Fiber-reinforced thermoplastic resin material and method for producing same, use thereof

Abstract

The application provides a kind of fiber reinforced thermoplastic resin material and its preparation method, application, belong to composite material technical field.The material includes thermoplastic resin uniformly distributed on fiber, the thermoplastic resin includes resin matrix, first resin and second resin, which are all thermoplastic, the raw material variety of resin matrix is different from the first resin and second resin, and the raw material particle size of resin matrix is greater than the raw material particle size of the first resin and second resin.By constructing the heterocyclic combination system of different resin powders, the dispersion stability of the suspension system and the deposition uniformity of the resin on the surface of continuous fiber are improved, and in the hot pressing process, the difference in melt flow is used, so that the finer first resin and second resin fill and infiltrate the surface layer or the small gap between the fiber bundles, and the coarser resin matrix forms a continuous resin phase and maintains the stability of the deposited layer and the melt flow space, thereby improving the uniformity of resin distribution and improving the mechanical properties of the composite material.

Description

Technical Field

[0001] This invention belongs to the field of composite material technology, specifically relating to a fiber-reinforced composite material based on the blending of thermoplastic resin powders of different mesh sizes, and also relating to the preparation method of the composite material and its application. Background Technology

[0002] Fiber-reinforced resin matrix composites have been widely used in aerospace, rail transportation, automotive lightweighting, and high-end equipment manufacturing due to their advantages such as high specific strength, high specific modulus, fatigue resistance, corrosion resistance, and strong designability. Among them, fiber-reinforced resin matrix composites based on thermoplastic resins have promising application prospects due to their short molding cycle, good toughness, reprocessability, and recyclability.

[0003] Currently, commonly used preparation processes for fiber-reinforced thermoplastic resin-based composite materials include melt impregnation, powder impregnation, solution impregnation, and suspension methods. For example, patent CN114685971B discloses a short-cut carbon fiber / polyether ketone ketone composite powder material and its preparation method. The composite powder is obtained through steps such as liquid-phase mixing, solidification precipitation, melt heat treatment, pulverization, and sieving. The key focus is on improving the uniformity of the composite between the short-cut fibers and the resin to meet subsequent processing requirements. Patent CN120269851A discloses a carbon fiber reinforced polyether ketone composite material and its preparation method. Polyether ketone powder and carbon fiber cloth are alternately layered, with the top and bottom layers both being polyether ketone powder, to obtain a preform. The preform is then pressurized and heated to form the carbon fiber reinforced polyether ketone composite material. However, high-performance thermoplastic resins typically have high melt viscosity. In continuous fiber or fiber fabric reinforced systems, the resin cannot fully wet the fiber bundle within a short time, easily leading to unwetted areas, pore defects, and insufficient interfacial bonding, thus affecting the densification degree, interlaminar properties, and compressive properties of the composite material. Therefore, the melt impregnation method is easily limited by the high melt viscosity of thermoplastic resins, resulting in limited wetting efficiency within the fiber bundle; the powder method mainly relies on subsequent heating and melting to achieve resin migration, making it difficult to control the interlaminar resin distribution and the uniformity of wetting within the bundle. For example, patent CN113583426B discloses a method for preparing carbon fiber / polyether ketone ketone composite material, which uses a polyether ketone ketone solution to impregnate carbon fiber bundles, followed by solvent removal, preheating, and hot pressing to obtain the composite material, which is a typical solution impregnation-solvent removal-hot pressing route. Patent CN118165333A discloses a carbon fiber / polyether ketone ketone prepreg, a composite material, and a method for preparing the same. It employs a combination of multi-nozzle scanning dripping and negative pressure filtration to promote the penetration of the polyether ketone ketone solution into the carbon fiber fabric, thereby obtaining the prepreg. Therefore, while the solution impregnation method can reduce the apparent viscosity of the system, it suffers from problems such as large solvent consumption and complex drying and removal processes.

[0004] In contrast, the suspension method disperses resin powder in a dispersion medium to form a suspension, which is then brought into contact with the fiber reinforcement. This utilizes a low-viscosity dispersion medium to ensure the resin powder fully contacts the fiber, resulting in more uniform adhesion of the resin powder to the fiber surface and penetration into the fiber bundle. This improves the resin's wetting effect on the fiber during subsequent hot pressing. However, there are few publicly disclosed technical solutions for achieving controllable deposition of resin particles on the fiber surface and / or within the fiber bundle using the suspension method. Furthermore, controlling the distribution of resin along the fiber surface, within the fiber bundle, and in the interlayer region in continuous reinforcement systems is more challenging than with chopped fiber reinforcements or composite powder particle morphologies.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a fiber-reinforced thermoplastic resin material, its preparation method, and its applications. By introducing a first resin and a second resin into a resin matrix, and considering the particle size matching of the multi-component resin powders, a system of different mesh sizes of resin powders is constructed. This improves the dispersion stability of the suspension system and the uniformity of resin deposition on the surface of continuous fibers. During hot pressing, the difference in melt flowability is utilized to allow the finer first and second resins to fill and wet the surface of the fiber bundles or the tiny gaps between bundles, while the coarser resin matrix forms a continuous resin phase and maintains the stability of the deposition layer and the space for melt flow. This improves the uniformity of resin distribution and enhances the mechanical properties of the composite material. This invention solves the problems of difficulty in controlling the distribution of resin along the fiber surface, inside the fiber bundle, and in the interlayer region in continuous reinforcement systems, as well as the difficulty in simultaneously achieving good interfacial bonding performance and mechanical properties, especially compressive strength, in composite materials.

[0007] To achieve the above objectives, the following technical solution is adopted: In a first aspect, a fiber-reinforced thermoplastic resin material includes a thermoplastic resin uniformly distributed on fibers. The thermoplastic resin includes a thermoplastic resin matrix, a first resin, and a second resin, all of which are thermoplastic. The raw material types of the resin matrix are different from those of the first and second resins, and the particle size of the raw material of the resin matrix is ​​larger than that of the raw material of the first and second resins.

[0008] Furthermore, the raw material of the resin matrix has a mesh size of 200-500 mesh, and the raw material of the first resin and the second resin both have a mesh size of 400-1000 mesh. And / or, the fiber is one or more of chopped fibers, long fibers, continuous fibers, and fiber fabrics; And / or, the thermoplastic resin is one or more selected from polyarylether, polycarbonate, polyethersulfone, polysulfone, polyarylether, thermoplastic polyimide, polyamide-imide, polyphenylene ether, and polyetherimide; And / or, the first resin and the second resin are the same or different, preferably, the raw materials or particle sizes of the first resin and the second resin are different; And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-75 parts of fiber, 10-55 parts of resin matrix, 1-20 parts of first resin, 1-20 parts of second resin, totaling 100 parts.

[0009] Furthermore, the first resin and the second resin can react with each other, and a three-dimensional covalent network is generated between the fiber and the resin matrix through the in-situ reaction of the first resin and the second resin, and the number average molecular weight of the resin matrix is ​​greater than the number average molecular weight of the first resin and the second resin; furthermore, the raw material of the first resin contains a first group, and the raw material of the second resin contains a second group, and the first group and the second group can react with each other.

[0010] Furthermore, the first group and the second group are each independently selected from alkynyl, azide, cyano, amino, isocyanate, hydroxyl, maleimide, thiol, allyl, acid anhydride, silyl, and furanyl; And / or, the number average molecular weight of both the first resin and the second resin is 3000~10000 g / mol; And / or, the number-average molecular weight of the resin matrix is ​​25,000 to 80,000 g / mol; And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-75 parts of fiber, 15-55 parts of resin matrix, 1-5 parts of first resin, 1-5 parts of second resin, totaling 100 parts.

[0011] Furthermore, the raw materials of the first resin and the second resin may be the same or different, and they are independently dispersed between the fiber and the resin matrix. And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-70 parts of fiber, 10-50 parts of resin matrix, 5-20 parts of first resin, 5-20 parts of second resin, totaling 100 parts.

[0012] Furthermore, the fiber is one or more of the following: carbon nanotube fiber, glass fiber, quartz fiber, carbon fiber, graphite fiber, alumina fiber, basalt fiber, aramid fiber, polyimide fiber, and poly(p-phenylenebenzoxazole) fiber. And / or, the thermoplastic resin is selected from one or a combination of at least two polymers having a structure as shown in formula (1), which is as follows: Where m≥0 and n≥0 are both integers; and m and n cannot be 0 at the same time. R1, R2, R3, and R4 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups. R1, R2, R3, and R4 may have the same or different structures. The alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure. The structure of —Ar1— is generated by the reaction of aromatic dihalogen monomers and is any combination of one or at least two of the following: ; ; ; ; R is selected from one or more of hydrogen, phenyl, alkyl or alkoxy, wherein the alkyl or alkoxy contains 1 to 20 carbon atoms and has a straight-chain or branched-chain structure; The structure of —Ar2— is generated by the reaction of bisphenol or bisphenol-like monomers, and is any combination of one or at least two of the following: 1, 2, 1, 3, or 1, 4 digits; , 2, 2' bits or 4, 4' bits; , 1, 4 bits, 1, 5 bits, 1, 6 bits, 2, 6 bits, or 2, 7 bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; ; ; R5, R6, R7, and R8 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups, and R5, R6, R7, and R8 may have the same or different structures; the alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure.

[0013] In a second aspect, a method for preparing the fiber-reinforced thermoplastic resin material described in the first aspect includes: mixing a first resin, a second resin, and a resin matrix to form a mixed resin powder with different mesh sizes, and adding a dispersant together to a solvent to form a suspension; mixing the suspension with fibers to allow the mixed resin powder to adhere to the fiber surface, and drying to obtain a prepreg; and hot-pressing the prepreg, wherein the hot pressing includes: first pre-pressing to degas at a temperature T1, and then heating to a temperature T2 to compact and fully impregnate the fibers to obtain the fiber-reinforced thermoplastic resin material.

[0014] Furthermore, the dispersant includes one or more of anionic dispersants, cationic dispersants, and nonionic dispersants; And / or, the mass ratio of the dispersant to the mixed resin powder is 0.001~0.5:1, more preferably 0.001~0.3:1, and even more preferably 0.001~0.2:1; And / or, the mass ratio of the sum of the masses of the first resin and the second resin to the mass ratio of the mixed resin powder is 0.03 to 0.9:1; And / or, the solvent is one or more of water, ethanol, ethylene glycol, and isopropanol; And / or, the mass concentration of the mixed resin powder in the solvent is 5-30 wt%, preferably 10-25 wt%; And / or, during the pre-pressure exhaust, the temperature T1 is 260~360 ℃, the pressure is 0.5~15 MPa, and the holding time is 5~40 min; And / or, during the pressure test, the temperature T2 is 280~370 ℃, the pressure is 0.5~15 MPa, and the holding time is 5~80 min.

[0015] Furthermore, the first resin and the second resin can react with each other, forming a three-dimensional covalent network between the fiber and the resin matrix through an in-situ reaction of the first resin and the second resin, and the number-average molecular weight of the resin matrix is ​​greater than that of the first resin and the second resin; the in-situ reaction temperature is T2 temperature; furthermore, the number-average molecular weight of both the first resin and the second resin is 3000~10000 g / mol; the number-average molecular weight of the resin matrix is ​​25000~80000 g / mol. Furthermore, the mass ratio of the first resin to the second resin is 0.05 to 40:1.

