A UTG laminated component for folding screen and its preparation method

Abstract

The present application relates to the field of folding screen glass cover plates, and specifically discloses a UTG laminate assembly for folding screens and a preparation method thereof. The UTG laminate assembly for folding screens comprises, from top to bottom, a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer, and a second thermoplastic polymer layer; the functional base film layer is made of raw materials comprising the following weight components: polyimide resin, polyarylether nitrile, vapor-phase nano-silica, polypentafluoropropyl methacrylate, modified black phosphorus quantum dots, grafted microcrystalline cellulose, a promoter, and an ultraviolet absorber; the grafted microcrystalline cellulose is obtained by grafting polymethyl methacrylate on microcrystalline cellulose; the modified black phosphorus quantum dots are obtained by modifying black phosphorus quantum dots with zinc-based metal organic framework materials. The UTG laminate assembly of the present application has strong impact resistance, and can have both high hardness and light transmittance, which can ensure that the folding screen has a good appearance and visual experience under long-term use.

Description

Technical Field

[0001] The present application relates to the field of folding screen glass cover plates, and more specifically, it relates to a UTG laminate assembly for folding screens and a preparation method thereof. Background Art

[0002] Currently, ultra-thin glass (UTG) is commonly used as a flexible cover material for foldable display devices. UTG's thinness offers excellent bending properties, meeting the stringent curvature radius requirements of flexible screens. However, UTG's mechanical properties are negatively correlated with its thickness: its impact resistance decreases significantly as thickness decreases. As a result, in pen drop tests (simulating drops or collisions experienced in everyday use), the critical failure height is typically less than 10mm, posing a high risk of crack propagation. These reliability limitations severely restrict the large-scale application of UTG in mobile devices and other applications.

[0003] To improve the impact resistance of UTG, existing technologies often use multi-layer composite structures for reinforcement. For example, patent document CN212749798U discloses a foldable glass cover with touch function, including ultra-thin glass. The upper surface of the ultra-thin glass is sequentially provided with a first optical adhesive layer, a first touch sensor, and a first PET layer. The lower surface of the ultra-thin glass is sequentially provided with a second optical adhesive layer, a second touch sensor, and a second PET layer. The UTG is bonded to a polyethylene terephthalate (PET) film using an optically clear adhesive (OCA) to form a "UTG-OCA-PET" laminated structure.

[0004] Although this flexible folding cover structure improves the impact resistance of UTG to a certain extent, due to the presence of multiple layers of low-modulus OCA adhesive and PET film on the UTG, the cover material has the defect of low hardness. Therefore, after a period of use, the folding screen will have uneven surface, severe creases, nail marks and other appearance problems, affecting the appearance and visual experience of the screen. In addition, the PET film as a protective layer has a lower light transmittance than the UTG body. After superimposing the OCA adhesive layer, the overall light transmittance further decreases, resulting in a loss of screen brightness. At the same time, the interfaces of each layer in the UTG-OCA-PET composite structure will produce reflection losses, and the total reflectivity will increase after superposition, significantly reducing the light transmittance efficiency. Therefore, the glass cover in the related art has the problems of low hardness and low light transmittance efficiency. Summary of the Invention

[0005] In order to improve the hardness and light transmittance of the cover material, and thereby ensure that the folding screen still has a good appearance and visual experience after long-term use, the present application provides a UTG laminate assembly for a folding screen and a preparation method thereof.

[0006] The UTG laminated assembly for a folding screen provided in this application adopts the following technical solution:

[0007] A UTG laminate assembly for a folding screen, comprising, from top to bottom, a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer, and a second thermoplastic polymer layer;

[0008] The first thermoplastic polymer layer and the second thermoplastic polymer layer are made by curing the same thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises the following components by weight: 40-60 parts of thermoplastic polyurethane elastomer, 20-30 parts of polycarbonate, and 1-3 parts of nano boron nitride;

[0009] The functional base film layer is made of the following raw materials by weight: 60-85 parts of polyimide resin, 20-30 parts of polyarylether nitrile, 5-15 parts of fumed nano-silica, 3-8 parts of polypentafluoropropyl methacrylate, 3-7 parts of modified black phosphorus quantum dots, 2-5 parts of grafted microcrystalline cellulose, 1-3 parts of accelerator, and 1-3 parts of ultraviolet absorber;

[0010] The grafted microcrystalline cellulose is obtained by grafting polymethyl methacrylate onto microcrystalline cellulose;

[0011] The modified black phosphorus quantum dots are obtained by modifying black phosphorus quantum dots with zinc-based metal organic framework materials.

[0012] By adopting the above technical solution, polyimide resin and poly(arylene ether nitrile) possess excellent heat resistance, mechanical properties, and chemical stability. Their combination provides the functional base film layer with a fundamental strength and stability framework, enhancing its overall hardness and deformation resistance. Nano-scale silica dispersed within the base film further enhances hardness and wear resistance, reducing surface irregularities. The presence of poly(pentafluoropropyl methacrylate) reduces the surface energy of the base film, imparting excellent anti-fouling and anti-fingerprint properties, preventing appearance issues such as nail marks. Its excellent optical properties also help maintain the base film's light transmittance.

