Method for synthesizing bisphenol A diphenyl ether type bismaleimide and catalytic composition

Abstract

This application relates to a method and catalytic composition for synthesizing bisphenol A diphenyl ether bismaleimide. The catalytic composition comprises p-toluenesulfonic acid and a sulfate, wherein the sulfate is selected from one or both of magnesium sulfate and sodium bisulfate. Using maleic anhydride and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane as raw materials and the catalytic composition as a catalytic system, the synthesized bisphenol A diphenyl ether bismaleimide exhibits a high melting point.

Description

Technical Field

[0001] The present invention relates to the technical field of bismaleimide resin preparation, and in particular to a method for synthesizing bisphenol A diphenyl ether-type bismaleimide and a catalytic composition. Background Art

[0002] As a class of high-performance polymer materials, bismaleimide (BMI) resins, with their exceptional heat resistance, high glass transition temperature (Tg), and low coefficient of thermal expansion (CTE), demonstrate broad application potential in a variety of high-tech fields, including aviation, aerospace, mechanical engineering, and electronics. In particular, they serve as key materials for advanced composite materials, high-temperature insulation layers, and high-performance adhesives. Bisphenol A diphenyl ether bismaleimide (BPA-BMI) has become a research focus in this field due to its exceptional thermal stability, superior mechanical strength, and excellent corrosion resistance.

[0003] Currently, the mainstream industrial process for synthesizing BPA-BMI uses maleic anhydride (MAH) and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP) as starting materials via a condensation reaction. This process, typically performed in an aqueous solution or organic solvent, involves an amidation reaction between the carboxyl group of MAH and the amino group of BAPP, followed by intramolecular cyclization to form a stable bismaleimide structure.

[0004] In order to further improve the synthesis efficiency and material properties of BPA-BMI, domestic and foreign research teams have carried out a series of modification studies and explorations of new synthesis methods. Specifically, through azeotropic distillation technology, researchers successfully prepared bismaleimide monomers with self-toughening properties. By introducing ether bond structures into the polymer molecular chain, the toughness of the resin was effectively improved, and its application range was broadened. In addition, microwave radiation synthesis, as an emerging synthesis strategy, provides new perspectives and possibilities for the preparation of BPA-BMI due to its advantages such as rapid reaction, high energy efficiency, simple operation and environmental friendliness. The microwave method can not only significantly shorten the reaction time, but also optimize the microstructure of the product by promoting intramolecular and intermolecular interactions, thereby improving the overall performance of the material.

[0005] However, while existing synthesis methods have made significant progress in promoting the industrial production of BPA-BMI, increasing usage requirements are also placing higher demands on the melting point of BPA-BMI. Currently, how to further increase the melting point of BPA-BMI to meet the demands of use in higher temperature environments has become an urgent issue. Summary of the Invention

[0006] The present application aims to provide a specific catalytic composition for synthesizing bisphenol A diphenyl ether bismaleimide. In the synthesis route of bisphenol A diphenyl ether bismaleimide using maleic anhydride and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane as raw materials, by introducing the catalytic composition of the present invention, the melting point of the resulting product can be significantly increased. At the same time, the present invention also provides a specific method for catalytically preparing bisphenol A diphenyl ether bismaleimide using the catalytic composition, providing a new technical approach for the efficient and high-quality production of bisphenol A diphenyl ether bismaleimide with a high melting point.

[0007] In one aspect of the present application, a catalytic composition for synthesizing bisphenol A diphenyl ether-type bismaleimide is provided, comprising p-toluenesulfonic acid and sulfate.

[0008] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 10-15:1.

[0009] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 13:1.

[0010] In one embodiment, the sulfate is selected from one or both of magnesium sulfate and sodium bisulfate.

[0011] In one embodiment, maleic anhydride and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane are used as reaction raw materials, and condensation reaction is carried out under the action of the catalytic composition to obtain bisphenol A diphenyl ether type bismaleimide.

[0012] In one embodiment, the molar ratio of the maleic anhydride to the 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 4-6:2.

[0013] In one embodiment, the molar ratio of the maleic anhydride to the 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 5:2.

[0014] In one embodiment, the mass ratio of the catalytic composition to the maleic anhydride is 1:1-3.

[0015] In another aspect of the present application, a method for synthesizing bisphenol A diphenyl ether bismaleimide is provided, comprising:

[0016] The organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane was added dropwise to the organic solution of maleic anhydride with heating and stirring;

[0017] Adding a catalyst composition and heating to reflux temperature to carry out a condensation reaction; the catalyst composition comprises p-toluenesulfonic acid and sulfate;

[0018] After the reaction is completed, the target product is obtained by washing and crystallization.

[0019] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 10-15:1.

[0020] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 13:1.

[0021] In one embodiment, the sulfate is selected from one or both of magnesium sulfate and sodium bisulfate.

