Flame-retardant impact-resistant fiber reinforced paving floor for coal mine and preparation method thereof

Abstract

The present application relates to the technical field of building materials, in particular to a coal mine-used flame-retardant impact-resistant fiber-reinforced paving floor and a preparation method thereof.The paving floor comprises the following raw materials: modified glass fiber, modified inorganic filler, modified epoxy resin, curing agent, toughening agent and flame-retardant synergist.In the present application, the glass fiber is etched by phosphoric acid and loaded with a composite flame-retardant layer of aluminum hydroxide and zinc borate, thereby improving the interface bonding and flame-retardant efficiency.The coal gangue-based inorganic filler is gradually coated with a composite salt of magnesium chloride and aluminum sulfate and ammonium polyphosphate, thereby constructing a stable and flame-retardant synergistic reinforcing framework.The epoxy resin is blended and intercalated with ammonium polyphosphate, melamine cyanurate and magnesium hydroxide, thereby realizing the organic combination of solidified phase and gas phase flame retardation, so that the final product has excellent flame-retardant grade, high-efficiency smoke suppression, improved impact strength, good moisture resistance and corrosion resistance, and can adapt to the humid and frequently-vibrated environment of the coal mine underground roadway.

Description

Technical Field

[0001] This invention relates to the field of building materials technology, specifically to a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines and its preparation method. Background Technology

[0002] Flame-retardant and impact-resistant fiber-reinforced paving flooring for coal mines is a high-performance composite material board tailored for the harsh underground environment. It is composed of flame-retardant engineering plastics and reinforcing fibers, possessing properties such as flame retardancy, antistatic properties, high strength, wear resistance, slip resistance, and corrosion resistance. Its main function is to construct safe and efficient underground transportation channels, fundamentally ensuring safe production by eliminating sparks, providing strong grip, and supporting heavy equipment.

[0003] Existing technologies suffer from insufficient flame retardancy, making it difficult to effectively suppress flame propagation in flammable underground environments. They also exhibit poor impact and fatigue resistance, easily developing cracks, spalling, or even structural damage under continuous crushing by heavy equipment and impact from mine cars. Furthermore, their service life is short, and the interfacial bonding between material components is weak, with poor compatibility between inorganic fillers and the organic resin matrix leading to stress concentration and poor overall mechanical properties. Therefore, this invention provides a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines and its preparation method. The flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines prepared by this invention not only has high compressive strength, but also low smoke density and limiting oxygen index.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, characterized in that it is composed of the following raw materials in parts by weight: 8-15 parts modified glass fiber, 30-50 parts modified inorganic filler, 20-30 parts modified epoxy resin, 5-10 parts curing agent, 4-8 parts toughening agent, and 6-12 parts flame retardant synergist;

[0006] The preparation method of the flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines is as follows:

[0007] S1. Mix and stir the modified epoxy resin with the curing agent to obtain the resin matrix;

[0008] S2. Add the modified inorganic filler and flame retardant synergist to a high-speed mixer and stir to obtain a mixed powder;

[0009] S3. Add the resin matrix to the mixed powder, and add the toughening agent at the same time. Stir and mix to obtain a mixed slurry.

[0010] S4. Add modified glass fiber to the mixed slurry, mix evenly with a vacuum mixer, inject into a mold, and after hot pressing, curing, cooling, and demolding, obtain flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines.

[0011] Furthermore, the preparation method of the modified glass fiber is as follows: the glass fiber is immersed in a phosphoric acid solution with a mass fraction of 5-8%, then washed with deionized water until neutral and dried; the treated glass fiber is immersed in a suspension formed by dispersing aluminum hydroxide and zinc borate in ethanol and ultrasonically treated; the treated glass fiber is taken out, drained, heat-treated, and cooled to obtain modified glass fiber, and a strong flame-retardant and reinforcing composite coating is formed on the surface. The phosphoric acid etching improves the surface roughness and reactivity of the fiber. The loading of aluminum hydroxide and zinc borate not only improves the flame-retardant and smoke-suppressing performance of the fiber itself, but also acts as a flame-retardant synergistic point in the composite material, while enhancing the interfacial bonding force between the fiber and the resin matrix, thereby synergistically improving the overall impact resistance and fire safety level of the paving floor.

