High-orientation heat-conducting insulating composite material as well as preparation method and application thereof
By combining dynamic Schiff base bonds and silane coupling agents to modify thermally conductive fillers, a high-extraction thermally conductive and insulating composite material was prepared, solving the problem of insufficient thermal conductivity and insulation reliability of traditional materials in high-power-density electronic devices. This resulted in a recyclable and highly efficient thermally conductive network suitable for applications such as 5G chip packaging and power module heat dissipation substrates.
Patent Information
- Application Number
- CN202511191962.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-25
- Publication Date
- 2025-11-18
AI Technical Summary
Traditional epoxy-based composite materials suffer from insufficient thermal conductivity and insulation reliability in high-power-density electronic devices. Furthermore, it is difficult to achieve long-range ordered arrangement of fillers, leading to relaxation and failure of the orientation structure under thermal stress. In addition, the materials are not recyclable, increasing the problem of electronic waste.
Dynamic Schiff base bonds are used to form covalent crosslinks of multilayer materials. The fillers are oriented by longitudinal cutting to form a highly ordered thermally conductive network that runs through the material. Silane coupling agents are used to modify the thermally conductive fillers to improve their compatibility with the polymer matrix. The material can be reversibly reshaped and recycled through stacking welding and longitudinal cutting.
It significantly improves the thermal conductivity and insulation of the material, while also possessing excellent flame retardancy and recyclability. It solves the problem of synergistic optimization of high thermal conductivity and insulation, achieving zero-waste manufacturing, and is suitable for fields such as 5G chip packaging and power module heat dissipation substrates.
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Figure CN120966243A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of heat-conducting insulation materials, in particular to a high-orientation heat-conducting insulation composite material and a preparation method and application thereof. BACKGROUND
[0002] With the miniaturization development of high-power-density electronic devices, thermal management materials are facing the dual challenges of heat conduction efficiency and insulation reliability. The traditional epoxy-based composite material is limited by the bottleneck of phonon scattering of randomly dispersed fillers, and the high interfacial thermal resistance, and the non-renewable petroleum-based resin and non-recyclable cross-linked structure exacerbate the electronic waste problem. Developing new materials with high intrinsic thermal conductivity, excellent electrical insulation and recyclable characteristics has become an urgent need to break through the barriers of electronic heat dissipation technology.
[0003] Traditional mechanical stretching, electric field orientation and other methods are difficult to achieve long-range ordered arrangement of fillers while maintaining high insulation, and the orientation structure is prone to relaxation failure under thermal stress. In order to realize the directional optimization of the heat conduction path, it is the core technology direction to construct vertically oriented heat conduction channels in the material. Therefore, it is urgent to develop a dynamic bonding strategy that can stably lock the orientation of fillers. SUMMARY
[0004] The present application provides a high-orientation heat-conducting insulation composite material and a preparation method and application thereof, which realizes precise welding and reconstruction of multi-layer materials through dynamic Schiff base bond, and can force the fillers to arrange in the cutting direction when longitudinally cutting, thereby forming a highly ordered heat conduction network throughout the material, improving the thermal conductivity and insulation of the material.
[0005] To solve the above technical problems, one of the purposes of the present application provides a high-orientation heat-conducting insulation composite material, which comprises the following components by weight: Polymer matrix: 100 parts; Modified heat-conducting filler: 50-1000 parts; Solvent: 20-120 parts; The polymer matrix comprises a binary aldehyde and a polyamine; the modified heat-conducting filler is a silane coupling agent modified heat-conducting filler, the heat-conducting filler is aluminum nitride and / or boron nitride, the heat-conducting filler is a two-dimensional sheet-shaped heat-conducting filler, and the average particle size of the heat-conducting filler is 20-120 μm.
[0006] The present application uses amino-containing polyamines and aldehyde-containing dialdehydes as reaction monomers to form Schiff base bonds to realize covalent cross-linking of the material. The dynamic imine bonds (-C=N-) contained therein can reversibly break and recombine under mild conditions, supporting the material to perform stack welding and multiple thermal reshaping, and the cutting waste can be recycled and welded, which can be recycled and reused, and basically realizes zero waste manufacturing. At the same time, the addition of the modified heat-conducting filler by the silane coupling agent helps to improve the compatibility with the polymer matrix, and the heat-conducting filler forms a heat-conducting network in the polymer matrix, improving the thermal conductivity of the material, while having excellent insulation and flame retardancy.
