High thermal conductive low dielectric epoxy resin composition and preparation method thereof

Abstract

This invention relates to a high thermal conductivity, low dielectric epoxy resin composition and its preparation method. By weight, the high thermal conductivity, low dielectric epoxy resin composition comprises the following raw materials: 13-16 parts of thermally conductive filler, 45-50 parts of epoxy resin, 23-27 parts of curing agent, and 0.3-0.7 parts of accelerator. The thermally conductive filler comprises attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.7-0.9:6-9:0.2-0.5. This invention uses attapulgite, modified boron nitride, and aramid fiber as thermally conductive fillers, and dicyclopentadiene epoxy resin and bisphenol A type epoxy resin as epoxy resin. By weakening intermolecular charge transfer, reducing polarization effects, and forming a three-dimensional thermally conductive network, an epoxy resin with high thermal conductivity and low dielectric properties is prepared.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to a high thermal conductivity, low dielectric epoxy resin composition and its preparation method. Background Technology

[0002] Epoxy resin is a high-molecular-weight polymer characterized by epoxy groups. It possesses excellent adhesion, electrical insulation, and chemical resistance, and is widely used in electronics, electrical engineering, and composite materials. However, epoxy resin itself has a low thermal conductivity, typically requiring a large amount of filler to enhance thermal conductivity. This can lead to material brittleness and increased processing difficulty.

[0003] CN117736549A discloses a method for preparing a high thermal conductivity epoxy resin composite. The method involves mixing 15-19 parts by weight of prismatic alumina, 7-9 parts by weight of flake boron nitride, 7-9 parts by weight of nano-silicon nitride, 1-3 parts by weight of silane coupling agent, and water, followed by drying to obtain a modified inorganic powder. This modified inorganic powder is then combined with 100 parts by weight of epoxy resin to prepare a high thermal conductivity epoxy resin composite. The above technical solution suffers from the problem of excessive thermally conductive filler content, leading to increased dielectric loss. Therefore, an epoxy resin composition with good thermal conductivity and excellent dielectric properties is needed. Summary of the Invention

[0004] In view of this, the present invention provides a high thermal conductivity, low dielectric epoxy resin composition and its preparation method, thereby solving the above problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A high thermal conductivity and low dielectric epoxy resin composition, by weight, comprises the following raw materials: 13-16 parts of thermally conductive filler, 45-50 parts of epoxy resin, 23-27 parts of curing agent and 0.3-0.7 parts of accelerator;

[0007] The thermally conductive filler comprises attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.7-0.9:6-9:0.2-0.5.

[0008] The method for preparing the modified boron nitride includes the following steps:

[0009] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2-3:1-2 and heated and stirred to obtain mixture 1. Water and surfactant are added to mixture 1 in sequence and stirred to obtain eutectic solvent.

[0010] S2: Boron nitride is added to a eutectic solvent, ultrasonically treated, centrifuged, washed, and dried to obtain modified boron nitride.

[0011] Furthermore, the particle size ratio of the attapulgite and the modified boron nitride is 1:40-60.

[0012] Furthermore, the epoxy resin comprises dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.5-2.

[0013] Further, the curing agent is at least one selected from methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylneodymethylenetetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and diaminodiphenyl sulfone, and the accelerator is at least one selected from 2-ethyl-4-methylimidazolium and 2,4,6-tris(dimethylaminomethyl)phenol. Even further, the curing agent is methylneodymethylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:0.8-1.2.

[0014] Further, in step S1, the surfactant is polyvinylpyrrolidone and / or sodium dodecyl sulfate, the amount of surfactant added is 0.2-0.5% of the mass of mixture 1, the amount of water added is 20-30% of the mass of mixture 1, the weight average molecular weight of polyethylene glycol is 1000-1500, and the weight average molecular weight of polyglutamic acid is 500-700.

[0015] Further, in step S2, the mass ratio of boron nitride to eutectic solvent is 1:13-18, the ultrasonic power of the ultrasonic treatment is 220-250W, the ultrasonic frequency is 150-200KHz, the ultrasonic time is 1.5-2.5h, and the centrifugation is performed at a speed of 10000-13000r / min for 8-12min.

[0016] Furthermore, the preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0017] (1) Mix epoxy resin, curing agent, accelerator and attapulgite to obtain mixture 2;

[0018] (2) Add the modified boron nitride to the mixture 2, stir and mix, heat and cure to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0019] Further, in step (1), the mixing is carried out by stirring at 150-170℃ and 200-250r / min for 20-40min.

