Preparation method of light-cured silicon-based release agent and PET release film

Abstract

This invention relates to a method for preparing a photocurable silicone-based release agent and a PET release film, belonging to the field of release film technology. The method involves mixing a prepolymer containing acrylate double bonds, modified carbon nanotubes containing double bonds, a fluorinated siloxane, and a compound initiator, and then coating the mixture onto a PET release film for UV curing. The amino silicone oil in the prepolymer provides low surface energy, and its long-chain structure forms a uniform lubricating layer on the release film surface. This, in conjunction with the fluorinated siloxane, reduces the surface energy of the PET release film, achieving efficient surface energy regulation at the molecular level and reducing intermolecular adsorption forces with the adhered material. Furthermore, the addition of modified carbon nanotubes to the crosslinking network further increases the heat resistance of the PET release film. Simultaneously, the fluorinated and silicone segments enhance the hydrophobic properties of the PET release film, reducing fluctuations in release force under high temperature and high humidity conditions and ensuring the reliability of the PET release film.

Description

Technical Field

[0001] This invention belongs to the field of release film technology, and relates to a method for preparing a photocurable silicone-based release agent and a PET release film. Background Technology

[0002] Release film, as an important industrial material, plays an indispensable role in many fields. It is made by coating one or both sides of environmentally friendly materials (such as PE, PET, OPP films) with silicone release agents, exhibiting stable and suitable release forces for various organic pressure-sensitive adhesives. It is widely used in packaging, printing, flexible circuits, insulating products, circuit boards, lamination, electronics, sealing materials, adhesive products, die-cutting and stamping processes, and other industries.

[0003] Silicone release agents hold a significant position in the release agent field due to their excellent transparency, superior isolation effect, widely adjustable peel strength, good high-temperature and solvent resistance, controllable coating thickness and silicone content, and excellent durability (reusable). Traditional silicone release agents typically consist of a polymer base (such as epoxy-modified silicone resin, acrylate-modified silicone resin, etc.), crosslinking agents, catalysts, solvents, and various additives. Among these, the polymer silicone resin, as a key formulation material, not only plays a decisive role in the release force but also profoundly affects the stability of the coating; the polymer resin and crosslinking agent work together to determine the adhesion of the coating to the base film.

[0004] Chinese invention patent application CN118389059B discloses a non-platinum curing release agent, a chemically stable release film, and a method for preparing the same. The non-platinum curing release agent is made from the following raw materials in parts by weight: 85 parts of siloxane, of which hexenyl polydimethylsiloxane accounts for more than 80 wt%, and the remainder is hydrogen-containing siloxane; 2-8 parts of sulfonic acid acrylic monomer; 0.1-1.2 parts of photocatalyst; 0.5-1.6 parts of metal salt; and 0.2-5 parts of initiator. The introduced sulfonic acid acrylic monomer can regulate the surface properties of the release film and enhance the chemical stability of the release film by complexing metal ions.

[0005] The release agent in the above technical solution introduces sulfonic acid acrylic monomers. Although the polar sulfonic acid groups contained therein can complex metal ions to enhance chemical stability, in high temperature and high humidity environments, water molecules in the air are easily adsorbed by the sulfonic acid groups, which causes changes in the surface energy of the release film, resulting in fluctuations in the release force and affecting the reliability of the release film. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a photocurable silicone-based release agent and a PET release film. The method involves mixing a prepolymer, modified carbon nanotubes containing double bonds, fluorine-containing siloxanes, and a compound initiator, then coating the mixture onto a PET film and curing it with UV to achieve antistatic properties and resistance to damp heat.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A photocurable silicone-based release agent, by weight, comprises 100-120g of a prepolymer containing acrylate double bonds, 0.5-0.7g of modified carbon nanotubes containing double bonds, 0.5-1g of a fluorinated siloxane, and 2.2-2.4g of a compound initiator.

[0009] Prepolymers containing acrylate double bonds are prepared by the following steps:

[0010] Amino silicone oil, hydroxyethyl acrylate, and isophorone diisocyanate are grafted together by chemical polymerization to obtain a prepolymer containing acrylate double bonds.

