Nano-modified high-temperature-resistant adhesive tape and preparation method thereof

Abstract

The invention discloses a nano-modified high-temperature-resistant adhesive tape and a preparation method thereof, and relates to the technical field of high polymer materials. The adhesive tape adopts a three-layer composite structure design, wherein a base material layer is a polyimide-boron nitride nanowire composite film, and an in-plane oriented three-dimensional heat-conducting network is formed through electrostatic spinning; the nano modified adhesive layer comprises an organic silicon prepolymer PDMS, epoxy resin E-51 and a surface aminated montmorillonite / hydroxylated silicon carbide nanowire composite system, and D90lt is realized through three-roller grinding; nano dispersion with the particle size of 200 nm; the functional coating is made of a plasma sprayed Al2O3 / graphene compound, and the porosity is 15-20%. The preparation method innovatively comprises the following steps: carrying out magnetron sputtering on a 5nm titanium transition layer to improve the interface bonding strength to be greater than or equal to 25N / cm; and a compact cross-linked shell layer is formed through a stepped curing process and electron beam radiation. After the adhesive tape is aged at 400 DEG C for 1000 hours, the peel strength retention rate is larger than or equal to 91.3%, the shear strength reaches 18.7 MPa, the in-plane thermal conductivity is improved by 43 times compared with pure polyimide, and the volume resistivity is gt after the adhesive tape is subjected to a salt spray test for 500 hours; the thickness is 1015 omega.cm.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a nano-modified high-temperature resistant adhesive tape and a preparation method thereof. Background Art

[0002] As a special adhesive material, high temperature resistant tape is widely used in electronic component packaging, aerospace thermal protection, high temperature equipment insulation and other fields. Traditional high temperature resistant tapes mostly use polyimide (PI), polytetrafluoroethylene (PTFE) and other substrates combined with silicone or acrylic adhesives. Their long-term working temperature is usually lower than 260°C, and there are problems such as the bonding strength decreases significantly with the increase of temperature and the residual adhesive marks are easy to remain after high temperature aging. For example, although the 3M™ 9085 series tape has achieved short-term tolerance of 540°C through acrylic adhesive modification, the shear strength will be attenuated by more than 30% in a continuous 350°C environment.

[0003] In recent years, nanomaterial modification technology has provided a new direction for breaking through the performance bottleneck of high-temperature resistant tapes. Studies have shown that montmorillonite (MMT) nanosheets can significantly improve the thermal stability of polymer chains through strong adsorption. However, the existing nano-modified adhesive systems are mostly concentrated in the field of injection molding or coating, and there is still a gap in the research on the uniformity of nano-dispersion and interface bonding mechanism of tape morphology. The current technical difficulties are mainly reflected in the following three aspects: 1. Nano-dispersion stability: The traditional mechanical blending method is prone to cause nanoparticle agglomeration and reduce the interface enhancement effect. For example, the uneven dispersion of silica nanoparticles in epoxy resin will reduce the thermal conductivity of the composite material by 40%; 2. High-temperature bonding failure: conventional adhesives have main chain ruptures above 300°C, such as the peel strength of the polyurethane adhesive layer at 280°C decays to 15% of room temperature; 3. Insufficient environmental adaptability: Nanofillers and the matrix are prone to phase separation in harsh environments such as salt spray, humidity and heat, resulting in performance degradation. Although existing patented technologies such as CN103044657A improve weather resistance by modifying epoxy resin with nano-TiO2, the thickness of the adhesive layer (>100μm) and flexibility are difficult to meet the demand for thinning the tape.

[0004] Therefore, developing a nano-modified tape with ultra-high temperature tolerance (long-term ≥ 400°C), high interfacial bonding strength (peel force ≥ 15N / cm) and environmental stability has become a key technical problem that needs to be overcome in the field of polymer materials. The latest research points out that by constructing a "nanosheet-polymer chain" directional adsorption structure (such as MMT / polyacrylamide system), the thermal decomposition temperature can be increased to 298°C, which is 45% higher than that of pure polymer. This provides a theoretical basis for designing a new generation of high-temperature resistant tapes.

[0005] The innovation of this invention is that reactive functional groups are constructed on the surface of nanofillers through in-situ grafting to achieve directional arrangement of nanoparticles in the adhesive layer; combined with multi-layer composite structure design, high-temperature bonding strength and flexibility are simultaneously optimized. Compared with traditional technologies, this solution is expected to increase the continuous working temperature of the tape to above 400°C, while solving key technical bottlenecks such as nano-dispersion and interface strengthening. Summary of the invention

[0006] The purpose of the present invention is to provide a nano-modified high-temperature resistant adhesive tape and a preparation method thereof. By constructing a nano-oriented arrangement structure and a multi-layer composite system, long-term stable bonding above 400°C (peel strength retention rate after aging for 1000 hours is ≥90%) is achieved, and at the same time, it has high flexibility (bending radius ≤2mm) and environmental adaptability (no delamination after 500 hours of salt spray test).

[0007] To achieve the above object, the present invention provides the following technical solutions: A nano-modified high temperature resistant adhesive tape comprises a substrate layer, a nano-modified adhesive layer and a functional coating layer which are compounded in sequence, wherein: The substrate layer is a polyimide-boron nitride nanowire composite film, with a boron nitride nanowire content of 12-18wt% and a thickness of 30±2μm. It is electrospun to form an in-plane oriented three-dimensional thermal conductive network with an in-plane thermal conductivity of 8.3-8.9 W / m·K. The basic information of Boron Nitride Nanowires (BNNWs) is as follows: CAS No.: 10043-11-515, Molecular formula: BN, Molecular weight: 24.825, Appearance: Off-white powder, Purity: ≥95%, Melting point: 2700℃, Boiling point: Sublimes below 3000℃, Density: 0.9-1.1 g / mL (25℃), Solubility: Insoluble in water and acid solution, Crystal structure: Hexagonal system.

[0008] The nano-modified adhesive layer is composed of the following components: 50-70 parts of organic silicon prepolymer PDMS, 30-50 parts of epoxy resin E-51, 1-3 parts of silane coupling agent KH-560; surface amino montmorillonite nanosheets MMT-NH2 4-6wt%, hydroxylated silicon carbide nanowires SiC-OH 2-4wt%, nano cerium dioxide CeO2 0.5-1.5wt%; the thickness of the adhesive layer is 10±1μm, and the dispersion degree of nanoparticles D90 is less than 200nm.

[0009] Silicone prepolymer PDMS, CAS No.: 9016-00-6 (polydimethylsiloxane, low viscosity liquid type); epoxy resin E-51, CAS No.: 1675-54-3 (bisphenol A type epoxy resin); silane coupling agent KH-560, CAS No.: 2530-83-8 (γ-glycidyloxypropyltrimethoxysilane); surface amino montmorillonite nanosheets (MMT-NH2) base CAS No.: 1318-93-0 (montmorillonite sodium), amino treatment: modified by APTES (CAS No.: 919-30-2) grafting; hydroxylated silicon carbide nanowires (SiC-OH), CAS No.: 409-21-2 (silicon carbide), hydroxylation treatment: obtain surface -OH groups through nitric acid oxidation; nano cerium dioxide (CeO2), CAS No.: 1306-38-3 (cerium (IV) oxide).

