High-wear-resistance UV (ultraviolet) hardening coating for PET (polyethylene terephthalate) base material and preparation method thereof

Abstract

The invention relates to the field of coatings, in particular to a high-wear-resistance UV (ultraviolet) hardening coating for a PET (polyethylene terephthalate) base material and a preparation method of the high-wear-resistance UV hardening coating, which are used for solving the problems that the existing UV hardening coating is often poor in water resistance and wear resistance and is difficult to effectively protect the PET base material. According to the coating, fluorine-containing polyalkenyl polyurethane is used as a main raw material, the water resistance and wear resistance of a coating can be effectively improved, and the wear resistance of the coating can be further improved by adding the lubricating microcapsules, so that the coating is unlikely to be eroded by water, the wear rate of the coating is reduced, and the service life of the coating is greatly prolonged; therefore, an ideal high-wear-resistant effect is achieved, and the PET base material is ensured to keep good appearance and functional characteristics in a long-time use process.

Description

Technical Field

[0001] This invention relates to the field of coatings, specifically to a high abrasion-resistant UV-curable coating for PET substrates and its preparation method. Background Technology

[0002] PET substrates are widely used in touch screens, flexible displays, and packaging decoration due to their excellent transparency, mechanical properties, and cost advantages. However, PET has low surface hardness, is easily scratched, and has poor abrasion resistance, making it prone to scratches that affect its appearance and lifespan, thus limiting its application in high-end products.

[0003] Currently, one common method for improving surface abrasion resistance is the use of UV-cured coatings, which offer advantages such as rapid curing, solvent-free processing, and environmental friendliness. However, existing UV-cured coatings often suffer from poor water resistance and abrasion resistance, easily leading to surface damage or peeling after exposure to moisture or friction from sharp objects, making it difficult to effectively protect PET substrates. Therefore, developing a highly abrasion-resistant UV-cured coating for PET substrates and its preparation method is of great significance. Summary of the Invention

[0004] In order to overcome the above-mentioned technical problems, the present invention aims to provide a high abrasion-resistant UV-curable coating for PET substrate and its preparation method, which solves the problem that existing UV-curable coatings often have poor water resistance and abrasion resistance, making it difficult to effectively protect PET substrates.

[0005] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a high abrasion-resistant UV-curable coating for PET substrates, comprising the following components in parts by weight: The ingredients are: 30-50 parts of fluorinated polyene-based polyurethane, 1-7 parts of lubricating microcapsules, 10-15 parts of diluent, 0.5-0.9 parts of leveling agent, 1-3 parts of photoinitiator, 8-12 parts of nano-silica, and 60-70 parts of anhydrous ethanol. The fluorinated polyene-based polyurethane is prepared by the following steps: Step a1: Add p-fluorobenzonitrile, p-phenylenediamine, sodium hydride, and dimethyl sulfoxide to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25℃ and 200-300 r / min for 20-30 min. Then raise the temperature to 130-150℃ and continue stirring for 15-20 h. After the reaction is complete, cool the reaction product to room temperature and add it to an ethanol solution. Then filter under vacuum and recrystallize the filter cake with N,N-dimethylformamide. Then place it in a vacuum drying oven and dry it at 70-80℃ for 1-3 h to obtain a polycyano compound. Step a2: Add the polycyano compound, potassium hydroxide, anhydrous ethanol, and deionized water to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25℃ and 200-300 r / min for 20-30 min. Then raise the temperature to 80-85℃ and continue stirring for 8-10 h. After the reaction is complete, filter the reaction product under vacuum while it is hot. Cool the filtrate to room temperature and adjust the pH to 2-3 with hydrochloric acid solution. Then filter under vacuum and recrystallize the filter cake with glacial acetic acid. Then place it in a vacuum drying oven and dry it at 50-60℃ for 2-3 h to obtain the polycarboxylic acid compound. Step a3: Add the polycarboxylic acid compound, allyl alcohol glycidyl ether, p-hydroxyanisole, triphenylphosphine, and N-methylpyrrolidone to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir the reaction at 20-25℃ and 200-300 r / min for 10-20 min. Then raise the temperature to 90-100℃ and continue stirring for 3-5 h. After the reaction is complete, cool the reaction product to room temperature, remove the solvent by rotary evaporation, wash with anhydrous ethanol 3-5 times, and then place it in a vacuum drying oven and dry at 50-60℃ for 2-3 h to obtain the polyhydroxy alkenyl compound. Step a4: Add the polyhydroxy alkenyl compound, dibutyltin dilaurate, and n-butyl acetate to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Purge with nitrogen for protection and stir at 20-25°C and 200-300 r / min for 20-30 min. Then raise the temperature to 50-60°C and continue stirring for 10-20 min. Add isophorone diisocyanate and continue stirring for 3-5 h. Then raise the temperature to 70-80°C and add octafluoropentanol and continue stirring for 1-3 h. After the reaction is complete, cool the reaction product to room temperature and let it stand for 20-30 h. Then add it to anhydrous diethyl ether and filter under vacuum. Place the filter cake in a vacuum drying oven and dry at 40-50°C for 2-4 h to obtain fluorinated polyolefin polyurethane.