[0007] When the material of the present application is subjected to subsequent stack welding and longitudinal cutting processing, the Schiff base bonds are used for thermal reshaping during stack welding, which can realize interlayer covalent cross-linking, and at the same time, the longitudinal cutting induces the heat-conducting filler to orient along the cutting surface to fix the efficient heat-conducting path, thereby forming a highly ordered heat-conducting network throughout the material, improving the thermal conductivity of the material; The present application uses two-dimensional sheet-shaped heat-conducting fillers, which are more efficient in forming heat-conducting paths after vertical orientation than one-dimensional fillers.
[0008] As a preferred solution, the high-orientation heat-conducting insulating composite material comprises the following components by weight: Polymer matrix: 100 parts; Modified heat-conducting filler: 50-150 parts; Solvent: 80-120 parts.
[0009] As a preferred solution, the molar ratio of aldehyde groups of the dialdehyde to amine groups of the polyamine is (1-2):(1-2).
[0010] As a preferred solution, the dialdehyde is at least one of C2-C18 aliphatic dialdehyde, p-phenylenedimethylaldehyde, m-phenylenedimethylaldehyde, o-phenylenedimethylaldehyde, 2,6-pyridine dimethylaldehyde, and 2,5-furan dimethylaldehyde.
[0011] As a preferred solution, the polyamine is a C2-C20 organic amine and its derivative.
[0012] As a preferred solution, the polyamine is at least one of polyether amine, 1,3,5-triaminobenzene, tris(4-aminophenyl)amine, melamine, tris(2-aminoethyl)amine, diethylene triamine, triethylene tetramine, tetraethylene pentamine, and triethylene tetramine.
[0013] As a preferred solution, the polyamine is a linear polyamine.
[0014] As a preferred solution, the linear polyamine is a polyether amine.
[0015] The polyamine of the present application is preferably a linear polyamine, which has a flexible long carbon chain, is more conducive to the exchange of dynamic bonds for thermal remodeling after stack welding processing, improves the welding fixing strength of the multi-layer composite material, and can induce the modified thermal conductive filler to orient along the cutting surface, promote the formation of a thermal conductive network, and further improve the thermal conductivity of the composite material.
[0016] As a preferred solution, the molecular weight of the polyether amine is 400-8000.
[0017] As a preferred solution, the average particle size of the thermal conductive filler is 20-120 μm.
[0018] If the size of the thermal conductive filler in the composite material is too large, it will easily affect the thickness of the product. In order to ensure the thin size of the product, the amount of filler added is required to be reduced, thereby affecting the thermal conductivity. If the size of the thermal conductive filler is too small, it is difficult for the modified thermal conductive filler to form an efficient vertical orientation thermal conductive path during subsequent stack welding and longitudinal cutting, thereby reducing the thermal conductivity of the composite material.
[0019] As a preferred solution, the solvent is at least one of acetone, butanone, toluene, dichloromethane, N,N-dimethylformamide and N,N-dimethylacetamide.
[0020] As a preferred solution, the silane coupling agent is at least one of KH-550, KH560, KH570, KH-580 and KH-590.
[0021] As a preferred solution, the preparation method of the modified thermal conductive filler comprises the following steps: adding the thermal conductive filler into an organic solution containing a silane coupling agent, the silane coupling agent being 0.5-5% of the mass fraction of the thermal conductive filler, heating and stirring at 50-70°C for 6-10 h, and then filtering and drying to obtain the modified thermal conductive filler.
[0022] As a preferred solution, the organic solvent is ethanol.
[0023] To solve the above technical problems, the second object of the present application provides a preparation method of a high-orientation thermal conductive insulating composite material, comprising the following steps: (1) uniformly mixing the polymer matrix, the modified thermal conductive filler and the solvent, and then pouring into a mold for pre-curing to obtain a semi-cured material; (2) hot pressing the semi-cured material, and then performing stack welding to obtain a stack welded material; (3) longitudinally cutting the stack welded material to obtain a high-orientation thermal conductive insulating composite material.