[0020] Further, in step (2), the stirring and mixing is carried out at 150-170℃ and 200-250r / min for 20-40min; the heating and curing is carried out by first keeping the temperature at 170-190℃ for 2-3h, then raising the temperature to 200-220℃ and keeping it at a pressure of 10-20MPa for 60-90min.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] This invention uses attapulgite, modified boron nitride, and aramid fibers as thermally conductive fillers, and dicyclopentadiene epoxy resin and bisphenol A type epoxy resin as epoxy resins. By weakening intermolecular charge transfer, reducing polarization effects, and forming a three-dimensional thermally conductive network, a high thermal conductivity and low dielectric constant epoxy resin is prepared. In this invention, a eutectic solvent is used to modify boron nitride. Polyethylene glycol and polyglutamic acid act as hydrogen bond donors, and choline chloride acts as a hydrogen bond acceptor, which can improve the surface activity of boron nitride, further enhancing its dispersibility and processing performance. Combining the modified boron nitride with attapulgite and aramid fibers allows the thermally conductive filler to form a three-dimensional thermally conductive network. Heat is transferred through this network, achieving high heat transfer efficiency and a reduced dielectric constant. Detailed Implementation

[0023] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] The sources of the raw materials used in the following examples and comparative examples are as follows:

[0025] In this invention, the weight-average molecular weight of polyethylene glycol is 1300, and the weight-average molecular weight of polyglutamic acid is 600.

[0026] The preparation method of attapulgite in this invention is as follows: attapulgite is pulverized and dried for later use; silane coupling agent KH550 is dissolved in a 90% v / v ethanol solution to obtain a silane coupling agent solution with a concentration of 4 wt%; the dried attapulgite is added to the silane coupling agent solution, and the mixture is stirred and reacted at 80°C and 100 r / min for 3 hours to obtain the finished product; wherein, the amount of silane coupling agent used is 5% of the mass of attapulgite.

[0027] The boron nitride, with the chemical formula h-BN, was purchased from Shanghai Yaotian Chemical Co., Ltd.

[0028] Aramid fibers have a diameter of 10 nm and a length of 8 μm.

[0029] Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0030] Example 1

[0031] A high thermal conductivity and low dielectric epoxy resin composition, by weight, comprises the following raw materials: 16 parts thermally conductive filler, 50 parts epoxy resin, 27 parts curing agent, and 0.7 parts accelerator.

[0032] The thermally conductive filler is composed of attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.9:9:0.5.

[0033] The method for preparing the modified boron nitride includes the following steps:

[0034] S1: Choline chloride, polyethylene glycol, and polyglutamic acid are mixed in a molar ratio of 1:3:2 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 30% of the mass of mixture 1, and the amount of sodium dodecyl sulfate added is 0.5% of the mass of mixture 1.

[0035] S2: Add boron nitride to a eutectic solvent, sonicate for 2.5 h at 250 W and 200 kHz, centrifuge at 13000 r / min for 12 min, remove the supernatant, wash the obtained solid three times with deionized water, and dry at 80 °C to constant weight to obtain the modified boron nitride, wherein the mass ratio of boron nitride to eutectic solvent is 1:18;

[0036] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:2.

[0037] The curing agent is composed of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.2;

[0038] The accelerator is 2-ethyl-4-methylimidazole;

[0039] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0040] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 170℃ and 250r / min for 40min to obtain mixture 2;

[0041] (2) Add modified boron nitride and aramid fiber to mixture 2, stir and mix at 170℃ and 250r / min for 40min, keep warm at 190℃ for 3h, then raise the temperature to 220℃, adjust the pressure to 20MPa, and continue to keep warm for 90min to obtain a high thermal conductivity and low dielectric epoxy resin composition.

[0042] Example 2

[0043] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0044] The thermally conductive filler is composed of attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.8:8:0.3, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50, and the particle size of attapulgite is 30nm.

[0045] The preparation method of modified boron nitride includes the following steps:

[0046] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0047] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0048] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0049] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0050] The accelerator is 2-ethyl-4-methylimidazole.

[0051] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0052] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0053] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0054] Example 3

[0055] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 13 parts thermally conductive filler, 45 parts epoxy resin, 23 parts curing agent, and 0.3 parts accelerator;

[0056] The thermally conductive filler is composed of attapulgite, modified boron nitride and aramid fiber in a mass ratio of 0.7:6:0.25, wherein the particle size ratio of attapulgite to modified boron nitride is 1:40 and the particle size of attapulgite is 30nm.

[0057] The preparation method of modified boron nitride includes the following steps:

[0058] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2:1 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 20% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.2% of the mass of mixture 1.