[0011] Modified carbon nanotubes containing double bonds are produced by grafting silane coupling agents containing double bonds onto modified carbon nanotubes.

[0012] Furthermore, the specific preparation process of modified carbon nanotubes containing double bonds is as follows:

[0013] Modified carbon nanotubes and a 95 vol% ethanol aqueous solution were added to a reaction vessel and ultrasonically dispersed for 10-15 min. The mixture was stirred at 80-85℃ for 6 h. Then, a silane coupling agent containing double bonds was added for graft modification, ultrasonically dispersed for 10-15 min, and reacted for 2-3 h. The mixture was then filtered, washed, and dried to obtain modified carbon nanotubes containing double bonds.

[0014] Furthermore, the silane coupling agent containing double bonds is one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

[0015] Furthermore, tridecafluorooctyltrimethoxysilane can be added during the grafting modification process.

[0016] Furthermore, the specific preparation process of the prepolymer containing acrylate double bonds is as follows:

[0017] Isophorone diisocyanate and dibutyltin dilaurate were added to a reaction vessel and stirred for 10-15 minutes under nitrogen protection at 40-45°C until homogeneous. Then, amino silicone oil was slowly added dropwise to the reaction vessel and stirred for 1-2 hours. The temperature was raised to 50-55°C, and hydroxyethyl acrylate was added to the reaction vessel and stirred for 1-2 hours. The mixture was then cooled to room temperature and distilled under reduced pressure to obtain a prepolymer containing acrylate double bonds.

[0018] Furthermore, the mass ratio of isophorone diisocyanate, dibutyltin dilaurate, amino silicone oil, and hydroxyethyl acrylate is 24.7-30:0.025-0.035:50-60:10-15.

[0019] Furthermore, the compound initiators include 1-hydroxycyclohexylphenylacetone and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone.

[0020] A method for preparing a PET release film includes the following steps:

[0021] Step 1: Prepare a photocurable silicone-based release agent.

[0022] Step 2: Pre-treat the optical-grade PET film to obtain a pre-treated PET film.

[0023] Step 3: Apply a photocurable silicone-based release agent to one side of the pretreated PET film, cure it under nitrogen atmosphere with ultraviolet light, cool it, and roll it up to obtain the PET release film.

[0024] Furthermore, the pretreatment includes corona treatment and dust removal.

[0025] Furthermore, the PET film speed during coating is 55±2m / min, and a honeycomb anilox roller is used for coating, with the ratio of the anilox roller linear speed to the film speed controlled at 1:1.05.

[0026] Furthermore, the wet coating weight is 6±0.5 g / m². 2 .

[0027] Furthermore, the UV curing time is 120-125 seconds.

[0028] The beneficial effects of this invention are:

[0029] 1. This invention mixes a prepolymer containing acrylate double bonds, modified carbon nanotubes containing double bonds, fluorinated siloxanes, and a compound initiator, and coats the mixture onto a PET release film for UV curing. The amino silicone oil in the prepolymer provides low surface energy, and its long-chain structure forms a uniform lubricating layer on the release film surface. It works synergistically with the fluorinated siloxanes to reduce the surface energy of the PET release film, achieving efficient surface energy regulation at the molecular level and reducing intermolecular adsorption forces with the adhered material. Furthermore, the modified carbon nanotubes added to the crosslinking network further increase the heat resistance of the PET release film. At the same time, the fluorinated and silicone segments enhance the hydrophobic properties of the PET release film, reducing the fluctuation of the release force of the PET release film under high temperature and high humidity conditions, and ensuring the reliability of the PET release film.

