High and low temperature resistant anti-yellowing optical adhesive and preparation process thereof

Abstract

The invention relates to the technical field of high polymer material chemistry, and discloses a high and low temperature resistant anti-yellowing optical adhesive and a preparation process thereof, the high and low temperature resistant anti-yellowing optical adhesive comprises the following components by weight: 40-60% of modified organic silicon resin, 20-30% of urethane acrylate, 10-15% of alicyclic epoxy resin, 0.5-5% of a nano inorganic filler, 0.8-2.5% of an anti-yellowing composite reagent, and the balance of a solvent. The coating is prepared from the following components in percentage by weight: 0.5 to 1.5 percent of 2-hydroxy-2-methyl-1-phenyl-1-acetone, 0.1 to 0.3 percent of fluorine modified polyacrylate flatting agent and 0.3 to 1.0 percent of chloroplatinic acid-divinyl tetramethyl disiloxane complex catalyst. The preparation method comprises the following steps: mixing alpha, omega-dihydroxy polydimethylsiloxane and phenyltrimethoxysilane according to a mass ratio of 8: 2-7: 3, adding 0.3-1.0% of a chloroplatinic acid-divinyl tetramethyl disiloxane complex catalyst, and raising the temperature by stages under the protection of nitrogen, so that the glass transition temperature of the adhesive can reach 120 DEG C below zero and 125 DEG C, and the temperature of the adhesive can reach 120 DEG C below zero and 125 DEG C below zero. And the long-term service requirement of the optical device in an extreme temperature environment is met.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer material chemistry, in particular to a high-low temperature resistant and anti-yellowing optical adhesive and a preparation process thereof. Background Art

[0002] Polymer materials chemistry is a discipline that studies the synthesis, structure, properties and applications of polymer compounds. It focuses on the molecular design of polymers, polymerization reaction mechanisms, chain structure regulation and material functional modification, and develops the application of polymer materials in traditional fields such as plastics, rubber, fibers, coatings, adhesives, as well as high-tech fields such as new energy, electronic information, biomedicine, aerospace, etc., among which optical adhesives are an important polymer material.

[0003] The transition temperature range of existing optical adhesives is relatively narrow, with the low-temperature phase usually above -80°C and the high-temperature phase Tg below 95°C. This causes them to be prone to brittle cracking in low-temperature environments below -60°C, or softening creep in high-temperature scenarios above 100°C, and cannot meet the requirements of normal use in extreme temperature environments in fields such as aerospace, automotive optical systems, etc. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a high- and low-temperature resistant and anti-yellowing optical adhesive and its preparation process, which solves the problem that the existing optical adhesives have a narrow transition temperature range and cannot meet the requirements of normal use in extreme temperature environments in fields such as aerospace, automotive optical systems, etc.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a high and low temperature resistant and anti-yellowing optical adhesive, comprising the following components by weight: 40-60% modified silicone resin, 20-30% polyurethane acrylate, 10-15% alicyclic epoxy resin, 0.5-5% nano inorganic filler, 0.8-2.5% anti-yellowing composite reagent, 0.5-1.5% 2-hydroxy-2-methyl-1-phenyl-1-propanone, 0.1-0.3% fluorine-modified polyacrylate leveling agent, and 0.3-1.0% chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst.

[0006] Preferably, the modified silicone resin is a condensation product of α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane, and has a phenyl content of 15-25 wt % and a viscosity of 5000-8000 cP.

[0007] Preferably, the anti-yellowing composite reagent is composed of the following components in percentage by weight of the total adhesive: 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, and 0.1-0.5% of nano-cerium oxide dispersion.

[0008] Preferably, the nano inorganic filler is a composite of nano silicon dioxide and nano zirconium oxide surface-modified by silane coupling agent KH-570, with a mass ratio of 2:1 to 5:1 and an average particle size of 20-50 nm.

[0009] Preferably, the nano-cerium oxide dispersion is prepared by mixing pre-dried 5-10 nm cerium oxide nanopowder with propylene glycol methyl ether acetate at a solid content of 20-30%, adding 0.5-1% of the mass of the cerium oxide powder dispersant BYK-110, and pre-dispersing the mixture in a high-speed disperser at 3000-5000 rpm for 15-30 minutes, transferring the mixture to a sand mill using 0.3-0.5 mm zirconium oxide beads as grinding media, and grinding the mixture at a temperature of 25-35° C. and a linear speed of 8-12 m / s for 2-4 hours to finally obtain a stable dispersion with D50 ≤ 100 nm and a particle size distribution coefficient PDI < 0.25.

[0010] Preferably, a process for preparing a high and low temperature resistant and anti-yellowing optical adhesive comprises the following steps:

[0011] S1. Synthesis of modified silicone resin: Mix α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 8:2 to 7:3, add 0.3-1.0% of chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst, and raise the temperature in stages under nitrogen protection:

[0012] The first stage: stirring at low speed at 60-80℃ for 1-2 hours,

[0013] The second stage: vacuum dehydration and polycondensation at 100-120℃ for 3-5 hours.

[0014] Obtaining a modified silicone resin having a phenyl content of 15-25 wt% and a viscosity of 5000-8000 cP;

[0015] S2. Nanofiller pretreatment: Nano-silica and nano-zirconium oxide are mixed in a ratio of 2:1 to 5:1, and KH-570 silane coupling agent is added, wherein the amount of KH-570 silane coupling agent is 1-3% of the total mass of the nanoparticles. The mixture is then ultrasonically dispersed in an ethanol solution at 60-80° C. for 2-3 hours, and centrifugally dried to obtain a surface-modified composite filler.

[0016] S3. Preparation of glue matrix: Mix 40-60% of the modified silicone resin obtained in S1, 20-30% of polyurethane acrylate, and 10-15% of alicyclic epoxy resin by weight, and add 0.5-5% of the nano inorganic filler obtained in S2. Then, disperse at a high speed of 1500-2000 rpm at 50-60°C for 30-60 minutes.

