Carbon fiber composite board and method for manufacturing the same

Abstract

The present application relates to a kind of carbon fiber composite board, including carbon fiber resin board, carbon fiber resin board includes energy-absorbing layer, reinforcing layer, the surface of energy-absorbing layer has filamentous protrusion, the filamentous protrusion of energy-absorbing layer is entangled with reinforcing layer, energy-absorbing layer, reinforcing layer include resin, carbon fiber.A kind of method for preparing carbon fiber resin board, including forming energy-absorbing layer, heating the surface of energy-absorbing layer so that the surface is fused, the fused surface is laminated on metal plate, then the metal plate is lifted up and peeled off to make the surface of energy-absorbing layer form filamentous protrusion, carbon fiber is attached to the surface of the energy-absorbing layer with filamentous protrusion and is spun, prepolymer is immersed carbon fiber and is cured to form reinforcing layer.The carbon fiber composite board prepared by the present application has excellent mechanical properties, especially has strong interlaminar shear strength, and can be widely used in mechanical, transportation tools, chemical devices and other fields.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a carbon fiber composite plate and its preparation method. Background Technology

[0002] With the development of the times, the requirements for materials in fields such as chemical engineering, machinery, and transportation are becoming increasingly stringent. Carbon fiber is a high-strength, low-density material, and composite materials based on carbon fiber modification are becoming more and more common. Carbon fiber not only possesses the inherent characteristics of carbon materials but also combines the flexibility and processability of textile fibers, making it a new generation of reinforcing fibers. Carbon fiber is a microcrystalline graphite material obtained from organic fibers through carbonization and graphitization. The main application of carbon fiber is in the manufacture of composite materials, where it is used as a reinforcing material for resin composite products based on thermosetting or thermoplastic resins.

[0003] However, carbon fiber resin materials also have some drawbacks. For example, due to the difference in elastic modulus between resin and carbon fiber, the interlaminar shear strength is low, making it prone to delamination when subjected to lateral impact. Furthermore, after repeated vibration, delamination can also easily occur between the layers. Therefore, in order to improve the application range and service life of carbon fiber resin materials, it is necessary to improve the interlaminar shear strength of carbon fiber resin materials.

[0004] See the patent with publication number CN211279424U, which reduces air bubbles during the lamination of resin and carbon fiber by negative pressure casting, thereby improving the interfacial adhesion between resin and carbon fiber. This method can improve the interlaminar shear strength of carbon fiber resin material, but the effect is not very significant. Summary of the Invention

[0005] One object of the present invention is to provide a carbon fiber composite plate, particularly a carbon fiber composite plate with high strength and high interlaminar shear strength.

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

[0007] A carbon fiber composite board includes a carbon fiber resin board, wherein the carbon fiber resin board includes an energy-absorbing layer and a reinforcing layer, the surface of the energy-absorbing layer has filamentous protrusions, the filamentous protrusions of the energy-absorbing layer are entangled with the reinforcing layer, and the energy-absorbing layer and the reinforcing layer comprise resin and carbon fiber.

[0008] The energy-absorbing layer is a structure that can absorb impact energy by absorbing energy through elastic deformation, thereby reducing the vibration caused by the impact.

[0009] The reinforcing layer is a high-strength layer containing carbon fiber, which can withstand impact without deformation and transfer the impact force to the energy-absorbing layer, effectively improving the impact resistance of the carbon fiber composite board and reducing damage and breakage.

[0010] The aforementioned filamentous protrusions are formed by the resin on the surface of the energy-absorbing layer forming a hair-like structure. The filamentous protrusions are generated by spinning. The filamentous protrusions are entangled with the carbon fibers of the reinforcing layer, thereby improving the interlayer shear strength of the carbon fiber resin plate.

[0011] Preferably, in the above technical solution, the length of the filamentous protrusions is 2-10mm. If the filamentous protrusions are too short, the entanglement effect will be insignificant, failing to effectively improve the interlaminar shear strength of the carbon fiber resin board. If the filamentous protrusions are too long, these protrusions will be too thin and more easily damaged, leading to a decrease in interlaminar shear strength.

[0012] More preferably, the length of the filamentous protrusions is 3 to 6 mm.

[0013] Preferably, in the above technical solution, the thickness of the energy-absorbing layer is 4-20mm. Considering the application range, processing cost, and mechanical properties of carbon fiber resin plates, if the energy-absorbing layer is too thin, it will be difficult to effectively provide a buffering effect; if the energy-absorbing layer is too thick, the cost will increase and the volume will increase, making it difficult to apply.

