An epoxy resin plate and a method for manufacturing the same

Abstract

This invention discloses an epoxy resin sheet and its preparation method. The epoxy resin sheet comprises a first semi-cured sheet layer, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet layer, and a third resin material layer connected in sequence. The first and / or second and / or third resin material layers comprise the following components in parts by weight: 100 parts epoxy resin, 70-120 parts modified PCB resin fiber powder, 25-45 parts filler, and 20-40 parts curing agent. The filler includes multi-walled carbon nanotubes, talc, and silica. The modified PCB resin fiber powder is PCB resin fiber powder with PE wax on its surface, and the PCB resin fiber powder includes glass fiber and epoxy resin. This invention eliminates the need for a backing plate during the preparation of the epoxy resin sheet and exhibits high static bending strength, overcoming the problems of low yield and high scrap rate of backing plates caused by the use of backing plates in the preparation of existing materials.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and more specifically, to an epoxy resin sheet and its preparation method. Background Technology

[0002] Boards are materials widely used in construction, furniture, decoration, and industrial manufacturing. They are usually presented in sheet or board form and can be classified by material into wood-based boards, metal-based boards, plastic-based boards, and composite boards, including epoxy resin boards. Currently, most existing technologies, including CN 108440906 B, use backing boards to support the raw materials during board preparation. However, after subsequent pre-pressing and hot-pressing, these backing boards are prone to warping, leading to uneven heating of the raw materials and scorch marks on the finished board. Furthermore, they tend to stick to the finished board, making demolding difficult and resulting in an uneven surface, ultimately affecting the static bending strength of the board. This also increases the scrap rate of the backing boards, making them difficult to reuse. Therefore, there is an urgent need to develop boards that do not require backing boards during preparation.

[0003] In addition, static bending strength is one of the important indicators for measuring the mechanical properties of sheet materials, reflecting the material's ability to resist failure under bending loads. Sheets with high static bending strength can withstand greater loads, have higher structural stability, and also have a longer service life.

[0004] Therefore, it is of great significance to develop an epoxy resin board that does not require a backing plate during preparation and has high static bending strength. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an epoxy resin board and its preparation method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides an epoxy resin sheet comprising a first prepreg layer, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second prepreg layer, and a third resin material layer connected in sequence.

[0008] The first and / or second and / or third resin material layers comprise the following components in parts by weight:

[0009] 100 parts epoxy resin, 70-120 parts modified PCB resin fiber powder, 25-45 parts filler, and 20-40 parts curing agent;

[0010] The filler includes multi-walled carbon nanotubes, talc, and silica.

[0011] The modified PCB resin fiber powder is a PCB resin fiber powder with PE wax on its surface, and the PCB resin fiber powder includes glass fiber and epoxy resin.

[0012] The epoxy resin board of the present invention does not require the use of a backing plate during preparation and has high static bending strength.

[0013] In this invention, the first semi-cured sheet in the epoxy resin board replaces the backing plate during the preparation of the epoxy resin board, thus achieving the goal of eliminating the need for a backing plate during the preparation of the board.

[0014] In the epoxy resin board of the present invention, the specific structure formed by the sequential connection of a first semi-cured sheet layer, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet layer and a third resin material layer of different materials and hardness can effectively disperse stress and avoid stress concentration, thereby improving the static bending strength of the epoxy resin board.

[0015] In addition, in the system formed by epoxy resin, modified PCB resin fiber powder and curing agent in the first, second or third resin material layer, fillers of specific types and different hardness components are uniformly distributed in the system to form a soft-hard balance structure. This not only changes the microstructure of the system, but also effectively transfers stress and avoids stress concentration, thereby helping to improve the static bending strength of epoxy resin boards.

[0016] Preferably, the filler comprises multi-walled carbon nanotubes, talc, and silica in a mass ratio of 10:(1-9):(2-8).

[0017] In the first, second, or third resin material layer of the present invention, a soft-hard balance structure is formed by dispersing multi-walled carbon nanotubes, talc powder, and fumed silica in a specific ratio and with different hardness in a system formed by epoxy resin, modified PCB resin fiber powder, and curing agent. This structure can better optimize the microstructure of the system and better transfer stress, thereby helping to further improve the static bending strength of the epoxy resin board.

