Conductive shielding wave-absorbing high-strength thermosetting plate and preparation process thereof

Abstract

The application relates to the technical field of B32B9 / 00, in particular to a conductive shielding wave-absorbing high-strength thermosetting plate and a preparation process thereof. The conductive shielding wave-absorbing high-strength thermosetting plate provided by the application at least comprises a carbon fiber base layer, an intermediate adhesive film layer and an upper shielding layer, has light weight, thin thickness and high strength, has electromagnetic shielding property and wave-absorbing property, and can be used for replacing metal plates to be used in light and thin electronic equipment or other fields requiring weight reduction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of B32B9 / 00, in particular to a conductive shielding wave-absorbing high-strength thermosetting plate and a preparation process thereof. BACKGROUND

[0002] Carbon fiber refers to carbon fiber formed by carbonizing organic fiber or pitch fiber in an inert atmosphere, and its structure is polycyclic structure between diamond and graphite, which has been widely used in various fields such as aerospace, nuclear power equipment, transportation and stealth weapons. However, carbon fiber has high brittleness, large axial stress and poor radial stress, and is easy to break when bending, which limits its application in the field of electronic products / equipment. For example, Chinese patent application CN113085290A discloses a conductive fireproof carbon fiber composite board and a preparation method thereof. By modifying the carbon fiber, introducing conductive flame-retardant fiber and conductive carbon black in the presence of a coupling agent, and after carding, stacking, needling and hot pressing treatment, a carbon fiber composite board is obtained, which has excellent flame-retardant and fireproof performance and conductive performance. However, the grammage of the board is very high, and it does not have corresponding electromagnetic shielding and wave-absorbing performance, which cannot be effectively applied to the field of electronic products / equipment.

[0003] Therefore, it is of great economic value and social benefit to develop an ultra-thin carbon fiber thermosetting plate with conductive shielding and wave-absorbing functions to replace metal plates for use in light and thin electronic equipment or other fields requiring weight reduction. SUMMARY

[0004] In order to solve the above problems, the present application provides a conductive shielding wave-absorbing high-strength thermosetting plate, which comprises at least a carbon fiber base layer, an intermediate adhesive film layer and an upper shielding layer.

[0005] As a preferred technical solution, the carbon fiber base layer is prepared by cross-laminating and hot pressing carbon fiber prepreg, the thickness of the carbon fiber base layer is 0.02-0.30mm, preferably 0.15-0.30mm.

[0006] Preferably, the carbon fiber prepreg is unidirectional carbon fiber prepreg, and the glue content of the unidirectional carbon fiber prepreg is 35-45wt%.

[0007] Preferably, the thickness of the unidirectional carbon fiber prepreg is 0.02-0.20mm, and the carbon fiber content in the carbon fiber prepreg is 20-200g / m 2 .

[0008] Preferably, the number of layers of the laminated layer is 3-5 layers.

[0009] Preferably, the hot-pressing conditions are: temperature 120-150℃, pressure 2MPa, time 30-60min.

[0010] Based on the system of the application, the unidirectional carbon fiber prepreg with a thickness of 0.02-0.20mm, a glue content of 35-45wt%, and a carbon fiber content of 20-200g / m 2 The carbon fiber-based layer is prepared from the unidirectional carbon fiber prepreg with a thickness of 0.02-0.20mm, a glue content of 35-45wt%, and a carbon fiber content of 20-200g / m

[0011] As a preferred technical solution, the preparation raw materials of the intermediate adhesive film layer include at least 60-100 parts by weight of thermosetting resin, 10-30 parts by weight of toughening agent, 20-40 parts by weight of conductive powder, and 8-15 parts by weight of curing agent.

[0012] Preferably, the thermosetting resin includes thermosetting resin A and thermosetting resin B, the thermosetting resin A is a phenolic epoxy resin, and the thermosetting resin B is a bisphenol A type epoxy resin. Preferably, the weight ratio of the thermosetting resin A and the thermosetting resin B is (2-4):(4-6).

