Photocurable modified fluorocarbon resin, and preparation method and application thereof

Abstract

This invention relates to the field of polymer materials technology, and discloses a photocurable modified fluorocarbon resin, its preparation method, and its application. The method includes: (1) mixing a hydroxyl-containing fluorocarbon resin with an organic solvent to obtain a resin solution with a concentration of 30-50 wt%; (2) contacting the resin solution with an allyl halide and an acid-binding agent, and carrying out a first reaction under inert gas protection to obtain mixture I; (3) sequentially filtering mixture I to remove inorganic salts, washing to neutrality, dehydrating, and concentrating to obtain a photocurable modified fluorocarbon resin. The photocurable modified fluorocarbon resin provided by this invention is suitable for dual protection processes of UTG acid etching and alkali etching, achieving residue-free peeling, and exhibiting a low Ra value for the UTG surface roughness after peeling. It has advantages such as strong etching resistance, fast curing speed, simple process, and low cost, making it suitable for large-scale production of foldable screen UTG.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a photocurable modified fluorocarbon resin, its preparation method, and its applications. Background Technology

[0002] Ultra-thin flexible glass (UTG) is a core substrate for flexible electronic products such as foldable screen phones and rollable displays. Its fabrication typically involves two thinning processes: hydrofluoric acid (HF) etching or sodium hydroxide (NaOH) alkaline etching. During etching, a protective material must be applied to the UTG surface to precisely control the etched area and thickness. This places stringent requirements on the protective material: it must withstand prolonged exposure to both strong acid (HF) and strong alkali (NaOH), be rapidly molded via photopolymerization, and allow for clean removal after etching.

[0003] Currently, UTG etching protection materials mainly suffer from the following technical defects: (1) It is difficult to achieve both acid and alkali resistance. Polyurethane / epoxy systems have acceptable alkali resistance, but HF molecules are small and have strong permeability, which can easily penetrate organic film layers and cause corrosion; while polytetrafluoroethylene (PTFE) systems have excellent HF resistance, but require high-temperature baking, and their alkali resistance decreases significantly after being compounded with alkali washing resin. Existing technologies are mostly designed for single resistance, and there is a lack of photocurable materials that can simultaneously resist strong acids and strong alkalis. (2) It is difficult to balance photocuring and etching resistance. Conventional photocurable resins (such as acrylates) contain ester bonds, which are easily saponified and hydrolyzed under strong alkaline conditions; although traditional fluorocarbon resins (such as GK570) have good etching resistance, they require isocyanate crosslinking, and room temperature curing requires 7 days or 80°C baking for 1 hour, which cannot meet the requirements of roll-to-roll continuous production for second-level curing. (3) High process complexity and high cost. The route of synthesizing fluorocarbon resin from monomers requires high-pressure equipment (0.4-0.9MPa), resulting in high raw material costs; the PTFE micro powder system requires special dispersion equipment and high-temperature baking (150-200℃), resulting in high energy consumption, low efficiency, and difficulty in ensuring film uniformity. (4) The contradiction between film removal and protection is prominent. Materials with good HF resistance are often difficult to remove, requiring strong mechanical peeling or high-temperature treatment; while materials that are easily washed with alkali have insufficient HF resistance and are easily damaged prematurely during etching.

[0004] Therefore, developing a low-cost protective material that can be rapidly photocured, withstand both HF acid etching and NaOH alkaline etching, and can be cleanly removed has become an urgent need for the large-scale production of UTG. Summary of the Invention

[0005] The purpose of this invention is to provide a low-cost protective material that can be rapidly photocured, withstand both HF acid etching and NaOH alkaline etching, and can be cleanly removed.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a photocurable modified fluorocarbon resin, comprising the following steps: (1) Mix the hydroxyl-containing fluorocarbon resin with an organic solvent to obtain a resin solution with a concentration of 30-50 wt%; (2) The resin solution is contacted with an allyl halide and an acid-binding agent, and a first reaction is carried out under an inert gas protection to obtain mixture I; (3) The mixture I was sequentially filtered to remove inorganic salts, washed until neutral, dehydrated and concentrated to obtain a photocurable modified fluorocarbon resin; In the hydroxyl-containing fluorocarbon resin, the solid content is 30-80 wt%, the hydroxyl value is 40-70 mg KOH / g, and the hydroxyl content is 0.7-1.25 mmol / g.

