Composite material plate as well as preparation method and application thereof

Abstract

The invention provides a composite material plate as well as a preparation method and application thereof, and relates to the technical field of advanced composite materials. The composite material plate is mainly composed of a hybrid resin matrix and a reinforced fiber body, and the hybrid resin matrix is mainly prepared from organic silicon resin, phenolic resin, a ceramic precursor polymer, a functional auxiliary agent and the like; through the design of a ternary hybrid resin matrix and the mixing of reinforced fiber bodies, the unification of extreme high temperature resistance and high structural strength is realized, so that the prepared composite material plate has ultrahigh fire resistance (1500 DEG C oxygen-acetylene flame 30 min +), high structural strength (the tensile strength is greater than or equal to 320 MPa, and the bending resistance is greater than or equal to 280 MPa) and good process adaptability; meanwhile, the composite material plate prepared by the invention also has relatively low density, realizes the unification of light weight and high structural strength, can replace a metal fireproof plate, is suitable for light-weight fireproof structural members such as a battery upper cover and a fireproof plate, and has important application value.

Description

Technical Field

[0001] This invention belongs to the field of advanced composite materials technology, specifically relating to a composite material sheet, its preparation method, and its application. Background Technology

[0002] With the development of new energy vehicles, aerospace, and high-end equipment manufacturing, the demand for composite materials that combine lightweight, high structural strength, and extreme fire resistance is becoming increasingly urgent. In existing technologies, while phenolic resin-based composites possess some flame retardancy, their long-term service temperature is typically below 300℃, and they rapidly carbonize and fail under flame impact at 1500℃; epoxy resin-based materials are even less heat-resistant. Inorganic ceramic-based materials, although heat-resistant, are brittle and difficult to mold into complex components. Existing fireproof boards are mostly metal or inorganic sheets, with high density and poor processability.

[0003] Chinese patent CN110776487B discloses a quartz fiber reinforced phenolic resin composite material that can be used for short periods at 1000℃, but it is difficult to withstand the impact of an oxy-acetylene flame at 1500℃ for more than 30 minutes. CN112694771A proposes a ceramic precursor modified phenolic resin, which improves the residual carbon rate, but increases the brittleness of the matrix and reduces mechanical properties. CN113736072B uses carbon fiber reinforced silicone resin, which can withstand temperatures up to 1200℃, but its tensile strength is less than 300MPa, making it difficult to meet structural load-bearing requirements.

[0004] Therefore, developing a lightweight composite material that combines ultra-high fire resistance (1500℃ oxy-acetylene flame for 30 minutes+), high structural strength (tensile strength ≥320MPa, bending strength ≥280MPa) and good process adaptability is a current technical challenge.

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

[0006] The present invention aims to provide a composite material sheet, its preparation method and application, in order to improve the above-mentioned problems existing in the prior art.

[0007] The primary objective of this invention is to provide a composite material sheet, mainly composed of a hybrid resin matrix and reinforcing fibers; Wherein, with the total mass fraction of each raw material in the hybrid resin matrix being 100%, the hybrid resin matrix comprises the following raw materials by mass fraction: 20-40% silicone resin, 30-50% phenolic resin, 10-30% ceramic precursor polymer and 0-5% functional additives.

[0008] Furthermore, based on the above-mentioned technical solution of the present invention, the hybrid resin matrix is ​​a hybrid polymer formed by copolymerization of organosilicon resin, phenolic resin, ceramic precursor polymer and functional additives to form an interpenetrating / semi-interpenetrating network structure. And / or, the reinforcing fiber body comprises one or more of the following: a hybrid woven fabric or unidirectional fabric made of at least one of glass fiber, carbon fiber, high silica fiber, basalt fiber, quartz fiber or alumina fiber.

[0009] Furthermore, based on the above-mentioned technical solution of the present invention, the organosilicon resin includes organosilicon resin containing phenyl, vinyl, methyl or epoxy groups, or at least one of MQ silicone resin, preferably including methylphenyl silicone resin, phenyl vinyl silicone resin, methyl vinyl silicone resin, MQ silicone resin or epoxy modified silicone resin. And / or, the phenolic resin includes at least one of linear phenolic resin, allylated phenolic resin, boron-modified phenolic resin, or molybdenum-modified phenolic resin; And / or, the ceramic precursor polymer includes at least one of polycarbosilane, polysilazane, or polyborosilicate.

[0010] Furthermore, based on the above technical solution of the present invention, the mass ratio of the hybrid resin matrix to the reinforcing fiber is (30-45):(55-70). And / or, the functional additives include at least one of condensation accelerators, leveling agents, or coupling agents.

[0011] Furthermore, based on the above-mentioned technical solution of the present invention, the condensation accelerator includes at least one of dibutyltin dilaurate, stannous octoate, p-toluenesulfonic acid, triethylamine, or cobalt isooctanoate. And / or, the leveling agent includes at least one of BYK-306, BYK-333, TEGO Glide 410, or a fluorocarbon leveling agent; And / or, the coupling agent comprises at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, or an aluminate coupling agent.

[0012] Furthermore, based on the above technical solution of the present invention, the burn-through time of a 1mm thick composite material plate under an oxy-acetylene flame with a flame temperature of 1500±50℃ is ≥30min. And / or, the tensile strength of the composite material sheet is ≥320MPa, and the flexural strength is ≥280MPa; And / or, the density of the composite material sheet is ≤2.2 g / cm³.

[0013] The second objective of this invention is to provide a method for preparing the above-mentioned composite material sheet, comprising the following steps: (a) Preparation of hybrid resin solution: Mix organosilicon resin, phenolic resin, ceramic precursor polymer and optional functional additives in proportion, heat and stir to react, and form a homogeneous and stable hybrid resin solution. (b) Molding: When molding or autoclaving is used, the surface-treated reinforcing fiber is impregnated in a hybrid resin solution to obtain a prepreg. The prepreg is then laid up according to the design and placed in a mold for curing; or, When using RTM process for molding, the dry, surface-treated reinforcing fiber is directly laid into the mold, and then a hybrid resin solution is injected into the mold for curing and molding. (c) Demold the molding material obtained after step (b) and then perform gradient heating post-treatment to obtain composite material sheet.

[0014] Furthermore, based on the above technical solution of the present invention, in step (a), the reaction is carried out at 60-80°C with heating and stirring for 2-4 hours; And / or, in step (b), the surface treatment includes plasma treatment or sizing agent treatment.

