An industrial high-temperature-resistant release film and a preparation method thereof

Abstract

The application relates to the field of release films, and discloses an industrial high-temperature-resistant release film and a preparation method thereof. The release film comprises a composite base film and a release layer, and the composite base film is prepared by coating a coating liquid on a polyimide nanofiber film; the coating liquid is prepared from phenol, tetrachloroethane, polyethylene terephthalate particles, modified silica microspheres and antioxidant tetra[beta-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester; the modified silica microspheres are prepared from anhydrous ethanol, gamma-aminopropyl triethoxysilane, an ammonia solution and tetraethyl orthosilicate; the polyimide nanofiber film is prepared from 4,4'-diamino diphenyl ether, N,N-dimethylacetamide and pyromellitic dianhydride; and the release layer is prepared from vinyl silicone oil, hydrogen-containing silicone oil, a platinum gold catalyst, inhibitor ethynylcyclohexanol and a toluene solvent. The release film has good mechanical properties and temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of release films, specifically to an industrial high-temperature resistant release film and its preparation method. Background Technology

[0002] Release film is a functional thin film material widely used in composite material processing, adhesive product manufacturing, and electronic component packaging. Its core function is to provide a stable isolation effect during processing and to be peeled off when needed. With the development of industrial technology, especially the popularization of high-temperature pressing processes, higher requirements have been placed on the heat resistance, dimensional stability, and release force durability of release films.

[0003] For example, Chinese invention patent CN105694084A discloses a release film, which includes: a film substrate, a release coating disposed on the surface of the film substrate, and a UV functional layer disposed on the back surface of the film substrate. The UV functional layer is prepared by a coating liquid, which includes: 20-60 parts by weight of acrylic resin, 50-80 parts by weight of solvent, 2-10 parts by weight of antifouling agent, and 0.3-6 parts by weight of antistatic agent.

[0004] In existing technologies, polyethylene terephthalate (PET) film is commonly used as a release film substrate due to its excellent mechanical properties and transparency. However, its glass transition temperature and melting point are relatively low, making it difficult to meet the requirements of high-end applications. To address the insufficient heat resistance of PET film, blending modification with inorganic nanoparticles is often employed. While this improves the heat distortion temperature of the film to some extent, the nanoparticles tend to agglomerate in the polymer melt, making uniform dispersion difficult. This results in stress concentration points in the film, leading to a decrease in mechanical properties. Furthermore, simple blending modification may cause separation between the inorganic particles and the matrix after long-term high-temperature aging due to poor interfacial compatibility. Summary of the Invention

[0005] The purpose of this invention is to provide an industrial high-temperature resistant release film and its preparation method, so as to solve the problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an industrial high-temperature resistant release film, the release film comprising a composite base film and a release layer, wherein the composite base film is prepared by coating a polyimide nanofiber film with a coating liquid; the coating liquid is prepared by phenol, tetrachloroethane, polyethylene terephthalate particles, modified silica microspheres and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the modified silica microspheres are prepared by anhydrous ethanol, γ-aminopropyltriethoxysilane, ammonia solution and tetraethyl orthosilicate; the polyimide nanofiber film is prepared by 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide and pyromellitic dianhydride; and the release layer is prepared by vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol and toluene solvent.

[0007] Furthermore, the mass fraction of the ammonia solution is 5%-10%.

