Touch panel cover glass, touch panel, and method for producing touch panel cover glass

Abstract

This cover glass is a touch panel cover glass on which pen input is performed. The cover glass has an uneven surface on the surface touched by the pen. With respect to the uneven surface, a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of a roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 90 μm0.5 to 180 μm0.5, and a value (RSm×√Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm1.5 to 110 μm1.5.

Description

Touch panel cover glass, touch panel, and method for manufacturing touch panel cover glass

[0001] The present disclosure relates to a cover glass for a touch panel, a touch panel, and a method for manufacturing a cover glass for a touch panel.

[0002] A touch panel has a display and a cover that protects the display screen. The cover may have a finely textured surface to suppress reflections of surrounding objects (including lighting). The cover is a resin cover or a glass cover. Resin covers are superior in terms of light weight and impact resistance. On the other hand, glass covers are superior in terms of weather resistance and abrasion resistance.

[0003] Pen input is sometimes performed on a touch panel. In this case, it is preferable to use a glass cover to suppress wear on the textured surface. However, when a glass cover is used, the frictional resistance between the cover and the pen is too low, causing the pen to slip. As a result, the writing experience becomes poor. Therefore, it is considered to improve the writing experience by improving the structure of the textured surface.

[0004] The cover glass described in Patent Document 1 has a roughness curve mean length RSm of 2500 nm to 6000 nm, a root mean square height Sq of 3 nm to 45 nm, and a negative skewness Ssk. Patent Document 1 also describes that if RSm is 6000 nm or less, there is no rough or uneven feeling during pen input, making it easy to write smoothly.

[0005] International Publication No. 2020 / 009081

[0006] The textured surface of Patent Document 1 has a fine structure and is too smooth, causing the pen to slide easily, resulting in an unsatisfactory writing experience. The fine structure of the textured surface can also be seen from the RSm of 6,000 nm or less. RSm represents the average pitch of the convex or concave portions.

[0007] One aspect of the present disclosure provides a technique for improving the writing comfort on a touch panel where pen input is performed.

[0008] A cover glass according to one aspect of the present disclosure is a cover glass for a touch panel for pen input. The cover glass has an uneven surface on the surface that is touched by a pen. The uneven surface has a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of a roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) of 90 μm. ０．５ ~180μm ０．５ and the value (RSm × √Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm. １．５ ~110μm １．５ is.

[0009] According to one aspect of the present disclosure, it is possible to improve the writing comfort on a touch panel where pen input is performed.

[0010] Fig. 1 is a cross-sectional view of a touch panel according to one embodiment. Fig. 2 is a flowchart showing a method for manufacturing a cover glass according to one embodiment. Fig. 3 is a cross-sectional view showing an example of a concave curved surface formed from microcracks. Fig. 4 is a diagram showing an example of the relationship between Ra, RSm, and writing comfort. Fig. 5 is a diagram showing an example of the relationship between (RSm / √Ra), (RSm×√Ra), and writing comfort.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In the specification, the symbol "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits. The range of values ​​includes the range rounded up or down.

[0012] A touch panel 1 according to one embodiment will be described with reference to Fig. 1 . The touch panel 1 is incorporated into portable or fixed electronic devices. Examples of portable electronic devices include mobile phones, smartphones, e-book readers, and notebook personal computers. Examples of fixed electronic devices include desktop personal computers, digital signage, in-vehicle displays, televisions, and interactive whiteboards (IFPs).

[0013] The touch panel 1 includes, for example, a display 2 and a cover glass 3. The display 2 and the cover glass 3 are adhered to each other with an adhesive layer (not shown), such as an OCA (Optical Clear Adhesive). The display 2 is not particularly limited, but may be, for example, a liquid crystal display or an organic EL display. The display 2 has a screen protected by the cover glass 3.

[0014] The display 2 includes a touch sensor 21 therein. The touch sensor 21 detects the proximity of a pen to the screen of the display 2. The touch sensor 21 may detect the proximity of a finger instead of a pen. When the touch panel 1 is for use in a vehicle, the touch sensor 21 accepts operations by a vehicle occupant.

