JPS62281846A - Production of n,n,n',n'-tetramethyl-1,6-hexanediamine - Google Patents

Abstract

PURPOSE:To obtain the titled compound which is a raw material for dispersing agents, emulsifying agents, foaming accelerators, etc., in high yield, by reacting hexanediamine with (para)formaldehyde and hydrogen in the presence of a noble metal catalyst in an alcoholic solvent. CONSTITUTION:1,6-Hexanediamine (HA) is reacted with formaldehyde and/or paraformaldehyde in an amount of 3.5-5.0 molar equivalents based on 1mol HA and hydrogen in the presence of a noble metal catalyst, e.g. Pd-active carbon, Pt-active carbon, etc., in a 1-4C aliphatic alcohol solvent or a mixed solvent of water and the alcohol containing >=30wt% above-mentioned alcohol at room temperature-150 deg.C, preferably 50-120 deg.C under pressure of hydrogen (3-9 atm gauge) to afford the aimed compound.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Industrial Field of Application] The present invention involves the addition of a nermylating agent and hydrogen to 1,6-hexanone amino (hereinafter abbreviated as HA) in the presence of a noble metal catalyst. to form N,N,N',N'-tetramethyl-1,6-
This invention relates to a method for producing hexalamine (hereinafter referred to as TM) (abbreviated as A).

TMHA is useful as a raw material for dispersants, emulsifiers, foam promoters, and the like.

[Conventional technology]

Conventionally, as a method for producing TMHA, a method in which HA+formalin is reacted with formic acid and a basic organic acid (Japanese Unexamined Patent Publication No. 166152/1982) is known.

On the other hand, in the production of aliphatic tertiary amines, formaldehyde is gradually added to aliphatic primary amines and aliphatic secondary amines containing hydrogenation catalysts maintained in the liquid phase under hydrogen pressure. For aliphatic primary amines or aliphatic secondary amines, about 0.05
An improved method for producing aliphatic tertiary methylamine using ~3% by weight of a basic organic acid (Japanese Patent Publication No. 39-17905) and the use of paranram in primary, secondary, or secondary amines. In the presence of platinum catalyst, 3-5 Q kt) /
Under hydrogen pressure of Cj (gauge pressure), temperature 80-180'
In the presence of a hydrogenation catalyst, a long-chain aliphatic primary or secondary amine is reacted with a formylating agent and hydrogen. A method for producing a tertiary amine by reacting with is known.

[Problem that the invention seeks to solve]

However, in the conventional method for producing TMHA, a method in which HA is first reacted with formalin, formic acid, and a basic organic acid is a method in which formic acid, which acts as a reducing agent (approximately 4 In addition to the basic organic acid that acts as a salt-forming agent, approximately 2 equivalents per mole of HA are required. Furthermore, in order to obtain free T M HA from the reaction product, it is necessary to neutralize the salt-forming agent using about 2 equivalents of alkali per 1 mol of TMHA.

In other words, the drawback of this method is that, in addition to using expensive formic acid as a reducing agent, large amounts of basic organic acids and alkalis are also used. For this reason, the neutralization process generates wastewater containing a large amount of alkali salts of basic organic acids, which has the drawback of increasing wastewater treatment costs.

On the other hand, conventional methods for producing long-chain aliphatic tertiary amines by reacting long-chain aliphatic primary amines or secondary amines with formalin and hydrogen in the presence of a hydrogenation catalyst are all special methods. In this method, the raw material long-chain aliphatic primary amine or secondary amine is charged in a nearly solvent-free state into a reactor, formalin is supplied, and reductive dimethylation is performed without using any solvent.

In this way, long-chain aliphatic primary amines or secondary amines are reductively dimethylated in almost solvent-free conditions.
The method of producing T M HA requires high pressure hydrogen to achieve sufficient reaction performance. When carrying out such a method on an industrial scale, a pressure-resistant reactor is required;
It has the disadvantage of high equipment costs. Also, advanced technology is required in terms of operation management.

