Ceramic fiber composite resin fireproof flame-retardant material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of flame-retardant materials, in particular to a ceramic fiber composite resin fireproof flame-retardant material and a preparation method and application thereof. The ceramic fiber composite resin fireproof flame-retardant material comprises a ceramic fiber fireproof layer and a continuous glass fiber RTM (Resin Transfer Molding) layer, the ceramic fiber fireproof layer comprises fireproof ceramic fibers and nano oxide / modified nano oxide, and the surface of the ceramic fiber fireproof layer is subjected to plasma activation operation and silane coupling agent treatment. The ceramic fiber composite resin fireproof flame-retardant material has an excellent thermal runaway protection effect, and the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer is excellent.

Description

Technical Field

[0001] This application relates to the technical field of flame-retardant materials, and more specifically, to a ceramic fiber composite resin fire-retardant material, its preparation method, and its application. Background Technology

[0002] As a core component of the battery system, the battery cover's design and performance directly affect the battery's safety, reliability, and lifespan. Traditional battery covers are primarily made of sheet metal, but with the rapid development of the new energy vehicle industry, the demand for vehicle lightweighting continues to rise. Therefore, overcoming the weight limitations of traditional sheet metal parts and adopting lighter materials as replacements has become a core focus of current battery cover R&D.

[0003] Currently, the mainstream solution for battery pack covers is the RTM cover, which stands out due to its lightweight characteristics and excellent balance of overall performance. RTM covers are usually manufactured using resin transfer molding (RTM) technology. The core principle is to inject resin into a vacuum-sealed mold under high pressure, so that the resin evenly impregnates the fiber preform, and finally molds it into a component with high overall performance.

[0004] However, it should be noted that the RTM cover uses epoxy resin as its core material, and the decomposition temperature of epoxy resin is generally below 300℃. When the battery cell experiences thermal runaway and high temperatures, the epoxy resin is prone to decomposition, causing the sealing performance and rigidity of the cover to drop rapidly. Ultimately, it will be unable to withstand the internal high-pressure impact and will be punctured, becoming a potential weakness in the safety protection of the battery pack. Summary of the Invention

[0005] To address the shortcomings of conventional battery pack covers in terms of fire resistance and flame retardancy, this application provides a ceramic fiber composite resin fire-retardant material, its preparation method, and its application.

[0006] In a first aspect, this application provides a ceramic fiber composite resin fireproof and flame-retardant material, which adopts the following technical solution: A ceramic fiber composite resin fireproof and flame-retardant material includes a ceramic fiber fireproof layer and a continuous glass fiber RTM layer; the ceramic fiber fireproof layer includes refractory ceramic fibers and nano-oxides, and the surface of the ceramic fiber fireproof layer is subjected to plasma activation and silane coupling agent treatment.

[0007] In this application, a ceramic fiber fireproof layer is composited on a continuous glass fiber RTM layer, making it resistant to temperatures above 1200℃. In the event of thermal runaway of the battery cell, the battery pack cover made of this composite material is not easily penetrated by high-temperature flammable substances, which can suppress the spread of fire and ensure the safety of the occupants. Moreover, this composite material can be integrally molded, with a simple process, which is convenient for mass production.

[0008] However, the applicant found in actual production that since both the ceramic fiber fireproof layer and the continuous glass fiber RTM layer are composite materials with fiber as the base, if they are not treated and are directly bonded by hot pressing, the bonding effect between the two is not ideal. As a result, the battery pack cover made from them often bulges and delaminates, which seriously affects the normal use of the product.

[0009] In response, the applicant sequentially performed plasma activation and silane coupling agent treatment on the ceramic fiber fireproof layer, thereby effectively improving the bonding strength between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0010] The purpose of plasma activation is to etch and clean the surface of the ceramic fiber fireproof layer, introduce polar or active groups such as hydroxyl groups into the surface of the ceramic fiber fireproof layer, improve the physicochemical state of the surface of the ceramic fiber fireproof layer, form active centers on the surface of the ceramic fiber fireproof layer, promote subsequent grafting or grafting polymerization reactions, and improve the interaction between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0011] The general molecular formula of silane coupling agents is YR-Si-X3, where X is a hydrolyzable group (such as methoxy-OCH3 or ethoxy-OC2H5). When water or moisture from the air is adsorbed on the surface of the ceramic fiber fireproof layer, the X group will hydrolyze to generate highly reactive silanol groups. These silanol groups can then undergo condensation reactions with hydroxyl groups formed on the surface of the ceramic fiber fireproof layer due to plasma activation and with hydroxyl groups on the surface of nano-oxides, forming stable Si-O-Si or Si-O-Al covalent bonds, thus "casting" strong "molecular anchors" on the surface of the ceramic fiber fireproof layer.

[0012] The Y group in a silane molecule is a non-hydrolyzable organic functional group (such as epoxy, amino, methacryloyloxy, etc.). These functional groups can react chemically with specific resins, exhibiting excellent compatibility and thus forming a strong chemical bond with the resin.

[0013] For example, when using KH-560 containing epoxy groups, its 2,3-epoxypropyl group can undergo synergistic curing and crosslinking with the epoxy groups of the epoxy resin composition, directly participating in the curing network. When using KH-570 containing methacryloyloxy double bonds, the methacryloyloxy double bonds, under UV irradiation, add to newly generated free radicals in the epoxy backbone to form a CC crosslinking network.

[0014] In summary, compared to treating with silane coupling agents alone, performing plasma activation before silane coupling agent treatment can generate more active sites, thereby promoting the grafting polymerization of silane coupling agents and significantly improving the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0015] Preferably, the ceramic fiber fireproof layer comprises the following raw materials in parts by weight: 20-40 parts refractory ceramic fiber, 2-5 parts nano oxide, 5-10 parts organic binder, 20-40 parts inorganic binder, 15-35 parts ceramic filler, 10-30 parts glass powder, and 0.05-0.3 parts flocculant.

