High-thermal-conductivity low-dielectric epoxy resin composition and preparation method thereof

Abstract

The invention relates to a high-thermal-conductivity low-dielectric epoxy resin composition and a preparation method thereof, and the high-thermal-conductivity low-dielectric epoxy resin composition comprises the following raw materials in parts by weight: 13-16 parts of a thermal conductive filler, 45-50 parts of epoxy resin, 23-27 parts of a curing agent and 0.3-0.7 part of an accelerant, the heat-conducting 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 attapulgite, the modified boron nitride and the aramid fiber are used as heat-conducting fillers, the dicyclopentadiene epoxy resin and the bisphenol A epoxy resin are used as epoxy resin, and the epoxy resin with high heat conductivity and low dielectric property is prepared by means of weakening charge transfer among molecules, reducing polarization effect, forming a three-dimensional heat-conducting network and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and in particular to a high thermal conductivity and low dielectric epoxy resin composition and a preparation method thereof. Background Art

[0002] Epoxy resin is a high-molecular polymer characterized by epoxy groups. It exhibits excellent adhesion, electrical insulation, and chemical resistance, making it widely used in electronics, electrical equipment, composite materials, and other fields. However, epoxy resin itself has a low thermal conductivity and typically requires a large amount of filler to enhance its thermal conductivity, which can make the material brittle and increase processing difficulties.

[0003] CN117736549A discloses a method for preparing a high thermal conductivity epoxy resin composite, comprising mixing 15-19 parts by mass of prismatic aluminum oxide, 7-9 parts by mass of flaky boron nitride, 7-9 parts by mass of nano-silicon nitride, 1-3 parts by mass of a silane coupling agent, and water, followed by drying to obtain a modified inorganic powder; the modified inorganic powder is then mixed with 100 parts by mass of epoxy resin to prepare a high thermal conductivity epoxy resin composite. However, the above technical solution suffers from the problem of excessive use of thermally conductive filler, which results in increased dielectric loss. Therefore, there is a need for an epoxy resin composition having both good thermal conductivity and excellent dielectric properties. Summary of the Invention

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

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

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

[0007] The thermal 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 preparation method of the modified boron nitride comprises the following steps:

[0009] S1: mixing choline chloride, polyethylene glycol, and polyglutamic acid in a molar ratio of 1:2-3:1-2, heating and stirring to form a eutectic to prepare a mixture 1, adding water and a surfactant to the mixture 1 in sequence, stirring and mixing, to prepare a deep eutectic solvent;

[0010] S2: Adding boron nitride to a low eutectic solvent, ultrasonically treating the boron nitride, centrifuging, washing, and drying the resulting solution to obtain modified boron nitride.

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

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

[0013] Furthermore, the curing agent is at least one of methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic 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. Furthermore, the curing agent is methylendomethylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:0.8-1.2.

[0014] Furthermore, in step S1, the surfactant is polyvinyl pyrrolidone and / or sodium lauryl sulfate, the amount of the surfactant added is 0.2-0.5% of the mass of the mixed material 1, the amount of water added is 20-30% of the mass of the mixed material 1, the weight average molecular weight of the polyethylene glycol is 1000-1500, and the weight average molecular weight of the polyglutamic acid is 500-700.

[0015] Furthermore, in step S2, the mass ratio of boron nitride to the deep eutectic solvent is 1:13-18, the ultrasonic power of the ultrasonic treatment is 220-250 W, the ultrasonic frequency is 150-200 KHz, the ultrasonic time is 1.5-2.5 h, and the centrifugation is performed at a speed of 10,000-13,000 r / min for 8-12 min.

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

[0017] (1) mixing epoxy resin, curing agent, accelerator and attapulgite to prepare mixed material 2;

[0018] (2) Adding the modified boron nitride to the mixed material 2, stirring and mixing, and heating and curing to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0019] Furthermore, in step (1), the mixing is carried out by stirring and mixing at 150-170° C. and a rotation speed of 200-250 r / min for 20-40 min.

