Bismaleimide organic matter and preparation method thereof

Abstract

The invention discloses a bismaleimide organic matter as shown in a formula (I) and a preparation method thereof, and is characterized in that the preparation method comprises the following steps: preparing 1, 6-bis (4-aminophenyl)-1, 5-hexadiene-3, 4-diketone by taking p-aminobenzaldehyde, 2, 3-butanedione and the like as raw materials; then reacting with substituted benzaldehyde, ammonium acetate, glacial acetic acid and the like to prepare 2-(4-substituted phenyl)-4, 5-bis (4-aminophenyl) imidazole; and reacting with maleic anhydride, acetic anhydride and the like, and carrying out post-treatment to obtain the bismaleimide organic matter. The bismaleimide organic matter is symmetrical in structure, large in structural size, suitable for being used as a high-performance polymer matrix composite material matrix and capable of being used independently or mixed with other resin for use, and an obtained cured product has good dielectric property, is suitable for preparing laminated boards for electronics and electric appliances and is high in practicability. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to organic compounds and their preparation, and relates to a bismaleimide organic compound and its preparation method. The bismaleimide organic compound (prepared) of the present invention is suitable for the preparation of laminated boards for electronics and electrical appliances. Background Art

[0002] Bismaleimide resin is a kind of high-performance thermosetting resin derived from polyimide resin with good heat resistance, stable dielectric properties, good electrical insulation and simple curing process. The molecular chain of bismaleimide resin (BMI for short) has two maleimide active end groups, and has good fluidity and moldability. The processing method is similar to that of epoxy resin, and the dielectric properties, mechanical properties and thermal properties are all excellent. The raw material sources of bismaleimide resin are very wide, and different raw materials can prepare bismaleimide resins of different structures. Different bridge bonds (-R-) in the molecular chain have a great influence on bismaleimide resin. The bridge bonds of ordinary aromatic bismaleimide resins are short, which leads to the shortcomings of high melting point and poor solubility of the resin. In view of this shortcoming, it is urgent to design and synthesize new bismaleimide monomers.

[0003] After searching, no literature report on the structure of introducing imidazole ring into bismaleimide molecule and its preparation method has been found in the prior art. Summary of the invention

[0004] The purpose of the present invention is to solve the defects of bismaleimide monomers in the prior art, provide a bismaleimide organic compound and a preparation method thereof, thereby providing a bismaleimide organic compound that can be used directly without modification, and a preparation method of the bismaleimide organic compound.

[0005] The present invention is a bismaleimide organic compound, characterized in that the bismaleimide organic compound has a chemical structure formula shown in (I):

[0006]

[0007] In formula (I): R is -H, -OH, -F, -Cl, -Br, -CH3, -OCH3, -NO2, -CN.

[0008] In the present invention, the bismaleimide organic compound is a light yellow to reddish brown solid powder with a melting point of 151°C to 267°C, an acid value of 0.2 to 1.0 mgKOH / g, and a HPLC (HPLC is the abbreviation of high performance liquid chromatography) purity of 95% to 99%.

[0009] Another aspect of the present invention is: a method for preparing bismaleimide organic compounds, characterized in that the steps are:

[0010] a. Add p-aminobenzaldehyde, catalyst and solvent into a four-necked round-bottom flask, stir and dissolve; (slowly) heat to 50-55°C, dropwise add a mixture of 2,3-butanedione and solvent, continue stirring for 2-3 hours after the dropwise addition is complete, then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0011] The solvent is any one of methanol, ethanol and n-butanol;

[0012] The catalyst is pyridine or piperidine;

[0013] b. Add 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, substituted benzaldehyde, ammonium acetate and glacial acetic acid into a four-necked round-bottom flask, heat to 115-120°C, react for 5-6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue into ice water, adjust the pH to 7-8 with ammonia water, filter, wash with water, recrystallize, and obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0014] The substituted benzaldehyde is any one of benzaldehyde, p-hydroxybenzaldehyde, p-fluorobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-cyanobenzaldehyde;

[0015] c. Add maleic anhydride and solvent A to a four-necked round-bottom flask, stir and dissolve; dropwise add a mixture of 2-(4-substituted phenyl)-4,5-di(4-aminophenyl)imidazole and solvent A, continue stirring for 2-3 hours after the addition is complete, then add acetic anhydride and a catalyst, raise the temperature to 60°C-65°C, react for 3-4 hours, then cool, precipitate with water, filter to obtain a solid, dissolve the solid in solvent B, wash with (a large amount of) water (many times), then remove water, crystallize, and obtain a bismaleimide organic compound;

[0016] The solvent A is any one of N,N-dimethylformamide, N,N-dimethylacetamide and acetone;

[0017] The solvent B is any one of toluene, xylene and chlorobenzene;

[0018] The catalyst is sodium acetate or nickel acetate.

