A kind of high thermal conductivity potting silica gel and preparation method thereof

Abstract

The invention relates to the technical field of potting silica gel, and specifically discloses a high thermal conductivity potting silica gel and a preparation method thereof; the high thermal conductivity potting silica gel comprises an A component and a B component; the A component comprises vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, hydrogen-containing silicone oil, and an inhibitor; the B component comprises vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, and a platinum catalyst; the preparation of the modified MQ resin comprises the following steps: S1: taking maleic anhydride and tetrakis(4-aminobiphenyl)ethylene to prepare an intermediate A; S2: taking the intermediate A, low-viscosity vinyl silicone oil, vinyl modified flaky boron nitride, and xylene, stirring evenly, adding benzoyl peroxide, stirring for reaction, removing the solvent, and obtaining a modifier; S3: taking the hydrogen-containing MQ resin, the modifier, and xylene, stirring evenly, adding a platinum catalyst under a nitrogen atmosphere, reacting, and post-processing to obtain the modified MQ resin.

Description

Technical Field

[0001] The invention relates to the technical field of potting silica gel, and specifically discloses a high thermal conductivity potting silica gel and a preparation method thereof. Background Art

[0002] Potting is the process of assembling the various parts that make up electronic components. Silicone has excellent high and low temperature resistance, high elasticity, chemical inertness and excellent electrical insulation, and is often used as a potting material.

[0003] As the market's requirements for electronic products increase, the requirements for potting silicone performance are also increasing. Unmodified silicone has a very low thermal conductivity coefficient. Direct use will cause difficulties in heat dissipation of electronic devices, so thermal conductive fillers are often added for modification; however, during the potting process, only a narrow potting gap is left for the potting parts, so the potting silicone is required to have good fluidity. Adding too much thermal conductive filler will lead to a decrease in fluidity. Increasing fluidity by reducing the viscosity of the base silicone will lead to a decrease in mechanical properties. Therefore, it is of great significance to study a potting silicone with good mechanical properties, good fluidity, and good thermal conductivity and its preparation method. Summary of the invention

[0004] The object of the present invention is to provide a high thermal conductivity potting silica gel and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: the high thermal conductivity potting silica gel comprises component A and component B in a mass ratio of (0.9-1.1):1;

[0006] The component A comprises the following raw materials, calculated by weight: 30-35 parts of vinyl silicone oil, 55-60 parts of vinyl modified silicon carbide microspheres, 20-25 parts of modified MQ resin, 6-10 parts of hydrogen-containing silicone oil, and 0.02 parts of inhibitor;

[0007] The B component includes the following raw materials, calculated by weight: 30-35 parts of vinyl silicone oil, 55-60 parts of vinyl modified silicon carbide microspheres, 20-25 parts of modified MQ resin, and 0.01 parts of platinum catalyst.

[0008] More optimally, the inhibitor is ethynyl cyclohexanol.

[0009] More optimally, the preparation of the modified MQ resin comprises the following steps: S1: taking maleic anhydride and tetrakis(4-aminobiphenyl)ethylene, adding them to acetone and stirring evenly, reacting under nitrogen protection, adding sodium acetate and acetic anhydride, stirring evenly, reflux reaction, filtering and collecting the liquid, and removing the solvent by rotary evaporation to obtain intermediate A;

[0010] S2: Take intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flake boron nitride, add them to xylene and stir evenly, add benzoyl peroxide, stir and react under nitrogen protection, remove the solvent, and obtain a modifier;

[0011] S3: taking hydrogen-containing MQ resin and a modifier, adding them into xylene and stirring evenly, adding a platinum catalyst under a nitrogen atmosphere, reacting, and post-treating to obtain a modified MQ resin.

[0012] More optimally, the intermediate A comprises the following raw materials, by weight: 10 to 12 parts of maleic anhydride, 100 parts of acetone, 20 to 25 parts of tetrakis(4-aminobiphenyl)ethylene, 8 to 10 parts of sodium acetate, and 8 to 10 parts of acetic anhydride;

[0013] The modifier comprises the following raw materials, calculated by weight: 8 to 10 parts of intermediate A, 8 to 10 parts of low-viscosity vinyl silicone oil, and 12 to 18 parts of vinyl-modified flaky boron nitride;

[0014] The modified MQ resin comprises the following raw materials, calculated by weight: 6 to 8 parts of hydrogen-containing MQ resin and 15 to 20 parts of a modifier.