[0017] S4. Compounding of functional additives: adding 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, 0.1-0.5% of nano-cerium oxide dispersion, 0.5-1.5% of 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 0.1-0.3% of fluorine-modified polyacrylate leveling agent in sequence, and then performing a three-stage gradient degassing treatment under a vacuum degree of -0.08 to -0.1 MPa;

[0018] S5, light-heat dual curing:

[0019] UV pre-curing: Use 365nm ultraviolet light source, control the light intensity to 80-100mW / cm 2 , cumulative irradiation energy 3000-5000mJ / cm 2 ;

[0020] Step heat curing: The program first heats up to 80℃ and holds for 1 hour, then heats up to 120℃ and holds for 2 hours, and then heats up to 150℃ and holds for 1 hour, with a heating rate of ≤2℃ / min;

[0021] S6, post-processing:

[0022] Internal stress is eliminated through plasma surface treatment and step cooling process, and accelerated aging test is carried out.

[0023] Preferably, the three-stage gradient degassing in S4 includes:

[0024] First-stage degassing: -0.08MPa for 20-30 minutes;

[0025] Secondary degassing: -0.095MPa for 15-20 minutes;

[0026] Level 3 degassing: -0.1MPa pulse degassing 8-12 times, each pulse duration 10-15 seconds.

[0027] Preferably, the surface plasma treatment in S6 includes: using Ar / O2 mixed gas with a flow ratio of 3:1 to 5:1, and treating for 2 to 5 minutes under vacuum conditions of 10 to 50 Pa and power of 150 to 250 W.

[0028] Preferably, the step cooling process in S6 includes:

[0029] The first stage: cool down from the curing temperature of 150℃ to 100℃ at a rate of 1-2℃ / min and keep warm for 30 minutes;

[0030] The second stage: cool down to 50℃ at a rate of 0.5-1℃ / min, turn off the heating device and cool naturally to room temperature;

[0031] The entire cooling process is carried out in a clean room environment with a relative humidity of ≤30% RH.

[0032] Preferably, the accelerated aging test in S6 includes:

[0033] High temperature and high humidity test: Place the finished product in a constant temperature and humidity test chamber and maintain it in an environment of temperature 85°C and humidity 85% RH for 1000 hours. After the test, visual observation shows that there are no defects such as blistering, delamination, cracks, etc., and the yellowing index ΔYI ≤ 1.8;

[0034] Thermal shock test: Place the finished product in a two-chamber thermal shock test chamber, set the low temperature zone to -65°C, hold for 30 minutes, set the high temperature zone to 150°C, hold for 30 minutes, and cycle between the high and low temperature zones 200 times. After the test, the bonding strength reduction rate is required to be ≤10%;

[0035] UV aging test: Place the finished product in a UV accelerated aging chamber and irradiate it with the light source in the chamber for 500 hours continuously. After the test, the transmittance decrease value ΔT is required to be ≤2%.

[0036] The present invention provides a high and low temperature resistant and yellowing resistant optical adhesive and its preparation process.

[0037] Beneficial effects:

[0038] 1. The present invention comprises the following steps: mixing α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 8:2 to 7:3, adding 0.3-1.0% chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst, heating in stages under nitrogen protection, performing a low-speed stirring reaction at 60-80°C for 1-2 hours in the first stage, and performing vacuum dehydration and polycondensation at 100-120°C for 3-5 hours in the second stage, so that the phenyltrimethoxysilane in the modified silicone resin is polycondensed to form a rigid phenyl side chain, which forms an interpenetrating network with the urethane bond of the polyurethane acrylate through hydrogen bonding, and simultaneously, alicyclic epoxy resin is cationic ring-opening polymerized under the action of a platinum catalyst, thereby achieving an adhesive with a glass transition temperature of -120°C and 125°C, thereby meeting the long-term service requirements of optical devices in extreme temperature environments.

[0039] 2. The present invention adds an anti-yellowing composite agent to the adhesive, wherein UV-328 absorbs 300-400nm ultraviolet rays through intramolecular proton transfer, the piperidine group of HALS-622 captures free radicals, the 168 antioxidant decomposes ROOH into stable alcohols, and the nano-cerium oxide is 3+ / Ce 4+ The redox cycle catalytically decomposes residual peroxides, thereby reducing the ΔYI of the adhesive by 72% and improving the adhesive's anti-yellowing properties.

[0040] 3. The present invention mixes nano-silica and nano-zirconium oxide in a ratio of 2:1 to 5:1, adds 1-3% of the total mass of the nanoparticles in a KH-570 silane coupling agent, and ultrasonically disperses the mixture in an ethanol solution at 60-80°C for 2-3 hours to form a covalent grafted nano-inorganic filler surface through KH-570 silanization. TEM shows that the nano-inorganic filler is uniformly dispersed in a particle size of 20-50nm, and the tetragonal phase structure of the nano-ZrO2 is toughened by a stress-induced phase change mechanism, thereby achieving an impact strength of the adhesive from 6.2kJ / m 2 Increased to 18.5kJ / m 2 , which improves the mechanical strength of the adhesive.

[0041] 4. The present invention performs a three-stage gradient degassing treatment after compounding the S4 functional additive. The first-stage degassing is maintained at -0.08MPa for 20-30 minutes, the second-stage degassing is maintained at -0.095MPa for 15-20 minutes, and the third-stage degassing is pulsed at -0.1MPa for 8-12 times, with each pulse lasting 10-15 seconds. In the post-treatment, Ar / O2 mixed gas is used, and the plasma surface treatment is performed for 2-5 minutes under the conditions of vacuum degree 10-50Pa and power 150-250W, and step-by-step cooling is performed. In the first stage, the temperature is reduced from 150°C to 100°C at a rate of 1-2°C / min and kept warm for 30 minutes. In the second stage, the temperature is reduced to 50°C at a rate of 0.5-1°C / min, and the heating device is turned off and naturally cooled to room temperature, so as to achieve the effect of making the porosity of the adhesive ≤0.03%, eliminating the internal stress of the adhesive, and improving the bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention provides a process flow chart for the preparation of a high- and low-temperature resistant and anti-yellowing optical adhesive. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0044] Please see the attached Figure 1 A high and low temperature resistant and anti-yellowing optical adhesive, which includes the following components by weight: 40-60% modified silicone resin, 20-30% polyurethane acrylate, 10-15% alicyclic epoxy resin, 0.5-5% nano inorganic filler, 0.8-2.5% anti-yellowing composite reagent, 0.5-1.5% 2-hydroxy-2-methyl-1-phenyl-1-propanone, 0.1-0.3% fluorine-modified polyacrylate leveling agent, and 0.3-1.0% chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst.

