JP2018040940A - Antireflection laminate, front plate for display, and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antireflection laminate that has good scratch resistance, which is the main purpose of the present invention.SOLUTION: The present invention solves the above-mentioned problem by providing an antireflection laminate comprising: a transparent substrate; a low refractive index layer that is formed on the transparent substrate and includes hollow fine particles and binder; and an overcoat layer that is formed on the low refractive index layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an antireflection laminate having good scratch resistance, a front plate for a display device, and a display device using the same.

  For example, a front plate for protecting the display device is provided on the front surface of a display device such as a liquid crystal display device or an organic electroluminescence display device. Further, a front plate is provided in a gaming machine such as a pachinko to protect the game board. When the front plate is provided, there is a problem that light is reflected due to a difference in refractive index at the interface between the front plate and air, and visibility of a display device, a game board, or the like is lowered. Therefore, it has been proposed to dispose an antireflection film on the outermost surface of the front plate (Patent Document 1) and dispose an antireflection layer.

Examples of the antireflection film include those obtained by forming an antireflection layer on a transparent substrate such as a TAC film or PET film, and examples of the antireflection layer include a high refractive index layer and a low refractive index layer laminated. The thing which was done is mentioned. Such an antireflection film is attached to the outermost surface of the front plate via an adhesive layer or an adhesive layer.
The antireflection film can be provided with antireflection properties simply by being attached to the front plate. However, since an antireflection film includes a transparent substrate and an adhesive layer or an adhesive layer, the optical design is complicated. Further, since the transparent substrate has waviness, the flatness is lowered and the display quality is deteriorated. Moreover, when sticking an antireflection film, troubles, such as mixing of a foreign material and a bubble, arise and a yield falls. Further, the transmittance is lowered by the transparent substrate and the adhesive layer or the adhesive layer.

On the other hand, examples of the antireflection layer include an inorganic film formed by a dry process such as a sputtering method or a vacuum deposition method. Since such an antireflection layer can be formed on a transparent substrate, the above-described problems in the antireflection film can be solved. In addition, an inorganic film has a high film strength, and an antireflection layer having a high surface hardness can be obtained.
However, it is difficult to lower the refractive index of an inorganic film. For example, an inorganic high refractive index layer having a refractive index (n) of 1.7 or more and an inorganic medium refractive index layer having a refractive index n of about 1.5 are alternately arranged. It is common to laminate. In this case, since a plurality of layers are laminated by a dry process, productivity is lowered and manufacturing costs are increased. In particular, in the case of a front plate used for a display device with a large area, the equipment becomes large and the cost increases. Further, in the case of a dry process, the in-plane distribution of the thickness of the antireflection layer varies, and the uniformity of antireflection properties is impaired.

For such problems, for example, a method of forming an antireflection layer on a transparent substrate by a wet process has been proposed (Patent Documents 2 to 3). This is advantageous in terms of productivity and cost.
As such an antireflection layer, for example, a configuration having a low refractive index layer containing hollow fine particles is preferably used. In addition, in order to impart an antireflection function at a lower cost, it has been studied to use a single low refractive index layer as an antireflection layer formed on a transparent substrate.

JP 2002-265866 A JP 2008-152199 A JP 2008-19358 A

By the way, since the antireflection layer used for the front plate or the like is usually disposed on the outermost surface on the operator side such as a display device, friction due to contact with the operator is likely to be applied. Therefore, high scratch resistance is required. On the other hand, in the low refractive index layer described above, sufficient scratch resistance is not obtained at present.
The present invention has been made in view of the above circumstances, and has as its main object to provide an antireflection laminate having a good scratch resistance, a front plate for a display device, and a display device using the same.

  In order to achieve the above object, the present invention provides a transparent base material, a low refractive index layer formed on the transparent base material and containing hollow fine particles and a binder, and an overcoat formed on the low refractive index layer. An antireflection laminate having a coat layer is provided.

  According to the present invention, by having an overcoat layer, smoothness can be imparted to the low refractive index layer side surface of the antireflection laminate. Therefore, an antireflection laminate having good scratch resistance can be obtained.

  In the said invention, it is preferable that the binder of the said low refractive index layer and the said overcoat layer contain an inorganic oxide. This is because the adhesion between the low refractive index layer and the overcoat layer can be improved, and the scratch resistance and pencil hardness of the antireflective laminate on the low refractive index layer side surface can be dramatically increased. .

  The present invention has a transparent substrate and a low refractive index layer formed on the transparent substrate and containing hollow fine particles and a binder, and the thickness of the low refractive index layer is 120 nm or less, Provided is an antireflection laminate having a ten-point average roughness (RzJIS) of a refractive index layer surface of 10 nm or less.