[0012] Furthermore, the aluminum hydroxide and zinc borate are dispersed in ethanol at a mass ratio of 2:1, and the total mass of the aluminum hydroxide and zinc borate accounts for 15-25% of the mass of ethanol.

[0013] Furthermore, the preparation method of the modified inorganic filler is as follows: coal gangue powder is placed in a reactor and heated and continuously stirred; magnesium chloride and aluminum sulfate are dissolved in water to prepare a mixed salt solution with a mass fraction of 10-15%; the solution is sprayed onto the heated coal gangue powder, and after continuous stirring and reaction, it is cooled down; ammonium polyphosphate powder is added, and the stirring and reaction are continued; after the reaction is completed, the resulting product is cooled, crushed, and sieved to obtain the modified inorganic filler. A dense inorganic and flame-retardant composite coating layer is constructed on the surface of the coal gangue powder. The composite oxide generated by the reaction of magnesium chloride and aluminum sulfate effectively improves the interfacial compatibility and bonding force between the filler and the resin, and the subsequently introduced ammonium polyphosphate adheres firmly, giving the filler itself a highly efficient flame-retardant function.

[0014] Furthermore, the magnesium chloride and aluminum sulfate are dissolved in water at a mass ratio of 1:1; the amount of ammonium polyphosphate added is 5-10% of the initial mass of the coal gangue powder; and the total amount of the mixed salt solution sprayed is 20-35% of the initial mass of the coal gangue powder.

[0015] Furthermore, the preparation method of the modified epoxy resin is as follows: heating the epoxy resin to 70-80℃; mixing ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide in a high-speed mixer to obtain a composite flame retardant modifier; adding the composite flame retardant modifier to the epoxy resin, and performing degassing treatment while high-speed shearing and stirring; cooling the degassed product to room temperature to obtain the modified epoxy resin. Through the compounding of ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide, a synergistic flame retardant system is constructed in the epoxy resin. The modified resin has both condensed phase and gas phase flame retardant mechanisms. When exposed to fire, it can promote the formation of a dense char layer, effectively inhibit flame spread and smoke generation, and improve the flame retardant rating. At the same time, high-speed shearing and degassing treatment ensure the uniform dispersion of flame retardant components and the density of the matrix, so that the material can obtain excellent fire resistance while maintaining good processability and mechanical strength.

[0016] Furthermore, the ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide are mixed in a mass ratio of 3-5:2-3:4-6; the amount of the composite flame retardant modifier added is 25-40% of the mass of the epoxy resin.

[0017] Furthermore, the curing agent is one of polyamide 650, phenolic amine T-31, and polyether-modified alicyclic amine.

[0018] Furthermore, the toughening agent is one of the following: carboxyl-terminated butadiene-acrylonitrile rubber, polyether-type polyurethane prepolymer, and core-shell structured rubber particles CMR-01.

[0019] Furthermore, the flame retardant synergist is a compound composed of zinc borate, silicon dioxide, and antimony oxide in a mass ratio of 5-7:2-3:1-2.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. This invention involves phosphoric acid etching of glass fibers. Phosphoric acid etching increases the surface roughness of the fibers and introduces active groups, enhancing the interfacial bonding between the fibers and the modified epoxy resin matrix. This allows the fibers to more efficiently transmit and disperse stress upon impact, thus improving the impact resistance and fatigue resistance of the flooring. Further flame-retardant loading treatment with aluminum hydroxide and zinc borate after etching transforms the fibers themselves into flame-retardant functional components. During combustion, these components form a thermal barrier at the fiber-resin interface, thus synergizing with other flame-retardant components in the system. This constructs a robust flame-retardant network at the microscopic level, solving the performance problems of traditional paving materials where fibers only serve a reinforcing role and flame retardancy relies on matrix additions. This avoids the difficulty of simultaneously achieving reinforcement and flame retardancy.

