JP3085609B2 - Method for producing bismaleimides - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing bismaleimides which are important as a raw material for addition type polyimide.

[0002]

2. Description of the Related Art A method for producing bismaleimides has been known for a long time, but bismaleimides generally have poor thermal stability. Usually, 2 moles of maleic anhydride are used per 1 mole of a diamine compound as a raw material. Using the above excess amount, a ring-opening addition reaction in an organic solvent to give bismaleamide acid, a base, a dehydration cyclization using acetic anhydride as a dehydrating agent in the presence of a metal salt catalyst to obtain bismaleimides. It has been known. For example, the method for producing N, N '-(4,4'-diphenylmethane) bismaleimide is based on the use of 1 mol of 4,4'-diaminodiphenylmethane and 2 mol or more of maleic anhydride in excess of acetone or N, N- A ring-opening addition reaction is carried out in an organic polar solvent such as dimethylformamide, and N,
N ′-(4,4′-diphenylmethane) bismaleamic acid and then dehydration cyclization at 50-60 ° C. using acetic anhydride as a dehydrating agent in the presence of triethylamine and cobalt acetate to form N, N ′-( 4,4'-diphenylmethane)
This is to obtain bismaleimide.

On the other hand, in general, the method for producing monomaleimides is different from the method for producing bismaleimides, in which a monoamidic acid is produced in an organic solvent by an azeotropic dehydration method in the presence of an acid catalyst. . For example, Japanese Patent Publication No. 51-40
No. 078 discloses a method for obtaining a monomaleimide by heating an amic acid and performing azeotropic dehydration using an organic solvent having a boiling point of 80 to 180 ° C. in the presence of an acid catalyst to obtain monomaleimides.
JP-B-57-42043 discloses a method in which 2-methylmaleic anhydride and aniline are reacted in xylene, sulfuric acid is subsequently added, and water produced is azeotroped with xylene to obtain monomaleimides. I have.

As described above, the methods for producing bismaleimides and monomaleimides are generally different. Monomaleimides are produced by heating monomaleamic acid to a high temperature using a solvent in the presence of an acid catalyst. In addition, bismaleimides are produced by reacting bismaleamic acid at a relatively low temperature using a large amount of an expensive reaction reagent such as acetic anhydride.

[0005] This is because the reaction rate of the dehydration cyclization reaction of bismaleamic acid is slow only with an acid catalyst. The reason is considered to be that bismaleamic acid is hardly dissolved in organic solvents azeotropic with water, such as toluene and xylene, for example, compared to monomaleamic acid. To perform the reaction, N,
It is necessary to carry out the reaction at a high temperature for a long time in the presence of an aprotic organic polar solvent for solubilizing bismaleamic acid to some extent such as N-dimethylformamide. In this method, the double bond portion of bismaleimides is generally used. The formation of by-products, such as gelation upon reaction, is unavoidable, and the resulting product becomes a solid, which makes isolation and purification difficult. For these reasons, as a method for producing bismaleimides, a heavy metal catalyst such as a cobalt salt is used in an organic solvent, and dehydration ring closure is performed with acetic anhydride.

However, Japanese Patent Application Laid-Open No. 4-99764 discloses a specific bismaleimide, 4,4'-bis (3-
A method for synthesizing (maleimidophenoxy) biphenyl and 4,4′-bis (4-maleimidophenoxy) biphenyl in an organic solvent by an azeotropic dehydration method in the presence of an acid catalyst is disclosed. In this method, 4,4'-bis (aminophenoxy) biphenyl is reacted with maleic anhydride in an organic solvent azeotropic with water in the presence of an acid catalyst. According to this method, there is a problem in the above-mentioned method for producing bismaleimides using acetic anhydride, for example, acetylation of an amino group or a maleimide group to a double bond part by acetic anhydride occurs as a side reaction. The purity of the product is low, the removal of acetic acid from the target product is difficult, the acetic anhydride is expensive, the cost and labor are required for the recovery of acetic acid together with the large amount of solvent used in the reaction, cobalt salts, etc. It is a method that can solve to a certain extent the need to eliminate pollution of heavy metal catalysts.

[0007]

However, in the above-mentioned method, the reaction speed is slow due to the low solubility of bismaleamic acid in an organic solvent azeotropic with water, such as toluene, and the reaction requires a long time. It is necessary to use a large amount of a catalyst such as p-toluenesulfonic acid. Furthermore, due to the low solubility of bismaleamic acid, a large amount of a reaction solvent is required to obtain bismaleimides, the volumetric efficiency is poor, and it must be said that this method is industrially disadvantageous. Japanese Patent Application Laid-Open No. 4-99764 discloses an example in which bismaleimides are synthesized using a mixed solvent of about 8 parts of N, N-dimethylformamide with respect to 100 parts of toluene. 14 by the end of the reaction
It takes time and the volumetric efficiency is poor. In fact, when N, N-dimethylformamide is used in a smaller amount, the reaction proceeds, but the reaction takes a long time, and when no N, N-dimethylformamide is used, the reaction hardly proceeds. .

