Resin matrix tung oil horse epoxy anhydride adhesive, its preparation method and application, and high-thermal-conductivity tung oil horse epoxy glass powder mica tape

Abstract

The application provides a resin matrix tung oil-maleic anhydride epoxy adhesive and a preparation method and application thereof and a high-thermal-conductivity tung oil-maleic epoxy glass mica tape, and belongs to the technical field of mica tape preparation. The application mixes a thermal conductive powder, KH550 and a solvent to perform first modification to obtain a modified filler; mixes epoxy resin, diphenylmethane bismaleimide, a tung oil anhydride curing agent, an accelerator and an organic solvent to obtain a matrix resin solution; mixes the matrix resin solution, the modified filler, fumed silica and A-186 to perform second modification to obtain the resin matrix tung oil-maleic epoxy anhydride adhesive. The application adopts a double coupling agent double modification method to perform surface modification on the filler, improves the dispersibility of the filler in the adhesive, reduces the thermal resistance of the filler-resin interface, and significantly improves the thermal conductivity; the fumed silica acts as an auxiliary thermal conductive filler in the adhesive, and the fumed silica also plays a role in interface wetting, thereby meeting the insulation and heat dissipation requirements.

Description

Technical Field

[0001] This invention relates to the field of mica tape preparation technology, and in particular to a resin-based tung oil epoxy anhydride adhesive, its preparation method and application, and a high thermal conductivity tung oil epoxy glass powder mica tape. Background Technology

[0002] Currently, the mainstream commonly used mica tape is made of Tongma epoxy glass powder. Its insulation structure consists of mica paper, glass cloth, and Tongma epoxy adhesive, offering good electrical insulation and heat resistance (F class and above), but poor thermal conductivity. Motors generate a large amount of heat during operation. Traditional mica tape has a low thermal conductivity, causing heat to accumulate within the insulation layer, leading to excessively high winding temperatures. This results in increased resistance in the copper conductors at high temperatures, leading to increased losses and a decrease in motor efficiency.

[0003] High temperature is a major cause of shortened motor lifespan. Insulation materials operating at high temperatures for extended periods age faster, significantly reducing their lifespan (according to the "10-degree rule," insulation lifespan is halved for every 10°C increase in temperature). As the rated voltage and installed capacity of large generators continue to increase, the losses generated during operation also increase, leading to more heat and a higher temperature rise in the motor. High temperature is a primary cause of decreased electrical and mechanical performance of the main insulation in large motors, resulting in a shortened insulation lifespan. Therefore, there is an urgent need to improve the thermal conductivity of the main insulation material of the windings.

[0004] The core value of developing high thermal conductivity mica tape made from tung oil epoxy glass powder lies in resolving the contradiction between insulation and heat dissipation in high-power-density electrical equipment. Meanwhile, the high price of high-performance thermally conductive powder fillers presents a significant challenge in reducing costs while achieving a balance in the performance indicators of high thermal conductivity mica tape. In the material composition of mica tape, the thermal conductivity of powdered mica paper is typically 0.47~0.51 W / (m·K), and that of glass cloth is approximately 0.8~1.2 W / (m·K). These two materials are inorganic and form the dispersed phase. The resin matrix, with a thermal conductivity typically between 0.17~0.22 W / (m·K), is an organic material and forms the continuous phase. In multiphase composite materials, the thermal conductivity is most significantly influenced by the thermal conductivity of the continuous phase. Among the components of mica tape, the resin matrix, as the continuous phase, has the lowest thermal conductivity. Therefore, the key to developing high thermal conductivity mica tape is to improve the thermal conductivity of the resin matrix. Currently, industrially, this is mainly achieved by adding high thermal conductivity inorganic powders to improve the polymer's thermal conductivity. For example, related technologies disclose the use of γ-glycidyl etheroxypropyltrimethoxysilane to surface modify inorganic fillers, obtaining an epoxy tungsten anhydride adhesive for the matrix resin, and then preparing a high thermal conductivity epoxy glass powder mica tape. However, the problem of low thermal conductivity still exists. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a resin-based tung oil epoxy anhydride adhesive, its preparation method and application, and a high thermal conductivity tung oil epoxy glass powder mica tape. The resin-based tung oil epoxy anhydride adhesive obtained by this invention has high thermal conductivity.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing a resin-based tung oil epoxy anhydride adhesive, comprising the following steps: The thermally conductive powder, γ-aminopropyltriethoxysilane (KH550) and solvent are mixed for the first modification to obtain the modified filler. The thermally conductive powder includes hexagonal boron nitride (h-BN) and aluminum oxide. An epoxy resin, diphenylmethane bismaleimide (N,N'-4,4'-diphenylmethane bismaleimide), tung oil anhydride curing agent, accelerator and organic solvent are mixed to obtain a matrix resin solution. The matrix resin solution, modified filler, fumed silica and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (A-186) are mixed for a second modification to obtain the resin matrix Tongma epoxy anhydride adhesive.

