Method for preparing silicone-based composite material with three-dimensional heat conduction network based on liquid / solid two-phase filler

Abstract

The application discloses a preparation method of an organic silicon-based composite material with a three-dimensional heat conduction network based on liquid / solid two-phase fillers, photocuring preparation of organic silicon microspheres, mixing of a base material and the organic silicon microspheres loaded with liquid heat conduction fillers and solidification, use of the organic silicon microspheres as a template, and formation of a stable heat conduction network passage by the solid fillers. The surface of the organic silicon microspheres is loaded with liquid heat conduction fillers, the organic silicon microspheres are used as a template for accumulation, a method of pouring organic silicon precursors mixed with solid heat conduction fillers is used, and the organic silicon composite material with the three-dimensional heat conduction network is constructed. The method has the following advantages: (1) the bridging between the organic silicon polymer interface and the three-dimensional heat conduction network is regulated, the synergistic effect between the liquid heat conduction fillers and the solid heat conduction fillers is used, and the interface thermal resistance is reduced; and (2) the three-dimensional high-heat-conduction network is formed by the accumulation of the organic silicon microspheres, and thus the filler content for forming the heat conduction passage is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of organosilicon-based composite materials, and more specifically to a method for preparing organosilicon-based composite materials with a three-dimensional thermally conductive network based on liquid / solid two-phase fillers. Background Technology

[0002] In recent years, with the rapid development of electronic information and 5G technology, electronic components and printed circuits are increasingly trending towards high integration, miniaturization, and high energy density. Efficient interface thermal management has become one of the bottleneck problems in this industry. Currently, one of the effective methods to enhance the thermal transfer of electronic materials is to use thermal interface materials with high thermal conductivity. Silicon-based materials, with their high elasticity, weather resistance, and resistance to high and low temperatures, have become one of the key materials in the thermal management of electronic devices. However, as a polymer material, silicone itself has a low thermal conductivity (0.17 W / m²). -1 K -1 Improving the thermal conductivity of organosilicon materials is key to their application in heat dissipation of electronic devices.

[0003] Currently, the main method to improve the thermal conductivity of organosilicon materials is to blend high thermal conductivity fillers (carbon fiber, carbon black, boron nitride, alumina, etc.) with the organosilicon matrix. This method often requires the addition of large amounts of fillers to form a boundary between the thermally conductive fillers and the matrix, thereby creating an effective thermal conductivity pathway. In dispersed composite organosilicon materials, the interfacial phonon vibration frequencies of the thermally conductive fillers and the soft organosilicon matrix are mismatched, resulting in a large interfacial thermal barrier and an actual thermal conductivity at least an order of magnitude lower than the theoretical value. Furthermore, high filler content often leads to a series of problems such as reduced processing performance, increased material modulus, and increased density. By constructing a three-dimensional interconnected filler network within the organosilicon matrix, the thermal barrier at the filler-polymer phase interface can be minimized, creating an efficient phonon percolation thermal conductivity pathway. This is expected to overcome the common bottleneck problem of low thermal conductivity in existing thermally conductive organosilicon materials.

[0004] Furthermore, to achieve higher thermal conductivity, filler blending is commonly used to achieve better thermal conductivity. Examples include blending fillers of different sizes, blending sheet-like and granular fillers, and blending linear and granular fillers. However, the thermal conductivity of composite materials mainly depends on the combined effect of the molecular chain vibrations, lattice vibrations of the silicone matrix, and the lattice vibrations of the inorganic fillers. The significant difference in modulus between the silicone matrix and the solid filler is the main reason for the high phonon scattering at the polymer / filler interface. Therefore, blending solid fillers makes it easier to form thermally conductive pathways and improve the thermal conductivity of silicone composites; however, the high interfacial thermal resistance between the polymer and solid filler still severely limits the improvement of the overall thermal conductivity of the composite material. Summary of the Invention

[0005] To address the technical challenges of existing high thermal conductivity organosilicon-based composite materials, the present invention aims to provide a method for preparing an organosilicon-based composite material with a three-dimensional thermally conductive network based on a liquid / solid two-phase filler. This novel organosilicon-based composite material can achieve high thermal conductivity with a significantly reduced filler content, thereby enabling its application in the field of heat dissipation for electronic devices.

