A two-component curable thermal insulation gel, its preparation method and application

Abstract

This application relates to the field of thermal insulation materials technology, and discloses a two-component curable thermal insulation gel, its preparation method, and its application. The two-component curable thermal insulation gel of this application consists of component A and component B in a mass ratio of 100:(5~12). Component A includes vinyl silicone oil, a composite thermal insulation filler composed of titanium dioxide powder and hollow glass microspheres in a specific ratio, a modifier, cage-like polysilsesquioxane, a composite plasticizer, and a flame retardant. Component B includes a crosslinking agent and a catalyst. Through specific proportions of the raw materials in the two components, the two-component curable thermal insulation gel can maintain excellent thermal insulation performance, good dispensing workability, and rapid room temperature curing capability even when made into a gel layer as thin as 0.3 mm. This effectively solves the technical problem of the contradiction between increasing the thickness of thermal insulation materials to pursue low thermal conductivity and the space requirements of electronic devices. The preparation method of this application has mild process conditions and strong controllability, making it suitable for large-scale production.

Description

Technical Field

[0001] This application relates to the field of thermal insulation materials technology, and in particular to a two-component cured thermal insulation gel, its preparation method and application. Background Technology

[0002] As electronic devices continue to evolve towards higher performance, higher integration, and miniaturization, internal thermal management has become increasingly prominent. High-power chips, power modules, and other components are densely packed in confined spaces, creating a heat island effect. This can not only lead to single-point overheating and failure but also cause thermal interference between adjacent components, affecting the stability and reliability of the entire system. Effective thermal management ensures stable operation of electronic devices, extends their lifespan, and reduces thermal interference and failure. It plays a crucial role in improving the performance of high-power-density electronic devices, new energy vehicles, 5G communication equipment, fast-charging power supplies, and other electronic products.

[0003] Currently, the main thermal insulation materials used in the electronics field include polymer-based thermal insulation films, ceramic fiber felts, and microsphere-filled composite materials. Polymer-based thermal insulation films possess a certain degree of flexibility and processability, allowing them to adapt to complex shapes and structures; ceramic fiber felts exhibit high high-temperature resistance, enabling their use in high-temperature environments; and microsphere-filled composite materials achieve thermal insulation by adding microspheres to the matrix to reduce the material's thermal conductivity. While these materials can meet the thermal insulation requirements of electronic devices to a certain extent, some problems also exist in practical applications.

[0004] The pursuit of low thermal conductivity often necessitates increased material thickness, which conflicts with the internal space requirements of electronic devices. Furthermore, traditional materials are prone to structural collapse or performance aging under high temperature and humidity conditions, leading to a decline in thermal insulation effectiveness over long-term service. In addition, in high power density scenarios, many materials struggle to simultaneously possess excellent thermal insulation performance, necessary mechanical strength, and electrical insulation. This limitation is particularly pronounced with the increasing operating temperatures and power densities brought about by third-generation semiconductors. Summary of the Invention

[0005] To at least overcome one of the problems existing in the prior art, one objective of this invention is to provide a two-component curable thermal insulation gel. The raw materials of this two-component curable thermal insulation gel are composed of component A and component B in a mass ratio of 100:(5~12). Component A includes vinyl silicone oil, composite thermal insulation filler, modifier, cage-like polysilsesquioxane, composite plasticizer, and flame retardant. Component B includes a crosslinking agent and a catalyst. The composite thermal insulation filler is composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of (1~2):(0.5~3). Through a specific two-component system, specific raw material composition and ratio, the two-component curable thermal insulation gel of this invention, without relying on traditional thermal insulation structures, possesses both high-efficiency thermal insulation performance, good dispensing workability, rapid room temperature curing capability, and flame retardant safety, meeting the comprehensive requirements for thermal insulation and safety reliability of high-power-density electronic devices, new energy vehicles, 5G communication modules, fast-charging power supplies, and other products. A second objective of this invention is to provide a method for preparing the aforementioned two-component curable thermal insulation gel. A third objective of this invention is to provide the application of the two-component cured thermal insulation gel in the thermal isolation of electronic devices.

[0006] Therefore, the present invention adopts the following technical solution: The first aspect of the present invention provides a two-component curable thermal insulation gel, wherein the raw materials of the two-component curable thermal insulation gel are composed of component A and component B in a mass ratio of 100:(5~12); the raw material components of component A include: vinyl silicone oil, composite thermal insulation filler, modifier, cage-like polysilsesquioxane, composite plasticizer and flame retardant; the raw material components of component B include: crosslinking agent and catalyst; the composite thermal insulation filler is composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of (1~2):(0.5~3).