[0015] Furthermore, based on the above technical solution of the present invention, in step (b), when the molding is carried out by compression molding, the pressure used is 5-15MPa, the temperature is 120-180℃, and the curing time is 30-90min. And / or, in step (b), when the molding is carried out using RTM molding, the injection pressure is 0.5-2MPa, the mold temperature is 70-90℃, the curing temperature is 120-180℃, and the curing time is 60-120min; And / or, in step (c), the gradient heating post-processing includes sequentially performing a first-stage heating process, a second-stage heating process, a third-stage heating process, and a fourth-stage heating process. The first stage of heating involves raising the temperature from room temperature to 75-85℃ and holding it at that temperature for 1-2 hours. The second stage of heating involves raising the temperature from the first stage to 110-130℃ and holding it at that temperature for 1-2 hours. The third stage of heating treatment involves raising the temperature from the second stage heating treatment temperature to 170-190℃ and holding it at that temperature for 1-2 hours. The fourth stage of heating treatment involves raising the temperature from the third stage of heating treatment to 240-260℃ and holding it at that temperature for 1-2 hours. The heating rate during each stage of the heating process is 1-2℃ / min.

[0016] Furthermore, based on the above technical solution of the present invention, in step (c), after the gradient heating post-treatment and before obtaining the composite material plate, a high-temperature pyrolysis treatment step is also included. Preferably, the high-temperature pyrolysis treatment is performed at a temperature of 800-1000℃, with a holding time of 1-2 hours, and in an inert atmosphere.

[0017] The third objective of this invention is to provide the application of the above-mentioned composite material sheet or the composite material sheet prepared by the above-mentioned preparation method in the fields of new energy vehicles, aerospace or shipbuilding industries.

[0018] Compared with the prior art, the technical solution of the present invention has at least the following technical effects: (1) This invention provides a composite material sheet, mainly composed of a hybrid resin matrix and reinforcing fibers. The hybrid resin matrix is ​​mainly made of silicone resin, phenolic resin, ceramic precursor polymer, functional additives, etc. By designing a ternary hybrid resin matrix and mixing it with reinforcing fibers, a balance between extreme high temperature resistance and high structural strength is achieved. This results in a composite material sheet with ultra-high fire resistance (1500℃ oxy-acetylene flame for 30 minutes+), high structural strength (tensile strength ≥320MPa, bending strength ≥280MPa), and good process adaptability. Furthermore, the composite material sheet obtained by this invention also has a low density, achieving a balance between lightweight (low density) and high structural strength. It can replace metal fireproof boards and is suitable for lightweight fireproof structural components such as battery covers and fireproof boards, possessing significant application value.

[0019] (2) The present invention also provides a method for preparing composite material plates. The raw materials used in the preparation method are environmentally friendly, low-smoke, and halogen-free, which meet the requirements of green manufacturing. At the same time, it has strong designability and is suitable for the integrated manufacturing of various complex structural components. Detailed Implementation

[0020] 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. Process parameters not specifically specified in the following embodiments are generally performed under conventional conditions.

[0021] 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.

[0022] According to a first aspect of the present invention, a composite material sheet is provided, which is mainly composed of a hybrid resin matrix and reinforcing fibers; The hybrid resin matrix is ​​mainly composed of organosilicon resin, phenolic resin, ceramic precursor polymer, and optional functional additives. Specifically, the hybrid resin matrix of the present invention is a ternary hybrid resin system formed by organosilicon resin, phenolic resin, and ceramic precursor polymer. The organosilicon resin mainly provides high flexibility and a Si-O framework; the phenolic resin mainly provides residual carbon content and flame retardancy; the ceramic precursor polymer (e.g., polycarbosilane, polysilazane, or polyborosilicate, etc.) can crosslink with the organosilicon resin and phenolic resin, and when subjected to high-temperature pyrolysis treatment, it can be transformed into a ceramic phase (e.g., SiC, Si3N4, or BN), filling microcracks in the matrix and forming an "organic-inorganic" gradient transition structure, effectively preventing flame and heat penetration into the interior, and significantly improving residual strength and oxidation resistance.

[0023] The hybrid resin matrix of this invention, through molecular-level design, achieves a synergistic enhancement of the flexibility of organosilicon, the high residual carbon flame retardancy of phenolic resin, and the high-temperature ceramicization capability of ceramic precursor polymers. This breaks through the temperature resistance limits of traditional resin matrices, achieving structural integrity under long-term flame impact at 1500°C. Furthermore, the hybrid resin matrix system exhibits good stability and a wide process window, making it suitable for large-scale production.

[0024] Functional additives mainly refer to additives that can improve the processing performance of composite material sheets or the performance of the final product, including but not limited to condensation accelerators, leveling agents, or coupling agents. "Optional functional additives" means that the functional additive can be added or not added according to actual needs. This functional additive is not essential, but its addition is preferred. Experiments show that composite material sheets can still be produced without adding functional additives, but their overall performance (especially interfacial bonding strength, resin wettability, and structural integrity after high-temperature pyrolysis) is somewhat reduced.

[0025] The main purpose of reinforcing the fiber body is to significantly improve the tensile and flexural strength of the composite material sheet while ensuring fire resistance, so as to meet the requirements of integrated structure and function.

[0026] The composite material sheet provided by this invention achieves a balance between extreme high-temperature resistance and high structural strength through a ternary hybrid resin matrix design and reinforcing fiber hybridization. This results in a composite material sheet with ultra-high fire resistance (1500℃ oxy-acetylene flame for 30+ minutes), high structural strength (tensile strength ≥320MPa, flexural strength ≥280MPa), and good process adaptability. Simultaneously, the composite material sheet produced by this invention also has low density, achieving a balance between lightweight (low density) and high structural strength. It can replace metal fireproof boards and is suitable for lightweight fireproof structural components such as battery covers and fireproof panels, demonstrating significant application value.

[0027] The amount of each raw material used in the hybrid resin matrix is ​​further limited. As an optional embodiment of the technical solution of the present invention, with the total mass fraction of each raw material used in the hybrid resin matrix being 100%, the hybrid resin matrix includes the following raw materials in the following mass fractions: 20-40% silicone resin, 30-50% phenolic resin, 10-30% ceramic precursor polymer, and 0-5% functional additives.

[0028] In this invention, the mass fraction of silicone resin is limited to 20-40%. If the mass fraction of silicone resin is too high (e.g., above 40%), it easily leads to excessively high cross-linking density in the resin matrix, increasing brittleness. Simultaneously, due to excessive softening or volatilization of the silicone resin at high temperatures, the surface of the composite material sheet easily melts and flows under flame impact at 1500°C, reducing structural integrity, accelerating back-side temperature rise, and potentially lowering residual char rate, thus weakening flame retardant performance. If the mass fraction of silicone resin is too low (e.g., below 20%), the hybrid resin matrix easily lacks sufficient Si-O flexible network, making it difficult to buffer thermal stress under high-temperature thermal shock, leading to rapid propagation of microcracks within the sheet. Simultaneously, insufficient high-temperature oxidation resistance and thermal shock stability result in cracking or peeling, failing to maintain structural protection for more than 30 minutes. Therefore, typical but non-limiting mass fractions of silicone resin are 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, or 40%, and any range between any two points.