[0016] Thirdly, the application of a fiber-reinforced thermoplastic resin material as described in the first aspect or a fiber-reinforced thermoplastic resin material prepared by the preparation method described in the second aspect in the preparation of main load-bearing structural components in the fields of aerospace, rail transportation, or lightweight high-end equipment.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention relates to a fiber-reinforced thermoplastic resin material. Based on a multi-component thermoplastic resin system, it achieves a more rational distribution of different functional components on the fiber surface and within the fiber bundle by controlling the mesh size of the resin particles in each component. The coarser resin matrix particles, acting as a continuous load-bearing phase, primarily undertake the functions of fiber wetting, interlayer bonding, and continuous load transfer, which helps maintain the stability of the deposited layer and the melt flow space, thus resulting in a more uniform resin distribution throughout the cross-section of the composite material. The finer first and second resin particles, acting as reinforcing phases, more easily penetrate the fiber bundle surface or the micro-gaps between bundles, assisting in wetting, improving the continuity of fiber surface coating and local filling capacity, and significantly reducing phenomena such as localized resin richness, resin poorness, powder agglomeration, and particle shedding. This avoids problems such as agglomeration, localized resin poorness / richness, and uneven adhesion caused by single-particle-size resin systems, leading to dry yarn, unwetted areas, and pore defects. It directly solves the problem of difficult-to-control resin distribution along the fiber surface, within the fiber bundle, and in the interlayer region in continuous reinforcement systems, while also taking into account the interfacial bonding performance and mechanical properties of the composite material, especially its compressive properties.

[0018] Specifically, by introducing additional components of different types, such as a first resin and a second resin, into the resin matrix to form a multi-component resin system, and by controlling the particle size of the raw material of the resin matrix to be larger than the particle size of the introduced additional components, namely the first resin and the second resin, a more reasonable distribution of the resin particles of each component on the fiber surface and / or inside the fiber bundle is achieved. That is, by regulating the particle size matching and surface adhesion state of at least two types of resin powders, the suspension stability of the resin, fiber wettability and interface uniformity are improved, porosity and interface defects are reduced, and the high viscosity of the thermoplastic resin melt, difficulty in wetting inside the fiber bundle, uneven distribution of resin on the fiber surface and inside the fiber bundle, and insufficient densification of the laminated structure are avoided, thereby improving the interfacial bonding performance and compressive strength of the fiber-reinforced thermoplastic resin material.

[0019] 2. The preparation method of the present invention, by setting up a multi-component thermoplastic resin system of resin matrix, first resin and second resin, and using different mesh sizes of resin powder, is beneficial to improving the dispersion stability of the suspension system and the uniformity of resin particle distribution (deposition) on the fiber surface and / or inside the fiber bundle.

[0020] This invention prepares prepregs using a suspension method, which enables the deposition and penetration of resin particles into continuous reinforcements such as continuous fiber bundles under low apparent viscosity conditions. This is beneficial for improving the stability of prepreg preparation and the resin wetting effect during subsequent hot pressing.

[0021] Even when the first and second resins cannot react with each other, this invention can still improve resin flow and densification of the laminated structure through the gradation distribution of multi-component thermoplastic resin powders. Specifically, by controlling the particle size matching and surface adhesion state of at least two types of resin powders, it improves resin suspension stability, fiber wettability, and interfacial uniformity, reduces porosity and interfacial defects, and avoids high thermoplastic resin melt viscosity, difficulty in wetting the fiber bundle interior, uneven resin distribution on the fiber surface and within the fiber bundle, and insufficient densification of the laminated structure. This, in turn, improves the interfacial bonding performance and compressive strength of fiber-reinforced thermoplastic resin materials.

[0022] When the first resin and the second resin can react with each other, a three-dimensional covalent network can be constructed between the fiber and the resin matrix through the in-situ reaction of the first resin and the second resin, thereby further improving the interfacial bonding performance and the mechanical properties of the composite material, especially the compressive load-bearing capacity.

[0023] The process of this invention is simple and highly adaptable, and it is suitable for the preparation of different fiber types, different thermoplastic resin systems and different main load-bearing structural components. It is particularly suitable for continuous preparation and the preparation of high-performance fiber-reinforced thermoplastic resin materials, and has good prospects for engineering applications. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the invention and should not be considered as specific limitations thereof. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0025] The process parameters in the following examples, unless otherwise specified, are generally performed under conventional conditions.

[0026] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0027] According to a first aspect of the present invention, a fiber-reinforced thermoplastic resin material includes a thermoplastic resin uniformly distributed on fibers, the thermoplastic resin comprising a thermoplastic resin matrix, a first resin, and a second resin, all of which are thermoplastic, wherein the raw material types of the resin matrix are different from those of the first resin and the second resin, and the particle size of the raw material of the resin matrix is ​​larger than that of the raw material of the first resin and the second resin.

[0028] This invention relates to a fiber-reinforced thermoplastic resin material based on a multi-component thermoplastic resin system. By controlling the mesh size of the resin particles in each component, the distribution of different functional components on the fiber surface and within the fiber bundle is made more rational. The first resin, second resin, and resin matrix are all thermoplastic resins, capable of fully wetting the fiber bundle and being compatible with each other. The coarser resin matrix particles, acting as a continuous load-bearing phase, primarily undertake the functions of fiber wetting, interlayer bonding, and continuous load transfer, which helps maintain the stability of the deposited layer and the melt flow space, thus resulting in a more uniform resin distribution throughout the cross-section of the composite material. The finer first and second resin particles, acting as reinforcing phases, more easily penetrate the fiber bundle surface or the tiny gaps between bundles, assisting in wetting, improving the continuity of fiber surface coating and local filling capacity, and significantly reducing phenomena such as localized resin richness, resin poorness, powder agglomeration, and particle shedding. This avoids problems such as agglomeration, localized resin poorness / richness, and uneven adhesion caused by single-particle-size resin systems, leading to dry yarn, unwetted areas, and pore defects. It directly solves the problem of difficult-to-control resin distribution along the fiber surface, inside the fiber bundle and in the interlayer region in continuous reinforcement systems, and can take into account the interfacial bonding performance and mechanical properties of composite materials, especially the compressive properties.

[0029] Compressive strength is a crucial indicator for evaluating the load-bearing capacity and damage tolerance of composite materials. Especially when composite materials are subjected to compressive loads, factors such as interfacial bonding state, resin distribution uniformity, porosity, and interlayer structural integrity significantly influence the final mechanical performance of the material. In multi-component thermoplastic resin systems, different resins may exhibit varying flowability, heat resistance, and reactivity. Therefore, this invention allows for the synergistic design of the mesh size and / or component ratios and deposition behavior of each resin component, fully leveraging the advantages of multi-component resin systems in improving prepreg stability, fiber wettability, and composite material performance. By introducing additional resin components of different types, such as a first resin and / or a second resin, into the resin matrix to form a multi-component resin system, and by controlling the particle size of the raw material of the resin matrix to be larger than the particle size of the introduced additional components, namely the first resin and the second resin, a more reasonable distribution of the resin particles of each component on the fiber surface and / or inside the fiber bundle is achieved. That is, by regulating the particle size matching and surface adhesion state of at least two types of resin powders, the resin suspension stability, fiber wettability and interface uniformity are improved, porosity and interface defects are reduced, and the high viscosity of thermoplastic resin melt, difficulty in wetting inside the fiber bundle, uneven distribution of resin on the fiber surface and inside the fiber bundle, and insufficient densification of the laminated structure are avoided, thereby improving the interfacial bonding performance and compressive strength of fiber-reinforced thermoplastic resin materials.

[0030] In this invention, the first resin and the second resin can be the same or different. They can be completely identical (e.g., identical particle size, material type, etc.), or differ in only one aspect (e.g., different particle size or type), or differ in at least two aspects (e.g., different material type and particle size). When the raw materials of the first resin and the second resin are the same or different and cannot react with each other, the first resin and the second resin are independently dispersed between the fiber and the resin matrix. When the raw materials of the first resin and the second resin are different and can react with each other, the first resin and the second resin generate a three-dimensional covalent network through in-situ reaction between the fiber and the resin matrix. The construction of the three-dimensional covalent network can effectively reduce porosity and interface defects, further improving the interfacial bonding quality between the fiber and the resin matrix and the compressive strength of the composite material. It is worth noting that the resin matrix itself does not need to participate in crosslinking as the main reactant. Instead, the crosslinking density and the degree of crosslinking enhancement can be independently designed by controlling the ratio of the first resin and the second resin, as well as the type, position, and amount of reactive groups. This design allows the resin matrix to primarily function as a continuous phase supporting the network, thus avoiding problems such as a narrowed processing window, excessively rapid increase in melt viscosity, and difficulty in precisely controlling crosslinking density that arise from matrix-based crosslinking designs. Simultaneously, it avoids the issues of localized crosslinking structures, insufficient reinforcement, and limited crosslinking network continuity that occur when relying on only a single crosslinkable resin component. Through the synergistic crosslinking effect of the first and second resins, the crosslinked reinforcement structure can be more rationally distributed within the matrix and near the fibers without significantly sacrificing processability, thereby balancing impregnation properties, densification capabilities, and final compressive strength.

[0031] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the raw material mesh size of the resin matrix is ​​200-500 mesh (e.g., 250 mesh, 300 mesh, 350 mesh, 400 mesh, 450 mesh, 500 mesh, etc.), and the raw material mesh size of the first resin and the second resin are both 400-1000 mesh (e.g., 400 mesh, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, 1000 mesh, etc.). By blending thermoplastic resin powders of different mesh sizes, the distribution state of resin particles on the fiber surface and / or inside the fiber bundle can be improved, thereby ensuring the melt flowability, fiber wettability, and densification of the laminated structure of the resin. Controlling the resin particle mesh size of the resin matrix / first resin / second resin as described above avoids the following problems: when the particle size is too large, it is not conducive to uniform adhesion on the surface of the fiber or fiber fabric, and the subsequent melt wetting efficiency is low; when the particle size is too small, problems such as particle agglomeration, difficult processing, and unstable deposition are likely to occur.

[0032] In this invention, the particle size control of resin particles can be achieved using existing crushing, sieving, and particle size classification technologies. For example, grinding and crushing can be carried out using one or more of the following methods: air jet milling, mechanical milling, ball milling, vibratory milling, and cryogenic grinding. Sieving can be carried out using one or more of the following methods: vibrating screen sieving, air classifying, centrifugal classifying, and electrostatic classifying.

[0033] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the fiber is one or more of chopped fibers, long fibers, continuous fibers, and fiber fabrics.

[0034] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the fiber is one or more of carbon nanotube fiber, glass fiber, quartz fiber, carbon fiber, graphite fiber, alumina fiber, basalt fiber, aramid fiber, polyimide fiber, and poly(p-phenylenebenzoxazole) fiber.

[0035] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the thermoplastic resin is one or more of polyarylene ether, polycarbonate, polyethersulfone, polysulfone, polyarylene ester, thermoplastic polyimide, polyamide-imide, polyphenylene ether, and polyetherimide; preferably one or more of heterocyclic polyarylene ether resin, thermoplastic polyimide, and polyetherimide; more preferably one or more of heterocyclic polyarylene ether resin; and even more preferably, the thermoplastic resin is selected from one or a combination of at least two polymers having the structure shown in formula (1), as follows: Where m≥0 and n≥0 are both integers; and m and n cannot be 0 at the same time. R1, R2, R3, and R4 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups. R1, R2, R3, and R4 may have the same or different structures. The alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure. The structure of —Ar1— is generated by the reaction of aromatic dihalogen monomers and is any combination of one or at least two of the following: ; ; ; ; R is selected from one or more of hydrogen, phenyl, alkyl (such as methyl) or alkoxy (such as methoxy), wherein the alkyl or alkoxy contains 1 to 20 carbon atoms and has a straight-chain or branched structure; The structure of —Ar2— is generated by the reaction of bisphenol or bisphenol-like monomers, and is any combination of one or at least two of the following: 1, 2, 1, 3, or 1, 4 digits; , 2, 2' bits or 4, 4' bits; , 1, 4 bits, 1, 5 bits, 1, 6 bits, 2, 6 bits, or 2, 7 bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; ; ; R5, R6, R7, and R8 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups, and R5, R6, R7, and R8 may have the same or different structures; the alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure.