[0008] Furthermore, a method for preparing an industrial high-temperature resistant release film includes the following steps:

[0009] (1) Add anhydrous ethanol, γ-aminopropyltriethoxysilane and ammonia solution to a reaction vessel equipped with a stirrer, stir at 25-30℃ and 300-400 rpm for 20-30 minutes, then add tetraethyl orthosilicate dropwise over 6-8 minutes. After the addition is complete, continue stirring for 4-5 hours, then let stand for 12-16 hours, centrifuge to obtain the precipitate, wash with anhydrous ethanol 2-4 times, and dry in a vacuum drying oven at 80-85℃ for 6-8 hours to obtain modified silica microspheres;

[0010] (2) In a reaction vessel under nitrogen protection and at a temperature of 0-10℃, 4,4'-diaminodiphenyl ether is dissolved in N,N-dimethylacetamide and mechanically stirred until completely dissolved. Pyromellitic dianhydride is added in three batches, with an interval of 20-30 minutes between each batch. The mixture is stirred at a speed of 300-400 rpm for 8-9 hours to obtain a spinning solution. Then, electrospinning is performed under nitrogen protection using an electrospinning device to obtain a polyamic acid fiber membrane. The polyamic acid fiber membrane is fixed on a tension frame and placed in a hot air oven. It is treated at 150-180℃ for 20-30 minutes, then heated to 280-320℃ at a heating rate of 2-3℃ / min and held for 60-90 minutes. It is then naturally cooled to room temperature to obtain a polyimide nanofiber membrane.

[0011] (3) Phenol and tetrachloroethane are mixed and stirred at 300-400 rpm for 20-30 minutes to obtain a phenol / tetrachloroethane mixed solvent; in a water bath at 80-85℃, polyethylene terephthalate particles with an intrinsic viscosity of 0.80-0.85 dL / g are mixed with the above phenol / tetrachloroethane mixed solvent and stirred in a closed container at 300-400 rpm for 4-6 hours to obtain a polyethylene terephthalate solution; The modified silica microspheres obtained in step (1) are mixed with the above-mentioned phenol / tetrachloroethane mixed solvent and ultrasonically dispersed at a power of 600-800W for 20-30 minutes to form a silica dispersion; the silica dispersion is added to a polyethylene terephthalate solution and an antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] is added and stirred at a speed of 400-500rpm for 2-3 hours to obtain a coating solution;

[0012] (4) The polyimide nanofiber membrane obtained in step (2) is flattened and fixed in a mold. Then, the coating liquid obtained in step (3) is coated onto the polyimide nanofiber membrane by a doctor blade. After that, it is treated at 60-70℃ for 20-30 minutes, then at 120-130℃ for 40-60 minutes, and finally at 180-200℃ for 10-15 minutes. Then, it is hot-pressed at 1-5MPa pressure and 180-200℃ for 5-10 minutes. After naturally cooling to room temperature, a composite base membrane is obtained. Then, the surface of the composite base membrane away from the polyimide nanofiber membrane is subjected to corona treatment. The frequency of the corona treatment is 20-30kHz, the power is 5-10kW, the treatment speed is 20-30m / min, and the electrode spacing is 1.5-2.0mm.

[0013] (5) Prepare a release agent solution, which is composed of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol and toluene solvent, wherein the viscosity of vinyl silicone oil is 5000-10000 Pa·s, the hydrogen content of hydrogen-containing silicone oil is 0.5%-1.0%, and the catalyst is a platinum catalyst with a platinum content of 0.3-0.5%. Coat the release agent onto the surface of the composite base film obtained in step (4) after corona treatment, and control the wet film thickness to be 3-5 μm. Place the coated release film in an oven at 100-120℃ to treat it so that the solvent evaporates and an organosilicon release layer is formed. After natural cooling, roll it up to obtain the industrial high-temperature resistant release film. The mass ratio of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent is 100:(5-15):(0.5-1.0):(0.1-0.3):(2500-4900).

[0014] Furthermore, in step (2), the mass ratio of 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide and pyromellitic dianhydride is 1:(9-10):(1.08-1.10).

[0015] Furthermore, in step (2), the electrospinning equipment is set with a spinneret diameter of 0.1-0.3mm, a receiving distance of 15-20cm, a voltage of 20-30kV, a spinning solution flow rate of 1.0-1.5ml / h, an ambient temperature of 25-30℃, a relative humidity of 30-40%, and a receiving device that is a rotating drum with a rotation speed of 800-1500rpm.

