CN106415333B

CN106415333B - The cover member and its manufacturing method of display

Info

Publication number: CN106415333B
Application number: CN201580005703.6A
Authority: CN
Inventors: 池上耕司; 佐原启; 佐原启一
Original assignee: Nippon Electric Glass Co Ltd
Current assignee: Nippon Electric Glass Co Ltd
Priority date: 2014-03-14
Filing date: 2015-03-03
Publication date: 2019-01-18
Anticipated expiration: 2035-03-03
Also published as: KR102225279B1; JP5979330B2; TW201546498A; JP2016153914A; TWI601982B; WO2015137196A1; JPWO2015137196A1; KR20160132813A; JP6402772B2; CN106415333A

Abstract

The present invention provide can obtain the mirroring less of background, display with high resolution ratio display cover member, an interarea (1a) of cover member (1) is made of male and fomale(M&F) (2).The average slope angle (θ) of the roughness curve of male and fomale(M&F) (2) is 0.5 °~1.5 °.In the endurance curves of the roughness curved surface of male and fomale(M&F) (2), height when by the area ratio being 70% is set as H₁, height when by the area ratio being 99% is set as H₂, by male and fomale(M&F) when being set as Ra according to arithmetic average roughness as defined in JIS B0601-2013, (H₁‑H₂)/Ra is 0.25 or more.

Description

Cover member for display and method of manufacturing the same

Technical Field

The invention relates to a cover component of a display and a manufacturing method thereof.

Background

Conventionally, in order to suppress specular reflection of light on the surface of a display, a configuration has been proposed in which a cover member having an Antiglare (AG) layer is disposed on the front surface of the display (see, for example, patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-504514

Disclosure of Invention

Problems to be solved by the invention

From the viewpoint of suppressing specular reflection of light on the surface of the cover member, it is preferable to increase the surface roughness of the antiglare layer so as to increase the haze of the cover member. However, a display device having a cover member with a large haze disposed on the front surface has a problem of low resolution. Therefore, it is desired to suppress front reflection, suppress reflection of a background, and obtain high resolution.

The main object of the present invention is to provide a cover member for a display capable of obtaining a display with less reflection of background and high resolution.

Means for solving the problems

In the cover member for a first display of the present invention, one main surface is formed of an uneven surface, an average inclination angle (θ) of a roughness curve of the uneven surface is 0.5 ° to 1.5 °, or an average length (RSm) of a roughness curve element of the uneven surface defined by JISB0601-2013 is 1.0 μm to 21.0 μm, and a height when an area ratio is 70% in a bearing curve of the roughness curve of the uneven surface is H₁H represents a height at 99% of the area ratio₂Wherein (H) is Ra as an arithmetic average roughness of the uneven surface defined in JIS B0601-2013₁-H₂) The value of/Ra is 0.25 or more.

In the cover member for the second display device of the present invention, one main surface is formed of an uneven surface, and the average inclination angle (θ) of the roughness curve of the uneven surface areThe product (theta x RSm) of the average length (RSm) of the roughness curve elements specified in JIS B0601-2013 is 0.5 DEG-mu m to 40 DEG-mu m, and the height when the area ratio is 70% is defined as H in the bearing curve of the roughness curved surface of the uneven surface₁H represents a height at 99% of the area ratio₂When the arithmetic mean roughness of the uneven surface defined by JISB0601-2013 is Ra, (H)₁-H₂) The value of/Ra is 0.25 or more.

The cover member of the first or second display of the present invention preferably has a haze of 0.5% or more and less than 10%. The cover member of the first or second display of the present invention preferably includes a light-transmitting plate and a coating film covering at least a part of one main surface of the light-transmitting plate to form the uneven surface.

The cover member of the first or second display of the present invention is preferably coated on the entire one main surface of the light-transmitting plate.

The cover member of the first or second display of the present invention is preferably composed of an inorganic film.

The cover member of the first or second display of the present invention preferably has a pencil hardness of 6H or more.

The cover part of the first or second display of the present invention is preferably constituted by a light-transmitting plate made of a reinforced glass plate.

The method for manufacturing the cover member of the display of the present invention is a method for manufacturing the cover member of the first or second display. In the method for manufacturing a cover member for a display device of the present invention, it is preferable that a coating film constituting the uneven surface is formed on the light-transmitting plate by a spray method.

In the method for manufacturing a cover member for a display device of the present invention, it is preferable that the light-transmitting plate is made of a glass plate, and after the coating film is formed, the glass plate is chemically strengthened.

In the method for manufacturing a cover member for a display device of the present invention, a strengthened glass plate is preferably used as the light-transmitting plate.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a cover member for a display that can provide a display with a high resolution with little reflection of background.

Drawings

Fig. 1 is a schematic cross-sectional view of a cover member of a display according to an embodiment of the present invention.

Fig. 2 is a roughness curve and a load graph of the concave-convex surface of the cover member manufactured in example 1.