[0006] The first aspect of the present invention relates to a method for preparing organosilicon microspheres by photocuring, wherein the surface of the microspheres is loaded with liquid thermally conductive filler.

[0007] Within the scope of this invention, there is a thermosetting liquid organosilicon base material mixed with solid thermally conductive filler. The base material is mixed with organosilicon microspheres loaded with liquid thermally conductive filler and then cured. Using the organosilicon microspheres as templates, the solid filler forms a stable thermally conductive network pathway.

[0008] According to an embodiment of the present invention, the filler content accounts for less than 50% of the total volume of the composite material, and the filler volume percentage is preferably 30%, more preferably 25% or less.

[0009] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0010] This invention provides a method for preparing an organosilicon-based composite material with a three-dimensional thermally conductive network based on a liquid / solid two-phase filler. The preparation method includes:

[0011] (1) Prepare a photocurable polysiloxane-based mixture, load it into a syringe, and drop the mixture into ethanol under light irradiation to prepare organosilicon elastomer microspheres.

[0012] (2) The organosilicon elastomer microspheres prepared in step (1) are mixed with liquid thermally conductive fillers to prepare organosilicon microspheres with liquid thermally conductive fillers loaded on the surface.

[0013] (3) After the solid thermally conductive filler is blended with the thermocurable polysiloxane-based mixture, it is then mixed with the organosilicon microspheres loaded with liquid thermally conductive filler obtained in step (2) and cross-linked and cured.

[0014] In step (1) of the method according to the invention, the polysiloxane microspheres may be UV-curable. An exemplary UV-curable polysiloxane base composition comprises the following two schemes:

[0015] Option 1: An exemplary photocurable polysiloxane-based composition comprises: 1-90% α,ω-vinyl diorganopolysiloxane (a1), 1-90% hydrogen-containing siloxane (b1), and 0.01-3% photoinitiator (c1).

[0016] (a1) At least one polysiloxane comprising at least two vinyl groups bonded to silicon atoms per molecule.

[0017] XR 2 SiO-(SiR 1 2-O-) h SiR 2 X(1)

[0018] Among them, R 1 Indicates methyl or phenyl. R 2 The symbol represents a hydrocarbon group or an alkoxy group, preferably 1 to 30, more preferably selected from CO-8 hydrocarbon groups or alkoxy groups, where CO-8 hydrocarbon group is (CH2)n, and n is 0 to 8. X represents a vinyl functional group. The value of h is an integer from 10 to 1500.

[0019] The preferred linear reactive polysiloxane is an α,ω-vinylened diorganopolysiloxane of general formula (1), wherein X = vinyl and h is an integer from 10 to 1500.

[0020] (b1) At least one molecule having at least one bonded to the same or different silicon atoms, capable of crosslinking with the vinyl polysiloxane of component (a). Therefore, it is a hydrogen-containing polysiloxane.

[0021] The hydrogen-containing polysiloxane with SiH groups can undergo a crosslinking reaction with component (a1), that is, a cured product is formed by reacting the SiH groups in component (a) with the vinyl groups in component (a). Preferably, as component (b1), at least one hydrogen-containing polysiloxane having two, three or more SiH groups per molecule is used. The hydrogen-containing polysiloxane can have a linear, branched or cyclic structure, and may also contain a network structure in the molecular chain without compromising the purpose of the invention.

[0022] (c1) One or more platinum-based photoinitiating catalysts: cyclopentadienyl platinum complex, 1,5-cyclooctadienyl platinum complex, platinum β-diketone coordination compound.