[0015] The cover glass 3 includes a first main surface 31 and a second main surface 32 facing opposite to the first main surface 31, and is laminated on the display 2 with the second main surface 32 facing the display 2. The first main surface 31 is the surface that is touched by the pen 5. The cover glass 3 has an uneven surface on the first main surface 31. The uneven surface may be formed in the area that is touched by the pen 5, and may be formed on at least a part of the first main surface 31.

[0016] The textured surface is formed by, for example, at least one selected from frosting, etching, and blasting the surface of the glass plate. The textured surface can disperse the direction of light reflection and suppress reflection of surrounding objects (including lighting). It is preferable that the textured surface is formed on the first main surface 31, but not on the second main surface 32. It is preferable that the second main surface 32 is protected with a mask when forming the textured surface on the first main surface 31.

[0017] The inventors of the present application, who will explain in detail in the section of Examples, focused on (RSm / √Ra) and (RSm×√Ra) in order to improve the writing comfort on the touch panel 1 where pen input is performed. Here, (RSm / √Ra) is the value (unit: μm) obtained by dividing the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm). ０．５) and (RSm × √Ra) is the value (unit: μm) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm). １．５ RSm and Ra are measured in accordance with JIS B0601:2001.

[0018] The inventors of the present application have found that the evaluation results of the sensitivity test can be accurately classified by using (RSm / √Ra) and (RSm×√Ra). It is estimated that if (RSm / √Ra) is within an appropriate range, the cover glass 3 can provide appropriate dynamic friction to the pen 5. It is also estimated that if (RSm×√Ra) is within an appropriate range, the cover glass 3 can provide appropriate vibration to the pen 5. It is believed that the writing comfort can be improved by the cover glass 3 providing appropriate dynamic friction and appropriate vibration to the pen 5.

[0019] The rough surface has a (RSm / √Ra) of 90 μm ０．５ ~180μm ０．５ And (RSm × √Ra) is 10 μm １．５ ~110μm １．５ This allows the cover crystal 3 to provide appropriate dynamic friction and appropriate vibration to the pen 5, improving the writing comfort.

[0020] In addition, the rough surface has a (RSm / √Ra) of 90 μm. ０．５ ~160μm ０．５ And (RSm × √Ra) is 52 μm １．５ ~95μm １．５ This allows the cover crystal 3 to provide more appropriate dynamic friction and vibration to the pen 5, thereby improving the writing comfort.

[0021] The uneven surface preferably has an RSm of 60 μm to 200 μm. RSm represents the average pitch of the convex or concave portions. The larger the RSm, the larger the average pitch of the convex or concave portions. If RSm is 60 μm to 200 μm, the cover glass 3 can provide appropriate dynamic friction and appropriate vibration to the pen 5. It is more preferable that RSm be 80 μm to 120 μm.

[0022] The uneven surface preferably has an Ra of 0.10 μm to 2.00 μm. Ra represents the average difference in height between the convex and concave portions. The larger the Ra, the greater the average difference in height between the convex and concave portions. If the Ra is 0.10 μm to 2.00 μm, the cover glass 3 can provide appropriate dynamic friction and appropriate vibration to the pen 5. It is more preferable that the Ra be 0.30 μm to 1.00 μm.

[0023] The haze value of the textured surface is preferably 50% or less. The haze value is measured using a commercially available measuring device, such as a Suga Test Instruments Haze Meter HZ-V3. The haze value is measured, for example, in accordance with Japanese Industrial Standards (JIS K 7136:2000) using a C-type light source. The haze value is determined as the percentage of transmitted light that deviates from the incident light by 2.5° or more due to forward scattering, among the transmitted light that passes through the cover glass 3 in the thickness direction.

[0024] The haze value is preferably 0% or more and 50% or less. If the haze value is 50% or less, the clarity of the transmitted image is good. The haze value is more preferably 40% or less, even more preferably 35% or less, particularly preferably 30% or less, and even more particularly preferably 25% or less. The haze value is more preferably 5% or more, even more preferably 10% or more, even more preferably 15% or more, and particularly preferably 20% or more.