[0014] Preferably, in the above technical solution, the reinforcement layer has a thickness of 1-4 mm. Considering the application range, processing cost, and mechanical properties of carbon fiber resin sheets, if the reinforcement layer is too thin, its impact resistance will be low and it will be easily damaged; if the reinforcement layer is too thick, the cost will be high and it will be difficult to process.

[0015] Preferably, the carbon fiber composite board described above comprises multiple layers of the aforementioned carbon fiber resin board.

[0016] Another object of the present invention is to provide a method for preparing carbon fiber composite plates.

[0017] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0018] A method for preparing carbon fiber resin sheets, comprising:

[0019] S1: Energy-absorbing layer made of resin and carbon fiber.

[0020] S2: Heat one surface of the energy-absorbing layer to melt it, then apply a metal plate to the molten surface. Next, lift the metal plate upwards and peel it off, causing filamentous protrusions to form on the surface of the energy-absorbing layer. Because the resin has a certain degree of adhesion, it will adhere to the metal plate, thus creating filamentous protrusions after peeling.

[0021] S3: Carbon fibers are bonded to the surface of the energy-absorbing layer with filamentous protrusions and spun; prepolymer is impregnated with carbon fibers and cured to form a reinforcing layer.

[0022] S4: Repeat S2 and S3 on the other surface of the energy-absorbing layer to obtain a carbon fiber resin plate.

[0023] Preferably, the resin in the above technical solution is selected from one or more of polyolefins, polystyrene, polyesters, polypropylene, and polyurethanes.

[0024] More preferably, the resin is polyurethane. The polyurethane is an organic polymer material formed by the reaction of polyisocyanates and polyols and possessing multiple urethane segments, which can improve impact resistance and abrasion resistance.

[0025] More preferably, the polyurethane is biomass polyurethane, which is a polyurethane whose synthetic raw materials contain biomass. Biomass polyurethane has excellent tensile strength, tear strength, impact resistance, abrasion resistance, weather resistance, hydrolysis resistance, and oil resistance. As a component of the energy-absorbing layer, it can effectively mitigate impact force and transfer it to the reinforcing layer.

[0026] The biomass polyurethane contains bio-based polyol segments, which are compounds containing two or more hydroxyl groups, using biomass as a raw material in whole or in part. The bio-based polyols are selected from one or more of bio-based polytrimethylene ether glycol, bio-based polyethylene glycol, and bio-based polylactic acid polyols.

[0027] Preferably, in the above technical solution, the carbon fiber used to form the energy-absorbing layer is carbon fiber powder. The carbon fiber powder is an aggregate of carbon fibers with an average particle size of less than 1000 μm, which can disperse the impact and prevent excessive local impact from causing the energy-absorbing layer to break.

[0028] More preferably, the average particle size of the carbon fiber powder is 10-100μm, which can more effectively disperse impact. If the average particle size of the carbon fiber powder is too large, the dispersion effect is poor. If the average particle size of the carbon fiber powder is too small, the viscosity of the polyurethane composition is too high and difficult to process.

[0029] More preferably, the carbon fiber used to form the reinforcing layer is carbon fiber fabric, which serves as the main body to withstand impact forces and has the characteristics of high strength, thereby improving the strength and toughness of the reinforcing layer.

[0030] Preferably, in the above technical solution, the prepolymer comprises uncured epoxy resin and a curing agent.

[0031] The epoxy resins mentioned are a class of organic polymers and their cured products containing two or more epoxy groups in their molecular structure. They possess advantages such as high strength, low shrinkage, high electrical insulation, good retention, corrosion resistance, curing over a wide temperature range, and fatigue resistance. Examples include bisphenol A type epoxy resins, halogenated bisphenol A type epoxy resins, bisphenol S epoxy resins, bisphenol F epoxy resins, alicyclic epoxy resins, aliphatic-alicyclic epoxy resins, aromatic-alicyclic epoxy resins, glycerol epoxy resins, ethylene glycol epoxy resins, phenolic epoxy resins, amino epoxy resins, unsaturated epoxy resins, acrylic epoxy resins, triphosphonium epoxy resins, dicyclopentadiene epoxy resins, polybutadiene epoxy resins, organotitanium epoxy resins, organosilicon epoxy resins, and fluorinated epoxy resins.

[0032] The curing agent can be an epoxy resin that undergoes cross-linking to form a network structure and then cures, such as polyamines, polycarboxylic acids, polythiols, tertiary amines, imidazoles, etc.

