Heat-conducting insulating material as well as preparation method and application thereof

Abstract

The invention discloses a heat-conducting insulating material as well as a preparation method and application thereof. The preparation method comprises the following steps: uniformly mixing silicone oil, a heat-conducting filler, a surface modifier, a flame retardant, a reinforcing agent and a lubricating material, stirring at room temperature, heating to a first preset temperature, preserving heat for a period of time, cooling to a second preset temperature, continuously adding an inhibitor and a cross-linking agent at the second preset temperature, stirring, cooling to room temperature, continuously adding a catalyst, stirring, and cooling to room temperature. The obtained mixture is subjected to pressing treatment and curing treatment in sequence, and the heat-conducting insulating material is obtained. The thermally conductive insulating material comprises the following components: 70-85 parts by weight of silicone oil; 85-150 parts by weight of a heat-conducting filler; 0.5 to 1.5 parts by weight of a surface modifier; 0-50 parts by weight of a flame retardant; 5-25 parts by weight of a reinforcing agent; 0-15 parts by weight of a lubricating material; 0.02 to 0.1 part by weight of an inhibitor; 0.5-3 parts by weight of a cross-linking agent; and 0.2-1 part by weight of a catalyst. In addition, the heat-conducting insulating material can be used as a heat dissipation layer to be directly used in a PTC (Positive Temperature Coefficient) heating module.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal conductivity and insulation, and in particular to a thermal conductivity and insulation material, a preparation method thereof, and an application thereof. Background Art

[0002] As electronic products and semiconductor devices rapidly develop towards higher frequencies, miniaturization, and higher power densities, their heat dissipation needs are growing exponentially. As the core medium for electronic packaging and heat dissipation engineering, thermally conductive insulating materials must simultaneously meet stringent requirements such as efficient thermal management, reliable electrical insulation, and mechanical stability. Especially in high-temperature operating conditions such as positive temperature coefficient (PTC) heating modules, traditional thermally conductive insulating materials generally adopt a composite structure of "polyimide (PI) film auxiliary insulation layer + thermally conductive silicone layer." However, this structure has the following inherent defects:

[0003] 1. Low heat conduction efficiency:

[0004] The thermal conductivity of the PI film auxiliary insulation layer itself is extremely low, and due to its rigidity, the thermal resistance of the interface with the heating element is significantly increased, greatly reducing the overall heat transfer efficiency.

[0005] 2. Contradiction between mechanical properties and thermal conductivity:

[0006] In order to improve the thermal conductivity of the silicone layer, the amount of thermally conductive filler needs to be significantly increased, but excessive filler will cause a sharp drop in the tensile strength of the silicone, making structural failure prone to occur under vibration or extrusion conditions.

[0007] 3. Risk of interface separation between layers:

[0008] The physical bonding between the PI film auxiliary insulation layer and the thermally conductive silicone layer is weak, and interlayer peeling is prone to occur during long-term high-temperature operation of the PTC heating module, especially the silicone layer is easily squeezed out, causing heat dissipation failure.

[0009] 4. Insufficient high temperature resistance:

[0010] Existing materials are prone to powdering and brittle cracking under continuous working conditions at 260°C, resulting in deterioration of insulation performance.

[0011] For example, the thermally conductive silicone sheet disclosed in Chinese patent CN110172249A improves thermal conductivity by combining a silicone rubber matrix with a thermally conductive agent. However, this fails to optimize the filler-matrix interface, resulting in insufficient mechanical strength under high filler loads and a lack of long-term verification of resistance to temperatures exceeding 260°C. Chinese patent CN111909522A proposes using an aluminum nitride / aluminum oxide composite filler to improve thermal conductivity, but fails to incorporate a reinforcing phase or lubricating component. This results in reduced reliability in high-pressure friction environments and the risk of delamination at high temperatures.

[0012] Therefore, the present invention provides a thermally conductive insulating material and a preparation method and application thereof. Summary of the Invention

[0013] The purpose of the present invention is to provide a thermally conductive insulating material and a preparation method and application thereof. The obtained thermal insulating material can be directly used as a heat dissipation layer in a PTC heating module.

[0014] The purpose of the present invention is achieved by the following technical solutions:

[0015] In one aspect, the present invention provides a thermally conductive insulating material comprising the following components:

[0016] 70-85 parts by weight of silicone oil;

[0017] 85-150 parts by weight of thermally conductive filler;

[0018] 0.5-1.5 parts by weight of surface modifier;

[0019] 0-50 parts by weight of flame retardant;

[0020] 5 to 25 parts by weight of a reinforcing agent;

[0021] 0-15 parts by weight of lubricating material;

[0022] 0.02-0.1 parts by weight of inhibitor;

[0023] 0.5-3 parts by weight of a cross-linking agent;

[0024] 0.2 to 1 part by weight of catalyst.