[0016] Furthermore, in step (3), phenol and tetrachloroethane are mixed in a mass ratio of 1:1.

[0017] Furthermore, in step (3), polyethylene terephthalate particles and phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of 1:(4-5).

[0018] Furthermore, in step (3), the modified silica microspheres and the phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of 1:(6-7).

[0019] Furthermore, in step (3), the mass ratio of silica dispersion, polyethylene terephthalate solution and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] is 24:(80-120):(0.5-1).

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0021] 1. The spinning solution forms a nanofiber network structure through electrospinning, which is then transformed into a polyimide nanofiber membrane through a thermal imidization process. Tetraethyl orthosilicate and γ-aminopropyltriethoxysilane are hydrolyzed and condensed to form modified silica microspheres, which are then uniformly distributed in a phenol / tetrachloroethane mixed solvent by ultrasonic dispersion. The organic chains on the surface of the modified silica microspheres improve their dispersion uniformity in the matrix. During hot pressing, the polyimide nanofiber membrane and the polyethylene terephthalate / modified silica microsphere composite matrix interpenetrate through molecular chains. The high heat resistance of the polyimide nanofibers provides high-temperature dimensional stability for the release film, and the inorganic properties of the modified silica microspheres can inhibit the high-temperature movement of polymer chain segments, thus giving the release film good mechanical properties and temperature resistance. Detailed Implementation

[0022] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0023] An industrial high-temperature resistant release film, comprising a composite base film and a release layer, wherein the composite base film is prepared by coating a polyimide nanofiber film with a coating solution; the coating solution is prepared by phenol, tetrachloroethane, polyethylene terephthalate particles, modified silica microspheres, and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; the modified silica microspheres are prepared by anhydrous ethanol, γ-aminopropyltriethoxysilane, ammonia solution, and tetraethyl orthosilicate; the polyimide nanofiber film is prepared by 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide, and pyromellitic dianhydride; and the release layer is prepared by vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent.

[0024] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products. Example 1

[0025] (1) Anhydrous ethanol, γ-aminopropyltriethoxysilane and 5% ammonia solution were added to a reaction vessel equipped with a stirrer and stirred at 25°C and 300 rpm for 20 minutes. Then, tetraethyl orthosilicate was added dropwise over 6 minutes. After the addition was completed, stirring was continued for 4 hours. The mixture was then allowed to stand for 12 hours. The precipitate was obtained by centrifugation, washed twice with anhydrous ethanol, and dried in a vacuum drying oven at 80°C for 6 hours to obtain modified silica microspheres. The mass ratio of anhydrous ethanol, γ-aminopropyltriethoxysilane, ammonia solution and tetraethyl orthosilicate was 200:6:60:30.

[0026] (2) In a nitrogen-protected reactor at 0°C, 4,4'-diaminodiphenyl ether was dissolved in N,N-dimethylacetamide and mechanically stirred until completely dissolved. Pyromellitic dianhydride was added in three batches, with a 20-minute interval between each batch. The mixture was stirred at 300 rpm for 8 hours to obtain the spinning solution. Electrospinning was then performed using an electrospinning device under nitrogen protection. The spinneret diameter was set to 0.1 mm, the receiving distance to 15 cm, the voltage to 20 kV, the spinning solution flow rate to 1.0 ml / h, and the ambient temperature to 25°C. With a relative humidity of 30%, a rotating drum was used as the receiving device at a speed of 800 rpm to obtain a polyamic acid fiber membrane with a thickness of 30 μm. The polyamic acid fiber membrane was fixed on a tension frame and placed in a hot air oven. It was treated at 150°C for 20 minutes, then heated to 280°C at a heating rate of 2°C / min and held at that temperature for 60 minutes. After natural cooling to room temperature, a polyimide nanofiber membrane was obtained. The mass ratio of 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide, and pyromellitic dianhydride was 1:9:1.08.

