Flexible ultrathin glass and preparation method thereof

Abstract

The invention discloses flexible ultra-thin glass and a preparation method thereof. The flexible ultra-thin glass comprises one or more layers of UTGs with the same or different thickness sizes; and an OCA (OCA for short) layer that is provided between adjacent UTGs and that constitutes a layer structure of UTG (1) + OCA (1) + UTG (2) + OCA (2) +... + OCA (n-1) + UTG (n). According to the invention, two or more than two layers of UTG are creatively laminated through OCA, so that the performance superior to that of a single-layer UTG is obtained, the thickness size of the UTG is similar to that of the single-layer UTG, and the preparation process is simple.

Description

Technical Field

[0001] The present invention relates to the field of ultra-thin glass (UTG) processing, which is applied to flexible and foldable active-matrix organic light-emitting diode (AMOLED) display screens or polymer dispersed liquid crystal (PDLC) dimming films of mobile terminals (such as mobile phones, tablet computers and notebooks, etc.), and in particular to a flexible ultra-thin glass and a preparation method thereof. Background Technology

[0002] Currently, most of the UTG used in mobile terminals (such as mobile phones, tablets and notebooks) on the market are single-layer structures. Its thickness is generally 30, 50, 70, 100, and 125 microns, and the average bending radius is generally around 1.0, 1.5, 2.0, 2.5, and 4.0 mm. The market hopes that the bending radius of each single UTG product falls within 1.0, 1.5, 2.0, 2.5, and 4.0 mm and the number of bends is at least 200,000 times. Among them, a small number of single UTG products with a thickness of 30 and 50 microns have a bending radius that cannot meet the requirements of customers, but this is often due to the fact that the UTG body is too thin or lacks rigidity, which affects the user's touch or use. Although the touch of UTG with a thickness of 70, 100, and 125 microns can meet the requirements of customers, the bending radius of curvature is too large and it is easy to stretch the flexible display interface of the mobile device terminal. In addition, due to the Young's modulus of UTG (73.3kN / mm 2 ) and torsional G modulus (30.1kN / mm 2 ) is too large, so it can neither meet the design requirements of mobile terminal manufacturers nor meet the needs of users.

[0003] In order to solve the above problems, as disclosed in US20230226802A1, a display protector is provided, comprising: a first transparent base layer having a first surface and a second surface facing each other; a second transparent substrate layer having a third surface and a fourth surface opposite to each other and arranged so that the third surface faces the second surface; an intermediate stress relief adhesive layer disposed between the second surface and the third surface; a first external stress relief adhesive layer on the first surface; a second external stress relief adhesive layer on the fourth surface; and an ultra-thin glass (UTG) layer located on the first external stress relief adhesive layer. This solution is still based on the improvement of a single-layer UTG, and its process is complex and the production cost is high. SUMMARY OF THE INVENTION

[0004] Aiming at the above problems of the prior art, the present invention provides a flexible ultra-thin glass having a thickness similar to that of a single-layer UTG but with better performance and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A flexible ultra-thin glass, comprising:

[0007] Two or more layers of UTG with the same or different thickness dimensions;

[0008] An OCA layer, disposed between adjacent UTGs, forming a layer structure of UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) of the layer structure.

[0009] The present invention creatively stacks two or more layers of UTG through OCA to obtain performance superior to that of a single-layer UTG, and its thickness dimension is similar to that of a single-layer UTG, and the preparation process is simple.

[0010] Further, the thickness of the UTG includes but is not limited to one, two or a combination of 30μm, 50μm, 70μm, 100μm, 125μm.

[0011] Further, the flexible ultra-thin glass is composed of 30μm UTG + OCA + 30μm UTG, 30μm UTG + OCA + 50μm UTG, 30μm UTG + OCA + 70μm UTG, 30μm UTG + OCA + 100μm UTG, 50μm UTG + OCA + 70μm UTG, or 30μm UTG + OCA + 70μm UTG + OCA + 30μm UTG.