[0025] Furthermore, the weight portion of the lubricating material is 5 to 15 parts.

[0026] Furthermore, the silicone oil is selected from a combination of one or more of vinyl silicone oil and phenyl silicone oil;

[0027] The thermally conductive filler is selected from a combination of one or more of aluminum oxide, aluminum nitride, boron nitride, silicon carbide, and silicon dioxide;

[0028] The surface modifier is selected from one or more combinations of silane coupling agents;

[0029] The flame retardant is aluminum hydroxide;

[0030] The reinforcing agent is selected from a combination of one or more of vinyl MQ silicone resin and methyl MQ silicone resin;

[0031] The cross-linking agent is selected from a combination of one or more of hydrogen-containing silicone oil, hydrogen-containing MQ silicone resin, and hydrogen-phenyl silicone oil;

[0032] The lubricating material is PTFE powder;

[0033] The inhibitor is a combination of one or more alkynol inhibitors;

[0034] The catalyst is one or more combinations of Custer catalysts.

[0035] Furthermore, the silicone oil is vinyl silicone oil, and the silicone oil is vinyl silicone oil and phenyl silicone oil;

[0036] The thermally conductive filler is boron nitride, or the thermally conductive filler is boron nitride and aluminum oxide;

[0037] The molecular formula of the silane coupling agent is (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] n –Si(CH3)3, where n=8-16;

[0038] The reinforcing agent is vinyl MQ silicone resin;

[0039] The inhibitor is 3,7,11-trimethyldodecyn-3-ol;

[0040] The catalyst is a Custer catalyst with a platinum content of 5000 ppm.

[0041] Furthermore, the viscosity of the vinyl silicone oil is 1000 to 50000 cps;

[0042] The viscosity of the phenyl silicone oil is 50 to 2000 cps;

[0043] The phenyl silicone oil is vinyl phenyl silicone oil;

[0044] The particle size of the PTFE powder is 1 to 3 μm.

[0045] In a second aspect, the present invention provides a thermally conductive insulating material, comprising the following components:

[0046] 70-85 parts by weight of silicone oil;

[0047] 85-150 parts by weight of thermally conductive filler;

[0048] 0.5-1.5 parts by weight of surface modifier;

[0049] 0-50 parts by weight of flame retardant;

[0050] 5 to 25 parts by weight of a reinforcing agent;

[0051] 0-15 parts by weight of lubricating material;

[0052] 0.02-0.1 parts by weight of inhibitor;

[0053] 0.5-3 parts by weight of a cross-linking agent;

[0054] 0.2 to 1 part by weight of catalyst.

[0055] In a third aspect, the present invention provides a method for preparing a thermally conductive insulating material, comprising the following steps:

[0056] Step a: uniformly mixing silicone oil, thermal conductive filler, surface modifier, flame retardant, reinforcing agent, and lubricating material, and stirring at room temperature to obtain a first mixture;

[0057] Step b: heating the first mixture to a first preset temperature, keeping the temperature for a period of time, and then cooling the mixture to a second preset temperature to obtain a second mixture;

[0058] Step c: adding an inhibitor and a cross-linking agent to the second mixture under a second preset temperature condition and stirring to obtain a third mixture;

[0059] Step d: After cooling the third mixture to room temperature, adding a catalyst to the third mixture and stirring to obtain a fourth mixture;

[0060] Step e: subjecting the fourth mixture to a pressing process and a curing process in sequence to obtain a thermally conductive insulating material.

[0061] Furthermore, in step a: the stirring time is 1 h;

[0062] In step b: the holding time is 2h to 3h;

[0063] In step c: stirring time is 0.5h;

[0064] In step d: stirring time is 0.5h;

[0065] The stirring processes from step a to step d are all carried out under the condition of a vacuum degree of less than or equal to -0.95 MPa to form a uniform mixture without bubbles.

[0066] Furthermore, the room temperature is 23°C to 25°C;

[0067] The first preset temperature is 110°C to 150°C;

[0068] The second preset temperature is less than or equal to 50°C;

[0069] During the curing process, the curing temperature is 110° C. to 160° C., and the curing time is 5 min to 25 min.

[0070] In a fourth aspect, the present invention provides an application of a thermally conductive insulating material in a PTC heating module, wherein the thermally conductive insulating material is directly used as a heat dissipation layer in the PTC heating module;

[0071] The thermally conductive insulating material is the thermally conductive insulating material mentioned above, or is the thermally conductive insulating material obtained by the method for preparing the thermally conductive insulating material mentioned above.

[0072] Compared with the prior art, the beneficial effects of the present invention include at least:

[0073] The thermally conductive insulating material of the present invention does not contain a polyimide (PI) film auxiliary insulating layer and has an integrated structure. Specifically, by discarding the PI film auxiliary insulating layer and directly constructing the integrated thermally conductive insulating material with a silicone resin matrix, the risk of interlayer separation (such as the silicone extrusion problem in PTC heating modules) is eliminated.