[0029] There are also certain limitations on the amount of phenolic resin used. If the mass fraction of phenolic resin is too high (e.g., above 50%), it can easily lead to a significant increase in the brittleness of the resin matrix. Because the carbon layer formed after the pyrolysis of phenolic resin lacks effective toughening and bonding from the organosilicon resin and ceramic phase, the carbon layer is prone to peeling off under the impact of a 1500℃ flame, resulting in a sharp drop in the thermal insulation performance of the board and an accelerated temperature rise on the back side. If the mass fraction of phenolic resin is too low (e.g., below 30%), it can easily lead to the inability to form a continuous and dense carbon skeleton structure after high-temperature pyrolysis, resulting in insufficient residual carbon and weakening the thermal barrier effect of the material. At the same time, the flame retardant performance decreases, the risk of flame penetration increases, and it is difficult to meet the core indicator of "withstanding a 1500℃ flame for more than 30 minutes". In addition, the overall thermal stability of the system is weakened, and it is prone to rapid ablation in a high-temperature oxidizing environment. Therefore, typical but non-limiting mass fractions of phenolic resin are 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, or 50%, as well as any range between any two points.

[0030] Typical, but not limiting, mass fractions of ceramic precursor polymers are 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, or 30%. If the mass fraction of the ceramic precursor polymer is too high (e.g., above 30%), it can easily lead to significant internal stress during curing and subsequent pyrolysis due to the large amount of pyrolysis shrinkage of the ceramic precursor, inducing microcracks or even macroscopic cracking. Furthermore, excessive ceramic phase results in high brittleness and a lack of effective transition at the organic / inorganic interface, which reduces the overall toughness and thermal shock resistance of the composite material. If the mass fraction of the ceramic precursor polymer is too low (e.g., below 10%), it can easily prevent the formation of a sufficiently continuous ceramic network at high temperatures (>1200℃), causing the material to soften or ablate rapidly in a 1500℃ flame. Insufficient oxidation resistance leads to rapid consumption of the carbon skeleton in a high-temperature oxidizing atmosphere, resulting in the failure of the thermal insulation barrier. Low residual strength after pyrolysis makes it difficult to maintain structural integrity, leading to a shortened piercing time and an inability to fully utilize the synergistic effect of the "organic-inorganic hybrid," ultimately failing to meet the overall refractory and mechanical properties required by this invention.

[0031] Typical, but not limiting, mass fractions of functional additives are 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, and the numerical range between any two points.

[0032] By further limiting the amount of each raw material in the hybrid resin matrix, the performance of the hybrid resin matrix can be made to reach a better level.

[0033] As an optional embodiment of the technical solution of the present invention, the hybrid resin matrix is ​​a hybrid polymer formed by copolymerization of organosilicon resin, phenolic resin, ceramic precursor polymer and functional additives to form an interpenetrating / semi-interpenetrating network structure.

[0034] This interpenetrating / semi-interpenetrating network structure can effectively suppress macroscopic phase separation of components during curing or high-temperature treatment, achieve uniform mixing at the molecular scale, realize gradient transition and synergistic improvement of mechanical and thermal properties, significantly increase the interfacial contact area and chemical bonding points between different components, effectively transfer loads and hinder crack propagation, thereby improving the structural strength of the material while maintaining high heat resistance.

[0035] As an optional embodiment of the technical solution of the present invention, the organosilicon resin includes at least one of organosilicon resins containing phenyl, vinyl, methyl or epoxy groups, or MQ silicone resin, preferably including at least one of methylphenyl silicone resin, phenyl vinyl silicone resin, methyl vinyl silicone resin, MQ silicone resin or epoxy modified silicone resin.

[0036] As an optional embodiment of the technical solution of the present invention, the phenolic resin includes at least one of linear phenolic resin, allylated phenolic resin, boron-modified phenolic resin, or molybdenum-modified phenolic resin.

[0037] As an optional embodiment of the technical solution of the present invention, the ceramic precursor polymer includes at least one of polycarbosilane, polysilazane, or polyborosilazane. Such ceramic precursor polymers can be pyrolyzed at high temperatures to form SiO2, SiC, Si3N4, or BN ceramic phases, significantly improving residual strength and oxidation resistance.

[0038] By further defining the specific types of silicone resin, phenolic resin, and ceramic precursor polymer, the overall performance of the composite material sheet provided by this invention is significantly optimized, specifically in terms of synergistic improvement in fire resistance, mechanical strength, process adaptability, and lightweight.

[0039] As an optional embodiment of the technical solution of the present invention, the reinforcing fiber body includes one or more of the following: a mixed woven fabric or unidirectional fabric made of at least one of glass fiber, carbon fiber, high silica fiber, basalt fiber, quartz fiber or alumina fiber, preferably at least two of the following: for example, the reinforcing fiber body includes quartz fiber woven fabric and carbon fiber woven fabric.

[0040] As an optional embodiment of the technical solution of the present invention, high-temperature resistant fibers such as quartz fiber, high-silica fiber, and alumina fiber are mixed with carbon fiber. By utilizing the complementary thermal stability and mechanical properties of different fibers, the tensile and flexural strength of the composite material is significantly improved while ensuring fire resistance, thus meeting the requirements of integrated structure and function.

[0041] As an optional embodiment of the technical solution of the present invention, the reinforcing fiber body adopts a mixture of quartz fiber and high silica fiber to balance temperature resistance and cost.

[0042] As an optional embodiment of the technical solution of the present invention, the functional additives include at least one of condensation accelerators, leveling agents, or coupling agents.

[0043] Condensation accelerators are used to accelerate the self-condensation reaction of silicone resins during heat treatment. They do not participate in the formation of the main crosslinking network of phenolic resins or ceramic precursors and are optional components. The purpose of this invention can be achieved without their addition, and the overall system still does not require an external curing agent. As a preferred embodiment of the technical solution of this invention, the condensation accelerator includes at least one of dibutyltin dilaurate (DBTDL), stannous octoate, p-toluenesulfonic acid, triethylamine, or cobalt isooctanoate. And / or, the leveling agent includes at least one of BYK-306, BYK-333, TEGO Glide 410 or fluorocarbon leveling agents; And / or, the coupling agent includes at least one of γ-aminopropyltriethoxysilane (KH-550), γ-glycidoxypropyltrimethoxysilane (KH-560), γ-methacryloyloxypropyltrimethoxysilane (KH-570), γ-(2,3-epoxypropoxy)propyltrimethoxysilane (A-187) or an aluminate coupling agent.

[0044] The specific types of condensation accelerators, leveling agents, and coupling agents mentioned above are all commercially available products and can be purchased.

[0045] As an optional embodiment of the technical solution of the present invention, the mass ratio of the hybrid resin matrix to the reinforcing fiber is (30–45):(55–70), and typical but non-limiting mass ratios are 30:70, 35:65, 40:60 or 45:55, etc.