[0022] In one embodiment, the solvent of the organic solution includes a polar organic solvent and a non-polar organic solvent.

[0023] In one embodiment, the polar organic solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide.

[0024] In one embodiment, the non-polar organic solvent is selected from one or more of toluene, o-xylene, m-xylene, and p-xylene.

[0025] In one embodiment, the molar ratio of the maleic anhydride to the 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 4-6:2.

[0026] In one embodiment, the molar ratio of the maleic anhydride to the 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 5:2.

[0027] In one embodiment, the mass ratio of the catalytic composition to the maleic anhydride is 1:1-3.

[0028] In one embodiment, the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is prepared under nitrogen protection.

[0029] In one embodiment, the process of adding the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane dropwise is performed under nitrogen protection.

[0030] In one embodiment, the condensation reaction is carried out under nitrogen protection conditions.

[0031] In one embodiment, the heating and stirring temperature is 50-55°C.

[0032] In one embodiment, the reflux temperature is 110-113°C.

[0033] In one embodiment, the crystallization is carried out at 20-25°C.

[0034] In one embodiment, the crystallized product is vacuum dried at a temperature of 70-80°C.

[0035] In another aspect of the present application, a catalytic composition is provided for preparing bisphenol A diphenyl ether-type bismaleimide, wherein the catalytic composition comprises p-toluenesulfonic acid and sulfate, wherein the sulfate is selected from one or both of magnesium sulfate and sodium bisulfate.

[0036] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 10-15:1.

[0037] In one embodiment, the mass ratio of p-toluenesulfonic acid to sulfate is 13:1.

[0038] Beneficial effects of this application:

[0039] This application provides a composite catalytic composition for synthesizing bisphenol A diphenyl ether bismaleimide using maleic anhydride and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane as the reaction raw materials. This composite catalytic composition can significantly increase the melting point and yield of the target product, bisphenol A diphenyl ether bismaleimide. Experimental results demonstrate that the resulting bisphenol A diphenyl ether bismaleimide has a melting point exceeding 160°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is the DSC curve of the product of Example 1 of the present application;

[0041] Figure 2 is the DSC curve of the product of Example 2 of the present application;

[0042] Figure 3 is the DSC curve of the product of Example 3 of the present application;

[0043] Figure 4 This is the DSC curve of the product of Comparative Example 1 of the present application;

[0044] Figure 5 This is the liquid phase spectrum of the product of Example 1 of the present application;

[0045] Figure 6 This is the liquid phase spectrum of the product of Example 3 of the present application;

[0046] Figure 7 This is the liquid phase spectrum of the product of Comparative Example 1 of the present application;

[0047] Figure 8 This is the phase spectrum of the product liquid of Comparative Example 4 of the present application. DETAILED DESCRIPTION

[0048] The technical scheme of the present application will be clearly and completely described below in conjunction with specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are some embodiments of the present application, rather than all embodiments, and are only used to illustrate the present application, and should not be considered as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present application. Those who do not specify specific conditions in the embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified as manufacturers are conventional products that can be purchased commercially.

[0049] In current industry, the preparation of bisphenol A diphenyl ether bismaleimide (BPA-BMI) using maleic anhydride (MAH) and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP) as key starting materials through a carefully designed condensation reaction pathway has become a mainstream and mature process. This synthesis process requires not only strict control of reaction conditions but also a deep understanding of the raw material purity and reaction mechanism.

[0050] In production practice, researchers have devoted significant effort to process optimization and innovation to continuously improve the efficiency of BPA-BMI synthesis. Through these tireless efforts, the synthesis purity of BPA-BMI has now consistently reached over 98%. However, the industry is not satisfied with this and continues to conduct research and exploration, aiming to further optimize reaction conditions, increase raw material conversion, and reduce by-product formation, thereby further improving overall product yield.

[0051] Against this backdrop, the applicants made a groundbreaking discovery during their research. Through systematic screening and optimization of catalytic systems, they stumbled upon a specific composite catalyst system that significantly increases the melting point of the synthesized product, BPA-BMI. This discovery is of great significance for improving the performance of BPA-BMI, as high-melting-point BPA-BMI exhibits superior properties in thermal stability, mechanical strength, and processability.

[0052] Specifically, in the synthesis process using maleic anhydride (MAH) and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP), the applicant innovatively introduced a composite catalytic system consisting of p-toluenesulfonic acid and sulfate. This composite catalyst not only effectively promotes the reaction and increases the reaction rate, but also significantly raises the melting point of BPA-BMI while maintaining product purity. This achievement not only provides new ideas and methods for the synthesis of BPA-BMI, but also brings potential technological innovation and industrial upgrading to related industrial production.

[0053] In one aspect of the present application, a catalytic composition for synthesizing bisphenol A diphenyl ether-type bismaleimide is provided, comprising p-toluenesulfonic acid and sulfate.