[0033] More preferably, the epoxy resin is selected from one or more of bisphenol A type epoxy resin, alicyclic epoxy resin, and glycerol epoxy resin, which improves the adhesion between carbon fiber and polyurethane and protects the carbon fiber.

[0034] More preferably, the curing agent is selected from one or more of polyamines, polycarboxylic acids, tertiary amines, and imidazoles.

[0035] Preferably, in step S1, the resin and carbon fiber are first mixed at a temperature of 100-160°C for 1-2 hours to obtain a mixture, and then the mixture is cured at a temperature of 100-160°C, a pressure of 2-5 MPa, and a time of 30-60 minutes.

[0036] Preferably, in S1, the energy-absorbing layer is formed by compression molding, vacuum bag molding, casting, etc.

[0037] Preferably, in S2, the melting conditions are: heating at 180-220°C for 1-3 minutes. If the temperature is too high or the time is too long, too much resin will be peeled off during the peeling process from the metal plate, resulting in holes at the carbon fiber. If the temperature is too low or the time is too short, the filamentous protrusions cannot be effectively formed, resulting in a small improvement in the bonding effect.

[0038] Preferably, in the above technical solution, in S2: melting includes blowing, hot pressing, roasting, etc.

[0039] Preferably, in the above technical solution, in S3: the spinning condition is to rotate the energy-absorbing layer by 90 to 180° under a pressure of 0.3 to 1 MPa. Spinning refers to applying a certain pressure to make the carbon fiber and the energy-absorbing layer fit tightly together while rotating the energy-absorbing layer, so that the filamentous protrusions on the surface of the energy-absorbing layer become entangled with the carbon fiber. If the pressure is too small, the filamentous protrusions cannot squeeze into the gaps of the carbon fiber and become entangled. If the pressure is too large, it is difficult to operate. If the rotation angle is too small, there is less friction between the filamentous protrusions and the carbon fiber, and less entanglement occurs. If the rotation angle is too large, the entangled filamentous protrusions will be torn off.

[0040] Preferably, in step S3, the forming of the reinforcing layer includes compression molding and vacuum injection molding, with a curing temperature of 50-80℃. Compression molding involves placing powdered, granular, or fibrous raw materials into a mold cavity at the molding temperature, then closing the mold and applying pressure to form and cure them. Vacuum injection molding refers to placing uncured raw materials into a vacuum bag, removing excess air by vacuuming to allow the raw materials to combine and cure.

[0041] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0042] The carbon fiber composite plate prepared by this invention has excellent mechanical properties, especially strong interlaminar shear strength, and can be widely used in machinery, transportation vehicles, chemical plants and other fields. Detailed Implementation

[0043] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Energy-absorbing layer resin

[0045] raw material:

[0046] Polytrimethylene ether glycol, ECOPROL H1000, manufactured by SK CHEMICAL, South Korea.

[0047] Polyethylene glycol, PEG-6000, produced by China National Pharmaceutical Group.

[0048] Polylactic acid polyol, produced by Fengyuan Biotechnology.

[0049] Isocyanate, Aquolin 161, produced by Wanhua Chemical Group Co., Ltd.

[0050] A1: Polytrimethylene ether glycol is heated to 30°C and then mixed with isocyanate at a weight ratio of 100:2 and stirred at 100 r / min for 10 min to obtain A1.

[0051] A2: Polyethylene glycol is heated to 60°C and then mixed with isocyanate at a weight ratio of 100:2 and stirred at 100 r / min for 10 min to obtain A2.

[0052] A3: Polylactic acid polyol is heated to 200℃ and mixed with isocyanate at a weight ratio of 100:2 and stirred at 100r / min for 10min to obtain A3.

[0053] Carbon fiber

[0054] B1: MLD-30, fiber length 30μm, manufactured by Toray Industries, Inc.

[0055] B2: Carbon fiber fabric, TB01, produced by Lofis (Shanghai) Industrial Co., Ltd.

[0056] Reinforcing layer resin

[0057] C1: Bisphenol A type epoxy resin, EPICLON3050, manufactured by Dai Nippon Ink Co., Ltd.

[0058] C2: Bisphenol A type epoxy resin, EPICLON4050, manufactured by Dai Nippon Ink Co., Ltd.

[0059] C3: Bisphenol A type epoxy resin, EPICLON7050, manufactured by Dai Nippon Ink Co., Ltd.

[0060] The preparation methods of Examples 1-13 are as follows, and the parameters are shown in Table 1:

[0061] S1: First, add biomass polyurethane and carbon fiber powder into a mixer and mix for 2 hours at 140℃ and 30r / min to obtain a mixture. Then, add the mixture into a hot press and hot press for 60 minutes at 140℃ and 3MPa. After cooling, a 10mm thick energy-absorbing layer is obtained.

