Liquid sealant as well as preparation method and application thereof

Abstract

The invention discloses a liquid sealant as well as a preparation method and application thereof. The liquid sealant is prepared from the following components in parts by weight: 30 to 70 parts of polyisobutene, 20 to 50 parts of light-cured release silicone oil resin, 0.1 to 10 parts of hydroxyl cyclohexane benzophenone, 10 to 30 parts of diluent, 1.1 to 10 parts of thixotropic agent and 0.1 to 5 parts of adhesion promoter. The light-cured release silicone oil resin is obtained by modifying a hydrosilylation polymer through an acrylic acid group. The liquid sealant prepared from the polyisobutene, the light-cured release silicone oil resin, the adhesion promoter and other materials has good bonding force and sealing effect on the graphite plate, and can be easily peeled off when the graphite plate is repaired.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesives, and more specifically, to a liquid sealant and its preparation method and application. Background Art

[0002] Graphite has very wide applications in the fields of semiconductor, solar cells, sensors, nanoelectronics, high-performance nanoelectronic devices, composite materials, field emission materials, etc. Especially in the special structure of bipolar plates of fuel cells and flow batteries, graphite plates have electrical conductivity and significantly improve the performance and stability of the battery as battery electrodes. Fuel cells and flow batteries are composed of many unit cells, and a unit cell is composed of a membrane electrode, a cathode plate, and an anode plate. Each layer is sealed with glue to prevent hydrogen and oxygen leakage. The unit cells are stacked layer by layer to form fuel cell and flow battery assemblies. There is a need for extremely high sealing performance between these unit cell layers. Even a very small gap can easily lead to hydrogen and oxygen leakage, triggering accidents such as explosion and combustion. Therefore, the sealing material connecting the unit cell layers must have good gas tightness. Commonly used sealing materials include sealing gaskets and liquid sealants. Solid gaskets are not easily sealed with the bonded interface and are prone to gas leakage; liquid sealants can flow into and fill complex interfaces due to their fluidity and have better adhesion compared to solid gaskets, and are not easily prone to leakage problems between interfaces. However, traditional liquid silicone-based sealants have a long curing time and poor weather resistance. Therefore, there is an urgent need for a liquid sealant with excellent comprehensive performance. Summary of the Invention

[0003] The present invention aims at the above technical problems and provides a liquid sealant and its preparation method and application.

[0004] To achieve the above object, the present application adopts the following technical solutions:

[0005] A liquid sealant, comprising the following components in parts by weight: 30 - 70 parts of polyisobutylene, 20 - 50 parts of photocurable release silicone resin, 0.1 - 10 parts of hydroxycyclohexanone phenyl ketone, 10 - 30 parts of diluent, 1.1 - 10 parts of thixotropic agent, 0.1 - 5 parts of adhesion promoter; the photocurable release silicone resin is obtained by modifying a silicon hydride addition polymer with acrylic groups.

[0006] The liquid sealant of the present application has at least the following characteristics:

[0007] (1) Strong weather resistance. The inventors found that traditional liquid silicone sealants have a long curing time and contain silane addition polymers. In the long-term strong acid and alkali process, the carbon-hydrogen bonds are easily broken, resulting in poor weather resistance and excessively high maintenance costs in the later stage. The polyisobutylene molecular chain has a certain flexibility, and polyisobutylene also has excellent antioxidant, UV resistance, and acid and alkali resistance. The light-cured release silicone oil resin obtained by modifying the silane addition polymer with acrylic acid groups will form a smooth, low surface energy film layer on the surface of the liquid sealant after light curing. The groups that can absorb or reflect ultraviolet rays can reduce the aging reactions such as breakage and cross-linking of the colloidal molecular chains caused by ultraviolet rays, thereby improving the weather resistance of the liquid glue. When polyisobutylene and light-cured release silicone oil resin work together, a composite protective system can be formed. Polyisobutylene enhances the structural stability of the liquid adhesive from the inside, while the light-cured release silicone resin provides protection from the surface, greatly improving the weather resistance of the sealant, avoiding hydrogen and oxygen leakage in fuel cells or flow batteries, and extending the service life of fuel cells and flow batteries.