  According to the present invention, when the ten-point average roughness of the surface of the low refractive index layer is within a predetermined range, the smoothness of the surface of the low refractive index layer can be improved. Therefore, an antireflection laminate having good scratch resistance can be obtained.

  The present invention provides a display device front plate for use in a display device, the display device front plate having the antireflection laminate described above.

  According to this invention, it can be set as the front plate for display apparatuses with favorable abrasion resistance by having the anti-reflection laminated body mentioned above.

  The present invention provides a display device having a front plate and a display panel, wherein the front plate is the above-described front plate for a display device.

  According to the present invention, by having the above-described front plate for a display device, it is possible to obtain a display device with good scratch resistance and visibility.

  The antireflection laminate of the present invention has an effect that the scratch resistance is good.

It is a schematic sectional drawing which shows an example of the reflection preventing laminated body of this invention. It is explanatory drawing explaining the abrasion resistance of the low refractive index layer side surface in this invention. It is a schematic sectional drawing which shows the other example of the reflection preventing laminated body of this invention. It is process drawing explaining the manufacturing method of the reflection preventing laminated body of this invention. It is a schematic sectional drawing which shows the other example of the reflection preventing laminated body of this invention. It is a schematic sectional drawing which shows an example of the front plate for display apparatuses of this invention, and a display apparatus. It is explanatory drawing explaining the abrasion resistance of the conventional low refractive index layer.

  Hereinafter, details of the antireflection laminate, the front plate for a display device, and the display device of the present invention will be described.

A. Antireflection laminate The antireflection laminate of the present invention has two embodiments. Each embodiment will be described below.

I. First Embodiment The antireflection laminate of the first embodiment is formed on a transparent base material, a low refractive index layer formed on the transparent base material and containing hollow fine particles and a binder, and the low refractive index layer. And an overcoat layer formed thereon.

  The antireflection laminate of the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the antireflection laminate of the first embodiment. As shown in FIG. 1, the antireflection laminate 10 of the first embodiment includes a transparent substrate 1, a low refractive index layer 2 formed on the transparent substrate 1 and containing hollow fine particles 2a and a binder 2b, And an overcoat layer 3 formed on the low refractive index layer 2.

  According to the present invention, by having an overcoat layer, smoothness can be imparted to the low refractive index layer side surface of the antireflection laminate. Therefore, an antireflection laminate having good scratch resistance can be obtained.

As described above, sufficient scratch resistance is not obtained in the low refractive index layer containing the conventional hollow fine particles. The reason is considered as follows.
As shown in FIG. 7A, in the low refractive index layer 2, the hollow fine particles 2a are likely to be unevenly distributed on the surface opposite to the transparent substrate 1 side. Therefore, the low refractive index layer 2 of the conventional antireflection laminate 11 has surface irregularities at the nano level. Therefore, when the load g is applied and the surface of the low refractive index layer 2 is rubbed with the steel wool s or the like, it is considered that the convex portions of the surface irregularities are easily caught with the steel wool s, and a force is easily applied in the friction direction. Thereby, as shown in FIG.7 (b), it is thought that the hollow microparticles 2a and the binder 2b which exist in a convex part become easy to peel. It is conceivable that the peeled portion is visually recognized as a scratch. Further, it is conceivable that the peeled hollow fine particles 2a and the binder 2b function as an abrasive and promote surface scraping. Furthermore, since the low refractive index layer 2 is formed of a relatively thin film, it is considered that the peeled portion is the starting point and cracks are likely to occur in the thickness direction.

  The reason why the hollow fine particles are likely to be unevenly distributed on the surface of the low refractive index layer is considered as follows. That is, the low refractive index layer is formed by applying a composition for a low refractive index layer containing hollow fine particles and a binder component onto a transparent substrate. Since the hollow fine particles have cavities inside, the specific gravity is light with respect to the binder component, and therefore, it is considered that the hollow fine particles exist in a state of floating on the surface in the coating film. In order to cure such a coating film, it is considered that hollow fine particles are unevenly distributed.

  On the other hand, in the first embodiment, the surface irregularities of the low refractive index layer can be filled with the overcoat layer, and smoothness can be imparted, so that the scratch resistance can be improved. Specifically, as shown in FIG. 2, when the surface of the overcoat layer 3 is rubbed, it is possible to suppress the local application of a force in the friction direction to the surface of the overcoat layer 3. Therefore, it is considered that peeling of the hollow fine particles and the binder due to the surface unevenness of the low refractive index layer can be suppressed, and the function of the peeled hollow fine particles and the like as an abrasive can also be suppressed. Moreover, it can be considered that the hardness of the surface on the low refractive index layer side can be increased by having the overcoat layer as a reason that the scratch resistance can be improved.