[Means for solving problems]

In order to solve the drawbacks of the above-mentioned prior art, the present inventors have made extensive studies and found that formaldehyde and/or hydrogen permeates HA using paraformaldehyde and hydrogen in the presence of a Kikanishin catalyst. Methylation reaction with 1 carbon number
By carrying out the reaction in an aliphatic alcohol solvent of ~4 or a mixed solvent of water and alcohol containing at least 30% by weight of the alcohol, high-quality TMHA can be produced in high yield even when using low pressure hydrogen. They discovered that it could be manufactured and arrived at the present invention.

1. (In the present invention, HA is dissolved in an aliphatic alcohol solvent having 1 to 4 carbon atoms, and the alcohol is 30% by weight.
The method for producing TMH'A is characterized in that formaldehyde and/or alcohol are reacted with paraformaldehyde and hydrogen in the presence of a noble metal catalyst in a mixed solvent of water and alcohol containing the above.

Below, the present invention will be described in detail.

The main raw material HA used in this invention is the arepino acid method, the acrylonitrile electrolysis method, the bucleeno method and the ε-
It can be produced by a known method such as the caprolactam method. The present invention can be smoothly carried out using HA produced by any of these methods. Furthermore, HA used in the reaction can be used in the present invention in any form, including anhydrous form and water/8 liquid form.

In the present invention, the initial concentration of HA in the reaction system is usually 5 to 50% by weight, preferably 10 to 40% by weight.
HA% will be shared so that The initial concentration of HA here refers to the amount of HA present in the liquid phase in weight% relative to the total amount of HA, water, and aliphatic alcohol having 1 to 4 carbon atoms present in the liquid phase at the initial stage of the reaction. This is the value expressed as . H.A.
If the initial concentration of HA is less than 5% by weight, it is not practical because the productivity is low.On the other hand, if the initial concentration of HA is more than 50% by weight, it is not preferable because the reaction results tend to deteriorate.

In the present invention, as a method for supplying HA to the reaction system, either a batch method or a continuous method can be adopted.

Formaldehyde and/or paraformaldehyde used in the present invention acts as a formylating agent. In the present invention, formaldehyde and paraformaldehyde are usually used alone, but in some cases, a mixture of formaldehyde and paraformaldehyde may be used. These formylating agents are also usually
For example, commercially available products in the form of mixtures with water and/or alcohol can be used as is. Particularly preferred in the present invention is the use of formaldehyde and/or paraformaldehyde in the form of a mixture with alcohol.

In the present invention, the amount of formaldehyde and/or paraformaldehyde used is usually 3 per mole of HAI.
．． It is 5 to 5.0 molar equivalent.

What is 1 molar equivalent of paraformaldehyde here?

One unit of formaldehyde that constitutes paraformaldehyde.

In the present invention, if the amount of formaldehyde and/or paraformaldehyde used is less than 3.5 molar equivalents per mole of HA, unreacted HA tends to remain in the reaction solution, making it particularly difficult to carry out the present invention industrially. In some cases, the cost of recovering unreacted HA increases, and this cannot be said to be an economical method for producing TMHA.

On the other hand, if the amount used exceeds 5.0 molar equivalent per mole of HA, the by-product of high-boiling compounds will increase and the quality of the product TMI (A) will tend to deteriorate. Usage amount is HA
It is 3.9 to 4.5 molar equivalents per z mole, that is, around 4.0 molar equivalents.

In the present invention, formaldehyde and/or paraformaldehyde may be supplied to the reaction system in any manner. As for the formaldehyde supply method, since formaldehyde is usually in a liquid form, it is suitable for either an intermittent or continuous method. On the other hand, since paraformaldehyde is usually in the form of powder, a batch method is suitable for supplying paraformaldehyde.