[0012] If the cost requirement is ignored, even 30μm UTG + OCA + 70μm UTG OCA + 30μm UTG (three-layer UTG) can be used to replace 125μm, or a multi-layer (i.e., N-layer, and the number of layers N is naturally limited by the harsh requirements of the usage scenario, the low total visible light transmittance of the UTG and OCA materials in the body, etc.) structure composite UTG for a rollable mobile device, such as a flexible protective cover of a small-sized polymer liquid crystal dimming film (PDLC) for a mobile handheld device;

[0013] The present invention can stack and compound two or more layers of UTG of the same thickness or different thicknesses in a single-layer UTG (the thickness is generally 30, 50, 70, 100, 125μm, a total of 5 types, but not limited to these 5 thicknesses) by a lamination method.

[0014] Utilize a foldable or bendable (Folding / Bending) OCA with a low Young's modulus (generally CEF35 or 36 series foldable or bendable OCA produced by 3M Company with thicknesses of 15, 25, 50, 75, 100μm, but not limited to these 5 thicknesses of OCA and only OCA produced by 3M Company).

[0015] Furthermore, the flexible ultra-thin glass includes two or more unit components and an OCA layer between the unit components. The unit component includes one or more layers of UTG with the same or different thickness dimensions and an OCA layer between the UTGs.

[0016] The present invention also provides a method for preparing flexible ultra-thin glass, comprising the following steps:

[0017] S1. Attach the OCA film to the bonding surface of the UTG.

[0018] S2. Bond the bonding surfaces of two or more UTGs to form a laminated structure.

[0019] Furthermore, in S1, after attaching the OCA film to the bonding surface of the UTG, place it in the furnace cavity of a defoaming device with heating and air pressure functions. First, heat at 40 - 50°C and maintain for 10 - 20 minutes; then apply an air pressure of 3 - 4 kgf / cm 2 and maintain for 20 - 30 minutes; then take it out.

[0020] In S2, attach one side of the second UTG to the OCA, so that the two UTGs are bonded together through the OCA, and then place it in the same furnace cavity of the defoaming device with heating and air pressure functions as above. Heat at 50 - 60°C and maintain for about 15 - 25 minutes; then apply an air pressure of 3 - 4 kgf / cm 2 and maintain for 30 - 40 minutes, then take it out. At this time, the double-layer UTG lamination superposition bonding product of UTG + OCA + UTG is completed.

[0021] Furthermore, repeat the steps of S1 and S2 to complete the triple-layer UTG lamination superposition bonding product of UTG + OCA + UTG + OCA + UTG;

[0022] Or, by analogy, complete the N-layer UTG lamination superposition bonding product of UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n)

[0023] ​Further, in S1, the OCA is attached to the UGT bonding surface by a bonding device, and the roller pressure of the bonding device is controlled at 0.1 - 0.2 MPa, and the roller speed is controlled at 0.5 - 1.0 m / min.

[0024] Further, in S2, one side of the second layer and subsequent layers of UTG is attached to the OCA on the upper layer UTG bonding surface by the same bonding device, and the roller pressure of the bonding device is controlled at 0.1 - 0.2 MPa, and the roller speed is controlled at 0.5 - 1.0 m / min.

[0025] Further, first prepare two or more layers of composite ultra-thin flexible glass as unit components according to the methods of S1 and S2, and then stack two or more unit components into multi-layer flexible ultra-thin glass through OCA and the above process methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figures 1 - 3 It is a schematic structural diagram of the flexible ultra-thin glass. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] As Figures 1 to 3 shown, a flexible ultra-thin glass includes:

[0029] One or more layers of UTG1 with the same or different thickness dimensions;

[0030] The OCA layer 2 is arranged between adjacent UTG1s to form a layer structure of UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) The layer structure.

[0031] The present invention creatively uses two or more layers of UTG1 to be laminated through OCA2 to obtain performance superior to that of a single-layer UTG, and its thickness dimension is similar to that of a single-layer UTG, and the preparation process is simple.

[0032] In practical applications, the thickness of the UTG1 includes, but is not limited to, one, two, or a combination of more than two of 30 μm, 50 μm, 70 μm, 100 μm, and 125 μm.

[0033] In practical applications, two layers or three layers of UTG are usually considered for lamination. For example, the flexible ultra-thin glass is composed of 30μm UTG + OCA + 30μm UTG, 30μm UTG + OCA + 50μm UTG, 30μm UTG + OCA + 70μm UTG, 30μm UTG + OCA + 100μm UTG, 50μm UTG + OCA + 70μm UTG, or 30μm UTG + OCA + 70μm UTG + OCA + 30μm UTG.