[0036] In this invention, the resin matrix, the first resin, or the second resin can all be heterocyclic polyarylene ether resins such as poly(phenylene ether nitrile ketone) (PPENK), poly(phenylene ether ketone) (PPEK), or poly(phenylene ether sulfone ketone) (PPESK). It should be noted that the particle size of the first resin or the second resin is different from that of the resin matrix.

[0037] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the first resin and the second resin may be the same or different; Preferably, the raw materials or particle sizes of the first resin and the second resin are different; More preferably, the raw materials and particle sizes of the first resin and the second resin are different, the first resin and the second resin can react with each other, and a three-dimensional covalent network is generated between the fiber and the resin matrix through the in-situ reaction of the first resin and the second resin; the number average molecular weight of the resin matrix is ​​greater than the number average molecular weight of the first resin and the second resin.

[0038] More preferably, the number average molecular weight of the first resin is 3000~10000 g / mol (e.g., 4000 g / mol, 5000 g / mol, 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol, 10000 g / mol, etc.). And / or, the number average molecular weight of the resin matrix is ​​25,000~80,000 g / mol (e.g., 27,000 g / mol, 30,000 g / mol, 32,000 g / mol, 34,000 g / mol, 36,000 g / mol, 38,000 g / mol, 25,000 g / mol, 42,000 g / mol, 44,000 g / mol, 46,000 g / mol, 48,000 g / mol, 50,000 g / mol, 52,000 g / mol, 54,000 g / mol, 56,000 g / mol, 58,000 g / mol, 60,000 g / mol, 62,000 g / mol, 64,000 g / mol, 66,000 g / mol, 68,000 g / mol, 70,000 g / mol, 72,000 g / mol, 74,000 g / mol). g / mol, 76000 g / mol, 78000 g / mol, etc.).

[0039] Furthermore, the raw material of the first resin contains a first group, and the raw material of the second resin contains a second group, wherein the first group and the second group can react with each other. Preferably, both the first group and the second group are terminal groups; Furthermore, the first group and the second group are each independently selected from alkynyl, azide, cyano, amino, isocyanate, hydroxyl, maleimide, thiol, allyl, acid anhydride, silyl, and furanyl.

[0040] As one form of the fiber-reinforced thermoplastic resin material of the present invention, by introducing a first resin and a second resin with relatively low number-average molecular weight into a resin matrix with higher molecular weight, a stable reinforcing structure can be constructed between the fiber and the resin matrix through the crosslinking reaction of the first and second resins while maintaining the continuous load-bearing capacity of the matrix. This improves the interfacial bonding performance and enhances the mechanical properties of the composite material. Specifically, the fiber-reinforced thermoplastic resin material includes a three-dimensional covalent network formed in situ by the in-situ reaction of the first and second resins within the resin matrix and near the fibers. By establishing a stable reinforcing structure with covalent connections, reactive reinforcing nodes and continuous load transfer channels are constructed, mechanistically improving the shear bearing capacity between the fiber and the resin matrix, as well as the lateral support capacity of the resin matrix. This enhances the interfacial load transfer and lateral support of the matrix in the composite material, suppressing longitudinal compressive instability problems such as fiber micro-buckling and matrix shear yielding. The three-dimensional covalent network of this invention is a chemical structure, not the structure formed solely by molecular chain entanglement, polar interactions, π-π interactions, hydrogen bonding, or van der Waals forces found in typical thermoplastic resin blends. The latter types of structures are essentially physical forces, prone to molecular chain slippage, phase separation, or interfacial relaxation during hot pressing, high-temperature service, or stress. Furthermore, in this invention, the number-average molecular weight of the first and second resins is relatively low (e.g., approximately 3000-10000) compared to the resin matrix, which facilitates their efficient reaction to form a synergistically cross-linked three-dimensional covalent network. Conversely, the number-average molecular weight of the resin matrix is ​​relatively high (e.g., approximately 25000-80000) compared to the first and second resins, enabling it to withstand stress under longitudinal compressive loads and provide continuous load transfer channels. Preferably, both the first and second resins undergo end-chain cross-linking reactions via their end groups, which not only constructs a long-chain-dominated three-dimensional continuous network, enhancing the overall interfacial load-bearing capacity, but also allows for adjustment of the cross-linking density through the number of end groups, facilitating the control of the three-dimensional continuous network and interfacial load-bearing capacity.

[0041] Therefore, this invention can adjust the crosslinking density of the three-dimensional covalent network by introducing a first resin and a second resin, and then controlling their ratio. This allows the resin matrix to act as a continuous phase supporting the network, rather than the main reactant, ensuring that the independent crosslinked network constructed by the first and second resins is embedded within it, thereby suppressing fiber microbending and matrix shear yielding. Firstly, it avoids the problems of narrowed processing windows caused by using the resin matrix for crosslinking, and the tendency of the crosslinkable resin matrix material to become rigid and brittle due to increased rigidity. Even when crosslinkable groups are introduced into the resin matrix molecular chain, the large number-average molecular weight of the resin matrix itself makes it difficult to control the crosslinking reaction and adjust the crosslinking density. Increased rigidity due to increased matrix functional groups and difficulty in controlling the crosslinking density easily leads to embrittlement. Secondly, it avoids the situation where there is no first resin and only the second resin is functionalized. Even if reactive groups are set in the polymer chain segments or repeating units of the resin matrix to achieve the connection between the two, it only promotes the dispersion of the second resin and improves the interfacial connection between the second resin and the resin matrix to a certain extent to increase the interlaminar shear strength. However, it cannot form a three-dimensional covalent network to improve the shear bearing capacity of the fiber and the resin matrix as well as the lateral support capacity of the resin matrix, thereby effectively suppressing fiber microbending or matrix shear yielding.

[0042] In this invention, if the first resin and the second resin do not undergo cross-linking reaction, it is not necessary to control their molecular weight, but it is essential to control their particle size to be smaller than that of the resin matrix.

[0043] As an optional embodiment of the fiber-reinforced thermoplastic resin material of the present invention, the raw materials in the fiber-reinforced thermoplastic resin material, by weight, include: 40-75 parts of fiber (e.g., 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, etc.), 10-55 parts of resin matrix (e.g., 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, etc.), 1-20 parts of first resin (e.g., 1 part, 3 parts, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts, 19 parts, etc.), 1-20 parts of second resin (e.g., 1 part, 3 parts, 5 parts, 7 parts, 9 parts, 11 parts, 13 parts, 15 parts, 17 parts, 19 parts, etc.), totaling 100 parts.

[0044] This invention, by setting up a quaternary system of a first resin, a second resin, a resin matrix, and fibers, can cover both non-reactive thermoplastic resin systems and thermoplastic resin systems that can react and crosslink with each other. Furthermore, by synergistically controlling the combination of resin components and particle size distribution, the uniformity of resin distribution on the fiber surface and / or within the fiber bundles can be improved, thereby enhancing the quality of the prepreg and the densification of the laminate, and improving the interfacial bonding performance and compressive strength of the composite material.

[0045] When the fiber-reinforced thermoplastic resin material of the present invention belongs to a non-reactive thermoplastic resin system, the raw materials in the fiber-reinforced thermoplastic resin material, by mass parts, include: 40-70 parts of fiber (e.g., 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, and 70 parts, etc.), 10-50 parts of resin matrix (e.g., 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, and 50 parts, etc.), 5-20 parts of first resin (e.g., 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 17 parts, 19 parts, and 20 parts, etc.), and 5-20 parts of second resin (e.g., 5 parts, 8 parts, 10 parts, 12 parts, 15 parts, 17 parts, 19 parts, and 20 parts, etc.), totaling 100 parts. Preferably, the fiber-reinforced thermoplastic resin material comprises, by weight, 40-60 parts of fiber (e.g., 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, and 60 parts), 20-30 parts of resin matrix (e.g., 21, 23, 25, 27, 29, and 30 parts), 5-15 parts of first resin (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 parts), and 5-15 parts of second resin (e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 parts), totaling 100 parts.

[0046] When the fiber-reinforced thermoplastic resin material of the present invention belongs to a reactive thermoplastic resin system, the raw materials in the fiber-reinforced thermoplastic resin material, by mass parts, include: 40-75 parts of fiber (e.g., 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, and 70 parts, etc.), 15-55 parts of resin matrix (e.g., 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, and 55 parts, etc.), 1-5 parts of first resin (e.g., 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, and 5 parts, etc.), and 1-5 parts of second resin (e.g., 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, and 5 parts, etc.). Preferably, the fiber-reinforced thermoplastic resin material comprises, by weight, 40-60 parts of fiber (e.g., 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, and 60 parts), 30-50 parts of resin matrix (e.g., 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, and 50 parts), 1-5 parts of first resin, and 1-5 parts of second resin, totaling 100 parts.

[0047] According to a second aspect of the present invention, a method for preparing the fiber-reinforced thermoplastic resin material of the first aspect is provided, comprising: mixing a first resin, a second resin, and a resin matrix to form a mixed resin powder of different mesh sizes, and adding a dispersant together to a solvent to form a suspension; mixing the suspension with fibers to allow the mixed resin powder to adhere to the fiber surface, and drying to obtain a prepreg; and hot-pressing the prepreg, wherein the hot pressing comprises: first pre-pressing to degas at a temperature T1, and then heating to a temperature T2 to compact and fully impregnate the fibers to obtain the fiber-reinforced thermoplastic resin material.

[0048] The preparation method of this invention, by formulating resin matrix, first resin, and second resin into resin powders with varying mesh sizes, constructs a resin particle distribution system more conducive to suspension deposition and subsequent melt wetting. Therefore, during the prepreg preparation stage, it achieves ordered deposition and optimized spatial distribution of resin particles of different sizes on the surface / inside the fiber or fiber fabric, and makes the distribution of different functional components on the fiber surface and inside the fiber bundle more rational. Coarser resin matrix particles act as a continuous supporting phase, forming a resin skeleton distribution that helps maintain the stability of the deposited layer; finer resin particles, as (crosslinked) reinforcing phases, are embedded and can preferentially fill the interior of the fiber bundle, fiber gaps, and interlayer micropores, assisting wetting, improving local filling degree and interface continuity, thereby making the resin distribution more uniform throughout the entire prepreg cross-section and significantly reducing phenomena such as localized resin-rich areas, resin-poor areas, powder agglomeration, and particle shedding.

[0049] By establishing a different mesh size combination relationship between the resin matrix and the additionally introduced first and second resins, not only can stable particle dispersion, uniform adhesion, and controllable resin content be ensured during the prepreg preparation stage, but a synergistic effect of "pre-softening, melting, and wetting, followed by cross-linking, consolidation, and reinforcement" can also be formed in the subsequent hot pressing stage. The resin matrix preferentially melts and wets the fibers in the early stage of hot pressing, while the first and second resins play a reinforcing or even reactive reinforcing role in the later stages. The initially established particle size distribution structure ensures a more reasonable distribution of different functional resin components around the fibers and within the matrix, thereby making the subsequently formed interfacial bonding structure and (cross-linking) reinforcing structure more continuous, uniform, and stable.

[0050] It is worth noting that this invention does not simply rely on increasing (crosslinkable) components or simply reducing powder particle size to improve performance. Instead, the relatively coarse resin matrix particles are conducive to forming a stable melt flow space during subsequent hot pressing, allowing the resin to continuously migrate and further impregnate between fiber bundles and layers. Thus, without significantly sacrificing the stability of the processing window and impregnation capacity, it simultaneously considers the uniformity of resin particle deposition, fiber bundle penetration potential, and the need for degassing and densification during the molding process. This achieves a balance between optimizing the prepreg deposition structure and improving subsequent molding performance, reducing problems such as particle agglomeration, localized rich / poor areas, dry yarn, unwetted areas, and pore defects that are prone to occur in traditional processes.

