JPS61236751A - Production of tertiary amine - Google Patents

Abstract

PURPOSE:The reaction of a primary or secondary amine with formaldehyde is carried out under the pressure of hydrogen, then a primary or secondary amine is added to the reaction mixture and distillation is effected to obtain a tertiary amine which is readily purified with reduced discoloration and increased storage stability. CONSTITUTION:A primary or secondary amine and a hydrogenation catalyst are charged in a reactor, the mixture is stirred, as hydrogen is introduced into the reactor. When the hydrogen pressure and the temperature reach 3-20kg/cm<2> G and 100-150 deg.C, respectively, formaldehyde, preferably 35-50% formalin, is continuously fed in a certain time to effect the reactions. After the completion of the reactions, the catalyst is filtered off, the filtrate is combined with a primary or secondary amine and they are heat treated and subjected to distilla tion to collect the tertiary amine. The amine which is added to the tiltrate is selected so that it has an appropriate difference in boiling point from the tertiary amine. EFFECT:The acid components such as formic acid which are formed in the reactions are varied by addition of amines to give the objective substance of lowered discoloration with the passage of time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing tertiary amines, and more specifically, the present invention relates to a method for producing tertiary amines, and more specifically, the present invention relates to a method for producing tertiary amines, and more specifically, a method for producing tertiary amines using a hydrogenation catalyst. In the production method of reacting under hydrogen pressure to obtain the corresponding tertiary amine by N-methylation, purification is easy and the addition of a primary amine or secondary amine to the reaction product is followed by distillation. The present invention relates to a method for producing a high-quality tertiary amine with little coloration in the product and excellent storage stability.

[Conventional technology and its problems]

As is well known, tertiary amines produced from various primary amines or secondary amines by the above method are used as emulsifiers, rust preventives, dyeing aids, intermediates for fiber softening agents, and urethane. It is a useful material that has various uses such as a 7 ohm catalyst.

In the presence of a hydrogenation catalyst on a primary amine or a secondary amine,
The tertiary amine obtained by reacting formaldehyde can be obtained from the reaction finished liquid by conventional separation and purification methods, such as distillation.
Grade amine 1 is easily colored, and even if a product with a low degree of coloring can be obtained by distillation or the like, it undergoes severe changes over time during storage and is extremely unstable in terms of quality.

This solves the hue instability of such tertiary amines.

A method that has been proposed to date is the addition of an alkaline metal salt. However, even if this method can prevent coloring, there are still problems such as solidification of the bottom after distillation, and problems remain in terms of industrialization.

[Means for solving problems]

As a result of intensive research into the above-mentioned problems, the present inventors have found that the hue instability of tertiary amines is due to the formation of formic acid or other acid components during the reaction.

Therefore, we have intensively investigated a method in which this formic acid or other acid components are converted into non-acidic substances through some kind of reaction, which can be separated and purified by distillation, and which does not cause problems in terms of industrialization such as bottom solidification.

If a primary amine or a secondary amine is added to the tertiary amine reaction-completed liquid obtained as a result of the reaction and separated by distillation, there will be very little coloring, and in particular, the degree of coloring over time will be low.
The present invention was achieved by discovering the fact that it is possible to obtain a tertiary amine with excellent storage stability, and also to obtain a high quality tertiary amine without causing various problems such as bottom solidification during distillation separation. That's why I did it.

The details of the manufacturing method according to the present invention will be explained below.

First, in order to generate a tertiary amine by reaction,
A reaction vessel is charged with one of various primary amines or secondary amines to be described later, and a hydrogenation catalyst is introduced into the reaction vessel while stirring the contents. Hydrogenation catalysts for this reaction include Raney nickel, Raney kova/l/
), noble metal catalysts such as platinum, rhodium, palladium, and ruthenium are used. Hydrogen pressure from 3 to 50 h/cm2 (
gauge pressure), preferably 5 to 20 Kf/儂2 (gauge pressure), and a predetermined temperature of 80 to 180°C, preferably 1
Raise the temperature to 00-150°C. After reaching a predetermined reaction temperature, formaldehyde is added to the reaction system. It is preferable that the addition be carried out continuously over time.

The formaldehyde used in this reaction may be formalin water or a methanol solution of formaldehyde.

The formaldehyde concentration is preferably 30 to 60%, preferably 35 to 50% formalin water. The amount of formaldehyde used may be equimolar to the raw material amine.

Strictly speaking, it may be an equimolar amount per active hydrogen group of the amine group. Usually, it is used in an amount of 1.0 to 1.2 times per active hydrogen group of an amino group. The reaction time is arbitrarily determined depending on the amount of catalyst added and the formaldehyde supply rate, but is usually 2 to 5 hours. The amount of catalyst added is 10 to 500% as a hydrogenation metal catalyst to the amine.
Use within ppm range.

During the reaction, the reactor may be sealed under hydrogen pressure, and the produced water,
Even if formalin water or the like coexists with the amine, it does not affect the catalyst activity. If there is an excess of formaldehyde, a method may be used in which a small amount of gas is continuously exhausted under hydrogen pressure in order to discharge the excess or to discharge lower gases derived from the raw materials.

After the reaction is completed in this way, the catalyst is filtered and the resulting P solution is added with primary amine 7 or secondary amine, and then subjected to heat treatment and product distillation. can reach the purpose of

As the primary amine or secondary amine that can be used, any amine having at least one active hydrogen group in its molecule can be selected from low-molecular to high-molecular amines. For example, ethylenediamine, diethylenetriamine,
triethylenetetramine, tetraethylenepentamine,
Boriaones having primary and secondary amino groups such as pentaethylene hexaone and polyethyleneimine, and aliphatic primary amines such as butylamine, octylamine, laurylamine, myristylamine, distearylamine, or mixtures thereof, etc. Also, aliphatic secondary amines such as diptylamine, dioctylamine, dilaurylamine, simiristylamine, distearylamine, or mixtures thereof, and morpholine, piperazine, piperidine, amine ester piperazine, aminopropylmononpholine, etc. Heterocyclic primary or secondary amines, aromatic or alicyclic amines such as benzylamine and cyclohexylamine, and aminoglopioxy group-containing
Examples include aliphatic primary or secondary diamines and triamines having ether-reduced primary amines or aminoprobyl groups, and amino alcohols such as monoethanolamine and jetanolamine.