[0008] (2) Peelability. The sealant prepared by the present application using materials such as polyisobutylene, photocurable release silicone oil resin, and adhesion promoter has good adhesion and sealing effect on graphite plates. The low surface energy characteristics of the photocurable release silicone oil resin improve the performance stability of the liquid sealant during operations such as demolding, so that the graphite plate can be easily removed during repair without wearing the graphite plate. The sealant has good fluidity and can be used in conjunction with automated dispensing and coating equipment.

[0009] (3) Fast curing speed. Hydroxycyclohexane phenone belongs to the benzophenone photoinitiator. Its specific functional group can have a special interaction with the monomer molecules in the system (such as the acrylic monomer in the diluent). This interaction can adjust the reaction rate constant between the free radicals and the monomers, thereby controlling the crosslinking and curing process of the liquid sealant. The test found that the liquid sealant of the present application can be completely cured within 10 seconds of UV lamp irradiation, which meets the requirements of industrial mass production.

[0010] Furthermore, the synthesis method of the light-curable release silicone resin comprises:

[0011] Reacting polymethyl hydrogen siloxane, trimethylolpropane monoallyl ether and a microcapsule-encapsulated platinum catalyst (the platinum content is 1000-5000 PPM) to obtain a hydrosilylation polymer;

[0012] The hydrosilylation polymer and isophorone diisocyanate are reacted at 75-85°C for 1-2 hours, toluene solvent is added and mixed for 1-2 hours, and then hydroxybutyl acrylate is added and the reaction is continued for 1-2 hours, and organic tin is continuously added dropwise for 1-2 hours, and the reaction is carried out for 0.5-1.5 hours, and the light-curing release silicone oil resin is obtained after being cooled to 35-45°C.

[0013] The hydrocarbon addition polymer is grafted with acrylic groups, and the obtained modified photocurable release silicone resin combines the excellent properties of silicone and acrylic resin, which can enhance the permanent compression rate of the sealant and the weather resistance in high temperature, low temperature or strong acid and strong base environments. Among them, organotin compounds are metal organic compounds formed by the direct combination of tin and carbon elements. Both alkyltin compounds and aryltin compounds can be used as the organotin catalysts in this application. Preferably, at least one of dibutyltin and stannous octoate is used.

[0014] Furthermore, the hydrogen content of the polymethylhydrogensiloxane is 0.1-1 wt%.

[0015] The polymethylhydrogensiloxane with a hydrogen content of 0.1-1 wt% meets the reaction activity requirements of the reaction system in this application. Polymethylhydrogensiloxane, also known as hydrogen-containing silicone oil, contains a large number of Si-H bonds and has extremely high reaction activity, capable of reacting with various chemical substances containing active groups such as double bonds and hydroxyl groups to ensure the high efficiency of chemical reactions.

[0016] Furthermore, the diluent includes at least one of isobornyl acrylate, isobornyl methacrylate, N,N-dimethylacrylamide, 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, and dicyclopentenyl acrylate.

[0017] The diluent can significantly improve the fluidity and viscosity of the sealant. The liquid sealant prepared with the above several substances as components has a very fast curing speed and can ensure the firmness and durability of the bonding part.

[0018] Furthermore, the thixotropic agent includes at least one of fumed silica and bentonite.

[0019] The thixotropic agent is used to improve the rheological properties of the colloid and prevent sedimentation. Fumed silica has a high specific surface area and adsorption properties, which can significantly improve the tensile strength and tear strength of the sealant; bentonite powder forms an efficient thixotropic effect through the processes of wetting, dispersion and activation, which can thicken the sealant and has an anti-settling effect.

