preferably 50 to 150 nm, more preferably 70 to 130 nm. Further, 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 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 in order to improve the slipperiness and improve the ease of operation and the prevention of fingerprint adhesion. A glass substrate having a fluorine coating layer on its surface is known, for example, from International Publication WO2013 / 115191, Japanese Patent Application Laid-Open No. 2014-218639, etc., and these known coating materials can also 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 a fluorine atom having 1 to 10 carbon atoms. A divalent organic group, and X ¹ is a hydrolyzable group such as a halogen atom or an alkoxy group.) Or a silane compound having a perfluoroalkyl group such as 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 polycondensation product of a perfluoro (poly) ether group-containing silane compound such as Si (CH ₂ CH═CH ₂ ) ₃ . A liquid in which these fluoropolymers are dispersed in a medium is applied on the DLC layer of the glass substrate, dried and heated to form a fluorine coating layer.
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 contains polysiloxane having a ureido group as described below. Thereby, a film having sufficient hardness and adhesion can be formed even at a low temperature of 100 to 300 ° C.
That is, the intermediate layer in the present invention is 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). Contains siloxane.

R ¹ {Si (OR ² ) ₃ } _P (1)
In the formula (1), R ¹ is a hydrocarbon group having 1 to 12 carbon atoms having a ureido group. 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. A group substituted with a ureido 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, 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) are listed below, but are not limited thereto. For example, γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, γ-ureidopropyltripropoxysilane, (R) -N-1-phenylethyl-N′-triethoxysilylpropylurea, (R) — And N-1-phenylethyl-N′-trimethoxysilylpropylurea. Among these, γ-ureidopropyltriethoxysilane or γ-ureidopropyltrimethoxysilane is particularly preferable because it is easily available as a commercial product.

Specific examples of the alkoxysilane represented by the formula (1-2) will be given, but the invention 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 and the like. Of these, bis [3- (triethoxysilyl) propyl] urea is particularly preferable because it is easily available as a commercial product.

The alkoxysilane represented by the formula (1) is preferably 0.5 mol% or more, more preferably 1.0 mol% or more, further preferably 2 in all alkoxysilanes used for obtaining the intermediate layer. 0.0 mol% or more. Moreover, 100 mol% may be sufficient as the alkoxysilane represented by Formula (1) in all the alkoxysilanes used in order to obtain an intermediate | middle layer.

Moreover, it is preferable to use the alkoxysilane represented by the following Formula (2) with the alkoxysilane represented by the said Formula (1) as the alkoxysilane which obtains an intermediate | middle layer.
(R ³ ) _n Si (OR ⁴ ) _4-n (2)
In the 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 the number 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 the formula (2) include aliphatic hydrocarbons; ring structures such as aliphatic rings, aromatic rings or heterocycles; unsaturated bonds; heteroatoms such as oxygen atoms, nitrogen atoms and sulfur atoms Or an organic group having 1 to 6 carbon atoms, which 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 methacryloxy group, an isocyanate group, an acryloxy group, or the like. R ⁴ has the same meaning as R ² described above, and the preferred range is also the same.

Although the specific example of the alkoxysilane represented by Formula (2) is given, it is not limited to this. 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. .

Other specific examples of the alkoxysilanes represented by formula (2) and formula (2) include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, 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) trie Xysilane, 3-mercaptopropyltriethoxysilane, mercaptomethyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, allyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3 -Acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, trifluoropropyltrimethoxysilane, chloropropyltriethoxysilane, bromopropyltriethoxysilane, 3-mercaptopropyltrimethoxy Silane, dimethyldiethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, diphenyldimeth Shishiran, diphenyl diethoxy silane, 3-aminopropyl methyl diethoxy silane, 3-aminopropyl dimethylethoxysilane, trimethylethoxysilane, trimethylmethoxysilane and the like.

In the alkoxysilane represented by the formula (2), the alkoxysilane in which n is 0 is 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 50%, based on the total alkoxysilane used for obtaining 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 in all alkoxysilanes used for obtaining the intermediate layer. is there.

The polysiloxane forming the intermediate layer in the present invention is preferably a polycondensation of an alkoxysilane represented by the formula (1) and, if necessary, an alkoxysilane containing the alkoxysilane represented by the formula (2). Obtained. As long as the properties of the intermediate layer are not impaired, a plurality of types of alkoxysilanes represented by formula (1) and alkoxysilanes represented by formula (2) may be used in combination.

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, it is sufficient to add 0.5 moles of water of all alkoxide groups in the alkoxysilane, but it is usually preferable to add an excess amount of water over 0.5 moles. The amount of water can be appropriately selected as desired, but it is preferably 0.5 to 2.5 moles of all alkoxy groups in the alkoxysilane.

In the present invention, for the purpose of promoting hydrolysis / condensation reaction, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, succinic acid, maleic acid and fumaric acid; alkalis such as ammonia, methylamine, ethylamine, ethanolamine and triethylamine A catalyst such as a metal salt such as hydrochloric acid, sulfuric acid or nitric acid is preferably used. It is also preferable to further promote hydrolysis / condensation reaction by heating a solution in which alkoxysilane is dissolved. At that time, the heating temperature and the heating time can be appropriately selected as desired. Examples thereof include a method of heating and stirring at 50 ° C. to reflux for 1 to 24 hours.