[0019] In another aspect of the present invention: the specific steps of the preparation method of the bismaleimide organic compound are:

[0020] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of catalyst and 120 mL of solvent to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; (slowly) heat to 50-55°C, and (using a constant pressure dropping funnel) dropwise add a mixture consisting of 0.15 mol of 2,3-butanedione and 240 mL of solvent at a dropping rate of 1-2 mL / min. After the dropwise addition is completed, continue stirring for 2-3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0021] The solvent is any one of methanol, ethanol and n-butanol;

[0022] The catalyst is pyridine or piperidine;

[0023] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol substituted benzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 115-120°C, react for 5-6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7-8 with ammonia water, filter, wash with water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0024] The substituted benzaldehyde is any one of benzaldehyde, p-hydroxybenzaldehyde, p-fluorobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-cyanobenzaldehyde;

[0025] c. Add 0.22 mol to 0.3 mol of maleic anhydride and 200 to 300 mL of solvent A to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; (using a constant pressure dropping funnel) dropwise add a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-di(4-aminophenyl)imidazole and 200 to 300 mL of solvent A at a dropping rate of 1 to 2 mL / min. After the dropwise addition is completed, continue stirring for 2 to 3 hours, then add 0.25 to 0.38 mol of acetic anhydride and 0.0001 to 0.001 mol of catalyst, raise the temperature to 60°C to 65°C, react for 3 to 4 hours, then cool, precipitate with water, and filter to obtain a solid, dissolve the solid in solvent B, wash (multiple times) with (a large amount of) water, then remove water, and crystallize to obtain a bismaleimide organic compound;

[0026] The solvent A is any one of N,N-dimethylformamide, N,N-dimethylacetamide and acetone;

[0027] The solvent B is any one of toluene, xylene and chlorobenzene;

[0028] The catalyst is sodium acetate or nickel acetate.

[0029] In another aspect of the present invention: the water in step b and step c is any one of tap water, deionized water and distilled water.

[0030] In another aspect of the present invention: the bismaleimide organic compound obtained in step c is a light yellow to reddish brown solid powder with a melting point of 151° C. to 267° C., an acid value of 0.2 to 1.0 mgKOH / g, and an HPLC purity of 95% to 99%.

[0031] Compared with the prior art, the present invention has the following characteristics and beneficial effects:

[0032] (1) The bismaleimide organic compound of the present invention introduces aromatic groups with different substituents on the imidazole ring to construct a series of nitrogen-containing heterocyclic compounds containing both maleimide structural units and imidazole rings. The reaction uses the simplest and cheapest benzaldehyde and its derivatives to synthesize the bismaleimide organic compound, providing a new idea for the construction of nitrogen-containing heterocyclic compounds containing both maleimide structural units and imidazole rings.

[0033] (2) The bismaleyl organic compound of the present invention has a symmetrical structure and a large volume, and is suitable for use as a matrix of a high-performance polymer-based composite material. It can be used alone or mixed with other resins, and the resulting cured product has better dielectric properties.

[0034] (3) The bismaleimide organic product preparation process of the present invention is simple, the process is simple, and the operation is easy. The obtained bismaleimide organic product has a melting point of 151°C to 267°C, an acid value of 0.2 to 1.0 mgKOH / g, and an HPLC purity of 95% to 99%. It has good performance and can be used for the preparation of laminated boards for electronics and electrical appliances, and has strong practicality. DETAILED DESCRIPTION

[0035] The following embodiments are intended to further illustrate the present invention, but should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0036] Embodiment 1:

[0037] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0038] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of piperidine and 120 mL of methanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of methanol at a dropping rate of 1.2 mL / min. After the dropping is completed, continue stirring for 2.3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0039] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-fluorobenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 115°C, react for 5 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7 with ammonia water, filter, wash with tap water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0040] c. Add 0.22 mol of maleic anhydride and 200 mL of N,N-dimethylformamide to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 mL of N,N-dimethylformamide at a dropping rate of 1.2 mL / min. After the addition is completed, continue stirring for 2.5 hours, then add 0.25 mol of acetic anhydride and 0.0003 mol of sodium acetate, raise the temperature to 60°C, react for 3 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in toluene, wash with a large amount of tap water for many times, then remove water and crystallize to obtain a bismaleimide organic compound as a yellow solid powder with a melting point of 156°C, an acid value of 0.36 mgKOH / g, and a purity of 98.8%.