[0007] The raw materials of the two-component curable thermal insulation gel of this application include: Component A, vinyl silicone oil, a composite thermal insulation filler composed of titanium dioxide powder and hollow glass microspheres in a specific ratio, a modifier, a cage-like polysilsesquioxane, a composite plasticizer, and a flame retardant; and Component B, a crosslinking agent and a catalyst. Component A uses vinyl silicone oil as the matrix material. The titanium dioxide powder in the composite thermal insulation filler provides a rigid framework, and the hollow glass microspheres provide closed cavities to cut off heat conduction pathways. The modifier helps improve the interfacial compatibility between the inorganic filler and the organic matrix. The cage-like polysilsesquioxane helps improve structural strength and heat resistance. The composite plasticizer mainly adjusts the flexibility to accommodate irregular gaps. The flame retardant imparts good safety and flame retardant properties to the gel. The crosslinking agent and catalyst in Component B work together to achieve controllable curing. Furthermore, the specific mass ratio of 100:(5~12) between Components A and B further ensures the appropriate viscosity for dispensing application.

[0008] Preferably, the vinyl silicone oil has a viscosity of 100~9000 mPa·s at 25°C. More preferably, the vinyl silicone oil has a viscosity of 500~9000 mPa·s at 25°C. Even more preferably, the vinyl silicone oil has a viscosity of 1000~9000 mPa·s at 25°C.

[0009] Within this viscosity range, the vinyl silicone oil exhibits good flowability in component A, effectively suspending the composite thermal insulation filler and preventing its settling during storage and construction. It also facilitates the rapid diffusion of the crosslinking agent and catalyst in component B during mixing, ensuring uniform crosslinking reaction and thus guaranteeing consistent gel performance after curing.

[0010] Preferably, the D50 of the titanium sub-powder is 1-5 μm; the D50 of the hollow glass microspheres is 20-60 μm, and the compressive strength at 90% retention is 40-90 MPa. More preferably, the D50 of the titanium sub-powder is 2-5 μm; the D50 of the hollow glass microspheres is 20-60 μm, and the compressive strength at 90% retention is 50-90 MPa. Even more preferably, the D50 of the titanium sub-powder is 2-5 μm; the D50 of the hollow glass microspheres is 20-60 μm, and the compressive strength at 90% retention is 60-90 MPa.

[0011] The above particle size combination allows the medium and fine-grained sub-titanium powder to be uniformly dispersed in the vinyl silicone oil matrix to form a dense rigid skeleton and enhance the mechanical strength of the gel. At the same time, it is conducive to the formation of a multi-level cavity structure to effectively block heat conduction. Furthermore, the 90% retention of compressive strength in the range of 40~90 MPa ensures that the hollow glass microspheres have sufficient compressive strength during processing, stirring and curing and are not easily broken, thereby maintaining the thermal insulation integrity of the closed cavity. The sub-titanium powder fills the gaps between the microspheres to reduce the thermal bridging effect.

[0012] Preferably, the modifier is selected from at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents. More preferably, the modifier is selected from at least one of silane coupling agents and titanate coupling agents.

[0013] Preferably, the cage-like polysilsesquioxane is selected from at least one of octavinyl cage-like polysilsesquioxane and vinyldimethylsiloxy cage-like polysilsesquioxane. More preferably, the cage-like polysilsesquioxane is selected from octavinyl cage-like polysilsesquioxane.

[0014] Preferably, the composite plasticizer is composed of dimethyl silicone oil and MDT-type silicone oil in a mass ratio of (2~7):1. More preferably, the composite plasticizer is composed of dimethyl silicone oil and MDT-type silicone oil in a mass ratio of (3~7):1. Even more preferably, the composite plasticizer is composed of dimethyl silicone oil and MDT-type silicone oil in a mass ratio of (4~7):1.

[0015] Preferably, the flame retardant is selected from at least one of aluminum hydroxide, magnesium hydroxide, and phosphate ester. More preferably, the flame retardant is selected from at least one of aluminum hydroxide and magnesium hydroxide.

[0016] By selecting at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents as modifiers for composite thermal insulation fillers, one end of the modifier can chemically bond with the hydroxyl groups on the surface of titanium dioxide powder and hollow glass microspheres, while the other end can be compatible with or react with the vinyl silicone oil matrix. This significantly improves the interfacial compatibility and bonding force between the inorganic filler and the organosilicon matrix, reduces interfacial defects, pores, and separation phenomena between the filler and the matrix, effectively improves the dispersion uniformity of the system during stirring and storage, and changes the filler surface from hydrophilic to hydrophobic to inhibit agglomeration, thereby achieving uniform and stable dispersion of the filler in the matrix.