When obtaining the desired tertiary amine by distillation, the added amine must have an appropriate boiling point difference with the tertiary amine produced by the reaction so that the amine can be separated by distillation. Preferably, primary or secondary amines are used. Therefore, an appropriate amine may be selected from the above-mentioned primary or secondary amines depending on the desired amine.

For example, in producing pentamethyldiethylenetriamine, low-boiling primary or secondary amines such as ethylenediamine, butylamine, octylamine, morpholine, piperazine, piperidine, benzylamine, cyclohexylamine, etc., and high-boiling primary or secondary amines are used. Secondary amines include triethylenetetramine, tetraethylenepentamine, pentaethylene hexaone, polyethyleneimine,
Suitable examples include dilaurylamine, diesteramine, and the like.

When adding these primary amines or secondary amines, the appropriate amount is usually approximately equal to the amount of formic acid or other acid components contained in the reaction-completed P solution, but depending on the added amine, (e.g. 1st class or 2nd class)
In other words, the amount of equivalent acid and amine group, and generally 0.1 wt% to 20 wt for the reaction-completed product.
% amine loading is preferred.

These amines may be added after the reaction product has passed through.

That is, it may be added before distillation, or if water is present, depending on the amine used, it may be added after water is distilled off from the reaction solution. After adding the amine, the reaction completed solution is heat-treated. The temperature is preferably in the range of 20°C to 200°C, preferably 60°C to 150°C.

This heat treatment can be effective even if it is carried out after adding the amine to the reaction F solution, but if water is present in the tertiary amine, it is recommended to heat it after distilling off the water. desirable. There is no need to set a particular heat treatment time for this heat treatment, and the heating and temperature raising operation during distillation serves as this treatment operation.

Further, when a separate heat treatment time is provided, there is no particular restriction and the heat treatment time may normally be in the range of 0.5 to 3.0 hours.

By distilling and separating the treated solution thus obtained, an almost colorless and transparent tertiary amine can be obtained, making it possible to obtain a high quality tertiary amine with excellent hue and storage stability. [Examples] The present invention will be explained in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited to these Examples.

Example 1 Palladium catalyst supported on a carbon carrier (5% loading) was added to laurylamine (99.5%) soo t.
．． Add 25ppm of radium (relative to amine) and add 1! Prepared in autoclave, hydrogen pressure 15
After increasing the hydrogen pressure to 1 m'' (gauge pressure), the temperature was maintained at 140°C, and a 37% formaldehyde aqueous solution was added in an equimolar amount of 440f to the amine over 4 hours.0.
After aging for 5 hours, the catalyst is filtered off. 16. stearyl diamine was added to the P liquid crystal thus obtained. After adding Of and removing the separated lower layer water, heat treatment was performed in a distiller, and the product was distilled and separated at 160°C. The purity of the obtained tertiary amine was 99% or more.

Furthermore, a portion of this purified product was subjected to a storage test. In the storage test, the samples were stored at 60°C and changes in coloring were observed.

Table 1 shows the test results of the hue storage stability of the obtained tertiary amine.

Comparative Example 1 A reaction-completed filtrate obtained in the same manner as in Example 1 was subjected to distillation separation without adding an amine to obtain a tertiary amine. Example 1 Regarding the hue storage stability of the obtained tertiary amine
It was subjected to a storage test under the same conditions. The results are shown in Table 1.

Table 1 The measurement was expressed as an APHA value.

From the results in Table 1, it can be seen that the tertiary amine obtained according to the present invention is a high quality amine with better hue storage stability.

Example 2 6 tons of palladium carbon catalyst a was used for 103 tons of diethylene triamine as the raw material amine (0.
6%) and charged into an autoclave 17, and after increasing the hydrogen pressure to 15 Kf/cm2 (gauge pressure), maintain the temperature at 140°C and add 37% formaldehyde aqueous solution 4.
60t was added in 6 hours. After aging for 1.0 hour, the reaction product was removed from the autoclave. After removing the catalyst from the reaction product by filtration, tetraethylenepentamine was added in 9. Of
After the water in the F solution was distilled off, the product was heated and separated by distillation to obtain pentamethyldiethylenetriamine. The bottom temperature during distillation, etc. was 50°C when water was distilled and 100°C during product distillation, and the purity of the reaction purified product was 99.0% or more.

A portion of the product thus obtained was taken and subjected to a storage test. In the storage test, the treated product was stored at room temperature or 60°C, and changes in coloring were observed.

The results are shown in Table 2.

Comparative Example 2 The reaction-completed F liquid crystal obtained in the same manner as in Example 2 was separated by distillation without any treatment to obtain pentamethyldiethylenetriamine. At this time, the product was a slightly yellowish liquid. A portion of this product was subjected to a storage test in the same manner as in Example 2.

The results are shown in Table 2.

Table 2 The results in Table 2 also show that high quality amines with excellent stability can be obtained by the method of the present invention.

Claims (1)

[Claims] In a production method for obtaining a tertiary amine by reacting a primary amine or a secondary amine with formaldehyde in the presence of a hydrogenation catalyst, the primary amine or secondary amine is added to the reaction product after the completion of the reaction. the third characterized by post-distillation;
A method for producing grade amines.