  In the first embodiment, the pencil hardness of the surface on the low reflection layer side of the antireflection laminate can be improved by having the overcoat layer. As the reason, as described above, since the surface of the low refractive index layer side can be flattened, it is considered that the pencil is hardly caught. It is also conceivable that the hardness of the surface on the low refractive index layer side can be increased by having an overcoat layer.

  Hereinafter, each configuration of the antireflection laminate of the first embodiment will be described.

1. Low Refractive Index Layer The low refractive index layer in the first embodiment is formed on a transparent substrate and contains hollow fine particles and a binder. The low refractive index layer usually has a lower refractive index than the transparent substrate. The low refractive index layer imparts an antireflection function to the transparent substrate.

  The low refractive index layer is not particularly limited as long as it is formed on the transparent substrate, and may be formed directly on the transparent substrate 1 as shown in FIG. 1, or transparent as shown in FIG. It may be formed on the substrate 1 via the high refractive index layer 4. The high refractive index layer will be described later.

Although it will not specifically limit if the refractive index of a low-refractive-index layer is lower than the refractive index of a transparent base material, For example, it is preferable to exist in the range of 1.2-1.4.
Here, the “refractive index” of each member refers to the refractive index with respect to light having a wavelength of 550 nm. The method for measuring the refractive index is not particularly limited, and examples thereof include a method of calculating from a spectral reflection spectrum, a method of measuring using an ellipsometer, and an Abbe method. Examples of the ellipsometer include UVSEL manufactured by Joban Yvon. Specifically, the refractive index can be measured with DF1030R manufactured by Techno Synergy.

The thickness of the low refractive index layer is appropriately selected depending on the refractive index and is not particularly limited. For example, the thickness is preferably 120 nm or less, more preferably 100 nm or less, and even more preferably 95 nm or less. Moreover, as thickness of a low refractive index layer, it is preferable that it is 80 nm or more, for example, and it is more preferable that it is 85 nm or more. This is because the low refractive index layer is easily formed when the thickness of the low refractive index layer is within the above-described range.
Here, the “thickness” of each member means a thickness obtained by a general measurement method. Thickness measurement methods include, for example, a stylus method that calculates the thickness by tracing the surface with a stylus, and an optical method that calculates the thickness based on the spectral reflection spectrum. Is mentioned. Specifically, the thickness can be measured using a stylus type film thickness meter P-15 manufactured by KLA-Tencor Corporation. In addition, as thickness, the average value of the thickness measurement result in the several location of the member used as object may be used.

(1) Hollow fine particles Hollow fine particles are used for adjusting the refractive index in the low refractive index layer. The hollow fine particles have, for example, a hollow core part and a shell part.
Examples of the particle shape of the hollow fine particles include a spherical shape.

The average particle diameter of the hollow fine particles is not particularly limited as long as a desired refractive index can be imparted to the low refractive index layer, but is preferably in the range of 30 nm to 70 nm, and more preferably in the range of 40 nm to 60 nm. . This is because the refractive index of the low refractive index layer can be easily adjusted when the average particle diameter of the hollow fine particles is within the above-described range.
The particle variation coefficient (CV value) of the hollow fine particles is, for example, preferably in the range of 1% to 50%, and more preferably in the range of 2% to 30%. This is because if the CV value is too large or too small, it may be difficult to sufficiently reduce the refractive index of the low refractive index layer.
The average particle size of the hollow fine particles is a value obtained by measuring the particle size of 100 arbitrary particles using an image taken by an electron microscope and obtaining the average value. The CV value is a value obtained by the following formula from the standard deviation and average particle diameter of 100 measured particles. The particle diameter of the hollow fine particles is a value measured by the outermost diameter of the shell.
CV value (%) = standard deviation of particle size (σ) / average particle size (D _n ) × 100

The refractive index of the silica-based hollow fine particles is, for example, preferably in the range of 1.10 to 1.40, more preferably in the range of 1.10 to 1.35. The thickness of the shell portion of the silica-based hollow fine particles varies depending on the particle diameter, but is preferably in the range of 1 nm to 20 nm, for example. The ratio of the thickness of the shell portion to the average particle size is preferably in the range of 0.025 to 0.25, for example.
The refractive index of the hollow fine particles is measured, for example, as the refractive index of the standard refractive liquid when the mixed liquid becomes transparent when hollow fine particles are mixed using a standard refractive liquid having a known refractive index. Can do. The thickness of the shell is a value obtained as an average value by measuring the thickness of the shell for 100 arbitrary particles using an image taken by an electron microscope.