[0054] p-Toluenesulfonic acid is an important organic compound commonly used as an acid catalyst in organic synthesis. It is moderately toxic and can irritate the skin, eyes, and mucous membranes. In catalytic reactions, p-toluenesulfonic acid can significantly increase reaction rate and product selectivity, particularly in reactions such as esterification, acylation, and acetylation. As a protic acid, p-toluenesulfonic acid can donate protons, promoting proton transfer between reactants, thereby lowering the activation energy and accelerating the reaction. Sulfates are a widely occurring class of inorganic salts, including sodium bisulfate, sodium sulfate, magnesium sulfate, potassium sulfate, and ammonium sulfate. Industrially, sulfates are commonly used as polymerization initiators in synthetic resins, synthetic fibers, and synthetic industrial rubber. The combined use of p-toluenesulfonic acid and sulfate can significantly improve catalytic efficiency, shorten reaction time, increase product yield and purity, and most importantly, significantly raise the melting point of the synthesized bisphenol A diphenyl ether bismaleimide.

[0055] In certain embodiments, the mass ratio of p-toluenesulfonic acid to sulfate is 10 to 15:1. Preferably, the mass ratio of p-toluenesulfonic acid to sulfate is 13:1. This dosage range of p-toluenesulfonic acid and sulfate exhibits an excellent synergistic effect, which not only significantly improves the yield and purity of the product, but also enables the prepared bisphenol A diphenyl ether bismaleimide to have a significant high melting point. Specifically, the mass ratio of p-toluenesulfonic acid to sulfate can be 10:1, 11:1, 12:1, 13:1, 14:1, or 15:1.

[0056] In certain embodiments, the sulfate is selected from magnesium sulfate or sodium bisulfate, or any combination thereof. Specifically, the catalytic composition can be constructed as a binary system of p-toluenesulfonic acid and magnesium sulfate, or a binary system of p-toluenesulfonic acid and sodium bisulfate, or even a ternary composite system comprising p-toluenesulfonic acid, magnesium sulfate, and sodium bisulfate. Regardless of the combination employed, p-toluenesulfonic acid serves as the dominant component in the catalytic composition, playing a core catalytic role. When the catalytic composition is designed as a ternary system comprising p-toluenesulfonic acid, magnesium sulfate, and sodium bisulfate, the present technical solution does not impose strict restrictions on the specific ratio of magnesium sulfate to sodium bisulfate, aiming to provide flexible ratio options to accommodate different catalytic requirements. However, from the perspective of optimizing catalytic performance, a preferred embodiment utilizes a binary combination of p-toluenesulfonic acid and sodium bisulfate. This combination exhibits excellent catalytic performance, not only significantly improving the yield and purity of the target product, but also performing well in enhancing the product's heat resistance, providing strong technical support for the synthesis of high-quality compounds such as bisphenol A diphenyl ether bismaleimide.

[0057] In certain embodiments, maleic anhydride (MA) and 2,2'-bis[4-(4-aminophenoxyphenyl)]propane (BAPP) are used as raw materials in a condensation reaction via a catalytic composition to synthesize bisphenol A diphenyl ether bismaleimide (BPA-BMI). Maleic anhydride serves as a key raw material for the synthesis of bismaleimide, providing the maleimide structural unit, while 2,2'-bis[4-(4-aminophenoxyphenyl)]propane serves as a precursor for the synthesis of bismaleimide, undergoing a condensation reaction with maleic anhydride. Specifically, maleic anhydride and BAPP are pretreated, such as by drying and purification, to ensure the purity and activity of the reaction raw materials. The pretreated maleic anhydride and BAPP are then mixed in a specific proportion, and an appropriate amount of solvent (such as benzene, toluene, etc.) and a catalyst composition are added. A condensation reaction is then carried out at an appropriate reaction temperature and time. During the reaction, the anhydride groups of the maleic anhydride undergo amidation with the amino groups of BAPP, followed by dehydration and ring closure to form bisphenol A diphenyl ether bismaleimide. After the reaction is completed, filtration, washing, and drying are performed to obtain the target product, bisphenol A diphenyl ether bismaleimide.

[0058] In certain embodiments, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 4 to 6:2. Preferably, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 5:2. In this system, the molar number of maleic anhydride is more than twice the molar number of BAPP, which helps to ensure that the anhydride groups of maleic anhydride and the amino groups of BAPP are fully in contact and react, increasing the collision frequency between the reactants and accelerating the reaction rate. However, too high a concentration may also lead to the occurrence of side reactions, so it is necessary to determine the optimal molar ratio. Specifically, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane can be 4:2, 5:2, or 6:2.

[0059] In certain embodiments, the mass ratio of the catalytic composition to the maleic anhydride is 1:1 to 3. The amount of the catalytic composition used directly affects its catalytic efficiency. An appropriate amount of the catalytic composition can provide sufficient active sites to promote the condensation reaction between maleic anhydride and BAPP. However, an excessive amount of the catalytic composition may lead to an overly complex reaction system, increase the risk of side reactions, and increase production costs. Specifically, the mass ratio of the catalytic composition to the maleic anhydride is 1:1, 1:2, or 1:3.

