JPH10130210A - Production of diamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a profitable method for producing a diamine, enabling to produce the diamine from a dialdehyde in a high yield and in a high selectivity at a step. SOLUTION: This method for producing a diamine comprises dissolving a dialdehyde in a lower alcohol, feeding the obtained solution into a reactor having a hydrogenation catalyst, a lower alcohol, ammonia and hydrogen therein, and subsequently subjecting the dialdehyde to a reducing amination reaction to obtain the corresponding diamine. Therein, the dialdehyde is dissolved in a lower alcohol in the presence of an amine compound excluding the ammonia in an amount of <=4mol% based on that of the dialdehyde and subsequently fed into the reactor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a diamine useful as a raw material for various polyamides or polyurethanes.

[0002]

2. Description of the Related Art As a method for producing a corresponding diamine in two steps by reacting a dialdehyde once with an excess amount of ammonia or a primary amine and then hydrogenating the same,
(1) A method of deriving diimine by reacting with ammonia followed by hydrogenation (see U.S. Pat. No. 4,197,260); (2) Deriving diazomethine by reacting with monoamine and then in the presence of excess ammonia (See JP-A-54-160307), and (3) a method of reacting with a primary amine in the presence of water and hydrogenating the reaction mixture in the presence of an excessive amount of ammonia ( JP-A-3-204840) is known. On the other hand, as a method of producing a diamine from a dialdehyde in one step, (1) the dialdehyde is dissolved in a solvent such as water or a lower alcohol without using a solvent, or substantially dissolved in a solvent such as a lower alcohol. Method for introducing into a reductive amination reactor at a modest rate (US Pat.
No. 051) and (2) a method in which dialdehyde is dissolved in alcohol to form hemiacetal and introduced into a reactor for reductive amination (French Patent No. 2,656,8).
No. 64 and JP-A-5-17413), and (3) the formation of hemiacetal is suppressed by limiting the temperature at which dialdehyde is mixed with a diluent such as alcohol to a maximum of 5 ° C. There is known a method of adding a mixture to a reductive amination reactor (see JP-A-7-69999).

[0003]

The process for producing a corresponding diamine by reacting a dialdehyde with an excess amount of ammonia or a primary amine and then hydrogenating it is a two-stage reaction. Industrially unfavorable. The process for producing diamines from dialdehydes in one step, whether via hemiacetal or not,
Basically, it is a similar reaction. U.S. Pat.
051, French Patent No. 2,656,864 and JP-A-5-17413 are advantageous in that diamines can be obtained in one step from dialdehydes. When the reaction is carried out using a lower alcohol such as methanol which is preferred as a solvent in these methods, the resulting diamine contains by-products of aminoacetals which are difficult to separate by distillation. In addition, it was recognized that when a polyamide was polymerized using a diamine containing these by-products, a desired degree of polymerization was not reached and a polyamide having desirable physical properties could not be obtained. Although this finding is not described in any of the above-mentioned documents, it is an important problem to be solved in developing a method for producing a diamine used as a raw material for a polyamide. Further, the method disclosed in Japanese Patent Application Laid-Open No. 7-69999 is not industrially preferable because cooling with a refrigerant is required for temperature control for the purpose of suppressing the formation of hemiacetal. Therefore, an object of the present invention is to provide an economical method for producing a diamine, which can produce a diamine from a dialdehyde in one step with high yield and high purity.