Fig. 3 is a roughness curve and a load graph of the concave-convex surface of the cover member manufactured in example 2.

Fig. 4 is a roughness curve and a load graph of the concave-convex surface of the cover member manufactured in example 3.

Fig. 5 is a roughness curve and a load curve graph of the concave-convex surface of the cover member manufactured in example 4.

Fig. 6 is a roughness curve and a load curve graph of the concave-convex surface of the cover member manufactured in comparative example 1.

Fig. 7 is a roughness curve and a load curve graph of the concave-convex surface of the cover member manufactured in comparative example 2.

Fig. 8 is a roughness curve and a load curve graph of the concave-convex surface of the cover member manufactured in comparative example 3.

Fig. 9 is a perspective view showing the shape of the concave-convex surface of the cover member manufactured in example 1.

Fig. 10 is a perspective view showing the shape of the concave-convex surface of the cover member manufactured in example 2.

Fig. 11 is a perspective view showing the shape of the uneven surface of the cover member manufactured in example 3.

Fig. 12 is a perspective view showing the shape of the uneven surface of the cover member manufactured in comparative example 1.

Fig. 13 is a perspective view showing the shape of the uneven surface of the cover member manufactured in comparative example 2.

Fig. 14 is a perspective view showing the shape of the uneven surface of the cover member manufactured in comparative example 3.

Detailed Description

An example of a preferred embodiment for carrying out the present invention will be described below. However, the following embodiments are only examples. The present invention is not limited to the following embodiments.

Fig. 1 is a schematic cross-sectional view of a cover member 1 of a display of the present embodiment. The cover member 1 is disposed in front of the display and used. Specifically, the cover member 1 is used by being provided on a display such that the first main surface 1a faces outward (viewer side) and the second main surface 1b faces inward. The cover member 1 may be a member constituting a front panel of a display, for example, or may be a member provided on the front panel.

The first main surface 1a of the cover member 1 is constituted by the uneven surface 2.

Specifically, in the present embodiment, the cover member 1 includes the light-transmissive plate 10 and the coating film 11. In particular, in the present invention, the cover member may be formed of one member.

The light-transmitting plate 10 is not particularly limited as long as it transmits light from the display. The light-transmitting plate 10 may be made of, for example, a glass plate such as alkali-free glass or soda-lime glass, or Li₂O-Al₂O₃-SiO₂A crystallized glass plate such as crystallized glass, a resin plate, etc. For example, when the cover member 1 requires high mechanical strength, the light-transmitting plate 10 is preferably formed of a reinforced glass plate.

The thickness of the light-transmitting plate 10 is not particularly limited. The thickness of the light-transmitting plate 10 may be, for example, about 0.03mm to 10 mm. The light-transmitting plate 10 may be rigid or flexible. The light-transmitting panel 10 may also be sheet-like.

Further, the strengthened glass plate suitable for use as the light-transmitting plate 10 preferably contains SiO in a glass composition in mass%₂ 50～80％、Al₂O₃ 5～25％、B₂O₃ 0～15％、Na₂O 1～20％、K₂0-10% of O. The reason why the content ranges of the respective components are limited as described above will be described below.

SiO₂Is a component forming the network structure of the glass. SiO 2₂The content of (B) is preferably 50 to 80%, 52 to 75%, 55 to 72%, 55 to 70%, particularly 55 to 67.5%. If SiO₂When the content of (b) is too small, vitrification becomes difficult, and the thermal expansion coefficient becomes too high, so that the thermal shock resistance is liable to decrease. On the other hand, if SiO₂When the content of (b) is too large, the meltability and moldability are liable to be deteriorated.

Al₂O₃Is a component for improving ion exchange performance, and is a component for improving strain point and Young's modulus. Al (Al)₂O₃The content of (C) is preferably 5 to 25%. If Al is present₂O₃When the content of (b) is too small, there is a problem that the thermal expansion coefficient becomes too high and the thermal shock resistance is liable to be lowered, and the ion exchange performance cannot be sufficiently exhibited. Thus, Al₂O₃The lower limit of the range is preferably 7% or more, 8% or more, 10% or more, 12% or more, 14% or more, 15% or more, particularly 16% or more. On the other hand, if Al₂O₃When the content of (b) is too large, devitrified crystals are likely to be precipitated from the glass, and it is difficult to form a glass sheet by an overflow down-draw method or the like. Further, the thermal expansion coefficient is excessively decreased, and it is difficult to match the thermal expansion coefficient of the peripheral material, and the high-temperature viscosity is increased, and the meltability is easily decreased. Thus, Al₂O₃The upper limit of the range is preferably 22% or less, 20% or less, 19% or less, 18% or less, particularly 17% or less.