[0007] Preferably, the mass of the γ-aminopropyltriethoxysilane is 1 to 1.5% of the mass of the thermally conductive powder.

[0008] Preferably, the epoxy resin includes epoxy resin E44, epoxy resin F51, epoxy resin E20 and epoxy resin E12.

[0009] Preferably, the mass of the modified filler is 30-40% of the total mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator and modified filler in the matrix resin solution.

[0010] Preferably, the mass of the fumed silica is 1.5 to 3% of the mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator in the matrix resin solution.

[0011] Preferably, the mass of the β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane is 1.5 to 2% of the mass of the thermally conductive powder.

[0012] Preferably, the promoter comprises an acetylacetone complex.

[0013] The present invention also provides a resin-based tung oil epoxy anhydride adhesive prepared by the preparation method described in the above technical solution.

[0014] This invention also provides the application of the resin-based tung oil epoxy anhydride adhesive described above in the field of mica tape.

[0015] The present invention also provides a high thermal conductivity tung oil epoxy glass powder mica tape, comprising a layered alkali-free glass fiber cloth, a first high thermal conductivity adhesive, calcined powder mica paper, a second high thermal conductivity adhesive, and alkali-free glass fiber cloth, wherein the first high thermal conductivity adhesive and the second high thermal conductivity adhesive are both resin-based tung oil epoxy anhydride adhesives as described in the above technical solutions.

[0016] This invention provides a method for preparing a resin-based tung oil anhydride adhesive, comprising the following steps: mixing thermally conductive powder, γ-aminopropyltriethoxysilane, and a solvent for a first modification to obtain a modified filler, wherein the thermally conductive powder comprises hexagonal boron nitride and alumina; mixing epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator, and organic solvent to obtain a matrix resin solution; and mixing the matrix resin solution, the modified filler, fumed silica, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane for a second modification to obtain the resin-based tung oil anhydride adhesive.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention employs a dual-coupling agent dual-modification method to surface-modify fillers (including thermally conductive powder and fumed silica), improving their dispersibility in adhesives and preventing significant agglomeration. The dual coupling agent forms an organic modified layer on the filler surface, enhancing interfacial bonding, reducing filler-resin interfacial thermal resistance, and significantly improving thermal conductivity. Fumed silica acts as an auxiliary thermally conductive filler in the adhesive. Utilizing its suspension and anti-settling properties, fumed silica constructs a three-dimensional network structure, acting like scaffolding to raise resin viscosity, holding h-BN and alumina in the middle, supporting all powders, preventing sedimentation, and improving the utilization rate of the thermally conductive powder. Simultaneously, fumed silica also acts as an interfacial wetting agent. With its large specific surface area and good compatibility with resin, fumed silica can function similarly to a wetting promoter, helping the resin to more uniformly coat BN and alumina, reducing interfacial voids, and meeting insulation and heat dissipation requirements. Furthermore, the preparation method of this invention is simple to operate and suitable for industrial application.

[0018] Furthermore, the present invention limits the mass of the fumed silica to 1.5-3% of the mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator in the matrix resin solution, thus avoiding the problem that the higher the amount of fumed silica added, the higher the viscosity, which is detrimental to the production of mica tape.

