A high-displacement, aging-resistant, deacidifying room-temperature vulcanizing silicone rubber and its preparation method

Abstract

This invention relates to the field of silicone rubber sealing materials technology, and discloses a high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber and its preparation method. The raw materials of this silicone rubber, by mass, include 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10-20 parts of reactive plasticizer, 5-30 parts of fumed silica, 2-4 parts of acidic chain extender, 2-4 parts of crosslinking agent, 0.5-5 parts of composite additives, 0.5-1 part of antioxidant, and 0.01-1 part of catalyst. This technical solution solves the problem of insufficient tensile displacement resistance due to thermal expansion and contraction in current glass sealant products on the market, ensuring stable performance after aging under harsh environmental conditions. It can be used as a sealing material for bonding large-pane glass in buildings, aquariums, and other glass applications, and has broad application prospects.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber sealing materials technology, specifically to a high displacement, aging-resistant, deacidifying room temperature vulcanizing silicone rubber and its preparation method. Background Technology

[0002] Glass construction is a growing trend in the construction industry, and the bonding of glass requires specialized glass adhesives to ensure a stable bond. Currently, there are many types of glass adhesives on the market, chemically classified into acidic, neutral, and alkaline adhesives, each with its own limitations. Neutral adhesives are chemically mild and suitable for sealing glass mirrors and aluminum-plastic composites. Alkaline adhesives, also known as stone-specific adhesives, are compatible with alkaline materials such as stone, cement, concrete, and ceramics; neither of these two types is suitable for bonding glass. A typical acidic adhesive, deacetic acid type single-component RTV silicone rubber, while having an irritating odor and some corrosiveness to metals, exhibits excellent adhesion to glass and other materials, demonstrating superior bonding strength and resistance to detachment in practical applications.

[0003] Due to the personalized development of the modern construction industry, aquarium products such as large-pane glass, skylights, oceanariums, and glass fish tanks are constantly emerging. Under different environmental conditions such as temperature and ultraviolet radiation, higher requirements are placed on the aging resistance, high strength, and high displacement capacity of glass sealant products.

[0004] Chinese patent CN201510880999.8 discloses a water-resistant, single-component, deacidifying silicone sealant composition and its preparation method. This method uses α,ω-dihydroxypolysiloxane, polydimethylsiloxane, a crosslinking agent, a catalyst, a waterproofing agent, and a tackifier as raw materials to synthesize the sealant. Although the product exhibits excellent water resistance, its resistance to displacement, which is required by specific applications, cannot meet the needs of practical applications. In situations where the bonding of glass in aquariums and marine life involves expansion, contraction, or shear deformation, this sealant cannot provide an effective seal. Therefore, there is an urgent need to develop a sealant with stronger resistance to displacement to meet the requirements of practical applications. Summary of the Invention

[0005] The present invention aims to provide a high displacement, aging-resistant, deacidifying room temperature vulcanizing silicone rubber and its preparation method, so as to solve the problem that the displacement resistance and post-aging stability of existing glass sealant products cannot meet the needs of practical applications.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a high displacement, aging-resistant, deacidifying room temperature vulcanizing silicone rubber, the raw materials, by mass, include 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10-30 parts of reactive plasticizer, 5-30 parts of fumed silica, 2-4 parts of acidic chain extender, 2-4 parts of crosslinking agent, 0.5-5 parts of composite additives, 0.5-1 parts of antioxidant, and 0.01-1 parts of catalyst.

[0007] Preferably, as an improvement, the mass parts of each raw material are: 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10-20 parts of reactive plasticizer, 15-20 parts of fumed silica, 2-4 parts of acidic chain extender, 2-4 parts of crosslinking agent, 0.8-2 parts of composite additive, 0.5-1 part of antioxidant, and 0.1-0.5 parts of catalyst.

[0008] In this technical solution, research has shown that the amount of each raw material added to the high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber has a crucial impact on its performance, and the relationship between the amount of raw material added and the performance of the silicone rubber is non-linear. Specifically, too little fumed silica will lead to thixotropic deviation, insufficient strength and modulus; too much will cause tensile strength to exceed adhesive strength, leading to bond failure, and will also result in excessive extrudability, poor workability, and affecting use. Too little acidic chain extender will not achieve the desired effect, while too much will cause the product to become sticky and have poor workability after storage, affecting product use.