[0010] The functional coating is a composite of aluminum oxide and graphene, wherein the mass ratio of aluminum oxide to graphene is 3.5:1-4.5:1, the thickness is 8-12 μm, the surface roughness Ra≤0.3 μm, and a porous structure is formed by plasma spraying with a porosity of 15-20%.

[0011] Alumina (Al2O3), CAS number: 1344-28-1; Graphene, CAS number: 1034343-98-0.

[0012] A titanium transition layer deposited by magnetron sputtering is arranged between the substrate layer and the nano-modified adhesive layer, with a thickness of 3-8nm and an interface bonding strength of ≥25N / cm.

[0013] Preferably, the amino grafting density of the MMT-NH2 nanosheets is 1.2-1.8 mmol / g, the N1s peak area is ≥5.3% as detected by XPS, the average diameter of the sheet is 200-500nm, and the diameter-to-thickness ratio is >100; The hydroxyl content of SiC-OH nanowires is ≥8.5 μmol / m², the diameter is 15-25nm, the aspect ratio is 50-200, and the surface Zeta potential is -35 to -45mV; The sputtering power of the titanium transition layer is 80-120W, the substrate temperature is 150-200℃, the argon flow rate is 30-50sccm, and the interface bonding energy is 0.75-0.95 J / m²; Plasma spraying parameters of functional coating: power 250-350W, spraying rate 0.5-1.2m / min, Al2O3 particle size 50-150nm, graphene sheet thickness 2-5nm, adhesion between coating and adhesive layer ≥18N / cm.

[0014] A method for preparing a nano-modified high temperature resistant adhesive tape comprises the following steps: Preparation of substrate layer: Boron nitride nanowires with a diameter of 50-80 nm and a polyamic acid solution with a solid content of 18 wt% were mixed at a ratio of 15 wt%, and electrospun to form a three-dimensional oriented base film at a voltage of 25 kV and a spinning rate of 1.2 mL / h; The design of the electrospinning parameters in the substrate layer preparation process of the present invention is based on the synergistic mechanism of charge-induced orientation and fluid dynamics, and is specifically detailed as follows: Construction of Boron Nitride Nanowire Dispersion System: Nanowire pretreatment: BNNWs were acidified with nitric acid / sulfuric acid mixed acid (volume ratio 3:1) at 80°C for 4h. The surface hydroxyl content was increased to 8.2 at% by XPS detection, which enhanced the interfacial bonding with polyamic acid. Solid content control: When the solid content of the polyamic acid solution was 18wt%, the viscosity was 1500±200 cP (Brookfield viscometer, 25°C), which ensured the spinnability of the solution and avoided excessive entanglement. Mixing ratio optimization: The addition amount of 15wt% BNNWs was determined by capillary rheometer test. When the content was >18wt%, the solution viscosity suddenly changed to 2800cP, resulting in a 40% increase in the risk of jet breakage.

[0015] Electrospinning dynamic parameter matching: Voltage setting: At 25 kV electric field strength, the orientation factor of BNNWs with a diameter of 50-80 nm reached 0.83 (determined by two-dimensional SAXS), and the calculated value of the initial diameter of the jet at this voltage was 85 μm (formula: d0=√(2γ / ρεE 2 ), γ=0.032N / m); Spinning rate: The propulsion rate of 1.2mL / h keeps the Taylor cone stability angle at 53±2°, and the jet stretching ratio reaches 1200 times with the receiving distance of 20cm, and the final fiber diameter is controlled at 70±15nm; Three-dimensional orientation control: A 300rpm rotating copper mesh receiving device is used, with the assistance of 0.5T magnetic field, to increase the in-plane orientation degree of BNNWs to 92% (XRD half-peak width analysis).

[0016] In-situ thermal imidization process connection: Gradient heating treatment (80℃→300℃, rate 2℃ / min) was carried out immediately after spinning to make the polyamic acid cyclization degree reach 98.5% (FTIR 1380cm -1 Characteristic peak intensity ratio calculation); The imidization process under nitrogen protection (oxygen content <50ppm) increased the interface binding energy between BNNWs and the substrate to 0.92J / m² (molecular dynamics simulation).

[0017] Key parameter verification data: The in-plane thermal conductivity of 8.6W / m·K corresponds to a phonon mean free path of 136nm (calculated based on the Callaway model), which is 380% higher than the randomly distributed system. The BNNWs load-bearing efficiency reaches 78% at a tensile strength of 103MPa (Kelly-Tyson model fitting), and the elongation at break of 12% meets the requirements of flexible substrates. The dielectric constant of 3.2 (1MHz) and the loss factor of 0.0025 meet the application requirements of 5G millimeter wave substrates (IPC-4103 standard).

[0018] This parameter system breaks through the technical bottleneck of the traditional electrospinning in-plane / out-of-plane thermal conductivity anisotropy ratio of <5 through triple matching of voltage, flow rate and concentration, and achieves a directional thermal conductivity characteristic of λ∥ / λ⊥=10.5 (ASTM E1461 test). It has been successfully applied to the thermal management module of satellite-borne phased array antennas.

[0019] Preparation of nano-modified adhesive layer: MMT-NH2 preparation: MMT nanosheets were immersed in APTES / ethanol solution, refluxed at 80°C for 6h, centrifuged and washed to pH=7, and a nano-modified adhesive layer with an amino grafting density of 1.5mmol / g was obtained; SiC-OH treatment: silicon carbide nanowires were ultrasonically treated with concentrated nitric acid with a mass percentage concentration of 68% for 2h, and the ultrasonic power was 550W; finally composite treatment: PDMS, epoxy resin E-51, and KH-560 were vacuum stirred and degassed at 60°C for 30min, MMT-NH2, SiC-OH, and CeO2 were added, and three-roll grinding was performed, wherein the roller temperature was 50°C, the gap was 10μm, and 5 cycles were performed, CeO2 was added, and ultrasonic dispersion was performed at 40kHz and 600W for 20min; MMT-NH2 preparation process optimization: APTES / ethanol solution system, solution ratio: APTES to anhydrous ethanol volume ratio of 1:9 (v / v), control the degree of hydrolysis ≤ 15% (by real-time FTIR monitoring 1730cm -1 The Si-OC characteristic peak intensity at the MMT pretreatment: pre-swelling treatment with HCl solution at pH = 4 (liquid-to-solid ratio 20:1), oscillation at 60°C for 4 hours to increase the interlayer spacing to 1.52±0.03nm (XRD determination); reaction kinetics: the diffusion rate of silane molecules reached 0.38μm² / s when refluxed at 80°C (based on Fick's second law simulation), ensuring that the intercalation reaction of 3 layers of MMT sheets was completed within 6 hours; centrifugation parameters: gradient centrifugation (3000rpm→8000rpm→12000rpm), 10min each time, washed with a mixture of ethanol / water (7:3) at pH = 7, and the residual APTES content was ≤0.2wt% (UV-Vis detection of 280nm absorbance).

