Preparation method of novel multifunctional flame-retardant material

Abstract

The invention relates to the technical field of flame retardance, in particular to a preparation method of a novel multifunctional flame-retardant material, which comprises the following steps: S1, preparing a composite molecular sieve; s2, preparing a mixed flame retardant; the novel multifunctional flame-retardant material is achieved through the synergistic effect of the molecular sieve loaded with the liquid flame retardant and the inorganic flame retardant, the liquid flame retardant is efficiently adsorbed in micropores of the molecular sieve, the liquid flame retardant and the inorganic flame retardant form a dual-flame-retardant system, and the compatibility with a base material is good; the molecular sieve is uniformly dispersed after being mixed with the inorganic flame retardant according to an optimized ratio, so that the problem of agglomeration when a traditional molecular sieve is compounded with an organic material is avoided, the compatibility with matrix materials such as polyolefin, polyurethane and polyester is remarkably improved, the problem that the traditional material is easily damped due to moisture absorption is solved, and the molecular sieve has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flame-retardant technology, and in particular to a preparation method of a novel multifunctional flame-retardant material. BACKGROUND

[0002] As a kind of porous material with regular pore structure and large specific surface area, molecular sieve has excellent catalytic and adsorption performance, and is widely used in petroleum chemical industry, fine chemical synthesis, adsorption separation and coal chemical industry. Due to its silicate composition, molecular sieve can be used as the matrix of flame-retardant material. When used in combination with halogen-containing or halogen-free flame retardants, it can reduce heat transfer and promote the formation of carbon layer through barrier effect and catalytic effect, thereby significantly improving the flame-retardant effect, and thus has good application prospects in the field of electronics and electrical appliances.

[0003] Y-type zeolite molecular sieve has a three-dimensional 12-membered ring pore opening (0.74 nm) and a nano-supercage (1.12 nm) structure, and is an important member of the molecular sieve family and the main active component of current industrial cracking catalysts, with the highest annual production and consumption among molecular sieve catalysts. Ultra-stable Y (USY) zeolite is obtained by dealuminating traditional Y zeolite, and has the advantages of low cost and stable performance.

[0004] At present, the flame-retardant material based on molecular sieve enhances the flame-retardant effect mainly through the synergistic effect of molecular sieve and flame retardant. However, in practical application, the following problems exist: poor uniformity when molecular sieve is compounded with organic materials; high cost of material preparation and application; easy generation of odor; easy absorption of water vapor leading to dampness; and high addition amount of flame retardant to achieve the expected flame-retardant grade.

[0005] Therefore, according to the related technology in the above, it is urgent to develop a preparation method of a novel multifunctional flame-retardant material. SUMMARY

[0006] Therefore, according to the related technology in the above, it is urgent to develop a preparation method of a novel multifunctional flame-retardant material.

[0007] Based on the above purpose, the present application provides a preparation method of a novel multifunctional flame-retardant material.

[0008] The preparation method of the novel multifunctional flame-retardant material comprises the following steps: Step S1. Preparing a composite molecular sieve; Step S2. Preparing a mixed flame retardant; Step S3. Preparing a novel multifunctional flame-retardant material; The composite molecular sieve of step S1 is a molecular sieve loaded with a liquid flame retardant; The mixed flame retardant mentioned in step S2 is prepared from a molecular sieve loaded with liquid flame retardant and an inorganic flame retardant; The mass ratio of the molecular sieve to the inorganic flame retardant in the loaded liquid flame retardant is 6-8:2-4.

[0009] Preferably, the molding method used in step S3 to prepare the novel multifunctional flame retardant material is either spray molding or sol-gel method.

[0010] Preferably, the molecular sieve in step S1 is any one or both of Y-type molecular sieve and USY zeolite molecular sieve.

[0011] Preferably, the composite molecular sieve in step S1 is either a Y-type molecular sieve loaded with liquid flame retardant or a USY zeolite molecular sieve loaded with liquid flame retardant.

[0012] Preferably, the liquid flame retardant in step S1 is any one of tricresyl phosphate, diphenyl octyl phosphate, tris(2-chloroethyl) phosphate, tris(2-chloropropyl) phosphate, triethyl phosphate, and tributyl phosphate.

[0013] Preferably, the preparation of the composite molecular sieve in step S1 is carried out using either the in-situ loading method or the post-impregnation loading method.

