Flame retardant based on molecular sieve, preparation method of flame retardant and application of flame retardant in polyurethane adhesive

Abstract

The invention belongs to the technical field of molecular sieves, and particularly relates to a flame retardant based on a molecular sieve, a preparation method of the flame retardant and application of the flame retardant in polyurethane adhesive. The flame retardant based on the molecular sieve is obtained by modifying a doped molecular sieve loaded inorganic flame retardant with a modifier; the doped molecular sieve is a NaY molecular sieve doped with Ca < 2 + > or / and K < + >; the modifying agent is prepared from silazane and isocyanate silane in sequence; the molecular sieve-based flame retardant provided by the invention can maintain certain water absorption and also has good dispersity and flame retardance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of molecular sieve, and particularly relates to a flame retardant based on molecular sieve, a preparation method thereof and application of the flame retardant in polyurethane glue. BACKGROUND

[0002] Molecular sieve is a crystalline material composed of silicon-oxygen and aluminum-oxygen tetrahedron, and has a large specific surface area and pore volume, and can play a catalytic and adsorbing role.

[0003] The conventional molecular sieve is usually used as an adsorbent when applied in polyurethane glue. During the synthesis of polyurethane glue, the isocyanate is very active and is easy to react with trace water in the polyol component to generate carbon dioxide, resulting in pinholes and bubbles in the glue film. The molecular sieve has a dual role of eliminating excess trace water in the polyurethane glue system and adsorbing carbon dioxide.

[0004] At present, many industries require polyurethane glue to have good flame retardancy, so the polyurethane glue in the prior art usually adds a flame retardant. In addition to the adsorbing role, the molecular sieve also has high specific surface area and high thermal stability, and a unique porous structure, and can also be used as a flame retardant. Therefore, it is of great significance to develop a flame retardant based on molecular sieve to simultaneously eliminate excess trace water in the polyurethane glue system and make the polyurethane glue have flame retardancy.

[0005] The prior art on the molecular sieve-based flame retardant is mainly applied in plastics. For example, a Chinese patent with publication number CN116589752A discloses a composite flame retardant based on hierarchical pore molecular sieve and a preparation method thereof, which comprises the following steps: S1, activating the hierarchical pore molecular sieve at high temperature; S2, adding the flame retardant and silane coupling agent into a reactor, stirring under inert gas protection for a certain time to obtain a silane coupling agent modified flame retardant; S3, under nitrogen protection, adding the activated hierarchical pore molecular sieve into a flask, adding deionized water, stirring and heating to 80℃, then adding the silane coupling agent modified flame retardant, vacuum impregnating, washing, filtering, drying and grinding to obtain the composite flame retardant. A Chinese patent with publication number CN119505372A discloses a molecular sieve-based flame retardant material and a preparation method thereof, which comprises a hollow molecular sieve and a flame retardant. The hollow molecular sieve has a microporous hollow structure, and the flame retardant is coated or embedded in the micropores and hollow structure of the hollow molecular sieve and / or the crystal surface of the hollow molecular sieve. The preparation method comprises the following steps: C1, introducing the flame retardant into the hollow molecular sieve by impregnation or dissolution method, so that the flame retardant is partially adsorbed in the micropores and / or surface of the hollow molecular sieve; C2, mixing the hollow molecular sieve containing the flame retardant with a crystallization solution, and performing hydrothermal recrystallization reaction at 120-180℃; C3, after the recrystallization reaction is completed, the sample is separated by filtration or centrifugation, and the sample is washed with deionized water to remove the unreacted crystallization solution; C4, drying the sample separated in step C3 to obtain the molecular sieve-based flame retardant material.

[0006] However, when applied in polyurethane glue, the molecular sieve has high surface activity and is easy to agglomerate, and the hydroxyl group on the surface of the molecular sieve makes it difficult to disperse in an organic medium, so the above-mentioned cannot be directly applied in the polyurethane glue system. SUMMARY

[0007] Therefore, one object of the present application is to provide a molecular sieve-based flame retardant. The molecular sieve-based flame retardant provided by the present application can maintain a certain water absorption while having good dispersibility and flame retardancy.

[0008] Another object of the present application is to provide a preparation method of the molecular sieve-based flame retardant.

[0009] Still another object of the present application is to provide an application of the molecular sieve-based flame retardant in polyurethane glue.