[0059] S2: Add boron nitride to a eutectic solvent and sonicate for 1.5 h at 220 W and 150 kHz. Centrifuge the sonicated boron nitride flakes at 10000 r / min for 8 min, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80 °C to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:13.

[0060] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.5.

[0061] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:0.8.

[0062] The accelerator is 2-ethyl-4-methylimidazole.

[0063] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0064] (1) Epoxy resin, curing agent, 2-ethyl-4-methylimidazolium and attapulgite were stirred and mixed at 150℃ and 200r / min for 20min to obtain mixture 2;

[0065] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 200 r / min for 20 min, keep the mixture at 170℃ for 2 h, then raise the temperature to 200℃, adjust the pressure to 10 MPa and keep it at 60 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0066] Comparative Example 1

[0067] Based on Example 2, the composition of the thermally conductive filler was adjusted, specifically as follows:

[0068] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0069] The thermally conductive filler is composed of modified boron nitride 1, modified boron nitride 2 and aramid fiber in a mass ratio of 0.8:8:0.3, wherein the particle size ratio of modified boron nitride 1 and modified boron nitride 2 is 1:50, and the particle size of modified boron nitride 1 is 30nm.

[0070] The preparation methods of modified boron nitride 1 and modified boron nitride 2 include the following steps:

[0071] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0072] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0073] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0074] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0075] The accelerator is 2-ethyl-4-methylimidazole.

[0076] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0077] (1) Epoxy resin, curing agent, accelerator and modified boron nitride 1 are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0078] (2) Add modified boron nitride 2 and aramid fiber to mixture 2, stir and mix at 230 r / min for 30 min, keep the stirred mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0079] Comparative Example 2

[0080] Based on Example 2, the composition of the thermally conductive filler was adjusted, specifically as follows:

[0081] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0082] The thermally conductive filler is composed of modified boron nitride and aramid fiber in a mass ratio of 8:0.3, wherein the particle size of the modified boron nitride is 150 nm.

[0083] The preparation method of modified boron nitride includes the following steps:

[0084] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0085] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0086] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0087] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0088] The accelerator is 2-ethyl-4-methylimidazole.

[0089] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0090] (1) Epoxy resin, curing agent, accelerator, modified boron nitride and aramid fiber are added to mixture 2 and stirred at 230 r / min for 30 min. The mixture is then kept at 180℃ for 2-3 h, then heated to 210℃ and kept at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0091] Comparative Example 3

[0092] Based on Example 2, the composition of the thermally conductive filler was adjusted, specifically as follows:

[0093] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0094] The thermally conductive filler is composed of attapulgite and modified boron nitride in a mass ratio of 0.8:8, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50, and the particle size of attapulgite is 30nm.

[0095] The preparation method of modified boron nitride includes the following steps:

[0096] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0097] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0098] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0099] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0100] The accelerator is 2-ethyl-4-methylimidazole.

[0101] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0102] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0103] (2) Add the modified boron nitride to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0104] Comparative Example 4

[0105] Based on Example 2, the proportion of the thermally conductive filler was adjusted as follows:

[0106] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0107] The thermally conductive filler is composed of attapulgite, modified boron nitride and aramid fiber in a mass ratio of 0.3:8:1, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50 and the particle size of attapulgite is 30nm.

[0108] The preparation method of modified boron nitride includes the following steps:

[0109] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0110] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0111] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0112] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0113] The accelerator is 2-ethyl-4-methylimidazole.

[0114] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0115] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0116] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0117] Comparative Example 5

[0118] Based on Example 2, the composition of the eutectic solvent was adjusted as follows:

[0119] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0120] The thermally conductive filler is composed of attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.8:8:0.3, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50, and the particle size of attapulgite is 30nm.

[0121] The preparation method of modified boron nitride includes the following steps:

[0122] S1: Choline chloride, urea and polyglutamic acid are mixed in a molar ratio of 1:2.5:1.5 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0123] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0124] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0125] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0126] The accelerator is 2-ethyl-4-methylimidazole.

[0127] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0128] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0129] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0130] Comparative Example 6

[0131] Based on Example 2, the molar ratio of the eutectic solvent was adjusted, specifically as follows:

[0132] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0133] The thermally conductive filler is composed of attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.8:8:0.3, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50, and the particle size of attapulgite is 30nm.

[0134] The preparation method of modified boron nitride includes the following steps:

[0135] S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 2:1:2 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0136] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0137] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0138] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0139] The accelerator is 2-ethyl-4-methylimidazole.