[0004]

According to the present invention, a solution obtained by dissolving a dialdehyde in a lower alcohol is supplied to a reactor in which a hydrogenation catalyst, a lower alcohol, ammonia and hydrogen are present, A method for producing a corresponding diamine by reductive amination of an aldehyde, wherein the dialdehyde is dissolved in a lower alcohol in the presence of an amine compound excluding ammonia of 4 mol% or less based on the dialdehyde. The above object can be achieved by providing a production method of

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The dialdehyde used in the present invention has 4 to 20 carbon atoms, preferably 6 to 1 carbon atoms.
6, more preferably a dialdehyde having a straight-chain aliphatic, branched-chain aliphatic, alicyclic or aromatic skeleton having 8 to 12 carbon atoms. For example, butanedial, hexanedial, octanedial, nonandial, decandial, undecandial, dodecandial, tetradecandial, hexadecandial, octadecandial, straight-chain aliphatic dialdehydes such as eicosandial, Branched aliphatic dialdehydes such as methyl octane dial, 2-methyl nonandial, 2,7-dimethyl octane dial, 1,3- or 1,4-
Cyclohexane dicarbaldehyde, 3 (4), 8 (9)
Alicyclic dialdehydes such as -tricyclo [5.2.1.0] decandicarbaldehyde, 2 (3), 5 (6) -bicyclo [2.2.1] heptanedicarbaldehyde, or terephthalaldehyde; Examples are aromatic dialdehydes such as isophthalaldehyde. These dialdehydes can be easily and inexpensively synthesized by, for example, an oxo reaction of an olefin having one fewer carbon atoms or a diolefin having two carbon atoms. Further, it can also be obtained by ozonolysis and subsequent reduction of a cyclic olefin having the same carbon number, oxidation of an aromatic hydrocarbon having the same carbon number, reduction of a dicarboxylic acid having the same carbon number, and the like.

Using the above dialdehydes as raw materials, corresponding 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 11-undecanediamine, 1,12-dodecanediamine, 1,14-
Linear aliphatic diamines such as tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,20-eicosanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,9 Branched aliphatic diamines such as -nonanediamine, 2,7-dimethyl-1,8-octanediamine, 1,3- or 1,4-cyclohexanedimethanamine, 3 (4), 8
Alicyclic diamines such as (9) -tricyclo [5.2.1.0] decandimethanamine, 2 (3), 5 (6) -bicyclo [2.2.1] heptanedimethanamine, or p
Aromatic diamines such as -xylylenediamine and m-xylylenediamine are produced.

As the lower alcohol solvent used in the reductive amination reaction for producing a diamine from a dialdehyde, for example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, isobutyl alcohol, t-butyl alcohol, 2-methoxyethanol, ethylene glycol, propylene glycol,
C1-C4 alcohols and polyols, such as 1,4-butanediol and glycerin, are mentioned.
The amount of the lower alcohol solvent to be used is not particularly limited, but is in the range of 0.1 to 50 times, preferably 1 to 10 times the weight of the dialdehyde. If the concentration is too low, it is practically disadvantageous, and if it is too high, the yield decreases.

As the amine compound other than ammonia used in the present invention, any of primary amine, secondary amine and tertiary amine can be used. For example, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, diethylamine Aliphatic amines such as isopropylamine, diisopropylethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, tributylamine, octylamine, dioctylamine, trioctylamine; ethanolamine, diethanolamine, triethanolamine, etc. Aliphatic amines having a hydroxyl group; aromatic amines such as aniline, N-methylaniline and N, N-dimethylaniline; including pyridine, picoline, lutidine and the like. Containing aromatic compound; may be used a diamine obtained by the reductive amination of a dialdehyde, in particular tertiary amines preferred.

According to the present invention, an amine compound excluding ammonia is added in an amount of 4 mol% or less based on dialdehyde, and the resulting solution is dissolved in a lower alcohol.
Hydrogenation catalyst, lower alcohol, ammonia and hydrogen are present, and the corresponding diamine is obtained in a high yield by supplying to a reactor which is kept in advance under reductive amination conditions.
Produced with high efficiency and high purity. If the amount of the amine compound other than ammonia is too large, the generation of by-products of aminoacetals, which is difficult to separate by distillation from the diamine, can be suppressed, but the yield of the diamine decreases. 4 mol% or less based on the aldehyde is suitable.