[0013] The modified black phosphorus quantum dots are evenly dispersed in the base film. The black phosphorus particles themselves possess high strength and rigidity, effectively resisting external forces and significantly improving the hardness of the base film, reducing surface dents and scratches during foldable screen use. After the black phosphorus quantum dots are modified with zinc-based metal-organic framework materials (such as ZIF-8), on the one hand, the high porosity and uniform pore size distribution of ZIF-8 reduce light scattering in the base film; on the other hand, the modified black phosphorus quantum dots optimize their interaction with other components in the base film. Their unique optoelectronic properties can regulate the absorption and transmission of light, making the base film's transmission of visible light more uniform and efficient, thereby improving overall light transmittance. The modified black phosphorus quantum dots form a synergistic effect with the other components of the base film. When impacted, they can effectively disperse and absorb impact energy through their own structural deformation and interaction with surrounding materials, enhancing the base film's impact resistance, protecting the ultra-thin glass layer, and reducing the occurrence of creases.

[0014] Microcrystalline cellulose has high strength and rigidity. By grafting polymethyl methacrylate, its compatibility with other polymers in the base film is improved, forming a well-dispersed state and a reinforced network structure in the base film, thereby significantly improving the base film's mechanical properties such as tensile strength and flexural strength, and further enhancing the base film's hardness and deformation resistance. Grafted microcrystalline cellulose forms a reinforced network structure in the base film, interwoven with polymers such as polyimide resin and polyarylethernitrile. This network structure makes the interior of the base film more dense and uniform, reducing internal voids and defects. During light propagation, the obstacles encountered are reduced, and reflection and scattering are reduced, thereby improving the overall light transmittance.

[0015] The thermoplastic polyurethane elastomer in the thermoplastic polymer layer imparts a degree of flexibility, allowing it to adapt to deformation when folded; polycarbonate provides high strength and rigidity; and the addition of nano-boron nitride further enhances hardness and wear resistance. The two thermoplastic polymer layers closely adhere to the functional base film layer and the ultra-thin glass layer, working synergistically with the functional base film layer to enhance the hardness of the entire cover material.

[0016] This laminated assembly utilizes a four-layer structure that is directly hot-pressed, eliminating the need for an OCA adhesive layer. The OCA adhesive layer not only has a low modulus, which affects the hardness of the cover, but also increases the number of interfaces, each of which generates reflection losses and reduces light transmission efficiency. This solution reduces the use of OCA adhesive layers and provides a high-performance functional base film layer and thermoplastic polymer layer, effectively enhancing the cover material's hardness and light transmittance.

[0017] Optionally, the modified black phosphorus quantum dots are prepared by the following method:

[0018] A. Mix zinc nitrate, 2-methylimidazole and N,N-dimethylformamide, stir and react at a speed of 500-700 r / min for 30-50 minutes, and then react at 100-120°C for 20-24 hours. After the reaction is completed, the reaction product is centrifuged, and then the reaction product is washed and dried to obtain ZIF-8 powder;

[0019] B. ZIF-8 powder is mixed with black phosphorus quantum dot dispersion, ultrasonically treated for 1-2 hours, and then stirred at 30-40°C at a speed of 200-300 r / min for 20-24 hours. After the reaction is completed, the product is centrifuged and then washed and dried to obtain modified black phosphorus quantum dots.

[0020] By adopting the above technical solution, the modified black phosphorus quantum dots prepared by this method, on the one hand, have high porosity and uniform pore size distribution to reduce the scattering of light in the base film, and on the other hand, the interaction with other components in the base film is optimized, which can regulate the absorption and transmission of light and improve the overall transmittance. At the same time, it can also enhance the impact resistance of the base film and reduce the generation of creases.

[0021] Optionally, in step A, the mass ratio of zinc nitrate, 2-methylimidazole and N,N-dimethylformamide is 1:(2-3):(20-30).

[0022] By adopting the above technical solution, this ratio helps to prepare ZIF-8 powder with good performance, thereby ensuring the performance of modified black phosphorus quantum dots, so that it can better play the role of improving the hardness, transmittance and impact resistance of the base film.

[0023] Optionally, the mass concentration of the black phosphorus quantum dot dispersion in step B is 25%-30%; the mass ratio of the ZIF-8 powder to the black phosphorus quantum dot dispersion is 1:(1-3).

[0024] By adopting the above technical solution, the mass concentration of the black phosphorus quantum dot dispersion and the mass ratio of ZIF-8 powder to the black phosphorus quantum dot dispersion are specified, which is conducive to obtaining modified black phosphorus quantum dots that are uniformly dispersed and have stable performance, so that they can more effectively enhance the hardness, improve the transmittance and impact resistance in the base film.

[0025] Optionally, the grafted microcrystalline cellulose is prepared by the following method:

[0026] (1) Add microcrystalline cellulose to a NaOH solution, stir at 200-400 r / min at 60-80°C for 10-12 hours, filter, and then wash with an ethanol-water mixture until the pH of the filtrate is 7-8 to obtain surface hydroxyl-activated cellulose;

[0027] (2) Add surface hydroxyl-activated cellulose, methyl methacrylate, azobisisobutyronitrile and dimethyl sulfoxide into a reaction vessel, and stir at 60-70°C and 300-400 r / min for 8-12 h under nitrogen protection; after the reaction, pour the reaction product into anhydrous ethanol for precipitation, filter and wash with anhydrous ethanol for 3-5 times, and finally vacuum dry at 50-60°C for 12-24 h to obtain grafted microcrystalline cellulose.

[0028] The grafted microcrystalline cellulose prepared by this method can form a good dispersion state and enhanced network structure in the basement membrane, significantly improving the mechanical properties of the basement membrane, increasing the hardness and deformation resistance of the basement membrane, and at the same time making the interior of the basement membrane more dense and uniform, reducing the obstruction of light propagation, and improving the overall light transmittance.

[0029] Optionally, the mass concentration of the NaOH solution in step (1) is 5%-10%, and the mass ratio of the microcrystalline cellulose to the NaOH solution is 1:(10-15).