[0014] Preferably, the in-situ loading method is used to prepare Y-type molecular sieves loaded with liquid flame retardants as follows: Step A1. Gel formation: Mix silicon source, aluminum source and alkali source at SiO2 / Al2O3 = 8-15, stir at 60℃ for 1 hour to form a uniform sol; Step A2. Add liquid flame retardant to the homogeneous sol, stir for 30 min to disperse it evenly, and crystallize at 140℃ for 24 h. The liquid flame retardant grows and embeds into the pores simultaneously with the molecular sieve. Step A3. After crystallization, filter and wash until neutral, dry at 120℃ for 1 hour, and calcine at 400℃ for 6 hours to remove free liquid flame retardant, while retaining the liquid flame retardant adsorbed in the pores.

[0015] Preferably, the silicon source in step A1 is either water glass (Na2SiO3·9H2O) or silica sol, and the SiO2 content in the silicon source is 20%-30%. The aluminum source is either sodium aluminate or aluminum sulfate, and the Al2O3 content in the aluminum source is 5%-10%. The alkali source is sodium hydroxide, which is used to adjust the pH to 10-12.

[0016] Preferably, the liquid flame retardant in step A2 accounts for 5%-15% of the mass of SiO2 in the homogeneous sol.

[0017] Preferably, the preparation process of the in-situ loading method for USY zeolite molecular sieves loaded with liquid flame retardants is as follows: Step B1. Add NaY raw powder to hydrochloric acid solution (liquid-solid ratio of 10:1), stir at 80℃ for 2 hours (dealuminization rate controlled at 30%-40%, target SiO2 / Al2O3=15-25), filter and wash until pH is 6-7 to obtain acid-treated Y-type molecular sieve; Step B2. Place the acid-treated Y-type molecular sieve in a tube furnace, introduce steam at a flow rate of 50 mL / min, and treat at 550℃ for 4 hours to form USY zeolite with a specific surface area of ​​600-700 m2 / g and a mesoporous content increased to 20%-30%, which is beneficial for the diffusion of liquid flame retardants. Step B3. Stir and exchange sodium ions twice with NH4Cl solution for 2 hours each time to remove residual sodium ions. Dry at 120℃ for 1 hour and calcine at 400℃ for 6 hours to obtain hydrogen form USY. Step B4. Add 100g of hydrogen-form USY powder and 15-20g of liquid flame retardant to 100mL of ethanol, and ultrasonically disperse at a frequency of 40kHz for 30min to form a uniform sol. Step B5. Stir at room temperature for 24 hours, centrifuge at 3000 rpm for 10 minutes to remove free liquid flame retardant, and vacuum dry at -0.1 MPa and 60℃ for 12 hours to obtain USY zeolite molecular sieve loaded with liquid flame retardant.

[0018] Preferably, the preparation process of the post-impregnation loading method for Y-type molecular sieves loaded with liquid flame retardants is as follows: Step C1. Dissolve the liquid flame retardant in ethanol to prepare a 10%-30% liquid flame retardant solution; Step C2. Add the liquid flame retardant solution to the Y-type molecular sieve and stir at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed, and obtain a mixed solution in which the mass ratio of liquid flame retardant solution to Y-type molecular sieve is 4:10. Step C3. Dry the mixture under vacuum at 60°C for 12 hours to prevent the liquid flame retardant from evaporating, and obtain a Y-type molecular sieve loaded with liquid flame retardant.

[0019] Preferably, the post-impregnation loading method for preparing USY zeolite molecular sieves loaded with liquid flame retardants is as follows: The liquid flame retardant was mixed with ethanol at a volume ratio of 1:3 to prepare a 30% liquid flame retardant solution. USY zeolite and the liquid flame retardant solution were mixed at a mass ratio of 10:4.5 and stirred at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed. During this process, the solution could be added dropwise using a peristaltic pump to avoid agglomeration. Finally, the solution was vacuum dried at 60°C and then calcined at 300°C for 1 hour to remove the weakly adsorbed liquid flame retardant on the surface, while retaining the chemically adsorbed liquid flame retardant in the pores.

[0020] Preferably, the inorganic flame retardant is any one or more of red phosphorus polyphosphate, ammonium dihydrogen phosphate, zinc phosphate, magnesium ammonium phosphate, aluminum hydroxide, and magnesium hydroxide.

[0021] Preferably, the surface hydrophobicity is designed during the preparation of the novel multifunctional flame retardant material in step S3.

[0022] Preferably, the hydrophobic modifier used in the surface hydrophobic design during spray molding is any one of silane coupling agents and fluorosilanes.

[0023] Preferably, the hydrophobic modifier used in the surface hydrophobic design during the sol-gel molding process is either methyltrimethoxysilane or fluoropropyltrimethoxysilane.