[0018] More preferably, the mass ratio of the multi-walled carbon nanotubes, talc, and silica is one or any two of the following: 10:1:3.5, 10:3.5:3.5, 10:6:3.5, 10:9:3.5, 10:3.5:5, 10:3.5:2, and 10:3.5:8.

[0019] More preferably, the mass ratio of the multi-walled carbon nanotubes, talc, and silica is 10:(3.5-6):(3.5-5).

[0020] Preferably, the length of the multi-walled carbon nanotube is 0.5-40 μm.

[0021] More preferably, the length of the multi-walled carbon nanotubes is a value within the range of one or any two of the following: 0.5μm, 1μm, 2μm, 4μm, 5μm, 6μm, 8μm, 10μm, 12μm, 14μm, 15μm, 16μm, 18μm, 20μm, 22μm, 24μm, 25μm, 26μm, 28μm, 30μm, 32μm, 34μm, 35μm, 36μm, 38μm, and 40μm.

[0022] More preferably, the length of the multi-walled carbon nanotubes is 0.5-30 μm.

[0023] More preferably, the length of the multi-walled carbon nanotube is 10-30 μm.

[0024] Preferably, the diameter of the multi-walled carbon nanotubes is 5-30 nm.

[0025] More preferably, the diameter of the multi-walled carbon nanotube is one or any combination of 5nm, 6nm, 8nm, 10nm, 12nm, 14nm, 15nm, 16nm, 18nm, 20nm, 22nm, 24nm, 25nm, 26nm, 28nm, and 30nm.

[0026] More preferably, the diameter of the multi-walled carbon nanotubes is 5-20 nm.

[0027] More preferably, the diameter of the multi-walled carbon nanotubes is 10-20 nm.

[0028] Preferably, the talc powder has a particle size of 1200-5000 mesh.

[0029] More preferably, the particle size of the talc powder is one or any two of the following: 1200 mesh, 1250 mesh, 1500 mesh, 2000 mesh, 2500 mesh, 3000 mesh, 3500 mesh, 4000 mesh, 4500 mesh, and 5000 mesh.

[0030] More preferably, the talc powder has a particle size of 1250-5000 mesh.

[0031] Furthermore, the talc powder has a particle size of 2500-3500 mesh.

[0032] Preferably, the particle size of the silica is 300-1300 mesh.

[0033] More preferably, the particle size of the silica is one or any two of the following: 300 mesh, 325 mesh, 400 mesh, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, 1100 mesh, 1200 mesh, 1250 mesh, and 1300 mesh.

[0034] More preferably, the particle size of the silica is 325-1250 mesh.

[0035] Furthermore, the particle size of the silica is 800-1250 mesh.

[0036] The epoxy resin of the present invention can be a commonly used epoxy resin in the art, or it can be an epoxy resin obtained after disassembly and processing from wind turbine blades.

[0037] Preferably, in the PCB resin fiber powder, the mass ratio of glass fiber to epoxy resin is one or any two of the following: 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20.

[0038] More preferably, in the PCB resin fiber powder, the mass ratio of glass fiber to epoxy resin is 1:(0.5-20).

[0039] More preferably, in the PCB resin fiber powder, the mass ratio of glass fiber to epoxy resin is 1:(1-10), specifically 1:(3-6).

[0040] Preferably, the particle size of the modified PCB resin fiber powder is 100-600 mesh.

[0041] More preferably, the particle size of the modified PCB resin fiber powder is one or any two of the following: 100 mesh, 150 mesh, 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, 550 mesh, and 600 mesh.

[0042] More preferably, the particle size of the modified PCB resin fiber powder is 150-350 mesh, specifically 250-350 mesh.

[0043] Preferably, the particle size of the PCB resin fiber powder is 200-1000 mesh.

[0044] More preferably, the particle size of the PCB resin fiber powder is one or any two of the following: 200 mesh, 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, 550 mesh, 600 mesh, 650 mesh, 700 mesh, 750 mesh, 800 mesh, 850 mesh, 900 mesh, 950 mesh, and 1000 mesh.

