Method for preparing touch screen and touch screen structure

Abstract

The present invention discloses a method for preparing a touch screen and a touch screen structure, wherein the preparation method comprises: performing an optimization treatment on a tin surface of a cover glass to remove residual impurities and defects on the glass surface and forming a plurality of fine pits evenly distributed on the tin surface; performing an antibacterial treatment on the cover glass to form an antibacterial surface with silver ions on the cover glass; covering the processed tin surface with a bonding layer so that the optical resin material of the bonding layer is filled into the fine pits on the tin surface, and the relative refractive index between the bonding layer and the cover glass is between 1.04 and 0.96; and providing a touch sensor, and sequentially and closely overlapping the cover glass, the bonding layer and the touch sensor to form a touch screen structure with high light transmittance and antibacterial effect.

Description

Technical Field

[0001] The present invention relates to the field of touch screens, and particularly to a preparation method and a touch screen structure for manufacturing a touch screen with high light transmittance and antibacterial effect using float glass. Background Art

[0002] Float glass has the advantage of low cost, but it is less used in the field of optical glass. As is known, float glass is formed by the tin bath method. On the surface where the glass contacts the tin surface, that is, the tin surface of the glass substrate, defects such as tin sticking, rainbow, spots or small ripples are likely to form on the stannous oxide (SnO) on the tin surface after the glass is formed. When such glass products are used as optical glass for touch screens, the tin surface of the glass needs to be optimized. For example, mechanical polishing or wet etching means are used to improve the defects of the tin surface. Among them, using mechanical polishing means to improve the defects of the tin surface, such as the glass surface grinding and peeling device disclosed in Chinese Patent Application Publication No. CN109926914A, has a high process technology difficulty for grinding and leveling, low production efficiency, high processing cost and equipment cost, and the length and width of the working area are mostly limited to less than 15 inches, which is not applicable to the large-size panels required for current widespread use in public places, causing troubles in application. In addition, the wet etching means has the advantages of high production efficiency, low process technology difficulty and low processing cost, so it has been widely used at present. After wet etching, the glass surface will be roughened to form a glass surface with haze. The glass surface with haze will cause the light passing through the glass plate to produce diffuse reflection, achieving the anti-glare and anti-reflection effects, but it will also reduce the light transmittance of the glass plate. Generally, the higher the haze of the glass surface, the more the light transmittance is reduced. If the glass plate treated by wet etching the tin surface is used as a laminated component of a touch screen, the light transmittance of the overall touch screen formed will be reduced. Therefore, overcoming this problem is the common goal of the industry.

[0003] In addition, if float glass is used as an antibacterial glass substrate, a significant degree of color change (golden yellow) usually occurs after silver ion antibacterial treatment. This is because on the surface of the glass substrate on the tin surface side, the tin component diffuses in the glass. If a silver ion diffusion layer is formed in this surface, the silver in the silver ion diffusion layer is reduced to silver colloid due to the tin component, causing the glass to be colored. The experimental results show that when the glass is colored due to silver colloid, the absorption wavelength in the wavelength band range of several hundred nanometers near 428 nm becomes very large, which also affects the light transmittance of the glass plate. As a result, it is difficult for relatively inexpensive float glass to be extended in the application of antibacterial glass. Summary of the Invention

[0004] In view of this, the main object of the present invention is to provide a preparation method and a touch screen structure for making a touch screen with high light transmittance and antibacterial effect using float glass.

[0005] To achieve the above object of the invention, the preparation method of the touch screen provided by the present invention mainly comprises the following steps:

[0006] Step 1: Perform an optimization treatment on the tin surface of a cover glass to remove residual impurities and defects on the glass surface, and form a plurality of micro-pits evenly distributed on the tin surface. Among them, the depth range of the plurality of micro-pits is between 0.5 µm and 10 µm, and the spacing range between two adjacent micro-pits is between 1 µm and 20 µm;

[0007] Step 2: Lay a bonding layer on the processed tin surface. The bonding layer is a soft and sticky thin layer made of a transparent optical resin material, and the optical resin material of the bonding layer is filled into the micro-pits on the tin surface. Among them, the relative refractive index between the bonding layer and the cover glass is between 1.04 and 0.96; and

[0008] Step 3: Bond the cover glass with a touch sensor, so that the touch sensor is closely laminated against the tin surface of the cover glass. Through the bonding layer, the touch sensor and the cover glass are combined into one body. After the cover glass with a hazy surface and the touch sensor are closely laminated and combined into one body, the light transmittance of the overall touch screen is improved.