[0024] The application uses a polyamine containing amino group and a dialdehyde containing aldehyde group as reaction monomers to form a Schiff base bond by pre-curing, the dynamic imine bond (-C=N-) can be remolded multiple times, and through layer-by-layer stacking and interface Schiff base bonding, interlayer covalent welding is realized; and then longitudinal cutting is performed to force the two-dimensional heat-conducting filler to be arranged in the cutting direction, thereby forming a highly ordered heat-conducting network throughout the material, which can fix the high-efficiency heat-conducting path and significantly improve the thermal conductivity of the material. Moreover, the composite material not only retains the reversible processing characteristics of the dynamic covalent bond, but also gives the filler a permanent orientation through physical cutting, realizes long-range ordered arrangement of the filler under the premise of maintaining high insulation, and improves the thermal stability.
[0025] As a preferred solution, in step (1), the pre-curing is pre-curing at 80-120℃ for 2-6h.
[0026] As a preferred solution, in step (2), the hot pressing is hot pressing at 120-160℃ and 3-5MPa for 0.5-2h.
[0027] As a preferred solution, in step (3), the stacking welding is stacking welding at 150-180℃ and 1-3MPa for 8-24h.
[0028] In order to solve the above technical problems, the third object of the application provides an application of the high-orientation heat-conducting insulation composite material in the field of preparing electronic packaging materials.
[0029] Compared with the prior art, the application has the following beneficial effects: 1、The polymer matrix of the application is covalently crosslinked by polyamine and dialdehyde using Schiff base bond, the dynamic imine bond (-C=N-) can be remolded to realize precise welding during the process of hot pressing and stacking, and longitudinal cutting induces the two-dimensional heat-conducting filler to be arranged in the cutting direction, thereby forming a fixed and highly ordered heat-conducting network, which significantly improves the thermal conductivity of the material. The physical cutting gives the filler a permanent orientation, realizes long-range ordered arrangement of the filler under the premise of maintaining high insulation, improves the thermal stability of the material, and has excellent insulation and flame retardance.
[0030] 2、The technology combines dynamic chemical bonds with directional physical processing through molecular design, simultaneously solves the problems of high thermal conductivity, insulation and recyclable utilization in a single material system, the dynamic bonds in the composite material support multiple thermal remolding of the material, the cutting waste can be recycled and reused, zero-waste manufacturing is realized, and the oriented heat-conducting insulation material prepared can be applied to the frontiers such as 5G chip packaging and power module heat dissipation substrate, thereby providing a new solution for green manufacturing and whole life cycle management of electronic devices. BRIEF DESCRIPTION OF DRAWINGS
[0031] Figure 1A scanning electron microscope image of the modified thermally conductive filler, silane-modified boron nitride, in Example 1 of the present invention; Figure 2 A scanning electron microscope image of the thermally conductive filler, boron nitride, in Comparative Example 8 of the present invention; Figure 3 A Fourier transform infrared spectroscopy image of the modified thermally conductive filler in Example 1 of the present invention and the thermally conductive filler in Comparative Example 8 of the present invention; Figure 4 A scanning electron microscope image of a cross-section of a highly oriented thermally conductive insulating composite material in Example 1 of the present invention; Figure 5 A scanning electron microscope image of a cross-section of a thermally conductive insulating composite material in Comparative Example 3 of the present invention. DETAILED DESCRIPTION
[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0033] It should be understood that the terms described in the present application are only for describing the specific embodiments, and are not used to limit the present application. In addition, for the numerical range in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value in the stated range, and any other stated value or intermediate value in the stated range, is also included in the present application. The upper limit and the lower limit of these smaller ranges can be independently included or excluded from the range.
[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict between the content of the specification and that of any document incorporated herein by reference, the content of the specification prevails.
[0035] As used herein the term: In these embodiments, the parts and percentages are by mass unless otherwise indicated.
[0036] "and / or" is used to indicate one or both stated cases can occur, for example, A and / or B includes (A and B) and (A or B).
[0037] To further illustrate the present application, the present application is described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present application. Table 1 below is the source and model of the raw materials used in the examples and comparative examples of the present application. Unless otherwise specified, the raw materials used are commercially available, and the same raw materials are used in parallel experiments.
