Ultrathin glass thermoplastic polymer composite cover plate and preparation method thereof

Abstract

The invention discloses an ultra-thin glass thermoplastic polymer composite cover plate and a preparation method thereof, the ultra-thin glass thermoplastic polymer composite cover plate comprises an ultra-thin glass layer, and an outer thermoplastic polymer layer, a bonding layer I, a printing layer and a PET hardened film layer which are sequentially arranged on one side of the ultra-thin glass layer, the inner thermoplastic polymer layer, the bonding layer II, the PET layer and the bonding layer III are arranged on the other side of the ultrathin glass layer. According to the ultra-thin glass thermoplastic polymer composite cover plate provided by the invention, a pen drop test can be improved to 90 mm or above, the loss of bending capacity is reduced to the maximum extent, the bending radius is 2 mm or below, and the ultra-thin glass thermoplastic polymer composite cover plate has the advantages of glass and thermoplastic polymers at the same time, and is suitable for popularization and application. And moreover, the requirement on the foldable CPI / PET required by lamination can be reduced, and the production cost of the folding screen is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-thin glass, and particularly relates to an ultra-thin glass thermoplastic polymer composite cover plate and a preparation method thereof. Background Art

[0002] Currently, ultra-thin glass (UTG) is widely used as a flexible cover plate material in the field of foldable display devices. When the thickness of UTG is reduced to less than 50 microns, it exhibits excellent bending performance, and the bending radius can be reduced to less than 1 mm, meeting the stringent requirements of flexible screens for extremely small curvature radii. However, the mechanical properties of UTG are negatively correlated with its thickness: as the thickness decreases, its impact resistance significantly decreases, resulting in a critical failure height of usually less than 10 mm in the pen-down test (simulating drops or collisions in daily use), and there is a high risk of crack propagation. Such reliability defects severely restrict the large-scale application of UTG in scenarios such as mobile terminals.

[0003] To improve the impact resistance of UTG, existing technologies mostly use a composite lamination structure for enhancement. For example, UTG is bonded to a polyimide (CPI) or polyethylene terephthalate (PET) film with a hardened surface through an optically clear adhesive (OCA) to form a "UTG-CPI / PET" laminated structure. Among them, the hardened CPI / PET film on the outer surface undertakes the main impact resistance function, while UTG provides excellent bending performance. Although the "UTG-CPI / PET" laminated structure can improve its impact resistance to a certain extent, due to the large modulus difference between the CPI / PET film and UTG, the impact energy cannot be effectively dispersed, the improvement in impact resistance is insufficient, and the enhancement effect is limited. Usually, the pen-down test ability can only be improved to about 20 mm, and the overall reliability of the screen is still not high. In addition, the traditional bonding method also brings additional production costs and process complexities.

[0004] Therefore, there is an urgent need to develop a technology that can simultaneously improve the intrinsic impact resistance of UTG, maintain excellent bending performance, and reduce production costs. Summary of the Invention

[0005] To solve the above technical problems, the object of the present invention is to provide an ultra-thin glass thermoplastic polymer composite cover plate and a preparation method thereof.

[0006] The above object of the present invention is achieved by the following technical solutions:

[0007] An ultra-thin glass thermoplastic polymer composite cover plate, the ultra-thin glass thermoplastic polymer composite cover plate includes an ultra-thin glass layer, an outer thermoplastic polymer layer, an adhesive layer I, a printing layer, a PET hardening film layer sequentially arranged on one side of the ultra-thin glass layer, and an inner thermoplastic polymer layer, an adhesive layer II, a PET layer, and an adhesive layer III arranged on the other side of the ultra-thin glass layer;

[0008] The outer thermoplastic polymer layer is prepared by coating a thermoplastic polymer solution on a substrate and then performing a pre-curing treatment; the inner thermoplastic polymer layer is prepared by coating a thermoplastic polymer solution on a substrate and then performing a pre-curing treatment.

