A non-uniform thickness flexible glass and method of making the same

Abstract

The application discloses a kind of unequal thickness flexible glass and its preparation method, belong to glass processing forming technical field;Including the following steps: S1, glass substrate double air surface is coated with acid-resistant film;S2, A surface is pretreated, that is, by CNC and is processed to form etching liquid flow reservation channel;S3, after pretreatment, glass is in cascade flow etching device, by adjusting glass position, so that the etching area of glass after pretreatment reaches predetermined thickness;S4, after etching, glass is immersed in pure water and / or lye, cleaned, further remove acid-resistant UV adhesion-reducing film, and glass is finely polished, to obtain product with excellent surface quality.The method is simple and efficient, and the obtained unequal thickness flexible glass has good bending performance and impact resistance.

Description

Technical Field

[0001] This invention belongs to the field of glass processing and forming technology, and relates to a flexible glass of unequal thickness and its preparation method. Background Technology

[0002] The rapid development of flexible displays has placed unprecedented high-performance demands on their core covering material—the cover glass. An ideal cover material not only needs excellent surface hardness to ensure scratch resistance and extremely high optical transmittance to present true image quality, but it must also be able to withstand hundreds of thousands or even millions of repeated bending cycles without failure. Traditional soda-lime glass or aluminosilicate glass, due to their inherent brittleness and low fracture toughness, are completely unable to meet the stringent requirements of flexible folding. Therefore, flexible foldable glass, as a highly promising solution, has become a strategic key material of common concern to the global materials science and display industries.

[0003] Flexible foldable glass typically refers to ultra-thin glass whose bending region is reduced to less than 100 micrometers in thickness. Through specific chemical strengthening processes and precise structural design, this type of glass achieves repeated bending capabilities with a small radius of curvature on a macroscopic scale. Compared to transparent polyimide (CPI) films as an alternative, flexible foldable glass exhibits a series of irreplaceable inherent advantages. It retains the inherent hardness, transparency, heat resistance, and stable mechanical and chemical properties of glass under oxidation and light conditions; while also adding the characteristics of bendability, lightweight, and ease of processing. With this excellent combination of properties, flexible foldable glass has become a research hotspot both domestically and internationally.

[0004] Despite the numerous advantages and strong demand for flexible foldable glass, current conventional ultra-thin flexible glass suffers from core weaknesses due to its uniform thickness and extreme thinness (folding area ≤0.1mm). This results in weak impact resistance and fragility. When applied to mobile phones and other end-products, it is extremely susceptible to cracking or even complete shattering due to accidental drops, bumps, or impacts from sharp objects. Dynamic impact loads pose a significant challenge to this ultra-thin structure, as its brittle fracture nature makes it difficult to absorb and disperse impact energy through plastic deformation. This severely restricts its large-scale and stable application in products such as foldable phones and flexible displays. Summary of the Invention

[0005] The purpose of this invention is to provide a flexible glass with unequal thickness and its preparation method, so as to solve the technical problem that the bending performance and impact resistance of the existing flexible glass are poor and cannot meet the current needs of flexible display applications.

[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a method for preparing flexible glass of unequal thickness, comprising the following steps: An acid-resistant film is coated on the entire surface of the glass substrate with two air pockets to complete the coating process; A pre-flow channel for the etching solution is fabricated on side A of the coated glass substrate. A waterfall etching apparatus is used to etch the pre-flow channel of the glass substrate to a preset thickness. The etched glass substrate is immersed and cleaned to remove the acid-resistant film and then polished to obtain flexible glass of varying thickness.

[0007] Furthermore, the acid-resistant film is a UV-resistant anti-sticking film.

[0008] Furthermore, the step of processing the etching solution pre-flow channel on the A side of the coated glass substrate is performed using a CNC machining machine.

[0009] Furthermore, the spindle speed of the CNC machining machine is 4000 rpm / min - 8000 rpm / min, and the feed rate is 500 rpm / min - 800 rpm / min.

[0010] Furthermore, the step of using a waterfall etching apparatus to etch the pre-flow channel of the glass substrate to a preset thickness specifically includes: placing the glass substrate in the waterfall etching apparatus for glass etching; and adjusting the glass position to exchange the pre-etching section and the post-etching section until both the pre-etching section and the post-etching section of the glass reach the preset thickness.