[0007] A second aspect of the present invention provides a photocurable modified fluorocarbon resin prepared by the method described in the first aspect.

[0008] The third aspect of the present invention provides an application of the photocurable modified fluorocarbon resin described in the second aspect in UTG etching protection, wherein the photocurable modified fluorocarbon resin is mixed with a photoinitiator to form a photocurable composition, and the photocurable composition is coated and cured by UV light irradiation to form a protective film, which is used as a mask layer in the etching process of ultrathin flexible glass.

[0009] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention achieves dual resistance of the same material to hydrofluoric acid (HF) and sodium hydroxide (NaOH), meeting the protection requirements of both acid etching and alkali etching processes in UTG. The film formed after curing of allyl etherified modified fluorocarbon resin retains the excellent HF resistance of the fluorocarbon backbone while the introduced ether bond structure endows the film with NaOH resistance. Experiments show that the film shows no change after immersion in 40wt% HF for 2 hours and no swelling or peeling after immersion in 10wt% NaOH (80℃) for 30 minutes. It can be used simultaneously for both acid etching and alkali etching processes in UTG, achieving residue-free peeling, and the surface roughness Ra value of UTG is low after peeling. In the prior art, the polyurethane / epoxy system is not resistant to HF, and the PTFE system requires high-temperature baking and has poor alkali resistance. Neither can achieve simultaneous resistance of a single material to two highly corrosive etching solutions and have outstanding peeling effect. (2) This invention introduces allyl double bonds into the side chain of fluorocarbon resin via the Williamson etherification reaction, enabling the obtained photocurable modified fluorocarbon resin to possess free radical photocuring capability. The curing time is shortened from 7 days (room temperature) or 1 hour (80℃ baking) required for traditional fluorocarbon resin isocyanate curing to 1-10 seconds (UV energy 100-500 mJ / cm²). 2Energy consumption is reduced by more than 90%. This feature is particularly suitable for continuous roll-to-roll (R2R) production of UTG, with line speeds reaching 1-10 m / min, significantly improving production efficiency and reducing manufacturing costs; (3) The preparation process of this invention is simple, the conditions are mild, and the equipment requirements are low, making it suitable for large-scale industrialization. Commercially available hydroxyl fluorocarbon resins (such as GK570) are directly used as raw materials, and modification is achieved in one step via a normal-pressure Williamson etherification reaction, eliminating the need for high-pressure polymerization equipment and starting from monomer synthesis. Compared with the existing route of high-pressure free radical copolymerization (0.4-0.9 MPa) from fluorinated olefin monomers, the process of this invention is safer, simpler to operate, and reduces raw material costs by approximately 40-50%, demonstrating significant advantages for industrialization. (4) This invention enables clean film removal, leaving no residue on the UTG surface after removal, thus meeting the requirements of high-precision processing. The ether bond structure in the photocurable modified fluorocarbon resin imparts moderate alkali sensitivity to the film layer, allowing for complete peeling after etching without mechanical scraping or high-temperature burning. After removal, the UTG surface is free of fluorine residue, has low surface roughness, and does not affect subsequent processes. In the prior art, materials with good HF resistance (such as PTFE and unmodified fluorocarbon resin) are often difficult to remove, requiring strong mechanical peeling or high-temperature treatment, which can easily damage ultra-thin glass; (5) The photocurable modified fluorocarbon resin provided by the present invention can be cured by UV curing in photolithography, and micron-level patterned coating can be achieved through a mask. Experiments show that the linewidth accuracy of the protective film after etching can be controlled within ±2μm, which meets the stringent requirements of foldable screen UTG for etching accuracy. Detailed Implementation

