A preparation method for continuously producing carbon fiber cloth reinforced thermoplastic composite prepreg

Abstract

The present invention belongs to the technical field of resin-based composite materials, and particularly relates to a preparation method for continuously producing a carbon fiber cloth-reinforced thermoplastic composite prepreg. The method comprises the following steps: subjecting the carbon fiber cloth to desizing treatment in a high-temperature furnace, passing it through an impregnating tank containing a polyarylether nitrile ketone resin solution, drying it to shape the fiber cloth, then applying thermoplastic resin films with a certain thickness to the upper and lower surfaces of the fiber cloth, melting the resin at high temperature, pressing it through a hot press roller, and winding it with a roller to obtain the prepreg. The prominent advantage of the present invention can solve the difficulty that the high-temperature melt viscosity of the thermoplastic resin is large and it cannot fully infiltrate the fibers. The resin of the prepreg is evenly distributed, and the interlayer performance of the composite material is excellent.

Description

Technical Field

[0001] The present invention belongs to the technical field of resin-based composite materials, and particularly relates to a preparation method for continuously producing a carbon fiber cloth-reinforced thermoplastic composite prepreg. Background Art

[0002] Thermoplastic resin-based composites have advantages such as good mechanical properties, impact resistance, short molding cycles, and recyclability. In recent years, they have become a research hotspot in the field of composite materials technology. Especially fiber-reinforced thermoplastic resin-based composites have a series of excellent properties such as high specific strength and modulus, infinite storage of prepregs, and weldability. They are widely used in fields such as aerospace, automotive, medical, and sports equipment. Polyaryletherketone belongs to high-performance special engineering plastics and has excellent comprehensive properties. By introducing large-volume groups, an amorphous polyaryletherketone resin can be prepared. The resin is soluble in organic solvents, and at the same time, the resin has good compatibility with other thermoplastic resins. Cyanide groups are introduced to improve the interfacial bonding force between the resin and the fiber.

[0003] Currently, the main methods for preparing thermoplastic composite prepregs are solution method, powder method, melt method, and film method. The solution method may have problems of environmental pollution. The melt method is likely to cause damage to the fibers, and it is difficult for the resin to infiltrate the fiber tow. The powder method has high requirements for the resin, and the resin particles need to reach the ultrafine powder level, resulting in high production costs. CN 111057346 B discloses a carbon fiber-reinforced PEEK unidirectional tape and its preparation method, using the method of powder suspension, but the suspension system introduces too many additives, which may affect the mechanical properties of the composite material. The film method does not introduce redundant additives, the resin content can be adjusted by the film thickness, and the distribution is uniform. However, for resins with a relatively high melt viscosity, applying too high an infiltration pressure will cause fiber distortion and local defects, especially for fiber fabrics with a relatively large areal density, it is difficult to fully infiltrate. Summary of the Invention

[0004] To solve the problems of the prior art, the present invention provides a preparation method for continuously producing a carbon fiber cloth-reinforced thermoplastic composite prepreg.

[0005] A preparation method for continuously producing a carbon fiber cloth-reinforced thermoplastic composite prepreg includes the following steps:

[0006] The carbon fiber cloth is desized by passing through a high-temperature furnace at 300 - 400 °C, passed through an impregnation tank containing a polyarylethernitrileketone resin solution, dried and shaped by passing through a hot air oven, then a thermoplastic resin film with a certain thickness is applied to the upper and lower surfaces of the carbon fiber cloth, the resin is melted at 300 - 400 °C, pressed by a hot press roller at 280 - 340 °C, and wound by a roller to obtain the prepreg;

[0007] In the prepreg, the mass fraction of polyarylether nitrile ketone is 2% to 6%; the mass fraction of the thermoplastic resin is 28 to 40%; the mass fraction of the carbon fiber cloth is 54 to 70%;

[0008] The polyarylether nitrile ketone sizing agent is formed by mixing polyarylether nitrile ketone resin and an organic solvent, and the organic solvent is one or more of dichloromethane, cyclohexanone, N,N-dimethylformamide, and N,N-dimethylacetamide;

[0009] The polyarylether nitrile ketone resin has the following structure:

[0010] where m:n = 2:8 to 8:2.

[0011] The thermoplastic resin film includes at least one of polyetherimide, polyphenylene sulfide, and polyetheretherketone, and the thickness is 20 to 100 μm.

[0012] Based on the above technical solutions, preferably, the time for desizing treatment in a high-temperature furnace at 300 to 400 °C is 2 to 8 min.