[0140] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0141] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0142] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0143] Comparative Example 7

[0144] Based on Example 2, the composition of the eutectic solvent was adjusted as follows:

[0145] A high thermal conductivity and low dielectric epoxy resin composition, comprising the following raw materials by weight: 15 parts thermally conductive filler, 48 parts epoxy resin, 25 parts curing agent, and 0.5 parts accelerator.

[0146] The thermally conductive filler is composed of attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.8:8:0.3, wherein the particle size ratio of attapulgite to modified boron nitride is 1:50, and the particle size of attapulgite is 30nm.

[0147] The preparation method of modified boron nitride includes the following steps:

[0148] S1: Choline chloride and polyethylene glycol are mixed in a molar ratio of 1:4 and stirred and eutectic at 80°C and 80 r / min to obtain mixture 1. Water and sodium dodecyl sulfate are added to mixture 1 in sequence and stirred until homogeneous to obtain a eutectic solvent. The amount of water added is 25% of the mass of mixture 1 and the amount of sodium dodecyl sulfate added is 0.3% of the mass of mixture 1.

[0149] S2: Add boron nitride to a eutectic solvent and sonicate for 2 hours at 230W and 180KHz. Centrifuge the sonicated boron nitride flakes at 12000r / min for 10 minutes, remove the supernatant, wash the resulting solid three times with deionized water, and dry it at 80℃ to constant weight to obtain modified boron nitride. The mass ratio of boron nitride to eutectic solvent is 1:15.

[0150] The epoxy resin is composed of dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.7.

[0151] The curing agent consists of methylin-methylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:1.

[0152] The accelerator is 2-ethyl-4-methylimidazole.

[0153] The preparation method of the high thermal conductivity and low dielectric epoxy resin composition includes the following steps:

[0154] (1) Epoxy resin, curing agent, accelerator and attapulgite are stirred and mixed at 160℃ and 220r / min for 30min to obtain mixture 2;

[0155] (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix at 230 r / min for 30 min, keep the mixture at 180℃ for 2-3 h, then raise the temperature to 210℃, adjust the pressure to 15 MPa and keep it at 15 MPa for 80 min to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0156] Experimental Example 1

[0157] The thermal conductivity of the finished products prepared in Examples 1-3 and Comparative Examples 1-7 at 105°C was determined according to GB / T 29313-2012.

[0158] The dielectric loss of the finished products obtained in Examples 1-3 and Comparative Examples 1-7 was tested using an Agilent E4980A dielectric spectrum analyzer.

[0159] name Thermal conductivity (W / (m·K)) <![CDATA[Dielectric loss (10 6 Hz)]]> Example 1 2.64 0.00125 Example 2 2.78 0.00124 Example 3 2.67 0.00129 Comparative Example 1 2.53 0.00463 Comparative Example 2 2.37 0.00367 Comparative Example 3 2.41 0.00271 Comparative Example 4 2.29 0.00448 Comparative Example 5 2.54 0.00219 Comparative Example 6 2.42 0.00286 Comparative Example 7 2.48 0.00358

[0160] Experimental results show that the epoxy resin composition prepared in this invention has good thermal conductivity and low dielectric loss.

[0161] Compared to Example 2, in Comparative Example 1, replacing attapulgite with modified boron nitride of the same specification did not significantly change the thermal conductivity of the finished product, but the dielectric loss increased significantly. In Comparative Example 2, reducing the use of attapulgite in the thermally conductive filler resulted in a significant decrease in the thermal conductivity of the finished product compared to the example, and a significant increase in dielectric loss, indicating that the addition of attapulgite can improve the thermal conductivity and reduce dielectric loss of the finished product. In Comparative Example 3, reducing the use of aramid fiber in the thermally conductive filler resulted in a significant decrease in the thermal conductivity of the finished product compared to the example, and a significant increase in dielectric loss, indicating that the addition of aramid fiber can improve the thermal conductivity and reduce dielectric loss of the finished product. In Comparative Example 4, adjusting the ratio of attapulgite, modified boron nitride, and aramid fiber in the thermally conductive filler resulted in a significant decrease in the thermal conductivity and a significant increase in the dielectric constant of the finished product compared to the example. In this invention, attapulgite, modified boron nitride, and aramid fiber are combined in a specific ratio as thermally conductive fillers. This combination can construct a more stable dispersion system, enhance the interfacial compatibility between the thermally conductive filler and epoxy resin, and enable the thermally conductive filler to form a three-dimensional thermally conductive network. Heat is transferred through the three-dimensional thermally conductive network, achieving high heat transfer efficiency and a reduced dielectric constant.