[0022] 2. This invention modifies coal gangue powder by gradient coating with magnesium chloride, aluminum sulfate composite salt, and ammonium polyphosphate. The composite salt reacts on the surface of the coal gangue to form a dense inorganic coating layer, which improves the compatibility and interfacial bonding between the filler and the organic resin. At the same time, the coating layer itself has a certain flame retardant function. Therefore, the modified filler in the matrix not only acts as a reinforcing skeleton to bear the load, but also becomes a uniformly distributed flame retardant node. The subsequently introduced ammonium polyphosphate is further firmly attached to the surface of the coating layer, giving the filler more efficient flame retardant performance. Thus, it realizes the integration of mechanical reinforcement and flame retardant function, and solves the problems of traditional fillers only increasing stiffness but may damage toughness and flame retardants being prone to agglomeration and failure. This improves the comprehensive performance and long-term durability of the material.

[0023] 3. This invention uses ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide to modify epoxy resin. Ammonium polyphosphate promotes the formation of a dense, expanded char layer during combustion. Melamine cyanurate decomposes upon heating, absorbing heat and releasing inert gases. Magnesium hydroxide decomposes at high temperatures to generate magnesium oxide and water vapor. The three components synergistically construct a highly efficient flame-retardant system with combined condensed and gas phase effects. Therefore, the modified resin can quickly form a stable char barrier during combustion, while simultaneously diluting the concentration of combustible gases, resulting in high flame-retardant efficiency and good smoke suppression. As a matrix material, the modified resin, together with the aforementioned modified glass fiber, modified inorganic filler, and added flame-retardant synergists, forms a multi-layered, multi-mechanism three-dimensional flame-retardant network, ensuring high-level fire safety and long-term stability of the product in the extremely humid and high-load environment of underground coal mines. Its comprehensive performance far exceeds that of traditional single-additive flame-retardant materials. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that the raw materials used in the following embodiments are all commercially available.

[0026] Example 1: A flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, composed of the following raw materials in parts by weight: 8 parts modified glass fiber, 30 parts modified inorganic filler, 20 parts modified epoxy resin, 5 parts curing agent, 4 parts toughening agent, and 6 parts flame retardant synergist.

[0027] A method for preparing flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines is as follows:

[0028] S1. Mix and stir the modified epoxy resin and curing agent at 60°C for 10 minutes to obtain the resin matrix;

[0029] S2. Add the modified inorganic filler and flame retardant synergist to a high-speed mixer and stir and mix at 800 rpm for 5 minutes to obtain a mixed powder.

[0030] S3. Add the resin matrix to the mixed powder, and add the toughening agent at the same time. Stir and mix at 80°C and 400 rpm for 10 minutes to obtain the mixed slurry.

[0031] S4. Add modified glass fiber to the mixed slurry and stir for 5 minutes at -0.08MPa using a vacuum mixer to disperse the fiber evenly. Inject the evenly dispersed fiber into a mold, and after hot pressing, curing, cooling, and demolding, obtain flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines.

[0032] The modified glass fiber is prepared as follows: glass fiber is placed in a 5% phosphoric acid solution and soaked at 50°C for 30 minutes. After removal, it is washed with deionized water until neutral and dried at 80°C. The treated glass fiber is then immersed in a suspension formed by dispersing aluminum hydroxide and zinc borate in ethanol and ultrasonically treated for 20 minutes. The treated glass fiber is then removed, drained, and heat-treated in an oven at 120°C for 1 hour. After cooling, the modified glass fiber is obtained. The fiber itself is transformed into a flame-retardant functional body, which synergizes with other flame-retardant components in the system, constructing a stable flame-retardant network at the microscopic level.

[0033] Aluminum hydroxide and zinc borate are dispersed in ethanol at a mass ratio of 2:1, and the total mass of aluminum hydroxide and zinc borate accounts for 15% of the mass of ethanol.