[0038] Table 1 - Source and model of raw materials used in examples and comparative examples of the present application Example 1 A highly oriented heat-conducting insulating composite material, comprising 5 g of a polymer matrix, 5 g of a modified heat-conducting filler, and 5 g of N,N-dimethylformamide (DMF), the polymer matrix comprising terephthaldehyde and a polyetheramine, the molar ratio of aldehyde groups of terephthaldehyde to amine groups of polyetheramine being 1:1, the polyetheramine being model T403, the modified heat-conducting filler being a two-dimensional sheet-like heat-conducting filler modified by a silane coupling agent, the two-dimensional sheet-like heat-conducting filler being boron nitride, the average particle size of the two-dimensional sheet-like heat-conducting filler being 30 μm, and the silane coupling agent being model KH-550.
[0039] The preparation method of the highly oriented heat-conducting insulating composite material in the above example 1, comprising the following steps: (1) adding the two-dimensional sheet-like heat-conducting filler to an ethanol solution containing 5% by mass of the silane coupling agent, the silane coupling agent being 1% by mass of the two-dimensional sheet-like heat-conducting filler, after heating and stirring at 60°C for 8 h, filtering and drying to obtain the modified heat-conducting filler; (2) adding the polymer matrix and the modified heat-conducting filler to N,N-dimethylformamide solvent, mixing uniformly by ultrasonic, and then pouring into a PTFE mold, pre-curing at 80°C for 6 h to obtain a semi-cured material; (3) hot pressing the semi-cured material at 160°C and 5 MPa for 0.5 h, and then stacking and welding at 160°C and 1 MPa for 12 h to obtain a stacked and welded material; (4) longitudinally cutting the stacked and welded material to obtain the highly oriented heat-conducting insulating composite material.
[0040] Example 2 A highly oriented heat-conducting insulating composite material, different from example 1 in that it comprises 20 g of a polymer matrix, 10 g of a modified heat-conducting filler, and 20 g of N,N-dimethylformamide (DMF), the polymer matrix comprising terephthaldehyde and a polyetheramine, the molar ratio of aldehyde groups of terephthaldehyde to amine groups of polyetheramine being 1:2, the polyetheramine being model T403, the modified heat-conducting filler being a two-dimensional sheet-like heat-conducting filler modified by a silane coupling agent, the two-dimensional sheet-like heat-conducting filler being boron nitride, the average particle size of the two-dimensional sheet-like heat-conducting filler being 30 μm, and the silane coupling agent being model KH-560.
[0041] Example 3 A high-orientation heat-conduction insulation composite material, different from example 1, comprises 10 g of a polymer matrix, 15 g of a modified heat-conduction filler, and 10 g of N,N-dimethylformamide (DMF), the polymer matrix comprises terephthaldehyde and polyetheramine, the molar ratio of aldehyde groups of terephthaldehyde to amine groups of polyetheramine is 2:1, the type of polyetheramine is T403, the modified heat-conduction filler is a two-dimensional sheet-shaped heat-conduction filler modified by a silane coupling agent, the two-dimensional sheet-shaped heat-conduction filler is boron nitride, the average particle size of the two-dimensional sheet-shaped heat-conduction filler is 30 μm, and the type of the silane coupling agent is KH-570.
[0042] Example 4 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a polymer matrix, the polymer matrix comprises terephthaldehyde and 1,3,5-triaminobenzene, and the molar ratio of aldehyde groups of terephthaldehyde to amine groups of 1,3,5-triaminobenzene is 1:1.
[0043] Example 5 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a polymer matrix, the polymer matrix comprises terephthaldehyde and polyetheramine, the type of polyetheramine is T8000, and the molar ratio of aldehyde groups of terephthaldehyde to amine groups of polyetheramine is 1:1.
[0044] Example 6 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a polymer matrix, the polymer matrix comprises terephthaldehyde and tris(4-aminophenyl)amine, and the molar ratio of aldehyde groups of terephthaldehyde to amine groups of tris(4-aminophenyl)amine is 1:1.
