Anti-aging sealing compound and preparation process thereof

Abstract

The invention relates to the technical field of sealing compounds, in particular to an anti-aging sealing compound and a preparation process thereof. The preparation process of the anti-aging sealing compound comprises the following steps: preparing the core crystal compound, preparing the anti-aging compound additive, and preparing the anti-aging sealing compound. According to the invention, a dual synergistic protection inner core of ultraviolet shielding and free radical capture is constructed, and mesoporous silica coating and organic modification are carried out, so that the dispersibility and interface bonding force of the auxiliary agent in organic colloid are improved; the nano titanium dioxide is added in batches, so that the dispersion uniformity of the nano titanium dioxide is improved, the nano titanium dioxide and the inner core form an anti-aging synergistic system, a continuous ultraviolet protection network is constructed, meanwhile, the bonding strength and flexibility of the sealing adhesive are enhanced, and the long-acting anti-aging life of the sealing adhesive is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of sealing adhesive technology, specifically to an aging-resistant sealing adhesive and its preparation process. Background Technology

[0002] Sealing adhesives, as an important bonding material, are widely used in packaging, construction, electronics, automotive, aerospace, and other fields. Their core function is to seal, fix, and protect bonded components, ensuring the structural integrity and performance stability of products during production, transportation, storage, and use. With the rapid development of industrial technology and the increasing complexity of application environments, the market has placed higher demands on the comprehensive performance of sealing adhesives. Among these, aging resistance, as a key indicator determining the service life and application reliability of sealing adhesives, has received increasing attention.

[0003] Existing sealing adhesives mainly include solvent-based, water-based, and hot-melt types. Different types of sealing adhesives vary in composition and manufacturing process, but they generally suffer from insufficient aging resistance. In natural or usage environments, sealing adhesives are often subjected to the combined effects of multiple aging factors, such as light (especially ultraviolet light), alternating high and low temperatures, humidity changes, oxygen, ozone, and chemical media. These factors lead to the destruction of their internal chemical structure, resulting in aging failure phenomena such as decreased adhesive strength, cracking, hardening, brittleness, and discoloration.

[0004] To improve the aging resistance of sealing adhesives, existing technologies typically employ methods such as directly adding single or compound aging inhibitors like antioxidants, UV absorbers, and light stabilizers to the adhesive system. Inorganic fillers are also sometimes added to further enhance performance. However, these existing technologies suffer from several insurmountable drawbacks: traditional aging inhibitors are mostly simple physical mixtures, failing to form a synergistic protective system, and exhibit poor compatibility with the adhesive matrix, leading to migration and precipitation problems. This results in a rapid decline in aging resistance over time, failing to achieve long-term stable protection. Furthermore, the added inorganic fillers have poor dispersibility, easily causing interface defects due to agglomeration, which affects the adhesive strength of the sealing adhesive.

[0005] Therefore, this application develops an aging-resistant sealing adhesive and its preparation process that can construct an efficient and synergistic aging-resistant system, achieve long-term stable effects of aging inhibitors, and improve the dispersion uniformity and interfacial bonding of inorganic fillers. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an aging-resistant sealing adhesive and its preparation process.

[0007] This invention provides a process for preparing an aging-resistant sealing adhesive, comprising: S1: Preparation of the core crystallization complex; Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole were dissolved in an ethanol / acetone mixture to form a homogeneous solution. After filtration through a filter membrane, the solution was allowed to stand and crystallize under low temperature and low humidity conditions. The solution was then washed and dried to obtain a core crystallized complex powder. S2: Preparation of anti-aging composite additives; The core crystallization complex powder was dispersed in an ethanol aqueous solution containing hexadecyltrimethylammonium bromide to obtain a suspension. Ammonia water was added and then tetraethyl orthosilicate solution was added dropwise to carry out the reaction. Then γ-(methacryloyloxy)propyltrimethoxysilane was added to continue the reaction. The resulting product was centrifuged, washed, dried and pulverized to obtain an anti-aging composite additive. S3: Preparation of aging-resistant sealing adhesive; An anti-aging composite additive was ultrasonically dispersed in ethyl acetate to obtain a pre-dispersion; an acrylate copolymer resin and hydrogenated petroleum resin were dissolved in ethyl acetate to obtain a base adhesive; the pre-dispersion was added to the base adhesive, and inorganic nano-reinforcing fillers were added stepwise and stirred and mixed. Then, leveling agent and defoamer were added, and after stirring and vacuum defoaming, an anti-aging sealing adhesive was obtained.