[0009] In an embodiment of the present invention, the optimization treatment includes: I. Provide an etching solution, the material composition of which at least includes water-soluble inorganic salts and acid solution. Preferably, the water-soluble inorganic salts account for 10% to 35% of the total weight, and the acid solution accounts for 5% to 60% of the total weight. Among them, the water-soluble inorganic salts are selected from one or a mixture of several of hydrofluoric acid, potassium fluoride, sodium bicarbonate, potassium bicarbonate, ammonium perchlorate, and the acid solution is selected from one or a mixture of several of phosphoric acid, citric acid, acetic acid, lactic acid, boric acid, tartaric acid; and II. Etch the tin surface with the etching solution, keep the temperature of the etching solution between 40 °C and 50 °C, act the etching solution on the tin surface for 10 minutes to 50 minutes, and then wash the tin surface to remove the residual etching solution.

[0010] In an embodiment of the present invention, after the optimization treatment, a selectively implementable Step 4 is further included: Perform an antibacterial treatment on the cover glass to form silver ions Ag on the cover glass +antibacterial surface without increasing the glass color value (golden yellow); the antibacterial treatment includes: I. subjecting the cover glass after the optimization treatment to a dealkalization treatment with ammonium chloride (NH 4 Cl) heated to 350°C to 600°C; II. then subjecting the cover glass to an ion exchange with a mixed molten salt of silver nitrate (AgNO 3 ) and potassium nitrate (KNO 3 ) heated to 360°C to 400°C, so that silver ions Ag + are distributed on the surface of the cover glass to form a surface with antibacterial efficacy; since the tin component on the surface of the cover glass has been completely removed after the optimization treatment, no silver colloid will be formed during the antibacterial treatment, thus avoiding the problem of glass coloring.

[0011] Another object of the present invention is to provide a touch screen structure, which can ensure good light transmittance of the overall touch screen after a cover glass with a hazy surface and a touch sensor are closely laminated and integrated.

[0012] According to the touch screen structure provided by the present invention, it includes a cover glass, an adhesive layer, and a touch sensor. On a processed surface of the cover glass, there are several micro-pits evenly distributed. The depth range of the micro-pits is between 0.5 µm and 10 µm, and the distance range between two adjacent micro-pits is between 1 µm and 20 µm; the adhesive layer is a soft and viscous thin layer made of a transparent optical resin material. The adhesive layer is coated on the processed surface, and the optical resin material of the adhesive layer is filled into the micro-pits. Among them, the relative refractive index between the adhesive layer and the cover glass is between 1.04 and 0.96; the touch sensor, the adhesive layer, and the cover glass are closely laminated in sequence, and the touch sensor and the cover glass are combined into one through the adhesive layer.

[0013] According to an embodiment of the present invention, the cover glass is selected as float glass with a refractive index of 1.523, and the adhesive layer is selected as an optical adhesive with a refractive index of 1.485.

[0014] In the touch screen structure of the present invention, the optical resin material of the adhesive layer is filled into the micro-pits on the surface of the cover glass to passivate the haze on the surface of the cover glass, and the cover glass and the adhesive layer have similar refractive indices. Accordingly, the diffusion effect of light passing through the cover glass plate can be reduced, thereby improving the light transmittance and visibility of the touch screen.

[0015] The following disclosure provides a simplified introduction to some selected concepts that are further described below in the Detailed Description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flowchart of the preparation method of an embodiment of the present invention.

[0017] Figure 2 It is a schematic diagram of the stacked structure of an embodiment of the present invention.

[0018] Figure 3 It is an electron microscope image of the tin surface after optimization treatment of an embodiment of the present invention.

[0019] Figure 4 is Figure 2 an enlarged schematic diagram at the IV site.

[0020] Figure 5 It is a flowchart of the antibacterial treatment in the preparation method of an embodiment of the present invention.