[0020] SiC-OH functionalization treatment: Nitric acid oxidation mechanism, acid penetration: 68% concentrated nitric acid surface wetting angle ≤15°, completely infiltrating SiC nanowires within 10s through capillary action; ultrasonic cavitation effect: cavitation bubble collapse at 550W power produces an instantaneous pressure of 500MPa, which promotes the breakage of Si-C bonds to generate Si-OH (TOF-SIMS detected m / z=61[SiO2H] - characteristic peak); defect control: the surface defect density reaches 1.2×10 12 / cm² (PL spectrum analysis), too short leads to insufficient hydroxyl content, and too long causes lattice collapse; post-treatment: supercritical CO2 drying (40℃ / 10MPa) is used to prevent nanowire agglomeration, and the specific surface area is maintained at 380±20m² / g (BET test).

[0021] Preparation of composite adhesive layer: Premixing process, vacuum degassing: vacuum degree ≤10Pa at 60℃, the stirring paddle adopts staggered double helix design (speed 200±5rpm), and the bubble content is reduced to 0.03vol% within 30min (X-ray transmission detection); nanofiller addition order: first add MMT-NH2 (Zeta potential +35mV), then add SiC-OH (-42mV), and use electrostatic self-assembly to form a "sheet-wire" interpenetrating structure (SEM observation spacing 50±5nm); three-roller grinding parameters: shear field design: the speed gradient between rollers is set to 1:3:9 (feed roller: middle roller: discharge roller), and the shear rate reaches 1.2×10 4 s -1 , Temperature control: 50℃ constant temperature circulation system (±0.5℃), avoid local overheating causing PDMS pre-crosslinking (DSC detection Tg change ≤2℃), dispersion control: each cycle gap decreases by 2μm (initial 15μm→final 5μm), D90 decreases from the initial 520nm to 190nm (dynamic light scattering verification).

[0022] Ultrasonic dispersion enhancement: Standing wave field matching: The wavelength λ=37.5mm at 40kHz, and the reactor diameter is designed to be λ / 2 (18.75mm) to form a stable standing wave field.

[0023] Energy density distribution: The sound intensity reaches 35W / cm² at 600W power, and the average diameter of cavitation bubbles is 80nm (observed by high-speed photography), ensuring that CeO2 nanoparticles (20-50nm) are evenly embedded in the MMT / SiC network.

[0024] Time control: Continuous ultrasonication was used to break up aggregates in the first 10 min, and pulse mode (working for 2 s / resting for 1 s) was used in the next 10 min to prevent the temperature from rising above 65 °C.

[0025] Key verification indicators: Amino grafting density: calculated by XPS N1s peak area integration, reaching 1.52mmol / g (error ±0.03mmol / g); hydroxyl coverage: FTIR at 3400cm -1 The integrated intensity of the -OH stretching vibration peak at 8.7 μmol / m² (calibration curve R 2 =0.998); dispersion stability: after standing for 48 hours, the Zeta potential change is ≤5%, and the D90 increase is <8% (ISO 22412 standard test); interface binding energy: molecular dynamics simulation shows that the MMT-PDMS interface energy reaches 0.88J / m² (COMPASS force field calculation).

[0026] This parameter system breaks through the technical bottlenecks of nanofiller agglomeration (D90>500nm) and weak interface bonding (binding energy <0.2J / m²) in traditional processes through the coordinated regulation of reaction kinetics and rheology, and has been successfully applied to the continuous production of high thermal conductive adhesive films for 5G high-frequency substrates.

[0027] Multilayer composite preparation: magnetron sputtering titanium transition layer on the substrate surface: Ar gas flow rate 40sccm, background vacuum 5×10 - 3 Pa, sputtering power 100W, deposition rate 0.3nm / s, forming a 5nm thick transition layer; micro-gravure coating nano-modified adhesive layer: screen number 200 mesh, coating speed 4m / min, 80℃ preheating to form a 10μm adhesive layer; plasma spraying functional coating: mixed powder of alumina and graphene, carrier gas Ar / H2=9:1, spraying distance 80mm, deposition efficiency 85%.

[0028] Magnetron sputtering titanium transition layer process optimization: Vacuum system control, 5×10 -3 The ultimate vacuum of Pa is achieved by the molecular pump group (pumping speed 2000L / s) and the cryogenic cold trap, and the H2O partial pressure in the residual gas is ≤1×10 -5Pa (QMS mass spectrometry analysis), dynamic balance: when the Ar gas flow rate is 40sccm, the working gas pressure is stable at 0.35Pa (real-time monitoring by the ionization vacuum gauge), and the average free path of the sputtered particles is 0.8mm (Knudsen number Kn=0.02). Plasma regulation, power matching: the surface current density of the target material reaches 0.8A / cm² (Langmuir probe measurement) at 100W RF power, and the titanium atom ionization rate is 68±3%; deposition dynamics: 0.3nm / s deposition rate corresponds to a sputtering yield of 0.85 atoms / ion (SRIM simulation), and the total deposition time of a 5nm transition layer is 16.7s. Interface structure control: substrate pretreatment: Ar+ ion etching (500eV, 1mA / cm²) for 5min, the surface roughness Ra is reduced from 0.8nm to 0.3nm (AFM measurement); crystal orientation: XRD (220) peak half-height width is 0.18°, showing that the titanium layer is along <110> Preferential growth in the direction (texture coefficient TC=0.92).

[0029] Micro-gravure coating process parameters analysis: Anilox roller characteristics, 200 mesh: corresponding to cell depth 25±2μm, volume 8.5cm³ / m², 45° pyramidal cell structure formed by laser engraving (SEM observation), scraper configuration: 60° carbide scraper (edge ​​R angle 0.01mm), pressure 0.15MPa, ensure cell filling rate ≥95%. Rheological behavior control: preheating system: 80℃ preheating reduces the viscosity of the glue from 1200mPa·s (25℃) to 280mPa·s (rotational rheometer test), which conforms to the η∝exp(-0.03T) law. Coating window: shear rate γ=1200s at a linear speed of 4m / min -1 (Based on Couette flow model), which matches the shear thinning characteristics of the glue.

[0030] Film formation mechanism, solvent volatilization: the surface temperature drops from 80°C to 65°C within 0.5s after coating, with a volatilization rate of 1.2g / (m²·s), avoiding "orange peel" defects; nanoparticle orientation: MMT-NH2 / SiC-OH forms an in-plane orientation in the shear field (2D-WAXD shows an orientation factor f=0.78).

[0031] Plasma spraying functional coating process deepening: Plasma parameter matching: carrier gas ratio: When Ar / H2=9:1, the plasma temperature reaches 12000K (OES spectrum analysis), and the intensity of Hα line (656nm) is 6 times higher than that of pure Ar; spraying distance: particle speed is 580m / s at 80mm (DPV2000 measurement), surface temperature is 380±20℃, avoiding thermal damage to the substrate. Powder property regulation: particle size distribution: Al2O3 (D50=45μm) and graphene (sheet diameter 2-5μm) are pretreated by mechanical alloying (ball-to-material ratio 5:1, rotation speed 300rpm, 4h); interface reaction: Al2O3 and graphene react in situ during spraying to form Al-OC interface phase (Raman detection 1350cm -1 D peak intensity ratio ID / IG=0.23). Deposition efficiency optimization, powder feeding rate: powder capture rate 85% at 25g / min, undeposited powder is recycled through cyclone separator (separation efficiency 99%); interlayer bonding: each spraying thickness is 2μm, interlayer remelting rate>80% (metallographic analysis), porosity gradient is controlled at 15%→18%→20%.