In the present invention, the reductive dimethylation of HA is carried out with a carbon number of 1 to
It is important to carry out the reaction in an aliphatic alcohol solvent or a mixed solvent of water and the alcohol described above. Examples of the aliphatic alcohol having 1 to 4 carbon atoms used here include:
Methanol, ethanol, n-propertool, 1so-
propatool, n-butanol, 1so-butanol,
Examples include 5ec-butanol and tert-butanol. These furcols can be used alone or in combination. Industrially, it is preferable to use inexpensive methanol.

Furthermore, in the present invention, when the reductive remethylation of HA is carried out in a mixed solvent of water and an aliphatic alcohol having 1 to 4 carbon atoms, the solvent must contain 30% by weight or more of an aliphatic alcohol having 1 to 4 carbon atoms. is important.

That is, in the present invention, the solvent is a single solvent consisting essentially of an aliphatic alcohol having 1 to 4 carbon atoms, or a mixed solvent with water containing 30% by weight or more of an aliphatic alcohol having 1 to 4 carbon atoms. It is necessary that there be.

In the present invention, when the mixed solvent of water and alcohol contains 30% by weight or more of aliphatic alcohol having 1 to 4 carbon atoms, it means that the mixed solvent of water and alcohol contains 30% by weight or more of aliphatic alcohol having 1 to 4 carbon atoms. The amount of aliphatic alcohols having 1 to 4 carbon atoms substantially present relative to the total amount of aliphatic alcohols having 1 to 4 carbon atoms (these act as a solvent in the reaction system) is expressed in weight%. This means that it is more than 30%.

In the present invention, when the amount of aliphatic alcohol having 1 to 4 carbon atoms in the mixed solvent with water is less than 30% by weight, TM
This is not preferable because the production rate of HA is significantly reduced.

As the noble metal catalyst used in the present invention, those used as ordinary hydrogenation catalysts can be used, such as palladium,
Mention may be made of platinum and ruthenium. In the present invention, usually
Commercially available charcoal-based activated carbons, balaraeumu activated carbon catalysts supported on Yanogara activated carbon, and platinum-activated carbon catalysts are preferably used. There is no limit to the amount of noble metal supported in the noble metal catalyst, but it is usually 0.1 to I
A material having 0% by weight of noble metal supported thereon should be used.

In the present invention, the noble metal catalyst is usually used suspended in the liquid phase of the reaction system. In order to smoothly proceed with the reductive remethylation of HA, it is important to thoroughly stir the liquid phase of the reaction system and disperse the noble metal catalyst as uniformly as possible.

Regarding the amount of noble metal catalyst used relative to HA, if the amount is too large, the reaction will proceed smoothly, whereas if it is too small, the production rate of TMHA will tend to decrease.

Usually, when an activated carbon catalyst containing 5% by weight of paraleum is used, the amount of the 5% by weight activated carbon catalyst used is in the range of about 1 to 50 parts by weight, preferably about 3 parts by weight, based on 0 parts by weight of the raw material HA I O. ~30 parts by weight. Once used, the catalyst in the reaction product liquid can be separated into solid and liquid, washed with water, alcohol, or a mixed solvent of water and alcohol as necessary, and then recycled and reused.

In the present invention, the reaction is carried out under pressure of hydrogen. That is, the reaction system is pressurized with hydrogen.

The range of pressure is not limited as long as side reactions are not induced, but a total pressure of 10 atm (gauge pressure) or less is sufficient, and the total pressure is usually 3 to 9 atm (gauge pressure). Hydrogen is supplied to the reaction system either intermittently or continuously while monitoring changes in the pressure gauge.

The reaction temperature in the present invention is usually in the range of room temperature to 150°C, preferably 50 to 120°C. It has been observed that if the reaction temperature is too high, side reactions tend to occur.
On the other hand, if the temperature is too low, a satisfactory reaction rate cannot be obtained and it is not practical.

In the present invention, the method for obtaining the target product TMHA from the reaction solution is usually to separate the catalyst in the reaction solution into solid and liquid, and then evaporate the alcohol and water to obtain a concentrated solution. A method of distilling the T M HA t, under reduced pressure, should be adopted.