[0074] The thermally conductive insulating material of the present invention utilizes boron nitride or a boron nitride / alumina composite filler as the thermally conductive medium (i.e., thermally conductive filler), overcoming the thermal conductivity bottleneck of traditional PI film (increasing the thermal conductivity to ≥2.0 W / m·K). Boron nitride's self-lubricating properties significantly reduce the coefficient of friction (from 0.12 to 0.24), improving wear resistance and overcoming the incompatibility between high thermal conductivity and strong mechanical properties in silicone filler systems. Furthermore, the thermally conductive insulating material of the present invention further reduces the dynamic friction coefficient by adding PTFE lubricating powder, imparting excellent scratch resistance and extending the device's service life.

[0075] The thermally conductive insulating material of the present invention has a thermal conductivity of ≥2.0 W / m·K; a tensile strength of ≥0.8 MPa, with enhanced reliability; a friction coefficient of ≤0.24; a thermal weight loss of <1% after being placed at 260° C. for 1000 hours, and no brittle cracking or powdering upon bending, thus meeting the long-term reliability requirements of high-temperature working conditions (such as automotive electronics and industrial heating). BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 1 is a flow chart of a method for preparing a thermally conductive insulating material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0077] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concepts of the example embodiments to those skilled in the art. Identical reference numerals in the drawings represent identical or similar structures, and thus repeated descriptions thereof will be omitted.

[0078] The words expressing positions and directions described in the present invention are all explained with reference to the accompanying drawings as examples, but can be modified as needed, and all such modifications are within the scope of protection of the present invention.

[0079] The present invention introduces a heat-resistant material with a high temperature resistance of 260°C, a tensile strength of ≥0.8MPa, a friction coefficient of ≤0.24 (preferably, it can reach 0.12 to 0.24), an electric strength of ≥12kV, a thermal conductivity of ≥2.0W / m·K, and a thermal impedance of <1.2°C.cm under a pressure of 100psi. 3 A thermally conductive insulating material having a Shore A hardness of 12 to 60, high strength, friction resistance, scratch resistance, high insulation and high thermal conductivity, and a preparation method and application thereof.

[0080] The thermally conductive insulating material of the present invention can be directly used as a heat dissipation layer in electronic cooling devices such as positive temperature coefficient (PTC) heating modules. As a heat dissipation layer, the thermally conductive insulating material of the present invention (e.g., a thermally conductive insulating sheet) exhibits high strength, friction and scratch resistance, and high insulation properties, significantly improving heat dissipation efficiency and extending service life while maintaining excellent environmental performance.

[0081] When used, the thermally conductive insulating material is an integrated structure, eliminating the polyimide (PI) film auxiliary insulation layer. This avoids the interface delamination problem between the thermally conductive silicone layer and the PI film auxiliary insulation layer in traditional composite structures (the silicone extrusion rate in the PTC heating module is reduced to 0%). In some embodiments, when directly attached to the PTC heating element, the thermally conductive insulating material shows no delamination or extrusion after 1000 hot and cold cycles (-40°C to 260°C).

[0082] In actual application, the thermally conductive insulating material of the present invention includes a silicone resin matrix, the components of which include: 70 to 85 parts by weight of silicone oil, 85 to 150 parts by weight of thermally conductive filler, 0.5 to 1.5 parts by weight of surface modifier, 0 to 50 parts by weight of flame retardant, 5 to 25 parts by weight of reinforcing agent, 0 to 15 parts by weight of lubricating material, 0.02 to 0.1 parts by weight of inhibitor, 0.5 to 3 parts by weight of cross-linking agent and 0.2 to 1 part by weight of catalyst. The present invention makes the tensile strength of the thermally conductive insulating material ≥ 0.8 MPa by coordinating silicone oil and reinforcing agent. In addition, the present invention ensures that the thermally conductive insulating material has a thermal weight loss of <1% after being placed at 260°C for 1000 hours through a specific component ratio.

[0083] In some embodiments, the thermally conductive insulating material of the present invention includes a silicone resin matrix, which is composed of the following components: 70 to 85 parts by weight of silicone oil, 85 to 150 parts by weight of thermally conductive filler, 0.5 to 1.5 parts by weight of surface modifier, 0 to 50 parts by weight of flame retardant, 5 to 25 parts by weight of reinforcing agent, 0 to 15 parts by weight of lubricating material, 0.02 to 0.1 parts by weight of inhibitor, 0.5 to 3 parts by weight of cross-linking agent and 0.2 to 1 parts by weight of catalyst.