[0060] In another aspect of the present application, a method for synthesizing bisphenol A diphenyl ether-type bismaleimide is provided, comprising: dropwise adding an organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane to an organic solution of maleic anhydride and heating with stirring; adding a catalytic composition and heating to reflux temperature to carry out a condensation reaction; the catalytic composition comprises p-toluenesulfonic acid and sulfate; and after the reaction is completed, washing and crystallizing to obtain the target product.

[0061] In this application, an organic solution refers to a homogeneous, stable liquid mixture consisting of one or more organic compounds as solvents, dissolving the reaction raw materials (e.g., 2,2'-bis[4-(4-aminophenoxyphenyl)]propane and maleic anhydride). The organic solvent should be selected to fully dissolve the reaction raw materials, ensuring uniform dispersion of the reactants in the solution to form a homogeneous reaction system; be chemically stable under the reaction conditions, resist chemical reactions with the raw materials or products, and avoid introducing impurities that could affect the reaction process; and possess suitable volatility to facilitate removal by distillation, evaporation, or other methods after the reaction is complete, thereby yielding a pure target product.

[0062] In certain embodiments, the solvent of the organic solution includes a polar organic solvent and a non-polar organic solvent. A polar organic solvent refers to an organic compound containing polar groups such as hydroxyl, carbonyl, and amino groups, and its molecules are polar. A non-polar organic solvent refers to a class of solvents with a low dielectric constant and a small dipole moment. Its molecular structure is symmetrical or its electron cloud is evenly distributed, and it cannot form hydrogen bonds or significant solvation with polar substances. The use of a solvent system comprising polar organic solvents and non-polar organic solvents can ensure that the process of synthesizing bisphenol A diphenyl ether type bismaleimide proceeds smoothly and obtains high-quality target products.

[0063] Furthermore, the polar organic solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide. The non-polar organic solvent is selected from one or more of toluene, o-xylene, m-xylene, and p-xylene. Specifically, the solvent system of the organic solution of the present application can be N,N-dimethylformamide and toluene, N,N-dimethylformamide and o-xylene, N,N-dimethylformamide and m-xylene, or N,N-dimethylformamide and p-xylene.

[0064] Preferably, the solvent system of the organic solution is N,N-dimethylformamide and toluene. N,N-dimethylformamide also has a catalytic effect in the process of synthesizing bisphenol A diphenyl ether type bismaleimide. The system of N,N-dimethylformamide and toluene helps to fully dissolve 2,2'-bis[4-(4-aminophenoxyphenyl)]propane. On the one hand, toluene is used as a solvent. On the other hand, it is insoluble in water. In the subsequent distillation and evaporation process, it azeotropes with water, removes moisture, and helps to improve the purity of the target product.

[0065] In certain embodiments, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 4 to 6:2. Preferably, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 5:2. Specifically, the molar ratio of maleic anhydride to 2,2'-bis[4-(4-aminophenoxyphenyl)]propane can be 4:2, 5:2, or 6:2.

[0066] In certain embodiments, the mass ratio of the p-toluenesulfonic acid to the sulfate is 10 to 15:1. Preferably, the mass ratio of the p-toluenesulfonic acid to the sulfate is 13:1. Specifically, the mass ratio of the catalytic composition to the maleic anhydride is 10:1, 11:1, 12:1, 13:1, 14:1, or 15:1.

[0067] In certain embodiments, the sulfate is selected from magnesium sulfate or sodium bisulfate, or any combination thereof. Specifically, the catalytic composition can be constructed as a binary system of p-toluenesulfonic acid and magnesium sulfate, or a binary system of p-toluenesulfonic acid and sodium bisulfate, or even a ternary composite system comprising p-toluenesulfonic acid, magnesium sulfate and sodium bisulfate. Regardless of the combination, p-toluenesulfonic acid is the leading component in the catalytic composition and plays a core catalytic role. When the catalytic composition is designed as a ternary system comprising p-toluenesulfonic acid, magnesium sulfate and sodium bisulfate, the technical solution does not set strict restrictions on the specific dosage ratio between magnesium sulfate and sodium bisulfate, and is intended to provide flexible ratio selection to adapt to different catalytic needs. However, from the perspective of catalytic performance optimization, a preferred embodiment is to use a binary combination of p-toluenesulfonic acid and sodium bisulfate. This combination demonstrates excellent catalytic performance, not only significantly improving the yield and purity of the target product, but also performing equally well in enhancing the heat resistance of the product, providing strong technical support for the synthesis of high-quality compounds such as bisphenol A diphenyl ether bismaleimide.

[0068] In certain embodiments, the mass ratio of the catalytic composition to the maleic anhydride is 1:1 to 3. Specifically, the mass ratio of the catalytic composition to the maleic anhydride is 1:1, 1:2, or 1:3.

