Dealcoholized silicone sealant with high tear strength and fatigue resistance and preparation method thereof

Abstract

The invention provides a dealcoholized silicone sealant with high tear strength and fatigue resistance and a preparation method thereof. The silicone sealant comprises the following components in parts by weight: 100 parts of alpha, omega-dihydroxy polysiloxane, 20-40 parts of polyborosiloxane, 5-15 parts of simethicone, 70-140 parts of nano active calcium carbonate, 3-7 parts of a cross-linking agent, 1-3 parts of a compound coupling agent, 2-5 parts of a titanate vulcanizing agent A and 2-4 parts of a titanate vulcanizing agent B. According to the method, polyborosiloxane and alpha, omega-dihydroxy polysiloxane are adopted as basic polymers, a titanate vulcanizing agent is compounded, and a filler, a cross-linking agent, a coupling agent and the like are matched to obtain the dealcoholized silicone sealant which has relatively high tear strength and excellent fatigue resistance; and obvious negative effects on the surface drying time, the tensile strength, the elongation at break and other mechanical properties and the adhesive property of the silicone sealant are avoided. The invention also overcomes the defects of poor mechanical fatigue resistance and tear resistance of the existing silicone sealant.

Description

Technical Field

[0001] The invention relates to the field of silicone sealants, and in particular to a dealcoholized silicone sealant with high tear strength and fatigue resistance and a preparation method thereof. Background Art

[0002] Dealcoholized one-component condensation type room temperature vulcanizing liquid (RTV-1) silicone rubber is a paste made of α,ω-polydimethylsiloxane as the base polymer, supplemented with crosslinking agent, filler, plasticizer, coupling agent and catalyst in a container isolated from moisture. It reacts with water in the air at room temperature and solidifies to form elastic silicone rubber. It has many excellent properties such as wide operating temperature range, excellent weather resistance, excellent electrical insulation performance, excellent biocompatibility and adhesion to materials.

[0003] Silicone weathering sealants for construction are a type of functional building material that can withstand joint displacement to achieve sealing purposes and is embedded in building joints. They are widely used in the sealing of curtain wall joints such as glass curtain walls, aluminum curtain walls, and stone curtain walls. In actual use environments, the width of the joints between panels will change due to temperature changes, deformation of the main structure, and other reasons. This also means that the sealant must also withstand periodic stress changes, and its durability becomes particularly important. When there are gaps in the joints due to construction or external reasons, the tear resistance is insufficient, which can easily cause the defective part of the glue joint to fail under the action of long-term displacement and deformation. Therefore, how to improve the mechanical fatigue resistance and tear resistance of silicone weathering sealants is of great significance to the service quality and service life of the sealant. Summary of the invention

[0004] The invention provides a dealcoholized silicone sealant with high tear strength and fatigue resistance and a preparation method thereof, and aims to solve the problems of mechanical fatigue resistance and tear resistance of existing silicone sealants.

[0005] In order to achieve the above-mentioned purpose, the embodiment of the present invention provides a high tear strength and fatigue resistance dealcoholized silicone sealant and a preparation method thereof. The present invention adopts polyborosiloxane and α,ω-dihydroxypolysiloxane as the base polymer, and adopts a compounded titanate vulcanizer, and uses a polymer, a filler, a cross-linking agent, a coupling agent, etc. in the dealcoholized silicone sealant system to obtain a dealcoholized silicone sealant, which obtains a high tear strength and excellent fatigue resistance, and does not cause a significant negative impact on the mechanical properties and bonding properties of the silicone sealant, such as the dry time, tensile strength, and elongation at break.

[0006] The embodiment of the present invention provides a dealcoholized silicone sealant with high tear strength and fatigue resistance, which comprises the following components in parts by weight:

[0007]

[0008] Preferably, the viscosity of the α,ω-dihydroxy polysiloxane at 25° C. is 40,000 to 60,000 mPa·s.