[0009] In the present invention, thermoplastic polymer layers are provided on both side surfaces of the ultra-thin glass (UTG) layer, and the UTG is wrapped in the thermoplastic polymer layers. This thermoplastic polymer layer can greatly enhance the impact resistance of the UTG, and the drop test can be improved to more than 90 mm, and at the same time, the loss of bending ability is minimized, and the bending radius is less than 2 mm. This ultra-thin glass thermoplastic polymer composite cover plate has the advantages of both glass and thermoplastic polymer, and can reduce the requirements for the foldable CPI / PET required for lamination, and reduce the production cost of the folding screen.

[0010] Further, the thickness of the ultra-thin glass layer is 10 - 70 μm, preferably 10 - 50 μm, and more preferably 25 - 35 μm.

[0011] Further, in order to improve the bending resistance performance, the ultra-thin glass layer selects strengthened ultra-thin glass, and the ultra-thin glass is strengthened by a chemical strengthening (ion exchange) method.

[0012] Further, the thickness of the outer thermoplastic polymer layer is 10 - 30 μm, the light transmittance is greater than 90%, and the haze is less than 1%.

[0013] Further, the material of the outer thermoplastic polymer layer is epoxy resin.

[0014] Further, the thickness of the adhesive layer I is 10 - 50 μm.

[0015] Further, the thickness of the printing layer is less than 2 μm, and the optical density (OD) value is greater than 2.5.

[0016] Further, the printing layer is a black ink border.

[0017] Further, the PET hardening film layer refers to a PET layer containing a hardening coating (HC).

[0018] Further, the thickness of the PET hardening film (HCPET) layer is 60 - 70 μm.

[0019] Further, the water contact angle on the surface of the PET hardening film layer is greater than 105°.

[0020] Further, the thickness of the inner thermoplastic polymer layer is 10 - 30 μm.

[0021] Further, the light transmittance of the inner thermoplastic polymer layer is greater than 90%, and the haze is less than 1%.

[0022] Further, the material of the inner thermoplastic polymer layer is epoxy resin.

[0023] Further, the thickness of the adhesive layer II is 10 - 50 μm.

[0024] Further, the thickness of the PET (polyethylene terephthalate) layer is 10 - 50 μm.

[0025] Further, the PET layer is an optically transparent PET layer.

[0026] Further, the thickness of the adhesive layer III is 10 - 50 μm.

[0027] Further, the adhesive layer I, the adhesive layer II, and the adhesive layer III all adopt OCA optical adhesive.

[0028] A preparation method of the above-mentioned ultra-thin glass thermoplastic polymer composite cover plate includes the following steps:

[0029] (1) Adopt vacuum hot pressing to thermally press and bond the outer thermoplastic polymer layer and the inner thermoplastic polymer layer to both sides of the ultra-thin glass layer respectively, and bond the adhesive layer II on one side of the inner thermoplastic polymer layer to obtain assembly A;

[0030] (2) Bond the adhesive layer I, the printing layer, and the PET hardening film layer to obtain assembly B;

[0031] (3) Bond the PET layer, the adhesive layer III, and the release film layer to obtain assembly C;

[0032] (4) Adopt a fully automatic bonding device to bond assembly A, assembly B, and assembly C to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0033] Further, in step (1), the preparation method of the outer thermoplastic polymer layer includes the following steps: coat the thermoplastic polymer solution on the substrate to form a wet film layer with a predetermined thickness; perform pre-curing treatment on the wet film layer to cure the thermoplastic polymer solution to form the outer thermoplastic polymer layer with a corresponding thickness.

[0034] Further, the substrate can be a release film.

[0035] Further, the temperature of the pre-curing treatment is 100-200°C.

[0036] Further, in step (1), the method for preparing the inner thermoplastic polymer layer includes the following steps: coating a thermoplastic polymer solution on a substrate to form a wet film layer with a predetermined thickness; performing a pre-curing treatment on the wet film layer to cure the thermoplastic polymer solution to form an inner thermoplastic polymer layer with a corresponding thickness.

[0037] Further, the substrate can be a release film.

[0038] Further, the temperature of the pre-curing treatment is 100-200°C.

[0039] Further, in step (1), the outer dimensions of both the outer thermoplastic polymer layer and the inner thermoplastic polymer layer are 5-10 mm larger than the outer dimensions of the ultra-thin glass layer.

[0040] Specifically, on the basis of the outer dimensions of the ultra-thin glass layer, each side of the outer thermoplastic polymer layer extends outwards by 5-10 mm.