[0025] The cover glass 3 may be a flat plate or a curved plate. The thickness of the cover glass 3 is preferably 5 mm or less, more preferably 3 mm or less. The thickness of the cover glass 3 is preferably 0.2 mm or more, more preferably 0.3 mm or more.

[0026] The glass of the cover glass 3 is, for example, aluminosilicate glass, alkali aluminosilicate glass, soda-lime glass, borosilicate glass, phosphosilicate glass, alkali aluminoborosilicate glass, lead glass, alkali barium glass, or aluminoborosilicate glass. Specific examples of the glass include the following glasses (i) to (v):

[0027] (i) In mole percent on an oxide basis, SiO ２50% to 80%, Al ２ O ３ 0% to 26%, Na ２ O is 1% to 25%, B ２ O ３ 0% to 10%, K ２ Glass containing 0 to 20% of O, 0 to 20% of MgO, and 0 to 15% of CaO.

[0028] (ii) In mole percent on an oxide basis, SiO ２ 50% to 80%, Al ２ O ３ 2% to 25%, Li ２ O from 0% to 10%, Na ２ O 0% to 18%, K ２ O 0% to 10%, MgO 0% to 15%, CaO 0% to 5%, ZrO ２ Glass containing 0% to 5% of each of the above.

[0029] (iii) In mole percent on an oxide basis, SiO ２ 50% to 74%, Al ２ O ３ 1% to 10%, Na ２ O 6% to 14%, K ２ O 3% to 11%, MgO 2% to 15%, CaO 0% to 6%, ZrO ２ Each of these contains 0% to 5% of SiO ２ and AlO ３ The total content of is 75% or less, Na ２ O and K ２ A glass having a total content of O of 12% to 25%, and a total content of MgO and CaO of 7% to 15%.

[0030] (iv) In mole percent on an oxide basis, SiO ２ 68% to 80%, Al ２ O ３ 4% to 10%, Na ２ O 5% to 15%, K ２ O 0% to 1%, MgO 4% to 15%, ZrO ２ Glass containing 0% to 1% of each of the above.

[0031] (v) In mole percent on an oxide basis, SiO ２ 67% to 75%, Al２ O ３ 0% to 4%, Na ２ O 7% to 15%, K ２ O 1% to 9%, MgO 6% to 14%, ZrO ２ Each of these contains 0% to 1.5% of SiO ２ and Al ２ O ３ The total content of 71% to 75%, Na ２ O and K ２ A glass having a total O content of 12% to 20%, and if CaO is contained, the content thereof is less than 1%.

[0032] At least one surface of the cover glass 3 may have a fingerprint smudge-removing film or an anti-reflection film. The fingerprint smudge-removing film is not particularly limited, but preferably contains a fluorine-containing organic compound, and is preferably a film obtained using a fluorine-containing ether compound having a poly(oxyfluoroalkylene) chain and a reactive silyl group. The anti-reflection film is not particularly limited, but preferably is formed by alternately laminating low-refractive index layers and high-refractive index layers, with the outermost layer being SiO ２ It is preferable that:

[0033] A method for manufacturing the cover glass 3 according to one embodiment will be described with reference to Figure 2. The method for manufacturing the cover glass 3 includes performing a wet blasting treatment (step S101) and a wet etching treatment (step S102) in this order on at least a portion of the first main surface 31 of the cover glass 3 to obtain a textured surface.

[0034] The method for manufacturing the cover glass 3 may include processes other than steps S101 and S102. For example, the method may include chemically strengthening the cover glass 3 after step S102. The chemical strengthening process is a process for forming a compressive stress layer on the glass surface by ion exchange at a temperature below the glass transition point. The compressive stress layer is formed by exchanging alkali metal ions, which have a small ionic radius and are contained in the glass, for alkali ions, which have a larger ionic radius.

