High-strength high-adhesion two-component addition type silicone silica gel and preparation method thereof

Abstract

The application belongs to the technical field of organic silicon material, and particularly relates to a high-strength and high-adhesion two-component addition type organic silicon silica gel and a preparation method thereof. The high-strength and high-adhesion two-component addition type organic silicon silica gel comprises an A component and a B component. The A component comprises end-vinyl polydimethylsiloxane, reinforcing filler, adhesion promoter, plasticizer and inhibitor. The B component comprises end-vinyl polydimethylsiloxane, hydrogen-containing crosslinking agent, catalyst and reinforcing filler. The reinforcing filler comprises azide gas phase white carbon black, MQ silicon resin and carboxylated polysiloxane microspheres. In order to improve the problems of low strength and poor adhesion of the existing two-component addition type organic silicon silica gel, the two-component addition type organic silicon silica gel has high tensile strength, shear strength and elongation at break, realizes the unity of high strength and high elasticity, and has excellent bonding performance on aluminum base without primer.

Description

Technical Field

[0001] This application belongs to the field of organosilicon material technology, specifically relating to a high-strength, high-adhesion two-component addition-type organosilicon silicone and its preparation method. Background Technology

[0002] Addition-cure liquid silicone rubber (LSR), a high-grade silicone rubber developed in the late 1970s, has made significant progress in research, production, and application. Compared with condensation-type liquid silicone rubber, addition-cure liquid silicone rubber has many significant advantages. Due to its small molecular weight and low viscosity, it is extremely convenient to process and mold, eliminating cumbersome processes such as mixing, preforming, and finishing, and is easy to automate. Currently, addition-cure silicone rubber has been increasingly widely used in many industries such as electronics, machinery, automobiles, and construction, playing a particularly important role in applications such as potting, bonding, sealing, and structural bonding of electronic components.

[0003] In the field of organic polymer materials technology, common methods to solve the problems of traditional addition-cured silicone in application scenarios include adding tackifiers to improve the adhesion between silicone and the substrate, using modified resins to improve the strength of silicone, and using primers to treat the substrate surface to enhance the adhesion effect.

[0004] However, excessive addition of tackifiers can interfere with the platinum catalytic system, leading to poor curing or decreased storage stability. While modified resins can improve strength, they sacrifice processability, causing a sharp increase in viscosity and a decrease in elongation. Using primers to treat the substrate surface increases production steps and time, reducing production efficiency, and primers often use flammable solvents, posing transportation hazards and environmental pollution problems. Furthermore, conventional addition-cure silicone rubbers have poor adhesion, are prone to interfacial delamination, and have poor strength. Increasing the crosslinking density makes the material hard and brittle, making it difficult to balance high strength and high elasticity. Due to the diversity of contact substrates and the ever-increasing requirements for strength and adhesion, the development of addition-cure silicone rubbers with high strength and high adhesion has become an urgent need and a research hotspot in this field. Summary of the Invention

[0005] To address the issues of low strength and poor adhesion in existing two-component addition-curing silicone rubber, this application provides a high-strength, high-adhesion two-component addition-curing silicone rubber and its preparation method.

[0006] In a first aspect, this application provides a high-strength, high-adhesion two-component addition-curing silicone rubber, employing the following technical solution: A high-strength, high-adhesion two-component addition-type silicone rubber comprises component A and component B. Component A comprises the following raw materials in parts by weight: 40-60 parts of vinyl-terminated polydimethylsiloxane, 15-25 parts of reinforcing filler, 3-8 parts of adhesion promoter, 5-10 parts of plasticizer, and 0.01-0.05 parts of inhibitor. Component B comprises the following raw materials in parts by weight: 40-55 parts of vinyl-terminated polydimethylsiloxane, 10-20 parts of hydrogen-containing crosslinking agent, 0.5-2 parts of catalyst, and 20-30 parts of reinforcing filler. The reinforcing filler includes azid-modified fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres.

[0007] This application leverages the inherent characteristics of addition-type hydrosilylation reactions. The two-component system disperses functional components such as the base polymer, reinforcing filler, and crosslinking agent in phases A and B respectively, significantly improving room temperature storage stability. Furthermore, the system exhibits uniform dispersion after mixing components A and B, with no localized differences in crosslinking density. The Si-C covalent three-dimensional network structure formed through the hydrosilylation reaction, combined with the multi-element dispersion and flexible structure buffering of the reinforcing filler, effectively reduces crosslinking shrinkage stress during the curing process. This prevents substrate adhesion failure and colloid embrittlement caused by internal stress concentration. The cured colloid possesses both high mechanical strength and high elasticity, making it suitable for various applications requiring thermal elements and rapid industrial production.