[0009] Preferably, as an improvement, the viscosity of α,ω-dihydroxypolydimethylsiloxane is 40,000-80,000 mPa·s.

[0010] In this technical solution, excessive viscosity of α,ω-dihydroxypolydimethylsiloxane will lead to poor product workability and negate the purpose of chain extension; excessive viscosity will affect the effect after chain extension and fail to achieve the expected strength.

[0011] Preferably, as an improvement, the reactive plasticizer is an organosilicon oil, and the viscosity of the reactive plasticizer is 100-500 mPa·s.

[0012] In this technical solution, by selecting organosilicone oil as the reactive plasticizer, the risk of migration during long-term storage can be reduced compared to using conventional dimethyl silicone oil.

[0013] Preferably, as an improvement, the fumed silica is a hydrophilic fumed silica silica with a specific surface area of ​​150 to 200.

[0014] In this technical solution, if the specific surface area of ​​fumed silica is too small, its thixotropic properties will be poor, while if the specific surface area is too large, it will affect its construction performance and use.

[0015] Preferably, as an improvement, the acidic chain extender is at least one of di-tert-butoxydiacetoxysilane, methylvinyldiacetoxysilane, and dimethyldiacetoxysilane.

[0016] Preferably, as an improvement, the composite additive is a mixture of a crosslinking agent and a coupling agent in a molar ratio of 1:1. The crosslinking agent is at least one of methyltriacetoxysilane, ethyltriacetoxysilane, and propyltriacetoxysilane; the coupling agent is at least one of octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, and hexadecyltriethoxysilane.

[0017] In this technical solution, the selected coupling agent has a certain degree of waterproofing and excellent adhesion. This product is used for bonding aquariums, maintaining excellent adhesion even after prolonged immersion in water. However, the compatibility of this coupling agent in acidic adhesives is relatively poor. Therefore, this technical solution optimizes the type and amount of crosslinking agent by compounding it. A 1:1 compounding ratio was found to improve compatibility, resulting in excellent aging resistance and water resistance of the composite additive. The crosslinking agent mainly reacts with hydroxyl-terminated polydimethylsiloxane. Excessive crosslinking agent addition, with some not participating in the reaction, can lead to stickiness after storage and affect deep curing; insufficient crosslinking agent addition will affect the product's shelf life.

[0018] In this technical solution, the composition of the composite additives is optimized. When the crosslinking agent and coupling agent are compounded in a 1:1 molar ratio, their compatibility can be guaranteed. In addition, to further improve their compatibility, this technical solution performs reflux treatment after compounding to allow them to undergo an initial reaction in advance, while also achieving an adhesive effect, improving the product's storage stability, and avoiding the problem of surface stickiness that may occur when the product is stored for too long.

[0019] Preferably, as an improvement, the antioxidant is at least one of liquid oxidants 1520, 1500, 1135, and 1613; and the catalyst is at least one of dibutyltin dilaurate, dimethyl dinedecanoate, dibutyltin diacetate, and tetraisopropyl titanate.

[0020] Preferably, as an improvement, a method for preparing a high-displacement, aging-resistant, deacidifying room-temperature vulcanizing silicone rubber includes the following steps:

[0021] S1: α,ω-dihydroxypolydimethylsiloxane and chain extender are stirred under vacuum to extend the chain and obtain mixture A;

[0022] S2: Add crosslinking agent and composite additive to mixture A, stir under vacuum conditions to obtain mixture B;

[0023] S3: After adding fumed silica to mixture B and dispersing it evenly, stir under vacuum conditions to obtain mixture C;

[0024] S4: After the reactive plasticizer, antioxidant, and catalyst are mixed evenly, they are added to mixture C and stirred under a vacuum of -0.08 to -0.095 MPa to obtain high displacement, aging-resistant, deacidified room temperature vulcanizing silicone rubber.

[0025] Preferably, as an improvement, in steps S1-S3, the vacuum degree is -0.08 to -0.095 MPa; in step S3, the fumed silica is dried at 120°C for 3 hours before use to remove moisture.

[0026] In this technical solution, since hydrophilic fumed silica has strong water absorption properties, it will absorb some water during storage. By performing water removal treatment, the product performance can be guaranteed.