[0015] More optimally, the preparation of the hydrogenated MQ resin comprises the following steps: taking 1,1,3,3-tetramethyldisiloxane, ethanol, water, ethyl orthosilicate, and concentrated hydrochloric acid, stirring and reacting at 30-40°C for 3-4h, adding xylene and stirring for 10-15min, standing for 12-15h, separating the liquids, taking the oil layer (the one with acidic pH is the water layer, and the other layer is the oil layer), adding sodium bicarbonate and stirring for 30min, filtering to remove impurities, and distilling under reduced pressure at 160°C for 1h to obtain the hydrogenated MQ resin.

[0016] More optimally, the molar ratio of 1,1,3,3-tetramethyldisiloxane to ethyl orthosilicate is (0.9-1):1.

[0017] Preferably, the viscosity of the vinyl silicone oil is 350±8% mm 2 / s.

[0018] Preferably, the viscosity of the low viscosity vinyl silicone oil is 10±20% mm 2 / s.

[0019] More optimally, the preparation of the vinyl-modified silicon nitride microspheres comprises the following steps: taking silicon carbide microspheres, adding water and ethanol, stirring evenly, adding a vinyl silane coupling agent, heating to 50-60° C., stirring for 4-6 hours, filtering and drying, and obtaining vinyl-modified silicon carbide microspheres;

[0020] The vinyl modified silicon carbide microspheres include the following raw materials, calculated by weight: 10 parts of silicon carbide microspheres, 50 to 70 parts of water, 40 to 50 parts of ethanol, and 0.2 to 0.5 parts of vinyl silane coupling agent.

[0021] More optimally, the preparation of the vinyl-modified flaky boron nitride comprises the following steps: taking flaky boron carbide, adding water and ethanol, stirring evenly, adding a vinyl silane coupling agent, heating to 50-60° C., stirring for 4-6 hours, filtering and drying, and obtaining vinyl-modified flaky boron nitride;

[0022] The vinyl-modified flaky boron nitride comprises the following raw materials, calculated by weight: 10 parts of flaky boron carbide, 50-70 parts of water, 40-50 parts of ethanol, and 0.2-0.5 parts of a vinyl silane coupling agent.

[0023] The preparation method of the above-mentioned high thermal conductivity potting silica gel is as follows: vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, hydrogen-containing silicone oil, and inhibitor are mixed to obtain component A; vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, and platinum catalyst are mixed to obtain component B.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: modified MQ resin is added, the raw materials include hydrogenated MQ resin and modifier, the addition of hydrogenated MQ resin helps to improve the mechanical properties of silicone rubber, the modifier includes intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flake boron nitride; intermediate A is tetrakis(4-aminobiphenyl)ethylene modified by maleic anhydride, contains multiple aromatic rings, increases the rigidity of the modifier, improves the mechanical properties and improves the thermal expansion coefficient; the introduction of low-viscosity vinyl silicone oil increases the compatibility of the modifier with the vinyl silicone oil on the one hand, and improves the fluidity of the potting silicone on the other hand; the above two substances and the vinyl-modified flake boron nitride Adding in a certain proportion can obtain a modifier with a branched structure, which can effectively improve the thermal conductivity, fluidity and mechanical properties of the potting silicone. The addition amount of the three raw materials and the reaction time determine the branching degree and molecular weight of the modifier, so they need to be strictly controlled. A low branching degree will lead to no obvious improvement in fluidity, and a too large molecular weight will lead to an increase in viscosity, which is also not conducive to fluidity. At the same time, when preparing the hydrogenated MQ resin, the molar ratio of 1,1,3,3-tetramethyldisiloxane and ethyl orthosilicate needs to be controlled to control the molecular weight of the hydrogenated MQ resin. If the molecular weight of the hydrogenated MQ resin is too small, the mechanical properties will not be improved much, and if the molecular weight is too large, the viscosity will increase and the fluidity will decrease.