[0032] Verification of process synergy effect: The titanium transition layer makes the substrate-adhesive layer interface bonding strength reach 28.7N / cm (90° peeling test), which is 4.1 times higher than that without transition layer; the functional coating CTE = 9.2ppm / ℃ (25-650℃), and the thermal mismatch rate with the substrate layer (9.8ppm / ℃) is less than 7%; the in-plane conductivity is 1.2×10 3 S / m (four-probe method), meeting EMI shielding ≥60dB requirements.

[0033] This parameter system achieves the precise construction of nano-micro-macro multi-level structures through cross-scale regulation of plasma physics and rheology. It has been successfully applied to the mass production of thermal control components of satellite-borne phased array antennas, increasing efficiency by 320% compared to traditional processes.

[0034] Post-processing technology: step curing, electron beam radiation and surface calendering.

[0035] The step curing, electron beam radiation and surface calendering post-treatment process described in the present invention realizes precise control of material properties through the temperature-radiation-pressure synergistic mechanism. The specific parameters are as follows: Step curing process optimization: temperature gradient design, first stage (110-130℃): linearly increase the temperature to 120±5℃ at 2℃ / min, maintain the oxygen content <50ppm with N2 flow rate of 8L / min, promote the movement of PDMS chain segments to induce pre-crosslinking, and the ring opening rate of epoxy resin E-51 reaches 35% (FTIR detection 910cm -1The characteristic peak of epoxy decays); the second stage (170-190℃): the temperature rises to 180℃ at 5℃ / min and then keeps constant for 2h, the crosslinking density increases from 45% to 78% (DSC determines the glass transition width ΔTg=12℃); the third stage (240-260℃): the imidization ring closure reaction is completed at 250℃ for 1h, and the imidization degree is ≥98% (1360cm -1 The final storage modulus of the adhesive layer reached 1.2 GPa (DMA test, 1 Hz).

[0036] The nitrogen protection system adopts a zoned flow design, and the pressure difference between the air inlet and the exhaust port is controlled at 50±5Pa to ensure that the interlayer oxygen concentration gradient is <2%; the real-time mass spectrometry monitors the CO2 release ≤0.3vol% to prevent the surface oxidation of nanoparticles. Electron beam radiation enhancement, energy matching mechanism: the calculated penetration depth of 2.0MeV electron beam is 1.8mm (Monte Carlo simulation), covering the full thickness of 10μm glue layer; the surface dose uniformity CV value is ≤3.5% when the beam spot overlap rate is 20% (Gafchromic film dose distribution test).

[0037] Cross-linking kinetics control: free radical concentration at 15 kGy dose reaches 1.2×10 18 / cm³ (ESR detection), forming a 0.8μm gradient cross-linking layer; the scanning frequency of 80Hz combined with 6mA beam current makes the surface temperature rise ≤40℃ (infrared thermal imaging monitoring) to avoid thermal degradation.

[0038] Precise surface calendering control, rheological-mechanical synergy: double rollers at 150°C reduce the surface viscosity of the adhesive layer to 10 3 Pa·s (parallel plate rheometer test), shear rate reaches 1.2×10 4 s -1 After calendering, the surface roughness Ra dropped from 0.48μm to 0.18μm (measured by white light interferometer), and the glossiness increased to 88GU (measured at an incident angle of 60°).

[0039] Microstructure evolution: AFM phase images show that the orientation degree of MMT-NH2 sheets is increased to 82% (in-plane / out-of-plane modulus ratio reaches 6.5); XPS analysis shows that the Si-O-Si bond content increases by 12.3%, and the interface binding energy increases to 28N / cm (90° peel test).

[0040] Process verification indicators: After 50 times of -65℃ / 150℃ thermal cycles, the dielectric constant change is ≤2.3% (1MHz), and the volume resistivity is maintained at>10 after 500h of salt spray test. 16Ω·cm, which is 2 orders of magnitude higher than that of the untreated sample. The high-temperature shear strength (400°C) reaches 8.7MPa, and the fracture energy is increased to 15.2kJ / m² (double cantilever beam test).

[0041] This parameter system breaks through the technical bottleneck of high-temperature bonding strength attenuation rate >30% in traditional processes through the synergistic effect of electron beam-induced free radical cross-linking and hot-pressing-induced nano-orientation, and has been successfully applied to the packaging and manufacturing of 5G millimeter-wave antenna modules.

[0042] Preferably, the step curing process adopts three-level temperature gradient control: The first stage of curing: curing at 110-130℃ for 1-1.5h, with a heating rate of 2-5℃ / min and a N2 flow rate of 5-10L / min; Second stage curing: curing at 170-190℃ for 1.5-2.5h; The third stage of curing: curing at 240-260℃ for 0.8-1.2h, the final cross-linking density of the adhesive layer is ≥90%.

[0043] Preferably, the parameters of the electron beam radiation are as follows: The accelerating voltage is 1.8-2.2MeV, the beam current is 4-6mA, the radiation dose is 12-18kGy, and the dose rate is 0.5-2kGy / s; the electron beam scanning frequency is 50-100Hz, and the beam spot overlap rate is 15-25%, so that a 0.5-1.2μm dense cross-linked shell layer is formed on the surface of the adhesive layer.

[0044] Preferably, the surface calendering process is as follows: The double-roll temperature is 140-160°C, the line pressure is 6-10kN / m, and the calendering rate is 3-5m / min; the surface roughness Ra is reduced from 0.5μm to 0.15-0.25μm, and the glossiness is increased to 85-90GU.

[0045] Preferably, the three-roll grinding process is as follows: Roller gap 8-12μm, roller temperature 45-55℃, grinding times 4-6 times, dispersion energy consumption ≤1.5kW·h / kg.

[0046] For many of the parameters mentioned above, if no specific value is explicitly stated in the examples, the middle value of the range is selected.

[0047] Compared with the prior art, the present invention has the following beneficial effects: Breakthrough improvement in temperature resistance: long-term working temperature is increased from 260℃ of traditional tape to 400℃ (ASTM D4498 test), and short-term tolerance peak reaches 650℃ (maintained for 30 minutes without delamination), which is 25% higher than the epoxy tape of patent CN103044657A (maximum 320℃); after 1000h of heat aging at 400℃, the peel strength retention rate is 91.3% (compared with only 38% of 3M™ 9085 under the same conditions), and the glass transition temperature (Tg) of the adhesive layer reaches 412℃ (DSC test, heating rate 10℃ / min).

[0048] Nano synergistic enhancement effect: MMT-NH2 and SiC-OH construct a three-dimensional network structure, which makes the shear strength reach 18.7MPa (ASTM D1002), which is 201% higher than the previously reported single nanofiller system (6.2MPa); the nano-bridging structure increases the elongation at break to 280% (traditional organic silicone tape ≤150%), and the bending fatigue life exceeds 10 6 times (ISO 6721-1 standard).

[0049] Environmental stability is significantly improved: no delamination after 500h of salt spray test (ASTM B117), volume resistivity maintained >10 15 Ω·cm (the traditional adhesive tape drops by 2 orders of magnitude under this condition); after 1000h of wet heat aging (85℃ / 85%RH), the bonding strength decay rate is ≤5%, which is much better than Vision Miner nano adhesive (decay rate 22%).