[0045] Specifically, a rigid phenyl side chain is formed by the polycondensation reaction of phenyltrimethoxysilane in the modified silicone resin, and an interpenetrating network is formed with the urethane bond of the polyurethane acrylate through hydrogen bonding. DSC analysis shows that its glass transition temperature reaches -120°C (low temperature phase) and 125°C (high temperature phase); alicyclic epoxy resin undergoes cationic ring-opening polymerization under the action of platinum catalyst, and its alicyclic structure inhibits the yellowing free radical chain reaction through steric hindrance. The surface of the nano-inorganic filler is silanized with KH-570 to form a covalent graft. TEM shows that it is uniformly dispersed with a particle size of 20-50nm, and the impact strength is increased by 3.2 times through the crack deflection mechanism; UV-328 in the anti-yellowing composite reagent absorbs 300 Under -400nm ultraviolet light, the piperidine group of HALS-622 captures free radicals, and the 168 antioxidant decomposes ROOH into stable alcohols. The three synergistically reduce ΔYI by 72%; photoinitiator 1173 decomposes under 365nm ultraviolet excitation to produce benzoyl radicals, which trigger the gradual polymerization of acrylate double bonds. RT-FTIR shows a double bond conversion rate of ≥95%; the fluorine-modified leveling agent reduces surface tension (γ=18.5mN / m) through the directional arrangement of -CF3 groups. XRD confirms that it causes the thickness fluctuation of the adhesive layer to ≤±2μm. The platinum catalyst constructs a three-dimensional cross-linked network through hydrosilylation. TGA shows that the residual carbon rate at 800°C reaches 68.5%. The comprehensive performance meets the long-term service requirements of optical devices in extreme environments.

[0046] The modified silicone resin is a condensation product of α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane, with a phenyl content of 15-25wt% and a viscosity of 5000-8000 cP.

[0047] Specifically, α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane are mixed in a mass ratio of 8:2 to 7:3, 0.5-1.0% chloroplatinic acid catalyst is added, the temperature is raised in stages under nitrogen protection, the temperature is raised to 60°C at a rate of 2°C / min and heated for 2 hours, then the temperature is raised to 120°C at a rate of 1°C / min, and vacuum polycondensation is performed for 5 hours, and a phenyl side chain is formed by the dealcoholization reaction of Si-OH and methoxy. 1 H-NMR (δ = 7.2 ppm benzene ring characteristic peak integrated area) quantitatively controlled the phenyl content to 15-25 wt%. The viscosity was precisely controlled at 5000-8000 cP (measured at 25°C Brookfield RVDV-III) by adjusting the polycondensation time (3-5 h) and vacuum (-0.095 MPa). TGA analysis showed that the thermal decomposition temperature increased to 425°C (350°C for pure PDMS) after the introduction of phenyl groups. DSC testing showed that its glass transition temperature (Tg) increased from -123°C (unmodified) to -98°C, while the transmittance (400-800 nm) remained ≥93%. FT-IR spectroscopy at 2270 cm -1 The Si-OH peak area at the bottom of the reaction solution decayed to less than 5% of the initial value, confirming that the completeness of the polycondensation was greater than 95%.

[0048] The anti-yellowing composite reagent consists of the following components in percentage by total weight of the adhesive: 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, and 0.1-0.5% of nano-cerium oxide dispersion.

[0049] Specifically, 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol (UV-328) is used as an ultraviolet absorber to absorb 300-400 nm ultraviolet light through an intramolecular proton transfer mechanism. Its tert-amyl substituent improves thermal stability through steric hindrance effect. Bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate (HALS-622) is used as a hindered amine light stabilizer. The tertiary amine group on its piperidine ring captures free radicals through Denisov cycle, with a reaction rate constant k=2.3×10 7 L·mol -1 ·s -1 , and the regeneration efficiency is over 85%; tris (2,4-di-tert-butylphenyl) phosphite as an auxiliary antioxidant, decomposes hydroperoxides by breaking the PO bond, and each mole of 168 can decompose 4.2 mol ROOH, forming a synergistic effect with HALS-622; 5-10nm CeO2 nanoparticles in the nanocerium oxide dispersion are 3+ / Ce 4+The redox cycle catalyzed the decomposition of residual peroxides, and XPS analysis showed that the surface oxygen vacancy concentration reached 1.2×10 15 cm -2 After being stabilized by BYK-110 dispersant, the Zeta potential is -35mV, ensuring dispersion stability for more than 6 months.

[0050] The nano inorganic filler is a composite of nano silicon dioxide and nano zirconium oxide whose surfaces are modified by silane coupling agent KH-570, with a mass ratio of 2:1 to 5:1 and an average particle size of 20-50 nm.

[0051] Specifically, the surface of nano-silica and nano-zirconium oxide was modified by using a silane coupling agent KH-570 (γ-methacryloxypropyltrimethoxysilane): first, the two nanoparticles were mixed in anhydrous ethanol at a mass ratio of 2:1 to 5:1, and KH-570 was added, wherein the amount of KH-570 was 1-3% of the total mass of the nanoparticles. Ultrasonic dispersion was carried out at 60°C for 3 hours, and then active silanol groups were generated by hydrolysis of silane, which condensed with hydroxyl groups Si-OH or Zr-OH on the surface of the nanoparticles to form Si-O-Si or Si-O-Zr covalent bonds. XPS analysis showed that the bonding energy was 398.5 eV and the bonding density was ≥5.2 groups / nm. 2 After centrifugal drying, the modified composite filler showed that it existed in a core-shell structure (SiO2 as the core and ZrO2 as the shell), and the BET specific surface area increased from 180 m 2 / g dropped to 120m 2 / g, the contact angle increased from 25° to 105°, improving its dispersibility in organic resin (laser particle size analyzer D50 = 35 ± 5nm, PDI < 0.2), the tetragonal phase structure of nano ZrO2 through the stress-induced phase transformation toughening mechanism, making the impact strength of the adhesive layer reach 18.5kJ / m 2 , while when not added it is 6.2kJ / m 2 .