[0027] The principle and advantages of this solution are as follows: In practical applications, large aquariums in the aquarium industry have high water pressure, which places high demands on the strength of silicone sealant products. Long-term thermal expansion and contraction also impose high requirements on the product's toughness and elongation. Furthermore, the long-term immersion of aquariums in water also places high demands on adhesion. The harsh environment of aquariums further complicates the adhesion requirements of silicone sealant products after aging and UV exposure. This technical solution addresses the problem that existing silicone sealant products cannot meet the actual application needs for displacement resistance, making them difficult to use in aquarium products. The inventors have comprehensively optimized the formula and preparation process of the silicone sealant product. By using an acidic chain extender, the organosilicon product of α,ω-dihydroxypolydimethylsiloxane is pre-reacted, reducing the product's modulus and improving its displacement resistance. Fumed silica is used to enhance the product's strength, and crosslinking agents, composite additives, and antioxidants are used to improve overall adhesion and UV oxidation resistance. In the optimization of the composite additives, a less commonly used coupling agent was added. The synergistic effect of the crosslinking agent and the coupling agent improved compatibility, resulting in excellent aging resistance and water immersion resistance of the composite additives. Furthermore, this technical solution, by adding an antioxidant, was found to not only possess traditional antioxidant properties but also promote product stability after aging, achieving unexpected technical effects. In the preparation process, this solution, while meeting the initial requirements for workability, involves temperature-controlled chain extension of the product. In S1, the addition of a reactive plasticizer can reduce the product's modulus while inhibiting exudation, further improving the product's displacement capacity (ordinary methyl silicone oil slowly exudes colloids over time). The high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber prepared by this technical solution exhibits good thixotropy and workability; after curing, it possesses high strength and displacement resistance, good elastic recovery rate, and excellent adhesive stability and weather resistance, ensuring the safety and service life of buildings. Furthermore, this high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber exhibits excellent chemical stability, weather resistance, thixotropy, and workability. Testing showed that the silicone rubber prepared using this method exhibited a sag of 0% according to GB / T13477.6.2002, an elastic recovery rate ≥80% according to GB / T14683-2017, no damage under water and UV adhesion according to GB / T 13477.8, and a high-temperature immersion temperature ≤10°C according to T / FSI 015-2019. This technical solution solves the problem of insufficient tensile displacement resistance due to thermal expansion and contraction in current market glass sealant products, ensuring stable performance after aging under harsh environmental conditions. It can be used as a sealing material for large-pane architectural glass, aquariums, and other glass applications, showing broad application prospects. Detailed Implementation

[0028] The following detailed description provides further details on specific embodiments, but the embodiments of the present invention are not limited thereto. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art; the experimental methods used are all conventional methods; and the materials and reagents used are all commercially available.

[0029] Overview of the plan:

[0030] A high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber, comprising, by weight, 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10-30 parts of reactive plasticizer, 5-30 parts of fumed silica, 2-4 parts of acidic chain extender, 2-4 parts of crosslinking agent, 0.5-5 parts of composite additives, 0.5-1 part of antioxidant, and 0.01-1 part of catalyst.

[0031] The viscosity of α,ω-dihydroxypolydimethylsiloxane is 40,000-80,000 mPa·s.

[0032] Reactive plasticizers include silicone oils and / or siloxanes with a viscosity of 100-500 mPa·s. Examples include M99 silicone oil (a silicone oil with a siloxane main chain and epoxy groups in the side chains); and 203 silicone oil (a siloxane with a siloxane main chain, one end being a hydroxyl group and the other end being a methyl group). The viscosity of reactive plasticizers is 100-500 mPa·s.

[0033] Fumed silica is a hydrophilic fumed silica silica with a specific surface area of ​​150-200, and it is dried at 120°C for 3 hours before use to remove moisture.

[0034] The acidic chain extender is at least one of di-tert-butoxydiacetoxysilane, methylvinyldiacetoxysilane, and dimethyldiacetoxysilane.

[0035] The crosslinking agent is at least one of methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, and vinyltriacetoxysilane.

[0036] The composite additive is a mixture of a crosslinking agent and a coupling agent in a 1:1 molar ratio. The crosslinking agent is at least one of methyltriacetoxysilane, ethyltriacetoxysilane, and propyltriacetoxysilane; the coupling agent is at least one of octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, and hexadecyltriethoxysilane. Too much or too little crosslinking agent and coupling agent will affect the uniformity of the composite additive. Too much coupling agent will lead to a longer surface drying time after storage, affecting the use of the product.