[0034] For example, 30μm UTG + OCA + 30μm UTG (double-layer UTG) is used to replace the traditional single-layer 50μm flexible ultra-thin glass; 30μm UTG + OCA + 50μm UTG (double-layer UTG) is used to replace the single-layer 70μm flexible ultra-thin glass for terminal mobile devices such as flexible protection covers for smartphones and tablets; 30μm UTG + OCA + 70μm UTG (double-layer UTG) is used to replace the single-layer 100μm flexible ultra-thin glass, 30μm UTG + OCA + 100μm UTG (double-layer UTG) is used to replace the single-layer 125μm flexible ultra-thin glass; or 50μm UTG + OCA + 70μm UTG (double-layer UTG) is used to replace the single-layer 125μm flexible ultra-thin glass for terminal mobile devices such as flexible protection covers for tablets and laptops, etc.

[0035] If cost requirements are not considered, 30μm UTG + OCA + 70μm UTG + OCA + 30μm UTG (triple-layer UTG) can even be used to replace the single-layer 125μm flexible ultra-thin glass, or multi-layer (i.e., N-layer, and the number of layers N is naturally limited by harsh requirements of the usage scenario, low total visible light transmittance of the UTG and OCA materials in their bulk state, etc.) structured composite UTG is used for large-size rollable mobile devices such as flexible protection covers for polymer liquid crystal dimming films.

[0036] The present invention can stack and compound double-layer or multi-layer UTG by lamination using the same or different thicknesses in a single-layer UTG (the thickness is generally 30, 50, 70, 100, 125μm, a total of 5 types, but not limited to these 5 thicknesses).

[0037] Use a foldable or bendable (Folding / Bending) OCA with a low Young's modulus (generally 15, 25, 50, 75, 100μm thick CEF35 or 36 series foldable or bendable OCA produced by 3M Company, but not limited to these 5 thicknesses of OCA and only OCA produced by 3M Company).

[0038] The present invention utilizes a foldable or bendable (Folding / Bending) OCA with a low Young's modulus (the thickness is generally 15, 25, 50, 75, 100 microns, but not limited to these 5 thicknesses) and places it in the middle of a thinner UTG to form a thicker composite flexible ultra-thin glass, overcoming the weakness of the relatively strong rigidity of the single-layer UTG with a thickness of 70, 100, 125 microns, and at the same time solving the disadvantage of the relatively weak rigidity of the single-layer UTG with a thickness of 30, 50 microns.

[0039] The present invention makes full use of the advantage of the small bending radius R of the thin UTG to make up for the disadvantage of the large bending radius R of the single-layer thick UTG; therefore, the thin single-layer UTG is used to form a double-layer or multi-layer structure UTG instead of only the single-layer thick UTG, overcoming the disadvantage of the large bending radius R of the single-layer thick UTG, and also solving the disadvantage of the relatively strong rigidity of the single-layer thick UTG.

[0040] Figure 1 The example of... shows a schematic diagram of the multi-layer UTG of the present invention bonded into a multi-layer structure through an OCA film layer. Figure 2 The schematic diagram shows the folding of a composite structure in which a 4-layer UTG flexible ultra-thin glass is bonded through 3 layers of OCA film layers. Figure 3 It is on the basis of... Figure 1 The schematic diagram shows the application to a display screen. The lowermost layer of the composite multi-layer flexible ultra-thin glass (shown at the top in the figure) is combined with the display layer 3 through an OCA film layer to form a schematic diagram of the display screen.

[0041] In some embodiments, the flexible ultra-thin glass includes two or more unit components and an OCA layer between the unit components, and the unit component includes one or more layers of UTG with the same or different thickness dimensions and an OCA layer between the UTGs.

[0042] The present invention has a method for preparing a flexible ultra-thin glass, which includes the following steps:

[0043] S1. Bond the OCA film to the bonding surface of the UTG.

[0044] S2. Bond the bonding surfaces of two or more UTGs to form a laminated structure.