[0045] Example 7 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a polymer matrix, the polymer matrix comprises terephthaldehyde and melamine, and the molar ratio of aldehyde groups of terephthaldehyde to amine groups of melamine is 1:1.
[0046] Example 8 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a modified heat-conduction filler, the modified heat-conduction filler is a two-dimensional sheet-shaped heat-conduction filler modified by a silane coupling agent, the two-dimensional sheet-shaped heat-conduction filler is aluminum nitride, the average particle size of the two-dimensional sheet-shaped heat-conduction filler is 30 μm, and the type of the silane coupling agent is KH-550.
[0047] Example 9 A high-orientation heat-conduction insulation composite material, different from example 1, comprises a modified heat-conduction filler, the modified heat-conduction filler is a two-dimensional sheet-shaped heat-conduction filler modified by a silane coupling agent, the two-dimensional sheet-shaped heat-conduction filler is boron nitride, the average particle size of the two-dimensional sheet-shaped heat-conduction filler is 20 μm, and the type of the silane coupling agent is KH-550.
[0048] Example 10 A high-orientation heat-conducting insulation composite material, different from Example 1, is that the modified heat-conducting filler is a two-dimensional sheet-like heat-conducting filler modified by a silane coupling agent, the two-dimensional sheet-like heat-conducting filler is boron nitride, and the average particle size of the two-dimensional sheet-like heat-conducting filler is 120 μm. The type of the silane coupling agent is KH-550.
[0049] Comparative Example 1 A heat-conducting insulation composite material, comprising 5 g of a polymer matrix, 5 g of a modified heat-conducting filler, and 5 g of N,N-dimethylformamide, the polymer matrix comprising an epoxy resin and a polyether amine, the molar ratio of the epoxy groups of the epoxy resin to the amine groups of the polyether amine being 1:1, the type of the epoxy resin being E44, the type of the polyether amine being T403, the modified heat-conducting filler being a two-dimensional sheet-like heat-conducting filler modified by a silane coupling agent, the two-dimensional sheet-like heat-conducting filler being boron nitride, the average particle size of the two-dimensional sheet-like heat-conducting filler being 30 μm, and the type of the silane coupling agent being KH-550.
[0050] The preparation method of the heat-conducting insulation composite material in the above Comparative Example 1 comprises the following steps: (1) The two-dimensional sheet-like heat-conducting filler is added to an ethanol solution containing 5% by mass of a silane coupling agent, the silane coupling agent being 1% by mass of the two-dimensional sheet-like heat-conducting filler, and after being heated and stirred at 60°C for 8 h, the modified heat-conducting filler is obtained by filtration and drying; (2) The polymer matrix and the modified heat-conducting filler are added to an N,N-dimethylformamide solvent, uniformly mixed by ultrasonic mixing, and then cast in a PTFE mold, and a heat-conducting insulation composite material with the same size as in Example 1 is obtained by curing at 160°C for 6 h.
[0051] Comparative Example 2 A heat-conducting insulation composite material, different from Example 1, is that the polymer matrix comprises an epoxy resin and a polyether amine, the molar ratio of the epoxy groups of the epoxy resin to the amine groups of the polyether amine being 1:1, and the type of the epoxy resin being E44, the type of the polyether amine being T403. The preparation method thereof comprises the following steps: (1) The two-dimensional sheet-like heat-conducting filler is added to an ethanol solution containing 5% by mass of a silane coupling agent, the silane coupling agent being 1% by mass of the two-dimensional sheet-like heat-conducting filler, and after being heated and stirred at 60°C for 8 h, the modified heat-conducting filler is obtained by filtration and drying; (2) The polymer matrix and the modified heat-conducting filler are added to an N,N-dimethylformamide solvent, uniformly mixed by ultrasonic mixing, and then cast in a PTFE mold, and a heat-conducting insulation composite material with the same size as in Example 1 is obtained by curing at 160°C for 6 h. (3) The semi-cured material is hot-pressed at 160°C and 5 MPa for 0.5 h, and then stacked and welded at 160°C and 1 MPa for 12 h. Since the epoxy resin does not contain an imine dynamic bond, the material cannot be stacked and welded.