[0013] The model of the phenolic epoxy resin is CNE-202, which is from Changchun Artificial Resin Factory Co., Ltd. in Taiwan. The model of the bisphenol A type epoxy resin is JER-YL980, which is from Mitsubishi in Japan.

[0014] As a preferred technical solution, the particle size of the conductive powder is 5-25μm. Preferably, the conductive powder is at least one of silver-coated copper powder, silver-coated nickel powder, and silver-coated aluminum powder. The conductive powder is silver-coated copper powder, the particle size (D50) is 5-8μm, the model is NX-510, and the source is Shenzhen Naxiang Conductive Material Technology Co., Ltd.

[0015] Based on the system, by adopting 5-25 μm conductive powder, especially adopting silver-coated copper powder with a particle size of 5-8 μm as the conductive powder, the system has good dispersion performance in the thermosetting resin system, the prepared intermediate adhesive film layer has super strong conductive performance, and the composite strength between the intermediate adhesive film layer and the carbon fiber base layer and the upper shielding layer is not affected, and the usability of the intermediate adhesive film layer is ensured.

[0016] As a preferred technical solution, the curing agent is liquid aromatic amine, model Ethacure200, from Shenzhen Jiadida New Material Technology Co., Ltd.

[0017] As a preferred technical solution, the toughening agent is liquid nitrile rubber, and the liquid nitrile rubber is at least one of carboxyl-terminated nitrile rubber, amine-terminated nitrile rubber and vinyl-terminated nitrile rubber; preferably, the liquid nitrile rubber is carboxyl-terminated nitrile rubber, model CTBN 1300X31, from Shenzhen Jiadida New Material Technology Co., Ltd.

[0018] As a preferred technical solution, the preparation process of the intermediate adhesive film layer is that the thermosetting resin, the toughening agent and the conductive powder are mixed according to the formula amount, then the formula amount of the curing agent is added, and the mixture is placed in an oven and cured at 80-90°C for 30-60 min to obtain the intermediate adhesive film layer.

[0019] Preferably, the thickness of the intermediate adhesive film layer is 30-50 μm.

[0020] As a preferred technical solution, the preparation raw materials of the upper shielding layer at least include 30-60 parts of modified bisphenol A type epoxy resin, 40-70 parts of polyurethane modified thermosetting resin, 120-180 parts of wave-absorbing powder and 8-15 parts of curing agent.

[0021] Preferably, the modified bisphenol A type epoxy resin is model EPALLOY 7200, from Shenzhen Jiadida New Material Technology Co., Ltd.

[0022] Preferably, the polyurethane modified thermosetting resin has an epoxy equivalent weight of 195-240 g.eq -1 The polyurethane modified thermosetting resin has an epoxy equivalent weight of 215 g.eq -1 , model HyPox UA11, from Shenzhen Jiadida New Material Technology Co., Ltd.

[0023] Preferably, the particle size (D50) of the wave-absorbing powder is 5-150 um, preferably 20-50 μm. Preferably, the wave-absorbing powder is two-dimensional wave-absorbing powder, model Wector TM CF30, from Suzhou Putaonew Material Technology Co., Ltd.

[0024] Preferably, the curing agent is a liquid aromatic amine, model Ethacure 200, from Shenzhen Jiadi New Material Technology Co., Ltd.

[0025] Based on the system of the application, the modified bisphenol A type epoxy resin and the polyurethane modified thermosetting resin are used as the resin matrix, the two-dimensional wave absorbing powder of 20-50 microns is introduced, and the shielding layer with excellent shielding performance is formed after the liquid aromatic amine in the system is cured, and the effective compounding with the middle adhesive film layer can be realized.

[0026] As a preferred technical solution, the preparation process of the upper shielding layer is that the modified bisphenol A type epoxy resin, the polyurethane modified thermosetting resin and the wave absorbing powder are mixed according to the formula amount, then the curing agent is added according to the formula amount, and the upper shielding layer is obtained after being cured at 80-90 DEG C for 30-60 min in an oven.