[0020] Hydroxycyclohexanone belongs to benzophenone photoinitiators. The specific functional groups in the structure of this initiator may have special interactions with monomer molecules. This interaction can adjust the reaction rate constant between free radicals and monomers, thereby controlling the crosslinking and curing process of the liquid glue. Preferably, 184 photoinitiator of Guangdong Lancol New Materials Co., Ltd. and IGM Omnirad 184 photosensitizer are used.

[0021] Further, the specific surface area of the fumed silica is less than 200 m² / g, and the particle size is less than 12 nm; the particle size of the bentonite is 0.5 - 38 µm.

[0022] An appropriate specific surface area of the fumed silica can not only maintain strong adsorption characteristics but also prevent agglomeration. WACKER's H18 and Evonik Degussa's R202 are preferred. When the bentonite powder has large particles or uneven particle sizes, problems such as clogging are likely to occur, thus affecting the viscosity stability. An appropriate particle size of the bentonite powder can improve the fluidity, viscosity, and even the viscosity stability of the liquid sealant. Bentonite powder with a particle size of 0.5 - 38 µm can pass through a 400 - 6000 mesh sieve.

[0023] Further, the adhesion promoter includes at least one of aminoethyl aminopropyl trimethoxysilane coupling agent, carboxyl acrylate, phosphate-modified acrylic resin, and 3-mercaptopropyl methyl dimethoxysilane.

[0024] The adhesion promoter can improve the adhesiveness of the sealant. The above several adhesion promoters can significantly improve the adhesion between the sealant and the substrate, making the sealant adhere more firmly to the substrate and not easily fall off or peel off.

[0025] Further, the molecular weight of the polyisobutene is 1000 - 2500.

[0026] Polyisobutene with an appropriate molecular weight can balance the cohesive strength and adhesion strength within the colloid, thereby obtaining the best bonding effect. Preferred polyisobutene liquids include at least one of Korea's Dalim Polyisobutene PB950, PB1300, PB2400, Germany's BASF Polyisobutene B15, Polyisobutene B15N, and Kaneka EP400A.

[0027] A method for preparing a liquid sealant includes the following steps:

[0028] Pre-stir the polyisobutene and the photocurable release silicone resin in an environment of yellow light, vacuum, and a temperature of 60 - 90 °C for 30 - 60 min;

[0029] Add the diluent, thixotropic agent, and adhesion promoter, and continue to stir in a vacuum and at a temperature of 60 - 90 °C for 1 - 3 h, then cool down to 15 - 40 °C;

[0030] Add hydroxycyclohexanone phenyl ketone, and continue to stir in a vacuum and at a temperature of 60 - 90 °C for 1 - 3 h, then cool down to 15 - 40 °C to obtain the liquid sealant.

[0031] Yellow light can prevent the system from undergoing polymerization reactions. Polyisobutene liquid and photo-curable release silicone oil can fully fuse and react at high temperatures of 60-90°C. Continuing to add diluents, thixotropic agents, and adhesion promoters can further mix them evenly. Finally, adding hydroxycyclohexanone phenyl ketone (184 photoinitiator) can ensure that no explosive polymerization occurs in the first two steps. Cooling can further ensure the stability of the sealant at room temperature.

[0032] Application of a liquid sealant in bonding graphite materials.

[0033] As a conductive material, it has a wide range of applications in various fields. Especially in fuel cells and flow batteries, graphite materials are used as electrodes, and the sealant used is required to have good gas tightness. The liquid sealant prepared in this application, which is made of materials such as polyisobutene, photo-curable release silicone oil resin, and adhesion promoter, has good weather resistance, good adhesion and sealing effect on graphite plates, avoids hydrogen and oxygen leakage problems in fuel cells and flow batteries, and facilitates the disassembly and repair of graphite materials.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] (1) Strong weather resistance. When polyisobutene and photo-curable release silicone oil resin act together, a composite protection system can be formed. Polyisobutene enhances the structural stability of the liquid adhesive from the inside, while photo-curable release silicone oil resin provides protection from the surface, greatly improving the weather resistance of the sealant, avoiding hydrogen and oxygen leakage in fuel cells or flow batteries, and extending the service life of fuel cells and flow batteries.