As another method, 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 can be used. For example, a method of polycondensation by heating a mixture of alkoxysilane, solvent and oxalic acid can be mentioned. Specifically, after adding succinic acid to alcohol in advance to make an alcohol solution of succinic acid, alkoxysilane is mixed while the solution is heated. In that case, the amount of succinic acid used is preferably 0.2 to 2 mol with respect to 1 mol of all alkoxy groups of the alkoxysilane. Heating in this method can be performed at a liquid temperature of 50 to 180 ° C. A method of heating for several tens of minutes to several tens of hours under reflux is preferred so that the liquid does not evaporate or volatilize.

In the case of using a plurality of types of alkoxysilanes when obtaining polysiloxane, a mixture of alkoxysilanes may be mixed in advance, or a plurality of types of alkoxysilanes may be mixed sequentially.
The solvent used for polycondensation of alkoxysilane (hereinafter also referred to as polymerization solvent) is not particularly limited as long as it can dissolve alkoxysilane. Moreover, even when alkoxysilane does not melt | dissolve, what melt | dissolves as the polycondensation reaction of alkoxysilane progresses is sufficient. In general, since an alcohol is generated by a polycondensation reaction of alkoxysilane, an alcohol, a glycol, a glycol ether, or an organic solvent having good compatibility with the alcohol 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-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, 1,6-hexanediol: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl Pill 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 Glycol ethers such as ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, γ -Butyrolactone, dimethyl sulfoxide, tetramethylurea, hexamethylphosphotriamide, m-cresol and the like. A plurality of the above organic solvents may be mixed and used.

The polysiloxane polymerization solution (hereinafter also referred to as polymerization solution) obtained by the above method is a concentration obtained by converting silicon atoms of all alkoxysilanes charged as raw materials into SiO ₂ (hereinafter referred to as SiO ₂ conversion concentration). ) Is preferably 20% by mass or less. By selecting an arbitrary concentration within this concentration range, it is possible to obtain a homogeneous solution while suppressing gel formation.
In the present invention, the polysiloxane polymerization solution obtained above may be used as it is to form an intermediate layer, and if necessary, the polymerization solution may be concentrated or a solvent may be added. It may be diluted or replaced with another solvent.
In that case, the solvent to be used (hereinafter also referred to as additive 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 one kind or plural kinds can be arbitrarily selected and used.

Specific examples of such an additive solvent include ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; esters such as methyl acetate, ethyl acetate, and ethyl lactate in addition to the solvents mentioned as examples of the polymerization solvent. It is done. A liquid whose viscosity is adjusted with these solvents can be applied on a substrate by spin coating, flexographic printing, ink jetting, slit coating, or the like, thereby improving the coating property when an intermediate layer is formed.

In the present invention, the coating liquid for forming the intermediate layer contains other components other than the above polysiloxane, for example, inorganic fine particles, metalloxane oligomers, metalloxane polymers, leveling agents, and further components such as surfactants. May be included.
As the 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 including inorganic fine particles in the coating liquid for forming the intermediate layer, it is possible to adjust the surface shape and refractive index of the formed cured film and to provide other functions. The inorganic fine particles preferably have an average particle diameter (D50) of 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 be lowered.

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

Examples of the organic solvent used for 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; Examples include ethers such as tetrahydrofuran and 1,4-dioxane. 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 Colcoat, and titanoxane oligomers such as titanium-n-butoxide tetramer manufactured by Kanto Chemical Co., Ltd. Can be mentioned. These may be used alone or in combination of two or more.

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

The intermediate layer can be obtained by applying the polysiloxane solution of the present invention on the DLC layer of the glass substrate and thermosetting. A known or well-known method can be employed 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 ink jet method, a slit coating method and the like can be employed. Among them, a good coating film can be formed by the flexographic printing method, the slit coating method, the ink jet method, the spray coating method, and the 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., followed by heat curing at 100 to 600 ° C., more preferably 150 ° C. or more. 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 provide 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 or the like) using a mercury lamp, a metal halide lamp, a xenon lamp, an excimer lamp or the like prior to thermosetting. By irradiating the dried coating with energy rays, the curing temperature can be further lowered, or the hardness of the coating can be increased. The irradiation amount of the energy beam can be appropriately selected as necessary, but it is usually preferably from 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 and baking the liquid containing the fluorine-containing polymer described above. The glass base plate 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.