[0010] To achieve the above-mentioned objects, the first aspect of the present application provides a molecular sieve-based flame retardant, which is obtained by doping a molecular sieve with an inorganic flame retardant and then modifying with a modifier. 2+ or / and K +a NaY molecular sieve; the modifiers successively include a silazane and an isocyanate silane; The application is based on a molecular sieve-based flame retardant which is obtained by doping a molecular sieve with an inorganic flame retardant and then modifying the same with a modifier. The flame retardant effect of the silazane and the flame retardant effect of the molecular sieve loaded with the inorganic flame retardant are utilized to achieve synergistic flame retardation. However, the application system of the molecular sieve-based flame retardant of the application is a polyurethane adhesive. In addition to the flame retardancy, the application also aims to use the molecular sieve-based flame retardant to absorb moisture and gas in the polyurethane adhesive to avoid the problem of blistering of the polyurethane adhesive. In addition, the molecular sieve-based flame retardant also needs to have good dispersibility in the polyurethane adhesive to avoid agglomeration and delamination. The inventors have found that the molecular sieve-based flame retardant obtained by modifying the molecular sieve loaded with the inorganic flame retardant with the silazane has good flame retardancy and good dispersibility. However, the loading of the inorganic flame retardant on the molecular sieve may affect the adsorption of the pore and the hydrophobic effect of the silazane, resulting in poor water absorption.

[0011] To further solve the problem, the inventors continue to modify the molecular sieve loaded with the inorganic flame retardant with the silazane and then modify the same with the isocyanate silane. The isocyanate group on the surface of the molecular sieve-based flame retardant is utilized to improve the water absorption of the same.

[0012] In addition, the inventors have found in the test process that the modification sequence of the silazane and the isocyanate silane has an effect on the water absorption and the flame retardancy.

[0013] As a preferred embodiment of the application, the preparation method of the doped molecular sieve comprises the following steps: adding aluminum chloride, sodium silicate, potassium silicate or / and calcium chloride into water to prepare a mixture, stirring to obtain a precursor; the precursor is further subjected to hydrothermal reaction, and after the hydrothermal reaction is completed, centrifugation, washing and drying are performed to obtain the doped molecular sieve.

[0014] As a preferred embodiment of the application, when the doped molecular sieve is a Ca 2+ doped NaY molecular sieve, the mass ratio of the aluminum chloride, the sodium silicate and the calcium chloride is 45-52:40-45:5-7.

[0015] As a preferred embodiment of the application, when the doped molecular sieve is a K + doped NaY molecular sieve, the mass ratio of the aluminum chloride, the sodium silicate and the potassium silicate is 45-52:19-25:24-30.

[0016] As a preferred embodiment of the application, when the doped molecular sieve is a Ca 2+ and K + doped NaY molecular sieve, the mass ratio of the aluminum chloride, the sodium silicate, the potassium silicate and the calcium chloride is 45-50:19-22:24-27:5-7.

[0017] As a preferred embodiment of the present application, the mass concentration of the mixture is 10-20%.

[0018] As a preferred embodiment of the present application, the stirring speed is 7000-10000 rpm, and the stirring time is 2-5 h.

[0019] As a preferred embodiment of the present application, the temperature of the hydrothermal reaction is 190-210℃, and the time of the hydrothermal reaction is 12-24 h.

[0020] As a preferred embodiment of the present application, the inorganic flame retardant is selected from nano-sized magnesium hydroxide and / or nano-sized aluminum hydroxide.

[0021] As a preferred embodiment of the present application, the particle size of the nano-sized magnesium hydroxide is 10-20 nm.

[0022] As a preferred embodiment of the present application, the particle size of the nano-sized aluminum hydroxide is 10-20 nm.

[0023] As a preferred embodiment of the present application, the silazane is selected from at least one of tetramethyldisilazane and hexamethyldisilazane.

[0024] As a preferred embodiment of the present application, the isocyanate group silane is selected from at least one of 3-isocyanate propyl trimethoxysilane and 3-isocyanate propyl triethoxysilane.

[0025] The second aspect of the present application provides a preparation method of a molecular sieve-based flame retardant, comprising the following steps: S1, dispersing an inorganic flame retardant in deionized water, first adding a dispersant and stirring uniformly, then adding a doped molecular sieve and stirring uniformly, soaking for 3-5 h, drying, and calcining to obtain a doped molecular sieve loaded with an inorganic flame retardant; S2, mixing silazane and ethanol to obtain a silazane solution; preheating the doped molecular sieve loaded with the inorganic flame retardant, spraying the silazane solution on the surface of the doped molecular sieve loaded with the inorganic flame retardant under stirring, continuing to stir, and drying to obtain a doped molecular sieve loaded with an inorganic flame retardant; S3, mixing isocyanate group silane coupling agent and methanol, adjusting pH, and stirring to obtain an isocyanate group silane coupling agent solution; preheating the doped molecular sieve loaded with the inorganic flame retardant, spraying the isocyanate group silane coupling agent solution on the surface of the doped molecular sieve loaded with the inorganic flame retardant under stirring, continuing to stir, and drying to obtain a molecular sieve-based flame retardant.

[0026] As a preferred embodiment of the present application, the mass ratio of the inorganic flame retardant, the dispersant, the doped molecular sieve, and the deionized water in step S1 is 1:0.1-0.3:3-5:10-15.