[0036] (2) Peelability. The low surface energy characteristic of photo-curable release silicone oil resin improves the performance stability of the liquid sealant during operations such as demolding, enabling the graphite plate to be easily removed during repair without abrasion to the graphite plate. The sealant has good fluidity and can be used in conjunction with automated dispensing and coating equipment.

[0037] (3) Fast curing speed. Specific functional groups of hydroxycyclohexanone phenyl ketone have special interactions with monomer molecules in the system (such as acrylic monomers in diluents). This interaction can regulate the reaction rate constant between free radicals and monomers, thereby controlling the cross-linking and curing process of the liquid sealant. It has been found through experiments that the liquid sealant of this application can be completely cured within 10 seconds under UV lamp irradiation, meeting the requirements of industrial mass production. Specific embodiments

[0038] The following examples are used to illustrate the present invention, but are not used to limit the scope of the present invention. Modifications or substitutions made to the methods, steps or conditions of the present invention without departing from the spirit and essence of the present invention all fall within the protection scope of the present invention. Unless otherwise specified, the experimental materials, reagents, instruments, etc. used in the embodiments of the present invention can be obtained commercially; unless specifically specified, all technical means in the embodiments of the present invention are conventional means well known to those skilled in the art.

[0039] An embodiment of the present application provides a liquid sealant, which comprises the following components in parts by weight: 30-70 parts of polyisobutene, 20-50 parts of photocurable release silicone oil resin, 0.1-10 parts of hydroxycyclohexanone phenyl ketone, 10-30 parts of diluent, 1.1-10 parts of thixotropic agent, 0.1-5 parts of adhesion promoter; the photocurable release silicone oil resin is obtained by modifying a silicon hydride addition polymer with acrylic groups.

[0040] It can be understood that the parts by weight of polyisobutene include but are not limited to: 30 parts, 33 parts, 36 parts, 40 parts, 43 parts, 46 parts, 50 parts, 53 parts, 56 parts, 60 parts, 62 parts, 65 parts, 68 parts, 70 parts; the parts by weight of the photocurable release silicone oil resin include but are not limited to: 20 parts, 25 parts, 30 parts, 33 parts, 36 parts, 40 parts, 42 parts, 46 parts, 50 parts; the parts by weight of hydroxycyclohexanone phenyl ketone include but are not limited to: 0.1 part, 0.8 part, 2 parts, 7 parts, 10 parts; the parts by weight of the diluent include but are not limited to: 10 parts, 12 parts, 17 parts, 22 parts, 28 parts, 30 parts; the parts by weight of the thixotropic agent include but are not limited to: 1.1 parts, 1.8 parts, 5 parts, 7 parts, 10 parts; the parts by weight of the adhesion promoter include but are not limited to: 0.1 part, 0.9 part, 2 parts, 3 parts, 4 parts, 5 parts.

[0041] In some embodiments, the synthesis method of the photocurable release silicone oil resin includes:

[0042] React polymethylhydrogensiloxane, trimethylolpropane monoallyl ether and microcapsule-coated platinum catalyst (platinum content is 1000-5000 PPM) to obtain a silicon hydride addition polymer;

[0043] React the silicon hydride addition polymer with isophorone diisocyanate at 75-85 °C for 1-2 hours, add toluene solvent and mix for 1-2 hours, then add hydroxybutyl acrylate and continue to react for 1-2 hours, continuously dropwise add organotin and react for 1-2 hours, keep warm for 0.5-1.5 hours, and cool to 35-45 °C to obtain the photocurable release silicone oil resin.