[0084] In some preferred embodiments, the lubricating material of the present invention is present in an amount of 5 to 15 parts by weight, reducing the friction coefficient of the thermally conductive insulating material to 0.13 to 0.16. Furthermore, the PTFE of the present invention forms a surface lubricating film, which increases the scratch resistance of the thermally conductive insulating material by more than three times.

[0085] The silicone oil of the present invention is selected from a combination of one or more of vinyl silicone oil and phenyl silicone oil. In some embodiments, the silicone oil is vinyl silicone oil; in some other embodiments, the silicone oil is a combination of vinyl silicone oil and phenyl silicone oil to increase the crosslinking density, so that the thermally conductive insulating material has a thermal weight loss of ≤0.52% after being stored at 260°C for 1000 hours.

[0086] In practice, the viscosity of the vinyl silicone oil of the present invention is 1,000 to 50,000 cps; the viscosity of the phenyl silicone oil is 50 to 2,000 cps, ensuring that the thermally conductive filler can be extruded and molded even under high loads. In practical applications, the phenyl silicone oil is vinyl phenyl silicone oil, which contains rigid benzene rings and improves interfacial compatibility with boron nitride, resulting in a thermally conductive insulating material with a tensile strength of 1.7 MPa.

[0087] The thermally conductive filler of the present invention is selected from a combination of one or more of aluminum oxide, aluminum nitride, boron nitride, silicon carbide, and silicon dioxide. In some embodiments, the thermally conductive filler is boron nitride; in some other embodiments, the thermally conductive filler is boron nitride and aluminum oxide.

[0088] When used, the particle size of the boron nitride of the present invention is 1 to 30 μm; the particle size of the aluminum oxide is 0.5 to 40 μm.

[0089] The surface modifier of the present invention is selected from one or more combinations of silane coupling agents. Further, the molecular formula of the silane coupling agent is (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] n -Si(CH3)3, wherein n=8 to 16. The present invention adopts a short chain structure -(CH3)2SiO-[Si(CH3)2O] n –Si(CH3)3 improves the bonding strength between the thermal conductive filler and the matrix, so that the strength retention rate of the thermal conductive insulation material after aging at 260°C is greater than 95%.

[0090] The flame retardant of the present invention is aluminum hydroxide.

[0091] When used, the particle size of aluminum hydroxide is 8 μm.

[0092] The reinforcing agent of the present invention is selected from a combination of one or more of vinyl MQ silicone resin and methyl MQ silicone resin. In some embodiments, the reinforcing agent of the present invention is vinyl MQ silicone resin.

[0093] The crosslinking agent of the present invention is selected from one or more combinations of hydrogen-containing silicone oil, hydrogen-containing MQ silicone resin, and hydrogen-phenyl silicone oil.

[0094] The lubricating material of the present invention is PTFE powder with a particle size of 1 to 3 μm, which can reduce the friction coefficient of the thermally conductive insulating material to 0.24 or less. Furthermore, the combination of boron nitride and PTFE can reduce the friction coefficient of the thermally conductive insulating material to as low as 0.13, while maintaining a thermal conductivity of 2.0 W / m·K or more.

[0095] The inhibitor of the present invention is a combination of one or more alkynol inhibitors. In some embodiments, the inhibitor of the present invention is 3,7,11-trimethyldodecene-3-ol. Using a high-boiling-point inhibitor (such as 3,7,11-trimethyldodecene-3-ol) to prevent premature setting during processing results in a finished product yield greater than 99%.

[0096] The catalyst of the present invention is a combination of one or more Custer catalysts. In some embodiments, the catalyst of the present invention is a Custer catalyst with a platinum content of 5000 ppm to ensure rapid curing in a low temperature environment (110-160° C. / 5-25 min).

[0097] refer to Figure 1 The method for preparing the thermally conductive insulating material of the present invention comprises steps a to e. Furthermore, the stirring process of steps a to d is performed under a vacuum degree of less than or equal to -0.95 MPa to form a uniform and bubble-free mixture.

[0098] Step a: uniformly mix silicone oil, thermal conductive filler, surface modifier, flame retardant, reinforcing agent, and lubricating material, and stir at room temperature to obtain a first mixture.

[0099] When used, the weight proportion of silicone oil is 70-85; the weight proportion of thermal conductive filler is 85-150; the weight proportion of surface modifier is 0.5-1.5; the weight proportion of flame retardant is 0-50; the weight proportion of reinforcing agent is 5-25; and the weight proportion of lubricating material is 0-15.

[0100] In practical application, the room temperature is 23° C. to 25° C.; and the stirring time is 1 h.

[0101] Step b: heating the first mixture to a first preset temperature, keeping the temperature for a period of time, and then cooling the mixture to a second preset temperature to obtain a second mixture.

[0102] When used, the first preset temperature is 110°C to 150°C; the insulation time is 2h to 3h; and the second preset temperature is less than or equal to 50°C.