[0008] As a preferred aspect, S1: the preparation of the core crystallization complex specifically includes the following steps: S1.1: Anhydrous ethanol and acetone are mixed in a volume ratio of 1:1 to obtain an ethanol / acetone mixed solution. Then, 10-12 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 10-12 parts by weight of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole are added to 100-120 parts by weight of the mixed solution at 60-65℃. The mixture is stirred at 300-500 rpm for 20-30 min to obtain a homogeneous solution. S1.2: The homogeneous solution was filtered through a 0.22 μm microporous membrane, and the filtrate was then transferred to a clean crystallizing dish. Several small holes were punched in the dish with a sealing film, and the dish was then placed in a low-temperature environment of 4-8℃ and kept at a humidity of 20-30%RH for 48-50 hours to obtain precipitated crystals. The crystals were then washed 3-5 times with a 0-4℃ ethanol / acetone mixed solution, and then vacuum dried to obtain the core crystallization complex powder.

[0009] As a preferred aspect, the preparation of S2: the aging-resistant composite additive specifically includes the following steps: S2.1: Add 1-2 parts by weight of hexadecyltrimethylammonium bromide to 120-140 parts by weight of 75wt% ethanol aqueous solution, then add 20-24 parts by weight of core crystallization complex powder at 2000-4000 rpm, and continue stirring for 20-30 min to obtain a suspension. Add 5-8 parts by weight of tetraethyl orthosilicate to 60-80 parts by weight of 75wt% ethanol aqueous solution, stir and mix to obtain a mixed solution. S2.2: Add 2-3 parts by weight of 25-28 wt% concentrated ammonia to the suspension at 30-35℃, then add the mixed solution dropwise over 2-3 hours. After the addition is complete, react at 30-35℃ for 12-16 hours. After the reaction is complete, add 2-4 parts by weight of γ-(methacryloyloxy)propyltrimethoxysilane at 30-35℃, then raise the temperature to 50-60℃ and react for 6-8 hours to obtain the reaction solution. S2.3: Centrifuge the reaction solution at 8000-10000 rpm for 10-12 min to obtain a precipitate. Then wash the precipitate 3-5 times with anhydrous ethanol and deionized water by alternating centrifugation. After drying at 60-62℃ for 20-24 h, pulverize it through a 400-mesh sieve to obtain the aging-resistant composite additive.

[0010] As a preferred aspect, S3: the preparation of the aging-resistant sealing adhesive specifically includes the following steps: S3.1: Add 3-8 parts by weight of the anti-aging composite additive to 10-12 parts by weight of ethyl acetate, and then perform pulsed ultrasonic dispersion at 25-30℃ and 500-520W, with ultrasonic on for 2 seconds and off for 1 second, for a total time of 20-30 minutes, to obtain the pre-dispersion of the anti-aging composite additive. S3.2: Add 30-50 parts by weight of acrylate copolymer resin and 15-25 parts by weight of hydrogenated petroleum resin to the reactor, then start stirring at 50-100 rpm and introduce nitrogen gas, then add 10-20 parts by weight of ethyl acetate, and then stir and mix at 55-60℃ for 2-3 hours to obtain the base adhesive solution. S3.3: At 45-50℃, add the pre-dispersion of the aging-resistant composite additive to the base adhesive, and then stir and mix for 20-30 minutes. Then, raise the temperature to 72-75℃, and add 5-10 parts by weight of inorganic nano-reinforcing filler in three portions over 15-20 minutes at 150-200 rpm. Then, stir at 100-150 rpm for 40-50 minutes, and then add 5-10 parts by weight of inorganic nano-reinforcing filler in three portions over 15-20 minutes at 100-150 rpm. After the addition is complete, stir at 76-78℃ for 50-60 minutes to obtain the mixture. S3.4: Cool the mixture to 48-50℃, then add 0.5-1 parts by weight of leveling agent and 0.5-1 parts by weight of defoamer, stir and mix at 200-300 rpm for 2-3 hours, and then defoam at -0.09 MPa and room temperature for 30-40 minutes to obtain aging-resistant sealing adhesive.