[0024] Preferably, the spray molding process is as follows: The hydrophobic modifier is added to anhydrous ethanol and stirred at 300 rpm and 50°C for 30 min to form a transparent solution in which the hydrophobic modifier is completely dissolved to avoid agglomeration. The powdered mixed flame retardant and the hydrophobic modifier solution are added to a high-speed mixer and stirred at 800 rpm and 30°C for 10 min to ensure that the hydrophobic modifier is uniformly adhered to the surface of the mixed flame retardant material. The mixed material is then fed into a spray drying tower, with the inlet air temperature controlled at 180-200°C, the outlet air temperature at 80-90°C, the atomization pressure at 0.3-0.5 MPa, and the droplet diameter at 50-100 μm. During the spray drying process, the hydrophobic modifier forms a uniform hydrophobic film on the surface. Finally, the material is baked in an oven at 120°C for 2 h to promote the chemical grafting of the hydrophobic modifier with the hydroxyl groups on the material surface, thus simultaneously completing the molding and hydrophobic modification.

[0025] Preferably, the sol-gel molding process is as follows: A hydrophobic modifier was added to the mixed flame retardant sol and stirred at 500 rpm and 50°C for 30 min to allow the hydrophobic modifier to react initially with the silanol groups in the sol. Hydrochloric acid catalyst was added to adjust the pH to 3-4, and the mixture was allowed to stand at room temperature for 1-2 h. The sol gradually gelled. During the gelation process, the methyl groups of the hydrophobic modifier spontaneously migrated to the surface due to their hydrophobicity, forming a structure rich in hydrophobic groups on the surface. Finally, the gel was transferred to a mold and vacuum dried at 60°C for 12 h to avoid air bubbles and remove free moisture. Then, it was baked at 120°C for 2 h to finally form a hydrophobic layer with a large number of methyl groups on the surface of the material.

[0026] The beneficial effects of this invention are: This invention provides a novel method for preparing a multifunctional flame-retardant material. The method achieves this through the synergistic effect of a molecular sieve loaded with a liquid flame retardant and an inorganic flame retardant: the liquid flame retardant (such as phosphate esters) is efficiently adsorbed in the micropores of the molecular sieve, forming a dual flame-retardant system with the inorganic flame retardant (such as ammonium polyphosphate or red phosphorus) (the liquid flame retardant catalyzes char formation, the inorganic flame retardant replenishes flame-retardant elements, and the molecular sieve physically blocks heat). When the two are mixed at a mass ratio of 6-8:2-4, an addition of only 10-20% to matrix materials such as polyolefins and polyurethanes is sufficient to achieve a UL94 V0 flame retardant rating, solving the problem of "high flame retardant addition" in traditional materials.

[0027] Good compatibility with matrix materials: The molecular sieve (Y-type or USY) loaded with liquid flame retardant is granular. After being mixed with inorganic flame retardant in an optimized ratio, it is evenly dispersed, avoiding the agglomeration problem when traditional molecular sieves are combined with organic materials, and significantly improving the compatibility with matrix materials such as polyolefins, polyurethanes, and polyesters.

[0028] Low odor: Molecular sieves (especially USY) have a porous structure (Y-type contains 0.74nm micropores and 1.12nm supercages, and USY has a mesopority of 20-30%). They can capture odor molecules (such as flame retardant volatiles and matrix small molecules) generated during material preparation and use through physical adsorption, reducing the odor level of the material to level 1-2 (close to odorless), thus solving the problem of traditional flame retardant materials "easily generating odors".

[0029] Low water absorption: During the molding process, a hydrophobic layer (containing hydrophobic groups such as -Si(CH3)3 and -CF3) is formed on the material surface through surface hydrophobic design (silane coupling agent / fluorosilane for spray molding, methyltrimethoxysilane / fluoropropyltrimethoxysilane for sol-gel method), which prevents water vapor from entering. The water absorption rate can be controlled at 0.2-0.5% in 24 hours, which solves the problem of traditional materials "easily absorbing water vapor and becoming damp".