[0027] (3) Phenol and tetrachloroethane are mixed at a mass ratio of 1:1 and stirred at 300 rpm for 20 minutes to obtain a phenol / tetrachloroethane mixed solvent; in an 80°C water bath, polyethylene terephthalate particles with an intrinsic viscosity of 0.80 dL / g and the above phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of 1:4 and stirred at 300 rpm for 4 hours in a sealed container to obtain a polyethylene terephthalate solution; the modified silica microspheres obtained in step (1) and the above phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of 1:4. Mix the silica and polyethylene terephthalate solutions and ultrasonically disperse them for 20 minutes at 600W to form a silica dispersion. Add the silica dispersion to the polyethylene terephthalate solution and add the antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. Stir at 400 rpm for 2 hours to obtain the coating solution. The mass ratio of silica dispersion, polyethylene terephthalate solution and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is 24:80:0.5.

[0028] (4) The polyimide nanofiber membrane obtained in step (2) is flattened and fixed in the film-coating mold. Then, the coating liquid obtained in step (3) is coated onto the polyimide nanofiber membrane by a doctor blade. The wet film thickness is controlled to be 200 μm. Then, it is treated at 60°C for 20 minutes, then at 120°C for 40 minutes, and finally at 180°C for 10 minutes. After that, it is hot-pressed at 180°C for 5 minutes under 1 MPa pressure. After naturally cooling to room temperature, a composite base film is obtained. Then, the surface of the composite base film away from the polyimide nanofiber membrane is subjected to corona treatment. The frequency of the corona treatment is 20 kHz, the power is 5 kW, the treatment speed is 20 m / min, and the electrode spacing is 1.5 mm.

[0029] (5) Prepare a release agent solution, which is composed of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent. The vinyl silicone oil has a viscosity of 5000 Pa·s, the hydrogen content of the hydrogen-containing silicone oil is 0.5%, and the catalyst is a platinum catalyst with a platinum content of 0.3%. Coat the release agent onto the surface of the composite base film obtained in step (4) after corona treatment, and control the wet film thickness to 3 μm. Place the coated release film in an oven at 100°C to allow the solvent to evaporate and form an organosilicon release layer. After natural cooling, wind it up to obtain the industrial high-temperature resistant release film. The mass ratio of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent is 100:5:0.5:0.1:2500. Example 2

[0030] (1) Anhydrous ethanol, γ-aminopropyltriethoxysilane and 7.5% ammonia solution were added to a reaction vessel equipped with a stirrer and stirred at 27.5℃ and 350 rpm for 25 minutes. Then, tetraethyl orthosilicate was added dropwise over 7 minutes. After the addition was completed, stirring was continued for 4.5 hours. The mixture was then allowed to stand for 14 hours. The precipitate was obtained by centrifugation, washed three times with anhydrous ethanol, and dried in a vacuum drying oven at 82.5℃ for 7 hours to obtain modified silica microspheres. The mass ratio of anhydrous ethanol, γ-aminopropyltriethoxysilane, ammonia solution and tetraethyl orthosilicate was 200:6.5:70:35.

[0031] (2) In a nitrogen-protected reactor at 5°C, 4,4'-diaminodiphenyl ether was dissolved in N,N-dimethylacetamide and mechanically stirred until completely dissolved. Pyromellitic dianhydride was added in three batches, with an interval of 25 min between each batch. The mixture was stirred at 350 rpm for 8.5 hours to obtain the spinning solution. Electrospinning was then performed using an electrospinning device under nitrogen protection. The spinneret diameter was set to 0.2 mm, the receiving distance to 17.5 cm, the voltage to 25 kV, the spinning solution flow rate to 1.25 ml / h, and the ambient temperature to 27.5°C. With a relative humidity of 35%, a rotating drum was used as the receiving device at a speed of 1150 rpm to obtain a polyamic acid fiber membrane with a thickness of 30 μm. The polyamic acid fiber membrane was fixed on a tension frame and placed in a hot air oven at 165°C for 25 minutes. Then, the temperature was raised to 300°C at a rate of 2.5°C / min and held for 75 minutes. After natural cooling to room temperature, a polyimide nanofiber membrane was obtained. The mass ratio of 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide, and pyromellitic dianhydride was 1:9.5:1.09.