The addition of the amine compound to the dialdehyde can be carried out at room temperature, but it may be cooled or heated as required. Next, the mixing of the dialdehyde to which the amine compound has been added and the lower alcohol solvent can be performed by supplying the lower alcohol solvent to the dialdehyde, supplying the dialdehyde to the lower alcohol solvent, or mixing the dialdehyde with the lower alcohol solvent. May be mixed by supplying the same at the same time. Since these mixtures are usually accompanied by heat generation, they are lower than the boiling point of the solvent, preferably lower than 50 ° C., particularly preferably lower than
It is appropriate to keep the temperature below ° C. Further, the obtained solution is kept at 40 ° C. or lower under an inert atmosphere such as nitrogen until the solution is completely supplied to the reductive amination reactor.
Preferably, it is stored at a temperature of 20 ° C. or less. The mixing of the dialdehyde to which the amine compound has been added and the lower alcohol solvent, and the supply of the resulting solution to the reductive amination reactor can be performed continuously or intermittently. The supply rate of the dialdehyde solution into the reductive amination reactor is preferably equal to or less than the reductive amination reaction rate so that unreduced components do not accumulate in the reactor. If the feed rate is too fast than the reaction rate, the yield of diamine will decrease, and if it is too slow, productivity will be impaired. The reductive amination reaction can be performed in any of a continuous system and a semi-continuous system.

The reductive amination reaction for producing a diamine from a dialdehyde can be carried out by a known method. Raney nickel, Raney cobalt,
Raney catalysts such as Raney copper, metals with hydrogenation activity such as nickel, cobalt, platinum, palladium, rhodium, ruthenium, and copper are converted to diatomaceous earth, silica, alumina, silica alumina, clay, titania, zirconia, magnesia, calcia, and oxidation. A supported catalyst supported on a carrier such as lanthanum, niobium oxide, or carbon can be used, and a nickel catalyst supported on an inorganic oxide or a nickel catalyst such as Raney nickel is particularly preferred. The carrier may contain an alkali metal, an alkaline earth metal, an oxide of phosphorus, or a mixture thereof. The main component of the catalyst metal is nickel, but nickel alone may be used, and cobalt, iron, copper, chromium, manganese, silver, molybdenum, rhenium, palladium, rhodium, ruthenium,
It may be modified with one or more metals such as platinum. The catalyst may be in the form of a powder, or a molded product having a granular or cylindrical shape. The amount of nickel catalyst used can be varied according to the desired reaction rate, and is selected in the range of 0.01 to 30% by weight, preferably 0.1 to 5% by weight, based on the reaction mixture. The catalyst may be used in a suspended state in the reaction liquid phase, or may be used as a fixed bed.

The amount of ammonia used in the reductive amination reaction is 2 to 100 times, preferably 5 to 50 times, the molar amount of the starting dialdehyde as the amount of ammonia in the reaction solution.
Particularly preferably, it is used in a range of 10 to 30 mol times. If the amount of ammonia is too small, the yield decreases, and if it is too large, it is practically disadvantageous.

The reaction temperature is 40 to 200 ° C., preferably 8
0-160 ° C, especially 100-140 ° C, is suitable. When the reaction temperature is lower than 40 ° C., the reaction does not proceed at a practically feasible rate, and when the reaction temperature is higher than 200 ° C., the amount of by-products increases and the yield decreases.

The reaction pressure is not particularly limited.
The range is from 0 to 200 atm. In addition, hydrogen may be added so as to replenish the hydrogen consumed in the reaction, or the reaction may be performed while flowing hydrogen at all times.

The diamine thus obtained can be purified by general purification means, for example, by removing the catalyst from the reaction mixture by filtration, and then distilling off ammonia and the solvent, followed by distillation or recrystallization. Thus, a highly pure diamine can be obtained.