[0046] As an optional embodiment of the technical solution of the present invention, the time for a 1mm thick composite material plate to burn through a flame at an oxy-acetylene flame with a flame temperature of 1500±50℃ is ≥30min. And / or, the tensile strength of the composite material sheet is ≥320MPa, and the flexural strength is ≥280MPa; And / or, the density of the composite material sheet is ≤2.2 g / cm³.

[0047] According to a second aspect of the present invention, a method for preparing the above-mentioned composite material sheet is also provided, comprising the following steps: (a) Mix organosilicon resin, phenolic resin, ceramic precursor polymer and functional additives in proportion, heat and stir to react, and the ceramic precursor polymer dissolves in liquid organosilicon resin or phenolic resin under heating conditions to form a homogeneous and stable hybrid resin (i.e. hybrid resin solution) in solution form. (b) Molding: When molding or autoclaving is used, the surface-treated reinforcing fiber is impregnated in a hybrid resin solution to obtain a prepreg. The prepreg is then laid up according to the design and placed in a mold for curing; or, When using RTM process for molding, the dry, surface-treated reinforcing fiber is directly laid into the mold, and then cured by injecting a hybrid resin solution into the mold. (c) Demold the molding material obtained after step (b) and then perform gradient heating post-treatment to obtain composite material sheet.

[0048] In step (a) of this invention, no solvent needs to be added during the heating and stirring reaction. Furthermore, partial Si–O–C condensation occurs during stirring, forming a pre-crosslinked hybrid system. The resulting hybrid resin solution system has moderate viscosity and a long pot life, making it compatible with various mainstream composite material molding processes such as compression molding, RTM, autoclave, and HP-RTM. It facilitates the low-cost, high-efficiency manufacturing of irregularly shaped components and possesses industrialization potential.

[0049] The method for preparing composite material sheets of the present invention uses environmentally friendly, low-smoke, and halogen-free raw materials, which meet the requirements of green manufacturing; at the same time, it has strong design flexibility and is suitable for the integrated manufacturing of various complex structural components.

[0050] As an optional embodiment of the technical solution of the present invention, in step (a), the reaction is stirred at 60-80℃ (e.g., 60℃, 65℃, 70℃, 75℃ or 80℃, etc.) for 2-4 hours (e.g., 2 hours, 3 hours or 4 hours, etc.).

[0051] As an optional embodiment of the technical solution of the present invention, in step (b), the surface treatment includes plasma treatment or sizing agent treatment; Plasma treatment mainly involves placing the reinforced fiber in a low-pressure plasma cleaner, introducing argon gas (flow rate, for example, 20-50 sccm), using a power of 80-150 W (e.g., 80W, 100W, 120W, or 150W), and processing for 2-5 min (e.g., 2 min, 4 min, or 5 min), thereby increasing the surface energy to ≥60 mN / m.

[0052] The sizing treatment mainly involves immersing the reinforcing fiber in a water-alcohol mixture containing 0.5-2.0 wt% (e.g., 0.5 wt%, 1.0 wt%, 1.5 wt%, or 2.0 wt%) of silane coupling agent (such as KH-550, KH-560, or A-187, etc.) (water:alcohol = 2:8 to 4:6, v / v), soaking at room temperature for 5-15 min (e.g., 5 min, 8 min, 10 min, 12 min, or 15 min, etc.), and drying at 70-90℃ (e.g., 70℃, 75℃, 80℃, 85℃, or 90℃) for 1-3 h (e.g., 1 h, 2 h, or 3 h, etc.).

[0053] By further defining the specific surface treatment methods and process parameters, the physicochemical properties of the reinforcing fiber surface can be improved or a dense silane coupling agent film can be formed on the reinforcing fiber surface, significantly improving its interfacial bonding strength and wettability with the hybrid resin matrix, thereby enhancing the mechanical properties and high-temperature service reliability of the composite material.

[0054] As an optional embodiment of the technical solution of the present invention, in step (b), when molding is carried out by compression molding or autoclave molding, the pressure used is 5-15MPa (e.g., 5MPa, 10MPa, 12MPa or 15MPa, etc.), the temperature is 120-180℃ (e.g., 120℃, 130℃, 140℃, 150℃, 160℃, 170℃ or 180℃, etc.), and the curing time is 30-90min (e.g., 30min, 45min, 60min, 80min or 90min, etc.).

[0055] As an optional embodiment of the technical solution of the present invention, in step (b), when RTM molding is used, the injection pressure is 0.5-2MPa (e.g., 0.5MPa, 1.0MPa, 1.5MPa or 2.0MPa, etc.), the mold temperature is 70-90℃ (e.g., 70℃, 75℃, 80℃, 85℃ or 90℃, etc., the mold is preheated in advance to improve fluidity), the curing temperature is 120-180℃ (e.g., 120℃, 130℃, 140℃, 150℃, 160℃, 170℃ or 180℃, etc.), and the curing time is 60-120min (e.g., 60min, 75min, 90min, 100min or 120min, etc.).

[0056] A gradient heating post-treatment with specific stages can ensure sufficient cross-linking of the resin. As an optional embodiment of the technical solution of the present invention, in step (d), the gradient heating post-treatment includes sequentially performing a first-stage heating treatment, a second-stage heating treatment, a third-stage heating treatment, and a fourth-stage heating treatment.

[0057] Specifically, the first stage of heating involves raising the temperature from room temperature to 75-85℃ (e.g., 75℃, 78℃, 80℃, 82℃, or 85℃) and holding it at that temperature for 1-2 hours (e.g., 1 hour, 1.5 hours, or 2 hours). The second stage of heating involves raising the temperature from the first stage (75-85℃) to 110-130℃ (e.g., 110℃, 115℃, 120℃, 125℃, or 130℃) and holding it at that temperature for 1-2 hours (e.g., 1 hour, 1.5 hours, or 2 hours). The third stage of heating involves raising the temperature from the second stage (i.e., 110-130℃) to 170-190℃ (e.g., 170℃, 175℃, 180℃, 185℃, or 190℃, etc.) and holding it at that temperature for 1-2 hours (e.g., 1 hour, 1.5 hours, or 2 hours, etc.). The fourth stage of heating involves raising the temperature from the third stage (i.e., 170-190℃) to 240-260℃ (e.g., 240℃, 245℃, 250℃, 255℃, or 260℃, etc.) and holding it at that temperature for 1-2 hours (e.g., 1 hour, 1.5 hours, or 2 hours, etc.). The heating rate during each stage of the heating process is 1-2℃ / min, for example, 1℃ / min, 1.5℃ / min or 2℃ / min.

[0058] As an optional embodiment of the technical solution of the present invention, step (d) includes a high-temperature pyrolysis treatment step after the gradient heating post-treatment and before obtaining the composite material plate. The high-temperature pyrolysis treatment can promote the transformation of the ceramic precursor polymer into the ceramic phase, further improving the high-temperature stability of the plate.