[0027] As a preferred embodiment of the present application, the dispersant in step S1 is polyacrylic acid.

[0028] As a preferred embodiment of the present application, the temperature of the calcination in step S1 is 300-500℃, and the time of the calcination is 3-6h.

[0029] The inventors found in the experiment that adding a dispersant polyacrylic acid in the preparation of the doped molecular sieve loaded inorganic flame retardant can effectively improve the flame retardant effect of the molecular sieve-based flame retardant, and the inventors guess that it is because the polyacrylic acid makes the inorganic flame retardant acidic, and the doped molecular sieve of the present application has more basic sites, thereby improving the loading of the inorganic flame retardant.

[0030] As a preferred embodiment of the present application, the mass ratio of the silazane, ethanol and the doped molecular sieve loaded inorganic flame retardant in step S2 is 6-10:40-60:10.

[0031] As a preferred embodiment of the present application, step S2 is specifically: mixing the silazane and ethanol to obtain a silazane solution; preheating the doped molecular sieve loaded inorganic flame retardant to 70-90℃, spraying the silazane solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continuing to stir for 1-2h, and drying to obtain an intermediate product 1; As a preferred embodiment of the present application, the mass ratio of the isocyanate-based silane coupling agent, methanol and the intermediate product 1 in step S3 is 3-6:80-120:10.

[0032] As a preferred embodiment of the present application, step S3 is specifically: mixing the isocyanate-based silane coupling agent and methanol, adjusting the pH to 3-4 with hydrochloric acid, stirring for 2-3h to obtain an isocyanate-based silane coupling agent solution; preheating the intermediate product 1 to 40-50℃, spraying the isocyanate-based silane coupling agent solution on the surface of the intermediate product 1 under stirring, continuing to stir for 1-2h, and drying to obtain the molecular sieve-based flame retardant.

[0033] The third aspect of the present application provides a use of the molecular sieve-based flame retardant in polyurethane glue.

[0034] Compared with the prior art, the present application has the following beneficial effects: 1. The molecular sieve-based flame retardant of the present application is obtained by modifying the doped molecular sieve loaded inorganic flame retardant with a modifier, and the flame retardant effect of silazane and the flame retardant effect of the molecular sieve loaded inorganic flame retardant are realized in a synergistic manner. 2. The present application continues to modify the doped molecular sieve loaded inorganic flame retardant with an isocyanate-based silane after modification with silazane, and the water absorption of the molecular sieve-based flame retardant is improved by the isocyanate group on the surface of the molecular sieve-based flame retardant. 3、The present application controls the modification sequence of silazane and isocyanate-based silane to improve the water absorption and flame retardancy of the molecular sieve-based flame retardant.

[0035] 4、The present application adds a dispersant polyacrylic acid in the preparation process of the doped molecular sieve loaded inorganic flame retardant, which can effectively improve the flame retardant effect of the molecular sieve-based flame retardant. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 X-ray diffraction patterns of NaCaKY, NaKY, NaCaY and NaY molecular sieves of Preparation Example 1-Preparation Example 4; Figure 2 Scanning electron microscope images of the molecular sieve-based flame retardants of Examples 1-4, wherein, Figure 2 (a) represents Example 4, Figure 2 (b) represents Example 3, Figure 2 (c) represents Example 2, Figure 2 (d) represents Example 1. DETAILED DESCRIPTION

[0037] In order to make the skilled in the art more clearly understand the technical solutions described in the present application, the following examples are listed for illustration. It should be pointed out that the following examples do not constitute a limitation on the scope of protection required by the present application.

[0038] The raw materials, reagents or devices used in the following examples and comparative examples can be obtained from conventional commercial channels or can be obtained by existing known methods, unless otherwise specified.

[0039] Preparation of molecular sieve (1) Preparation of NaCaKY molecular sieve Aluminum chloride, sodium silicate, potassium silicate and calcium chloride were added to water in a mass ratio of 47.17:20.91:25.68:6.24 to prepare a mixture with a mass concentration of 15%, which was stirred at 25°C and a rotation speed of 8000 rpm for 4h to obtain a precursor. The precursor was further subjected to hydrothermal reaction at 200°C in a stainless steel pressure cooker for 24h. After the hydrothermal reaction was completed, centrifugation, washing and drying were performed to obtain the product.

[0040] (2) Preparation of NaKY molecular sieve Aluminum chloride, sodium silicate and potassium silicate were added to water in a mass ratio of 50.31:22.3:27.39 to prepare a mixture with a mass concentration of 15%, which was stirred at 25°C and a rotation speed of 8000 rpm for 4h to obtain a precursor. The precursor was further subjected to hydrothermal reaction at 200°C in a stainless steel pressure cooker for 24h. After the hydrothermal reaction was completed, centrifugation, washing and drying were performed to obtain the product.