[0035] Step S101 includes performing a wet blasting process on at least a part of the first main surface 31 of the cover glass 3. The wet blasting process is a process in which a slurry containing particles is sprayed from a nozzle by gas pressure and caused to collide with an object, thereby forming minute cracks (microcracks) in the object.

[0036] The slurry contains particles, which will be described later, and a dispersion medium. Examples of the dispersion medium include water, a water-soluble organic solvent, or a mixture of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent include lower alcohols and ketones. Specific examples of lower alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, and tert-butanol. Specific examples of ketones include acetone.

[0037] The slurry may also contain a dispersing aid. Examples of dispersing aids include carboxymethyl cellulose, polyacrylic acid derivatives or salts thereof, polycarboxylic acid derivatives or salts thereof, and polyureaurethane. Specific examples of polyacrylic acid derivatives or salts thereof include polyacrylic acid, ammonium polyacrylate, sodium polyacrylate, polyacrylamide, acrylic acid ester-acrylate copolymer, acrylamide-acrylate copolymer, or acrylic acid ester-acrylamide-acrylate copolymer. Specific examples of polycarboxylic acid derivatives or salts thereof include ammonium polycarboxylate or sodium polycarboxylate. The proportion of the dispersing aid in the slurry is preferably 0.03% by mass or more and 2.0% by mass or less.

[0038] From the viewpoint of processability, the particles contained in the slurry are preferably particles having a Mohs hardness higher than that of glass, and are preferably inorganic particles other than spherical particles. The material of the inorganic particles may be a metal (including alloys) or an inorganic compound. The inorganic compound may be a metal compound or a non-metal compound. Examples of metals include stainless steel, zinc, and copper. Examples of inorganic compounds include silica, glass, garnet, zirconia, alumina, silicon carbide, boron carbide, and CO. ２ (dry ice), etc. Among these, alumina is preferred. Commercially available products can be used as the particles contained in the slurry. An example of a commercially available product is white alumina manufactured by Fujimi Incorporated.

[0039] The particle concentration in the slurry is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, from the viewpoint of productivity, while the particle concentration in the slurry is preferably 30% by mass or less, more preferably 10% by mass or less, from the viewpoint of fluidity of the slurry.

[0040] The wet blasting process forms microcracks 311 in at least a portion of the first main surface 31, as shown in Fig. 3. Then, in step S102 (described later), the glass is isotropically etched starting from the microcracks 311, forming a concave curved surface 312, as shown in Fig. 3. In Fig. 3, multiple dashed lines indicate changes in the surface shape of the glass over time. When the glass is isotropically etched, the depth H of the concave curved surface 312 becomes approximately the same as the depth of the microcracks 311.

[0041] The depth of the microcracks 311 varies depending on factors such as the particle diameter d of the particles. The larger the particle diameter d, the greater the impact of the particles, and the deeper the microcracks 311. The deeper the microcracks 311, the greater the area S of the concave curved surface 312 in plan view. Furthermore, the deeper the microcracks 311, the greater the depth H of the concave curved surface 312.

[0042] The particles contained in the slurry have an average particle size d ＡＶＥ (Hereinafter, average particle diameter dＡＶＥ It is preferable that the average particle diameter d is 13 μm or more. ＡＶＥ If the average particle size d is 13 μm or more, (RSm / √Ra) and (RSm×√Ra) can be adjusted to an appropriate range. ＡＶＥ is more preferably 18 μm or more, and further preferably 24 μm or more. ＡＶＥ is preferably 60 μm or less.

[0043] Average particle size d ＡＶＥ The average particle diameter d is 5 μm or more, which corresponds to a particle size (number) of 2500 or less. ＡＶＥ The average particle diameter d is 13 μm or more, which corresponds to a particle size (number) of 1200 or less. ＡＶＥ The average particle size d is 18 μm or more, which corresponds to a particle size of 800 or less. ＡＶＥ The average particle size d is 24 μm or more, which corresponds to a particle size of 600 or less. ＡＶＥ A particle size of 60 μm or less corresponds to a particle size of 240 or less.