Hereinafter, examples of the present invention will be shown and the present invention will be specifically described. However, the present invention is not construed as being limited to the following examples. The meanings of the abbreviations below and the measurement methods 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 Fluoromat P-5425 "

[Measurement of residual alkoxysilane monomer]
The residual alkoxysilane monomer in the polysiloxane solution was measured by gas chromatography (hereinafter referred to as GC). GC measurement was performed under the following conditions using Shimadzu GC-14B (manufactured by Shimadzu Corporation).
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. at 15 ° C./min to reach an ultimate temperature of 290 ° C. (holding time 3 minutes).
Sample injection volume: 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]
Steel wool scratch resistance tester (manufactured by Daiei Seiki Co., Ltd.), Bonster commercial use (pound roll) # 0000 (Bonster sales company), speed: 25 reciprocations / minute, distance: 6 cm, area: 2 cm × 2 cm, load: After rubbing steel wool on the substrate with 1 kg, the water contact angle was measured.

[Water contact angle]
Using a contact angle meter DM-701 (manufactured by Kyowa Interface Chemical Co., Ltd.), 3 μm (liter) of water was dropped on 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 measured with respect 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). Thus, a value obtained by multiplying the weighting coefficient obtained from the daylight spectrum and the wavelength distribution of the relative luminous sensitivity and performing weighted averaging was defined as the average transmittance. The results measured according to JIS R3106 (1998) are shown in Table 1.
[Average reflectance]
The glass substrates of Samples 1 to 3 obtained in the Examples and Comparative Examples were prepared using an ultraviolet-visible spectrophotometer UV-3600 (product name of Shimadzu Corporation), an absolute specular reflection measuring apparatus ASR3145, and a multipurpose large sample chamber MPC-3100. Using 45 ° reflectance, the value obtained by multiplying the reflectance spectrum at the visible light wavelength (380 to 780 nm) by the weighting coefficient obtained from the daylight spectrum and the wavelength distribution of the relative luminous sensitivity, and calculating the weighted average. Average reflectance was used. The results measured according to JIS R3106 (1998) are shown in Table 1. The results are shown in Table 1.

[Production Example 1]
In a four-necked 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, 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, and then 92% UPS (2.39 g) and MeOH (2.39 g) were added as alkoxysilane, refluxed for another 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 this polysiloxane solution was measured by GC, no alkoxysilane monomer was detected.

[Comparative Production Example 1]
In a four-necked 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, 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 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 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 is diluted with PGME (30 g), HG (10 g), BCS (5 g), and PB (5 g), and a coating solution for film formation (A1) It was.
On the DLC layer of the glass substrate (thickness: 0.7 mm) on which the DLC layer having a thickness of 100 nm was formed by the sputtering method, the coating solution for coating film formation (A1) was applied with a spin coater to form a coating film. Next, after the glass plate on which the coating film has been formed is dried on a hot plate at 80 ° C. for 3 minutes, the glass plate is cured in a clean oven at 300 ° C. for 30 minutes to have a coating film (intermediate layer) having a thickness of 100 nm. Got.
On the intermediate layer of the glass substrate, AF was applied 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, after drying at 80 ° C. for 3 minutes on a hot plate, the glass substrate of Sample 1 (Example 1) was obtained by 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 and without forming an intermediate layer. A glass substrate of Sample 2 (Comparative Example 1) was obtained by carrying out in the same manner as in Example 1 except that the coating film of the fluorine coating layer was formed.

[Comparative Example 2]
In Example 1, it carries out similarly to Example 1 except having used the polysiloxane solution (B) obtained by the comparative manufacture example 1 instead of the polysiloxane solution (A) obtained by manufacture example 1. Thus, a 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 after steel wool scratch resistance test, the average transmittance, and The average reflectance was measured, and the results are shown in Tables 1 and 2. In the table, “-” means not measured.

As shown in Tables 1 and 2, in the examples, even when the steel wool scratch resistance test was repeated 9000, the water contact angle was 90 ° or more and the transmittance was as high as 94% or more, and the average reflectance 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 5,000 round trips or less, and both had a water contact angle of 90 ° or less and low scratch resistance, but the average transmittance was 94% or less. The average reflectance was 6% or more, which was a high value compared to 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.

It should be noted that 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

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, the following formula (2) A glass substrate comprising an intermediate layer containing polysiloxane obtained by polycondensation of an alkoxysilane containing an alkoxysilane, 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 is 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 having 1 to 8 carbon atoms. A hydrocarbon group, R 4 is an alkyl group having 1 to 5 carbon atoms, and n is an integer of 0 to 3.)
The alkoxysilane represented by the formula (1) is at least one selected from the group consisting of γ-ureidopropyltriethoxysilane, γ-ureidopropyltrimethoxysilane, and γ-ureidopropyltripropoxysilane. A glass substrate as described in 1.
The glass substrate of Claim 1 or 2 whose alkoxysilane represented by Formula (2) is tetraalkoxysilane whose n is 0 in 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) in the total alkoxysilane is 40 to 99.5 mol. The glass substrate according to claim 1, wherein the glass substrate is contained in an amount of 1%.
The glass substrate according to any one of claims 1 to 5, wherein the fluorine coating layer is formed from a polycondensate of a silane compound of perfluoroalkyl or perfluoropolyether.
7. The glass substrate according to claim 1, 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 comprising the glass substrate according to any one of claims 1 to 7.