[0030] Optionally, in step (2), the mass ratio of the surface hydroxyl-activated cellulose, methyl methacrylate, azobisisobutyronitrile and dimethyl sulfoxide is (1-2): (3-4): (0.05-0.1): 15.

[0031] Optionally, the ultraviolet absorber is thiospiropyran.

[0032] By adopting the above technical solution, thiospiropyran has the advantages of good photosensitivity and a wide absorption wavelength range. In addition, thiospiropyran has good chemical stability and is not easy to deteriorate due to chemical reactions during the processing of the glass cover and the use environment. It can maintain its ultraviolet absorption and other properties for a long time, ensuring that the folding screen glass cover continues to play a protective and optimization role during long-term use.

[0033] This application also provides a method for preparing a UTG laminate assembly for a folding screen, which adopts the following technical solution:

[0034] A method for preparing a UTG laminate assembly for a folding screen, comprising the following steps:

[0035] S1. Preparing a functional base film layer: uniformly mixing polyimide resin, polyarylether nitrile, fumed nano-silica, polypentafluoropropyl methacrylate, modified black phosphorus quantum dots, grafted microcrystalline cellulose, an accelerator, an ultraviolet absorber, and a solvent to obtain a base film coating, coating the base film coating on a polyester release film, drying and curing the coating, and peeling the polyester release film off to obtain a functional base film layer;

[0036] S2. Preparing a thermoplastic polymer layer: mixing a thermoplastic polyurethane elastomer, polycarbonate, and nano-boron nitride to obtain a thermoplastic polymer composition, then melt-blending and extruding the composition through a twin-screw extruder at 190-200° C. to form a sheet, which is then sheared to obtain a first thermoplastic polymer layer and a second thermoplastic polymer layer, respectively;

[0037] S3. Assemble the laminated components: stack the functional base film layer, the first thermoplastic polymer layer, the ultra-thin glass layer and the second thermoplastic polymer layer in sequence, put the stacked four layers of materials into a vacuum hot press, and hot press them at 110-130°C and 1.5-2.5MPa pressure for 15-25 minutes. After the hot pressing is completed, wait for the temperature to cool down to obtain the UTG laminated component for the folding screen.

[0038] The above scheme provides a preparation method of UTG laminated components for folding screens. The laminated components prepared by this method adopt a four-layer structure directly hot-pressed, without the need to add an OCA adhesive layer, avoiding the problem of low modulus of the OCA adhesive layer affecting the hardness of the cover plate and increasing interface reflection loss to reduce light transmittance. At the same time, each layer of material can better exert its performance through this preparation method, effectively enhancing the hardness and light transmittance of the cover plate material.

[0039] Optionally, the temperature during the drying and curing in S1 is 80-120° C., and the drying and curing time is 1-3 hours.

[0040] Under the above conditions, the base film coating is fully dried and cured to obtain a functional base film layer with good performance, ensuring its hardness, anti-fouling, anti-fingerprint, light transmittance and other properties, thereby improving the performance of the entire laminated assembly.

[0041] In summary, this application has the following beneficial effects:

[0042] 1. This application introduces black phosphorus quantum dots modified with zinc-based metal-organic framework materials into the base film layer. The modified black phosphorus quantum dots play a key role in improving the performance of UTG laminated components for folding screens. Their own high strength and rigidity, like rigid reinforcing particles, are evenly dispersed in the functional base film layer, effectively resisting external forces, significantly enhancing the hardness of the base film, and reducing surface dents and scratches. After modification, the high porosity and uniform pore size distribution of the zinc-based metal-organic framework material are utilized to reduce light scattering within the base film, while optimizing the interaction with other components of the base film, regulating light absorption and transmission, and improving overall light transmittance. When impacted, they synergize with other components of the base film to deform, disperse and absorb impact energy, enhance the impact resistance of the base film, protect the ultra-thin glass layer, and reduce the occurrence of creases.

[0043] 2. The grafted microcrystalline cellulose introduced in this application can significantly enhance the performance of functional basement membranes. The grafting modification improves the compatibility of microcrystalline cellulose with other polymers in the basement membrane, allowing it to be well dispersed within the basement membrane and form a reinforced network structure, interwoven between polymers such as polyimide resin and polyarylethernitrile. This significantly improves the basement membrane's tensile and bending mechanical properties, further enhancing its hardness and deformation resistance. This reinforced network structure also makes the basement membrane more dense and uniform, reducing voids and defects, reducing light propagation obstacles, and reducing reflection and scattering, thereby effectively improving the overall light transmittance of the basement membrane.

[0044] 3. The laminated component of the present application adopts a four-layer structure of a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer and a second thermoplastic polymer layer, and effectively overcomes the defects of the prior art through a direct hot pressing preparation process. In the four-layer structure, the functional base film layer and the thermoplastic polymer layer work together to give the component high hardness; the components in the thermoplastic polymer layer take into account both flexibility and rigidity to ensure folding adaptability. The direct hot pressing process does not require the addition of a low-modulus OCA adhesive layer, reducing the problem of hardness reduction caused by the OCA adhesive layer; at the same time, it reduces the number of interfaces, reduces interface reflection loss, and improves light transmission efficiency, ultimately effectively enhancing the hardness and light transmittance of the cover material, ensuring a good appearance and visual experience under long-term use of the folding screen. DETAILED DESCRIPTION

[0045] The present application is further described in detail below with reference to the embodiments.