[0032] (3) Phenol and tetrachloroethane were mixed at a mass ratio of 1:1 and stirred at 350 rpm for 25 minutes to obtain a phenol / tetrachloroethane mixed solvent; in a water bath at 82.5℃, polyethylene terephthalate particles with an intrinsic viscosity of 0.83 dL / g and the above phenol / tetrachloroethane mixed solvent were mixed at a mass ratio of 1:4.5 and stirred at 350 rpm for 5 hours in a sealed container to obtain a polyethylene terephthalate solution; the modified silica microspheres obtained in step (1) and the above phenol / tetrachloroethane mixed solvent were mixed at a mass ratio of 1: 6.5 Mix and ultrasonically disperse at 700W for 25 minutes to form a silica dispersion; add the silica dispersion to the polyethylene terephthalate solution and add the antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], stir at 450 rpm for 2.5 hours to obtain the coating solution; wherein, the mass ratio of silica dispersion, polyethylene terephthalate solution and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is 24:100:0.75.

[0033] (4) The polyimide nanofiber membrane obtained in step (2) is flattened and fixed in a film-coating mold. Then, the coating liquid obtained in step (3) is coated onto the polyimide nanofiber membrane by a doctor blade. The wet film thickness is controlled to be 200 μm. Then, it is treated at 65°C for 25 minutes, then at 125°C for 50 minutes, and finally at 190°C for 12.5 minutes. After that, it is hot-pressed at 3 MPa pressure and 190°C for 7.5 minutes. After naturally cooling to room temperature, a composite base film is obtained. Then, the surface of the composite base film away from the polyimide nanofiber membrane is subjected to corona treatment. The frequency of the corona treatment is 25 kHz, the power is 7 kW, the treatment speed is 25 m / min, and the electrode spacing is 1.7 mm.

[0034] (5) Prepare a release agent solution, which is composed of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent. The vinyl silicone oil has a viscosity of 7500 Pa·s, the hydrogen content of the hydrogen-containing silicone oil is 0.75%, and the catalyst is a platinum catalyst with a platinum content of 0.4%. Coat the release agent onto the surface of the composite base film obtained in step (4) after corona treatment, controlling the wet film thickness to 4 μm. Place the coated release film in an oven at 110°C to allow the solvent to evaporate, forming an organosilicon release layer. After natural cooling, wind up to obtain the industrial high-temperature resistant release film. The mass ratio of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent is 100:10:0.75:0.2:3700. Example 3

[0035] (1) Anhydrous ethanol, γ-aminopropyltriethoxysilane and 10% ammonia solution were added to a reaction vessel equipped with a stirrer and stirred at 30°C and 400 rpm for 30 minutes. Then, tetraethyl orthosilicate was added dropwise over 8 minutes. After the addition was completed, stirring was continued for 5 hours. The mixture was then allowed to stand for 16 hours. The precipitate was obtained by centrifugation, washed 4 times with anhydrous ethanol, and dried in a vacuum drying oven at 85°C for 8 hours to obtain modified silica microspheres. The mass ratio of anhydrous ethanol, γ-aminopropyltriethoxysilane, ammonia solution and tetraethyl orthosilicate was 200:7:80:40.