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

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses attapulgite, modified boron nitride and aramid fiber as thermally conductive filler, using dicyclopentadiene epoxy resin and bisphenol A type epoxy resin as epoxy resin, by weakening intermolecular charge transfer, reducing polarization effect, forming the approach such as three-dimensional heat-conducting network, prepares a kind of high thermal conductivity low dielectric epoxy resin. Boron nitride is modified using deep eutectic solvent in the present invention, wherein, polyethylene glycol and polyglutamic acid are used as hydrogen bond donors, and choline chloride is used as hydrogen bond acceptor, and boron nitride surface activity can be improved, and the dispersibility and processing properties of boron nitride are further improved. Modified boron nitride is combined with attapulgite, aramid fiber, so that thermally conductive filler forms three-dimensional heat-conducting network, and heat is transferred by three-dimensional heat-conducting network, reaches the effect that heat transmission efficiency is high, and dielectric constant reduces. DETAILED DESCRIPTION

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

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

[0025] In the present 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 the attapulgite of the present invention comprises the following steps: crushing and drying the attapulgite for standby use; dissolving a silane coupling agent KH550 in a 90% v / v ethanol solution to prepare a silane coupling agent solution with a concentration of 4wt%; adding the dried attapulgite to the silane coupling agent solution, stirring and reacting at 80°C and a rotation speed of 100 r / min for 3 hours to prepare a finished product; wherein the amount of the silane coupling agent used is 5% of the mass of the attapulgite.

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

[0028] The diameter of the aramid fiber is 10 nm and the length is 8 μm.

[0029] Unless otherwise specified, other materials, reagents, etc. used in the Examples and Comparative Examples can be obtained from commercial sources.

[0030] Example 1

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

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

[0033] The preparation method of the modified boron nitride comprises the following steps:

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

[0035] S2: adding boron nitride to a deep eutectic solvent, ultrasonicating the solution at 250W and 200kHz for 2.5 hours, centrifuging the solution at 13,000 rpm for 12 minutes, removing the supernatant, washing the resulting solid with deionized water three times, and drying the solid at 80°C to a constant weight to obtain the modified boron nitride, wherein the mass ratio of boron nitride to the deep eutectic solvent is 1:18;

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

[0037] The curing agent is composed of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0040] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 170° C. and 250 rpm for 40 min to prepare a mixture 2;

[0041] (2) Add modified boron nitride and aramid fiber to mixed material 2, stir and mix at 170°C and 250 r / min for 40 minutes, keep the mixture at 190°C for 3 hours, then increase the temperature to 220°C, adjust the pressure to 20 MPa, and continue to keep the mixture for 90 minutes 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 is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0044] The thermal conductive filler consists 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 and modified boron nitride is 1:50, and the particle size of the attapulgite is 30 nm.

[0045] The preparation method of modified boron nitride comprises 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 the mixture is stirred and eutectic at 80°C and 80 r / min to obtain a mixture 1. Water and sodium lauryl sulfate are added to the mixture 1 in sequence, and the mixture is stirred and mixed to obtain a deep eutectic solvent, wherein the amount of water added is 25% by mass of the mixture 1, and the amount of sodium lauryl sulfate added is 0.3% by mass of the mixture 1.

[0047] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0049] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0052] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0053] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it 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 is prepared by weighing the following raw materials in parts by weight: 13 parts of thermal conductive filler, 45 parts of epoxy resin, 23 parts of curing agent, and 0.3 parts of accelerator;

[0056] The thermal conductive filler consists 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 and modified boron nitride is 1:40, and the particle size of the attapulgite is 30 nm.

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

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

[0059] S2: Boron nitride was added to a low eutectic solvent, and ultrasonicated at 220W and 150kHz for 1.5 hours. The ultrasonicated boron nitride flakes were centrifuged at 10,000 rpm for 8 minutes, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:13.