[0011] As a preferred aspect, the inorganic nano-reinforcing filler in step S3.3 is nano-titanium dioxide.

[0012] As a preferred aspect, the leveling agent in step S3.4 is polyether-modified polydimethylsiloxane.

[0013] As a preferred aspect, the defoamer in step S3.4 is a polyether defoamer.

[0014] The present invention also provides an aging-resistant sealing adhesive, which is prepared by the preparation process of any one of the aging-resistant sealing adhesives described in the present invention.

[0015] The present invention has the following advantages: 1. This invention combines 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate at the molecular level to form a dual synergistic protection system of "UV shielding + free radical capture". The core is then encapsulated with mesoporous silica to construct a "core-shell" structure. The resulting anti-aging composite additive, when added to an anti-aging sealant, helps the sealant physically shield the core active ingredients from direct attack by external aging factors such as UV radiation, heat, and oxygen. It can also achieve controlled and slow release of core stabilizers, thereby significantly extending the long-term aging resistance of the sealing adhesive. It overcomes the shortcomings of traditional direct addition of additives, such as easy migration and easy loss. Furthermore, the silica shell is organically modified by using γ-(methacryloyloxy)propyltrimethoxysilane, which introduces double bond functional groups that are compatible with acrylate resins. This greatly improves the dispersion uniformity and interfacial bonding of the aging-resistant composite additives in organic colloids, avoiding performance inconsistencies or stress weaknesses caused by agglomeration or phase separation.

[0016] 2. This invention incorporates inorganic nano-reinforcing filler nano-titanium dioxide in batches. By adding it in batches and controlling the intervals and stirring conditions between each addition, each batch of nanoparticles can obtain sufficient dispersion time and space in the adhesive solution, avoiding excessive local particle concentration. This significantly improves dispersion uniformity, inhibits agglomeration, and the nano-titanium dioxide also possesses excellent UV shielding and photocatalytic stabilization functions. It forms an anti-aging synergistic system with the core crystallization complex. The uniformly dispersed nanoparticles can construct a continuous UV protection network, comprehensively blocking UV penetration and preventing degradation of polymer resin chains. At the same time, it reduces the absence of local anti-aging components caused by agglomeration, ensuring consistent weather resistance of the sealing adhesive and extending its service life. In addition, the uniformly dispersed nano-titanium dioxide can form a tighter interfacial bond with acrylate copolymer resin and hydrogenated petroleum resin, improving the cohesiveness of the adhesive solution, enhancing bonding strength and flexibility, and avoiding interfacial defects caused by particle agglomeration. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the preparation process of the aging-resistant sealing adhesive used in an embodiment of the present invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this invention.