[0036] (2) In a nitrogen-protected reactor at 10°C, 4,4'-diaminodiphenyl ether was dissolved in N,N-dimethylacetamide and mechanically stirred until completely dissolved. Pyromellitic dianhydride was added in three batches, with a 30-minute interval between each batch. The mixture was stirred at 400 rpm for 9 hours to obtain the spinning solution. Electrospinning was then performed under nitrogen protection using an electrospinning device with a spinneret diameter of 0.3 mm, a receiving distance of 20 cm, a voltage of 30 kV, a spinning solution flow rate of 1.5 ml / h, and an ambient temperature of 30°C. With a humidity of 40% and a receiving device consisting of a rotating drum at a speed of 1500 rpm, a polyamic acid fiber membrane with a thickness of 30 μm was obtained. The polyamic acid fiber membrane was fixed on a tension frame and placed in a hot air oven. It was treated at 180°C for 30 minutes, then heated to 320°C at a heating rate of 3°C / min and held at that temperature for 90 minutes. After natural cooling to room temperature, a polyimide nanofiber membrane was obtained. The mass ratio of 4,4'-diaminodiphenyl ether, N,N-dimethylacetamide, and pyromellitic dianhydride was 1:10:1.10.

[0037] (3) Phenol and tetrachloroethane are mixed at a mass ratio of 1:1 and stirred at 400 rpm for 30 minutes to obtain a phenol / tetrachloroethane mixed solvent; in an 85°C water bath, polyethylene terephthalate particles with an intrinsic viscosity of 0.85 dL / g and the above phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of 1:5 and stirred at 400 rpm for 6 hours in a sealed container to obtain a polyethylene terephthalate solution; the modified silica microspheres obtained in step (1) and the above phenol / tetrachloroethane mixed solvent are mixed at a mass ratio of The silica dispersion was prepared by mixing the silica dispersion in a 1:7 ratio and ultrasonically dispersing it at 800W for 30 minutes. The silica dispersion was then added to a polyethylene terephthalate solution, along with the antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]. The mixture was stirred at 500 rpm for 3 hours to obtain the coating solution. The mass ratio of the silica dispersion, polyethylene terephthalate solution, and antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] was 24:120:1.

[0038] (4) The polyimide nanofiber membrane obtained in step (2) is flattened and fixed in the film-coating mold. Then, the coating liquid obtained in step (3) is coated onto the polyimide nanofiber membrane by a doctor blade. The wet film thickness is controlled to be 200 μm. Then, it is treated at 70°C for 30 minutes, then at 130°C for 60 minutes, and finally at 200°C for 15 minutes. After that, it is hot-pressed at 5 MPa pressure and 200°C for 10 minutes. After naturally cooling to room temperature, a composite base film is obtained. Then, the surface of the composite base film away from the polyimide nanofiber membrane is subjected to corona treatment. The frequency of the corona treatment is 30 kHz, the power is 10 kW, the treatment speed is 30 m / min, and the electrode spacing is 2.0 mm.

[0039] (5) Prepare a release agent solution, which is composed of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent. The viscosity of the vinyl silicone oil is 10000 Pa·s, the hydrogen content of the hydrogen-containing silicone oil is 1.0%, and the catalyst is a platinum catalyst with a platinum content of 0.5%. Coat the release agent onto the surface of the composite base film obtained in step (4) after corona treatment, and control the wet film thickness to 5 μm. Place the coated release film in an oven at 120°C to allow the solvent to evaporate and form an organosilicon release layer. After natural cooling, wind up to obtain the industrial high-temperature resistant release film. The mass ratio of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol, and toluene solvent is 100:15:1.0:0.3:4900.

[0040] Comparative Example 1

[0041] The only difference between Comparative Example 1 and Example 1 is that modified silica microspheres are not added.

[0042] Comparative Example 2

[0043] The only difference between Comparative Example 2 and Example 1 is that the antioxidant pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] is not added.

[0044] Comparative Example 3

[0045] The only difference between Comparative Example 3 and Example 1 is that γ-aminopropyltriethoxysilane is not added.

[0046] Tensile strength was tested according to GB / T1040.3-2006.

[0047] After placing the sample statically in an oven at 180℃ for 1 hour, it was cooled to room temperature in a standard environment (23℃, 50%RH) and then its tensile strength retention rate (tensile strength after aging / tensile strength before aging × 100%) was tested.