[0069] In certain embodiments, the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is prepared under nitrogen protection. 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is sensitive to oxygen and easily undergoes oxidation reactions, resulting in a decrease in the purity of the target product. Nitrogen is a chemically stable gas that does not readily react with other substances. Therefore, it is often used as a shielding gas to isolate oxygen and water vapor in the air and prevent oxidation of reactants or intermediates.

[0070] In certain embodiments, the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is added dropwise under nitrogen protection. The addition process under nitrogen protection can effectively prevent the reactants from contacting with oxygen in the air during the addition process, thereby avoiding the occurrence of oxidation reaction and ensuring the smooth progress of the reaction. Specifically, before the addition operation is performed, the reaction system must first be placed in a nitrogen atmosphere. This is usually achieved by introducing nitrogen into the reaction vessel and exhausting the air in the container. After the addition is completed, nitrogen is continued to be introduced for a period of time to ensure that the oxygen in the reaction system is fully excluded.

[0071] In certain embodiments, the condensation reaction is carried out under nitrogen protection. Specifically, while the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is dropwise added to the organic solution of maleic anhydride and heated and stirred, nitrogen should be continuously introduced to maintain a nitrogen atmosphere in the reaction system. After adding the catalytic composition (p-toluenesulfonic acid and sulfate), the nitrogen protection should continue while the temperature is raised to reflux for the condensation reaction to prevent the reactants or intermediates from reacting with oxygen in the air at high temperatures. After the condensation reaction is completed, subsequent steps such as washing and crystallization can be carried out under nitrogen protection to obtain a pure target product.

[0072] In certain embodiments, the heating and stirring temperature is 50-55°C. In the process of adding the organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane dropwise to the organic solution of maleic anhydride, the reaction mixture needs to be heated and stirred, and the heating temperature range is controlled between 50°C and 55°C. At this temperature, the reactants can be fully mixed, which is conducive to a uniform reaction during the dropwise addition process. At the same time, the temperature is not too high, avoiding possible side reactions or decomposition of the reactants. Heating can be carried out in a water bath, oil bath or electric heating jacket. Stirring while heating can ensure that the reaction mixture is evenly heated to avoid local overheating or uneven reaction.

[0073] In certain embodiments, the reflux temperature is 110-113°C. Reflux is typically achieved by heating the reaction mixture above its boiling point, condensing the evaporated solvent in a condenser, and then refluxing it back into the reaction flask. In this application, appropriate heating equipment (such as an electric heating mantle, oil bath, etc.) and a condensing device (such as a reflux condenser) are required to control and maintain the reflux state. After the reflux reaction is complete, heating is stopped and the reaction mixture is allowed to cool to room temperature. Specifically, the reflux temperature may be 110°C, 111°C, 112°C, or 113°C.

[0074] In certain embodiments, the crystallization is carried out at 20-25°C. Crystallization is an important step in the post-processing of a chemical reaction. By lowering the temperature or changing the solvent conditions, the solute is precipitated from the solution to form crystals. Crystallization is usually performed by cooling the reaction mixture to a certain temperature and keeping it at this temperature for a period of time to gradually precipitate the solute. In the present application, a cooling water bath, an ice-water mixture or other appropriate cooling means can be used to control and maintain the crystallization temperature. Precise control of the crystallization temperature is crucial to ensuring the quality and yield of the crystals. Too high a temperature may cause the crystals to grow too fast, forming irregular or agglomerated crystals; too low a temperature may slow the crystallization rate too much, prolonging the crystallization time. Selecting 20-25°C as the crystallization temperature can ensure that the target product is precipitated at an appropriate rate to form good quality crystals.

[0075] In certain embodiments, the crystallized product is vacuum dried at a drying condition of 70 to 80°C. Vacuum drying is a process by which the boiling point of a substance is lowered by heating under a low-pressure environment, thereby accelerating the evaporation of water and the removal of solvents. For the crystallized product in this application, vacuum drying can remove residual organic solvents and water, thereby improving the purity and stability of the product. Selecting 70 to 80°C as the drying temperature can ensure that the product will not decompose or deteriorate due to excessively high temperature, while being able to efficiently remove residual solvents and water. Vacuum drying usually needs to be carried out in a vacuum drying oven or a vacuum oven, which can provide the required low-pressure environment and heating conditions. During the drying process, the crystallized product needs to be placed on an appropriate container or tray, and ensure that the container or tray has good air permeability so that water and solvent can evaporate smoothly.

[0076] In another aspect of the present application, a catalytic composition is provided for preparing bisphenol A diphenyl ether-type bismaleimide, wherein the catalytic composition comprises p-toluenesulfonic acid and sulfate, wherein the sulfate is selected from one or both of magnesium sulfate and sodium bisulfate.