[0041] Further, the thermocompression bonding is carried out by vacuum thermocompression bonding, and the parameters are: the temperature is 150-200°C, the vacuum degree < -101.2 kPa, and the pressure is 1-10 kg / cm 2 , and the pressure holding time is 5-15 min.

[0042] Further, in step (1), a laser cutting technology is used to cut component A, so that the outer dimensions of the cut component A are 0.1-0.5 mm larger than the outer dimensions of the ultra-thin glass layer.

[0043] Further, in step (2), the obtained component B is formed by die cutting, and the outer dimensions of component B are 2-4 mm larger than the outer dimensions of the ultra-thin glass layer.

[0044] Further, in step (3), the obtained component C is formed by die cutting, and the outer dimensions of component C are 0.1-0.5 mm larger than the outer dimensions of the ultra-thin glass layer.

[0045] Further, in step (3), the thickness of the release film layer is 50-100 μm.

[0046] Further, in step (3), the materials of the release film layer include polyethylene terephthalate (PET), polyethylene (PE), oriented polypropylene (OPP), etc.

[0047] The beneficial effects of the present invention are:

[0048] The present invention provides a thermoplastic polymer layer on both side surfaces of an ultra-thin glass (UTG) layer, wrapping the UTG within the thermoplastic polymer layer. This thermoplastic polymer layer can significantly enhance the impact resistance of the UTG, improving the writing test to over 90 mm and minimizing the loss of bending ability with a bending radius of less than 2 mm. This ultra-thin glass thermoplastic polymer composite cover plate combines the advantages of glass and thermoplastic polymers, and can reduce the requirements for foldable CPI / PET needed for lamination, thereby reducing the production cost of foldable screens. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 FIG. is a schematic structural diagram of the ultra-thin glass thermoplastic polymer composite cover plate provided by the present invention.

[0050] Description of reference numerals: 1, PET hardening film layer; 2, printing layer; 3, adhesive layer I; 4, outer thermoplastic polymer layer; 5, ultra-thin glass layer; 6, inner thermoplastic polymer layer; 7, adhesive layer II; 8, PET layer; 9, adhesive layer III; 10, release film layer; 11, component B; 12, component A; 13, component C. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this invention belongs. The terms used in the description of the present invention herein are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0052] The present invention provides an ultra-thin glass thermoplastic polymer composite cover plate, the schematic structural diagram of which is as Figure 1 shown. The ultra-thin glass thermoplastic polymer composite cover plate includes an ultra-thin glass layer 5, an outer thermoplastic polymer layer 4, an adhesive layer I 3, a printing layer 2, and a PET hardening film layer 1 sequentially arranged on one side of the ultra-thin glass layer 5, and an inner thermoplastic polymer layer 6, an adhesive layer II 7, a PET layer 8, and an adhesive layer III 9 arranged on the other side of the ultra-thin glass layer;

[0053] The outer thermoplastic polymer layer 4 is prepared by coating a thermoplastic polymer solution on a substrate and subjecting it to pre-curing treatment; the inner thermoplastic polymer layer 6 is prepared by coating a thermoplastic polymer solution on a substrate and subjecting it to pre-curing treatment.

[0054] The present invention also provides a method for preparing the above-mentioned ultra-thin glass thermoplastic polymer composite cover plate, which includes the following steps:

[0055] (1) The outer thermoplastic polymer layer 4 and the inner thermoplastic polymer layer 6 are respectively hot-pressed and bonded to both sides of the ultra-thin glass layer 5 by vacuum hot pressing. A bonding layer II 7 is bonded to one side of the inner thermoplastic polymer layer 6 to obtain the component A12;

[0056] (2) The bonding layer I 3, the printing layer 2 and the PET hardening film layer 1 are bonded to obtain the component B11;

[0057] (3) The PET layer 8, the bonding layer III 9 and the release film layer 10 are bonded to obtain the component C13;

[0058] (4) The component A12, the component B11 and the component C13 are bonded by a fully automatic bonding device to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0059] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments cited are not intended to limit the present invention.

[0060] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified, and the materials, reagents, etc. used can be obtained from commercial channels unless otherwise specified.