[0010] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0011] As mentioned above, the first aspect of the present invention provides a method for preparing a photocurable modified fluorocarbon resin, comprising the following steps: (1) Mix the hydroxyl-containing fluorocarbon resin with an organic solvent to obtain a resin solution with a concentration of 30-50 wt%; (2) The resin solution is contacted with an allyl halide and an acid-binding agent, and a first reaction is carried out under an inert gas protection to obtain mixture I; (3) The mixture I was sequentially filtered to remove inorganic salts, washed until neutral, dehydrated and concentrated to obtain a photocurable modified fluorocarbon resin; In the hydroxyl-containing fluorocarbon resin, the solid content is 30-80 wt%, the hydroxyl value is 40-70 mg KOH / g, and the hydroxyl content is 0.7-1.25 mmol / g.

[0012] It should be noted that the hydroxyl-containing fluorocarbon resin described in this invention refers to a polymer whose main chain or side chain contains fluorocarbon structural units and hydroxyl functional groups, including but not limited to fluoroolefin-vinyl ether copolymers (FEVE type), fluoroolefin-vinyl ester copolymers, or fluorinated polyurethanes. The hydroxyl value and hydroxyl content of the hydroxyl-containing fluorocarbon resin are both based on solids.

[0013] In a preferred embodiment, the hydroxyl-containing fluorocarbon resin is a commercially available FEVE-type fluorocarbon resin.

[0014] More preferably, the hydroxyl-containing fluorocarbon resin is selected from at least one of the ZEFFLE GK series (GK570, K550, GK580) manufactured by Daikin Industries, Ltd. of Japan and the LUMIFLON series manufactured by Asahi Glass Co., Ltd.

[0015] According to a preferred embodiment, in step (1), the organic solvent is a ketone solvent.

[0016] More preferably, the organic solvent is methyl ethyl ketone and / or methyl isobutyl ketone. In this preferred embodiment, the solubility of the material can be ensured while balancing the subsequent removal effect.

[0017] In a preferred embodiment, in step (2), the allyl halide is selected from one or more of allyl bromide, allyl chloride, and allyl iodide.

[0018] More preferably, the allyl halide is allyl bromide. In this preferred embodiment, the reaction rate and material cost can be balanced.

[0019] According to a preferred embodiment, in step (2), the acid-binding agent is an inorganic base and / or an organic base; The inorganic base is selected from at least one of potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate, and the organic base is selected from at least one of triethylamine, pyridine, and N,N-dimethylaniline.

[0020] More preferably, the acid-binding agent is selected from at least one of potassium carbonate, sodium carbonate, potassium bicarbonate, and triethylamine.

[0021] Preferably, in step (2), the first reaction is a Williamson etherification reaction.

[0022] Preferably, in step (2), the inert gas is nitrogen.

[0023] In step (2), the conditions for the first reaction must at least be met: reaction temperature 60-120℃, reaction time 4-24 hours.

[0024] More preferably, in step (2), the conditions for the first reaction are at least: reaction temperature 80-100℃ and reaction time 8-12 hours.

[0025] In a preferred embodiment, in step (2), the molar ratio of the allyl halide to the molar ratio of the hydroxyl group in the fluorocarbon resin is 1.0-1.2:1.

[0026] In a preferred embodiment, in step (2), the molar ratio of the acid-binding agent to the molar ratio of the allyl halide is 1.0-1.5:1.

[0027] Preferably, in step (3), the concentration is carried out by vacuum distillation, and the conditions are at least: pressure of 1-200 mbar, temperature of 20-80℃, and time of 0.5-6 hours.

[0028] As previously stated, a second aspect of the present invention provides a photocurable modified fluorocarbon resin prepared by the method described in the first aspect.

[0029] Preferably, the double bond content of the photocurable modified fluorocarbon resin is 0.5-2.0 mmol / g, and the hydroxyl residual rate is less than 10%.

[0030] As mentioned above, a third aspect of the present invention provides the application of the photocurable modified fluorocarbon resin described in the second aspect in UTG etching protection, wherein the photocurable modified fluorocarbon resin is mixed with a photoinitiator to form a photocurable composition, and the photocurable composition is coated and cured by UV light irradiation to form a protective film, which is used as a mask layer in the etching process of ultrathin flexible glass.