B₂O₃The high-temperature viscosity and density are reduced, and the glass is stabilized, so that the crystal is not easy to separate out, and the liquid phase isA reduced temperature component. Further, it is a component for improving crack resistance. However, if B₂O₃When the content of (b) is too large, coloring of a surface called burn occurs by ion exchange treatment, and thus water resistance is lowered, a compressive stress value of a compressive stress layer is lowered, and a stress depth of the compressive stress layer tends to be small. Thus, B₂O₃The content of (B) is preferably 0 to 15%, 0.1 to 12%, 1 to 10%, more than 1% and not more than 8%, 1.5 to 6%, particularly 2 to 5%.

Na₂O is a main ion exchange component, and is a component that lowers the high-temperature viscosity and improves the meltability and moldability. In addition, Na₂O is also a component for improving resistance to devitrification. Na (Na)₂The content of O is 1-20%. If Na is present₂When the content of O is too small, the meltability decreases, the thermal expansion coefficient decreases, and the ion exchange performance tends to decrease. Thereby introducing Na₂In the case of O, Na₂The lower limit of O is preferably 10% or more, 11% or more, particularly 12% or more. On the other hand, if Na₂When the content of O is too large, the thermal expansion coefficient becomes too high, and the thermal shock resistance is lowered, and the thermal expansion coefficient is not easily matched with that of the surrounding material. In addition, the strain point may be excessively lowered, the compositional balance of the glass composition may be lost, and the devitrification resistance may be rather lowered. Thus, Na₂A suitable upper limit range of O is 17% or less, particularly 16% or less.

K₂O is a component that promotes ion exchange, and in the alkali metal oxide, it is a component that has a large effect of increasing the stress depth of the compressive stress layer. Further, the component is a component which lowers the high-temperature viscosity and improves the meltability and moldability. Further, the composition also improves resistance to devitrification. K₂The content of O is 0-10%. If K is₂When the content of O is too large, the thermal expansion coefficient becomes too high, and the thermal shock resistance is lowered, and the thermal expansion coefficient is not easily matched with that of the surrounding material. Further, the strain point is excessively lowered, the compositional balance of the glass composition is lost, and the devitrification resistance tends to be rather lowered. Thus, K₂The upper limit of O is preferably 8% or less and 6% or lessLower, 4% or less, particularly less than 2%.

In addition to the above components, for example, the following components may be introduced.

Li₂O is an ion exchange component and is a component that lowers the high-temperature viscosity and improves the meltability and moldability. Further, it is a component for increasing the Young's modulus. Further, in the alkali metal oxide, the effect of increasing the compressive stress value is large. However, if Li₂When the content of O is too large, the viscosity of the liquid phase decreases, and the glass is easily devitrified. In addition, the thermal expansion coefficient becomes too high, and the thermal shock resistance is lowered, and it is difficult to match the thermal expansion coefficient of the surrounding material. Further, if the viscosity at low temperature is excessively lowered and stress relaxation is likely to occur, the compressive stress value may be rather decreased. Thus, Li₂The content of O is preferably 0 to 3.5%, 0 to 2%, 0 to 1%, 0 to 0.5%, particularly 0.01 to 0.2%.

Li₂O+Na₂O+K₂The appropriate content of O is 5-25%, 10-22%, 15-22%, particularly 17-22%. If Li is present₂O+Na₂O+K₂When the content of O is too small, the ion exchange performance and meltability tend to be deteriorated. On the other hand, if Li₂O+Na₂O+K₂When the content of O is too large, the glass is easily devitrified, and the thermal expansion coefficient becomes too high, so that the thermal shock resistance is lowered, and it is difficult to match the thermal expansion coefficient of the peripheral materials. In addition, the strain point may be excessively lowered, and it may be difficult to obtain a high compressive stress value. In addition, the viscosity near the liquidus temperature may decrease, and it may be difficult to ensure a high liquidus viscosity. In addition, "Li₂O+Na₂O+K₂O' is Li₂O、Na₂O and K₂The total amount of O.

MgO is a component that lowers the high-temperature viscosity, improves the meltability and formability, and improves the strain point and young's modulus, and among alkaline earth metal oxides, MgO is a component having a large effect of improving the ion exchange performance. However, if the content of MgO is too large, the density and the thermal expansion coefficient tend to be high, and the glass tends to devitrify. Accordingly, a suitable upper limit range of MgO is 12% or less, 10% or less, 8% or less, 5% or less, and particularly 4% or less. When MgO is introduced into the glass composition, the lower limit of the amount of MgO is preferably 0.1% or more, 0.5% or more, 1% or more, and particularly 2% or more.

CaO has a higher effect of improving the meltability and formability and increasing the strain point and Young's modulus than other components by reducing the high-temperature viscosity without causing a decrease in devitrification resistance. The preferable content of CaO is 0-10%. However, if the content of CaO is too large, the density and the thermal expansion coefficient become high, and the compositional balance of the glass composition is lost, so that the glass is liable to devitrify and the ion exchange performance is liable to deteriorate. Thus, the preferable content of CaO is 0 to 5%, 0.01 to 4%, 0.1 to 3%, particularly 1 to 2.5%.