[0011] Furthermore, the preset thickness does not exceed 0.03 mm.

[0012] Furthermore, the etching solution is an acid etching solution.

[0013] Furthermore, the etching solution comprises hydrofluoric acid, sulfuric acid, and oxalic acid; the mass ratio of the hydrofluoric acid, sulfuric acid, and oxalic acid is 5:(2~4):2.

[0014] Furthermore, the soaking and cleaning process specifically includes: immersing and cleaning the etched glass substrate in an alkaline solution; then removing the glass from the alkaline solution, immersing it in pure water for ultrasonic cleaning, and finally cleaning it horizontally.

[0015] Secondly, the present invention provides a flexible glass with unequal thickness, which is prepared according to the above-described method for preparing a flexible glass with unequal thickness.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a flexible glass with unequal thickness and its preparation method. First, the glass is protected with an acid-resistant film. Then, an etching area is pre-defined. Next, a waterfall-style etching process combined with glass rotation and slow chemical etching is used to gradually create a thickness difference, ultimately etching the etched area to the target thickness. The unequal thickness flexible glass prepared using this method has no streaks or step defects in the unequal thickness areas. Furthermore, the unetched areas of the prepared unequal thickness flexible glass have good impact resistance and are not easily broken, while the etched groove areas have good bending performance, making it suitable for use in flexible equipment.

[0017] Furthermore, this invention uses a CNC machining machine to process the A-side of the glass, precisely forming a pre-flow channel for the etching solution. This ensures that the etching solution flows uniformly and directionally in subsequent processes, avoiding localized over-etching or uneven thickness, thereby guaranteeing the forming accuracy of structures with unequal thicknesses. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a method for preparing flexible glass with unequal thickness according to the present invention. Detailed Implementation

[0020] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0021] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0022] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0023] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”

[0024] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 1 This invention discloses a method for preparing flexible glass of unequal thickness, comprising the following steps: S1, apply an acid-resistant film to the entire surface of the glass substrate with two air pockets to complete the coating process; In this step, the acid-resistant film is a UV anti-sticking film.

[0026] S2, A pre-flow channel for etching solution is processed on side A of the coated glass substrate; In this step, a CNC machining center is used to pre-flow the etching solution through the channel. The spindle speed of the CNC machining center is 4000 rpm / min - 8000 rpm / min, and the feed rate is 500 rpm / min - 800 rpm / min. Surface A refers to the glass opening surface.

[0027] S3 uses a waterfall etching device to etch the pre-flow channel of the glass substrate to a preset thickness. In this step, the glass substrate is placed in a waterfall etching apparatus for glass etching. The glass position is adjusted so that the pre-etching and post-etching sections are interchanged until both sections reach a preset thickness. The preset thickness does not exceed 0.03 mm. The etching solution used is an acid etching solution comprising hydrofluoric acid, sulfuric acid, and oxalic acid; the mass ratio of hydrofluoric acid, sulfuric acid, and oxalic acid is 5:(2~4):2.

[0028] S4. The etched glass substrate is immersed and cleaned to remove the anti-acid film and polished to obtain flexible glass of varying thickness.

[0029] In this step, the soaking and cleaning process specifically includes: immersing and cleaning the etched glass substrate in an alkaline solution; then removing the glass from the alkaline solution, immersing it in pure water for ultrasonic cleaning, and finally cleaning it horizontally.

[0030] This invention also discloses a flexible glass with unequal thickness, prepared according to the aforementioned method. The flexible glass with unequal thickness features a differentiated thickness design between the folded area (groove area) and the non-folded area. The thickness of the folded area can be precisely controlled to ultra-thin specifications (e.g., 0.03mm), meeting the requirements of high-frequency bending; and significantly improving overall impact resistance and mechanical strength. This effectively solves the technical bottleneck of the fragility of traditional uniform ultra-thin glass, enabling it to combine flexibility and durability in folding devices.

[0031] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0032] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.

[0033] Example 1: This embodiment discloses a method for preparing flexible glass with unequal thickness, including the following steps: S1, Coating treatment Before lamination, the A-side and the air-side are distinguished. The glass substrate is ultrasonically cleaned and then transferred to a laminating machine for coating. During lamination, the anti-acid UV anti-tack film is first applied to the entire air-side of the glass substrate, ensuring complete adhesion between the film and the glass surface. The glass substrate with the air-side film applied is then flipped over so that the air-side is facing down and placed on the laminating machine's worktable. The anti-acid UV anti-tack film is then applied to the A-side. After lamination, the glass surface must be free of defects such as bubbles, wrinkles, and impurities.