[0031] Preferably, in the photocurable composition, the photocurable modified fluorocarbon resin accounts for 100 parts by weight, and the photoinitiator accounts for 1-5 parts by weight; the photocurable composition also optionally contains 0-20 parts by weight of an active diluent.

[0032] More preferably, the photocurable composition, with 100 parts by weight of the photocurable modified fluorocarbon resin, optionally also contains 0.1-2 parts by weight of a leveling agent.

[0033] Preferably, the reactive diluent is selected from at least one of trimethylolpropane triacrylate, dipropylene glycol diacrylate, and dipentaerythritol hexaacrylate.

[0034] Preferably, the photoinitiator is selected from at least one of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 1-hydroxycyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0035] Preferably, the UTG etching process in the UTG etching protection is acid etching and / or alkaline etching; and, When the UTG etching process in the UTG etching protection is acid etching, the acid etching conditions are: HF concentration 1-40wt%, temperature 20-40℃, time 10-120min, and the protective film can withstand these conditions. When the UTG etching process in the UTG etching protection is alkaline etching, the alkaline etching conditions are: NaOH concentration 10-50wt%, temperature 50-120℃, time 5-60min, and the protective film can withstand these conditions.

[0036] Preferably, the UV curing conditions for the protective film are: wavelength 200-400 nm, energy 100-500 mJ / cm². 2 Curing time is 1-10 seconds.

[0037] Preferably, the thickness of the protective film is 5-50 μm.

[0038] Preferably, the UTG etching protection method includes the following steps: S1. The photocurable composition is coated onto the surface of an ultrathin flexible glass to form a wet film; S2. The wet film is cured by UV light irradiation to form the protective film; S3. Etching is performed on the ultra-thin flexible glass covered with the protective film; S4. After etching, use a stripping solution to treat at 50-80℃ for 10-20 minutes to peel off the protective film.

[0039] Preferably, in step S1, the coating method is spin coating, spray coating, or slot coating.

[0040] Preferably, in step S2, the wavelength of the UV light is 365nm or 395nm, and the energy is 200-300mJ / cm². 2 .

[0041] Preferably, in step S4, the stripping solution is a stripping solution containing 5-10 wt% of a strong oxidizing component and an organic solvent.

[0042] More preferably, the oxidant is hydrogen peroxide or potassium permanganate, and the solvent is dimethyl sulfoxide (DMSO) or dimethylformamide (DMF).

[0043] The present invention will be described in detail below through examples. Unless otherwise specified, the raw materials used are all commercially available products.

[0044] Hydroxyl-containing fluorocarbon resins: Hydroxyl-containing fluorocarbon resin I: ZEFFLE GK series GK570 manufactured by Daikin Industries, Ltd. of Japan, with a solid content of 65wt%, and a hydroxyl value of 60mg KOH / g and a hydroxyl content of 0.86mmol / g based on solid content; Hydroxyl-containing fluorocarbon resin II: JF-3X (or JF-2X / JF-2XA) produced by Changshu Sanai Fuzhonghao Chemical New Materials Co., Ltd., with a solid content of 50wt%, and a hydroxyl value of 50±5mg KOH / g based on solid content, and a hydroxyl content of approximately 0.89mmol / g; Photocurable mask: Dymax 730-BT, purchased from Dymax Corporation, USA; Organic solvents: Organic solvent I: methyl ethyl ketone, purchased from Xilong Scientific Co., Ltd.; Organic solvent II: dimethyl sulfoxide, purchased from Xilong Scientific Co., Ltd.; Allyl halides: Allyl halide I: Allyl bromide, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Allyl halide II: Allyl chloride, purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; Acid-binding agent: potassium carbonate, purchased from Xilong Scientific Co., Ltd.; Photoinitiator: Diphenyl-(2,4,6-trimethylbenzoyl (TPO)); Reactive diluent: Trimethylolpropane triacrylate (TMPTA), purchased from Changxing Chemical Industry (China) Co., Ltd. Leveling agent: BYK-333, purchased from BYK Chemical Company, Germany.