SrO is a component that reduces high-temperature viscosity without reducing devitrification resistance, improves meltability and moldability, and increases strain point and young's modulus. However, if the content of SrO is too large, the density and thermal expansion coefficient become high, the ion exchange performance is lowered, the compositional balance of the glass composition is lost, and the glass is liable to devitrify. The content of SrO is preferably 0 to 5%, 0 to 3%, 0 to 1%, particularly 0 to less than 0.1%.

BaO is a component that lowers the high-temperature viscosity without lowering the resistance to devitrification, improves the meltability and moldability, and increases the strain point and young's modulus. However, if the content of BaO is too large, the density and the thermal expansion coefficient become high, the ion exchange performance is lowered, the compositional balance of the glass composition is lost, and the glass is liable to devitrify. BaO is preferably contained in a range of 0 to 5%, 0 to 3%, 0 to 1%, particularly 0 to less than 0.1%.

ZnO is a component for improving ion exchange performance, and particularly has a large effect of increasing the compression stress value. Further, it is a component that does not lower the low-temperature viscosity but lower the high-temperature viscosity. However, if the content of ZnO is too large, the glass phase separates, the devitrification resistance decreases, the density increases, and the stress depth of the compressive stress layer tends to decrease. Therefore, the content of ZnO is preferably 0 to 6%, 0 to 5%, 0 to 1%, 0 to 0.5%, and particularly preferably 0 to less than 0.1%.

ZrO₂Is a component which remarkably improves the ion exchange performance and also improves the viscosity and strain point in the vicinity of the liquid phase viscosity, but if the content thereof is too large, there is a problem that the devitrification resistance is remarkably reduced and further, there is a problem that the density becomes too high. Thereby, ZrO₂The upper limit of the range is preferably 10% or less, 8% or less, 6% or less, particularly 5% or less. In addition, when it is desired to improve the ion exchange performance, it is preferable to introduce ZrO into the glass composition₂In this case, ZrO₂The lower limit of the content is preferably 0.001% or more, 0.01% or more, 0.5% or more, particularly 1% or more.

P₂O₅The component is a component for improving the ion exchange performance, and particularly a component for increasing the stress depth of the compressive stress layer. However, if P₂O₅Too much content of (b) makes the glass easily phase-separated. Thus, P₂O₅The upper limit of the range is preferably 10% or less, 8% or less, 6% or less, 4% or less, 2% or less, 1% or less, and particularly preferably less than 0.1%.

As a clarifying agent, it is also possible to select from As₂O₃、Sb₂O₃、SnO₂、F、Cl、SO₃(preferably selected from SnO₂、Cl、SO₃) 0 to 30000ppm (3%) of one or more than two of them. SnO from the viewpoint of ensuring a clarifying effect₂+SO₃The content of + Cl is preferably 0 to 10000ppm, 50 to 5000ppm, 80 to 4000ppm, 100 to 3000ppm, particularly 300 to 3000 ppm. Wherein "SnO₂+SO₃+ Cl "means SnO₂、SO₃And the sum of Cl.

SnO₂Preferably 0 to 10000ppm, particularly 50 to 6000ppm, Cl is preferably contained in a range of 0 to 1500ppm, 0 to 1200ppm, 0 to 800ppm, 0 to 500ppm,particularly 50 to 300 ppm. SO (SO)₃The content of (B) is preferably in the range of 0 to 1000ppm, 0 to 800ppm, particularly 10 to 500 ppm.

Nd₂O₃、La₂O₃The rare earth oxide is a component for improving the young's modulus, and when a complementary color is added, the color of the glass can be decolored and controlled. However, the cost of the raw material itself is high, and if the raw material is introduced in a large amount, the devitrification resistance is liable to be lowered. Accordingly, the content of the rare earth oxide is preferably 4% or less, 3% or less, 2% or less, 1% or less, and particularly 0.5% or less.

In the present invention, it is preferable that substantially no As is contained from the environmental viewpoint₂O₃、F、PbO、Bi₂O₃. Wherein "substantially no As₂O₃"" means that As is not positively added As a glass component₂O₃However, the case where the impurity level is allowed to be mixed is specifically referred to As₂O₃Is less than 500 ppm. "substantially not containing F" means that F is not positively added as a glass component, but is allowed to be mixed in at an impurity level, and specifically means that the content of F is less than 500 ppm. "substantially free of PbO" means that PbO is not positively added as a glass component, but is allowed to be mixed in at an impurity level, and specifically, the content of PbO is less than 500 ppm. "substantially free of Bi₂O₃"" means that Bi is not positively added as a glass component₂O₃However, the case where the impurity level is allowed to be mixed, specifically, Bi₂O₃Is less than 500 ppm.