[0025] Vinyl resin viscosity is 350±8%mm 2 / s, viscosity is related to molecular weight and also affects mechanical properties. Vinyl resin with this viscosity can produce potting silicone with good mechanical properties. Adding low-viscosity vinyl silicone oil (viscosity of 10±20% mm2 / s) modifier, the potting silica gel also has good fluidity;

[0026] The thermal conductive filler used in the present invention includes vinyl-modified silicon carbide microspheres and vinyl-modified flaky boron nitride; the vinyl-modified flaky boron nitride has a high specific surface area, and is distributed in the modifier after being compounded with the intermediate A and the low-viscosity vinyl silicone oil to form a thermal conductive channel; the vinyl-modified silicon carbide microspheres are directly added to the vinyl silicone oil to increase the contact points between the fillers and serve as cross-linking points, which is helpful to improve the mechanical properties and thermal conductivity;

[0027] In summary, the high thermal conductivity potting silica gel prepared by the present invention has good thermal conductivity, as well as good mechanical properties and fluidity. DETAILED DESCRIPTION

[0028] The following is a preferred implementation of the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. For ordinary technicians in this technical field, all other embodiments obtained by ordinary technicians in this field without creative work without departing from the principle of the embodiment of the present invention are within the scope of protection of the present invention.

[0029] The following parts are by mass unless otherwise specified;

[0030] Preparation of vinyl-modified silicon carbide microspheres: Take 10 parts of silicon carbide microspheres, add 60 parts of water and 40 parts of ethanol, stir evenly, add 0.5 parts of vinyl silane coupling agent, heat to 55°C, stir for 6 hours, filter and dry to obtain vinyl-modified silicon carbide microspheres;

[0031] Preparation of vinyl-modified flake boron nitride: Take 10 parts of flake boron carbide, add 60 parts of water and 40 parts of ethanol, stir evenly, add 0.5 parts of vinyl silane coupling agent, heat to 55°C, stir for 6 hours, filter and dry to obtain vinyl-modified flake boron nitride;

[0032] Preparation of hydrogen-containing MQ resin: 1,1,3,3-tetramethyldisiloxane, ethanol, water, tetraethyl orthosilicate, and concentrated hydrochloric acid are taken, stirred at 40°C for 3h, xylene is added and stirred for 15min, and the mixture is allowed to stand for 12h. The oil layer is separated and added with sodium bicarbonate and stirred for 30min, and impurities are removed by filtration. The mixture is distilled under reduced pressure at 160°C for 1h to obtain hydrogen-containing MQ resin; the amount of the concentrated hydrochloric acid, water, ethanol, xylene, and sodium bicarbonate is 10%, 35%, 25%, 12%, and 8% of the total mass of 1,1,3,3-tetramethyldisiloxane and tetraethyl orthosilicate; the molar ratio of 1,1,3,3-tetramethyldisiloxane to tetraethyl orthosilicate is 1:1;

[0033] Example 1: S1: Take 12 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis (4-aminobiphenyl) ethylene, react for 8 hours under nitrogen protection, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react for 12 hours at 56.1°C, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 10 parts of intermediate A, 8 parts of low-viscosity vinyl silicone oil, and 15 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of xylene of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, add 0.3% of the total mass of benzoyl peroxide of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, react for 8 hours at 80°C under nitrogen protection, remove the solvent, and obtain a modifier;