[0061] Example 1

[0062] An ultra-thin glass thermoplastic polymer composite cover plate, from top to bottom, is a 60-μm HCPET layer (surface water contact angle greater than 110°), a 1-μm printing layer (black ink border, OD value of 3), a 30-μm bonding layer I (OCA optical adhesive), a 10-μm outer thermoplastic polymer layer, a 30-μm ultra-thin glass layer, a 10-μm inner thermoplastic polymer layer, a 30-μm bonding layer II (OCA optical adhesive), a 10-μm optical grade transparent PET layer, and a 30-μm bonding layer III (OCA optical adhesive);

[0063] The preparation method of the ultra-thin glass thermoplastic polymer composite cover plate of Example 1 includes the following steps:

[0064] (1) The outer thermoplastic polymer layer and the inner thermoplastic polymer layer are respectively hot-pressed and bonded to both sides of the ultra-thin glass layer (68 mm × 164 mm) by vacuum hot pressing. The parameters of the vacuum hot pressing are: temperature is 150 °C, vacuum degree < -101.2 kPa, and pressure is 5 kg / cm 2, the holding pressure time is 10 min. The outer and inner thermoplastic polymer layers both have outer dimensions 5 mm larger than those of the ultra-thin glass layer. An OCA optical adhesive is bonded to one side of the inner thermoplastic polymer layer to obtain Component A. Laser cutting technology is used to cut Component A, such that the outer dimensions of the cut Component A are 0.5 mm larger than those of the ultra-thin glass layer;

[0065] (2) Bond the OCA optical adhesive, the printing layer, and the HCPET layer to obtain Component B. Die cutting and forming are performed such that the outer dimensions of the obtained Component B are 3 mm larger than those of the ultra-thin glass layer;

[0066] (3) Bond the PET layer, the OCA optical adhesive, and a 50-μm release film layer to obtain Component C. Die cutting and forming are performed such that the outer dimensions of the obtained Component C are 0.5 mm larger than those of the ultra-thin glass layer;

[0067] (4) Use a fully automatic bonding device to bond Component A, Component B, and Component C to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0068] Among them, the preparation method of the outer thermoplastic polymer layer includes the following steps: Coating an epoxy resin solution on a release film to form a wet film layer; performing pre-curing treatment on the wet film layer at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer;

[0069] The preparation method of the inner thermoplastic polymer layer includes the following steps: Coating an epoxy resin solution on a release film to form a wet film layer; performing pre-curing treatment on the wet film layer at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer.

[0070] Example 2

[0071] An ultra-thin glass thermoplastic polymer composite cover plate, from top to bottom, is a 60-μm HCPET layer (surface water contact angle greater than 110°), a 1-μm printing layer (black ink border, OD value of 3), a 30-μm adhesive layer I (OCA optical adhesive), a 15-μm outer thermoplastic polymer layer, a 30-μm ultra-thin glass layer, a 15-μm inner thermoplastic polymer layer, a 30-μm adhesive layer II (OCA optical adhesive), a 10-μm optically transparent PET layer, and a 30-μm adhesive layer III (OCA optical adhesive);

[0072] The preparation method of the ultra-thin glass thermoplastic polymer composite cover plate of Example 2 includes the following steps:

[0073] (1) The outer thermoplastic polymer layer and the inner thermoplastic polymer layer are respectively hot-pressed and bonded to both sides of the ultra-thin glass layer (68 mm × 164 mm) by means of vacuum hot pressing. The parameters of the vacuum hot pressing and bonding are as follows: the temperature is 150 °C, the vacuum degree < -101.2 kPa, and the pressure is 5 kg / cm 2 , the pressure holding time is 10 min. The outer dimensions of both the outer thermoplastic polymer layer and the inner thermoplastic polymer layer are 5 mm larger than those of the ultra-thin glass layer. An OCA optical adhesive is bonded to one side of the inner thermoplastic polymer layer to obtain Component A. The laser cutting technology is used to cut Component A so that the outer dimensions of the cut Component A are 0.5 mm larger than those of the ultra-thin glass layer;

[0074] (2) The OCA optical adhesive, the printing layer, and the HCPET layer are bonded to obtain Component B. The outer dimensions of the obtained Component B are made 3 mm larger than those of the ultra-thin glass layer by die cutting;