Examples of the hollow fine particles include inorganic hollow fine particles whose shell portion contains an inorganic material. Examples of inorganic materials contained in the inorganic hollow fine particles include silicon compounds, aluminum compounds, and composites thereof. As the inorganic hollow fine particles, for example, silica-based hollow fine particles disclosed in JP 2014-058683 A can be used.
Further, the hollow fine particles may be subjected to a surface treatment. Specifically, the surface treatment may be performed using an organosilicon compound of the formula (1) described in the section “(2) Binder” described later.

  The content of the hollow fine particles in the low refractive index layer is, for example, preferably in the range of 40% by mass to 60% by mass, particularly in the range of 40% by mass to 50% by mass. This is because if the content of the hollow fine particles is too small, it may be difficult to sufficiently reduce the refractive index of the refractive index layer. This is because, since the content is reduced, it may be difficult to ensure the strength of the low refractive index layer.

(2) Binder The binder is for dispersing and holding hollow fine particles.
The binder used in the first embodiment is not particularly limited as long as hollow fine particles can be dispersed and a desired refractive index can be imparted to the low refractive index layer. The binder may be a resin material or may contain an inorganic oxide, but more preferably contains an inorganic oxide. Examples of the inorganic oxide include silicon oxide, aluminum oxide, and composite oxides thereof. In the first embodiment, it is preferable to include silicon oxide. This is because the refractive index and thickness of the low refractive index layer can be easily adjusted. Moreover, it is because the intensity | strength of a low refractive index layer can be adjusted favorably.
Specific examples of the binder containing an inorganic oxide (inorganic binder) include a cured product of a sol-gel material, that is, a hydrolysis condensate of a metal alkoxide.

  In particular, the binder in the first embodiment is preferably a hydrolytic condensate of an organosilicon compound represented by the following general formula (1).

R _n —SiX _4-n (1)
(In the formula, R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms and may be the same or different from each other. X is an alkoxy group or silanol group having 1 to 4 carbon atoms. , Halogen and hydrogen, n is an integer of 0 to 3.)

  Examples of the organosilicon compound represented by the formula (1) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane. , Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, 3,3,3- Trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glyci Xymethyltrimethoxysilane, γ-glycidoxymethyltriexylsilane, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycid Xylpropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- (β-glycidoxyethoxy) propyltrimethoxysilane, γ- (meth) acrylooxymethyl Trimethoxysilane, γ- (meth) acrylooxymethyltrioxysilane, γ- (meth) acrylooxyethyltrimethoxysilane, γ- (meth) acrylooxyethyltriethoxysilane, γ- (meth) acrylo Oxypropyltrimethoxysilane, γ- (meth) acrylooxy Propyltrimethoxysilane, γ- (meth) acrylooxypropyltriethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, butyltrimethoxysilane, isobutyltriethoxysilane, hexyltriethoxysilaoctyltriethoxysilane, Decyltriethoxysilane, butyltriethoxysilane, isobutyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltriethoxysilane, 3-ureidoisopropylpropyltriethoxysilane, perfluorooctylethyltrimethoxysilane, perfluorooctyl Ethyltriethoxysilane, perfluorooctylethyltriisopropoxysilane, trifluoropropyltrimethoxysilane, N-β (aminoethyl) γ Aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, trimethylsilanol, methyltrichlorosilane, etc. It is done. Of these, tetramethoxysilane and its derivatives are desirable because of their high crosslink density.

The content of the binder in the low refractive index layer is not particularly limited as long as a desired refractive index can be imparted to the low refractive index layer. For example, it is in the range of 40% by mass to 60% by mass, especially 50% by mass. It is preferable that it is in the range of% -60 mass%.
This is because if the binder content is too small, it may be difficult to ensure the strength of the low refractive index layer. On the other hand, if the binder content is too large, it may be difficult to adjust the refractive index of the low refractive index layer.

(3) Others The low refractive index layer only needs to contain hollow fine particles and a binder, and necessary components can be appropriately added and used. For example, a surfactant, a dispersant and the like can be mentioned.

  Examples of the method for forming the low refractive index layer include a sol-gel method. Specifically, there can be mentioned a method in which a composition for low refractive index layer containing hollow fine particles and a binder component is applied on a transparent substrate with a coating solution for low refractive index layer and cured by polycondensation.

The content of the hollow fine particles and the content of the binder component in the solid content of the composition for the low refractive index layer are appropriately adjusted according to the content of the hollow fine particles and the content of the binder in the low refractive index layer.
The composition for low refractive index layers may further contain a solvent as necessary.
As a method for applying the composition for the low refractive index layer, a general method can be used. For example, a low refractive index is applied to the entire transparent substrate such as a die coating method, a spin coating method, a dip coating method, or a roll coating method. Examples include a method for applying a layer composition, a method for discharging a composition for a low refractive index layer on a transparent substrate such as an inkjet method, a printing method such as a gravure printing method, an offset printing method, and a silk screen printing method. It is done.