[0045] In some embodiments, further, in S1, after bonding the OCA film to the bonding surface of the UTG, place it in the furnace cavity of a defoaming device with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions, first heat at 40 - 50 °C and keep it for 10 - 20 minutes; then apply pressure of 3 - 4 kgf / cm 2 Keep it for 20 - 30 minutes; then take it out.

[0046] In S2, attach one side of the second piece of UTG to the OCA, so that the two pieces of UTG are attached together through the OCA, and then place them in the furnace cavity of a defoaming device with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions, heat at 50 - 60 °C and keep for about 15 - 25 minutes; then apply pressure of 3 - 4 kgf / cm 2 Keep for 30 - 40 minutes. At this time, the double-layer UTG laminated superposition product of UTG + OCA + UTG is completed.

[0047] When preparing a composite product with three or more layers, repeat steps S1 and S2 to complete the three-layer UTG laminated superposition product of UTG + OCA + UTG + OCA + UTG;

[0048] Or, by analogy, complete the (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) N-layer UTG laminated superposition product.

[0049] In a preferred solution, in S1, use a laminating device to attach the OCA to the UGT lamination surface. The roller pressure of the laminating device is controlled at 0.1 - 0.2 MPa, and the roller speed is controlled at 0.5 - 1.0 m / min. Bubbles can be eliminated and the lamination quality can be improved.

[0050] Furthermore, in S2, attach one side of the second layer and subsequent layers of UTG to the OCA on the upper layer of UTG lamination surface with the same laminating device. The roller pressure of the laminating device is controlled at 0.1 - 0.2 MPa, and the roller speed is controlled at 0.5 - 1.0 m / min. Each time when laminating the OCA film and when laminating the upper layer of UTG to the OCA, it is recommended to use the laminating device and control the roller pressure and its speed, and then place it in a defoaming device furnace with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions for the above treatment to achieve the best lamination effect and quality.

[0051] In some embodiments, the present invention also has a method for preparing flexible ultra-thin glass, including the following steps:

[0052] S1. Attach the OCA film to the lamination surface of the UTG;

[0053] S2. Attach the lamination surfaces of two or more pieces of UTG through the OCA to form a laminated structure.

[0054] In some embodiments, further, in S1, after the OCA film is laminated to the laminating surface of the UTG, it is placed in a defoaming equipment furnace chamber with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions, first heated at 40-50° C. for 10-20 minutes; then pressurized at 3-4 kgf / cm 2 Keep it for 20-30 minutes; then remove.

[0055] In S2, one side of the second UTG sheet is bonded to the OCA, so that the two UTG sheets are bonded together through the OCA, and then placed in a defoaming equipment furnace cavity with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions, heated at 50-60°C and maintained for about 15-25 minutes; then pressurized to 3-4 kgf / cm 2 Keep it for 30 to 40 minutes, and then the double-layer UTG lamination method of UTG+OCA+UTG is completed.

[0056] When a composite product with an even number (4, 6, 8, etc.) of more than 4 layers needs to be prepared, repeat steps S1 and S2 to complete the (UTG+OCA+UTG)+OCA+(UTG+OCA+UTG) two-layer UTG lamination method to stack and bond into a 4-layer UTG product;

[0057] When it is necessary to prepare a composite product with an odd number (5, 7, 9, etc.) of more than 5 layers, repeat steps S1 and S2 to complete a three-layer UTG (UTG+OCA+UTG+OCA+UTG)+OCA+(UTG+OCA+UTG) and double-layer lamination to form a 5-layer UTG product;

[0058] And so on to complete UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) N-layer UTG lamination method superposition and bonding product.

[0059] That is, first prepare two or more layers of composite ultra-thin flexible glass as unit components, and then stack two or more unit components through OCA and the above-mentioned process method. The unit components can be prepared in advance, and then different numbers of unit components can be selected according to the required number of stacked layers to combine, which can shorten the delivery cycle.

