JPH115768A - Production method of diamine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly pure diamine in high yield from a dialdehyde as a raw material. A crude reaction solution obtained by performing a reductive amination reaction is provided with sulfur having an unshared electron pair. A compound containing atoms is added and distilled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to various polyamides,
The present invention relates to a method for producing an industrially useful diamine as a raw material of polyurethane.

[0002]

2. Description of the Related Art There are known several methods for producing a diamine by performing a reductive amination reaction using dialdehyde as a starting material in the presence of ammonia or an amine, hydrogen and a hydrogenation catalyst. For example, Japanese Patent Publication No. 58-26902 discloses a method for reductive amination of an aliphatic or alicyclic dialdehyde in the presence of a hydrogenation catalyst comprising ammonia or an amine, hydrogen and a support containing nickel, magnesium oxide and silicic acid. Have been. JP-A-3-20
No. 4840 discloses a nickel catalyst containing a carrier as a hydrogenation catalyst (Ni 50-54%, commercially available from Hoechst AG: RCH Ni 52/3).
A method for producing an α, ω-diamine by performing a reductive amination reaction using 5) is described. Further, Japanese Unexamined Patent Publication No.
No. 17413 describes a method for producing a diamine by performing a reductive amination reaction using a Raney nickel catalyst.

[0003]

[Problems to be Solved by the Invention] Japanese Patent Publication No. 58-2690
No. 2 discloses that the reaction yield is 90 to 95 in the Examples.
% To obtain a crude reaction solution containing a diamine,
There is no description on the method for purifying the diamine from the crude reaction solution and the yield of the diamine after the purification. JP-A-3-204840 discloses that the crude reaction solution obtained in Example 1 is distilled using a column having 9 theoretical plates,
There is a description that the diamine was obtained with a yield of 1.7% and a selectivity of 95%, but there is no detailed description of a method for purifying the diamine. On the other hand, JP-A-5-17413 discloses a method for purifying a crude reaction solution containing a diamine obtained by the reaction by a general isolation and purification method, for example, removing the catalyst from the reaction solution by filtration, and then purifying by distillation. It is described that by employing the method described above, a high-purity target diamine can be easily obtained. However, the present inventors conducted a supplementary test of the method described in JP-A-5-17413, and found that when diamine obtained by the above-mentioned production method was purified by distillation of a crude reaction solution, the diamine was removed at the lower portion of the distillation apparatus. It has been found that a phenomenon of decomposition and / or high boiling occurs.
When this phenomenon occurs, not only does the distillation recovery of the diamine decrease, but also the accumulation of high-boiling substances makes it difficult to continue the distillation, which is a very serious obstacle to the production of the diamine on an industrial scale. As described above, no industrial method for diamines has been hitherto known in which diamines are subjected to reductive amination reaction to distill and recover high-purity diamines from crude diamines in high yield.

Accordingly, an object of the present invention is to distill and purify a crude reaction solution obtained by performing a reductive amination reaction using dialdehyde as a starting material in the presence of a hydrogenation catalyst, hydrogen and ammonia and / or amine. Accordingly, the present invention provides an industrially advantageous production method for recovering a high-purity diamine with a high yield.

[0005]

According to the present invention, the above object is achieved by using a dialdehyde as a starting material, a hydrogenation catalyst,
A crude reaction solution obtained by performing a reductive amination reaction in the presence of hydrogen and ammonia and / or an amine is added with a compound containing a sulfur atom having an unshared electron pair, followed by purification by distillation. This is achieved by providing a process for the production of diamines.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the dialdehyde used as a starting material for diamine synthesis has 4 to 20 carbon atoms.
More preferred are dialdehydes having a straight-chain aliphatic, branched-chain aliphatic, alicyclic or aromatic skeleton having 8 to 12 carbon atoms. Specifically, linear aliphatic dialdehydes such as butanedial, hexanedial, octanedial, nonandial, decandial, dodecandal, hexadecandial, octadecandial, eicosandial, and the like; 2-methyloctanedial , 2
Branched aliphatic dialdehydes such as -methyl-nonandial, 2,7-dimethyloctanedial; 1,3- or 1,4-cyclohexanedicarbaldehyde, 3
Alicyclics such as (4), 8 (9) -tricyclo [5.2.1.0] decanedicarbaldehyde, 2 (3), 5 (6) -bicyclo [2.2.1] heptanedicarbaldehyde Examples are formula dialdehydes; or aromatic dialdehydes such as terephthalaldehyde, isophthalaldehyde.

