Flame-retardant glass fiber prepreg as well as preparation method and application thereof

Abstract

The invention discloses a flame-retardant glass fiber prepreg and a preparation method and application thereof, and the preparation method comprises the following steps: immersing glass fiber in a KH550 solution, then coating the surface of the dried glass fiber with a modified emulsion by using an interlayer coating method, drying to obtain modified glass fiber, stirring and mixing the modified glass fiber with epoxy resin in acetone, and carrying out extrusion molding to obtain the flame-retardant glass fiber prepreg. After acetone is removed, high-temperature curing is performed to obtain the flame-retardant glass fiber prepreg; according to the prepared flame-retardant glass fiber prepreg, through the synergistic effect of the black phosphorus nanosheets and magnesium hydroxide, the flame retardance of the flame-retardant glass fiber prepreg is improved, formation of a carbon layer is further promoted through the iron metal organic framework, the conductivity of the flame-retardant glass fiber prepreg is improved through ionic liquid in the iron metal organic framework, and the flame retardance of the flame-retardant glass fiber prepreg is improved. The antistatic performance of the flame-retardant glass fiber prepreg is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer compound compositions, and in particular relates to a flame-retardant glass fiber prepreg and a preparation method and application thereof. Background Art

[0002] With the improvement of prepreg preparation technology and the reduction of cost, the application of prepreg curing and molding composite material technology has greatly promoted the development and application of fiber composite materials. Among them, composite materials prepared from glass fiber / epoxy resin prepreg have the advantages of high specific strength, large specific modulus, fatigue resistance and corrosion resistance, and mature preparation technology. Due to its low cost, strong process adaptability, high strength and good plasticity, it is widely used in the field of composite material manufacturing in aerospace, automobile manufacturing, sporting goods, electronic components and other industries.

[0003] Since epoxy resin is flammable, glass fiber prepreg needs to be flame-retardant modified. However, the addition of a large amount of flame retardants will increase the viscosity of the resin matrix of the polymer material and reduce the fluidity, thereby destroying the dispersion uniformity of the flame retardant filler and the interfacial bonding strength between the filler and the fiber, affecting the mechanical properties of the glass fiber prepreg. In recent years, due to the rapid development of high-frequency and highly integrated electronic equipment and its component process technology, static electricity will be generated in the use scenarios of glass fiber prepreg due to the operation of electronic equipment. The accumulation of static electricity may cause a breakdown effect, causing damage to parts.

[0004] The Chinese invention patent application with publication number CN110229415A discloses a flame-retardant continuous glass fiber reinforced polypropylene prepreg tape material and a preparation method thereof. The flame-retardant continuous reinforced polypropylene prepreg tape material is directly prepared by a melt impregnation method, which ensures the stability of the flame retardant performance, reduces the risk of bonding between different sheets, and improves the mechanical properties of the laminated board. However, this solution has low antistatic ability.

[0005] A Chinese invention patent application with publication number CN110229415A discloses a high-strength antistatic 3D sheet and a method for preparing the same. Nano-diamond components are added to a traditional glue solution consisting of a resin and a curing agent to improve the mechanical strength, wear resistance, heat resistance and aging resistance of the 3D sheet. Hydroxylated diamond powder is used to enhance the compatibility with the organic resin system, so that the nano-diamonds are evenly distributed in the organic resin, which helps to improve the antistatic properties of the 3D sheet. However, the flame retardant properties of the sheet produced by this solution are poor.

[0006] In order to be suitable for application in the field of electronic component housing materials, a flame retardant glass fiber prepreg is needed, which has antistatic properties on the basis of good flame retardant and mechanical properties, so as to be suitable for application development in corresponding fields. Summary of the invention

[0007] The purpose of the present invention is to solve the problem of how to improve the antistatic performance of flame retardant glass fiber prepreg, and to provide a flame retardant glass fiber prepreg and a preparation method and application thereof.

[0008] The present invention coats a modified emulsion on the surface of the glass fiber. The modified emulsion utilizes an ionic liquid with antistatic properties grafted into an iron metal organic skeleton to synergistically act with magnesium hydroxide and black phosphorus nanosheets to improve the flame retardant and antistatic properties of the flame retardant glass fiber prepreg.