[0013] Based on the above technical solutions, preferably, the solid content of the polyarylether nitrile ketone sizing agent is 4 to 10%.

[0014] Based on the above technical solutions, preferably, the carbon fiber cloth is impregnated in the polyarylether nitrile ketone resin sizing agent for 2 to 8 min.

[0015] Based on the above technical solutions, preferably, the melt index of the polyarylether nitrile ketone resin is 2 to 15 g / 10 min; the melt index of the thermoplastic resin is 20 to 100 g / 10 min.

[0016] Based on the above technical solutions, preferably, the time for melting the resin at 300 to 400 °C is 10 to 20 min.

[0017] Based on the above technical solutions, preferably, the hot pressing roller presses at 280 to 340 °C with 0.5 to 2 MPa for 1 to 4 s.

[0018] Based on the above technical solutions, preferably, the winding speed of the roller is 0.5 to 2 m / min.

[0019] Advantages of the present invention: The preparation method of a continuous production of carbon fiber cloth reinforced thermoplastic composite prepreg provided by the present invention effectively solves the problem of fiber distortion and deformation caused by the traditional film impregnation method. By pre-impregnating the carbon fiber cloth with a polyarylether nitrile ketone resin solution, it acts as a "shaping agent". Polyarylether nitrile ketone has a relatively high modulus and good mechanical properties, and will not reduce the mechanical properties of the composite material. At the same time, the melt viscosity of polyarylether nitrile ketone is slightly higher than that of the thermoplastic matrix resin, ensuring that the fibers do not undergo obvious buckling during high-temperature hot pressing impregnation. The thermoplastic resin has good compatibility with the polyarylether nitrile ketone resin, making it easier to fully infiltrate the fibers. Especially when preparing thin-layer thermoplastic prepregs, the process stability is greatly improved, which is conducive to continuous industrial production. The prominent advantage of the present invention is to solve the technical difficulties in preparing composite prepregs by the film method, avoid the problems of high melt viscosity of thermoplastic resins at high temperatures, inability to fully infiltrate the fibers, excessive impregnation pressure, and fiber distortion. The resin distribution of the prepreg is uniform, and the interlayer properties of the composite material are excellent. Description of the Drawings

[0020] Figure 1 It is an electron micrograph of the prepregs prepared in Comparative Example 1 and Example 1. It can be seen from the figure that there are exposed fibers in the picture of Comparative Example 1, and the fibers in the cross-section of the composite material in Example 1 can be seen to be well wrapped by the resin. Detailed Embodiments

[0021] The following non-limiting embodiments can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way.

[0022] Comparative Example 1

[0023] After the 200 g / m 2 carbon fiber cloth is treated in a high-temperature furnace at 300 °C for 8 min, then a 50-μm PEEK (melt index 40 g / 10 min) film is applied to the upper and lower surfaces of the fiber cloth. After passing through a high-temperature air-circulating oven, it is preheated at 350 °C for 10 min and the resin is melted at 400 °C for 10 min, and then hot-pressed by a hot press roller at 340 °C for 4 s and wound at 0.5 m / min to obtain the prepreg. The mass fraction of PEEK in the prepreg is 36%, and the mass fraction of carbon fiber is 64%.

[0024] Example 1

[0025] After the 200 g / m 2The carbon fiber cloth is treated in a high-temperature furnace at 300 °C for 8 minutes, then impregnated in an impregnating tank containing a polyarylether nitrile ketone sizing solution with a solid content of 6% for 8 minutes. The solvent used is DMF. After drying in a hot air oven at 160 °C to remove the solvent and shape the fiber cloth, 50-μm PEEK (melt index 40 g / 10 min) films are pasted on the upper and lower surfaces of the fiber cloth. After passing through a hot air oven, it is preheated at 350 °C for 10 minutes and the resin is melted at 400 °C for 10 minutes. The hot press roller presses at 340 °C and 1 MPa for 4 seconds, and is wound at 0.5 m / min to obtain the prepreg. The mass fraction of polyarylether nitrile ketone in the prepreg is 4%, the mass fraction of PEEK is 32%, and the mass fraction of carbon fiber is 64%.

[0026] The polyarylether nitrile ketone resin has the following structure:

[0027] where m:n = 5:5 and the melt index is 8 g / 10 min.