[0052] Comparative Example 3 A thermally conductive and insulating composite material differs from Example 1 in that the preparation method comprises the following steps: (1) The two-dimensional sheet-shaped thermally conductive filler is added to an ethanol solution containing 5% by mass of a silane coupling agent, which is 1% of the mass fraction of the two-dimensional sheet-shaped thermally conductive filler. After heating and stirring at 60°C for 8 h, the modified thermally conductive filler is obtained by filtering and drying. (2) The polymer matrix and the modified thermally conductive filler are added to N,N-dimethylformamide solvent and uniformly mixed by ultrasonic mixing, and then poured into a PTFE mold and cured at 160°C for 6 h to obtain a thermally conductive and insulating composite material with the same size as Example 1.
[0053] Comparative Example 4 A thermally conductive and insulating composite material differs from Example 1 in that the modified thermally conductive filler is a two-dimensional sheet-shaped thermally conductive filler modified by a silane coupling agent, the two-dimensional sheet-shaped thermally conductive filler is two-dimensional graphene, the average particle size of the two-dimensional sheet-shaped thermally conductive filler is 30 μm, and the type of silane coupling agent is KH-550.
[0054] Comparative Example 5 A thermally conductive and insulating composite material differs from Example 1 in that the modified thermally conductive filler is a two-dimensional sheet-shaped thermally conductive filler modified by a silane coupling agent, the two-dimensional sheet-shaped thermally conductive filler is aluminum oxide, the average particle size of the two-dimensional sheet-shaped thermally conductive filler is 30 μm, and the type of silane coupling agent is KH-550.
[0055] Comparative Example 6 A thermally conductive and insulating composite material differs from Example 1 in that the modified thermally conductive filler is a two-dimensional sheet-shaped thermally conductive filler modified by a silane coupling agent, the two-dimensional sheet-shaped thermally conductive filler is boron nitride, the average particle size of the two-dimensional sheet-shaped thermally conductive filler is 10 μm, and the type of silane coupling agent is KH-550.
[0056] Comparative Example 7 A thermally conductive and insulating composite material differs from Example 1 in that the modified thermally conductive filler is replaced by an equal amount of a two-dimensional sheet-shaped thermally conductive filler, the two-dimensional sheet-shaped thermally conductive filler is boron nitride, and the average particle size of the two-dimensional sheet-shaped thermally conductive filler is 30 μm.
[0057] Table 2 - Components and contents of the composite materials of the examples and comparative examples Performance testing 1. The modified thermally conductive filler of Example 1 and the thermally conductive filler boron nitride of Comparative Example 8 were observed using a scanning electron microscope and tested using a Fourier transform infrared spectroscopy (FTIR). The SEM images of the fillers in Example 1 and Comparative Example 8 are shown below. Figures 1-2 As shown, the tested FT-IR plot is as follows: Figure 3 As shown. FT-IR analysis indicates that the original boron nitride of Comparative Example 8 at 1380 cm⁻¹ 1 and 800cm 1 A characteristic BN bond vibration peak exists at 3400 cm⁻¹. 1 The OH peak indicates hydrophilicity; a new 2900 cm⁻¹ peak was observed in the silane-modified boron nitride spectrum of Example 1. 1 (CH) and 1640cm 1 The presence of organic peaks such as (C=O) and a significantly weakened OH peak confirms the successful grafting of the silane coupling agent modifier.
[0058] Meanwhile, the cross-sections of the thermally conductive and insulating composite materials of Example 1 and Comparative Example 3 were observed using a scanning electron microscope, and the test results are as follows: Figures 4-5 As shown, boron nitride in the composite material of Comparative Example 3 without stack welding was found to be randomly distributed, while boron nitride in the composite material of Example 1 after stack welding was neatly arranged. This indicates that longitudinal cutting after stack welding can induce the two-dimensional thermally conductive filler to oriented along the cutting direction, thereby fixing the efficient thermal conduction path and improving the thermal conductivity of the composite material.
[0059] 2. Thermal conductivity: The thermal conductivity of the thermally conductive and insulating composite materials prepared in the examples and comparative examples was tested using a hot disk instrument according to the ISO22007-2.2 standard method. The test results are shown in Table 3 below.
