JP2012131721A - Method of producing 4,4'-methylenedianiline - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a producing method that can obtain the most useful 4,4'-methylenedianiline in high selectivity among isomers of methylenedianiline derivatives, under presence of zeolite catalyst.SOLUTION: N,N'-diphenylmethylenediamine is subjected to reaction under presence of zeolite having an EMT structure or including an EMT structure, as catalyst.

Description

  The present invention relates to a method for producing 4,4'-methylenedianiline.

  Methylenedianiline (MDA) has several isomers depending on the position of the amino group. For example, 2,2′-MDA, 2,4′-MDA, 4,4′-MDA and the like are known. . Industrially, 4,4'-MDA is preferably obtained selectively.

  Conventionally, as a method for producing MDA, for example, a method of reacting aniline or a derivative thereof with formaldehyde using a mineral acid such as hydrochloric acid as a catalyst has been used. However, in this method, corrosion of the apparatus and neutralization of the reaction solution obtained after the reaction require an alkali of equimolar or more with a mineral acid, and there is a problem that waste is generated as a salt.

  As a method for solving such problems, methods for producing MDA using various zeolites as catalysts have been proposed (see, for example, Patent Document 1 to Patent Document 3). No consideration has been given to selectivity.

  Thus, a production method capable of highly selectively obtaining the industrially most useful 4,4'-MDA has been desired.

JP 2001-26571 A Special table 2003-529577 gazette JP-T-2005-521722

  The present invention has been made in view of the above-mentioned background art, and the object thereof is to highly selectively obtain the most useful 4,4′-MDA among isomers of MDA derivatives in the presence of a zeolite catalyst. It is to provide a manufacturing method.

  In order to solve the above-mentioned problems, the present inventors have intensively studied and as a result, the present invention has been completed.

  That is, this invention is a manufacturing method of 4,4'-MDA as shown below.

  [1] A process for producing 4,4′-methylenedianiline, comprising reacting N, N′-diphenylmethylenediamine as a catalyst in the presence of a zeolite having an EMT structure or containing an EMT structure.

  [2] The above-mentioned [1], wherein the zeolite having or including the EMT structure is selected from the group consisting of EMC-2, ECR-20, ZSM-2, ZSM-3, and ZSM-30. ] The manufacturing method of 4,4'-methylenedianiline of description.

  The present invention is extremely useful industrially because 4,4'-MDA can be produced using a zeolite catalyst with an unprecedented high selectivity.

  The present invention is characterized in that 4,4'-MDA is produced by reacting N, N'-diphenylmethylenediamine as a catalyst in the presence of an EMT structure or a zeolite containing an EMT structure.

  In the present invention, the method for producing N, N′-diphenylmethylenediamine is not particularly limited, but for example, it can be produced by reacting aniline and formaldehyde.

  There is no restriction | limiting in particular as aniline used by this reaction, For example, a commercial item, a synthetic item, what was collect | recovered later by using the manufacturing method of this invention, or these mixed products etc. can be used. On the other hand, formaldehyde is usually used in the form of an aqueous solution containing 20 to 50% by weight of formaldehyde. There is no problem even if this aqueous formaldehyde solution contains a usual stabilizer such as methanol. The ratio of aniline to formaldehyde is not particularly limited, but a molar ratio of aniline / formaldehyde is preferably in the range of 2-50. If the aniline / formaldehyde molar ratio is less than 2, the efficiency decreases because formaldehyde is present in excess. On the other hand, when the ratio is larger than 50, since a large excess of aniline is present, the efficiency in producing 4,4'-MDA in the presence of the subsequent zeolite is lowered.

  When aniline and formaldehyde are reacted, they may be reacted in the presence of a catalyst or in the absence of a catalyst. Further, it is sufficient that aniline and formaldehyde are sufficiently mixed, and any of a batch system, a semi-batch system, and a continuous system may be used. The reactor may be either a tank type or a tube type. When aniline and formaldehyde are mixed, any method may be used regardless of whether formaldehyde is added to aniline or aniline is added to formaldehyde.

  Although the temperature which makes aniline and formaldehyde react is not specifically limited, For example, it is preferable to implement in the range of 0 degreeC-80 degreeC. When the temperature is lower than 0 ° C., there is no problem in reaction efficiency, but energy for cooling is required, which is not economical. When the temperature is higher than 80 ° C., the reaction efficiency is not a problem, but energy for heating is required, which is also not economical.

  Moreover, the reaction time is not particularly limited, but for example, it is preferably carried out for 0.5 hours to 5 hours. If it is shorter than 0.5 hour, the reaction between aniline and formaldehyde may not proceed sufficiently. Further, even if the reaction time is longer than 5 hours, further progress of the reaction cannot be expected.