[0045] More preferably, the particle size of the PCB resin fiber powder is 200-400 mesh, specifically 300-400 mesh.

[0046] Preferably, the modified PCB resin fiber powder is obtained by melting and atomizing PE paraffin at a temperature above 100°C onto the PCB resin fiber powder.

[0047] The PCB resin fiber powder of the present invention can be directly formulated using glass fiber and epoxy resin, or it can be obtained by decomposition and refining from waste circuit boards containing glass fiber and epoxy resin. When the PCB resin fiber powder is formulated using glass fiber and epoxy resin, the preparation method of the PCB resin fiber powder is as follows: mix glass fiber and epoxy resin, melt extrude, and the PCB resin fiber powder is obtained; the temperature of the melt extrusion is 180-210℃.

[0048] Preferably, the curing agent is at least one selected from ethylenediamine, hexamethylenediamine, maleic anhydride, phthalic anhydride, and m-phenylenediamine.

[0049] Preferably, the first and / or second and / or third resin materials further include at least one of antioxidants and flame retardants.

[0050] In this invention, the antioxidants and flame retardants are commonly used antioxidants and flame retardants in the art, such as: the antioxidants include, but are not limited to, at least one of antioxidant 1010, antioxidant 1076, and antioxidant 168; and the flame retardants include, but are not limited to, at least one of decabromodiphenyl ether, tetrabromobisphenol A, triphenyl phosphate (TPP), tricresyl phosphate (TCP), phosphite, and aluminum diethylphosphonate.

[0051] More preferably, the antioxidant is present in 5-20 parts by weight.

[0052] More preferably, the flame retardant is present in 15-40 parts by weight.

[0053] Preferably, the thickness of the first and / or second semi-cured sheet is 0.4-5 mm.

[0054] More preferably, the thickness of the first and / or second semi-cured sheet is a value within the range of one or any two of the following: 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.8 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, and 5 mm.

[0055] In this invention, the prepregs used for the first and / or second prepreg layers are obtained by purchasing commercially available prepregs or by dismantling prepregs from recycled circuit boards.

[0056] Preferably, the thickness of the first and / or second and / or third resin material layer is 0.8-30 mm.

[0057] More preferably, the thickness of the first and / or second and / or third resin material layer is a value within the range of one or any two of the following: 0.8 mm, 0.9 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, 2 mm, 2.2 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.8 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 4 mm, 5 mm, 6 mm, 7 mm, 28 mm, 29 mm, and 30 mm.

[0058] In this invention, the carbon fiber cloth used for the carbon fiber cloth layer is obtained by purchasing commercially available materials.

[0059] Preferably, the thickness of the carbon fiber cloth layer is 0.1-1 mm.

[0060] More preferably, the thickness of the carbon fiber cloth layer is a value within the range of one or any two of the following: 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.54mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, and 100mm.

[0061] More preferably, the thickness of the carbon fiber cloth layer is 0.15-0.55 mm.

[0062] More preferably, the thickness of the carbon fiber cloth layer is 0.25-0.40 mm.

[0063] Secondly, the present invention provides a method for preparing epoxy resin sheets, comprising the following steps:

[0064] S1. The mixture of raw materials of the first resin material layer, the carbon fiber cloth layer, the mixture of raw materials of the second resin material layer, the mixture of raw materials of the second semi-cured sheet layer and the mixture of raw materials of the third resin material layer are sequentially laid on the first semi-cured sheet layer, and pre-pressed to obtain a blank.

[0065] S2. Hot-press the slab to obtain epoxy resin board.

[0066] Preferably, the hot pressing is performed using a continuous press or a large-format press.

[0067] Preferably, the hot pressing pressure is 1-21 MPa and the hot pressing temperature is 100-230℃.

[0068] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0069] The epoxy resin board of the present invention does not require the use of a backing plate during preparation and has high static bending strength.

[0070] In this invention, the first semi-cured sheet in the epoxy resin board replaces the backing plate during the preparation of the epoxy resin board, thus achieving the goal of eliminating the need for a backing plate during the preparation of the board.

[0071] In the epoxy resin board of the present invention, the specific structure formed by the sequential connection of a first semi-cured sheet layer, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet layer and a third resin material layer of different materials and hardness can effectively disperse stress and avoid stress concentration, thereby improving the static bending strength of the epoxy resin board.