[0019] Furthermore, the present invention specifies that the epoxy resin includes epoxy resin E44, epoxy resin F51, epoxy resin E20 and epoxy resin E12. Epoxy resin itself has excellent insulation properties. After curing with the addition of tung oil anhydride, it can form a dense three-dimensional network structure, which further reduces conductivity and dielectric loss, and improves arc resistance and corona resistance. It exhibits stable insulation performance under high temperature, high humidity, or high frequency environments, making it suitable for high-voltage electrical equipment. Using tung oil anhydride as a curing agent, its flexible long-chain structure effectively toughens the epoxy resin, reducing brittleness and resisting cracking caused by mechanical impact and thermal cycling. The addition of dimethane bismaleimide increases the glass transition temperature of the overall resin matrix, improving heat resistance and thermal stability. The epoxy resin formulation is optimized for the mica tape's processing performance, ensuring it is soft, adherent, and moderately viscous when wrapped around wire rods. No chemical reaction occurs during the adhesive and tape manufacturing processes; the main chemical reaction is the high-temperature curing reaction during application. The epoxy resin of this invention ensures stability at room temperature in the initial stage.

[0020] The present invention also provides a resin-based tung oil epoxy anhydride adhesive prepared by the preparation method described above, wherein the resin-based tung oil epoxy anhydride adhesive of the present invention has high thermal conductivity.

[0021] The present invention also provides a high thermal conductivity Tongma epoxy glass powder mica tape, which is a double-sided glass cloth reinforced type. The Tongma epoxy glass powder mica tape of the present invention has high thermal conductivity, high strength, and low dielectric loss factor. Detailed Implementation

[0022] This invention provides a method for preparing a resin-based tung oil epoxy anhydride adhesive, comprising the following steps: A first modification is performed by mixing thermally conductive powder, γ-aminopropyltriethoxysilane, and a solvent to obtain a modified filler, wherein the thermally conductive powder comprises hexagonal boron nitride and aluminum oxide; Epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator and organic solvent are mixed to obtain a matrix resin solution; The matrix resin solution, modified filler, fumed silica and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane are mixed for a second modification to obtain the resin matrix Tongma epoxy anhydride adhesive.

[0023] Unless otherwise specified, all raw materials used in this invention are commercially available products in the field.

[0024] The present invention involves mixing thermally conductive powder, γ-aminopropyltriethoxysilane and solvent for a first modification to obtain a modified filler, wherein the thermally conductive powder comprises hexagonal boron nitride and aluminum oxide.

[0025] In this invention, the particle size of the hexagonal boron nitride is preferably 1~5μm, specifically 1, 2, 3, 4 or 5μm; the particle size of the alumina is preferably 5~15μm, specifically 5, 10 or 15μm. Using two different particle sizes of hexagonal boron nitride and alumina as the framework of a high thermal conductivity pathway, and employing fumed silica as filler and auxiliary heat conduction, primarily addresses the core issue of "sedimentation." Flake-shaped BN (hexagonal boron nitride) and alumina have high density, while the resin adhesive used in the production of mica tape is of low viscosity. Flake-shaped BN and alumina easily settle in this low-viscosity resin, reducing their utilization rate as thermally conductive powder fillers, thus lowering the thermal conductivity and wasting costs. Fumed silica can construct a three-dimensional network structure, acting like scaffolding to increase resin viscosity, holding the flake-shaped BN and alumina in the middle, supporting all the powder, preventing sedimentation, and improving the utilization rate of the thermally conductive powder. At the same time, fumed silica can also play a role in "interfacial wetting". Fumed silica has a very large specific surface area and good compatibility between surface silanol groups and resin. It can act as a wetting promoter, helping the resin to more evenly coat BN and alumina and reduce interfacial voids.

[0026] In this invention, the mass ratio of hexagonal boron nitride to aluminum oxide is preferably 7:3 or 5:2.

