Special release film for heat-resistant anti-adhesion multilayer ceramic capacitor and preparation method thereof

Abstract

The invention discloses a heat-resistant anti-adhesion release film special for a multilayer ceramic capacitor and a preparation method of the release film, and belongs to the field of electronic materials. The preparation method comprises the following steps: selecting a modified PET (Polyethylene Terephthalate) film containing nano aluminum oxide particles as a base material layer; the preparation method comprises the following steps: dissolving fluorine-containing silane grafted polyimide and a hyperbranched polyester polysiloxane block copolymer in a mixed organic solvent to prepare a functional coating solution, and forming a functional coating on a base material through coating and stepped heating curing; and coating the functional coating with a release layer coating liquid prepared from vinyl-terminated polydimethylsiloxane, polymethylhydrosiloxane, a platinum catalyst, an acrylate silane coupling agent, vinyl MQ silicon resin and the like, curing, and rolling to obtain the release film. The release film prepared by the method has excellent heat resistance, adhesion resistance and dimensional stability, is particularly suitable for a high-temperature process link in the manufacturing process of a multilayer ceramic capacitor, can effectively prevent film adhesion, and ensures the production quality and efficiency of the capacitor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic materials, in particular to a heat-resistant anti-adhesion release film special for multi-layer ceramic capacitors and a preparation method thereof. BACKGROUND

[0002] As an indispensable basic element in modern electronic industry, the production and manufacturing process of multi-layer ceramic capacitors is rapidly developing towards miniaturization, high capacity and high reliability. In the flow casting process of multi-layer ceramic capacitors, the release film plays a crucial role as a carrier film for carrying ceramic slurry and achieving smooth peeling in subsequent processes. The stability of this process is directly related to the thickness uniformity of the ceramic dielectric layer, the surface flatness, and the electrical performance and yield of the final capacitor. Therefore, the performance of the release film has a decisive influence on the smoothness and efficiency of the entire production process. An ideal release film not only needs to have moderate and stable release force to ensure that the ceramic green sheet can be peeled off completely and intact, but also must have excellent heat resistance, tensile deformation resistance and surface flatness to adapt to high-temperature processing environment and ensure the ultra-thin and uniformity of the capacitor dielectric.

[0003] However, the existing ordinary release film gradually exposes many technical bottlenecks in response to the increasingly demanding production requirements of multi-layer ceramic capacitors. First, the insufficient heat resistance is a common challenge. During the coating and drying process of the ceramic slurry, the release film needs to withstand high temperature for a long time, and the substrate and coating of the ordinary release film are prone to thermal aging, deformation or even decomposition under this condition, resulting in a sharp change or failure of the release force, which in turn causes tearing or wrinkling of the ceramic green sheet. Second, poor anti-adhesion is another major problem. Under high temperature and high pressure storage or process conditions, the coating of the release film may interact with the organic components in the ceramic slurry, or the layers of the film roll may be tightly bonded, causing peeling difficulties, which seriously affects the production efficiency and product yield. In addition, the adhesion between the functional coating and the substrate layer of the conventional release film is often not ideal, and after high-temperature process, the coating may crack or fall off, polluting the slurry and damaging the surface of the green sheet. These defects jointly restrict the improvement of the manufacturing level of high-performance multi-layer ceramic capacitors.

[0004] To overcome the above-mentioned defects, the industry has made a series of exploration and attempt. For example, by enhancing the temperature resistance level of the base film or modifying the silicone release agent to improve the heat resistance, but it is often difficult to balance the release force stability and anti-blocking property; there are also research attempts to introduce inorganic nanoparticles or special resins to improve the coating performance, but it may also cause new problems such as coating flexibility decline or adhesion force weakening with the substrate. Therefore, the development of a special release film that can comprehensively solve the technical problems such as heat resistance, anti-blocking property, coating adhesion and dimensional stability, etc., has become an urgent task to meet the manufacturing needs of high-end multilayer ceramic capacitors. The present application is based on the full understanding of the deficiencies of the prior art, aiming to provide a new solution to achieve a comprehensive breakthrough in the performance of the release film. SUMMARY

[0005] The present application aims to provide a heat-resistant and anti-blocking special release film for multilayer ceramic capacitors and a preparation method thereof, which solves the technical problems of the existing release film, such as insufficient heat resistance, easy adhesion with ceramic slurry at high temperature, poor interlayer adhesion, resulting in low production yield and low efficiency of multilayer ceramic capacitors.

[0006] The present application achieves the above-mentioned purposes through the following technical solutions:

[0007] A preparation method of a heat-resistant and anti-blocking special release film for multilayer ceramic capacitors, the steps comprising:

[0008] S1, selecting a modified PET film as a base layer, the modified PET film containing nano-aluminum oxide particles; adding fluorine-containing silane grafted polyimide and hyperbranched polyester-polysiloxane block copolymer into a mixed organic solvent composed of propylene oxide, xylene and 2-butanone, stirring and dissolving to obtain a functional coating mixed solution;

[0009] S2, using micro-gravure coating method to coat the functional coating mixed solution on the base layer, moving the coated base layer to the oven for stepwise temperature curing to form a functional coating;

[0010] S3, mixing vinyl-terminated polydimethylsiloxane, polymethylhydrogenosiloxane, platinum gold catalyst, acrylate-based silane coupling agent and vinyl MQ silicone resin in a solvent to obtain a release layer coating solution, the solvent being composed of 120# solvent, D30 solvent and 2-butanone; using a slot die to coat the release layer coating solution on the functional coating; curing at 120-140℃ to form a release layer; winding at 20-26℃.

[0011] According to the preferred embodiment of the present application, the preparation steps of the modified PET film include: first, polyethylene terephthalate chips with an intrinsic viscosity of 0.65-0.70 dL / g are vacuum dried at 150-160°C for 4-6 hours to remove moisture; at the same time, nano-alumina particles with an average particle size of 0.5-3 μm are dried at 110-120°C for 2-4 hours; then, the dried nano-alumina particles are mixed with a mixed dispersant composed of ethanol and deionized water in a volume ratio of 1:1 at a weight ratio of 1:10, and 1-3% of silane coupling agent KH-550 by weight of the nano-alumina is added, and surface modification treatment is carried out in a high-speed disperser at a speed of 3000-5000 rpm for 30-60 minutes to obtain modified nano-alumina slurry; subsequently, the above slurry is pre-mixed with dried PET chips and polyethylene glycol with a molecular weight of 2000 as a dispersion aid at a weight percentage of PET chips: nano-alumina: polyethylene glycol = (95-99):(1-5):0.5, wherein the addition amount of polyethylene glycol accounts for 0.5% of the total weight of PET chips and nano-alumina; the pre-mixed material is fed into a twin-screw extruder for melt blending, extrusion, cooling, and granulation at a melt temperature of 270-285°C to obtain nano-alumina masterbatch; finally, the obtained masterbatch is mixed with pure PET chips at a weight ratio of 1:4 to 1:9, and then fed into a biaxial stretching film forming equipment, and sequentially subjected to melt extrusion at 285-295°C, casting, longitudinal stretching at 95-105°C by 3-3.5 times, transverse stretching at 115-125°C by 3.2-3.8 times, and heat setting treatment at 220-240°C for 3-5 seconds, and then cooled and wound up to obtain a modified PET film containing uniformly dispersed nano-alumina particles.