[0048] Table 1 below shows the performance analysis results of the embodiments and comparative examples of the present invention.

[0049] Table 1

[0050] Sample number Tensile strength (MPa) before aging Tensile strength retention rate (%) Example 1 250 95.5 Example 2 258 96.2 Example 3 253 95.8 Comparative Example 1 215 88.0 Comparative Example 2 240 82.1 Comparative Example 3 235 91.7

[0051] Experimental data from the examples and comparative examples show that the present invention uses a polyimide nanofiber membrane prepared by electrospinning as a reinforcing skeleton, and pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] as a heat stabilizer. The polyimide nanofiber membrane provides structural support for the release film through its good thermal stability and mechanical properties. The organic chains on the surface of the modified silica microspheres improve its interfacial compatibility and dispersion uniformity. When heated, the modified silica microspheres act as physical crosslinking points, restricting the movement of polymer chain segments and improving the thermal stability of the release film, thereby giving the release film good mechanical properties and temperature resistance.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. An industrial high-temperature resistant release film, characterized by, The release film comprises a composite base film and a release layer, the composite base film is prepared by coating a coating liquid on a polyimide nanofiber film; the coating liquid is prepared from phenol, tetrachloroethane, polyethylene terephthalate particles, modified silica microspheres and antioxidant tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester; the modified silica microspheres are prepared from anhydrous ethanol, γ-aminopropyl triethoxysilane, ammonia solution and tetraethyl orthosilicate; the polyimide nanofiber film is prepared from 4,4'-diamino diphenyl ether, N,N-dimethylacetamide and pyromellitic dianhydride, and the release layer is prepared from vinyl silicone oil, hydrogen-containing silicone oil, platinum gold catalyst, inhibitor ethynyl cyclohexanol and toluene solvent; The application discloses a preparation method of an industrial high-temperature-resistant release film, and belongs to the technical field of high-temperature-resistant release films. (1) anhydrous ethanol, γ-aminopropyl triethoxysilane and ammonia solution are added into a reaction kettle with a stirrer, stirring is carried out at 25-30 DEG C and a rotating speed of 300-400 rpm for 20-30 minutes, then tetraethyl orthosilicate is added dropwise, the dropwise adding time is 6-8 minutes, after the dropwise adding is completed, stirring is continuously carried out for 4-5 hours, then standing is carried out for 12-16 hours, centrifugal separation is carried out to obtain a precipitate, the precipitate is washed 2-4 times with anhydrous ethanol, and drying is carried out in a vacuum drying box at 80-85 DEG C for 6-8 hours, so that modified silica microspheres are obtained; (2) in a reaction kettle with nitrogen protection and at a temperature of 0-10 DEG C, 4,4'-diamino diphenyl ether is dissolved in N,N-dimethylacetamide by mechanical stirring until complete dissolution, pyromellitic dianhydride is added in three batches with an interval of 20-30 minutes, and stirring is carried out at a rotating speed of 300-400 rpm for 8-9 hours, so that a spinning solution is obtained; then electrospinning is carried out in nitrogen protection by using an electrospinning equipment, so that a polyamide acid fiber film is obtained; the polyamide acid fiber film is fixed on a tension frame and is placed into a hot air oven, treatment is carried out at 150-180 DEG C for 20-30 minutes, then the temperature is increased to 280-320 DEG C at a temperature increasing rate of 2-3 DEG C / minute, heat preservation is carried out for 60-90 minutes, and natural cooling is carried out to room temperature, so that a polyimide nanofiber film is obtained; (3) phenol and tetrachloroethane are mixed, stirring is carried out at a rotating speed of 300-400 rpm for 20-30 minutes, so that a phenol / tetrachloroethane mixed solvent is obtained; polyethylene terephthalate particles with a specific viscosity of 0.80-0.85 dL / g and the phenol / tetrachloroethane mixed solvent are mixed in an 80-85 DEG C water bath, stirring is carried out in a sealed container at a rotating speed of 300-400 rpm for 4-6 hours, so that a polyethylene terephthalate solution is obtained; the modified silica microspheres prepared in step (1) and the phenol / tetrachloroethane mixed solvent are mixed, ultrasonic dispersion is carried out for 20-30 minutes at a power of 600-800 W, so that a silica dispersion liquid is formed; the silica dispersion liquid is added into the polyethylene terephthalate solution, antioxidant tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid] pentaerythritol ester is added, and stirring is carried out at a rotating speed of 400-500 rpm for 2-3 hours, so that a coating liquid is obtained; (4) The polyimide nanofiber membrane prepared in step (2) is fixed flat in a casting die, and then the coating solution obtained in step (3) is coated on the polyimide nanofiber membrane by a doctor blade, followed by treatment at 60-70℃ for 20-30 minutes, then treatment at 120-130℃ for 40-60 minutes, and finally treatment at 180-200℃ for 10-15 minutes, and then hot pressing at a pressure of 1-5 MPa, 180-200℃ for 5-10 minutes, and then natural cooling to room temperature to obtain a composite base film, and then the surface of the composite base film away from the polyimide nanofiber membrane is subjected to corona treatment; the frequency of the corona treatment is 20-30 kHz, the power is 5-10 kW, the treatment speed is 20-30 m / min, and the electrode spacing is 1.5-2.0 mm; (5) A release agent solution is prepared, which is composed of vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol and toluene solvent, wherein the viscosity of the vinyl silicone oil is 5000-10000 Pa·s, the hydrogen content of the hydrogen-containing silicone oil is 0.5%-1.0%, and the catalyst is a platinum catalyst with a platinum content of 0.3-0.5%; the release agent is coated on the surface of the composite base film obtained in step (4) after corona treatment, and the wet film thickness is controlled to be 3-5 μm; the coated release film is placed in an oven at 100-120℃ for treatment to volatilize the solvent and form a silicone release layer, and then it is naturally cooled and wound up to obtain the industrial high-temperature-resistant release film; the mass ratio of the vinyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, inhibitor ethynylcyclohexanol and toluene solvent is 100:(5-15):(0.5-1.0):(0.1-0.3):(2500-4900).