[0034] S2: Take 7 parts of hydrogenated MQ resin and 16 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, mix well, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0035] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of vinyl silicone oil, 8 parts of hydrogenated silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0036] Example 2: S1: Take 10 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis(4-aminobiphenyl)ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 8 parts of intermediate A, 8 parts of low-viscosity vinyl silicone oil, and 12 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of xylene of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, add 0.3% of the total mass of benzoyl peroxide of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0037] S2: Take 6 parts of hydrogenated MQ resin and 15 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, stir evenly, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0038] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of vinyl silicone oil, 6 parts of hydrogenated silicone oil, 55 parts of vinyl-modified silicon carbide microspheres, 20 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of vinyl silicone oil, 55 parts of vinyl-modified silicon carbide microspheres, 20 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0039] Example 3: S1: Take 12 parts of maleic anhydride, 100 parts of acetone, and 25 parts of tetrakis (4-aminobiphenyl) ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 10 parts of intermediate A, 10 parts of low-viscosity vinyl silicone oil, and 18 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of xylene of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, add 0.3% of the total mass of benzoyl peroxide of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0040] S2: Take 8 parts of hydrogenated MQ resin and 20 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, stir evenly, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0041] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 35 parts of vinyl silicone oil, 10 parts of hydrogenated silicone oil, 560 parts of vinyl-modified silicon carbide microspheres, 25 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 35 parts of vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 25 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0042] Comparative Example 1 (changing the amount of the modifier raw material added, the remaining method steps are consistent with Example 1): S1: Take 12 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis (4-aminobiphenyl) ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 15 parts of intermediate A, 10 parts of low-viscosity vinyl silicone oil, and 10 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in xylene, stir evenly, add 0.3% of the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in benzoyl peroxide, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0043] S2: Take 7 parts of hydrogenated MQ resin and 16 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, mix well, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0044] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of vinyl silicone oil, 8 parts of hydrogenated silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0045] Comparative Example 2 (changing the amount of the modifier raw material added, the remaining method steps are consistent with Example 1): S1: Take 12 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis (4-aminobiphenyl) ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 5 parts of intermediate A, 5 parts of low-viscosity vinyl silicone oil, and 20 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in xylene, stir evenly, add 0.3% of the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in benzoyl peroxide, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0046] S2: Take 7 parts of hydrogenated MQ resin and 16 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, mix well, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0047] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of vinyl silicone oil, 8 parts of hydrogenated silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0048] Comparative Example 3 (the preparation steps of the hydrogen-containing MQ resin are changed, and the remaining steps are consistent with those of Example 1): S1: 1,1,3,3-tetramethyldisiloxane, ethanol, water, tetraethyl orthosilicate, and concentrated hydrochloric acid are taken, stirred at 40°C for 3h, xylene is added and stirred for 15min, allowed to stand for 12h, the oil layer is separated and taken, sodium bicarbonate is added and stirred for 30min, impurities are removed by filtration, and the hydrogen-containing MQ resin is obtained by reduced pressure distillation at 160°C for 1h; the amount of concentrated hydrochloric acid, water, ethanol, xylene, and sodium bicarbonate is 10%, 35%, 25%, 12%, and 8% of the total mass of 1,1,3,3-tetramethyldisiloxane and tetraethyl orthosilicate; the molar ratio of 1,1,3,3-tetramethyldisiloxane to tetraethyl orthosilicate is 0.6:1;

[0049] S2: Take 12 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis(4-aminobiphenyl)ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 10 parts of intermediate A, 8 parts of low-viscosity vinyl silicone oil, and 15 parts of vinyl-modified flake boron nitride, add 12 times the total mass of xylene of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flake boron nitride, stir evenly, add 0.3% of the total mass of benzoyl peroxide of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flake boron nitride, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0050] S3: Take 7 parts of hydrogenated MQ resin and 16 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, mix well, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0051] S4: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of vinyl silicone oil, 8 parts of hydrogenated silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0052] Comparative Example 4 (using Shandong Boyue New Material Technology Co., Ltd. model 201-100 vinyl silicone oil (viscosity 100±8% mm 2 / s) replaces 201-350 vinyl silicone oil, and the remaining steps are consistent with Example 1): S1: Take 12 parts of maleic anhydride, 100 parts of acetone, and 20 parts of tetrakis (4-aminobiphenyl) ethylene, react under nitrogen protection for 8 hours, add 9 parts of sodium acetate and 9 parts of acetic anhydride, react at 56.1°C for 12 hours, filter the liquid, and remove the solvent by rotary evaporation to obtain intermediate A; take 10 parts of intermediate A, 8 parts of low-viscosity vinyl silicone oil, and 15 parts of vinyl-modified flaky boron nitride, add 12 times the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in xylene, stir evenly, add 0.3% of the total mass of intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flaky boron nitride in benzoyl peroxide, stir evenly, react at 80°C for 8 hours under nitrogen protection, remove the solvent, and obtain a modifier;