  When aniline and formaldehyde are reacted, they may be synthesized without using a solvent or may be synthesized with a solvent. When a solvent is used, for example, aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic hydrocarbons such as pentane, hexane and octane, and halogen-based hydrocarbons such as dichloromethane and carbon tetrachloride can be used.

  After completion of the reaction between aniline and formaldehyde, the reaction solution is usually separated into two phases. The aqueous phase contains an aqueous formaldehyde stabilizer such as aqueous formaldehyde and methanol. The organic phase includes N, N'-diphenylmethylenediamine and aniline, and some water. It is preferable to separate a mixture of aniline and N, N′-diphenylmethylenediamine from such a two-phase reaction solution. Although it does not specifically limit as a method to isolate | separate, For example, well-known methods, such as physical separation, such as liquid separation, and distillation, can be used. When the aqueous layer is removed by liquid separation, the water may be further removed by drying under reduced pressure or a dehydrating agent. When the reaction is performed using a solvent, the solvent may or may not be removed.

In the present invention, zeolites with the general _{formula: M 2 / n O · Al} 2 O 3 · ySiO 2 · zH in 2 O (wherein, M represents Na, K, Ca, a metal such as Ba, n represents positive It represents the valence of the ion M. In addition, y represents a number of 2 or more, and z represents a number of 0 or more.) Many types are known as natural products and synthetic products. It has been.

  The zeolite used in the present invention has an EMT structure or contains an EMT structure. The EMT structure is a structure defined by the International Zeolite Society. As a zeolite containing an EMT structure, EMC-2, ECR-20, ZSM-2, ZSM-3, and ZSM-30 are preferable. The content of the EMT structure is not particularly limited, but in order to obtain a high 4,4′-MDA selectivity, the EMT structure should be 20% by weight or more based on the entire zeolite. Is preferred. Further, the EMT structure and zeolite having another structure may be physically mixed.

In the zeolite used in the present invention, the type of ion exchanged cation is not particularly limited, and may be ion exchanged with a sodium cation, a potassium cation or the like, or may be a proton. Further, the SiO ₂ / Al ₂ O ₃ molar ratio of zeolite is not particularly limited, but in order to obtain high durability, the SiO ₂ / Al ₂ O ₃ molar ratio is preferably 5 or more.

  In the present invention, when N, N′-diphenylmethylenediamine is reacted in the presence of the above-mentioned zeolite, the reaction temperature is not particularly limited. preferable. When reaction temperature is lower than 50 degreeC, there exists a possibility that a catalyst action may become weak and it may become impossible to obtain high catalyst performance. When the reaction temperature is higher than 300 ° C., a large amount of energy is required to maintain the reaction temperature, which is not economical.

  Moreover, reaction time is not specifically limited, For example, it is preferable to make it react in the range of 0.5 hour-50 hours. When the reaction time is shorter than 0.5 hours, the catalyst does not function sufficiently, and high catalyst performance may not be obtained. Even if the reaction time is longer than 50 hours, no further progress of the reaction can be expected.

  The reaction of the present invention may be carried out by any of batch, semi-batch, or fixed bed methods.

  In the present invention, the shape of the zeolite is not particularly limited, and those having a known shape such as powder, pellets and beads can be used. Also, some pretreatment may be performed on the zeolite. Although it does not specifically limit as a density | concentration of a zeolite, 0.1-500 weight% normally with respect to the reaction liquid containing N, N'- diphenylmethylenediamine, Preferably it is 1.0-100 weight%. It is a range. If the amount is less than 0.1% by weight, sufficient catalyst performance may not be obtained. If it exceeds 500% by weight, a large amount of catalyst is required, which is not economical.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is limited to these Examples and is not interpreted.

(Measurement of 4,4′-MDA)
For the gas chromatographic analysis, the produced MDA derivative was measured using a gas chromatograph GC-17A (manufactured by Shimadzu Corporation). DB-5 (manufactured by Agilent Technologies) was used for the column, and FID was used for the detector. The selectivity of 4,4′-MDA was calculated from the amount of 4,4′-MDA relative to the amount of MDA determined by gas chromatographic analysis.

Preparation example.
Aniline and 37% by weight formaldehyde were mixed at room temperature so that the molar ratio of aniline and formaldehyde was 4, and stirred at 50 ° C. for 2 hours. After allowing to cool, the aqueous phase was separated to obtain an aniline solution of N, N′-diphenylmethylenediamine as an intermediate.

Example 1.
Tetraethoxysilane (TEOS), tetramethylammonium hydroxide (TMAOH), aluminum, and lithium hydroxide were mixed in the following composition to obtain 300 g of a mixed slurry.

_{SiO 2: 0.29Al: 1.56TMAOH: 101H} 2 O: 0.51Li.