[0027] Preferably, the thickness of the upper shielding layer is 0.02-0.03 mm.

[0028] Another aspect of the application provides a preparation process of the conductive shielding wave-absorbing high-strength thermosetting plate, which comprises the following steps: pasting the middle adhesive film layer on the upper surface of the carbon fiber base layer, covering the upper shielding layer on the upper surface of the middle adhesive film layer, and then putting the whole into a hot press for compression to obtain the conductive shielding wave-absorbing high-strength thermosetting plate.

[0029] Preferably, the compression conditions are 120-150 DEG C, 2 MPa and 30-60 min.

[0030] Beneficial effects:

[0031] (1) The application provides a conductive shielding wave-absorbing high-strength thermosetting plate, which has the advantages of light weight, thin thickness, high strength, electromagnetic shielding and wave-absorbing, and can replace metal plates to be used in light and thin electronic equipment or other fields requiring weight reduction.

[0032] (2) Based on the system of the application, the unidirectional carbon fiber prepreg with a glue content of 35-45 wt%, a carbon fiber content of 20-200 g / m 2 The thickness of the unidirectional carbon fiber prepreg is 0.02-0.20 mm, and the thermosetting plate formed by compounding the carbon fiber base layer, the middle adhesive film layer and the upper shielding layer has high tensile strength and elastic modulus.

[0033] (3) Based on the system of the application, the carbon fiber base layer with a thickness of 0.15-0.30 mm is obtained by using a lamination process after 3-5 layers are laminated, the comprehensive performance of the thermosetting plate is ensured, the application advantages of light weight and thin thickness are realized, and the thermosetting plate can be used as an isolation bottom plate and a supporting back plate of electronic products such as mobile phones, tablets and notebook computers.

[0034] (4) Based on the system of the present application, by using 5-25 μm conductive powder, especially using silver-coated copper powder with a particle size of 5-8 μm as the conductive powder, the prepared intermediate adhesive film layer has excellent dispersing performance in the thermosetting resin system, so that the prepared intermediate adhesive film layer has super strong conductive performance, and does not affect the composite strength between the intermediate adhesive film layer and the carbon fiber base layer and the upper shielding layer, and ensures the usability of the intermediate adhesive film layer.

[0035] (5) Based on the system of the present application, the formula amount of modified bisphenol A type epoxy resin and polyurethane modified thermosetting resin is used as the resin matrix, and 20-50 μm two-dimensional wave absorbing powder is introduced, and after the liquid aromatic amine in the system is cured, a shielding layer with excellent shielding performance is formed, and effective compounding with the intermediate adhesive film layer can be achieved. DETAILED DESCRIPTION

[0036] Example 1

[0037] The embodiment 1 of the present application provides a conductive shielding wave-absorbing high-strength thermosetting plate, which comprises a carbon fiber base layer, an intermediate adhesive film layer and an upper shielding layer.

[0038] The carbon fiber base layer is prepared by cross-laminating and hot-pressing carbon fiber prepreg, and the thickness of the carbon fiber base layer is 0.18 mm.

[0039] The carbon fiber prepreg is unidirectional carbon fiber prepreg, and the glue content of the unidirectional carbon fiber prepreg is 38 wt%.

[0040] The thickness of the unidirectional carbon fiber prepreg is 0.06 mm, and the carbon fiber content in the carbon fiber prepreg is 50 g / m 2 .

[0041] The model of the unidirectional carbon fiber prepreg is UCS50E38, and it is from Shenzhen Enecarbon Composites Co., Ltd.

[0042] The number of layers of the lamination is 3 layers, 2 layers in x direction and 1 layer in y direction.

[0043] The hot-pressing condition is that the temperature is 150℃, the pressure is 2 MPa, and the time is 30 min.

[0044] According to the weight parts, the preparation raw materials of the intermediate adhesive film layer include 80 parts of thermosetting resin, 20 parts of toughening agent, 30 parts of conductive powder and 10 parts of curing agent.