[0030] 2. In this invention, carbon nanotubes are first acidified to introduce hydroxyl groups. Then, a silane coupling agent containing double bonds is grafted onto the modified carbon nanotubes. Subsequently, the modified carbon nanotubes are cross-linked and cured with a prepolymer containing acrylate double bonds. This increases the compatibility between the carbon nanotubes and the prepolymer, preventing migration during use. By introducing carbon nanotubes into the polymer through chemical grafting, the antistatic properties are improved, and dust adsorption is avoided, thus preventing it from affecting product performance. In addition, the tridecafluorooctyltrimethoxysilane grafted onto the carbon nanotubes can form a fluorine-silicon synergistic hydrophobic environment with the siloxane structure in the prepolymer and the fluorine element in trifluoropropyl polysiloxane, further reducing surface energy and enhancing the moisture resistance of the release agent.

[0031] 3. This invention subjectes the PET film to corona treatment to enhance surface polarity, forming hydrogen bonds with the polar groups urea bonds and urethane bonds in the photocurable silicone-based release agent, significantly improving adhesion. The honeycomb textured roller coating ensures uniform distribution of the release agent. Ultraviolet curing initiates free radical polymerization and cross-linking to form a dense cross-linked network, which, in synergy with the physical reinforcement of carbon nanotubes, improves the tear resistance of the PET release film. At the same time, siloxanes ensure the flexibility of the material, synergistically optimizing the release force while preventing the release layer from becoming brittle. Detailed Implementation

[0032] To further illustrate the technical means and effects of the present invention in achieving the intended purpose, the following detailed description of the specific implementation methods, features and effects of the present invention, in conjunction with preferred embodiments, is provided below.

[0033] Example 1: This example provides a method for preparing a photocurable silicone-based release agent, comprising the following steps:

[0034] S1: Add 40g of carbon nanotubes with a diameter of 10-20nm and a length of 0.3-5μm, 35mL of concentrated sulfuric acid and 12mL of concentrated nitric acid to a reaction vessel, stir at 150r / min for 30min, filter, wash, wash with deionized water until neutral, and vacuum dry to constant weight to obtain modified carbon nanotubes.

[0035] S2: 25g of modified carbon nanotubes and 850mL of 95vol% ethanol aqueous solution were added to a reaction vessel and ultrasonically dispersed for 12min. The mixture was stirred at 82℃ for 6h. Then, 3g of silane coupling agent KH-570 (γ-methacryloyloxypropyltrimethoxysilane) and 2g of tridecafluorooctyltrimethoxysilane were added and ultrasonically dispersed for 12min. The reaction was carried out for 2.5h. The silane coupling agent KH-570 and tridecafluorooctyltrimethoxysilane hydrolyzed and reacted with the hydroxyl groups on the carbon nanotubes to form Si-OC bonds. The mixture was filtered, washed, and vacuum dried to constant weight to obtain modified carbon nanotubes containing double bonds.

[0036] S3: 27.4g of isophorone diisocyanate and 0.03g of dibutyltin dilaurate were added to a reactor and stirred for 12 minutes under nitrogen protection at 42℃ until homogeneous. Then, 55g of amino silicone oil was slowly added dropwise to the reactor and stirred for 1.5h. The isocyanate groups in isophorone diisocyanate reacted with the amino groups in amino silicone oil to form urea bonds. The temperature was raised to 52℃, and 12.5g of hydroxyethyl acrylate was added to the reactor and stirred for 1.5h. The unreacted isocyanate groups reacted with the hydroxyl groups in hydroxyethyl acrylate to form urethane bonds. The mixture was cooled to room temperature and distilled under reduced pressure to obtain a prepolymer containing acrylate double bonds.

[0037] S4: Mix 110g of prepolymer containing acrylate double bonds, 0.6g of modified carbon nanotubes containing double bonds, 0.75g of trifluoropropylmethylpolysiloxane, 1.5g of compound initiator 1-hydroxycyclohexylphenylacetone (184), and 0.8g of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, stir at 250r / min for 30min until uniformly mixed to obtain a photocurable silicone-based release agent.

[0038] This embodiment also provides a method for preparing a PET release film, including the following steps:

[0039] Step 1: The 25μm thick optical grade PET film is corona treated using a dual-electrode corona treatment machine. During corona treatment, the dyne value is 52mN / m, and the difference in dyne value between any two points is guaranteed to be no more than 5mN / m. Then, dust removal treatment is performed to obtain the pretreated PET film.