[0044] The particle size distribution of particles contained in the slurry is measured, for example, using an electrical resistance particle size distribution analyzer, Multisizer 4e, manufactured by Beckman Coulter, Inc. The particle size distribution obtained using the particle size distribution analyzer is based on the so-called "Coulter principle," in which the change in impedance caused by the passage of individual particles in an electrolyte solution through a measurement site is directly detected, the particle size of each particle is measured one by one as a spherical equivalent particle size, and the number distribution is then organized as an integrated histogram (or integrated frequency curve) with particle size on the horizontal axis and number (frequency) on the vertical axis. Average particle size d ＡＶＥ is calculated as the so-called arithmetic mean diameter according to the number distribution.

[0045] Step S102 includes performing a wet etching process on at least a portion of the first main surface 31 of the cover glass 3. The wet etching process is a process in which an etching solution containing an acid or alkali is supplied to the first main surface 31 of the cover glass 3 to form concave curved surfaces 312 starting from the microcracks 311. The etching solution may be supplied by a dipping method in which the glass plate is immersed in the etching solution, or by a spraying method in which the etching solution is applied to the glass plate. Compared to dry etching, the wet etching process can isotropically etch the glass.

[0046] The etching solution is, for example, a solution containing an acid. The acid concentration in the etching solution is preferably 1 to 15% by mass, and particularly preferably 3 to 10% by mass. As the acid, for example, hydrogen fluoride is used. A combination of hydrogen fluoride and hydrogen chloride may also be used.

[0047] When the etching solution is a solution containing an acid, etching is preferably carried out at a temperature of 10° C. or higher and 40° C. or lower, preferably 15° C. or higher and 35° C. or lower, for 2 minutes to 1 hour.

[0048] When the etching solution is a solution containing an acid, the etching rate is preferably 0.5 μm / min or more, more preferably 1.0 μm / min or more, and even more preferably 2.0 μm / min or more, from the viewpoint of ensuring a sufficient anti-glare effect. The etching rate is preferably 20 μm / min or less.

[0049] The etching solution may be a solution containing an alkali. The alkali concentration in the etching solution is preferably 1% by mass to 50% by mass, and more preferably 3% by mass to 50% by mass. As the alkali, for example, at least one base selected from sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate is used. These bases may be used alone or in combination.

[0050] The etching solution preferably contains a chelating agent in addition to alkali. The chelating agent forms a chelate complex with metal ions of the glass dissolved in the etching solution, thereby suppressing recrystallization of the glass. The content of the chelating agent in the etching solution is preferably 0.1 mol / L or more and 0.5 mol / L or less. Examples of the chelating agent that can be used include ethylenediaminetetraacetic acid (EDTA), citric acid, gluconic acid, succinic acid, oxalic acid, tartaric acid, and hydroxyethylidene diphosphinic acid (HEDP).

[0051] When the etching solution is a solution containing an alkali, etching is preferably carried out at a temperature of 65° C. or higher and 150° C. or lower, preferably 80° C. or higher and 150° C. or lower, for 20 minutes to 40 hours.

[0052] When the etching solution is a solution containing an alkali, the etching rate is preferably 0.05 μm / min or more, more preferably 0.10 μm / min or more, and even more preferably 0.15 μm / min or more, from the viewpoint of ensuring a sufficient anti-glare effect. The etching rate is preferably 1.50 μm / min or less.

[0053] The experimental data will be explained below. Examples 1 to 13 below are working examples, and Examples 14 to 18 are comparative examples.

[0054] [Example 1] In Example 1, a cover glass was produced by subjecting a first main surface of a glass plate to a wet blasting treatment and a wet etching treatment in this order. The glass plate was manufactured by AGC Inc. and sold under the trade name Dragontrail (registered trademark). The glass plate had dimensions of 100 mm x 100 mm and a thickness of 0.4 mm.