[0045] The thermosetting resin includes thermosetting resin A and thermosetting resin B, the thermosetting resin A is a phenolic type epoxy resin, and the thermosetting resin B is a bisphenol A type epoxy resin. The weight ratio of the thermosetting resin A and the thermosetting resin B is 3:5.

[0046] The phenolic epoxy resin is CNE-202 from Changchun Synthetic Resin Factory Co., Ltd. in Taiwan. The bisphenol A epoxy resin is JER-YL980 from Mitsubishi in Japan.

[0047] The conductive powder is silver-coated copper powder with a particle size (D50) of 5-8 μm, and is NX-510 from Shenzhen Naxiang Conductive Material Technology Co., Ltd.

[0048] The curing agent is liquid aromatic amine, and is Ethacure 200 from Shenzhen Jiadada New Material Technology Co., Ltd.

[0049] The toughening agent is liquid nitrile rubber, and the liquid nitrile rubber is carboxyl-terminated nitrile rubber, and is CTBN1300X31 from Shenzhen Jiadada New Material Technology Co., Ltd.

[0050] The preparation process of the intermediate adhesive film layer is as follows: the thermosetting resin, the toughening agent and the conductive powder are mixed according to the formula amount, then the formula amount of the curing agent is added, and the mixture is placed in an oven and cured at 85°C for 30 min to obtain the intermediate adhesive film layer.

[0051] The thickness of the intermediate adhesive film layer is 40 μm.

[0052] According to weight parts, the preparation raw materials of the upper shielding layer include 50 parts of modified bisphenol A epoxy resin, 50 parts of polyurethane modified thermosetting resin, 150 parts of wave-absorbing powder and 10 parts of curing agent.

[0053] The modified bisphenol A epoxy resin is EPALLOY 7200 from Shenzhen Jiadada New Material Technology Co., Ltd.

[0054] The polyurethane modified thermosetting resin has an epoxy equivalent weight of 215 g.eq, and is HyPox UA11 from Shenzhen Jiadada New Material Technology Co., Ltd. -1

[0055] The wave-absorbing powder has a particle size (D50) of 20-30 μm. The wave-absorbing powder is two-dimensional wave-absorbing powder, and is Wector TM CF30 from Suzhou Putaoteng New Material Technology Co., Ltd.

[0056] The curing agent is liquid aromatic amine, and is Ethacure 200 from Shenzhen Jiadada New Material Technology Co., Ltd.

[0057] ​The preparation process of the upper shielding layer is as follows: the modified bisphenol A type epoxy resin, the polyurethane modified thermosetting resin and the wave absorbing powder are mixed according to the formula amount, then the formula amount of the curing agent is added, and the mixture is placed in an oven and cured at 85 DEG C for 30 min to obtain the upper shielding layer.

[0058] The thickness of the upper shielding layer is 0.03 mm.

[0059] In another aspect, the embodiment 1 of the present application provides a preparation process of the conductive shielding wave-absorbing high-strength thermosetting plate, which comprises the following steps: pasting the middle adhesive film layer on the upper surface of the carbon fiber base layer, covering the upper shielding layer on the upper surface of the middle adhesive film layer, and then putting the whole into a hot press for compression to obtain the conductive shielding wave-absorbing high-strength thermosetting plate.

[0060] The compression condition is 150 DEG C, 2 MPa and 30 min.

[0061] Embodiment 2

[0062] The embodiment 2 of the present application provides a conductive shielding wave-absorbing high-strength thermosetting plate and a preparation method thereof, and the specific implementation manner is the same as that of the embodiment 1, except that the carbon fiber prepreg is a unidirectional carbon fiber prepreg, and the glue content of the unidirectional carbon fiber prepreg is 40 wt%.

[0063] The carbon fiber base layer is prepared by cross-laminating and hot pressing the carbon fiber prepreg, and the thickness of the carbon fiber base layer is 0.15 mm.

[0064] The thickness of the unidirectional carbon fiber prepreg is 0.03 mm, and the carbon fiber content in the carbon fiber prepreg is 30 g / m 2 .