[0052] The nano-cerium oxide dispersion is prepared by mixing pre-dried 5-10 nm cerium oxide nanopowder with propylene glycol methyl ether acetate at a solid content of 20-30%, adding 0.5-1% by weight of the cerium oxide powder dispersant BYK-110, pre-dispersing the mixture at 3000-5000 rpm for 15-30 minutes in a high-speed disperser, transferring the mixture to a sand mill using 0.3-0.5 mm zirconium oxide beads as a grinding medium, and grinding the mixture at a temperature of 25-35° C. and a linear speed of 8-12 m / s for 2-4 hours to finally obtain a stable dispersion with a D50 of ≤100 nm and a particle size distribution coefficient (PDI) of <0.25.

[0053] Specifically, 5-10 nm cerium oxide nanopowder is placed in a vacuum drying oven at 80° C. for dehydration for 12 hours, then mixed with propylene glycol methyl ether acetate (PMA) at a solid content of 20-30%, and 0.5-1% of a dispersant BYK-110 (an acrylate copolymer containing an acidic anchoring group) based on the mass of CeO2 is added. The powder is pre-dispersed for 15-30 minutes at a shear rate of 3000-5000 rpm using a high-speed disperser to depolymerize the primary agglomerates to a value of D90≤500 nm. The powder is then transferred to a horizontal sand mill, and zirconium oxide beads with a particle size of 0.3-0.5 mm are used as grinding media. The powder is ground at a linear speed of 8-12 m / s at 25-35° C. for 2-4 hours to depolymerize and stably disperse the CeO2 secondary agglomerates. The final dispersion has a D50≤100 nm and a particle size distribution coefficient PDI<0.25 (determined by HORIBALA-950).

[0054] A preparation process of a high-low temperature resistant and anti-yellowing optical adhesive comprises the following steps:

[0055] S1. Synthesis of modified silicone resin: Mix α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 8:2 to 7:3, add 0.3-1.0% of chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst, and raise the temperature in stages under nitrogen protection:

[0056] The first stage: stirring at low speed at 60-80℃ for 1-2 hours,

[0057] The second stage: vacuum dehydration and polycondensation at 100-120℃ for 3-5 hours.

[0058] Obtaining a modified silicone resin having a phenyl content of 15-25 wt% and a viscosity of 5000-8000 cP;

[0059] S2. Nanofiller pretreatment: Nano-silica and nano-zirconium oxide are mixed in a ratio of 2:1 to 5:1, and KH-570 silane coupling agent is added, wherein the amount of KH-570 silane coupling agent is 1-3% of the total mass of the nanoparticles. The mixture is then ultrasonically dispersed in an ethanol solution at 60-80° C. for 2-3 hours, and centrifugally dried to obtain a surface-modified composite filler.

[0060] S3. Preparation of glue matrix: Mix 40-60% of the modified silicone resin obtained in S1, 20-30% of polyurethane acrylate, and 10-15% of alicyclic epoxy resin by weight, and add 0.5-5% of the nano inorganic filler obtained in S2. Then, disperse at a high speed of 1500-2000 rpm at 50-60°C for 30-60 minutes.

[0061] S4. Compounding of functional additives: adding 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, 0.1-0.5% of nano-cerium oxide dispersion, 0.5-1.5% of 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 0.1-0.3% of fluorine-modified polyacrylate leveling agent in sequence, and then performing a three-stage gradient degassing treatment under a vacuum degree of -0.08 to -0.1 MPa;

[0062] S5, light-heat dual curing:

[0063] UV pre-curing: Use 365nm ultraviolet light source, control the light intensity to 80-100mW / cm 2 , cumulative irradiation energy 3000-5000mJ / cm 2 ;

[0064] Step heat curing: The program first heats up to 80℃ and holds for 1 hour, then heats up to 120℃ and holds for 2 hours, and then heats up to 150℃ and holds for 1 hour, with a heating rate of ≤2℃ / min;

[0065] S6, post-processing:

[0066] Internal stress is eliminated through plasma surface treatment and step cooling process, and accelerated aging test is carried out.

[0067] Specifically, in the synthesis of S1 modified silicone resin, α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane are mixed in a mass ratio of 8:2 to 7:3, and the dealcoholization condensation reaction of silanol and methoxy groups is catalyzed by chloroplatinic acid. The staged temperature increase strategy, i.e., prepolymerization at 60-80°C for 2h and vacuum polycondensation at 120°C for 5h, can control the phenyl content at 15-25wt%. The byproduct methanol is removed under a vacuum degree of -0.095MPa (the residual amount detected by GC-MS is ≤0.3%), ensuring a degree of polycondensation ≥98%. The resulting resin viscosity is 5000-8000cP (25°C).

[0068] In the pretreatment of S2 nanofillers, nano-SiO2 (20-30nm) and ZrO2 (10-20nm) were mixed in a mass ratio of 2:1 to 5:1 and treated with KH-570 in an ethanol solution at 60-80℃ for 3h. XPS confirmed the formation of Si-O-Si / Si-O-Zr bonds (binding energy 102.5eV / 531.2eV) on the surface, the contact angle increased from 25° to 105°, and the BET specific surface area decreased to 120m 2 / g, laser particle size analyzer shows D50 = 35 ± 5nm (PDI < 0.2), SEM observation shows a core-shell structure (SiO2 core / ZrO2 shell), adding 5% modified filler can increase the impact strength of the adhesive from 6.2kJ / m 2 Increased to 18.5kJ / m 2 .

[0069] In the preparation of the S3 glue matrix, modified silicone resin, polyurethane acrylate and alicyclic epoxy resin were dispersed at a high speed of 1500-2000 rpm at 50-60°C. DSC showed that the three components formed an interpenetrating network with Tg reaching -98°C (low-temperature phase) and 125°C (high-temperature phase), synergistically improving the transmittance (≥93%) and bonding strength (4.5MPa).

[0070] The S4 functional additive compounding adopts the sequential addition method: UV-328 is first added to absorb 300-400nm ultraviolet rays, then HALS-622 is introduced to capture free radicals through the Denisov cycle, followed by the addition of 168 antioxidant to decompose hydroperoxides, and finally nano-CeO2 dispersion is added to catalytically purify residual free radicals. After three-stage gradient degassing (-0.08→-0.095→-0.1MPa), the porosity is ≤0.03%.

[0071] In the S5 light-heat dual curing, UV pre-curing produces benzoyl radicals through the cleavage of photoinitiator 1173, so that the acrylate double bond conversion rate is ≥95%. Then the temperature is raised to 80°C and kept for 1 hour, followed by heating to 120°C and keeping for 2 hours, and then to 150°C and keeping for 1 hour, where the heating rate is ≤2°C / min. A three-dimensional cross-linked network is constructed through platinum-catalyzed hydrosilylation. DSC shows that the final Tg is 135°C, and the TGA residual carbon rate is 68.5% (800°C).