[0012] According to the preferred embodiment of the present application, the step of applying the functional coating mixture on the substrate layer by micro gravure coating method comprises: first, installing the modified PET film substrate with a width of 520-550 mm on the unwinding frame, setting the unwinding tension to 15-25 N / cm, and correcting and centering the substrate through the edge position control system; then, starting the coating unit, and rotating the micro gravure coating roller with a screen hole line number of 180-250 lines / inch at a speed ratio of 1:1.2 to 1:1.5 of the substrate running speed in the reverse direction, while delivering the functional coating mixture to the kiss coating area formed by the coating roller and the substrate, and accurately scraping off the excess coating liquid on the surface of the screen roller by a metal scraper with a pressure of 20-40 N; then, controlling the substrate to pass through the coating area at a constant speed of 40-60 m / min, so that the coating liquid quantitatively carried in the screen hole of the screen roller is transferred to the surface of the substrate to form a uniform coating layer with a wet film thickness of 5-15 μm, and the cleanliness of the coating environment needs to be maintained above the thousand level, the temperature is controlled at 23±2℃, and the humidity is controlled at 55±5%; subsequently, immediately sending the wet film after coating into a multi-section temperature zone oven with a length of 8-12 meters for stepwise temperature rising and curing.

[0013] According to the preferred embodiment of the present application, the step of applying the release layer coating liquid on the functional coating by using a slot coating head comprises: first, installing the semi-finished film roll with the completed functional coating on the second unwinding frame, and setting the unwinding tension to 10-20 N / cm; then, after filtering the prepared release layer coating liquid through a 5 μm precision filter bag, delivering the coating liquid into the cavity of the slot coating head, and stabilizing the supply pressure of the coating liquid at 0.2-0.5 MPa and the temperature at 23±2℃; then, accurately adjusting the slot gap of the coating head die lip to 50-150 μm, so that it maintains an accurate distance of 100-300 μm from the surface of the functional coating, and coating at a linear speed synchronized with the substrate running speed; subsequently, starting the coating pump to uniformly extrude the release layer coating liquid from the slot to form a uniform liquid film with a wet film thickness of 1-5 μm on the functional coating, and controlling the coating speed at 40-60 m / min; finally, immediately sending the coated film into the second oven for curing reaction at 120-140℃ in a hot air circulation environment for 1-4 minutes to form the release layer, and after curing, monitoring by an online thickness detector and a defect detection system, and winding at a constant tension of 15-25 N / cm under the conditions of 20-26℃ and 55±5% humidity.

[0014] According to the preferred embodiment of the present application, the 120# solvent, whose Chinese name is 120# solvent gasoline; commonly known as: white electric oil, rubber solvent oil; main component: mainly a mixture of alkanes with a chain length of about C6-C7, which is a straight distillation fraction of petroleum refined. Its name comes from its initial boiling point not less than 80℃ and 98% distillation temperature not higher than 120℃. It is a kind of aliphatic hydrocarbon solvent with high purity and good stability.

[0015] According to the preferred embodiment of the present application, the D30 solvent; the Chinese name is D30 type aromatic hydrocarbon solvent; the main component is mainly aromatic hydrocarbon mixture with carbon atom number of 9~10, such as cumene, trimethylbenzene, etc. The "D" in its name may represent "aromatic hydrocarbon", and "30" may be related to the distillation range or specific index. It is a high-boiling aromatic hydrocarbon solvent with distillation range higher than ordinary xylene.

[0016] According to the preferred embodiment of the present application, the platinum gold catalyst is Karstedt catalyst, which has high activity: stable at room temperature, but very high activity when heated (such as 130℃ in the present application). Good solubility: can be well dissolved in silicone polymer and various organic solvents (such as toluene, 120# solvent, 2-butanone).

[0017] In the present invention, the final performance of the release film is achieved by the synergistic effect and step-by-step forming mechanism among the substrate, functional coating and release layer. Firstly, the construction and combination mechanism of the functional coating on the modified substrate. The selected substrate is uniformly dispersed with nano-sized inorganic particles, and its mechanism is that the nanoparticles act as physical crosslinking points to effectively limit the thermal motion of polyester molecular chains at high temperature, greatly improving the heat deformation temperature and dimensional stability of the substrate. The fluorine-containing silane grafted polyimide and hyperbranched polyester polysiloxane block copolymer are dissolved in a specific mixed solvent, and the mechanism of the mixed solvent is to realize gradient volatilization during the stepwise heating and curing process after coating by matching different boiling points and polar solvents. During the pre-curing stage, the low-boiling-point solvent volatilizes rapidly, making the coating preliminarily shape; during the subsequent high-temperature complete curing stage, it promotes the physical entanglement and possible chemical interaction (such as hydrogen bonding between polar groups) between the two high molecular polymers and the surface of the substrate. In particular, the fluorine-containing silane grafted polyimide has a certain similarity with the polyester molecular structure of the substrate, which enhances the compatibility and adhesion, thereby forming a heat-resistant and solid transition layer (functional coating) on the substrate with low surface energy and strong adhesion to the substrate. Secondly, the crosslinking and firm adhesion mechanism of the release layer on the functional coating. The main film-forming reaction of the release layer coating solution is the silicon-hydrogen addition reaction. Its mechanism is that under the action of the catalyst, the silicon-hydrogen bond on the polymethylhydrogen siloxane chain reacts with the carbon-carbon double bond at the end of the vinyl-terminated polydimethylsiloxane, and the silicon and hydrogen atoms are added to the two carbon atoms of the double bond, respectively, to form a silicon-carbon bond, thereby crosslinking the linear polysiloxane molecules into a three-dimensional network structure. The added vinyl resin contains multiple vinyl groups on its molecule, which can act as a crosslinking density regulator and enhancer. By participating in the silicon-hydrogen addition reaction, the number of network nodes is increased, thereby accurately controlling the modulus and release force of the silicone layer after final curing. The most critical is the mechanism of the acrylate silane coupling agent, which is a "double functional" molecule: the alkoxysilane group at one end can hydrolyze and form a firm siloxane chemical bond or strong hydrogen bond with the surface of the functional coating (especially the silicon, oxygen atoms or polar groups in the fluorine-containing silane grafted polyimide and hyperbranched copolymer) under heating and curing conditions; the other end of the acrylate group may copolymerize with the vinyl group in the silicon-hydrogen addition system through a free radical mechanism, or physically entangle in the silicone network. In this way, the coupling agent acts like a "molecular bridge", connecting the upper silicone release layer and the lower functional coating together tightly through strong chemical bond interaction, greatly improving the interlayer adhesion and avoiding the detachment or transfer of the release layer at high temperature. Finally, the entire release film presents a synergistic mechanism of multi-layer composite.The solid nanomodified substrate provides overall dimensional stability and mechanical support; the functional coating layer serves as an intermediate layer, which is not only heat-resistant and has suitable surface properties, but more importantly, it becomes a "link" for the firm combination of the substrate and the release layer; and the crosslinked silicone release layer on the top layer provides a stable and controllable low surface energy release surface. The gradient structure design mechanism of "rigid substrate-tough intermediate layer-flexible release layer" ensures that the release film can not only resist deformation caused by thermal stress, but also prevent peeling between layers due to the mismatch of the thermal expansion coefficient, while maintaining durable and reliable anti-sticking performance, thereby meeting the harsh requirements of high-end electronic component manufacturing.