[0077] The mass ratio of p-toluenesulfonic acid to sulfate is 10 to 15: 1. Preferably, the mass ratio of p-toluenesulfonic acid to sulfate is 13: 1.

[0078] During the synthesis of bisphenol A diphenyl ether bismaleimide, a catalytic combination of p-toluenesulfonic acid and sulfate can promote the condensation reaction. By adding an organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane dropwise to an organic solution of maleic anhydride, adding the catalytic combination under heating and stirring conditions, and raising the temperature to reflux, a condensation reaction can be carried out. The use of the catalytic combination can improve the efficiency and yield of the reaction. The synergistic effect of p-toluenesulfonic acid and sulfate can accelerate the reaction and reduce the formation of by-products, thereby improving the purity and yield of the target product. At the same time, the melting point of the synthesized bisphenol A diphenyl ether bismaleimide can be significantly increased, giving the product excellent heat resistance.

[0079] The technical solution of this application is described in detail below with reference to specific example embodiments.

[0080] Example 1

[0081] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of sodium bisulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 185 g of yellow solid.

[0082] Example 2

[0083] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 60 g of p-toluenesulfonic acid and 4.5 g of sodium bisulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 180 g of yellow solid.

[0084] Example 3

[0085] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. Maintain the temperature at 50-55°C and stir for 1 hour after the addition is complete. Then add 80 g of p-toluenesulfonic acid and 6 g of sodium bisulfate to the system, heat to 110-113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75-80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20-25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 175 g of yellow solid.

[0086] Example 4

[0087] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of magnesium sulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 160 g of yellow solid.

[0088] Example 5

[0089] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C waterbath (Solution 1). Under a nitrogen atmosphere, dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF (Solution 2). Add Solution 2 dropwise to Solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. After the addition is complete, maintain the temperature at 50-55°C and stir for 1 hour. Then, add 86 g of a catalyst composition composed of p-toluenesulfonic acid and sodium bisulfate in a 10:1 mass ratio. Heat to 110~113℃ and reflux for reaction. After reflux for 3h, cool to 75~80℃ and wash with 300ml of water 5 times. Wash the system with weak alkaline water twice to neutrality and then wash with clean water three times. Then heat to 110℃ and reflux to separate the residual water in the system. Then cool to 20~25℃ and crystallize for 8h. Filter and obtain the product. After vacuum drying at 75℃, obtain 170g of yellow solid.

[0090] Example 6

[0091] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C waterbath (Solution 1). Under a nitrogen atmosphere, dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF (Solution 2). Add Solution 2 dropwise to Solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. After the addition is complete, maintain the temperature at 50-55°C and stir for 1 hour. Then, add 86 g of a catalyst composition composed of p-toluenesulfonic acid and sodium bisulfate in a 15:1 mass ratio. The mixture was heated to 110-113°C and refluxed for 3 hours. After reflux for 3 hours, the mixture was cooled to 75-80°C and washed with 300 ml of water for 5 times. The first two times of washing were with weak alkaline water to neutralize the system, and the last three times were washed with clean water. The mixture was then heated to 110°C and refluxed to remove the residual water in the system. The mixture was then cooled to 20-25°C and crystallized for 8 hours. The product was filtered and dried in vacuo at 75°C to obtain 172 g of a yellow solid.

[0092] Example 7

[0093] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, stirring in a 50°C water bath. This is referred to as solution 1. Dissolve 0.5 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete, maintaining the temperature at 50-55°C. Then add 39 g of p-toluenesulfonic acid and 3 g of magnesium sulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 150 g of yellow solid.

[0094] Example 8

[0095] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.3 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of magnesium sulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 180 g of yellow solid.

[0096] Comparative Example 1

[0097] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 86 g of p-toluenesulfonic acid to the system, heat it to 110 ° C and reflux it for 3 hours. After reflux, cool it to 75-80 ° C and wash it with 300 ml of water 5 times. Wash the system with weak alkaline water twice until it is neutral, and then wash it with clean water three times. Then heat it to 110 ° C and reflux to separate the residual water in the system. Then cool it to 20-25 ° C and crystallize it for 8 hours. Filter and obtain the product, which is vacuum dried at 75 ° C to obtain 162 g of a yellow solid.

[0098] Comparative Example 2

[0099] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then, 86 g of sodium bisulfate was added to the system, the temperature was raised to 110-113° C. and refluxed for 3 hours. After reflux, the temperature was lowered to 75-80° C. and washed with 300 ml of water five times. The first two times the system was washed with weak alkaline water until neutral, and the last three times with clean water. The temperature was then raised to 110° C. and refluxed to separate the residual water in the system. The temperature was then lowered to 20-25° C. and crystallized for 8 hours. The product was filtered and vacuum dried at 75° C. No effective product was obtained after chromatographic detection.