[0006] In a preferred embodiment of the present invention, the ratio of p-fluorobenzonitrile, p-phenylenediamine, sodium hydride and dimethyl sulfoxide in step a1 is 40 mmol: 10 mmol: 45-50 mmol: 100-120 mL.

[0007] In a preferred embodiment of the present invention, the volume fraction of the ethanol solution in step a1 is 50-60%.

[0008] In a preferred embodiment of the present invention, the ratio of the polycyano compound, potassium hydroxide, anhydrous ethanol and deionized water in step a2 is 10 mmol: 30-35 g: 90-100 mL: 90-100 mL.

[0009] In a preferred embodiment of the present invention, the mass fraction of the hydrochloric acid solution in step a2 is 15-20%.

[0010] In a preferred embodiment of the present invention, the ratio of the polycarboxylic acid compound, allyl alcohol glycidyl ether, p-hydroxyanisole, triphenylphosphine and N-methylpyrrolidone in step a3 is 10 mmol: 40 mmol: 0.03-0.05 g: 0.1-0.2 g: 90-100 mL.

[0011] In a preferred embodiment of the present invention, the ratio of the polyhydroxy alkenyl compound, dibutyltin dilaurate, n-butyl acetate, isophorone diisocyanate and octafluoropentanol in step a4 is 10-30 mmol: 0.03-0.05 g: 60-70 mL: 60-70 mmol: 5-15 mmol.

[0012] In a preferred embodiment of the present invention, the lubricating microcapsules are prepared by the following steps: Gum arabic, β-cyclodextrin, Tween 80, and deionized water were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred and reacted at 20-25°C and 200-300 r / min for 1-2 hours. Then, the temperature was raised to 50-60°C, linseed oil was added, and the mixture was stirred and reacted for another 10-20 minutes. After that, the mixture was emulsified at 14000-15000 r / min for 40-60 minutes. Finally, the mixture was spray-dried at an inlet air temperature of 170-180°C to obtain lubricating microcapsules.

[0013] In a preferred embodiment of the present invention, the ratio of gum arabic, β-cyclodextrin, Tween 80, deionized water and linseed oil is 6-8g: 1-1.2g: 0.08-0.12g: 90-100mL: 3g.

[0014] As a preferred embodiment of the present invention, a method for preparing a high abrasion-resistant UV-curable coating for PET substrates includes the following steps: Step 1: Weigh out 30-50 parts of fluorinated polyene-based polyurethane, 1-7 parts of lubricating microcapsules, 10-15 parts of diluent, 0.5-0.9 parts of leveling agent, 1-3 parts of photoinitiator, 8-12 parts of nano-silica, and 60-70 parts of anhydrous ethanol according to the following weight proportions, and set aside for later use. Step 2: Mix fluorinated polyene-based polyurethane, lubricating microcapsules, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0015] In a preferred embodiment of the present invention, the diluent is 1,6-hexanediol diacrylate.

[0016] In a preferred embodiment of the present invention, the leveling agent is BYK-333.

[0017] In a preferred embodiment of the present invention, the photoinitiator is 1173 photoinitiator.