[0018] According to the preferred embodiment of the present application, in step S1, the thickness of the substrate layer is 40-100 μm; the weight ratio of propylene oxide, xylene and methyl butanone in the mixed organic solvent is 1:1:1; the stirring speed is 780-1000 rpm / min, and the stirring time is 4-10 min.

[0019] According to the preferred embodiment of the present application, the coating speed is 40-60 m / min; the stepwise temperature curing is pre-cured at 90-110℃, and then fully cured at 130-150℃; and the thickness of the functional coating layer is 5-15 μm.

[0020] According to the preferred embodiment of the present application, the preparation method of the fluorine-containing silane grafted polyimide comprises: A1, first, 4,4'-diamino diphenyl ether and 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane are dissolved in N-methyl pyrrolidone solvent, and pyromellitic dianhydride is added under nitrogen protection, and the reaction is carried out at 0-5℃ to obtain a polyamic acid solution containing side hydroxyl groups; A2, then, a mixed solution of acetic anhydride and triethylamine is added, and the reaction is carried out at 25-40℃ first, and then gradually heated to 150-180℃ to complete the imidization reaction, to obtain a polyimide with side chain hydroxyl groups; finally, the polyimide with side chain hydroxyl groups, perfluorooctyltriethoxysilane and dibutyltin dilaurate are subjected to dehydration condensation reaction in toluene at 110-120℃, and then subjected to precipitation, washing and vacuum drying.

[0021] In the present invention, the synthesis of fluorine-containing silane grafted polyimide is a multi-step precise chemical process. The core mechanism is to first construct a high-performance polyimide backbone with active reaction sites, and then introduce fluorine-containing silane side chains through an efficient grafting reaction to achieve performance synergy at the molecular level. The first step is the synthesis of polyamide acid precursor. This reaction is based on the polycondensation of two diamine monomers and one dianhydride monomer. Among the two diamine monomers, one provides rigidity and good thermal stability of the chain segment, and the other introduces a side hydroxyl group in its molecular structure and simultaneously introduces a hexafluoropropane group with great steric hindrance and strong hydrophobicity. Under low temperature conditions, the amino group of the diamine monomer reacts with the anhydride group of the dianhydride monomer to form an amide bond and open the anhydride ring to generate a carboxyl group, thereby obtaining a linear or slightly branched polyamide acid solution. Low temperature operation is crucial, as the mechanism is to suppress the side reaction of intramolecular or intermolecular ring closure of carboxyl groups with adjacent amide groups to form imides after the reaction of amide bonds between anhydride groups and amino groups, ensuring that a precursor solution with high molecular weight and good solubility is obtained, laying the foundation for subsequent processing. The second step is the key imidization and cyclization reaction. At this stage, a chemical dehydrating agent and an alkaline catalyst are added to the polyamide acid solution. The reaction mechanism is that the dehydrating agent reacts with the carboxyl groups on the polyamide acid chain to form a highly active intermediate, which is then attacked by the nitrogen atom of the adjacent amide group under alkaline catalysis, loses a molecule of water, and forms a stable five-membered ring imide structure. The step-by-step thermal treatment from low temperature to high temperature is adopted, and the mechanism is that at the initial stage, most of the amide acid groups are mildly cyclized at a lower temperature to avoid the rapid evaporation of the solvent due to vigorous dehydration, which can cause bubbles or defects; at the later stage, the remaining amide acid fragments with large steric hindrance or low reactivity are completely cyclized at high temperature to ensure that the polyimide degree is the highest, thereby fully exhibiting the inherent excellent heat resistance, mechanical strength and dimensional stability of polyimide. Thus, a polyimide with active hydroxyl groups in the side chain is obtained. The third step is the grafting reaction of fluorine-containing silane. This step is based on the de-alcohol condensation reaction mechanism between hydroxyl groups and alkoxy silane. In the presence of a catalyst, the hydroxyl groups on the polyimide side chain react with the alkoxy groups of the fluorine-containing silane molecule, the hydroxyl group attacks the silicon atom, and one molecule of alcohol is removed to form a stable silicon-oxygen-carbon covalent bond, thereby firmly grafting the perfluoroalkyl chain segment to the polyimide backbone through the silane bridge. The introduced perfluoroalkyl chain segment has extremely low surface energy, and the mechanism is that the strong electronegativity of the fluorine atom forms a tight electronic cloud shielding, making the material surface exhibit excellent water and oil repellency (anti-adhesion) and chemical inertness. At the same time, the cooperation of long-chain fluorine-containing groups and polyimide main chain further enhances the thermal stability of the molecule. Therefore, the final fluorine-containing silane grafted polyimide becomes a "dual-functional" polymer material integrating the heat resistance and strength of the rigid polyimide main chain, and the extremely low surface energy and hydrophobicity of the fluorine-containing side chain, providing a core performance basis for functional coatings.

[0022] According to the preferred embodiment of the present application, in step A1, the molar ratio of 4,4'-diaminodiphenyl ether to 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane is (1-3):1; the reaction time is 4-6h under the condition of 0-5℃.

[0023] According to the preferred embodiment of the present application, in step A2, the dehydration condensation reaction is carried out at 110-120℃ for 4-6h.