[0065] The model of the unidirectional carbon fiber prepreg is UCS30E40, and the unidirectional carbon fiber prepreg is from Shenzhen Enecarbon Composites Co., Ltd.

[0066] The number of layers of the lamination is 5 layers, 3 layers in the x direction and 2 layers in the y direction.

[0067] Comparative Example 1

[0068] The comparative example 1 of the present application provides a conductive shielding wave-absorbing high-strength thermosetting plate and a preparation process thereof, and the specific implementation manner is the same as that of the embodiment 1, except that the carbon fiber base layer is a single-layer carbon fiber prepreg, and the model of the unidirectional carbon fiber prepreg is UCS175E32, and the unidirectional carbon fiber prepreg is from Shenzhen Enecarbon Composites Co., Ltd.

[0069] Comparative Example 2

[0070] The comparative example 2 of the present application provides a conductive shielding wave-absorbing high-strength thermosetting plate and a preparation process thereof, the specific implementation manner is the same as that of the example 1, and the difference lies in that the upper shielding layer is replaced by a wave-absorbing film, and the model is Wector TM MS50, from Suzhou Putaoxin Material Technology Co., Ltd.

[0071] Performance test method

[0072] (1) Shielding effectiveness: the thermosetting plates provided by the examples and the comparative examples are tested for shielding effectiveness with reference to MIL-G-83528, and the results are shown in Table 1.

[0073] (2) Tensile strength: the thermosetting plates provided by the examples and the comparative examples are tested for tensile strength with reference to GB / T 33501-2017, and the results are shown in Table 1.

[0074] (3) Magnetic permeability: the magnetic permeability of the thermosetting plates provided by the examples and the comparative examples is tested by using E4991A (impedance analyzer).

[0075] Table 1

[0076]

Claims

1. A conductive shielding, wave-absorbing, high-strength, thermoset panel, characterized in that, The carbon fiber base layer is prepared by cross-laminating and hot-pressing carbon fiber prepreg, the number of layers of the laminated layer is 3-5, and the thickness of the carbon fiber base layer is 0.02-0.30 mm; the carbon fiber prepreg is unidirectional carbon fiber prepreg, the glue content of the unidirectional carbon fiber prepreg is 35-45 wt%, the thickness of the unidirectional carbon fiber prepreg is 0.02-0.20 mm, and the carbon fiber content in the carbon fiber prepreg is 20-200 g / m 2 ; the preparation raw materials of the intermediate adhesive film layer at least include thermosetting resin 60-100 parts by weight, toughening agent 10-30 parts by weight, conductive powder 20-40 parts by weight, and curing agent 8-15 parts by weight; the conductive powder is silver-coated copper powder, and the particle size D50 is 5-8 μm; the preparation raw materials of the upper shielding layer at least include modified bisphenol A type epoxy resin 30-60 parts by weight, polyurethane modified thermosetting resin 40-70 parts by weight, wave-absorbing powder 120-180 parts by weight, and curing agent 8-15 parts by weight; the particle size D50 of the wave-absorbing powder is 20-50 μm, and the wave-absorbing powder is two-dimensional wave-absorbing powder.

2. The electrically conductive shielding, wave-absorbing, high-strength, thermoset panel of claim 1, wherein, The hot pressing is performed at a temperature of 120-150 DEG C, a pressure of 2 MPa and for 30-60 min.

3. The electrically conductive shielding, wave-absorbing, high-strength, thermoset panel of claim 1, wherein, The thermosetting resin comprises a thermosetting resin A and a thermosetting resin B, the thermosetting resin A is a phenolic type epoxy resin, and the thermosetting resin B is a bisphenol A type epoxy resin.

4. A process for the preparation of a conductive shielding, wave-absorbing, high-strength, thermoset panel according to any one of claims 1-3, characterized in that, After the intermediate adhesive film layer is attached to the upper surface of the carbon fiber base layer, the upper shielding layer is covered on the upper surface of the intermediate adhesive film layer, and then the whole is put into a hot press for compression to obtain the product.

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