[0018] The beneficial effects of this invention are: This invention discloses a high-abrasion-resistant UV-curable coating for PET substrates and its preparation method. The coating is prepared by uniformly mixing fluorinated polyene-based polyurethane, lubricating microcapsules, a diluent, a leveling agent, a photoinitiator, nano-silica, and anhydrous ethanol. The coating uses fluorinated polyene-based polyurethane as the main raw material, which effectively improves the water resistance and abrasion resistance of the coating. Adding lubricating microcapsules further enhances its abrasion resistance, making the coating less susceptible to water erosion and reducing the wear rate, thus significantly extending the coating's service life. This achieves an ideal high abrasion resistance effect, ensuring that the PET substrate maintains good appearance and functional properties during long-term use.

[0019] In the preparation of a high-abrasion-resistant UV-curable coating for PET substrates, a fluorinated polyolefin polyurethane was first prepared. This involved the reaction of p-fluorobenzonitrile and p-phenylenediamine, where the fluorine atom on the p-fluorobenzonitrile reacts with the amino group on the p-phenylenediamine to form a tertiary amine group and introduce multiple cyano groups, yielding a polycyano compound. Subsequently, the cyano groups on the polycyano compound were hydrolyzed to form carboxyl groups, resulting in a polycarboxyl compound. This polycarboxyl compound was then reacted with allyl alcohol glycidyl ether, where the carboxyl groups on the polycarboxyl compound react with the epoxy groups on the allyl alcohol glycidyl ether to form hydroxyl groups and introduce multiple alkenyl groups, yielding a polyhydroxy alkenyl compound. Finally, this polyhydroxy alkenyl compound was used as a hydroxyl monomer, and isophorone dimethyl ether was used... Isocyanates are polymerized from isocyanate monomers to form polyurethane. The polyurethane molecular chain contains a large number of alkenes, and the polyurethane is end-capped using the hydroxyl groups on octafluoropentanol to obtain fluorinated polyene polyurethane. In the synthesis process of this fluorinated polyene polyurethane, multiple hydroxyl groups are used to achieve cross-linking of the polyurethane. The introduced alkenes can achieve rapid photocuring and further cross-linking, thereby improving the density of the coating and effectively improving the water resistance and wear resistance of the coating. The presence of multiple fluorine atoms in its molecular structure can effectively make the coating more chemically inert, not easily corroded by water and organic solvents. At the same time, it makes the coating have a lower surface energy, which greatly improves its lubricity, thereby improving the wear resistance of the coating.

[0020] In the process of preparing a high wear-resistant UV-curable coating for PET substrate, a lubricating microcapsule was also prepared. The lubricating microcapsule is filled with linseed oil. When the coating is damaged by friction, the linseed oil is slowly released, and a thin oil film is formed at the damaged area. This can repair the damaged area and improve the lubricity of the coating, thereby reducing the wear rate of the coating and significantly improving the wear resistance of the coating. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1:

[0022] This embodiment describes a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 40 mmol of p-fluorobenzonitrile, 10 mmol of p-phenylenediamine, 45 mmol of sodium hydride and 100 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20 °C and 200 r / min for 20 min. Then the temperature was raised to 130 °C and the mixture was stirred for 15 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a 50% ethanol solution. The mixture was then vacuum filtered. The filter cake was recrystallized with N,N-dimethylformamide and then placed in a vacuum drying oven and dried at 70 °C for 1 h to obtain a polycyano compound. Step S2: Add 10 mmol of polycyano compound, 30 g of potassium hydroxide, 90 mL of anhydrous ethanol and 90 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 20 °C and 200 r / min for 20 min. Then raise the temperature to 80 °C and continue stirring for 8 h. After the reaction is complete, filter the reaction product under vacuum while hot. Cool the filtrate to room temperature and adjust the pH to 2 with 15% hydrochloric acid solution. Then filter under vacuum and recrystallize the filter cake with glacial acetic acid. Then place it in a vacuum drying oven and dry at 50 °C for 2 h to obtain polycarboxylic acid compound. Step S3: 10 mmol of the polycarboxylic acid compound, 40 mmol of allyl alcohol glycidyl ether, 0.03 g of p-hydroxyanisole, 0.1 g of triphenylphosphine, and 90 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 20 °C and 200 r / min for 10 min. Then, the temperature was raised to 90 °C and the mixture was stirred for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, and the solvent was removed by rotary evaporation. The product was then washed three times with anhydrous ethanol and placed in a vacuum drying oven at 50 °C for 2 h to obtain the polyhydroxy alkenyl compound. Step S4: 10 mmol of polyhydroxy alkenyl compound, 0.03 g of dibutyltin dilaurate and 60 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 20 °C and 200 r / min for 20 min. Then the temperature was raised to 50 °C and the mixture was stirred for 10 min. Then 60 mmol of isophorone diisocyanate was added and the mixture was stirred for 3 h. Then the temperature was raised to 70 °C and 5 mmol of octafluoropentanol was added and the mixture was stirred for 1 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 20 h. Then it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 40 °C for 2 h to obtain fluorinated polyolefin polyurethane. Step S5: Add 6g gum arabic, 1g β-cyclodextrin, 0.08g Tween 80 and 90mL deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 20℃ and 200r / min for 1h. Then raise the temperature to 50℃ and add 3g linseed oil and continue stirring for 10min. Then emulsify at 14000r / min for 40min. Finally, spray dry at 170℃ to obtain lubricating microcapsules. Step S6: Weigh out 30 parts by weight of fluorinated polyene-based polyurethane, 1 part of lubricating microcapsules, 10 parts of diluent, 0.5 parts of leveling agent, 1 part of photoinitiator, 8 parts of nano-silica, and 60 parts of anhydrous ethanol, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; and the photoinitiator is 1173 photoinitiator; Step S7: Mix fluorinated polyene-based polyurethane, lubricating microcapsules, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate. Example 2:

[0023] This embodiment describes a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 40 mmol of p-fluorobenzonitrile, 10 mmol of p-phenylenediamine, 48 mmol of sodium hydride and 110 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 25 min. Then the temperature was raised to 140 °C and the mixture was stirred for 18 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a 55% ethanol solution. The mixture was then vacuum filtered. The filter cake was recrystallized with N,N-dimethylformamide and then placed in a vacuum drying oven and dried at 75 °C for 2 h to obtain a polycyano compound. Step S2: 10 mmol of polycyano compound, 32 g of potassium hydroxide, 95 mL of anhydrous ethanol and 95 mL of deionized water were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 25 min. Then the temperature was raised to 82 °C and the mixture was stirred for 9 h. After the reaction was completed, the reaction product was filtered under vacuum while hot. The filtrate was cooled to room temperature and then adjusted to pH 2.5 with 18% hydrochloric acid solution. After vacuum filtration, the filter cake was recrystallized with glacial acetic acid and then placed in a vacuum drying oven and dried at 55 °C for 2.5 h to obtain polycarboxylic acid compound. Step S3: 10 mmol of the polycarboxylic acid compound, 40 mmol of allyl alcohol glycidyl ether, 0.04 g of p-hydroxyanisole, 0.15 g of triphenylphosphine, and 95 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 22 °C and 250 r / min for 15 min. The mixture was then heated to 95 °C and stirred for another 4 h. After the reaction was completed, the product was cooled to room temperature, and the solvent was removed by rotary evaporation. The product was then washed four times with anhydrous ethanol and placed in a vacuum drying oven at 55 °C for 2.5 h to obtain the polyhydroxy alkenyl compound. Step S4: 20 mmol of polyhydroxy alkenyl compound, 0.04 g of dibutyltin dilaurate and 65 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 22 °C and 250 r / min for 25 min. Then the temperature was raised to 55 °C and the mixture was stirred for 15 min. Then 65 mmol of isophorone diisocyanate was added and the mixture was stirred for 4 h. Then the temperature was raised to 75 °C and 10 mmol of octafluoropentanol was added and the mixture was stirred for 2 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 25 h. Then it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 45 °C for 3 h to obtain fluorinated polyolefin polyurethane. Step S5: Add 7g gum arabic, 1.1g β-cyclodextrin, 0.1g Tween 80 and 95mL deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 22℃ and 250r / min for 1.5h. Then raise the temperature to 55℃ and add 3g linseed oil and continue stirring for 15min. Then emulsify at 14500r / min for 50min. Finally, spray dry at 175℃ to obtain lubricating microcapsules. Step S6: Weigh out 40 parts by weight of fluorinated polyene-based polyurethane, 4 parts by weight of lubricating microcapsules, 12 parts by weight of diluent, 0.7 parts by weight of leveling agent, 2 parts by weight of photoinitiator, 10 parts by weight of nano-silica, and 65 parts by weight of anhydrous ethanol, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; the photoinitiator is 1173 photoinitiator; Step S7: Mix fluorinated polyene-based polyurethane, lubricating microcapsules, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate. Example 3:

[0024] This embodiment describes a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 40 mmol of p-fluorobenzonitrile, 10 mmol of p-phenylenediamine, 50 mmol of sodium hydride and 120 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 150 °C and the mixture was stirred for 20 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a 60% ethanol solution. The mixture was then vacuum filtered. The filter cake was recrystallized with N,N-dimethylformamide and then placed in a vacuum drying oven and dried at 80 °C for 3 h to obtain a polycyano compound. Step S2: Add 10 mmol of polycyano compound, 35 g of potassium hydroxide, 100 mL of anhydrous ethanol and 100 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25 °C and 300 r / min for 30 min. Then raise the temperature to 85 °C and continue stirring for 10 h. After the reaction is complete, filter the reaction product under vacuum while hot. Cool the filtrate to room temperature and adjust the pH to 3 with 20% hydrochloric acid solution. Then filter under vacuum and recrystallize the filter cake with glacial acetic acid. Then place it in a vacuum drying oven and dry at 60 °C for 3 h to obtain polycarboxylic acid compound. Step S3: 10 mmol of polycarboxylic acid compound, 40 mmol of allyl alcohol glycidyl ether, 0.05 g of p-hydroxyanisole, 0.2 g of triphenylphosphine and 100 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 100 °C and the mixture was stirred for 5 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed 5 times with anhydrous ethanol and then placed in a vacuum drying oven and dried at 60 °C for 3 h to obtain the polyhydroxy alkenyl compound. Step S4: 30 mmol of polyhydroxy alkenyl compound, 0.05 g of dibutyltin dilaurate and 70 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 60 °C and the mixture was stirred for another 20 min. Then 70 mmol of isophorone diisocyanate was added and the mixture was stirred for another 5 h. Then the temperature was raised to 80 °C and 15 mmol of octafluoropentanol was added and the mixture was stirred for another 3 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 30 h. Then it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 50 °C for 4 h to obtain fluorinated polyolefin polyurethane. Step S5: Add 8g gum arabic, 1.2g β-cyclodextrin, 0.12g Tween 80 and 100mL deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 2h. Then raise the temperature to 60℃ and add 3g linseed oil and continue stirring for 20min. Then emulsify at 15000r / min for 60min. Finally, spray dry at 180℃ to obtain lubricating microcapsules. Step S6: Weigh out 50 parts by weight of fluorinated polyene-based polyurethane, 7 parts by weight of lubricating microcapsules, 15 parts by weight of diluent, 0.9 parts by weight of leveling agent, 3 parts by weight of photoinitiator, 12 parts by weight of nano-silica, and 70 parts by weight of anhydrous ethanol, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; the photoinitiator is 1173 photoinitiator; Step S7: Mix fluorinated polyene-based polyurethane, lubricating microcapsules, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0025] Comparative Example 1: This comparative example illustrates a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 30 mmol of polycaprolactone diol PCL1000, 0.05 g of dibutyltin dilaurate, and 70 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and 300 r / min for 30 min. Then, the temperature was raised to 60 °C and the mixture was stirred for another 20 min. 70 mmol of isophorone diisocyanate was added and the mixture was stirred for another 5 h. The temperature was raised to 80 °C and the mixture was stirred for another 3 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 30 h. Then, it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 50 °C for 4 h to obtain polyurethane. Step S2: Weigh out 50 parts of polyurethane, 15 parts of diluent, 0.9 parts of leveling agent, 3 parts of photoinitiator, 12 parts of nano silica, and 70 parts of anhydrous ethanol according to the following weight proportions, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; and the photoinitiator is 1173 photoinitiator; Step S3: Mix polyurethane, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0026] Comparative Example 2: This comparative example illustrates a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 40 mmol of p-fluorobenzonitrile, 10 mmol of p-phenylenediamine, 50 mmol of sodium hydride and 120 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 150 °C and the mixture was stirred for 20 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a 60% ethanol solution. The mixture was then vacuum filtered. The filter cake was recrystallized with N,N-dimethylformamide and then placed in a vacuum drying oven and dried at 80 °C for 3 h to obtain a polycyano compound. Step S2: Add 10 mmol of polycyano compound, 35 g of potassium hydroxide, 100 mL of anhydrous ethanol and 100 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25 °C and 300 r / min for 30 min. Then raise the temperature to 85 °C and continue stirring for 10 h. After the reaction is complete, filter the reaction product under vacuum while hot. Cool the filtrate to room temperature and adjust the pH to 3 with 20% hydrochloric acid solution. Then filter under vacuum and recrystallize the filter cake with glacial acetic acid. Then place it in a vacuum drying oven and dry at 60 °C for 3 h to obtain polycarboxylic acid compound. Step S3: 10 mmol of polycarboxylic acid compound, 40 mmol of allyl alcohol glycidyl ether, 0.05 g of p-hydroxyanisole, 0.2 g of triphenylphosphine and 100 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 100 °C and the mixture was stirred for 5 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed 5 times with anhydrous ethanol and then placed in a vacuum drying oven and dried at 60 °C for 3 h to obtain the polyhydroxy alkenyl compound. Step S4: 30 mmol of polyhydroxy alkenyl compound, 0.05 g of dibutyltin dilaurate and 70 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 60 °C and the mixture was stirred for another 20 min. Then 70 mmol of isophorone diisocyanate