[0034] S2, A-side preprocessing The coated glass is placed in a CNC machining machine with side A facing up. The spindle speed is 4000 rpm / min and the feed rate is 500 rpm / min to process the area reserved by the etching solution.

[0035] S3, Etching Process The glass, after the S2 process, is placed in a waterfall etching apparatus for etching. By adjusting the glass position, the pre-treated glass etching zone achieves a predetermined thickness.

[0036] The process involves adjusting the glass position by rotating it, thus exchanging the front and rear etching sections to achieve a predetermined thickness (0.03 mm) for both sections. The etching solution consists of hydrofluoric acid, sulfuric acid, and oxalic acid in a mass ratio of 5:2:2.

[0037] S4. After etching, the glass is removed and immersed in an alkaline solution for cleaning to remove residual acid. The glass is then removed from the alkaline solution and ultrasonically cleaned in pure water, followed by horizontal cleaning. The adhesive is then removed to remove the acid-resistant UV-resistant coating from the glass surface, and fine polishing is performed to further eliminate micro-cracks, thus obtaining flexible glass of varying thickness. Testing shows that the unequal thickness areas of the obtained flexible glass have no step marks or streaks, indicating good forming quality.

[0038] Example 2: This embodiment discloses a method for preparing flexible glass with unequal thickness, including the following steps: S1, Coating treatment Before lamination, the A-side and the air-side are distinguished. The glass substrate is ultrasonically cleaned and then transferred to a laminating machine for coating. During lamination, the anti-acid UV anti-tack film is first applied to the entire air-side of the glass substrate, ensuring complete adhesion between the film and the glass surface. The glass substrate with the air-side film applied is then flipped over so that the air-side is facing down and placed on the laminating machine's worktable. The anti-acid UV anti-tack film is then applied to the A-side. After lamination, the glass surface must be free of defects such as bubbles, wrinkles, and impurities.

[0039] S2, A-side preprocessing The coated glass is placed in a CNC machining machine with side A facing up. The spindle speed is 8000 rpm / min and the feed rate is 800 rpm / min to process the area reserved by the etching solution.

[0040] S3, Etching Process The glass, after the S2 process, is placed in a waterfall etching apparatus for etching. By adjusting the glass position, the pre-treated glass etching zone achieves a predetermined thickness.

[0041] The process involves adjusting the glass position by rotating it, thus exchanging the front and rear etching sections to achieve a predetermined thickness (0.03 mm) for both sections. The etching solution consists of hydrofluoric acid, sulfuric acid, and oxalic acid in a mass ratio of 5:4:2.

[0042] S4. After etching, the glass is removed and immersed in an alkaline solution for cleaning to remove residual acid. The glass is then removed from the alkaline solution and ultrasonically cleaned in pure water, followed by horizontal cleaning. The adhesive is then removed to remove the acid-resistant UV-resistant coating from the glass surface, and fine polishing is performed to further eliminate micro-cracks, thus obtaining flexible glass of varying thickness. Testing shows that the unequal thickness areas of the obtained flexible glass have no step marks or streaks, indicating good forming quality.

[0043] Example 3: This embodiment discloses a method for preparing flexible glass with unequal thickness, including the following steps: S1, Coating treatment Before lamination, the A-side and the air-side are distinguished. The glass substrate is ultrasonically cleaned and then transferred to a laminating machine for coating. During lamination, the anti-acid UV anti-tack film is first applied to the entire air-side of the glass substrate, ensuring complete adhesion between the film and the glass surface. The glass substrate with the air-side film applied is then flipped over so that the air-side is facing down and placed on the laminating machine's worktable. The anti-acid UV anti-tack film is then applied to the A-side. After lamination, the glass surface must be free of defects such as bubbles, wrinkles, and impurities.

[0044] S2, A-side preprocessing The coated glass is placed in a CNC machining machine with side A facing up. The spindle speed is 5000 rpm / min and the feed rate is 700 rpm / min to process the area reserved by the etching solution.