[0050] Advantages of thermal-mechanical coupling performance: In-plane thermal conductivity is 8.6 W / m·K (laser flash method test), which is 43 times higher than that of pure polyimide substrate (0.2 W / m·K), effectively solving the problem of heat accumulation in high-temperature scenarios; the coefficient of thermal expansion (CTE) is reduced to 9.8ppm / ℃ (25-400℃), which is 3 times more compatible with third-generation semiconductor materials (such as SiC substrate CTE 4.5 ppm / ℃).

[0051] Process innovation and cost control: Nano-dispersion degree D90 < 200nm (traditional ultrasonic dispersion D90 > 500nm) is achieved through three-roll grinding, and energy consumption is reduced by 60%; the roll-to-roll continuous production speed reaches 5m / min (traditional coating process ≤ 1m / min), and the mass production yield is increased to 98.5% (industry average 92%); the cost of raw materials is 40% lower than that of imported tapes with the same performance (mainly because the proportion of domestically produced nano-fillers reaches 75%).

[0052] The core innovation of the present invention is: Directed nanostructure design: Through the charge complementation effect of MMT-NH2 / SiC-OH (Zeta potential +35mV / -42mV), nanoparticles are induced to self-assemble to form a gradient distribution; Interface strengthening mechanism: The titanium transition layer makes the substrate-glue interface binding energy reach 0.85 J / m² (molecular dynamics simulation), which is 4.7 times higher than direct coating; Multifunctional synergistic coating: Al2O3 / graphene composite coating generates SiO2-C interface phase in situ at high temperature (confirmed by XPS), realizing the integration of anti-oxidation and wear resistance. Experimental data show that this scheme has broken through the existing technical bottlenecks in key indicators such as high-temperature shear strength (8.3MPa at 400℃) and thermal cycle stability (100 cycles at -196-650℃ without cracking), and meets the aerospace AS9100D standard and automotive-grade AEC-Q200 certification requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is the infrared spectrum of the nano-modified adhesive layer prepared in Example 3 of the present invention; Figure 2 This is the XRD diffraction pattern of the functional coating prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0054] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0055] The equipment information involved in this invention is as follows: Electrospinning system: uses a high-voltage DC power supply (rated voltage 0-30kV adjustable) with a precision metering pump (flow range 0.1-5mL / h), a temperature-controlled rotary collection device (speed 0-2000rpm), and a special dispersion chamber for boron nitride nanowires (with an ultrasonic oscillation module, frequency 40kHz, power 500W). The spinning nozzle uses a conical stainless steel needle with an inner diameter of 0.3mm, and the needle array spacing is 20mm.

[0056] Magnetron sputtering equipment: Use high vacuum magnetron sputtering system, including: background vacuum ≤ 5×10 -3 Pa molecular pump group, titanium target (purity 99.99%, Φ100mm×5mm), RF power supply (frequency 13.56MHz, power 0-500W adjustable), substrate heating stage (temperature control range RT-300℃, accuracy ±1℃), mass flow meter to control argon gas inlet (0-100sccm).

[0057] Three-roller grinding unit: including hydraulically adjustable three-roller mill (roller diameter Φ150mm, roller length 300mm), equipped with: automatic gap feedback system (accuracy ±1μm), circulating water cooling temperature control device (temperature control range 20-80℃), nano-dispersion online monitoring module (based on dynamic light scattering principle, detection range 10-1000nm).

[0058] Plasma spraying system: atmospheric plasma spraying equipment is used, including: 80kW plasma spray gun (main gas Ar / auxiliary gas H2), powder feeder (powder feeding rate 0.5-50g / min), infrared thermometer (temperature measurement range 200-1500℃), six-axis manipulator (repeat positioning accuracy ±0.05mm), and the spraying cabin is equipped with a negative pressure dust removal device (filtration efficiency ≥99.9%).

[0059] Step curing device: program-controlled temperature box furnace, technical parameters: three independent temperature zones (maximum operating temperature 300°C), programmable heating rate 0.1-10°C / min, nitrogen protection system (flow rate 0-20L / min), oxygen content monitor (detection limit 0.1ppm).

[0060] Electron beam radiation equipment: 2.0MeV electron accelerator, including: beam scanning system (scanning frequency 1-200Hz), real-time dose monitor (range 0.1-100kGy), automatic transmission device (speed 0.1-10m / min), radiation shielding cabin (lead equivalent ≥10mm). Precision calendering unit, double-roller structure hot press, configuration: hard chrome-plated mirror steel roller (surface hardness HRC62-65), infrared heating system (temperature control accuracy ±0.5℃), pressure sensor (range 0-20kN, accuracy 0.1%), online roughness detector (Ra detection range 0.01-10μm).

[0061] The MES system is used to realize the linkage control of process parameters between each device. The key process is equipped with a CCD visual inspection module (resolution 5μm) and an online FTIR analyzer (wave number range 4000-400cm -1 ), ensuring the traceability and quality stability of the manufacturing process.

[0062] Example 1 The nano-modified high temperature resistant adhesive tape comprises a substrate layer, a nano-modified adhesive layer and a functional coating layer which are laminated in sequence, wherein: The substrate layer is a polyimide-boron nitride nanowire composite film with a boron nitride nanowire content of 12wt% and a thickness of 30μm. It is electrospun to form an in-plane oriented three-dimensional thermal conductive network with an in-plane thermal conductivity of 8.3 W / m·K. The nano-modified adhesive layer is composed of the following components: 50 parts of organic silicon prepolymer PDMS, 50 parts of epoxy resin E-51, 1 part of silane coupling agent KH-560; surface amino montmorillonite nanosheets MMT-NH24wt%, hydroxylated silicon carbide nanowires SiC-OH 4wt%, nano-cerium dioxide CeO20.5wt%; the adhesive layer thickness is 10μm, and the nanoparticle dispersion D90 is less than 200nm; The functional coating is a composite of aluminum oxide and graphene, where the mass ratio of aluminum oxide to graphene is 3.5:1, the thickness is 12 μm, the surface roughness Ra ≤ 0.3 μm, and a porous structure is formed by plasma spraying with a porosity of 15%; A titanium transition layer deposited by magnetron sputtering is arranged between the substrate layer and the nano-modified adhesive layer, with a thickness of 3nm and an interface bonding strength of ≥25N / cm.

[0063] The amino grafting density of MMT-NH2 nanosheets is 1.2 mmol / g, and the N1s peak area accounts for ≥5.3% through XPS detection. The average diameter of the sheet is 200-500nm, and the diameter-to-thickness ratio is >100. The hydroxyl content of SiC-OH nanowires is ≥8.5 μmol / m 2 , diameter 15nm, aspect ratio 200, surface Zeta potential -35; The sputtering power of the titanium transition layer is 80W, the substrate temperature is 200℃, the argon flow rate is 30sccm, and the interface bonding energy reaches 0.95J / m²; Plasma spraying parameters of functional coating: power 250W, spraying rate 1.2m / min, Al2O3 particle size 50nm, graphene sheet thickness 5nm, adhesion between coating and adhesive layer ≥18N / cm.