[0059] Preferably, the temperature used for high-temperature pyrolysis is 800-1000℃, such as 800℃, 820℃, 850℃, 880℃, 900℃, 920℃, 950℃, 980℃ or 1000℃, etc., the holding time is 1-2h, such as 1h, 1.5h or 2h, etc., and the atmosphere is an inert atmosphere, such as high-purity nitrogen or argon atmosphere.

[0060] It should be noted that the preparation of the composite material sheet of the present invention does not depend on the addition of an external curing agent. The crosslinking and densification mechanism of the hybrid resin system of the present invention depends on the type of raw materials selected and the preparation process, as follows: (1) Crosslinking mechanism: If the phenolic resin is an allylated phenolic resin, its molecular structure contains active allyl groups (–CH2–CH=CH2), which can undergo free radical cross-linking reaction during heat treatment at 150–250℃; If the phenolic resin is a linear phenolic resin, an allylated phenolic resin, a boron-modified phenolic resin, or a molybdenum-modified phenolic resin, it can condense and crosslink with Si-OH in the organosilicon resin during heat treatment at 150–260℃. Organosilicon resins contain Si–OH, which can undergo self-condensation or co-condensation; The ceramic precursor polymer participates in crosslinking and does not transform into a ceramic phase during heat treatment, but it will transform into a high-density ceramic phase when subjected to high-temperature pyrolysis treatment.

[0061] (2) Densification mechanism: Molding processes (such as RTM / molding / autoclave) achieve initial densification; Gradient heating post-processing can achieve further densification; High-temperature pyrolysis (optional) enables ceramic transformation and ultra-densification.

[0062] Therefore, regardless of the type of phenolic resin combined with organosilicon resin or ceramic precursor polymer as defined in this invention, the hybrid resin system of this invention can form a stable cross-linked network within 260°C; and high-temperature pyrolysis treatment is a preferred step for improving performance in extreme environments. Thus, this invention achieves densification (or hyperdensification) through a thermally driven stepwise self-crosslinking and high-temperature pyrolysis conversion mechanism, which is fundamentally different from conventional systems that rely on external curing agents such as amines, platinum, or free radical initiators.

[0063] According to a third aspect of the present invention, the application of the above-described composite material sheet or the composite material sheet prepared by the above-described preparation method in the fields of new energy vehicles, aerospace or high-end equipment manufacturing (e.g., ships) is also provided.

[0064] The composite material sheet provided by this invention combines resistance to extreme high-temperature flames, high structural strength, and lightweight characteristics, making it promising for applications in new energy vehicles, aerospace, or high-end equipment manufacturing (such as ships). For example, it can precisely target the market for high-end fire-resistant structural components such as battery pack covers for new energy vehicles, meeting the protection requirements for extreme operating conditions such as battery thermal runaway and filling a technological gap.

[0065] The present invention will now be described in further detail with reference to specific embodiments and comparative examples.

[0066] Example 1 This embodiment provides a composite material sheet, which is mainly made of a hybrid resin matrix and reinforcing fibers.

[0067] The hybrid resin matrix comprises the following raw materials in the indicated mass fractions: 30% silicone resin, 45% phenolic resin, 20% ceramic precursor polymer, and 5% functional additives; The silicone resin is methylphenyl silicone resin, purchased from Wacker Chemie, brand name POWERSIL® Resin700; the phenolic resin is industrial-grade allylated phenolic resin, purchased from Beijing Jinjiete New Material Technology Co., Ltd., with an allyl substitution degree of 0.4-0.7 mol / per phenolic unit, a softening point of 75-90°C, and a free phenol content of less than 2.0 wt%; the ceramic precursor polymer is industrial-grade polycarbosilane, purchased from Ningbo Zhongxing New Material Technology Co., Ltd., which is liquid polycarbosilane (LiquidPCS), with a number-average molecular weight (Mn), a viscosity of 500-2000 mPa·s at 25°C, and a Si / C atomic ratio of 1.0-1.2; the functional additives include the condensation accelerator dibutyltin dilaurate and the coupling agent KH550, with a mass ratio of condensation accelerator to coupling agent of 2:3.

[0068] The reinforcing fiber body includes quartz fiber cloth and carbon fiber cloth. The quartz fiber cloth is plain weave (area density 200 g / m²), and the carbon fiber cloth is T700-12K plain weave (area density 200 g / m²).

[0069] The method for preparing the composite material sheet in this embodiment includes the following steps: (a) Preparation of hybrid solution: Mix organosilicon resin, phenolic resin, ceramic precursor polymer, coupling agent KH-550 and condensation accelerator in proportion, and stir at 80°C for 3 hours to obtain hybrid resin solution.

[0070] (b) The reinforcing fiber body is surface treated (sizing agent treatment), specifically: the quartz fiber cloth and carbon fiber cloth are respectively immersed in an ethanol aqueous solution containing 1.5 wt% KH-550 (water:ethanol volume ratio 7:3), soaked at room temperature for 10 min, and dried at 80℃ for 2 h.

[0071] Four layers of surface-treated quartz fiber cloth and four layers of carbon fiber cloth are stacked alternately, for a total of eight layers. The mixture is then impregnated with a hybrid resin solution. The mass ratio of the hybrid resin solution to the reinforcing fibers (quartz fiber cloth and carbon fiber cloth) is 40:60. The impregnation temperature is 70°C and the impregnation time is 2 hours to obtain a prepreg.

[0072] (c) The prepreg is molded at 150°C and 10MPa pressure for 60 minutes.

[0073] (d) Demold the molded material and then perform gradient heating post-treatment as required below: First stage of heating treatment: The temperature is increased from room temperature to 80℃ at a heating rate of 2℃ / min, and held at that temperature for 1.5 hours; Second stage of heating treatment: Increase the temperature to 120℃ at a rate of 2℃ / min and hold for 1.5 hours; The third stage of heating treatment: then the temperature is increased to 180℃ at a rate of 1.5℃ / min and held for 1.5 hours; Fourth stage of heating treatment: Finally, the temperature is increased to 250℃ at a rate of 1℃ / min and held for 2 hours; The composite material sheet is obtained by naturally cooling to room temperature.

[0074] Example 2 This embodiment provides a composite material plate, except that the mass fraction of the organosilicon resin in the hybrid resin matrix of Example 1 is adjusted from 30% to 35%, the mass fraction of the phenolic resin is adjusted from 45% to 50%, and the mass fraction of the ceramic precursor polymer is adjusted from 20% to 10%. The other raw material types, amounts, and preparation methods of the composite material plate are the same as in Example 1.

[0075] Example 3 This embodiment provides a composite material plate, except that the mass fraction of the organosilicon resin in the hybrid resin matrix of Example 1 is adjusted from 30% to 20%, and the mass fraction of the ceramic precursor polymer is adjusted from 20% to 30%. The other raw material types, amounts, and preparation methods of the composite material plate are the same as in Example 1.