[0046] Preparation example of modified black phosphorus quantum dots

[0047] Preparation Example 1

[0048] Modified black phosphorus quantum dots are prepared by the following method:

[0049] A. 1 kg zinc nitrate, 2 kg 2-methylimidazole and 20 kg N, N-dimethylformamide were mixed, stirred at 500 r / min for 30 min, and then reacted at 100 ° C for 20 h. After the reaction, the reaction product was centrifuged, and then the reaction product was washed alternately with ethanol and DMF 5 times, and vacuum dried at 60 ° C for 12 h to obtain ZIF-8 powder;

[0050] B. Take 1 kg of ZIF-8 powder and mix it with 1 kg of black phosphorus quantum dot dispersion with a mass concentration of 25%, ultrasonically treat it for 1 hour, and then stir and react at a speed of 200 r / min at 30°C for 20 hours. After the reaction is completed, the product is centrifuged and then washed alternately with ethanol and DMF 5 times, and vacuum dried at 40°C for 12 hours to obtain modified black phosphorus quantum dots.

[0051] Preparation Example 2

[0052] Modified black phosphorus quantum dots are prepared by the following method:

[0053] A. 1 kg zinc nitrate, 2.5 kg 2-methylimidazole and 25 kg N, N-dimethylformamide were mixed, stirred at 600 r / min for 40 min, and then reacted at 110 ° C for 22 h. After the reaction, the reaction product was centrifuged, and then the reaction product was washed alternately with ethanol and DMF 5 times, and vacuum dried at 60 ° C for 12 h to obtain ZIF-8 powder;

[0054] B. Take 1 kg of ZIF-8 powder and mix it with 2 kg of black phosphorus quantum dot dispersion with a mass concentration of 28%, ultrasonically treat it for 1.5 hours, and then stir it at 250 r / min at 35°C for 22 hours. After the reaction is completed, the product is centrifuged and then washed alternately with ethanol and DMF 5 times, and vacuum dried at 40°C for 12 hours to obtain modified black phosphorus quantum dots.

[0055] Preparation Example 3

[0056] Modified black phosphorus quantum dots are prepared by the following method:

[0057] A. 1 kg zinc nitrate, 3 kg 2-methylimidazole and 30 kg N, N-dimethylformamide were mixed, stirred at 700 r / min for 50 min, and then reacted at 120 ° C for 24 h. After the reaction, the reaction product was centrifuged, and then the reaction product was washed alternately with ethanol and DMF 5 times, and vacuum dried at 60 ° C for 12 h to obtain ZIF-8 powder;

[0058] B. Take 1 kg of ZIF-8 powder and mix it with 3 kg of black phosphorus quantum dot dispersion with a mass concentration of 30%, ultrasonically treat it for 2 hours, and then stir and react at a speed of 300 r / min at 40°C for 24 hours. After the reaction is completed, the product is centrifuged and then washed alternately with ethanol and DMF 5 times, and vacuum dried at 40°C for 12 hours to obtain modified black phosphorus quantum dots.

[0059] Preparation Example 4

[0060] The modified black phosphorus quantum dots are different from those in Preparation Example 1 in that the mass concentration of the black phosphorus quantum dot dispersion in step B of this Preparation Example is 35%.

[0061] Preparation example of grafted microcrystalline cellulose

[0062] Preparation Example 5

[0063] Grafted microcrystalline cellulose is prepared by the following method:

[0064] (1) 1 kg of microcrystalline cellulose was added to 10 kg of 5% NaOH solution, stirred at 200 r / min at 60 °C for 10 h, filtered, and then washed with a 1:1 mixture of ethanol and water until the pH of the filtrate reached 7 to obtain surface hydroxyl-activated cellulose;

[0065] (2) 1 kg of surface hydroxyl-activated cellulose, 3 kg of methyl methacrylate, 0.05 kg of azobisisobutyronitrile and 15 kg of dimethyl sulfoxide were added to the reactor, and stirred at 60 °C and 300 r / min for 8 h under nitrogen protection. After the reaction, the reaction product was poured into anhydrous ethanol for precipitation, filtered and washed with anhydrous ethanol three times, and finally vacuum dried at 50 °C for 12 h to obtain grafted microcrystalline cellulose.

[0066] Preparation Example 6

[0067] Grafted microcrystalline cellulose is prepared by the following method:

[0068] (1) 2 kg of microcrystalline cellulose was added to 25 kg of 8% NaOH solution, stirred at 300 r / min at 70 °C for 11 h, filtered, and then washed with a 1:1 mixture of ethanol and water until the pH of the filtrate reached 7.5 to obtain surface hydroxyl activated cellulose;

[0069] (2) 1.5 kg of surface hydroxyl-activated cellulose, 3.5 kg of methyl methacrylate, 0.08 kg of azobisisobutyronitrile and 15 kg of dimethyl sulfoxide were added to the reactor and stirred at 65 °C and 350 r / min for 10 h under nitrogen protection. After the reaction, the reaction product was poured into anhydrous ethanol for precipitation, filtered and washed with anhydrous ethanol for 4 times, and finally vacuum dried at 55 °C for 18 h to obtain grafted microcrystalline cellulose.

[0070] Preparation Example 7

[0071] Grafted microcrystalline cellulose is prepared by the following method:

[0072] (1) 2 kg of microcrystalline cellulose was added to 30 kg of 10% NaOH solution, stirred at 400 r / min at 80 °C for 12 h, filtered, and then washed with a 1:1 mixture of ethanol and water until the pH of the filtrate reached 8 to obtain surface hydroxyl-activated cellulose;

[0073] (2) 2 kg of surface hydroxyl-activated cellulose, 4 kg of methyl methacrylate, 0.1 kg of azobisisobutyronitrile and 15 kg of dimethyl sulfoxide were added to the reactor and stirred at 70 °C and 400 r / min for 12 h under nitrogen protection. After the reaction, the reaction product was poured into anhydrous ethanol for precipitation, filtered and washed with anhydrous ethanol for 5 times, and finally vacuum dried at 60 °C for 24 h to obtain grafted microcrystalline cellulose.