[0034] The modified inorganic filler is prepared as follows: Coal gangue powder passing through a 200-mesh sieve is placed in a reactor, heated to 150°C and continuously stirred; magnesium chloride and aluminum sulfate are dissolved in water to prepare a mixed salt solution with a mass fraction of 10%, and the solution is evenly sprayed onto the heated coal gangue powder, and the reaction is continuously stirred for 30 minutes; when the temperature of the reactants drops to 80°C, ammonium polyphosphate powder is added, and the reaction is continued to be stirred for 20 minutes; after the reaction is completed, the resulting product is cooled, pulverized, and sieved to obtain the modified inorganic filler.

[0035] Magnesium chloride and aluminum sulfate are dissolved in water at a mass ratio of 1:1; the amount of ammonium polyphosphate added is 5% of the initial mass of coal gangue powder; the total amount of mixed salt solution sprayed is 20% of the initial mass of coal gangue powder.

[0036] The modified epoxy resin is prepared as follows: Bisphenol A type epoxy resin is heated to 70℃ to reduce its viscosity; ammonium polyphosphate, melamine cyanurate and magnesium hydroxide are mixed evenly in a high-speed mixer at 60℃ to obtain a composite flame retardant modifier; the composite flame retardant modifier is added to the epoxy resin, and the mixture is simultaneously sheared and stirred at a high speed of 500 rpm, and degassed under a vacuum of -0.05 MPa for 30 minutes; the degassed product is cooled to room temperature to obtain the modified epoxy resin.

[0037] Ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide are mixed in a mass ratio of 3:2:4; the amount of composite flame retardant modifier added is 25% of the mass of epoxy resin.

[0038] The curing agent is polyamide 650.

[0039] The toughening agent is carboxyl-terminated butadiene-acrylonitrile rubber.

[0040] The flame retardant synergist is a compound composed of zinc borate, silicon dioxide and antimony oxide in a mass ratio of 5:2:1.

[0041] Example 2: A flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, composed of the following raw materials in parts by weight: 11.5 parts modified glass fiber, 40 parts modified inorganic filler, 25 parts modified epoxy resin, 7.5 parts curing agent, 6 parts toughening agent, and 9 parts flame retardant synergist.

[0042] A method for preparing flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines is as follows:

[0043] S1. Mix and stir the modified epoxy resin and curing agent at 65°C for 12 minutes to obtain the resin matrix;

[0044] S2. Add the modified inorganic filler and flame retardant synergist to a high-speed mixer and stir and mix at 900 rpm for 6 minutes to obtain a mixed powder.

[0045] S3. Add the resin matrix to the mixed powder, and add the toughening agent at the same time. Stir and mix at 85°C and 500 rpm for 12 minutes to obtain the mixed slurry.

[0046] S4. Add modified glass fiber to the mixed slurry and stir for 7 minutes at -0.09MPa using a vacuum mixer to disperse the fiber evenly. Inject the evenly dispersed fiber into a mold, and after hot pressing, curing, cooling, and demolding, obtain flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines.

[0047] The modified glass fiber is prepared as follows: glass fiber is placed in a 6.5% phosphoric acid solution and soaked at 55°C for 37 min. After removal, it is washed with deionized water until neutral and dried at 85°C. The treated glass fiber is then immersed in a suspension formed by dispersing aluminum hydroxide and zinc borate in ethanol and ultrasonically treated for 25 min. The treated glass fiber is then removed, drained, and placed in an oven at 130°C for 1.5 h for heat treatment. After cooling, the modified glass fiber is obtained.

[0048] Aluminum hydroxide and zinc borate are dispersed in ethanol at a mass ratio of 2:1, and the total mass of aluminum hydroxide and zinc borate accounts for 20% of the mass of ethanol.

[0049] The modified inorganic filler is prepared as follows: Coal gangue powder passing through a 300-mesh sieve is placed in a reactor, heated to 165°C and continuously stirred; magnesium chloride and aluminum sulfate are dissolved in water to prepare a mixed salt solution with a mass fraction of 12.5%, and the solution is evenly sprayed onto the heated coal gangue powder, and the reaction is continuously stirred for 37 minutes; when the temperature of the reactants drops to 90°C, ammonium polyphosphate powder is added, and the reaction is continued to be stirred for 25 minutes; after the reaction is completed, the resulting product is cooled, pulverized, and sieved to obtain the modified inorganic filler.