[0037] The preparation method of the composite additive is as follows: crosslinking agent and coupling agent are refluxed at 80℃ for 2 hours in a molar ratio of 1:1, and then cooled and allowed to stand.

[0038] The antioxidant is at least one of the liquid oxidants 1520, 1500, 1135, and 1613.

[0039] The catalyst is at least one of dibutyltin dilaurate, dimethyl dinedecanoate, dibutyltin diacetate, and tetraisopropyl titanate.

[0040] A method for preparing a high-displacement, aging-resistant, deacidification-resistant room-temperature vulcanizing silicone rubber includes the following steps:

[0041] S1: α,ω-dihydroxypolydimethylsiloxane and chain extender were stirred at 35±5℃ and a vacuum of -0.08 to -0.095MPa for 80 min to obtain mixture A;

[0042] S2: Add crosslinking agent and composite additive to mixture A, and stir for 30 min under a vacuum of -0.08 to -0.095 MPa to obtain mixture B;

[0043] S3: After adding fumed silica to mixture B and dispersing it evenly, stir it for 10 minutes under a vacuum of -0.08 to -0.095 MPa to obtain mixture C; wherein, the fumed silica is dried at 120°C for 3 hours before use to remove moisture.

[0044] S4: After the reactive plasticizer, antioxidant, and catalyst are mixed evenly, they are added to mixture C and stirred for 30 minutes under a vacuum of -0.08 to -0.095 MPa to obtain high displacement aging-resistant deacidified room temperature vulcanizing silicone rubber.

[0045] Example 1

[0046] A high-displacement, aging-resistant, deacidified room-temperature vulcanizing silicone rubber, the raw materials, by weight, include 100 parts of α,ω-dihydroxypolydimethylsiloxane, 10 parts of reactive plasticizer, 15 parts of fumed silica, 2 parts of acidic chain extender, 2 parts of crosslinking agent, 0.8 parts of composite additives, 0.5 parts of antioxidant, and 0.5 parts of catalyst.

[0047] A method for preparing a high-displacement, aging-resistant, deacidification-resistant room-temperature vulcanizing silicone rubber includes the following steps:

[0048] S1: 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 40000 mPa.s and 2 parts of chain extender di-tert-butoxydiacetoxysilane were stirred under vacuum at 35±5℃ for 80 min to obtain mixture A.

[0049] S2: Add 2 parts of crosslinking agent propyltriacetoxysilane and 0.8 parts of composite additive to mixture A, and stir under vacuum at a degree of -0.08 to -0.095 MPa for 30 minutes to obtain mixture B. In this example, the composite additive is propyltriacetoxysilane and octyltrimethoxysilane compounded in a molar ratio of 1:1.

[0050] S3: Add 15 parts of hydrophilic silica with a specific surface area of ​​150 to mixture B and disperse evenly. Then, stir under vacuum at a pressure of -0.08 to -0.095 MPa for 10 minutes to obtain mixture C. The hydrophilic silica is dried at 120°C for 3 hours before use to remove moisture. The main purpose is to remove moisture from the filler and improve the production efficiency and shelf life of the product.

[0051] S4: Add 10 parts of reactive plasticizer M99 silicone oil, 0.5 parts of oxidant 1520, and 0.5 parts of catalyst dibutyltin dilaurate. Mix them evenly and then add them to mixture C. Stir under vacuum at a pressure of -0.08 to -0.095 MPa for 30 minutes to obtain high displacement aging resistant deacidification type room temperature vulcanizing silicone rubber.

[0052] Note: "Vacuum-assisted mixing (stirring)" and "vacuum-controlled mixing (stirring)" are standard operating procedures in this technical field. "Vacuum-controlled mixing" refers to closing the vacuum valve after reaching a vacuum level of -0.08 to -0.095 MPa. Because the product solidifies with moisture in the air, mixing of the materials in the equipment is required under these conditions, ensuring that the vacuum level does not drop below -0.06 MPa during mixing. This vacuum-controlled operation is specifically performed to prevent the chain extender from being removed and to ensure complete reaction. "Vacuum-assisted mixing" refers to stirring and mixing under these conditions after reaching a vacuum level of -0.08 to -0.095 MPa without closing the vacuum valve.