[0008] In this system, azido-modified fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres are used as reinforcing fillers. Together with adhesion promoters, they enhance the strength and adhesion of the system. The azido-modified fumed silica retains the nano-inorganic rigid structure and high specific surface area of ​​fumed silica. The surface azido groups not only improve its interfacial compatibility with the silicone matrix but also form hydrogen bonds with the silanol groups in the MQ silicone resin molecules, strengthening the bond strength. This allows the organic toughness reinforcement effect of the MQ silicone resin to be transferred to the inorganic rigid reinforcing phase through these hydrogen bonds, mitigating the embrittlement effect caused by the inorganic filler reinforcement. This balances the system's strength and toughness, effectively preventing the silicone matrix molecular chains from detaching. Slippage and fracture under force significantly improve the tensile strength, shear strength, and tear resistance of the system, serving as the core structural support for the system's high strength. The carboxylated polysiloxane microspheres retain the flexible polysiloxane spherical structure, and the surface carboxyl groups further optimize their bonding with the matrix and other fillers. Their spherical structure can be embedded in the molecular gaps between azidized fumed silica and MQ silicone resin, achieving filling reinforcement while buffering curing stress. The three components combine to form a synergistic system of inorganic rigid reinforcement, organic toughness reinforcement, and flexible filling reinforcement, significantly improving the synergistic efficiency of the reinforcing fillers and laying a solid foundation for the system's high strength.

[0009] Meanwhile, the azide groups in azido-modified fumed silica and the carboxyl groups in carboxylated polysiloxane microspheres can interact with the functional groups of adhesion promoters, enabling the adhesion promoters to firmly bond to the surface of the reinforcing filler system. This allows the reinforcing filler system to transfer high strength to the substrate-silicone interface, improving the cohesive strength of the interface bonding area and preventing insufficient interface strength from affecting peel performance. At the same time, the nano-rigid structure of azido-modified fumed silica can act as a physical support for the adhesion promoter at the interface, reducing the interface migration of the adhesion promoter and strengthening its anchoring effect with the substrate. The adhesion promoter, through its own substrate anchoring functional groups, interacts with the substrate, achieving a synergistic improvement in system strength and interface adhesion, ensuring the controllability and storage stability of the organosilicon silicone system.

[0010] Preferably, the preparation method of the adhesion promoter includes the following steps: under nitrogen protection, cyclohexane is added sequentially to octamethylcyclotetrasiloxane, 3-glycidyl etheroxypropyltriethoxysilane, methyltrimethoxysilane, and acetoxypropyltrimethoxysilane and stirred, then tetramethylammonium hydroxide is added and reacted at 75-85℃ for 3-5 hours, and then cooled to room temperature to obtain an organosilane copolymer, i.e., the adhesion promoter.

[0011] More preferably, the mass ratio of octamethylcyclotetrasiloxane to 3-glycidyl etheroxypropyltriethoxysilane is (3.5-4):1.

[0012] The adhesion promoter is formed as a linear organosilane copolymer with polydimethylsiloxane as the main chain and epoxy, alkoxy, and acetoxy groups oriented grafted onto the side chains and end groups. The polydimethylsiloxane main chain and the vinyl-terminated polydimethylsiloxane of the silicone matrix are homologous structures with excellent compatibility, forming good chain entanglement with the matrix. The epoxy, alkoxy, and acetoxy groups give the adhesion promoter high compatibility with the silicone matrix. At the same time, the siloxane structure in its molecule can form a weak interaction with the hydrogen-containing crosslinking agent, helping to improve the uniformity of the crosslinking network of the matrix and avoiding stress concentration caused by excessive local crosslinking density. Its flexible main chain can also buffer the crosslinking shrinkage stress generated during hydrosilylation curing, reduce the internal stress of the system, and improve the toughness and elongation at break of the matrix, preventing the system from becoming embrittled due to the pursuit of high strength. Combined with the flexible filling effect of the reinforcing filler, it further improves the elastic recovery ability and tear resistance of the system, allowing the system to maintain excellent elongation at break and toughness while maintaining high tensile strength.