[0023] Option 2: An exemplary photocurable polysiloxane base composition comprises: 50-95% α,ω-vinyl diorganopolysiloxane; 10-30% (mercapto)methylsiloxane-dimethylsiloxane copolymer (13-17%); and 0.01-3% photoinitiator.

[0024] (b2) At least one (thiol) methylsiloxane-dimethylsiloxane copolymer having at least one bonded to the same or different silicon atoms per molecule, capable of photocuring and crosslinking with the vinyl polysiloxane of component (a).

[0025] The thiol-containing polysiloxane with SH groups can undergo a click chemical reaction with vinyl groups to form a cured product. Preferably, as component (b2), at least one hydrogen-containing polysiloxane having two, three or more SH groups per molecule is used.

[0026] (c2) At least one photoinitiator, preferably diphenyl(2,4,6-trimethylbenzoyl)oxidase (TPO). Ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate (TPO-L)

[0027] In step (2) of the method according to the present invention, the thermally conductive filler used is liquid metal; preferably a gallium indium tin alloy.

[0028] In step (3) of the method according to the present invention, the thermally conductive filler used may preferably be selected from metal oxides (alumina, zinc oxide, calcium oxide, magnesium oxide); nitrides (boron nitride); carbon materials (graphene, graphite, carbon nanotubes); metals (gold, silver, copper); preferably graphite.

[0029] In step (3) of the method according to the present invention, the polysiloxane microspheres may be a polysiloxane-based composition that has been thermosetting.

[0030] Option 1: An exemplary thermosetting polysiloxane base composition comprises: 5-50% thioctic acid, 10%-80% single-ended epoxy-modified polysiloxane (d1), and 10%-80% double-ended epoxy-modified polysiloxane (e1).

[0031] (d1) A polysiloxane containing at least one epoxy group bonded to a silicon atom.

[0032] XR 5 SiO-(SiR 3 2-O-) n SiR 4 (2)

[0033] Among them, R 3 Indicates methyl or phenyl. R 4 R 5 The symbol represents a hydrocarbon group or an alkoxy group, preferably 1 to 30, more preferably selected from C1-8 hydrocarbon groups or alkoxy groups. X = epoxy, epoxycyclohexyl. h is an integer from 10 to 1500.

[0034] (e1) At least one polysiloxane containing at least two epoxy groups bonded to silicon atoms per molecule.

[0035] XR 7 SiO-(SiR 6 2-O-) n SiR 7 X(3)

[0036] Among them, R 6 Indicates methyl or phenyl. R 7 The symbol represents a hydrocarbon group or an alkoxy group, preferably 1 to 30, more preferably selected from C1-8 hydrocarbon groups or alkoxy groups. X = epoxy, epoxycyclohexyl. h is an integer from 10 to 1500.

[0037] Option 2: An exemplary thermosetting polysiloxane base composition comprises: a vinyl diorganopolysiloxane, a hydrogen-containing siloxane (b1), and a platinum catalyst (f1).

[0038] (f1) At least one platinum catalyst, preferably Karstedt's catalyst or Speier's catalyst.

[0039] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in:

[0040] Liquid thermally conductive fillers are loaded onto the surface of organosilicon microspheres. These organosilicon microspheres are then stacked as templates, and an organosilicon composite material with a three-dimensional thermally conductive network is constructed by casting an organosilicon precursor mixed with solid thermally conductive fillers. The advantages of this method are: (1) it regulates the bridging between the organosilicon polymer interface and the three-dimensional thermally conductive network, and reduces the interfacial thermal resistance through the synergistic effect between the liquid and solid thermally conductive fillers; (2) the stacking of organosilicon microspheres forms a three-dimensional high thermal conductivity network, thereby significantly reducing the filler content required to form the thermally conductive pathway. Attached Figure Description