[0041] (3) Preparation of NaCaY molecular sieve Aluminum chloride, sodium silicate, and calcium chloride were added to water in a mass ratio of 49.83:43.58:6.59 to prepare a mixture with a mass concentration of 15%. The mixture was stirred at 25°C and 8000 rpm for 4 hours to obtain a precursor. The precursor was further subjected to a hydrothermal reaction in a stainless steel pressure cooker at 200°C for 24 hours. After the hydrothermal reaction was completed, the precursor was centrifuged, washed, and dried to obtain the final product.

[0042] (4) Preparation of NaY molecular sieve Aluminum chloride and sodium silicate were added to water at a mass ratio of 53.35:46.65 to prepare a mixture with a mass concentration of 15%. The mixture was stirred at 25°C and 8000 rpm for 4 hours to obtain a precursor. The precursor was further subjected to a hydrothermal reaction in a stainless steel pressure cooker at 200°C for 24 hours. After the hydrothermal reaction was completed, the precursor was centrifuged, washed, and dried to obtain the final product.

[0043] X-ray diffraction patterns of NaY, NaCaY, NaKY, and NaCaKY molecular sieves are shown below. Figure 1 As shown, three characteristic diffraction peaks appeared at 2θ = 27.7°, 38.3°, and 49.2°. These peaks exhibit a typical three-dimensional structure of Y-type molecular sieves, indicating that Ca... 2+ and K + The doping of Ca does not disrupt the crystal structure of the NaY molecular sieve. Furthermore, no characteristic peaks of other impurities were observed, indicating that Ca... 2+ and K + It has been incorporated into the cage-like structure of NaY.

[0044] Example 1: Preparation of a molecular sieve-based flame retardant S1. Disperse the inorganic flame retardant in deionized water, first add the dispersant and stir evenly, then add NaCaKY molecular sieve and stir evenly, soak for 4 hours, dry, and calcine at 400℃ for 6 hours to obtain the doped molecular sieve-loaded inorganic flame retardant. S2. Tetramethyldisilazane and ethanol are mixed to obtain a silazane solution; the inorganic flame retardant loaded on the doped molecular sieve is preheated to 80°C, and the silazane solution is sprayed onto the surface of the inorganic flame retardant loaded on the doped molecular sieve under stirring. Stirring is continued for 2 hours, and the product is dried to obtain intermediate product 1. S3. Mix 3-isocyanate-propyltrimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2 hours to obtain an isocyanate-based silane coupling agent solution; preheat intermediate product 1 to 50°C, spray the isocyanate-based silane coupling agent solution onto the surface of intermediate product 1 with stirring, continue stirring for 2 hours, and dry to obtain a molecular sieve-based flame retardant.

[0045] The mass ratio of the inorganic flame retardant, dispersant, NaCaKY molecular sieve and deionizer in step S1 is 1:0.2:4:15.

[0046] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0047] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0048] The mass ratio of tetramethyldisilazane, ethanol and inorganic flame retardant loaded with doped molecular sieve in step S2 is 8:50:10.

[0049] The mass ratio of 3-isocyanate propyl trimethoxysilane, methanol and intermediate product 1 in step S3 is 4:100:10.

[0050] Example 2 Preparation of molecular sieve-based flame retardant S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add NaKY molecular sieve and stir uniformly, soak for 4h, dry, calcine at 400℃ for 6h to obtain inorganic flame retardant loaded with doped molecular sieve; S2, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat the inorganic flame retardant loaded with doped molecular sieve to 80℃, spray the silazane solution on the surface of the inorganic flame retardant loaded with doped molecular sieve under stirring, continue stirring for 2h, dry to obtain intermediate product 1; S3, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, stir for 2h to obtain an isocyanate silane coupling agent solution; preheat the intermediate product 1 to 50℃, spray the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continue stirring for 2h, dry to obtain the molecular sieve-based flame retardant.

[0051] The mass ratio of inorganic flame retardant, dispersant, NaKY molecular sieve and deionized water in step S1 is 1:0.2:4:15.

[0052] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0053] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0054] The mass ratio of tetramethyldisilazane, ethanol and inorganic flame retardant loaded with doped molecular sieve in step S2 is 8:50:10.

[0055] The mass ratio of 3-isocyanate propyl trimethoxysilane, methanol and intermediate product 1 in step S3 is 4:100:10.

[0056] Example 3 Preparation of the molecular sieve-based flame retardant S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add NaCaY molecular sieve and stir uniformly, soak for 4h, dry, calcine at 400℃ for 6h to obtain the doped molecular sieve loaded inorganic flame retardant; S2, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat the doped molecular sieve loaded inorganic flame retardant to 80℃, spray the silazane solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continue to stir for 2h, and dry to obtain an intermediate product 1; S3, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2h to obtain an isocyanate silane coupling agent solution; preheat the intermediate product 1 to 50℃, spray the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continue to stir for 2h, and dry to obtain the molecular sieve-based flame retardant.