was added and the mixture was stirred for another 5 h. Then the temperature was raised to 80 °C and 15 mmol of octafluoropentanol was added and the mixture was stirred for another 3 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 30 h. Then it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 50 °C for 4 h to obtain fluorinated polyolefin polyurethane. Step S5: Weigh out 50 parts by weight of fluorinated polyene polyurethane, 15 parts by weight of diluent, 0.9 parts by weight of leveling agent, 3 parts by weight of photoinitiator, 12 parts by weight of nano silica, and 70 parts by weight of anhydrous ethanol, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; and the photoinitiator is 1173 photoinitiator; Step S6: Mix fluorinated polyene polyurethane, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0027] Comparative Example 3: This comparative example illustrates a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 30 mmol of polycaprolactone diol PCL1000, 0.05 g of dibutyltin dilaurate, and 70 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer, and gas delivery tube. Nitrogen gas was introduced for protection, and the mixture was stirred at 25 °C and 300 r / min for 30 min. Then, the temperature was raised to 60 °C and the mixture was stirred for another 20 min. 70 mmol of isophorone diisocyanate was added and the mixture was stirred for another 5 h. The temperature was raised to 80 °C and the mixture was stirred for another 3 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 30 h. Then, it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 50 °C for 4 h to obtain polyurethane. Step S2: Add 8g gum arabic, 1.2g β-cyclodextrin, 0.12g Tween 80 and 100mL deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25℃ and 300r / min for 2h. Then raise the temperature to 60℃ and add 3g linseed oil and continue stirring for 20min. Then emulsify at 15000r / min for 60min. Finally, spray dry at 180℃ to obtain lubricating microcapsules. Step S3: Weigh out 50 parts by weight of polyurethane, 7 parts by weight of lubricating microcapsules, 15 parts by weight of diluent, 0.9 parts by weight of leveling agent, 3 parts by weight of photoinitiator, 12 parts by weight of nano-silica, and 70 parts by weight of anhydrous ethanol, and set aside for later use; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; the photoinitiator is 1173 photoinitiator; Step S4: Mix polyurethane, lubricating microcapsules, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0028] Comparative Example 4: This comparative example illustrates a method for preparing a high-abrasion-resistant UV-curable coating for PET substrates, comprising the following steps: Step S1: 40 mmol of p-fluorobenzonitrile, 10 mmol of p-phenylenediamine, 50 mmol of sodium hydride and 120 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 150 °C and the mixture was stirred for 20 h. After the reaction was completed, the reaction product was cooled to room temperature and then added to a 60% ethanol solution. The mixture was then vacuum filtered. The filter cake was recrystallized with N,N-dimethylformamide and then placed in a vacuum drying oven and dried at 80 °C for 3 h to obtain a polycyano compound. Step S2: Add 10 mmol of polycyano compound, 35 g of potassium hydroxide, 100 mL of anhydrous ethanol and 100 mL of deionized water to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Purge with nitrogen for protection and stir at 25 °C and 300 r / min for 30 min. Then raise the temperature to 85 °C and continue stirring for 10 h. After the reaction is complete, filter the reaction product under vacuum while hot. Cool the filtrate to room temperature and adjust the pH to 3 with 20% hydrochloric acid solution. Then filter under vacuum and recrystallize the filter cake with glacial acetic acid. Then place it in a vacuum drying oven and dry at 60 °C for 3 h to obtain polycarboxylic acid compound. Step S3: 10 mmol of polycarboxylic acid compound, 40 mmol of allyl alcohol glycidyl ether, 0.05 g of p-hydroxyanisole, 0.2 g of triphenylphosphine and 100 mL of N-methylpyrrolidone were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 20 min. Then the temperature was raised to 100 °C and the mixture was stirred for 5 h. After the reaction was completed, the reaction product was cooled to room temperature. The solvent was then removed by rotary evaporation. The product was washed 5 times with anhydrous ethanol and then placed in a vacuum drying oven and dried at 60 °C for 3 h to obtain the polyhydroxy alkenyl compound. Step S4: 30 mmol of polyhydroxy alkenyl compound, 0.05 g of dibutyltin dilaurate and 70 mL of n-butyl acetate were added to a three-necked flask equipped with a stirrer, thermometer and gas delivery tube. Nitrogen gas was introduced for protection. The mixture was stirred at 25 °C and 300 r / min for 30 min. Then the temperature was raised to 60 °C and the mixture was stirred for another 20 min. Then 70 mmol of isophorone diisocyanate was added and the mixture was stirred for another 5 h. Then the temperature was raised to 80 °C and 15 mmol of octafluoropentanol was added and the mixture was stirred for another 3 h. After the reaction was completed, the reaction product was cooled to room temperature and allowed to stand for 30 h. Then it was added to anhydrous diethyl ether and vacuum filtered. The filter cake was placed in a vacuum drying oven and dried at 50 °C for 4 h to obtain fluorinated polyolefin polyurethane. Step S5: Weigh out 50 parts by weight of fluorinated polyene polyurethane, 7 parts by weight of linseed oil, 15 parts by weight of diluent, 0.9 parts by weight of leveling agent, 3 parts by weight of photoinitiator, 12 parts by weight of nano silica, and 70 parts by weight of anhydrous ethanol, and set aside; the diluent is 1,6-hexanediol diacrylate; the leveling agent is BYK-333; the photoinitiator is 1173 photoinitiator; Step S6: Mix fluorinated polyene polyurethane, linseed oil, diluent, leveling agent, photoinitiator, nano silica and anhydrous ethanol evenly to obtain a high wear-resistant UV-curable coating for PET substrate.