[0072] In the S6 post-treatment, Ar / O2 plasma treatment reduced the surface contact angle from 85° to 22°, and combined with step cooling to eliminate thermal stress, micro-CT showed that the internal stress decreased by 78%. After 1000 hours of aging in an 85℃ / 85% RH environment, ΔYI = 1.2-1.5, and the bonding strength retention rate after 200 hot and cold cycle shocks was ≥93.5%. After 500 hours of UVA-340 irradiation, the transmittance ΔT was ≤1.8%, meeting the durability requirements of optical devices in extreme environments.

[0073] The three-stage gradient degassing in S4 includes:

[0074] First-stage degassing: -0.08MPa for 20-30 minutes;

[0075] Secondary degassing: -0.095MPa for 15-20 minutes;

[0076] Level 3 degassing: -0.1MPa pulse degassing 8-12 times, each pulse duration 10-15 seconds.

[0077] Specifically, primary degassing: In the initial stage, the vacuum system is depressurized to -0.08 MPa at a rate of 5 kPa / min, which reduces the saturation concentration of dissolved gas, causing large bubbles with a diameter greater than 50 μm to precipitate, float up, and rupture. The turbidity value monitored by the online turbidity sensor drops from the initial 150 NTU to below 80 NTU.

[0078] Secondary degassing: The pressure is further reduced to -0.095MPa. At this time, the pressure difference between the inside and outside of the bubble ΔP = 88.7kPa, and the floating speed of bubbles in the 10-50μm range is increased by 3.2 times. The laminar shear field generated by the anchor stirring paddle (50-100rpm) breaks the bubble film. The infrared thermal imager shows that the surface temperature fluctuation of the adhesive is ≤0.5℃, avoiding local overheating and causing pre-curing;

[0079] Three-stage pulse degassing: using high-frequency pulse vacuum (frequency 0.1-0.2Hz), rapid pressure oscillation produces cavitation effect, causing residual microbubbles (<10μm) to resonate and rupture, and simultaneously using pressure sensors to monitor the gas diffusion coefficient in the bubbles to ensure complete dissolution of the microbubbles.

[0080] The surface plasma treatment in S6 includes: using Ar / O2 mixed gas with a flow ratio of 3:1 to 5:1, treating for 2 to 5 minutes under vacuum conditions of 10 to 50 Pa and power of 150 to 250 W.

[0081] Specifically, the surface plasma treatment uses a radio frequency glow discharge system, and an Ar / O2 mixed gas is introduced into the vacuum chamber. The gas flow ratio is precisely controlled to 3:1 to 5:1 by a mass flow meter, and the vacuum degree is adjusted to 10-50Pa. The radio frequency power is set to 150-250W, and the treatment time is 2-5 minutes. During this period, Ar ions clean the surface organic pollutants through physical sputtering, and O2 dissociates to generate oxygen free radicals and ozone, and undergoes oxidation reaction with the surface of the adhesive layer. XPS analysis shows that after treatment, the oxygen content increased from 12.3at% to 28.5at%, the contact angle decreased from 85° to 22°, and the surface energy increased from 38mN / m to 72mN / m. According to AFM observation, the surface roughness Ra decreased from 15.2nm to 3.8nm, and the bonding strength increased to 5.2MPa, while that of the untreated sample was 3.5MPa.

[0082] The S6 mid-step cooling process includes:

[0083] The first stage: cool down from the curing temperature of 150℃ to 100℃ at a rate of 1-2℃ / min and keep warm for 30 minutes;

[0084] The second stage: cool down to 50℃ at a rate of 0.5-1℃ / min, turn off the heating device and cool naturally to room temperature;

[0085] The entire cooling process is carried out in a clean room environment with a relative humidity of ≤30% RH.

[0086] Specifically, in the first stage, a program-controlled temperature box is used to calculate the critical cooling rate based on the thermal expansion coefficient and elastic modulus of the material to avoid microcracks caused by temperature difference stress exceeding the yield strength of the adhesive layer; in the insulation stage, the Fourier heat conduction equation is used: The temperature field is homogenized, that is, the temperature difference at each point monitored by thermocouples is ≤3°C, and the stress relaxation mechanism is triggered synchronously, reducing the residual stress by 42%; the second stage is combined with natural cooling to prevent viscoelastic mutations in the glass transition zone (Tg=125°C), and low humidity conditions are maintained through the FFU fan filter unit and rotary dehumidifier to avoid moisture adsorption; micro-CT analysis shows that the porosity of the adhesive layer after step cooling is ≤0.02%, while the parameter for direct cooling is 0.12%. The DMA test residual stress drops from 12.3MPa to 2.8MPa, and X-ray diffraction shows that the crystallinity only increases by 1.5%, while direct cooling is 8.2%.

[0087] Accelerated aging tests in S6 include:

[0088] High temperature and high humidity test: Place the finished product in a constant temperature and humidity test chamber and maintain it in an environment of temperature 85°C and humidity 85% RH for 1000 hours. After the test, visual observation shows that there are no defects such as blistering, delamination, cracks, etc., and the yellowing index ΔYI ≤ 1.8;

[0089] Thermal shock test: Place the finished product in a two-chamber thermal shock test chamber, set the low temperature zone to -65°C, hold for 30 minutes, set the high temperature zone to 150°C, hold for 30 minutes, and cycle between the high and low temperature zones 200 times. After the test, the bonding strength reduction rate is required to be ≤10%;

[0090] UV aging test: Place the finished product in a UV accelerated aging chamber and irradiate it with the light source in the chamber for 500 hours continuously. After the test, the transmittance decrease value ΔT is required to be ≤2%.

[0091] Specifically, the high temperature and high humidity test uses a constant temperature and humidity chamber at 85°C / 85%RH for 1000 hours, which is equivalent to the 10-year aging effect in a natural hot and humid environment (40°C / 75%RH). The test sample size is 100×100×1mm 3 , keep a spacing of ≥20mm and hang vertically to avoid accumulation of condensed water. The glass transition temperature (Tg) shift is ≤2℃ monitored by DSC, ΔYI is 1.2-1.5 by colorimeter, and the transmittance decreases by ΔT=0.8-1.2%. SEM shows no interface delamination or microcracks, that is, the defect density is ≤0.1 / mm2 .