[0072] In addition, in the system formed by epoxy resin, modified PCB resin fiber powder and curing agent in the first, second or third resin material layer, fillers of specific types and different hardness components are uniformly distributed in the system to form a soft-hard balance structure. This not only changes the microstructure of the system, but also effectively transfers stress and avoids stress concentration, thereby helping to improve the static bending strength of epoxy resin boards.

[0073] In the first, second, or third resin material layer of the present invention, a soft-hard balance structure is formed by dispersing multi-walled carbon nanotubes, talc powder, and fumed silica in a specific ratio and with different hardness in a system formed by epoxy resin, modified PCB resin fiber powder, and curing agent. This structure can better optimize the microstructure of the system and better transfer stress, thereby helping to further improve the static bending strength of the epoxy resin board. Detailed Implementation

[0074] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0075] The experimental methods used in the following examples and comparative examples, unless otherwise specified, are generally performed under conventional conditions in the art or as recommended by the manufacturer. Unless otherwise specified, all raw materials and reagents used are commercially available from the general market. Furthermore, unless otherwise specified, "parts" and "%" refer to weight or mass.

[0076] The reagents used in the various embodiments and comparative examples of this invention are as follows:

[0077] Epoxy resin, epoxy resin E-20, Laizhou Baichen;

[0078] Modified PCB resin fiber powder-A, 250 mesh, is prepared by: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:3, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 300 mesh PCB resin fiber powder-A; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 300 mesh PCB resin fiber powder-A, sieving to obtain 250 mesh modified PCB resin fiber powder-A;

[0079] Modified PCB resin fiber powder-B, 350 mesh, is prepared by: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:3, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 400 mesh PCB resin fiber powder-B; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 400 mesh PCB resin fiber powder-B, sieving to obtain 350 mesh modified PCB resin fiber powder-B;

[0080] Modified PCB resin fiber powder-C, 150 mesh, is prepared by: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:3, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 200 mesh PCB resin fiber powder-C; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 200 mesh PCB resin fiber powder-C, sieving to obtain 150 mesh modified PCB resin fiber powder-C;

[0081] Modified PCB resin fiber powder-D, 250 mesh, is prepared by: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:6, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 300 mesh PCB resin fiber powder-D; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 300 mesh PCB resin fiber powder-D, sieving to obtain 250 mesh modified PCB resin fiber powder-D;

[0082] The modified PCB resin fiber powder-E, 250 mesh, is prepared by the following method: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:10, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 300 mesh PCB resin fiber powder-E; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 300 mesh PCB resin fiber powder-E, sieving to obtain 250 mesh modified PCB resin fiber powder-E;

[0083] Modified PCB resin fiber powder-F, 250 mesh, is prepared by: (1) mixing glass fiber (ECS13-03-508A, China Jushi Co., Ltd., average length 3mm, average diameter 13μm) and epoxy resin (epoxy resin E-20, Laizhou Baichen) in a mass ratio of 1:1, melting and extruding at 190℃, granulating, crushing, and sieving to obtain 300 mesh PCB resin fiber powder-F; (2) melting and atomizing PE paraffin (HI-WAX420P, Mitsui Chemicals, Japan) at 130℃ onto 300 mesh PCB resin fiber powder-F, sieving to obtain 250 mesh modified PCB resin fiber powder-F;

[0084] Multi-walled carbon nanotubes-1, XFM13, 100253, length 10-30 μm, diameter 10-20 nm, Jiangsu Xianfeng Nanomaterials;

[0085] Multi-walled carbon nanotubes-2, XFM04, 100235, length 0.5-2μm, diameter 5-15nm, Jiangsu Xianfeng Nanomaterials;

[0086] Talc-1, GY925, 2500 mesh, Changzhou Antai Chemical Co., Ltd.

[0087] Talc-2, GY935, 3500 mesh, Changzhou Antai Chemical Co., Ltd.

[0088] Talc-3, GY915, 1250 mesh, Changzhou Antai Chemical Co., Ltd.

[0089] Talc-4, GY950, 5000 mesh, Changzhou Antai Chemical Co., Ltd.