[0045] Example 1: This example illustrates the preparation method of the photocurable modified fluorocarbon resin provided by the present invention, which includes the following steps: Equation (1); (1) Dissolve 100g of hydroxyl-containing fluorocarbon resin (fluorocarbon resin I) in 85.7g of organic solvent (organic solvent I) to obtain a resin solution with a concentration of 35wt%; (2) The resin solution is contacted with allyl halide (allyl halide I) and acid-binding agent, and the first reaction is carried out for 12 hours under the protection of inert gas (nitrogen) and at a temperature of 80°C (Williamson etherification reaction, the reaction principle is shown in formula (1)) to obtain mixture I; The molar ratio of the allyl halide to the molar ratio of the hydroxyl groups in the fluorocarbon resin is 1.1:1; The molar ratio of the acid-binding agent to the allyl halide is 1.25:1; (3) The mixture I was filtered to remove inorganic salts (KBr) and excess acid binder, then washed with deionized water until neutral, and then dried with anhydrous sodium sulfate to remove water. The mixture was concentrated by vacuum distillation (pressure 35 mbar, oil bath temperature 45℃, time 1.5 hours) to obtain photocurable modified fluorocarbon resin, named P1. The double bond content was determined to be 1.2 mmol / g and the hydroxyl residue rate was 5%.

[0046] Example 2: This example is carried out using a method similar to that of Example 1. The difference is that in step (1), the hydroxyl-containing fluorocarbon resin used is fluorocarbon resin II. Specifically: (1) 100g of hydroxyl-containing fluorocarbon resin (fluorocarbon resin II) is dissolved in 42.9g of organic solvent (organic solvent I) to obtain a resin solution with a concentration of 35wt%. Finally, a photocurable modified fluorocarbon resin was obtained, named P2. Its double bond content was measured to be 1.0 mmol / g and its hydroxyl residue rate was 8%.

[0047] Example 3: This example uses a similar method to Example 1, except that the organic solvent used is Organic Solvent II. Due to the problem of slow concentration rate, the oil bath temperature of vacuum distillation is increased to 100°C and the time is extended to 5 hours. Finally, a photocurable modified fluorocarbon resin was obtained, named P3. Its double bond content was measured to be 1.15 mmol / g and its hydroxyl residue rate was 6%.

[0048] Example 4: This example is carried out using a method similar to that of Example 1, except that the allyl halide used is allyl halide II; Finally, a photocurable modified fluorocarbon resin was obtained, named P4. Its double bond content was measured to be 0.8 mmol / g and its hydroxyl residue rate was 15%.

[0049] Comparative Example 1: This comparative example was conducted using a method similar to that of Example 1, except that in step (1), the amount of organic solvent was changed so that the concentration of the resulting resin solution was 15 wt%. Finally, a photocurable modified fluorocarbon resin was obtained, named DP1. Its double bond content was measured to be 0.6 mmol / g and its hydroxyl residual rate was 25%.

[0050] Comparative Example 2: Preparation of polyurethane acrylate system: 100g of polycaprolactone diol (PCL, molecular weight 1000), 100g of dimethylformamide, 0.15g of dilauryl dibutyltin, and 43.5g of toluene diisocyanate (TDI) were reacted at 80°C for 2 hours under nitrogen protection to obtain an NCO-terminated polyurethane prepolymer. Then, 28g of hydroxyethyl acrylate (HEA) was added for end-capping reaction, and the reaction was carried out at 70°C for 3 hours to obtain a polyurethane acrylate prepolymer. Finally, 3g of photoinitiator TPO and 5g of reactive diluent TMPTA were added and stirred evenly to obtain a polyurethane acrylate photocurable system. Finally, a polyurethane acrylate photocurable composition was obtained and named DP2.