[0016] Preferably, the nano-oxide is treated with a silane coupling agent.

[0017] In addition, nano-oxide particles are added to the ceramic fiber fireproof layer in this application. The nano-oxide particles are dispersed on the surface of the ceramic fiber fireproof layer or fill the pores, thereby significantly increasing the specific surface area and roughness of the ceramic fiber fireproof layer. When the epoxy resin composition is injected, the epoxy resin composition will penetrate into the nanoscale uneven structure, thereby forming a strong mechanical anchoring effect after the epoxy resin composition is cured, and obtaining a stronger bonding effect than microporous interlocking.

[0018] Moreover, the uniformly dispersed nano-oxide particles can also serve as pinning points. When cracks appear at the interface and attempt to propagate, the nano-oxide particles dispersed on the surface of the ceramic fiber fireproof layer will force the cracks to deflect and bypass, thereby consuming more energy and improving the fracture toughness of the interface.

[0019] The surface of nano-oxide particles is rich in hydroxyl groups. When the surface of nano-oxide particles is treated with a silane coupling agent, the nano-oxide particles dispersed on the surface of the ceramic fiber fireproof layer can provide a large number of additional reaction sites for the epoxy resin composition, thereby significantly increasing the total density of chemical bonds. Moreover, the nano-oxide particles treated with the silane coupling agent can also construct a nano-bridge network in the interfacial region. One end is bonded to the ceramic fiber fireproof layer through silane bonds, and the other end reacts with the continuous glass fiber RTM layer through organic functional groups, thereby efficiently transferring stress and reducing the possibility of separation between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0020] Preferably, the refractory ceramic fiber is one or more of the following: aluminosilicate fiber, high-alumina aluminosilicate fiber, alumina fiber, polycrystalline alumina fiber, polycrystalline mullite fiber, quartz fiber, silicon carbide fiber, zirconium oxide fiber, and nitride fiber.

[0021] Preferably, the refractory ceramic fiber is high-alumina aluminosilicate fiber.

[0022] Preferably, the nano-oxide is one or more of nano-silica and nano-alumina.

[0023] Preferably, the nano-oxide is nano-silica.

[0024] Preferably, the organic adhesive is one or more of starch, water-based acrylic adhesive, and water-based polyurethane.

[0025] The inorganic binder is silica sol.

[0026] Preferably, the ceramic filler is one or more of wollastonite, diatomite, kaolin, calcium carbonate, and mica powder.

[0027] Preferably, the glass powder is one or more of sodium-calcium-silicon glass powder and boron oxide glass powder.

[0028] Preferably, the flocculant is one or more of polyacrylamide, polyethyleneimine, aluminum sulfate, ferric sulfate, and polyaluminum chloride.

[0029] Preferably, the silane coupling agent is one or more of KH-560 and KH-570.

[0030] Preferably, the thickness ratio of the ceramic fiber fireproof layer to the continuous glass fiber RTM layer is 2:(2-4).

[0031] Preferably, the continuous glass fiber RTM layer comprises a continuous glass fiber fabric and an epoxy resin composition, and the number of layers in the continuous glass fiber RTM layer is 1-5.

[0032] Preferably, the mass ratio of the continuous glass fiber fabric to the epoxy resin composition is (3-4):(6-7).

[0033] Preferably, the epoxy resin composition is a mixture of E51 epoxy resin, dispersant and modified amine curing agent.

[0034] Preferably, the epoxy resin is a flame-retardant, low-foaming epoxy resin composition; the flame-retardant, low-foaming epoxy resin composition comprises the following raw materials in parts by weight: 80-120 parts of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin, 2-4 parts of dispersant and 20-30 parts of curing agent.

[0035] Preferably, the preparation method of the polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin includes the following steps: Preparation of polyphosphoric acid / octadecanoic acid intermediate: First, octadecanoic acid and polyphosphoric acid are mixed at a molar ratio of 1:(0.7-0.9). Then, 0.5-2 wt% of p-toluenesulfonic acid catalyst and 30-40% of toluene dehydrating agent are added. The mixture is heated to 120-160℃ and reacted for 2-4 hours. The mixture is continuously refluxed to remove water. After the reaction is completed, the temperature is lowered to 70-80℃. The organic phase is removed after separation to obtain the polyphosphoric acid / octadecanoic acid intermediate. Preparation of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin: E51 epoxy resin, polypropylene glycol diglycidyl ether and polyphosphoric acid / octadecanoic acid intermediate were mixed in a molar ratio of 10:1:(7-9), and then heated to 90-100℃ under nitrogen atmosphere and stirred continuously. Then, 1-2wt% of p-toluenesulfonic acid catalyst was added and the temperature was raised to 130-150℃. The reaction was maintained at this temperature and stirred continuously for 2-4 hours. Then, the solution was neutralized to pH=6-7 with Na2CO3 solution, toluene was removed by rotary evaporation, and finally cooled and dried to obtain polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin.

[0036] Residual air bubbles are a common defect in RTM (Regenerative Thermal Mold) processes, primarily forming at the fiber bundles. Excessive bubble content significantly reduces the mechanical properties and adhesion of the continuous glass fiber RTM layer. Currently, adding defoamers is one of the mainstream methods for controlling bubbles in RYM (Regenerative Thermal Mold) layers. However, when using defoamers, the mechanical properties and adhesion of the continuous glass fiber RTM layer may still be reduced due to the defoamer molecular chains embedding into the epoxy system and forming an interface, or due to a weak reaction with the curing agent. Furthermore, since the continuous glass fiber RTM layer in this application is used in the thermal runaway scenario of a battery cover, its flame retardant performance requirements are relatively high.