[0041] Figure 1 The 1H NMR spectrum of a single-ended epoxy-modified polysiloxane;

[0042] Figure 2 The 1H NMR spectrum of double-ended epoxy-modified polysiloxane;

[0043] Figure 3 The 1H NMR spectrum of α,ω-divinyl-hexamethyltrisiloxane;

[0044] Figure 4 Photograph of organosilicon microspheres;

[0045] Figure 5 Photograph of organosilicon microspheres encapsulating liquid metal;

[0046] Figure 6 Microscopic image of a cross-section of an organosilicon composite material with a three-dimensional thermally conductive network. Detailed Implementation

[0047] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto:

[0048] Example 1

[0049] Preparation of single-end epoxy-modified polysiloxanes:

[0050] (1) Weigh 50g of hexamethylcyclotrisiloxane crystals into a flask and evacuate the vacuum by circulating nitrogen gas.

[0051] (2) Add 140 ml of dry tetrahydrofuran solvent, mix and stir until dissolved to obtain solution A;

[0052] (3) Add 13 ml of n-butyllithium solution to solution A and stir at room temperature for 1.5 h;

[0053] (4) Add 4.8 ml of dimethylchlorosilane to the mixture from step (3) and stir overnight at room temperature;

[0054] (5) The mixture obtained in step (4) is concentrated by rotary evaporation, treated with n-hexane, and lithium chloride is filtered out.

[0055] (6) The mixture obtained in step (5) was distilled under reduced pressure at 160°C for 2 hours to obtain a transparent monofunctional hydride polydimethylsiloxane solution B.

[0056] (7) Add 3.1g of allyl glycidyl ether and 52μl of Pt-xylene solution to the obtained 48.2g solution B and react in an oil bath at 80℃ for 10h to obtain solution C;

[0057] (8) Add 5g of activated carbon to solution C obtained in step (7), stir evenly and filter to obtain solution D;

[0058] (9) The obtained solution was distilled under reduced pressure at 160℃ for 2 hours to obtain a transparent liquid single-end epoxy modified polysiloxane.

[0059] The product obtained was a transparent liquid with a yield of 94% and a molecular weight of 2650 gmol. -1 The hydrogen NMR spectrum is attached. Figure 1 The structural formula of the single-end epoxy-modified polysiloxane is shown in (2).

[0060] XR 5 SiO-(SiR 3 2-O-) n SiR 4 (2)

[0061] Among them, R 3 R represents methyl. 4 R represents n-butyl. 5 It represents (CH2)3, h is 33.

[0062] Preparation of double-ended epoxy-modified polysiloxanes:

[0063] (1) Mix 120g of octamethylcyclotetrasiloxane and 5.2g of 1,1,3,3-tetramethyldisiloxane evenly, then add 310μl of trifluoromethanesulfonic acid and react in an oil bath at 80℃ for 10h to obtain solution E.

[0064] (2) Add 5g of magnesium oxide to the obtained solution E, stir thoroughly and filter to obtain solution F;

[0065] (3) Distill solution F under reduced pressure at 160℃ for 2 hours to obtain bifunctional hydride polydimethylsiloxane solution G;

[0066] (4) Mix 110g of solution G obtained in step (3) with 7.3g of allyl glycidyl ether and 120μl of Pt~

[0067] Xylene solution was mixed and reacted in an oil bath at 80℃ for 10 hours to obtain solution H;

[0068] (5) Add activated carbon to the solution H obtained in step (4), stir evenly and filter to obtain solution I;

[0069] (6) The obtained solution I was distilled under reduced pressure at 160℃ for 2 hours to obtain a transparent liquid double-ended epoxy modified polysiloxane.

[0070] The product obtained was a transparent liquid with a yield of 88% and a molecular weight of 4800 gmol. -1 The hydrogen NMR spectrum is attached. Figure 2 .