[0041] Embodiment 2:

[0042] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0043] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of piperidine and 120 mL of ethanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of ethanol at a dropping rate of 1.5 mL / min. After the dropping is completed, continue stirring for 3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0044] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-chlorobenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 118°C, react for 6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7 with ammonia water, filter, wash with tap water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0045] c. Add 0.25 mol of maleic anhydride and 300 mL of acetone to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 mL of acetone at a dropping rate of 1.5 mL / min. After the addition is completed, continue stirring for 3 hours, then add 0.28 mol of acetic anhydride and 0.0005 mol of catalyst, raise the temperature to 63°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in toluene, wash with a large amount of tap water for many times, then remove water and crystallize to obtain a bismaleimide organic compound, which is an orange-yellow solid powder with a melting point of 172°C, an acid value of 0.43 mgKOH / g, and a purity of 98.4%.

[0046] Embodiment 3:

[0047] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0048] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of piperidine and 120 mL of ethanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of ethanol at a dropping rate of 1.5 mL / min. After the dropping is completed, continue stirring for 2 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0049] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-methylbenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 118°C, react for 5.5 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7-8 with ammonia water, filter, wash with deionized water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0050] c. Add 0.28 mol of maleic anhydride and 200 N, N-dimethylacetamide to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop 0.1 mol of a mixed solution consisting of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 N, N-dimethylacetamide at a dropping rate of 1.3 mL / min. After the addition is completed, continue stirring for 2.5 hours, then add 0.3 mol of acetic anhydride and 0.0003 mol of nickel acetate, raise the temperature to 62°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in toluene, wash with a large amount of deionized water for many times, then remove water and crystallize to obtain a bismaleimide organic compound as a yellow solid powder with a melting point of 168°C, an acid value of 0.23 mgKOH / g, and a purity of 99.1%.

[0051] Embodiment 4:

[0052] A bismaleimide organic compound, characterized in that the bismaleimide organic compound has a chemical structural formula shown in (I):

[0053]

[0054] In formula (I), R is -H, -OH, -F, -Cl, -Br, -CH3, -OCH3, -NO2, -CN. The highly heat-resistant bismaleimide organic compound is a light yellow to reddish brown solid powder with a melting point of 151°C-267°C and an acid value of 0.2-1.0 mgKOH / g.

[0055] Embodiment 5:

[0056] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0057] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of pyridine and 120 mL of methanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of methanol at a dropping rate of 1.2 mL / min. After the dropping is completed, continue stirring for 3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0058] b. Add 0.1 mol 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol benzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 117°C, react for 6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 8 with ammonia water, filter, wash with deionized water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-di(4-aminophenyl)imidazole;

[0059] c. Add 0.24 mol of maleic anhydride and 300 mL of acetone to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-di(4-aminophenyl)imidazole and 200 mL of acetone at a dropping rate of 1.6 mL / min. After the addition is completed, continue stirring for 2.5 hours, then add 0.28 mol of acetic anhydride and 0.0005 mol of sodium acetate, raise the temperature to 63°C, react for 3 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in xylene, wash with a large amount of deionized water for many times, then remove water and crystallize to obtain a bismaleimide organic compound, which is a light yellow solid powder with a melting point of 152°C, an acid value of 0.26 mgKOH / g, and a purity of 98.6%.

[0060] Embodiment 6:

[0061] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0062] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of piperidine and 120 mL of n-butanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of n-butanol at a dropping rate of 1.4 mL / min. After the dropping is completed, continue stirring for 3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0063] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-chlorobenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 118°C, react for 5 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7 with ammonia water, filter, wash with deionized water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole.

[0064] c. Add 0.23 mol of maleic anhydride and 200 mL of N,N-dimethylformamide to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 mL of N,N-dimethylformamide at a dropping rate of 2 mL / min. After the addition is completed, continue stirring for 3 hours, then add 0.27 mol of acetic anhydride and 0.0006 mol of sodium acetate, raise the temperature to 65°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in toluene, wash with a large amount of deionized water for many times, then remove water and crystallize to obtain a bismaleimide organic compound, which is an orange-yellow solid powder with a melting point of 173°C, an acid value of 0.46 mgKOH / g, and a purity of 99.0%.