[0053] Examples 2-6 are embodiments of the present invention. The difference between each embodiment and Example 1 lies in some raw material components and the amount added, as detailed in Table 1. In this example, "α,ω-dihydroxypolydimethylsiloxane 40,000107" refers to α,ω-dihydroxypolydimethylsiloxane with a viscosity of 40,000 mPa·s.

[0054] Table 1

[0055]

[0056] Comparative Examples 1-5 are comparative examples of the present invention. The difference between each comparative example and Example 1 lies in the composition and amount of some raw materials. For details, please refer to Table 2. Note: The hydrophilic silica in Comparative Example 4 was not subjected to high-temperature drying at 120°C for 3 hours before use.

[0057] Table 2

[0058]

[0059]

[0060] Taking Comparative Example 1 as an example, the preparation method of high displacement, aging-resistant, deacidification-resistant room temperature vulcanizing silicone rubber is described in detail:

[0061] A high displacement, aging-resistant, deacidified room temperature vulcanizing silicone rubber, the raw materials, by weight, include 100 parts of α,ω-dihydroxy polydimethylsiloxane, 15 parts of reactive plasticizer, 18 parts of fumed silica, 3 parts of acidic chain extender, 3 parts of crosslinking agent, 2 parts of composite additives, 0.5 parts of antioxidant, and 0.1 parts of catalyst.

[0062] A method for preparing a high-displacement, aging-resistant, deacidification-resistant room-temperature vulcanizing silicone rubber includes the following steps:

[0063] S1: 100 parts of α,ω-dihydroxy polydimethylsiloxane with a viscosity of 500,000 mPa.s and 3 parts of chain extender methyl vinyl diacetoxysilane were stirred under vacuum at 35±5℃ for 80 min to obtain mixture A.

[0064] S2: Add 3 parts of crosslinking agent ethyltriacetoxysilane and 2 parts of composite additive to mixture A, and stir under vacuum at -0.08 to -0.095 MPa for 30 min to obtain mixture B;

[0065] S3: Add 18 parts of hydrophilic silica with a specific surface area of ​​200 to mixture B and disperse evenly. Then, stir under vacuum at a pressure of -0.08 to -0.095 MPa for 10 minutes to obtain mixture C. The hydrophilic silica is dried at 120°C for 3 hours before use to remove moisture. The main purpose is to remove moisture from the filler and improve the production efficiency and shelf life of the product.

[0066] S4: Add 15 parts of reactive plasticizer M99 silicone oil, 0.5 parts of oxidant 1135, and 0.1 parts of catalyst dibutyltin dilaurate. Mix them evenly and then add them to mixture C. Stir under vacuum at a pressure of -0.08 to -0.095 MPa for 30 minutes to obtain high displacement aging-resistant deacidified room temperature vulcanizing silicone rubber.

[0067] Comparative Example 6

[0068] The difference between this comparative example and Example 1 is that no composite additive was added in this comparative example, only 0.8 parts of the coupling agent octyltrimethoxysilane were added.

[0069] Comparative Example 7

[0070] The difference between this comparative example and Example 1 is that the chain extender added in this comparative example is 1,4-butanediol.

[0071] Experimental Example

[0072] The products prepared in the above embodiments and comparative examples were subjected to performance tests. Each group was repeated three times. The test methods, standards and test results are shown in the table below. "Stored at 70℃ for 5 days, min" means the surface drying time of the product after 5 days of storage at 70℃, which mainly simulates the storage stability of the product after long-term storage.

[0073] Table 3

[0074]

[0075] Table 4

[0076]

[0077]