[0071] Preparation of α,ω-vinylened diorganopolysiloxanes:

[0072] (1) Mix 120g of octamethylcyclotetrasiloxane and 3.9g of 1,3-tetramethyldivinyldisiloxane evenly, then add 305μl of trifluoromethanesulfonic acid and react in an oil bath at 80℃ for 10h to obtain solution J.

[0073] (2) Add 5g of magnesium oxide to the obtained solution J, stir thoroughly and filter to obtain solution K;

[0074] (3) The obtained solution K was distilled under reduced pressure at 160℃ for 2 hours to obtain a transparent solution 1,5-divinyl-hexamethyltrisiloxane.

[0075] The product obtained was a transparent liquid with a yield of 84% and a molecular weight of 7500 gmol. -1 The hydrogen NMR spectrum is attached. Figure 3 The vinylized polysiloxane is an α,ω-vinylened diorganopolysiloxane, with the structural formula shown in formula (1):

[0076] XR 2 SiO-(SiR 1 2-O-)h SiR 2 X(1)

[0077] Among them, R 1 R represents methyl. 2 Let (CH2)n be an expression where n is 0, X = vinyl, and h is 99. Further, the specific structure of α,ω-vinylened diorganopolysiloxane can be written as follows:

[0078]

[0079] Preparation of organosilicon microspheres: A photocurable organosilicon polysiloxane reactant was prepared: 1.4208 g of α,ω-vinyl diorganosiloxane; 0.3071 g of (mercapto)methylsiloxane-dimethylsiloxane copolymer (SMS142, Gelest Inc.); and 0.0120 g of TPO-L. The photocurable reactant was loaded into a syringe with a needle (0.3 × 13 mm) and titrated dropwise into UV-irradiated ethanol. The resulting organosilicon microspheres (see attached image) were collected. Figure 4 ).

[0080] 13-17% (mercapto)methylsiloxane-dimethylsiloxane copolymer (SMS142, Gelest, Inc.), with the structure shown below.

[0081]

[0082] Coating of microspheres with liquid thermally conductive filler: Organosilicon microspheres are mixed with gallium indium tin alloy until all gallium indium tin alloy is uniformly coated on the surface of the organosilicon microspheres. The amount of gallium indium tin alloy added is 2% of the volume of the organosilicon microspheres (see attached figure). Figure 5 ).

[0083] A three-dimensional thermally conductive silicone-based composite material was constructed using liquid / solid two-phase fillers: Graphite, thermosetting silicone precursors (0.2416 g thioctic acid; 0.6237 g single-ended epoxy polysiloxane; 0.8947 g double-ended epoxy modified polysiloxane), and surface-coated liquid metal-silicone microspheres were mixed and cured at 150℃ and 180℃ for 2 h each. The graphite content accounted for 20% of the total volume of the silicone composite material. The silicone-based thermally conductive composite material obtained through the above steps had dimensions of 40 × 25 × 4 mm. The cross-section of the composite material demonstrates the successful construction of a continuous three-dimensional thermally conductive filler network (see attached image). Figure 6 The resulting composite material has a thermal conductivity of 5.40 W / m². -1 K -1 .

[0084] Comparative Example 1

[0085] The preparation methods for single-end epoxy-modified polysiloxane and double-end epoxy-modified polysiloxane are the same as in Example 1.

[0086] Solid filler was used to construct a dispersed organosilicon-based composite material: Graphite and a thermosetting organosilicon precursor (0.4832 g thioctic acid; 1.2475 g single-ended epoxy polysiloxane; 1.7893 g double-ended epoxy modified polysiloxane) were mixed and cured at 150℃ and 180℃ for 2 h each. The graphite content accounted for 20% of the total volume of the organosilicon composite material. The organosilicon-based thermally conductive composite material obtained through the above steps had dimensions of 40 × 25 × 4 mm. The thermal conductivity of the resulting composite material was 2.28 W / m². -1 K -1 .