[0009] The purpose of the present invention can be achieved through the following technical solutions:

[0010] A method for preparing a flame retardant glass fiber prepreg comprises the following steps:

[0011] Step 1: Mix deionized water, sodium bicarbonate and ammonium persulfate in a reactor, add butyl acrylate, acrylic acid, sodium dioctyl sulfosuccinate and nonylphenol polyoxyethylene ether, heat to 70-80°C, stir and react for 30-40 minutes under nitrogen protection, then add modified black phosphorus nanosheets and ionic liquid impregnated flame retardant powder, stir for 30-40 minutes to obtain a modified emulsion.

[0012] Step 2: immerse the glass fiber in the KH550 solution, take out the glass fiber and wait for the solution to dry, apply the modified latex on the surface of the dried glass fiber by an interlayer coating method, and obtain the modified glass fiber after drying. Disperse the modified glass fiber in acetone in a reactor, add epoxy resin to the reactor, stir and mix, heat to 60-70°C under vacuum conditions to remove acetone, and then cure at 100-150°C for 2-3h to obtain a flame-retardant glass fiber prepreg.

[0013] Furthermore, in step one, the dosage ratio of deionized water, sodium bicarbonate, ammonium persulfate, butyl acrylate, acrylic acid, sodium dioctyl sulfosuccinate, nonylphenol polyoxyethylene ether, modified black phosphorus nanosheets and ionic liquid for impregnating flame retardant powder is 300-350g: 0.6-0.7g: 0.8-1g: 150-180g: 4-5g: 4-5g: 9-10g: 1-1.2g: 15-20g.

[0014] Furthermore, in step 2, the usage ratio of the modified glass fiber, acetone and epoxy resin is 30-40 g: 200-250 mL: 120-150 g.

[0015] Further, the modified black phosphorus nanosheets are prepared by the following steps:

[0016] Melamine is dispersed in deionized water in a reaction kettle, formaldehyde solution is slowly added dropwise, and 0.1M sodium carbonate solution is added dropwise to adjust the pH value to 8-9, the temperature is raised to 80-85°C and stirred for reaction for 30-40 minutes, the black phosphorus nanosheet dispersion is added to the reaction kettle, the reaction is stirred for 5-6 hours under nitrogen protection, the precipitate is collected by centrifugation, the precipitate is washed, and the modified black phosphorus nanosheet is obtained by vacuum drying.

[0017] Furthermore, the black phosphorus nanosheet dispersion is prepared by ultrasonically dispersing the black phosphorus nanosheets in N-methylpyrrolidone, and the amount ratio of the black phosphorus nanosheets to the N-methylpyrrolidone is 1-1.2 g: 500-700 mL.

[0018] Furthermore, the dosage ratio of melamine, deionized water, formaldehyde solution and black phosphorus nanosheet dispersion is 20-30 g: 300-400 mL: 40-60 mL: 500-700 mL.

[0019] Further, the ionic liquid impregnated flame retardant powder is prepared by the following steps:

[0020] In a reaction kettle, tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide is dissolved in acetone, and then magnesium hydroxide flame retardant powder is added and stirred for 12-14 hours. Then, the solution is evaporated and the precipitate is vacuum dried to obtain ionic liquid impregnated flame retardant powder.

[0021] Furthermore, the usage ratio of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide, acetone and magnesium hydroxide flame retardant powder is 3-4 g: 150-200 mL: 25-30 g.

[0022] Further, magnesium hydroxide flame retardant powder is prepared by the following steps:

[0023] In a reaction kettle, magnesium hydroxide powder is dispersed in DMF, ferric chloride hexahydrate and 2-aminoterephthalic acid are added, stirred and dissolved, heated to 120-130° C. and reacted for 12-14 hours, cooled and centrifuged to collect the precipitate, washed the precipitate with DMF and ethanol, and vacuum dried at 60-70° C. to obtain magnesium hydroxide flame retardant powder.

[0024] Furthermore, the usage ratio of magnesium hydroxide powder, DMF, ferric chloride hexahydrate and 2-aminoterephthalic acid is 15-20 g: 500-700 mL: 4-6 g: 6-8 g.