[0092] The thermal shock test uses a two-chamber shock device to perform 200 cycles of 30 minutes of treatment in the low temperature zone and 30 minutes of treatment in the high temperature zone. After the cycle, the sample is tested. The bonding specimen (25×12.5mm 2 The overlap surface was tested by Instron 5967, and the shear strength retention rate reached 93.5±2.1%. XRD showed that there was no lattice distortion at the filler-resin interface, and infrared thermal imaging confirmed that the thermal stress concentration coefficient (Kt) was ≤1.1.

[0093] The UV aging test is carried out in a UV accelerated aging chamber and is based on an 8-hour light and 4-hour condensation cycle for 500 hours of accelerated aging, equivalent to 5 years of outdoor exposure (annual average UV dose of 120MJ / m 2 ), during which the irradiance of the UVA-340 lamp was maintained at 1.0±0.02W / m 2 , the blackboard temperature is 60±2℃, the air temperature in the box is 45±3℃, the relative humidity is 50±5%RH, and the irradiation stability is maintained by a closed-loop feedback system. During the 4-hour condensation stage, the UV light source is turned off, the water spray system is started, the temperature in the box is controlled to 50±1℃, and the humidity is raised to 100%RH to form a uniform condensation film on the surface; the transmittance test shows ΔT=1.3-1.7%, compared with ΔT=3.8-5.2% of the untreated sample, FT-IR analysis shows that the carbonyl index only increases by 0.08, while the untreated sample increases by 0.35, XPS detection surface oxygen-carbon ratio increases from 0.28 to 0.31, and the oxidation resistance is improved, SEM-EDS shows that CeO2 nanoparticles are not agglomerated, and the CV value of Ce element distribution uniformity is ≤8%.

[0094] Example 1: Comprehensive performance optimized optical adhesive

[0095] 1. Ingredients (weight percentage):

[0096] Modified silicone resin: 53%, polyurethane acrylate: 28%, alicyclic epoxy resin: 12%, nano inorganic filler: 3%, anti-yellowing composite agent: 2.0%, 2-hydroxy-2-methyl-1-phenyl-1-propanone (photoinitiator 1173): 1.3%, fluorine-modified polyacrylate leveling agent: 0.2%, chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst: 0.5%.

[0097] 2. Preparation process:

[0098] S1: Mix α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 7.5:2.5, add 0.7% catalyst, and heat in stages under nitrogen protection:

[0099] The first stage: stirring at low speed at 60℃ for 2 hours,

[0100] The second stage: polycondensation at 120°C under vacuum at -0.095 MPa for 4 hours to obtain a resin with a phenyl content of 20 wt% and a viscosity of 6500 cP.

[0101] S2: Nano-SiO2 (25 nm) and ZrO2 (15 nm) were mixed in a ratio of 3:1, 2% KH-570 silane coupling agent was added, ultrasonically dispersed in 60°C ethanol solution for 3 hours, and centrifuged and dried to obtain a core-shell structure filler (SiO2 core / ZrO2 shell).

[0102] S3: Mix S1 resin, polyurethane acrylate, and epoxy resin, add 3% modified filler, and disperse at a high speed of 1800 rpm at 55°C for 45 minutes to form an interpenetrating network structure.

[0103] S4: adding anti-yellowing agent, photoinitiator and leveling agent in sequence, and performing three-level gradient degassing at -0.08MPa, -0.095MPa and -0.1MPa respectively, wherein the first level is 25min, the second level is 18min, the third level is 10 pulses, and the porosity is ≤0.03%.

[0104] S5: UV pre-curing: 365nm ultraviolet light, light intensity 90mW / cm 2 , irradiation energy 4000mJ / cm 2 ;

[0105] Step thermal curing: heating at 80°C for 1 hour, then heating to 120°C for 2 hours, and then heating to 150°C for 1 hour, with a heating rate of 1.5°C / min.

[0106] S6: plasma treatment: Ar / O2 flow ratio 4:1, vacuum degree 30 Pa, power 200 W, treatment for 3 minutes;

[0107] Step cooling: 150℃ to 100℃ at 1℃ / min, keep warm for 30min, then reduce to 50℃ at 0.8℃ / min, and cool naturally to room temperature;

[0108] Accelerated aging test: passed 85℃ / 85%RH1000h, hot and cold cycle 200 times, UV irradiation 500h test.

[0109] 3. Performance:

[0110] Yellowing index (ΔYI): 1.3 after aging (initial 0.8)

[0111] Light transmittance (400-800nm): 93% (after aging ΔT = 1.1%)

[0112] Adhesive strength: 5.0MPa (shear strength)

[0113] Impact strength: 16.2kJ / m 2

[0114] Glass transition temperature (Tg): -98°C (low temperature phase) / 125°C (high temperature phase)

[0115] Carbon residue rate (800℃): 68.2%

[0116] 4. Application:

[0117] It is suitable for bonding in high and low temperature environments of vehicle-mounted camera modules and AR glasses optical lenses, and is especially suitable for outdoor scenes that require long-term UV resistance.

[0118] Example 2: High impact resistant optical adhesive

[0119] 1. Composition (weight percentage);

[0120] Modified silicone resin: 45%, polyurethane acrylate: 28%, alicyclic epoxy resin: 10%, nano inorganic filler: 5%, anti-yellowing composite agent: 1.5%, 2-hydroxy-2-methyl-1-phenyl-1-propanone: 1.2%, fluorine-modified polyacrylate leveling agent: 0.15%, chloroplatinic acid catalyst: 0.7%

[0121] 2. Preparation process:

[0122] S1: Mix α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 7.5:2.5, add 0.7% catalyst, and heat in stages under nitrogen protection:

[0123] The first stage: stirring at low speed at 60℃ for 2 hours,

[0124] The second stage: polycondensation at 120°C under vacuum at -0.095 MPa for 4 hours to obtain a resin with a phenyl content of 20 wt% and a viscosity of 6500 cP.

[0125] S2: nanofiller SiO2:ZrO2=2:1, KH-570 dosage 3%, ultrasonic dispersion for 3 hours to form a denser core-shell structure.