[0050] Magnesium chloride and aluminum sulfate were dissolved in water at a mass ratio of 1:1; the amount of ammonium polyphosphate added was 7.5% of the initial mass of the coal gangue powder; the total amount of the mixed salt solution sprayed was 27.5% of the initial mass of the coal gangue powder.

[0051] The modified epoxy resin is prepared as follows: Bisphenol A type epoxy resin is heated to 75°C to reduce its viscosity; ammonium polyphosphate, melamine cyanurate and magnesium hydroxide are mixed uniformly in a high-speed mixer at 65°C to obtain a composite flame retardant modifier; the composite flame retardant modifier is added to the epoxy resin, and the mixture is simultaneously sheared and stirred at a high speed of 650 rpm, and degassed under a vacuum of -0.06 MPa for 37 minutes; the degassed product is cooled to room temperature to obtain the modified epoxy resin.

[0052] Ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide are mixed in a mass ratio of 4:2.5:5; the amount of composite flame retardant modifier added is 32.5% of the mass of epoxy resin.

[0053] The curing agent is phenolic amine T-31.

[0054] The toughening agent is a polyether-type polyurethane prepolymer.

[0055] The flame retardant synergist is a compound composed of zinc borate, silicon dioxide, and antimony oxide in a mass ratio of 6:2.5:1.5.

[0056] Example 3: A flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, composed of the following raw materials in parts by weight: 15 parts modified glass fiber, 50 parts modified inorganic filler, 30 parts modified epoxy resin, 10 parts curing agent, 8 parts toughening agent, and 12 parts flame retardant synergist.

[0057] A method for preparing flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines is as follows:

[0058] S1. Mix and stir the modified epoxy resin and curing agent at 70°C for 15 minutes to obtain the resin matrix;

[0059] S2. Add the modified inorganic filler and flame retardant synergist to a high-speed mixer and stir and mix at 1000 rpm for 8 minutes to obtain a mixed powder.

[0060] S3. Add the resin matrix to the mixed powder, and add the toughening agent at the same time. Stir and mix at 90°C and 600 rpm for 15 minutes to obtain the mixed slurry.

[0061] S4. Add modified glass fiber to the mixed slurry and stir for 10 minutes at -0.1MPa using a vacuum mixer to disperse the fiber evenly. Inject the evenly dispersed fiber into a mold, and after hot pressing, curing, cooling, and demolding, obtain flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines.

[0062] The modified glass fiber is prepared as follows: glass fiber is placed in a phosphoric acid solution with a mass fraction of 8% and soaked at 60°C for 45 min. After removal, it is washed with deionized water until neutral and dried at 90°C. The treated glass fiber is then immersed in a suspension formed by dispersing aluminum hydroxide and zinc borate in ethanol and ultrasonically treated for 30 min. The treated glass fiber is then removed, drained, and placed in an oven at 140°C for heat treatment for 2 h. After cooling, the modified glass fiber is obtained.

[0063] Aluminum hydroxide and zinc borate are dispersed in ethanol at a mass ratio of 2:1, and the total mass of aluminum hydroxide and zinc borate accounts for 25% of the mass of ethanol.

[0064] The modified inorganic filler is prepared as follows: Coal gangue powder passing through a 400-mesh sieve is placed in a reactor, heated to 180°C and continuously stirred; magnesium chloride and aluminum sulfate are dissolved in water to prepare a mixed salt solution with a mass fraction of 15%, and the solution is evenly sprayed onto the heated coal gangue powder, and the reaction is continuously stirred for 45 minutes; when the temperature of the reactants drops to 100°C, ammonium polyphosphate powder is added, and the reaction is continued to be stirred for 30 minutes; after the reaction is completed, the resulting product is cooled, pulverized, and sieved to obtain the modified inorganic filler.