[0017] By employing a composite plasticizer consisting of cage-like polysilsesquioxanes with specific vinyl functional groups, dimethyl silicone oil and MDT-type silicone oil in specific ratios, and a specific flame retardant, the cage-like polysilsesquioxanes can fully participate in the cross-linking reaction of the system. This helps to improve the density, heat resistance, and dimensional stability of the cured network, and reduce deformation and aging under high-temperature conditions during use. The composite plasticizer can reduce the risk of high-temperature precipitation and migration while ensuring the plasticizing effect, which helps to improve the long-term reliability of the material. The flame retardant can quickly form a dense heat-insulating protective layer during combustion, achieving efficient halogen-free flame retardancy and meeting the relevant safety standards for electronic equipment.

[0018] Preferably, the crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.1% to 2%. More preferably, the crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.3% to 2%. Even more preferably, the crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.4% to 2%.

[0019] Preferably, the catalyst is a platinum catalyst with a platinum content of 500-4000 ppm. More preferably, the catalyst is a platinum catalyst with a platinum content of 700-4000 ppm. Even more preferably, the catalyst is a platinum catalyst with a platinum content of 1000-4000 ppm.

[0020] In the above technical solution, the crosslinking agent with the specified hydrogen content range matches the vinyl content in the vinyl silicone oil, ensuring a moderate number of crosslinking sites. This allows the cured material to possess both flexibility and mechanical strength, preventing brittleness due to excessive crosslinking or stickiness and insufficient strength due to insufficient crosslinking. The specified platinum concentration range provides sufficient catalytic activity, enabling rapid curing at room temperature after mixing components A and B, improving construction efficiency, suppressing side reactions, and stabilizing the performance of the cured product.

[0021] Preferably, in the A component of the two-component curable thermal insulation gel, the weight ratio of vinyl silicone oil, composite thermal insulation filler, and modifier is 100:(40~110):(2~7).

[0022] Preferably, in the A component of the two-component curable thermal insulation gel, the weight ratio of vinyl silicone oil, composite thermal insulation filler, modifier, and cage-like polysilsesquioxane is 100:(40~110):(2~7):(6~25).

[0023] Preferably, in the A component of the two-component curable thermal insulation gel, the weight ratio of vinyl silicone oil, composite thermal insulation filler, modifier, cage-like polysilsesquioxane, and composite plasticizer is 100:(40~110):(2~7):(6~25):(5~20).

[0024] Preferably, in the A component of the two-component curable thermal insulation gel, the weight ratio of vinyl silicone oil, composite thermal insulation filler, modifier, cage-like polysilsesquioxane, composite plasticizer, and flame retardant is 100:(40~110):(2~7):(6~25):(5~20):(10~23).

[0025] Preferably, in the B component of the two-component curable thermal insulation gel, the weight ratio of crosslinking agent to catalyst is 100:(0.5~6).

[0026] In the above technical solution, the specific weight ratio of raw materials in components A and B of the two-component curable thermal insulation gel allows the matrix, thermal insulation filler, modifier, cage-like polysilsesquioxane, plasticizer, flame retardant, crosslinking agent, and catalyst in the system to exert a better synergistic effect. While ensuring that the composite thermal insulation filler fully exerts its thermal insulation function, it maintains good fluidity, curability, and mechanical properties of the system, avoiding the increase in viscosity and construction difficulties caused by too much filler or the insufficient thermal insulation effect caused by too little filler. At the same time, it allows functional additives such as flame retardants, plasticizers, and reinforcing agents to exert their best effects, ensuring the stability of the overall performance of the product.

[0027] A second aspect of the present invention provides a method for preparing a two-component cured thermal insulating gel according to the first aspect of the present invention, comprising the following steps: S1. Mix titanium dioxide powder, hollow glass microspheres and modifier, and stir at 50~120℃ for 0.5~3h to obtain modified composite thermal insulation filler; S2. Add cage-like polysilsesquioxane, vinyl silicone oil, composite plasticizer and flame retardant to the modified composite thermal insulation filler, stir, and obtain component A; S3. Mix the crosslinking agent and catalyst, stir, and obtain component B; S4. Mix component A and component B at a mass ratio of 100:(5~12) to obtain the two-component cured thermal insulation gel.