[0028] Example 2

[0029] For 400 g / m 2 The carbon fiber cloth is treated in a high-temperature furnace at 400 °C for 2 minutes, then impregnated in an impregnating tank containing a polyarylether nitrile ketone sizing solution with a solid content of 10% for 2 minutes. The solvent used is a composite solvent with a volume ratio of dichloromethane to cyclohexanone of 2:8. After drying in a hot air oven at 150 °C to remove the solvent and shape the fiber cloth, 125-μm PPS (melt index 80 g / 10 min) films are pasted on the upper and lower surfaces of the fiber cloth. After passing through a hot air oven, it is preheated at 300 °C for 2.5 minutes and the resin is melted at 330 °C for 2.5 minutes. The hot press roller presses at 280 °C and 0.5 MPa for 1 second, and is wound at 2 m / min to obtain the prepreg. The mass fraction of polyarylether nitrile ketone in the prepreg is 6%, the mass fraction of PPS is 40%, and the mass fraction of carbon fiber is 54%.

[0030] The polyarylether nitrile ketone resin has the following structure:

[0031] where m:n = 8:2 and the melt index is 15 g / 10 min.

[0032] Example 3

[0033] For 100 g / m 2The carbon fiber cloth is treated in a high-temperature furnace at 350°C for 4 minutes, then impregnated in an impregnation tank containing a polyarylether nitrile ketone sizing solution with a solid content of 4% for 4 minutes. The solvent used is DMAC. After drying in a forced-air oven at 180°C to remove the solvent and shape the fiber cloth, a 13-μm PEI (melt index 20 g / 10 min) film is applied to the upper and lower surfaces of the fiber cloth. Then, it passes through a high-temperature forced-air oven, is preheated at 330°C for 5 minutes, and the resin is melted at 350°C for 5 minutes. The hot press roller presses at 300°C and 2 MPa for 2 seconds, and is wound at 1 m / min to obtain the prepreg. The mass fraction of polyarylether nitrile ketone in the prepreg is 2%, the mass fraction of PEI is 28%, and the mass fraction of carbon fiber is 70%.

[0034] The polyarylether nitrile ketone resin has the following structure:

[0035] where m:n = 2:8 and the melt index is 2 g / 10 min.

[0036] The prepreg is tested according to the national standards GB / T3356 and GB / T3357, indicating that Example 1 has more excellent mechanical properties. The performance data of the prepregs prepared in Comparative Example 1 and Example 1 are shown in the following table:

[0037]

Claims

1. A preparation method for continuously producing a carbon fiber cloth reinforced thermoplastic composite prepreg, comprising the following steps: The carbon fiber cloth is desized in a high-temperature furnace at 300-400 °C, passed through an impregnating tank containing a polyarylether nitrile ketone sizing solution, dried in a hot air oven to shape the fiber cloth, and then thermoplastic resin films are laminated on the upper and lower surfaces of the carbon fiber cloth. The resin is melted at 300-400 °C, and a hot press roller presses at 280-340 °C with a pressure of 0.5-2 MPa for 1-4 s, and then the roller winds up to obtain the prepreg; In the prepreg, the mass fraction of polyarylether nitrile ketone is 2%-6%; the mass fraction of the thermoplastic resin is 28-40%; the mass fraction of the carbon fiber is 54-70%; The polyarylether nitrile ketone sizing solution is composed of a polyarylether nitrile ketone resin and an organic solvent, and the organic solvent is one or more of dichloromethane, cyclohexanone, N,N-dimethylformamide, and N,N-dimethylacetamide; The polyarylether nitrile ketone resin has the following structure: where m:n = 2:8 to 8:2; The thermoplastic resin film includes at least one of polyetherimide, polyphenylene sulfide, and polyether ether ketone, and the thickness is 20-100 μm.

2. The preparation method according to claim 1, characterized in that the solid content of the polyarylether nitrile ketone sizing solution is 4-10%.

3. The preparation method according to claim 1, characterized in that the melt index of the polyarylether nitrile ketone resin is 2-15 g / 10 min; the melt index of the thermoplastic resin is 20-100 g / 10 min.

4. The preparation method according to claim 1, characterized in that the time for desizing in the 300-400 °C high-temperature furnace is 2-8 min.

5. The preparation method according to claim 1, characterized in that the carbon fiber cloth is impregnated in the polyarylether nitrile ketone resin sizing solution for 2-8 min.

6. The preparation method according to claim 1, characterized in that the time for melting the resin at 300-400 °C is 10-20 min.

7. The preparation method according to claim 1, characterized in that the winding speed of the roller is 0.5-2 m / min.

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