〔Example〕

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

Example 1 In a volume +6 autoclave equipped with a reflux condenser, a stirrer, a formalin supply pot, a thermometer, a gas inlet, and a gas outlet, 580 da (0.32 mol) of a 65% HA aqueous solution, 111 methanol, Oy, and 5% Balaleumu carbon powder (50% quartz crystal) 1.25F CHA10
5% Balareum carbon powder (50 parts by weight)
33 parts by weight (% quartz-containing crystal).

The HA concentration at the time of preparation was 22% (a: based on the total amount of HA, water and methanol), and the amount of methanol in the mixed solvent at the time of preparation was 84% by weight (based on the total amount of HA, water and methanol). (total nails).

After the autoclave was replaced with nitrogen twice and once with hydrogen, the temperature was raised to 100°C and 8 to 9 kq/
113.0y of 37% formalin aqueous solution while introducing hydrogen gas to maintain hydrogen pressure of d-G (gauge pressure).
(Aqueous solution composition.

HCHO41,8F (1,39 mol), water 63.3y
, methanol (stabilizer) 7.91'] was added over 1.33 hours to perform a reductive alkylation reaction.

After the reaction was completed, the mixture was aged for 0.5 hours, cooled to 40°C, and the catalyst was removed. As a result of analyzing the reaction solution obtained from each house by gas chromatography (GC), the HA conversion rate and the TMHA production rate relative to the charged HA were both 100%.

Example 2 HA crystal (anhydrous) 250y (0,
22 mol), 95% rose formaldehyde powder 28.6
y (0.90 mol), methanol 225, Oy and 5% Balajiram-carbon powder (50% quartz) 3.7
Prepare 5y. HA Q degree during preparation is 10% (based on the total amount of HA, water and methanol during preparation)
The amount of methanol in the mixed solvent at the time of preparation is 99
% (based on the total amount of water and methanol charged).

After replacing the autoclave with nitrogen twice and replacing it with hydrogen once, the temperature was raised to loo'c and the temperature was increased to 8~gtg7.
Reductive alkylation reaction was carried out for 3 hours while introducing hydrogen gas to maintain hydrogen pressure of ci-G (gauge pressure).

After the reaction was completed, the reaction solution was cooled to 40°C and the catalyst was separated, and the resulting reaction solution was analyzed by GC method. As a result, the HA conversion rate was 100%.
, the TMHA production rate was 95.5%.

Example 3 A 65% HA aqueous solution 70.01' (
0,39 mol), methanol so, o y and 5
% Balanumu carbon powder (50% quartz crystal) 4.50
Prepare y and t. The HA concentration at the time of preparation was 30% (relative to the total amount of HA, water, and methanol in the preparation), and the amount of methanol in the mixed solvent at the time of preparation was 75% (relative to the total amount of water and methanol in the preparation). ).

After the autoclave was replaced with nitrogen twice and once with hydrogen, the temperature was raised to 80°C and the temperature was increased to 8-9 with 9/cj-
While introducing hydrogen gas to maintain the full hydrogen pressure of G (gauge pressure), add 140.0 f of a 37% formalin aqueous solution (aqueous solution composition: HCHO51,8y (1,72 mol), water 78,49 and methanol (stabilizer). 39.8f) to 1
．． It was added for 25 hours to carry out a reductive alkylation reaction.

After the reaction was completed, the mixture was aged for 0.5 hours, cooled to 40° C., and the catalyst was recovered separately from P.

After that, the reaction conditions other than the catalyst were the same as the first reaction, and the catalyst was recycled by replenishing the recovered catalyst with 1/36 (0,125y) of the charged amount of new catalyst, and the reductive alkylation reaction was carried out five times in total, including the first reaction. I did it. As for the reaction results, both the HA conversion rate and the TMHA production rate were 100%, and no tendency to deactivation of the catalyst activity was observed.