[0051] Test Example 1: The photocurable modified fluorocarbon resins obtained in the above examples were used to prepare photocurable compositions and compared with the applications of polyurethane acrylate photocurable compositions (DP2), GK570, and photocurable masks in UTG etching (acid etching) protection: Preparation of photocurable compositions: 100g of the photocurable modified fluorocarbon resin prepared in the above example was mixed with 3g of photoinitiator, 5g of reactive diluent and 0.5g of leveling agent to form a photocurable composition.

[0052] S1. Apply the photocurable composition or DP2, GK570 to the surface of an ultrathin flexible glass (UTG) with a thickness of 100μm by spin coating (1500rpm, 30 seconds) to form a wet film. S2. Uses UV light (wavelength 365nm, energy 300mJ / cm²). 2 Irradiation for 5 seconds forms a protective film with a thickness of approximately 20 μm; S3. Etching the ultrathin flexible glass covered with the protective film: Immerse the UTG obtained in step S2 in a 40wt% HF solution and etch at 25°C for 30 minutes; after removal, check and record the state of the protective film and the non-etched area of ​​the UTG. S4. After etching, immerse the protective film in stripping solution at 60°C for 15 minutes to peel off the protective film. Record the peeling condition and surface roughness. The results are shown in Table 1. The curing conditions in step S2 of group GK570 are: isocyanate curing, baking at 80°C for 1 hour.

[0053] Test Example 2: The photocurable modified fluorocarbon resin obtained in the above examples was used to prepare a photocurable composition, and its application in UTG etching (alkaline etching) protection was compared with that of polyurethane acrylate photocurable composition (DP2), GK570, and photocurable mask: Preparation of photocurable compositions: 100g of the photocurable modified fluorocarbon resin prepared in the above example was mixed with 3g of photoinitiator, 5g of reactive diluent and 0.5g of leveling agent to form a photocurable composition: S1. Apply the photocurable composition or DP2, GK570 to the surface of an ultrathin flexible glass (UTG) with a thickness of 150μm by spin coating (1500rpm, 30 seconds) to form a wet film. S2. Use UV light (wavelength 395nm, energy 250mJ / cm²). 2 Irradiation for 4 seconds forms a protective film with a thickness of approximately 15 μm; S3. Etching the ultrathin flexible glass covered with the protective film: Immerse the UTG obtained in step S2 in a 10wt% sodium hydroxide solution and etch at 80°C for 20 minutes; after removal, check and record the state of the protective film and the non-etched area of ​​the UTG, as well as the etching line width accuracy. S4. After etching, immerse the protective film in stripping solution at 70°C for 10 minutes to peel off the protective film. Record the peeling condition and surface roughness. The results are shown in Table 1. The curing conditions in step S2 of group GK570 are: isocyanate curing, baking at 80°C for 1 hour.

[0054] Test Example 3 This test case was conducted using a method similar to that of Test Case 1. The difference was that step S4 was not performed. Instead, the soaking time in step S3 was extended until the protective film failed (penetration, bubbling, or peeling occurred), and the time was recorded. The results are shown in Table 2. The curing conditions in step S2 of group GK570 are: isocyanate curing, baking at 80°C for 1 hour.

[0055] Test Example 4 This test case uses a similar method to Test Case 1, except that step S3 is different. Step S3 involves acid etching and alkaline etching sequentially, specifically: S3. Etching process is performed on the ultra-thin flexible glass covered with the protective film: First, immerse the UTG obtained in step S2 in a 40wt% HF solution and etch it at 25°C for 30 minutes; Then, the obtained UTG was rinsed with deionized water and then immersed in a 10wt% sodium hydroxide solution and etched at 80℃ for 20min. After removal, the condition of the protective film and the non-etched area of ​​the UTG, as well as the etching linewidth accuracy, were checked and recorded. S4. After etching, immerse the protective film in a stripping solution at 65°C for 10 minutes to peel off the protective film. Record the peeling condition and surface roughness. See Table 2 for the results. The curing conditions in step S2 of group GK570 are: isocyanate curing, baking at 80°C for 1 hour; Table 1 Note: In the table, "A" indicates no swelling or detachment, "B" indicates slight swelling or localized blistering, and "C" indicates significant swelling or detachment. "0" indicates no residue, "1" indicates trace residue, "2" indicates significant residue, and "-" indicates no test. Table 2 Note: In the table, "A" indicates no swelling or detachment of the membrane layer; "B" indicates slight swelling or localized blistering of the membrane layer; "C" indicates significant swelling or detachment of the membrane layer; and "D" indicates severe damage or complete detachment of the membrane layer. "0" indicates no residue, "1" indicates trace residue, "2" indicates significant residue, and "-" indicates no test.