[0019] Example 1: A preparation process for an aging-resistant sealing adhesive, referring to... Figure 1 ,include: S1: Preparation of the core crystallization complex S1.1: Anhydrous ethanol and acetone were mixed in a volume ratio of 1:1 to obtain an ethanol / acetone mixed solution. Then, 10 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 10 parts by weight of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole were added to 100 parts by weight of the mixed solution at 60°C. The mixture was stirred at 300 rpm for 20 min to obtain a homogeneous solution. S1.2: The homogeneous solution was filtered through a 0.22 μm microporous membrane, and the filtrate was then transferred to a clean crystallizing dish. Several small holes were punched in the dish with a sealing film, and the dish was then placed in a low-temperature environment of 4°C and kept at a humidity of 20%RH for 48 hours to obtain precipitated crystals. The crystals were then washed three times with a 0°C ethanol / acetone mixed solution and then vacuum dried to obtain the core crystallization complex powder. S2: Preparation of anti-aging composite additives S2.1: Add 1 part by weight of hexadecyltrimethylammonium bromide to 120 parts by weight of 75 wt% ethanol aqueous solution, then add 20 parts by weight of core crystallization complex powder at 2000 rpm, and continue stirring for 20 min to obtain a suspension. Add 5 parts by weight of tetraethyl orthosilicate to 60 parts by weight of 75 wt% ethanol aqueous solution, stir and mix to obtain a mixed solution. S2.2: Add 2 parts by weight of 25wt% concentrated ammonia to the suspension at 30℃, then add the mixed solution dropwise over 2 hours. After the addition is complete, react at 30℃ for 12 hours. After the reaction is complete, add 2-4 parts by weight of γ-(methacryloyloxy)propyltrimethoxysilane at 30℃, then raise the temperature to 50℃ and react for 6 hours to obtain the reaction solution. S2.3: Centrifuge the reaction solution at 8000 rpm for 10 min to obtain a precipitate. Then wash the precipitate three times with anhydrous ethanol and deionized water by alternating centrifugation. After drying at 60℃ for 20 h, pulverize it through a 400-mesh sieve to obtain the anti-aging composite additive. S3: Preparation of aging-resistant sealing adhesive S3.1: Add 3 parts by weight of anti-aging composite additive to 10 parts by weight of ethyl acetate, and then perform pulsed ultrasonic dispersion at 25°C and 500W, with ultrasonic on for 2 seconds and off for 1 second, for a total time of 20 minutes, to obtain the pre-dispersion of anti-aging composite additive. S3.2: Add 30 parts by weight of acrylate copolymer resin and 15 parts by weight of hydrogenated petroleum resin to the reactor, then start stirring at 50 rpm and introduce nitrogen gas, then add 10 parts by weight of ethyl acetate, and then stir and mix at 55°C for 2 hours to obtain the base adhesive solution. S3.3: At 45℃, add the pre-dispersion liquid of the aging-resistant composite additive to the base adhesive liquid, and then stir and mix for 20 min. Then, raise the temperature to 72℃, and add 2 parts by weight of nano titanium dioxide in three portions over 15 min at 150 rpm. Then, stir at 100 rpm for 40 min, and then add 2 parts by weight of nano titanium dioxide in three portions over 15 min at 100 rpm. After the addition is complete, stir at 76℃ for 50 min to obtain the mixture. S3.4: Cool the mixture to 48°C, then add 0.5 parts by weight of polyether-modified polydimethylsiloxane leveling agent and 0.5 parts by weight of polyether defoamer, stir and mix at 200 rpm for 2 hours, and then defoam at -0.09 MPa and room temperature for 30 minutes to obtain aging-resistant sealing adhesive.