[0021] SYMBOLS USED IN THE DRAWINGS:

[0022] 10 Cover glass;

[0023] 11 Tin surface;

[0024] 12 Microscopic pits;

[0025] 20 Bonding layer;

[0026] 30 Touch sensor;

[0027] S1~S4 Steps. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in the accompanying drawings below. In order to provide a clearer description and easier understanding of the technical features of the present invention, the various parts in the drawings are not drawn according to their relative sizes, and some sizes have been exaggerated compared to other relevant scales; irrelevant details are not fully drawn to simplify the drawings.

[0029] Please refer to Figure 1 and Figure 2 as shown, the preparation method of the touch screen of the present invention includes steps S1 to S3, and an optionally implemented step S4; wherein,

[0030] Step S1: Perform an optimization treatment on the tin surface 11 of the cover glass 10, and form a plurality of uniformly distributed microscopic pits 12 on the tin surface 11:

[0031] Provide a cover glass 10, which is made of float glass with a length and width of more than 15 inches and a refractive index of about 1.523. For example, it is float glass with the international glass code 523515.250 of N-KF9; perform an optimization treatment on the tin surface 11 of the cover glass 10 to remove residual impurities and defects on the glass surface, and form several uniformly distributed micro pits 12 on the tin surface 11.

[0032] The aforementioned optimization treatment includes: I. Provide an etching solution, which is a solution uniformly mixed with materials such as water-soluble inorganic salts, acid solutions, dispersants, stabilizers, and deionized water; in particular, the water-soluble inorganic salts account for 10% to 35% of the total weight, the acid solution accounts for 5% to 60% of the total weight, the dispersant accounts for 0.5% to 5% of the total weight, the stabilizer accounts for 1% to 10% of the total weight, and the remaining amount is deionized water; the water-soluble inorganic salts are selected from one or a mixture of several of hydrofluoric acid, potassium fluoride, sodium bicarbonate, potassium bicarbonate, ammonium perchlorate, the acid solution is selected from one or a mixture of several of phosphoric acid, citric acid, acetic acid, lactic acid, boric acid, tartaric acid, the dispersant is selected from one or a mixture of several of nitric acid, sulfuric acid, hydrofluoric acid, hydrochloric acid, and the stabilizer is selected from one or a mixture of several of ethyl thiostannate, magnesium chloride, sodium silicate, organic nickel compounds.

[0033] II. Apply the etching solution to the tin surface 11, keep the temperature of the etching solution between 40°C and 50°C, and the action time is about 10 to 30 minutes. Then, clean the tin surface 11 to remove the residual etching solution. Therefore, several micro pits are formed on the tin surface 11, and the surface is roughened to achieve the effects of reducing reflected light and anti-glare; in particular, the action mode of the aforementioned etching solution on the tin surface 11 can be practiced by various means. For example, the etching solution can be filled in a working tank, and the cover glass 10 is put into the working tank so that the tin surface 11 is completely immersed in the etching solution for etching. Those skilled in the art know that in addition to the aforementioned action mode, a continuous spraying method can also be used. For example, the etching solution is continuously sprayed on the tin surface 10a for etching; therefore, the action mode of the etching solution on the tin surface 11 is not limited to the aforementioned technical means.

[0034] In the optimization process of the present invention, in addition to the tin surface 10a to be processed on the cover glass 10 remaining exposed, the remaining surfaces can be shielded by corrosion-resistant shielding. Those skilled in the art know that the shielding can be selected from plastics such as polymethyl methacrylate glue and silicone rubber, and can be arranged on the surface of the cover glass 10 by technical means such as screen printing method, spin coating method, slot coating method or capillary coating method, and film laminating method. In addition, the sandblasting means of the aforementioned optimization process, that is, by using wind pressure to impact the tin surface 11 of the cover glass with fine steel sand at a high speed, roughening the surface to achieve the effect of reducing reflected light, and performing a polishing process after sandblasting to form a glass surface with both anti-glare and anti-reflection effects.