[0087] Comparative Example 2

[0088] The preparation methods for single-end epoxy-modified polysiloxane and double-end epoxy-modified polysiloxane are the same as in Example 1.

[0089] Preparation of organosilicon microspheres: 1.4372 g of 1,5-vinyl diorganopolysiloxane; 0.3107 g of 13-17% (mercapto)methylsiloxane-dimethylsiloxane copolymer (SMS142, Gelest); 0.0122 g of TPO-L. The photocurable base reactants were loaded into a syringe with a needle (0.3 × 13 mm) and titrated dropwise into UV-irradiated ethanol to obtain organosilicon microspheres.

[0090] A silicone-based composite material with a three-dimensional thermally conductive network was constructed using solid fillers: Graphite, thermosetting silicone precursors (0.2416 g thioctic acid; 0.6237 g single-ended epoxy polysiloxane; 0.8947 g double-ended epoxy modified polysiloxane), and silicone microspheres were mixed and cured at 150℃ and 180℃ for 2 h each. The graphite content accounted for 20% of the total volume of the silicone composite material. The silicone-based thermally conductive composite material obtained through the above steps had dimensions of 40 × 25 × 4 mm. The thermal conductivity of the resulting composite material was 4.97 W / m². -1 K -1 .

[0091] A comparison of Example 1 and Comparative Example 1 shows that, using organosilicon microspheres as a template, solid fillers can be effectively arranged to form a three-dimensional thermally conductive network, significantly improving the thermal conductivity of the composite material under the same parameters. A comparison of Example 1 and Comparative Example 2 shows that liquid thermally conductive fillers coat the surface of the microspheres, bridging the organosilicon polymer / solid filler thermally conductive network and further improving the thermal conductivity of the composite material.

[0092] Example 2

[0093] The preparation methods for single-end epoxy-modified polysiloxane and double-end epoxy-modified polysiloxane are the same as in Example 1.

[0094] Preparation of organosilicon microspheres: 1.3473 g of 1,5-vinyl diorganopolysiloxane; 0.2913 g of 13-17% (mercapto)methylsiloxane-dimethylsiloxane copolymer (SMS142, Gelest); 0.0114 g of TPO-L. The photocurable base reactants were loaded into a syringe with a needle (0.3 × 13 mm) and titrated dropwise into UV-irradiated ethanol to obtain organosilicon microspheres.

[0095] Coating of microspheres with liquid thermally conductive filler: Organosilicon microspheres are mixed with gallium indium tin alloy until all gallium indium tin alloy is uniformly coated on the surface of the organosilicon microspheres. The amount of gallium indium tin alloy added is 10% of the volume of the organosilicon microspheres.

[0096] A three-dimensional thermally conductive silicone-based composite material was constructed using liquid / solid two-phase fillers: Graphite, thermosetting silicone precursors (0.2416 g thioctic acid; 0.6237 g single-ended epoxy polysiloxane; 0.8947 g double-ended epoxy modified polysiloxane), and surface-coated liquid metal-silicone microspheres were mixed and cured at 150℃ and 180℃ for 2 h each. The graphite content accounted for 20% of the total volume of the silicone composite material. The silicone-based thermally conductive composite material obtained through the above steps had dimensions of 40 × 25 × 4 mm. The thermal conductivity of the resulting composite material was 5.52 W / m². -1 K -1 .

[0097] Example 3

[0098] Preparation of organosilicon microspheres: 1.4208 g of α,ω-vinyl diorganopolysiloxane; 0.3071 g of 13-17% (mercapto)methylsiloxane-dimethylsiloxane copolymer (SMS142, Gelest); 0.0120 g of TPO-L. The photocurable base reactants were loaded into a syringe with a needle (0.3 × 13 mm) and titrated dropwise into UV-irradiated ethanol to obtain organosilicon elastomer microspheres.