[0044] In some embodiments, the hydrogen content of the polymethylhydrogensiloxane is 0.1-1 wt%. It is understandable that the hydrogen content of the polymethylhydrogensiloxane includes, but is not limited to: 0.1 wt%, 0.3 wt%, 0.6 wt%, 1 wt%.

[0045] In some embodiments, the diluent includes at least one of isobornyl acrylate, isobornyl methacrylate, N,N-dimethylacrylamide, 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, and dicyclopentenyl acrylate.

[0046] In some embodiments, the thixotropic agent includes at least one of fumed silica and bentonite.

[0047] In some embodiments, the specific surface area of the fumed silica is less than 200 m² / g, and the particle size is less than 12 nm; the particle size of the bentonite is 0.5-38 µm.

[0048] In some embodiments, the adhesion promoter includes at least one of aminoethyl aminopropyl trimethoxysilane coupling agent, carboxyl acrylate, phosphate-modified acrylic resin, and 3-mercaptopropyl methyldimethoxysilane.

[0049] In some embodiments, the molecular weight of the polyisobutene is 1000-2500.

[0050] An embodiment of the present application provides a method for preparing a liquid sealant, including the following steps:

[0051] Pre-stir polyisobutene and photo-curable release silicone resin in an environment of yellow light, vacuum, and a temperature of 60-90 °C for 30-60 min;

[0052] Add the diluent, thixotropic agent, and adhesion promoter, and continue to stir in a vacuum and at a temperature of 60-90 °C for 1-3 h, then cool down to 15-40 °C;

[0053] Add hydroxycyclohexanone benzophenone, and continue to stir in a vacuum and at a temperature of 60-90 °C for 1-3 h, then cool down to 15-40 °C to obtain the liquid sealant.

[0054] An embodiment of the present application provides an application of the liquid sealant in bonding graphite materials.

[0055] The preparation method of the photo-curable release silicone resin used in the following examples is as follows:

[0056] 1) Synthesis of hydrosilylation polymer: 80 g of polymethylhydrogensiloxane (hydrogen content: 0.3 wt%), 20 g of trimethylolpropane monoallyl ether, and 0.2 g of microcapsule-coated platinum catalyst (platinum content: 2000 PPM) were added to a reaction kettle equipped with a stirrer, reflux condenser, thermometer, and dropping funnel. The temperature was raised to 80 °C and the reaction was carried out for 3 hours, then the temperature was lowered to about 40 °C to obtain the hydrosilylation polymer.

[0057] 2) Synthesis of photocurable release silicone resin: The hydrosilylation polymer was poured into the reaction kettle. Under the protection of nitrogen, when heated to 80 °C, 10 g of isophorone diisocyanate was added and reacted for 1 - 2 hours. Then 10 g of toluene solvent was added and mixed for 1 hour. Then 50 g of hydroxybutyl acrylate was added and the reaction continued for 1 hour. 1 g of dibutyltin was added dropwise from another funnel within 2 hours. After that, it was kept warm for 1 hour and cooled to 38 °C to obtain the photocurable release silicone resin.

[0058] Preparation of Liquid Sealing Adhesive in Example 1

[0059] The liquid sealing adhesive prepared in this example comprises the following components in parts by weight: 30 parts of polyisobutene, 50 parts of photocurable release silicone resin, 30 parts of diluent, 10 parts of thixotropic agent, 10 parts of initiator, and 0.1 part of adhesion promoter.

[0060] A method for preparing a liquid sealing adhesive, comprising the following steps:

[0061] S1, 30 g of BASF polyisobutene B15 from Germany, 50 g of photocurable release silicone resin were stirred in an environment of yellow light, vacuum and a temperature of 60 - 90 °C for 30 min for sufficient fusion;

[0062] S2, slowly add 30 g of N,N-dimethylacrylamide, 6 g of fumed silica, 4 g of bentonite, and 0.1 g of aminoethylaminopropyltrimethoxysilane coupling agent, and continue to stir in an environment of yellow light, vacuum and a temperature of 60 - 90 °C for 1 h to mix evenly, and then cool to 40 °C;

[0063] S3, add 10 g of hydroxycyclohexanone benzophenone, stir in a vacuum and at a temperature of 60 - 90 °C for 3 h, stir evenly and then cool to 40 °C, and discharge the material.