[0037] In this application, octadecanoic acid is used as a modified matrix, and an intermediate containing organic flame-retardant groups is constructed by linking it with polyphosphoric acid through an esterification reaction. In the preparation of the polyphosphoric acid / octadecanoic acid intermediate, the excess of octadecanoic acid and the lack of stirring during the reaction process are intended to ensure that the polyphosphoric acid reacts only with one of the carboxyl groups in octadecanoic acid. Then, the other carboxyl group in octadecanoic acid is linked with the epoxy resin composition through a ring-opening addition reaction, so that the organic flame-retardant groups in the continuous glass fiber RTM layer and the inorganic flame-retardant particles in the ceramic fiber fireproof layer synergistically achieve a better flame-retardant effect through the organic-inorganic combination.

[0038] Furthermore, octadecanoic acid possesses a long-chain aliphatic hydrophobic flexible carbon chain structure. Therefore, when it is introduced into an epoxy resin composition via ring-opening addition, the epoxy resin composition exhibits excellent toughness and reduced surface energy. This reduction in surface energy decreases gas-liquid tension, thereby lowering the pressure difference between the inside and outside of bubbles and promoting bubble rupture. Moreover, the low surface tension epoxy resin composition provides superior wetting of the substrate, effectively reducing air trapping caused by substrate surface roughness or porosity, further reducing bubble formation. Additionally, since the polyphosphoric acid / octadecanoic acid intermediate is directly linked to the molecular chain of the epoxy resin composition, it is less prone to interfacial formation.

[0039] Preferably, the dispersant is BYK P-104S; the curing agent is cashew nut shell oil modified phenolic amine.

[0040] Preferably, the preparation method of the flame-retardant low-foaming epoxy system is as follows: first, polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin is mixed and dispersed with a dispersant, then a curing agent is added and mixed and dispersed again, and finally the flame-retardant low-foaming epoxy system is obtained.

[0041] Secondly, this application provides a method for preparing a ceramic fiber composite resin fire-retardant material, which adopts the following technical solution: A method for preparing a ceramic fiber composite resin fireproof and flame-retardant material includes a ceramic fiber fireproof layer forming step and a ceramic fiber composite resin fireproof and flame-retardant material preparation step. The ceramic fiber fireproof layer forming steps include: Add water to the mixing tank; Add 15-35 parts of ceramic filler and 10-30 parts of glass powder, rotate at 300-2000 r / min, and time 3-6 min; Add 2-5 parts of nano-oxide or nano-oxide treated with silane coupling agent, rotate at 300-2000 r / min, and for 2-5 min; Add 20-40 parts of aluminum silicate fiber, rotate at 300-2000 r / min, and time 2-10 min; Add 5-10 parts of organic binder, rotate at 300-2000 r / min, and time 2-6 min; Add 20-40 parts of inorganic binder, rotate at 300-2000 r / min, and time 2-6 min; Add 0.05-3 parts flocculant, rotate at 300-2000 r / min, and time 1-5 min; Pour the prepared slurry into the slurry tank of the molding machine, place the mold in it and perform vacuum adsorption. The vacuum degree is between -0.06MPa and -0.08MPa, and the time is 0.5-3min. The shaped material is transferred to the mold of a hot press for hot pressing and drying at a temperature of 120-180℃ for 1-5 minutes to obtain a ceramic fiber fireproof layer.

[0042] Preferably, the preparation steps of the ceramic fiber composite resin fireproof and flame-retardant material include: S1. Mix silane coupling agent, water and acetic acid to prepare silane hydrolysis agent; S2. The surface to be laminated with the ceramic fiber fireproof layer is subjected to plasma activation treatment, and then the silane hydrolysate is sprayed onto the surface to be laminated using a spray gun to form a wetted film. S3. Place the ceramic fiber fireproof layer at room temperature for 5-10 minutes. S4. Place the ceramic fiber fireproof layer in an oven and cure it at 100-120℃ for 15-30 minutes. S5. Cut and spread the continuous glass fiber fabric and layer it with the ceramic fiber fireproof layer, then place it in a mold for pre-pressing to obtain the preform; S6. The preform is subjected to plasma activation treatment, then placed in a mold, the mold is closed, an epoxy resin composition is injected, and hot pressing is performed to obtain a ceramic fiber composite resin fireproof and flame-retardant material.

[0043] In the preparation steps of ceramic fiber composite resin fireproof and flame-retardant material, the ceramic fiber fireproof layer is first placed at room temperature to allow excess water and acetic acid to evaporate. Then, it is placed in an oven for curing to completely remove moisture and solvents. This promotes the condensation reaction between silanol (-SiOH) and hydroxyl groups (-OH) on the surface of the ceramic fiber board, forming strong -Si-O-Si- (siloxane) covalent bonds. This promotes partial condensation between silane molecules, forming a stable network structure, which further enhances the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0044] Preferably, the specific operation of plasma activation treatment is as follows: the preform is placed in a plasma treatment machine and pretreated with N2 plasma under a vacuum of 0.1 mmHg for 20-40 minutes.

[0045] Preferably, the silane hydrolysant is an aqueous solution of KH-560 with a specific gravity of 0.5-2 wt%, and the pH value is adjusted to 3-5 by acetic acid.

[0046] Thirdly, this application provides an application of a ceramic fiber composite resin fire-retardant material, employing the following technical solution: An application of a ceramic fiber composite resin fire-retardant material, used for automotive battery covers or energy storage battery protection.

[0047] In summary, this application has the following beneficial effects: 1. In this application, a fire-retardant board with ceramic fiber substrate is composited on a continuous glass fiber RTM layer, which makes the composite cover heat-resistant to over 1200℃. At the same time, in the event of thermal runaway of the battery cell, the composite cover is not easily punctured, suppressing the spread of fire and ensuring the safety of the people inside the vehicle. Moreover, the composite method is integral molding, which is simple and easy to mass-produce.