Next, the reaction liquids of the five reductive alkylation reactions, that is, the first reaction and the first to fourth reaction of the catalyst recycling reaction, were mixed and concentrated using a vacuum bottom-tally evaporator. The liquid was further fractionally distilled under reduced pressure to obtain 121
A main fraction of 290.1 mHg was obtained. The purity of the obtained main fraction was 100% (GC method), and the TMHA production rate with respect to the charged HA was 860%. As a result of measuring the water content in the reaction solution by Karl Finoyer method, the weight ratio of methanol to water was 40:60.

Example 4 HA crystal (anhydrous) 5Q, 0 da (
0.43 mol), ethanol 95. Charge 1.259 kg of 5% platinum-carbon powder.

The HAa degree at the time of charging was 35% (based on the total amount of HA and ethanol during charging), and the reaction solvent was substantially 1.00% ethanol.

After the autoclave was replaced with nitrogen twice and once with hydrogen, the temperature was raised to 100℃ and the temperature was increased to 8 to 9 kq/ca.
- While introducing hydrogen gas to maintain the hydrogen pressure of -G (gauge pressure), 37% formalin aqueous solution 138. oy(
Aqueous solution composition: HCHO5-L I I (170 mol)
, water 77.2 f and methanol (stabilizer) 9.7 y
1 is added over 1.75 hours to carry out the reductive alkylation reaction.

After the completion of the reaction, the mixture was aged for 0.5 hours, cooled to 40°C, and the catalyst was removed separately.The reaction solution obtained was analyzed by GC, and the HA conversion rate and TMHA production rate were both 100%.

Example 5 A 65% HA aqueous solution 58,0f (0
, 32 mol), methanol 55. Of and 2.50f of 5% palladium-carb/powder (50% quartz) were charged. The HAI degree at the time of charging was 33% (relative to the total amount of HA, water and methanol charged), and the amount of methanol in the mixed solvent at the time of charging was 72% (relative to the total amount of water and methanol charged). )Met.

After replacing the autoclave with nitrogen twice and once with hydrogen, warm the autoclave to 100°C and heat it to 8~gkq/d-
While introducing hydrogen gas to maintain a hydrogen pressure of G (gauge pressure), 167.6 y of a 25% formalin-water-methanol solution (HCHO41.9f (1 ,40
mole).

63.49 water and 62.31 methanol], 1.
t: was added for 33 hours to carry out the reductive fullkylation reaction.

After the reaction was completed, the mixture was aged for 0.5 hours, cooled to 40°C, and the catalyst was removed from each house.The result of GC analysis of the reaction solution obtained was as follows.
Both the HA conversion rate and the TMHA production rate were 100%.

Comparative Example 1 65% HA aqueous solution 76.9y<o in the same apparatus as Example 1
. 43 mol), water 64. Or and 5% Balareumu carbon powder (50% quartz crystal) 2.502 were charged.
Go. The HA concentration at the time of charging was 35% (based on the total amount of HA and water charged), and no alcohol was present in the reaction solvent.

After replacing the autoclave with nitrogen twice and with hydrogen once, the temperature was raised to 100°C and 8-gkg7CA
-154.0 g of 37% formalin aqueous solution while introducing hydrogen gas to maintain the hydrogen pressure of G (gauge pressure).
(Aqueous solution composition: HCHO57,0 y (1,90 mol), water 86,29 and methanol (stabilizer 310,8
y) was added over 1.5 hours to carry out a reductive alkylation reaction.

After the reaction was completed, the reaction solution was aged for 5 hours, cooled to 40°C, and the catalyst was separated. As a result of GC analysis of the obtained reaction solution, HA
The conversion rate was 100%, and the TM)IA production rate was 44.2%.

Comparative Example 2 A 65% HA aqueous solution 60.0 f (0
, 34 mol) and 5% palladium-carbon powder (5%
Pour 2.50y of 0% quartz crystal.

The HAa degree at the time of charging was 64% (based on the total amount of HA and water during charging), and no alcohol was present in the reaction solvent.