[0051] Therefore, this invention does not simply pursue a higher resin coverage, but rather uses a gradation design of "fine particle filling - coarse particle guidance" and a suspension deposition method to jointly construct a uniform deposition and stable adhesion system of resin particles on the surface of continuous fibers. This ensures that the prepreg has good initial resin distribution uniformity while avoiding premature dense accumulation that would hinder subsequent resin melting and flow and gas expulsion. While ensuring resin adhesion stability, it also considers the open channels and flowable space required for subsequent fiber bundle wetting, creating conditions for full wetting and overall densification during the hot pressing stage. This achieves full-process synergistic control between the prepreg preparation process and subsequent hot pressing behavior. Because in existing technologies, there are often problems such as: excessively fine particles to improve powder dispersibility, while beneficial for initial dispersion, easily causing particle agglomeration, unstable suspension, or overly dense deposition layers, leading to impeded resin flow and difficulty in venting during hot pressing; conversely, if the particle size is too large, while beneficial for maintaining flow channels, it easily causes insufficient fiber surface coating, inadequate inter-bundle filling, and localized unwetting defects.

[0052] It is also worth noting that the method of this invention can construct a segmented hot-pressing synergistic molding system of "first melt impregnation, then cross-linking and consolidation": After the prepreg preparation is completed, the invention further triggers the cross-linking reaction of the reactive first and second resins through a compaction stage, i.e., when the hot pressing temperature is raised to a higher level. This allows the previously optimized cross-linked components to form a further stable and reinforced three-dimensional covalent network structure around the fiber and inside the matrix. This structure can further reduce porosity, enhance interfacial connectivity, and improve mechanical properties, especially compressive properties. This is because, on the one hand, it can improve the shear bearing capacity and load transfer efficiency of the fiber / matrix interface region, and on the other hand, it can enhance the lateral support of the resin matrix for the fiber, suppress the micro-buckling instability of the fiber under longitudinal compressive load, and at the same time reduce the tendency of the matrix to shear yield under the coupled action of compressive and shear stresses.

[0053] Therefore, the preparation method of this invention can simultaneously solve the common problems in the preparation of continuous fiber reinforced thermoplastic resin materials: (1) the difficulty in coordinating and controlling the particle size distribution of multi-component resin powders, particle agglomeration, and uneven deposition; (2) the difficulty in simultaneously ensuring the uniformity of resin particle adhesion on the fiber surface and subsequent melt wetting ability; and (3) the limitations in prepreg porosity suppression, interlayer densification, and interface continuity improvement. It provides a stable process and structural basis for improving the interfacial bearing capacity, matrix lateral support capacity, and longitudinal compressive strength of continuous fiber reinforced thermoplastic resin materials. It fills the technical gap in achieving controllable deposition of resin particles on the fiber surface and / or inside the fiber bundle through heterogeneous blending and suspension methods for different thermoplastic resin powders.

[0054] The preparation method of this invention enables controlled deposition of resin particles on the fiber surface and / or inside the fiber bundle using a suspension method based on the graded blending of thermoplastic resin powders of different mesh sizes. This allows for complete melt wetting of the resin during subsequent hot pressing. Particularly noteworthy is the ability to construct a stable three-dimensional covalent network through in-situ reaction between the first and second resins when needed, thereby improving the stability of prepreg preparation, the densification of the laminated structure, and the interfacial bonding and mechanical properties of the composite material. The two-stage hot pressing process in this invention involves pre-pressing and venting at temperature T1, which facilitates the removal of interlayer gases and reduces porosity defects. The subsequent temperature increase to T2 further promotes complete wetting of the fibers by the resin matrix, the first resin, and the second resin, and triggers in-situ crosslinking reactions between the first and second resins when necessary, thereby forming a stable three-dimensional covalent network in the interfacial region and further improving the structural integrity and overall performance of the composite material.

[0055] As an optional embodiment of the preparation method of the present invention, the dispersant includes one or more of anionic dispersants, cationic dispersants, and nonionic dispersants. Further, the dispersant is selected from one or more of sodium dodecyl sulfate, dodecyltrimethylammonium chloride, sodium dodecylbenzene sulfonate, lignin sulfonate, naphthalene sulfonate formaldehyde condensate, polyacrylic acid, polymethacrylate, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, fatty alcohol polyoxyethylene ether, Tween, Span, polyurethane dispersants, hexadecyltrimethylammonium bromide, octadecyltrimethylammonium chloride, sodium hexametaphosphate, sodium pyrophosphate, sodium silicate, citrate, silane coupling agents, titanate coupling agents, and aluminate coupling agents. Further, the mass ratio of the dispersant to the dispersed substance, i.e., the mixed resin powder, is 0.001~0.5:1 (e.g., 0.005:1, 0.01:1, 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, etc.); even further, it is 0.001~0.3:1 (e.g., 0.001:1, 0.005:1, 0.01:1, 0.05:1, 0.1:1, 0.2:1, 0.3:1). (etc.); further, the ratio is 0.001~0.2:1 (such as 0.001:1, 0.003:1, 0.005:1, 0.008:1, 0.009:1, 0.01:1, 0.05:1, 0.07:1, 0.12:1, 0.15:1, 0.17:1, 0.2:1, etc.); the amount of the dispersed substance is the total mass of the resin matrix, the first resin and the second resin powder, that is, the total mass of the mixed resin powder.

[0056] As an optional embodiment of the preparation method of the present invention, the ratio of the sum of the masses of the first resin and the second resin to the sum of the masses of the first resin, the second resin and the resin matrix (i.e., the total mass of the mixed resin powder) is 0.03~0.9:1 (e.g., 0.04:1, 0.05:1, 0.06:1, 0.07:1, 0.08:1, 0.09:1, 0.1:1, 0.15:1, 0.2:1, 0.25:1, 0.3:1, 0.35:1, 0.4:1, 0.45:1, 0.5:1, 0.55:1, 0.6:1, 0.65:1, 0.7:1, 0.75:1, 0.8:1, 0.85:1, etc.); further, it is 0.04~0.7:1, and even further, it is 0.04~0.5:1. The uniformity of resin particle adhesion on the fiber or fiber fabric surface and the melt-wetting behavior during subsequent molding processes can be improved by adjusting the mesh size combination and blending ratio of the first resin, the second resin, and the resin matrix. When the total addition amount of the first resin and the second resin is too low, their distribution on the fiber surface, inside the fiber bundle, and in the resin matrix is ​​insufficient, making it difficult to fully exert the effects of fine particle filling, interface regulation, or in-situ reaction enhancement. This results in limited improvement on suspension stability, prepreg uniformity, fiber wetting effect, and interfacial bonding performance of the composite material. When the total addition amount of the first resin and the second resin is too high, it may lead to an excessive amount of fine particles in the system, increasing the viscosity of the suspension, increasing the risk of particle agglomeration or sedimentation, and affecting the formation and melt flow of the continuous phase of the resin matrix during subsequent hot pressing. This can easily cause local resin enrichment, interfacial defects, or decreased matrix toughness, which is detrimental to the densification of the composite laminate structure and the improvement of comprehensive mechanical properties.

[0057] As an optional embodiment of the preparation method of the present invention, the solvent is one or more of water, ethanol, ethylene glycol, and isopropanol.

[0058] As an optional embodiment of the preparation method of the present invention, the mass concentration of the mixed resin powder in the solvent is 5~30 wt% (e.g., 6wt%, 7wt%, 9wt%, 11wt%, 13wt%, 15wt%, 17wt%, 19wt%, 21wt%, 23wt%, 25wt%, 27wt%, 29wt%, etc.), preferably 10~25 wt% (e.g., 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, etc.). By adjusting the ratio of resin to solvent (total resin mass concentration), a suitable impregnation viscosity is obtained, allowing the adhesive to fully wet and penetrate into the fiber bundle, reducing defects such as dry yarn, unwetted areas, and pores, and improving the molding stability of the laminate.

[0059] As an optional embodiment of the preparation method of the present invention, the suspension is mixed with the fiber by impregnation, and the impregnation method is one or more of the following: bath impregnation, spray impregnation, scraping impregnation, roller pressing impregnation, or continuous traction impregnation. Specifically, continuous fiber bundles can be introduced into the suspension for continuous traction impregnation, or fiber fabrics can be placed in the suspension for bath impregnation. The impregnation temperature is 20~60 ℃, and the impregnation time is 1~20 min; for continuous fiber bundles, a traction speed of 0.2~1 m / min can be used to continuously pass through the suspension, and the liquid volume can be adjusted by scraping rollers or fixed thickness gaps; for fiber fabrics, they can be completely immersed in the suspension and kept for 1~20 min, so that resin particles adhere to the fiber surface and partially enter the interior of the fiber bundle or the pores of the fabric.

[0060] As an optional embodiment of the preparation method of the present invention, the drying temperature is 110~240℃ (e.g., 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, etc.), preferably a two-stage heating drying. The first stage uses a lower temperature pre-drying (e.g., 110~140°C), mainly used to gradually remove low-boiling-point solvents such as water, ethanol, and isopropanol, and reduce resin particle migration, thereby reducing particle agglomeration, local enrichment, and surface skinning. The second stage uses a higher temperature, such as 180~240°C, to further remove residual solvents, especially high-boiling-point solvents such as ethylene glycol, and improve the adhesion stability of resin particles on the fiber surface and / or inside the fiber bundle. That is, the low-temperature stage is mainly used for solvent removal, and the high-temperature stage is mainly used to enable the blended resin particles to form a stable adhesion on the fiber or fiber fabric surface. Compared to single-stage high-temperature rapid drying, two-stage heating and drying is more conducive to uniform resin distribution, reduces porosity defects in subsequent hot pressing, and improves the quality of the prepreg tape and the performance of the composite material. In this invention, the drying method is not specifically limited; existing methods such as infrared drying, forced-air drying, or vacuum drying can be used. In this invention, the dispersant is mainly used for the dispersion and stability of resin particles during suspension preparation and impregnation. Complete removal of the dispersant is not required during the drying stage; the dispersant may partially migrate or be removed with the solvent, or a small amount may be adsorbed or remain on the surface of resin particles and fibers. Since the amount of dispersant used is low, its small amount of residue will not affect the melt wetting of the resin matrix and the performance of the composite material during subsequent hot pressing.

[0061] As an optional embodiment of the preparation method of the present invention, during the pre-pressure exhaust, the temperature T1 is 260~360℃ (e.g., 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, etc.), the pressure is 0.5~15 MPa (e.g., 1 MPa, 3 MPa, 5 MPa, 7 MPa, 9 MPa, 11 MPa, 13 MPa, etc.), and the holding time is 5~40 min (e.g., 6 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, etc.). And / or, during the pressing process, the T2 temperature is 280~370℃ (e.g., 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, etc.), the pressure is 0.5~15 MPa (e.g., 1 MPa, 3 MPa, 5 MPa, 7 MPa, 9 MPa, 11 MPa, 13 MPa, etc.), and the holding time is 5~80 min (e.g., 6 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, etc.). Preferably, the T2 temperature is 10~80℃ higher than the T1 temperature (e.g., 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, etc.) to avoid excessively high temperatures, which can easily cause the resin matrix to age and is also detrimental to energy conservation.

[0062] In an optional embodiment of the preparation method of the present invention, the first resin and the second resin can react with each other, forming a three-dimensional covalent network between the fiber and the resin matrix through in-situ reaction of the first and second resins. The number-average molecular weight of the resin matrix is ​​greater than that of the first and second resins. Preferably, the number-average molecular weight of the first resin is 3000~10000 g / mol (e.g., 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, 8000 g / mol, 10000 g / mol, etc.); the number-average molecular weight of the resin matrix is ​​25000~80000 g / mol (e.g., 27000 g / mol, 30000 g / mol, 32000 g / mol, 34000 g / mol, 36000 g / mol, 38000 g / mol, 25000 g / mol, 42000 g / mol, 44000 g / mol, 46000 g / mol, etc.). g / mol, 48000 g / mol, 50000 g / mol, 52000g / mol, 54000 g / mol, 56000 g / mol, 58000 g / mol, 60000 g / mol, 62000 g / mol, 64000 g / mol, 66000 g / mol, 68000 g / mol, 70000 g / mol, 72000 g / mol, 74000 g / mol, 76000 g / mol, 78000 g / mol, etc.); The temperature of the in-situ reaction is T2. Further, the mass ratio of the first resin to the second resin is 0.05~40:1 (e.g., 0.1:1, 1:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, etc.); even further, the mass ratio of the first resin to the second resin is 1~20:1 (e.g., 1:1, 3:1, 5:1, 7:1, 9:1, 11:1, 13:1, 15:1, 17:1, 19:1, etc.); and still further, the mass ratio of the first resin to the second resin is 1:1. During the compaction process of the composite material, the first resin and the second resin undergo a cross-linking reaction, which can improve the interfacial bonding performance, structural stability, and compressive strength of the composite material. However, when the mass ratio of the first resin to the second resin (A / B) is too low, the proportion of the second resin in the system is too high, which is not conducive to maintaining the dispersion stability of the adhesive and the wetting of the fiber bundles, and it is easy to have insufficient organic bridging segments; when A / B is too high, the number of reaction nodes is insufficient, making it difficult to form a sufficiently dense and continuous synergistic network.