[0100] Comparative Example 3

[0101] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of sodium sulfate to the system, heat to 110 ° C and reflux for reaction. After reflux for 3 hours, cool to 75-80 ° C and wash with 300 ml of water 5 times. Wash the system with weak alkaline water twice to neutrality and then wash with clean water three times. Then heat to 110 ° C and reflux to separate the residual water in the system. Then cool to 20-25 ° C and crystallize for 8 hours. Filter to obtain the product and vacuum dry it at 75 ° C to obtain 166 g of yellow solid.

[0102] Comparative Example 4

[0103] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then, 39 g of p-toluenesulfonic acid and 3 g of zinc acetate were added to the system, and the temperature was raised to 110°C for reflux reaction. After reflux reaction for 3 hours, the temperature was lowered to 75-80°C and washed with 300 ml of water 5 times. The first two times were washed with weak alkaline water to neutralize the system, and the last three times were washed with clean water. Then, the temperature was raised to 110°C and refluxed to separate the residual water in the system. Then, the temperature was lowered to 20-25°C and crystallized for 8 hours. The product was filtered and dried in vacuo at 75°C to obtain 157 g of a yellow solid.

[0104] Comparative Example 5

[0105] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of sodium acetate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 150 g of yellow solid.

[0106] Comparative Example 6

[0107] Dissolve 1 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C water bath. This is referred to as solution 1. Dissolve 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, maintaining the temperature at 50-55°C. Stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of magnesium acetate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 162 g of yellow solid.

[0108] Comparative Example 7

[0109] Dissolve 1.7 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, stirring in a 50°C water bath. This is referred to as solution 1. Dissolve 0.68 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF under a nitrogen atmosphere. This is referred to as solution 2. Add solution 2 dropwise to solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. Maintain the temperature at 50-55°C and stir for 1 hour after the addition is complete. Then add 39 g of p-toluenesulfonic acid and 3 g of sodium bisulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 255 g of yellow solid.

[0110] Comparative Example 8

[0111] Dissolve 1.7 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C waterbath (Solution 1). Under a nitrogen atmosphere, dissolve 0.68 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF (Solution 2). Add Solution 2 dropwise to Solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. After the addition is complete, maintain the temperature at 50-55°C and stir for 1 hour. Then, add 86 g of a catalyst composition composed of p-toluenesulfonic acid and sodium bisulfate in a mass ratio of 8:1. The mixture was heated to 110-113°C and refluxed for 3 hours. After reflux for 3 hours, the mixture was cooled to 75-80°C and washed with 300 ml of water for 5 times. The first two times of washing were with weak alkaline water to neutralize the system, and the last three times were washed with clean water. The mixture was then heated to 110°C and refluxed to remove the residual water in the system. The mixture was then cooled to 20-25°C and crystallized for 8 hours. The product was filtered and dried in vacuo at 75°C to obtain 258 g of a yellow solid.

[0112] Comparative Example 9

[0113] Dissolve 1.7 mol of maleic anhydride in 600 ml of toluene and 12 g of DMF, then stir in a 50°C waterbath (Solution 1). Under a nitrogen atmosphere, dissolve 0.68 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane in 600 ml of toluene and 40 g of DMF (Solution 2). Add Solution 2 dropwise to Solution 1 under a nitrogen atmosphere, controlling the temperature at 50-55°C. After the addition is complete, maintain the temperature at 50-55°C and stir for 1 hour. Then, add 86 g of a catalyst composition composed of p-toluenesulfonic acid and sodium bisulfate in a 17:1 mass ratio. The mixture was heated to 110-113°C and refluxed for 3 hours. After reflux for 3 hours, the mixture was cooled to 75-80°C and washed with 300 ml of water for 5 times. The first two times the system was washed with weak alkaline water until neutrality, and the last three times the system was washed with clean water. The mixture was then heated to 110°C and refluxed to remove the residual water in the system. The mixture was then cooled to 20-25°C and crystallized for 8 hours. The product was filtered and dried in vacuo at 75°C to obtain 246.5 g of a yellow solid.

[0114] Comparative Example 10

[0115] Solution ② was prepared and the reaction process was performed without nitrogen protection: 1 mol of maleic anhydride was dissolved in 600 ml of toluene and 12 g of DMF, then stirred in a 50°C waterbath. This was referred to as Solution ①. 0.4 mol of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane was dissolved in 600 ml of toluene and 40 g of DMF. This was referred to as Solution ②. Solution ② was added dropwise to Solution ①, maintaining the temperature at 50-55°C. After the addition was complete, the temperature was maintained at 50-55°C and stirred for 1 hour. Then add 39 g of p-toluenesulfonic acid and 3 g of sodium bisulfate to the system, heat to 110~113 ° C and reflux reaction, reflux reaction for 3 hours, cool to 75~80 ° C, wash with 300 ml of water 5 times, wash the system with weak alkaline water twice to neutrality, and then wash with clean water three times, then heat to 110 ° C and reflux to separate the residual water in the system, then cool to 20~25 ° C and crystallize for 8 hours to obtain the product by filtration, and then vacuum dry at 75 ° C to obtain 175 g of yellow solid.