  The coating film of the composition for a low refractive index layer may be cured by heat treatment as necessary. This is because it is possible to facilitate the polycondensation (thermal condensation) of the sol-gel material in the low refractive index layer composition. As heat processing temperature, it can be in the range of 60 to 250 degreeC, for example. The said heat processing temperature is normally adjusted suitably according to the heat resistance of a transparent base material.

2. Overcoat layer The overcoat layer used in the first embodiment is formed on the low refractive index layer. The overcoat layer is usually formed directly on the low refractive index layer and has a function of filling the surface irregularities of the low refractive index layer.

  In the first embodiment, “the overcoat layer is formed on the low refractive index layer” means that the interface is observed when, for example, a cross-sectional SEM image in the thickness direction of the antireflection laminate is observed. Can be confirmed. For example, it can confirm by investigating the difference in content of the additive contained in an overcoat layer and a low refractive index layer.

  The refractive index of the overcoat layer may be a level that does not hinder the antireflective function of the low refractive index layer. For example, the refractive index of the laminate of the low refractive index layer and the overcoat layer is 1.2 to 1. It is preferable that the refractive index be in the range of .4.

The overcoat layer imparts smoothness to the surface on the low refractive index layer side in the antireflection laminate of the first embodiment. The specific ten-point average roughness (RzJIS) of the overcoat layer surface is preferably 10 nm or less, particularly preferably 5 nm or less.
This is because the scratch resistance can be improved by setting the ten-point average roughness of the surface of the overcoat layer within the above-described range.
The ten-point average roughness of the overcoat layer can be obtained, for example, by measuring the thickness profile of the surface irregularities with a surface observation image of an atomic force microscope (AFM) or a stylus-type film thickness meter. . As a stylus type film thickness meter and a surface level gauge, a ten-point average roughness can be calculated by measuring a thickness profile using a stylus type film thickness meter P-15 manufactured by KLA-Tencor Corporation. it can.

  The thickness of the overcoat layer is not particularly limited as long as the surface unevenness of the low refractive index layer can be filled, but is preferably in the range of 10 nm to 30 nm. This is because if the overcoat layer is too thin, it may be difficult to impart sufficient scratch resistance to the antireflection laminate. On the other hand, if the overcoat layer is too thick, the low reflection characteristics may not be sufficiently obtained.

The material for the overcoat layer is not particularly limited as long as the surface irregularities of the low reflection layer can be filled. For example, it can be appropriately selected and used from the materials mentioned for the binder of the low refractive index layer described above, and may be a resin material or an inorganic oxide. Among them, the material for the overcoat layer is preferably one containing an inorganic oxide. Specifically, as the material for the overcoat layer, it is preferable to use a cured product of a sol-gel material, that is, a hydrolysis condensate of a metal alkoxide.
In the first embodiment, it is preferable that the binder and the overcoat layer of the low refractive index layer contain an inorganic oxide. This is because the adhesion between the low refractive index layer and the overcoat layer can be improved. Moreover, it is because the scratch resistance and pencil hardness of the surface of the low refractive index layer in the first embodiment can be dramatically improved.

  The materials for the binder and the overcoat layer of the low refractive index layer may be the same or different, but are preferably the same. This is because the adhesion between both layers can be improved.

  The overcoat layer preferably further contains fluorine. This is because antifouling property, water repellency, fingerprint resistance and slipperiness on the surface of the overcoat layer can be improved. Moreover, since the slipperiness can be improved, the scratch resistance can also be improved. As a method for containing fluorine in the overcoat layer, for example, a method of adding a fluorine surface agent may be used, or a method using a material containing fluorine in the material of the overcoat layer itself may be used. For example, among the organosilicon compounds described in the above-mentioned binder section, those containing fluorine may be used.

  Examples of the method for forming the overcoat layer include a method in which the low refractive index layer is formed by the sol-gel method and then the overcoat layer is formed by the sol-gel method. Specifically, the low refractive index layer composition described above is cured by polycondensation to form a refractive index layer. Next, a method of forming an overcoat layer by applying a composition for overcoat layer on the obtained low refractive index layer, polycondensing it, and curing it can be mentioned. The specific application method and curing method can be the same as those described in the above-mentioned section of the method for forming the low refractive index layer, and thus the description thereof is omitted here.

3. Transparent base material A transparent base material supports the low reflection layer and overcoat layer which were mentioned above.
Here, the transparency of the transparent substrate is not particularly limited as long as it does not hinder the viewing of the observation target when the observer views the observation target through the antireflection laminate of the first embodiment. The antireflection laminate of the first embodiment can be appropriately selected depending on the application.
Moreover, although the refractive index of a transparent base material changes suitably according to material, for example, it is preferable that tempered glass is about 1.51.