[0035] Through the aforementioned optimization process, defects such as tin contamination, rainbow, spots or small ripples on the tin surface 11 can be removed, and several fine pits 12 are evenly distributed on the tin surface 11 to form an anti-glare and low-reflection surface. The depth range of these fine pits 12 is between 0.5 µm and 10 µm, and the spacing range between adjacent fine pits is between 1 µm and 20 µm; the several fine pits 12 distributed on the tin surface 11 can be clearly shown after being magnified several times by a microscope, with several irregular polygon pits evenly distributed on the glass surface, and these pits together form a tortoise shell-like reticular pattern (as Figure 3 shown); furthermore, the microscopic geometry of the aforementioned anti-glare and low-reflection surface composed of several fine pits 12 formed on the glass surface can adjust the reflectivity and light transmittance of the glass surface by controlling the distribution density of these fine pits 12 and the depth difference of the pits; for example, the present invention can adjust the roughness, haze, anti-glare and low-reflection effects of the glass tin surface 12 by increasing the action time of the etching solution on the tin surface 11 or performing the aforementioned optimization process repeatedly multiple times to control the distribution pattern of these several fine pits 12 on the tin surface 11.

[0036] Step S2: Coat a bonding layer 20 on the processed tin surface 11 so that the optical resin material of the bonding layer 20 is filled into the fine pits 12 on the tin surface:

[0037] Provide an adhesive layer 20, which is a soft and sticky thin layer made of a transparent optical resin material, such as an optical resin based on polymethyl methacrylate (PMMA), and has excellent light transmittance and step filling properties; wherein, the relative refractive index between the adhesive layer 20 and the cover glass 10 is between 1.04 and 0.96. For example, the adhesive layer is selected from a solid optical adhesive (SOCA, Solid Optically Clear Adhesive) or a liquid optical adhesive (LOCA, Liquid Optically Clear Adhesive) with a refractive index of about 1.485.

[0038] Step S3: Bond the cover glass and a touch sensor into one body:

[0039] Provide a touch sensor 30, which is made of one of an ITO conductive glass plate (ITO glass), an ITO conductive film (ITO film), a metal mesh, or a nano transparent conductive film. The touch sensor 30 is closely laminated against the tin surface 11 of the cover glass, and the touch sensor 30 and the cover glass 10 are combined into one body through the adhesive layer 20 to form a touch screen.

[0040] As Figure 2 shown, the high light transmittance touch screen of the present invention is composed of a cover glass 10, an adhesive layer 20, and a touch sensor 30 that are closely laminated in sequence. In the combined structure of the touch screen, when the adhesive layer 20 is coated on the processed tin surface 11, the optical resin material of the adhesive layer 20 will be filled into the fine pits 12 of the tin surface 11 (please refer to Figure 4 ), to passivate the haze of the tin surface 11, and the cover glass 10 and the adhesive layer 20 have similar refractive indices, and the relative refractive index between the two materials approaches 1. Therefore, the diffuse effect of light passing through the cover glass and the adhesive layer 20 can be greatly reduced, thereby improving the light transmittance and visibility of the overall touch screen.

[0041] Furthermore, after the cover glass 10 undergoes the aforementioned optimization treatment, step S4 can be selectively performed: perform an antibacterial treatment on the cover glass 10 to form an antibacterial surface with silver ions Ag + . Please refer to Figure 5 shown, the manufacturing method of the aforementioned antibacterial treatment can be through the use of silver nitrate (AgNO 3 ) and potassium nitrate (KNO 3) is achieved by an ion exchange method using a hybrid molten salt. The specific implementation methods include: I. Subject the cover glass 10 that has undergone the above optimization treatment to a de-alkalization treatment with ammonium chloride (NH 4 Cl) heated to 350°C to 600°C. The alkali metal ions in the cover glass 10, such as sodium ions Na + , have strong mobility when the temperature rises and exchange with the hydrogen ions H + decomposed from ammonium chloride; II. Then subject the cover glass 10 to an ion exchange with a hybrid molten salt of silver nitrate (AgNO 3 ) and potassium nitrate (KNO 3 ) heated to 360°C to 400°C; wherein, the weight ratio of potassium nitrate (KNO 3 ) in the aforementioned hybrid molten salt is 95% - 99.99%, and the weight ratio of silver nitrate (AgNO 3 ) is 0.01 - 5%; so that the potassium ions K + and silver ions Ag + in the hybrid molten salt replace the alkali metal ions on the glass substrate, thereby distributing the silver ions Ag + to the surface of the cover glass 10 to form a surface with antibacterial efficacy; through the above-mentioned ion exchange preparation means, antibacterial and strengthening effects can be formed on the surface of the cover glass 10. The experimental results show that the antibacterial value of the antibacterial test against Escherichia coli of JIS2801 reaches above 5, and the antibacterial value against Staphylococcus aureus reaches above 3.8 - 4.7; in addition, since the tin component on the surface of the cover glass 10 has been completely removed after the above optimization treatment, the problem of glass coloring caused by the formation of silver colloid during the antibacterial treatment can be eliminated. Therefore, the present invention can expand the application of inexpensive float glass in antibacterial glass.