[0064] The preparation method of the nano-modified high temperature resistant adhesive tape comprises the following steps: Preparation of substrate layer: Boron nitride nanowires and polyamic acid solution with a solid content of 18wt% were mixed in a ratio of 15wt%, and electrospun to form a three-dimensional oriented base film, wherein the voltage was 25kV and the spinning rate was 1.2mL / h; Preparation of nano-modified adhesive layer: MMT-NH2 preparation: MMT nanosheets were immersed in APTES / ethanol solution, refluxed at 80°C for 6h, centrifuged and washed to pH=7, and a nano-modified adhesive layer with an amino grafting density of 1.5mmol / g was obtained; SiC-OH treatment: silicon carbide nanowires were ultrasonically treated with concentrated nitric acid with a mass percentage concentration of 68% for 2h, and the ultrasonic power was 550W; finally composite treatment: PDMS, epoxy resin E-51, and KH-560 were vacuum stirred and degassed at 60°C for 30min, MMT-NH2, SiC-OH, and CeO2 were added, and three-roll grinding was performed, wherein the roller temperature was 50°C, the gap was 10μm, and 5 cycles were performed, CeO2 was added, and ultrasonic dispersion was performed at 40kHz and 600W for 20min; Multilayer composite preparation: magnetron sputtering titanium transition layer on the substrate surface: Ar gas flow rate 40sccm, background vacuum 5×10 - 3 Pa, sputtering power 100W, deposition rate 0.3nm / s, forming a 5nm thick transition layer; micro-gravure coating nano-modified adhesive layer: mesh number 200, coating speed 4m / min, 80℃ preheating to form a 10μm adhesive layer; plasma spraying functional coating: mixed powder of alumina and graphene, carrier gas Ar / H2=9:1, spraying distance 80mm, deposition efficiency 85%; Post-processing technology: step curing, electron beam radiation and surface calendering.

[0065] The step curing process adopts three-level temperature gradient control: The first stage of curing: curing at 110℃ for 1.5h, with a heating rate of 2℃ / min and a N2 flow rate of 10L / min; Second stage curing: curing at 170℃ for 2.5h; The third stage of curing: curing at 240℃ for 1.2h, the final cross-linking density of the adhesive layer is ≥90%.

[0066] The parameters of the electron beam radiation are as follows: The accelerating voltage was 1.8 MeV, the beam current was 6 mA, the radiation dose was 12 kGy, and the dose rate was 2 kGy / s. The electron beam scanning frequency was 50 Hz, and the beam spot overlap rate was 25%, so that a 0.5 μm dense cross-linked shell layer was formed on the surface of the adhesive layer.

[0067] The surface calendering process is as follows: The double-roll temperature is 140°C, the line pressure is 10kN / m, and the calendering rate is 3m / min; the surface roughness Ra is reduced from 0.5μm to 0.25μm, and the glossiness is increased to 85GU.

[0068] The processing of the three-roll grinding is as follows: Roll gap 8μm, roller temperature 55℃, grinding times 4 times, dispersion energy consumption ≤1.5kW·h / kg.

[0069] Example 2 The nano-modified high temperature resistant adhesive tape comprises a substrate layer, a nano-modified adhesive layer and a functional coating layer which are laminated in sequence, wherein: The substrate layer is a polyimide-boron nitride nanowire composite film with a boron nitride nanowire content of 18wt% and a thickness of 30μm. It is electrospun to form an in-plane oriented three-dimensional thermal conductive network with an in-plane thermal conductivity of 8.9 W / m·K. The nano-modified adhesive layer is composed of the following components: 70 parts of organic silicon prepolymer PDMS, 30 parts of epoxy resin E-51, 3 parts of silane coupling agent KH-560; 6wt% of surface amino montmorillonite nanosheets MMT-NH2, 2wt% of hydroxylated silicon carbide nanowires SiC-OH, and 1.5wt% of nano-cerium dioxide CeO2; the thickness of the adhesive layer is 10μm, and the dispersion degree of nanoparticles D90 is less than 200nm; The functional coating is a composite of aluminum oxide and graphene, where the mass ratio of aluminum oxide to graphene is 4.5:1, the thickness is 8 μm, the surface roughness Ra≤0.3 μm, and a porous structure is formed by plasma spraying with a porosity of 20%; A titanium transition layer deposited by magnetron sputtering is arranged between the substrate layer and the nano-modified adhesive layer, with a thickness of 8nm and an interface bonding strength of ≥25N / cm.

[0070] The amino grafting density of MMT-NH2 nanosheets is 1.8 mmol / g, and the N1s peak area is ≥5.3% as detected by XPS. The average diameter of the sheet is 500nm, and the diameter-to-thickness ratio is >100. The hydroxyl content of SiC-OH nanowires is ≥8.5 μmol / m 2 , diameter 25nm, aspect ratio 50, surface Zeta potential -45mV; The sputtering power of the titanium transition layer is 120W, the substrate temperature is 150℃, the argon flow rate is 50sccm, and the interface bonding energy reaches 0.75 J / m²; Plasma spraying parameters of functional coating: power 350W, spraying rate 0.5m / min, Al2O3 particle size 150nm, graphene sheet thickness 2nm, adhesion between coating and adhesive layer ≥18N / cm.

[0071] The preparation method of the nano-modified high temperature resistant adhesive tape comprises the following steps: Preparation of substrate layer: Boron nitride nanowires and polyamic acid solution with a solid content of 18wt% were mixed in a ratio of 15wt%, and electrospun to form a three-dimensional oriented base film, wherein the voltage was 25kV and the spinning rate was 1.2mL / h; Preparation of nano-modified adhesive layer: MMT-NH2 preparation: MMT nanosheets were immersed in APTES / ethanol solution, refluxed at 80°C for 6h, centrifuged and washed to pH=7, and a nano-modified adhesive layer with an amino grafting density of 1.5mmol / g was obtained; SiC-OH treatment: silicon carbide nanowires were ultrasonically treated with concentrated nitric acid with a mass percentage concentration of 68% for 2h, and the ultrasonic power was 550W; finally composite treatment: PDMS, epoxy resin E-51, and KH-560 were vacuum stirred and degassed at 60°C for 30min, MMT-NH2, SiC-OH, and CeO2 were added, and three-roll grinding was performed, wherein the roller temperature was 50°C, the gap was 10μm, and 5 cycles were performed, CeO2 was added, and ultrasonic dispersion was performed at 40kHz and 600W for 20min; Multilayer composite preparation: magnetron sputtering titanium transition layer on the substrate surface: Ar gas flow rate 40sccm, background vacuum 5×10 - 3 Pa, sputtering power 100W, deposition rate 0.3nm / s, forming a 5nm thick transition layer; micro-gravure coating nano-modified adhesive layer: mesh number 200, coating speed 4m / min, 80℃ preheating to form a 10μm adhesive layer; plasma spraying functional coating: mixed powder of alumina and graphene, carrier gas Ar / H2=9:1, spraying distance 80mm, deposition efficiency 85%; Post-processing technology: step curing, electron beam radiation and surface calendering.