The light-transmitting sheet 10 has a first main surface 10a and a second main surface 10 b. In the present embodiment, the first and second main surfaces 10a and 10b are flat surfaces, respectively. The second main surface 1b of the cover member 1 is constituted by the second main surface 10b of the light-transmitting sheet 10. The first main surface 10a of the light-transmitting sheet 10 is provided with a coating film 11. At least a part of the first main surface 10a constituting the uneven surface 2 is covered with the coating film 11. The coating film 11 may cover the entire first main surface 10a, or may cover a part of the first main surface 10 a. The coating film 11 may also be provided in an island shape, for example. When the coating film 11 covers a part of the first main surface 10a, the first main surface 1a of the cover member 1 is constituted by the coating film 11 and the first main surface 1 a.

When the cover member 1 is used for a touch sensor or the like, for example, the surface of the cover member 1 is required to have high durability (scratch resistance or the like). Therefore, the coating film 11 is preferably hard. The pencil hardness of the coating film 11 is preferably 6H or more, more preferably 7H or more, further preferably 8H or more, and further preferably 9H or more.

The coating film 11 may be formed of, for example, SiO₂、TiO₂、Al₂O₃、ZrO₂And the like. Among them, it is preferable that the coating film 11 is made of SiO₂And (4) forming.

The thickness of the coating film 11 is preferably 0.1 to 5 μm, for example.

In the present embodiment, an example in which the coating film 11 is directly provided on the first main surface 10a of the light-transmitting plate 10 will be described. However, the present invention is not limited to this configuration. For example, an antireflection film or the like may be provided between the coating film and the light-transmitting plate. Further, an antireflection film, a transparent conductive film, or the like may be provided on the second main surface 10b of the light-transmitting sheet.

The antireflection film may be a dielectric multilayer film formed by alternately stacking a low refractive index film having a lower refractive index than the light-transmitting plate 10, a low refractive index layer having a relatively low refractive index, and a high refractive index layer having a relatively high refractive index, for example. The antireflection film can be formed by, for example, a sputtering method, a CVD method, or the like.

When the light-transmitting plate 10 is used as cover glass, the transparent conductive film functions as an electrode for a touch sensor. Examples of the transparent conductive film include an Indium Tin Oxide (ITO) doped film, a tin fluorine oxide (FTO) doped film, and an Antimony Tin Oxide (ATO) doped film. Among them, an ITO film is preferably used because of its low resistance. The ITO film can be formed by sputtering, for example. In addition, the FTO film and the ATO film can be formed by a CVD (Chemical Vapor Deposition) method.

In the present embodiment, the coating film 11 constitutes the surface of the cover member 1. However, the present invention is not limited to this configuration. On the coating film, other films such as a fingerprint-proof film (AF film) for preventing adhesion of fingerprints and imparting water repellency and oil repellency, an antireflection film, and the like may be further provided.

In addition, the AF film preferably includes a fluoropolymer containing silicon in the main chain. Examples of the fluoropolymer include polymers having a-Si-O-Si-unit in the main chain and having a fluorine-containing water-repellent functional group in the side chain. The fluoropolymer can be synthesized, for example, by dehydrating and condensing silanol.

When the antireflection film and the AF film are formed on the uneven surface side of the light-transmitting plate 10, it is preferable to form the antireflection film on the uneven surface and form the AF film on the antireflection film.

As described above, from the viewpoint of suppressing specular reflection of light on the surface of the cover member, it is preferable to increase the haze of the cover member. However, a display device in which the cover member having a large haze is disposed on the front surface has a problem of low resolution. That is, only by adjusting the haze, it is not possible to simultaneously obtain suppression of reflection of the background and high resolution.

As a result of intensive studies, the inventors of the present invention have conceived that reflection of a background can be suppressed by satisfying the following conditions (a) and (C), or the following conditions (B) and (C), or the following conditions (C) and (D), even when the haze is reduced to some extent in order to obtain a high resolution.

Condition (a): the average inclination angle (theta) of the roughness curve of the concave-convex surface is 0.5-1.5 DEG

Condition (B): the average length (RSm) of the roughness curve element of the uneven surface defined by JIS B0601-2013 is 1.0-21.0 μm

Condition (C): (H₁-H₂)/Ra≥0.25

Condition (D): the product (theta x RSm) of the average inclination angle (theta) of the roughness curve of the concave-convex surface and the average length (RSm) of the roughness curve element specified according to JIS B0601-2013 of the concave-convex surface is 0.5-40 DEG.mu.m

Wherein,

H₁: is the height of the rough curved surface of the concave-convex surface 2 when the area ratio is 70%,

h2: is the height of the concave-convex surface 2 when the area ratio is 99% in the bearing curve of the roughness curved surface,

ra: the arithmetic mean roughness of the concave-convex surface is defined in accordance with JIS B0601-2013.