[0074] Preparation Example 8

[0075] The difference between the grafted microcrystalline cellulose and Preparation Example 1 is that the surface hydroxyl activation treatment of the microcrystalline cellulose is not performed in this Preparation Example, that is, step (1) is not performed, and in step (2), the microcrystalline cellulose is directly used to participate in the grafting reaction.

[0076] Example

[0077] Example 1

[0078] A UTG laminate assembly for folding screens, comprising, from top to bottom, a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer, and a second thermoplastic polymer layer. The functional base film is 30 μm thick; the first thermoplastic polymer layer is 20 μm thick; the ultra-thin glass layer is 30 μm thick; and the second thermoplastic polymer layer is 20 μm thick.

[0079] The first thermoplastic polymer layer and the second thermoplastic polymer layer are made by curing the same thermoplastic polymer composition, wherein the raw materials of the thermoplastic polymer composition include 4 kg of thermoplastic polyurethane elastomer, 2 kg of polycarbonate and 0.1 kg of nano boron nitride.

[0080] The raw material components and amounts of the functional base film layer are shown in Table 1, wherein the modified black phosphorus quantum dots are selected from the modified black phosphorus quantum dots prepared in Preparation Example 1; the grafted microcrystalline cellulose is selected from the grafted microcrystalline cellulose prepared in Preparation Example 5; the accelerator is benzyldimethylamine; and the ultraviolet absorber is thiospiropyran.

[0081] A method for preparing a UTG laminate assembly for a folding screen, comprising the following steps:

[0082] S1. Preparation of functional base film layer: polyimide resin, polyarylether nitrile, fumed nanosilica, polypentafluoropropyl methacrylate, modified black phosphorus quantum dots, grafted microcrystalline cellulose, accelerator, ultraviolet absorber and solvent are mixed, stirred at 70°C at a speed of 500r / min for 4h, and fully mixed to form a base film coating, wherein the solvent is N,N-dimethylacetamide, and the solvent dosage is 30kg. The base film coating is then coated on a polyester release film by a casting method with a film thickness of 25μm, and then transferred to a vacuum oven at 80°C for drying for 3h. After complete curing, it is cooled to room temperature and peeled off from the release film to obtain a functional base film layer;

[0083] S2. Preparing a thermoplastic polymer layer: A thermoplastic polyurethane elastomer, polycarbonate, and nano-boron nitride are mixed to obtain a thermoplastic polymer composition, which is then melt-blended and extruded through a twin-screw extruder at 190° C. to form a sheet having a thickness of 20 μm, which is then sheared to obtain a first thermoplastic polymer layer and a second thermoplastic polymer layer, respectively;

[0084] S3. Assemble the laminated components: stack the functional base film layer, the first thermoplastic polymer layer, the ultra-thin glass layer and the second thermoplastic polymer layer in sequence, put the stacked four layers of materials into a vacuum hot press, and hot press them at 110°C and 1.5MPa pressure for 25 minutes. After the hot pressing is completed, wait for the temperature to cool down to obtain the UTG laminated component for the folding screen.

[0085] Example 2

[0086] A UTG laminate assembly for folding screens, comprising, from top to bottom, a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer, and a second thermoplastic polymer layer. The functional base film is 30 μm thick; the first thermoplastic polymer layer is 30 μm thick; the ultra-thin glass layer is 30 μm thick; and the second thermoplastic polymer layer is 30 μm thick.

[0087] The first thermoplastic polymer layer and the second thermoplastic polymer layer are made by curing the same thermoplastic polymer composition. The raw materials of the thermoplastic polymer composition include 5 kg of thermoplastic polyurethane elastomer, 2.5 kg of polycarbonate and 0.2 kg of nano boron nitride.

[0088] The raw material components and amounts of the functional base film layer are shown in Table 1, wherein the modified black phosphorus quantum dots are selected from the modified black phosphorus quantum dots prepared in Preparation Example 1; the grafted microcrystalline cellulose is selected from the grafted microcrystalline cellulose prepared in Preparation Example 5; the accelerator is benzyldimethylamine; and the ultraviolet absorber is thiospiropyran.

[0089] A method for preparing a UTG laminate assembly for a folding screen, comprising the following steps:

[0090] S1. Preparation of functional base film layer: polyimide resin, polyarylether nitrile, fumed nano-silica, poly(pentafluoropropyl methacrylate), modified black phosphorus quantum dots, grafted microcrystalline cellulose, accelerator, ultraviolet absorber and solvent are mixed, stirred at 70°C at a speed of 500r / min for 4h, and fully mixed to form a base film coating, wherein the solvent is N,N-dimethylacetamide, and the solvent dosage is 33kg. The base film coating is then coated on a polyester release film by a casting method with a film thickness of 30μm, and then transferred to a vacuum oven at 100°C for drying for 2h. After complete curing, it is cooled to room temperature and peeled off from the release film to obtain a functional base film layer;

[0091] S2. Preparing a thermoplastic polymer layer: A thermoplastic polyurethane elastomer, polycarbonate, and nano-boron nitride are mixed to obtain a thermoplastic polymer composition, which is then melt-blended and extruded through a twin-screw extruder at 195° C. to form a sheet having a thickness of 30 μm, which is then sheared to obtain a first thermoplastic polymer layer and a second thermoplastic polymer layer, respectively;

[0092] S3. Assemble the laminated components: stack the functional base film layer, the first thermoplastic polymer layer, the ultra-thin glass layer and the second thermoplastic polymer layer in sequence, put the stacked four layers of materials into a vacuum hot press, and hot press them at 120°C and 2.0MPa pressure for 20 minutes. After the hot pressing is completed, wait for the temperature to cool down to obtain the UTG laminated component for the folding screen.