[0103] Step c: adding an inhibitor and a cross-linking agent to the second mixture and stirring at a second preset temperature to obtain a third mixture.

[0104] When used, the weight portion of the inhibitor is 0.02 to 0.1; the weight portion of the cross-linking agent is 0.5 to 3.

[0105] In actual application, the stirring time is 0.5h.

[0106] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred to obtain a fourth mixture.

[0107] When used, the weight portion of the catalyst is 0.2 to 1.

[0108] In actual application, the stirring time is 0.5h.

[0109] Step e: subjecting the fourth mixture to a pressing process and a curing process in sequence to obtain a thermally conductive insulating material.

[0110] During application, the fourth mixture is poured onto a fluoroplastic release film and pressed into a 0.15mm to 0.3mm thick film layer using a flatbed vulcanizer or rollers. The film is then cured at a temperature of 110°C to 160°C for 5 to 25 minutes to obtain a thermally conductive insulating material, i.e., a thermally conductive insulating sheet.

[0111] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail by setting specific embodiments and comparative examples. It should be understood that the specific embodiments and comparative examples described herein are only used to explain the present invention and are not intended to limit the present invention.

[0112] It should be noted that in the embodiments and comparative examples of the present invention: the manufacturer of 1000cps vinyl silicone oil is Ambiy Special Silicone (Nantong) Co., Ltd., model VS1000LV; the manufacturer of 5000cps vinyl silicone oil is Ambiy Special Silicone (Nantong) Co., Ltd., model VS 5000LV; the manufacturer of 10000cps vinyl silicone oil is Shandong Dayi Chemical Co., Ltd., model DY-V401-10000; the manufacturer of 100cps vinyl phenyl silicone oil is Shandong Dayi Chemical Co., Ltd.; the manufacturer of 2000cps vinyl phenyl silicone oil is Ambiy Special Silicone (Nantong) Co., Ltd., model SF 1421; the manufacturer of 1μm boron nitride is Wuhu Weishi New Material Technology Co., Ltd., model WBN-E01 T; the manufacturer of 5μm boron nitride is Wuhu Weishi New Material Technology Co., Ltd., model WBN-E05 T; 30μm boron nitride is manufactured by Wuhu Weishi New Material Technology Co., Ltd., model WBN-30T; 0.5μm spherical alumina is manufactured by Wuhu Weishi New Material Technology Co., Ltd., model MS 05T; 5μm spherical alumina is manufactured by Wuhu Weishi New Material Technology Co., Ltd., model MS 5T; 40μm spherical alumina is manufactured by Wuhu Weishi New Material Technology Co., Ltd., model MS 40T; silane coupling agent ((CH3O)3Si(CH3)2SiO–[Si(CH3)2O] n –Si(CH3)3, n=8~16) is manufactured by Shandong Sike New Materials Co., Ltd.; the manufacturer of dodecyltrimethoxysilane is Shandong Sike New Materials Co., Ltd., and the model is SICO-N1213; the manufacturer of 8μm aluminum hydroxide is Hangzhou Xiaoshan Great Wall Aluminum Materials Co., Ltd.; the manufacturer of vinyl MQ resin is Ambiya Special Silicone (Nantong) Co., Ltd., and the model is VQM 1; the manufacturer of 3,7,11-trimethyldodecyn-3-ol is Forsman Technology (Beijing) Co., Ltd., and the model is TMDO; the manufacturer of hydrogen-containing silicone oil is Ambiya Special Silicone (Nantong) Co., Ltd., and the model is XL 1B; the manufacturer of hydrogen-containing MQ resin is Ambiya Special Silicone (Nantong) Co., Ltd., and the model is MQH 9; the manufacturer of hydrogen-phenyl silicone oil is Ambiya Special Silicone (Nantong) Co., Ltd., and the model is XL 245PT; the manufacturer of Castel catalyst with a platinum content of 5000ppm is Heraeus.

[0113] Example 1

[0114] The components of the thermally conductive insulating sheet of this embodiment are as follows:

[0115]

[0116] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0117] Step a: Vinyl silicone oil, boron nitride, aluminum hydroxide, (CH3O)3Si(CH3)2SiO–[Si(CH3)2O]8–Si(CH3)3, and vinyl MQ resin are uniformly mixed and stirred at room temperature for 1 hour to obtain a first mixture.

[0118] Step b: heating the first mixture to 130° C. and keeping the temperature for 3 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0119] Step c: adding hydrogen-containing silicone oil, hydrogen-containing MQ resin, and inhibitor to the second mixture at 50° C., and stirring for 30 minutes to obtain a third mixture.

[0120] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture, and stirring is continued for 30 minutes to obtain a fourth mixture.