[0048] 2. Compared to treating only with silane coupling agents, performing plasma activation before silane coupling agent treatment can generate more active sites, thereby promoting the grafting polymerization of silane coupling agents and significantly improving the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0049] 3. The surface of nano-oxide particles is rich in hydroxyl groups. When the surface of nano-oxide particles is treated with silane coupling agents, the nano-oxide particles can provide a large number of additional reaction sites that are evenly distributed, thereby significantly increasing the total density of chemical bonds. Moreover, nano-oxide particles treated with silane coupling agents can also build a nano-bridge network in the interface region. One end is bonded to the ceramic fiber fireproof layer through silane bonds, and the other end reacts with the continuous glass fiber RTM layer through organic functional groups, thereby efficiently transferring stress and reducing the possibility of separation between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0050] 4. In this application, octadecanoic acid is used as the modified matrix. An intermediate containing organic flame retardant groups is constructed by linking it with polyphosphoric acid through an esterification reaction. Then, it is linked with an epoxy resin composition through a ring-opening addition reaction, so that the organic flame retardant groups in the continuous glass fiber RTM layer and the inorganic flame retardant particles in the ceramic fiber fireproof layer synergistically achieve a better flame retardant effect through the combination of organic and inorganic. In addition, octadecanoic acid has a long-chain aliphatic hydrophobic flexible carbon chain structure. Therefore, when it is introduced into the epoxy resin composition through the ring-opening addition structure, the epoxy resin composition will have excellent toughness and reduce surface energy, thereby effectively reducing the bubble content in the continuous glass fiber RTM layer. Attached Figure Description

[0051] Figure 1 This is a structural diagram of the battery pack cover made of ceramic fiber composite resin fire-retardant material; Figure 2 It is the cross-section of a ceramic fiber composite resin fireproof and flame-retardant material. Detailed Implementation

[0052] The following combination Figures 1-2 Examples 1-7 and Comparative Example 1 provide further detailed description of this application.

[0053] Raw materials: The particle size of nano-silica and sodium-calcium-silica glass powder can be arbitrarily selected according to production needs. In this application, 100nm nano-silica and 10μm sodium-calcium-silica glass powder are used as examples. They are from commercially available sources. The concentration of Na2CO3 solution can be arbitrarily selected according to actual needs. In this application, 10wt% Na2CO3 solution is used as an example. It is from commercially available sources. The curing agent—cashew shell oil modified phenolic amine—was purchased from Hubei Shuaiyan Ligao.

[0054] High-alumina aluminum silicate fiber with alumina content ≥55%; silica sol CAS: 14808-60-7; starch CAS: 9005-25-8; kaolin CAS: 1332-58-7, sourced from commercially available sources; polyacrylamide CAS: 9003-05-8; octadecanoic acid CAS: 871-70-5; polyphosphoric acid CAS: 8017-16-1; p-toluenesulfonic acid CAS: 104-15-4; toluene CAS: 108-88-3; polypropylene glycol diglycidyl ether CAS: 26142-30-3.

[0055] General Embodiment: A ceramic fiber composite resin fireproof and flame-retardant material, comprising a ceramic fiber fireproof layer and a continuous glass fiber RTM layer, wherein the thickness ratio of the ceramic fiber fireproof layer to the continuous glass fiber RTM layer is 2:(2-4), and the total thickness is 2-5mm.

[0056] The ceramic fiber fireproof layer comprises the following raw materials in parts by weight: 20-40 parts refractory ceramic fiber, 2-5 parts nano oxides, 5-10 parts organic binder, 20-40 parts inorganic binder, 15-35 parts ceramic filler, 10-30 parts glass powder, and 0.05-0.3 parts flocculant.

[0057] The refractory ceramic fiber is one or more of the following: aluminosilicate fiber, high-alumina aluminosilicate fiber, alumina fiber, polycrystalline alumina fiber, polycrystalline mullite fiber, quartz fiber, silicon carbide fiber, zirconium oxide fiber, and nitride fiber. Nano-oxides are one or more of nano-silica and nano-alumina; The organic adhesive is one or more of starch, water-based acrylic adhesive, and water-based polyurethane; The inorganic binder is silica sol; The ceramic filler is one or more of the following: wollastonite, diatomite, kaolin, calcium carbonate, and mica powder; The glass powder is one or more of sodium-calcium-silicon glass powder and boron oxide glass powder; The flocculant is one or more of polyacrylamide, polyethyleneimine, aluminum sulfate, ferric sulfate, and polyaluminum chloride; The silane coupling agent is one or more of KH-560 and KH-570.

[0058] The continuous glass fiber RTM layer comprises a continuous glass fiber fabric and an epoxy resin composition, wherein the mass ratio of the continuous glass fiber fabric to the refractory ceramic fiber is 1:1; the mass ratio of the continuous glass fiber fabric to the epoxy resin composition is (3-4):(6-7), and the number of layers of the continuous glass fiber RTM layer is 1-5. A method for preparing ceramic fiber composite resin fireproof and flame-retardant materials includes a ceramic fiber fireproof layer forming step and a ceramic fiber composite resin fireproof and flame-retardant material preparation step. The steps for forming a ceramic fiber fireproof layer include: 1) Add water to the mixing tank; 2) Add 15-35 parts of ceramic filler and 10-30 parts of glass powder, rotate at 300-2000 r / min, and time for 3-6 min; 3) Add 2-5 parts of nano-oxide or silane coupling agent to modify nano-oxide, rotate at 300-2000 r / min, and wait for 2-5 min; 4) Add 20-40 parts of refractory ceramic fiber, rotate at 300-2000 r / min, and wait for 2-10 min; 5) Add 5-10 parts of organic binder, rotate at 300-2000 r / min, and time 2-6 min; 6) Add 20-40 parts of inorganic binder, rotate at 300-2000 r / min, and time 2-6 min; 7) Add 0.05-3 parts flocculant, rotate at 300-2000 r / min, and time 1-5 min; 8) Pour the prepared slurry into the slurry tank of the molding machine, place the mold in it and perform vacuum adsorption. The vacuum degree is between -0.06MPa and -0.08MPa, and the time is 0.5-3min. 9) Transfer the shaped material to the mold of the hot press for hot pressing and drying at a temperature of 120-180℃ for 1-5 minutes to obtain a ceramic fiber fireproof layer.