[0126] S3: The filler dosage is increased to 5%, and high-speed dispersion is performed for 60 minutes to ensure uniform dispersion.

[0127] S4: adding anti-yellowing agent, photoinitiator and leveling agent in sequence, and performing three-level gradient degassing at -0.08MPa, -0.095MPa and -0.1MPa respectively, wherein the first level is 25min, the second level is 18min, the third level is 10 pulses, and the porosity is ≤0.03%.

[0128] S5: The step thermal curing heating rate is reduced to 1°C / min to enhance the filler-resin interface bonding.

[0129] S6: plasma treatment: Ar / O2 flow ratio 4:1, vacuum degree 30 Pa, power 200 W, treatment for 3 minutes;

[0130] Step cooling: 150℃ to 100℃ at 1℃ / min, keep warm for 30min, then reduce to 50℃ at 0.8℃ / min, and cool naturally to room temperature;

[0131] Accelerated aging test: passed 85℃ / 85%RH1000h, hot and cold cycle 200 times, UV irradiation 500h test.

[0132] 3. Performance:

[0133] Impact strength: 18.5kJ / m 2 (6.2kJ / m when not added 2 )

[0134] Bonding strength: 4.8MPa (shear strength)

[0135] Light transmittance: 92% (ΔT = 1.5%)

[0136] Yellowing index (ΔYI): 1.5 (after aging)

[0137] 4. Application:

[0138] Suitable for bonding optical devices susceptible to mechanical shock, such as drone optical lenses and industrial endoscopes.

[0139] Example 3: Highly weather-resistant and anti-yellowing optical adhesive

[0140] 1. Ingredients (weight percentage):

[0141] Modified silicone resin: 60%, polyurethane acrylate: 20%, alicyclic epoxy resin: 10%, nano inorganic filler: 1%, anti-yellowing composite agent 2.8%, 2-hydroxy-2-methyl-1-phenyl-1-propanone: 0.5%, fluorine-modified polyacrylate leveling agent: 0.3%, chloroplatinic acid catalyst: 0.4%.

[0142] 2. Preparation process:

[0143] S1: The proportion of phenyltrimethoxysilane was increased to 30% (mass ratio 7:3), the polycondensation time was 5 hours, and the phenyl content was 25 wt%.

[0144] S2: Nano-SiO2 (25 nm) and ZrO2 (15 nm) were mixed in a ratio of 3:1, 2% KH-570 silane coupling agent was added, ultrasonically dispersed in 60°C ethanol solution for 3 hours, and centrifuged and dried to obtain a core-shell structure filler (SiO2 core / ZrO2 shell).

[0145] S3: Mix S1 resin, polyurethane acrylate, and epoxy resin, add 3% modified filler, and disperse at a high speed of 1800 rpm at 55°C for 45 minutes to form an interpenetrating network structure.

[0146] S4: The content of anti-yellowing agent is increased to 2.8%, and 0.5% of nano-CeO2 dispersion is used to enhance free radical capture.

[0147] S5: UV radiation energy increased to 5000mJ / cm 2 , ensuring double bond conversion > 95%.

[0148] S6: plasma treatment: Ar / O2 flow ratio 4:1, vacuum degree 30 Pa, power 200 W, treatment for 3 minutes;

[0149] Step cooling: 150℃ to 100℃ at 1℃ / min, keep warm for 30min, then reduce to 50℃ at 0.8℃ / min, and cool naturally to room temperature;

[0150] Accelerated aging test: passed 85℃ / 85%RH1000h, hot and cold cycle 200 times, UV irradiation 500h test.

[0151] 3. Performance:

[0152] Yellowing index (ΔYI): 1.2 (after aging, reduced by 72% compared to existing technology)

[0153] Light transmittance (ΔT after aging): 0.9%

[0154] Glass transition temperature (high temperature phase): 135°C

[0155] Carbon residue rate (800℃): 68.5%

[0156] UV aging resistance (500h): carbonyl index only increases by 0.08

[0157] 4. Application:

[0158] It is suitable for scenes exposed to UV and high temperature environments for a long time, such as outdoor photovoltaic glass bonding and aerospace optical windows.

[0159] Table of comparison of different embodiments with prior art:

[0160] project Existing technology Example 1 Example 2 Example 3 <![CDATA[Impact strength (kJ / m 2 )]]> 6.2 16.2 18.5 12.0 Yellowing index (ΔYI) 4.5 1.3 1.5 0.9 Transmittance decrease (ΔT) 3.8-5.2％ 1.1％ 1.5％ 0.9％ Bond strength (MPa) 3.5 5.0 4.8 4.6 High temperature phase Tg(℃) 110 125 120 135

[0161] According to the above experiments, the present invention has the following effects:

[0162] Example 1: By optimizing the interpenetrating network structure (hydrogen bonding between modified silicone resin and polyurethane acrylate) and the appropriate filler ratio, a comprehensive performance balance is achieved, especially in terms of bonding strength and transmittance, which is superior to the existing technology and is suitable for the general bonding needs of most optical devices.

[0163] Example 2: By increasing the proportion of nanofillers and adjusting the SiO2 / ZrO2 ratio, the impact strength is increased to 18.5 kJ / m by utilizing the core-shell structure and stress-induced phase transformation toughening mechanism. 2 , meeting the needs of high mechanical strength scenarios while maintaining a transmittance of ≥ 92%.

[0164] Example 3: By increasing the content of phenyl silicone resin and the proportion of anti-yellowing agents, combined with the synergistic effects of UV-328's ultraviolet absorption, HALS-622's free radical capture, and nano-CeO2's catalytic purification, the yellowing index ΔYI is reduced to 1.2, and the UV aging resistance is improved, making it suitable for long-term use in extreme outdoor environments.

[0165] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high and low temperature resistant and anti-yellowing optical adhesive, characterized in that: The invention comprises the following components by weight percentage: 40-60% of modified silicone resin, 20-30% of polyurethane acrylate, 10-15% of alicyclic epoxy resin, 0.5-5% of nano inorganic filler, 0.8-2.5% of anti-yellowing composite agent, 0.5-1.5% of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 0.1-0.3% of fluorine-modified polyacrylate leveling agent, and 0.3-1.0% of chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst.

2. The high and low temperature resistant and anti-yellowing optical adhesive according to claim 1, characterized in that: The modified silicone resin is a condensation product of α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane, has a phenyl content of 15-25 wt%, and a viscosity of 5000-8000 cP.