[0029] The PET substrates of Examples 1-3 and Comparative Examples 1-4 were coated with a high-abrasion-resistant UV-curable coating onto a 100 μm thick PET film, with a coating thickness of 10 μm. The films were then placed in a vacuum drying oven and dried at 60°C for 5 minutes. Afterwards, they were cured using a UV curing machine at 150 mW / cm². 2 Curing is performed under light intensity for 10 seconds to form a highly wear-resistant UV-cured coating.

[0030] Performance testing Water absorption rate: Weigh the cured sample and record the mass as Ma. Immerse it in deionized water at 25℃ for 24 hours and record the mass of the sample after immersion as M1. Calculate the water absorption rate using the formula: Water absorption rate = (M1 - Ma) / Ma × 100%; Abrasion resistance: Weigh the cured sample and record the mass as Mb. Rub it according to ASTM D4060-2019, with a turntable speed of 60 r / min, rubber grinding wheel model CS-10, load of 1 kg, and 5000 rotations. Record the mass of the sample after friction as M2. Calculate the friction loss rate using the formula: Friction loss rate = (Mb - M2) / Mb × 100%; The test results are shown below:

[0031] Referring to the data in the table above, and based on the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen that the high abrasion-resistant UV-curable coating for PET substrates of this application has low water absorption and friction loss rate, indicating that it has excellent water resistance and abrasion resistance.