[0028] In the preparation method of the two-component curable thermal insulation gel of this application, titanium dioxide powder, hollow glass microspheres and modifier are first stirred at 50~120℃ for 0.5~3h to fully modify the surface of the thermal insulation filler and disperse it evenly. Then, cage-like polysilsesquioxane, vinyl silicone oil, composite plasticizer and flame retardant are added in sequence to prepare component A. Crosslinking agent and catalyst are mixed to prepare component B. Finally, the two components are mixed in a specific ratio to obtain the two-component curable thermal insulation gel. The independent packaging of the two components can effectively avoid the premature contact of the reactants and the pre-crosslinking caused by the reaction components, thus extending the shelf life of the product. When using, a stable thermal insulation gel can be obtained by simple mixing. The overall process conditions are mild, the operation is simple and the controllability is strong.

[0029] The method for forming a thermal insulation layer using the two-component curable thermal insulation gel of this application or the two-component curable thermal insulation gel prepared by the preparation method of this application includes: applying the mixed two-component curable thermal insulation gel to the part that needs thermal insulation through a dispensing device, and curing it at room temperature to form a thermal insulation gel layer.

[0030] A third aspect of this application provides the application of a two-component cured thermal insulation gel in the thermal isolation of electronic devices, wherein the two-component cured thermal insulation gel is the two-component cured thermal insulation gel described above, or is prepared by the above preparation method.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects: 1) The two-component curable thermal insulation gel of this application is composed of component A and component B in a mass ratio of 100:(5~12). Component A includes vinyl silicone oil, a composite thermal insulation filler composed of titanium dioxide powder and hollow glass microspheres in a specific ratio, a modifier, cage-like polysilsesquioxane, a composite plasticizer, and a flame retardant. Component B includes a crosslinking agent and a catalyst. Through the specific ratio of each raw material in the specific two-component, the composite thermal insulation filler provides a rigid skeleton and a closed cavity with synergistic effect, and the modifier improves interfacial compatibility, etc., so that the two-component curable thermal insulation gel can maintain excellent thermal insulation performance, good dispensing workability, rapid room temperature curing ability, and flame retardant safety even when the thickness is as thin as 0.3 mm without relying on traditional thermal conductive fillers. It effectively solves the technical problems in the prior art, such as the contradiction between the need to increase the thickness of thermal insulation materials to pursue low thermal conductivity and the space requirements of electronic devices, and the difficulty in balancing thermal insulation performance and mechanical strength.

[0032] 2) In the two-component curable thermal insulation gel of this application, the composite thermal insulation filler is composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of (1~2):(0.5~3). The fine particles of titanium dioxide powder are uniformly dispersed in the vinyl silicone oil matrix to form a dense rigid skeleton to enhance mechanical strength. At the same time, the D50 of the hollow glass microspheres is 20~60μm, which helps to form a multi-level cavity structure to effectively block heat conduction. Furthermore, 90% of the hollow glass microspheres have a compressive strength of 40~90MPa, which is beneficial to ensure that they have sufficient compressive strength and are not easily broken during processing, stirring and curing. The use of titanium dioxide powder to fill the gaps between the microspheres also reduces the thermal bridging effect, so that the gel can maintain a low thermal conductivity after curing.

[0033] 3) The preparation method of this application involves first modifying the titanium dioxide powder and hollow glass microspheres, and then mixing them with the matrix and other additives. This allows the modifier to form a strong coating layer on the surface of the filler beforehand, preventing the modifier from becoming free or ineffective during subsequent mixing. Simultaneously, the independent packaging of the two components effectively prevents premature contact between the reactants, thus avoiding pre-crosslinking and extending the product's shelf life. The overall process conditions are mild and highly controllable, making it suitable for large-scale production. Detailed Implementation

[0034] The present invention will be further described in detail below through specific embodiments, comparative examples and tables, but is not limited to all the discussions and data.

[0035] Vinyl silicone oil: Anhui Aiyota Silicone Oil Co., Ltd., model IOTA 20566, CAS No. 26710-23-6, viscosity at 25℃ is 250~5000mPa·s.

[0036] Titanium dioxide powder: Guangdong Qichen New Material Technology Co., Ltd., model Y663, D50 is 2.32μm.

[0037] Hollow glass microspheres: Shanxi Hainuo Technology Co., Ltd., model HN46HS, D50 is 20 μm, 90% of the compressive strength is 69 MPa.

[0038] Silane coupling agent KH-560: Commercially available, CAS No. 2530-83-8.

[0039] Octadecyl cage-like polysilsesquioxane: Guangzhou Yixin Technology Co., Ltd., model Ecotion® POSS106.

[0040] Dimethyl silicone oil: Xin'an Chemical Group Co., Ltd., model XHG-201-500, viscosity at 25℃ is 500±25mPa·s.

[0041] MDT type silicone oil: Jiangxi Sibo Chemical Co., Ltd., model JG-2107 methyl branched silicone oil.