[0076] Example 4 This embodiment provides a composite material board. Except that the reinforcing fiber in Embodiment 1 is made of only quartz fiber cloth, the other raw material types, amounts, and preparation methods of the composite material board are the same as in Embodiment 1.

[0077] Example 5 This embodiment provides a composite material sheet, and the types and amounts of raw materials used are the same as in Embodiment 1.

[0078] The preparation method of the composite material plate in this embodiment is the same as that in Example 1, except that after the gradient heating post-treatment in step (d) of Example 1, a high-temperature pyrolysis treatment is performed. The temperature used for the high-temperature pyrolysis treatment is 900°C, the holding time is 1.5h, and the atmosphere is a high-purity nitrogen inert atmosphere. Then, the plate is cooled to room temperature in the furnace to obtain the composite material plate.

[0079] Example 6 This embodiment provides a composite material sheet, which is mainly made of a hybrid resin matrix and reinforcing fibers.

[0080] The hybrid resin matrix comprises the following raw materials in the indicated mass fractions: 40% silicone resin, 30% phenolic resin, 25% ceramic precursor polymer, and 5% functional additives; The silicone resin is methylphenyl silicone resin, purchased from Wacker Chemie, brand name POWERSIL® Resin 700; the phenolic resin is industrial-grade allylated phenolic resin, purchased from Beijing Jinjiete New Material Technology Co., Ltd., with an allyl substitution degree of 0.4-0.7 mol / per phenolic unit, a softening point of 75–90°C, and a free phenol content of less than 2.0 wt%; the ceramic precursor polymer is polyborosilazane (PBSZ), purchased from Anhui Aiyota Silicone Oil Co., Ltd., which is a colorless to pale yellow transparent liquid with a viscosity of 800-1500 mPa·s at 25°C, a number-average molecular weight (Mn), and a B / Si atomic ratio of 0.8-1.2; the functional additives include a condensation accelerator (dibutyltin dilaurate) and a coupling agent KH550, with a mass ratio of 2:3.

[0081] The reinforcing fiber body includes high silica fiber cloth and basalt fiber cloth. The high silica fiber cloth is plain weave (area density 200 g / m²) and the basalt fiber cloth is plain weave (area density 240 g / m²).

[0082] The method for preparing the composite material sheet in this embodiment includes the following steps: (a) Preparation of hybrid resin solution: Mix organosilicon resin, phenolic resin, allylated phenolic resin, coupling agent KH-550 and condensation accelerator in proportion, and stir at 65°C for 4 hours to obtain hybrid resin solution.

[0083] (b) The reinforcing fiber body is subjected to surface treatment (plasma treatment), specifically: the high silica fiber cloth and basalt fiber are arranged in a low-pressure plasma cleaner, argon gas is introduced, the argon gas flow rate is 30 sccm, the power is 100 W, the treatment time is 3 min, and the surface energy is increased to ≥60 mN / m.

[0084] Plasma-treated high-silica fiber cloth and basalt fiber cloth were stacked alternately in 4 layers each, for a total of 8 layers. The mixture was then impregnated with a hybrid resin solution. The mass ratio of the hybrid resin solution to the reinforcing fibers (quartz fiber cloth and carbon fiber cloth) was 30:70. The impregnation temperature was 70℃ and the impregnation time was 2 hours to obtain the prepreg.

[0085] (c) The prepreg is molded at 150°C and 10MPa pressure for 60 minutes.

[0086] (d) Demold the molded material and then perform gradient heating post-treatment as required below: The temperature was increased from room temperature to 80℃ at a rate of 2℃ / min and held for 1.5 hours; then increased to 120℃ at a rate of 2℃ / min and held for 1.5 hours; then increased to 180℃ at a rate of 1.5℃ / min and held for 1.5 hours; finally increased to 250℃ at a rate of 1℃ / min and held for 2 hours; and then naturally cooled to room temperature to obtain the composite material board.

[0087] Example 7 This embodiment provides a composite material sheet, and the types and amounts of raw materials used are the same as in Embodiment 1.

[0088] The method for preparing the composite material sheet in this embodiment, except that after the gradient heating post-treatment in step (d) of Example 6, a high-temperature pyrolysis treatment is performed. The temperature used for the high-temperature pyrolysis treatment is 900°C, the holding time is 1.5h, and the atmosphere is a high-purity nitrogen inert atmosphere. Then, the sheet is cooled to room temperature in the furnace to obtain the composite material sheet.

[0089] Example 8 This embodiment provides a composite material sheet, and the types and amounts of raw materials used are the same as in Embodiment 1.

[0090] The method for preparing the composite material sheet in this embodiment differs from that in steps (b) and (c) of Example 1, which uses the RTM process. The specific details are as follows: Four layers each of surface-treated quartz fiber cloth and carbon fiber cloth were laid dry in an 80℃ mold. After the mold was closed, a hybrid resin solution was injected. The mass ratio of the hybrid resin solution to the reinforcing fiber body (quartz fiber cloth and carbon fiber cloth) was 40:60. The injection pressure was 0.5 MPa, and the curing was carried out at 150℃ for 2 hours. The remaining steps are the same as in Example 1, to obtain the composite material sheet.

[0091] Example 9 This embodiment provides a composite material sheet, and the types and amounts of raw materials used are the same as in Embodiment 8.

[0092] The preparation method of the composite material plate in this embodiment is the same as that in Example 8, except that after the gradient heating post-treatment in step (d) of Example 8, a high-temperature pyrolysis treatment is performed. The temperature used for the high-temperature pyrolysis treatment is 900°C, the holding time is 1.5h, the atmosphere is a high-purity nitrogen atmosphere, and then the furnace is cooled to room temperature to obtain the composite material plate.

[0093] Comparative Example 1 This comparative example provides a composite material sheet, except that the mass fraction of the organosilicon resin in the hybrid resin matrix of Example 1 is adjusted from 30% to 50%, the mass fraction of the phenolic resin is adjusted from 45% to 10%, and the mass fraction of the ceramic precursor polymer is adjusted from 20% to 35%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0094] Comparative Example 2 This comparative example provides a composite material sheet, except that the mass fraction of the organosilicon resin in the hybrid resin matrix of Example 1 is adjusted from 30% to 15%, the mass fraction of the phenolic resin is adjusted from 45% to 75%, and the mass fraction of the ceramic precursor polymer is adjusted from 20% to 5%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0095] Comparative Example 3 This comparative example provides a composite material sheet, except that no silicone resin was added to the hybrid resin matrix in Example 1, and the mass fraction of phenolic resin was adjusted from 45% to 65.8%, and the mass fraction of ceramic precursor polymer was adjusted from 20% to 29.2%, so that the mass ratio of phenolic resin to ceramic precursor polymer remained the same as in Example 1, and the sum of their mass fractions reached 95%. The other raw material types, amounts, and preparation methods of the composite material sheet were the same as in Example 1.