[0063] Furthermore, the raw material of the first resin contains a first group, and the raw material of the second resin contains a second group, wherein the first group and the second group constitute a group pair that can react with each other; optionally, the group pair includes at least one of the following: (a) alkynyl / azido; (b) nitrile / amino; (c) isocyanate / hydroxy; (d) maleimide / thiol; (e) allyl / thiol; (f) maleimide / amino; (g) acid anhydride / amino; (h) acid anhydride / hydroxy; (i) silyl / hydroxy; (j) furanyl / maleimide; This preparation method achieves the following effects: 1. In-situ crosslinking: The three-dimensional covalent network is generated in-situ inside the laminate, resulting in a more uniform and continuous network; 2. Avoids agglomeration caused by high-temperature pre-reaction; 3. Controllable crosslinking density; 4. Does not affect the flow window of the adhesive. It also solves the problem of fiber-reinforced thermoplastic resin materials easily failing under longitudinal compressive loads due to fiber micro-bending or matrix shear yielding.

[0064] As an optional embodiment of the preparation method of the present invention, the prepreg is cut and laid in a predetermined layup sequence and then hot-pressed. The layup method includes one of unidirectional layup, cross layup, symmetrical layup or quasi-isotropic layup.

[0065] According to a third aspect of the present invention, a fiber-reinforced thermoplastic resin material as described in the first aspect is provided for use in the fabrication of main load-bearing structural components in the fields of aerospace, rail transportation, or lightweighting of high-end equipment. This fiber-reinforced thermoplastic resin material is not prone to failure under longitudinal compressive loads and can be used in the fabrication of main load-bearing structural components. Preferably, this material is a fiber-reinforced thermoplastic resin material based on an organically synergistically crosslinked three-dimensional covalent network, in which fibers are uniformly dispersed in a resin matrix, and an organically synergistically crosslinked three-dimensional covalent network is distributed between the resin matrix and the fibers.

[0066] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. Unless otherwise specified, specific conditions in the embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available products. The materials used in the embodiments and comparative examples are listed below: 1. The main fiber raw materials are as follows: 1) T700 grade continuous carbon fiber tow is T700S grade polyacrylonitrile-based carbon fiber produced by Toray Industries, with a specification of 12K and a single filament diameter of about 7 μm. 2) Carbon fiber T300 fabric, which is T300 grade polyacrylonitrile-based carbon fiber fabric, and the fabric structure is unidirectional fabric; 3) Fiberglass fabric, specifically EWR600E fiberglass fabric produced by China Jushi Co., Ltd., with a plain weave structure and a unit area mass of approximately 600 g / m². 2 ; 4) Continuous basalt fiber bundles are produced by Jiangsu Tianlong Basalt Continuous Fiber Co., Ltd., with a single filament linear density of 2400 tex and a single filament diameter of approximately 13 μm.

[0067] 2. The main resin raw materials are as follows: 1) Poly(phenylene ether nitrile ketone) (PPENK), with the following structure: a and b are positive integers, and the number-average molecular weight is approximately 40,000 g / mol.

[0068] The preparation method is as follows: Diazanaphthyl ketone biphenyl (DHPZ), 4,4′-difluorobenzophenone (DFK), 2,6-difluorobenzonitrile (DFBN), anhydrous potassium carbonate, tetramethylene sulfone, and toluene were added to a reaction flask. The molar ratio of DHPZ to the total amount of DFK and DFBN was 1:1, the molar ratio of DFK to DFBN was 7:3, and the amount of anhydrous potassium carbonate was 1.1 times the molar amount of DHPZ. The reaction system was heated to 140 °C under nitrogen protection, stirred to form a salt, and dehydrated by azeotropic dehydration with toluene for 4 h. Subsequently, the temperature was raised to 160 °C to remove toluene, and then raised to 190 °C to allow DHPZ to undergo a nucleophilic aromatic substitution polymerization reaction with DFK and DFBN. After the reaction was complete, the solid was filtered, washed, and dried to obtain PPENK with a number average molecular weight of approximately 40,000 g / mol.

[0069] 2) Polyetherimide resin (PEI), with a number average molecular weight of approximately 4000 g / mol; silyl-terminated polyetherimide resin (silyl-terminated PEI), with a number average molecular weight of approximately 4000 g / mol; maleimide-terminated polyetherimide resin (maleimide-terminated PEI), with a number average molecular weight of approximately 6000 g / mol. Preparation of PEI: 4,4′-O-diphthalic anhydride (ODPA) and 4,4′-diaminodiphenyl ether (ODA) were added to anhydrous N-methylpyrrolidone (NMP), wherein the molar ratio of ODPA to ODA was 1:1. The reaction system was stirred at 40 °C for 6 h under nitrogen protection to obtain a polyamic acid solution; subsequently, the temperature was raised to 160 °C for a thermal imidization reaction for 4 h, causing the polyamic acid to dehydrate and cyclize to form polyetherimide. After the reaction, the solid was filtered, washed, and dried to obtain PEI with a number average molecular weight of approximately 4000 g / mol. Preparation of silyl-terminated PEI: The preparation process was carried out based on the aforementioned PEI preparation process, except that ODPA was added in slight excess relative to ODA, and 4-aminophenol was added as a capping agent to introduce terminal hydroxyl groups, resulting in hydroxyl-terminated PEI with a number-average molecular weight of approximately 4000 g / mol. Then, 10 g of dried hydroxyl-terminated PEI and 90 g of anhydrous N,N-dimethylacetamide (DMAc) were dissolved by stirring at 80 °C. Next, 0.6 g of 3-isocyanate propyltriethoxysilane (ICPTES) and 0.005 g of dibutyltin dilaurate (DBTDL) were added, and the reaction was carried out under nitrogen protection at 80 °C for 6 h. After the reaction, the solid was filtered, washed, and dried to obtain silyl-terminated PEI with a number-average molecular weight of approximately 4000 g / mol.

[0070] Preparation of maleimide-terminated PEI: ODA and ODPA were added to anhydrous NMP, with ODA in slight excess relative to ODPA, so that the resulting polymer chain ends retained amino groups. The reaction system was stirred at 40 °C for 8 h under nitrogen protection to obtain an amino-terminated polyamic acid solution; subsequently, the temperature was raised to 170 °C for thermal imidization reaction for 5 h, causing the polyamic acid to dehydrate and cyclize to form polyetherimide. After the reaction, the solid was filtered, washed, and dried to obtain amino-terminated PEI with a number average molecular weight of approximately 6000 g / mol. Then, 10 g of the dried amino-terminated PEI and 90 g of anhydrous NMP were dissolved by stirring at 60 °C. Next, 0.5 g of maleic anhydride was added, and the reaction was carried out under nitrogen protection at 60 °C for 3 h to obtain a maleamide-terminated intermediate. Subsequently, 2.0 g of acetic anhydride and 1.0 g of pyridine were added to the system, and the temperature was raised to 80 °C for another 4 h to further dehydrate and cyclize the terminal groups to form maleimide groups. After the reaction, the solid was filtered, washed, and dried to obtain maleimide-terminated PEI with a number average molecular weight of approximately 6000 g / mol.

[0071] 3) Polyaryletherketone (PPEK) with a number average molecular weight of approximately 9000 g / mol; Hydroxyl-terminated polyaryletherketone (hydroxyl-terminated PPEK) with a number average molecular weight of approximately 9000 g / mol; PPEK preparation: DHPZ, DFK, anhydrous potassium carbonate, tetramethylene sulfone, and toluene were added to a reaction flask, with a molar ratio of DHPZ to DFK of 1:1. The reaction system was stirred at 140 °C for 2 h under nitrogen protection to form a salt, followed by azeotropic dehydration with toluene for 4 h. Subsequently, the temperature was raised to 160 °C to remove toluene, and then raised to 190 °C to allow nucleophilic aromatic substitution polymerization of DHPZ and DFK. After the reaction was complete, the solid was filtered, washed, and dried to obtain PPEK with a number average molecular weight of approximately 9000 g / mol. Preparation of hydroxyl-terminated PPEK: 5.02 g of bisphenol A, 8.61 g of 4,4′-difluorobenzophenone, 3.18 g of anhydrous potassium carbonate, 60 g of anhydrous DMAc, and 20 g of toluene were added to a reaction flask and stirred at 130 °C for 1 h under nitrogen protection to allow the phenolic hydroxyl groups to fully form salts. Then, the temperature was raised to 150 °C for azeotropic dehydration for 2 h. After dehydration, the temperature was raised to 170 °C to distill off the toluene, and then the temperature was raised to 180 °C for polymerization. By controlling a slight excess of bisphenol A relative to 4,4′-difluorobenzophenone, the resulting polymer chain retained hydroxyl groups. After the reaction, the solid was filtered, washed, and dried to obtain hydroxyl-terminated PPEK with a number average molecular weight of approximately 9000 g / mol.

[0072] 4) Polyethersulfone resin (PES), with a number average molecular weight of approximately 9000 g / mol; allyl-terminated polyethersulfone resin (allyl-terminated PES), with a number average molecular weight of approximately 9000 g / mol; Preparation of PES: 4,4′-dihydroxydiphenyl sulfone, 4,4′-dichlorodiphenyl sulfone, anhydrous potassium carbonate, anhydrous DMAc, and toluene were added to a reaction flask, wherein the molar ratio of 4,4′-dihydroxydiphenyl sulfone to 4,4′-dichlorodiphenyl sulfone was 1:1. The reaction system was stirred at 130 °C for 1 h under nitrogen protection to form a salt, followed by azeotropic dehydration at 150 °C for 2 h. Then, the temperature was raised to 170 °C to remove toluene, and then raised to 180 °C to allow nucleophilic aromatic substitution polymerization of 4,4′-dihydroxydiphenyl sulfone and 4,4′-dichlorodiphenyl sulfone. After the reaction was complete, the solid was filtered, washed, and dried to obtain PES with a number average molecular weight of approximately 9000 g / mol.

[0073] Preparation of allyl-terminated PES: The preparation process was carried out based on the aforementioned PES preparation process, except that 4,4′-dihydroxydiphenyl sulfone was added in slight excess relative to 4,4′-dichlorodiphenyl sulfone to retain hydroxyl groups at the ends of the polymer chains, thus obtaining hydroxyl-terminated PES with a number-average molecular weight of approximately 9000 g / mol. Subsequently, 10 g of dried hydroxyl-terminated PES and 100 g of anhydrous N,N-dimethylformamide (DMF) were dissolved by stirring at 70 °C; then 0.8 g of anhydrous potassium carbonate and 0.7 g of allyl bromide were added, and the reaction was carried out under nitrogen protection at 70 °C for 8 h. After the reaction, the solid was filtered, washed, and dried to obtain allyl-terminated polyethersulfone resin with a number-average molecular weight of approximately 9000 g / mol.

