JP3194240B2 - Method for producing tertiary aliphatic amine having long-chain aliphatic group - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a tertiary aliphatic amine having a long-chain aliphatic group through an amination step and a methylation step using a long-chain aliphatic nitrile as a starting material. The tertiary aliphatic amine produced according to the present invention is a useful substance having various uses as a bactericide, an emulsifier, a dispersant, a rust inhibitor, a fiber softening agent, an intermediate of a shampoo base and the like.

[0002]

2. Description of the Related Art In a method for producing a tertiary aliphatic amine having a long-chain aliphatic group (hereinafter, also simply referred to as a tertiary amine), an amination step and a methylation step are performed using an aliphatic nitrile as a starting material. This method can be said to be an excellent method as an industrial method since the long-chain aliphatic nitrile as a raw material is synthesized from higher fatty acids and can be produced at low cost. However, in the case of this method, since the two steps are different or require a new catalyst, the reaction operation is complicated, and from this point of view, it is not yet satisfactory. Further, in this method, the catalyst used in the amination step can be continuously used as it is, but in this case, the selectivity of the reaction is deteriorated, and the purity is high.
High quality tertiary amines cannot be obtained. On the other hand, a method is known in which a primary amine or a secondary amine is used as a starting material and reacted with formaldehyde and hydrogen in the presence of a hydrogenation catalyst to obtain a tertiary amine. However, in the case of this method, if the methylation reaction is simply performed in the presence of a hydrogenation catalyst, a large amount of by-products are generated, and the yield of the desired tertiary amine is reduced, which is not practical. There is. As a method for solving such a problem, Japanese Patent Publication No. 39-17905 has been proposed.
And Japanese Patent Application Laid-Open No. 64-16751. In Japanese Patent Publication No. 39-17905,
A method is described in which a primary or secondary amine is used as a starting material, Raney nickel is used as a hydrogenation catalyst, and a lower fatty acid such as acetic acid or propionic acid is added as a co-catalyst to suppress by-products. However, in this method, the yield of the tertiary amine is up to 88%, and by-products are generated at 10% or more, and the suppression of by-products is insufficient. Japanese Unexamined Patent Publication (Kokai) No. 64-16751 discloses that a primary or secondary amine is used as a starting material, and an acid type Raney-nickel catalyst obtained by treating a Raney-nickel catalyst with an organic acid is used as a by-product. It describes a method of suppressing the occurrence. However, in this method, although the target product can be obtained at a high conversion rate by using an acidic Raney-nickel catalyst, the Raney-nickel catalyst is used.
It has the drawback that it is difficult to handle because of its ignitability and that the preparation of the catalyst is complicated. Further, these conventional methods have the effect of improving the reaction rate, but have the disadvantage that the reactants are colored yellow, and require complicated purification steps such as distillation and decolorization.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems in the conventional method, and produces a tertiary aliphatic amine having a long-chain aliphatic group excellent in color tone with very little coloration in high yield. The task is to provide a method.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, an amination step of reacting a long-chain aliphatic nitrile with hydrogen in the presence of a hydrogenation catalyst to aminate the obtained long-chain aliphatic amine in the presence of a hydrogenation catalyst A method for producing a tertiary aliphatic amine having a long-chain aliphatic group, comprising a methylation step of reacting formaldehyde with hydrogen for methylation, wherein (i) a nickel catalyst supported on a carrier as a hydrogenation catalyst in the amination step (Ii) using, as the hydrogenation catalyst in the methylation step, the spent catalyst obtained in the amination step with the long- chain aliphatic nitrite.
It is used at a ratio of 0.01 to 0.6 mol% with respect to ril, and as its co-catalyst, PKa against water is 2 to 6 mol%.
(Iii) the presence of ammonia in the amination step
Primary amine as the main component
To obtain a reaction product, in (iv) the methylation step, N, N-dimethylated length
To obtain a chain aliphatic amines, the same reaction (v) the amination step and the methylation step
The method for producing a tertiary aliphatic amine having a long-chain aliphatic group , which is performed in a container, is provided.

As the long-chain aliphatic nitrile used as a starting material of the present invention, preferably, a saturated aliphatic nitrile or unsaturated aliphatic nitrile having 8 to 22 carbon atoms, or a mixture of both is preferably used. . In addition, the long-chain aliphatic nitrile may contain an aliphatic primary amine having 8 to 22 carbon atoms as an impurity. In addition, the long-chain aliphatic nitriles may have the same carbon number, or may be a mixture of nitriles having different carbon numbers. This raw material nitrile is represented by the following general formula. R-CN In the above formula, R is a saturated or unsaturated long-chain aliphatic group,
Its carbon number is preferably 8-22. Specific examples of the long-chain aliphatic group include, for example, octyl, dodecyl, tetradecyl, hexadecyl, octadecyl, docosyl, docosenyl, dodecenyl, octadecenyl and the like. Preferred specific examples of the long-chain aliphatic nitrile include oleonitrile, stearonitrile, lauronitrile, bovine fatty acid nitrile, and coconut fatty acid nitrile.