[0065] Embodiment 7:

[0066] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0067] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of pyridine and 120 mL of ethanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of ethanol at a dropping rate of 1.5 mL / min. After the dropping is completed, continue stirring for 2.5 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0068] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-nitrobenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 118°C, react for 6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7 with ammonia water, filter, wash with distilled water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0069] c. Add 0.22 mol of maleic anhydride and 300 mL of acetone to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 300 mL of acetone at a dropping rate of 1.2 mL / min. After the addition is completed, continue stirring for 2 hours, then add 0.28 mol of acetic anhydride and 0.0004 mol of sodium acetate, raise the temperature to 63°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in xylene, wash with a large amount of distilled water for many times, then remove water and crystallize to obtain a bismaleimide organic compound, which is a brown solid powder with a melting point of 203°C, an acid value of 0.58 mgKOH / g, and a purity of 99.3%.

[0070] Embodiment 8:

[0071] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0072] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of pyridine and 120 mL of methanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of methanol at a dropping rate of 2 mL / min. After the dropping is completed, continue stirring for 3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0073] b. Add 0.1 mol 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-methylbenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 118°C, react for 5 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 8 with ammonia water, filter, wash with deionized water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-di(4-aminophenyl)imidazole;

[0074] c. Add 0.26 mol of maleic anhydride and 200 mL of N,N-dimethylacetamide to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 mL of N,N-dimethylacetamide at a dropping rate of 1.6 mL / min. After the addition is completed, continue stirring for 3 hours, then add 0.28 mol of acetic anhydride and 0.0006 mol of nickel acetate, raise the temperature to 63°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in solvent B, wash with a large amount of deionized water for many times, then remove water and crystallize to obtain a bismaleimide organic compound as a yellow solid powder with a melting point of 167°C, an acid value of 0.26 mgKOH / g, and a purity of 98.5%.

[0075] Embodiment 9:

[0076] A method for preparing bismaleimide organic compounds, comprising the following steps:

[0077] a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of piperidine and 120 mL of ethanol to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; slowly heat to 50°C, and use a constant pressure dropping funnel to drop a mixture of 0.15 mol of 2,3-butanedione and 240 mL of ethanol at a dropping rate of 1.7 mL / min. After the dropping is completed, continue stirring for 3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione;

[0078] b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol p-bromobenzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 117°C, react for 5 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7 with ammonia water, filter, wash with distilled water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole;

[0079] c. Add 0.22 mol of maleic anhydride and 300 mL of acetone to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; use a constant pressure dropping funnel to drop a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 mL of acetone at a dropping rate of 1 mL / min. After the addition is completed, continue stirring for 3 hours, then add 0.28 mol of acetic anhydride and 0.0002 mol of catalyst, raise the temperature to 65°C, react for 4 hours, then cool, precipitate with water, and filter to obtain a solid. Dissolve the solid in chlorobenzene, wash with a large amount of distilled water for many times, then remove water and crystallize to obtain a bismaleimide organic compound, which is a khaki solid powder with a melting point of 193°C, an acid value of 0.72 mgKOH / g, and a purity of 97.9%.

[0080] In the above embodiments: the percentages used, unless otherwise specified, are all mass (weight) percentages or percentages known to those skilled in the art; the proportions used, unless otherwise specified, are all mass (weight) proportions; and the weights may be in grams or kilograms.

[0081] In the above embodiments, the process parameters (temperature, time, speed, etc.) in each step and the numerical values ​​of the amounts of each component are ranges, and any point can be applied.

[0082] The technical contents not specifically described in the present invention and the above embodiments are the same as the prior art, and the raw materials are all commercially available products.

[0083] The present invention is not limited to the above embodiments, and all of the contents of the present invention can be implemented and have the above good effects.

Claims

1. A bismaleimide organic compound, characterized in that: The bismaleimide organic compound has the chemical structure formula shown in (I): In formula (I): R is -H, -OH, -F, -Cl, -Br, -CH3, -OCH3, -NO2, -CN.

2. The bismaleimide organic compound according to claim 1, characterized in that: The bismaleimide organic compound has a melting point of 151° C. to 267° C. and an acid value of 0.2 to 1.0 mgKOH / g.