As the transparent substrate, for example, a material having rigidity can be suitably used.
The transparent substrate is appropriately selected according to light transmittance, rigidity, strength, durability, etc., for example, glass such as soda glass, alkali glass such as borosilicate glass, alkali-free glass, tempered glass, etc. And resins such as polycarbonate, polystyrene, and acrylic. Among these, the transparent substrate is preferably a glass substrate.
Here, “tempered glass” is a glass in which a compressive stress layer is provided on the surface of the glass. The compressive stress layer is formed, for example, by replacing sodium in the glass with potassium. Examples of the glass having a compressive stress layer formed on the surface include Corning Gorilla Glass (registered trademark), Asahi Glass Company Dragontrail (registered trademark), and the like.

  The thickness of the transparent substrate can be appropriately selected according to the use of the antireflection laminate, and is not particularly limited, but is preferably within a range of 0.1 mm to 1.5 mm, for example.

4). High Refractive Index Layer In the present invention, a high refractive index layer 4 may be formed between the transparent substrate 1 and the low refractive index layer 2 as shown in FIG. By forming the high refractive index layer, the reflectance on the low refractive index layer side of the antireflection laminate can be reduced. Moreover, coloring of the antireflection laminate can be suppressed.

  The high refractive index layer is a layer having a higher refractive index than the transparent substrate and the low reflection layer. The refractive index of the high refractive index layer is preferably adjusted within a range of 1.55 to 1.61, for example.

  The high refractive index layer is not particularly limited as long as it has a desired refractive index and can be formed between the transparent substrate and the low refractive index layer. Examples of the high refractive index layer include those containing high refractive index fine particles 4a and a binder 4b as shown in FIG.

The high refractive index fine particles are not particularly limited as long as a high refractive index layer satisfying the above-mentioned refractive index can be obtained, but among them, the refractive index of the high refractive index fine particles is 1.5-2. It is preferably about 8. Specific examples of the high refractive index fine particles include metal oxide fine particles. Specifically, zirconium oxide (ZrO ₂ , refractive index: 2.10), antimony oxide (Sb ₂ O ₅ , refractive index: 2.04), antimony tin oxide (ATO, refractive index: 1.75 to 1.95), indium tin oxide (ITO, refractive index: 1.95 to 2.00), phosphorus tin compound (PTO, refractive) Ratio: 1.75 to 1.85), gallium zinc oxide (refractive index: 1.90 to 2.00), β-Al ₂ O ₅ (refractive index: 1.63 to 1.76), γ-Al ₂ O ₅ (refractive index: 1.63 to 1.76), BaTiO ₃ (refractive index: 2.4), titanium oxide (TiO ₂ , refractive index: 2.71), cerium oxide (CeO ₂ , refractive index: 2.20), tin oxide (SnO _2, refractive index: 2.00), aluminum Zinc oxide (AZO, refractive index: 1.90 to 2.00), gallium zinc oxide (GZO, refractive index: 1.90 to 2.00), zinc antimonate (ZnSb ₂ O _6, refractive index: 1 .9-2.0) and the like.
The high refractive index fine particles may be surface-treated.

The average particle diameter of the high refractive index fine particles is not limited as long as a high refractive index layer having a uniform thickness can be formed. Of these, it is particularly preferable to be within the range of 10 nm to 80 nm. If the average particle diameter of the high refractive index fine particles is within the above range, the transparency of the high refractive index layer is not impaired, and a good dispersion state of the high refractive index fine particles can be obtained. As long as the average particle size of the high refractive index fine particles is within the above range, the average particle size may be either the primary particle size or the secondary particle size, and the high refractive index fine particles are connected in a chain. May be.
The shape of the high refractive index fine particles is not particularly limited, and examples thereof include a spherical shape, a chain shape, and a needle shape.

  The binder used for the high refractive index layer is not particularly limited as long as the above-described high refractive index layer can be formed. For example, from the binder described in the above section “1. Low refractive index layer”. It can be appropriately selected and used. The binder of the low refractive index layer and the high refractive index layer may be the same or different.

  The contents of the binder and the high refractive index fine particles in the high refractive index layer are appropriately set so that the refractive index of the entire high refractive index layer satisfies the above refractive index.

  The thickness of the high refractive index layer varies depending on the refractive index, but is preferably in the range of 140 nm to 180 nm.

  Examples of the method for forming the high refractive index layer include a method of applying and curing the composition for a high refractive index layer. The specific application method and curing method can be the same as those described in the above-mentioned section of the method for forming the low refractive index layer, and thus the description thereof is omitted here.