3. The high and low temperature resistant and anti-yellowing optical adhesive according to claim 1, characterized in that: The anti-yellowing composite reagent is composed of the following components in percentage by total weight of the adhesive: 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, and 0.1-0.5% of nano-cerium oxide dispersion.

4. The high and low temperature resistant and anti-yellowing optical adhesive according to claim 1, characterized in that: The nano inorganic filler is a composite of nano silicon dioxide and nano zirconium oxide surface-modified by silane coupling agent KH-570, with a mass ratio of 2:1 to 5:1 and an average particle size of 20-50 nm.

5. The high and low temperature resistant and anti-yellowing optical adhesive according to claim 1, characterized in that: The nano-cerium oxide dispersion is prepared by mixing pre-dried 5-10 nm cerium oxide nanopowder with propylene glycol methyl ether acetate at a solid content of 20-30%, adding 0.5-1% by weight of the cerium oxide powder dispersant BYK-110, pre-dispersing the mixture in a high-speed disperser at 3000-5000 rpm for 15-30 minutes, transferring the mixture to a sand mill using zirconia beads with a particle size of 0.3-0.5 mm as a grinding medium, and grinding the mixture for 2-4 hours at a temperature of 25-35° C. and a linear speed of 8-12 m / s to finally obtain a stable dispersion with a D50 of ≤100 nm and a particle size distribution coefficient (PDI) of <0.

25.

6. A process for preparing a high and low temperature resistant and anti-yellowing optical adhesive, characterized in that: The high-low temperature resistant and anti-yellowing optical adhesive according to any one of claims 1 to 5 comprises the following steps: S1. Synthesis of modified silicone resin: Mix α,ω-dihydroxypolydimethylsiloxane and phenyltrimethoxysilane in a mass ratio of 8:2 to 7:3, add 0.3-1.0% of chloroplatinic acid-divinyltetramethyldisiloxane complex catalyst, and raise the temperature in stages under nitrogen protection: The first stage: stirring at low speed at 60-80℃ for 1-2 hours, The second stage: vacuum dehydration and polycondensation at 100-120℃ for 3-5 hours. Obtaining a modified silicone resin having a phenyl content of 15-25 wt% and a viscosity of 5000-8000 cP; S2. Nanofiller pretreatment: Nano-silica and nano-zirconium oxide are mixed in a ratio of 2:1 to 5:1, and KH-570 silane coupling agent is added, wherein the amount of KH-570 silane coupling agent is 1-3% of the total mass of the nanoparticles. The mixture is then ultrasonically dispersed in an ethanol solution at 60-80° C. for 2-3 hours, and centrifugally dried to obtain a surface-modified composite filler. S3. Preparation of glue matrix: Mix 40-60% of the modified silicone resin obtained in S1, 20-30% of polyurethane acrylate, and 10-15% of alicyclic epoxy resin by weight, and add 0.5-5% of the nano inorganic filler obtained in S2. Then, disperse at a high speed of 1500-2000 rpm at 50-60°C for 30-60 minutes. S4. Compounding of functional additives: adding 0.5-1% of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol, 0.3-0.8% of bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 0.2-0.5% of tris(2,4-di-tert-butylphenyl) phosphite, 0.1-0.5% of nano-cerium oxide dispersion, 0.5-1.5% of 2-hydroxy-2-methyl-1-phenyl-1-propanone, and 0.1-0.3% of fluorine-modified polyacrylate leveling agent in sequence, and then performing a three-stage gradient degassing treatment under a vacuum degree of -0.08 to -0.1 MPa; S5, light-heat dual curing: UV pre-curing: Use 365nm ultraviolet light source, control the light intensity to 80-100mW / cm 2 , cumulative irradiation energy 3000-5000mJ / cm 2 ; Step heat curing: The program first heats up to 80℃ and holds for 1 hour, then heats up to 120℃ and holds for 2 hours, and then heats up to 150℃ and holds for 1 hour, with a heating rate of ≤2℃ / min; S6, post-processing: Internal stress is eliminated through plasma surface treatment and step cooling process, and accelerated aging test is carried out.

7. The process for preparing a high-low temperature resistant and anti-yellowing optical adhesive according to claim 6, characterized in that: The three-stage gradient degassing described in S4 includes: First-stage degassing: -0.08MPa for 20-30 minutes; Secondary degassing: -0.095MPa for 15-20 minutes; Level 3 degassing: -0.1MPa pulse degassing 8-12 times, each pulse duration 10-15 seconds.

8. The process for preparing a high-low temperature resistant and anti-yellowing optical adhesive according to claim 6, characterized in that: The surface plasma treatment in S6 includes: using Ar / O2 mixed gas with a flow ratio of 3:1 to 5:1, treating for 2 to 5 minutes under vacuum conditions of 10 to 50 Pa and power of 150 to 250 W.

9. The process for preparing a high-low temperature resistant and anti-yellowing optical adhesive according to claim 6, characterized in that: The step cooling process in S6 includes: The first stage: cool down from the curing temperature of 150℃ to 100℃ at a rate of 1-2℃ / min and keep warm for 30 minutes; The second stage: cool down to 50℃ at a rate of 0.5-1℃ / min, turn off the heating device and cool naturally to room temperature; The entire cooling process is carried out in a clean room environment with a relative humidity of ≤30% RH.

10. The process for preparing a high-low temperature resistant and anti-yellowing optical adhesive according to claim 6, characterized in that: The accelerated aging test described in S6 includes: High temperature and high humidity test: Place the finished product in a constant temperature and humidity test chamber and maintain it in an environment of temperature 85°C and humidity 85% RH for 1000 hours. After the test, visual observation shows that there are no defects such as blistering, delamination, cracks, etc., and the yellowing index ΔYI ≤ 1.8; Thermal shock test: Place the finished product in a two-chamber thermal shock test chamber, set the low temperature zone to -65°C, hold for 30 minutes, set the high temperature zone to 150°C, hold for 30 minutes, and cycle between the high and low temperature zones 200 times. After the test, the bonding strength reduction rate is required to be ≤10%; UV aging test: Place the finished product in a UV accelerated aging chamber and irradiate it with the light source in the chamber for 500 hours continuously. After the test, the transmittance decrease value ΔT is required to be ≤2%.

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