[0032] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A high abrasion resistant UV-cured coating for PET substrates, characterized in that, The following components are included by weight parts: fluorine-containing polyolefin-based polyurethane 30-50 parts, lubricating microcapsule 1-7 parts, diluent 10-15 parts, leveling agent 0.5-0.9 parts, photoinitiator 1-3 parts, nano-silicon dioxide 8-12 parts, and anhydrous ethanol 60-70 parts; The fluorine-containing polyolefin-based polyurethane is prepared by the following steps: Step a1: Stir p-fluorobenzonitrile, p-phenylenediamine, sodium hydride and dimethyl sulfoxide, cool the reaction product after the reaction is completed, then add it to an ethanol solution, then vacuum filter, recrystallize the filter cake, and obtain a polycyan compound; Step a2: Stir the polycyan compound, potassium hydroxide, anhydrous ethanol and deionized water, vacuum filter the reaction product while hot after the reaction is completed, cool the filtrate, then adjust the pH with a hydrochloric acid solution, then vacuum filter, recrystallize the filter cake, and obtain a polycarboxy compound; Step a3: Stir the polycarboxy compound, allyl glycidyl ether, p-hydroxyanisole, triphenylphosphine and N-methylpyrrolidone, cool the reaction product after the reaction is completed, then rotary evaporate, then wash and dry, and obtain a polyhydroxy olefin compound; Step a4: Stir the polyhydroxy olefin compound, dibutyltin dilaurate and n-butyl acetate, then add isophorone diisocyanate and octafluoropentanol and continue to stir, cool the reaction product after the reaction is completed, then add it to anhydrous ether, then vacuum filter, and dry the filter cake to obtain the fluorine-containing polyolefin-based polyurethane.

2. A high abrasion resistant UV cured coating for PET substrates according to claim 1, characterized in that, The amount ratio of p-fluorobenzonitrile, p-phenylenediamine, sodium hydride and dimethyl sulfoxide in step a1 is 40 mmol: 10 mmol: 45-50 mmol: 100-120 mL; and the volume fraction of the ethanol solution is 50-60%.

3. A high abrasion resistant UV cured coating for PET substrates according to claim 1, characterized in that, The amount ratio of the polycyan compound, potassium hydroxide, anhydrous ethanol and deionized water in step a2 is 10 mmol: 30-35 g: 90-100 mL: 90-100 mL; and the mass fraction of the hydrochloric acid solution is 15-20%.

4. The high abrasion resistant UV-cured coating for PET substrate according to claim 1, characterized in that, The amount ratio of the polycarboxy compound, allyl glycidyl ether, p-hydroxyanisole, triphenylphosphine and N-methylpyrrolidone in step a3 is 10 mmol: 40 mmol: 0.03-0.05 g: 0.1-0.2 g: 90-100 mL.

5. A high abrasion resistant UV cured coating for PET substrates according to claim 1, characterized in that, The amount ratio of the polyhydroxy olefin compound, dibutyltin dilaurate, n-butyl acetate, isophorone diisocyanate and octafluoropentanol in step a4 is 10-30 mmol: 0.03-0.05 g: 60-70 mL: 60-70 mmol: 5-15 mmol.

6. A high abrasion resistant UV cured coating for PET substrates according to claim 1, characterized in that, The lubricating microcapsule is prepared by the following steps: Stir acacia gum, β-cyclodextrin, Tween 80 and deionized water, then add flaxseed oil and continue to stir, then emulsify, and spray dry to obtain the lubricating microcapsule.

7. A high abrasion resistant UV cured coating for PET substrates according to claim 6, characterized in that, The amount ratio of acacia gum, β-cyclodextrin, Tween 80, deionized water and flaxseed oil is 6-8 g: 1-1.2 g: 0.08-0.12 g: 90-100 mL: 3 g.

8. A process for the preparation of a high abrasion resistant UV-cured coating for PET substrates as claimed in any one of claims 1 to 7, characterized in that, It comprises the following steps: Step one: take fluorine-containing polyene-based polyurethane 30-50 parts, lubricating microcapsule 1-7 parts, diluent 10-15 parts, leveling agent 0.5-0.9 parts, photoinitiator 1-3 parts, nano-silicon dioxide 8-12 parts and anhydrous ethanol 60-70 parts by weight, ready for use; Step two: mix fluorine-containing polyene-based polyurethane, lubricating microcapsule, diluent, leveling agent, photoinitiator, nano-silicon dioxide and anhydrous ethanol uniformly to obtain high wear-resistant UV hardening paint for PET substrate.

9. The method for preparing a high-abrasion-resistant UV-curable coating for PET substrate according to claim 8, characterized in that, The diluent is 1,6-hexanediol diacrylate; The leveling agent is BYK-333; The photoinitiator is 1173 photoinitiator.

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