[0030] Low cost: USY zeolite molecular sieve (obtained from Y-type molecular sieve through dealumination, with a cost 30% lower than pure Y-type) is used as the carrier; the amount of flame retardant is optimized (10-20% addition is sufficient to meet the standard), reducing raw material consumption; the preparation process (spray molding, sol-gel method) is simple and suitable for large-scale production. This comprehensively reduces the cost of material preparation and application, solving the problem of "high cost" of traditional materials. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0032] Preparation Example 1: A method for preparing Y-type molecular sieves loaded with liquid flame retardants by in-situ loading, comprising the following steps: S1. Mix the silicon source, aluminum source, and alkali source at a ratio of SiO2 / Al2O3=8, stir at 60℃ for 1 hour to form a uniform sol. The silicon source is water glass (Na2SiO3·9H2O) with a SiO2 content of 20%. The aluminum source is sodium aluminate with an Al2O3 content of 5%. The alkali source is sodium hydroxide, which is used to adjust the pH to 10-12. S2. Add tricresyl phosphate to the homogeneous sol and stir for 30 min to disperse it evenly. Crystallize at 140℃ for 24 h. The tricresyl phosphate grows and embeds into the channels simultaneously with the molecular sieve. The tricresyl phosphate accounts for 5% of the mass of SiO2 in the homogeneous sol. S3. After crystallization, filter and wash until neutral, dry at 120℃ for 1 hour, and calcine at 400℃ for 6 hours to remove free tricresyl phosphate, while retaining the liquid flame retardant adsorbed in the pores, to obtain a Y-type molecular sieve loaded with liquid flame retardant.

[0033] Preparation Example 2: A method for preparing Y-type molecular sieves loaded with liquid flame retardants by in-situ loading, comprising the following steps: S1. Mix the silicon source, aluminum source, and alkali source at a ratio of SiO2 / Al2O3=15, stir at 60℃ for 1 hour to form a homogeneous sol. The silicon source is a silica sol with a SiO2 content of 30%, the aluminum source is aluminum sulfate with an Al2O3 content of 10%, and the alkali source is sodium hydroxide, which is used to adjust the pH to 10-12. S2. Add diphenyl octyl phosphate to the homogeneous sol, stir for 30 min to disperse it evenly, and crystallize at 140℃ for 24 h. Diphenyl octyl phosphate grows and embeds into the channels synchronously with the molecular sieve, wherein diphenyl octyl phosphate accounts for 15% of the mass of SiO2 in the homogeneous sol; S3. After crystallization, filter and wash until neutral, dry at 120℃ for 1 hour, calcine at 400℃ for 6 hours to remove free diphenyl octyl phosphate, and retain the liquid flame retardant adsorbed in the pores to obtain Y-type molecular sieve loaded with liquid flame retardant.

[0034] Preparation Example 3: A method for preparing Y-type molecular sieves loaded with liquid flame retardants using a post-impregnation loading method, comprising the following steps: S1. Dissolve tris(2-chloroethyl) phosphate in ethanol to prepare a 10%-30% liquid flame retardant solution; S2. Add the liquid flame retardant solution to the Y-type molecular sieve and stir at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed, and obtain a mixed solution in which the mass ratio of liquid flame retardant solution to Y-type molecular sieve is 4:10. S3. The mixture is vacuum dried at 60℃ for 12h to prevent the liquid flame retardant from evaporating, thus obtaining a Y-type molecular sieve loaded with liquid flame retardant.

[0035] Preparation Example 4: A method for preparing Y-type molecular sieves loaded with liquid flame retardants by a post-impregnation loading method, comprising the following steps: S1. Dissolve tris(2-chloropropyl)phosphate in ethanol to prepare a 30% liquid flame retardant solution; S2. Add the liquid flame retardant solution to the Y-type molecular sieve and stir at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed, and obtain a mixed solution in which the mass ratio of liquid flame retardant solution to Y-type molecular sieve is 4:10. S3. The mixture is vacuum dried at 60℃ for 12h to prevent the liquid flame retardant from evaporating, thus obtaining a Y-type molecular sieve loaded with liquid flame retardant.

[0036] Preparation Example 5: A method for preparing USY zeolite molecular sieves loaded with liquid flame retardants by in-situ loading, comprising the following steps: S1. Add NaY raw powder to hydrochloric acid solution (liquid-solid ratio of 10:1), stir at 80℃ for 2h (dealuminization rate controlled at 30%, target SiO2 / Al2O3=15), filter and wash until pH is 6-7 to obtain acid-treated Y-type molecular sieve; S2. The acid-treated Y-type molecular sieve was placed in a tube furnace, and steam was introduced at a flow rate of 50 mL / min. The mixture was treated at 550 °C for 4 hours to form a specific surface area of ​​600 m². 2 / g, USY zeolite with increased mesoporous content to 20% facilitates the diffusion of liquid flame retardants; S3. Stir and exchange with NH4Cl solution twice, 2 hours each time, to remove residual sodium ions. Dry at 120℃ for 1 hour and calcine at 400℃ for 6 hours to obtain hydrogen form USY. S4. Add 100g of hydrogen-form USY powder and 15-20g of triethyl phosphate to 100mL of ethanol, and ultrasonically disperse at a frequency of 40kHz for 30min to form a uniform sol. S5. Stir at room temperature for 24 h, centrifuge at 3000 rpm for 10 min to remove free triethyl phosphate, and vacuum dry at -0.1 MPa and 60 °C for 12 h to obtain USY zeolite molecular sieve loaded with liquid flame retardant.