The load curve is a curve created by a load curve mapping method for analyzing the height distribution of a rough surface on the surface. The load graph is as follows: in a graph in which only the reference area is extracted from a curved surface expressed by surface roughness data, when the position (height component) of a cutting plane parallel to the center plane is changed, the area ratio (the ratio of the total cross-sectional area of the mountain cut by the cutting plane to the reference area) that changes with the change is expressed as a curve. In the load curve, the vertical axis represents the area ratio (%), and the horizontal axis represents the height (nm). For example, at a point of the bearing curve where (height, area ratio) is (Hnm, S%), the ratio of the area of the region having a height of Hnm or more to the area of the entire concave-convex surface ((area of the region having a height of H or more)/(area of the entire concave-convex surface)) is S%.

Then, in the cover member 1, the average inclination angle (θ) of the roughness curve of the uneven surface 2 is set to 0.5 ° to 1.5 ° and (H)₁-H₂) The value of/Ra is 0.25 or more. Therefore, by using the cover member 1, a display with less reflection of the background and high resolution can be obtained. This effect will be described in more detail below.

In the present embodiment, the unevennessThe average inclination angle (θ) of the roughness curve of the surface 2 is set to 0.5 ° to 1.5 ° (condition (a)). Therefore, the uneven surface 2 is formed of small-gradient unevenness. In addition, (H)₁-H₂) The value of/Ra is 0.25 or more (condition (C)). Wherein (H)₁-H₂) the/Ra can be regarded as an index of the area ratio of the flat surface in the valley portion of the concave-convex surface 2. The more flat portions are in the valley portions of the concave-convex surface 2, (H)₁-H₂) The smaller the Ra, the less flat parts are in the valley parts of the uneven surface 2 (H)₁-H₂) The larger the Ra is. Therefore, the area parallel to the first main surface 10a occupies a small proportion of the valley portion of the uneven surface 2. This makes it difficult for the transmitted light to diffuse and specular reflection to occur. Therefore, by using the cover member 1, a display with less reflection of the background and high resolution can be obtained.

For example, when the haze is constant, the smaller the average inclination angle θ, the closer the irregularities constituting the irregular surface are to flatness, and the larger the proportion of the area parallel to the first main surface 10a in the irregular surface tends to be. Also, (H)₁-H₂) The smaller the Ra, the more the area parallel to the first main surface 10a occupies the valley portion of the uneven surface. Therefore, the average tilt angle θ is large or (H)₁-H₂) When the/Ra is small, specular reflection easily occurs, and the background easily reflects.

Similarly, when the first main surface 10a is exposed, the background is easily reflected. Therefore, the coating film 11 preferably covers the entire first main surface 10 a. For example, when the coating film 11 is in an island shape, the exposure rate of the first main surface 10a is high. Therefore, it is preferable that the coating film 11 is not island-shaped.

By satisfying the condition (B) (the average length (RSm) of the roughness curve element of the uneven surface defined in JIS B0601-2013 is 1.0 μm to 21.0 μm), scratch resistance and high resolution can be obtained at the same time. If the average length (RSm) of the roughness curve element is too small, the durability (scratch resistance) of the surface may be reduced. If the average length (RSm) of the roughness curve elements is too large, the resolution may be reduced.

By satisfying the condition (D) (the product theta x RSm of the average inclination angle (theta) of the roughness curve of the uneven surface and the average length (RSm) of the roughness curve element of the uneven surface defined by JISB0601-2013 is 0.5-40 DEG.mu m), reflection can be suppressed and high resolution can be obtained. If the product θ × RSm is too small, the image may be conspicuous. If the product θ × RSm is too large, the resolution may be reduced.

From the viewpoint of setting the conditions (a), (B), and (D) for θ and RSm to preferable ranges, it is preferable to provide the coating film 11 covering at least a part of the one main surface of the light-transmitting plate 10 and constituting the uneven surface.

The coating film 11 preferably does not contain scattering particles like a fine particle dispersion film or the like, and is preferably a homogeneous film. In this case, the resolution can be further improved, and reflection can be more effectively suppressed.

The coated film 11 preferably has a lower refractive index than the light-transmitting plate 10. In this case, reflection can be more effectively suppressed.

From the viewpoint of more efficiently obtaining a display having high resolution, the average tilt angle θ is preferably 0.9 ° or less, and more preferably 0.8 ° or less.

From the viewpoint of more effectively suppressing reflection, (H)₁-H₂) The value of/Ra is more preferably 0.45 or more, and still more preferably 0.5 or more.

From the viewpoint of more efficiently obtaining a display having a high resolution, the average length (RSm) of the roughness curve element is preferably 20.0 μm or less, and more preferably 18.0 μm or less.

From the viewpoint of more efficiently obtaining a display having high resolution, the product θ × RSm is preferably 39 °. μm or less, and more preferably 38 °. μm or less.

Specifically, in the present invention, the average inclination angle θ can be measured, for example, in the following manner.

Method for measuring average tilt angle θ: the average tilt angle θ is defined by the following equation (1).