[0013] The epoxy and alkoxy groups in adhesion promoters can interact with hydroxyl groups on the surface of substrates such as metals, ceramics, and nanocrystalline ribbons to achieve a strong bond between silicone and the substrate, significantly improving the interfacial bonding strength. The acetoxy groups in adhesion promoters can also form hydrogen bonds with the azido groups on the surface of azidized fumed silica, enhancing the cohesive strength of the interfacial bonding region. Through adhesion promoters, the reinforcing effect of silicone is transferred to the interface, and reinforcing fillers provide physical support and structural assurance for the interfacial anchoring of the adhesion promoter. Ultimately, this achieves a synergistic improvement in the high strength, high toughness, low internal stress of silicone, and high interfacial adhesion, giving the two-component addition-curing silicone excellent mechanical and adhesive properties. However, if the octamethylcyclotetrasiloxane content is too low, insufficient main chain flexibility will increase the internal stress of the system, reduce toughness and elongation at break, and affect the stability and durability of the interfacial bond.

[0014] Preferably, the preparation method of azidized fumed silica includes: dispersing fumed silica in toluene, adding 3-azidopropyltrimethoxysilane, refluxing at 70-80℃ for 4-6 hours, centrifuging, washing, and drying to obtain azidized fumed silica.

[0015] Preferably, the preparation of carboxylated polysiloxane microspheres includes: dispersing polysiloxane microspheres in tetrahydrofuran, adding 3-carboxypropyltriethoxysilane, refluxing at 55-65℃ for 4-8 hours, centrifuging, washing, and drying to obtain carboxylated polysiloxane microspheres.

[0016] Preferably, the mass ratio of azidized fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres is (3-5):(0.8-1.2):(1-2).

[0017] The three types of reinforcing fillers achieve rigid, tough, and flexible reinforcement effects, significantly improving the synergistic efficiency of the compound reinforcing fillers and laying a solid foundation for the high strength of the system. If the content of azidized fumed silica is too low, its nano-rigid structure provides insufficient reinforcement, and steric hindrance reinforcement is inadequate, leading to a significant decrease in the tensile and shear strength of the silica gel. Simultaneously, its interaction with adhesion promoters weakens, reducing interfacial cohesive strength and affecting high adhesion performance. Conversely, if the content of carboxylated polysiloxane microspheres is too high, excessive flexible microspheres tend to aggregate, increasing internal stress and reducing elongation at break and toughness.

[0018] Preferably, the catalyst is selected from one or more of chloroplatinic acid, modified platinum complex, and platinum tetrachloride.

[0019] Preferably, the hydrogen-containing silicone oil is a methyl hydrogen-containing silicone oil with a hydrogen content of 0.5-1%.

[0020] Secondly, this application provides a method for preparing a high-strength, high-adhesion two-component addition-type silicone rubber, using the following technical solution: A method for preparing a high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: Add terminal vinyl polydimethylsiloxane, reinforcing filler, adhesion promoter, plasticizer and inhibitor to a planetary mixer in proportion and stir and mix, and then vacuum stir and degas to obtain component A; (2) Preparation of component B: Add terminal vinyl polydimethylsiloxane, hydrogen-containing crosslinking agent, catalyst and reinforcing filler to the mixture and then vacuum stir and degas to obtain component B; (3) Mix component A and component B evenly, and then vacuum remove all bubbles to obtain a high-strength, high-adhesion two-component addition-type silicone silicone.

[0021] Preferably, the mixing is carried out at a speed of 30-40 rpm for 10-20 minutes.

[0022] In summary, this application has the following beneficial effects: 1. This application relies on the inherent characteristics of addition-type hydrosilylation reaction. The two-component system disperses functional components such as the base polymer, reinforcing filler, and crosslinking agent in phases A and B, respectively. The Si-C covalent three-dimensional network structure formed by the hydrosilylation reaction significantly improves room temperature storage stability. Combined with the multi-element dispersion filling of the reinforcing filler and the flexible structure buffer, it effectively reduces the crosslinking shrinkage stress during the curing process, avoiding substrate adhesion failure and colloid embrittlement caused by internal stress concentration. The colloid formed after curing has both high mechanical strength and high elasticity, which is suitable for different application requirements of thermal elements and rapid industrial production.