[0121] Step e: pour the fourth mixture onto a fluoroplastic release film, use a fluoroplastic release film on the upper part, and press it into a film layer with a thickness of 0.3 mm using a flat vulcanizer, and cure it at 160° C. for 5 minutes to obtain a thermally conductive insulating sheet.

[0122] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0123] Thermal conductivity is 3.3W / mK; thermal impedance is 0.8℃.cm at 100psi pressure 3 / W; tensile strength of 1.2MPa; friction coefficient of 0.2; Shore A hardness of 40; dielectric strength of 20KV; thermal weight loss after being placed at 260°C for 1000h is 0.67%, and the thermally conductive insulating sheet can bend without cracking or powdering.

[0124] Example 2

[0125] The components of the thermally conductive insulating sheet of this embodiment are as follows:

[0126]

[0127] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0128] Step a: Vinyl silicone oil, vinylphenyl silicone oil, boron nitride, aluminum oxide, aluminum hydroxide, (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] 12–Si(CH 3 ) 3 and vinyl MQ resin were mixed evenly and stirred at room temperature for 1 h to obtain a first mixture.

[0129] Step b: heating the first mixture to 150° C. and keeping the temperature therefor for 2 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0130] Step c: adding hydrogen-containing silicone oil, hydrogen-containing MQ resin, hydrogen phenyl silicone oil and inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0131] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture, and the mixture is stirred for 30 minutes to obtain a fourth mixture.

[0132] Step e: Pour the fourth mixture onto the fluoroplastic release film, use the fluoroplastic release film on the upper part, press it into a 0.3 mm thick film layer through a flat vulcanizer, and cure it at 150° C. for 20 minutes to obtain a thermally conductive insulating sheet.

[0133] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0134] Thermal conductivity is 3.5W / mK; thermal impedance is 0.7℃.cm at 100psi pressure 3 / W; tensile strength of 1.5MPa; friction coefficient of 0.24; Shore A hardness of 52; dielectric strength of 15KV; thermal weight loss of 0.3% after being placed at 260°C for 1000h, and the thermally conductive insulating sheet can bend without cracking or powdering.

[0135] Example 3

[0136] The components of the thermally conductive insulating sheet of this embodiment are as follows:

[0137]

[0138]

[0139] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0140] Step a: Vinyl silicone oil, vinylphenyl silicone oil, boron nitride, aluminum oxide, (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] 16 –Si(CH 3 ) 3 and vinyl MQ resin were mixed uniformly and stirred at room temperature for 1 h to obtain a first mixture.

[0141] Step b: heating the first mixture to 150° C. and keeping the temperature for 2 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0142] Step c: adding hydrogen-containing silicone oil, hydrogen-containing MQ resin, hydrogen phenyl silicone oil and inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0143] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred for 30 minutes to obtain a fourth mixture.

[0144] Step e: Pour the fourth mixture onto a fluoroplastic release film, then apply the fluoroplastic release film on top, and roll-press the mixture to a 0.25 mm thick film layer. Then, cure the mixture at 150° C. for 20 minutes to obtain a thermally conductive insulating sheet.

[0145] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0146] Thermal conductivity is 2.2W / mK; thermal impedance is 1.2℃.cm at 100psi pressure 3 / W; tensile strength of 1.7MPa; friction coefficient of 0.21; Shore A hardness of 58; dielectric strength of 18KV; thermal weight loss of 0.43% after being placed at 260°C for 1000h, and the thermally conductive insulating sheet can bend without cracking or powdering.

[0147] Example 4

[0148] The components of the thermally conductive insulating sheet of this embodiment are as follows:

[0149]

[0150]

[0151] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0152] Step a: Vinyl silicone oil, boron nitride, aluminum oxide, (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] 12 -Si(CH3)3, vinyl MQ resin, and 1-3 μm PTFE were mixed uniformly and stirred at room temperature for 1 h to obtain a first mixture.

[0153] Step b: heating the first mixture to 120° C., maintaining the temperature for 2.5 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0154] Step c: adding hydrogen-containing silicone oil, hydrogen-containing MQ resin and inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0155] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred for 30 minutes to obtain a fourth mixture.

[0156] Step e: The fourth mixture was applied to a fluoroplastic release film, with the fluoroplastic release film on top, and rolled to form a 0.3 mm thick film layer. The film was then cured at 150° C. for 20 minutes to obtain a thermally conductive insulating sheet.

[0157] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0158] Thermal conductivity is 2W / mK; thermal impedance is 1.3℃.cm at 100psi pressure 3 / W; tensile strength of 1.3MPa; friction coefficient of 0.16; Shore A hardness of 47; dielectric strength of 21KV; thermal weight loss of 0.52% after being placed at 260°C for 1000h, and the thermally conductive insulating sheet can bend without cracking or powdering.