Average tilt angle θ tan^-1Δ a … … (1) in the formula (1), Δ a is a value obtained by dividing the sum (h1+ h2+ h3 … … + hn) of the absolute values of the differences (heights h) between the peaks and the valleys of adjacent mountains by a reference length l of the roughness curve defined in JIS B0601-2013, as shown in the following formula (2).

Specifically, the average tilt angle Δ a is (h1+ h2+ h3 … + hn)/l … … (2) and can be measured in the following manner.

The height of the surface of the uneven surface 2 is measured in one direction by scanning a laser or a stylus over the uneven surface 2 in one direction. The length (measurement length) in one direction in which the height is measured may be, for example, about 200 to 350 μm. The height can be measured at 0.5 μm intervals, for example.

Next, a centerline L is determined. Specifically, a center line L passing through an average value of the heights of the uneven surface is determined.

Subsequently, the absolute value of the magnitude of the angle formed by the uneven surface 2 and the center line L was measured at intervals of 0.5 μm. The average inclination angle θ can be calculated by averaging the absolute values of the magnitudes of the angles formed by the uneven surface 2 and the center line L at 0.5 μm intervals measured at 0.5 μm intervals.

Haze is the proportion of diffuse transmitted light relative to full-light transmitted light. Therefore, by reducing the haze, the diffused transmitted light can be reduced. Therefore, high resolution can be obtained. The haze of the cover member 1 is preferably less than 10%, more preferably less than 4%, more preferably 3% or less, and further preferably 2% or less. However, if the haze of the cover member 1 is too small, the background may be easily reflected. Therefore, the haze of the cover member 1 is preferably 0.5% or more, and more preferably 0.8% or more.

Next, an example of a method for manufacturing the cover member 1 will be described.

First, the light-transmitting plate 10 is prepared. Next, the light transmissive material is applied to the first main surface 10a of the light transmissive plate 10 by a spray coating method, and dried, whereby the coating film 11 can be formed. By forming the coating film 11 by the spray coating method, the conditions (a), (B), and (D) for θ and RSm are easily set to preferable ranges.

More specifically, the coating film 11 can be formed as follows. In the coating chamber, while the light-transmitting plate 10 is conveyed, the nozzle is reciprocated in a direction perpendicular to the conveying direction of the light-transmitting plate 10, and the light-transmitting material is discharged from the nozzle to the light-transmitting plate 10. After that, the obtained coating film is dried, whereby the coating film 11 can be completed. In the film formation, it is preferable to provide a laminar flow flowing from the top to the bottom to the coating chamber.

Average inclination angles θ and (H) of the fabricated shroud component 1₁-H₂) the/Ra can be adjusted by controlling, for example, the particle diameter of the liquid droplets discharged from the nozzle, the discharge pressure, the amount of discharge per unit area, the flow rate of the laminar flow, and the like.

For example, by making the particle diameter of the droplets discharged from the nozzle small, the average inclination angle θ can be made small, and (H) can be made₁-H₂) The ratio of Ra is large. The average length (RSm) of the roughness curve element can be made small. The particle diameter of the droplets discharged from the nozzle is preferably 20 μm or less, and more preferably 10 μm or less.

For example, by increasing the discharge pressure from the nozzle, the average inclination angle θ can be made small, and (H) can be made₁-H₂) The ratio of Ra is large. The discharge pressure from the nozzle is preferably 0.25MPa or more, and more preferably 0.3MPa or more, for example.

By lowering the discharge pressure from the nozzle, the average length (RSm) of the roughness curve element can be made small. From this viewpoint, the discharge pressure from the nozzle is preferably 0.34MPa or less.

For example, by making eachThe amount of coating per unit area is small, the average tilt angle theta can be made small, and (H) can be made₁-H₂) The ratio of Ra is large. The amount of coating per unit area is preferably 50g/m, for example²Hereinafter, more preferably 48g/m²The following.

For example, by increasing the flow rate of the laminar flow, the average inclination angle θ can be made small, and (H) can be made₁-H₂) The ratio of Ra is large. The flow rate of the laminar flow is preferably 25m, for example³More than one minute.

In the case where the light-transmitting plate 10 is formed of a strengthened glass plate, the coating film 11 may be formed on the strengthened glass plate, or the glass plate may be strengthened by chemical strengthening or air-cooled strengthening after the coating film 11 is formed on the glass plate.

The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to the following examples, and can be carried out with appropriate modifications within a scope not changing the gist thereof.

Examples 1 to 3 and comparative example 1A glass plate (alkali-free glass plate manufactured by Nippon Denko Co., Ltd., thickness 0.7mm) was coated with SiO-containing glass by a spray coating method₂The coating film is formed by drying the liquid of the component (a) to obtain the cap member. The detailed conditions are shown in table 1.