[0055] In the wet blasting treatment, a wet blasting machine (manufactured by Maco Corporation, machine name: Robot Blast RB-6) was used. The slurry was prepared by mixing ceramic particles, a dispersing agent, and water as a dispersion medium. The content of ceramic particles in the entire slurry (slurry concentration) was 20 wt %. The ceramic particles were white alumina (trade name: Macoundum, particle size: #600, average particle size d ＡＶＥThe particle size was 21.1 μm. The injection pressure (gas pressure) of the slurry was 0.15 MPa, the projection distance (WD) (the distance between the nozzle and the glass plate) was 70 mm, the nozzle scanning speed was 200 mm / sec, and the number of nozzle scans was 20. The slurry was injected together with compressed air. The gas pressure refers to the pressure of the compressed air. After the wet blasting process, the glass plate was washed with pure water and dried before the wet etching process.

[0056] In the wet etching treatment, the glass plate was immersed in an etching solution at 36°C for 1110 seconds to etch 109 μm of the first main surface of the glass plate. The second main surface of the glass plate was protected with an acid-resistant protective film that had been attached in advance. The etching solution was an aqueous solution containing 5% by mass of hydrogen fluoride and 5% by mass of hydrogen chloride. After the wet etching treatment, the protective film was peeled off. No chemical strengthening treatment was then performed.

[0057] [Examples 2 to 18] In Examples 2 to 18, cover glasses were produced under the same conditions as in Example 1, except for the conditions listed in Table 1. The average particle size d ＡＶＥ is 41.1 μm, and the average particle size d ＡＶＥ is 9.9 μm, and the average particle size d ＡＶＥ was 5.6 μm.

[0058] [Summary] Table 1, Figures 4, and 5 show the evaluation results for Examples 1 to 18. RSm and Ra were measured using a laser microscope (VK-X3000, manufactured by Keyence Corporation). The number of acquired data points was 1024 x 768 pixels, the measurement area was 285 μm x 214 μm, and line roughness measurements were made at more than 20 locations within the measurement area. The writing feel was categorized into three levels (good, fair, and poor) based on the results of a sensory test in which all evaluators (10 people) evaluated the writing feel on a three-point scale. Specifically, a rating of "good" was given for cases in which 80% or more of the evaluators rated the writing feel as "good." A rating of "△" was given for cases in which 80% or more of the evaluators rated the writing feel as "good," but not "good," or "fair." All other cases were categorized as "x."

[0059]

[0060] As shown in Table 1, in Examples 1 to 13, unlike Examples 14 to 20, (RSm / √Ra) was 90 μm. ０．５ ~180μm ０．５ And (RSm × √Ra) is 10 μm １．５ ~110μm １．５ Therefore, the writing comfort was evaluated as either "△" or "◯."

[0061] Furthermore, as shown in Table 1, in Examples 1 to 7, unlike Examples 8 to 20, (RSm / √Ra) was 90 μm ０．５ ~160μm ０．５ And (RSm × √Ra) is 52 μm １．５ ~95μm １．５ Therefore, the writing feel was rated as "good."

[0062] Furthermore, from Figures 4 and 5, it can be seen that the evaluation results of the sensitivity test can be classified with high accuracy by using (RSm / √Ra) and (RSm × √Ra) instead of Rsm and Ra.