[0159] Example 5

[0160] The components of the thermally conductive insulating sheet of this embodiment are as follows:

[0161]

[0162]

[0163] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0164] Step a: Vinyl silicone oil, vinyl MQ resin, vinyl phenyl silicone oil, boron nitride, aluminum oxide, (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] 12 -Si(CH3)3, vinyl MQ resin, and 1-3 μm PTFE were mixed uniformly and stirred at room temperature for 1 h to obtain a first mixture.

[0165] Step b: heating the first mixture to 120° C., maintaining the temperature for 2.5 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0166] Step c: adding hydrogen-containing silicone oil, hydrogen-containing MQ resin, hydrogen phenyl silicone oil and inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0167] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred for 30 minutes to obtain a fourth mixture.

[0168] Step e: Pour the fourth mixture onto a fluoroplastic release film, then apply the fluoroplastic release film on top, and roll-press the mixture to a 0.2 mm thick film layer. Then, cure the mixture at 150° C. for 20 minutes to obtain a thermally conductive insulating sheet.

[0169] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0170] Thermal conductivity is 2.1W / mK; thermal impedance is 1.3℃.cm at 100psi pressure 3 / W; tensile strength of 0.9MPa; friction coefficient of 0.13; Shore A hardness of 55; dielectric strength of 16KV; thermal weight loss of 0.33% after being placed at 260°C for 1000h, and the thermally conductive insulating sheet can bend without cracking or powdering.

[0171] Comparative Example 1

[0172] The thermally conductive insulating sheet of this comparative example adopts a composite structure of a PI film auxiliary insulating layer + a thermally conductive silicone layer, and the components are as follows:

[0173]

[0174]

[0175] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0176] Step a: Stir vinyl silicone oil, aluminum oxide, and dodecyltrimethoxysilane coupling agent at room temperature for 1 hour to obtain a first mixture.

[0177] Step b: heating the first mixture to 130° C., keeping the temperature for 2 h, and then cooling the mixture to 50° C. to obtain a second mixture.

[0178] Step c: adding hydrogenated silicone oil and an inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0179] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred for 30 minutes to obtain a fourth mixture.

[0180] Step e: Pour the fourth mixture onto a 38 μm thick PI film, top it with a fluoroplastic release film, and roll-press it to a 0.3 mm thick film layer. Then, cure it at 150°C for 20 minutes to obtain a thermally conductive insulating sheet.

[0181] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0182] Thermal conductivity is 3W / mK (heat-conducting insulation layer without PI film); thermal impedance is 2.1℃.cm under 100psi pressure 3 / W; tensile strength is 0.24MPa (thermal insulation layer without PI film); friction coefficient is 0.35; Shore A hardness is 22; dielectric strength is 16KV; after being placed at 260°C for 1000h, thermal weight loss is 0.88%, and the thermal insulation sheet can bend, crack, and powder.

[0183] Comparative Example 2

[0184] The thermally conductive insulating sheet of this comparative example adopts a composite structure of a PI film auxiliary insulating layer + a thermally conductive silicone layer, and the components are as follows:

[0185]

[0186]

[0187] The preparation method of the thermally conductive insulating sheet of this embodiment is as follows (the stirring process from step a to step d is performed under the condition of a vacuum degree of less than or equal to -0.95 MPa):

[0188] Step a: Stir vinyl silicone oil, aluminum oxide, and dodecyltrimethoxysilane coupling agent at room temperature for 1 hour to obtain a first mixture.

[0189] Step b: Heat the first mixture to 130°C, keep it warm for 2 hours, and then cool it to 50°C to obtain a second mixture.

[0190] Step c: adding hydrogenated silicone oil and an inhibitor to the second mixture at 50° C. and stirring for 30 minutes to obtain a third mixture.

[0191] Step d: After the third mixture is cooled to room temperature, a catalyst is added to the third mixture and stirred for 30 minutes to obtain a fourth mixture.

[0192] Step e: Pour the fourth mixture onto a 38 μm thick PI film, top it with a fluoroplastic release film, and roll-press it to a 0.3 mm thick film layer. Then, cure it at 150°C for 20 minutes to obtain a thermally conductive insulating sheet.

[0193] The performance parameters of the thermally conductive insulating sheet of this embodiment are as follows:

[0194] Thermal conductivity is 3W / mK; thermal impedance is 1.4℃.cm at 100psi pressure 3 / W; tensile strength of 0.18MPa (excluding PI film); friction coefficient of 0.37; Shore A hardness of 27; dielectric strength of 12KV; thermal weight loss of 0.57% after being placed at 260°C for 1000h; the thermal insulating sheet cannot be bent, and the thermal insulating layer will crack, fall off, and powder when bent.

[0195] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limiting the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the invention without departing from the principles and purpose of the present invention. All such changes shall fall within the scope of protection of the claims of the present invention.