[0009] Preferably, the viscosity of the polyborosiloxane at 25° C. is 40,000 to 60,000 mPa·s.

[0010] Preferably, the viscosity of the dimethyl silicone oil at 25° C. is 100 to 1000 mPa.s.

[0011] Preferably, the particle size of the nano-active calcium carbonate is 100-140 nm.

[0012] Preferably, the crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane and propyltriethoxysilane.

[0013] Preferably, the complex coupling agent is at least two of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, N-βaminoethylγ-aminopropyltriethoxysilane, epoxypropyltriethoxysilane, and epoxypropyltrimethoxysilane.

[0014] Preferably, the titanate vulcanizing agent A is diisopropoxytitanium bis(ethyl acetoacetate) chelate.

[0015] Preferably, the titanate vulcanizing agent B is isopropyl titanate tristearate.

[0016] Based on a general inventive concept, an embodiment of the present invention further provides a method for preparing the above-mentioned dealcoholized silicone sealant, comprising the following steps:

[0017] S1: Add α,ω-dihydroxy polysiloxane, polyborosiloxane, dimethyl silicone oil and nano-activated calcium carbonate into a kneader at a temperature of 80 to 150°C and a vacuum degree of -0.06 to -0.099 MPa, dehydrate and blend for 30 to 300 minutes to obtain a base material, and then cool and set aside;

[0018] S2: at room temperature, adding the base material into a planetary mixer or a high-speed disperser, and then adding the crosslinking agent into the planetary mixer or the high-speed disperser together with the base material to carry out chemical reaction at a vacuum degree of -0.02 to 0.04 MPa and a rotation speed of 10 to 800 rpm for 5 to 30 minutes;

[0019] S3: Add the complex coupling agent, titanate vulcanizer A and titanate vulcanizer B into a planetary mixer or a high-speed disperser together with the base material and carry out chemical reaction for 30 to 120 minutes at a vacuum degree of -0.06 to -0.099 MPa and a rotation speed of 10 to 800 rpm to prepare the dealcoholized silicone sealant.

[0020] The above scheme of the present invention has the following beneficial effects:

[0021] The present invention provides a method for preparing a silicone sealant with high tear strength and fatigue resistance, which solves the shortcomings of existing silicone sealants in terms of poor mechanical fatigue resistance and tear resistance. By introducing polyborosiloxane as a base polymer, polyborosiloxane (PBDMS) is an amorphous cross-linked network structure based on boron-oxygen dynamic bonds. It is very soft in its natural state. As the external impact load increases, the shear-hardening glue can undergo a phase change from a viscous flow state to a highly elastic state, or even a glassy state, so that it can better resist impact deformation and absorb impact energy. When the impact load disappears, it can not only return to the original viscous flow state, but also re-bond after breaking and shattering, showing certain self-repairing properties, and therefore has excellent fatigue resistance and tear resistance. In addition, isopropyl titanate tristearate is introduced as a compound vulcanizing agent. The saturated long-chain fatty acids it carries can well coat and modify the surface of nano-calcium carbonate particles. At the same time, it is introduced into the polymer through the vulcanizing agent molecules, avoiding the shortcomings of poor system compatibility and easy precipitation caused by direct addition of stearic acid. It effectively enhances the interaction between organic polymer and inorganic particles, making them more tightly combined, and can also improve the mechanical fatigue resistance and tear resistance of silicone sealant to a certain extent. DETAILED DESCRIPTION

[0022] In order to make the technical problems to be solved, technical solutions and advantages of the present invention more clear, they are described in detail below in conjunction with specific embodiments.

[0023] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0024] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0025] In view of the existing problems, an embodiment of the present invention provides a dealcoholized silicone sealant with high tear strength and fatigue resistance, which comprises the following components in parts by weight:

[0026]

[0027] Preferably, the viscosity of the α,ω-dihydroxy polysiloxane at 25° C. is 40,000 to 60,000 mPa·s.