[0056] The above data shows that the present invention modifies commercially available hydroxyl fluorocarbon resin by allyl etherification through Williamson etherification. The resulting resin, after UV curing, forms a film that can simultaneously withstand 40 wt% HF and 10 wt% sodium hydroxide solution, making it suitable for dual protection processes of UTG acid etching and alkaline etching. The curing time is only 1-10 seconds, reducing energy consumption by more than 90%. After etching, the film can be cleanly removed, and the surface roughness Ra < 0.5 nm. The present invention has the advantages of strong etching resistance, fast curing speed, simple process, and low cost, making it suitable for large-scale production of foldable screen UTG.

[0057] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a photocurable modified fluorocarbon resin, characterized in that, Includes the following steps: (1) Mix the hydroxyl-containing fluorocarbon resin with an organic solvent to obtain a resin solution with a concentration of 30-50 wt%; (2) The resin solution is contacted with an allyl halide and an acid-binding agent, and a first reaction is carried out under an inert gas protection to obtain mixture I; (3) The mixture I was sequentially filtered to remove inorganic salts, washed until neutral, dehydrated and concentrated to obtain a photocurable modified fluorocarbon resin; In the hydroxyl-containing fluorocarbon resin, the solid content is 30-80 wt%, the hydroxyl value is 40-70 mg KOH / g, and the hydroxyl content is 0.7-1.25 mmol / g.

2. The method according to claim 1, characterized in that, The hydroxyl-containing fluorocarbon resin is a commercially available FEVE-type fluorocarbon resin.

3. The method according to claim 1 or 2, characterized in that, In step (1), the organic solvent is a ketone solvent.

4. The method according to claim 1 or 2, characterized in that, In step (2), the allyl halide is selected from one or more of allyl bromide, allyl chloride, and allyl iodide.

5. The method according to claim 1 or 2, characterized in that, In step (2), the acid-binding agent is an inorganic base and / or an organic base; The inorganic base is selected from at least one of potassium carbonate, sodium carbonate, potassium bicarbonate, and sodium bicarbonate, and the organic base is selected from at least one of triethylamine, pyridine, and N,N-dimethylaniline.

6. The method according to claim 1 or 2, characterized in that, In step (2), the conditions for the first reaction must at least be met: reaction temperature 60-120℃, reaction time 4-24 hours.

7. The method according to claim 1 or 2, characterized in that, In step (2), the molar ratio of the allyl halide to the molar ratio of the hydroxyl group in the fluorocarbon resin is 1.0-1.2:1; The molar ratio of the acid-binding agent to the allyl halide is 1.0-1.5:

1.

8. A photocurable modified fluorocarbon resin prepared by the method according to any one of claims 1-7.

9. The application of the photocurable modified fluorocarbon resin according to claim 8 in UTG etching protection, characterized in that, The photocurable modified fluorocarbon resin is mixed with a photoinitiator to form a photocurable composition. The photocurable composition is coated and cured by UV light to form a protective film. The protective film is used as a mask layer in the etching process of ultrathin flexible glass.

10. The application according to claim 9, characterized in that, The UTG etching process in the UTG etching protection is acid etching and / or alkaline etching; and... When the UTG etching process in the UTG etching protection is acid etching, the acid etching conditions are: HF concentration 1-40wt%, temperature 20-40℃, time 10-120min, and the protective film can withstand these conditions. When the UTG etching process in the UTG etching protection is alkaline etching, the alkaline etching conditions are: NaOH concentration 10-50wt%, temperature 50-120℃, time 5-60min, and the protective film can withstand these conditions.

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