[0042] Hydrogen-containing silicone oil crosslinking agent: Anhui Aiyota Silicone Oil Co., Ltd., model IOTA 20567, hydrogen content is 0.1%~1.2%.

[0043] Platinum catalyst: Dongguan Dongsheng Synthetic Materials Co., Ltd., platinum catalyst, platinum content is 1000ppm.

[0044] It is particularly important to emphasize that, unless otherwise specified, the raw materials, reagents, or devices used in this invention can all be obtained through conventional commercial channels. Unless otherwise specified, "parts" refers to parts by weight.

[0045] Examples of two-component cured thermal insulation gels: A two-component curable thermal insulation gel is prepared by the following steps: S1. Mix 40-110 parts of composite thermal insulation filler (composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of (1-2):(0.5-3)) and 2-7 parts of modifier, and stir at 50-120℃ for 0.5-3h to obtain modified composite thermal insulation filler. S2. Add 6-25 parts of cage-like polysilsesquioxane, 100 parts of vinyl silicone oil, 5-20 parts of composite plasticizer and 10-23 parts of flame retardant to the modified composite heat insulation filler, stir evenly to obtain component A. S3. Mix 100 parts of crosslinking agent and 0.5-6 parts of catalyst, stir evenly to obtain component B; S4. Mix component A and component B evenly at a mass ratio of 100:(5~12) to obtain the two-component cured heat insulation gel.

[0046] Regarding step S1, in some specific embodiments, the amount of composite thermal insulation filler can be 40 parts, 60 parts, 80 parts, or 110 parts. The composite thermal insulation filler is composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of 1:0.5, 2:0.5, 1.5:2, or 1:3. The D50 of the titanium dioxide powder can be 1 μm, 2 μm, 4 μm, or 5 μm; the D50 of the hollow glass microspheres can be 20 μm, 35 μm, 50 μm, or 60 μm, and the 90% retained compressive strength can be 40 MPa, 60 MPa, 70 MPa, 80 MPa, or 90 MPa. The modifier can be selected from at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents. The stirring temperature can be 50℃, 70℃, 90℃, 100℃, or 120℃, and the stirring time can be 0.5 h, 1 h, 2 h, or 3 h.

[0047] Regarding step S2, in some specific embodiments, the cage-like polysilsesquioxane may be selected from at least one of octavinyl cage-like polysilsesquioxane and vinyl dimethylsiloxy cage-like polysilsesquioxane. The viscosity of the vinyl silicone oil at 25°C may be 100 mPa·s, 500 mPa·s, 2000 mPa·s, 4000 mPa·s, 7500 mPa·s, or 9000 mPa·s. The composite plasticizer is composed of dimethyl silicone oil and MDT-type silicone oil in a mass ratio of 2:1, 4:1, 5:1, or 7:1. The flame retardant may be selected from at least one of aluminum hydroxide, magnesium hydroxide, and phosphate ester. The amount of cage-like polysilsesquioxane may be 6 parts, 10 parts, 14 parts, 18 parts, or 25 parts. The amount of composite plasticizer may be 5 parts, 10 parts, 15 parts, or 20 parts. The amount of flame retardant can be 10 parts, 13 parts, 16 parts, 20 parts or 23 parts.

[0048] For step S3, in some specific embodiments, the crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.1%, 0.6%, 1.2%, 1.5%, or 2%. The catalyst is a platinum catalyst with a platinum content of 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm, or 4000 ppm. The amount of catalyst used can be 0.5 parts, 1 part, 3 parts, 5 parts, or 6 parts.

[0049] Regarding step S4, in some specific implementations, component A and component B are mixed evenly in a mass ratio of 100:5, 100:7, 100:9 or 100:12. Example 1

[0050] A two-component curable thermal insulation gel is prepared by the following steps: S1. Mix 40 parts of composite thermal insulation filler (i.e., 10 parts of titanium dioxide powder and 30 parts of hollow glass microspheres) and 5 parts of silane coupling agent KH-560, and stir at 60℃ for 2 hours to obtain modified composite thermal insulation filler. S2. Add 18 parts of octavinyl cage-like polysilsesquioxane, 100 parts of vinyl ethyl silicone oil IOTA 20566, 7 parts of composite plasticizer (i.e., 6 parts of XHG-201-500 type dimethyl silicone oil and 1 part of JG-2107 methyl branched silicone oil) and 12 parts of aluminum hydroxide to the modified composite thermal insulation filler, stir evenly, and obtain component A; S3. Mix 100 parts of hydrogen-containing ethyl silicone oil IOTA 20567 and 3 parts of platinum catalyst with a platinum content of 1000ppm, stir evenly, and obtain component B. S4. Mix component A and component B evenly at a mass ratio of 100:6 to obtain the two-component cured thermal insulation gel. Example 2