[0028] Preferably, the viscosity of the polyborosiloxane at 25° C. is 40,000 to 60,000 mPa·s.

[0029] Preferably, the viscosity of the dimethyl silicone oil at 25° C. is 100 to 1000 mPa.s.

[0030] Preferably, the particle size of the nano-active calcium carbonate is 100-140 nm.

[0031] Preferably, the crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane and propyltriethoxysilane.

[0032] Preferably, the complex coupling agent is at least two of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, N-βaminoethylγ-aminopropyltriethoxysilane, epoxypropyltriethoxysilane, and epoxypropyltrimethoxysilane.

[0033] Preferably, the titanate vulcanizing agent A is diisopropoxytitanium bis(ethyl acetoacetate) chelate.

[0034] Preferably, the titanate vulcanizing agent B is isopropyl titanate tristearate.

[0035] Based on a general inventive concept, an embodiment of the present invention further provides a method for preparing the above-mentioned dealcoholized silicone sealant, comprising the following steps:

[0036] S1: Add α,ω-dihydroxy polysiloxane, polyborosiloxane, dimethyl silicone oil and nano-activated calcium carbonate into a kneader at a temperature of 80 to 150°C and a vacuum degree of -0.06 to -0.099 MPa, dehydrate and blend for 30 to 300 minutes to obtain a base material, and then cool and set aside;

[0037] S2: at room temperature, adding the base material into a planetary mixer or a high-speed disperser, and then adding the crosslinking agent into the planetary mixer or the high-speed disperser together with the base material to carry out chemical reaction at a vacuum degree of -0.02 to 0.04 MPa and a rotation speed of 10 to 800 rpm for 5 to 30 minutes;

[0038] S3: Add the complex coupling agent, titanate vulcanizer A and titanate vulcanizer B into a planetary mixer or a high-speed disperser together with the base material and carry out chemical reaction for 30 to 120 minutes at a vacuum degree of -0.06 to -0.099 MPa and a rotation speed of 10 to 800 rpm to prepare the dealcoholized silicone sealant.

[0039] The following is a detailed description through specific embodiments.

[0040] Example 1

[0041] This embodiment provides a method for preparing a dealcoholized silicone sealant with high tear strength and fatigue resistance.

[0042] The method of this embodiment specifically includes the following steps:

[0043] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 40000mPa·s, 25 parts of polyborosiloxane with a viscosity of 50000mPa·s, 10 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0044] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0045] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 2.5 parts of isopropyl tristearate titanate are reacted at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm for 40 minutes to prepare an alcohol-type silicone sealant.

[0046] Example 2

[0047] This embodiment provides a method for preparing a dealcoholized silicone sealant with high tear strength and fatigue resistance.

[0048] The method of this embodiment specifically includes the following steps:

[0049] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 45000mPa·s, 30 parts of polyborosiloxane with a viscosity of 50000mPa·s, 10 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0050] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0051] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 3 parts of isopropyl tristearate titanate are reacted at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm for 40 minutes to prepare an alcohol-type silicone sealant.

[0052] Example 3

[0053] This embodiment provides a method for preparing a dealcoholized silicone sealant with high tear strength and fatigue resistance.

[0054] The method of this embodiment specifically includes the following steps:

[0055] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000mPa·s, 35 parts of polyborosiloxane with a viscosity of 50000mPa·s, 10 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0056] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0057] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 3 parts of isopropyl tristearate titanate are reacted at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm for 40 minutes to prepare an alcohol-type silicone sealant.

[0058] Example 4

[0059] This embodiment provides a method for preparing a dealcoholized silicone sealant with high tear strength and fatigue resistance.

[0060] The method of this embodiment specifically includes the following steps:

[0061] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 55000mPa·s, 35 parts of polyborosiloxane with a viscosity of 50000mPa·s, 15 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0062] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0063] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 3.5 parts of isopropyl tristearate titanate are reacted at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm for 40 minutes to prepare an alcohol-type silicone sealant.