[0078] As shown in Tables 3 and 4, the silicone rubber products prepared in each example of this invention meet the relevant national standards in terms of extrudability, elastic recovery rate, tensile modulus at room temperature and -20℃, adhesion, bond strength after aging, water resistance (high-temperature water immersion adhesion performance), and product stability, and are significantly better than the relevant standard requirements. However, in Comparative Example 1, the excessive viscosity of α,ω-dihydroxypolydimethylsiloxane led to a significant deterioration in the extrudability and tensile modulus of the prepared silicone rubber product; Comparative Example 2 did not add an antioxidant, resulting in poor anti-aging performance of the product, and the area of ​​bond failure after water-UV irradiation could not meet the standard requirements; Comparative Example 3 did not add a chain extender, and Comparative Example 4 involved dehydration treatment of hydrophilic fumed silica, both of which had a certain impact on the elastic recovery rate, adhesion performance, displacement resistance, and water resistance of the product. Comparative Example 5 did not add composite additives, resulting in deterioration of the product's aging resistance and water immersion resistance; Comparative Example 6 only added the coupling agent octyltrimethoxysilane, which deteriorated the product's stability, and the surface drying time of the product after long-term high-temperature storage was more than twice the original; Comparative Example 7 replaced the acidic chain extender in this technical solution with an alcohol chain extender, resulting in deterioration of the product's water immersion resistance, and the area of ​​bonding damage due to high-temperature water immersion could not meet the standard requirements.

[0079] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A high-displacement, aging-resistant, deacidification-resistant room-temperature vulcanizing silicone rubber, characterized in that: The raw materials, by weight, include 100 parts α,ω-dihydroxypolydimethylsiloxane, 10-30 parts reactive plasticizer, 5-30 parts fumed silica, 2-4 parts acidic chain extender, 2-4 parts crosslinking agent, 0.5-5 parts composite additive, 0.5-1 part antioxidant, and 0.01-1 part catalyst; the viscosity of α,ω-dihydroxypolydimethylsiloxane is 40000-80000 mPa·s; the acidic chain extender is di-tert-butoxydiacetoxysilane, methylvinyldiacetoxysilane, or dimethyldi... At least one of acetyloxysilanes; the composite additive is a mixture of a crosslinking agent and a coupling agent in a molar ratio of 1:1, wherein the crosslinking agent is at least one of methyltriacetyloxysilane, ethyltriacetyloxysilane, and propyltriacetyloxysilane; and the coupling agent is at least one of octyltrimethoxysilane, octyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, and hexadecyltriethoxysilane; the fumed silica is dried at 120°C for 3 hours before use to remove moisture.

2. The high displacement, aging-resistant, deacidification-resistant room temperature vulcanizing silicone rubber according to claim 1, characterized in that, The mass fractions of each raw material are as follows: 100 parts α,ω-dihydroxypolydimethylsiloxane, 10-20 parts reactive plasticizer, 15-20 parts fumed silica, 2-4 parts acidic chain extender, 2-4 parts crosslinking agent, 0.8-2 parts composite additive, 0.5-1 part antioxidant, and 0.1-0.5 parts catalyst.

3. The high displacement, aging-resistant, deacidification-resistant room temperature vulcanizing silicone rubber according to claim 2, characterized in that: The reactive plasticizer is an organosilicon oil, and the viscosity of the reactive plasticizer is 100-500 mPa·s.

4. The high displacement, aging-resistant, deacidification-resistant room temperature vulcanizing silicone rubber according to claim 3, characterized in that: The fumed silica produced by the gas phase method has a specific surface area of ​​150~200 g / m². 2 Hydrophilic fumed silica.

5. The high displacement, aging-resistant, deacidification-resistant room temperature vulcanizing silicone rubber according to claim 4, characterized in that: The antioxidant is at least one of liquid antioxidants 1520, 1500, 1135, and 1613; the catalyst is at least one of dibutyltin dilaurate, dimethyl dinedecanoate, dibutyltin diacetate, and tetraisopropyl titanate.

6. A method for preparing a high-displacement, aging-resistant, deacidifying room-temperature vulcanizing silicone rubber according to any one of claims 1-5, characterized in that, Includes the following steps: S1: α,ω-dihydroxypolydimethylsiloxane and chain extender are stirred under vacuum to extend the chain and obtain mixture A; S2: Add crosslinking agent and composite additive to mixture A, stir under vacuum conditions to obtain mixture B; S3: After adding fumed silica to mixture B and dispersing it evenly, stir under vacuum conditions to obtain mixture C; S4: After the reactive plasticizer, antioxidant and catalyst are mixed evenly, they are added to the mixture C and stirred under a vacuum of -0.08 to -0.095 MPa to obtain high displacement aging resistant deacidification type room temperature vulcanizing silicone rubber.

7. The method for preparing a high-displacement, aging-resistant, deacidifying room-temperature vulcanizing silicone rubber according to claim 6, characterized in that: In steps S1-S3, the vacuum degree is -0.08 to -0.095 MPa.

Images