Using the above dialdehydes as raw materials, linear aliphatic diamines such as butanediamine, hexanediamine, octanediamine, nonanediamine, decanediamine, dodecanediamine, hexadecanediamine, octadecanediamine and eicosanediamine;
Branched aliphatic diamines such as -methyloctanediamine, 2-methyl-nonanediamine, and 2,7-dimethyloctanediamine; 1,3- or 1,4-cyclohexanedimetamine, 3 (4), 8 (9)- Tricyclo [5.
2.1.0] Decandimethanamine, 2 (3), 5 (6)
Alicyclic diamines such as -bicyclo [2.2.1] heptanedimethanamine; or aromatic diamines such as p-xylenediamine, m-xylenediamine.

In the present invention, the hydrogenation catalyst used for the reductive amination of the synthesis of diamine includes a Raney catalyst such as Raney nickel, Raney cobalt and Raney copper, and a hydrogenation catalyst such as nickel, cobalt, platinum, palladium, rhodium, ruthenium and copper. Diatomaceous earth, silica,
A supported catalyst supported on a carrier such as alumina, silica alumina, clay, titania, zirconia, magnesia, calcia, lanthanum oxide, niobium oxide, carbon, or a metal and organic such as nickel, cobalt, platinum, palladium, rhodium, ruthenium, copper, etc. Alternatively, a metal complex catalyst comprising an inorganic ligand can be used.

In the reductive amination reaction for synthesizing the diamine, conditions such as temperature, hydrogen pressure, amount of ammonia used, solvent, reaction method and reaction apparatus are not particularly limited, and the same method as known methods can be used. Is done.

In the present invention, the hydrogenation catalyst contained in the crude reaction solution obtained by the reductive amination reaction is removed by a general method such as filtration, adsorption, extraction, etc., and the separation and recovery of ammonia, the distillation of the solvent, and the like. After separation, recovery and distillation, the obtained diamine can be purified and distilled to obtain the desired diamine with high purity.

The time when the compound containing a sulfur atom having an unshared electron pair used in the present invention is added is such that the diamine is substantially decomposed in the distillation purification step and the boiling point is increased to a high temperature of 120 to 150 ° C. or higher. In the stage before the liquid is heated, it may be before the ammonia is recovered and distilled, before the solvent is recovered and distilled, or before the crude diamine liquid after the solvent is removed is rectified. Further, before heating the crude reaction solution to which the sulfur compound is added to a temperature at which the diamine is substantially decomposed and increased to a high boiling point, the diamine is decomposed by mixing and stirring at a lower temperature for several minutes to several hours. In addition, high boiling can be suppressed more effectively.

The compound containing a sulfur atom having an unshared electron pair used in the present invention includes an organic sulfur-containing compound and an inorganic sulfur-containing compound. As the organic sulfur-containing compound, for example, sulfides, disulfides,
Mercaptans, thioureas, mercaptobenzothiazoles, thiocarbamic acids and the like, more specifically, di-n-butyl sulfide, di-n-octyl sulfide, di-n-dodecyl sulfide, diphenyl sulfide, thiodipropion Acids, sulfides such as dodecyl thiodipropionate and thiodiglycol, di-n-butyl disulfide, di-n-octyl disulfide, di-n-dodecyl disulfide, disulfides such as diphenyl disulfide and dithiodipropionic acid, n −
Butyl mercaptan, n-octyl mercaptan, n-
Dodecyl mercaptan, t-butyl mercaptan, t-
Mercaptans such as octylmercaptan and t-nonylmercaptan; thioureas such as diphenylthiourea, diethylthiourea, dibutylthiourea and dilaurylthiourea; 2-mercaptobenzothiazole; sodium 2-mercaptobenzothiazole; zinc 2-mercaptobenzothiazole; Thiocarbamic acids such as mercaptobenzothiazoles, diethyldithiocarbamic acid, sodium diethyldithiocarbamate, zinc diethyldithiocarbamate, sodium dibutyldithiocarbamate and zinc dibutyldithiocarbamate. Examples of the inorganic sulfur-containing compound include carbon disulfide, hydrogen sulfide, sodium sulfide, sodium hydrosulfide, and sodium sulfite. Of these, it is preferable to use a compound containing a sulfur atom that can be separated to a higher boiling point by distillation purification than the target diamine. For example, if the target diamine is 1,9-nonanediamine or 2-methyl-1,8-
In the case of octanediamine, di-n-dodecyl sulfide, diphenyl sulfide, diphenyl thiourea,
It is preferable to use mercaptobenzothiazole, sodium diethyldithiocarbamate and the like.