[0037] Preparation Example 6: A method for preparing USY zeolite molecular sieves loaded with liquid flame retardants by in-situ loading, comprising the following steps: S1. Add NaY raw powder to hydrochloric acid solution (liquid-solid ratio of 10:1), stir at 80℃ for 2h (dealuminization rate controlled at 40%, target SiO2 / Al2O3=25), filter and wash until pH is 6-7 to obtain acid-treated Y-type molecular sieve; S2. The acid-treated Y-type molecular sieve was placed in a tube furnace, and steam was introduced at a flow rate of 50 mL / min. The mixture was treated at 550 °C for 4 hours to form a specific surface area of ​​700 m². 2 / g, USY zeolite with increased mesoporous content to 30% facilitates the diffusion of liquid flame retardants; S3. Stir and exchange with NH4Cl solution twice, 2 hours each time, to remove residual sodium ions. Dry at 120℃ for 1 hour and calcine at 400℃ for 6 hours to obtain hydrogen form USY. S4. Add 100g of hydrogen-form USY powder and 20g of tributyl phosphate to 100mL of ethanol, and ultrasonically disperse at a frequency of 40kHz for 30min to form a uniform sol. S5. Stir at room temperature for 24 h, centrifuge at 3000 rpm for 10 min to remove free tributyl phosphate, and vacuum dry at -0.1 MPa and 60℃ for 12 h to obtain USY zeolite molecular sieve loaded with liquid flame retardant.

[0038] Preparation Example 7: A method for preparing USY zeolite molecular sieves loaded with liquid flame retardants using a post-impregnation loading method, comprising the following steps: Trimethylbenzene phosphate and ethanol were mixed at a volume ratio of 1:3 to prepare a 30% liquid flame retardant solution. USY zeolite and the liquid flame retardant solution were mixed at a mass ratio of 10:4.5 and stirred at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed. During this process, the solution could be added dropwise using a peristaltic pump to avoid agglomeration. Finally, the solution was vacuum dried at 60°C and then calcined at 300°C for 1 hour to remove the weakly adsorbed liquid flame retardant on the surface, while retaining the chemically adsorbed liquid flame retardant in the pores, thus obtaining USY zeolite molecular sieve loaded with liquid flame retardant.

[0039] Preparation Example 8: A method for preparing USY zeolite molecular sieves loaded with liquid flame retardants using a post-impregnation loading method, comprising the following steps: Diphenyl octyl phosphate and ethanol were mixed at a volume ratio of 1:3 to prepare a 30% liquid flame retardant solution. USY zeolite and the liquid flame retardant solution were mixed at a mass ratio of 10:4.5 and stirred at room temperature for 2 hours to allow the liquid flame retardant solution to be completely adsorbed. During this process, the solution could be added dropwise using a peristaltic pump to avoid agglomeration. Finally, the solution was vacuum dried at 60°C and then calcined at 300°C for 1 hour to remove the weakly adsorbed liquid flame retardant on the surface, while retaining the chemically adsorbed liquid flame retardant in the pores, thus obtaining USY zeolite molecular sieve loaded with liquid flame retardant.

[0040] Example 1: A method for preparing a novel multifunctional flame-retardant material using spray molding, comprising the following steps: S1. Mix Y-type molecular sieve loaded with liquid flame retardant and ammonium polyphosphate in a mass ratio of 6:2 to obtain a mixed flame retardant; S2. Add the silane coupling agent to anhydrous ethanol and stir at 300 rpm and 50°C for 30 min to form a transparent solution in which the hydrophobic modifier is completely dissolved to avoid agglomeration. Add the powdered mixed flame retardant and the hydrophobic modifier solution to a high-speed mixer and stir at 800 rpm and 30°C for 10 min to ensure that the hydrophobic modifier is uniformly attached to the surface of the mixed flame retardant material. Send the mixed material into a spray drying tower, control the inlet air temperature to 180°C, the outlet air temperature to 80°C, the atomization pressure to 0.3 MPa, and the droplet diameter to 50-100 μm. During the spray drying process, the hydrophobic modifier forms a uniform hydrophobic film on the surface. Finally, bake in an oven at 120°C for 2 h to promote the chemical grafting of the hydrophobic modifier with the hydroxyl groups on the material surface, and simultaneously complete the molding and hydrophobic modification to obtain a new type of multifunctional flame retardant material.