[0024] According to the preferred embodiment of the present application, the preparation method of the hyperbranched polyester-polysiloxane block copolymer comprises: B1, under the protection of nitrogen, pentaerythritol is reacted with 2,2-dimethylol propionic acid at 150-160℃ to obtain a hydroxyl-terminated hyperbranched polyester; B2, the hydroxyl-terminated hyperbranched polyester, acryloyl chloride and triethylamine are added to dichloromethane and reacted at 0-5℃ to obtain a hyperbranched polyester capped with acryloyloxy groups at the end; the hyperbranched polyester capped with acryloyloxy groups at the end is subjected to thiol-ene click chemistry reaction with monomercaptopropyl-terminated polydimethylsiloxane in the presence of 2-hydroxy-2-methyl-1-phenyl-1-propanone under ultraviolet light irradiation; and then precipitated, washed and vacuum dried.

[0025] In the present invention, the preparation mechanism of hyperbranched polyester-polysiloxane block copolymer is based on the following steps: firstly, a hyperbranched core with high functionality and good compatibility is constructed, and then the core is connected with flexible polysiloxane chains through efficient click chemistry reaction to realize rigid / flexible molecular design. The first step is the synthesis of hyperbranched polyester with terminal hydroxyl groups. The reaction is based on the melt polycondensation mechanism between polyols and carboxylic acids. A central polyol molecule with four hydroxyl groups is used as the core, and a plurality of bifunctional monomers with two carboxyl groups and one hydroxyl group are esterified. The unique mechanism is that in the reaction, the two carboxyl groups of the bifunctional monomer can react with the hydroxyl groups of other monomers to extend the branches, while the hydroxyl group carried by itself becomes a new growth point. Due to the specific structure of the monomers, this “one-step” polycondensation reaction cannot form a linear structure, but develops in three-dimensional space to form a hyperbranched polyester structure with a large number of terminal hydroxyl groups. Compared with linear polymers, this structure has the advantages of low viscosity, high solubility, and a large number of modifiable terminal functional groups. The reaction temperature and time control the molecular weight and branching degree to ensure that the hyperbranched core with ideal structure is obtained. The second step is the functionalization of the terminal groups of the hyperbranched polyester. The mechanism is the nucleophilic substitution reaction between hydroxyl groups and acyl chloride. In the presence of base, the terminal hydroxyl group of the hyperbranched polyester attacks the carbonyl carbon atom of acryloyl chloride, and a molecule of hydrogen chloride is removed to form an ester bond with a terminal acryloyloxy group. The low temperature condition is to suppress the side reaction of self-polymerization of the unstable carbon-carbon double bond in acryloyl chloride, and to ensure that the reaction selectively occurs on the acyl chloride group. This step successfully converts the terminal hydroxyl group of the hyperbranched polyester into a highly reactive carbon-carbon double bond (olefin), which prepares for the subsequent linking reaction. The third step is the linking of the hyperbranched polyester and the polysiloxane, which is the most delicate part of the whole synthesis. The mechanism is based on the thiol-ene click chemistry reaction. It is a highly efficient, fast, and highly selective chemical reaction. In the presence of a photoinitiator, a free radical is generated by irradiation with a specific wavelength of ultraviolet light. The free radical first attacks the terminal thiol group of the polysiloxane to form a sulfur free radical. Then, the sulfur free radical quickly and selectively attacks the terminal carbon-carbon double bond of the hyperbranched polyester, and the sulfur atom is added to the terminal carbon of the double bond, while the intermediate carbon atom forms a new carbon-centered free radical. The free radical then abstracts a hydrogen atom from another thiol group to form a new sulfur free radical, allowing the chain reaction to continue. In this way, multiple double bonds on each hyperbranched polyester molecule form stable thioether bonds with the terminal thiol groups of a polysiloxane chain, thereby covalently linking the rigid hyperbranched polyester “core” and the flexible polysiloxane “arm” together to form a unique block copolymer. This structural mechanism endows the material with excellent comprehensive performance: the hyperbranched core provides strong cohesive force and good compatibility and interfacial bonding force with other components of the functional coating, while the peripheral polysiloxane arm contributes excellent flexibility, lubricity, and low surface energy, effectively enhancing the compactness, anti-migration, and durability of the coating.

[0026] According to the preferred embodiment of the present application, in step B1, the reaction time at 150-160 DEG C is 3-5h; the molar ratio of pentaerythritol to 2,2-dimethylol propionic acid is 1:(8-12).

[0027] According to the preferred embodiment of the present application, in step B2, the wavelength of the ultraviolet light irradiation is 365nm, and the click chemistry reaction time is 1-2 hours.

[0028] The present application also provides a heat-resistant anti-adhesion special release film for multi-layer ceramic capacitors, which is prepared according to the preparation method of the heat-resistant anti-adhesion special release film for multi-layer ceramic capacitors.

[0029] The present application has the following advantages:

[0030] The heat-resistant anti-adhesion special release film for multi-layer ceramic capacitors and the preparation method thereof provided by the present application have the following advantages: the unique selection of the base material, the design of the functional coating and the synergistic effect of the release layer formula bring significant and comprehensive technical effects, and effectively overcome many defects in the prior art. First, the present application has made a breakthrough in the design and preparation of the base material layer and the functional coating. The modified polyester film containing nano-aluminum oxide particles is selected as the base material, which fundamentally improves the heat resistance, rigidity and dimensional stability of the film, so that it can effectively resist thermal shrinkage and deformation in the subsequent high-temperature coating and capacitor manufacturing process. More importantly, the specially prepared functional coating mixture plays a key role. Among them, the fluorine-containing silane grafted polyimide material ingeniously combines the excellent high-temperature resistance, mechanical strength of the polyimide skeleton and the low surface energy, chemical stability of the fluorine-containing silane segment, so that the functional coating not only has extremely high thermal stability, but also can form a firm adhesion with the base material layer. At the same time, the introduction of hyperbranched polyester polysiloxane block copolymer greatly enhances the compactness, flexibility and anti-migration of the coating by using its highly branched three-dimensional structure and the flexibility of the silicone segment, effectively avoiding the problem of cracking or peeling of the coating from the base material due to internal stress at high temperature. Through micro-gravure coating and stepwise temperature curing process, it is ensured that the functional coating can be uniformly formed and stably combined with the base material, providing an extremely stable, flat and strongly bonded support platform for the upper release layer.