[0040] Step 2: Coat the pretreated PET film at a speed of 55 m / min using a honeycomb anilox roller. The ratio of the anilox roller's linear speed to the film speed is controlled at 1:1.05. Apply a photocurable silicone-based release agent to the pretreated PET film with a coating wet weight of 6 g / m². 2 Then, it is cured under ultraviolet light for 122 seconds in a nitrogen atmosphere, with a distance of 17.5 cm between the lamp and the film. After being cooled by a cooling roller, it is wound up to obtain a PET release film.

[0041] Amino silicone oil, commercially available, purchased from Anhui Aiyota Silicone Oil Co., Ltd.

[0042] Isophorone diisocyanate, commercially available, purchased from Shanghai Maclean Biotechnology Co., Ltd.

[0043] Hydroxyethyl acrylate, commercially available, purchased from Shandong Hongrun Chemical Co., Ltd.

[0044] Example 2: This example provides a method for preparing a photocurable silicone-based release agent, comprising the following steps:

[0045] S1: Add 30g of carbon nanotubes with a diameter of 10-20nm and a length of 0.3-5μm, 30mL of concentrated sulfuric acid and 10mL of concentrated nitric acid to a reaction vessel, stir at 100r / min for 30min, filter, wash, wash with deionized water until neutral, and vacuum dry to constant weight to obtain modified carbon nanotubes.

[0046] S2: 20g of modified carbon nanotubes and 700mL of 95vol% ethanol aqueous solution were added to a reaction vessel and ultrasonically dispersed for 10min. The mixture was stirred at 80℃ for 6h. Then, 2g of silane coupling agent KH-570 (γ-methacryloyloxypropyltrimethoxysilane) and 1g of tridecafluorooctyltrimethoxysilane were added and ultrasonically dispersed for 10min. The reaction was carried out for 2h. The silane coupling agent KH-570 and tridecafluorooctyltrimethoxysilane hydrolyzed and reacted with the hydroxyl groups on the carbon nanotubes to form Si-OC bonds. The mixture was filtered, washed, and vacuum dried to constant weight to obtain modified carbon nanotubes containing double bonds.

[0047] S3: Add 24.7g of isophorone diisocyanate and 0.025g of dibutyltin dilaurate to a reactor and stir for 10min under nitrogen protection at 40℃ until homogeneous. Then slowly add 50g of amino silicone oil to the reactor and stir for 1h. The isocyanate groups in isophorone diisocyanate react with the amino groups in amino silicone oil to form urea bonds. Raise the temperature to 50℃ and add 10g of hydroxyethyl acrylate to the reactor. Stir for 1h. The unreacted isocyanate groups react with the hydroxyl groups in hydroxyethyl acrylate to form urethane bonds. Cool to room temperature and distill under reduced pressure to obtain a prepolymer containing acrylate double bonds.

[0048] S4: Mix 100g of prepolymer containing acrylate double bonds, 0.5g of modified carbon nanotubes containing double bonds, 0.5g of trifluoropropylmethylpolysiloxane, 1.5g of compound initiator 1-hydroxycyclohexylphenylacetone (184), and 0.8g of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, stir at 200r / min for 30min until uniformly mixed to obtain a photocurable silicone-based release agent.

[0049] This embodiment also provides a method for preparing a PET release film, including the following steps:

[0050] Step 1: The 25μm thick optical grade PET film is corona treated using a dual-electrode corona treatment machine. During corona treatment, the dyne value is 50mN / m, and the difference in dyne value between any two points is guaranteed to be no more than 5mN / m. Then, dust removal treatment is performed to obtain the pretreated PET film.

[0051] Step 2: Coating the pretreated PET film at a speed of 53 m / min using a honeycomb anilox roller, with the ratio of the anilox roller's linear speed to the film speed controlled at 1:1.05. Applying a UV-curable silicone-based release agent to the pretreated PET film with a coating wet weight of 5.5 g / m², then curing it under UV light for 120 s in a nitrogen atmosphere with a distance of 15 cm between the lamp and the film. After cooling by a cooling roller, the film is wound up to obtain the PET release film.