[0096] Comparative Example 4 This comparative example provides a composite material sheet, except that no phenolic resin was added to the hybrid resin matrix of Example 1, and the mass fraction of the silicone resin was adjusted from 30% to 57%, and the mass fraction of the ceramic precursor polymer was adjusted from 20% to 38%, so that the mass ratio of silicone resin to ceramic precursor polymer is consistent with that of Example 1, and the sum of their mass fractions reaches 95%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as those of Example 1.

[0097] Comparative Example 5 This comparative example provides a composite material sheet, except that no ceramic precursor polymer was added to the hybrid resin matrix in Example 1, the mass fraction of silicone resin was adjusted from 30% to 38%, and the mass fraction of phenolic resin was adjusted from 45% to 57%, so that the mass ratio of silicone resin to phenolic resin is consistent with that in Example 1, and the sum of their mass fractions reaches 95%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0098] Comparative Example 6 This comparative example provides a composite material sheet, except that no silicone resin and ceramic precursor polymer were added to the hybrid resin matrix in Example 1, and the mass fraction of phenolic resin was adjusted from 45% to 95%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0099] Comparative Example 7 This comparative example provides a composite material sheet, except that no phenolic resin and ceramic precursor polymer were added to the hybrid resin matrix in Example 1, and the mass fraction of the organosilicon resin was adjusted from 30% to 95%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0100] Comparative Example 8 This comparative example provides a composite material sheet, except that no silicone resin and phenolic resin were added to the hybrid resin matrix in Example 1, and the mass fraction of the ceramic precursor polymer was adjusted from 20% to 95%. The other raw material types, amounts, and preparation methods of the composite material sheet are the same as in Example 1.

[0101] Comparative Example 9 This comparative example provides a composite material sheet, using the same types and amounts of raw materials as in Example 1.

[0102] The preparation method of this comparative example composite material sheet differs from that in step (d) of Example 1, which does not employ a gradient heating post-treatment. Instead, the temperature is directly raised to 250°C at a heating rate of 120°C / h and held at this temperature for 2 hours to obtain the composite material sheet.

[0103] Comparative Example 10 This comparative example provides a composite material sheet, using the same types and amounts of raw materials as in Example 1.

[0104] The preparation method of this comparative example composite material sheet, except for step (d) which involves subjecting the molded material to gradient heating post-treatment (curing) according to the following requirements (two-stage heating treatment), is as follows: First stage of heating treatment: The temperature is increased from room temperature to 120℃ at a heating rate of 2℃ / min, and held at that temperature for 1.5 hours; Second stage of heating treatment: Then the temperature is increased to 250℃ at 1℃ / min and held for 2 hours; After naturally cooling to room temperature, composite material sheets are obtained. The remaining steps are the same as in Example 1.

[0105] Comparative Example 11 This comparative example provides a composite material sheet, using the same types and amounts of raw materials as in Example 1.

[0106] The preparation method of this comparative example composite material sheet, except for step (d) where the molded material is demolded, involves gradient heating post-treatment (curing) according to the following requirements (three-stage heating treatment), as detailed below: First stage of heating treatment: The temperature is increased from room temperature to 80℃ at a heating rate of 2℃ / min, and held at that temperature for 1.5 hours; Second stage of heating treatment: Increase the temperature to 120℃ at a rate of 2℃ / min and hold for 1.5 hours; The third stage of heating treatment: finally, the temperature is increased to 250℃ at a rate of 1℃ / min and held for 2 hours; After naturally cooling to room temperature, composite material sheets are obtained. The remaining steps are the same as in Example 1.

[0107] To illustrate the technical effects of the various embodiments and comparative examples, the following experimental examples are provided.

[0108] Experimental Example 1 The properties of the composite material sheets prepared in each embodiment and comparative example were tested. The oxy-acetylene flame test method was performed according to the test conditions of GJB323A-96. Under a flame temperature of 1500±50℃ at the hot-face contact area, an ablation test was conducted on 1mm thick sheet samples, with the time to burn through the hole as the main evaluation criterion. Tensile strength was tested according to GB / T 1447-2005, flexural strength according to GB / T 1449-2005, and density according to GB / T 1033.1-2008. Specific test results are shown in Table 1.

[0109] Table 1

[0110] As can be seen from the data in Table 1, the composite material plates prepared by the various embodiments of the present invention have excellent ultra-high fire resistance and mechanical properties, and also have low density.

[0111] Specifically, comparing Examples 1 and 5, as well as Examples 6 and 7, it can be seen that after the gradient heating post-treatment in step (d) of the preparation of composite material plates, the high-temperature pyrolysis treatment can further improve the fire resistance and mechanical strength of the plates under an oxy-acetylene flame at 1500℃.

[0112] By comparing Example 4 with Example 1, it can be found that when only one type of fiber is used as the reinforcing fiber, its fire resistance and mechanical properties will decrease significantly. This also shows that using different fiber materials as reinforcing fibers can help to further improve the fire resistance and mechanical properties of composite material sheets.

[0113] Comparative Examples 1-9 are comparative experiments of Example 1. Among them, Comparative Examples 1 and 2 mainly examine the effect of the amount of each raw material on the performance of the board. As can be seen from the data in Table 1, when the amount of each raw material exceeds the numerical range defined by the present invention, the fire resistance and mechanical strength of the prepared composite material board under an oxy-acetylene flame at 1500℃ decrease to a certain extent.

[0114] The hybrid resin matrices in Comparative Examples 3-8 were prepared by compounding one or two of the following: silicone resin, phenolic resin, and ceramic precursor polymer. As can be seen from the data in Table 1, compared to Example 1, the fire resistance and mechanical strength of the composite material plates prepared in Comparative Examples 3-8 under an oxy-acetylene flame at 1500°C decreased significantly. This indicates that there is a certain synergistic relationship between the silicone resin, phenolic resin, and ceramic precursor polymer in the composite material plates of this invention. This synergistic effect is crucial for obtaining the ultra-high fire resistance and strength properties of the composite material plates.

[0115] Compared to Example 1, Comparative Examples 9-11 mainly investigated the effect of step (d) gradient heating post-treatment on the properties of the composite material sheets during the preparation process. As can be seen from the data in Table 1 for Example 1 and Comparative Example 9, gradient heating post-treatment can improve the fire resistance and mechanical strength of the composite material sheets under an oxy-acetylene flame at 1500℃. This is mainly because, compared to direct heating post-treatment, gradient heating post-treatment is more conducive to the full cross-linking of the hybrid resin matrix. Comparing the data of Comparative Examples 10 and 11 with Example 1 shows that only by using the specific treatment stage (four stages) gradient heating post-treatment of this invention can the prepared composite material sheets simultaneously obtain superior fire resistance and strength properties.