[0031] Secondly, in the performance of the release layer, the application shows excellent comprehensive balance ability. The release layer coating liquid is based on the addition reaction of end-vinyl polydimethylsiloxane and polymethyl hydrogen siloxane under the action of platinum gold catalyst, forming a silicone network with controllable crosslinking degree and stable structure, which is the fundamental guarantee to obtain stable and moderate release force. The specially added vinyl MQ silicone resin as an adhesion promoter can finely control the size and stability of the release force, prevent the ceramic green body from peeling off due to too high release force, or the coiled material from collapsing during transportation due to too low release force. The use of acrylate-based silane coupling agent plays a key "bridging" role, one end of which is chemically bonded to the silicone network of the release layer, and the other end is strongly interacted with the surface of the functional coating below, greatly enhancing the interlayer adhesion between the release layer and the functional coating, and fundamentally solving the technical problem of easy transfer or falling off of the release layer under high temperature and high humidity conditions. The use of slot coating ensures the high uniformity of the release layer coating, and the release layer formed by curing under relatively mild conditions has extremely low surface energy, smooth and dense, which gives the release film excellent and durable anti-blocking performance, even in high temperature and high pressure storage environment, it can be easily peeled off, and the release force decay is extremely small.

[0032] Finally, the overall technical effect of the application is reflected in the prepared release film product with unprecedented comprehensive performance. Its heat resistance temperature is significantly higher than that of ordinary release film, which can completely adapt to the high temperature environment in the flow casting process of multilayer ceramic capacitor without curling, deformation or performance degradation. The excellent anti-blocking property ensures the integrity and smooth peeling of the ceramic green body, greatly improving the production yield. The strong interlayer adhesion between the functional coating and the release layer ensures the reliability and durability of the product during use, avoiding the contamination of the ceramic slurry caused by the peeling of the coating. In addition, the preparation method has clear process steps and accurate parameter control, with excellent repeatability and stability, suitable for large-scale industrial production. In summary, the application successfully provides a special release film that can meet the harsh requirements of high-end multilayer ceramic capacitors, providing an effective solution to the long-standing technical bottleneck in the industry, and playing a positive role in promoting the manufacturing level of electronic components. DETAILED DESCRIPTION

[0033] The following detailed description is only used to further illustrate the application, and cannot be understood as limiting the scope of protection of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application based on the above application content.

[0034] The main related equipment and material suppliers in China are as follows:

[0035] The propylene oxide is purchased from Qilu Petrochemical Company of China Petrochemical Corporation.

[0036] The xylene is purchased from Fushun Petrochemical Company of China Petroleum.

[0037] The 2-butanone is purchased from Jinan Mingwei Chemical Co., Ltd.

[0038] The end-vinyl polydimethylsiloxane is purchased from Zhejiang Xian Chemical Group Co., Ltd.

[0039] The polymethylhydrogenosiloxane is purchased from Shandong Dongyue Organic Silicon Material Co., Ltd.

[0040] The platinum gold catalyst is purchased from Sinopec Catalyst Co., Ltd.

[0041] The acrylate-based silane coupling agent is purchased from Hubei Xinlantian New Material Co., Ltd.

[0042] The vinyl MQ silicone resin is purchased from Chengdu Silicon Bao Technology Co., Ltd.

[0043] The 120# solvent is purchased from Sinopec Zhenhai Refining and Chemical Co., Ltd.

[0044] The D30 solvent is purchased from PetroChina Dushanzi Petrochemical Company.

[0045] The 4,4'-diamino diphenyl ether is purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0046] The 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane is purchased from Zhonghao Chen Guang Chemical Research Institute Co., Ltd.

[0047] The pyromellitic dianhydride is purchased from Changzhou Sunshine Pharmaceutical Co., Ltd.

[0048] The acetic anhydride is purchased from Anhui Wanwei New Material Co., Ltd.

[0049] The triethylamine is purchased from Zhejiang Jianye Chemical Co., Ltd.

[0050] The polyimide is purchased from Changchun Gaoci Polyimide Material Co., Ltd.

[0051] The perfluorooctyl triethoxysilane is purchased from China Blue Sky Group Co., Ltd.

[0052] The dibutyltin dilaurate is purchased from Beijing Dick Fine Chemical Technology Co., Ltd.

[0053] The toluene is purchased from PetroChina Jilin Petrochemical Company.

[0054] The pentaerythritol is purchased from Hubei Yihua Group Co., Ltd.

[0055] The 2,2-dimethylol propionic acid is purchased from Guangzhou Kefengyuan New Material Technology Co., Ltd.

[0056] The terminal hydroxyl hyperbranched polyester is purchased from Weihai Chen Yuan Molecular New Material Co., Ltd.

[0057] The acryloyl chloride is purchased from Shandong Jinling Chemical Co., Ltd.

[0058] The single terminal mercaptopropyl-terminated polydimethylsiloxane is purchased from Guangzhou Jiecheng Technology Co., Ltd.

[0059] The 2-hydroxy-2-methyl-1 -phenyl-1 -propanone is purchased from Tianjin Jiuri New Material Co., Ltd.

[0060] Example 1

[0061] Preparation of fluorine-containing silane grafted polyimide, 4,4'-diamino diphenyl ether 10 g and 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 5 g are dissolved in N-methyl pyrrolidone solvent 100 g, under the protection of nitrogen, add pyromellitic dianhydride 12 g, react at 3 ℃ for 5 h to obtain a solution of polyamide acid containing side hydroxyl groups; then add a mixture of acetic anhydride 20 g and triethylamine 10 g, first react at 30 ℃ for 2 h, then gradually heat to 160 ℃ to complete the imidization reaction, to obtain polyimide with side chain hydroxyl groups; finally, polyimide with side chain hydroxyl groups 15 g, perfluorooctyl triethoxysilane 5 g and catalyst dibutyl tin dilaurate 0.5 g are dehydrated and condensed in toluene 50 g at 115 ℃ for 5 h, to obtain fluorine-containing silane grafted polyimide by precipitation, washing and vacuum drying. Preparation of hyperbranched polyester-polysiloxane block copolymer, under the protection of nitrogen, pentaerythritol 5 g and 2,2-dimethylol propionic acid 50 g are reacted at 155 ℃ for 4 h to obtain a hyperbranched polyester with terminal hydroxyl groups; the hyperbranched polyester with terminal hydroxyl groups 20 g, acryloyl chloride 10 g and triethylamine 5 g are added to dichloromethane 100 g, and reacted at 3 ℃ for 3 h to obtain a hyperbranched polyester capped with acryloyloxy groups; the hyperbranched polyester capped with acryloyloxy groups 15 g and monomercaptopropyl capped polydimethylsiloxane 10 g are subjected to thiol-ene click chemistry reaction in the presence of 2-hydroxy-2-methyl-1-phenyl-1-propanone 1 g under 365 nm ultraviolet light irradiation for 1.5 h, to obtain a hyperbranched polyester-polysiloxane block copolymer by precipitation, washing and vacuum drying. Preparation of heat-resistant and anti-adhesion multi-layer release film for special ceramic capacitor, a modified PET film with a thickness of 70 μm is selected as a substrate layer, fluorine-containing silane grafted polyimide 10 g and hyperbranched polyester-polysiloxane block copolymer 5 g are added to a mixed organic solvent composed of propylene oxide 50 g, xylene 50 g and 2-butanone 50 g, and stirred at 890 rpm / min for 7 min to dissolve and obtain a functional coating mixed solution; the functional coating mixed solution is coated on the substrate layer by micro-gravure coating at a coating speed of 50 m / min; the coated substrate layer is moved to an oven, and pre-cured at 100 ℃ for 2 min, and then fully cured at 140 ℃ for 3 min to form a functional coating layer with a thickness of 10 μm; vinyl-terminated polydimethylsiloxane 20 g, polymethylhydrogenosiloxane 5 g, platinum catalyst 0.5 g, acrylate silane coupling agent 1 g and vinyl MQ silicone resin 5 g are mixed in a solvent composed of No. 120 solvent 30 g, D30 solvent 30 g and 2-butanone 30 g to obtain a release layer coating solution by stirring; the release layer coating solution is coated on the functional coating layer by using a slot die coating head; and the release layer is cured at 130 ℃ for 1 min to form a release layer; and the winding is carried out at 23 ℃.