[0062] S2: Heat one surface of the energy-absorbing layer until it melts, then apply a metal plate to the molten surface. Next, lift the metal plate upwards and peel it off, creating filamentous protrusions on the surface of the energy-absorbing layer.

[0063] S3: The carbon fiber fabric is bonded to the surface of the energy-absorbing layer with filamentous protrusions. Pressure is applied to the carbon fiber fabric and the energy-absorbing layer is rotated. Then, it is placed in a vacuum bag, filled with prepolymer, vacuumed, and heated to 60°C for curing. The prepolymer is formulated with 100 parts by weight of epoxy resin and 5 parts by weight of curing agent. The thickness of the resulting reinforcing layer is 2 mm.

[0064] S4: Repeat S2 and S3 on the other surface of the energy-absorbing layer to obtain a carbon fiber resin plate.

[0065] The performance testing methods are as follows:

[0066] 1. Length of filamentous protrusions: Place the treated energy-absorbing layer on the table and use a carving knife to remove it along the root of the filamentous protrusions. Repeat this process five times and take the average length.

[0067] 2. Breaking Impact Strength: Tested according to ASTM D7136-2007. An Instron 9350 fully automatic drop hammer impact testing machine was used. The total mass of the drop hammer was 1 ± 0.05 kg, and the diameter of the impact head was 3 ± 0.1 mm. Each group of specimens was tested starting with a kinetic energy of 100 J, with increments of 10 J, until the specimen broke to obtain its breaking impact strength.

[0068] The destructive impact strength = W / S, which is the kinetic energy of the falling hammer when the sample is destroyed, and S is the area of ​​the impact head.

[0069] 3. Interlaminar shear performance testing standard: The interlaminar shear failure stress shall be tested according to the test method of GB / T28889-2012.

[0070]

[0071] As shown in Table 1, compared with Comparative Example 1, the interlaminar shear failure strength of the embodiment is significantly improved and the mechanical strength is not reduced. The carbon fiber resin plate of this embodiment can effectively improve the interlaminar shear failure strength.

[0072] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A carbon fiber composite plate, characterized in that: The product includes a carbon fiber resin board, which comprises an energy-absorbing layer and a reinforcing layer. The surface of the energy-absorbing layer has filamentous protrusions that are entangled with the reinforcing layer. The length of the filamentous protrusions is 2-10 mm. The carbon fiber resin board is prepared by the following method: S1: An energy-absorbing layer is formed using resin and carbon fiber. The resin is one or more of polyolefin, polystyrene, polyester, and polyurethane. The carbon fiber used to form the energy-absorbing layer is carbon fiber powder with an average particle size of 10-100 μm. The resin and carbon fiber are first mixed at a temperature of 100-160℃ for 1-2 hours to obtain a mixture. Then, the mixture is cured at a temperature of 100-160℃, a pressure of 2-5 MPa, and a time of 30-60 minutes. S2: Heat one surface of the energy-absorbing layer until it melts, then place a metal plate onto the molten surface. Next, lift the metal plate upwards and peel it off, causing filamentous protrusions to form on the surface of the energy-absorbing layer. The melting conditions are heating at 180–220°C for 1–3 minutes. S3: Carbon fibers are bonded to the surface of the energy-absorbing layer with filamentous protrusions and spun. A prepolymer is impregnated with the carbon fibers and cured to form a reinforcing layer. The prepolymer comprises uncured epoxy resin and a curing agent. The epoxy resin is selected from one or more of bisphenol A type epoxy resin, alicyclic epoxy resin, and glycerol epoxy resin. The curing agent is selected from one or more of polyamines, polycarboxylic acids, tertiary amines, and imidazoles. The carbon fibers used to form the reinforcing layer are carbon fiber fabric. The spun conditions are a pressure of 0.3–1 MPa with a rotation of 90–180° around the energy-absorbing layer, and the curing temperature is 50–80°C. S4: Repeat S2 and S3 on the other surface of the energy-absorbing layer to obtain a carbon fiber resin plate.

2. The carbon fiber composite plate according to claim 1, characterized in that: The thickness of the energy-absorbing layer is 4-20 mm; and / or the thickness of the reinforcing layer is 1-4 mm.

3. The carbon fiber composite plate according to claim 1, characterized in that: The carbon fiber composite board comprises multiple layers of the carbon fiber resin board.

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