[0051] The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Example 2, the total amount of composite thermal insulation filler is 80 parts (i.e., 20 parts of titanium dioxide powder and 60 parts of hollow glass microspheres). Example 3

[0052] The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Example 3, in 40 parts of composite thermal insulation filler, there are 18 parts of titanium dioxide powder and 22 parts of hollow glass microspheres. Example 4

[0053] The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Example 4, the amount of octavinyl cage-like polysilsesquioxane is 12 parts. Example 5

[0054] The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Example 5, the mass ratio of component A to component B in step S4 is 100:9.

[0055] Comparative Example 1: A two-component curable thermal insulation gel is prepared in the same way as in Example 1, except that in Comparative Example 1, no modifier is added in step S1.

[0056] Comparative Example 2: The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Comparative Example 2, 40 parts of composite thermal insulation filler contain 25 parts of titanium dioxide powder and 15 parts of hollow glass microspheres.

[0057] Comparative Example 3: The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Comparative Example 3, all 40 parts of composite thermal insulation filler are titanium dioxide powder.

[0058] Comparative Example 4: The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Comparative Example 4, all 40 parts of composite thermal insulation filler are hollow glass microspheres.

[0059] Comparative Example 5: The preparation method of a two-component curable thermal insulation gel is the same as in Example 1, except that in Comparative Example 5, octavinyl cage-like polysilsesquioxane is not added in step S2.

[0060] Comparative Example 6: The preparation method of a two-component curable thermal insulation gel is the same as that in Example 1, except that in Comparative Example 6, the mass ratio of component A to component B in step S4 is 100:15.

[0061] Material performance testing: The two-component cured thermal insulation gels of Examples 1-5 and Comparative Examples 1-6 were subjected to various performance tests, and the test methods are as follows: 1. Curing time (finger touch method): 5g of the two-component cured thermal insulation gel obtained by mixing in step S4 of Examples 1-5 and Comparative Examples 1-6 were placed in disposable petri dishes, and the time from the end of mixing to the gel surface no longer sticky to the touch was recorded.

[0062] 2. Evaluation of adhesive application workability: Using an adhesive dispensing machine, apply a 50mm long line to the PCB board and observe whether the adhesive is continuous, whether there is any blockage or dripping.

[0063] 3. The two-component curable thermal insulation gels obtained from step S4 of Examples 1-5 and Comparative Examples 1-6 were uniformly coated onto a polytetrafluoroethylene release substrate using an automatic dispensing machine. The coating amount was controlled so that the cured thicknesses were 0.3 mm and 0.6 mm, respectively. After curing at room temperature, a thermal insulation gel layer was formed. After standing for 48 hours, tests were conducted according to the following test methods: ① Thermal conductivity: Tested according to ASTM D5470 standard.

[0064] ② Hardness: Tested using a Shore 00 hardness tester according to ASTM D2240 standard.

[0065] ③ Flame retardancy rating: Prepare a 125mm×13mm×0.5mm sample and test it according to the UL 94 vertical burning method.

[0066] ④ Thermal aging test: Place the thermal conductivity test sample in a 150℃ oven for 1000h for aging, take it out and test the thermal conductivity again, and calculate the rate of change.

[0067] The curing properties of the two-component curable thermal insulation gels of Examples 1-5 and Comparative Examples 1-6 are shown in Table 1 below:

[0068] The two-component curable thermal insulation gels in Examples 1-5 are composed of component A and component B in a mass ratio of 100:(5-12). Component A includes vinyl silicone oil, a composite thermal insulation filler composed of titanium dioxide powder and hollow glass microspheres in a specific ratio, a modifier, cage-like polysilsesquioxane, a composite plasticizer, and a flame retardant. Component B includes a crosslinking agent and a catalyst. Through the specific proportions of the raw materials in the specific two-component mixture, the composite thermal insulation filler provides a rigid skeleton and a closed cavity with synergistic effect, the modifier improves interfacial compatibility, and the cage-like polysilsesquioxane participates in crosslinking. This results in a gel layer with excellent thermal insulation performance, good dispensing application, rapid room temperature curing ability, flame retardant safety, and thermal aging stability at ultra-thin thicknesses of 0.3 mm and 0.6 mm. The results show that the thermal conductivity at a thickness of 0.3 mm is 0.060~0.072 W / m·K, and at a thickness of 0.6 mm it is 0.058~0.070 W / m·K. The Shore 00 hardness is 36~53, and the flame retardancy rating reaches UL 94 V-0. The change rate of thermal conductivity after thermal aging is only +4.8%~+6.2%. At the same time, the dispensing application is smooth, and the curing time is 3.6~4.9 hours. It effectively solves the technical problems in the existing technology, such as the contradiction between increasing the thickness of thermal insulation materials to pursue low thermal conductivity and the space requirements of electronic devices, and the difficulty in balancing thermal insulation performance and mechanical strength.