[0062] Example 2

[0063] The specific implementation is the same as that of Example 1, except that the fluorine-containing silane grafted polyimide is prepared, 4,4'-diamino diphenyl ether 12 g and 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 4 g are dissolved in N-methyl pyrrolidone solvent 120 g, 15 g of pyromellitic dianhydride is added under nitrogen protection, and the reaction is carried out at 2°C for 4.5 hours to obtain a polyamide acid solution containing side hydroxyl groups; then a mixture of 25 g of acetic anhydride and 12 g of triethylamine is added, first reacted at 35°C for 1.5 hours, and then gradually heated to 155°C to complete the imidization reaction, to obtain a polyimide with side chain hydroxyl groups; finally, 18 g of polyimide with side chain hydroxyl groups, 6 g of perfluorooctyl triethoxysilane and 0.6 g of catalyst dibutyl tin dilaurate are dehydrated and condensed in toluene 60 g at 112°C for 4.5 hours, and the fluorine-containing silane grafted polyimide is obtained by precipitation, washing and vacuum drying. The hyperbranched polyester-polysiloxane block copolymer is prepared, pentaerythritol 4 g and 2,2-dimethylol propionic acid 48 g are reacted at 152°C for 4.5 hours under nitrogen protection to obtain a hyperbranched polyester with terminal hydroxyl groups; the hyperbranched polyester with terminal hydroxyl groups 22 g, acryloyl chloride 12 g and triethylamine 6 g are added to dichloromethane 110 g, and the reaction is carried out at 2°C for 3.5 hours to obtain a hyperbranched polyester capped with acryloyloxy groups; the hyperbranched polyester capped with acryloyloxy groups 18 g and monomer-terminated mercaptopropyl capped polydimethylsiloxane 12 g are subjected to thiol-ene click chemistry reaction in the presence of 2-hydroxy-2-methyl-1-phenyl-1-propanone 1.2 g under 365 nm ultraviolet light irradiation for 1.2 hours, and the hyperbranched polyester-polysiloxane block copolymer is obtained by precipitation, washing and vacuum drying. The heat-resistant and anti-blocking multi-layer release film for special ceramic capacitor is prepared, a modified PET film with a thickness of 50 μm is selected as the base layer, 12 g of fluorine-containing silane grafted polyimide and 4 g of hyperbranched polyester-polysiloxane block copolymer are added to a mixed organic solvent composed of propylene oxide 40 g, xylene 40 g and 2-butanone 40 g, and stirred at 850 rpm / min for 8 minutes to obtain a functional coating mixed solution; the micro-gravure coating method is used for coating, and the coating speed is 45 m / min; the coated base layer is pre-cured at 95°C for 2.5 minutes, and then fully cured at 135°C for 3.5 minutes to form a functional coating layer with a thickness of 8 μm; 18 g of vinyl-terminated polydimethylsiloxane, 4 g of polymethylhydrogenosiloxane, 0.4 g of platinum gold catalyst, 0.8 g of acrylate silane coupling agent and 4 g of vinyl MQ silicone resin are mixed in a solvent composed of 120 g of solvent, 25 g of D30 solvent and 25 g of 2-butanone to obtain a release layer coating solution by stirring; the release layer coating solution is coated on the functional coating layer by using a slot die coating head; and the release layer is formed by curing at 125°C for 1.2 minutes; and the release layer is wound at 22°C.

[0064] Example 3

[0065] The specific implementation is the same as Example 1, except that the fluorine-containing silane grafted polyimide is prepared, 4,4'-diamino diphenyl ether 8 g and 2,2-bis(3-amino-4-hydroxyphenyl) hexafluoropropane 6 g are dissolved in N-methyl pyrrolidone solvent 80 g, 10 g of pyromellitic dianhydride is added under nitrogen protection, and the reaction is carried out at 4°C for 5.5 hours to obtain a polyamide acid solution containing side hydroxyl groups; then a mixture of 18 g of acetic anhydride and 8 g of triethylamine is added, first reacted at 28°C for 2.5 hours, and then gradually heated to 165°C to complete the imidization reaction, to obtain a polyimide with side chain hydroxyl groups; finally, 12 g of polyimide with side chain hydroxyl groups, 4 g of perfluorooctyl triethoxysilane and 0.4 g of dibutyl tin dilaurate catalyst are dehydrated and condensed in toluene 40 g at 118°C for 5.5 hours, and the fluorine-containing silane grafted polyimide is obtained by precipitation, washing and vacuum drying. The hyperbranched polyester-polysiloxane block copolymer is prepared, pentaerythritol 6 g and 2,2-dimethylol propionic acid 52 g are reacted at 158°C for 3.5 hours under nitrogen protection to obtain a hyperbranched polyester with terminal hydroxyl groups; the hyperbranched polyester with terminal acryloyl group 12 g, acryloyl chloride 8 g and triethylamine 4 g are added to dichloromethane 90 g, and the reaction is carried out at 4°C for 2.5 hours to obtain a hyperbranched polyester capped with terminal acryloyl group; the hyperbranched polyester capped with terminal acryloyl group 12 g and monomer-terminated mercaptopropyl capped polydimethylsiloxane 8 g are subjected to thiol-ene click chemistry reaction in the presence of 2-hydroxy-2-methyl-1-phenyl-1-propanone 0.8 g under 365 nm ultraviolet light irradiation for 1.8 hours, and the hyperbranched polyester-polysiloxane block copolymer is obtained by precipitation, washing and vacuum drying. The heat-resistant and anti-blocking multi-layer release film for special ceramic capacitor is prepared, the modified PET film with a thickness of 90 μm is selected as the base layer, 8 g of fluorine-containing silane grafted polyimide and 6 g of hyperbranched polyester-polysiloxane block copolymer are added to a mixed organic solvent composed of propylene oxide 60 g, xylene 60 g and 2-butanone 60 g, stirred at 950 rpm / min for 6 minutes to dissolve and obtain a functional coating mixed solution; the micro-gravure coating method is used for coating, and the coating speed is 55 m / min; the coated base layer is pre-cured at 105°C for 1.5 minutes, and then fully cured at 145°C for 2.5 minutes to form a functional coating layer with a thickness of 12 μm; 22 g of vinyl-terminated polydimethylsiloxane, 6 g of polymethylhydrogenosiloxane, 0.6 g of platinum gold catalyst, 1.2 g of acrylate silane coupling agent and 6 g of vinyl MQ silicone resin are mixed in a solvent composed of 120# solvent 35 g, D30 solvent 35 g and 2-butanone 35 g to obtain a release layer coating solution; the release layer coating solution is coated on the functional coating layer by using a slot die coating head; the release layer is formed by curing at 135°C for 0.8 minutes; and the release layer is wound at 24°C.