[0060] 3. Withstand voltage: The thermally conductive and insulating composite materials prepared in the examples and comparative examples were tested using a Chroma 19073 withstand voltage tester from Taiwan, China, in accordance with the GB / T 1408.1-2016 standard. The test results are shown in Table 3 below.
[0061] 4. Limiting Oxygen Index (LOI) Test: The limiting oxygen index of the thermally conductive and insulating composite materials prepared in the examples and comparative examples was tested according to ASTM D2863 standard. LOI represents the minimum oxygen concentration that can just sustain combustion of the material in a mixture of oxygen and nitrogen. The test results are shown in Table 3 below.
[0062] Table 3 - Performance test results of composite materials prepared in the embodiments and comparative examples of this application Test item Thermal conductivity (W / mK) Voltage resistance (kV / mm) LOI (%) Example 1 8.34 35.5 36.5 Example 2 6.32 33.4 35.1 Example 3 10.21 35.9 36.9 Example 4 8.67 36.4 36.9 Example 5 8.35 36.1 36.6 Example 6 8.21 35.2 36.3 Example 7 8.18 35.1 36.5 Example 8 8.27 35.9 36.2 Example 9 8.03 35.5 36.5 Example 10 8.35 35.7 36.6 Comparative Example 1 3.35 30.6 35.1 Comparative Example 2 - - 35.1 Comparative Example 3 4.16 33.2 36.9 Comparative Example 4 10.24 Conductive 35.8 Comparative Example 5 6.43 28.5 37.8 Comparative Example 6 7.03 33.7 34.2 Comparative Example 7 7.11 33.2 33.3 As shown in Table 1, Example 1 adopts benzene-dialdehyde to form Schiff base bond with polyether amine to realize covalent crosslinking of the material, and simultaneously adds two-dimensional boron nitride filler modified by silane coupling agent in the composite material for subsequent construction of heat conduction network. Through hot pressing and stacking of the multi-layer material, the dynamic imine bond contained in the composite material can realize thermal remodeling and precise welding. After longitudinal cutting, the two-dimensional heat conduction filler is induced to arrange in the cutting direction, thereby forming an ordered and highly heat-conductive network throughout the material, which can improve the thermal conductivity and insulation of the material.
[0063] Compared with Example 1, Comparative Example 1 adopts epoxy resin and polyether amine for covalent crosslinking, adopts conventional curing process, and does not perform stacking and welding and longitudinal cutting processes. The two-dimensional heat-conduction filler in the composite material is distributed in disorder, and the thermal conductivity is greatly reduced. Comparative Example 2 also adopts epoxy resin and polyether amine for covalent crosslinking, and performs hot pressing and stacking and welding processes. In the stacking and welding process, since the composite material does not contain dynamic bonds for thermal remodeling, the multi-layer material cannot be welded and fixed.
[0064] Compared with Example 1, the composite material of Comparative Example 3 adopts a conventional curing process and does not perform hot pressing, stacking and welding and longitudinal cutting steps. The two-dimensional heat-conduction filler in the composite material is distributed in disorder and cannot form an ordered and efficient heat-conduction network. Finally, the thermal conductivity of the composite material is significantly lower than that of Example 1.
[0065] Compared with Example 1, the heat-conduction filler of Comparative Example 4 adopts two-dimensional sheet-shaped graphene. Although graphene has higher thermal conductivity than boron nitride, it also has excellent electrical conductivity, resulting in poor insulation of the composite material, which cannot meet the application requirements of electronic packaging materials. The heat-conduction filler of Comparative Example 5 adopts alumina. After stacking and welding, the heat-conduction network formed by the longitudinal cutting-induced directional arrangement of the filler cannot effectively improve the heat conduction effect, and affects the voltage resistance of the composite material, so that the thermal conductivity and insulation of the composite material are both inferior to those of Example 1.
[0066] Compared with Example 1, the modified heat-conduction filler of Comparative Example 7 has a particle size of 10 μm, which is too small. During subsequent stacking and welding and longitudinal cutting, the modified heat-conduction filler is difficult to form an efficient vertically oriented heat-conduction path, thereby reducing the thermal conductivity of the composite material.