[0020] Example 2, a preparation process for an aging-resistant sealing adhesive, see [link to example]. Figure 1 ,include: S1: Preparation of the core crystallization complex S1.1: Anhydrous ethanol and acetone were mixed in a volume ratio of 1:1 to obtain an ethanol / acetone mixed solution. Then, 12 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 12 parts by weight of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole were added to 120 parts by weight of the mixed solution at 65°C. The mixture was stirred at 500 rpm for 30 min to obtain a homogeneous solution. S1.2: The homogeneous solution was filtered through a 0.22 μm microporous membrane, and the filtrate was transferred to a clean crystallizing dish. Several small holes were punched in the dish with a sealing film, and the dish was placed in a low temperature environment of 8°C and kept at 30% RH for 50 h to obtain precipitated crystals. The crystals were then washed five times with an ethanol / acetone mixed solution at 4°C and then vacuum dried to obtain the core crystallization complex powder. S2: Preparation of anti-aging composite additives S2.1: Add 2 parts by weight of hexadecyltrimethylammonium bromide to 140 parts by weight of 75wt% ethanol aqueous solution, then add 24 parts by weight of core crystallization complex powder at 4000 rpm, and continue stirring for 30 min to obtain a suspension. Add 8 parts by weight of tetraethyl orthosilicate to 80 parts by weight of 75wt% ethanol aqueous solution, stir and mix to obtain a mixed solution. S2.2: Add 3 parts by weight of 28wt% concentrated ammonia to the suspension at 35℃, then add the mixed solution dropwise over 3 hours. After the addition is complete, react at 35℃ for 16 hours. After the reaction is complete, add 4 parts by weight of γ-(methacryloyloxy)propyltrimethoxysilane at 35℃, then raise the temperature to 60℃ and react for 8 hours to obtain the reaction solution. S2.3: Centrifuge the reaction solution at 10000 rpm for 12 min to obtain a precipitate. Then wash the precipitate 5 times with anhydrous ethanol and deionized water by alternating centrifugation. After drying at 62℃ for 24 h, pulverize it through a 400-mesh sieve to obtain the anti-aging composite additive. S3: Preparation of aging-resistant sealing adhesive S3.1: Add 8 parts by weight of the anti-aging composite additive to 12 parts by weight of ethyl acetate, and then perform pulsed ultrasonic dispersion at 30°C and 520W, with ultrasonic on for 2 seconds and off for 1 second, for a total time of 30 minutes, to obtain the anti-aging composite additive pre-dispersion. S3.2: Add 50 parts by weight of acrylate copolymer resin and 25 parts by weight of hydrogenated petroleum resin to the reactor, then start stirring at 100 rpm and introduce nitrogen gas, then add 20 parts by weight of ethyl acetate, and then stir and mix at 60°C for 3 hours to obtain the base adhesive solution. S3.3: At 50℃, add the pre-dispersion liquid of the aging-resistant composite additive to the base adhesive liquid, and then stir and mix for 30 min. Then, raise the temperature to 75℃, and add 3 parts by weight of nano titanium dioxide in three portions over 20 min at 200 rpm. Then, stir at 150 rpm for 50 min, and then add 3 parts by weight of nano titanium dioxide in three portions over 20 min at 150 rpm. After the addition is complete, stir at 78℃ for 60 min to obtain the mixture. S3.4: Cool the mixture to 50°C, then add 1 part by weight of polyether modified polydimethylsiloxane leveling agent and 1 part by weight of polyether defoamer, stir and mix at 300 rpm for 3 hours, and then defoam at -0.09 MPa and room temperature for 40 minutes to obtain aging resistant sealing adhesive.