[0025] Beneficial effects of the present invention:

[0026] (1) The flame retardant glass fiber prepreg prepared by the present invention improves the flame retardant properties of the flame retardant glass fiber prepreg through the synergistic effect of black phosphorus nanosheets and magnesium hydroxide, the iron metal organic skeleton further promotes the formation of the carbon layer, and the ionic liquid in the iron metal organic skeleton is used to improve the conductivity of the flame retardant glass fiber prepreg, thereby improving the antistatic performance of the flame retardant glass fiber prepreg.

[0027] (2) The preparation method of the present invention generates an iron metal organic skeleton in situ on the surface of magnesium hydroxide powder and grafts ionic liquid into the iron metal organic skeleton, so that the bonding strength of the flame retardant powder impregnated with the prepared ionic liquid is good, and the dispersibility of the black phosphorus nanosheets in the modified latex is improved by modifying the black phosphorus nanosheets with melamine resin, thereby solving the problem that the black phosphorus nanosheets are difficult to disperse when used as flame retardant fillers. The dispersibility of the magnesium hydroxide powder is improved by intercalating the layered magnesium hydroxide powder and the black phosphorus nanosheets, thereby obtaining a modified latex with good filler dispersion, and utilizing the compatibility of butyl acrylate and epoxy resin to improve the fusion degree of the modified latex and epoxy resin, thereby obtaining a flame retardant glass fiber prepreg with excellent flame retardant and antistatic properties. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1: A method for preparing a flame retardant glass fiber prepreg, comprising the following steps:

[0030] S1. Disperse 15 g of magnesium hydroxide powder in 500 mL of DMF in a reactor, add 4 g of ferric chloride hexahydrate and 6 g of 2-aminoterephthalic acid, stir to dissolve, heat to 120 ° C and react for 12 h, cool and centrifuge to collect the precipitate, wash the precipitate with DMF and ethanol, and dry in vacuo at 60 ° C to obtain magnesium hydroxide flame retardant powder.

[0031] S2. Dissolve 3 g of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide in 150 mL of acetone in a reactor, then add 25 g of magnesium hydroxide flame retardant powder, stir for 12 h, then evaporate the solution, and dry the precipitate under vacuum at 70° C. for 2 h to obtain ionic liquid impregnated flame retardant powder.

[0032] S3. Disperse 20 g of melamine in 300 mL of deionized water in a reactor, slowly drop 40 mL of 35 wt% formaldehyde solution, and drop 0.1 M sodium carbonate solution to adjust the pH value to 8, heat to 80 ° C and stir to react for 30 min, disperse 1 g of black phosphorus nanosheets in 500 mL of N-methylpyrrolidone, ultrasonically disperse for 30 min to obtain a black phosphorus nanosheet dispersion, add 500 mL of the black phosphorus nanosheet dispersion into the reactor, stir and react for 5 h under nitrogen protection, collect the precipitate by centrifugation, wash the precipitate with ethanol, and vacuum dry at 110 ° C to obtain modified black phosphorus nanosheets.

[0033] S4. In a reactor, 300 g of deionized water, 0.8 g of sodium bicarbonate and 0.6 g of ammonium persulfate were mixed, 150 g of butyl acrylate, 4 g of acrylic acid, 4 g of sodium dioctyl sulfosuccinate and 9 g of nonylphenol polyoxyethylene ether were added, and the mixture was heated to 70° C. The mixture was stirred for 30 min under nitrogen protection, and then 1 g of modified black phosphorus nanosheets and 15 g of ionic liquid impregnated flame retardant powder were added, and the mixture was stirred for 30 min to obtain a modified latex.

[0034] S5. KH550, ethanol and deionized water are mixed in a mass ratio of 1:5:30 to obtain a KH550 solution. The glass fiber is immersed in acetone for cleaning, and then immersed in the KH550 solution. The glass fiber is taken out and the solution is dried. The modified latex is coated on the surface of the dried glass fiber by an interlayer coating method, and the modified glass fiber is obtained after drying at 60°C. In a reactor, 30g of the modified glass fiber is dispersed in 200mL of acetone, 120g of epoxy resin is added to the reactor, and the mixture is stirred for 30min. The temperature is raised to 60°C under vacuum to remove the acetone, and then cured at 100°C for 2h to obtain a flame-retardant glass fiber prepreg.