5. Production method of antireflection laminate The production method of the antireflection laminate of the first embodiment is not particularly limited as long as the antireflection laminate having the above-described configurations can be formed. For example, it can be manufactured by using the manufacturing method of the antireflection laminate illustrated in FIG. As shown to Fig.4 (a), the composition for low refractive index layers is apply | coated on the transparent base material 1, and a coating film is hardened | cured by polycondensation, and the low refractive index layer 2 is formed. Next, as shown in FIG.4 (b), the composition for overcoat layers is apply | coated on the low-refractive-index layer 2, and a coating film is hardened | cured by polycondensation, and the overcoat layer 3 is formed.

6). Others The antireflection laminate of the present invention can be used for a front plate, for example.
Examples of the front plate include a display device front plate and a gaming machine front plate. Among these, the antireflection laminate of the first embodiment is preferably a display device front plate. The display device front plate using the antireflection laminate of the first embodiment will be described in the section “B. Display device front plate” described later.

  In the first embodiment, it is preferable that the transparent substrate, the low refractive index layer, and the overcoat layer all contain silicon. This is because the adhesion of each layer can be improved and the scratch resistance can be improved.

II. Second Embodiment The antireflection laminate of the second embodiment has a transparent substrate and a low refractive index layer formed on the transparent substrate and containing hollow fine particles and a binder, and the low refractive index layer. Is 10 nm or less, and the ten-point average roughness (RzJIS) of the surface of the low refractive index layer is 10 nm or less.

  The antireflection laminate of the second embodiment will be described with reference to the drawings. FIG. 5 is a schematic sectional view showing an example of the antireflection laminate of the second embodiment. As shown in FIG. 5, the antireflection laminate 10 of the second embodiment comprises a transparent substrate 1 and a low refractive index layer 2 formed on the transparent substrate 1 and containing hollow fine particles 2a and a binder 2b. And the thickness of the low refractive index layer 2 and the ten-point average roughness of the surface of the low refractive index layer 2 are not more than predetermined values.

  According to the second embodiment, when the ten-point average roughness of the surface of the low refractive index layer is within a predetermined range, the smoothness of the surface of the low refractive index layer can be improved. Therefore, an antireflection laminate having good scratch resistance can be obtained. In the second embodiment, the pencil hardness can be improved. This reason is the same as the reason described in the section “I. First embodiment” described above.

  The second embodiment is characterized in that the surface of the low refractive index layer itself has smoothness. The ten-point average roughness on the surface of the low refractive index layer is preferably 10 nm or less, particularly preferably 5 nm or less.

  The low refractive index layer in the second embodiment is not particularly limited as long as it has the smoothness described above, and may be composed of one layer apparently or may be composed of two layers. “The low refractive index layer is apparently composed of one layer” can be confirmed, for example, by observing a cross-sectional SEM image in the thickness direction of the antireflection laminate, in which no interface is observed. .

  As a method for producing the low refractive index layer in the second embodiment, a first low refractive index layer having hollow fine particles and a binder is formed by a sol-gel method, and then a cured product of a sol-gel material on the first low refractive index layer. Examples thereof include a method of forming the second low refractive layer by a sol-gel method. Specifically, the composition for the first low refractive index layer containing the hollow fine particles and the binder component is applied on a transparent substrate to form a coating film, and the coating film is cured to form the first low refractive index layer. Form. Next, the composition for the second low refractive index layer containing the sol-gel material is applied on the first low refractive index layer and cured, whereby a low refractive index layer having a smooth surface can be obtained. The material for the first low-refractive index layer and the material for the second refractive index layer are selected from the materials for the low-refractive index layer and the overcoat layer described in the section “I. First Embodiment” above. Can be used.

  Regarding the antireflection laminate of the second embodiment, the points other than those described above can be the same as the contents described in the above-mentioned section “I. First embodiment”, and thus the description thereof is omitted here. .

B. Front plate for display device The front plate for display device of the present invention is a front plate for display device used in a display device, and has the antireflection laminate described in “A. Antireflection laminate”. To do.

  The front plate for a display device of the present invention will be described with reference to the drawings. FIG. 6 is a schematic cross-sectional view showing an example of a display device front plate and a display device according to the present invention. As shown in FIG. 6, the front plate 10 a for a display device of the present invention is used for a display device 30. In the present invention, the display device front plate 10 is disposed between the observer X and the display panel 20. Further, the display device front plate 10 has a surface on the low reflection layer 2 side on the viewer X side of the display device 30 and a surface on the transparent substrate 1 side on the display surface D side of the display panel 20.

  According to this invention, it can be set as the front plate for display apparatuses with favorable abrasion resistance by having the anti-reflection laminated body mentioned above.