[0027] In this invention, the mass of the γ-aminopropyltriethoxysilane is preferably 1 to 1.5% of the mass of the thermally conductive powder, specifically 1%, 1.1%, 1.2%, 1.3%, 1.4%, or 1.5%. The γ-aminopropyltriethoxysilane KH550 contains an amino group at its end, has high activity, and can react with epoxy resin, firmly gripping the thermally conductive powder (alumina and hexagonal boron nitride) like a "claw".

[0028] The dual coupling agent of this invention is modified in two steps because hexagonal boron nitride is a powder with high thermal conductivity but inert surface, which is difficult to disperse. Therefore, it is first treated with KH550 to introduce amino groups, and then modified with A-186 for the second step.

[0029] In this invention, the solvent preferably includes anhydrous ethanol, and the amount of solvent used is preferably adjusted to make the solid content of the thermally conductive powder 70-80%.

[0030] In this invention, the first modification is preferably carried out under stirring conditions, the stirring speed is preferably 2000~2800 r / min, specifically 2000, 2200, 2400, 2600 or 2800 r / min, and the time is preferably 1~1.5h.

[0031] After the first modification is completed, the present invention preferably dries the material to obtain the modified filler.

[0032] In this invention, the drying process preferably uses two temperature gradients. First, the powder is dried at 65-70°C for 5 hours. At this point, the powder is basically dried but remains in a clump. Then, it is crushed and dispersed, and then dried at 110°C for 1 hour to remove the moisture adsorbed by the powder due to its large specific surface area. After natural cooling, it is sealed and stored for later use.

[0033] This invention involves mixing epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator, and organic solvent to obtain a matrix resin solution.

[0034] In this invention, the epoxy resin preferably includes epoxy resin E44, epoxy resin F51, epoxy resin E20 and epoxy resin E12. Epoxy resin itself has excellent insulation properties. After curing with tung oil anhydride, it can form a dense three-dimensional network structure, further reducing conductivity and dielectric loss, and improving arc resistance and corona resistance. It exhibits stable insulation performance under high temperature, high humidity, or high frequency environments, making it suitable for high-voltage electrical equipment. Using tung oil anhydride as a curing agent, its flexible long-chain structure effectively toughens the epoxy resin, reducing brittleness and resisting cracking caused by mechanical impact and thermal cycling. The addition of dimethane bismaleimide increases the glass transition temperature of the overall resin matrix, improving heat resistance and thermal stability. The epoxy resin formulation is optimized for the mica tape's processing performance, ensuring it is soft, adherent, and moderately viscous when wrapped around wire rods. No chemical reaction occurs during the adhesive and tape manufacturing processes; the main chemical reaction is the high-temperature curing reaction during application. The epoxy resin of this invention ensures stability at room temperature in the initial stage.

[0035] In this invention, the promoter preferably includes an acetylacetone complex, more preferably one or more of acetylacetone titanium oxyacetate (CAS: 14024-64-7), cobalt acetylacetone (including cobalt (II) and / or cobalt (III)) acetylacetone, neodymium acetylacetone, and chromium acetylacetone.

[0036] In this invention, the preferred mass ratio of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator is 21:7:10:7:8:46:1.

[0037] In this invention, the organic solvent preferably includes toluene and / or acetone.

[0038] In this invention, the sum of the mass percentages of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent and accelerator in the matrix resin solution is preferably 56-62%, specifically 56%, 58.5%, 60% or 62%.

[0039] The present invention preferably involves mixing epoxy resin E44, epoxy resin F51, epoxy resin E20, and epoxy resin E12, heating the mixture to 115°C, then adding diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator, circulating and cooling the mixture, and then adding the organic solvent to dilute the mixture to obtain the matrix resin solution.

[0040] After obtaining the matrix resin solution and the modified filler, the present invention mixes the matrix resin solution, the modified filler, fumed silica and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane for a second modification to obtain the resin matrix Tongma epoxy anhydride adhesive.

[0041] In this invention, the mass of the modified filler is preferably 30-40% of the total mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator and modified filler in the matrix resin solution, specifically 30%, 32%, 34%, 35%, 36%, 38% or 40%.