[0057] The mass ratio of the inorganic flame retardant, the dispersant, the NaCaY molecular sieve and the deionized water in step S1 is 1:0.2:4:15.

[0058] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20nm, ZH-AlOH-01 from Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0059] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P from Beijing Aisel Technology Co., Ltd.

[0060] The mass ratio of the tetramethyldisilazane, ethanol and the doped molecular sieve loaded inorganic flame retardant in step S2 is 8:50:10.

[0061] The mass ratio of the 3-isocyanate propyl trimethoxysilane, methanol and the intermediate product 1 in step S3 is 4:100:10.

[0062] Example 4 Preparation of the molecular sieve-based flame retardant S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add NaCaY molecular sieve and stir uniformly, soak for 4h, dry, calcine at 400℃ for 6h to obtain the doped molecular sieve loaded inorganic flame retardant; S2, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat the doped molecular sieve loaded inorganic flame retardant to 80℃, spray the silazane solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continue to stir for 2h, and dry to obtain an intermediate product 1; S3, mixing 3-isocyanate propyl trimethoxysilane and methanol, adjusting pH to 3 with hydrochloric acid, stirring for 2h to obtain isocyanate silane coupling agent solution; preheating intermediate product 1 to 50℃, spraying the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continuing to stir for 2h, and drying to obtain the molecular sieve-based flame retardant.

[0063] The mass ratio of the inorganic flame retardant, the dispersant, the NaY molecular sieve and the deionized water in step S1 is 1:0.2:4:15.

[0064] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20nm, ZH-AlOH-01 from Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0065] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P from Beijing Aisel Science and Technology Co., Ltd.

[0066] The mass ratio of the tetramethyldisilazane, the ethanol and the inorganic flame retardant doped with the molecular sieve in step S2 is 8:50:10.

[0067] The mass ratio of the 3-isocyanate propyl trimethoxysilane, the methanol and the intermediate product 1 in step S3 is 4:100:10.

[0068] The scanning electron microscope images of the molecular sieve-based flame retardants of Examples 1-4 are shown in Figure 2 Figure 2 (a) is the NaY molecular sieve-based flame retardant of Example 4, which contains flat plates with a small number of pores; Figure 2 (b) is the NaCaY molecular sieve-based flame retardant of Example 3, Figure 2 (c) is the NaKY molecular sieve-based flame retardant of Example 2, Figure 2 (d) is the NaCaKY molecular sieve-based flame retardant of Example 1, which is Figure 2 As can be seen from (b)-(d), the NaCaY molecular sieve-based flame retardant, the NaKY molecular sieve-based flame retardant and the NaCaKY molecular sieve-based flame retardant have a hierarchical pore structure, and the solid surface becomes more loose. In particular, the NaCaKY molecular sieve, the lamellar structure is basically eliminated, and the surface is composed of a porous structure with a mesopore size of 20nm, and the pores are uniform and dense.

[0069] Comparative Example 1 for preparing a molecular sieve-based flame retardant Dispersing the inorganic flame retardant in deionized water, first adding the dispersant and stirring uniformly, then adding the NaCaKY molecular sieve and stirring uniformly, soaking for 4h, drying, and calcining at 400℃ for 6h to obtain the inorganic flame retardant doped with the molecular sieve; ​The mass ratio of the inorganic flame retardant, dispersant, NaCaKY molecular sieve and deionized water is 1:0.2:4:15.

[0070] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0071] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0072] Preparation of a molecular sieve-based flame retardant in Comparative Example 2 S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add the NaCaKY molecular sieve and stir uniformly, soak for 4 h, dry, and calcine at 400°C for 6 h to obtain the doped molecular sieve loaded inorganic flame retardant; S2, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat the doped molecular sieve loaded inorganic flame retardant to 80°C, spray the silazane solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continue to stir for 2 h, and dry to obtain the product.

[0073] The mass ratio of the inorganic flame retardant, dispersant, NaCaKY molecular sieve and deionized water in step S1 is 1:0.2:4:15.

[0074] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0075] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0076] The mass ratio of tetramethyldisilazane, ethanol and the doped molecular sieve loaded inorganic flame retardant in step S2 is 8:50:10.

[0077] Preparation of a molecular sieve-based flame retardant in Comparative Example 3 S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add the NaCaKY molecular sieve and stir uniformly, soak for 4 h, dry, and calcine at 400°C for 6 h to obtain the doped molecular sieve loaded inorganic flame retardant; S2, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2 h to obtain an isocyanate silane coupling agent solution; preheat the doped molecular sieve loaded inorganic flame retardant to 50°C, spray the isocyanate silane coupling agent solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continue to stir for 2 h, and dry to obtain the molecular sieve-based flame retardant.