[0065] Magnesium chloride and aluminum sulfate are dissolved in water at a mass ratio of 1:1; the amount of ammonium polyphosphate added is 10% of the initial mass of coal gangue powder; the total amount of mixed salt solution sprayed is 35% of the initial mass of coal gangue powder.

[0066] The modified epoxy resin is prepared as follows: bisphenol A type epoxy resin is heated to 80℃ to reduce its viscosity; ammonium polyphosphate, melamine cyanurate and magnesium hydroxide are mixed uniformly in a high-speed mixer at 70℃ to obtain a composite flame retardant modifier; the composite flame retardant modifier is added to the epoxy resin, and simultaneously sheared and stirred at a high speed of 800 rpm, and degassed under a vacuum of -0.08 MPa for 45 minutes; the degassed product is cooled to room temperature to obtain the modified epoxy resin.

[0067] Ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide are mixed in a mass ratio of 5:3:6; the amount of composite flame retardant modifier added is 40% of the mass of epoxy resin.

[0068] The curing agent is a polyether-modified alicyclic amine.

[0069] The toughening agent is core-shell structured rubber particles CMR-01.

[0070] The flame retardant synergist is a compound composed of zinc borate, silicon dioxide and antimony oxide in a mass ratio of 7:3:2.

[0071] Comparative Example 1: The difference between this comparative example and Example 1 is that the modified glass fiber in this comparative example is replaced with untreated glass fiber.

[0072] Comparative Example 2 differs from Example 1 in that the modified inorganic filler is replaced with untreated coal gangue powder.

[0073] Comparative Example 3 differs from Example 1 in that the modified epoxy resin in this comparative example is replaced with untreated epoxy resin.

[0074] Performance testing: The relevant properties of the samples prepared by the method of flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines provided in Examples 1 to 3 and Comparative Examples 1 to 3 were tested respectively, and the test data are recorded in Table 1 below:

[0075] Table 1 - Performance Test Data of Flame-Retardant and Impact-Resistant Fiber Reinforced Paving Flooring

[0076]

[0077] Among them, the smoke density rating test of a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines was prepared using the test methods in GB / T 8627-2007, namely Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3.

[0078] A test of the compressive strength of a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, prepared according to the test methods in GB / T 1041-2008, Examples 1, 2, 3, Comparative Examples 1, 2, and 3.

[0079] The limiting oxygen index test of a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines was conducted using the test methods in GB / T 2406.2-2009, as described in Examples 1, 2, 3, Comparative Examples 1, 2, and 3.

[0080] By comparing and analyzing the relevant data in the table, it can be seen that the flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines prepared in this invention has improved stress transmission efficiency because the modified glass fiber has increased surface roughness after phosphoric acid etching, and is further treated with aluminum hydroxide and zinc borate, which enhances the interfacial bonding force between the fiber and the modified epoxy resin matrix. Simultaneously, the modified inorganic filler forms a dense coating layer on the surface of coal gangue powder through a magnesium chloride and aluminum sulfate composite salt, and is further modified with ammonium polyphosphate, improving the compatibility between the filler and resin and resulting in better filling effect. The synergistic effect of both makes the internal structure of the material denser and improves its compressive strength. Therefore, it has high compressive strength. The flame-retardant system of ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide is introduced into the modified epoxy resin, which promotes the formation of a dense, expanded char layer during combustion. The modified glass fiber effectively isolates oxygen and inhibits smoke release; the aluminum hydroxide and zinc borate loaded on the surface of the modified glass fiber play a synergistic role in smoke suppression during combustion, capturing smoke particles; the ammonium polyphosphate coated in the modified inorganic filler also participates in char formation and flame retardancy. These three elements work together at different levels to construct a three-dimensional smoke suppression barrier, significantly reducing smoke production during combustion, resulting in a low smoke density level; the synergistic flame retardant mechanism between the condensed phase and gas phase constructed in the modified epoxy resin plays a highly efficient role during combustion, with the char layer barrier and inert gas dilution jointly inhibiting flame propagation; the flame-retardant coating on the surface of the modified glass fiber forms a thermal barrier at the fiber-resin interface, delaying the thermal decomposition of the matrix; the uniformly distributed flame-retardant components in the modified inorganic filler form dense flame-retardant nodes within the material. These three elements work synergistically to require a higher concentration of oxygen to maintain combustion, resulting in a low limiting oxygen index. Therefore, the preparation method of a flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines provided by this invention has a broader market prospect and is more suitable for promotion.