[0090] Silica-1, 800 mesh, is obtained by grinding and crushing 325 mesh silica (McLean S915312) and then sieving it.

[0091] Silica-2, S915311, 1250 mesh, McLean;

[0092] Silica-3, S915312, 325 mesh, McLean;

[0093] Curing agent, m-phenylenediamine, commercially available;

[0094] Antioxidant, Antioxidant 1010, commercially available;

[0095] Flame retardant, triphenyl phosphate (TPP), commercially available;

[0096] Precursor sheet, PP, FR-4, yellow, 1.5mm thick, made by Dongguan Humen Xinhuiyang;

[0097] Carbon fiber cloth-1, S-CT200, 0.25mm thick, Changzhou Ruite Composite Materials;

[0098] Carbon fiber cloth-2, S-CT320, 0.40mm thick, Changzhou Ruite Composite Materials;

[0099] Carbon fiber cloth-3, S-CT120, 0.15mm thick, Changzhou Ruite Composite Materials;

[0100] Carbon fiber cloth-4, S-CT400, 0.54mm thick, Changzhou Ruite Composite Materials;

[0101] Graphene, XF001H, Jiangsu Xianfeng Nanomaterials.

[0102] Example 1

[0103] This embodiment provides an epoxy resin sheet, comprising a first semi-cured sheet, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet, and a third resin material layer connected in sequence.

[0104] Both the first and second semi-cured sheets are semi-cured sheets with a thickness of 1.5 mm;

[0105] The carbon fiber cloth layer is carbon fiber cloth-1 with a thickness of 0.25 mm;

[0106] The thickness of the first, second, and third resin material layers is 2 mm.

[0107] The first, second, and third resin material layers each comprise the following components in parts by weight:

[0108] 100 parts epoxy resin, 100 parts modified PCB resin fiber powder-A, 35 parts filler, 30 parts curing agent (m-phenylenediamine), 10 parts antioxidant (antioxidant 1010), and 25 parts flame retardant (triphenyl phosphate).

[0109] The filler comprises multi-walled carbon nanotubes-1, talc-1, and silica-1 in a mass ratio of 10:3.5:3.5;

[0110] The modified PCB resin fiber powder-A is a PCB resin fiber powder-A with PE wax on its surface, and the PCB resin fiber powder-A includes glass fiber and epoxy resin in a mass ratio of 1:3.

[0111] The preparation method of the above-mentioned epoxy resin board includes the following steps:

[0112] S1. On the first semi-cured sheet, the mixture of each raw material of the first resin material layer, the carbon fiber cloth layer, the mixture of each raw material of the second resin material layer, the mixture of each raw material of the second semi-cured sheet layer and the third resin material layer are laid in sequence, pre-pressed and trimmed to obtain a blank.

[0113] S2. At 10MPa, the slab is hot-pressed at 200℃ for 15 minutes using a large-format press, then trimmed, flipped and cooled to obtain epoxy resin board.

[0114] Examples 2-7 and Comparative Examples 1-5

[0115] Examples 2-7 and Comparative Examples 1-5 provide different epoxy resin sheets. The difference between them and Example 1 is that the mass ratio of multi-walled carbon nanotubes-1, talc-1, and silica-1 in the first and third resin material layers is different. The rest are the same as in Example 1, as shown in the table below:

[0116] Table 1. Mass ratios of multi-walled carbon nanotubes-1, talc-1, and silica-1 in Examples 1-7 and Comparative Examples 1-5.

[0117]

[0118]

[0119] In the table above, Comparative Example 5 “10 (graphene):3.5:3.5” means that the mass ratio of graphene, talc-1 and silica-1 is 10:3.5:3.5, that is, Comparative Example 5 uses graphene instead of multi-walled carbon nanotubes-1.

[0120] For the same embodiment or comparative example, the mass ratio of multi-walled carbon nanotubes-1, talc-1 and silica-1 in the first resin material layer is the same as that in the second resin material layer, and also the same as that in the third resin material layer.