[0023] 2. The three reinforcing fillers, namely azidized fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres, provide rigid reinforcement, toughness reinforcement, and flexible filling reinforcement, significantly improving the synergistic effect efficiency of the compound reinforcing fillers. This lays a solid filler foundation for the high strength of the system and enhances the stability and durability of the silicone. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the embodiments.

[0025] raw material Some of the raw materials used in the preparation examples and embodiments: Vinyl-terminated polydimethylsiloxane, SiSiB® VF6030-1000; hydrogen-containing crosslinking agent, methyl hydrogen silicone oil, HMS-151 Dow Corning; modified platinum complex, Karstedt-Cat-300; inhibitor, 1-ethynylcyclohexanol; fumed silica, AEROSIL 200 Evonik Industries; MQ silicone resin, vinylphenyl MQ silicone resin purchased from Hubei Yamed Biomedical Co., Ltd.; polysiloxane microspheres, polymethylsilsesquioxane purchased from Hubei Langbowan Biomedical Co., Ltd.; plasticizer, polydimethylsiloxane (100cs). Unless otherwise specified, all raw materials used in the examples and comparative examples are commercially available products.

[0026] Preparation Example 1 Preparation of adhesion promoter: Under nitrogen protection, 100 parts of cyclohexane were added sequentially to 40 parts of octamethylcyclotetrasiloxane, 10 parts of 3-glycidyl etheroxypropyltriethoxysilane, 7 parts of methyltrimethoxysilane, and 8 parts of acetoxypropyltrimethoxysilane. The mixture was stirred at 350 r / min at room temperature for 20 min. Then, 0.4 parts of tetramethylammonium hydroxide were added and reacted at 75℃ for 4 h. The temperature was raised to 110℃, the vacuum was adjusted to -0.099 MPa, and the mixture was kept at a constant temperature for 4 h. The mixture was then cooled to room temperature to obtain an organosilane copolymer, i.e., the adhesion promoter.

[0027] Preparation Example 2 Preparation of adhesion promoter: Under nitrogen protection, 100 parts of cyclohexane were added sequentially to 30 parts of octamethylcyclotetrasiloxane, 20 parts of 3-glycidyl etheroxypropyltriethoxysilane, 7 parts of methyltrimethoxysilane, and 8 parts of acetoxypropyltrimethoxysilane. The mixture was stirred at 350 r / min at room temperature for 20 min. Then, 0.4 parts of tetramethylammonium hydroxide were added and reacted at 75℃ for 4 h. The temperature was raised to 110℃, the vacuum was adjusted to -0.099 MPa, and the mixture was kept at a constant temperature for 4 h. The mixture was then cooled to room temperature to obtain an organosilane copolymer, i.e., the adhesion promoter.

[0028] Preparation Example 3 Preparation of adhesion promoter: Under nitrogen protection, 100 parts of cyclohexane were added sequentially to 45 parts of octamethylcyclotetrasiloxane, 5 parts of 3-glycidyl etheroxypropyltriethoxysilane, 7 parts of methyltrimethoxysilane, and 8 parts of acetoxypropyltrimethoxysilane. The mixture was stirred at 350 r / min at room temperature for 20 min. Then, 0.4 parts of tetramethylammonium hydroxide were added and reacted at 75℃ for 4 h. The temperature was raised to 110℃, the vacuum was adjusted to -0.099 MPa, and the mixture was kept at a constant temperature for 4 h. The mixture was then cooled to room temperature to obtain an organosilane copolymer, i.e., the adhesion promoter.

[0029] Preparation Example 4 Preparation of fumed silica by azidation: Take 100 parts of fumed silica, add 200 parts of dry toluene, ultrasonically disperse for 30 min, add 5 parts of 3-azidopropyltrimethoxysilane, stir and heat to 80℃ for 4 h, centrifuge to separate, wash 3 times with anhydrous toluene, and vacuum dry at 80℃ for 6 h to obtain fumed silica by azidation.