[0069] Compared with Example 1, Comparative Example 1 was prepared using the same method, except that no modifier was added in step S1. The results showed that the gel dispensing workability of Comparative Example 1 deteriorated, exhibiting intermittent dispensing and needle clogging. At a thickness of 0.3 mm, the thermal conductivity increased sharply to 0.142 W / m·K, the Shore 00 hardness rose to 61, and the thermal conductivity change rate after thermal aging was as high as +29%. This may be because the lack of a modifier resulted in poor interfacial compatibility between the filler (titanium dioxide powder), hollow glass microspheres, and the vinyl silicone oil matrix, leading to filler agglomeration, significant interfacial defects, and localized thermal bridges, resulting in a substantial decrease in thermal insulation performance. Simultaneously, uneven dispersion caused viscosity fluctuations and decreased flowability, further affecting the smoothness of dispensing. Insufficient interfacial bonding made the material prone to structural loosening during thermal aging, leading to rapid degradation of thermal insulation performance.

[0070] Compared with Example 1, Comparative Example 2 was prepared using the same method, except that in Comparative Example 2, the 40 parts of composite thermal insulation filler contained 25 parts of sub-titanium powder and 15 parts of hollow glass microspheres, which are outside the scope of this invention. The results showed that the thermal conductivity of the 0.3 mm thick gel layer in Comparative Example 2 increased to 0.074 W / m·K, the Shore 00 hardness increased to 57, and the rate of change of thermal conductivity after thermal aging increased to +6.6%. This may be because the proportion of sub-titanium powder was too high and the proportion of hollow glass microspheres was too low, resulting in insufficient closed-cavity thermal insulation structure and weakened thermal barrier effect; at the same time, the increased proportion of rigid filler made the system harder and reduced its flexibility, affecting stress buffering capacity, and consequently reducing thermal insulation performance under thermal aging.

[0071] Compared with Example 1, Comparative Example 3 was prepared using the same method, except that all 40 parts of the composite thermal insulation filler in Comparative Example 3 were made of titanium dioxide powder and did not contain hollow glass microspheres. The results showed that the thermal conductivity of the 0.3 mm thick gel layer in Comparative Example 3 increased sharply to 0.188 W / m·K, with a Shore 00 hardness as high as 77. The material was brittle, and the thermal conductivity changed by +17% after thermal aging, indicating severely insufficient thermal insulation performance. This may be because the lack of a closed cavity structure with hollow glass microspheres prevents effective interruption of heat conduction pathways, resulting in continuous solid-phase thermal conduction and a significant reduction in thermal insulation effect. Simultaneously, the all-titanium dioxide powder system is too rigid, lacks flexibility, and has weak stress buffering capacity. During thermal aging, the mismatch in thermal expansion coefficients easily leads to microcracks, resulting in a significant decrease in thermal insulation performance.

[0072] Compared with Example 1, Comparative Example 4 was prepared using the same method, except that all 40 composite thermal insulation fillers in Comparative Example 4 were hollow glass microspheres, without any titanium dioxide powder. The results showed that the thermal conductivity of the 0.3 mm thick gel layer in Comparative Example 4 increased to 0.106 W / m·K, and the Shore 00 hardness was only 21. The material was too soft and prone to collapse, and the thermal conductivity changed by as much as +44% after thermal aging, resulting in poor workability and stability. This may be because the lack of rigid skeleton support and gap filling provided by titanium dioxide powder made it easy for gaps and thermal bridges to form between the hollow glass microspheres, leading to a decrease in thermal insulation efficiency. Simultaneously, the overall strength of the system was insufficient, making it more prone to deformation and collapse during stirring, dispensing, and heating. The microstructure damage was more significant after thermal aging, resulting in a substantial decrease in thermal insulation performance.

[0073] Compared with Example 1, Comparative Example 5 was prepared using the same method, except that octavinyl cage-like polysilsesquioxane was not added in step S2. The results showed that the thermal conductivity of the 0.3 mm thick gel layer in Comparative Example 5 increased to 0.077 W / m·K, the Shore 00 hardness was only 26, the UL 94 flame retardancy rating decreased to V-2, and the thermal conductivity change rate after thermal aging reached +19%. This may be because the lack of the crosslinking enhancement and heat resistance improvement effect of cage-like polysilsesquioxane resulted in a decrease in the density of the cured crosslinked network. During thermal aging, the looser crosslinked network was more prone to thermal oxidative degradation, leading to an increase in thermal conductivity.