[0041] Example 2: A method for preparing a novel multifunctional flame-retardant material using spray molding, comprising the following steps: S1. Mix USY zeolite molecular sieve loaded with liquid flame retardant and ammonium dihydrogen phosphate in a mass ratio of 7:3 to obtain a mixed flame retardant; S2. Fluorosilane is added to anhydrous ethanol and stirred at 300 rpm and 50°C for 30 min to form a transparent solution in which the hydrophobic modifier is completely dissolved to avoid agglomeration. The powdered mixed flame retardant and the hydrophobic modifier solution are added to a high-speed mixer and stirred at 800 rpm and 30°C for 10 min to ensure that the hydrophobic modifier is uniformly attached to the surface of the mixed flame retardant material. The mixed material is then fed into a spray drying tower, with the inlet air temperature controlled at 190°C, the outlet air temperature at 85°C, the atomization pressure at 0.4 MPa, and the droplet diameter at 50-100 μm. During the spray drying process, the hydrophobic modifier forms a uniform hydrophobic film on the surface. Finally, the material is baked in an oven at 120°C for 2 h to promote the chemical grafting of the hydrophobic modifier with the hydroxyl groups on the material surface, thus simultaneously completing the molding and hydrophobic modification to obtain a novel multifunctional flame retardant material.

[0042] Example 3: A method for preparing a novel multifunctional flame-retardant material using spray molding, comprising the following steps: S1. Mix Y-type molecular sieve loaded with liquid flame retardant and zinc phosphate at a mass ratio of 8:4 to obtain a mixed flame retardant; S2. Add the silane coupling agent to anhydrous ethanol and stir at 300 rpm and 50°C for 30 min to form a transparent solution in which the hydrophobic modifier is completely dissolved to avoid agglomeration. Add the powdered mixed flame retardant and the hydrophobic modifier solution to a high-speed mixer and stir at 800 rpm and 30°C for 10 min to ensure that the hydrophobic modifier is uniformly attached to the surface of the mixed flame retardant material. Send the mixed material into a spray drying tower, control the inlet air temperature to 200°C, the outlet air temperature to 90°C, the atomization pressure to 0.5 MPa, and the droplet diameter to 50-100 μm. During the spray drying process, the hydrophobic modifier forms a uniform hydrophobic film on the surface. Finally, bake in an oven at 120°C for 2 h to promote the chemical grafting of the hydrophobic modifier with the hydroxyl groups on the material surface, and simultaneously complete the molding and hydrophobic modification to obtain a new type of multifunctional flame retardant material.

[0043] Example 4: A method for preparing a novel multifunctional flame-retardant material using the sol-gel method, comprising the following steps: S1. Mix Y-type molecular sieve loaded with liquid flame retardant and ammonium polyphosphate at a mass ratio of 6:2 to obtain a mixed flame retardant; S2. Methyltrimethoxysilane was added to the mixed flame retardant sol and stirred at 500 rpm and 50°C for 30 min to allow the hydrophobic modifier to react initially with the silanol groups in the sol. Hydrochloric acid catalyst was added to adjust the pH to 3-4, and the mixture was allowed to stand at room temperature for 1 h. The sol gradually gelled. During the gelation process, the methyl groups of the hydrophobic modifier spontaneously migrated to the surface due to their hydrophobicity, forming a structure rich in hydrophobic groups on the surface. Finally, the gel was transferred to a mold and vacuum dried at 60°C for 12 h to avoid air bubbles and remove free water. Then, it was baked at 120°C for 2 h to finally form a hydrophobic layer with a large number of methyl groups on the surface of the material, thus obtaining a novel multifunctional flame retardant material.

[0044] Example 5: A method for preparing a novel multifunctional flame-retardant material using the sol-gel method, comprising the following steps: S1. Mix USY zeolite molecular sieve loaded with liquid flame retardant and ammonium dihydrogen phosphate in a mass ratio of 7:3 to obtain a mixed flame retardant; S2. Fluoropropyltrimethoxysilane was added to the mixed flame retardant sol and stirred at 500 rpm and 50°C for 30 min to allow the hydrophobic modifier to react initially with the silanol groups in the sol. Hydrochloric acid catalyst was added to adjust the pH to 3-4, and the mixture was allowed to stand at room temperature for 1.5 h. The sol gradually gelled. During the gelation process, the methyl groups of the hydrophobic modifier spontaneously migrated to the surface due to their hydrophobicity, forming a structure rich in hydrophobic groups on the surface. Finally, the gel was transferred to a mold and vacuum dried at 60°C for 12 h to avoid air bubbles and remove free moisture. Then, it was baked at 120°C for 2 h to finally form a hydrophobic layer with a large number of methyl groups on the surface of the material, thus obtaining a novel multifunctional flame retardant material.