[0059] The preparation steps of ceramic fiber composite resin fireproof and flame-retardant materials include: S1. Mix silane coupling agent, water and acetic acid to prepare silane hydrolysis agent; The silane hydrolysate is an aqueous solution of KH-560 or KH-570, with a weight percentage of 0.5-2 wt%, and the pH is adjusted to 3-5 by acetic acid. S2. The surface to be laminated with the ceramic fiber fireproof layer is subjected to plasma activation treatment, and then the silane hydrolysate is sprayed onto the surface to be laminated using a spray gun to form a wetted film. The specific operation of plasma activation treatment is as follows: place the ceramic fiber fireproof layer in the plasma surface treatment machine, and pretreat it with N2 plasma under a vacuum of 0.1 mmHg for 20-40 minutes; S3. Place the sprayed ceramic fiber fireproof layer at room temperature for 5-10 minutes. S4. Place the sprayed ceramic fiber fireproof layer into an oven and cure it at 100-120℃ for 15-30 minutes. S5. Cut and spread the continuous glass fiber fabric and layer it with the ceramic fiber fireproof layer, then place it in a mold for pre-pressing to obtain the preform; S6. Place the preform into the mold, close the mold, inject the epoxy resin composition, and hot press it. The hot pressing temperature is 120-180℃, and finally obtain the ceramic fiber composite resin fireproof and flame-retardant material.

[0060] It should be noted that the ceramic fiber composite resin fire-retardant material can be cut or left uncut as needed. When left uncut or using only a single continuous glass fiber fabric, the epoxy resin composition simultaneously coats the ceramic fiber fire-retardant layer. When using a single continuous glass fiber fabric, a pure epoxy resin composition layer is formed on the side of the ceramic fiber fire-retardant layer away from the continuous glass fiber RTM layer. Additionally, the ceramic fiber composite resin fire-retardant material is used for automotive battery covers or energy storage battery protection.

[0061] Example 1: A ceramic fiber composite resin fireproof and flame-retardant material, comprising a ceramic fiber fireproof layer and a continuous glass fiber RTM layer, wherein the thickness ratio of the ceramic fiber fireproof layer to the continuous glass fiber RTM layer is 2:3, and the total thickness is 2mm.

[0062] The ceramic fiber fireproof board comprises the following raw materials in parts by weight: 30 parts refractory ceramic fiber, 3 parts nano oxide, 8 parts organic binder, 30 parts inorganic binder, 25 parts ceramic filler, 15 parts glass powder and 0.2 parts flocculant, and the surface of the nano oxide is treated with silane coupling agent; the treatment method is to immerse the nano oxide in silane coupling agent, and then take it out and dry it.

[0063] The refractory ceramic fiber is high-alumina aluminosilicate fiber; the nano-oxide is nano-silica; the organic binder is starch; the inorganic binder is silica sol; the ceramic filler is kaolin; the glass powder is sodium-calcium-silica glass powder; the flocculant is polyacrylamide; and the silane coupling agent is KH-560. The continuous glass fiber RTM layer includes a continuous glass fiber fabric and an epoxy resin composition. The mass ratio of the continuous glass fiber fabric to the refractory ceramic fiber is approximately 1:1, and the mass ratio of the continuous glass fiber fabric to the epoxy resin composition is 3:7. A method for preparing ceramic fiber composite resin fireproof and flame-retardant materials includes a ceramic fiber fireproof layer forming step and a ceramic fiber composite resin fireproof and flame-retardant material preparation step. The steps for forming a ceramic fiber fireproof layer include: 1) Add water to the mixing tank; 2) Add ceramic filler and glass powder, rotate at 1000 r / min, for 5 min; 3) Add nano-oxides treated with silane coupling agent, rotate at 1000 r / min, for 5 min; 4) Add refractory ceramic fibers, rotate at 1000 r / min, for 5 min; 5) Add organic binder, rotate at 1200 r / min, for 4 min; 6) Add inorganic binder, rotate at 1200 r / min, for 4 min; 7) Add flocculant, rotate at 1200 r / min, for 4 min; 8) Pour the prepared slurry into the slurry tank of the molding machine, place the mold in it and perform vacuum adsorption. The vacuum degree is -0.08MPa and the time is 2min. 9) Transfer the shaped material to the mold of the hot press for hot pressing and drying at 150°C for 3 minutes to obtain the ceramic fiber fireproof layer.

[0064] The preparation steps of ceramic fiber composite resin fireproof and flame-retardant materials include: S1. Mix silane coupling agent, water and acetic acid to prepare silane hydrolysis agent; S2. The surface to be laminated with the ceramic fiber fireproof layer is subjected to plasma activation treatment, and then the silane hydrolysate is sprayed onto the surface to be laminated using a spray gun to form a wetted film. The specific operation of plasma activation treatment is as follows: the ceramic fiber fireproof layer is placed in a plasma surface treatment machine and pretreated for 30 minutes using N2 plasma under a vacuum of 0.1 mmHg; the silane hydrolysant is an aqueous solution of KH-560 with a weight percentage of 2 wt%, and the pH value is adjusted to 4 by acetic acid. S3. Place the ceramic fiber fireproof layer at room temperature for 10 minutes. S4. Place the ceramic fiber fireproof layer in an oven and cure it at 110℃ for 20 minutes. S5. Cut and spread the continuous glass fiber fabric and layer it with the ceramic fiber fireproof layer, then place it in a mold for pre-pressing to obtain the preform; S6. Place the preform into the mold, close the mold, inject the epoxy resin composition, and hot press it at a temperature of 150°C to obtain a ceramic fiber composite resin fireproof and flame-retardant material.