[0072] The step curing process adopts three-level temperature gradient control: The first stage of curing: curing at 130℃ for 1h, with a heating rate of 5℃ / min and a N2 flow rate of 5L / min; Second stage curing: curing at 190℃ for 1.5h; The third stage of curing: curing at 260℃ for 0.8h, the final cross-linking density of the adhesive layer is ≥90%.

[0073] The parameters of the electron beam radiation are as follows: The accelerating voltage was 2.2 MeV, the beam current was 4 mA, the radiation dose was 18 kGy, and the dose rate was 0.5 kGy / s. The electron beam scanning frequency was 100 Hz, and the beam spot overlap rate was 15%, so that a 1.2 μm dense cross-linked shell layer was formed on the surface of the adhesive layer.

[0074] The surface calendering process is as follows: The double-roll temperature is 160°C, the line pressure is 6 kN / m, and the calendering rate is 5 m / min; the surface roughness Ra is reduced from 0.5 μm to 0.25 μm, and the glossiness is increased to 85 GU.

[0075] The processing of the three-roll grinding is as follows: Roller gap 12μm, roller temperature 45℃, grinding times 6 times, dispersion energy consumption ≤1.5kW·h / kg.

[0076] Example 3 The nano-modified high temperature resistant adhesive tape comprises a substrate layer, a nano-modified adhesive layer and a functional coating layer which are laminated in sequence, wherein: The substrate layer is a polyimide-boron nitride nanowire composite film with a boron nitride nanowire content of 15wt% and a thickness of 30μm. It is electrospun to form an in-plane oriented three-dimensional thermal conductive network with an in-plane thermal conductivity of 8.6 W / m·K. The nano-modified adhesive layer is composed of the following components: 60 parts of organic silicon prepolymer PDMS, 40 parts of epoxy resin E-51, 2 parts of silane coupling agent KH-560; surface amino montmorillonite nanosheets MMT-NH25wt%, hydroxylated silicon carbide nanowires SiC-OH 3wt%, nano cerium dioxide CeO21.0wt%; the thickness of the adhesive layer is 10μm, and the dispersion degree of nanoparticles D90 is less than 200nm; The functional coating is a composite of aluminum oxide and graphene, in which the mass ratio of aluminum oxide to graphene is 4:1, the thickness is 10 μm, the surface roughness Ra ≤ 0.3 μm, and a porous structure is formed by plasma spraying with a porosity of 18%; A titanium transition layer deposited by magnetron sputtering is arranged between the substrate layer and the nano-modified adhesive layer, with a thickness of 5nm and an interface bonding strength of ≥25N / cm.

[0077] The amino grafting density of MMT-NH2 nanosheets is 1.6 mmol / g, and the N1s peak area accounts for ≥5.3% as detected by XPS. The average diameter of the sheet is 400nm, and the diameter-to-thickness ratio is >100. The hydroxyl content of SiC-OH nanowires is ≥8.5 μmol / m 2 , diameter 20nm, aspect ratio 100, surface Zeta potential -40mV; The sputtering power of the titanium transition layer is 100W, the substrate temperature is 180℃, the argon flow rate is 40sccm, and the interface bonding energy reaches 0.85 J / m²; Plasma spraying parameters of functional coating: power 300W, spraying rate 0.8m / min, Al2O3 particle size 100nm, graphene sheet thickness 4nm, adhesion between coating and adhesive layer ≥18N / cm.

[0078] The preparation method of the nano-modified high temperature resistant adhesive tape comprises the following steps: Preparation of substrate layer: Boron nitride nanowires and polyamic acid solution with a solid content of 18wt% were mixed in a ratio of 15wt%, and electrospun to form a three-dimensional oriented base film, wherein the voltage was 25kV and the spinning rate was 1.2mL / h; Preparation of nano-modified adhesive layer: MMT-NH2 preparation: MMT nanosheets were immersed in APTES / ethanol solution, refluxed at 80°C for 6h, centrifuged and washed to pH=7, and a nano-modified adhesive layer with an amino grafting density of 1.5mmol / g was obtained; SiC-OH treatment: silicon carbide nanowires were ultrasonically treated with concentrated nitric acid with a mass percentage concentration of 68% for 2h, and the ultrasonic power was 550W; finally composite treatment: PDMS, epoxy resin E-51, and KH-560 were vacuum stirred and degassed at 60°C for 30min, MMT-NH2, SiC-OH, and CeO2 were added, and three-roll grinding was performed, wherein the roller temperature was 50°C, the gap was 10μm, and 5 cycles were performed, CeO2 was added, and ultrasonic dispersion was performed at 40kHz and 600W for 20min; Multilayer composite preparation: magnetron sputtering titanium transition layer on the substrate surface: Ar gas flow rate 40sccm, background vacuum 5×10 - 3 Pa, sputtering power 100W, deposition rate 0.3nm / s, forming a 5nm thick transition layer; micro-gravure coating nano-modified adhesive layer: mesh number 200, coating speed 4m / min, 80℃ preheating to form a 10μm adhesive layer; plasma spraying functional coating: mixed powder of alumina and graphene, carrier gas Ar / H2=9:1, spraying distance 80mm, deposition efficiency 85%; Post-processing technology: step curing, electron beam radiation and surface calendering.

[0079] The step curing process adopts three-level temperature gradient control: The first stage of curing: curing at 120℃ for 1.2h, with a heating rate of 4℃ / min and a N2 flow rate of 8L / min; Second stage curing: curing at 180℃ for 2h; The third stage of curing: curing at 250℃ for 1.0h, the final cross-linking density of the adhesive layer is ≥90%.

[0080] The parameters of the electron beam radiation are as follows: The accelerating voltage was 2.0 MeV, the beam current was 5 mA, the radiation dose was 16 kGy, and the dose rate was 1 kGy / s. The electron beam scanning frequency was 80 Hz, and the beam spot overlap rate was 20%, so that a 0.8 μm dense cross-linked shell layer was formed on the surface of the adhesive layer.

[0081] The surface calendering process is as follows: The double-roll temperature is 150°C, the line pressure is 8kN / m, and the calendering rate is 4m / min; the surface roughness Ra is reduced from 0.5μm to 0.20μm, and the glossiness is increased to 88GU.

[0082] The processing of the three-roll grinding is as follows: Roll gap 10μm, roller temperature 50℃, grinding times 5 times, dispersion energy consumption ≤1.5kW·h / kg.

[0083] Test plan In order to verify the performance of the nano-modified high temperature resistant adhesive tape of the present invention, the following test scheme will be used for evaluation: Temperature resistance test Long-term heat resistance: According to ASTM D4498 standard, a 1000h heat aging test was performed at 400℃ to evaluate the peel strength retention rate. Short-term heat resistance: The tape was exposed to 650℃ for 30min to observe whether there was delamination. Glass transition temperature (Tg): The Tg of the adhesive layer was tested using a differential scanning calorimeter at a heating rate of 10℃ / min.

[0084] Nano-synergistic enhancement effect test Shear strength: According to ASTM D1002 standard, the shear strength of the tape is tested. Elongation at break: The elongation at break of the tape is tested. Flexural fatigue life: According to ISO 6721-1 standard, the flexural fatigue life of the tape is tested.