[0042] In this invention, the mass of the fumed silica is preferably 1.5 to 3% of the mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator in the matrix resin solution. Specifically, it can be 1.5%, 2%, 2.5%, or 3%. This avoids the problem that the higher the amount of fumed silica added, the higher the viscosity, which is detrimental to the production of mica tape.

[0043] In this invention, the particle size of the fumed silica is preferably 7-14 nm, and the specific surface area is preferably 140-180 m². 2 / g.

[0044] In this invention, the mass of the β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane is preferably 1.5-2% of the mass of the thermally conductive powder, specifically 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%. Compared to KH560 (chemical name: γ-glycidyl etheroxypropyltrimethoxysilane), the silane coupling agent A-186 has unique alicyclic epoxy groups and a longer carbon chain. It retains the advantage of KH560's epoxy groups being able to participate in the curing reaction of the epoxy resin system and form chemical bonds between the resin and the powder. At the same time, A-186 has higher thermal stability and better adhesive strength.

[0045] The dual-coupling agent dual-modification method of the present invention uses silane coupling agent A-186 (epoxy group, long-chain macromolecule) + silane coupling agent KH550 (amino group, short-chain monomolecule). The two coupling agent components are used in combination, utilizing the chemical bond of epoxy group + amino group. This bond is stronger than that of single silane, has better thermal conductivity, stronger adhesion, reduced interface defects, and better insulation performance.

[0046] In this invention, the second modification is preferably carried out under stirring conditions, wherein the stirring speed is preferably 2300~2800 r / min, specifically 2300, 2400, 2500, 2600 or 2800 r / min, and the stirring time is preferably 1~2 h.

[0047] After the second modification is completed, the present invention preferably cools naturally to room temperature to obtain the resin matrix tungma epoxy anhydride adhesive.

[0048] The present invention also provides a resin-based tung oil epoxy anhydride adhesive prepared by the preparation method described in the above technical solution.

[0049] This invention also provides the application of the resin-based tung oil epoxy anhydride adhesive described above in the field of mica tape.

[0050] The present invention also provides a high thermal conductivity tung oil epoxy glass powder mica tape, comprising a layered alkali-free glass fiber cloth, a first high thermal conductivity adhesive, calcined powder mica paper, a second high thermal conductivity adhesive, and alkali-free glass fiber cloth, wherein the first high thermal conductivity adhesive and the second high thermal conductivity adhesive are both resin-based tung oil epoxy anhydride adhesives as described in the above technical solutions.

[0051] The present invention does not impose any special limitations on the parameters of the alkali-free glass fiber cloth and calcined mica paper, and adopts the specifications known to those skilled in the art.

[0052] In this invention, the thermal conductivity of the calcined mica paper is preferably 0.47~0.51 W / m·K; the thermal conductivity of the alkali-free glass fiber cloth is preferably 0.8~1.2 W / m·K. In this invention, the calcined mica paper and the alkali-free glass fiber cloth are inorganic materials, forming the dispersed phase, while the resin matrix, tung oil epoxy anhydride adhesive, is an organic material, forming the continuous phase.

[0053] This invention also provides a method for preparing the high thermal conductivity mica tape made of tung oil epoxy glass powder described in the above technical solution, comprising the following steps: The calcined mica paper is unwound, and the two layers of alkali-free glass fiber cloth are unwound as well. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. After the resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth, it is bonded to the calcined mica paper, baked, and wound up. After being cut according to the specifications required by the user, the high thermal conductivity tungma epoxy glass powder mica tape is obtained.

[0054] In this invention, the unwinding rate of the calcined mica paper is preferably 80~160 g / m. 2 The unwinding rate of the upper and lower layers of the alkali-free glass fiber cloth is preferably 0.025~0.04mm.

[0055] In this invention, the bonding time is preferably 10-15 seconds.

[0056] In this invention, the baking process preferably involves a first baking, a second baking, and a third baking in sequence. The temperature of the first baking is preferably 55-70°C, and the holding time is preferably 5-8 minutes. The temperature of the second baking is preferably 80-100°C, and the holding time is preferably 5-8 minutes. The temperature of the third baking is preferably 105-125°C, and the holding time is preferably 5-8 minutes. After each of the first, second, and third baking processes is completed, the mixture is preferably rolled up and cut into trays according to the customer's required dimensions.