3. A method for preparing bismaleimide organic compounds, The method is characterized in that the steps are: a. Add p-aminobenzaldehyde, catalyst and solvent into a four-necked round-bottom flask, stir and dissolve; heat to 50-55°C, dropwise add a mixture of 2,3-butanedione and solvent, continue stirring for 2-3 hours after the dropwise addition is complete, then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione; The solvent is any one of methanol, ethanol and n-butanol; The catalyst is pyridine or piperidine; b. Add 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, substituted benzaldehyde, ammonium acetate and glacial acetic acid into a four-necked round-bottom flask, heat to 115-120°C, react for 5-6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue into ice water, adjust the pH to 7-8 with ammonia water, filter, wash with water, recrystallize, and obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole; The substituted benzaldehyde is any one of benzaldehyde, p-hydroxybenzaldehyde, p-fluorobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-cyanobenzaldehyde; c. Add maleic anhydride and solvent A to a four-necked round-bottom flask, stir and dissolve; dropwise add a mixture of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and solvent A, continue stirring for 2-3 hours after the addition is complete, then add acetic anhydride and a catalyst, raise the temperature to 60°C-65°C, react for 3-4 hours, then cool, precipitate with water, filter to obtain a solid, dissolve the solid in solvent B, wash with water, then remove water, crystallize, and obtain a bismaleimide organic compound; The solvent A is any one of N,N-dimethylformamide, N,N-dimethylacetamide and acetone; The solvent B is any one of toluene, xylene and chlorobenzene; The catalyst is sodium acetate or nickel acetate.

4. The method for preparing bismaleimide organic compounds according to claim 3, characterized in that The specific steps are: a. Add 0.3 mol of p-aminobenzaldehyde, 0.15 mol of catalyst and 120 mL of solvent to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, and stir to dissolve; raise the temperature to 50-55°C, and dropwise add a mixture consisting of 0.15 mol of 2,3-butanedione and 240 mL of solvent at a dropwise rate of 1-2 mL / min. After the dropwise addition is completed, continue stirring for 2-3 hours, and then cool, crystallize, filter and recrystallize to obtain 1,6-di(4-aminophenyl)-1,5-hexadiene-3,4-dione; The solvent is any one of methanol, ethanol and n-butanol; The catalyst is pyridine or piperidine; b. Add 0.1 mol 1,6-bis(4-aminophenyl)-1,5-hexadiene-3,4-dione, 0.12 mol substituted benzaldehyde, 1 mol ammonium acetate and 500 mL glacial acetic acid to a four-necked round-bottom flask equipped with a stirrer, a thermometer and a reflux condenser, heat to 115-120°C, react for 5-6 hours, evaporate part of the glacial acetic acid under reduced pressure, add the residue to ice water, adjust the pH to 7-8 with ammonia water, filter, wash with water, and recrystallize to obtain 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole; The substituted benzaldehyde is any one of benzaldehyde, p-hydroxybenzaldehyde, p-fluorobenzaldehyde, p-chlorobenzaldehyde, p-bromobenzaldehyde, p-tolualdehyde, p-methoxybenzaldehyde, p-nitrobenzaldehyde and p-cyanobenzaldehyde; c. Add 0.22 mol to 0.3 mol of maleic anhydride and 200 to 300 mL of solvent A to a four-necked round-bottom flask equipped with a stirrer, a thermometer, and a reflux condenser, and stir to dissolve; dropwise add a mixture of 0.1 mol of 2-(4-substituted phenyl)-4,5-bis(4-aminophenyl)imidazole and 200 to 300 mL of solvent A at a rate of 1 to 2 mL / min. After the dropwise addition is complete, continue stirring for 2 to 3 hours, then add 0.25 to 0.38 mol of acetic anhydride and 0.0001 to 0.001 mol of catalyst, raise the temperature to 60°C to 65°C, react for 3 to 4 hours, then cool, precipitate with water, and filter to obtain a solid, dissolve the solid in solvent B, wash with water, then remove water, and crystallize to obtain a bismaleimide organic compound; The solvent A is any one of N,N-dimethylformamide, N,N-dimethylacetamide and acetone; The solvent B is any one of toluene, xylene and chlorobenzene; The catalyst is sodium acetate or nickel acetate.

5. The method for preparing bismaleimide organic compounds according to claim 3 or 4, characterized in that: The water in step b and step c is any one of tap water, deionized water and distilled water.

6. The method for preparing bismaleimide organic compounds according to claim 3 or 4, characterized in that: The bismaleimide organic compound prepared in step c has a melting point of 151° C. to 267° C. and an acid value of 0.2 to 1.0 mgKOH / g.

Images