[0008]

The present inventors have made intensive studies to solve these problems, and as a result, as for certain bismaleimides, an organic solvent which is azeotropic with water has a proportion exceeding a certain ratio. The present inventors have found that it can be efficiently produced by an azeotropic dehydration method in a mixed solvent obtained by mixing an aprotic organic polar solvent, and have completed the present invention.
That is, the present invention provides a compound represented by the general formula (1):

[0009]

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[Wherein X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group,
A group selected from the group consisting of a carbonyl group, a thio group, and a sulfonyl group, wherein a nitrogen atom independently occupies a p-, o-, or m-position with respect to X, and Y _{1 to} Y ₄ are Each independently represents a group selected from the group consisting of hydrogen, lower alkyl group, lower alkoxy group, chlorine and bromine. A diamine compound and maleic anhydride represented by
In the presence of an acidic or basic catalyst, a mixed solvent obtained by mixing 15 parts to 100 parts of an aprotic organic polar solvent with respect to 100 parts of an organic solvent azeotropic with water as a reaction solvent is produced under heating and reflux. General formula (2) wherein the reaction is carried out while removing water out of the system.

[0011]

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Wherein X is a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group,
A group selected from the group consisting of a carbonyl group, a thio group, and a sulfonyl group, wherein a nitrogen atom independently occupies a p-, o-, or m-position with respect to X, and Y _{1 to} Y ₄ are Each independently represents a group selected from the group consisting of hydrogen, lower alkyl group, lower alkoxy group, chlorine and bromine. ] The method for producing bismaleimides represented by the formula:

According to the manufacturing method of the present invention, Japanese Patent Laid-Open No.
(1) Shorter reaction time than the method disclosed in No. 9764. (2) It has good volumetric efficiency and can be manufactured efficiently. There are advantages such as.

Hereinafter, a specific method of the present invention will be described. This production method comprises a diamine compound represented by the general formula (1):
By dissolving or dispersing maleic anhydride together with an acidic or basic catalyst in a predetermined solvent, and heating and refluxing the mixture.

The diamine compound used in the method of the present invention includes bis [4- (3-aminophenoxy) phenyl] methane, 1,1-bis [4- (3-aminophenoxy) phenyl] ethane, 1,2 -Bis [4- (3-aminophenoxy) phenyl] ethane, 2,2-bis [4-
(3-aminophenoxy) phenyl] propane, 2,2
-Bis [4- (3-aminophenoxy) phenyl] butane, 2,2-bis [4- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 4, 4'-bis (3-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl]
Ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy)
Phenyl] sulfoxide, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl] ether, and the like, but are not limited thereto.

[0016] As the acidic catalyst,
Sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, p-toluenesulfonic acid, phosphotungstic acid, phosphomolybdic acid, methanesulfonic acid, trichloroacetic acid, dichloroacetic acid, chloroacetic acid, trifluoroacetic acid, difluoroacetic acid, fluoroacetic acid, polyphosphoric acid Examples thereof include acids, phosphorus oxychloride, trifluoromethanesulfonic acid, benzenesulfonic acid, phosphorous acid, sulfurous acid, and sulfuric anhydride, with sulfuric acid, phosphoric acid, and p-toluenesulfonic acid being particularly preferred. These acids may be in the form of a salt with a diamine compound.

Examples of the basic catalyst include inorganic base compounds such as sodium hydroxide, potassium hydroxide and ammonium hydroxide, and organic base compounds such as pyridine, picoline, quinoline, isoquinoline and triethylamine. Sodium oxide is preferred.

Although these catalysts vary depending on their types, it is generally desirable to use them in an amount of 0.1 to 10% by weight based on the total amount of maleic anhydride and the diamine compound represented by the general formula (1). . If the amount of the catalyst is less than 0.1% by weight, the desired catalytic effect cannot be achieved, and
Even if it is used in an amount of more than 10% by weight, a certain effect or more cannot be obtained, which is not only economically disadvantageous but also makes it difficult to remove the remaining catalyst.

The organic solvent azeotropic with water used in the reaction includes aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. As the aliphatic hydrocarbon, hexane,
Heptane and the like, cyclohexane and the like as alicyclic hydrocarbons, and benzene, toluene, xylene and the like as the aromatic hydrocarbons.