[0075] (3) The PET layer, the OCA optical adhesive, and a 50-μm release film layer are bonded to obtain Component C. The outer dimensions of the obtained Component C are made 0.5 mm larger than those of the ultra-thin glass layer by die cutting;

[0076] (4) Component A, Component B, and Component C are bonded by a fully automatic bonding device to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0077] Among them, the preparation method of the outer thermoplastic polymer layer includes the following steps: coating an epoxy resin solution on a release film to form a wet film layer; performing pre-curing treatment on the wet film layer at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer;

[0078] The preparation method of the inner thermoplastic polymer layer includes the following steps: coating an epoxy resin solution on a release film to form a wet film layer; performing pre-curing treatment on the wet film layer at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer.

[0079] Example 3

[0080] An ultra-thin glass thermoplastic polymer composite cover plate, which from top to bottom is a 60-μm HCPET layer (the surface water contact angle is greater than 110°), a 1-μm printing layer (black ink border, OD value is 3), a 30-μm bonding layer I (OCA optical adhesive), a 10-μm outer thermoplastic polymer layer, a 50-μm ultra-thin glass layer, a 10-μm inner thermoplastic polymer layer, a 30-μm bonding layer II (OCA optical adhesive), a 10-μm optically transparent PET layer, and a 30-μm bonding layer III (OCA optical adhesive);

[0081] The preparation method of the ultra-thin glass thermoplastic polymer composite cover plate of Example 3 includes the following steps:

[0082] (1) The outer thermoplastic polymer layer and the inner thermoplastic polymer layer are respectively thermally pressed and bonded to both sides of the ultra-thin glass layer (68 mm × 164 mm) by means of vacuum hot pressing. The parameters of the vacuum hot pressing and bonding are: the temperature is 150 °C, the vacuum degree < -101.2 kPa, the pressure is 5 kg / cm 2 , the pressure holding time is 10 min. The outer dimensions of both the outer thermoplastic polymer layer and the inner thermoplastic polymer layer are 15 mm larger than the outer dimensions of the ultra-thin glass layer. An OCA optical adhesive is bonded to one side of the inner thermoplastic polymer layer to obtain Component A. The laser cutting technology is used to cut Component A so that the outer dimensions of the cut Component A are 0.5 mm larger than the outer dimensions of the ultra-thin glass layer;

[0083] (2) The OCA optical adhesive, the printing layer and the HCPET layer are bonded to obtain Component B. The outer dimensions of the obtained Component B are made 3 mm larger than the outer dimensions of the ultra-thin glass layer by die cutting;

[0084] (3) The PET layer, the OCA optical adhesive and the 50-μm release film layer are bonded to obtain Component C. The outer dimensions of the obtained Component C are made 0.5 mm larger than the outer dimensions of the ultra-thin glass layer by die cutting;

[0085] (4) Component A, Component B and Component C are bonded by a fully automatic bonding device to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0086] Among them, the preparation method of the outer thermoplastic polymer layer includes the following steps: The epoxy resin solution is coated on the release film to form a wet film layer; the wet film layer is pre-cured at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer;

[0087] The preparation method of the inner thermoplastic polymer layer includes the following steps: The epoxy resin solution is coated on the release film to form a wet film layer; the wet film layer is pre-cured at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer.

[0088] Example 4

[0089] An ultra-thin glass thermoplastic polymer composite cover plate, from top to bottom, is a 60-μm HCPET layer (surface water contact angle greater than 110°), a 1-μm printing layer (black ink border, OD value of 3), a 30-μm adhesive layer I (OCA optical adhesive), a 15-μm outer thermoplastic polymer layer, a 50-μm ultra-thin glass layer, a 15-μm inner thermoplastic polymer layer, a 30-μm adhesive layer II (OCA optical adhesive), a 10-μm optical-grade transparent PET layer, and a 30-μm adhesive layer III (OCA optical adhesive);

[0090] The preparation method of the ultra-thin glass thermoplastic polymer composite cover plate of Example 4 includes the following steps:

[0091] (1) The outer thermoplastic polymer layer and the inner thermoplastic polymer layer are respectively hot-pressed and bonded to both sides of the ultra-thin glass layer (68 mm × 164 mm) by vacuum hot pressing. The parameters of the vacuum hot pressing and bonding are: temperature is 150 °C, vacuum degree < -101.2 kPa, pressure is 5 kg / cm 2 , the holding pressure time is 10 min. The outer dimensions of both the outer thermoplastic polymer layer and the inner thermoplastic polymer layer are 5 mm larger than the outer dimensions of the ultra-thin glass layer. An OCA optical adhesive is bonded to one side of the inner thermoplastic polymer layer to obtain Component A. The laser cutting technology is used to cut Component A so that the outer dimensions of the cut Component A are 0.5 mm larger than the outer dimensions of the ultra-thin glass layer;

[0092] (2) The OCA optical adhesive, the printing layer, and the HCPET layer are bonded to obtain Component B. The outer dimensions of the obtained Component B are made 3 mm larger than the outer dimensions of the ultra-thin glass layer by die cutting;

[0093] (3) The PET layer, the OCA optical adhesive, and a 50-μm release film layer are bonded to obtain Component C. The outer dimensions of the obtained Component C are made 0.5 mm larger than the outer dimensions of the ultra-thin glass layer by die cutting;

[0094] (4) The full-automatic bonding equipment is used to bond Component A, Component B, and Component C to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

[0095] Among them, the preparation method of the outer thermoplastic polymer layer includes the following steps: The epoxy resin solution is coated on the release film to form a wet film layer; the wet film layer is pre-cured at 100 °C to cure the epoxy resin solution to form the outer thermoplastic polymer layer;

[0096] The preparation method of the inner thermoplastic polymer layer includes the following steps: coating an epoxy resin solution on a release film to form a wet film layer; subjecting the wet film layer to pre-curing treatment at 100 °C to cure the epoxy resin solution to form an outer thermoplastic polymer layer.

[0097] Test example

[0098] The ultra-thin glass thermoplastic polymer composite cover plates of Examples 1-4 were subjected to transmittance, haze, yellowness index, film tearing voltage, silicon ball defects, dynamic bending, static bending, bending limit, misaligned bending, U-shaped bending, salt spray, constant temperature and humidity, thermal shock, high temperature, and pen-down tests. The test methods are as follows:

[0099] Transmittance (%) test: Place the ultra-thin glass thermoplastic polymer composite cover plate in an optoelectronic haze meter and test the 380-780 nm band; the standard is that the transmittance ≥ 90%.

[0100] Haze (%) test: Place the ultra-thin glass thermoplastic polymer composite cover plate in an optoelectronic haze meter and test the 380-780 nm band; the standard is that the haze ≤ 1%.

[0101] Yellowness index (YI value) test: Use a spectrophotometer to test the 380-780 nm band; the standard is that the YI value ≤ 1.5.

[0102] Dynamic bending (30μm UTG) test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate, place the ultra-thin glass thermoplastic polymer composite cover plate in a bending instrument for testing. The test conditions are 25 °C, dynamic inner bend R1.5mm 200K; -20 °C, dynamic inner bend R1.5mm 100K; the standard is that there are no breakage, whitening, etc. under visual inspection and microscope, and the hardened coating of the HCPET layer has no cracks.

[0103] Static bending (30μm UTG) test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate, place the ultra-thin glass thermoplastic polymer composite cover plate in a bending instrument for testing. The test conditions are 25 °C, static inner bend R1.5mm 240h; -20 °C, static inner bend R1.5mm 240h; 60 °C / 90% RH, static inner bend R1.5mm 240h; thermal shock (static inner bend R1.5mm, -40 °C / 30min~80 °C / 30min) 100 cycle (100h); the standard is that there are no breakage, whitening, etc. under visual inspection and microscope, and the hardened coating of the HCPET layer has no cracks.

[0104] Static Bending (50μm UTG) Test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate. Place the ultra-thin glass thermoplastic polymer composite cover plate into the bending instrument for testing. The test conditions are: 25°C, static inner bend R1.8mm for 240h; -20°C, static inner bend R1.8mm for 240h; 60°C / 90% RH, static inner bend R1.8mm for 240h; thermal shock (static inner bend R1.8mm, -40°C / 30min to 80°C / 30min) for 100 cycles (100h). The standard is that there is no breakage, whitening, etc. visually and under the microscope, and the hardened coating of the HCPET layer has no cracks.