[0045] Example 6: A method for preparing a novel multifunctional flame-retardant material using the sol-gel method, comprising the following steps: S1. Mix Y-type molecular sieve loaded with liquid flame retardant and zinc phosphate at a mass ratio of 8:4 to obtain a mixed flame retardant; S2. Methyltrimethoxysilane was added to the mixed flame retardant sol and stirred at 500 rpm and 50°C for 30 min to allow the hydrophobic modifier to react initially with the silanol groups in the sol. Hydrochloric acid catalyst was added to adjust the pH to 3-4, and the mixture was allowed to stand at room temperature for 2 h. The sol gradually gelled. During the gelation process, the methyl groups of the hydrophobic modifier spontaneously migrated to the surface due to their hydrophobicity, forming a structure rich in hydrophobic groups on the surface. Finally, the gel was transferred to a mold and vacuum dried at 60°C for 12 h to avoid air bubbles and remove free moisture. Then, it was baked at 120°C for 2 h to finally form a hydrophobic layer with a large number of methyl groups on the surface of the material, thus obtaining a novel multifunctional flame retardant material.

[0046] Comparative Example 1: Compared with Example 1, no liquid flame retardant was loaded (only Y-type molecular sieve: ammonium polyphosphate = 6:2), and all other steps and parameters were the same, finally obtaining a novel multifunctional flame retardant material.

[0047] Comparative Example 2: Compared with Example 1, no surface hydrophobic modification was performed (only spray molding, no silane coupling agent), and all other steps and parameters were the same, finally obtaining a novel multifunctional flame retardant material.

[0048] Comparative Example 3: Compared with Example 1, only the ratio of Y-type molecular sieve loaded with liquid flame retardant to ammonium polyphosphate was adjusted to 5:5 (deviating from the recommended ratio of 6-8:2-4). All other steps and parameters were the same, and a new type of multifunctional flame retardant material was finally obtained.

[0049] Comparative Example 4: Compared with Example 4, conventional molecular sieves (non-dealuminized NaY) were used instead of USY (comparing the cost reduction and dispersibility advantages of USY).

[0050] Performance testing: 1. Flame retardancy rating test: According to the UL94 vertical burning standard, the sample size is 127mm×12.7mm×3.2mm. The burning time and dripping situation are recorded to determine the flame retardancy rating (V0 / V1 / V2).

[0051] 2. Oxygen Index (LOI) Test: According to GB / T 2406.2-2009, with a sample size of 80mm×10mm×4mm, determine the minimum oxygen concentration required to sustain combustion (the higher the LOI value, the better the flame retardancy).

[0052] 3. Water absorption test: According to GB / T 1034-2008, the sample is weighed after drying (m0), soaked in deionized water for 24 hours, wiped dry and weighed (m1), and the water absorption rate is calculated as (m1-m0) / m0×100%.

[0053] 4. Odor rating test: According to VDA 270 standard, 10g of sample is placed in a 5L sealed container and heated at 80℃ for 2 hours. The sample is evaluated by 3 professionals according to a rating of 1-6 (level 1: no odor, level 6: strong odor), and the average value is taken.

[0054] Table 1 Summary of performance test results in Examples 1-6 and Comparative Examples 1-4

[0055] Table 2 Summary of performance test results in Examples 1-6 and Comparative Examples 1-4

[0056] Data Analysis: 1. Flame retardant performance analysis (core advantages: high flame retardancy, low additive dosage): Examples 1-6 all achieved V0 rating with an LOI ≥ 31%, and the matrix addition was only 13-16%, verifying the technical effectiveness of "achieving V0 rating with an addition of 10-20%". The core reason is that the loaded liquid flame retardant (such as tricresyl phosphate) combines with the micropores of the molecular sieve to achieve a high adsorption ratio. At the same time, it works synergistically with the inorganic flame retardant (such as ammonium polyphosphate) – the liquid flame retardant catalyzes char formation, the inorganic flame retardant replenishes phosphorus, and the molecular sieve physically blocks heat, all three working together to improve flame retardant efficiency.

[0057] Comparative Example 1, lacking a liquid flame retardant, relied solely on the synergistic effect of molecular sieves and inorganic flame retardants, resulting in a LOI of only 24% and a flame retardant rating of only V2. Furthermore, even with the addition of 30%, it still could not reach V0, demonstrating that the "high flame retardant synergy" of liquid flame retardants is irreplaceable.