[0085] Environmental stability test Salt spray test: 500h salt spray test according to ASTM B117 standard to evaluate the delamination and volume resistivity change. Damp heat aging test: 1000h damp heat aging test at 85℃ / 85%RH to evaluate the bonding strength attenuation rate.

[0086] Thermal-mechanical coupling performance test In-plane thermal conductivity: The in-plane thermal conductivity is measured using the laser flash method.

[0087] Coefficient of Thermal Expansion (CTE): CTE was tested in the range of 25-400°C.

[0088] Interface bonding strength test The titanium transition layer makes the substrate-adhesive layer interface bonding strength reach 28.7N / cm (90° peel test).

[0089] Table 1

[0090] As shown in Table 1, these test data indicate that the nano-modified high temperature resistant adhesive tape provided by the present invention exhibits excellent performance in terms of temperature resistance, mechanical properties and environmental stability.

[0091] The nano-modified high temperature resistant adhesive tape prepared in Example 3, wherein Figure 1 The infrared spectrum of the nano-modified adhesive layer is shown; Figure 2 The XRD diffraction pattern of the functional coating prepared in Example 3 is shown.

[0092] It should be additionally explained that the range of some parameters of the present invention or the preferred implementation of this patent are described in detail above, but this patent is not limited to the above implementation. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the purpose of this patent.

Claims

1. A nano-modified high temperature resistant adhesive tape, characterized in that: It comprises a substrate layer, a nano-modified adhesive layer and a functional coating layer which are compounded in sequence, wherein: The substrate layer is a polyimide-boron nitride nanowire composite film, with a boron nitride nanowire content of 12-18wt% and a thickness of 30±2μm. It is electrospun to form an in-plane oriented three-dimensional thermal conductive network with an in-plane thermal conductivity of 8.3-8.9 W / m·K. The nano-modified adhesive layer is composed of the following components: 50-70 parts of organic silicon prepolymer PDMS, 30-50 parts of epoxy resin E-51, 1-3 parts of silane coupling agent KH-560; 4-6wt% of surface amino montmorillonite nanosheets MMT-NH2, 2-4wt% of hydroxylated silicon carbide nanowires SiC-OH, and 0.5-1.5wt% of nano-cerium dioxide CeO2; the thickness of the adhesive layer is 10±1μm, and the dispersion degree of nanoparticles D90 is less than 200nm; The functional coating is a composite of aluminum oxide and graphene, wherein the mass ratio of aluminum oxide to graphene is 3.5:1-4.5:1, the thickness is 8-12 μm, the surface roughness Ra≤0.3 μm, and a porous structure is formed by plasma spraying with a porosity of 15-20%; A titanium transition layer deposited by magnetron sputtering is arranged between the substrate layer and the nano-modified adhesive layer, with a thickness of 3-8nm and an interface bonding strength of ≥25N / cm.

2. The nano-modified high temperature resistant adhesive tape according to claim 1, characterized in that: The amino grafting density of MMT-NH2 nanosheets is 1.2-1.8 mmol / g, and the N1s peak area is ≥5.3% as detected by XPS. The average diameter of the sheet is 200-500nm, and the diameter-to-thickness ratio is >100. The hydroxyl content of SiC-OH nanowires is ≥8.5 μmol / m², the diameter is 15-25nm, the aspect ratio is 50-200, and the surface Zeta potential is -35 to -45mV; The sputtering power of the titanium transition layer is 80-120W, the substrate temperature is 150-200℃, the argon flow rate is 30-50sccm, and the interface bonding energy is 0.75-0.95 J / m²; Plasma spraying parameters of functional coating: power 250-350W, spraying rate 0.5-1.2m / min, Al2O3 particle size 50-150nm, graphene sheet thickness 2-5nm, adhesion between coating and adhesive layer ≥18N / cm.

3. A method for preparing a nano-modified high temperature resistant adhesive tape, comprising the following steps: Preparation of substrate layer: Boron nitride nanowires with a diameter of 50-80 nm and a polyamic acid solution with a solid content of 18 wt% were mixed at a ratio of 15 wt%, and electrospun to form a three-dimensional oriented base film at a voltage of 25 kV and a spinning rate of 1.2 mL / h; Preparation of nano-modified adhesive layer: MMT-NH2 preparation: MMT nanosheets were immersed in APTES / ethanol solution, refluxed at 80°C for 6h, centrifuged and washed to pH=7, and a nano-modified adhesive layer with an amino grafting density of 1.5mmol / g was obtained; SiC-OH treatment: silicon carbide nanowires were ultrasonically treated with concentrated nitric acid with a mass percentage concentration of 68% for 2h, and the ultrasonic power was 550W; finally composite treatment: PDMS, epoxy resin E-51, and KH-560 were vacuum stirred and degassed at 60°C for 30min, MMT-NH2, SiC-OH, and CeO2 were added, and three-roll grinding was performed, wherein the roller temperature was 50°C, the gap was 10μm, and 5 cycles were performed, CeO2 was added, and ultrasonic dispersion was performed at 40kHz and 600W for 20min; Multilayer composite preparation: magnetron sputtering titanium transition layer on the substrate surface: Ar gas flow rate 40sccm, background vacuum 5×10 -3 Pa, sputtering power 100W, deposition rate 0.3nm / s, forming a 5nm thick transition layer; micro-gravure coating nano-modified adhesive layer: mesh number 200, coating speed 4m / min, 80℃ preheating to form a 10μm adhesive layer; plasma spraying functional coating: mixed powder of alumina and graphene, carrier gas Ar / H2=9:1, spraying distance 80mm, deposition efficiency 85%; Post-processing technology: step curing, electron beam radiation and surface calendering.

4. The method for preparing the nano-modified high temperature resistant adhesive tape according to claim 3, characterized in that: The step curing process adopts three-level temperature gradient control: The first stage of curing: curing at 110-130℃ for 1-1.5h, with a heating rate of 2-5℃ / min and a N2 flow rate of 5-10L / min; Second stage curing: curing at 170-190℃ for 1.5-2.5h; The third stage of curing: curing at 240-260℃ for 0.8-1.2h, the final cross-linking density of the adhesive layer is ≥90%.

5. The method for preparing the nano-modified high temperature resistant adhesive tape according to claim 3, characterized in that The parameters of the electron beam radiation are as follows: The accelerating voltage is 1.8-2.2MeV, the beam current is 4-6mA, the radiation dose is 12-18kGy, and the dose rate is 0.5-2kGy / s; the electron beam scanning frequency is 50-100Hz, and the beam spot overlap rate is 15-25%, so that a 0.5-1.2μm dense cross-linked shell layer is formed on the surface of the adhesive layer.

6. The method for preparing the nano-modified high temperature resistant adhesive tape according to claim 3, characterized in that The surface calendering process is as follows: The double-roll temperature is 140-160°C, the line pressure is 6-10kN / m, and the calendering rate is 3-5m / min; the surface roughness Ra is reduced from 0.5μm to 0.15-0.25μm, and the glossiness is increased to 85-90GU.

7. The method for preparing the nano-modified high temperature resistant adhesive tape according to claim 3, characterized in that The processing of the three-roll grinding is as follows: Roller gap 8-12μm, roller temperature 45-55℃, grinding times 4-6 times, dispersion energy consumption ≤1.5kW·h / kg.

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