[0016]

Next, the method of the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 0.18 g of triethylamine (to dialdehyde) was added to 20.0 g of a dialdehyde solution containing nonandial and 2-methyloctanedial (the ratio of these dialdehydes was 72:28, and the total content was 85%). (1.6 mol% based on the total amount) and stirred at room temperature for 30 minutes. This was added to 40.0 g of methanol at 20 ° C. or lower under a nitrogen atmosphere to prepare a methanol solution of the dialdehyde. 300ml
Raney nickel 4.0 in a magnetically stirred autoclave
g, methanol 38.0 g and ammonia 30.0 g
, And the temperature was raised to 120 ° C. by applying 10 atm of hydrogen, and then the total pressure was adjusted to 40 atm. The methanol solutions of nonandial and 2-methyloctanedial prepared above were supplied to the autoclave by a high-pressure metering pump over 1.5 hours. During the supply, the pressure was maintained at 40 atm by replenishing hydrogen. After the completion of the supply, stirring was continued at 120 ° C. for another hour. After cooling, the autoclave was returned to normal pressure. The catalyst was removed from the reaction solution by filtration, and the filtrate was concentrated to obtain 23.0 g of a crude product. Gas chromatography analysis revealed that the total yield of nonanediamine and 2-methyloctanediamine was 92%, and that by-products of aminoacetals that were difficult to separate by distillation from the diamine were found not to be detected.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that triethylamine was not added to a dialdehyde solution containing nonandial and 2-methyloctanedial. According to gas chromatographic analysis of the crude product, the total yield of nonanediamine and 2-methyloctanediamine was 85.
%, And it was found that aminoacetals which were difficult to separate by distillation from the diamine were by-produced by 0.4%.

Example 2 The amount of triethylamine added to a dialdehyde solution containing nonandial and 2-methyloctanedial was 4 m.
The reaction was carried out in the same manner as in Example 1 except that g (0.04 mol% based on dialdehyde) was changed. Gas chromatographic analysis of the crude product showed that the total yield of nonanediamine and 2-methyloctanediamine was 95%, and that the diamine and the by-products of aminoacetals difficult to separate by distillation were 0.06%. Was.

Examples 3 to 9 The reaction was carried out in the same manner as in Example 1 except that the amine compound to be added to the dialdehyde was replaced with 0.18 g of triethylamine and those shown in Table 1. Table 1 shows the results.

[0021]

[Table 1]

COMPARATIVE EXAMPLE 2 The amount of triethylamine added to a dialdehyde solution containing nonandial and 2-methyloctanedial was set at 0.1.
The reaction was carried out in the same manner as in Example 1, except that the amount was changed to 54 g (4.8 mol% based on dialdehyde). Gas chromatographic analysis of the crude product revealed that the total yield of nonanediamine and 2-methyloctanediamine was reduced to 85%, and that the diamine and aminoacetals which were difficult to separate by distillation were not produced as by-products. As described above, when the addition amount of triethylamine exceeds 4 mol% with respect to dialdehyde, the diamine and the by-product of aminoacetals which are difficult to separate by distillation are not generated,
It is not preferable because the yield of the diamine is reduced to the same level as when no triethylamine is added.

[0023]

According to the present invention, a diamine can be produced from a dialdehyde in one step with excellent economical efficiency and in high yield and high purity.

Claims (4)

[Claims] A solution obtained by dissolving a dialdehyde in a lower alcohol is supplied to a reactor in which a hydrogenation catalyst, a lower alcohol, ammonia and hydrogen are present, and the dialdehyde is reductively aminated to form a corresponding diamine. In the method for producing, the content of the dialdehyde is 4 mol% or less,
A method for producing a diamine, comprising dissolving the dialdehyde in a lower alcohol in the presence of an amine compound excluding ammonia. 2. The method according to claim 1, wherein the amine to be added is a tertiary amine. 3. The method according to claim 1, wherein the lower alcohol is methanol. 4. The method according to claim 1, wherein the dialdehyde is nonandial, 2-methyloctanedial, or a mixture thereof.