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

[0061] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0064] (1) Epoxy resin, curing agent, 2-ethyl-4-methylimidazole and attapulgite were stirred and mixed at 150° C. and 200 rpm for 20 minutes to prepare a mixture 2;

[0065] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 200 r / min for 20 minutes, keeping the stirred mixture at 170°C for 2 hours, then heating it to 200°C, adjusting the pressure to 10 MPa and keeping it warm for 60 minutes 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 to be:

[0068] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0069] The thermal conductive filler consists 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 to modified boron nitride 2 is 1:50, and the particle size of modified boron nitride 1 is 30 nm.

[0070] The preparation method of modified boron nitride 1 and modified boron nitride 2 comprises 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 the mixture is stirred and eutectic at 80°C and 80 r / min to obtain a mixture 1. Water and sodium lauryl sulfate are added to the mixture 1 in sequence, and the mixture is stirred and mixed to obtain a deep eutectic solvent, wherein the amount of water added is 25% by mass of the mixture 1, and the amount of sodium lauryl sulfate added is 0.3% by mass of the mixture 1.

[0072] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0074] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0077] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0078] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it for 80 min, to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0079] Comparative Example 2

[0080] On the basis of 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 is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0082] The thermal conductive filler consists of modified boron nitride and aramid fiber in a mass ratio of 8:0.3, wherein the particle sizes of attapulgite and modified boron nitride are 150 nm.

[0083] The preparation method of modified boron nitride comprises 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 the mixture is stirred and eutectic at 80°C and 80 r / min to obtain a mixture 1. Water and sodium lauryl sulfate are added to the mixture 1 in sequence, and the mixture is stirred and mixed to obtain a deep eutectic solvent, wherein the amount of water added is 25% by mass of the mixture 1, and the amount of sodium lauryl sulfate added is 0.3% by mass of the mixture 1.

[0085] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0087] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0090] (1) Epoxy resin, curing agent, accelerator, modified boron nitride and aramid fiber are added to the mixture 2, and stirred at 230 r / min for 30 minutes. The stirred mixture is first kept at 180° C. for 2-3 hours, then heated to 210° C., and kept at the pressure of 15 MPa for 80 minutes 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 to be:

[0093] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

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

[0095] The preparation method of modified boron nitride comprises 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 the mixture is stirred and eutectic at 80°C and 80 r / min to obtain a mixture 1. Water and sodium lauryl sulfate are added to the mixture 1 in sequence, and the mixture is stirred and mixed to obtain a deep eutectic solvent, wherein the amount of water added is 25% by mass of the mixture 1, and the amount of sodium lauryl sulfate added is 0.3% by mass of the mixture 1.

[0097] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0099] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0102] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

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

[0104] Comparative Example 4

[0105] On the basis of Example 2, the ratio of the thermal conductive filler was adjusted as follows:

[0106] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

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

[0108] The preparation method of modified boron nitride comprises 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 the mixture is stirred and eutectic at 80°C and 80 r / min to obtain a mixture 1. Water and sodium lauryl sulfate are added to the mixture 1 in sequence, and the mixture is stirred and mixed to obtain a deep eutectic solvent, wherein the amount of water added is 25% by mass of the mixture 1, and the amount of sodium lauryl sulfate added is 0.3% by mass of the mixture 1.

[0110] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0112] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0115] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0116] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it 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 components of the deep eutectic solvent were adjusted, specifically as follows:

[0119] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0120] The thermal conductive filler consists 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 and modified boron nitride is 1:50, and the particle size of the attapulgite is 30 nm.

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

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

[0123] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0125] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0128] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0129] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it for 80 min, to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0130] Comparative Example 6

[0131] On the basis of Example 2, the molar ratio of the deep eutectic solvent was adjusted, specifically as follows:

[0132] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0133] The thermal conductive filler consists 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 and modified boron nitride is 1:50, and the particle size of the attapulgite is 30 nm.