[0081] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0082] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines, characterized in that, It is composed of the following raw materials in parts by weight: 8-15 parts modified glass fiber, 30-50 parts modified inorganic filler, 20-30 parts modified epoxy resin, 5-10 parts curing agent, 4-8 parts toughening agent, and 6-12 parts flame retardant synergist. The modified glass fiber is prepared by: soaking the glass fiber in a 5-8% phosphoric acid solution, washing it with deionized water until neutral, and then drying it; immersing the treated glass fiber in a suspension formed by dispersing aluminum hydroxide and zinc borate in ethanol and ultrasonically treating it; and then taking out the treated glass fiber, draining it, heat-treating it, and cooling it to obtain the modified glass fiber. The aluminum hydroxide and zinc borate are dispersed in ethanol at a mass ratio of 2:1, and the total mass of the aluminum hydroxide and zinc borate accounts for 15-25% of the mass of ethanol. The modified inorganic filler is prepared as follows: coal gangue powder is placed in a reactor and heated while continuously stirred; magnesium chloride and aluminum sulfate are dissolved in water to prepare a mixed salt solution with a mass fraction of 10-15%; the solution is sprayed onto the heated coal gangue powder, and after continuous stirring and reaction, it is cooled down; ammonium polyphosphate powder is added, and the stirring and reaction are continued; after the reaction is completed, the resulting product is cooled, pulverized, and sieved to obtain the modified inorganic filler. The magnesium chloride and aluminum sulfate are dissolved in water at a mass ratio of 1:1; the amount of ammonium polyphosphate added is 5-10% of the initial mass of the coal gangue powder; the total amount of the mixed salt solution sprayed is 20-35% of the initial mass of the coal gangue powder. The modified epoxy resin is prepared by heating the epoxy resin to 70-80℃; mixing ammonium polyphosphate, melamine cyanurate and magnesium hydroxide in a high-speed mixer to obtain a composite flame retardant modifier; adding the composite flame retardant modifier to the epoxy resin, and performing degassing treatment while high-speed shearing and stirring; cooling the degassed product to room temperature to obtain the modified epoxy resin. The ammonium polyphosphate, melamine cyanurate, and magnesium hydroxide are mixed in a mass ratio of 3-5:2-3:4-6; the amount of the composite flame retardant modifier added is 25-40% of the mass of the epoxy resin.

2. The flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines according to claim 1, characterized in that: The curing agent is one of polyamide 650, phenolic amine T-31, or polyether-modified alicyclic amine.

3. The flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines according to claim 1, characterized in that: The toughening agent is one of the following: carboxyl-terminated butadiene-acrylonitrile rubber, polyether-type polyurethane prepolymer, and core-shell structured rubber particles CMR-01.

4. The flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines according to claim 1, characterized in that: The flame retardant synergist is a compound composed of zinc borate, silicon dioxide and antimony oxide in a mass ratio of 5-7:2-3:1-2.

5. A method for preparing the flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines as described in any one of claims 1-4, characterized in that, The preparation method is as follows: S1. Mix and stir the modified epoxy resin with the curing agent to obtain the resin matrix; S2. Add the modified inorganic filler and flame retardant synergist to a high-speed mixer and stir to obtain a mixed powder; S3. Add the resin matrix to the mixed powder, and add the toughening agent at the same time. Stir and mix to obtain a mixed slurry. S4. Add modified glass fiber to the mixed slurry, mix evenly with a vacuum mixer, inject into a mold, and after hot pressing, curing, cooling, and demolding, obtain flame-retardant and impact-resistant fiber-reinforced paving floor for coal mines.

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