[0035] Embodiment 2: A method for preparing a flame retardant glass fiber prepreg, comprising the following steps:

[0036] S1. In a reactor, 17.5 g of magnesium hydroxide powder was dispersed in 600 mL of DMF, 5 g of ferric chloride hexahydrate and 7,2-aminoterephthalic acid were added, the mixture was stirred and dissolved, the temperature was raised to 125° C. and the mixture was reacted for 13 h. After cooling, the precipitate was collected by centrifugation, the precipitate was washed with DMF and ethanol, and the precipitate was dried in vacuo at 65° C. to obtain magnesium hydroxide flame retardant powder.

[0037] S2. Dissolve 3.5 g of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide in 175 mL of acetone in a reactor, then add 27.5 g of magnesium hydroxide flame retardant powder, stir for 13 h, then evaporate the solution, and dry the precipitate in vacuum at 80° C. for 2.5 h to obtain ionic liquid impregnated flame retardant powder.

[0038] S3. Disperse 25 g of melamine in 350 mL of deionized water in a reactor, slowly drop 50 mL of 37 wt% formaldehyde solution, and drop 0.1 M sodium carbonate solution to adjust the pH value to 8.5, heat to 82.5°C and stir to react for 35 min, disperse 1.1 g of black phosphorus nanosheets in 600 mL of N-methylpyrrolidone, and ultrasonically disperse for 35 min to obtain a black phosphorus nanosheet dispersion, add 600 mL of the black phosphorus nanosheet dispersion into the reactor, stir and react for 5.5 h under nitrogen protection, collect the precipitate by centrifugation, wash the precipitate with ethanol, and vacuum dry at 115°C to obtain modified black phosphorus nanosheets.

[0039] S4. In a reactor, 325 g of deionized water, 0.9 g of sodium bicarbonate and 0.65 g of ammonium persulfate were mixed, 165 g of butyl acrylate, 4.5 g of acrylic acid, 4.5 g of sodium dioctyl sulfosuccinate and 9.5 g of nonylphenol polyoxyethylene ether were added, and the mixture was heated to 75 ° C. The mixture was stirred for 35 min under nitrogen protection, and then 1.1 g of modified black phosphorus nanosheets and 17.5 g of ionic liquid impregnated flame retardant powder were added, and the mixture was stirred for 35 min to obtain a modified latex.

[0040] S5. KH550, ethanol and deionized water are mixed in a mass ratio of 1:5:30 to obtain a KH550 solution. The glass fiber is immersed in acetone for cleaning, and then immersed in the KH550 solution. The glass fiber is taken out and the solution is dried. The modified latex is coated on the surface of the dried glass fiber by an interlayer coating method, and the modified glass fiber is obtained after drying at 65°C. In a reactor, 35g of the modified glass fiber is dispersed in 225mL of acetone, 135g of epoxy resin is added to the reactor, and the mixture is stirred for 35min. The temperature is raised to 65°C under vacuum to remove the acetone, and then cured at 125°C for 2.5h to obtain a flame-retardant glass fiber prepreg.

[0041] Embodiment 3: A method for preparing a flame retardant glass fiber prepreg, comprising the following steps:

[0042] S1. Disperse 20 g of magnesium hydroxide powder in 700 mL of DMF in a reactor, add 6 g of ferric chloride hexahydrate and 8 g of 2-aminoterephthalic acid, stir to dissolve and heat to 130 ° C for 14 h, cool and collect the precipitate by centrifugation, wash the precipitate with DMF and ethanol, and dry in vacuo at 70 ° C to obtain magnesium hydroxide flame retardant powder.

[0043] By in-situ generating an iron metal organic framework on the surface of magnesium hydroxide powder, the porous iron metal organic framework promotes the catalytic carbonization effect of the flame retardant during flame retardancy.

[0044] S2. Dissolve 4 g of tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide (purchased from Hubei Deant Chemical Technology Co., Ltd.) in 200 mL of acetone in a reactor, then add 30 g of magnesium hydroxide flame retardant powder, stir for 14 h, then evaporate the solution, and dry the precipitate under vacuum at 90 ° C for 3 h to obtain ionic liquid impregnated flame retardant powder.