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

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

[0136] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0138] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0141] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0142] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it 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 components of the deep eutectic solvent were adjusted, specifically as follows:

[0145] A high thermal conductivity and low dielectric epoxy resin composition is prepared by weighing the following raw materials in parts by weight: 15 parts of thermal conductive filler, 48 parts of epoxy resin, 25 parts of curing agent, and 0.5 parts of accelerator;

[0146] The thermal conductive filler consists 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 and modified boron nitride is 1:50, and the particle size of the attapulgite is 30 nm.

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

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

[0149] S2: Boron nitride was added to a low eutectic solvent and ultrasonicated at 230W and 180kHz for 2h. The ultrasonicated boron nitride flakes were centrifuged at 12000r / min for 10min, and the supernatant was removed. The obtained solid was washed three times with deionized water and dried at 80°C to constant weight to obtain modified boron nitride, wherein the mass ratio of boron nitride to the low eutectic solvent was 1:15.

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

[0151] The curing agent consists of methylendomethylenetetrahydrophthalic 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 comprises the following steps:

[0154] (1) The epoxy resin, curing agent, accelerator, and attapulgite were stirred and mixed at 160° C. and 220 rpm for 30 min to prepare a mixture 2;

[0155] (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing at 230 r / min for 30 min, keeping the stirred mixture at 180° C. for 2-3 h, then heating it to 210° C., adjusting the pressure to 15 MPa and keeping it for 80 min, to obtain the high thermal conductivity and low dielectric epoxy resin composition.

[0156] Test Example 1

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

[0158] The finished products obtained in Examples 1-3 and Comparative Examples 1-7 were tested for dielectric loss using a dielectric spectrometer of Agilent Model E4980A, USA.

[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 by the present invention has good thermal conductivity and low dielectric loss.

[0161] Compared with Example 2, in Comparative Example 1, the attapulgite is replaced with modified boron nitride of the same specification. The thermal conductivity of the finished product does not change significantly compared with the example, but the dielectric loss increases significantly. In Comparative Example 2, the use of attapulgite in the thermal conductive filler is reduced, and the thermal conductivity of the finished product is significantly reduced compared with the example, and the dielectric loss also increases significantly, indicating that the addition of attapulgite can improve the thermal conductivity of the finished product and reduce the dielectric loss. In Comparative Example 3, the use of aramid fiber in the thermal conductive filler is reduced, and the thermal conductivity of the finished product is significantly reduced compared with the example, and the dielectric loss also increases significantly, indicating that the addition of aramid fiber can improve the thermal conductivity of the finished product and reduce the dielectric loss. In Comparative Example 4, the dosage ratio of attapulgite, modified boron nitride and aramid fiber in the thermal conductive filler is adjusted, and the thermal conductivity of the finished product is significantly reduced compared with the example, and the dielectric constant also increases significantly. In the present invention, attapulgite, modified boron nitride and aramid fiber are combined in specific dosage ratios as thermally conductive fillers, which can construct a more stable dispersion system, enhance the interfacial compatibility between the thermally conductive filler and the 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 with Example 2, in Comparative Example 5, the polyethylene glycol in the low eutectic solvent is replaced with urea, and the thermal conductivity of the finished product decreases compared with the example, and the dielectric constant is also significantly increased. In Comparative Example 6, the amount of raw materials in the low eutectic solvent is adjusted, and the thermal conductivity of the finished product decreases significantly compared with the example, and the dielectric constant is also significantly increased. In Comparative Example 7, the low eutectic solvent uses choline chloride and polyethylene glycol as raw materials, and the thermal conductivity of the finished product decreases significantly compared with the example, and the dielectric constant is also significantly increased. The use of choline chloride, polyethylene glycol and polyglutamic acid in a molar ratio of 1:2-3:1-2 in the present invention can improve the dispersion performance of boron nitride, improve the compatibility of boron nitride and other thermally conductive fillers, reduce the interfacial thermal resistance, and facilitate the formation of a three-dimensional thermal conductive network by the thermally conductive filler.