[0116] The purity and melting point of the products of Examples 1 to 8 and Comparative Examples 1 to 10 were tested.

[0117] The melting point of bisphenol A diphenyl ether bismaleimide monomer was analyzed using a NETZSCH STA449C thermal analyzer in a nitrogen atmosphere at a heating rate of 10°C / min. Figure 1 is the DSC curve of the product of Example 1, Figure 2 is the DSC curve of the product of Example 2, Figure 3 is the DSC curve of the product of Example 3, Figure 4 The DSC curve of the product of Comparative Example 1 was obtained. The purity of the product was analyzed using an Agilent 1100 high performance liquid chromatograph. Figure 5 This is the liquid phase spectrum of the product in Example 1, Figure 6 This is the liquid phase spectrum of the product of Example 3, Figure 7 This is the liquid phase spectrum of the product of Comparative Example 1, Figure 8 This is the liquid phase spectrum of the product of Comparative Example 4.

[0118] The results are shown in Table 1.

[0119] Table 1 Characterization of synthetic BPA-BMI

[0120]

[0121] Based on the experimental data from Examples 1-3 and Comparative Example 7, it can be observed that the yield and melting point of bisphenol A diphenyl ether bismaleimide both show a downward trend with changes in the amount of the catalytic composition used. This indicates that a good catalytic effect can be achieved when the mass ratio of the catalytic composition to maleic anhydride is controlled within the range of 1:1 to 1:3.

[0122] Further comparative analysis of Examples 1 to 4 and Comparative Examples 3 to 6 shows that when the catalytic composition is a combination of toluenesulfonic acid and magnesium sulfate or sodium bisulfate, the product exhibits higher levels of purity, yield and melting point.

[0123] Furthermore, comparative studies of Example 3 with Comparative Examples 1-2, and Examples 5-6 with Comparative Examples 8-9, revealed that when the catalytic composition employs toluenesulfonic acid and magnesium sulfate or sodium bisulfate in a mass ratio within the range of 10 to 15:1, the catalytic composition exhibits significant synergistic effects. This synergistic effect not only improves product purity but also significantly enhances product yield and melting point.

[0124] Finally, the importance of a nitrogen atmosphere for the synthesis of the target product can be confirmed by comparing Example 1 with Comparative Example 10. Carrying out the condensation reaction in a nitrogen atmosphere can effectively promote the formation of the product, increase the yield and melting point of the product, and further optimize the synthesis process.

[0125] Although the embodiments of the present application are described above, the present application is not limited to the above-mentioned specific embodiments and application fields. The above-mentioned specific embodiments are merely illustrative and instructive, and not restrictive. A person of ordinary skill in the art, guided by this specification and without departing from the scope of protection of the claims of this application, may also devise various forms, all of which fall within the scope of protection of this application.

Claims

1. A method for synthesizing bisphenol A diphenyl ether type bismaleimide, characterized in that: include: The organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane was added dropwise to the organic solution of maleic anhydride with heating and stirring; Adding a catalyst composition and heating to reflux temperature to carry out a condensation reaction; the catalyst composition comprises p-toluenesulfonic acid and sodium bisulfate; After the reaction is completed, washing and crystallization are performed to obtain the target product; The mass ratio of p-toluenesulfonic acid to sodium bisulfate is 10-15:1; The mass ratio of the catalytic composition to the maleic anhydride is 1:1-3.

2. The method according to claim 1, characterized in that The mass ratio of the p-toluenesulfonic acid to the sodium bisulfate is 13:

1.

3. The method according to claim 1, characterized in that The molar ratio of the maleic anhydride to the 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is 4-6:

2.

4. The method according to claim 1, wherein The organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is prepared under nitrogen protection; The organic solution of 2,2'-bis[4-(4-aminophenoxyphenyl)]propane is added dropwise under nitrogen protection; The condensation reaction is carried out under nitrogen protection.

5. The method according to claim 1, wherein The reflux temperature is 110-113°C; The heating and stirring temperature is 50-55°C; The crystallization is carried out at 20-25°C; The crystallized product was vacuum dried at a temperature of 70-80°C.

6. The method according to claim 1, characterized in that The solvent of the organic solution includes a polar organic solvent and a non-polar organic solvent; The polar organic solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone, and dimethyl sulfoxide; The non-polar organic solvent is selected from one or more of toluene, o-xylene, m-xylene and p-xylene.

7. The method according to claim 6, characterized in that The solvent of the organic solution is selected from a combination of N,N-dimethylformamide and toluene.

8. Use of the catalytic composition in the preparation of bisphenol A diphenyl ether type bismaleimide; in, The catalytic composition comprises p-toluenesulfonic acid and sodium bisulfate, and the mass ratio of the p-toluenesulfonic acid to the sodium bisulfate is 10-15:1.

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