The mixed slurry was placed in an autoclave charged with a Teflon (registered trademark) inner cylinder and crystallized at 100 ° C. for 30 hours. The slurry after crystallization was dried at 110 ° C. after filtration and washing. Furthermore, TMAOH was removed by baking at 600 ° C. under air flow. X-ray peaks corresponding to EMT structure zeolite and FAU structure zeolite were observed by powder X-ray diffraction, and the ratio of EMT structure to FAU structure was 2: 8. Zeolite had a SiO ₂ / Al ₂ O ₃ (molar ratio) of 5.0, and the type of ion exchanged cation was proton.

  10 g of the intermediate aniline solution obtained in the preparation example was added to 0.5 g of the zeolite thus prepared at room temperature in a nitrogen atmosphere.

  The mixture was stirred at 140 ° C. for 24 hours under a nitrogen atmosphere. As a result of gas chromatographic analysis of the reaction solution from which the zeolite catalyst had been removed after being allowed to cool to room temperature, the selectivity for 4,4'-MDA was 82%.

Example 2
Tetraethoxysilane (TEOS), tetramethylammonium hydroxide (TMAOH), aluminum, and lithium hydroxide were mixed in the following composition to obtain 300 g of a mixed slurry.

_{SiO 2: 0.29Al: 1.76TMAOH: 101H} 2 O: 0.31Li.

  The mixed slurry was placed in an autoclave charged with a Teflon (registered trademark) inner cylinder and crystallized at 100 ° C. for 30 hours. The slurry after crystallization was dried at 110 ° C. after filtration and washing. Furthermore, TMAOH was removed by baking at 600 ° C. under air flow. X-ray peaks corresponding to EMT structure zeolite and FAU structure zeolite were observed by powder X-ray diffraction, and the ratio of EMT structure to FAU structure was 6: 4.

Example 1 was performed except that the zeolite thus prepared was used. Zeolite had a SiO ₂ / Al ₂ O ₃ (molar ratio) of 5.0, and the type of ion exchanged cation was proton. As a result of gas chromatographic analysis, the selectivity for 4,4′-MDA was 82%.

Example 3
Silica sol, crown ether (18-crown-6) and sodium aluminate were mixed in the following composition to obtain 300 g of a mixed slurry.

SiO _2: 0.2Al: 0.0087 crown ether: _14H 2 O.

  The mixed slurry was placed in an autoclave equipped with a Teflon (registered trademark) inner cylinder, allowed to stand at room temperature for 1 day, heated to 110 ° C., and crystallized for 12 days. The slurry after crystallization was dried at 110 ° C. after filtration and washing. Further, the crown ether was removed by firing at 600 ° C. under air flow. Only X-ray peaks corresponding to EMT-structured zeolite were observed by powder X-ray diffraction.

Example 1 was performed except that the zeolite thus prepared was used. Zeolite had a SiO ₂ / Al ₂ O ₃ (molar ratio) of 5.0, and the type of ion exchanged cation was proton. As a result of gas chromatographic analysis, the selectivity for 4,4′-MDA was 90%.

Comparative Example 1
The same procedure as in Example 1 was performed except that the zeolite was FAU type zeolite (product name: HSZ320HOA, manufactured by Tosoh Corporation). The zeolite had a SiO ₂ / Al ₂ O ₃ (molar ratio) of 5.5, and the type of ion exchanged cation was proton.

  As a result of gas chromatographic analysis, the selectivity for 4,4'-MDA was 75%.

Comparative Example 2
The same procedure as in Example 1 was performed except that the zeolite was BEA type zeolite (manufactured by Tosoh Corporation, product name: HSZ930NHA). The SiO ₂ / Al ₂ O ₃ (molar ratio) of the zeolite was 27, and the type of ion exchanged cation was proton.

  As a result of gas chromatographic analysis, the selectivity for 4,4'-MDA was 58%.

  The selectivity of 4,4'-MDA obtained in Examples 1 to 3 and Comparative Examples 1 and 2 is shown in Table 1 below.

この表によれば、Ｎ，Ｎ’−ジフェニルメチレンジアミンを、触媒として、ＥＭＴ構造を有する又はＥＭＴ構造を含むゼオライトの存在下で反応させることで、高選択率で４，４’−ＭＤＡを製造できることが分かる。

According to this table, 4,4′-MDA is produced with high selectivity by reacting N, N′-diphenylmethylenediamine as a catalyst in the presence of a zeolite having an EMT structure or containing an EMT structure. I understand that I can do it.

  The 4,4'-MDA produced according to the present invention is widely used as a raw material for polyurethane, for example.

Claims (2)

A process for producing 4,4'-methylenedianiline, characterized by reacting N, N'-diphenylmethylenediamine as a catalyst in the presence of a zeolite having or containing an EMT structure. 2. The zeolite according to claim 1, wherein the zeolite having or including the EMT structure is selected from the group consisting of EMC-2, ECR-20, ZSM-2, ZSM-3, and ZSM-30. A method for producing 4,4′-methylenedianiline.