[0042] In summary, the present invention can use inexpensive float glass to manufacture a touch screen with high light transmittance and antibacterial effects, and enhance the application scope of float glass in optical glass.

[0043] Although the present invention has been disclosed as above with embodiments, it is not intended to limit the present invention. Any person skilled in this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims of the invention patent application.

Claims

1. A method for preparing a touch screen, characterized in that: The following steps are involved: An optimization treatment is performed on the tin surface of a cover glass to remove residual impurities and defects on the glass surface, and a plurality of uniformly distributed micro pits are formed on the tin surface, wherein the depth of the plurality of micro pits ranges from 0.5µm to 10µm, and the distance between two adjacent micro pits ranges from 1µm to 20µm; A bonding layer is provided on the processed tin surface, wherein the bonding layer is a soft and sticky thin layer made of a transparent optical resin material, and the optical resin material of the bonding layer is filled into the fine pits on the tin surface, wherein the relative refractive index between the bonding layer and the cover glass is between 1.04 and 0.96; and Laminating the cover glass with a touch sensor so that the touch sensor is closely overlapped on the tin surface facing the cover glass, and the touch sensor and the cover glass are combined into one body by the bonding layer; The optimization process comprises: Providing an etching solution, the material components of which at least include water-soluble inorganic salts and acid solution; and The tin surface is etched with the etching solution, the temperature of the etching solution is maintained between 40° C. and 50° C., the etching solution is applied to the tin surface for 10 to 50 minutes, and then the tin surface is cleaned to remove residual etching solution.

2. The method for preparing a touch screen according to claim 1, characterized in that: The water-soluble inorganic salts in the etching solution account for 10% to 35% of the total weight, and the acid accounts for 5% to 60% of the total weight.

3. The method for preparing a touch screen according to claim 1, characterized in that: The water-soluble inorganic salts are selected from one or a mixture of hydrofluoric acid, potassium fluoride, sodium bicarbonate, potassium bicarbonate, and ammonium perchlorate.

4. The method for preparing a touch screen according to claim 1, wherein: The acid solution is selected from phosphoric acid, citric acid, acetic acid, lactic acid, boric acid, tartaric acid or a mixture of several thereof.

5. The method for preparing a touch screen according to claim 1, wherein: It also includes performing an antibacterial treatment on the cover glass to form an antibacterial surface with silver ions on the cover glass; the antibacterial treatment includes: I. subjecting the cover glass that has passed the optimization treatment to a dealkalization treatment with ammonium chloride heated to 350°C to 600°C; II. subjecting the cover glass to an ion exchange with a mixed molten salt of silver nitrate and potassium nitrate heated to 360°C to 400°C, so that the silver ions are distributed on the surface of the cover glass to form a surface with antibacterial properties.

6. A touch screen structure, characterized in that: Include: A cover glass, having a plurality of uniformly distributed micro pits on a processed surface of the cover glass, wherein the depth of the micro pits ranges from 0.5 μm to 10 μm, and the distance between two adjacent micro pits ranges from 1 μm to 20 μm; a bonding layer, which is a soft and sticky thin layer made of a transparent optical resin material, the bonding layer is coated on the processed surface, and the optical resin material of the bonding layer is filled into the fine pits, wherein the relative refractive index between the bonding layer and the cover glass is between 1.04 and 0.96; and A touch sensor is provided, wherein the cover glass, the bonding layer and the touch sensor are closely overlapped in sequence, and the touch sensor and the cover glass are combined into one body by the bonding layer.

7. The touch screen structure according to claim 6, characterized in that: The cover glass is float glass with a refractive index of 1.523, and the bonding layer is optical glue with a refractive index of 1.485.

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