[0099] Coating of microspheres with liquid thermally conductive filler: Organosilicon elastomer microspheres are mixed with gallium indium tin alloy until all gallium indium tin alloy is uniformly coated on the surface of the organosilicon microspheres. The amount of gallium indium tin alloy added is 2% by volume of the organosilicon elastomer microspheres.

[0100] A three-dimensional thermally conductive silicone-based composite material was constructed using liquid / solid two-phase fillers: Graphite, thermosetting silicone precursors (0.1812 g thioctic acid; 0.4678 g single-ended epoxy polysiloxane; 0.6710 g double-ended epoxy modified polysiloxane), and surface-coated liquid metal-silicone microspheres were mixed and cured at 150℃ and 180℃ for 2 h each. The graphite content accounted for 30% of the total volume of the silicone composite material. The silicone-based thermally conductive composite material obtained through the above steps had dimensions of 40 × 25 × 4 mm. The thermal conductivity of the resulting composite material was 7.21 W / m². -1 K -1 .

[0101] The above embodiments of the present invention are illustrative and not limiting. Any changes within the meaning and scope of the claims should be considered to be included within the scope of the claims.

Claims

1. A method for preparing an organosilicon-based composite material with a three-dimensional thermally conductive network based on a liquid / solid two-phase filler, characterized in that, Includes the following steps: (1) Prepare a photocurable polysiloxane-based mixture, load it into a syringe, and drop the mixture into ethanol under light irradiation to prepare organosilicon elastomer microspheres; The photocurable polysiloxane-based mixture comprises the following components in weight percentage: α,ω-vinyl diorganopolysiloxane 50-95%; 13-17% (mercapto)methylsiloxane-dimethylsiloxane copolymer 10-30%; photoinitiator 0.01-3%; (2) The organosilicon elastomer microspheres prepared in step (1) are mixed with liquid thermally conductive fillers to prepare organosilicon microspheres with liquid thermally conductive fillers loaded on the surface; The liquid thermally conductive filler is a gallium indium tin alloy; (3) After mixing the solid thermally conductive filler with a thermosetting polysiloxane-based mixture, it is then mixed with the organosilicon microspheres with liquid thermally conductive filler on the surface obtained in step (2) and crosslinked and cured to obtain an organosilicon-based composite material with a three-dimensional thermally conductive network based on liquid / solid two-phase filler. The solid thermally conductive filler is graphite; The thermosetting polysiloxane-based mixture consists of the following components in weight percentage: Thioctic acid 5-50%, single-ended epoxy-modified polysiloxane 10%-80%, double-ended epoxy-modified polysiloxane 10%-80%.

2. The method for preparing an organosilicon-based composite material with a three-dimensional thermally conductive network based on a liquid / solid two-phase filler according to claim 1, characterized in that, In step (1), the photoinitiator is one or both of diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and ethyl phenyl(2,4,6-trimethylbenzoyl)phosphine.

3. The method for preparing an organosilicon-based composite material with a three-dimensional thermally conductive network based on a liquid / solid two-phase filler according to claim 1, characterized in that, In step (3), the single-ended epoxy-modified polysiloxane contains at least one epoxy group bonded to a silicon atom, as shown in formula (2): XR 5 SiO-(SiR 3 2-O-) h SiR 4 (2) Among them, R 3 R indicates methyl or phenyl 4 R 5 It represents a C1-8 hydrocarbon group or alkoxy group, X = epoxy or epoxycyclohexyl, and h is an integer from 10 to 1500; The double-ended epoxy-modified polysiloxane is at least one polysiloxane containing at least two epoxy groups bonded to silicon atoms per molecule, with the structural formula shown in formula (3): XR 7 SiO-(SiR 6 2-O-) h SiR 7 X(3) Among them, R 6 R indicates methyl or phenyl 7 It represents a C1-8 hydrocarbon group or alkoxy group, X = epoxide or epoxide cyclohexyl, and h is an integer from 10 to 1500.

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