The hydrogenation catalyst used in the present invention is:
It is preferable to use a nickel-based hydrogenation catalyst supported on a carrier, particularly a nickel-based hydrogenation catalyst supported on a carrier selected from the group consisting of nickel-diatomaceous earth , nickel-alumina, and nickel-silica-alumina. The average particle size of the catalyst is 0.1 to 200 μm , preferably 1 to 50 μm . The amount of the catalyst used is preferably 0.1 to 0.5 part by weight per 100 parts by weight of the raw nitrile.

In the method of the present invention, the starting nitrile is converted into a tertiary amine by using an amination step and a methylation step. Each step will be described in detail below. (Amination Step) This step is a step in which a raw material nitrile and a catalyst are charged into a reaction vessel and reacted with hydrogen while stirring the raw material nitrile and the catalyst. This amination step, raw nitrile is converted to a primary amine emissions. In order to carry out the reaction using the primary amine as a main product, the reaction is carried out in the presence of ammonia in the reaction system. When the reaction conditions of this amination step are shown, the reaction temperature is 80 to 300 ° C, preferably 100 ° C.
~ 250 ° C and hydrogen pressure is 0 ~ 80kg / cm
² G, preferably 0.1 to 50 kg / cm ² G.

[0008] (methylation step) This step is a primary Amin produced in the amination step
The amino group of the presence of a hydrogenation catalyst, by reacting hydrogen with formaldehyde, is a step to produce a tertiary amine. In the present invention, the spent catalyst used in the amination step is used as a hydrogenation catalyst in the methylation step, and PKa (acid dissociation constant at a temperature of 25 ° C.) of water is 2 to 6 as a co-catalyst. Preferably, 3 to 5 organic acids are used. The organic acid can be a monobasic or polybasic acid. Specific examples of such organic acids include carboxylic acids such as caproic acid, adipic acid, sebacic acid, benzoic acid, terephthalic acid, lactic acid, and malic acid. The organic acid can be supplied to the reaction system as it is or after being dissolved in an appropriate solvent such as methanol or formaldehyde. The usage ratio of the organic acid used as the co-catalyst can be determined according to the usage amount of the raw material nitrile.
The amount is preferably 0.6 to 0.6 mol%, preferably 0.05 to 0.3 mol%. When the use ratio of the organic acid is larger than the above range, when the primary amine is converted into a tertiary amine by N, N-dimethylation, the amount of secondary amine by-product increases and the product Also tends to deteriorate .

Formaldehyde used as a reactant in the methylation step can be supplied to the reaction system as formalin or paraformaldehyde. The proportion of formaldehyde, for the primary Amin, 1 equivalent or more, and it is preferably in the range of 1.05 to 1.5 equivalents.
When the reaction conditions of the methylation step are shown, the reaction temperature is 100 to
The temperature is 250 ° C., preferably 130 to 200 ° C., and the hydrogen pressure is 0.5 to 50 kg / cm ² G (gauge pressure), preferably 3 to 20 kg / cm ² G. The supply of hydrogen to the reactor may or may not flow in the reaction vessel. When hydrogen is allowed to flow in the reaction vessel, the generated water vapor is continuously removed from the reactor, so there is no need to separate the product and water after the reaction. It is preferable to add formaldehyde to the reaction system in 3 to 6 hours. After completion of the reaction, the product is cooled and then filtered to separate the hydrogenation catalyst. This filtration can be performed using a usual solid-liquid separation device such as a pressure filter.

The method of the present invention uses the same reaction vessel,
The amination step and the methylation step can be performed continuously. That is, the starting nitrile and the catalyst are placed in a reaction vessel, and while the contents are stirred, an amination reaction is performed under hydrogen pressure, and then an organic acid as a cocatalyst and formaldehyde as a reactant are added to the reaction vessel. And a methylation reaction is performed under hydrogen pressure while stirring the contents.