[0030] Preparation Example 5 Preparation of carboxylated polysiloxane microspheres: 100 parts of polysiloxane microspheres were added to 200 parts of tetrahydrofuran and ultrasonically dispersed for 20 min. 6 parts of 3-carboxypropyltriethoxysilane were added and the mixture was heated to 60℃ and reacted for 5 h. After centrifugation, the microspheres were washed three times with anhydrous tetrahydrofuran and vacuum dried at 70℃ for 8 h to obtain carboxylated polysiloxane microspheres. Example 1

[0031] A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4, MQ silicone resin, and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 3:1:1.5. Example 2

[0032] A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 2, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4, MQ silicone resin, and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 3:1:1.5. Example 3

[0033] A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 3, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4, MQ silicone resin, and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 3:1:1.5. Example 4

[0034] A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4, MQ silicone resin, and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 2.5:1:2. Example 5

[0035] A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4, MQ silicone resin, and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 2:1:2.5.

[0036] Comparative Example 1 A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing filler was fumed silica and MQ silicone resin in a mass ratio of 3:1:1.5, and the carboxylated polysiloxane microspheres prepared in Example 5 were used.

[0037] Comparative Example 2 A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing filler was prepared in Example 4 with a mass ratio of 3:1:1.5, consisting of azidized fumed silica, MQ silicone resin, and polysiloxane microspheres.

[0038] Comparative Example 3 A high-strength, high-adhesion two-component addition-type silicone rubber comprises the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuum removal of bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone rubber. The reinforcing filler is azidized fumed silica and MQ silicone resin prepared in Preparation Example 4 at a mass ratio of 3:2.5.

[0039] Comparative Example 4 A high-strength, high-adhesion two-component addition-type silicone silicone includes the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring and degassing are then performed to obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuuming to remove air bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone silicone. The reinforcing fillers were azidized fumed silica prepared in Preparation Example 4 and carboxylated polysiloxane microspheres prepared in Preparation Example 5, with a mass ratio of 4:1.5.

[0040] Comparative Example 5 A high-strength, high-adhesion two-component addition-type silicone rubber comprises the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuum removal of bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone rubber. The reinforcing filler is MQ silicone resin with a mass ratio of 4:1.5 and carboxylated polysiloxane microspheres prepared in Preparation Example 5.

[0041] Comparative Example 6 A high-strength, high-adhesion two-component addition-type silicone rubber comprises the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuum removal of bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone rubber. The reinforcing filler is azidized fumed silica prepared in Preparation Example 4.

[0042] Comparative Example 7 A high-strength, high-adhesion two-component addition-type silicone rubber comprises the following steps: (1) Preparation of component A: 55 parts of vinyl-terminated polydimethylsiloxane, 20 parts of reinforcing filler, 6 parts of adhesion promoter prepared in Preparation Example 1, 5 parts of plasticizer, and 0.05 parts of inhibitor are added to a planetary mixer and stirred at 40 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component A; (2) Preparation of component B: 40 parts of vinyl-terminated polydimethylsiloxane, 12 parts of hydrogen-containing crosslinking agent, 1 part of catalyst, and 20 parts of reinforcing filler are stirred at 30 rpm for 20 min. Vacuum stirring is then performed to remove bubbles and obtain component B; (3) Component A and component B are mixed and stirred evenly at a mass ratio of 1:1. After vacuum removal of bubbles, the mixture is cured at room temperature for 24 h to obtain a high-strength, high-adhesion two-component addition-type silicone rubber. The reinforcing filler is MQ silicone resin.

[0043] The performance of the high-strength, high-adhesion two-component addition-curing silicone rubbers prepared in Examples 1-5 and Comparative Examples 1-7 was tested using the following methods: a. Shear strength: The shear strength between aluminum and aluminum was tested in accordance with GB / T 7124-2008; b. Adhesion test: Refer to GB / T 13477.18-2002 for the test of peel adhesion. The sealant layer formed by curing the silicone silicone in the comparative example is cut and peeled off from the test substrate with a blade. If the silicone silicone adheres firmly to the test substrate, the adhesive interface does not fall off and the cohesive failure is considered as qualified. c. Tensile strength and elongation at break: Tested according to GB / T 528-2009; properties are shown in Table 1: Table 1 Performance Test Results

[0044] As shown in Table 1, the elongation at break in the examples was 320-350%, the tensile strength was 1.9-2.5 MPa, and the aluminum shear strength was 2.2-2.8 MPa, demonstrating excellent adhesion to aluminum substrates without a primer. Comparing Examples 1-3, analysis suggests that the adhesion promoter facilitated the transfer of the silicone's reinforcing effect to the interface. The reinforcing filler provided physical support and structural assurance for the interface anchoring of the adhesion promoter, ultimately achieving a synergistic improvement in the silicone's high strength, high toughness, low internal stress, and high interfacial adhesion. The two-component addition-cured silicone exhibits both excellent mechanical and adhesive properties. If the octamethylcyclotetrasiloxane content is too low, insufficient main chain flexibility will increase the internal stress of the system, reduce toughness and elongation at break, and affect the stability and durability of the interfacial adhesion.