[0045] The ionic liquid tri-n-butyl methyl ammonium bis (trifluoromethyl sulfonyl) imide is dissolved in acetone and then impregnated into the pores of the iron metal organic framework on the surface of the magnesium hydroxide flame retardant powder by an impregnation method. The sulfonyl group in the tri-n-butyl methyl ammonium bis (trifluoromethyl sulfonyl) imide reacts with the amino group in 2-aminoterephthalic acid, so that the ionic liquid with antistatic property is grafted on the surface of the magnesium hydroxide flame retardant powder to obtain the flame retardant powder with antistatic property.

[0046] S3. Disperse 30 g of melamine in 400 mL of deionized water in a reactor, slowly drop 60 mL of 40 wt% formaldehyde solution, and drop 0.1 M sodium carbonate solution to adjust the pH value to 9, heat to 85 ° C and stir to react for 40 min, disperse 1.2 g of black phosphorus nanosheets (99.9%, purchased from Suzhou Beike Nano Technology Co., Ltd.) in 700 mL of N-methylpyrrolidone, ultrasonically disperse for 40 min to obtain a black phosphorus nanosheet dispersion, add 700 mL of the black phosphorus nanosheet dispersion into the reactor, stir and react for 6 h under nitrogen protection, collect the precipitate by centrifugation, wash the precipitate with ethanol, and vacuum dry at 120 ° C to obtain modified black phosphorus nanosheets.

[0047] Black phosphorus nanosheets with good flame retardancy are mixed with amino resin and combined through physical adsorption. Under the action of heating and mechanical stirring, the phosphorus on the black phosphorus nanosheets combines with the nitrogen on melamine formaldehyde to form NP bonds, thereby enhancing the bonding strength between the black phosphorus nanosheets and melamine formaldehyde.

[0048] S4. In a reactor, 350 g of deionized water, 1 g of sodium bicarbonate and 0.7 g of ammonium persulfate were mixed, 180 g of butyl acrylate, 5 g of acrylic acid, 5 g of sodium dioctyl sulfosuccinate and 10 g of nonylphenol polyoxyethylene ether were added, the mixture was heated to 80 ° C, and the reaction was stirred for 40 min under nitrogen protection. Then, 1.2 g of modified black phosphorus nanosheets and 20 g of ionic liquid impregnated flame retardant powder were added, and the mixture was stirred for 40 min to obtain a modified latex.

[0049] Butyl acrylate and acrylic acid are polymerized into an emulsion under the action of emulsifier nonylphenol polyoxyethylene ether, sodium dioctyl sulfosuccinate and initiator ammonium persulfate, and modified black phosphorus nanosheets with flame retardant ability and ionic liquid impregnated flame retardant powder with flame retardant and antistatic ability are compounded with the emulsion. The amino resin on the surface of the modified black phosphorus nanosheet has a cross-linking effect with the emulsion, which can improve the bonding strength between the modified black phosphorus nanosheet and the emulsion. The black phosphorus nanosheet will be intercalated with the magnesium hydroxide sheet structure in the ionic liquid impregnated flame retardant powder during the mechanical mixing process, so that the black phosphorus nanosheet and the ionic liquid impregnated flame retardant powder are compounded with the high bonding strength. After the compounding, the flame retardant performance is further enhanced, and the antistatic performance is also provided. The black phosphorus nanosheet modified by melamine formaldehyde resin has good dispersibility in the emulsion, and the dispersibility of the ionic liquid impregnated flame retardant powder is also improved through the compounding.

[0050] S5. KH550, ethanol and deionized water are mixed in a mass ratio of 1:5:30 to obtain a KH550 solution. The glass fiber is immersed in acetone for cleaning, and then immersed in the KH550 solution. The glass fiber is taken out and the solution is dried. The modified latex is coated on the surface of the dried glass fiber by an interlayer coating method, and the modified glass fiber is obtained after drying at 70°C. In a reactor, 40g of the modified glass fiber is dispersed in 250mL of acetone, 150g of epoxy resin is added to the reactor, and the mixture is stirred for 40min. The temperature is raised to 70°C under vacuum to remove the acetone, and then cured at 150°C for 3h to obtain a flame-retardant glass fiber prepreg.