[0064] Example 5

[0065] This embodiment provides a method for preparing a dealcoholized silicone sealant with high tear strength and fatigue resistance.

[0066] The method of this embodiment specifically includes the following steps:

[0067] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 60000mPa·s, 40 parts of polyborosiloxane with a viscosity of 50000mPa·s, 15 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0068] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0069] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 3.5 parts of isopropyl tristearate titanate are reacted at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm for 40 minutes to prepare an alcohol-type silicone sealant.

[0070] Comparative Example 1

[0071] This comparative example provides a method for preparing a silicone sealant, which is different from the example in that only polyborosiloxane is added, and isopropyl titanate tristearate is not added. The method specifically comprises the following steps:

[0072] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000mPa·s, 30 parts of polyborosiloxane with a viscosity of 50000mPa·s, 10 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0073] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0074] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, and 3 parts of diisopropoxytitanium bis(ethyl acetoacetate) chelate are reacted for 40 minutes at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm to prepare an alcohol-type silicone sealant.

[0075] Comparative Example 2

[0076] This comparative example provides a method for preparing a silicone sealant, which is different from the example in that only isopropyl titanate tristearate is added, and polyborosiloxane is not added. The method specifically comprises the following steps:

[0077] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000mPa·s, 5 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0078] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 10 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04 MPa and a rotation speed of 150 rpm for 15 minutes;

[0079] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, 3 parts of diisopropoxytitanium bis(ethyl acetate) chelate, and 3.5 parts of isopropyl tristearate titanate are reacted for 40 minutes at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm to prepare an alcohol-type silicone sealant.

[0080] Comparative Example 3

[0081] This comparative example provides a method for preparing a silicone sealant, which is different from the example in that neither polyborosiloxane nor isopropyl titanate tristearate is added, and specifically comprises the following steps:

[0082] Step 1: Add 100 parts of α,ω-dihydroxypolydimethylsiloxane with a viscosity of 50000mPa·s, 10 parts of dimethyl silicone oil with a viscosity of 500mPa·s, and 110 parts of nano-activated calcium carbonate with a particle size of 120nm into a kneader, the temperature is 120°C, the vacuum degree is -0.095MPa, dehydrate and blend for 180 minutes, and cool to obtain the base material for use.

[0083] Step 2: At room temperature, add the base material obtained above into a planetary mixer or a high-speed disperser, then add 5 parts of methyltrimethoxysilane into the planetary mixer or the high-speed disperser and carry out chemical reaction with the base material at a vacuum degree of -0.04MPa and a rotation speed of 150rpm for 15 minutes;

[0084] Step 3: 2 parts of γ-aminopropyltrimethoxysilane, 0.5 parts of γ-glycidyloxypropyltrimethoxysilane, and 3 parts of diisopropoxytitanium bis(ethyl acetoacetate) chelate are reacted for 40 minutes at a vacuum degree of -0.09 MPa and a rotation speed of 300 rpm to prepare an alcohol-type silicone sealant.

[0085] Performance Testing:

[0086] The silicone sealants of the above examples and comparative examples were tested for tensile bonding strength at 23°C, bonding failure area, and elongation at maximum tensile strength at 23°C according to the tensile bonding test index requirements in GB 16776-2005. The tear strength test was carried out according to ASTM D624, and the test results are shown in Table 1 below.

[0087] The test method for mechanical fatigue resistance includes the following process:

[0088] First, the silicone weather-resistant sealant in the above-mentioned embodiment and comparative example is made into an H-type specimen according to "GB / T 13477.8-2017 Test Method for Building Sealing Materials Part 8: Determination of Tensile Adhesion", and cured for 28 days under standard conditions of temperature 23 (±2) ° C and relative humidity 50 (±10)%. The tension-compression cycle fatigue mode is set on the tensile fatigue machine so that the H-type specimen is subjected to repeated tension and compression, and the tension and compression displacement is ±35%, with 600s as a fatigue cycle. The fatigue test results are determined according to the national standard "GB / T 13477.10-2017 Test Method for Building Sealing Materials Part 10: Determination of Fixed Elongation Adhesion", and the sample is checked for cohesive failure or adhesive failure. When the specimen failure depth is >2mm, it is determined that the fatigue test has ended, and the number of fatigue cycles is recorded and reported.