[0078] The mass ratio of the inorganic flame retardant, the dispersant, the NaCaKY molecular sieve and deionized water in step S1 is 1:0.2:4:15.

[0079] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0080] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0081] The mass ratio of 3-isocyanate propyl trimethoxysilane, methanol and the inorganic flame retardant loaded with the doped molecular sieve in step S2 is 4:100:10.

[0082] Preparation of the flame retardant based on the molecular sieve in Comparative Example 4 S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add the NaCaKY molecular sieve and stir uniformly, soak for 4 h, dry, and calcine at 400°C for 6 h to obtain the inorganic flame retardant loaded with the doped molecular sieve; S2, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2 h to obtain an isocyanate silane coupling agent solution; preheat the inorganic flame retardant loaded with the doped molecular sieve to 50°C, spray the isocyanate silane coupling agent solution on the surface of the inorganic flame retardant loaded with the doped molecular sieve under stirring, continue to stir for 2 h, and dry to obtain intermediate product 1; S3, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat intermediate product 1 to 80°C, spray the silazane solution on the surface of intermediate product 1 under stirring, continue to stir for 2 h, and dry to obtain the flame retardant based on the molecular sieve.

[0083] The mass ratio of the inorganic flame retardant, the dispersant, the NaCaKY molecular sieve and deionized water in step S1 is 1:0.2:4:15.

[0084] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0085] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0086] The mass ratio of 3-isocyanate propyl trimethoxysilane, methanol and the inorganic flame retardant loaded with the doped molecular sieve in step S2 is 4:100:10.

[0087] The mass ratio of tetramethyldisilazane, ethanol and intermediate product 1 in step S3 is 8:50:10.

[0088] Preparation of the molecular sieve-based flame retardant in Comparative Example 5 S1, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat NaCaKY molecular sieve to 80℃, spray the silazane solution on the surface of the NaCaKY molecular sieve under stirring, continue stirring for 2h, and dry to obtain intermediate product 1; S2, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2h to obtain an isocyanate silane coupling agent solution; preheat the intermediate product 1 to 50℃, spray the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continue stirring for 2h, dry, and add inorganic flame retardant to mix evenly to obtain the molecular sieve-based flame retardant.

[0089] The mass ratio of tetramethyldisilazane, ethanol and inorganic flame retardant loaded on the doped molecular sieve in step S1 is 8:50:10.

[0090] The mass ratio of 3-isocyanate propyl trimethoxysilane, methanol and intermediate product 1 in step S2 is 4:100:10.

[0091] The inorganic flame retardant in step S2 is nano-sized aluminum hydroxide with a particle size of 10-20nm, ZH-AlOH-01 from Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0092] The amount of the inorganic flame retardant added in step S2 is 25% of the amount of NaCaKY added in step S1.

[0093] Preparation of the molecular sieve-based flame retardant in Comparative Example 6 S1, disperse the inorganic flame retardant in deionized water, first add a dispersant and stir evenly, then add NaCaKY molecular sieve and stir evenly, soak for 4h, dry, and calcine at 400℃ for 6h to obtain inorganic flame retardant loaded on the doped molecular sieve; S2, mix γ-aminopropyl triethoxysilane and ethanol to obtain a siloxane solution; preheat the inorganic flame retardant loaded on the doped molecular sieve to 80℃, spray the siloxane solution on the surface of the inorganic flame retardant loaded on the doped molecular sieve under stirring, continue stirring for 2h, and dry to obtain intermediate product 1; S3, mix isocyanate silane coupling agent and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2h to obtain an isocyanate silane coupling agent solution; preheat the intermediate product 1 to 50℃, spray the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continue stirring for 2h, and dry to obtain the molecular sieve-based flame retardant.

[0094] The mass ratio of the inorganic flame retardant, the dispersant, the NaCaKY molecular sieve and deionized water in step S1 is 1:0.2:4:15.

[0095] The inorganic flame retardant in step S1 is nano aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0096] The dispersant in step S1 is polyacrylic acid with a molecular weight Mw of 5000, AC-10P, Beijing Aisel Technology Co., Ltd.

[0097] The mass ratio of the γ-aminopropyl triethoxysilane, ethanol and the inorganic flame retardant loaded molecular sieve in step S2 is 8:50:10.

[0098] The mass ratio of the isocyanate silane coupling agent, methanol and the intermediate product 1 in step S3 is 4:100:10.