[0065] The epoxy resin composition comprises E51 epoxy resin, dispersant BYK P-104S, and cashew nut shell oil-modified phenolic amine, with a mass ratio of 4:0.1:1. The preparation method of the epoxy resin composition is as follows: first, E51 epoxy resin and dispersant BYK P-104S are mixed and dispersed, then the curing agent cashew nut shell oil-modified phenolic amine is added and mixed and dispersed again, finally obtaining the epoxy resin composition.

[0066] Example 2: The difference from Example 1 is that the surface of the nano-oxide was not treated with a silane coupling agent.

[0067] Example 3: The difference from Example 1 is that 0.5 parts of defoamer BYK-A530 are added to the epoxy resin composition.

[0068] Example 4: The difference from Example 1 is that the E51 epoxy resin in the epoxy resin composition is replaced with polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin.

[0069] The preparation method of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin includes the following steps: Preparation of polyphosphoric acid / octadecanoic acid intermediate: First, octadecanoic acid and polyphosphoric acid were mixed at a molar ratio of 1:0.8. Then, 2 wt% of p-toluenesulfonic acid catalyst and 35% of toluene dehydrating agent were added. The mixture was heated to 140℃ and esterified for 3 hours. The mixture was continuously refluxed to remove water. After the reaction was completed, the temperature was lowered to 70℃. The organic phase was removed after separation to obtain the polyphosphoric acid / octadecanoic acid intermediate. Preparation of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin: E51 epoxy resin, polypropylene glycol diglycidyl ether, and polyphosphoric acid / octadecanoic acid intermediate were mixed in a molar ratio of 10:1:8. The mixture was then heated to 100°C under nitrogen atmosphere and stirred continuously. Then, 2 wt% of p-toluenesulfonic acid catalyst was added and the temperature was raised to 140°C. The mixture was kept at this temperature and stirred continuously for 3 hours. The mixture was then neutralized to pH=7 with 10 wt% Na2CO3 solution. Toluene was removed by rotary evaporation. Finally, the mixture was cooled and dried to obtain polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin.

[0070] The preparation method of the flame-retardant low-foaming epoxy resin composition is as follows: First, polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin is mixed and dispersed with dispersant BYK P-104S, and then the curing agent - cashew nut shell oil modified phenolic amine is added and mixed and dispersed again, finally obtaining the flame-retardant low-foaming epoxy resin composition.

[0071] Example 5: The difference from Example 4 is that in the preparation of polyphosphoric acid / octadecanoic acid intermediate, stirring is continuously carried out during the esterification reaction at a stirring speed of 800 r / min.

[0072] Example 6: The difference from Example 4 is that in the preparation of the polyphosphoric acid / octadecanoic acid intermediate, the molar ratio of octadecanoic acid to polyphosphoric acid is 1:1.2.

[0073] Example 7: The difference from Example 4 is that the polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin is replaced with a mixture of octadecanoic acid synergistic modified epoxy resin and polyphosphoric acid with the same amount of added content; Preparation of a mixture of octadecanoic acid-modified epoxy resin and polyphosphoric acid: E51 epoxy resin, polypropylene glycol diglycidyl ether, and octadecanoic acid were mixed in a molar ratio of 10:1:8. The mixture was then heated to 100°C under nitrogen atmosphere and stirred continuously. 2 wt% of p-toluenesulfonic acid catalyst was added, and the temperature was raised to 140°C. The mixture was kept at this temperature and stirred continuously for 3 hours. The solution was then neutralized to pH 7 with 10 wt% Na₂CO₃ solution. Toluene was removed by rotary evaporation. The mixture was then cooled, and polyphosphoric acid was added and stirred continuously. The molar ratio of polyphosphoric acid to octadecanoic acid was 1:0.8. The resulting mixture of octadecanoic acid-modified epoxy resin and polyphosphoric acid was then obtained.

[0074] Comparative Example 1: The difference from Example 1 is that in S2, the ceramic fiber fireproof layer was not subjected to plasma activation treatment. Performance testing

[0075] Shear strength test Three samples were taken from Examples 1-7 and Comparative Example 1 respectively, and the shear strength of the above samples was tested in accordance with GB / T 7124-2008 "Determination of Tensile Shear Strength of Adhesives", and the average value was recorded.

[0076] Tensile strength test Three samples were taken from Examples 1-7 and Comparative Example 1, and the tensile strength of the samples was tested according to ASTM D897, "Standard Test Method for Tensile Properties of Adhesives", and the average value was recorded.

[0077] Fire resistance test Three samples were taken from Examples 1-7 and Comparative Example 1, and then the samples were burned with an oxyacetylene flame at 1300℃ for 30 minutes, and the sample state was recorded.

[0078] The test data are shown in Table 1.

[0079] Table 1. Detection data of Examples 1-7 and Comparative Example 1

[0080] Referring to Examples 1-7 and Comparative Example 1 and in conjunction with Table 1, it can be seen that Examples 1-7 and Comparative Example 1 all exhibit extremely excellent flame retardant properties during the fire test.

[0081] Referring to Example 1 and Comparative Example 1 and in conjunction with Table 1, it can be seen that the shear strength and tensile strength of Example 1 are significantly improved compared to Comparative Example 1. This indicates that plasma activation treatment of the ceramic fiber fireproof layer can effectively improve the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0082] The reason for this is that there is a significant interface between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer, resulting in poor bonding between the two. Plasma activation can etch and clean the surface of the ceramic fiber fireproof layer, introduce polar or active groups such as hydroxyl groups, and form active centers on the surface of the ceramic fiber fireproof layer, promoting subsequent grafting or graft polymerization reactions and improving the physicochemical state of the ceramic fiber fireproof layer surface.