The amount of the compound containing a sulfur atom having a lone pair is in the range of 1 to 5000 ppm, preferably 10 to 1000 ppm, based on the weight of the diamine present in the target aminated crude reaction solution. . If the amount used is less than 1 ppm, the effect of suppressing the reduction of the diamine recovery rate and the accumulation of high-boiling substances in the distillation step is not sufficient, and if the amount used is more than 5000 ppm, there is an economical problem as an industrial method due to the cost of sulfur compounds. There is.

A series of operations in the distillation step do not require special consideration for temperature, pressure, etc., and are performed according to a known method.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 1,9-Nonandial and 2-methyl-butanol were used in accordance with JP-A-5-17413, except that a diatomaceous earth-supported catalyst containing 50% of nickel was used as a hydrogenation catalyst.
Using 78.4 g of a mixture of 1,8-octanedial as a raw material, a reductive amination reaction was carried out in the presence of a catalyst, a methanol solvent, ammonia, and hydrogen, and 1,9-nonanediamine and 2-methyl-1, A crude reaction solution containing 8-octanediamine was obtained. Next, the catalyst was separated from the crude reaction solution by filtration, and then ammonia, water and a methanol solvent were removed by evaporation at a temperature of 40 ° C. or lower to obtain 75.2 g of a crude diamine. As a result of gas chromatography analysis, the diamine content in the crude diamine was 9
It was 5 wt%. From this, the yield of diamine is 71.4.
g, and the selectivity to the starting dial was 90%. After adding 500 ppm of diphenyl sulfide to the diamine to this crude diamine, it was charged into a metallic pressure-resistant tube under a nitrogen atmosphere, and a diamine heat stability test was performed at 180 ° C. for 2 hours. The residual ratio of the diamine after 2 hours was 100%. Further, the crude diamine to which the diphenyl sulfide was added was purified by distillation using a distillation column having 20 theoretical plates at a lower temperature of the distillation column of 170 to 180 ° C. and a top pressure of 5 to 2 torr. 67.8 g of 9.9% diamine
(85% yield based on the starting material dial). The recovery from the generated crude diamine was 95%.

Examples 2 to 10 The crude diamine obtained in the same manner as in Example 1
In the same manner as in Example 1 except that the additives shown in Table 1 were used in place of the diphenyl sulfide used in
A thermal stability test of the diamine at 2 ° C. for 2 hours was performed. The result

[0018]

[Table 1]

Are shown below.

Comparative Example 1 To a crude diamine obtained in the same manner as in Example 1, without adding any compound containing a sulfur atom having an lone pair,
As a result of conducting a thermal stability test of the diamine at 180 ° C. for 2 hours in the same manner as in Example 1, the residual ratio of the diamine was 60%.
%Met.

Comparative Example 2 The same procedure as in Example 1 was repeated except that 0.8 ppm of diphenyl sulfide was added to the crude diamine obtained in the same manner as in Example 1. As a result of a heat stability test, the residual ratio of the diamine was 72%.

[0022]

Industrial Applicability According to the present invention, a crude reaction solution obtained by performing a reductive amination reaction using a dialdehyde as a raw material is distilled to recover a high-purity diamine in a high yield, which is industrially advantageous. A law is provided.

Claims (5)

[Claims] 1. A crude reaction solution obtained by performing a reductive amination reaction using a dialdehyde as a starting material in the presence of a hydrogenation catalyst, hydrogen and ammonia and / or an amine,
A process for producing a diamine, comprising adding a compound containing a sulfur atom having an unshared electron pair and performing distillation. 2. The compound containing a sulfur atom having an unshared electron pair is at least one compound selected from the group consisting of sulfides, disulfides, mercaptans, thioureas, mercaptobenzothiazoles, and thiocarbamic acids. A method for producing a diamine according to claim 1. 3. The method for producing a diamine according to claim 1, wherein the compound containing a sulfur atom having an unshared electron pair is a sulfide having 12 or more carbon atoms and / or a thiourea having 12 or more carbon atoms. 4. The compound containing a sulfur atom having an unshared electron pair, wherein at least one selected from the group consisting of mercaptobenzothiazoles, metal salts of mercaptobenzothiazoles, thiocarbamic acids, and metal salts of thiocarbamic acids. The method for producing a diamine according to claim 1, which is a compound. 5. The diamine is 1,9-nonanediamine,
The method for producing a diamine according to any one of claims 1 to 5, wherein the method is 2-methyl-1,8-octanediamine or a mixture thereof.