[0021] Example 3, a preparation process for an aging-resistant sealing adhesive, see [link to example]. Figure 1 ,include: S1: Preparation of the core crystallization complex S1.1: Anhydrous ethanol and acetone were mixed in a volume ratio of 1:1 to obtain an ethanol / acetone mixed solution. Then, 11 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 11 parts by weight of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole were added to 110 parts by weight of the mixed solution at 62.5℃. The mixture was stirred at 400 rpm for 25 min to obtain a homogeneous solution. S1.2: The homogeneous solution was filtered through a 0.22 μm microporous membrane, and the filtrate was then transferred to a clean crystallizing dish. Several small holes were punched in the dish with a sealing film, and the dish was then placed in a low temperature environment of 6°C and kept at a humidity of 25%RH for 49 hours to obtain precipitated crystals. The crystals were then washed four times with an ethanol / acetone mixed solution at 2°C and then vacuum dried to obtain the core crystallization complex powder. S2: Preparation of anti-aging composite additives S2.1: Add 1.5 parts by weight of hexadecyltrimethylammonium bromide to 130 parts by weight of 75 wt% ethanol aqueous solution, then add 22 parts by weight of core crystallization complex powder at 3000 rpm, and continue stirring for 25 min to obtain a suspension. Add 6.5 parts by weight of tetraethyl orthosilicate to 70 parts by weight of 75 wt% ethanol aqueous solution, stir and mix to obtain a mixed solution. S2.2: Add 2.5 parts by weight of 26.5 wt% concentrated ammonia to the suspension at 32.5℃, then add the mixed solution dropwise over 2.5 h. After the addition is complete, react at 32.5℃ for 14 h. After the reaction is complete, add 3 parts by weight of γ-(methacryloyloxy)propyltrimethoxysilane at 32.5℃, then raise the temperature to 55℃ and react for 7 h to obtain the reaction solution. S2.3: Centrifuge the reaction solution at 9000 rpm for 11 min to obtain a precipitate. Then, wash the precipitate 4 times with anhydrous ethanol and deionized water by alternating centrifugation. After drying at 61℃ for 22 h, pulverize it through a 400-mesh sieve to obtain the anti-aging composite additive. S3: Preparation of aging-resistant sealing adhesive S3.1: Add 5.5 parts by weight of the anti-aging composite additive to 11 parts by weight of ethyl acetate, and then perform pulsed ultrasonic dispersion at 27.5℃ and 510W, with ultrasonic on for 2 seconds and off for 1 second, for a total time of 25 minutes, to obtain the pre-dispersion of the anti-aging composite additive. S3.2: Add 40 parts by weight of acrylate copolymer resin and 20 parts by weight of hydrogenated petroleum resin to the reactor, then start stirring at 75 rpm and introduce nitrogen gas, then add 15 parts by weight of ethyl acetate, and then stir and mix at 57.5℃ for 2.5 h to obtain the base adhesive solution. S3.3: At 47.5℃, the pre-dispersion liquid of the aging-resistant composite additive is added to the base adhesive liquid and stirred for 25 min. Then, the temperature is raised to 73.5℃, and 2.5 parts by weight of nano titanium dioxide is added in three portions at 175 rpm for 17.5 min. Then, the mixture is stirred at 125 rpm for 45 min. Then, 2.5 parts by weight of nano titanium dioxide is added in three portions at 125 rpm for 12.5 min. After the addition is completed, the mixture is stirred at 77℃ for 57 min to obtain the mixture. S3.4: Cool the mixture to 49°C, then add 0.75 parts by weight of polyether-modified polydimethylsiloxane leveling agent and 0.75 parts by weight of polyether defoamer, stir and mix at 250 rpm for 2.5 h, then defoam at -0.09 MPa and room temperature for 35 min to obtain aging-resistant sealing adhesive.

[0022] Comparative Example 1 differs from Example 1 in that the anti-aging composite additive pre-dispersion liquid in steps S1-S2, S3.1 and S3.3 is removed, while the remaining steps remain unchanged to prepare the anti-aging sealing adhesive, and it is referred to as Comparative Example 1.

[0023] Comparative Example 2 differs from Example 1 in that step S3.3 is replaced with "at 45°C, the pre-dispersion liquid of the anti-aging composite additive is added to the base adhesive liquid, and then stirred for 20 min. After that, the temperature is raised to 72°C, and 4 parts by weight of titanium dioxide is added at 150 rpm for 15 min. After the addition is completed, the mixture is stirred for 50 min to obtain the mixture". The remaining steps are unchanged to prepare the anti-aging sealing adhesive, which is referred to as Comparative Example 2.

[0024] Comparative Example 3 differs from Example 3 in that steps S1-S2 and S3.1 are removed, and the aging-resistant composite additive pre-dispersion liquid in step S3.3 is replaced with 3 parts by weight of ultraviolet absorber UV-326. The remaining steps are unchanged to prepare the aging-resistant sealing adhesive, and it is referred to as Comparative Example 3.

[0025] The sealing adhesives prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to UV aging resistance tests. The tests were conducted three times and the average value was taken. The test results are shown in Table 1.