The aprotic organic polar solvents include N,
N-dimethylformamide, N-methylpyrrolidone, acetonitrile, N, N-dimethylacetamide, dimethylsulfoxide, sulfolane, anisole, n-butylether, diphenylsulfoxide, diphenylsulfone, 1,3-dimethyl-2-imidazolidinone and the like. Can be

In the present invention, an aprotic organic polar solvent is mixed with an organic solvent azeotropic with water to obtain a reaction solvent. Depending on the type of solvent to be mixed, the aprotic organic polar solvent is mixed so as to be 15 parts or more with respect to 100 parts of the organic solvent azeotropic with water, but the range of 15 parts to 100 parts is preferable. Range. In a solvent mixed at a concentration lower than 15 parts, the solubility of bismaleamic acid is low, and it takes a long time to complete the reaction. 10
In a solvent mixed at a concentration higher than 0 parts, the solubility of bismaleamic acid increases, so the reaction rate increases,
Since it becomes difficult for water to azeotrope with the organic solvent, the rate of distilling water out of the system is reduced, and the reaction sometimes becomes difficult to proceed. In addition, when the reaction is carried out in a mixed solvent having a large proportion of the aprotic organic polar solvent, the solubility increases even after the reaction is completed, even if the reaction vessel is cooled down to room temperature, so that the bismaleimides still dissolve in the solvent. Therefore, the removal becomes difficult, which leads to a decrease in the removal yield.

The amount of the mixed solvent used varies depending on the solvent and the composition used, but it is generally preferable that the amount be 1 to 5 times the total amount of maleic anhydride and the diamine compound.

The reaction temperature under reflux under heating varies slightly depending on the composition ratio of the organic solvent azeotropic with water and the aprotic organic polar solvent, but is generally 80-190 ° C.
A range from 100 to 160 ° C. is particularly preferred.

The pressure may be any of pressurized, normal or reduced pressure, and is appropriately selected according to the solvent used and the reaction temperature.

The reaction time varies depending on the amount of the catalyst and the composition of the mixed solvent, but generally ranges from about 2 to 10 hours.

It is preferable that the maleic anhydride is charged so as to be slightly excessive with respect to the diamine compound. In general, maleic anhydride / diamine compound = 2 on a molar basis.
It is preferable to charge them so as to be 0 to 3.0. Excessive charging is not only unpreferable because it increases the cost but also increases the amount of impurities. Also, if the diamine compound is excessively charged, there will be a diamine compound in which maleic anhydride reacts only on one side, so that residual amino groups may deteriorate the color tone or add to the bismaleimide double bond. It is not preferable because it causes a reaction.

After completion of the condensation reaction, the obtained product is separated by filtration, washed with water to remove the remaining catalyst, solvent and unreacted maleic anhydride, and further dried to obtain a pale yellow powder.

[0028]

EXAMPLES The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 In a reactor equipped with a thermometer, a stirrer and a reflux condenser equipped with a water separator, 96.9 g (0.99 mol) of maleic anhydride,
4'-bis (3-aminophenoxy) biphenyl 16
A mixed solvent consisting of 5.6 g (0.45 mol), 1.98 g of p-toluenesulfonic acid, 300 g of toluene as a solvent, and 100 g of N, N-dimethylformamide was charged, and the temperature was raised to a value of 6 under reflux of toluene. Reflux dehydration was performed for hours. From the start of the reaction to the end of the reaction, water generated in the reaction was collected by a water separator provided in a reflux condenser. Distilled water weighed 15.9 g, 98% of theory. After the reaction was completed, the reaction mixture was cooled to room temperature, and the precipitated pale yellow crystals were separated by filtration, washed with 2000 g of water, and dried to obtain 4,4′-bis (3-maleimidophenoxy) biphenyl. Yield: 232.8 g, 98%, HP
The purity by LC analysis was 95.2%.

Example 2 An experiment was conducted in the same manner as in Example 1 except that 4,4'-bis (4-aminophenoxy) biphenyl was used as a raw material.
4,4'-bis (4-maleimidophenoxy) biphenyl was obtained. The amount of water distilled was 15.6 g, which was 96% of the theoretical amount. Yield: 228.9 g, yield: 96.3%, HP
The purity by LC analysis was 94.6%.

Example 3 An experiment was conducted in the same manner as in Example 1 except that 2.5 g of sulfuric acid was used as a catalyst to obtain 4,4'-bis (3-maleimidophenoxy) biphenyl. Distilled water weighed 15.9 g, 98% of theory. The yield was 225.3 g and the yield was 9
4.8% and purity by HPLC analysis was 93.3%.