[0162] Compared to Example 2, in Comparative Example 5, replacing polyethylene glycol in the eutectic solvent with urea resulted in a decrease in the thermal conductivity of the finished product and a significant increase in the dielectric constant. In Comparative Example 6, adjusting the amount of raw materials in the eutectic solvent significantly decreased the thermal conductivity of the finished product compared to the examples, while also significantly increasing the dielectric constant. In Comparative Example 7, using choline chloride and polyethylene glycol as the eutectic solvent resulted in a significant decrease in the thermal conductivity of the finished product compared to the examples, while also significantly increasing the dielectric constant. The use of a molar ratio of choline chloride, polyethylene glycol, and polyglutamic acid of 1:2-3:1-2 in this invention improves the dispersion performance of boron nitride, enhances the compatibility between boron nitride and other thermally conductive fillers, reduces interfacial thermal resistance, and facilitates the formation of a three-dimensional thermally conductive network by the fillers.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A high thermal conductivity, low dielectric epoxy resin composition, characterized in that, By weight, it includes the following raw materials: 13-16 parts of thermally conductive filler, 45-50 parts of epoxy resin, 23-27 parts of curing agent and 0.3-0.7 parts of accelerator; The thermally conductive filler comprises attapulgite, modified boron nitride, and aramid fiber in a mass ratio of 0.7-0.9:6-9:0.2-0.

5. The method for preparing the modified boron nitride includes the following steps: S1: Choline chloride, polyethylene glycol and polyglutamic acid are mixed in a molar ratio of 1:2-3:1-2 and heated and stirred to obtain mixture 1. Water and surfactant are added to mixture 1 in sequence and stirred to obtain eutectic solvent. S2: Boron nitride is added to a eutectic solvent, ultrasonically treated, centrifuged, washed, and dried to obtain the modified boron nitride.

2. The high thermal conductivity, low dielectric epoxy resin composition as described in claim 1, characterized in that, The epoxy resin comprises dicyclopentadiene epoxy resin and bisphenol A type epoxy resin in a mass ratio of 1:1.5-2.

3. The high thermal conductivity, low dielectric epoxy resin composition as described in claim 1, characterized in that, The curing agent is at least one of methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylmethylenetetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and diaminodiphenyl sulfone, and the accelerator is at least one of 2-ethyl-4-methylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol.

4. The high thermal conductivity, low dielectric epoxy resin composition as described in claim 3, characterized in that, The curing agent is methylmethylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:0.8-1.

2.

5. The high thermal conductivity, low dielectric epoxy resin composition as described in claim 1, characterized in that, In step S1, the surfactant is polyvinylpyrrolidone and / or sodium dodecyl sulfate, the amount of surfactant added is 0.2-0.5% of the mass of mixture 1, the amount of water added is 20-30% of the mass of mixture 1, the weight average molecular weight of polyethylene glycol is 1000-1500, and the weight average molecular weight of polyglutamic acid is 500-700.

6. The high thermal conductivity, low dielectric epoxy resin composition as described in claim 1, characterized in that, In step S2, the mass ratio of boron nitride to eutectic solvent is 1:13-18, the ultrasonic power of the ultrasonic treatment is 220-250W, the ultrasonic frequency is 150-200KHz, the ultrasonic time is 1.5-2.5h, and the centrifugation is performed at a speed of 10000-13000r / min for 8-12min.

7. The method for preparing the high thermal conductivity, low dielectric epoxy resin composition according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Mix epoxy resin, curing agent, accelerator and attapulgite to obtain mixture 2; (2) Add the modified boron nitride and aramid fiber to the mixture 2, stir and mix, heat and cure to obtain the high thermal conductivity and low dielectric epoxy resin composition.

8. The method for preparing the high thermal conductivity, low dielectric epoxy resin composition as described in claim 7, characterized in that, In step (1), the mixing is carried out by stirring and mixing at 150-170℃ and 200-250r / min for 20-40min.

9. The method for preparing the high thermal conductivity, low dielectric epoxy resin composition as described in claim 7, characterized in that, In step (2), the stirring and mixing is carried out at 150-170℃ and 200-250r / min for 20-40min; the heating and curing is carried out at 170-190℃ for 2-3h, then heated to 200-220℃ and held at 10-20MPa for 60-90min.

10. The use of the high thermal conductivity, low dielectric epoxy resin composition according to any one of claims 1-6 in the preparation of electronic device components having high thermal conductivity and low dielectric properties.