[0051] A coating with flame retardant and antistatic properties is applied to the surface of the glass fiber, and the glass fiber is used to form a conductive circuit to improve the conductive property, thereby improving the antistatic property of the prepreg. The modified black phosphorus nanosheets and the flame retardant powder impregnated with the ionic liquid are compounded with the glass fiber through the coating, which also solves the problem of easy agglomeration of the modified black phosphorus nanosheets and the flame retardant powder impregnated with the ionic liquid. The emulsion formed by the polymerization of butyl acrylate has good compatibility with epoxy resin, and a flame retardant glass fiber prepreg with good flame retardancy and antistatic properties is obtained.

[0052] Comparative Example 1: The difference from Example 1 is that in S2, conductive carbon black and magnesium hydroxide powder are used to replace the ionic liquid flame retardant powder to prepare a flame retardant glass fiber prepreg.

[0053] Comparative Example 2: The difference from Example 1 is that in S4, black phosphorus nanosheets are used to replace the modified black phosphorus nanosheets to prepare a flame-retardant glass fiber prepreg.

[0054] Comparative Example 3: The difference from Example 1 is that, S3, 30g of epoxy resin and 500mL of black phosphorus nanosheet dispersion are mixed in a reactor, the temperature is raised to 80°C under nitrogen protection, and the reaction is stirred for 5h to obtain modified black phosphorus nanosheets, and the modified black phosphorus nanosheets are used to prepare flame-retardant glass fiber prepreg.

[0055] The flame retardant glass fiber prepregs prepared in Example 1 to Example 3 and Comparative Example 1 to Comparative Example 3 were subjected to performance tests. The tensile strength and flexural strength were tested according to the standards of ASTM D790 and ASTM D 3039 at a speed of 2 mm / min at room temperature; the limiting oxygen index (OI) was tested according to the GB / T2406-80 standard, and a 60-second vertical burning test was performed according to the BSS7230 specification; the surface resistance of the sample was tested according to the standard GB / T 3048.5, and the results were shown in Table 1:

[0056] Table 1: Flame retardant glass fiber prepreg test performance table

[0057]

[0058] As can be seen from Table 1, the flame retardant glass fiber prepreg prepared by the present invention has excellent mechanical properties, high tensile strength and flexural strength, a limiting oxygen index of more than 70, and a short vertical burning length of 60 seconds, indicating that it has good flame retardant properties. At the same time, the surface resistance reaches 10 7 Ω / m, has strong anti-static ability.

[0059] In Comparative Example 1, since the ionic liquid and the metal organic framework are replaced by conductive carbon black, the conductive carbon black is easy to agglomerate in the emulsion, the antistatic performance is slightly improved, and the flame retardant performance is also reduced.

[0060] In Comparative Example 2, since the black phosphorus nanosheets are not modified, the black phosphorus nanosheets are easy to agglomerate and have poor dispersibility in the emulsion, which greatly affects the flame retardant performance.

[0061] In Comparative Example 3, since the black phosphorus nanosheets are modified with epoxy resin, the epoxy resin has good compatibility in the modified emulsion, but lacks the cross-linking effect of the amino resin and the modified emulsion. When mixed with the epoxy resin prepreg, the modified black phosphorus nanosheets are easy to migrate from the surface of the glass fiber, and will bring out a part of the ionic liquid impregnated flame retardant powder. Therefore, the flame retardant properties, mechanical properties and antistatic properties are all lower than those of Examples 1-3.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a flame retardant glass fiber prepreg, characterized in that: The steps include: Step 1: In a reaction kettle, deionized water, sodium bicarbonate and ammonium persulfate are mixed, butyl acrylate, acrylic acid, sodium dioctyl sulfosuccinate and nonylphenol polyoxyethylene ether are added, and the mixture is heated to 70-80° C., and stirred for reaction for 30-40 minutes under nitrogen protection, and then modified black phosphorus nanosheets and ionic liquid impregnated flame retardant powder are added, and stirred for 30-40 minutes to obtain a modified emulsion; Step 2: immerse the glass fiber in the KH550 solution, take out the glass fiber and wait for the solution to dry, apply the modified latex on the surface of the dried glass fiber by an interlayer coating method, and obtain the modified glass fiber after drying. Disperse the modified glass fiber in acetone in a reactor, add epoxy resin to the reactor, stir and mix, heat to 60-70°C under vacuum conditions to remove acetone, and then cure at 100-150°C for 2-3h to obtain a flame-retardant glass fiber prepreg.