[0026] Referring to GB / T14522-2008 "Artificial Climate Aging Test Method for Plastics, Coatings and Rubber Materials for Mechanical Industry Products", UVB-313 lamp tubes were used for accelerated aging, and the color change (ΔE*) before and after aging was measured. The degree of yellowing was evaluated using a colorimeter.

[0027] Test conditions: Irradiation temperature 60℃, 8 hours of illumination; condensation temperature 50℃, 4 hours of condensation. This constitutes one cycle, with a measurement period of 480 hours.

[0028] The tensile strength before and after aging was determined according to GB / T 1040.1-2018, and the tensile strength retention rate was calculated.

[0029]

[0030] As can be seen from the data in Table 1, the sealing adhesive prepared by this invention has good UV aging resistance and significantly extends the long-term aging resistance life of the sealing adhesive. As can be seen from the data in Comparative Example 1 and Comparative Example 3, the added anti-aging composite additive has a better anti-aging effect than the existing UV absorber UV-326, and can significantly improve the anti-aging performance of the sealing adhesive. As can be seen from the data in Comparative Example 2, the nano titanium dioxide added in batches can further improve the anti-aging performance of the sealing adhesive.

[0031] The mechanical properties of the sealing adhesives prepared in Examples 1-3 and Comparative Example 2 were tested three times, and the average value was taken. The test results are shown in Table 2.

[0032] Adhesion strength: determined according to GB / T2791-1995 "Adhesives T Peel Strength Test Method".

[0033] Tensile strength was determined in accordance with GB / T 1040.1-2018.

[0034]

[0035] As can be seen from the data in Table 2, the present invention uses the batch addition of nano-titanium dioxide, which can effectively improve the adhesive bonding strength.

[0036] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A preparation process for an aging-resistant sealing adhesive, characterized in that, include: S1: Preparation of the core crystallization complex; Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole were dissolved in an ethanol / acetone mixture to form a homogeneous solution. After filtration through a filter membrane, the solution was allowed to stand and crystallize under low temperature and low humidity conditions. The solution was then washed and dried to obtain a core crystallized complex powder. S2: Preparation of anti-aging composite additives; The core crystallization complex powder was dispersed in an ethanol aqueous solution containing hexadecyltrimethylammonium bromide to obtain a suspension. Ammonia water was added and then tetraethyl orthosilicate solution was added dropwise to carry out the reaction. Then γ-(methacryloyloxy)propyltrimethoxysilane was added to continue the reaction. The resulting product was centrifuged, washed, dried and pulverized to obtain an anti-aging composite additive. S3: Preparation of aging-resistant sealing adhesive; An anti-aging composite additive was ultrasonically dispersed in ethyl acetate to obtain a pre-dispersion; an acrylate copolymer resin and hydrogenated petroleum resin were dissolved in ethyl acetate to obtain a base adhesive. The pre-dispersed liquid is added to the base adhesive, and inorganic nano-reinforcing fillers are added step by step and stirred and mixed. Then, leveling agent and defoamer are added. After stirring and vacuum defoaming, aging-resistant sealing adhesive is obtained.

2. The preparation process of the aging-resistant sealing adhesive according to claim 1, characterized in that, S1: Preparation of the core crystallization complex, specifically including the following steps: S1.1: Anhydrous ethanol and acetone are mixed in a volume ratio of 1:1 to obtain an ethanol / acetone mixed solution. Then, 10-12 parts by weight of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 10-12 parts by weight of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole are added to 100-120 parts by weight of the mixed solution at 60-65℃. The mixture is stirred at 300-500 rpm for 20-30 min to obtain a homogeneous solution. S1.2: The homogeneous solution was filtered through a 0.22 μm microporous membrane, and the filtrate was then transferred to a clean crystallizing dish. Several small holes were punched in the dish with a sealing film, and the dish was then placed in a low-temperature environment of 4-8℃ and kept at a humidity of 20-30%RH for 48-50 hours to obtain precipitated crystals. The crystals were then washed 3-5 times with a 0-4℃ ethanol / acetone mixed solution, and then vacuum dried to obtain the core crystallization complex powder.