[0074] Compared with Example 1, Comparative Example 6 was prepared using the same method, except that the mass ratio of component A to component B in step S4 of Comparative Example 6 was 100:15, which is outside the scope of this invention. The results showed that the gel curing time of Comparative Example 6 was shortened to 2.9 h, exhibiting excessively rapid curing and easy needle clogging. The thermal conductivity of the 0.3 mm thick gel layer increased to 0.070 W / m·K, the Shore 00 hardness was 48, and the rate of change in thermal conductivity after thermal aging increased to +6.9%, resulting in poor workability and stability. This may be because the crosslinking agent ratio was too high, causing the system to react too quickly and curing to be difficult to control, easily leading to premature curing and needle clogging during dispensing. Simultaneously, excessive crosslinking increased internal stress and decreased flexibility of the material, resulting in more significant performance fluctuations after thermal aging.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. Any obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A two-component curable thermal insulation gel, characterized in that, The raw materials of the two-component curable thermal insulation gel are composed of component A and component B in a mass ratio of 100:(5~12); The raw material components of component A include: vinyl silicone oil, composite heat-insulating filler, modifier, cage-like polysilsesquioxane, composite plasticizer and flame retardant; The raw material components of component B include: crosslinking agent and catalyst; The composite thermal insulation filler is composed of titanium dioxide powder and hollow glass microspheres in a mass ratio of (1~2):(0.5~3).

2. The two-component cured thermal insulation gel according to claim 1, characterized in that, The viscosity of the vinyl silicone oil at 25°C is 100~9000 mPa·s.

3. The two-component curable thermal insulation gel according to claim 1, characterized in that, The D of the titanium dioxide powder 50 The size is 1~5μm; The hollow glass microspheres D 50 The thickness is 20~60μm, and the compressive strength of 90% retention is 40~90MPa.

4. The two-component curable thermal insulation gel according to claim 1, characterized in that, The modifier is selected from at least one of silane coupling agents, titanate coupling agents, and aluminate coupling agents.

5. The two-component cured thermal insulation gel according to claim 1, characterized in that, The cage-like polysilsesquioxane is selected from at least one of octavinyl cage-like polysilsesquioxane and vinyl dimethylsiloxy cage-like polysilsesquioxane. And / or, the composite plasticizer is composed of dimethyl silicone oil and MDT-type silicone oil in a mass ratio of (2~7):1; And / or, the flame retardant is selected from at least one of aluminum hydroxide, magnesium hydroxide, and phosphate ester.

6. The two-component cured thermal insulation gel according to claim 1, characterized in that, The crosslinking agent is a hydrogen-containing silicone oil with a hydrogen content of 0.1% to 2%; And / or, the catalyst is a platinum catalyst with a platinum content of 500~4000ppm.

7. The two-component cured thermal insulation gel according to claim 1, characterized in that, Component A comprises the following raw material components in parts by weight: 100 parts vinyl silicone oil; 40-110 parts of composite thermal insulation filler; 2-7 parts of modifier; 6-25 parts of cage-like polysilsesquioxane; 5-20 parts of compound plasticizer; 10-23 parts flame retardant; Component B comprises the following raw material components in parts by weight: 100 parts of crosslinking agent; Catalyst 0.5-6 parts.

8. A method for preparing a two-component curable thermal insulating gel as described in any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix titanium dioxide powder, hollow glass microspheres and modifier, and stir at 50~120℃ for 0.5~3h to obtain modified composite thermal insulation filler; S2. Add cage-like polysilsesquioxane, vinyl silicone oil, composite plasticizer and flame retardant to the modified composite thermal insulation filler, stir, and obtain component A; S3. Mix the crosslinking agent and catalyst, stir, and obtain component B; S4. Mix component A and component B at a mass ratio of 100:(5~12) to obtain the two-component cured thermal insulation gel.

9. A method for forming a thermal insulation layer using a two-component cured thermal insulation gel according to any one of claims 1 to 7 or a two-component cured thermal insulation gel prepared by the preparation method of claim 8, characterized in that, include: The mixed two-component curable thermal insulation gel is applied to the area requiring thermal insulation using a dispensing device and cured at room temperature to form a thermal insulation gel layer.

10. The application of a two-component cured thermal insulation gel as described in any one of claims 1 to 7 or a two-component cured thermal insulation gel prepared by the preparation method as described in claim 8 in the thermal isolation of electronic devices.

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