[0093] Example 3

[0094] A UTG laminate assembly for folding screens, comprising, from top to bottom, a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer, and a second thermoplastic polymer layer. The functional base film is 40 μm thick; the first thermoplastic polymer layer is 35 μm thick; the ultra-thin glass layer is 30 μm thick; and the second thermoplastic polymer layer is 35 μm thick.

[0095] The first thermoplastic polymer layer and the second thermoplastic polymer layer are made by curing the same thermoplastic polymer composition, wherein the raw materials of the thermoplastic polymer composition include 6 kg of thermoplastic polyurethane elastomer, 3 kg of polycarbonate and 0.3 kg of nano boron nitride.

[0096] The raw material components and amounts of the functional base film layer are shown in Table 1, wherein the modified black phosphorus quantum dots are selected from the modified black phosphorus quantum dots prepared in Preparation Example 1; the grafted microcrystalline cellulose is selected from the grafted microcrystalline cellulose prepared in Preparation Example 5; the accelerator is benzyldimethylamine; and the ultraviolet absorber is thiospiropyran.

[0097] A method for preparing a UTG laminate assembly for a folding screen, comprising the following steps:

[0098] S1. Preparation of functional base film layer: polyimide resin, polyarylether nitrile, fumed nano-silica, poly(pentafluoropropyl methacrylate), modified black phosphorus quantum dots, grafted microcrystalline cellulose, accelerator, ultraviolet absorber and solvent are mixed, stirred at 70°C at a speed of 500r / min for 4h, and fully mixed to form a base film coating, wherein the solvent is N,N-dimethylacetamide, and the solvent dosage is 33kg. The base film coating is then coated on a polyester release film by a casting method with a film thickness of 40μm, and then transferred to a vacuum oven at 120°C for drying for 1h. After complete curing, it is cooled to room temperature and peeled off from the release film to obtain a functional base film layer;

[0099] S2. Preparing a thermoplastic polymer layer: A thermoplastic polyurethane elastomer, polycarbonate, and nano-boron nitride are mixed to obtain a thermoplastic polymer composition, which is then melt-blended and extruded through a twin-screw extruder at 200° C. to form a sheet having a thickness of 35 μm, which is then sheared to obtain a first thermoplastic polymer layer and a second thermoplastic polymer layer, respectively;

[0100] S3. Assemble the laminated components: stack the functional base film layer, the first thermoplastic polymer layer, the ultra-thin glass layer and the second thermoplastic polymer layer in sequence, put the stacked four layers of materials into a vacuum hot press, and hot press them at 130°C and 2.5MPa pressure for 15 minutes. After the hot pressing is completed, wait for the temperature to cool down to obtain the UTG laminated component for the folding screen.

[0101] Table 1 Raw material components and dosage of functional base film layer in Examples 1-3 (kg)

[0102]

[0103] Example 4

[0104] A UTG laminate assembly for a folding screen, which differs from Example 1 in that the modified black phosphorus quantum dots in this embodiment are the modified black phosphorus quantum dots obtained in Preparation Example 2; and the grafted microcrystalline cellulose is the grafted microcrystalline cellulose obtained in Preparation Example 6.

[0105] Example 5

[0106] A UTG laminate assembly for a folding screen, which differs from Example 1 in that the modified black phosphorus quantum dots in this embodiment are the modified black phosphorus quantum dots obtained in Preparation Example 3; and the grafted microcrystalline cellulose is the grafted microcrystalline cellulose obtained in Preparation Example 7.

[0107] Example 6

[0108] A UTG laminate assembly for a folding screen, which differs from Example 1 in that the modified black phosphorus quantum dots in this embodiment are the modified black phosphorus quantum dots prepared in Preparation Example 4.

[0109] Example 7

[0110] A UTG laminate assembly for a folding screen, which differs from Example 1 in that the grafted microcrystalline cellulose in this embodiment is the grafted microcrystalline cellulose obtained in Preparation Example 8.

[0111] Example 8

[0112] A UTG laminate assembly for a folding screen, which differs from Example 1 in that the ultraviolet absorber in this embodiment is 2-hydroxy-4-n-octyloxybenzophenone.

[0113] Comparative Example

[0114] Comparative Example 1

[0115] A glass cover plate for a folding screen comprises, from top to bottom, a PET film layer, an OCA optical adhesive layer, an ultra-thin glass layer, an OCA optical adhesive layer and a POP film layer.

[0116] A glass cover plate for a folding screen, comprising the following preparation methods: cleaning a PET film layer and a POP film layer with deionized water to remove surface dust and impurities; cleaning the ultrathin glass with deionized water and then drying it; applying an appropriate amount of OCA optical adhesive to one side of the PET film, both sides of the ultrathin glass, and one side of the POP layer, respectively; laminating the adhesive-coated surface of the PET film to one side of the ultrathin glass, and laminating the adhesive-coated surface of the POP layer to the other side of the ultrathin glass; and performing hot pressing at a temperature of 60°C and a pressure of 0.2 MPa to expel bubbles and tightly bond the layers to obtain a glass cover plate for a folding screen.