3. The preparation process of the aging-resistant sealing adhesive according to claim 2, characterized in that, S2: The preparation of the aging-resistant composite additive includes the following steps: S2.1: Add 1-2 parts by weight of hexadecyltrimethylammonium bromide to 120-140 parts by weight of 75wt% ethanol aqueous solution, then add 20-24 parts by weight of core crystallization complex powder at 2000-4000 rpm, and continue stirring for 20-30 min to obtain a suspension. Add 5-8 parts by weight of tetraethyl orthosilicate to 60-80 parts by weight of 75wt% ethanol aqueous solution, stir and mix to obtain a mixed solution. S2.2: Add 2-3 parts by weight of 25-28 wt% concentrated ammonia to the suspension at 30-35℃, then add the mixed solution dropwise over 2-3 hours. After the addition is complete, react at 30-35℃ for 12-16 hours. After the reaction is complete, add 2-4 parts by weight of γ-(methacryloyloxy)propyltrimethoxysilane at 30-35℃, then raise the temperature to 50-60℃ and react for 6-8 hours to obtain the reaction solution. S2.3: Centrifuge the reaction solution at 8000-10000 rpm for 10-12 min to obtain a precipitate. Then wash the precipitate 3-5 times with anhydrous ethanol and deionized water by alternating centrifugation. After drying at 60-62℃ for 20-24 h, pulverize it through a 400-mesh sieve to obtain the aging-resistant composite additive.

4. The preparation process of the aging-resistant sealing adhesive according to claim 3, characterized in that, S3: Preparation of aging-resistant sealing adhesive, specifically including the following steps: S3.1: Add 3-8 parts by weight of the anti-aging composite additive to 10-12 parts by weight of ethyl acetate, and then perform pulsed ultrasonic dispersion at 25-30℃ and 500-520W, with ultrasonic on for 2 seconds and off for 1 second, for a total time of 20-30 minutes, to obtain the pre-dispersion of the anti-aging composite additive. S3.2: Add 30-50 parts by weight of acrylate copolymer resin and 15-25 parts by weight of hydrogenated petroleum resin to the reactor, then start stirring at 50-100 rpm and introduce nitrogen gas, then add 10-20 parts by weight of ethyl acetate, and then stir and mix at 55-60℃ for 2-3 hours to obtain the base adhesive solution. S3.3: At 45-50℃, add the pre-dispersion of the aging-resistant composite additive to the base adhesive and stir for 20-30 minutes. Then, raise the temperature to 72-75℃ and add 2-3 parts by weight of inorganic nano-reinforcing filler in three portions over 15-20 minutes at 150-200 rpm. Then, stir at 100-150 rpm for 40-50 minutes. Then, add 2-3 parts by weight of inorganic nano-reinforcing filler in three portions over 15-20 minutes at 100-150 rpm. After the addition is complete, stir at 76-78℃ for 50-60 minutes to obtain the mixture. S3.4: Cool the mixture to 48-50℃, then add 0.5-1 parts by weight of leveling agent and 0.5-1 parts by weight of defoamer, stir and mix at 200-300 rpm for 2-3 hours, and then defoam at -0.09 MPa and room temperature for 30-40 minutes to obtain aging-resistant sealing adhesive.

5. The preparation process of the aging-resistant sealing adhesive according to claim 4, characterized in that, In step S3.3, the inorganic nano-reinforcing filler is nano-titanium dioxide.

6. The preparation process of the aging-resistant sealing adhesive according to claim 4, characterized in that, The leveling agent in step S3.4 is polyether-modified polydimethylsiloxane.

7. The preparation process of the aging-resistant sealing adhesive according to claim 4, characterized in that, The defoamer in step S3.4 is a polyether defoamer.

8. An aging-resistant sealing adhesive, characterized in that, It is prepared by the preparation process of an aging-resistant sealing adhesive as described in any one of claims 1-7.

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