[0121] Example 8

[0122] This embodiment provides an epoxy resin board, which differs from Embodiment 1 in that multi-walled carbon nanotubes-2 (length 0.5-2μm, diameter 5-15nm) are used instead of multi-walled carbon nanotubes-1 (length 10-30μm, diameter 10-20nm) in Embodiment 1 in the first and second and third resin material layers, while the rest is the same as Embodiment 1.

[0123] Examples 9-11

[0124] Examples 9-11 provide different epoxy resin boards, which differ from Example 1 in that the types of talc in the first and third resin material layers are different; otherwise, they are the same as in Example 1, as shown in the table below:

[0125] Table 2. Types of talc in Examples 1 and 9-11

[0126] Types of talcum powder Particle size of talc Example 1 Talc-1 2500 mesh Example 9 Talc-2 3500 mesh Example 10 Talc-3 1250 mesh Example 11 Talc-4 5000 mesh

[0127] In the table above, for the same embodiment or comparative example, the type of talc in the first resin material layer is the same as that in the second resin material layer and also the same as that in the third resin material layer.

[0128] Examples 12-13

[0129] Examples 12-13 provide different epoxy resin sheets, which differ from Example 1 in that the types of silica in the first and third resin material layers are different, while the rest are the same as in Example 1, as shown in the table below:

[0130] Table 3 shows the types of silica in Examples 1, 12-13.

[0131] Types of silica Particle size of silica Example 1 Silica-1 800 mesh Example 12 Silica-2 1250 mesh Example 13 Silica-3 325 mesh

[0132] In the table above, for the same embodiment or comparative example, the type of silica in the first resin material layer is the same as that in the second resin material layer and also the same as that in the third resin material layer.

[0133] Examples 14-18

[0134] Examples 14-18 provide different epoxy resin boards, which differ from Example 1 in that the types of modified PCB resin fiber powder in the first and third resin material layers are different, while the rest are the same as in Example 1, as shown in the table below:

[0135] Table 4. Types of modified PCB resin fiber powder in Examples 1, 14-18

[0136]

[0137] In the table above, for the same embodiment or comparative example, the type of modified PCB resin fiber powder in the first resin material layer is the same as that in the second resin material layer and also the same as that in the third resin material layer.

[0138] Examples 19-21

[0139] Examples 19-21 provide different epoxy resin sheets, which differ from Example 1 in the type of carbon fiber cloth layer; otherwise, they are the same as Example 1, as shown in the table below:

[0140] Table 5. Types of carbon fiber fabric layers in Examples 1 and 19-21

[0141] Types of carbon fiber fabric layers Thickness of carbon fiber cloth layer Example 1 Carbon fiber cloth-1 0.25mm Example 19 Carbon fiber cloth-2 0.40mm Example 20 Carbon fiber cloth-3 0.15mm Example 21 Carbon fiber cloth-4 0.54mm

[0142] Example 22

[0143] This embodiment provides an epoxy resin sheet, comprising a first semi-cured sheet, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet, and a third resin material layer connected in sequence.

[0144] Both the first and second semi-cured sheets are semi-cured sheets with a thickness of 1.5 mm;

[0145] The carbon fiber cloth layer is carbon fiber cloth-1 with a thickness of 0.25 mm;

[0146] The thickness of the first resin material layer is 1.5 mm, the thickness of the second resin material layer is 3 mm, and the thickness of the first resin material layer is 1.5 mm.

[0147] The first, second, and third resin material layers each comprise the following components in parts by weight:

[0148] 100 parts epoxy resin, 70 parts modified PCB resin fiber powder-A, 25 parts filler, 20 parts curing agent (m-phenylenediamine), 5 parts antioxidant (antioxidant 1010), and 15 parts flame retardant (triphenyl phosphate).

[0149] The filler comprises multi-walled carbon nanotubes-1, talc-1, and silica-1 in a mass ratio of 10:3.5:3.5;

[0150] The modified PCB resin fiber powder-A is a PCB resin fiber powder-A with PE wax on its surface, and the PCB resin fiber powder-A includes glass fiber and epoxy resin in a mass ratio of 1:3.

[0151] The preparation method of the above-mentioned epoxy resin board includes the following steps:

[0152] S1. On the first semi-cured sheet, the mixture of each raw material of the first resin material layer, the carbon fiber cloth layer, the mixture of each raw material of the second resin material layer, the mixture of each raw material of the second semi-cured sheet layer and the third resin material layer are laid in sequence, pre-pressed and trimmed to obtain a blank.