[0116] During gradient temperature curing (75→260℃), the hybrid resin system of this invention forms a stable organic-inorganic hybrid semi-interpenetrating network structure through condensation and copolymerization reactions between organosilicon resin, phenolic resin, and ceramic precursor polymer, endowing the material with excellent mechanical properties and preliminary heat resistance. Furthermore, after high-temperature pyrolysis treatment at 800–1000℃, the ceramic precursor polymer undergoes pyrolytic transformation, and the original hybrid network partially transforms into a high-density ceramic phase, significantly improving the material's tolerance to extreme environments. This structure possesses the following synergistic strengthening mechanism: (1) Phenolic resin provides a high-rigidity three-dimensional network to bear the main mechanical load; (2) The flexible segments of organosilicon resin effectively buffer stress concentration and inhibit the initiation and propagation of microcracks; (3) The ceramic precursor polymer initially participates in the crosslinking of phenolic resin and organosilicon resin. When subjected to high-temperature pyrolysis treatment, the nano-sized SiC, Si3N4 or SiBNOC ceramic phases generated can be dispersed in the matrix, playing a role in dispersion strengthening and high-temperature stabilization. (4) The three phases form strong interfacial bonds through chemical bonds such as Si–O–C or B–O–C (when boron-modified phenolic resin or boron-containing ceramic precursor polymer is used, during the gradient post-treatment process, boron atoms can react with active oxygen / hydroxyl groups on carbon sources (such as phenolic resin) or silicon sources (such as organosilicon) in the system to form B–O–C and / or B–O–Si), which significantly improves the shear strength of the fiber-matrix interface.

[0117] The aforementioned multi-scale synergistic effect enables the composite material sheet to maintain ultra-high fire resistance and ultra-low density (≤2.2 g / cm³), while achieving excellent tensile strength (≥320 MPa) and flexural strength (≥250 MPa, preferably ≥280 MPa).

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.

Claims

1. A composite material sheet, characterized in that, It is mainly made of hybrid resin matrix and reinforcing fiber body; Wherein, with the total mass fraction of each raw material in the hybrid resin matrix being 100%, the hybrid resin matrix comprises the following raw materials by mass fraction: 20-40% silicone resin, 30-50% phenolic resin, 10-30% ceramic precursor polymer and 0-5% functional additives.

2. The composite material sheet according to claim 1, characterized in that, The hybrid resin matrix is ​​a hybrid polymer formed by copolymerization of organosilicon resin, phenolic resin, ceramic precursor polymer and functional additives to form an interpenetrating / semi-interpenetrating network structure. And / or, the reinforcing fiber body comprises one or more of the following: a hybrid woven fabric or unidirectional fabric made of at least one of glass fiber, carbon fiber, high silica fiber, basalt fiber, quartz fiber or alumina fiber.

3. The composite material sheet according to claim 1, characterized in that, The organosilicon resin includes at least one of silicone resins containing phenyl, vinyl, methyl or epoxy groups, or MQ silicone resin, preferably methylphenyl silicone resin, phenyl vinyl silicone resin, methyl vinyl silicone resin, epoxy modified silicone resin or MQ silicone resin. And / or, the phenolic resin includes at least one of linear phenolic resin, allylated phenolic resin, boron-modified phenolic resin, or molybdenum-modified phenolic resin; And / or, the ceramic precursor polymer includes at least one of polycarbosilane, polysilazane, or polyboronsilazane; And / or, the functional additives include at least one of condensation accelerators, leveling agents, or coupling agents; And / or, the mass ratio of the hybrid resin matrix to the reinforcing fiber is (30-45):(55-70).

4. The composite material sheet according to claim 3, characterized in that, The condensation accelerator includes at least one of dibutyltin dilaurate, stannous octanoate, p-toluenesulfonic acid, triethylamine, or cobalt isooctanoate. And / or, the leveling agent includes at least one of BYK-306, BYK-333, TEGO Glide 410, or a fluorocarbon leveling agent; And / or, the coupling agent comprises at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, or an aluminate coupling agent.

5. The composite material sheet according to any one of claims 1-4, characterized in that, The time for a 1mm thick composite material sheet to burn through a flame at an oxy-acetylene flame temperature of 1500±50℃ is ≥30min. And / or, the tensile strength of the composite material sheet is ≥320MPa, and the flexural strength is ≥280MPa; And / or, the density of the composite material sheet is ≤2.2 g / cm³.

6. The method for preparing the composite material plate according to any one of claims 1-5, characterized in that, Includes the following steps: (a) Mix organosilicon resin, phenolic resin, ceramic precursor polymer and optional functional additives in proportion, heat and stir to allow the mixture to react and form a hybrid resin solution. (b) Molding: When molding or autoclaving is used, the surface-treated reinforcing fiber body is impregnated in a hybrid resin solution to obtain a prepreg. The prepreg is then laid up according to the design and placed in a mold for curing. or, When using RTM process for molding, the dry, surface-treated reinforcing fiber is directly laid into the mold, and then a hybrid resin solution is injected into the mold for curing and molding. (c) Demold the molding material obtained after step (b) and then perform gradient heating post-treatment to obtain composite material sheet.

7. The method for preparing composite material plates according to claim 6, characterized in that, In step (a), the reaction is stirred at 60-80℃ for 2-4 hours; And / or, in step (b), the surface treatment includes plasma treatment or sizing agent treatment.

8. The method for preparing composite material plates according to claim 6, characterized in that, In step (b), when the molding is carried out by compression molding or autoclave molding, the pressure used is 5-15MPa, the temperature is 120-180℃, and the curing time is 30-90min; And / or, in step (b), when the molding is performed using RTM process, the injection pressure is 0.5-2MPa, the mold temperature is 70-90℃, the curing temperature is 120-180℃, and the curing time is 60-120min; And / or, in step (c), the gradient heating post-processing includes sequentially performing a first-stage heating process, a second-stage heating process, a third-stage heating process, and a fourth-stage heating process. The first stage of heating involves raising the temperature from room temperature to 75-85℃ and holding it at that temperature for 1-2 hours. The second stage of heating involves raising the temperature from the first stage to 110-130℃ and holding it at that temperature for 1-2 hours. The third stage of heating treatment involves raising the temperature from the second stage heating treatment temperature to 170-190℃ and holding it at that temperature for 1-2 hours. The fourth stage of heating treatment involves raising the temperature from the third stage of heating treatment to 240-260℃ and holding it at that temperature for 1-2 hours. The heating rate during each stage of the heating process is 1-2℃ / min.

9. The method for preparing composite material plates according to any one of claims 6-8, characterized in that, In step (c), after the gradient heating post-treatment and before obtaining the composite material plate, a high-temperature pyrolysis treatment step is also included; Preferably, the high-temperature pyrolysis treatment is performed at a temperature of 800-1000℃, with a holding time of 1-2 hours, and in an inert atmosphere.

10. The application of the composite material sheet according to any one of claims 1-5 or the composite material sheet prepared by the preparation method according to any one of claims 6-9 in the fields of new energy vehicles, aerospace or shipbuilding industries.

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