[0063] The following supplementary notes are disclosed regarding the above-described embodiments. [Supplementary Note 1] A cover glass for a touch panel for pen input, the cover glass having an uneven surface on the surface touched by the pen, wherein the uneven surface has a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of a roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) of 90 μm. ０．５ ~180μm ０．５ The value (RSm × √Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm. １．５ ~110μm １．５ [Appendix 2] The uneven surface has a (RSm / √Ra) of 90 μm. ０．５ ~160μm ０．５ And the (RSm × √Ra) is 52 μm １．５ ~95μm １．５The cover glass for a touch panel according to Supplementary Note 1, wherein the RSm of the uneven surface is 60 μm to 200 μm. [Supplementary Note 4] The cover glass for a touch panel according to any one of Supplementary Notes 1 to 3, wherein the Ra of the uneven surface is 0.10 μm to 2.00 μm. [Supplementary Note 5] The cover glass for a touch panel according to any one of Supplementary Notes 1 to 4, wherein the haze value of the uneven surface is 50% or less. [Supplementary Note 6] A touch panel comprising the cover glass according to any one of Supplementary Notes 1 to 5 and a display having a screen protected by the cover glass, wherein the display has a touch sensor that detects proximity of a pen to the screen of the display. [Supplementary Note 7] A method for manufacturing a cover glass of a touch panel for pen input, comprising the steps of: performing a wet blasting process and a wet etching process in this order on the surface of the cover glass that is touched by a pen, thereby obtaining an uneven surface; and the uneven surface has a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of a roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) of 90 μm. ０．５ ~180μm ０．５ The value (RSm × √Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm. １．５ ~110μm １．５ [Appendix 8] The uneven surface is formed so that the (RSm / √Ra) is 90 μm. ０．５ ~160μm ０．５ And the (RSm × √Ra) is 52 μm １．５ ~95μm １．５ The method for manufacturing a cover glass for a touch panel according to claim 7, wherein the cover glass is formed so that the average particle diameter d ＡＶＥ 9. The method for manufacturing a cover glass for a touch panel according to claim 7 or 8, wherein the thickness is 13 μm or more.

[0064] The touch panel cover glass, touch panel, and method for manufacturing the touch panel cover glass according to the present disclosure have been described above, but the present disclosure is not limited to the above embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure.

[0065] This application claims priority based on Japanese Patent Application No. 2023-117741 filed with the Japan Patent Office on July 19, 2023, the entire contents of which are incorporated herein by reference.

[0066] 1 touch panel 3 cover glass 31 first main surface 32 second main surface

Claims

1. A cover glass for a touch panel on which pen input is performed, the surface touched by the pen has an uneven surface, and the uneven surface has a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) of 90 μm. ０．５ ~180μm ０．５ And the value (RSm×√Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm. １．５ ~110μm １．５ That is, the cover glass for the touch panel.

2. The uneven surface has a (RSm / √Ra) of 90 μm ０．５ ~160μm ０．５ And, (RSm×√Ra) is 52 μm １．５ ~95μm １．５ The cover glass of the touch panel according to claim 1 , 3. The cover glass for a touch panel according to claim 1 or 2, wherein the uneven surface has an RSm of 60 μm to 200 μm.

4. The cover glass for a touch panel according to claim 1 or 2, wherein the uneven surface has an Ra of 0.10 μm to 2.00 μm.

5. The cover glass for a touch panel according to claim 1 or 2, wherein the uneven surface has a haze value of 50% or less.

6. A touch panel comprising the cover glass according to claim 1 or 2 and a display having a screen protected by said cover glass, said display having a touch sensor for detecting the proximity of a pen to the screen of said display.

7. A method for manufacturing a cover glass of a touch panel for pen input, comprising the steps of performing wet blasting and wet etching in this order on the surface of the cover glass that is touched by the pen to obtain an uneven surface, and the uneven surface has a value (RSm / √Ra) obtained by dividing the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) of 90 μm. ０．５ ~180μm ０．５ And the value (RSm×√Ra) obtained by multiplying the element mean length RSm (unit: μm) of the roughness curve by the square root of the arithmetic mean roughness Ra (unit: μm) is 10 μm. １．５ ~110μm １．５ The method for manufacturing a cover glass for a touch panel, 8. The uneven surface has a (RSm / √Ra) of 90 μm ０．５ ~160μm ０．５ And, (RSm×√Ra) is 52 μm １．５ ~95μm １．５ The method for manufacturing a cover glass of a touch panel according to claim 7, wherein the cover glass is formed as follows:

9. The wet blasting process is carried out with a slurry having an average particle size d ＡＶＥ The method for manufacturing a cover glass for a touch panel according to claim 7 or 8, wherein the thickness is 13 μm or more.

Images