[0074] 5) Poly(phenylene ether sulfone ketone) (PPESK), with the following structure: a and b are positive integers, and the number-average molecular weight is approximately 30,000 g / mol; The preparation method is as follows: DHPZ, 4,4′-difluorodiphenyl sulfone, DFK, anhydrous potassium carbonate, tetramethylene sulfone, and toluene were added to a reaction flask, wherein the molar ratio of DHPZ to the total amount of 4,4′-difluorodiphenyl sulfone and DFK was 1:1, and the molar ratio of 4,4′-difluorodiphenyl sulfone to DFK was 8:2. The reaction system was stirred at 140 °C for 2 h under nitrogen protection to form a salt, followed by azeotropic dehydration with toluene for 4 h. Then, the temperature was raised to 170 °C to remove toluene, and then raised to 190 °C for 10 h to allow nucleophilic aromatic substitution polymerization of DHPZ with 4,4′-difluorodiphenyl sulfone and DFK. After the reaction was complete, the solid was filtered, washed, and dried to obtain PPESK with a number average molecular weight of approximately 30,000 g / mol.

[0075] 6) Polyarylene ether sulfone resin (PAES), with a number-average molecular weight of approximately 50,000 g / mol; prepared as follows: 4,4′-Bisphenol A, 4,4′-dichlorodiphenyl sulfone, anhydrous potassium carbonate, anhydrous N,N-dimethylacetamide, and toluene were added to a reaction flask, with the molar ratio of 4,4′-biphenyl A to 4,4′-dichlorodiphenyl sulfone being 1:1. The reaction system was stirred at 130 °C for 1 h under nitrogen protection to form a salt, followed by azeotropic dehydration with toluene at 150 °C for 2 h. Then, the temperature was raised to 170 °C to remove toluene, and the reaction was further raised to 190 °C for 10 h to allow nucleophilic aromatic substitution polymerization of 4,4′-biphenyl A and 4,4′-dichlorodiphenyl sulfone. After the reaction was complete, the solid was filtered, washed, and dried to obtain PAES with a number average molecular weight of approximately 50,000 g / mol.

[0076] 7) Polyphenylene oxide resin (PPO), with a number-average molecular weight of approximately 5000 g / mol, was prepared according to the preparation method in patent CN201110444346.7; 8) Polyether ether ketone resin (PEEK), with a number average molecular weight of approximately 50,000 g / mol, was prepared according to the preparation method in patent CN202512026117.8.

[0077] Unless otherwise specified, the resins used in the examples and comparative examples are commercially available. For specific applications, the required particle size can be obtained using existing grinding and sieving techniques. Air jet milling offers advantages such as high grinding efficiency, minimal heat-affected zone, low contamination, and good particle size controllability, making it suitable for preparing high-performance resin powders. Vibrating screen sieving allows for effective classification of resin powders with different pore sizes. Therefore, the resins used in the examples and comparative examples were subjected to air jet milling and vibrating screen sieving, respectively. They were then blended and suspensions were prepared based on particle size matching. The suspension was then used to attach the resin particles to the surface of fibers or fiber fabrics to improve the deposition state of resin particles on the fiber surface, the flow and wetting behavior during subsequent molding processes, and the final interfacial structure of the composite material.

[0078] 3. Other raw materials are as follows: Solvents such as ethanol, ethylene glycol, isopropanol, and deionized water are all commercially available analytical grade reagents; All dispersants were purchased from commercially available analytical grade or industrial grade reagents. Specifically, polyethylene glycol was PEG-4000, with a number-average molecular weight of approximately 4000 g / mol; polyvinyl alcohol had a degree of alcoholysis of 87.0%–89.0% and an average degree of polymerization of approximately 1700–1800; and polyvinylpyrrolidone was PVP K30, with a weight-average molecular weight of approximately 111.14 g / mol. All dispersants were dried as needed before use.

[0079] Examples 1-5 and Comparative Example 1 Examples 1-5 and Comparative Example 1 all provide a fiber-reinforced thermoplastic resin material, comprising thermoplastic resin uniformly distributed on fibers. The thermoplastic resin comprises a thermoplastic resin matrix, a first resin, and a second resin (Comparative Example 1 does not have a first and second resin; the resin matrix is ​​used to supplement its composition during preparation). The fiber raw material is T700 grade continuous carbon fiber tow, and the resin matrix is ​​500 mesh PPENK particles. The specific raw materials of the first and second resins in Examples 1-5 and Comparative Example 1 are shown in Table 1. Table 1. Additional Components and Raw Materials of Examples 1-5 and Comparative Example 1 The fiber-reinforced thermoplastic resin materials of Examples 1-5 and Comparative Example 1 are prepared by the following specific methods: (1) Preparation of suspension The resin matrix, the mixed resin powder of the first resin and the second resin, and the polyethylene glycol dispersant were added together to a mixed solvent of ethanol / ethylene glycol (volume ratio of 5:5). The mass concentration of the mixed resin powder in the solvent was controlled at 18 wt%, and the mass ratio of the dispersant to the mixed resin powder was 0.1:1. After mechanical stirring and ultrasonic dispersion, a suspension was obtained.

[0080] (2) Prepreg preparation Continuous carbon fiber bundles were introduced into a suspension for impregnation (impregnation temperature was 40 °C, impregnation time was 20 min, and the traction speed of the continuous fiber bundles through the suspension was 0.5 m / min), so that resin particles adhered to the fiber surface and partially penetrated into the fiber bundle; then dried at 140 °C for 20 min, and then heated to 240 °C for 10 min to obtain prepreg.

[0081] (3) Hot pressing The prepreg was laid up in a unidirectional layup and then hot-pressed. First, it was pre-pressed at 320 °C and 5 MPa for 5 min to remove air, then heated to 370 °C and held at 10 MPa for 45 min to allow the resin matrix, first resin, and second resin to fully melt and impregnate the fibers before compaction. After cooling, a fiber-reinforced resin matrix composite material, i.e., a laminated fiber-reinforced thermoplastic resin material, was obtained. In the composites obtained in Examples 1-4, the first and second resins were independently dispersed between the fibers and the resin matrix. In the composite material obtained in Example 5, a three-dimensional covalent network was formed between the fibers and the resin matrix through an in-situ reaction of the first and second resins. In the composite material obtained in Comparative Example 1, only the resin matrix was distributed on the fibers; neither the first nor second resin was present.

[0082] Example 6 and Comparative Example 2 Example 6 and Comparative Example 2 each provide a fiber-reinforced thermoplastic resin material, comprising thermoplastic resin uniformly distributed on fibers. The thermoplastic resin includes a thermoplastic resin matrix, a first resin, and a second resin. The fiber raw material is carbon fiber T300 fabric, the first resin raw material is 800-mesh PES, and the second resin raw material is 900-mesh PPEK. The specific raw materials of the resin matrix in Example 6 and Comparative Example 2 are shown in Table 2. Table 2 Raw material list of resin matrix for Example 6 and Comparative Example 2 The specific preparation methods for the fiber-reinforced thermoplastic resin materials in Examples 6 and 2 are as follows: (1) Preparation of suspension The resin matrix, the mixed resin powder of the first resin and the second resin, and the polyvinyl alcohol dispersant were added together to a mixed solvent of ethanol / isopropanol (volume ratio of 7:3). The mass concentration of the mixed resin powder in the solvent was controlled to be 12 wt%, and the mass ratio of the dispersant to the mixed resin powder was 0.005:1. After mechanical stirring and ultrasonic dispersion, a suspension was obtained.

[0083] (2) Prepreg preparation The carbon fiber T300 fabric was immersed in a suspension (immersion temperature 40 ℃, immersion time 20 min) to allow the resin particles to adhere to the fiber surface and partially penetrate into the fiber bundle or fabric pores; then dried at 110 ℃ for 35 min, and then heated to 180 ℃ for 15 min to obtain the prepreg.

[0084] (3) Hot pressing After the prepreg is laid up in a unidirectional layup manner, it is hot-pressed. First, it is pre-pressed at 280 ℃ and 2 MPa for 15 min to remove air, and then the temperature is raised to 345 ℃ and held at 9 MPa for 45 min to allow the resin matrix, the first resin and the second resin to fully melt and impregnate the fiber and compact it. After cooling, a laminated fiber-reinforced thermoplastic resin material is obtained.

[0085] Example 7 and Comparative Example 3 Example 7 and Comparative Example 3 each provide a fiber-reinforced thermoplastic resin material, comprising thermoplastic resin uniformly distributed on fibers. The thermoplastic resin comprises a thermoplastic resin matrix, a first resin, and a second resin. The fiber raw material is glass fiber fabric, the first resin raw material is 700-mesh PES, and the second resin raw material is 700-mesh PPO. The specific raw materials of the resin matrix in Example 7 and Comparative Example 3 are shown in Table 3. Table 3. Raw material list of resin matrix for Example 7 and Comparative Example 3 The specific preparation methods for the fiber-reinforced thermoplastic resin materials in Examples 7 and 3 are as follows: (1) Preparation of suspension The resin matrix, the mixed resin powder of the first resin and the second resin, and the polyethylene glycol dispersant were added together to a mixed solvent of ethylene glycol / water (volume ratio of 6:4). The mass concentration of the mixed resin powder in the solvent was controlled at 25 wt%, and the mass ratio of the dispersant to the mixed resin powder was 0.05:1. After mechanical stirring and ultrasonic dispersion, a suspension was obtained.

[0086] (2) Prepreg preparation The glass fiber fabric was immersed in a suspension (immersion temperature 40 ℃, immersion time 20 min) to allow resin particles to adhere to the fiber surface and partially penetrate into the fiber bundle or fabric pores; then dried at 130 ℃ for 25 min, and then heated to 220 ℃ for 10 min to obtain the prepreg.

[0087] (3) Hot pressing After the prepreg is laid up in a unidirectional layup manner, it is hot-pressed. First, it is pre-pressed at 320 ℃ and 15 MPa for 40 min to remove air, and then the temperature is raised to 370 ℃ and held at 15 MPa for 80 min to allow the resin matrix, the first resin and the second resin to fully melt and impregnate the fiber and compact it. After cooling, a laminated fiber-reinforced thermoplastic resin material is obtained.

[0088] Example 8 This embodiment provides a fiber-reinforced thermoplastic resin material, comprising thermoplastic resin uniformly distributed on fibers. The thermoplastic resin includes a thermoplastic resin matrix, a first resin, and a second resin. The raw material of the fibers is continuous basalt fiber bundles, the resin matrix is ​​200 mesh PEEK, the raw material of the first resin is 500 mesh PES, and the raw material of the second resin is 900 mesh PPESK.

[0089] The specific preparation method includes the following steps: (1) Preparation of suspension By weight, take 40 parts fiber, 30 parts resin matrix, 15 parts first resin, and 15 parts second resin.

[0090] The resin matrix, the mixed resin powder of the first resin and the second resin, and the polyvinylpyrrolidone dispersant were added together to a mixed solvent of isopropanol / water (volume ratio of 9:1). The mass concentration of the mixed resin powder in the solvent was controlled to be 10 wt%, and the mass ratio of the dispersant to the mixed resin powder was 0.2:1. After mechanical stirring and ultrasonic dispersion, a suspension was obtained.

[0091] (2) Prepreg preparation Continuous basalt fiber bundles were introduced into a suspension for impregnation (impregnation temperature was 40 ℃, impregnation time was 20 min, and the traction speed of the continuous fiber bundles through the suspension was 0.5 m / min), so that resin particles adhered to the fiber surface and partially penetrated into the fiber bundle; then dried at 120 ℃ for 30 min, and then heated to 200 ℃ for 10 min to obtain prepreg.

[0092] (3) Hot pressing After the prepreg is laid up in a unidirectional layup manner, it is hot-pressed. First, it is pre-pressed at 300 ℃ and 3 MPa for 15 min to remove air, and then the temperature is raised to 370 ℃ and held at 10 MPa for 45 min to allow the resin matrix, the first resin and the second resin to fully melt and impregnate the fiber and compact it. After cooling, a laminated fiber-reinforced thermoplastic resin material is obtained.