[0052] Example 3: This example provides a method for preparing a photocurable silicone-based release agent, including the following steps:

[0053] S1: Add 50g of carbon nanotubes with a diameter of 10-20nm and a length of 0.3-5μm, 40mL of concentrated sulfuric acid and 15mL of concentrated nitric acid to a reaction vessel, stir at 200r / min for 30min, filter, wash, wash with deionized water until neutral, and vacuum dry to constant weight to obtain modified carbon nanotubes.

[0054] S2: 30g of modified carbon nanotubes and 1000mL of 95vol% ethanol aqueous solution were added to a reaction vessel and ultrasonically dispersed for 15min. The mixture was stirred at 85℃ for 6h. Then, 4g of silane coupling agent KH-570 (γ-methacryloyloxypropyltrimethoxysilane) and 3g of tridecafluorooctyltrimethoxysilane were added and ultrasonically dispersed for 15min. The reaction was carried out for 3h. The silane coupling agent KH-570 and tridecafluorooctyltrimethoxysilane hydrolyzed and reacted with the hydroxyl groups on the carbon nanotubes to form Si-OC bonds. The mixture was filtered, washed, and vacuum dried to constant weight to obtain modified carbon nanotubes containing double bonds.

[0055] S3: Add 30g of isophorone diisocyanate and 0.035g of dibutyltin dilaurate to a reactor and stir for 15min under nitrogen protection at 45℃ until homogeneous. Then slowly add 60g of amino silicone oil to the reactor and stir for 2h. The isocyanate groups in isophorone diisocyanate react with the amino groups in amino silicone oil to form urea bonds. Raise the temperature to 55℃ and add 15g of hydroxyethyl acrylate to the reactor. Stir for 2h. The unreacted isocyanate groups react with the hydroxyl groups in hydroxyethyl acrylate to form urethane bonds. Cool to room temperature and distill under reduced pressure to obtain a prepolymer containing acrylate double bonds.

[0056] S4: Mix 120g of prepolymer containing acrylate double bonds, 0.7g of modified carbon nanotubes containing double bonds, 1g of trifluoropropylmethylpolysiloxane, 1.5g of compound initiator 1-hydroxycyclohexylphenylacetone (184), and 0.8g of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone, stir at 300r / min for 30min until uniformly mixed to obtain a photocurable silicone-based release agent.

[0057] This embodiment also provides a method for preparing a PET release film, including the following steps:

[0058] Step 1: The 25μm thick optical grade PET film is corona treated using a dual-electrode corona treatment machine. During corona treatment, the dyne value is 55mN / m, and the difference in dyne value between any two points is guaranteed to be no more than 5mN / m. Then, dust removal treatment is performed to obtain the pretreated PET film.

[0059] Step 2: Coating the pretreated PET film at a speed of 57 m / min using a honeycomb anilox roller, with the ratio of the anilox roller speed to the film speed controlled at 1:1.05. Applying a photocurable silicone-based release agent to the pretreated PET film with a coating wet weight of 6.5 g / m², then curing it under ultraviolet light for 125 s in a nitrogen atmosphere with a distance of 20 cm between the lamp and the film. After cooling by a cooling roller, the film is wound up to obtain the PET release film.

[0060] Example 4: Based on Example 1, in step S2, tridecafluorooctyltrimethoxysilane was removed, while the other steps remained unchanged, and a photocurable silicone-based release agent was prepared. A PET release film was then prepared using this photocurable silicone-based release agent.

[0061] Comparative Example 1: Based on Example 1, in step S4, the modified carbon nanotubes prepared in step S1 were used instead of the modified carbon nanotubes containing double bonds, while the other steps remained unchanged, to prepare a photocurable silicon-based release agent, and a PET release film was prepared using this photocurable silicon-based release agent.