[0064] Preparation of Liquid Sealing Adhesive in Example 2

[0065] The liquid sealing adhesive prepared in this example comprises the following components in parts by weight: 50 parts of polyisobutene, 30 parts of photocurable release silicone resin, 10 parts of diluent, 4 parts of thixotropic agent, 5 parts of initiator, and 1 part of adhesion promoter.

[0066] A method for preparing a liquid sealing adhesive, comprising the following steps:

[0067] S1, Mix 50 g of polyisobutylene B15N and 30 g of photocurable release silicone oil resin. Stir for 60 min in an environment of yellow light, vacuum and a temperature of 60 - 90 °C for sufficient fusion.

[0068] S2, Slowly add 10 g of isobornyl acrylate, 2 g of fumed silica, 2 g of bentonite, and 1 g of carboxyl acrylate. Continue to stir for 3 h in an environment of yellow light, vacuum and a temperature of 60 - 90 °C until evenly mixed, and then cool down to 40 °C.

[0069] S3, Add 5 g of hydroxycyclohexanone phenyl ketone. Stir for 1 h in a vacuum and at a temperature of 60 - 90 °C. After stirring evenly, cool down to 15 °C and discharge the material.

[0070] Preparation of Liquid Sealant in Example 3

[0071] The liquid sealant prepared in this example comprises the following components in parts by weight: 70 parts of polyisobutylene, 20 parts of photocurable release silicone oil resin, 20 parts of diluent, 1.1 parts of thixotropic agent, 0.1 part of initiator, and 5 parts of adhesion promoter.

[0072] A method for preparing a liquid sealant, comprising the following steps:

[0073] S1, Mix 70 g of polyisobutylene EP400A and 20 g of photocurable release silicone oil resin. Stir for 45 min in an environment of yellow light, vacuum and a temperature of 60 - 90 °C for sufficient fusion.

[0074] S2, Slowly add 20 g of dicyclopentenyloxyethyl acrylate, 0.8 g of fumed silica, 0.3 g of bentonite, and 5 g of 3-mercaptopropylmethyldimethoxysilane. Continue to stir for 2 h in an environment of yellow light, vacuum and a temperature of 60 - 90 °C until evenly mixed, and then cool down to 40 °C.

[0075] S3, Add 0.1 g of hydroxycyclohexanone phenyl ketone. Stir for 2 h in a vacuum and at a temperature of 60 - 90 °C. After stirring evenly, cool down to 25 °C and discharge the material.

[0076] The raw materials and dosages (g) used in Examples 1 - 3 are shown in Table 1.

[0077] Table 1

[0078]

[0079] Performance Test

[0080] Perform performance tests on the liquid sealants prepared in Experimental Examples 1 - 3 and traditional sealants. The test results are shown in Tables 2 and 3.

[0081] Among them, the test standard for viscosity refers to: GBT15357-2014;

[0082] The test standard for hardness refers to: GB T 531.1-2008;

[0083] The test standard for elongation at break refers to: GB / T528-1998;

[0084] The standard for permanent compression set refers to: GB / T 7759-2015;

[0085] The ethylene glycol solution immersion liquid is a special hydrogen fuel coolant, and the vanadium redox flow electrolyte has an electrolyte concentration of 1.5 to 2.0 moles per liter (mol / L); the traditional sealant 1 is Japan's threebond TB1153E; the traditional sealant 2 is Wacker 988.