[0083] The general molecular formula of silane coupling agents is YR-Si-X3, where X is a hydrolyzable group (such as methoxy-OCH3 or ethoxy-OC2H5). When water or moisture from the air is adsorbed on the surface of the ceramic fiber fireproof layer, the X group will hydrolyze to generate highly reactive silanol groups. These silanol groups can then undergo condensation reactions with hydroxyl groups formed on the surface of the ceramic fiber fireproof layer due to plasma activation and with hydroxyl groups on the surface of nano-oxides, forming stable Si-O-Si or Si-O-Al covalent bonds, thus "casting" strong "molecular anchors" on the surface of the ceramic fiber fireproof layer.

[0084] The Y group in a silane molecule is a non-hydrolyzable organic functional group (such as epoxy, amino, methacryloyloxy, etc.). These functional groups can react chemically with specific resins, exhibiting excellent compatibility and thus forming a strong chemical bond with the resin.

[0085] In summary, compared to treating with silane coupling agents alone, performing plasma activation before silane coupling agent treatment can generate more active sites, thereby promoting the grafting polymerization of silane coupling agents and significantly improving the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0086] Referring to Examples 1 and 2 and in conjunction with Table 1, it can be seen that, compared to Example 1, the shear strength and tensile strength of Example 2 are significantly reduced. This indicates that treating the surface of the nano-oxide with a silane coupling agent can effectively improve the adhesion between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0087] The reason for this lies in the fact that the surface of nano-oxide particles is rich in hydroxyl groups. When the surface of nano-oxide particles is treated with a silane coupling agent, the nano-oxide particles can provide a large number of additional reaction sites that are evenly distributed, thereby significantly increasing the total density of chemical bonds. Moreover, nano-oxide particles treated with silane coupling agents can also construct a nano-bridge network in the interfacial region. One end is bonded to the ceramic fiber fireproof layer through silane bonds, and the other end reacts with the continuous glass fiber RTM layer through organic functional groups, thereby efficiently transferring stress and reducing the possibility of separation between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0088] Referring to Examples 1 and 3 and in conjunction with Table 1, it can be seen that, compared to Example 1, the shear strength and tensile strength of Example 3 are both reduced to a certain extent. This indicates that adding too much defoamer will reduce the bonding effect between the ceramic fiber fireproof layer and the continuous glass fiber RTM layer.

[0089] The reason for this may be that when using defoamers, the defoamer molecular chains embed into the epoxy system and form an interface, or they react weakly with the curing agent, which leads to a reduction in the mechanical properties and bonding effect of the continuous glass fiber RTM layer.

[0090] Referring to Examples 1, 3, and 4 and in conjunction with Table 1, it can be seen that the shear strength and tensile strength of Example 4 are significantly improved compared to Examples 1 and 3. This indicates that, compared to using a defoamer, grafting polyphosphoric acid / octadecanoic acid onto the epoxy resin composition can promote a better bonding effect in the continuous glass fiber RTM layer.

[0091] The reason for this is that residual bubbles are one of the more common defects in the RTM process. They mainly form at the fiber bundles. If the bubble content is too high, it will significantly reduce the mechanical properties and bonding effect of the continuous glass fiber RTM layer.

[0092] Octadectic acid possesses a long-chain aliphatic hydrophobic flexible carbon chain structure. Therefore, when it is introduced into an epoxy resin composition through a ring-opening addition structure, the epoxy resin composition will exhibit excellent toughness and reduced surface energy. The reduction in surface energy decreases the gas-liquid tension, thereby reducing the pressure difference between the inside and outside of the bubble and promoting bubble rupture. Moreover, the epoxy resin composition with low surface tension has a better wetting effect on the substrate, effectively reducing air encapsulation caused by substrate surface roughness or pores, further reducing bubble formation. Furthermore, since the polyphosphoric acid / octadecanoic acid intermediate is directly linked to the molecular chain of the epoxy resin composition, it is less likely to form an interface.

[0093] Referring to Examples 4-6 and Table 1, it can be seen that compared with Example 4, the shear strength and tensile strength of Examples 5-6 are reduced to varying degrees. The reason for this is that the excess of octadecanoic acid and the lack of stirring during the reaction process can cause polyphosphoric acid to react with only one of the carboxyl groups in octadecanoic acid. Then, the other carboxyl group in octadecanoic acid is linked with the epoxy resin composition through a ring-opening addition reaction, so that polyphosphoric acid and octadecanoic acid can be linked to the molecular chain of the epoxy resin composition as much as possible, indirectly reducing the formation of the interface and improving the adhesion effect of the continuous glass fiber RTM layer.

[0094] Referring to Examples 4 and 7 and in conjunction with Table 1, it can be seen that, compared to Example 4, the shear strength and tensile strength of Example 7 are significantly reduced. The reason for this is that the free state of polyphosphoric acid will promote the formation of an interface within the continuous glass fiber RTM layer, indirectly reducing the bonding effect of the continuous glass fiber RTM layer.

[0095] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A ceramic fiber composite resin fire-retardant material, characterized in that: It includes a ceramic fiber fireproof layer and a continuous glass fiber RTM layer; the ceramic fiber fireproof layer includes refractory ceramic fibers and nano-oxides, and the surface of the ceramic fiber fireproof layer is subjected to plasma activation and silane coupling agent treatment.

2. The ceramic fiber composite resin fireproof and flame-retardant material according to claim 1, characterized in that, The ceramic fiber fireproof layer comprises the following raw materials in parts by weight: 20-40 parts refractory ceramic fiber, 2-5 parts nano oxides, 5-10 parts organic binder, 20-40 parts inorganic binder, 15-35 parts ceramic filler, 10-30 parts glass powder, and 0.05-0.3 parts flocculant.

3. The ceramic fiber composite resin fireproof and flame-retardant material according to claim 2, characterized in that: The nano-oxides are treated with silane coupling agents.