Claims

1. A thermally conductive insulating material, characterized in that: The thermally conductive insulating material is an integrated structure, and the thermally conductive insulating material includes the following components: 70-85 parts by weight of silicone oil; 85-150 parts by weight of thermally conductive filler; 0.5-1.5 parts by weight of surface modifier; 0-50 parts by weight of flame retardant; 5 to 25 parts by weight of a reinforcing agent; 0-15 parts by weight of lubricating material; 0.02-0.1 parts by weight of inhibitor; 0.5-3 parts by weight of a cross-linking agent; 0.2 to 1 part by weight of catalyst.

2. The thermally conductive insulating material according to claim 1, wherein The weight portion of the lubricating material is 5 to 15.

3. The thermally conductive insulating material according to claim 1, wherein The silicone oil is selected from a combination of one or more of vinyl silicone oil and phenyl silicone oil; The thermally conductive filler is selected from a combination of one or more of aluminum oxide, aluminum nitride, boron nitride, silicon carbide, and silicon dioxide; The surface modifier is selected from one or more combinations of silane coupling agents; The flame retardant is aluminum hydroxide; The reinforcing agent is selected from a combination of one or more of vinyl MQ silicone resin and methyl MQ silicone resin; The cross-linking agent is selected from a combination of one or more of hydrogen-containing silicone oil, hydrogen-containing MQ silicone resin, and hydrogen-phenyl silicone oil; The lubricating material is PTFE powder; The inhibitor is a combination of one or more alkynol inhibitors; The catalyst is one or more combinations of Custer catalysts.

4. The thermally conductive insulating material according to claim 3, characterized in that The silicone oil is vinyl silicone oil, and the silicone oil is vinyl silicone oil and phenyl silicone oil; The thermally conductive filler is boron nitride, or the thermally conductive filler is boron nitride and aluminum oxide; The molecular formula of the silane coupling agent is (CH3O)3Si(CH3)2SiO–[Si(CH3)2O] n –Si(CH3)3, where n=8-16; The reinforcing agent is vinyl MQ silicone resin; The inhibitor is 3,7,11-trimethyldodecyn-3-ol; The catalyst is a Custer catalyst with a platinum content of 5000 ppm.

5. The thermally conductive insulating material according to claim 3, wherein: The viscosity of the vinyl silicone oil is 1000 to 50000 cps; The viscosity of the phenyl silicone oil is 50 to 2000 cps; The phenyl silicone oil is vinyl phenyl silicone oil; The particle size of the PTFE powder is 1 to 3 μm.

6. A thermally conductive insulating material, characterized in that: It is composed of the following components: 70-85 parts by weight of silicone oil; 85-150 parts by weight of thermally conductive filler; 0.5-1.5 parts by weight of surface modifier; 0-50 parts by weight of flame retardant; 5 to 25 parts by weight of a reinforcing agent; 0-15 parts by weight of lubricating material; 0.02-0.1 parts by weight of inhibitor; 0.5-3 parts by weight of a cross-linking agent; 0.2 to 1 part by weight of catalyst.

7. A method for preparing a thermally conductive insulating material, characterized in that: The following steps are involved: Step a: uniformly mixing silicone oil, thermal conductive filler, surface modifier, flame retardant, reinforcing agent, and lubricating material, and stirring at room temperature to obtain a first mixture; Step b: heating the first mixture to a first preset temperature, keeping the temperature for a period of time, and then cooling the mixture to a second preset temperature to obtain a second mixture; Step c: adding an inhibitor and a cross-linking agent to the second mixture under a second preset temperature condition and stirring to obtain a third mixture; Step d: After cooling the third mixture to room temperature, adding a catalyst to the third mixture and stirring to obtain a fourth mixture; Step e: subjecting the fourth mixture to a pressing process and a curing process in sequence to obtain a thermally conductive insulating material.

8. The method for preparing a thermally conductive insulating material according to claim 7, wherein: In step a: stirring time is 1h; In step b: the holding time is 2h to 3h; In step c: stirring time is 0.5h; In step d: stirring time is 0.5h; The stirring processes from step a to step d are all carried out under the condition of a vacuum degree of less than or equal to -0.95 MPa to form a uniform mixture without bubbles.

9. The method for preparing a thermally conductive insulating material according to claim 7, wherein: The room temperature is 23°C to 25°C; The first preset temperature is 110°C to 150°C; The second preset temperature is less than or equal to 50°C; During the curing process, the curing temperature is 110° C. to 160° C., and the curing time is 5 min to 25 min.

10. Application of a thermally conductive insulating material in a PTC heating module, characterized in that: The thermally conductive insulating material is directly used as a heat dissipation layer in the PTC heating module; The thermally conductive insulating material is the thermally conductive insulating material according to any one of claims 1 to 6, or the thermally conductive insulating material obtained by the preparation method of the thermally conductive insulating material according to any one of claims 7 to 9.

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