[0093] Example 9 This embodiment provides a fiber-reinforced thermoplastic resin material, comprising thermoplastic resin uniformly distributed on fibers. The thermoplastic resin includes a thermoplastic resin matrix, a first resin, and a second resin. The raw material for the fibers is T700 grade continuous carbon fiber tow. The resin matrix is ​​400 mesh PEEK. The raw material for the first resin is 500 mesh allyl-terminated PES. The raw material for the second resin is 900 mesh maleimide-terminated PEI.

[0094] The specific preparation method includes the following steps: (1) Preparation of suspension By weight, take 40 parts fiber, 48 parts resin matrix, 1 part first resin, and 1 part second resin.

[0095] The resin matrix, the mixed resin powder of the first resin and the second resin, and the polyvinylpyrrolidone dispersant were added together to a mixed solvent of ethanol / water (volume ratio of 9:1). The mass concentration of the mixed resin powder in the solvent was controlled to be 10 wt%, and the mass ratio of the dispersant to the mixed resin powder was 0.001:1. After mechanical stirring and ultrasonic dispersion, a suspension was obtained.

[0096] (2) Prepreg preparation Continuous carbon fiber bundles were introduced into a suspension for impregnation (impregnation temperature was 40 °C, impregnation time was 20 min, and the traction speed of the continuous fiber bundles through the suspension was 0.5 m / min), so that resin particles adhered to the fiber surface and partially penetrated into the fiber bundle; then dried at 110 °C for 35 min, and then heated to 190 °C for 15 min to obtain prepreg.

[0097] (3) Hot pressing The prepreg is laid up in a unidirectional layup and then hot-pressed. First, it is pre-pressed at 300 ℃ and 3 MPa for 15 min to remove air, and then heated to 350 ℃ and held at 10 MPa for 50 min to allow the resin system to fully impregnate the fiber. At the same time, the first resin and the second resin react in situ to form a three-dimensional covalent network between the fiber and the resin matrix. After cooling, a laminated fiber-reinforced thermoplastic resin material is obtained.

[0098] Tests and Results To verify the effectiveness of the technical solution of this invention, the prepregs and 2mm thick laminates (i.e., fiber-reinforced thermoplastic resin materials in laminate form) obtained in Examples 1-9 and Comparative Examples 1-3 were subjected to process performance and performance testing and analysis. The compressive strength and compressive modulus were tested according to SACMA SRM 1R; the interlaminar shear strength (ILSS) was tested according to ASTM D2344; and the flexural strength was tested according to ASTM D7264. If necessary, the porosity of the laminate was statistically analyzed. The porosity was tested according to ASTM D2734, calculated by the difference between the theoretical density and the measured density of the composite material. The measured density can be determined using the liquid displacement method according to ASTM D792, and the theoretical density is calculated from the density and ratio of the resin and fiber.

[0099] 1. Process characteristics during prepreg preparation First, the effects of different combinations of different mesh sizes on the stability of the suspension system, the deposition behavior of resin particles, and the apparent quality of the prepreg were investigated. Suspension stability was assessed by the time it took for stratification to occur after standing at 25±2 ℃. A time of at least 6 hours for obvious stratification was considered good; a time of less than 6 hours but not less than 4 hours was considered relatively good; and a time of less than 4 hours was considered average.

[0100] Fiber surface coverage: The evaluation is based on the continuity and uniformity of resin coverage on the fiber surface. This is achieved through visual observation combined with optical microscopy or scanning electron microscopy to assess whether the fiber surface is continuously covered by resin particles and whether there are any exposed areas. Uniform: Indicates that the fiber surface is continuously and completely covered by resin particles with no obvious exposed areas. Relatively uniform: Indicates that the fiber surface is mostly covered by resin particles with a very small number of microscopically visible uncovered areas. Basically uniform: Indicates that the fiber surface is basically covered by resin particles but has a small number of microscopically visible uncovered areas.

[0101] Fiber Internal Penetration: The extent to which resin penetrates the fiber bundle or fabric pores is assessed. Preferably, the distribution of resin within the fiber bundle or fabric pores is observed using an optical microscope and / or scanning electron microscope on a cross-section of the prepreg or laminate. **Sufficient:** Resin clearly penetrates the fiber bundle or fabric pores; a continuous resin phase is observed in the central interstitial region of the fiber bundle, and most of the pore areas are filled with resin. **Slightly Sufficient:** Resin penetrates the fiber bundle or fabric pores, but the continuity and uniformity of its distribution are slightly lower than the "sufficient" level. Resin is still observed in the central interstitial region of the fiber bundle, but there may be a small number of incompletely filled areas or a slight phenomenon of being rich in resin on the outside and poor in the inside in some localized areas. **General:** Resin is mainly distributed on the fiber surface, around the fiber bundle, or in localized areas of the fabric. It is difficult to fully penetrate the fiber bundle or fabric pores. Obvious unwetted areas, blank areas within the bundle, or a phenomenon of being rich in resin on the outside and poor in the inside are present in the cross-section.

[0102] The appearance of prepregs is evaluated based on their continuity and smoothness. "Continuous" means the prepreg remains intact overall, without obvious breaks, gaps, or holes; "mostly continuous" means the prepreg is generally intact, but with slight edge irregularities or small gaps in some areas. "Smooth" means the prepreg surface is smooth, with uniform thickness distribution, without obvious wrinkles, ripples, or areas of insufficient or excessive resin; "mostly smooth" means the prepreg is generally smooth, but with slight ripples, thickness fluctuations, or slight areas of insufficient or excessive resin in some areas.

[0103] The specific results are shown in Table 4: Table 4. Process performance parameters during prepreg preparation 2. Performance Comparison of Laminates in the Examples and Comparative Examples The performance of the laminates obtained in Examples 1-9 and corresponding Examples 1-3 was tested, and the results are shown in Table 5: Table 5. Performance comparison of laminates in the examples and comparative examples Based on the test results in Tables 4 and 5, under the same fiber, resin matrix, and preparation process, Examples 1-5 introduced a first resin and a second resin on the basis of Comparative Example 1, and while making the resin matrix, the first resin, and the second resin form a combination of different mesh sizes, the particle size of the raw material of the resin matrix was controlled to be larger than that of the raw material of the first resin and the second resin. Compared with the general suspension stability of Comparative Example 1, the suspension stability of Examples 1-5 is good or better, which should be because the resin particles of different particle sizes can form a more reasonable particle distribution in the suspension. At the same time, during the preparation of the prepregs in Examples 1-5, the fiber surface was uniformly or relatively uniformly covered, the fiber bundles were fully or relatively fully penetrated, the prepreg surface was smooth, and the compressive strength, compressive modulus, interlaminar shear strength, and flexural strength of the resulting composite materials were all higher than those of Comparative Example 1, while the porosity was lower than that of Comparative Example 1. This should be because the stable suspension formed by resin particles of different particle sizes is conducive to the adhesion of resin particles to the fiber surface and into the fiber bundle, thereby improving the uniformity of resin distribution in the prepreg and the wetting, flow, and compaction effects in the subsequent hot pressing process.

[0104] Furthermore, as can be seen from Examples 1-4, when the particle size of the resin matrix is ​​larger than that of the first resin and the second resin, the material types and mesh sizes of the first resin and the second resin can be further adjusted. Compared to Example 1, in Example 2, the second and first resins still have different mesh sizes but the same material type, resulting in a suspension with good stability. Furthermore, during prepreg preparation, the fiber surface is uniformly covered, the fiber bundles are fully penetrated, and the prepreg is smooth and continuous. However, the mechanical properties of the resulting composite material are slightly reduced, and the porosity is increased. In Example 3, the second and first resins still have different material types but the same mesh size. The stability of the resulting suspension decreases, and the uniformity of fiber surface coverage and the fullness of fiber bundle penetration decrease during prepreg preparation. The resulting prepreg is smooth but has slight local edge irregularities. The mechanical properties of the resulting composite material decrease, and the porosity increases. In Example 4, the second and first resins have the same material type and mesh size. The stability of the resulting suspension decreases, and the uniformity of fiber surface coverage and the fullness of fiber bundle penetration decrease during prepreg preparation. The resulting prepreg has slight local ripples and local micro-notch defects. The mechanical properties of the resulting composite material decrease, and the porosity increases. Therefore, in Examples 1 and 2, the first resin (600 mesh), the second resin (800 mesh / 1000 mesh), and the resin matrix (500 mesh) constitute a three-mesh-size combination. Compared with Examples 3 and 4, where the first and second resins have the same mesh size (600 mesh) and the resin matrix (500 mesh), forming a two-mesh-size combination, the suspension system exhibits better dispersion stability and resin deposition uniformity on the continuous fiber surface, resulting in lower porosity in the final material. Further comparison between Examples 4 and 3 shows that, under the condition that the first and second resins have the same mesh size, changing the second resin from PEI to PPEK in Example 3 also leads to a certain improvement in performance, indicating that differences in material type have an auxiliary regulatory effect on system performance. In summary, the gradation matching of resin powders with different mesh sizes is a key factor in improving suspension deposition, fiber wetting, and laminate performance. Differences in material type can further optimize the distribution and overall performance of the resin system.

[0105] Furthermore, as demonstrated in Example 8, even with relatively low amounts of the first and second resins, the resin powder can still maintain a good dispersion in the suspension through the differences in particle size between the resin matrix, the first and second resins, and the assistance of the dispersant, thus achieving effective adhesion to the fiber surface and preparation of the prepreg. Example 8 uses a basalt fiber system with a compressive strength and compressive modulus of 970 MPa and 56.8 GPa, respectively, which is lower than that of the T700 continuous carbon fiber system. This is mainly related to the type of reinforcing fiber and its intrinsic mechanical properties. However, despite the porosity of 1.4% in Example 8, the prepreg and laminate still maintain good molding quality, indicating that the suspension method with varying mesh counts of the present invention can also be applied to non-carbon fiber reinforced systems.

[0106] Furthermore, this invention further demonstrates the influence of the particle size relationship between the resin matrix, the first resin, and the second resin on the preparation of suspension prepreg through comparative analysis. A comparison of Example 7 and Comparative Example 3 shows that using a combination of resin matrix, first resin, and second resin with different mesh sizes is more beneficial for improving the distribution of resin particles on the fiber surface and within the fiber bundle, compared to a combination of all three being 700 mesh. Example 7 also illustrates that the combination design of thermoplastic resin powders with different mesh sizes is applicable not only to carbon fiber systems but also to other reinforcing fiber systems such as glass fiber, demonstrating good versatility. Meanwhile, a comparison of Example 6 and Comparative Example 2 shows that when the resin matrix particles are smaller than the first and second resins, it is not conducive to forming a reasonable resin distribution, easily causing large particles to settle or locally accumulate in the suspension, thereby weakening the suspension stability. Furthermore, during prepreg molding, a smaller resin matrix makes it difficult to maintain the melt flow space, affecting molding quality and ultimately leading to a reduction in the mechanical properties of the composite material.

[0107] The above results demonstrate that the multi-component resin powder system of the present invention, while controlling the particle size of the resin matrix raw material to be larger than that of the first and second resin raw materials, still possesses a wide range of material selection and particle size combination space, which can be adjusted according to fiber type, resin system, and molding requirements. It is not limited to a single fixed resin combination, but rather, by adjusting the particle size, type, and ratio of the resin matrix, the first resin, and the second resin, comprehensive regulation of suspension stability, fiber coverage, prepreg quality, and the final composite material performance can be achieved.