[0153] S2. At 10MPa, the slab is hot-pressed at 200℃ for 15 minutes using a large-format press, then trimmed, flipped and cooled to obtain epoxy resin board.

[0154] Example 23

[0155] This embodiment provides an epoxy resin sheet, comprising a first semi-cured sheet, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet, and a third resin material layer connected in sequence.

[0156] Both the first and second semi-cured sheets are semi-cured sheets with a thickness of 1.5 mm;

[0157] The carbon fiber cloth layer is carbon fiber cloth-1 with a thickness of 0.25 mm;

[0158] The thickness of the first resin material layer is 1 mm, the thickness of the second resin material layer is 2 mm, and the thickness of the first resin material layer is 3 mm.

[0159] The first, second, and third resin material layers each comprise the following components in parts by weight:

[0160] 100 parts epoxy resin, 120 parts modified PCB resin fiber powder-A, 45 parts filler, 40 parts curing agent (m-phenylenediamine), 20 parts antioxidant (antioxidant 1010), and 40 parts flame retardant (triphenyl phosphate).

[0161] The filler comprises multi-walled carbon nanotubes-1, talc-1, and silica-1 in a mass ratio of 10:3.5:3.5;

[0162] The modified PCB resin fiber powder-A is a PCB resin fiber powder-A with PE wax on its surface, and the PCB resin fiber powder-A includes glass fiber and epoxy resin in a mass ratio of 1:3.

[0163] The preparation method of the above-mentioned epoxy resin board includes the following steps:

[0164] S1. On the first semi-cured sheet, the mixture of each raw material of the first resin material layer, the carbon fiber cloth layer, the mixture of each raw material of the second resin material layer, the mixture of each raw material of the second semi-cured sheet layer and the third resin material layer are laid in sequence, pre-pressed and trimmed to obtain a blank.

[0165] S2. At 10MPa, the slab is hot-pressed at 200℃ for 15 minutes using a large-format press, then trimmed, flipped and cooled to obtain epoxy resin board.

[0166] Comparative Example 6

[0167] This comparative example provides an epoxy resin sheet, comprising a first semi-cured sheet, a first resin material layer, a second semi-cured sheet, a second resin material layer, a carbon fiber cloth layer, and a third resin material layer connected in sequence.

[0168] Everything else is the same as in Example 1.

[0169] Comparative Example 7

[0170] This comparative example provides an epoxy resin sheet, which differs from Example 1 in that it does not use a carbon fiber cloth layer, but is otherwise identical to Example 1.

[0171] Comparative Example 8

[0172] This comparative example provides an epoxy resin board, which differs from Example 1 in that it does not use a second semi-cured layer, but is otherwise identical to Example 1.

[0173] Comparative Example 9

[0174] This comparative example provides an epoxy resin board, which differs from Example 1 in that it does not use a second semi-cured sheet layer and a third resin material layer, while all other aspects are the same as in Example 1.

[0175] Performance testing

[0176] The epoxy resin boards of each embodiment and comparative example were subjected to the following tests:

[0177] 1. Static bending strength test

[0178] The epoxy resin sheets of each embodiment or comparative example were cut into specimens with a length of 200 mm and a width of 50 mm. Then, the static bending strength (MPa) of the specimens was measured according to the "4.7 Static Bending Strength - Three-Point Bending Method" of GB / T17657-2022 standard.

[0179] 2. Internal bonding strength test

[0180] Each example or comparative epoxy resin board was cut into a sample with a length of 50 mm and a width of 50 mm. Then, the internal bond strength (MPa) of the sample was measured according to "4.11 Internal Bond Strength" of GB / T17657-2022 standard.

[0181] The experimental results are shown in the table below:

[0182] Table 6 Performance test results of each embodiment and comparative example

[0183]

[0184]

[0185] As shown in Table 6, the epoxy resin sheet of the present invention has high static bending strength, reaching 110.0 MPa or higher. Furthermore, the epoxy resin sheet of the present invention also has high internal bonding strength, reaching 1.90 MPa or higher.