[0067] Compared with Example 1, the heat-conduction filler of Comparative Example 8 is boron nitride, which is not grafted and modified by a silane coupling agent. The compatibility of boron nitride with the polymer matrix is poor, the heat-conduction filler is prone to aggregation, and the dispersion is uneven, which affects the vertical orientation of the two-dimensional heat-conduction filler and cannot form an ordered heat-conduction network. The thermal conductivity, insulation and flame retardancy of the composite material are all reduced.
[0068] As shown in Table 3, the linear polyamine polyether amine is used in the composite material of Example 1 and 5, the nonlinear polyamine tri(4-aminophenyl)amine and melamine are used in the composite material of Example 6-7, and the thermal conductivity of the composite material of Example 6-7 is lower than that of Example 1 and 5. This is because the linear polyamine has a flexible long carbon chain, which is more conducive to the exchange of dynamic bonds for thermal remodeling after the stack welding process, improves the welding fixing strength of the multilayer composite material, and can induce the modified thermal conductive filler to orient along the cutting surface, promote the formation of the thermal conductive network, and further improve the thermal conductivity of the composite material.
[0069] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A high thermal conductivity insulating composite material, characterized in that, Includes the following components by weight: Polymer matrix: 100 parts; Modified thermally conductive filler: 50-1000 parts; Solvent: 20-120 parts; The polymer matrix includes dialdehyde and polyamine; the modified thermally conductive filler is a silane coupling agent modified thermally conductive filler, the thermally conductive filler is aluminum nitride and / or boron nitride, and the thermally conductive filler is a two-dimensional sheet-like thermally conductive filler.
2. The high thermal conductivity insulating composite material as described in claim 1, characterized in that, The molar ratio of the aldehyde group to the amino group of the dialdehyde is (1-2):(1-2).
3. The high thermal conductivity insulating composite material as described in claim 2, characterized in that, The dialdehyde is at least one of C2-C18 aliphatic dialdehyde, terephthalaldehyde, isophthalaldehyde, o-phthalaldehyde, 2,6-pyridinedialdehyde, and 2,5-furandialdehyde; And / or, the polyamine is a C2-C20 organic amine or its derivative.
4. The high thermal conductivity insulating composite material as described in claim 3, characterized in that, The polyamine is at least one selected from polyetheramine, 1,3,5-triaminobenzene, tris(4-aminophenyl)amine, melamine, tris(2-aminoethyl)amine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and triethylenetetramine. And / or, the polyamine is a linear polyamine.
5. The high thermal conductivity insulating composite material as described in claim 4, characterized in that, The linear polyamine is a polyetheramine.
6. The high thermal conductivity insulating composite material as described in claim 1, characterized in that, The average particle size of the thermally conductive filler is 20-120 μm; And / or, the solvent is at least one selected from acetone, butanone, toluene, dichloromethane, N,N-dimethylformamide and N,N-dimethylacetamide; And / or, the silane coupling agent is at least one of KH-550, KH560, KH570, KH-580, and KH-590.
7. The high thermal conductivity insulating composite material as described in claim 1, characterized in that, The preparation method of the modified thermally conductive filler includes the following steps: adding the thermally conductive filler to an organic solution containing a silane coupling agent, wherein the silane coupling agent is 0.5-5% of the mass fraction of the thermally conductive filler, heating and stirring at 50-70℃ for 6-10 hours, and then filtering and drying to obtain the modified thermally conductive filler.
8. A method for preparing a high thermal conductivity insulating composite material as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) The polymer matrix, modified thermally conductive filler and solvent are mixed evenly, and then poured into a mold for pre-curing to obtain a semi-cured material; (2) The semi-cured material is hot-pressed and then stacked and welded to obtain a stacked and welded material; (3) The stacked welding material is longitudinally cut to obtain a high thermal conductivity insulating composite material.
9. The method for preparing a high thermal conductivity insulating composite material as described in claim 8, characterized in that, In step (1), pre-curing is performed at 80-120℃ for 2-6 hours; In step (2), hot pressing is performed at 120-160℃ and 3-5MPa for 0.5-2h; In step (3), the stack welding is performed at 150-180℃ and 1-3MPa for 8-24 hours.
10. The application of a high thermal conductivity insulating composite material as described in any one of claims 1-7 in the preparation of electronic packaging materials and electronic heat dissipation materials.