4. The ceramic fiber composite resin fireproof and flame-retardant material according to claim 2, characterized in that: The refractory ceramic fiber is one or more of the following: aluminosilicate fiber, high-alumina aluminosilicate fiber, alumina fiber, polycrystalline alumina fiber, polycrystalline mullite fiber, quartz fiber, silicon carbide fiber, zirconium oxide fiber, and nitride fiber; and / or The nano-oxide is one or more of nano-silica and nano-alumina; and / or The organic adhesive is one or more of starch, water-based acrylic adhesive, and water-based polyurethane; and / or The inorganic binder is silica sol; and / or The ceramic filler is one or more of wollastonite, diatomite, kaolin, calcium carbonate, and mica powder; and / or The glass powder is one or more of sodium-calcium-silicon glass powder and boron oxide glass powder; and / or The flocculant is one or more of polyacrylamide, polyethyleneimine, aluminum sulfate, ferric sulfate, and polyaluminum chloride; and / or The silane coupling agent is one or more of KH-560 and KH-570.

5. The ceramic fiber composite resin fireproof and flame-retardant material according to claim 1, characterized in that: The thickness ratio of the ceramic fiber fireproof layer to the continuous glass fiber RTM layer is 2:(2-4). The continuous glass fiber RTM layer comprises a continuous glass fiber fabric and an epoxy resin composition, and the number of layers in the continuous glass fiber RTM layer is 1-5. The mass ratio of the continuous fiberglass fabric to the epoxy resin composition is (3-4):(6-7).

6. The ceramic fiber composite resin fireproof and flame-retardant material according to claim 5, characterized in that: The epoxy resin composition is a flame-retardant, low-foaming epoxy resin composition; the flame-retardant, low-foaming epoxy resin composition comprises the following raw materials in parts by weight: 80-120 parts of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin, 2-4 parts of dispersant and 20-30 parts of curing agent.

7. The ceramic fiber composite resin fire-retardant material according to claim 6, characterized in that, The preparation method of the polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin includes the following steps: Preparation of polyphosphoric acid / octadecanoic acid intermediate: First, octadecanoic acid and polyphosphoric acid are mixed at a molar ratio of 1:(0.7-0.9). Then, 0.5-2 wt% of p-toluenesulfonic acid catalyst and 30-40% of toluene dehydrating agent are added. The mixture is heated to 120-160℃ and reacted for 2-4 hours. The mixture is continuously refluxed to remove water. After the reaction is completed, the temperature is lowered to 70-80℃. The organic phase is removed after separation to obtain the polyphosphoric acid / octadecanoic acid intermediate. Preparation of polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin: E51 epoxy resin, polypropylene glycol diglycidyl ether and polyphosphoric acid / octadecanoic acid intermediate were mixed in a molar ratio of 10:1:(7-9), and then heated to 90-100℃ under nitrogen atmosphere and stirred continuously. Then, 1-2 wt% of p-toluenesulfonic acid catalyst was added and the temperature was raised to 130-150℃. The reaction was maintained at this temperature and stirred continuously for 2-4 hours. Then, the solution was neutralized to pH=6-7 with Na2CO3 solution, toluene was removed by rotary evaporation, and finally cooled and dried to obtain polyphosphoric acid / octadecanoic acid synergistic modified epoxy resin.

8. A method for preparing the ceramic fiber composite resin fire-retardant material according to any one of claims 1-7, characterized in that: This includes the steps for forming the ceramic fiber fireproof layer and the steps for preparing the ceramic fiber composite resin fireproof and flame-retardant material. The ceramic fiber fireproof layer forming steps include: Add water to the mixing tank; Add 15-35 parts of ceramic filler and 10-30 parts of glass powder, rotate at 300-2000 r / min, and time 3-6 min; Add 2-5 parts of nano-oxide or nano-oxide treated with silane coupling agent, rotate at 300-2000 r / min, and for 2-5 min; Add 20-40 parts of aluminum silicate fiber, rotate at 300-2000 r / min, and time 2-10 min; Add 5-10 parts of organic binder, rotate at 300-2000 r / min, and time 2-6 min; Add 20-40 parts of inorganic binder, rotate at 300-2000 r / min, and time 2-6 min; Add 0.05-3 parts flocculant, rotate at 300-2000 r / min, and time 1-5 min; Pour the prepared slurry into the slurry tank of the molding machine, place the mold in it and perform vacuum adsorption. The vacuum degree is between -0.06MPa and -0.08MPa, and the time is 0.5-3min. The shaped material is transferred to the mold of a hot press for hot pressing and drying at a temperature of 120-180℃ for 1-5 minutes to obtain a ceramic fiber fireproof layer.

9. The preparation method of the ceramic fiber composite resin fire-retardant material according to claim 8, characterized in that, The preparation steps of the ceramic fiber composite resin fire-retardant material include: S1. Mix silane coupling agent, water and acetic acid to prepare silane hydrolysis agent; S2. The surface to be laminated with the ceramic fiber fireproof layer is subjected to plasma activation treatment, and then the silane hydrolysate is sprayed onto the surface to be laminated using a spray gun to form a wetted film. S3. Place the ceramic fiber fireproof layer at room temperature for 5-10 minutes. S4. Place the ceramic fiber fireproof layer in an oven and cure it at 100-120℃ for 15-30 minutes. S5. Cut and spread the continuous glass fiber fabric and layer it with the ceramic fiber fireproof layer, then place it in a mold for pre-pressing to obtain the preform; S6. Place the preform into the mold, close the mold, inject the epoxy resin composition, and hot press to obtain the ceramic fiber composite resin fireproof and flame-retardant material.

10. The application of the ceramic fiber composite resin fire-retardant material according to any one of claims 1-7, characterized in that: The ceramic fiber composite resin fire-retardant material is used for automotive battery covers or energy storage battery protection.

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