[0186] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An epoxy resin board, characterized in that, It includes a first semi-cured sheet layer, a first resin material layer, a carbon fiber cloth layer, a second resin material layer, a second semi-cured sheet layer, and a third resin material layer connected in sequence; The first and / or second and / or third resin material layers comprise the following components in parts by weight: 100 parts epoxy resin, 70-120 parts modified PCB resin fiber powder, 25-45 parts filler, and 20-40 parts curing agent; The filler comprises multi-walled carbon nanotubes, talc, and silica in a mass ratio of 10:(3.5-6):(3.5-5). The modified PCB resin fiber powder is a PCB resin fiber powder with PE wax on its surface, and the PCB resin fiber powder includes glass fiber and epoxy resin.

2. The epoxy resin board as described in claim 1, characterized in that, Includes at least one of the following (1)-(4): (1) The length of the multi-walled carbon nanotubes is 0.5-40 μm; (2) The diameter of the multi-walled carbon nanotubes is 5-30 nm; (3) The particle size of the talc powder is 1200-5000 mesh; (4) The particle size of the silica is 300-1300 mesh.

3. The epoxy resin board as described in claim 2, characterized in that, Includes at least one of the following (1)-(4): (1) The length of the multi-walled carbon nanotubes is 10-30 μm; (2) The diameter of the multi-walled carbon nanotubes is 10-20 nm; (3) The particle size of the talc powder is 2500-3500 mesh; (4) The particle size of the silica is 800-1250 mesh.

4. The epoxy resin board as described in claim 1, characterized in that, Includes at least one of the following (1)-(4): (1) In the PCB resin fiber powder, the mass ratio of glass fiber to epoxy resin is 1:(0.5-20); (2) The particle size of the modified PCB resin fiber powder is 100-600 mesh; (3) The particle size of the PCB resin fiber powder is 200-1000 mesh; (4) The modified PCB resin fiber powder is obtained by melting and atomizing PE paraffin at a temperature above 100°C onto the PCB resin fiber powder.

5. The epoxy resin board as described in claim 4, characterized in that, Includes at least one of the following (1)-(3): (1) In the PCB resin fiber powder, the mass ratio of glass fiber to epoxy resin is 1:(3-6); (2) The particle size of the modified PCB resin fiber powder is 250-350 mesh; (3) The particle size of the PCB resin fiber powder is 300-400 mesh.

6. The epoxy resin board as described in claim 1, characterized in that, Includes at least one of the following (1)-(2): (1) The curing agent is at least one of ethylenediamine, hexamethylenediamine, maleic anhydride, phthalic anhydride, and m-phenylenediamine; (2) The first and / or second and / or third resin materials also include at least one of antioxidants and flame retardants.

7. The epoxy resin board as described in claim 6, characterized in that, Includes at least one of the following (1)-(4): (1) The antioxidant includes at least one of antioxidant 1010, antioxidant 1076, and antioxidant 168; (2) The flame retardant includes at least one of decabromodiphenyl ether, tetrabromobisphenol A, triphenyl phosphate, tricresyl phosphate, phosphite, and aluminum diethylphosphonate; (3) The antioxidant is present in 5-20 parts by weight; (4) The flame retardant is 15-40 parts by weight.

8. The epoxy resin board as described in claim 1, characterized in that, Includes at least one of the following (1)-(3): (1) The thickness of the first and / or second semi-cured sheet is 0.4-5 mm; (2) The thickness of the first and / or second and / or third resin material layer is 0.8-30 mm; (3) The thickness of the carbon fiber cloth layer is 0.1-1mm.

9. The epoxy resin board as described in claim 8, characterized in that, The thickness of the carbon fiber cloth layer is 0.25-0.40 mm.

10. A method for preparing an epoxy resin sheet as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. The mixture of raw materials of the first resin material layer, the carbon fiber cloth layer, the mixture of raw materials of the second resin material layer, the mixture of raw materials of the second semi-cured sheet layer and the mixture of raw materials of the third resin material layer are sequentially laid on the first semi-cured sheet layer, and pre-pressed to obtain a blank. S2. Hot-press the slab to obtain epoxy resin board.

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