[0011]

According to the present invention, since the spent catalyst used in the amination step is used as a catalyst in the subsequent methylation step, it is not necessary to separate the catalyst from the amination reaction product, and the catalyst is contained. The next methylation reaction can be performed using the amination reaction product as it is. Moreover,
Since the amination reaction and the methylation reaction can be continuously performed in the same reaction vessel, the reaction operation is also simple. Further, in the present invention, since a nickel catalyst supported on a carrier was used as the hydrogenation catalyst, catalyst deterioration was small even after the completion of the amination reaction, and the hydrogenation catalyst in the methylation reaction was allowed to coexist with the organic acid. As a catalyst. When an unsupported catalyst such as a Raney nickel catalyst is used, the intended purpose cannot be achieved. Further, the first Kyua Min obtained in the amination step, when the methylated with an organic acid as a cocatalyst and the spent catalyst in the amination process, tertiary amine obtained is very good There is also an advantage of having a different color tone.

[0012]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 A 2- liter induction rotary autoclave was charged with 500 g of lauronitrile and 2.5 g of a nickel-diatomaceous earth catalyst, and ammonia and hydrogen were supplied into the lauronitrile solution.
The reaction pressure was maintained at 30 kg / cm ² G (gauge pressure). Since reduction in hydrogen pressure due to reduction of the catalyst was observed with heating under stirring, the reaction temperature was raised to 150 ° C. while correcting the hydrogen pressure, and a reduction reaction was performed for 3 hours. A part of the contents was taken out and analyzed, and it was found that an amine mixture composed of 97.0% of primary amine and 3.0% of secondary amine was obtained. Then, a solution of 0.40 g of adipic acid (0.1 mol% based on the starting nitrile) in methanol as a co-catalyst was added to the crude primary amine containing this catalyst, and then 8 kg / cm ² G
Hydrogen was replaced and introduced into the autoclave while maintaining the hydrogen pressure at (gauge pressure). Heat to 150 with stirring
When the temperature reached 0 ° C., formalin containing 37% by weight of formaldehyde was continuously added over 4 hours. After completion of the reaction, the temperature was lowered to 60 ° C., and the catalyst was filtered off to obtain an amine composed of 100.0% of a tertiary amine. In this amine,
The target ratio of lauryl dimethylamine is 97.0%
And the side reaction product was mainly dilaurylmethylamine, the ratio of which was 3.0%.

Examples 2 to 12 Example 3 was repeated under the same conditions as in Example 1 except that the starting nitrile, the type of the catalyst and the promoter, and the amount of the promoter and the solvent were changed.
A secondary amine was synthesized. Table 1 shows the results of the reaction. Table 1 also shows the results of Comparative Examples. The amounts of the cocatalysts shown in Table 1 are mol% based on the starting nitrile, and the color tone was evaluated by visual judgment according to the following criteria. ○: pale yellow △: yellow to brown ×: brownish brown The main component of the by-product is dialkylmethylamine.

[0014]

[Table 1]

As a result, it was found that the desired tertiary amine having a high yield and very little coloration can be produced from the aliphatic nitrile in a high yield as in Examples 1 to 11. Further, the iodine value of the unsaturated alkyldimethylamine obtained in Example 12 was as high as 66.4 (theoretical value = 67). Therefore, it was also understood from the above that in the case of the present invention, an unsaturated tertiary amine having a high yield and very little coloration can be produced from an unsaturated aliphatic nitrile while maintaining its iodine value.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C07C 211/02 C07C 209/26 C07C 209/48

Claims (2)

(57) [Claims] 1. The presence of a catalyst for hydrogenating long-chain aliphatic nitriles
An amination step of reacting with hydrogen under an amination,
The resulting long-chain aliphatic amine is formalized in the presence of a hydrogenation catalyst.
Methyl methylated by reacting aldehyde with hydrogen
Tertiary aliphatic amine having a long chain aliphatic group comprising
(I) carrying a carrier as a hydrogenation catalyst in the amination step.
(Ii) as a hydrogenation catalyst in the methylation step,
The spent catalyst obtained in the mining processThe long-chain aliphatic nitro
0.01 to 0.6 mol% relative to rilWhen used
In both cases, PKa for water is 2 to 6 as a co-catalyst.
Using an organic acid that is(iii) in the amination step, the presence of ammonia
Primary amine as the main component
Obtaining a reaction product; (Iv) In the methylation step, N, N-dimethylation length
Obtaining a chain aliphatic amine, (V) the same reaction in the amination step and the methylation step
Done in a container,  Tertiary aliphatic amine having a long-chain aliphatic group, characterized by the following:
Manufacturing method. 2. A carrier supported nickel-based hydrogenation catalyst, nickel - diatomaceous earth, nickel - alumina and nickel - The process of claim 1 is at least one of a nickel-based catalyst selected from the group consisting of silica-alumina.