Example 4 Bis [4- (3-aminophenoxy) phenyl] was used as a raw material.
Except for using 178.2 g (0.45 mol) of ketone,
An experiment was conducted in the same manner as in Example 1 to obtain bis [4- (3-maleimidophenoxy) phenyl] ketone. Distilled water weighed 15.9 g, 98% of theory. Yield 2
38.9 g, the yield was 95.5%, and the purity by HPLC analysis was 94.2%.

Example 5 Example 1 except that 5 g of sodium hydroxide was used as the catalyst.
An experiment was carried out in the same manner as in the above to obtain 4,4′-bis (3-maleimidophenoxy) biphenyl. Distilled water is 15.0
g, 93% of theory. The yield was 216 g, the yield was 90.9%, and the purity by HPLC was 91.5%.

Example 6 193.8 g (2 mol) of maleic anhydride, 331.2 g of 4,4'-bis (3-aminophenoxy) biphenyl
(0.9 mol), 1.98 g of p-toluenesulfonic acid,
The experiment was carried out in the same manner as in Example 1 except that a mixed solvent consisting of 200 g of toluene and 200 g of N, N-dimethylformamide was used as a solvent to obtain 4,4′-bis (3-maleimidophenoxy) biphenyl. Distilled water is 31.
8 g, 98% of theory. Yield 465.2
g, yield 98%, purity by HPLC analysis 95.0.
%Met.

Comparative Example 1 An experiment was carried out in the same manner as in Example 1 except that N, N-dimethylformamide was not used. However, even after a reaction time of 20 hours, 4,4′-bis (3-maleimidophenoxy) was used. )
Biphenyl was not formed. No water was distilled.

Comparative Example 2 32.3 g (0.33 mol) of maleic anhydride, 4,4 '
-Bis (3-aminophenoxy) biphenyl 55.2 g
(0.15 mol) and 3.96 p-toluenesulfonic acid
g, and an experiment was performed in the same manner as in Example 1 except that a mixed solvent of 300 g of toluene and 25 g of N, N-dimethylformamide was used as a solvent. After a reaction time of 6 hours, the yield was 72.0 g, the yield was 91%, and the purity by HPLC analysis was 93.6%. After a reaction time of 10 hours, the yield was 77.6 g, the yield was 98%, and the purity by HPLC analysis was 95.1%.

Comparative Example 3 An experiment was carried out in the same manner as in Example 6 except that a mixed solvent consisting of 150 g of toluene and 250 g of N, N-dimethylformamide was used as a solvent, and 4,4'-bis (3-maleimidophenoxy) was used. Biphenyl was obtained. Distilled water is 1
4.5 g, 44.7% of theory. Yield 26
1 g, yield 55%, purity by HPLC analysis 93.
It was 0%.

[0038]

The present invention is a novel method for producing bismaleimides which are important as a raw material for a polyimide resin as described above. ADVANTAGE OF THE INVENTION According to this invention, bismaleimides of high purity can be synthesize | combined, without using acetic anhydride and a heavy metal salt like the conventional manufacturing method of bismaleimides. Also,
This is a method that can be synthesized more efficiently in a shorter time than the conventional azeotropic dehydration method. The amount of the catalyst is small, the recovery of the solvent is easy, the volumetric efficiency of the reactor is good, and it is excellent as an industrial production method, and the significance of the present invention is great.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-99764 (JP, A) JP-A-63-122666 (JP, A) JP-A 1-211563 (JP, A) (58) Field (Int. Cl. ⁷ , DB name) C07D 207/00-207/50 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound represented by the general formula (1): [Wherein, X represents a group selected from the group consisting of a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, and a sulfonyl group; The nitrogen atom independently occupies the p-, o- or m-position with respect to X, and Y _{1 to} Y ₄ each independently represent a group consisting of hydrogen, a lower alkyl group, a lower alkoxy group, chlorine or bromine. Shows selected groups. The diamine compound and maleic acid represented by, acidic or in the presence of a basic catalyst, relative to the organic solvent to 100 parts of an azeotrope with water as a reaction solvent, an aprotic organic polar solvent 15 parts to
The reaction is carried out by using a mixed solvent obtained by mixing 100 parts while removing water generated under heating and refluxing out of the system, wherein the reaction is carried out by the general formula (2). [Wherein, X represents a group selected from the group consisting of a direct bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, a hexafluorinated isopropylidene group, a carbonyl group, a thio group, and a sulfonyl group; The nitrogen atom independently occupies the p-, o- or m-position with respect to X, and Y _{1 to} Y ₄ each independently represent a group consisting of hydrogen, a lower alkyl group, a lower alkoxy group, chlorine or bromine. Shows selected groups. ] The manufacturing method of the bismaleimide represented by this. 2. The method according to claim 1, wherein the organic solvent capable of azeotroping with water is an aliphatic hydrocarbon, an alicyclic hydrocarbon or an aromatic hydrocarbon.