[0057] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0058] In the embodiments and comparative examples of this invention, fumed silica is HDK. ® H15 was purchased from WACKER, a German company.

[0059] Test standard for thermally conductive epoxy glass powder mica tape GB / T5019.2-2009.

[0060] Example 1 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0061] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0062] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 40% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. Fumed silica and A-186 coupling agent were added. The mass of fumed silica was 2% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerators. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0063] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0064] Comparative Example 1 Same as Example 1, except that the addition of fumed silica is omitted.

[0065] Comparative Example 2 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 3wt% of KH560 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0066] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0067] Modified fillers are added to the matrix resin solution. The mass of the modified fillers is 40% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. After stirring is stopped, the mixture is allowed to cool naturally to obtain a resin-based tung oil anhydride epoxy anhydride adhesive.

[0068] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and each temperature segment is baked for 5 minutes. After each segment is completed, it is rolled up and then cut into 25mm wide strips to obtain high thermal conductivity tungma epoxy glass powder mica tape 3.

[0069] The test results of Example 1 and Comparative Examples 1-2 are shown in Table 1.

[0070] Table 1. Test results of Example 1 and Comparative Examples 1-2

[0071] Example 2 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0072] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0073] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 30% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. Fumed silica and A-186 coupling agent were added. The mass of fumed silica was 1.5% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerators. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0074] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0075] Example 3 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0076] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0077] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 30% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. Fumed silica and A-186 coupling agent were added. The mass of fumed silica was 3% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerators. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0078] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0079] Comparative Example 3 Same as Example 3, except that fumed silica is omitted.

[0080] The test results of Examples 2-3 and Comparative Example 3 are shown in Table 2.

[0081] Table 2 Test results of Examples 2-3 and Comparative Example 3

[0082] Example 4 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0083] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0084] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 35% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. Fumed silica and A-186 coupling agent were added. The mass of fumed silica was 2% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerators. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0085] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0086] Comparative Example 4 Same as Example 4, except that fumed silica is omitted.

[0087] Example 5 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0088] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0089] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 38% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. Fumed silica and A-186 coupling agent were added. The mass of fumed silica was 2% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerators. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0090] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0091] Comparative Example 5 Same as Example 5, except that fumed silica is omitted.

[0092] Comparative Example 6 First, two types of hexagonal boron nitride and alumina with different particle sizes were selected as the framework for high thermal conductivity pathways, with a mass ratio of 7:3 (h-BN: 1~5μm, Al2O3: 5~10μm). Anhydrous ethanol was added to adjust the solid content of the thermally conductive powder to 75wt%. Then, 1.5wt% of KH550 silane coupling agent (based on the mass of the thermally conductive powders (hexagonal boron nitride and alumina)) was added, and the mixture was emulsified and dispersed at 2300 r / min for 1 h. Next, it was dried at 65℃ for 5 h under ventilation, then ground and dispersed, and finally dried again at 110℃ for 1 h under ventilation to obtain the modified filler. After natural cooling, it was sealed and stored.

[0093] To prepare the matrix resin solution, take 21 wt% epoxy resin E44, 7 wt% epoxy resin F51, 10 wt% epoxy resin E20, and 7 wt% epoxy resin E12, heat to 115℃, and add 8% diphenylmethane bismaleimide, 46 wt% tung oil anhydride curing agent, and 1 wt% accelerator (chromium acetylacetone). Circulate and cool, then dilute with toluene and acetone solvents to a solids content of 58.5 wt%.

[0094] Modified fillers were added to the matrix resin solution. The mass of the modified fillers was 50% of the mass of epoxy resin E44, epoxy resin F51, epoxy resin E20, epoxy resin E12, diphenylmethane bismaleimide, tung oil anhydride curing agent, modified fillers, and accelerators. A-186 coupling agent was added. The mass of A-186 coupling agent was 1.5% of the mass of the thermally conductive powder. The mixture was emulsified and dispersed at 2300 r / min for 2 h for secondary modification. After stirring was stopped, the mixture was allowed to cool naturally to obtain the resin-based tung oil anhydride epoxy anhydride adhesive.