2. The method for preparing a flame-retardant glass fiber prepreg according to claim 1, characterized in that: The dosage ratio of deionized water, sodium bicarbonate, ammonium persulfate, butyl acrylate, acrylic acid, sodium dioctyl sulfosuccinate, nonylphenol polyoxyethylene ether, modified black phosphorus nanosheets and ionic liquid impregnated flame retardant powder in step 1 is 300-350g: 0.6-0.7g: 0.8-1g: 150-180g: 4-5g: 4-5g: 9-10g: 1-1.2g: 15-20g.

3. The method for preparing a flame-retardant glass fiber prepreg according to claim 1, characterized in that: The usage ratio of the modified glass fiber, acetone and epoxy resin in step 2 is 30-40g: 200-250mL: 120-150g.

4. The method for preparing a flame-retardant glass fiber prepreg according to claim 2, characterized in that: The modified black phosphorus nanosheets are prepared by the following steps: Disperse melamine in deionized water in a reaction kettle, slowly add formaldehyde solution, and add 0.1M sodium carbonate solution to adjust the pH value to 8-9, heat to 80-85°C and stir to react for 30-40 minutes, add black phosphorus nanosheet dispersion into the reaction kettle, stir to react for 5-6 hours under nitrogen protection, collect precipitate by centrifugation, wash precipitate, and vacuum dry to obtain modified black phosphorus nanosheet; The black phosphorus nanosheet dispersion is prepared by ultrasonically dispersing the black phosphorus nanosheets in N-methylpyrrolidone, and the usage ratio of the black phosphorus nanosheets to the N-methylpyrrolidone is 1-1.2 g: 500-700 mL.

5. The method for preparing a flame-retardant glass fiber prepreg according to claim 4, characterized in that: The dosage ratio of the melamine, deionized water, formaldehyde solution and black phosphorus nanosheet dispersion is 20-30 g: 300-400 mL: 40-60 mL: 500-700 mL.

6. The method for preparing a flame-retardant glass fiber prepreg according to claim 2, characterized in that: The ionic liquid impregnated flame retardant powder is prepared by the following steps: In a reaction kettle, tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide is dissolved in acetone, and then magnesium hydroxide flame retardant powder is added and stirred for 12-14 hours. Then, the solution is evaporated and the precipitate is vacuum dried to obtain ionic liquid impregnated flame retardant powder.

7. The method for preparing a flame-retardant glass fiber prepreg according to claim 6, characterized in that: The dosage ratio of the tri-n-butylmethylammonium bis(trifluoromethylsulfonyl)imide, acetone and magnesium hydroxide flame retardant powder is 3-4g:150-200mL:25-30g.

8. The method for preparing a flame-retardant glass fiber prepreg according to claim 7, characterized in that: The magnesium hydroxide flame retardant powder is prepared by the following steps: Dispersing magnesium hydroxide powder in DMF in a reaction kettle, adding ferric chloride hexahydrate and 2-aminoterephthalic acid, stirring and dissolving, heating to 120-130° C. and reacting for 12-14 hours, cooling, centrifuging and collecting precipitates, washing the precipitates, and vacuum drying to obtain magnesium hydroxide flame retardant powder; The dosage ratio of the magnesium hydroxide powder, DMF, ferric chloride hexahydrate and 2-aminoterephthalic acid is 15-20 g: 500-700 mL: 4-6 g: 6-8 g.

9. A flame retardant glass fiber prepreg, characterized in that: The flame retardant glass fiber prepreg is prepared by the preparation method of any one of claims 1 to 8.

10. Use of the flame-retardant glass fiber prepreg according to claim 9 in electronic component housing materials.

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