[0066] Comparative Example 1

[0067] The specific embodiment is the same as Example 1, except that the common polyimide is prepared by dissolving 4,4'-diaminodiphenyl ether 10 g and pyromellitic dianhydride 12 g in N-methylpyrrolidone 100 g, and reacting at 3°C for 5 hours to obtain polyamic acid, then adding acetic anhydride 20 g and triethylamine 10 g, and reacting at 30°C for 2 hours, and gradually increasing the temperature to 160°C for imidization to obtain the common polyimide. The preparation of the hyperbranched polyester-polysiloxane block copolymer is the same as in Example 1. When preparing the release film, the common polyimide 10 g is used instead of the fluorine-containing silane grafted polyimide, and the other steps are the same as in Example 1.

[0068] Comparative Example 2

[0069] The specific embodiment is the same as Example 1, except that the fluorine-containing silane grafted polyimide is prepared as in Example 1. When preparing the release film, only the fluorine-containing silane grafted polyimide 15 g is used, without adding the hyperbranched polyester-polysiloxane block copolymer, and the other steps are the same as in Example 1.

[0070] Comparative Example 3

[0071] The specific embodiment is the same as Example 1, except that the fluorine-containing silane grafted polyimide and the hyperbranched polyester-polysiloxane block copolymer are prepared as in Example 1. When preparing the release film, the release layer coating solution is prepared by mixing vinyl-terminated polydimethylsiloxane 20 g, polymethylhydrosiloxane 5 g, acrylate-based silane coupling agent 1 g, and vinyl MQ silicone resin 5 g in a solvent, without adding platinum catalyst, and the other steps are the same as in Example 1.

[0072] Performance Test

[0073] The heat-resistant anti-blocking multi-layer ceramic capacitor special release film prepared according to Examples 1-3 and Comparative Examples 1-3 is tested according to the following performance test methods:

[0074] The performance test method of the heat-resistant anti-sticking release film for multi-layer ceramic capacitors of the present application is described as follows. All tests are conducted in a standard laboratory environment, temperature 23±2℃, relative humidity 50±5%, and the samples are equilibrated for 24 hours under this condition before testing. The release force test refers to the ASTM D3330 standard, using a universal material testing machine, with a 180° peeling angle and a 300 mm / min peeling speed, measuring the force required to peel the standard pressure-sensitive adhesive tape (3M #610) from the surface of the release layer, in units of N / 25mm, and testing 5 times for each sample to take the average value. The heat resistance test refers to the ASTM D1204 standard, cutting the sample into a size of 100mm×100 mm, placing it in a forced air oven for 1 hour at 150℃, measuring the size change rate (%) after cooling, and observing whether wrinkles, discoloration or delamination phenomenon appear on the surface. The anti-sticking test refers to the ASTM D3354 standard, stacking two pieces of release film with the release layers opposite each other, applying a pressure of 0.2 MPa at 23℃ for 24 hours, then separating at a peeling angle of 180° and a speed of 300 mm / min, measuring the peeling force (N / 25mm) and evaluating the sticking grade (0 grade no sticking to 5 grade complete sticking). The thermal stability test uses a thermal gravimetric analyzer (TGA) according to the ISO 11358 standard, under a nitrogen atmosphere, with a temperature rise rate of 10℃ / min from 50℃ to 800℃, recording the 5% weight loss temperature (Td5%) and the maximum decomposition temperature (Tmax). The coating adhesion test refers to the ASTM D3359 standard, using the crosshatch method, using a blade to draw a 1 mm×1 mm grid on the functional coating, and then quickly peeling off the 3M #610 tape to observe the percentage of coating area peeled off and evaluate the grade (0B to 5B). The surface contact angle test refers to the ASTM D5946 standard, using a contact angle measuring instrument to measure the water contact angle (°) to evaluate the surface hydrophobicity.

[0075] Performance test results:

[0076] Table 1: Performance test results of each example and comparative example

[0077] Test item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Release force (N / 25 mm) 0.05 0.06 0.04 0.15 0.08 0.12 Dimensional change rate in heat resistance (%) 0.5 0.6 0.4 2.1 1.2 1.8 Anti-blocking peel force (N / 25 mm) 0.08 0.09 0.07 0.35 0.20 0.30 Anti-blocking grade 0 grade 0 grade 0 grade 3 grade 2 grade 3 grade Td5% (°C) 520 515 525 480 500 490 Tmax (°C) 560 555 565 520 540 530 Coating adhesion grade 5B 5B 5B 3B 4B 2B Water contact angle (°) 110 108 112 85 95 80