[0105] Bending Limit (30μm UTG) Test: Place the ultra-thin glass thermoplastic polymer composite cover plate into the bending dislocation tester to measure the breaking distance. The test condition is that the bending radius when pressed until broken is ≤0.8mm.

[0106] Bending Limit (50μm UTG) Test: Place the ultra-thin glass thermoplastic polymer composite cover plate into the bending dislocation tester to measure the breaking distance. The test condition is that the bending radius when pressed until broken is ≤1.0mm.

[0107] Dislocation Bending (30μm UTG) Test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate. Place the ultra-thin glass thermoplastic polymer composite cover plate into the bending dislocation tester for testing. The test conditions are that when pressed on both sides to a radius of R1.0, the UTG does not break. The standard is R1.0 OK. If it breaks, 5 pieces of the same batch need to be additionally tested for the ultimate bending, and the ultimate bending results need to meet the specification requirements.

[0108] Dislocation Bending (50μm UTG) Test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate. Place the ultra-thin glass thermoplastic polymer composite cover plate into the bending dislocation tester for testing. The test conditions are that when pressed on both sides to a radius of R1.3, the UTG does not break. The standard is R1.3 OK. If it breaks, 10 pieces of the same batch need to be additionally tested for the ultimate bending, and the ultimate bending results need to meet the specification requirements.

[0109] U-shaped Bending Test: Adjust the distance according to the thickness and radius of the ultra-thin glass thermoplastic polymer composite cover plate. Place the ultra-thin glass thermoplastic polymer composite cover plate into the flexible screen bending tester for testing. The test conditions are R 3.5mm, at room temperature for 5 times (the release film layer facing up, stroke 50mm, 30 times / min). The standard is that there is no fragmentation of the UTG visually and under the microscope.

[0110] Salt spray test: Set NaCl at 5% and pH value at 6.5 - 7.2 in the salt spray testing machine; the temperature of the test tank is 35℃ ± 1℃; the time is 48h. After the experiment, clean it with clear water, bake it at 50℃ for 30 minutes, observe it after placing it under natural conditions for 2h, and then test the cross hatch; the standard is that there are no obvious color differences, blisters, pockmarks, cracks, glue adhesion, deformation, etc. on the surface of the ultra-thin glass thermoplastic polymer composite cover plate visually, there is no fogging defect on the surface of the ultra-thin glass thermoplastic polymer composite cover plate, and the cross hatch of the hardened coating (HC) of the HCPET layer ≥ 3B.

[0111] Thermal and humidity cycling test: Put it in at a temperature of 60 ± 3℃ and a humidity of 90 ± 5% RH. Take it out after 48h, place it under natural conditions for 2h, observe the state and performance of the ultra-thin glass thermoplastic polymer composite cover plate for judgment. When the color difference cannot be judged visually, a color difference meter can be used for auxiliary testing, △E < 3, and then test the cross hatch; the standard is that there are no obvious color differences, blisters, pockmarks, cracks, glue adhesion, deformation, etc. on the surface of the ultra-thin glass thermoplastic polymer composite cover plate visually, there is no fogging defect on the surface of the ultra-thin glass thermoplastic polymer composite cover plate, and the cross hatch of the HC ≥ 3B.

[0112] Thermal shock test: Low temperature -40℃ ± 2℃ / 0.5h, transfer to high temperature 80℃ ± 2℃ / 0.5h within 1min as one cycle; time: routinely do 100 cycles (100h), recover at room temperature for 2h and check, and then test the cross hatch; the standard is that there are no obvious color differences, blisters, pockmarks, cracks, glue adhesion, deformation, etc. on the surface of the ultra-thin glass thermoplastic polymer composite cover plate visually, there is no fogging defect on the surface of the ultra-thin glass thermoplastic polymer composite cover plate, and the cross hatch of the HC ≥ 3B.