[0053] S2: Take 7 parts of hydrogenated MQ resin and 16 parts of modifier, add xylene 5 times the mass of hydrogenated MQ resin, add 10 ppm of platinum catalyst under nitrogen atmosphere, mix well, react at 70°C for 6 hours, add 100 parts of activated carbon and stir for 2 hours after cooling, remove the solvent, and obtain modified MQ resin;

[0054] S3: The high thermal conductivity potting silicone comprises component A and component B; preparation of component A: take 30 parts of 201-100 vinyl silicone oil, 8 parts of hydrogenated silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.02 parts of inhibitor ethynyl cyclohexanol, mix them evenly to obtain component A; preparation of component B: take 30 parts of 201-100 vinyl silicone oil, 60 parts of vinyl-modified silicon carbide microspheres, 22 parts of modified MQ resin, and 0.01 parts of platinum catalyst and mix them evenly to obtain component B.

[0055] In the above examples, the test methods used are conventional methods unless otherwise specified; the raw materials used are commercially available unless otherwise specified, and the sources of the raw materials are as follows: benzoyl peroxide (CAS: 94-36-0); ethanol (CAS: 64-17-5); xylene (CAS: 1330-20-7); vinyltrimethoxysilane (CAS: 2768-02-7); maleic anhydride (CAS: 108-31-6); acetone (CAS: 67-64-1); sodium acetate (CAS: 127-09-3); acetic anhydride (CAS: 108-24-7); hydrogenated silicone oil (LI1061, Hubei Xinhongli Chemical Co., Ltd.); 1,1,3,3-tetramethyldisiloxane (CAS :3277-26-7); tetraethyl orthosilicate (CAS: 78-10-4); concentrated hydrochloric acid (36%, Guangzhou Chemical Reagent); sodium bicarbonate (S24153, Shanghai Yuanye); silicon carbide microspheres (model: YM-SiC-01W, Yumu Nano); flake boron carbide (hBN-CM-01, Yamei Nano); tetrakis (4-aminobiphenyl) ethylene (CAS: 2252187-21-4); low viscosity vinyl silicone oil (model: 201-10, Shandong Boyue New Materials Technology Co., Ltd.); platinum catalyst (A122, Xuzhou Jie Innovation Materials Technology Co., Ltd.); vinyl silicone oil (model: 201-350, Shandong Boyue New Materials Technology Co., Ltd.); ethynyl cyclohexanol (CAS: 78-27-3).

[0056] Experiment: Take component A and component B prepared in Examples 1 to 3 and Comparative Examples 1 to 4; (1) Mix them evenly in a mass ratio of 1:1 within 5 minutes, and test them using a digital rotational viscometer at 25°C, with a rotation speed of 60 r / min, and complete the test within 10 minutes; (2) Mix them evenly in a mass ratio of 1:1, cure at room temperature for 24 hours, obtain a sample, and test the tensile properties with reference to GBT 528-2009; (3) Use TC-3000E thermal conductivity tester to test thermal conductivity; see the table below for specific data;

[0057]

[0058] Conclusion: Comparative Example 1 and Comparative Example 2 change the addition ratio of low-viscosity vinyl silicone oil, intermediate A, and vinyl-modified flaky boron nitride in the modifier, and the performance decreases. It can be seen that the ratio of the modifier raw materials is of great significance; Comparative Example 3 changes the preparation steps of the hydrogenated MQ resin, and the molar ratio of 1,1,3,3-tetramethyldisiloxane and tetraethyl orthosilicate is 0.6:1. The molecular weight of the obtained hydrogenated MQ resin increases, resulting in increased viscosity and poor fluidity; Comparative Example 4 uses vinyl silicone oil with lower viscosity. Although the fluidity is better, the mechanical properties decrease significantly; In summary, the high thermal conductivity potting silicone prepared by the present invention not only has good thermal conductivity, but also has good fluidity and good mechanical properties.

[0059] Finally, it should be noted that the above is only a preferred embodiment of the present invention, but the protection scope of this application is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the spirit and principle of the present invention and within the technical scope disclosed in this application should be included in the protection scope of this application; in the absence of conflict, the embodiments of this application and the features in the embodiments can be combined with each other. Therefore, the protection scope of this application shall be based on the protection scope of the claims.