[0117] Comparative Example 2

[0118] A UTG laminate assembly for a folding screen, which differs from Example 1 in that modified black phosphorus quantum dots and grafted microcrystalline cellulose are not added to the functional base film raw materials in this comparative example, and the difference is supplemented by polyimide resin.

[0119] Comparative Example 3

[0120] A UTG laminate assembly for a folding screen, which differs from Example 1 in that unmodified black phosphorus quantum dots are used in the functional base film raw materials in this comparative example instead of modified black phosphorus quantum dots.

[0121] Comparative Example 4

[0122] A UTG laminate assembly for a folding screen, which differs from Example 1 in that ungrafted microcrystalline cellulose is used as the functional base film raw material in this comparative example instead of grafted microcrystalline cellulose.

[0123] Performance testing

[0124] Test objects: laminated assemblies prepared in Examples 1-8 and Comparative Examples 1-4.

[0125] Test content:

[0126] 1. Impact resistance test

[0127] Place a glass cover horizontally on a fixture. Select a 20mm diameter, 32.6g mass and drop it freely from different heights to impact the glass cover surface. Observe the surface damage after the impact, such as cracks, breakage, or edge collapse. Record the critical height at which damage begins to appear on the glass cover under different impact heights to assess its impact resistance.

[0128] 2. Hardness test

[0129] Use standard minerals of different hardness to scratch the surface of the glass cover and observe the scratches on the surface of the glass cover to determine its Mohs hardness level. The Mohs hardness level is divided into 10 levels, from 1 (talc) to 10 (diamond). The higher the level, the harder the glass cover.

[0130] 3. Light transmittance detection

[0131] Using a UV-Vis spectrophotometer, the UTG laminate assembly was placed in the light path and the transmittance within specific wavelength ranges of 500nm, 600nm, and 700nm was measured, and the results were averaged.

[0132] Test results: See Table 2.

[0133] Table 2 Test results

[0134]

[0135] The critical impact resistance height of Examples 1-5 is between 1930-2000mm, indicating that the UTG laminated assembly for folding screens prepared in this application has good impact resistance. This is because the modified black phosphorus quantum dots in the functional base film layer work synergistically with other components to effectively disperse and absorb impact energy when impacted; the grafted microcrystalline cellulose forms a reinforced network structure in the base film, which also helps to improve the overall impact resistance; at the same time, the thermoplastic polyurethane elastomer in the thermoplastic polymer layer gives the material flexibility, polycarbonate provides strength and rigidity, and nano-boron nitride further enhances hardness and wear resistance. Each layer synergistically protects the ultra-thin glass layer, thereby improving the impact resistance of the assembly.

[0136] The critical impact resistance height of Comparative Example 1 is only 980 mm. This is because it adopts the "PET-OCA-UTG-OCA-POP" structure. The OCA adhesive layer has a low modulus and cannot effectively disperse the impact energy. The protective effect of the PET film and POP film is limited. Comparative Example 2 does not add modified black phosphorus quantum dots and grafted microcrystalline cellulose. The critical impact resistance height is 1300 mm, which is lower than that of Example 1. This shows that these two substances play an important role in improving impact resistance. Comparative Example 3 uses unmodified black phosphorus quantum dots and Comparative Example 4 uses ungrafted microcrystalline cellulose. Its impact resistance is also not as good as the example, further proving the necessity of modification and grafting treatment to enhance impact resistance.

[0137] Examples 1-8 all achieved a hardness rating of 6, indicating relatively high hardness. This is because the polyimide resin and poly(arylene ether nitrile) in the functional base film layer provide the basic strength and stability framework, while nano-silica, modified black phosphorus quantum dots, and grafted microcrystalline cellulose further enhance hardness. The polycarbonate and nano-boron nitride in the thermoplastic polymer layer also contribute to enhanced hardness. The two thermoplastic polymer layers and the functional base film layer work synergistically to improve the hardness of the entire cover material.

[0138] Comparative Example 1 achieved a relatively low hardness rating of 3, primarily due to the low modulus of the OCA adhesive layer and the relatively low hardness of the PET and POP films. Comparative Examples 2-4 achieved hardness ratings of 4-5, lower than those of the Examples. This demonstrates that the modified black phosphorus quantum dots and grafted microcrystalline cellulose significantly enhance hardness. The modification and grafting treatments enable them to better synergize with other components of the base film, enhancing the base film's hardness.

[0139] The transmittance of Examples 1-5 is between 96.0% and 96.9%, which has a high transmittance. This is because after the modified black phosphorus quantum dots are modified with zinc-based metal organic framework materials, their high porosity and uniform pore size distribution reduce the scattering of light in the base film, and at the same time, the interaction with other components in the base film is optimized, which can regulate the absorption and transmission of light; the grafted microcrystalline cellulose makes the interior of the base film more dense and uniform, reduces the obstruction of light propagation, and reduces reflection and scattering; in addition, the laminated assembly of the present application adopts a four-layer structure directly hot-pressed, without the need for an OCA adhesive layer, reducing interface reflection loss, thereby improving the overall transmittance, so that the folding screen has a good appearance and visual experience.

[0140] The transmittance of Comparative Example 1 is 83.1%, which is relatively low. This is because the presence of the OCA adhesive layer and the PET film and POP film increases the interface reflection loss, and the transmittance of the PET film and POP film itself is lower than that of UTG. Comparative Example 2 does not add modified black phosphorus quantum dots and grafted microcrystalline cellulose, and the transmittance is 84.2%, indicating that the modified black phosphorus quantum dots and grafted microcrystalline cellulose have a significant effect on improving the transmittance. Comparative Example 3 uses unmodified black phosphorus quantum dots, and Comparative Example 4 uses ungrafted microcrystalline cellulose. The transmittances are 87.2% and 89.6%, respectively, which are lower than those in the examples. Further modification and grafting of black phosphorus quantum dots and microcrystalline cellulose, respectively, play a key role in optimizing the scattering, absorption and transmission of light and improving the transmittance.