[0099] Comparative Example 7 Preparation of a molecular sieve-based flame retardant S1, the inorganic flame retardant is dispersed in deionized water and stirred uniformly, the NaCaKY molecular sieve is added and stirred uniformly, soaked for 4h, dried, calcined at 400℃ for 6h to obtain the inorganic flame retardant loaded molecular sieve; S2, the tetramethyldisilazane and ethanol are mixed to obtain a silazane solution; the inorganic flame retardant loaded molecular sieve is preheated to 80℃, the silazane solution is sprayed on the surface of the inorganic flame retardant loaded molecular sieve under stirring, and stirring is continued for 2h, and drying is performed to obtain the intermediate product 1; S3, the 3-isocyanate propyl trimethoxysilane and methanol are mixed, hydrochloric acid is used to adjust the pH to 3, stirring is performed for 2h to obtain an isocyanate silane coupling agent solution; the intermediate product 1 is preheated to 50℃, the isocyanate silane coupling agent solution is sprayed on the surface of the intermediate product 1 under stirring, and stirring is continued for 2h, and drying is performed to obtain the molecular sieve-based flame retardant.

[0100] The mass ratio of the inorganic flame retardant, the NaCaKY molecular sieve and deionized water in step S1 is 1:4:15.

[0101] The inorganic flame retardant in step S1 is nano aluminum hydroxide with a particle size of 10-20 nm, ZH-AlOH-01, Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0102] The mass ratio of the tetramethyldisilazane, ethanol and the inorganic flame retardant loaded molecular sieve in step S2 is 8:50:10.

[0103] The mass ratio of the 3-isocyanate propyl trimethoxysilane, methanol and the intermediate product 1 in step S3 is 4:100:10.

[0104] Comparative Example 8 Preparation of a molecular sieve-based flame retardant S1, disperse the inorganic flame retardant in deionized water, first add the dispersant and stir uniformly, then add the NaCaKY molecular sieve and stir uniformly, soak for 4h, dry, and calcine at 400℃ for 6h to obtain the doped molecular sieve loaded inorganic flame retardant; S2, mix tetramethyldisilazane and ethanol to obtain a silazane solution; preheat the doped molecular sieve loaded inorganic flame retardant to 80℃, spray the silazane solution on the surface of the doped molecular sieve loaded inorganic flame retardant under stirring, continue to stir for 2h, and dry to obtain an intermediate product 1; S3, mix 3-isocyanate propyl trimethoxysilane and methanol, adjust the pH to 3 with hydrochloric acid, and stir for 2h to obtain an isocyanate silane coupling agent solution; preheat the intermediate product 1 to 50℃, spray the isocyanate silane coupling agent solution on the surface of the intermediate product 1 under stirring, continue to stir for 2h, and dry to obtain the molecular sieve-based flame retardant.

[0105] The mass ratio of the inorganic flame retardant, the dispersant, the NaCaKY molecular sieve and the deionized water in step S1 is 1:0.2:4:15.

[0106] The inorganic flame retardant in step S1 is nano-sized aluminum hydroxide with a particle size of 10-20nm, ZH-AlOH-01 from Anhui Zhonghang Nanometer Technology Development Co., Ltd.

[0107] The dispersant in step S1 is sodium polyacrylate with a molecular weight Mw of 6000, AC-103 from Beijing Aisel Technology Co., Ltd.

[0108] The mass ratio of the tetramethyldisilazane, the ethanol and the doped molecular sieve loaded inorganic flame retardant in step S2 is 8:50:10.

[0109] The mass ratio of the 3-isocyanate propyl trimethoxysilane, the methanol and the intermediate product 1 in step S3 is 4:100:10.

[0110] Performance test Static water adsorption: refer to the Chinese patent with the authorized announcement number CN118931421B: place the molecular sieve-based flame retardants of the examples and the comparative examples in a saturated sodium chloride solution in a closed container, set the temperature to 25℃ and the relative humidity to 75%, reach adsorption equilibrium, and measure the static water adsorption of the molecular sieve activated powder at this time, and the results are shown in Table 1 below.

[0111] Dispersibility: Refer to the granted patent CN118931421B: Castor oil as medium, add the flame retardant based on molecular sieve of the examples and comparative examples at room temperature, the amount of addition is 33% of castor oil, after stirring evenly at 1000 rpm for 15 min, observe after standing, repeat the stirring step every week, the storage condition is: temperature 25℃, relative humidity 60%, observe for 3 months, whether there is obvious particle sedimentation phenomenon, whether there is scattered flame retardant based on molecular sieve particles or whether the stirring rod is sticky with flame retardant based on molecular sieve particles, if one of them appears, it is unqualified, otherwise if none of them appears, it is qualified, the results are as follows in Table 1.

[0112] Flame retardancy: add the flame retardant based on molecular sieve of the examples and comparative examples to the polyurethane adhesive (DSG30 of Shanghai Daisheng New Material Technology Co., Ltd.) A component, the amount of addition is 5%, after curing, test the flame retardancy according to UL94, the results are as follows in Table 1.