[0095] Calcined mica paper is unwound and two layers of alkali-free glass fiber cloth are unwound. The resin matrix tungma epoxy anhydride adhesive is placed in the upper and lower glue tanks. The resin matrix tungma epoxy anhydride adhesive in the upper and lower glue tanks is impregnated and coated with the upper and lower layers of alkali-free glass fiber cloth and then bonded to the calcined mica paper for 10 seconds. Then it is baked at 55, 80 and 105℃ respectively, and baked for 5 minutes at each temperature. After each section is completed, it is rolled up and then cut into 25mm wide strips to obtain the high thermal conductivity tungma epoxy glass powder mica tape.

[0096] The test results of Examples 4-5 and Comparative Examples 4-6 are shown in Table 3.

[0097] Table 3 Test results of Examples 4-5 and Comparative Examples 4-6

[0098] Comparative Example 7 The existing technology produces a 5440-1W Tongma epoxy powder mica tape. Its thermal conductivity is 0.27 W / (m·K), its normal dielectric loss factor is 0.6%, and its dielectric loss factor at 155℃ is 1.50%. Therefore, the high thermal conductivity Tongma epoxy glass powder mica tape produced by this invention has a dielectric loss factor that is almost identical to that of conventional mica tapes produced by the existing technology. However, its dielectric loss factor at 155℃ is superior to that of conventional mica tapes produced by the existing technology, and its thermal conductivity is significantly improved, reaching a maximum value of 0.51 W / (m·K).

[0099] As shown in Tables 1-3, compared with the high thermal conductivity mica tape produced by adding fumed silica as a filler and thermal conductivity aid, the amount of thermally conductive powder added to the high thermal conductivity mica tape produced by adding fumed silica as a filler is significantly reduced, but the thermal conductivity is improved.

[0100] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a resin-based epoxy anhydride adhesive, characterized in that, Includes the following steps: A first modification is performed by mixing thermally conductive powder, γ-aminopropyltriethoxysilane, and a solvent to obtain a modified filler, wherein the thermally conductive powder comprises hexagonal boron nitride and aluminum oxide; Epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator and organic solvent are mixed to obtain a matrix resin solution; The matrix resin solution, modified filler, fumed silica and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane are mixed for a second modification to obtain the resin matrix Tongma epoxy anhydride adhesive.

2. The preparation method according to claim 1, characterized in that, The mass of the γ-aminopropyltriethoxysilane is 1 to 1.5% of the mass of the thermally conductive powder.

3. The preparation method according to claim 1, characterized in that, The epoxy resins include epoxy resin E44, epoxy resin F51, epoxy resin E20, and epoxy resin E12.

4. The preparation method according to claim 1, characterized in that, The mass of the modified filler is 30-40% of the total mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, accelerator and modified filler in the matrix resin solution.

5. The preparation method according to claim 1, characterized in that, The mass of the fumed silica is 1.5 to 3% of the mass of epoxy resin, diphenylmethane bismaleimide, tung oil anhydride curing agent, and accelerator in the matrix resin solution.

6. The preparation method according to claim 1 or 5, characterized in that, The mass of the β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane is 1.5 to 2% of the mass of the thermally conductive powder.

7. The preparation method according to claim 1, characterized in that, The promoter includes an acetylacetone complex.

8. The resin-based tung oil epoxy anhydride adhesive prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the resin-based epoxy anhydride adhesive of claim 8 in the field of mica tape.

10. A high thermal conductivity mica tape made of tung oil epoxy glass powder, characterized in that, It includes a layered arrangement of alkali-free glass fiber cloth, a first high thermal conductivity adhesive, calcined mica paper, a second high thermal conductivity adhesive, and alkali-free glass fiber cloth, wherein the first high thermal conductivity adhesive and the second high thermal conductivity adhesive are both resin-based epoxy anhydride adhesives as described in claim 8.

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