[0141] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A UTG laminate assembly for a folding screen, characterized in that: From top to bottom, it includes: a functional base film layer, a first thermoplastic polymer layer, an ultra-thin glass layer and a second thermoplastic polymer layer; The first thermoplastic polymer layer and the second thermoplastic polymer layer are made by curing the same thermoplastic polymer composition, wherein the thermoplastic polymer composition comprises the following components by weight: 40-60 parts of thermoplastic polyurethane elastomer, 20-30 parts of polycarbonate, and 1-3 parts of nano boron nitride; The functional base film layer is made of the following raw materials by weight: 60-85 parts of polyimide resin, 20-30 parts of polyarylether nitrile, 5-15 parts of fumed nano-silica, 3-8 parts of polypentafluoropropyl methacrylate, 3-7 parts of modified black phosphorus quantum dots, 2-5 parts of grafted microcrystalline cellulose, 1-3 parts of accelerator, and 1-3 parts of ultraviolet absorber; The grafted microcrystalline cellulose is obtained by grafting polymethyl methacrylate onto microcrystalline cellulose; The modified black phosphorus quantum dots are obtained by modifying black phosphorus quantum dots with zinc-based metal organic framework materials.

2. The UTG laminate assembly for a folding screen according to claim 1, characterized in that: The modified black phosphorus quantum dots are prepared by the following method: A. Mix zinc nitrate, 2-methylimidazole, and N,N-dimethylformamide, stir at 500-700 r / min for 30-50 min, and then react at 100-120°C for 20-24 h. After the reaction, centrifuge the reaction product, wash, and dry it to obtain ZIF-8 powder; B. Mix ZIF-8 powder with black phosphorus quantum dot dispersion, ultrasonicate for 1-2 hours, and then stir at 200-300 r / min for 20-24 hours at 30-40°C. After the reaction, centrifuge the product, wash, and dry it to obtain modified black phosphorus quantum dots.

3. The UTG laminate assembly for a folding screen according to claim 2, characterized in that: In step A, the mass ratio of zinc nitrate, 2-methylimidazole and N,N-dimethylformamide is 1:(2-3):(20-30).

4. The UTG laminate assembly for a folding screen according to claim 2, characterized in that: The mass concentration of the black phosphorus quantum dot dispersion in step B is 25%-30%; the mass ratio of the ZIF-8 powder to the black phosphorus quantum dot dispersion is 1:(1-3).

5. The UTG laminate assembly for a folding screen according to claim 1, characterized in that: The grafted microcrystalline cellulose is prepared by the following method: (1) Add microcrystalline cellulose to a NaOH solution, stir at 200-400 r / min at 60-80°C for 10-12 hours, filter, and then wash with an ethanol-water mixture until the pH of the filtrate is 7-8 to obtain surface hydroxyl-activated cellulose; (2) Add surface hydroxyl-activated cellulose, methyl methacrylate, azobisisobutyronitrile and dimethyl sulfoxide into a reaction vessel, and stir at 60-70°C and 300-400 r / min for 8-12 hours under nitrogen protection; after the reaction, pour the reaction product into anhydrous ethanol for precipitation, filter and wash with anhydrous ethanol for 3-5 times, and finally vacuum dry at 50-60°C for 12-24 hours to obtain grafted microcrystalline cellulose.

6. The UTG laminate assembly for a folding screen according to claim 5, characterized in that: The mass concentration of the NaOH solution in step (1) is 5%-10%, and the mass ratio of the microcrystalline cellulose to the NaOH solution is 1:(10-15).

7. The UTG laminate assembly for a folding screen according to claim 5, characterized in that: The mass ratio of the surface hydroxyl activated cellulose, methyl methacrylate, azobisisobutyronitrile and dimethyl sulfoxide in step (2) is (1-2): (3-4): (0.05-0.1):

15.

8. A method for preparing a UTG laminate assembly for a folding screen according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Preparing a functional base film layer: uniformly mixing polyimide resin, polyarylether nitrile, fumed nano-silica, polypentafluoropropyl methacrylate, modified black phosphorus quantum dots, grafted microcrystalline cellulose, an accelerator, an ultraviolet absorber, and a solvent to obtain a base film coating, coating the base film coating on a polyester release film, drying and curing the coating, and peeling the polyester release film off to obtain a functional base film layer; S2. Preparing a thermoplastic polymer layer: mixing a thermoplastic polyurethane elastomer, polycarbonate, and nano-boron nitride to obtain a thermoplastic polymer composition, then melt-blending and extruding the composition through a twin-screw extruder at 190-200° C. to form a sheet, which is then sheared to obtain a first thermoplastic polymer layer and a second thermoplastic polymer layer, respectively; S3. Assemble the laminated components: stack the functional base film layer, the first thermoplastic polymer layer, the ultra-thin glass layer and the second thermoplastic polymer layer in sequence, put the stacked four layers of materials into a vacuum hot press, and hot press them at 110-130°C and 1.5-2.5MPa pressure for 15-25 minutes. After the hot pressing is completed, wait for the temperature to cool down to obtain the UTG laminated component for the folding screen.

9. The method for preparing a UTG laminate assembly for a folding screen according to claim 8, characterized in that: The drying and curing in S1 is performed at a temperature of 80-120° C. and a drying and curing time of 1-3 hours.

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