[0113] Performance test results Table 1

[0114] From Table 1, it can be seen that: The flame retardant based on molecular sieve of examples 1-3 can maintain a certain water absorption while also having good dispersibility and flame retardancy; The flame retardant based on molecular sieve of example 4 is not doped, and the water absorption decreases; Comparative example 1 only uses doped molecular sieve loaded with inorganic flame retardant, the water absorption is good, but the dispersibility is unqualified, and the flame retardancy decreases; Comparative example 2 uses silazane modified molecular sieve, the flame retardancy is good, but the water absorption is poor, and the dispersibility is unqualified; Comparative example 3 uses isocyanate silane modified molecular sieve, the water absorption is good, but the dispersibility is unqualified, and the flame retardancy is poor; Comparative example 4 changes the modification order of silazane and isocyanate silane, the dispersibility is qualified, but the water absorption and flame retardancy are poor; Comparative example 5 adds nano aluminum hydroxide after modifying NaCaKY molecular sieve with silazane and isocyanate silane, the water absorption is good, but the dispersibility and flame retardancy are poor; Comparative example 6 replaces silazane with siloxane to modify the molecular sieve, the water absorption is good, the dispersibility is qualified, but the flame retardancy is poor.

[0115] Comparative example 7 does not add dispersant in the preparation process of doped molecular sieve loaded with inorganic flame retardant, the water absorption is good, the dispersibility is qualified, but the flame retardancy is poor; Comparative example 8 adds dispersant sodium polyacrylate in the preparation process of doped molecular sieve loaded with inorganic flame retardant, the water absorption is good, the dispersibility is qualified, but the flame retardancy is poor.

[0116] Finally, it should be noted that the above is merely to illustrate the technical solutions of the present application, and is not a limitation on the scope of protection of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A molecular sieve based flame retardant characterized in that, The molecular sieve-based flame retardant is obtained by doping a molecular sieve with an inorganic flame retardant and then modifying with a modifier; the doped molecular sieve is a NaY molecular sieve doped with Ca 2+ or / and K + ; and the modifier comprises, in sequence, a silazane and an isocyanate-based silane.

2. The molecular sieve-based flame retardant of claim 1, wherein, The preparation method of the doped molecular sieve comprises the following steps: adding aluminum chloride, sodium silicate, potassium silicate or / and calcium chloride into water for stirring to obtain a precursor; the precursor is further subjected to hydrothermal reaction, and after the hydrothermal reaction is completed, centrifugal separation, washing and drying are performed.

3. The molecular sieve-based flame retardant of claim 2, wherein, When the doped molecular sieve is doped with Ca 2+ When using NaY molecular sieves, the mass ratio of aluminum chloride, sodium silicate, and calcium chloride is 45-52:40-45:5-7; when the doped molecular sieve is K-doped... + When preparing NaY molecular sieves, the mass ratio of aluminum chloride, sodium silicate, and potassium silicate is 45-52:19-25:24-30.

4. The molecular sieve-based flame retardant of claim 3, wherein, When the doped molecular sieve is a NaY molecular sieve doped with Ca 2+ and K + , the mass ratio of the aluminum chloride, sodium silicate, potassium silicate, and calcium chloride is 45-50: 19-22: 24-27: 5-7.

5. The molecular sieve-based flame retardant of claim 1, wherein, The inorganic flame retardant is selected from nano-sized magnesium hydroxide and / or nano-sized aluminum hydroxide.

6. The molecular sieve-based flame retardant of claim 1, wherein, The silazane is selected from at least one of tetramethyldisilazane and hexamethyldisilazane.

7. The molecular sieve-based flame retardant of claim 1, wherein, The isocyanate-based silane is selected from at least one of 3-isocyanate propyl trimethoxysilane and 3-isocyanate propyl triethoxysilane.

8. A process for the preparation of a molecular sieve based flame retardant according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, dispersing the inorganic flame retardant in deionized water, first adding a dispersant and stirring uniformly, then adding the doped molecular sieve and stirring uniformly, soaking for 3-5 hours, drying and calcining to obtain the doped molecular sieve loaded with the inorganic flame retardant; S2, mixing the silazane and ethanol to obtain a silazane solution; preheating the doped molecular sieve loaded with the inorganic flame retardant, spraying the silazane solution on the surface of the doped molecular sieve loaded with the inorganic flame retardant under stirring, continuing to stir and drying to obtain an intermediate product 1; S3, mixing the isocyanate-based silane coupling agent and methanol, adjusting pH, stirring to obtain an isocyanate-based silane coupling agent solution; preheating the intermediate product 1, spraying the isocyanate-based silane coupling agent solution on the surface of the intermediate product 1 under stirring, continuing to stir and drying to obtain the molecular sieve-based flame retardant.

9. The method for preparing a molecular sieve-based flame retardant according to claim 8, characterized in that, The dispersant in step S1 is polyacrylic acid.

10. Use of the molecular sieve-based flame retardant according to any one of claims 1-8 in polyurethane glue.

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