[0060] In the preferred solution, in S1, the OCA is attached to the UGT bonding surface by a bonding device, and the roller pressure of the bonding device is controlled at 0.1-0.2MPa, and the roller speed is controlled at 0.5-1.0m / min. This can eliminate bubbles and improve the bonding quality.​​​​​​​​​​

[0061] Further, in S2, one side of the UTG of the second layer and subsequent layers is attached to the OCA on the bonding surface of the upper layer UTG by the same bonding device. The roller pressure of the bonding device is controlled at 0.1 - 0.2 MPa, and the roller speed is controlled at 0.5 - 1.0 m / min. Each time when bonding the OCA film and when laminating the upper layer UTG to the OCA, it is recommended to use the bonding device and control the roller pressure and its speed, and then place it in a defoaming device furnace with heating (including but not limited to electric heating, liquid medium heating, steam or gas heating, etc.) and air pressure functions for the above-mentioned treatment to achieve the best bonding effect and quality.

[0062] As described above, only the preferred specific embodiments of the present invention are given, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A flexible ultra-thin glass, characterized in that: include: Two or more layers of UTG with the same or different thickness and size; The OCA layer is set between adjacent UTGs to form the UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) layer structure.

2. The flexible ultra-thin glass according to claim 1, characterized in that: The thickness of the UTG includes but is not limited to one or a combination of two or more of 30 μm, 50 μm, 70 μm, 100 μm, and 125 μm.

3. The flexible ultra-thin glass according to claim 2, characterized in that: The flexible ultra-thin glass consists of 30μm UTG+OCA+30μm UTG, 30μm UTG+OCA+50μm UTG, 30μm UTG+OCA+70μm UTG, 30μm UTG+OCA+100μmUTG, 50μm UTG+OCA+70μm UTG, or 30μm UTG+OCA+70μm UTG+OCA+30μm UTG.

4. The flexible ultra-thin glass according to any one of claims 1 to 3, characterized in that: The flexible ultra-thin glass includes two or more unit components and OCA layers between the unit components. The unit components include one or more UTGs with the same or different thicknesses and OCA layers between the UTGs.

5. A method for preparing flexible ultra-thin glass, characterized in that: The following steps are involved: S1. Laminating the OCA film on the laminating surface of UTG; S2. Two or more UTG sheets are bonded together through OCA to form a laminated structure.

6. The method for preparing flexible ultra-thin glass according to claim 5, characterized in that: In S1, after the OCA film is laminated to the laminating surface of the UTG, it is placed in a defoaming equipment chamber with heating and air pressure functions, first heated at 40-50°C for 10-20 minutes; then air pressure is applied at 3-4 kgf / cm 2 Leave on for 20-30 minutes; then remove. In S2, one side of the second UTG sheet is bonded to the OCA, so that the two UTG sheets are bonded together through the OCA, and then placed in the same defoaming equipment chamber with heating and air pressure function as mentioned above, heated at 50-60°C and maintained for about 15-25 minutes; then the air pressure is 3-4 kgf / cm 2 Keep it for 30 to 40 minutes, then take it out to complete the double-layer UTG lamination method of UTG+OCA+UTG superimposed bonding product.

7. The method for preparing flexible ultra-thin glass according to claim 6, characterized in that: Repeat steps S1 and S2 to complete the three-layer UTG lamination method stacking and bonding product of UTG+OCA+UTG+OCA+UTG; Or, and so on to complete UTG (1) +OCA (1) +UTG (2) +OCA (2) +…+OCA (n-1) +UTG (n) N-layer UTG lamination method superimposed bonding product.

8. The method for preparing flexible ultra-thin glass according to any one of claims 5 to 7, characterized in that: In S1, the OCA is attached to the UGT bonding surface by a bonding device, and the roller pressure of the bonding device is controlled at 0.1-0.2 MPa, and the roller speed is controlled at 0.5-1.0 m / min.

9. The method for preparing flexible ultra-thin glass according to claim 8, characterized in that: In S2, one side of the UTG of the second and subsequent layers is attached to the OCA on the bonding surface of the previous UTG layer using the same bonding equipment. The roller pressure of the bonding equipment is controlled at 0.1-0.2 MPa, and the roller speed is controlled at 0.5-1.0 m / min.

10. The method for preparing flexible ultra-thin glass according to claim 9, characterized in that: First, two or more layers of composite ultra-thin flexible glass are prepared as unit components according to the methods of S1 and S2, and then two or more unit components are stacked into multiple layers of flexible ultra-thin glass through OCA and the above-mentioned process method.

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