[0058] Comparative Example 3, due to deviation in dosage ratio (excessive inorganic flame retardant), resulted in uneven dispersion caused by the aggregation of inorganic flame retardant, causing the LOI to drop to 28%. It required the addition of 25% to reach V0, verifying the rationality of the "6-8:2-4" dosage ratio - the dominant proportion of molecular sieve can ensure dispersibility and the function of flame retardant adsorption carrier.

[0059] 2. Water absorption performance analysis (core advantage: low water absorption): Examples 1-6 have a water absorption rate of only 0.2-0.5%, which is much lower than the 2.8% of Comparative Example 2. This is because surface hydrophobic modification (such as silane coupling agent) forms a hydrophobic layer (containing -Si(CH3)3 groups) on the material surface, which blocks water vapor penetration.

[0060] Comparative Example 2 was not modified to be hydrophobic, and the material surface had no hydrophobic layer. Water vapor could easily enter through the micropores, causing the water absorption rate to soar. This proves that "surface hydrophobic design" is the key to achieving "low water absorption".

[0061] 3. Odor and Cost Analysis (Core Advantages: Low Odor, Cost Reduction): Examples 1-6 all had an odor level of 1-2 (close to no odor) because the porous structure of the molecular sieve adsorbed odor molecules (liquid flame retardant and matrix volatiles); Comparative Example 4 used a traditional NaY molecular sieve, whose microporous structure was not optimized (low mesoporous rate), and its odor adsorption capacity was weak, with the odor level rising to level 3, proving that the "mesoporous rate improvement (20-30%)" of USY can enhance the low odor effect.

[0062] Examples 1-6 use USY molecular sieve (dealuminized, cost 30% lower than NaY) with an addition amount of only 13-16%. The overall cost is 20% lower than that of Comparative Example 4 (traditional NaY + high addition amount), which verifies the "cost reduction" effect.

[0063] III. Conclusion: This invention achieves the core advantages of a material—high flame retardancy (V0 grade, 10-20% addition), low water absorption (≤0.5%), low odor (1-2 grade), and low cost—through a combination of "liquid flame retardant-loaded molecular sieve + synergistic effect of inorganic flame retardant (6-8:2-4 dosage ratio) + surface hydrophobic modification." Comparative data shows that the absence of any step (such as lack of liquid flame retardant loading, lack of hydrophobic modification, or deviation in dosage ratio) leads to a significant decrease in performance, further demonstrating the rationality and synergistic effect of the invention's technical solution. This material can be stably applied to polyolefin, polyurethane, and other matrices, meeting the stringent requirements of the electronics and electrical appliance industries.

[0064] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

[0065] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for preparing a novel multifunctional flame-retardant material, characterized in that, Includes the following steps: Step S1. Prepare composite molecular sieves; Step S2. Prepare the mixed flame retardant; Step S3. Prepare a novel multifunctional flame-retardant material; The composite molecular sieve mentioned in step S1 is a molecular sieve loaded with liquid flame retardant; The mixed flame retardant mentioned in step S2 is prepared from a molecular sieve loaded with liquid flame retardant and an inorganic flame retardant; The mass ratio of the molecular sieve to the inorganic flame retardant in the loaded liquid flame retardant is 6-8:2-4.

2. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The molding method used in step S3 to prepare the novel multifunctional flame retardant material is either spray molding or sol-gel method.

3. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The molecular sieve mentioned in step S1 is any one or both of Y-type molecular sieve and USY zeolite molecular sieve.

4. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The liquid flame retardant mentioned in step S1 is any one of tricresyl phosphate, diphenyl octyl phosphate, tris(2-chloroethyl) phosphate, tris(2-chloropropyl) phosphate, triethyl phosphate, and tributyl phosphate.

5. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, In step S1, the preparation of the composite molecular sieve can be carried out using either the in-situ loading method or the post-impregnation loading method.

6. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The inorganic flame retardant is any one or more of red phosphorus polyphosphate, ammonium dihydrogen phosphate, zinc phosphate, magnesium ammonium phosphate, aluminum hydroxide, and magnesium hydroxide.

7. The method for preparing the novel multifunctional flame-retardant material according to claim 1, characterized in that, In step S3, the surface hydrophobicity is designed during the preparation of the novel multifunctional flame-retardant material.

8. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The hydrophobic modifier used in the surface hydrophobic design during spray molding is either a silane coupling agent or a fluorosilane.

9. The preparation method of the novel multifunctional flame-retardant material according to claim 1, characterized in that, The hydrophobic modifier used in the surface hydrophobic design during the sol-gel molding process is either methyltrimethoxysilane or fluoropropyltrimethoxysilane.

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