[0062] Comparative Example 2: Based on Example 1, the modified carbon nanotubes containing double bonds were removed in step S4, while the other steps remained unchanged, and a photocurable silicon-based release agent was prepared. A PET release film was then prepared using this photocurable silicon-based release agent.

[0063] Comparative Example 3: Based on Example 1, amino silicone oil was removed in step S4 to prepare a prepolymer containing acrylate double bonds. The remaining steps remained unchanged to prepare a photocurable silicone-based release agent, and a PET release film was prepared using this photocurable silicone-based release agent.

[0064] Comparative Example 4: Based on Example 1, trifluoropropylmethylpolysiloxane was removed in step S4, while the other steps remained unchanged, to prepare a photocurable silicone-based release agent, and a PET release film was prepared using this photocurable silicone-based release agent.

[0065] The performance of the PET release films prepared in Examples 1-4 and Comparative Examples 1-4 was tested:

[0066] Release performance test: Referring to GB2792-1998 standard, standard tape was applied to a standard-sized stainless steel plate with release film already applied. Surface air bubbles were removed using a standard pressure roller. The plate was left at room temperature for 24 hours, then at 70°C for 24 hours. The tape left at 70°C for 24 hours was then reapplied to the polished standard stainless steel plate, and surface air bubbles were removed again using a standard pressure roller. A 180° peel strength test was then performed on an AR-1000 peel strength tester at a peel speed of 30 cm / min. The resulting peel force was recorded as the release force.

[0067] Transmittance: Characterization was performed using a WGT-2S transmittance / haze analyzer. The transmittance of light between 200-800 nm was measured using UV-Vis spectrophotometry. The prepared release film sample, a standard rectangular specimen, was placed vertically in the sample chamber of the spectrophotometer, ensuring the surface was free of contaminants.

[0068] Contact angle test: The room temperature static contact angle of the cured release film surface was measured using an OCA20 contact angle meter, and five sets of contact angle data of deionized water on the release film surface were recorded.

[0069] Antistatic properties: Referring to the national standard GB / T 31838.3-2019 and the ASTM D257 standard, the surface resistivity of the photocurable silicone release agent sample was measured by a Keithley 6175B high-resistivity meter. The test conditions were 23℃, relative humidity of 45-65%RH, and test voltage of 1000V.

[0070] The test results are shown in the table below:

[0071] Table 1 Performance Test Overview

[0072] project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Release force (g / 25mm) after 24 hours at room temperature 254 261 256 320 267 280 520 405 Release force (g / 25mm) after being placed at 70℃ for 24 hours 213 223 217 281 221 228 380 315 Light transmittance T (%) 89.34 88.24 87.89 90.12 85.65 91.23 87.67 89.01 Contact angle (°) 86.5 83.5 87.2 89.2 84.3 78.5 70.2 84.1 Surface resistivity (Ω / sq) <![CDATA[1.2×10 8 ]]> <![CDATA[1.1×10 8 ]]> <![CDATA[1.3×10 8 ]]> <![CDATA[1.2×10 8 ]]> <![CDATA[2.5×10 8 ]]> <![CDATA[5.0×10 9 ]]> <![CDATA[1.0×10 10 ]]> <![CDATA[1.1×10 8 ]]>

[0073] As shown in Table 1, the release forces of PET release films placed at room temperature for 24 hours in Examples 1-4 are less than those in Comparative Examples 3 and 4. This indicates that the silicon segments of amino silicone oil can reduce surface energy and have a synergistic effect with fluorinated groups such as tridecafluorooctylsilane and trifluoropropylpolysiloxane, thereby reducing the surface energy of the PET release film and thus reducing the release force of the PET release film at room temperature. The release force of PET release film placed at 70°C for 24 hours in Comparative Example 3 decreased the most, indicating that the segments of amino silicone oil have high temperature resistance and can reduce the fluctuation of the release force of PET release film at high temperatures.