After the autoclave was replaced with nitrogen twice and once with hydrogen, the temperature was raised to 8-gt.
While introducing hydrogen gas to maintain a hydrogen pressure of g7ci-G (gauge pressure), dilute a 37% formalin aqueous solution with methanol to adjust the concentration. 19% formalin-water-methanol solution 228, Oy CHCHO43, 4y (
1,45 mol), 657 y of water and 118 mol of methanol.
9f) was added over 1.92 hours to perform a reductive alkylation reaction.

After the reaction was completed, the reaction solution was aged for 0.5 hours, cooled to 40°C, and the catalyst was removed. As a result of GC analysis of the reaction solution obtained, H
The A conversion rate was 100%, and the TMHA survival rate was 69.0%.

Comparative Example 3 100 HA crystals (anhydrous) were placed in the same apparatus as in Example 1 (08
6 mol) and 5% palladium-carbon powder (50%
Water-containing product) 2.50 yr of moss was charged, but no alcohol or water was used as a reaction solvent.

After replacing the Au J-Crepe with nitrogen twice and with hydrogen once, the temperature was raised to 100°C and the temperature was increased to 8-9 to 9/c.
While introducing hydrogen gas to maintain the hydrogen pressure of i-G (gauge pressure), add 307.0 y of 37% formalin aqueous solution.
(Aqueous solution composition HCHO113,6y (3,78 mol)
, water 171.9 and methanol (stabilizer) 21.5
y] was added over 4.0 hours to carry out the reductive alkylation reaction.

After the reaction was completed, the mixture was aged for 0.5 hours, cooled to 40°C, and the catalyst was separated.The reaction solution obtained was analyzed by GC, and the results showed that the HA conversion rate was 100%, and the T MHA production rate was 51.8.
%Met.

Comparative Example 4 A 65% HA aqueous solution 700F (0,
39 mol), methanol 32. Oy 1 water 48, Oy
and 5% palladium-carbohydrate powder (50% quartz)
4: Prepare 50g. HAa content during preparation is 30%
(based on the total amount of A, water and methanol), and the amount of methanol in the mixed solvent at the time of charging was 30% (based on the total amount of water and methanol).

After the autoclave was replaced with nitrogen twice and once with hydrogen, the temperature was raised to 100°C and the temperature was increased to 8 to 9 hq/c.
While introducing hydrogen gas to maintain the hydrogen pressure of i-G<gauge pressure), add 133.5f of 37% formalin aqueous solution.
(Aqueous solution composition: HCH○49.4y (1.65 mol),
74.8y of water and 9.3f of methanol (stabilizer) were added over 1.50 hours to carry out a reductive alkylation reaction.

After the reaction was completed, it was aged for 0.5 hours, cooled to 40°C, and the catalyst was removed from each house.The reaction solution obtained was analyzed using the GC method.
The HA conversion rate was 100%, and the TMHA production rate was 61.2%. In addition, as a result of moisture measurement using the Karl Fischer method,
The weight ratio of methanol to water in the reaction solution was 19:81.

〔Effect of the invention〕

According to the present invention, inexpensive hydrogen is used as a reducing agent instead of expensive formic acid, and excessive basic organic acids and alkalis are not used (in addition, conventionally known noble metal catalysts, formylating agents, and hydrogen T by reductive dimethylation using
Compared to the method for producing MHA, high-grade TM)IA can be obtained in high yield even at low reaction pressure. Therefore, the present invention is an excellent method for producing TMHA that can be put into practical use industrially.

Claims (1)

[Claims] 1,6-hexanediamine in an aliphatic alcohol solvent having 1 to 4 carbon atoms or in a mixed solvent of water and alcohol containing 30% by weight or more of the alcohol in the presence of a noble metal catalyst, formaldehyde and/or paraformaldehyde and A method for producing N,N,N',N'-tetramethyl-1,6-hexanediamine, which comprises reacting with hydrogen.