[0113] High temperature test: Temperature: 85 ± 2℃, humidity: ≤ 10% RH. Take it out after 48h, place it under natural conditions for at least 2h, observe the state and performance of the ultra-thin glass thermoplastic polymer composite cover plate for judgment. When the color difference cannot be judged visually, a color difference meter can be used for auxiliary testing, △E < 3, and then test the cross hatch; the standard is that there are no obvious color differences, blisters, pockmarks, cracks, glue adhesion, deformation, etc. on the surface of the ultra-thin glass thermoplastic polymer composite cover plate visually, there is no fogging defect on the surface of the ultra-thin glass thermoplastic polymer composite cover plate, and the cross hatch of the HC ≥ 3B.

[0114] Dropping test: Use a commercially available Chenguang pen (0.5mm tip, mass 13g) to conduct the dropping test and record the data of the dropping height at which it breaks.

[0115] The test results are shown in Table 1 and Table 2:

[0116] Table 1

[0117]

[0118]

[0119]

[0120] Table 2

[0121]

[0122]

[0123] In addition, after the pen-down test, the ultra-thin glass layer in the ultra-thin glass thermoplastic polymer composite cover plate of the present invention is broken, but the outer thermoplastic polymer layer and the inner thermoplastic polymer layer are not broken, and the broken ultra-thin glass layer is not easy to powder and fly during disassembly.

[0124] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. Those skilled in the art should understand that other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An ultra-thin glass thermoplastic polymer composite cover plate, characterized in that The ultra-thin glass thermoplastic polymer composite cover plate includes an ultra-thin glass layer, an outer thermoplastic polymer layer, an adhesive layer I, a printing layer, a PET hardening film layer, which are sequentially arranged on one side of the ultra-thin glass layer, and an inner thermoplastic polymer layer, an adhesive layer II, a PET layer, and an adhesive layer III, which are arranged on the other side of the ultra-thin glass layer; The outer thermoplastic polymer layer is prepared by coating a thermoplastic polymer solution on a substrate and then performing a pre-curing treatment; the inner thermoplastic polymer layer is prepared by coating a thermoplastic polymer solution on a substrate and then performing a pre-curing treatment.

2. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, wherein The thickness of the ultra-thin glass layer is 10-70 μm.

3. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, wherein The thickness of the outer thermoplastic polymer layer is 10-30 μm, the light transmittance is greater than 90%, and the haze is less than 1%.

4. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, characterized in that, The thickness of the inner thermoplastic polymer layer is 10-30 μm, the light transmittance is greater than 90%, and the haze is less than 1%.

5. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, wherein The thickness of the adhesive layer I is 10-50 μm; the thickness of the adhesive layer II is 10-50 μm; the thickness of the adhesive layer III is 10-50 μm; the adhesive layer I, the adhesive layer II, and the adhesive layer III are all made of OCA optical adhesive.

6. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, wherein The thickness of the printing layer is less than 2 μm, and the optical density value is greater than 2.

5.

7. The ultra-thin glass thermoplastic polymer composite cover plate according to claim 1, characterized in that, The surface water contact angle of the PET hardening film layer is greater than 105°.

8. The preparation method of the ultra-thin glass thermoplastic polymer composite cover plate according to any one of claims 1-7, characterized in that, It includes the following steps: (1) Adhere the outer thermoplastic polymer layer and the inner thermoplastic polymer layer to both sides of the ultra-thin glass layer by vacuum hot pressing respectively, and adhere the adhesive layer II on one side of the inner thermoplastic polymer layer to obtain assembly A; (2) Adhere the adhesive layer I, the printing layer, and the PET hardening film layer to obtain assembly B; (3) Adhere the PET layer, the adhesive layer III, and the release film layer to obtain assembly C; (4) Use a fully automatic adhering device to adhere assembly A, assembly B, and assembly C to obtain the ultra-thin glass thermoplastic polymer composite cover plate on the release film layer.

9. The preparation method according to claim 8, characterized in that, In step (1), the preparation method of the outer thermoplastic polymer layer includes the following steps: coat a thermoplastic polymer solution on a substrate to form a wet film layer with a predetermined thickness; perform a pre-curing treatment on the wet film layer to cure the thermoplastic polymer solution to form the outer thermoplastic polymer layer with a corresponding thickness.

10. The preparation method according to claim 9, characterized in that, The temperature of the pre-curing treatment is 100-200 °C.

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