Example 4A glass plate (tempered glass plate manufactured by Nippon Denshi Co., Ltd., thickness 0.7mm) was coated with a coating solution containing SiO by a spray coating method₂The coating film is formed by drying the liquid of the component (a) to obtain the cap member. The detailed conditions are shown in table 1.

Comparative examples 2 and 3A cover member was obtained by etching one main surface of a glass plate (alkali-free glass plate manufactured by Nippon Denko Co., Ltd., thickness: 0.7mm) to form irregularities.

(measurement of haze) the haze of the cover members prepared in examples 1 to 4 and comparative examples 1 to 3 was measured in accordance with JIS K7136 (2000). The results are shown in Table 1.

(average inclination angles θ and (H)₁-H₂) Measurement of/Ra) the average tilt angle θ of the cover members produced in examples 1 to 4 and comparative examples 1 to 3 was determined by the above-described method for measuring the average tilt angle θ. In the present measurement, the reference length was 317 μm. Further, from the surface roughness curved surface in the range of 317 μm × 238 μm, (H) was obtained by the load curve mapping method₁-H₂) and/Ra. The results are shown in Table 1. Fig. 2 to 8 show the measured roughness curve of the uneven surface and the load graph. Fig. 9 to 14 are perspective views of the concave-convex surface of each cover member.

(evaluation of resolution) A cover member was placed at a position of 20mm height above a character "c" of 1mm thickness, 4mm height and 4mm width of the line, and the character "c" was visually observed from a position of 500mm distance, and in this case, it was judged that the character "c" was clearly visible at ◎, slightly blurred at ○ although clearly visible, at △ when blurred, and not discernible at x when blurred.

(evaluation of degree of reflection) A repair tape (manufactured by 3M.) was attached to the back surface of the cover member to reflect the fluorescent lamp on the uneven surface of the cover member. it was judged that ◎ was the case where the reflected fluorescent lamp was completely invisible, ○ was the case where the fluorescent lamp was slightly visible but was slightly opaque, △ was the case where the fluorescent lamp was visible but was slightly opaque, and x was the case where the fluorescent lamp was clearly visible.

[ Table 1]

As is clear from the results shown in table 1, even when the haze is reduced to some extent, it is possible to obtain a high resolution and suppress reflection of a background by satisfying the following condition (a), condition (B), and condition (C), or satisfying the following condition (C) and condition (D).

Reference numerals

1: cover component

1 a: first main surface

1 b: second main surface

2: concave-convex surface

10: light-transmitting plate

10 a: first main surface

10 b: second main surface

11: coating film

Claims

1. A cover part for a display, characterized in that:

one main surface is composed of a concave-convex surface,

the average inclination angle theta of the roughness curve of the concave-convex surface is 0.5-1.5 DEG or the average length RSm of the roughness curve element specified by JISB0601-2013 of the concave-convex surface is 1.0-21.0 mu m, and the height when the area ratio is 70% in the bearing curve of the roughness curve of the concave-convex surface is H₁H represents a height at 99% of the area ratio₂The uneven surface is formed according to JISRa is the arithmetic average roughness defined in B0601-2013, (H)₁-H₂) The value of/Ra is 0.25 or more.

2. A cover part for a display, characterized in that:

one main surface is composed of a concave-convex surface,

the product theta x RSm of the average inclination angle theta of the roughness curve of the concave-convex surface and the average length RSm of the roughness curve element specified according to JIS B0601-2013 is 0.5 DEG-40 DEG-mum, and the height when the area ratio is 70% is defined as H in the bearing curve of the roughness curve of the concave-convex surface₁H represents a height at 99% of the area ratio₂Wherein (H) is Ra as an arithmetic average roughness of the uneven surface defined in JIS B0601-2013₁-H₂) The value of/Ra is 0.25 or more.

3. A cover part for a display as claimed in claim 1 or 2, characterized in that:

the haze is 0.5% or more but less than 10%.

4. The cover member for a display device according to claim 1 or 2, comprising:

a light-transmitting plate; and

and a coating film covering at least a part of one main surface of the light-transmitting plate to form the uneven surface.

5. The cover part of a display of claim 4, wherein:

the coating film covers the entire one main surface of the light-transmitting plate.

6. The cover part of a display of claim 4, wherein:

the coating film is composed of an inorganic film.

7. The cover part of a display of claim 4, wherein:

the pencil hardness of the coating film is more than 6H.

8. The cover part of a display of claim 4, wherein:

the light-transmitting plate is composed of a reinforced glass plate.

9. A method for manufacturing a cover member for a display device according to any one of claims 1 to 8, the method comprising:

a coating film constituting the uneven surface is formed on the light-transmitting plate by a spray coating method.

10. The method of manufacturing a cover member for a display device according to claim 9, wherein:

the light-transmitting plate is formed by a glass plate,

after the coating film is formed, the glass plate is chemically strengthened.

11. The method of manufacturing a cover member for a display device according to claim 9, wherein:

as the light-transmitting plate, a strengthened glass plate is used.