[0074] The transmittance of Examples 1-4 is greater than that of Comparative Example 1, indicating that the modified carbon nanotubes are unevenly distributed in the photocurable silicone-based release agent and are prone to agglomeration, which leads to a decrease in the transmittance of the PET release film. The modified carbon nanotubes with double bonds can achieve molecular-level anchoring and form a three-dimensional cross-linked network, thus achieving a uniform dispersion effect.

[0075] The water contact angles in Examples 1-4 were greater than those in Comparative Examples 2 and 3, indicating that trifluoropropylmethylpolysiloxane can increase the contact angle with water and play a hydrophobic role. At the same time, the segments containing amino silicone oil also have a certain hydrophobic effect, and the two play a synergistic role.

[0076] The surface resistivity in Examples 1-4 is lower than that in Comparative Examples 1, 2 and 3, indicating that there is a cross-linking effect between the modified carbon nanotubes containing double bonds and the prepolymer containing acrylate double bonds, and a three-dimensional cross-linked network is formed with amino silicone oil to form a conductive path, which plays an antistatic role, reduces the intermolecular adsorption force with the adhered material, and makes the PET release film less prone to static electricity adsorption of dust during the tearing process.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A photocurable silicone-based release agent, characterized in that, By weight, it includes 100-120g of prepolymer containing acrylate double bonds, 0.5-0.7g of modified carbon nanotubes containing double bonds, 0.5-1g of fluorinated siloxanes and 2.2-2.4g of compound initiator; The fluorinated siloxane is trifluoropropylmethylpolysiloxane; The compound initiator includes 1-hydroxycyclohexylphenylacetone and 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylphenylacetone; The specific preparation process of the modified carbon nanotubes containing double bonds is as follows: Modified carbon nanotubes and a 95 vol% ethanol aqueous solution were added to a reaction vessel and ultrasonically dispersed for 10-15 min. The mixture was stirred at 80-85℃ for 6 h. Then, a silane coupling agent containing double bonds was added for grafting modification. The mixture was ultrasonically dispersed for 10-15 min and reacted for 2-3 h. The mixture was then filtered, washed, and dried to obtain modified carbon nanotubes containing double bonds. The specific preparation process of the prepolymer containing acrylate double bonds is as follows: Isophorone diisocyanate and dibutyltin dilaurate were added to a reaction vessel and stirred for 10-15 minutes under nitrogen protection at 40-45°C until homogeneous. Then, amino silicone oil was slowly added dropwise to the reaction vessel and stirred for 1-2 hours. The temperature was raised to 50-55°C, and hydroxyethyl acrylate was added to the reaction vessel and stirred for 1-2 hours. The mixture was then cooled to room temperature and distilled under reduced pressure to obtain a prepolymer containing acrylate double bonds.

2. The photocurable silicone-based release agent according to claim 1, characterized in that, The silane coupling agent containing double bonds is one of γ-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

3. The photocurable silicone-based release agent according to claim 1, characterized in that, The grafting modification process involves the addition of tridecafluorooctyltrimethoxysilane.

4. The photocurable silicone-based release agent according to claim 1, characterized in that, The mass ratio of isophorone diisocyanate, dibutyltin dilaurate, amino silicone oil, and hydroxyethyl acrylate is 24.7-30:0.025-0.035:50-60:10-15.

5. A method for preparing a PET release film, characterized in that, The steps include the following: Step 1: Prepare the photocurable silicone-based release agent according to any one of claims 1-4; Step 2: Pre-treat the optical-grade PET film to obtain a pre-treated PET film; Step 3: Apply the photocurable silicone-based release agent to one side of the pretreated PET film, cure it under nitrogen atmosphere with ultraviolet light, cool it, and roll it up to obtain a PET release film.

6. The method for preparing a PET release film according to claim 5, characterized in that, The pretreatment consists of corona treatment and dust removal.

7. The method for preparing a PET release film according to claim 5, characterized in that, The coating process involves pretreating the PET film at a speed of 55±2 m / min, using a honeycomb anilox roller with a linear speed ratio of 1:1.05 between the roller and the pretreating PET film; the coating wet weight is 6±0.5 g / m. 2 The UV curing time is 120-125 seconds.