[0108] Furthermore, as can be seen from Examples 1 and 5, Example 5, based on Example 1, simply uses silane-terminated polyetherimide resin and hydroxyl-terminated heteronaphthyl biphenyl polyaryletherketone resin to form a three-dimensional covalent network during hot pressing. The mechanical properties of the resulting composite material are further improved. This is likely because the three-dimensional covalent network enhances the interfacial bonding between the fiber and the resin matrix, improves the lateral support of the resin system for the fiber, and thus further improves the mechanical properties of the composite material. Moreover, the slightly lower porosity of Example 5 compared to Example 1 shows that even if the first and second resins undergo in-situ crosslinking during hot pressing, the suspension prepreg preparation process still maintains good process stability. The resulting prepreg still exhibits good suspension stability, uniform fiber surface coverage, sufficient fiber penetration, and a smooth and continuous appearance. This indicates that the introduction of reactive end-capping groups did not significantly disrupt the dispersion stability of the resin powder in the suspension or its deposition behavior on the fiber surface and inside the fiber bundle; on the contrary, it can undergo in-situ reaction near the fiber / resin interface during the subsequent hot pressing stage, forming a more stable interfacial connection structure, reducing defects and promoting further densification of the laminated structure.

[0109] Similar to Example 5, Example 9 used allyl-terminated PES and maleimide-terminated PEI. The resulting composite material achieved compressive strength, compressive modulus, interlaminar shear strength, and flexural strength of 1328 MPa, 86.4 GPa, 69.2 MPa, and 1510 MPa, respectively, with a porosity of 1.2%. This demonstrates that the core technical solution of this invention lies firstly in constructing a multi-particle-size thermoplastic resin powder system suitable for suspension prepreg preparation by combining different mesh sizes of the resin matrix, first resin, and second resin. This allows resin particles to adhere more uniformly to the fiber surface and penetrate into the fiber bundle, thereby improving the uniformity of the prepreg, the fiber wetting effect, and the densification of the laminated structure. Furthermore, when the first and second resins contain mutually reactive groups, an in-situ reaction can occur during the hot-pressing stage to form a three-dimensional covalent network, achieving a synergistic effect of resin powder particle size distribution and in-situ interfacial reinforcement, thereby further improving the interfacial bonding performance and mechanical properties of the fiber-reinforced thermoplastic resin material.

[0110] Therefore, through the above comparison, it can be seen that this invention, based on a multi-component thermoplastic resin system, improves the dispersion stability of the suspension system and the uniformity of resin deposition on the continuous fiber surface by controlling the mesh size of the resin particles of each component (the particle size of the resin matrix is ​​larger than that of the first and second resin particles). This makes the distribution of different functional components on the fiber surface and inside the fiber bundle more reasonable. During hot pressing, the difference in melt flowability is utilized so that the finer first and second resins fill and wet the surface of the fiber bundle or the tiny gaps between the bundles, while the coarser resin matrix forms a continuous resin phase and maintains the stability of the deposition layer and the melt flow space, thereby improving the uniformity of resin distribution and enhancing the mechanical properties of the composite material. Without relying on the chemical reaction between the first and second resins for enhancement, the distribution of resin particles on the fiber surface and inside the fiber bundle can be improved simply by combining the different mesh sizes of the resin matrix, the first resin, and the second resin. This improves the melt wetting and compaction effect of the resin during subsequent hot pressing, thereby reducing porosity and improving the interfacial bonding performance and mechanical properties of the composite material. It directly solves the problem of difficult-to-control resin distribution along the fiber surface, inside the fiber bundle and in the interlayer region in continuous reinforcement systems, and can take into account the interfacial bonding performance and mechanical properties of composite materials, especially the compressive properties.

[0111] In summary, the technical effects of this invention mainly stem from the following two aspects: (1) The combination of different mesh numbers is a fundamental factor in improving the quality of suspension prepreg preparation.

[0112] By designing the resin matrix, first resin, and second resin as thermoplastic resin powders of different mesh sizes, the dispersion state and deposition behavior of resin particles in the suspension can be improved. Finer first and second resin particles are more easily carried by the dispersion medium into the fine regions of the fiber surface and the interstitial spaces within the fiber bundles, which is beneficial for improving initial coverage and intra-bundle penetration. Coarser resin matrix particles provide the main resin source during subsequent hot pressing and connect and replenish the previously deposited areas through melt flow. The combination of coarse and fine particles helps reduce localized resin deficiency, localized accumulation, and porosity defects, thereby improving the uniformity of the prepreg, the densification of the laminated structure, and the mechanical properties of the composite material.

[0113] (2) The in-situ interaction between the first resin and the second resin is a further enhancing factor.

[0114] Building upon the improved resin particle distribution and fiber impregnation achieved through varying mesh counts, if the first and second resins undergo an in-situ reaction during the hot-pressing stage, a three-dimensional covalent network can be further formed between the fibers and the resin matrix. This network structure enhances the interfacial bonding strength between the fibers and the resin matrix, strengthens the constraint and support of the resin matrix on the fibers, and improves the mechanical properties of the composite material.

[0115] Therefore, this invention employs a combination of different mesh sizes of thermoplastic resin powders, combined with a suspension method for preparing prepregs and a segmented hot-pressing process, to enable resin particles to adhere more uniformly to the fiber surface and penetrate into the fiber bundle, thereby improving the resin's wetting effect on the fiber and the densification of the laminated structure. On this basis, through the in-situ mutual reaction between the first and second resins during the hot-pressing stage, a stable three-dimensional covalent network can be further constructed, thereby significantly improving the interfacial bonding performance and mechanical properties of fiber-reinforced thermoplastic resin materials.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fiber-reinforced thermoplastic resin material, characterized in that: The resin includes a thermoplastic resin uniformly distributed on fibers. The thermoplastic resin comprises a thermoplastic resin matrix, a first resin, and a second resin. The raw material types of the resin matrix are different from those of the first and second resins. The particle size of the raw material of the resin matrix is ​​larger than that of the raw material of the first and second resins.

2. The fiber-reinforced thermoplastic resin material according to claim 1, characterized in that: The raw material of the resin matrix has a mesh size of 200-500 mesh, and the raw material of the first resin and the second resin both have a mesh size of 400-1000 mesh. And / or, the fiber is one or more of chopped fibers, long fibers, continuous fibers, and fiber fabrics; And / or, the thermoplastic resin is one or more selected from polyarylether, polycarbonate, polyethersulfone, polysulfone, polyarylether, thermoplastic polyimide, polyamide-imide, polyphenylene ether, and polyetherimide; And / or, the first resin and the second resin are the same or different, preferably, the raw materials or particle sizes of the first resin and the second resin are different; And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-75 parts of fiber, 10-55 parts of resin matrix, 1-20 parts of first resin, 1-20 parts of second resin, totaling 100 parts.

3. The fiber-reinforced thermoplastic resin material according to claim 1, characterized in that: The first resin and the second resin can react with each other, and a three-dimensional covalent network is generated between the fiber and the resin matrix through the in-situ reaction of the first resin and the second resin. The number average molecular weight of the resin matrix is ​​greater than the number average molecular weight of the first resin and the second resin. Furthermore, the raw material of the first resin contains a first group, and the raw material of the second resin contains a second group. The first group and the second group can react with each other.

4. The fiber-reinforced thermoplastic resin material according to claim 3, characterized in that: The first group and the second group are each independently selected from alkynyl, azide, cyano, amino, isocyanate, hydroxyl, maleimide, thiol, allyl, acid anhydride, silyl, and furanyl; And / or, the number average molecular weight of both the first resin and the second resin is 3000~10000 g / mol; And / or, the number-average molecular weight of the resin matrix is ​​25,000 to 80,000 g / mol; And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-75 parts of fiber, 15-55 parts of resin matrix, 1-5 parts of first resin, 1-5 parts of second resin, totaling 100 parts.

5. The fiber-reinforced thermoplastic resin material according to claim 1, characterized in that: The first resin and the second resin may be made from the same or different types of raw materials, and they are independently dispersed between the fiber and the resin matrix. And / or, in the fiber-reinforced thermoplastic resin material, the raw materials, by mass parts, include: 40-70 parts of fiber, 10-50 parts of resin matrix, 5-20 parts of first resin, 5-20 parts of second resin, totaling 100 parts.

6. The fiber-reinforced thermoplastic resin material according to claim 1, characterized in that: The fiber is one or more of the following: carbon nanotube fiber, glass fiber, quartz fiber, carbon fiber, graphite fiber, alumina fiber, basalt fiber, aramid fiber, polyimide fiber, and poly(p-phenylenebenzoxazole) fiber. And / or, the thermoplastic resin is selected from one or a combination of at least two polymers having a structure as shown in formula (1), which is as follows: Where m≥0 and n≥0 are both integers; and m and n cannot be 0 at the same time. R1, R2, R3, and R4 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups. R1, R2, R3, and R4 may have the same or different structures. The alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure. The structure of —Ar1— is generated by the reaction of aromatic dihalogen monomers and is any combination of one or at least two of the following: ； ； ; ; R is selected from one or more of hydrogen, phenyl, alkyl or alkoxy, wherein the alkyl or alkoxy contains 1 to 20 carbon atoms and has a straight-chain or branched-chain structure; The structure of —Ar2— is generated by the reaction of bisphenol or bisphenol-like monomers, and is any combination of one or at least two of the following: 1, 2, 1, 3, or 1, 4 digits; , 2, 2' bits or 4, 4' bits; , 1, 4 bits, 1, 5 bits, 1, 6 bits, 2, 6 bits, or 2, 7 bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; , 3, 3' bits or 4, 4' bits; ； ； R5, R6, R7, and R8 are each independently selected from one or more of hydrogen, halogen substituents, phenyl, phenoxy, alkyl, or alkoxy groups, and R5, R6, R7, and R8 may have the same or different structures; the alkyl or alkoxy groups each contain at least one carbon atom and have a straight-chain or branched-chain structure.

7. A method for preparing a fiber-reinforced thermoplastic resin material as described in any one of claims 1 to 6, characterized in that: include: The first resin, the second resin, and the resin matrix are mixed to form a mixed resin powder with different mesh sizes. The powder and the dispersant are then added to a solvent and mixed to form a suspension. The suspension is mixed with the fiber to allow the mixed resin powder to adhere to the fiber surface, and then dried to obtain a prepreg. The prepreg is hot-pressed, the hot pressing comprising: first pre-pressing to degas at temperature T1, then heating to temperature T2 to compact and fully impregnate the fibers, thereby obtaining the fiber-reinforced thermoplastic resin material.

8. The preparation method according to claim 7, characterized in that: The dispersant includes one or more of anionic dispersants, cationic dispersants, and nonionic dispersants; And / or, the mass ratio of the dispersant to the mixed resin powder is 0.001~0.5:1, more preferably 0.001~0.3:1, and even more preferably 0.001~0.2:1; And / or, the mass ratio of the sum of the masses of the first resin and the second resin to the mass ratio of the mixed resin powder is 0.03 to 0.9:1; And / or, the solvent is one or more of water, ethanol, ethylene glycol, and isopropanol; And / or, the mass concentration of the mixed resin powder in the solvent is 5-30 wt%, preferably 10-25 wt%; And / or, during the pre-pressure exhaust, the temperature T1 is 260~360 ℃, the pressure is 0.5~15 MPa, and the holding time is 5~40 min; And / or, during the pressure test, the temperature T2 is 280~370 ℃, the pressure is 0.5~15 MPa, and the holding time is 5~80 min.

9. The preparation method according to claim 7, characterized in that: The first resin and the second resin can react with each other, forming a three-dimensional covalent network between the fiber and the resin matrix through an in-situ reaction of the first resin and the second resin. The number-average molecular weight of the resin matrix is ​​greater than that of the first resin and the second resin. The in-situ reaction temperature is T2. Further, the number-average molecular weights of the first resin and the second resin are both 3000~10000 g / mol, and the number-average molecular weight of the resin matrix is ​​25000~80000 g / mol. Furthermore, the mass ratio of the first resin to the second resin is 0.05 to 40:

1.

10. The fiber-reinforced thermoplastic resin material as described in any one of claims 1 to 6, or the fiber-reinforced thermoplastic resin material prepared by the preparation method as described in any one of claims 7 to 9, is used in the preparation of main load-bearing structural components in the fields of aerospace, rail transportation, or lightweight high-end equipment.

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