The antireflection laminate used in the present invention is the same as the contents described in the above-mentioned section “A. Antireflection laminate”, and thus the description thereof is omitted here.
The front plate for a display device of the present invention is not particularly limited as long as it has an antireflection laminate, and a necessary configuration can be appropriately selected. Examples of such a configuration include a decorative layer and a touch panel sensor.

  The display device front plate of the present invention is used in a display device together with a display panel. A display device using the front plate for a display device of the present invention will be described in the section “C. Display device” described later.

C. Display device The display device of the present invention has a front plate and a display panel, and the front plate is a front plate for a display device described in the section "B. Front plate for display device". It is what.

  FIG. 6 is a schematic sectional view showing an example of the display device of the present invention. Since FIG. 6 has been described in the above-mentioned section “B. Front plate for display device”, description thereof is omitted here.

  According to the present invention, by having the above-described front plate for a display device, it is possible to obtain a display device with good scratch resistance and visibility.

  The display device front plate used in the present invention is the same as that described in the above-mentioned section “B. Display device front plate”, and thus the description thereof is omitted here.

  Examples of the display panel include display panels used for display devices such as liquid crystal display devices, plasma display panels, organic EL display devices, inorganic EL display devices, and electronic paper.

  Moreover, as a use of the display apparatus of this invention, a smart phone, a mobile phone, a tablet terminal, a notebook personal computer, a television, digital signage, a wearable terminal etc. can be mentioned, for example.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the details of the present invention will be described with reference to Examples and Comparative Examples.

[Example]
(Preparation of low refractive index layer)
As a transparent substrate, tempered glass (Dragonrail size 100 mm × 100 mm, thickness 0.7 mm, refractive index 1.51 manufactured by Asahi Glass Co., Ltd.) was prepared.
Next, as a composition for a low refractive index layer, P-5102 manufactured by JGC Catalysts & Chemicals Co., Ltd. was prepared. P-5012 includes hollow silica having an average particle diameter of 50 nm and silica sol gel. The composition for low refractive index layers was applied on a transparent substrate using a spin coater. Thereafter, the coating film was sintered in an oven at 230 ° C. for 30 minutes to obtain a low reflection layer having a thickness of 0.09 μm and a refractive index of 1.33.

(Preparation of overcoat layer)
Next, P-8510 (silica sol gel) manufactured by JGC Catalysts & Chemicals Co., Ltd. was prepared as an overcoat layer composition. The overcoat layer composition was applied on the low refractive index layer. Thereafter, the coating film was sintered in an oven at 230 ° C. for 30 minutes to obtain an overcoat layer having a thickness of 0.10 μm. The refractive index of the laminate of the low refractive index layer and the overcoat layer was 1.35.

[Comparative example]
A low-refractive index layer was formed on the transparent substrate by the same procedure as in Example except that the overcoat layer was not formed to obtain an antireflection laminate.

[Evaluation]
(Abrasion resistance)
The obtained front plate was visually evaluated for the presence or absence of scratches after 10 reciprocations of # 0000 steel wool under each load condition. Table 1 shows the load at which damage occurred.

(Pencil hardness)
The pencil hardness of the surface of the low reflection layer of the antireflection laminate was measured by a method based on JIS K 5600-5-4. The results are shown in Table 1.

(10-point average roughness)
Ten-point average roughness was determined from the surface observation image by AFM. The results are shown in Table 1.

As shown in the Examples and Comparative Examples, the scratch resistance was dramatically improved by forming the overcoat layer.
From the viewpoint of manufacturing cost, it is considered that a low refractive index layer obtained by one application process is preferable as in the comparative example, but in this example, two application processes are intentionally performed. It was shown that by forming an overcoat layer on the low refractive index layer, the scratch resistance and pencil hardness can be dramatically improved.

DESCRIPTION OF SYMBOLS 1 ... Transparent base material 2 ... Low-refractive-index layer 2a ... Hollow fine particle 2b ... Binder 3 ... Overcoat layer 10 ... Antireflection laminated body 10a ... Front plate for display apparatus 20 ... Display panel 30 ... Display apparatus

Claims (5)

A transparent substrate;
A low refractive index layer formed on the transparent substrate and containing hollow fine particles and a binder;
And an overcoat layer formed on the low refractive index layer.   The antireflection laminate according to claim 1, wherein the binder and the overcoat layer of the low refractive index layer include an inorganic oxide. A transparent substrate;
A low refractive index layer formed on the transparent substrate and containing hollow fine particles and a binder,
A thickness of the low refractive index layer is 120 nm or less, and a ten-point average roughness (RzJIS) of the surface of the low refractive index layer is 10 nm or less. A front plate for a display device used for a display device,
A front plate for a display device, comprising the antireflection laminate according to any one of claims 1 to 3. A display device having a front panel and a display panel,
The display device according to claim 4, wherein the front plate is a front plate for a display device according to claim 4.

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