Claims

1. A high thermal conductivity potting silica gel, characterized by: The following steps are involved: The high thermal conductivity potting silica gel comprises component A and component B in a mass ratio of (0.9-1.1):1; The component A comprises the following raw materials, by weight: 30-35 parts of vinyl silicone oil, 55-60 parts of vinyl modified silicon carbide microspheres, 20-25 parts of modified MQ resin, 6-10 parts of hydrogen-containing silicone oil, and 0.02-0.22 parts of inhibitor; The B component includes the following raw materials, calculated by weight: 30-35 parts of vinyl silicone oil, 55-60 parts of vinyl modified silicon carbide microspheres, 20-25 parts of modified MQ resin, and 0.01-0.02 parts of platinum catalyst; Preparation of the modified MQ resin The following steps are involved: S1: maleic anhydride and tetrakis(4-aminobiphenyl)ethylene are added to acetone and stirred evenly, and reacted at room temperature for 8-9 hours under nitrogen protection, and sodium acetate and acetic anhydride are added, and stirred at 56-57°C for 10-12 hours, and post-treated to obtain intermediate A; S2: Take intermediate A, low-viscosity vinyl silicone oil, and vinyl-modified flake boron nitride, add them to xylene and stir evenly, add benzoyl peroxide, stir and react at 80-85°C for 6-8 hours under nitrogen protection, remove the solvent, and obtain a modifier; S3: adding hydrogen-containing MQ resin and modifier into xylene and stirring evenly, adding platinum catalyst under nitrogen atmosphere, reacting at 70-75° C. for 6-7 hours, and post-treating to obtain modified MQ resin; The intermediate A comprises the following raw materials, calculated by weight: 10-12 parts of maleic anhydride, 100-110 parts of acetone, 20-25 parts of tetrakis(4-aminobiphenyl)ethylene, 8-10 parts of sodium acetate, and 8-10 parts of acetic anhydride; The modifier comprises the following raw materials, calculated by weight: 8 to 10 parts of intermediate A, 8 to 10 parts of low-viscosity vinyl silicone oil, and 12 to 18 parts of vinyl-modified flaky boron nitride; The modified MQ resin comprises the following raw materials, calculated by weight: 6 to 8 parts of hydrogen-containing MQ resin, 15 to 20 parts of modifier; The viscosity of the vinyl silicone oil is 350±8% mm 2 / s, the viscosity of the low viscosity vinyl silicone oil is 10±20% mm 2 / s; The preparation of the hydrogen-containing MQ resin comprises the following steps: mixing 1,1,3,3-tetramethyldisiloxane and ethyl orthosilicate, adding ethanol, water and concentrated hydrochloric acid in sequence, stirring and reacting at 30-40° C. for 3-4 hours, and post-treating to obtain the hydrogen-containing MQ resin; The molar ratio of 1,1,3,3-tetramethyldisiloxane to ethyl orthosilicate is (0.9-1):

1.

2. The high thermal conductivity potting silica gel according to claim 1, characterized in that: The vinyl modified silicon carbide microspheres include the following raw materials, calculated by weight: 10 parts of silicon carbide microspheres, 50-70 parts of water, 40-50 parts of ethanol, and 0.2-0.5 parts of vinyl silane coupling agent.

3. The high thermal conductivity potting silica gel according to claim 1, characterized in that: The vinyl-modified flaky boron nitride comprises the following raw materials, calculated by weight: 10 parts of flaky boron carbide, 50-70 parts of water, 40-50 parts of ethanol, and 0.2-0.5 parts of a vinyl silane coupling agent.

4. A method for preparing a high thermal conductivity potting silica gel according to any one of claims 1 to 3, characterized in that: Step 1: Mix vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, hydrogen-containing silicone oil, and inhibitor to obtain component A; Step 2: Mix vinyl silicone oil, vinyl modified silicon carbide microspheres, modified MQ resin, and platinum catalyst to obtain component B; Step 3: When using, mix component A and component B to obtain high thermal conductivity potting silicone.

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