[0089] Table 1

[0090]

[0091]

[0092] From Table 1, by comparing Examples 1, 2, 3, 4, 5 with Comparative Examples 2, 3, it can be seen that the polyborosiloxane introduced in the present invention can improve the tensile strength of silicone sealant. By comparing Examples 1, 2, 3, 4, 5 with Comparative Examples 1, 3, it can be seen that tristearate titanate isopropyl can improve the elongation at the maximum tensile strength of silicone sealant. By comparing Examples 1, 2, 3, 4, 5 with Comparative Examples 1, 2, 3, it can be seen that the polyborosiloxane introduced in the present invention and tristearate titanate isopropyl can improve the tear strength and fatigue resistance of silicone sealant when used alone, and can further improve the tear strength and fatigue resistance of silicone sealant when used in combination.

[0093] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A dealcoholized silicone sealant with high tear strength and fatigue resistance, characterized in that: According to parts by weight, it includes the following components:

2. The dealcoholized silicone sealant according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy polysiloxane at 25° C. is 40,000 to 60,000 mPa·s.

3. The dealcoholized silicone sealant according to claim 1, characterized in that: The viscosity of the polyborosiloxane at 25° C. is 40,000 to 60,000 mPa·s.

4. The dealcoholized silicone sealant according to claim 1, characterized in that: The viscosity of the dimethyl silicone oil at 25° C. is 100 to 1000 mPa.s.

5. The dealcoholized silicone sealant according to claim 1, characterized in that: The particle size of the nano active calcium carbonate is 100-140nm.

6. The dealcoholized silicone sealant according to claim 1, characterized in that: The crosslinking agent is at least one of methyltrimethoxysilane, methyltriethoxysilane, propyltrimethoxysilane and propyltriethoxysilane.

7. The dealcoholized silicone sealant according to claim 1, characterized in that: The complex coupling agent is at least two of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidyloxypropyltriethoxysilane, N-βaminoethylγ-aminopropyltriethoxysilane, epoxypropyltriethoxysilane and epoxypropyltrimethoxysilane.

8. The dealcoholized silicone sealant according to claim 1, characterized in that: The titanate vulcanizing agent A is diisopropoxytitanium bis(ethyl acetoacetate) chelate.

9. The dealcoholized silicone sealant according to claim 1, characterized in that: The titanate vulcanizing agent B is isopropyl titanate tristearate.

10. The method for preparing the dealcoholized silicone sealant according to any one of claims 1 to 9, characterized in that: The steps include: S1: Add α,ω-dihydroxy polysiloxane, polyborosiloxane, dimethyl silicone oil and nano-activated calcium carbonate into a kneader at a temperature of 80 to 150°C and a vacuum degree of -0.06 to -0.099 MPa, dehydrate and blend for 30 to 300 minutes to obtain a base material, and then cool and set aside; S2: at room temperature, adding the base material into a planetary mixer or a high-speed disperser, and then adding the crosslinking agent into the planetary mixer or the high-speed disperser together with the base material to carry out chemical reaction at a vacuum degree of -0.02 to 0.04 MPa and a rotation speed of 10 to 800 rpm for 5 to 30 minutes; S3: Add the complex coupling agent, titanate vulcanizer A and titanate vulcanizer B into a planetary mixer or a high-speed disperser together with the base material and carry out chemical reaction for 30 to 120 minutes at a vacuum degree of -0.06 to -0.099 MPa and a rotation speed of 10 to 800 rpm to prepare the dealcoholized silicone sealant.

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