[0045] Comparing Examples 1 and 4-5 with Comparative Examples 1-7, it can be seen that the three reinforcing fillers achieve rigid reinforcement, toughness reinforcement, and flexible filling reinforcement effects, significantly improving the synergistic efficiency of the compound reinforcing fillers and laying a solid foundation for the high strength of the system. However, if the content of azidized fumed silica is too low, its nano-rigid structure reinforcement effect is insufficient, and steric hindrance reinforcement is inadequate, leading to a significant decrease in the tensile and shear strength of the silica gel. Simultaneously, its interaction with the adhesion promoter is weakened, and the interfacial cohesive strength decreases, affecting high adhesion performance.

[0046] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A high-strength, high-adhesion two-component addition-curing silicone rubber, characterized in that: The high-strength, high-adhesion two-component addition-type silicone rubber comprises component A and component B. Component A comprises the following raw materials in parts by weight: 40-60 parts of vinyl-terminated polydimethylsiloxane, 15-25 parts of reinforcing filler, 3-8 parts of adhesion promoter, 5-10 parts of plasticizer, and 0.01-0.05 parts of inhibitor. Component B comprises the following raw materials in parts by weight: 40-55 parts of vinyl-terminated polydimethylsiloxane, 10-20 parts of hydrogen-containing crosslinking agent, 0.5-2 parts of catalyst, and 20-30 parts of reinforcing filler. The reinforcing filler includes azid-modified fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres.

2. The high-strength, high-adhesion two-component addition-curing silicone rubber according to claim 1, characterized in that: The preparation method of the adhesion promoter includes the following steps: under nitrogen protection, cyclohexane is added sequentially to octamethylcyclotetrasiloxane, 3-glycidyl etheroxypropyltriethoxysilane, methyltrimethoxysilane, and acetoxypropyltrimethoxysilane and stirred, then tetramethylammonium hydroxide is added and reacted at 75-85℃ for 3-5 hours, and then cooled to room temperature to obtain an organosilane copolymer, i.e., the adhesion promoter.

3. The high-strength, high-adhesion two-component addition-curing silicone rubber according to claim 2, characterized in that: The mass ratio of the octamethylcyclotetrasiloxane to 3-glycidyl etheroxypropyltriethoxysilane is (3.5-4):

1.

4. The high-strength, high-adhesion two-component addition-curing silicone rubber according to claim 1, characterized in that: The mass ratio of the azidized fumed silica, MQ silicone resin, and carboxylated polysiloxane microspheres is (3-5):(0.8-1.2):(1-2).

5. The high-strength, high-adhesion two-component addition-curing silicone rubber according to claim 1, characterized in that: The catalyst is selected from one or more of chloroplatinic acid, modified platinum complex, and platinum tetrachloride.

6. The high-strength, high-adhesion two-component addition-curing silicone rubber according to claim 1, characterized in that: The hydrogen-containing silicone oil is a methyl hydrogen-containing silicone oil with a hydrogen content of 0.5-1%.

7. The method for preparing the high-strength, high-adhesion two-component addition-type silicone rubber according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Preparation of component A: Add vinyl-terminated polydimethylsiloxane, reinforcing filler, adhesion promoter, plasticizer and inhibitor to a planetary mixer according to the proportion and stir and mix. Vacuum stirring and degassing are used to obtain component A; (2) Preparation of component B: Add vinyl-terminated polydimethylsiloxane, hydrogen-containing crosslinking agent, catalyst and reinforcing filler to a mixture and stir and mix. Vacuum stirring and degassing are used to obtain component B; (3) Mix component A and component B evenly and vacuum to remove bubbles to obtain a high-strength and high-adhesion two-component addition-type silicone silicone.

8. The method for preparing high-strength, high-adhesion two-component addition-type silicone rubber according to claim 7, characterized in that: The mixing process involves stirring at a speed of 30-40 rpm for 10-20 minutes.

Images