[0078] As can be seen from Table 1, the embodiments 1-3 effectively solve the technical problems of insufficient heat resistance, easy adhesion to ceramic slurry at high temperature, and poor interlayer adhesion of the prior art represented by the comparative examples 1-3 through their unique material design and synergy, thereby providing high yield and high efficiency guarantee for the production of multilayer ceramic capacitors. Specifically, the release force of the embodiments 1-3 is stably at an extremely low level of 0.04-0.06 N / 25 mm, and the dimensional change rate after 150°C heat treatment is less than 0.6%, and the surface is normal, which is significantly better than that of the comparative example 1 (release force 0.15 N / 25 mm, dimensional change rate 2.1%). This indicates that the fluorine-containing silane grafted polyimide used in the embodiments greatly enhances the thermal stability and hydrophobicity of the polymer bulk by introducing fluorine atoms and silane segments into the molecular chain, effectively avoiding excessive shrinkage and deformation of the film at high temperature, and solving the core problem of insufficient heat resistance. In terms of anti-adhesion, the peel force of the embodiments 1-3 is only 0.07-0.09 N / 25 mm and the grade is all 0 (no adhesion), while the comparative examples 1 and 2 both show obvious adhesion (grade 2-3). This outstanding performance is attributed to the synergistic effect of the fluorine-containing silane grafted polyimide and the hyperbranched polyester-polysiloxane block copolymer in the functional coating in the embodiments: the fluorine-containing component provides excellent heat resistance and low surface energy, while the three-dimensional spherical structure of the hyperbranched polymer plays a physical isolation role, together building an anti-adhesion surface that is still stable under high temperature and high pressure, and is difficult to diffuse and entangle molecular chains, thereby completely solving the problem of adhesion to ceramic slurry at high temperature. The anti-adhesion of comparative example 2, which only uses fluorine-containing silane grafted polyimide and lacks hyperbranched copolymer, immediately decreases, proving the key physical role of the latter in preventing adhesion. In terms of interlayer adhesion, the grid method adhesion grade of the embodiments 1-3 all reaches the highest 5B, while the comparative example 3 (without adding platinum catalyst in the release layer) seriously decreases to 2B. This shows that the platinum catalyst contained in the release layer coating solution in the embodiments ensures that the silicon-hydrogen addition cross-linking reaction between the vinyl-terminated polydimethylsiloxane and the polymethylhydrosiloxane occurs completely and completely, forming a release layer network with stable mechanical properties and forming a firm chemical bond with the underlying functional coating through the coupling agent. While the incomplete cross-linking and curing of comparative example 3 results in a serious lack of cohesive strength and bonding force with the functional layer, which is prone to peeling and damage. In summary, the innovative material system of the embodiments 1-3 ensures heat resistance and basic release force through fluorine-containing polyimide, gives excellent anti-adhesion through hyperbranched copolymer, and ensures excellent adhesion through complete curing of the release layer, systematically overcoming the technical bottlenecks that lead to low yield and low efficiency in the production of multilayer ceramic capacitors.

[0079] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. A method for preparing a heat-resistant, anti-adhesion release film for multilayer ceramic capacitors, characterized in that the steps include... include: S1. Select a modified PET film as the substrate layer, wherein the modified PET film contains nano-alumina particles; add fluorinated silane-grafted polyimide and hyperbranched polyester-polysiloxane block copolymer to a mixed organic solvent composed of propylene oxide, xylene and 2-butanone, stir to dissolve, and obtain a functional coating mixture. S2. The functional coating mixture is applied to the substrate layer using a micro-gravure coating method. The coated substrate layer is then transferred to an oven for step-by-step temperature curing to form the functional coating. S3. Mix vinyl-terminated polydimethylsiloxane, polymethylhydrosiloxane, platinum catalyst, acrylate-based silane coupling agent, and vinyl MQ silicone resin in a solvent and stir to obtain a release layer coating liquid. The solvent consists of 120# solvent, D30 solvent, and 2-butanone. Apply the release layer coating liquid to the functional coating layer using a slit coating head. Cure at 120-140℃ to form a release layer. Wind up at 20-26℃.

2. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 1, characterized in that, In step S1, the thickness of the substrate layer is 40-100 μm; the weight ratio of propylene oxide, xylene, and methyl ethyl ketone in the mixed organic solvent is 1:1:1; the stirring speed is 780-1000 rpm / min, and the stirring time is 4-10 min.

3. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 1, characterized in that, The coating speed is 40-60 m / min; stepped temperature curing: first pre-curing at 90-110℃, then fully curing at 130-150℃; the functional coating thickness is 5-15 μm.

4. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 1, characterized in that, The preparation method of the fluorinated silane-grafted polyimide includes: A1, firstly, dissolving 4,4'-diaminodiphenyl ether and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane in N-methylpyrrolidone solvent, adding pyromellitic dianhydride under nitrogen protection, and reacting at 0-5℃ to obtain a polyamic acid solution containing side hydroxyl groups; A2, subsequently, adding a mixture of acetic anhydride and triethylamine, reacting first at 25-40℃, and then gradually raising the temperature to 150-180℃ to complete the imidization reaction to obtain a polyimide with side hydroxyl groups; finally, carrying out a dehydration condensation reaction of the polyimide with side hydroxyl groups, perfluorooctyltriethoxysilane, and the catalyst dibutyltin dilaurate in toluene at 110-120℃, followed by precipitation, washing, and vacuum drying.

5. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 4, characterized in that, In step A1, the molar ratio of 4,4'-diaminodiphenyl ether to 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane is (1-3):1; the reaction time is 4-6 h at 0-5 °C.

6. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 4, characterized in that, In step A2, the dehydration condensation reaction is carried out at 110-120℃ for 4-6 hours.

7. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 1, characterized in that, The preparation method of the hyperbranched polyester-polysiloxane block copolymer includes: B1, reacting pentaerythritol with 2,2-dimethylolpropionic acid at 150-160°C under nitrogen protection to obtain a hydroxyl-terminated hyperbranched polyester; B2, adding the hydroxyl-terminated hyperbranched polyester, acryloyl chloride, and triethylamine to dichloromethane and reacting at 0-5°C to obtain an acryloyloxy-terminated hyperbranched polyester; reacting the acryloyloxy-terminated hyperbranched polyester with a mercaptopropyl-terminated polydimethylsiloxane in the presence of 2-hydroxy-2-methyl-1-phenyl-1-propanone under ultraviolet light irradiation to carry out a mercapto-olefin click chemical reaction; and then subjecting the reaction to precipitation, washing, and vacuum drying.

8. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 7, characterized in that, In step B1, the reaction time is 3-5 h at 150-160℃; the molar ratio of pentaerythritol to 2,2-dimethylolpropionic acid is 1:(8-12).

9. The method for preparing the heat-resistant, anti-adhesion release film for multilayer ceramic capacitors according to claim 7, characterized in that, In step B2, the wavelength of ultraviolet light irradiation is 365nm, and the click chemical reaction time is 1-2 hours.

10. A release film for heat-resistant, anti-adhesion, multilayer ceramic capacitors, characterized in that, The heat-resistant and anti-adhesion release film for multilayer ceramic capacitors is prepared by the method described in any one of claims 1-9.