2. The high temperature resistant release film for industrial use according to claim 1, characterized by The mass fraction of the aqueous ammonia solution is 5%-10%.

3. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (1), the mass ratio of anhydrous ethanol, γ-aminopropyl triethoxysilane, aqueous ammonia solution and tetraethyl orthosilicate is 200:(6-7):(60-80):(30-40).

4. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (2), the mass ratio of 4,4'-diamino diphenyl ether, N,N-dimethylacetamide and pyromellitic dianhydride is 1:(9-10):(1.08-1.10).

5. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (2), the electrospinning equipment is set to have a spinneret diameter of 0.1-0.3 mm, a receiving distance of 15-20 cm, a voltage of 20-30 kV, a spinning solution flow rate of 1.0-1.5 ml / h, an ambient temperature of 25-30℃, a relative humidity of 30-40%, and a rotating drum as the receiving device with a rotating speed of 800-1500 rpm.

6. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (3), phenol and tetrachloroethane are mixed in a mass ratio of 1:

1.

7. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (3), polyethylene terephthalate particles and phenol / tetrachloroethane mixed solvent are mixed in a mass ratio of 1:(4-5).

8. The high temperature resistant release film for industrial use according to claim 1, characterized by In step (3), modified silica microspheres and phenol / tetrachloroethane mixed solvent are mixed in a mass ratio of 1:(6-7).

9. The high temperature resistant release film for industrial use according to claim 1, characterized by The mass ratio of the silica dispersion liquid, the polyethylene terephthalate solution and the antioxidant tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid]pentaerythritol ester in step (3) is 24:(80-120):(0.5-1).