[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 the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A high thermal conductivity and low dielectric epoxy resin composition, characterized in that: The raw materials include the following by weight: 13-16 parts of thermal conductive filler, 45-50 parts of epoxy resin, 23-27 parts of curing agent and 0.3-0.7 parts of accelerator; The thermal 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 preparation method of the modified boron nitride comprises the following steps: S1: mixing choline chloride, polyethylene glycol, and polyglutamic acid in a molar ratio of 1:2-3:1-2, heating and stirring to form a eutectic mixture to prepare a mixture material 1, adding water and a surfactant to the mixture material 1 in sequence, and stirring to mix well to prepare a deep eutectic solvent; S2: adding boron nitride to a low eutectic solvent, subjecting it to ultrasonic treatment, centrifuging, washing, and drying to obtain the modified boron nitride.

2. The high thermal conductivity and low dielectric epoxy resin composition according to claim 1, wherein The epoxy resin comprises dicyclopentadiene epoxy resin and bisphenol A epoxy resin in a mass ratio of 1:1.5-2.

3. The high thermal conductivity and low dielectric epoxy resin composition according to claim 1, wherein: The curing agent is at least one of methylhexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetrahydrophthalic anhydride, and diaminodiphenyl sulfone; the accelerator is at least one of 2-ethyl-4-methylimidazole and 2,4,6-tris(dimethylaminomethyl)phenol.

4. The high thermal conductivity and low dielectric epoxy resin composition according to claim 3, wherein: The curing agent is methylendomethylenetetrahydrophthalic anhydride and diaminodiphenyl sulfone in a mass ratio of 1:0.8-1.

2.

5. The high thermal conductivity and low dielectric epoxy resin composition according to claim 1, wherein: In step S1, the surfactant is polyvinyl pyrrolidone and / or sodium lauryl sulfate, the amount of the surfactant added is 0.2-0.5% of the mass of the mixed material 1, the amount of water added is 20-30% of the mass of the mixed material 1, the weight average molecular weight of the polyethylene glycol is 1000-1500, and the weight average molecular weight of the polyglutamic acid is 500-700.

6. The high thermal conductivity and low dielectric epoxy resin composition according to claim 1, wherein: In step S2, the mass ratio of boron nitride to the deep eutectic solvent is 1:13-18, the ultrasonic power of the ultrasonic treatment is 220-250 W, the ultrasonic frequency is 150-200 KHz, the ultrasonic time is 1.5-2.5 h, and the centrifugation is performed at a speed of 10,000-13,000 r / min for 8-12 min.

7. The method for preparing the high thermal conductivity and low dielectric epoxy resin composition according to any one of claims 1 to 6, wherein: The following steps are involved: (1) mixing epoxy resin, curing agent, accelerator and attapulgite to prepare mixed material 2; (2) Adding modified boron nitride and aramid fiber to the mixture 2, stirring and mixing, and heating and curing to obtain the high thermal conductivity and low dielectric epoxy resin composition.

8. The method for preparing the high thermal conductivity and low dielectric epoxy resin composition according to claim 7, wherein: In step (1), the mixing is carried out by stirring and mixing at 150-170° C. and 200-250 r / min for 20-40 min.

9. The method for preparing the high thermal conductivity and low dielectric epoxy resin composition according to claim 7, wherein: In step (2), the stirring and mixing is carried out at 150-170°C and 200-250 r / min for 20-40 minutes; and the heating and curing is carried out by first keeping the temperature at 170-190°C for 2-3 hours, then heating the temperature to 200-220°C and keeping the temperature at a pressure of 10-20 MPa for 60-90 minutes.

10. Use of the high thermal conductivity and low dielectric epoxy resin composition according to any one of claims 1 to 9 in preparing electronic equipment components with high thermal conductivity and low dielectric properties.