[0045] S3, Etching Process The glass, after the S2 process, is placed in a waterfall etching apparatus for etching. By adjusting the glass position, the pre-treated glass etching zone achieves a predetermined thickness.

[0046] The process involves adjusting the glass position by rotating it, thus exchanging the front and rear etching sections to achieve a predetermined thickness (0.03 mm) for both sections. The etching solution consists of hydrofluoric acid, sulfuric acid, and oxalic acid in a mass ratio of 5:3:2.

[0047] S4. After etching, the glass is removed and immersed in an alkaline solution for cleaning to remove residual acid. The glass is then removed from the alkaline solution and ultrasonically cleaned in pure water, followed by horizontal cleaning. The adhesive is then removed to remove the acid-resistant UV-resistant coating from the glass surface, and fine polishing is performed to further eliminate micro-cracks, thus obtaining flexible glass of varying thickness. Testing shows that the unequal thickness areas of the obtained flexible glass have no step marks or streaks, indicating good forming quality.

[0048] Performance testing: The bending cycles and pen drop performance of the unequal thickness glass obtained in Examples 1-3 above were tested. The test methods and results are shown below: Bending times: The non-bending parts of the glass of unequal thickness are fixed to the surface of the bending fatigue testing machine with tape. The glass is then bent using the bending fatigue testing machine. The bending angle is switched between the two plates being pressed together and 180°. The bending frequency is 40 times / min. The number of times the glass breaks is recorded.

[0049] Pen drop height: During the test, a marble test surface was used, and 50um OCA and 50um PET were attached to the upper and lower surfaces of glass of unequal thickness, respectively. A 12g M&G pen with a 0.5mm lead diameter was dropped freely from different heights. The height at which the glass broke is the pen drop height. The test results are shown in Table 1 below: Table 1. Test results of the number of bends and the height of the pen drop.

[0050] As shown in Table 1, the unequal thickness flexible glass prepared by the present invention has excellent bending resistance and outstanding impact resistance.

[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing flexible glass of unequal thickness, characterized in that, Includes the following steps: An acid-resistant film is coated on the entire surface of the glass substrate with two air pockets to complete the coating process; A pre-flow channel for the etching solution is fabricated on side A of the coated glass substrate. A waterfall etching apparatus is used to etch the pre-flow channel of the glass substrate to a preset thickness. The etched glass substrate is immersed and cleaned to remove the acid-resistant film and then polished to obtain flexible glass of varying thickness.

2. The method for preparing flexible glass of unequal thickness according to claim 1, characterized in that, The acid-resistant film is a UV-resistant anti-sticking film.

3. The method for preparing flexible glass of unequal thickness according to claim 1, characterized in that, The step of processing the etching solution pre-flow channel on the A side of the coated glass substrate is performed using a CNC machining machine.

4. The method for preparing flexible glass of unequal thickness according to claim 3, characterized in that, The spindle speed of the CNC machining machine is 4000 rpm / min - 8000 rpm / min, and the feed rate is 500 rpm / min - 800 rpm / min.

5. The method for preparing flexible glass of unequal thickness according to claim 1, characterized in that, The step of using a waterfall etching apparatus to etch the pre-flow channel of the glass substrate to a preset thickness specifically includes: placing the glass substrate in the waterfall etching apparatus for glass etching; and adjusting the glass position to exchange the pre-etching section and the post-etching section until both the pre-etching section and the post-etching section of the glass reach the preset thickness.

6. A method for preparing flexible glass of unequal thickness according to claim 1 or 5, characterized in that, The preset thickness does not exceed 0.03 mm.

7. The method for preparing flexible glass of unequal thickness according to claim 1, characterized in that, The etching solution is an acid etching solution.

8. The method for preparing flexible glass of unequal thickness according to claim 7, characterized in that, The etching solution comprises hydrofluoric acid, sulfuric acid, and oxalic acid; the mass ratio of hydrofluoric acid, sulfuric acid, and oxalic acid is 5:(2~4):

2.

9. The method for preparing flexible glass of unequal thickness according to claim 1, characterized in that, The soaking and cleaning process specifically includes: immersing and cleaning the etched glass substrate in an alkaline solution; then removing the glass from the alkaline solution, immersing it in pure water for ultrasonic cleaning, and finally cleaning it horizontally.

10. A flexible glass of unequal thickness, characterized in that, The glass is prepared according to any one of claims 1 to 9.

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