[0086] Table 2

[0087]

[0088]

[0089] Table 3

[0090]

[0091] It can be seen from Table 2 and Table 3 that compared with the traditional sealant 1 and the traditional sealant 2, the sealants prepared in Examples 1 to 3 have a short curing time and excellent hardness, elongation at break, and permanent compression set characteristics. Whether in a low-temperature or high-temperature environment, the sealant still has strong stability in the ethylene glycol solution and the vanadium redox flow electrolyte environment for 1000 hours, and the change rate affected by the environment is extremely low. It can be easily peeled off during the graphite plate repair without damaging the graphite plate. However, the traditional sealant has a long curing time. Whether in a low-temperature or high-temperature environment, the two traditional sealants cannot withstand the ethylene glycol solution and the vanadium redox flow electrolyte, and dissolution occurs during the immersion process, making them unable to be used normally.

[0092] It can be understood that the above embodiments only represent the preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention patent; it should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, the above technical features can be freely combined, and several deformations and improvements can also be made, which all belong to the protection scope of the present invention; therefore, all equivalent transformations and modifications made to the scope of the claims of the present invention should fall within the scope covered by the claims of the present invention.

Claims

1. A liquid sealant, characterized in that, It comprises the following components in parts by weight: 30-70 parts of polyisobutene, 20-50 parts of photocurable release silicone oil resin, 0.1-10 parts of hydroxycyclohexanone phenyl ketone, 10-30 parts of diluent, 1.1-10 parts of thixotropic agent, and 0.1-5 parts of adhesion promoter; the photocurable release silicone oil resin is obtained by modifying a hydrosilylation polymer with acrylic groups.

2. The liquid sealant according to claim 1, characterized in that, The synthesis method of the photocurable release silicone oil resin comprises: Reacting polymethylhydrogensiloxane, trimethylolpropane monoallyl ether and microcapsule-coated platinum catalyst to obtain a hydrosilylation polymer; Reacting the hydrosilylation polymer with isophorone diisocyanate at 75-85 °C for 1-2 hours, adding toluene solvent and mixing for 1-2 hours, then adding hydroxybutyl acrylate and continuing to react for 1-2 hours, continuously dropping organic tin and reacting for 1-2 hours, keeping warm for 0.5-1.5 hours, cooling to 35-45 °C to obtain the photocurable release silicone oil resin.

3. A liquid sealant according to claim 2, wherein The hydrogen content of the polymethylhydrogensiloxane is 0.1-1 wt%.

4. A liquid sealant according to claim 1, characterized in that, The diluent comprises at least one of isobornyl acrylate, isobornyl methacrylate, N,N-dimethylacrylamide, 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, and dicyclopentenyl acrylate.

5. A liquid sealant according to claim 1, wherein The thixotropic agent comprises at least one of fumed silica and bentonite.

6. A liquid sealant according to claim 5, wherein, The specific surface area of the fumed silica is less than 200 square meters per gram and the particle size is less than 12 nm; the particle size of the bentonite is 0.5-38 µm.

7. A liquid sealant according to claim 1, characterized in that The adhesion promoter comprises at least one of aminoethylaminopropyltrimethoxysilane coupling agent, carboxyl acrylate, phosphate-modified acrylic resin, and 3-mercaptopropylmethyldimethoxysilane.

8. A liquid sealant according to claim 1, wherein, The molecular weight of the polyisobutene is 1000-2500.

9. The preparation method of a liquid sealant according to claim 1, characterized in that, It comprises the following steps: Pre-stirring polyisobutene and photocurable release silicone oil resin in a yellow light, vacuum and environment with a temperature of 60-90 °C for 30-60 min; Adding the diluent, thixotropic agent and adhesion promoter, and continuing to stir in a vacuum and environment with a temperature of 60-90 °C for 1-3 h, and cooling to 15-40 °C; Adding hydroxycyclohexanone phenyl ketone, and continuing to stir in a vacuum and environment with a temperature of 60-90 °C for 1-3 h, and cooling to 15-40 °C to obtain a liquid sealant.

10. The application of a liquid sealant according to any one of claims 1-8 in bonding graphite materials.

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